[PATCH] D136554: Implement CWG2631

[Arthur Eubanks via Phabricator via cfe-commits]

aeubanks added a comment.

In D136554#4059723 , @aeubanks wrote:

> one more regression bisected to this: 
> https://bugs.chromium.org/p/chromium/issues/detail?id=1408177
> `incomplete type 'blink::ResourceClient' used in type trait expression`
> I'll try to come up with a smaller repro

sorry, false alarm due to faulty bisection


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Arthur Eubanks via Phabricator via cfe-commits]

aeubanks added a comment.

one more regression bisected to this: 
https://bugs.chromium.org/p/chromium/issues/detail?id=1408177
`incomplete type 'blink::ResourceClient' used in type trait expression`
I'll try to come up with a smaller repro


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Chris Bowler via Phabricator via cfe-commits]

cebowleratibm added a comment.

In D136554#4056862 , @cor3ntin wrote:

> Yes please! However the warning looks correct to me in that case. A
> constructs x which constructs A etc.

https://github.com/llvm/llvm-project/issues/60082

Please set the project/labels as appropriate.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Re: [PATCH] D136554: Implement CWG2631

[Corentin via cfe-commits]

Yes please! However the warning looks correct to me in that case. A
constructs x which constructs A etc.

On Mon, Jan 16, 2023, 18:00 Chris Bowler via Phabricator <
revi...@reviews.llvm.org> wrote:

> cebowleratibm added a comment.
>
> I've reduced a regression on:
>
> commit ca619613801233ef2def8c3cc7d311d5ed0033cb <
> https://reviews.llvm.org/rGca619613801233ef2def8c3cc7d311d5ed0033cb>
> (HEAD, refs/bisect/bad)
> Author: Corentin Jabot 
> Date:   Sun Oct 23 17:32:58 2022 +0200
>
>   template  int f(T) { return 42; }
>
>   struct A {
>  int x = f(A());
>  A() { }
>   };
>
>   void foo() { A(); }
>
>
>
>   clang++ t2.C -c
>   t2.C:4:12: warning: stack nearly exhausted; compilation time may suffer,
> and crashes due to stack overflow are likely [-Wstack-exhausted]
>  int x = f(A());
>  ^
>   Segmentation fault (core dumped)
>
> @cor3ntin would you like me to open a new issue?
>
>
> Repository:
>   rG LLVM Github Monorepo
>
> CHANGES SINCE LAST ACTION
>   https://reviews.llvm.org/D136554/new/
>
> https://reviews.llvm.org/D136554
>
>
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Chris Bowler via Phabricator via cfe-commits]

cebowleratibm added a comment.

I've reduced a regression on:

commit ca619613801233ef2def8c3cc7d311d5ed0033cb 
 (HEAD, 
refs/bisect/bad)
Author: Corentin Jabot 
Date:   Sun Oct 23 17:32:58 2022 +0200

  template  int f(T) { return 42; }
  
  struct A {
 int x = f(A());
 A() { }
  };
  
  void foo() { A(); }



  clang++ t2.C -c
  t2.C:4:12: warning: stack nearly exhausted; compilation time may suffer, and 
crashes due to stack overflow are likely [-Wstack-exhausted]
 int x = f(A());
 ^
  Segmentation fault (core dumped)

@cor3ntin would you like me to open a new issue?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGca6196138012: Implement CWG2631 (authored by cor3ntin).

Changed prior to commit:
  https://reviews.llvm.org/D136554?vs=486510=487151#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/AST/ast-dump-records.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new line
+  S{}.i);
+
+template 
+constexpr int f(int i = G{}.line) {
+return i;
+}
+
+static_assert(f() != // intentional new line
+  f());
+}
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

Unless something else pops up, I'll try to land that this week end.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 486510.
cor3ntin added a comment.

formatting


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/AST/ast-dump-records.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new line
+  S{}.i);
+
+template 
+constexpr int f(int i = G{}.line) {
+return i;
+}
+
+static_assert(f() != // intentional new line
+  f());
+}
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 486508.
cor3ntin added a comment.

I've convinced myself that the assertition case should be removed.

Before this patch, CXXDefaultInitExpr where never visited
by UsedDeclVisitor.

After this patch, when doing that visitation,
a variable can appear in an unevaluated context without having been mark
non odr used (and doing so would require to unconditionally transform
default member initializers, which we want to avoid).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/AST/ast-dump-records.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new line
+  S{}.i);
+
+template 
+constexpr int f(int i = G{}.line) {
+return i;
+}
+
+static_assert(f() != // 

[PATCH] D136554: Implement CWG2631

[Fangrui Song via Phabricator via cfe-commits]

MaskRay added a comment.

In D136554#4021754 , @cor3ntin wrote:

> In D136554#4020387 , @MaskRay wrote:
>
>> @rupprecht You may consider contributing some interesting tests (which work 
>> before this patch) in a separate patch:)
>
> Well, all the failures reported have been reduced and added as test cases.
> The coverage for member initializers was a bit spotty, that's for sure!

Thanks for checking! I was asking whether some tests worked before the patch 
and served as good regression tests. Then they can be pushed separately.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

reduced to this lovely thing

  template  
  struct d {};
  template  struct f : d<__is_constructible(e)> {
  using type = bool;
  };
  template ::type> int *l;
  int m;
  struct p {
int o = m;
p() {}
  };
  
  int* i(l);

SemaExpr.cpp:19857: void DoMarkVarDeclReferenced(clang::Sema &, 
clang::SourceLocation, clang::VarDecl *, clang::Expr *, llvm::DenseMap &): Assertion `(!E || isa(E)) && "missing 
non-odr-use marking for unevaluated decl ref"' failed.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

I found a new issue doing a bootstrap build, I'm currently reducing


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#4024719 , @rupprecht wrote:

> In D136554#4024628 , @rupprecht 
> wrote:
>
>> I still see one behavior change (actually it was there before, but I missed 
>> it in the test results), but as far as I can tell, it's a good one? If I 
>> reduce it too much, I get the warning with the baseline toolchain, so it's 
>> not erroneous AFAICT. Although I won't pretend I know all the intricacies of 
>> `static` and `inline`.
>
> I missed another place in the unreduced repro that was referencing this 
> method, and that was the trick. I reduced the newly-enabled warning case to 
> this:
>
>   // a.h
>   static const std::pair& GetFakePairRef() {
> static constexpr std::pair fake = {1.0, 2.0};
> return fake;
>   }
>   
>   struct Metadata {
> const std::pair& data = GetFakePairRef();
>   };
>   
>   // main.cc, compiled with -Wunused-function
>   #include "a.h"
>   int main() { return 0; }
>
> Again, still LGTM.

Yes, this is a nice improvement.
It make sense. We now only mark default member initializers odr used when they 
are actually odr used.
default constructing an instance of MetaData silences the warning, which is 
expected!

I'll probably land today.
Thanks a lot for helping me find and reduce all of these corner cases, it was 
very useful and appreciated :)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

In D136554#4024628 , @rupprecht wrote:

> I still see one behavior change (actually it was there before, but I missed 
> it in the test results), but as far as I can tell, it's a good one? If I 
> reduce it too much, I get the warning with the baseline toolchain, so it's 
> not erroneous AFAICT. Although I won't pretend I know all the intricacies of 
> `static` and `inline`.

I missed another place in the unreduced repro that was referencing this method, 
and that was the trick. I reduced the newly-enabled warning case to this:

  // a.h
  static const std::pair& GetFakePairRef() {
static constexpr std::pair fake = {1.0, 2.0};
return fake;
  }
  
  struct Metadata {
const std::pair& data = GetFakePairRef();
  };
  
  // main.cc, compiled with -Wunused-function
  #include "a.h"
  int main() { return 0; }

Again, still LGTM.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht accepted this revision.
rupprecht added a comment.

I still see one behavior change (actually it was there before, but I missed it 
in the test results), but as far as I can tell, it's a good one? If I reduce it 
too much, I get the warning with the baseline toolchain, so it's not erroneous 
AFAICT. Although I won't pretend I know all the intricacies of `static` and 
`inline`.

  // a.h
  static const std::pair& GetFakePair() {
static constexpr std::pair kFakePair = {123.0, 456.0};
return kFakePair;
  }
  
  // b.h
  #include "a.h"
  
  class X {
void Foo(..., const std::pair& x = GetFakePair()) const;
  };
  
  // main.cc, compiled with -Wunused-function
  #include "b.h"
  int main() { return 0; }

Yields this error:

  In file included from main.cc:9:
  In file included from ./b.h:16:
  ./a.h:40:41: error: 'static' function 'GetFakePair' declared in header file 
should be declared 'static inline' [-Werror,-Wunneeded-internal-declaration]
  static const std::pair& GetFakePair() {

Unless I'm missing something, it seems that, in regards to this warning, this 
change is just enabling an existing warning to have more coverage, and 
therefore this change looks ready to ship. Thanks for letting me provide all my 
repros before landing this one again :)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#4020387 , @MaskRay wrote:

> @rupprecht You may consider contributing some interesting tests (which work 
> before this patch) in a separate patch:)

Well, all the failures reported have been reduced and added as test cases.
The coverage for member initializers was a bit spotty, that's for sure!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Fangrui Song via Phabricator via cfe-commits]

MaskRay added a comment.

@rupprecht You may consider contributing some interesting tests in a separate 
patch:)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 485703.
cor3ntin added a comment.

Finding the issue took about all day.
I reduced your example to

  template 
  int templated_func() {
  return 0;
  }
  struct test_body {
int mem = templated_func();
  };
  
  struct S {
int a = [] { test_body{}; return 0;}(); // #1
  } s;

When parsing the lambda #1 , we were not considering test_body{} to be 
odr used, on account of the lambda being in the default initializer of a.

However, as it turns out, expressions in the body of a lambda are always 
considered ODR used even if the lambda appear in a default parameter, 
which I think makes sense.
(as the standard specifies that the body of a lambda is not a sub expression)

The actual code fix is to simplify the check we do to see if we are 
in a nested default initializer.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/AST/ast-dump-records.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

I threw this at the "test everything" test (some millions of targets) and it 
found only one breakage, so this is very very close. Without further ado, here 
is this silly looking thing:

File `blah.h`:

  #include 
  #include 
  
  template 
  struct Base {
virtual ~Base() = default;
  };
  
  class Impl : public Base {};
  
  struct ImplHolder {
std::unique_ptr> impl = std::make_unique();
  };
  
  struct GetImplCreators {
std::function impl_creator = []() { return ImplHolder{}; };
  };
  
  void UseImpl(GetImplCreators impl_creators = GetImplCreators{});

And `blah.cc`:

  #include "blah.h"
  
  void UseImpl(GetImplCreators impl_creators) {}

And lastly, `blah_main.cc`:

  #include "blah.h"
  
  void Func1() { UseImpl(); }
  // Note: it also fails when we explicitly specify the default arg, in case 
that is interesting.
  // void Func2() { UseImpl(GetImplCreators()); }
  
  int main(int argc, char* argv[]) { return 0; }

And here's the LLD output:

  ld: error: undefined hidden symbol: 
std::__u::__unique_if::__unique_single std::__u::make_unique()
  >>> referenced by blah_main.cc
  >>>   blah_main.o:(ImplHolder 
std::__u::__function::__policy_invoker::__call_impl>(std::__u::__function::__policy_storage const*))
  
  ld: error: undefined hidden symbol: std::__u::unique_ptr>::~unique_ptr()
  >>> referenced by blah_main.cc
  >>>   blah_main.o:(ImplHolder 
std::__u::__function::__policy_invoker::__call_impl>(std::__u::__function::__policy_storage const*))

I'm out of time today so I don't have a repro script to offer, but I can dig 
into that when I get back next year if the source-only example is insufficient.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 485605.
cor3ntin added a comment.

Another fun one.
I really apreciate your help on this.

The constructor of `Wrapper` causes
the constructor of `Option` to be defined, but not yet used
(as default parameters are not odr used) - 
so none of the default member initializers where marked ODR used.

When `Option::Option()` is called by `Func`, it is marked
as referenced and ODR used, but its default member initializers
are not.

When marking a constructor as referenced, we therefore must make sure
to reference its default member initializers.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/AST/ast-dump-records.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new 

[PATCH] D136554: Implement CWG2631

[Fangrui Song via Phabricator via cfe-commits]

MaskRay added a comment.

In D136554#4019135 , @rupprecht wrote:

> [...]
> The undefined symbols before are all provided by libc++, so those are fine. 
> After, the new undefined symbol for the lambda cannot be resolved. Depending 
> on how the linker is invoked, this may or may not be fine -- IIUC the linker 
> can sometimes recognize that it doesn't actually need the undefined symbol, 
> so it doesn't matter if it can't find it.
>
> Here is the build script I'm using, although you will likely need to tweak it 
> for your own environment:

The behavior is expected.

For `/tmp/main.o -Wl,--start-lib /tmp/b.o -Wl,--end-lib`, `b.o` is a lazy 
object file (with archive semantics) which is not extracted.
The result is as if the linker discards the input file, so its undefined 
references do not cause a linker error ([[ 
https://maskray.me/blog/2021-06-13-dependency-related-linker-options#z-defs | 
`-z defs` ]]: unresolved undefined non-weak symbol from a relocatable object 
file; an unextracted lazy file is not considered a relocatable object file ).

For `/tmp/main.o /tmp/b.o`, `b.o` is parsed as a relocatable object file. Its 
undefined reference causes by this patch (experiment locally with `git revert 
-n 339a7687e1c036a5f91c9d5391523b93e2e76cd3`) leads to a `-z defs` linker error.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

I'm not sure what to make of the new failure when I try it out this time. Given 
a source like this:

  #include 
  
  struct Options {
std::function identity = [](bool x) -> bool { return x; };
  };
  
  struct Wrapper {
explicit Wrapper(const Options& options = Options()) {}
  };
  
  void Func() { Options options; }

The object file reports many fewer symbols as a result of this patch, but one 
new problematic one. Before:

   T Func()
   W 
std::__1::__function::__func, bool 
(bool)>::target_type() const
   W 
std::__1::__function::__func, bool 
(bool)>::target(std::type_info const&) const
   W 
std::__1::__function::__func, bool 
(bool)>::__clone(std::__1::__function::__base*) const
   W 
std::__1::__function::__func, bool (bool)>::__clone() 
const
   W std::__1::__function::__base::~__base[abi:v16]()
   W 
std::__1::__function::__func, bool 
(bool)>::destroy_deallocate()
   W 
std::__1::__function::__func, bool (bool)>::destroy()
   W 
std::__1::__function::__func, bool (bool)>::~__func()
   W 
std::__1::__function::__func, bool 
(bool)>::operator()(bool&&)
   V typeinfo for Options::identity::'lambda'(bool)
   V typeinfo for std::__1::__function::__base
   V typeinfo for 
std::__1::__function::__func, bool (bool)>
   V typeinfo name for Options::identity::'lambda'(bool)
   V typeinfo name for std::__1::__function::__base
   V typeinfo name for 
std::__1::__function::__func, bool (bool)>
   U vtable for __cxxabiv1::__class_type_info
   U vtable for __cxxabiv1::__si_class_type_info
   V vtable for 
std::__1::__function::__func, bool (bool)>
   U operator delete(void*)
   U operator new(unsigned long)

And after:

   T Func()
   U std::__1::function::function(Options::identity::'lambda'(bool))

The undefined symbols before are all provided by libc++, so those are fine. 
After, the new undefined symbol for the lambda cannot be resolved. Depending on 
how the linker is invoked, this may or may not be fine -- IIUC the linker can 
sometimes recognize that it doesn't actually need the undefined symbol, so it 
doesn't matter if it can't find it.

Here is the build script I'm using, although you will likely need to tweak it 
for your own environment:

  ${CLANG} \
-std=gnu++17 -stdlib=libc++ \
-c main.cc \
-o /tmp/main.o
  
  echo "main.o symbols:"
  llvm-nm -C /tmp/main.o
  
  echo Building b.cc
  
  ${CLANG} \
-std=gnu++17 -stdlib=libc++ \
-O1 -fno-exceptions \
-c b.cc \
-o /tmp/b.o
  
  echo "b.o symbols:"
  llvm-nm -C /tmp/b.o
  
  echo Linking, and expecting success
  
  ${CLANG} \
-fuse-ld=lld \
-o /tmp/main \
/tmp/main.o \
-Wl,--start-lib /tmp/b.o -Wl,--end-lib \
/usr/lib/x86_64-linux-gnu/libc++.so
  
  echo Linking, and expecting failure with D136554
  
  ${CLANG} \
-fuse-ld=lld \
-o /tmp/main \
/tmp/main.o \
/tmp/b.o \
/usr/lib/x86_64-linux-gnu/libc++.so \
-Wl,--export-dynamic

(Here `b.cc` is the first snippet above, and `main.cc` is a trivial file with 
just `int main(int argc, char* argv[]) { return 0; }`)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

In D136554#4018870 , @rupprecht wrote:

> All good now! The latest revision of this patch doesn't seem to break 
> anything, unless I ran our tests wrong. From my perspective this is OK to 
> reland now.

... and yep, I was holding it wrong. There are still build failures, this time 
in linking, where LLD reports some symbols are undefined. I'm not certain yet 
if this really a problem with this patch (e.g. sometimes we see files break 
like this when users put their template code in the .cpp files and not the .h 
files), but the source code doesn't look immediately wrong. Once again, I'll 
try to reduce something.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

All good now! The latest revision of this patch doesn't seem to break anything, 
unless I ran our tests wrong. From my perspective this is OK to reland now.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 485067.
cor3ntin added a comment.

I hope we will get there...

It further reduces to

  consteval void immediate(){};
  
  struct h {
int g = 0;
int blah = (immediate(), g);
  };
  struct k {
   h j{};
  }_;

The issue was that nested expressions are all transformed in the context of 
the outermost (k) class and transforming the this pointer pick up 
the current this pointer. 
Because when we do the replacenent we no longer have templates,
we can just skip the transformation of the this pointer.

This is a cleaner way to handke the this pointer than
having a CXXThisScopeRAII on the outer scope, 
so I removed that.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/AST/ast-dump-records.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

In D136554#4013463 , @rupprecht wrote:

> Glad the test case made sense to you, it was convoluted to me :)
>
> Still seeing one more error, and it's not modules-related so I might be able 
> to get it reduced today. Generally, it looks like this:
>
>   struct Inner {
> Foo& foo;
> const std::unique_ptr<...> x = blah(blah(
> ()));
>   };
>   
>   class Outer {
>private:
> Foo foo_;
> Inner inner{foo_};
>   }
>
> With the error being:
>
>   error: 'Inner::foo' is not a member of class 'Outer'
> ()));
>
> I think this build failure is wrong? `foo` should be referring to the 
> definition inside `Inner`, but clang seems to be expecting it to refer to 
> something in `Outer`.
>
> Is it expected that this patch will cause some previously "working" code to 
> no longer build? At some point I expect to hand you a reduction that's 
> actually a bug in the user code.

Fully reduced as:

  template  int c(a, b);
  struct d {
static d e(const char * = __builtin_FILE());
  };
  struct f {
f(d = d::e());
  };
  struct h {
int 
int blah = c(g, f());
  };
  struct k {
k();
int i;
h j{i};
  };
  k::k() {}

With the error: `repro.cc:10:16: error: 'h::g' is not a member of class 'k'`


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

Glad the test case made sense to you, it was convoluted to me :)

Still seeing one more error, and it's not modules-related so I might be able to 
get it reduced today. Generally, it looks like this:

  struct Inner {
Foo& foo;
const std::unique_ptr<...> x = blah(blah(
()));
  };
  
  class Outer {
   private:
Foo foo_;
Inner inner{foo_};
  }

With the error being:

  error: 'Inner::foo' is not a member of class 'Outer'
()));

I think this build failure is wrong? `foo` should be referring to the 
definition inside `Inner`, but clang seems to be expecting it to refer to 
something in `Outer`.

Is it expected that this patch will cause some previously "working" code to no 
longer build? At some point I expect to hand you a reduction that's actually a 
bug in the user code.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 484802.
cor3ntin added a comment.

Thanks @rupprecht

As all good bugs, this was very confusing up 
until the moment it became obvious.

I did not make the initializer a full expression during parsing,
(but on use), as I thought that was unecessary.
But then if that initializer had any cleanup, the next expression 
being parsed would get cleanups instead.

So here kFooDelimiter initializer would be wrapped in ExprWithCleanup 
(it clearly should not), if an only if Xyz was parsed before hand.

I added an ast dump test for that case.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/AST/ast-dump-records.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new line
+  

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

Sorry for the delay, I was out on vacation for a bit. I have a repro for this 
new issue now: F25778542: repro.tar.gz 

  $ CLANG=~/dev/clang ./repro.sh
  ++ dirname /tmp/repro/repro.sh
  + DIR=/tmp/repro
  + : /tmp/D136554
  + rm -rf /tmp/D136554
  + mkdir -p /tmp/D136554
  + cd /tmp/D136554
  + cp /tmp/repro/lib.h /tmp/repro/outer.h /tmp/repro/x.h /tmp/repro/y.h 
/tmp/repro/z.h /tmp/repro/lib.cppmap /tmp/repro/outer.cppmap 
/tmp/repro/x.cppmap /tmp/repro/y.cppmap /tmp/repro/z.cppmap .
  + COMMON_ARGS=('-Wno-mismatched-tags' '-Xclang=-fmodules-embed-all-files' 
'-Xclang=-fmodules-local-submodule-visibility' '-fmodules' 
'-fno-implicit-modules' '-fno-implicit-module-maps' '-std=gnu++17' 
'-Xclang=-fmodule-map-file-home-is-cwd')
  + export COMMON_ARGS
  + /home/rupprecht/dev/clang -Wno-mismatched-tags 
-Xclang=-fmodules-embed-all-files -Xclang=-fmodules-local-submodule-visibility 
-fmodules -fno-implicit-modules -fno-implicit-module-maps -std=gnu++17 
-Xclang=-fmodule-map-file-home-is-cwd -fmodule-name=x 
-fmodule-map-file=x.cppmap -fmodule-map-file=lib.cppmap -xc++ 
-Xclang=-emit-module -c x.cppmap -o x.pcm
  + /home/rupprecht/dev/clang -Wno-mismatched-tags 
-Xclang=-fmodules-embed-all-files -Xclang=-fmodules-local-submodule-visibility 
-fmodules -fno-implicit-modules -fno-implicit-module-maps -std=gnu++17 
-Xclang=-fmodule-map-file-home-is-cwd -fmodule-name=y 
-fmodule-map-file=y.cppmap -fmodule-map-file=lib.cppmap 
-fmodule-map-file=z.cppmap -xc++ -Xclang=-emit-module -c y.cppmap -o y.pcm
  + /home/rupprecht/dev/clang -Wno-mismatched-tags 
-Xclang=-fmodules-embed-all-files -Xclang=-fmodules-local-submodule-visibility 
-fmodules -fno-implicit-modules -fno-implicit-module-maps -std=gnu++17 
-Xclang=-fmodule-map-file-home-is-cwd -fmodule-name=outer 
-fmodule-map-file=outer.cppmap -Xclang=-fmodule-file=x.pcm 
-Xclang=-fmodule-file=y.pcm -fmodule-map-file=lib.cppmap 
-fmodule-map-file=x.cppmap -fmodule-map-file=y.cppmap -xc++-header 
-fsyntax-only -c outer.h -o outer.h.processed
  In module 'x':
  ./lib.h:5:25: error: 'Foo' has different definitions in different modules; 
first difference is definition in module 'x.x.h' found data member 'kConstant' 
with an initializer
static constexpr char kConstant = '+';
~~^~~
  ./lib.h:5:25: note: but in 'y.y.h' found data member 'kConstant' with a 
different initializer
static constexpr char kConstant = '+';
~~^~~
  1 error generated.



In D136554#4000654 , @cor3ntin wrote:

> In D136554#4000363 , @rupprecht 
> wrote:
>
>> I applied this version of the patch and the crash is now gone 
>>
>> However, now I get this inexplicable error -- I'm not entirely sure it's 
>> related, maybe I'm holding it wrong:
>>
>>   In module '':
>>   foo.h$line:$num: error: 'foo::FooClass' has different definitions in 
>> different modules; first difference is definition in module 'something.h' 
>> found data member 'kFooDelimiter' with an initializer
>> static constexpr char kFooDelimiter = '+';
>> ~~^~~
>>   foo.h:$line:$num note: but in 'other.h' found data member 'kFooDelimiter' 
>> with a different initializer
>> static constexpr char kFooDelimiter = '+';
>> ~~^~~
>>
>> The definition seems straightforward:
>>
>>   class FooClass final {
>> ...
>> static constexpr char kFooDelimiter = '+';
>> ...
>>   };
>
> This is *very* surprising to me.
> I could explain it if  the member was not static though, as it would be the 
> kind of things the patch affects. But static data members are handled very 
> differently.
>
> Was that liking chrome? It didn't come up in my tests

No, it's some other internal target. There isn't any way for you to be able to 
test against these targets, so unfortunately the best I can offer is I'll patch 
in any updated versions of this patch, see what breaks, and try to reduce it 
when reporting.

There's barely any code in the repro I attached, it's just a bunch of 
header/module layering. My guess is that clang is usually able to see that the 
two definitions in different modules is the same and therefore dedupes them, 
but this change adds some unique bit of information that makes clang think it's 
different. Note that the headers need to be in a particular order to break.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#4000363 , @rupprecht wrote:

> I applied this version of the patch and the crash is now gone 
>
> However, now I get this inexplicable error -- I'm not entirely sure it's 
> related, maybe I'm holding it wrong:
>
>   In module '':
>   foo.h$line:$num: error: 'foo::FooClass' has different definitions in 
> different modules; first difference is definition in module 'something.h' 
> found data member 'kFooDelimiter' with an initializer
> static constexpr char kFooDelimiter = '+';
> ~~^~~
>   foo.h:$line:$num note: but in 'other.h' found data member 'kFooDelimiter' 
> with a different initializer
> static constexpr char kFooDelimiter = '+';
> ~~^~~
>
> The definition seems straightforward:
>
>   class FooClass final {
> ...
> static constexpr char kFooDelimiter = '+';
> ...
>   };

This is *very* surprising to me.
I could explain it if  the member was not static though, as it would be the 
kind of things the patch affects. But static data members are handled very 
differently.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

I applied this version of the patch and the crash is now gone 

However, now I get this inexplicable error -- I'm not entirely sure it's 
related, maybe I'm holding it wrong:

  In module '':
  foo.h$line:$num: error: 'foo::FooClass' has different definitions in 
different modules; first difference is definition in module 'something.h' found 
data member 'kFooDelimiter' with an initializer
static constexpr char kFooDelimiter = '+';
~~^~~
  foo.h:$line:$num note: but in 'other.h' found data member 'kFooDelimiter' 
with a different initializer
static constexpr char kFooDelimiter = '+';
~~^~~

The definition seems straightforward:

  class FooClass final {
...
static constexpr char kFooDelimiter = '+';
...
  };


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 483133.
cor3ntin added a comment.

Properly transform the this pointer in member initializers 
that need to be rewritten.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new line
+  S{}.i);
+
+template 
+constexpr int f(int i = G{}.line) {
+return i;
+}
+
+static_assert(f() != // intentional new line
+  f());
+}
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#3996643 , @rupprecht wrote:

> Here's a well-formed reproducer:

Thanks a lot.
We were transforming the initializer in a context where the this pointer was 
not set up properly, so if it was referring to this, explicitly or implicitly, 
it would crash.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

Here's a well-formed reproducer:

  struct MyStringView {
MyStringView(const char *);
  };
  
  struct SourceLocation {
static SourceLocation current(const char * = __builtin_FILE(),
  unsigned int = __builtin_LINE());
  };
  
  template 
  int Wrap(T);
  
  template 
  struct Fixed {
using name = MyStringView;
  };
  
  struct Metadata {
Metadata(SourceLocation = SourceLocation::current());
  };
  
  struct Name {
Name(int *);
  };
  
  template 
  struct C {
static C New(Name, typename Fixed::name..., Metadata);
  };
  struct X {
int ();
  };
  struct Foo {
X x;
int i = Wrap(C::New((), "", "", Metadata()));
  };
  void func() { new Foo{}; }


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

Actually, that assertion failure is pre-existing. However, this is newly 
failing in a no-asserts clang, so I wonder if something about this patch is 
just surfacing an existing bug in clang. Anyway, I hope to have a better repro 
by EOD.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

Ugh, I left cvise running overnight and forgot to include the validity check by 
building with a previous clang, so my reduction is invalid. I'm going to run it 
again, but here's the invalid crasher in the meantime:

  struct SourceLocation {
static SourceLocation current(const char * = __builtin_FILE()) {
  struct Metadata {
Metadata(SourceLocation = current());
namespace struct {
  int x = z(x, Metadata())
} y {
}

stack trace:

  clang: /home/rupprecht/src/llvm-project/clang/include/clang/AST/Type.h:752: 
const ExtQualsTypeCommonBase *clang::QualType::getCommonPtr() const: Assertion 
`!isNull() && "Cannot retrieve a NULL type pointer"' failed.
  PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ 
and include the crash backtrace, preprocessed source, and associated run script.
  Stack dump:
  0.  Program arguments: bin/clang -c /tmp/repro.cc -std=c++17 -o 
/tmp/repro.o
  1.   parser at end of file
  2.  /tmp/repro.cc:1:1: parsing struct/union/class body 'SourceLocation'
  3.  /tmp/repro.cc:2:66: parsing function body 'SourceLocation::current'
  4.  /tmp/repro.cc:2:66: in compound statement ('{}')
   #0 0x5645aaceaaba llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) 
/home/rupprecht/src/llvm-project/llvm/lib/Support/Unix/Signals.inc:567:11
   #1 0x5645aaceac6b PrintStackTraceSignalHandler(void*) 
/home/rupprecht/src/llvm-project/llvm/lib/Support/Unix/Signals.inc:641:1
   #2 0x5645aace92f6 llvm::sys::RunSignalHandlers() 
/home/rupprecht/src/llvm-project/llvm/lib/Support/Signals.cpp:104:5
   #3 0x5645aacea3ae llvm::sys::CleanupOnSignal(unsigned long) 
/home/rupprecht/src/llvm-project/llvm/lib/Support/Unix/Signals.inc:367:1
   #4 0x5645aac01187 (anonymous 
namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) 
/home/rupprecht/src/llvm-project/llvm/lib/Support/CrashRecoveryContext.cpp:0:7
   #5 0x5645aac015dc CrashRecoverySignalHandler(int) 
/home/rupprecht/src/llvm-project/llvm/lib/Support/CrashRecoveryContext.cpp:398:1
   #6 0x7f34de23daa0 (/lib/x86_64-linux-gnu/libc.so.6+0x3daa0)
   #7 0x7f34de28957c __pthread_kill_implementation 
./nptl/pthread_kill.c:44:76
   #8 0x7f34de23da02 gsignal ./signal/../sysdeps/posix/raise.c:27:6
   #9 0x7f34de228469 abort ./stdlib/abort.c:81:7
  #10 0x7f34de228395 _nl_load_domain ./intl/loadmsgcat.c:1177:9
  #11 0x7f34de236ab2 (/lib/x86_64-linux-gnu/libc.so.6+0x36ab2)
  #12 0x5645ab1dae17 clang::QualType::getCommonPtr() const 
/home/rupprecht/src/llvm-project/clang/include/clang/AST/Type.h:0:5
  #13 0x5645ab1dada5 clang::QualType::getTypePtr() const 
/home/rupprecht/src/llvm-project/clang/include/clang/AST/Type.h:6622:26
  #14 0x5645ab1da995 clang::QualType::operator->() const 
/home/rupprecht/src/llvm-project/clang/include/clang/AST/Type.h:794:5
  #15 0x5645b071fe92 clang::computeDependence(clang::CXXThisExpr*) 
/home/rupprecht/src/llvm-project/clang/lib/AST/ComputeDependence.cpp:312:43
  #16 0x5645aed30c16 clang::CXXThisExpr::CXXThisExpr(clang::SourceLocation, 
clang::QualType, bool) 
/home/rupprecht/src/llvm-project/clang/include/clang/AST/ExprCXX.h:1154:19
  #17 0x5645af7f7c53 clang::Sema::BuildCXXThisExpr(clang::SourceLocation, 
clang::QualType, bool) 
/home/rupprecht/src/llvm-project/clang/lib/Sema/SemaExprCXX.cpp:1400:30
  #18 0x5645af7d46a8 
clang::TreeTransform::RebuildCXXThisExpr(clang::SourceLocation,
 clang::QualType, bool) 
/home/rupprecht/src/llvm-project/clang/lib/Sema/TreeTransform.h:3196:22
  #19 0x5645af7b09ae 
clang::TreeTransform::TransformCXXThisExpr(clang::CXXThisExpr*)
 /home/rupprecht/src/llvm-project/clang/lib/Sema/TreeTransform.h:12139:23
  #20 0x5645af7a9ec5 
clang::TreeTransform::TransformExpr(clang::Expr*)
 
/home/rupprecht/src/llvm-build/dev/tools/clang/include/clang/AST/StmtNodes.inc:907:1
  #21 0x5645af7b5097 
clang::TreeTransform::TransformMemberExpr(clang::MemberExpr*)
 /home/rupprecht/src/llvm-project/clang/lib/Sema/TreeTransform.h:11224:34
  #22 0x5645af7aa857 
clang::TreeTransform::TransformExpr(clang::Expr*)
 
/home/rupprecht/src/llvm-build/dev/tools/clang/include/clang/AST/StmtNodes.inc:1249:1
  #23 0x5645af7b945a 
clang::TreeTransform::TransformRecoveryExpr(clang::RecoveryExpr*)
 /home/rupprecht/src/llvm-project/clang/lib/Sema/TreeTransform.h:10929:36
  #24 0x5645af7aade4 
clang::TreeTransform::TransformExpr(clang::Expr*)
 
/home/rupprecht/src/llvm-build/dev/tools/clang/include/clang/AST/StmtNodes.inc:1431:1
  #25 0x5645af71b9fe 
clang::TreeTransform::TransformInitializer(clang::Expr*,
 bool) /home/rupprecht/src/llvm-project/clang/lib/Sema/TreeTransform.h:4006:25
  #26 0x5645af533e03 
clang::Sema::BuildCXXDefaultInitExpr(clang::SourceLocation, clang::FieldDecl*) 
/home/rupprecht/src/llvm-project/clang/lib/Sema/SemaExpr.cpp:6090:19
  #27 0x5645af995bcf (anonymous 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#3993791 , @rupprecht wrote:

> Looks like the latest reland still has some issue remaining. With asserts 
> enabled, I get: `assert.h assertion failed at 
> clang/include/clang/AST/Type.h:752 in const ExtQualsTypeCommonBase 
> *clang::QualType::getCommonPtr() const: !isNull() && "Cannot retrieve a NULL 
> type pointer"`. I'm going to work on reducing it now.

Oh no! I'd love a reduced repro if you can. Or at worse, a stack trace, I'd be 
happy to investigate. Thanks!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Jordan Rupprecht via Phabricator via cfe-commits]

rupprecht added a comment.

Looks like the latest reland still has some issue remaining. With asserts 
enabled, I get: `assert.h assertion failed at 
clang/include/clang/AST/Type.h:752 in const ExtQualsTypeCommonBase 
*clang::QualType::getCommonPtr() const: !isNull() && "Cannot retrieve a NULL 
type pointer"`. I'm going to work on reducing it now.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGf1f1b60c7ba6: Implement CWG2631 (authored by cor3ntin).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new line
+  S{}.i);
+
+template 
+constexpr int f(int i = G{}.line) {
+return i;
+}
+
+static_assert(f() != // intentional new line
+  f());
+}
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 482377.
cor3ntin added a comment.

remove llvm::None


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new line
+  S{}.i);
+
+template 
+constexpr int f(int i = G{}.line) {
+return i;
+}
+
+static_assert(f() != // intentional new line
+  f());
+}
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // 

[PATCH] D136554: Implement CWG2631

[Dan McGregor via Phabricator via cfe-commits]

dankm added inline comments.



Comment at: clang/include/clang/Sema/Sema.h:9688
+}
+return llvm::None;
+  }

llvm::None has been deprecated in favour of std::nullopt.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Arthur Eubanks via Phabricator via cfe-commits]

aeubanks added a comment.

I'm fine with relanding and seeing if anything else pops up


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

@aeubanks I just completed a compilation of all of chrome including tests. let 
me know if you want to run more tests on your side and thanks again for 
reporting these issues. I think we are getting there.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 482051.
cor3ntin added a comment.

When a CXXDefaultInitExpr calls a Constructor,
make sure that the fields default initialized by that 
constructor are also marked odr used.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new line
+  S{}.i);
+
+template 
+constexpr int f(int i = G{}.line) {
+return i;
+}
+
+static_assert(f() != // intentional new line
+  f());
+}
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#3987122 , @aeubanks wrote:

> no, I got
>
>   $ ninja -C out/MyClang/ content_unittests
>   ld.lld: error: undefined symbol: 
> mojo::Receiver mojo::RawPtrImplRefTraits>::Receiver(content::mojom::TestInterfaceForDefer*)
>   >>> referenced by mojo_binder_policy_applier_unittest.cc:90 
> (../../content/browser/mojo_binder_policy_applier_unittest.cc:90)
>   >>>   
> obj/content/test/content_unittests/mojo_binder_policy_applier_unittest.o:(content::TestReceiverCollector::TestReceiverCollector())
>   
>   ld.lld: error: undefined symbol: 
> mojo::Receiver mojo::RawPtrImplRefTraits>::Receiver(content::mojom::TestInterfaceForGrant*)
>   >>> referenced by mojo_binder_policy_applier_unittest.cc:91 
> (../../content/browser/mojo_binder_policy_applier_unittest.cc:91)
>   >>>   
> obj/content/test/content_unittests/mojo_binder_policy_applier_unittest.o:(content::TestReceiverCollector::TestReceiverCollector())
>   
>   ld.lld: error: undefined symbol: 
> mojo::Receiver mojo::RawPtrImplRefTraits>::Receiver(content::mojom::TestInterfaceForCancel*)
>   >>> referenced by mojo_binder_policy_applier_unittest.cc:92 
> (../../content/browser/mojo_binder_policy_applier_unittest.cc:92)
>   >>>   
> obj/content/test/content_unittests/mojo_binder_policy_applier_unittest.o:(content::TestReceiverCollector::TestReceiverCollector())
>   
>   ld.lld: error: undefined symbol: 
> mojo::Receiver mojo::RawPtrImplRefTraits>::Receiver(content::mojom::TestInterfaceForUnexpected*)
>   >>> referenced by mojo_binder_policy_applier_unittest.cc:93 
> (../../content/browser/mojo_binder_policy_applier_unittest.cc:93)
>   >>>   
> obj/content/test/content_unittests/mojo_binder_policy_applier_unittest.o:(content::TestReceiverCollector::TestReceiverCollector())
>   clang++: error: linker command failed with exit code 1 (use -v to see 
> invocation)
>
> https://crsrc.org/c/content/browser/mojo_binder_policy_applier_unittest.cc;drc=4e1b7bc33d42b401d7d9ad1dcba72883add3e2af;l=90

Thanks, that was really helpful.
After most of the day spent on compiling clang and reducing, i got it down to

  template  
  struct MissingCtr {
MissingCtr() {}
  };
  class k {
  //public:
MissingCtr a{};
  };
  struct b {
k c{};
  };
  int main() { b d; }

It would appear to be related to access. I had not yet encountered something 
access related with this patch!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Arthur Eubanks via Phabricator via cfe-commits]

aeubanks added a comment.

no, I got

  $ ninja -C out/MyClang/ content_unittests
  ld.lld: error: undefined symbol: 
mojo::Receiver>::Receiver(content::mojom::TestInterfaceForDefer*)
  >>> referenced by mojo_binder_policy_applier_unittest.cc:90 
(../../content/browser/mojo_binder_policy_applier_unittest.cc:90)
  >>>   
obj/content/test/content_unittests/mojo_binder_policy_applier_unittest.o:(content::TestReceiverCollector::TestReceiverCollector())
  
  ld.lld: error: undefined symbol: 
mojo::Receiver>::Receiver(content::mojom::TestInterfaceForGrant*)
  >>> referenced by mojo_binder_policy_applier_unittest.cc:91 
(../../content/browser/mojo_binder_policy_applier_unittest.cc:91)
  >>>   
obj/content/test/content_unittests/mojo_binder_policy_applier_unittest.o:(content::TestReceiverCollector::TestReceiverCollector())
  
  ld.lld: error: undefined symbol: 
mojo::Receiver>::Receiver(content::mojom::TestInterfaceForCancel*)
  >>> referenced by mojo_binder_policy_applier_unittest.cc:92 
(../../content/browser/mojo_binder_policy_applier_unittest.cc:92)
  >>>   
obj/content/test/content_unittests/mojo_binder_policy_applier_unittest.o:(content::TestReceiverCollector::TestReceiverCollector())
  
  ld.lld: error: undefined symbol: 
mojo::Receiver>::Receiver(content::mojom::TestInterfaceForUnexpected*)
  >>> referenced by mojo_binder_policy_applier_unittest.cc:93 
(../../content/browser/mojo_binder_policy_applier_unittest.cc:93)
  >>>   
obj/content/test/content_unittests/mojo_binder_policy_applier_unittest.o:(content::TestReceiverCollector::TestReceiverCollector())
  clang++: error: linker command failed with exit code 1 (use -v to see 
invocation)

https://crsrc.org/c/content/browser/mojo_binder_policy_applier_unittest.cc;drc=4e1b7bc33d42b401d7d9ad1dcba72883add3e2af;l=90


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#3986779 , @cor3ntin wrote:

> In D136554#3986713 , @aeubanks 
> wrote:
>
>> yes, it was chrome
>> I went ahead and tried the latest patch, it successfully compiles the file 
>> that crashed before. I built all of chrome, and now I'm getting one last 
>> linker error, I'll try to get some more info about that
>
> Thanks for confirming :)
> If you have the message of that linker error, i might be able to infer a 
> repro from that. Otherwise, I'm going to build chromium

I got 
`x86_64-linux-gnu/libnspr4.so: undefined reference to gettid`

But otherwise it works fine.
linking with `mold` fixes the issue.
I can't find an instance of `gettid()` that would be called from a default 
parameter or mem initializer list so I would be surprise if it's related. Was 
that the issue you encountered?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#3986713 , @aeubanks wrote:

> yes, it was chrome
> I went ahead and tried the latest patch, it successfully compiles the file 
> that crashed before. I built all of chrome, and now I'm getting one last 
> linker error, I'll try to get some more info about that

Thanks for confirming :)
If you have the message of that linker error, i might be able to infer a repro 
from that. Otherwise, I'm going to build chromium


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Arthur Eubanks via Phabricator via cfe-commits]

aeubanks added a comment.

yes, it was chrome
I went ahead and tried the latest patch, it successfully compiles the file that 
crashed before. I built all of chrome, and now I'm getting one last linker 
error, I'll try to get some more info about that


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

@aeubanks I think i got it. Were you having this issue with an open source 
project by any chance?  Maybe i could try it locally before commiting


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 481850.
cor3ntin added a comment.

- Make sure cleanups expressions are created in the correct evaluation context. 
This simplifies and reduce the numbers of nested evaluation contexts we create, 
notably to make sure the creation of the initialier and cleanup expressions are 
done in the same context

- Add tests for calls to source location builtin in dependant initializers


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,73 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
+
+namespace check_immediate_invocations_in_templates {
+
+template 
+struct G {
+T line = __builtin_LINE();
+};
+template 
+struct S {
+int i = G{}.line;
+};
+static_assert(S{}.i != // intentional new line
+  S{}.i);
+
+template 
+constexpr int f(int i = G{}.line) {
+return i;
+}
+
+static_assert(f() != // intentional new line
+  f());
+}
Index: 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

Thanks!

Cleaned up version:

  struct string {
constexpr string(const char*) {};
constexpr ~string();
  };
  struct AutocompleteParsingResult;
  struct optional {
  template  
  constexpr optional(U &&) {}
  };
  struct AutocompleteParsingResult {
  string StringPiece;
  optional expected_result;
  int max_length = 0;
  } kAutocompleteTestcases {
  "", {
  { "", 0 }
  }
  };

And yes, this is about as reduced as I can make it.
I'll investigate later


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Arthur Eubanks via Phabricator via cfe-commits]

aeubanks added a comment.

a really bad reduced repro which also has random syntax errors:

  using string = struct basic_string {
constexpr basic_string(char *) {} constexpr ~basic_string(
  } struct AutocompleteParsingResult struct optional {
template  constexpr optional(U &&) 
{}
namespace enum { kName } struct AutocompleteParsingResult {
  string StringPiece;
  optional expected_result;
  int max_length = 0
} kAutocompleteTestcases {
  "", {
{ "", kName }
  }
  }

`clang -cc1 -x c++ -triple x86_64-unknown-linux-gnu  -std=c++20  -fsyntax-only  
/tmp/reduced.cpp.orig -ferror-limit 1`
working on a reduced repro with -ferror-limit=1


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Arthur Eubanks via Phabricator via cfe-commits]

aeubanks reopened this revision.
aeubanks added a comment.
This revision is now accepted and ready to land.

I've bisected another crash to this change. Reverting, and currently creducing 
a repro.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGc9a6713b4788: Implement CWG2631 (authored by cor3ntin).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 481411.
cor3ntin added a comment.

Correctly visit array filer when marking 
default member init as ODR-used


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin reopened this revision.
cor3ntin added a comment.
This revision is now accepted and ready to land.

In D136554#3982161 , @aeubanks wrote:

> the following now produces a link error:
>
>   $ cat /tmp/a.cc
>   #include 
>   #include 
>   
>   struct S {
>   std::map a;
>   };
>   
>   using T = std::array;
>   
>   class C {
>   T t{};
>   };
>   
>   int main() {
>   C c;
>   }
>   $ ./build/rel/bin/clang++ -o /dev/null /tmp/a.cc -stdlib=libc++ -fuse-ld=lld
>   ld.lld: error: undefined hidden symbol: std::__2::map std::__2::less, std::__2::allocator int>>>::map[abi:v16]()
>   >>> referenced by a.cc
>   >>>   /tmp/a-042a0e.o:(C::C())
>   clang: error: linker command failed with exit code 1 (use -v to see 
> invocation)
>
> using a ToT libc++
>
> is this expected?




Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Arthur Eubanks via Phabricator via cfe-commits]

aeubanks added a comment.

the following now produces a link error:

  $ cat /tmp/a.cc
  #include 
  #include 
  
  struct S {
  std::map a;
  };
  
  using T = std::array;
  
  class C {
  T t{};
  };
  
  int main() {
  C c;
  }
  $ ./build/rel/bin/clang++ -o /dev/null /tmp/a.cc -stdlib=libc++ -fuse-ld=lld
  ld.lld: error: undefined hidden symbol: std::__2::map, std::__2::allocator>>::map[abi:v16]()
  >>> referenced by a.cc
  >>>   /tmp/a-042a0e.o:(C::C())
  clang: error: linker command failed with exit code 1 (use -v to see 
invocation)

using a ToT libc++

is this expected?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rGa96a6ed83230: Implement CWG2631 (authored by cor3ntin).

Changed prior to commit:
  https://reviews.llvm.org/D136554?vs=479395=481194#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15593,7 +15593,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is 

[PATCH] D136554: Implement CWG2631

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman accepted this revision.
aaron.ballman added a comment.

The new changes LGTM as well and the bots seem to be happy with things.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

@aaron.ballman if you don't scream, I'll probably try again this week end. I 
did multiple stage 2 full builds to be sure this time. The fix is pretty small 
but the investigation took a while...


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 479395.
cor3ntin added a comment.



- Member initializers wwere not marked odr used properly
- Fixing that unearthed an other bug:  consteval calls in a nested member 
initializers were not properly detected if the member was list initialized to 
its default value (`= {}`).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Sema/UsedDeclVisitor.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/CodeGenCXX/meminit-initializers-odr.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15594,7 +15594,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin reopened this revision.
cor3ntin added a comment.
This revision is now accepted and ready to land.

There is still an ODR issue which caused linkers errors
I think I managed to reduce the issue to

  template 
  struct function_ref {
  function_ref(auto) {}
  };
  
  struct S {
  function_ref X = nullptr;
  };
  
  void Do(S = {}) {
  }
  
  int main() {
  Do();
  }

We mark nullptr odr used but that does not mark 
`function_ref::function_ref()` ODR used.
We should make sure that's properly marked once the constructor call is 
resolved.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

Thanks Aaron. I hope it sticks this time!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
cor3ntin marked 2 inline comments as done.
Closed by commit rG26fa17ed2914: Implement CWG2631 (authored by cor3ntin).

Changed prior to commit:
  https://reviews.llvm.org/D136554?vs=478328=478863#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp
  clang/www/cxx_dr_status.html

Index: clang/www/cxx_dr_status.html
===
--- clang/www/cxx_dr_status.html
+++ clang/www/cxx_dr_status.html
@@ -15594,7 +15594,7 @@
 https://wg21.link/cwg2631;>2631
 DR
 Immediate function evaluations in default arguments
-Unknown
+Clang 16
   
   
 https://wg21.link/cwg2632;>2632
Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+   

[PATCH] D136554: Implement CWG2631

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman accepted this revision.
aaron.ballman added a comment.

LGTM!




Comment at: clang/include/clang/Sema/Sema.h:9654-9655
+return true;
+  if (Ctx.isConstantEvaluated() || Ctx.isImmediateFunctionContext() ||
+  Ctx.isUnevaluated())
+return false;

cor3ntin wrote:
> cor3ntin wrote:
> > aaron.ballman wrote:
> > > We repeat this pattern four times in this patch; perhaps we should make a 
> > > helper function for this predicate? Not certain of the best name for it, 
> > > but removing the duplication might not be a bad idea.
> > `isNotPotentiallyEvaluatedContext`? Something like that
> Actually, Maybe we should leave it as is in this patch, 
> and clean it up as part of 
> https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2564r0.html
> IE, I'm not sure i can come up with a completely correct name now.
That's fine by me; naming is hard.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added inline comments.



Comment at: clang/include/clang/Sema/Sema.h:9654-9655
+return true;
+  if (Ctx.isConstantEvaluated() || Ctx.isImmediateFunctionContext() ||
+  Ctx.isUnevaluated())
+return false;

cor3ntin wrote:
> aaron.ballman wrote:
> > We repeat this pattern four times in this patch; perhaps we should make a 
> > helper function for this predicate? Not certain of the best name for it, 
> > but removing the duplication might not be a bad idea.
> `isNotPotentiallyEvaluatedContext`? Something like that
Actually, Maybe we should leave it as is in this patch, 
and clean it up as part of 
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2564r0.html
IE, I'm not sure i can come up with a completely correct name now.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 478328.
cor3ntin added a comment.

Update DR status


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CXX/drs/dr26xx.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+  // expected-note  {{declared 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added inline comments.



Comment at: clang/include/clang/AST/ExprCXX.h:1274
+  *getTrailingObjects() = RewrittenExpr;
 setDependence(computeDependence(this));
   }

aaron.ballman wrote:
> Do we need to update `computeDependence()` to account for the rewritten `Expr 
> *`?
Looking at the code again, `computeDependence` do use the rewritten expr if 
there is one already (contracticting what I previously stated offline)



Comment at: clang/include/clang/Sema/Sema.h:9654-9655
+return true;
+  if (Ctx.isConstantEvaluated() || Ctx.isImmediateFunctionContext() ||
+  Ctx.isUnevaluated())
+return false;

aaron.ballman wrote:
> We repeat this pattern four times in this patch; perhaps we should make a 
> helper function for this predicate? Not certain of the best name for it, but 
> removing the duplication might not be a bad idea.
`isNotPotentiallyEvaluatedContext`? Something like that


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 478216.
cor3ntin added a comment.

Remove extra ;


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+  // expected-note  {{declared here}} \
+  

[PATCH] D136554: Implement CWG2631

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added reviewers: usaxena95, erichkeane, hubert.reinterpretcast.
aaron.ballman added a comment.

The changes generally LGTM, but I'd appreciate a second set of eyes on the 
changes just to double-check we're implementing the resolution properly.




Comment at: clang/include/clang/AST/ExprCXX.h:1274
+  *getTrailingObjects() = RewrittenExpr;
 setDependence(computeDependence(this));
   }

Do we need to update `computeDependence()` to account for the rewritten `Expr 
*`?



Comment at: clang/include/clang/Sema/Sema.h:1344
+assert(Decl && Context && "invalid initialization context");
+  };
+

It took me a moment to realize this wasn't the end of the structure 
declaration. :-D



Comment at: clang/include/clang/Sema/Sema.h:9654-9655
+return true;
+  if (Ctx.isConstantEvaluated() || Ctx.isImmediateFunctionContext() ||
+  Ctx.isUnevaluated())
+return false;

We repeat this pattern four times in this patch; perhaps we should make a 
helper function for this predicate? Not certain of the best name for it, but 
removing the duplication might not be a bad idea.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 477003.
cor3ntin added a comment.

Properly mark default members initializers as ODR-used.

default members initializers were marked as maybe odr-used
but never actually odr-used.

We fix that by checking that an initializer consitutes 
a full expression at the point it is used - which will in turn
handle cleanups and odr-use marking properly.

(This needs to be done after MarkDeclarationsReferencedInExpr, 
which took me a while to fully figure out)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+  

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

reduced to

  struct a {
  } constexpr b;
  class c {
  public:
c(a);
  };
  class d {
d() {}
c e = b;
  }


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#3909488 , @dblaikie wrote:

> fwiw, @rsmith came up with a crasher reproducer from this patch here:
>
>   template struct F {
>   template F(const U&) {}
>   };
>   
>   struct A {
>   static constexpr auto x = [] {};
>   F f = x;
>   };
>   
>   void f(A a = A()) { }
>   
>   int main() {
>   f();
>   }
>
> This was still failing at52ffc728181bc2d3c889f7f80c252c3433b9e7b6 immediately 
> prior to the revert.

This is very helpful, thanks to both Richard and you.
Both issues seem to be related somewhat, there are scenarios in which entities 
are not marked odr used properly. 
The other bug is still reducing, hopefully I'll have a test case for it 
tomorrow. I don't expect to be able to fix the issue in the next couple of 
weeks though


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[David Blaikie via Phabricator via cfe-commits]

dblaikie added a comment.

Looks like it's distinct from the other reported crash, this one crashes with:

  clang-16: 
/usr/local/google/home/blaikie/dev/llvm/src/clang/lib/CodeGen/CGExpr.cpp:2811: 
clang::CodeGen::LValue clang::CodeGen::CodeGenFunction::EmitDeclRefLValue(const 
clang::DeclRefExpr *): Assertion `(ND->isUsed(false) || !isa(ND) || 
E->isNonOdrUse() || !E->getLocation().isValid()) && "Should not use decl 
without marking it used!"' failed.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[David Blaikie via Phabricator via cfe-commits]

dblaikie added subscribers: rsmith, dblaikie.
dblaikie added a comment.

fwiw, @rsmith came up with a crasher reproducer from this patch here:

  template struct F {
  template F(const U&) {}
  };
  
  struct A {
  static constexpr auto x = [] {};
  F f = x;
  };
  
  void f(A a = A()) { }
  
  int main() {
  f();

This was still failing at52ffc728181bc2d3c889f7f80c252c3433b9e7b6 immediately 
prior to the revert.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 473341.
cor3ntin added a comment.

Reopening with subsequent changes merged.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,68 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+  // expected-note  {{declared here}} \
+  // expected-note  {{undefined 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

@abrachet Reverted, sorry again
@aaron.ballman @shafik feel free to investigate the issue, i won't have the 
opportunity over the next two weeks


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

Reverting now, just re-running the tests to be sure


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

Fascinating. Looking more at the error it seems slightly different than what we 
fixed this morning.
I'll revert soon when I'm at a computer. Feel free to do it earlier if it's 
urgent for you
Sorry for the inconvenience.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Alex Brachet via Phabricator via cfe-commits]

abrachet added a comment.

In D136554#3909198 , @cor3ntin wrote:

> In D136554#3909196 , @abrachet 
> wrote:
>
>> Hi, we're hitting an assertion failure after this patch
>>
>>   llvm-project/clang/lib/Sema/SemaDecl.cpp:15589: Decl 
>> *clang::Sema::ActOnFinishFunctionBody(Decl *, Stmt *, bool): Assertion 
>> `MaybeODRUseExprs.empty() && "Leftover expressions for odr-use checking"' 
>> failed.
>>
>> Here is a reproducer 
>> https://storage.googleapis.com/fuchsia-artifacts/builds/8798414214460746113/build-debug/clang-crashreports/symbol_server_unittest-48a521.cpp
>>  and 
>> https://storage.googleapis.com/fuchsia-artifacts/builds/8798414214460746113/build-debug/clang-crashreports/symbol_server_unittest-48a521.sh
>>  unfortunately creduce was taking too long before I gave up on it, so sorry 
>> it hasn't been reduced at all.
>>
>> I've verified that with this reverted the problem goes away. Could we revert 
>> unless there is a quick fix forward?
>
> Thanks for reporting that. Did you tried a more recent commit? We fixed that 
> issue today. (Along with z couple additional issues)

Yes, this happens at HEAD (currently ba65584d 
)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#3909196 , @abrachet wrote:

> Hi, we're hitting an assertion failure after this patch
>
>   llvm-project/clang/lib/Sema/SemaDecl.cpp:15589: Decl 
> *clang::Sema::ActOnFinishFunctionBody(Decl *, Stmt *, bool): Assertion 
> `MaybeODRUseExprs.empty() && "Leftover expressions for odr-use checking"' 
> failed.
>
> Here is a reproducer 
> https://storage.googleapis.com/fuchsia-artifacts/builds/8798414214460746113/build-debug/clang-crashreports/symbol_server_unittest-48a521.cpp
>  and 
> https://storage.googleapis.com/fuchsia-artifacts/builds/8798414214460746113/build-debug/clang-crashreports/symbol_server_unittest-48a521.sh
>  unfortunately creduce was taking too long before I gave up on it, so sorry 
> it hasn't been reduced at all.
>
> I've verified that with this reverted the problem goes away. Could we revert 
> unless there is a quick fix forward?

Thanks for reporting that. Did you tried a more


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Alex Brachet via Phabricator via cfe-commits]

abrachet added a comment.

Hi, we're hitting an assertion failure after this patch

  llvm-project/clang/lib/Sema/SemaDecl.cpp:15589: Decl 
*clang::Sema::ActOnFinishFunctionBody(Decl *, Stmt *, bool): Assertion 
`MaybeODRUseExprs.empty() && "Leftover expressions for odr-use checking"' 
failed.

Here is a reproducer 
https://storage.googleapis.com/fuchsia-artifacts/builds/8798414214460746113/build-debug/clang-crashreports/symbol_server_unittest-48a521.cpp
 and 
https://storage.googleapis.com/fuchsia-artifacts/builds/8798414214460746113/build-debug/clang-crashreports/symbol_server_unittest-48a521.sh
 unfortunately creduce was taking too long before I gave up on it, so sorry it 
hasn't been reduced at all.

I've verified that with this reverted the problem goes away. Could we revert 
unless there is a quick fix forward?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG7acfe3629479: Implement CWG2631 (authored by cor3ntin).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,68 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+  // 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 473213.
cor3ntin added a comment.

clamg-format


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,68 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+  // expected-note  {{declared here}} \
+  // expected-note  {{undefined function 'undefined'}}
+   

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 473202.
cor3ntin added a comment.

Cleaner fix:

Only use MaybeCreateExprWithCleanups for member inits.
For default arguments, this is already handled in
ConvertParamDefaultArgument.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,68 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+ 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 473198.
cor3ntin added a comment.

Make sure cleanup expressions are correctly 
added to rewritten initializers (I'm assuming this
did not manifest in C++20 mode because of copy elision)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/Decl.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/builtin-source-location.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,68 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+ 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D136554#3907761 , @royjacobson 
wrote:

> In D136554#3907661 , @cor3ntin 
> wrote:
>
>> I pushed a tentative fix for the bot failure,
>> alas I'm completely unable to reproduce the issue locally, even
>> though it does not appear to be architecture dependant afaict.
>
> It seems like those are the Sony CI bots... They default to C++14 (and a 
> slightly different ABI) so if they fail alone usually it means someone didn't 
> add a `-std` flag to the test.

Thanks! this is super useful information and I can now reproduce locally, 
Investigating ( the test crashes, so it's not just a missing flag )


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Roy Jacobson via Phabricator via cfe-commits]

royjacobson added a comment.

In D136554#3907661 , @cor3ntin wrote:

> I pushed a tentative fix for the bot failure,
> alas I'm completely unable to reproduce the issue locally, even
> though it does not appear to be architecture dependant afaict.

It seems like those are the Sony CI bots... They default to C++14 (and a 
slightly different ABI) so if they fail alone usually it means someone didn't 
add a `-std` flag to the test.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 473177.
cor3ntin added a comment.

I pushed a tentative fix for the bot failure,
alas I'm completely unable to reproduce the issue locally, even
though it does not appear to be architecture dependant afaict.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,68 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+  // expected-note  {{declared here}} \
+

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

The bots are unhappy, I'll investigate later 
https://lab.llvm.org/buildbot/#/builders/139/builds/30564


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

As discussed with Shafik and Aaron, I'm landing that now so there is some 
buffer to handle unforeseen issues as i won't be available next week and the 
one after. Further comments are of course welcomed.
If we don't find any issues we can land  https://reviews.llvm.org/D120634 in 
the coming weeks


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

This revision was automatically updated to reflect the committed changes.
cor3ntin marked an inline comment as not done.
Closed by commit rGbf1e235695a7: Implement CWG2631 (authored by cor3ntin).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,68 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+  // expected-note  {{declared here}} \
+  // expected-note  {{undefined 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin marked an inline comment as done and an inline comment as not done.
cor3ntin added inline comments.



Comment at: clang/lib/Sema/SemaExpr.cpp:5918
+if (const FunctionDecl *FD = E->getDirectCallee())
+  HasImmediateCalls |= FD->isConsteval();
+return RecursiveASTVisitor::VisitStmt(E);

cor3ntin wrote:
> @shafk 
Oups, nvm


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin marked 8 inline comments as done.
cor3ntin added inline comments.



Comment at: clang/include/clang/Sema/Sema.h:9602-9604
+return Ctx.Context ==
+   ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed ||
+   Ctx.IsCheckingDefaultArgumentOrInitializer;

shafik wrote:
> aaron.ballman wrote:
> > Hmm, it'd be nice to not name this with the same identifier as the `bool` 
> > member on line 1333, that surprised me a little bit when I ran into it 
> > below.
> Why are we logically ORing an enumerator w/ a `bool`?
I added parentheses here to make that clearer!



Comment at: clang/lib/Sema/SemaExpr.cpp:5918
+if (const FunctionDecl *FD = E->getDirectCallee())
+  HasImmediateCalls |= FD->isConsteval();
+return RecursiveASTVisitor::VisitStmt(E);

@shafk 



Comment at: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp:10
+{
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 
'undefined'}}

cor3ntin wrote:
> shafik wrote:
> > I don't think we expect a diagnostic here since `check_lambdas_unused` is 
> > never called.
> We do because the body of a lambda is not considered a subexpression. I 
> confirmed that with core.
> 
> See https://lists.isocpp.org/core/2022/10/13364.php
I added a comment


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 473006.
cor3ntin added a comment.

Add parentheses to make check clearer


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,68 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+  // expected-note  {{declared here}} \
+  // expected-note  {{undefined function 'undefined'}}
+return defaulted;
+}(),  // expected-note {{in 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin updated this revision to Diff 473002.
cor3ntin added a comment.

- rename

`/IsCheckingDefaultArgumentOrInitializer/IsCurrentlyCheckingDefaultArgumentOrInitializer`

following offline discussion with Aaron

- Address Shafik comments
- Revert WS change
- add comment explaining the `check_lambdas_unused` test.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/AST/ExprCXX.h
  clang/include/clang/AST/Stmt.h
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/include/clang/Sema/Sema.h
  clang/lib/AST/ASTImporter.cpp
  clang/lib/AST/ExprCXX.cpp
  clang/lib/Parse/ParseCXXInlineMethods.cpp
  clang/lib/Parse/ParseDeclCXX.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaExpr.cpp
  clang/lib/Sema/SemaTemplateInstantiate.cpp
  clang/lib/Sema/TreeTransform.h
  clang/lib/Serialization/ASTReaderStmt.cpp
  clang/lib/Serialization/ASTWriterStmt.cpp
  clang/test/CXX/class/class.local/p1-0x.cpp
  clang/test/CodeGenCXX/default-arguments-with-immediate.cpp
  clang/test/PCH/default-argument-with-immediate-calls.cpp
  clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
  clang/test/SemaCXX/source_location.cpp

Index: clang/test/SemaCXX/source_location.cpp
===
--- clang/test/SemaCXX/source_location.cpp
+++ clang/test/SemaCXX/source_location.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -fcxx-exceptions -fexceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fcxx-exceptions -DUSE_CONSTEVAL -fexceptions -verify %s
 // expected-no-diagnostics
 
 #define assert(...) ((__VA_ARGS__) ? ((void)0) : throw 42)
@@ -8,15 +9,22 @@
 template 
 struct Printer;
 
+#ifdef USE_CONSTEVAL
+#define SOURCE_LOC_EVAL_KIND consteval
+#else
+#define SOURCE_LOC_EVAL_KIND constexpr
+#endif
+
 namespace std {
 class source_location {
   struct __impl;
 
 public:
-  static constexpr source_location current(const __impl *__p = __builtin_source_location()) noexcept {
-source_location __loc;
-__loc.__m_impl = __p;
-return __loc;
+  static SOURCE_LOC_EVAL_KIND source_location
+current(const __impl *__p = __builtin_source_location()) noexcept {
+  source_location __loc;
+  __loc.__m_impl = __p;
+  return __loc;
   }
   constexpr source_location() = default;
   constexpr source_location(source_location const &) = default;
@@ -593,3 +601,51 @@
   }
   static_assert(test());
 }
+
+namespace Lambda {
+#line 8000 "TestLambda.cpp"
+constexpr int nested_lambda(int l = []{
+  return SL::current().line();
+}()) {
+  return l;
+}
+static_assert(nested_lambda() == __LINE__ - 4);
+
+constexpr int lambda_param(int l = [](int l = SL::current().line()) {
+  return l;
+}()) {
+  return l;
+}
+static_assert(lambda_param() == __LINE__);
+
+
+}
+
+constexpr int compound_literal_fun(int a =
+  (int){ SL::current().line() }
+) { return a ;}
+static_assert(compound_literal_fun() == __LINE__);
+
+struct CompoundLiteral {
+  int a = (int){ SL::current().line() };
+};
+static_assert(CompoundLiteral{}.a == __LINE__);
+
+
+// FIXME
+// Init captures are subexpressions of the lambda expression
+// so according to the standard immediate invocations in init captures
+// should be evaluated at the call site.
+// However Clang does not yet implement this as it would introduce
+// a fair bit of complexity.
+// We intend to implement that functionality once we find real world
+// use cases that require it.
+constexpr int test_init_capture(int a =
+[b = SL::current().line()] { return b; }()) {
+  return a;
+}
+#ifdef USE_CONSTEVAL
+static_assert(test_init_capture() == __LINE__ - 4);
+#else
+static_assert(test_init_capture() == __LINE__ );
+#endif
Index: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
===
--- /dev/null
+++ clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -0,0 +1,68 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2b %s
+
+consteval int undefined();  // expected-note 4 {{declared here}}
+
+void check_lambdas_unused(
+int a = []
+{
+// The body of a lambda is not a subexpression of the lambda
+// so this is immediately evaluated even if the parameter
+// is never used.
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 'undefined'}}
+}(),
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) {
+return defaulted;
+}()
+) {}
+
+int check_lambdas_used(
+int b = [](int no_error = undefined()) {
+return no_error;
+}(0),
+int c = [](int defaulted = undefined()) { // expected-error {{not a constant expression}} \
+ 

[PATCH] D136554: Implement CWG2631

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

Thanks for the review Shafik, I'll address the other comments later.




Comment at: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp:10
+{
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 
'undefined'}}

shafik wrote:
> I don't think we expect a diagnostic here since `check_lambdas_unused` is 
> never called.
We do because the body of a lambda is not considered a subexpression. I 
confirmed that with core.

See https://lists.isocpp.org/core/2022/10/13364.php


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Shafik Yaghmour via Phabricator via cfe-commits]

shafik added inline comments.



Comment at: clang/include/clang/Sema/Sema.h:9602-9604
+return Ctx.Context ==
+   ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed ||
+   Ctx.IsCheckingDefaultArgumentOrInitializer;

aaron.ballman wrote:
> Hmm, it'd be nice to not name this with the same identifier as the `bool` 
> member on line 1333, that surprised me a little bit when I ran into it below.
Why are we logically ORing an enumerator w/ a `bool`?



Comment at: clang/lib/Serialization/ASTReaderStmt.cpp:3831
+  S = CXXDefaultArgExpr::CreateEmpty(
+  Context, /*HasRewrittenInit*/ Record[ASTStmtReader::NumExprFields]);
   break;





Comment at: clang/lib/Serialization/ASTReaderStmt.cpp:3836
+  S = CXXDefaultInitExpr::CreateEmpty(
+  Context, /*HasRewrittenInit*/ Record[ASTStmtReader::NumExprFields]);
   break;





Comment at: clang/test/SemaCXX/cxx2a-consteval-default-params.cpp:10
+{
+return undefined();  // expected-error {{not a constant expression}} \
+ // expected-note  {{undefined function 
'undefined'}}

I don't think we expect a diagnostic here since `check_lambdas_unused` is never 
called.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D136554: Implement CWG2631

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman accepted this revision.
aaron.ballman added a comment.
This revision is now accepted and ready to land.

LGTM!




Comment at: clang/docs/ReleaseNotes.rst:782-783
   operator.
-- ``clang_Cursor_getNumTemplateArguments``, 
``clang_Cursor_getTemplateArgumentKind``, 
-  ``clang_Cursor_getTemplateArgumentType``, 
``clang_Cursor_getTemplateArgumentValue`` and 
+- ``clang_Cursor_getNumTemplateArguments``, 
``clang_Cursor_getTemplateArgumentKind``,
+  ``clang_Cursor_getTemplateArgumentType``, 
``clang_Cursor_getTemplateArgumentValue`` and
   ``clang_Cursor_getTemplateArgumentUnsignedValue`` now work on struct, class,

Accidental whitespace changes


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136554/new/

https://reviews.llvm.org/D136554

___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits