[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-15 Thread via cfe-commits 

alexfh wrote:

The internal code was fixed. Thanks everyone for helping to figure this out!

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-14 Thread via cfe-commits 

alexfh wrote:

It turns out debug build of clang before this patch generated an assertion on 
the original code as well:
```
assert.h assertion failed at llvm-project/clang/lib/AST/ExprConstant.cpp:15739 
in bool clang::Expr::EvaluateAsConstantExpr(EvalResult &, const ASTContext &, 
ConstantExprKind) const: !isValueDependent() && "Expression evaluator can't be 
called on a dependent expression."
...
@ 0x5643bcdac9e4  __assert_fail
@ 0x5643b9734df7  clang::Expr::EvaluateAsConstantExpr()
@ 0x5643b89f7fea  calculateConstraintSatisfaction<>()
@ 0x5643b89f1bcf  CheckConstraintSatisfaction()
@ 0x5643b89f193e  clang::Sema::CheckConstraintSatisfaction()
@ 0x5643b90d9f23  clang::Sema::CheckConceptTemplateId()
@ 0x5643b9259656  
clang::TreeTransform<>::TransformConceptSpecializationExpr()
@ 0x5643b925ce00  clang::TreeTransform<>::TransformCXXFoldExpr()
@ 0x5643b924b6e0  clang::Sema::SubstConstraintExpr()
@ 0x5643b89f9097  calculateConstraintSatisfaction()::$_0::operator()()
@ 0x5643b89f7f50  calculateConstraintSatisfaction<>()
@ 0x5643b89f1bcf  CheckConstraintSatisfaction()
@ 0x5643b89f193e  clang::Sema::CheckConstraintSatisfaction()
@ 0x5643b9237c6d  FinishTemplateArgumentDeduction<>()
@ 0x5643b9236cd2  llvm::function_ref<>::callback_fn<>()
@ 0x5643b888fa2f  clang::Sema::runWithSufficientStackSpace()
@ 0x5643b91c2e17  clang::Sema::DeduceTemplateArguments()
@ 0x5643b9248e19  clang::Sema::InstantiateClassTemplateSpecialization()
@ 0x5643b9334e73  llvm::function_ref<>::callback_fn<>()
@ 0x5643b888fa2f  clang::Sema::runWithSufficientStackSpace()
@ 0x5643b931fdc4  clang::Sema::RequireCompleteTypeImpl()
@ 0x5643b931f535  clang::Sema::RequireCompleteType()
@ 0x5643b891bad7  clang::Sema::RequireCompleteDeclContext()
@ 0x5643b90eda4d  clang::Sema::CheckTypenameType()
@ 0x5643b926edd2  clang::TreeTransform<>::TransformDependentNameType()
@ 0x5643b9243d1c  clang::TreeTransform<>::TransformType()
@ 0x5643b92436ff  clang::TreeTransform<>::TransformType()
@ 0x5643b9244293  clang::Sema::SubstType()
@ 0x5643b90d0e8a  clang::Sema::CheckTemplateIdType()
@ 0x5643b90d5015  clang::Sema::ActOnTemplateIdType()
@ 0x5643b8674084  clang::Parser::AnnotateTemplateIdTokenAsType()
@ 0x5643b86536cf  clang::Parser::ParseDeclarationSpecifiers()
@ 0x5643b864fffa  clang::Parser::ParseSpecifierQualifierList()
@ 0x5643b863da31  clang::Parser::ParseTypeName()
@ 0x5643b86262bd  clang::Parser::ParseAliasDeclarationAfterDeclarator()
@ 0x5643b8624ea0  clang::Parser::ParseUsingDeclaration()
@ 0x5643b8623e70  clang::Parser::ParseUsingDirectiveOrDeclaration()
@ 0x5643b864b6ef  clang::Parser::ParseDeclaration()
@ 0x5643b868a9a4  
clang::Parser::ParseStatementOrDeclarationAfterAttributes()
@ 0x5643b8689d78  clang::Parser::ParseStatementOrDeclaration()
@ 0x5643b8693bc0  clang::Parser::ParseCompoundStatementBody()
@ 0x5643b8694bce  clang::Parser::ParseFunctionStatementBody()
@ 0x5643b85da8ad  clang::Parser::ParseFunctionDefinition()
@ 0x5643b864df89  clang::Parser::ParseDeclGroup()
@ 0x5643b85d8ec9  clang::Parser::ParseDeclOrFunctionDefInternal()
@ 0x5643b85d868e  clang::Parser::ParseDeclarationOrFunctionDefinition()
@ 0x5643b85d7434  clang::Parser::ParseExternalDeclaration()
@ 0x5643b8622693  clang::Parser::ParseInnerNamespace()
@ 0x5643b8621893  clang::Parser::ParseNamespace()
@ 0x5643b864b7de  clang::Parser::ParseDeclaration()
@ 0x5643b85d6fb6  clang::Parser::ParseExternalDeclaration()
@ 0x5643b85d516b  clang::Parser::ParseTopLevelDecl()
@ 0x5643b85ceebe  clang::ParseAST()
@ 0x5643b831a4c3  clang::FrontendAction::Execute()
@ 0x5643b8294efd  clang::CompilerInstance::ExecuteAction()
@ 0x5643b717f84e  clang::ExecuteCompilerInvocation()
@ 0x5643b71737c6  cc1_main()
@ 0x5643b7171066  ExecuteCC1Tool()
@ 0x5643b843fe3e  llvm::function_ref<>::callback_fn<>()
@ 0x5643bcc44415  llvm::CrashRecoveryContext::RunSafely()
@ 0x5643b843f5bb  clang::driver::CC1Command::Execute()
@ 0x5643b8400494  clang::driver::Compilation::ExecuteCommand()
@ 0x5643b84007af  clang::driver::Compilation::ExecuteJobs()
@ 0x5643b841ea80  clang::driver::Driver::ExecuteCompilation()
@ 0x5643b717061b  clang_main()
@ 0x5643b716d834  main
```

I'll try to figure out what's wrong with the original code.

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-14 Thread via cfe-commits 

alexfh wrote:

I guess the reduction could have dropped some important parts of this. Let me 
try the original code with assertions-enabled clang build...

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-13 Thread Younan Zhang via cfe-commits 

zyn0217 wrote:

> I have a reduced test case, which is accepted by clang 18, but fails with 
> this patch: https://gcc.godbolt.org/z/zMbKvsf7K
> A bit more compact one: https://gcc.godbolt.org/z/4rzYPKaze

Your case is rejected by all mainstream compilers as of now: 
https://gcc.godbolt.org/z/nrMf3zvfY
Again, it was an accept-invalid before because of the constant evaluation on 
dependent expressions, which **is** an assertion failure if you compile it with 
debug mode. https://gcc.godbolt.org/z/eascd7j1G

To clarify why the requirement should be evaluated to false:

> The enclosing _requires-expression_ will evaluate to false if substitution of 
> template arguments into the expression fails.

https://eel.is/c++draft/expr.prim.req#simple-1.sentence-2


https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-13 Thread David Blaikie via cfe-commits 

dwblaikie wrote:

FWIW, @jyknight's example fails to compile with GCC - succeeds with clang 18 
release but assert-fails with clang 18 +Asserts build. (not sure about the 
original/full internal reproduction - we have a way to run compile with 
assertions enaled, but I'm not sure I'm holding it right... )

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-13 Thread James Y Knight via cfe-commits 

jyknight wrote:

Can reduce further to:
```
template 
concept h = requires(T i) { [] {}(i); };

template  struct k;
template  struct k {
  struct n;
};
using o = k::n;
```

But, is `requires(T i) { [] {}(i); };` actually valid? I think that _should_ 
fail the requirement, since you cannot call that lambda with an argument? Maybe 
that's just an artifact of the reduction?

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-13 Thread via cfe-commits 

alexfh wrote:

A bit more compact one: https://gcc.godbolt.org/z/4rzYPKaze

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-13 Thread via cfe-commits 

alexfh wrote:

I have a reduced test case, which is accepted by clang 18, but fails with this 
patch: https://gcc.godbolt.org/z/zMbKvsf7K

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-12 Thread Younan Zhang via cfe-commits 

zyn0217 wrote:

> I'm reducing the test case. In the meantime, should this be reverted?

I think this depends on the case. Note the issues addressed by this patch may 
not only cause some crashes in debug build, but probably lead to incorrect 
constraint evaluation in release build, which means there's possibility that 
your case was an accept-invalid before.

(Sorry for making confusion earlier; my office hour just begins and I'm sitting 
here for your case. If there is really something wrong caused by this PR, I'll 
revert it in time. Don't worry.)

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-12 Thread via cfe-commits 

alexfh wrote:

I'm reducing the test case. In the meantime, should this be reverted?

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-12 Thread Younan Zhang via cfe-commits 

zyn0217 wrote:

> Was this sort of a behavior change expected?

I don't think so; a reproducer would be really appreciated.

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-12 Thread via cfe-commits 

alexfh wrote:

Hi folks, we've started seeing "implicit instantiation of undefined template" 
compilation errors after this commit. In all cases code used to compile fine 
before this commit. I haven't spotted any particular issues in the code (though 
the examples are looked at are rather convoluted, thus, I'm not 100% sure). 
I'll try to prepare a self-sufficient test case.

Was this sort of a behavior change expected?

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 closed 
https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 updated 
https://github.com/llvm/llvm-project/pull/83997

>From 69414d7352b170f6fcff22c6f5dfa91cc76b0b58 Mon Sep 17 00:00:00 2001
From: Younan Zhang 
Date: Tue, 5 Mar 2024 19:56:59 +0800
Subject: [PATCH 1/3] gh56556

---
 clang/lib/Sema/TreeTransform.h | 6 --
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 7389a48fe56fcc..c96ffcb97a7591 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -13649,10 +13649,12 @@ 
TreeTransform::TransformLambdaExpr(LambdaExpr *E) {
   // use evaluation contexts to distinguish the function parameter case.
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
+  DeclContext *DC = getSema().CurContext;
+  if (DC->getDeclKind() == Decl::Kind::RequiresExprBody)
+DC = DC->getParent();
   if ((getSema().isUnevaluatedContext() ||
getSema().isConstantEvaluatedContext()) &&
-  (getSema().CurContext->isFileContext() ||
-   !getSema().CurContext->getParent()->isDependentContext()))
+  (DC->isFileContext() || !DC->getParent()->isDependentContext()))
 DependencyKind = CXXRecordDecl::LDK_NeverDependent;
 
   CXXRecordDecl *OldClass = E->getLambdaClass();

>From b905083e5d5186ad08ac3d553be3e8f47dabc1b6 Mon Sep 17 00:00:00 2001
From: Younan Zhang 
Date: Wed, 6 Mar 2024 13:46:43 +0800
Subject: [PATCH 2/3] Tests & release notes

---
 clang/docs/ReleaseNotes.rst |  2 +
 clang/lib/Sema/TreeTransform.h  | 17 +++
 clang/test/SemaTemplate/concepts-lambda.cpp | 52 +
 3 files changed, 71 insertions(+)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index d4e6bcf661da1a..141099fb68a200 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -302,6 +302,8 @@ Bug Fixes to C++ Support
   our attention by an attempt to fix in (#GH77703). Fixes (#GH83385).
 - Fix evaluation of some immediate calls in default arguments.
   Fixes (#GH80630)
+- Fixed an issue where the ``RequiresExprBody`` was involved in the lambda 
dependency
+  calculation. (#GH56556), (#GH82849).
 
 Bug Fixes to AST Handling
 ^
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index c96ffcb97a7591..84348e13567e71 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -13650,6 +13650,23 @@ TreeTransform::TransformLambdaExpr(LambdaExpr 
*E) {
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
   DeclContext *DC = getSema().CurContext;
+  // A RequiresExprBodyDecl is not interesting for dependencies.
+  // For the following case,
+  //
+  // template 
+  // concept C = requires { [] {}; };
+  //
+  // template 
+  // struct Widget;
+  //
+  // template 
+  // struct Widget {};
+  //
+  // While we are here in substitution for Widget, the parent of DC would be
+  // the template specialization itself. Thus, the lambda expression
+  // will be deemed as dependent even if we have non-dependent template
+  // arguments.
+  // (A ClassTemplateSpecializationDecl is always a dependent context.)
   if (DC->getDeclKind() == Decl::Kind::RequiresExprBody)
 DC = DC->getParent();
   if ((getSema().isUnevaluatedContext() ||
diff --git a/clang/test/SemaTemplate/concepts-lambda.cpp 
b/clang/test/SemaTemplate/concepts-lambda.cpp
index 0b7580f91043c7..ef04cad4eef98b 100644
--- a/clang/test/SemaTemplate/concepts-lambda.cpp
+++ b/clang/test/SemaTemplate/concepts-lambda.cpp
@@ -90,6 +90,58 @@ struct Foo {
 
 static_assert(ConstructibleWithN);
 
+namespace GH56556 {
+
+template 
+inline constexpr It declare ();
+
+template  typename Template>
+concept D = requires {
+   { []  (Template &) {}(declare()) };
+};
+
+template 
+struct B {};
+
+template 
+struct Adapter;
+
+template  T>
+struct Adapter {};
+
+template struct Adapter>;
+
+} // namespace GH56556
+
+namespace GH82849 {
+
+template 
+concept C = requires(T t) {
+  [](T) {}(t);
+};
+
+template 
+struct Widget;
+
+template 
+struct Widget {
+  static F create(F from) {
+return from;
+  }
+};
+
+template 
+bool foo() {
+  return C;
+}
+
+void bar() {
+  // https://github.com/llvm/llvm-project/issues/49570#issuecomment-1664966972
+  Widget::create(0);
+}
+
+} // namespace GH82849
+
 }
 
 // GH60642 reported an assert being hit, make sure we don't assert.

>From 6b36f74b6aede38766674c99a803c86becacd01d Mon Sep 17 00:00:00 2001
From: Younan Zhang 
Date: Wed, 6 Mar 2024 18:56:53 +0800
Subject: [PATCH 3/3] Address Corentin's comments

---
 clang/lib/Sema/TreeTransform.h  | 6 +++---
 clang/test/SemaTemplate/concepts-lambda.cpp | 8 +++-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 84348e13567e71..409aee73d960eb 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/Tr

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread Yuxuan Chen via cfe-commits 

https://github.com/yuxuanchen1997 approved this pull request.

Thank you so much! This looks good. 

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread via cfe-commits 

https://github.com/cor3ntin approved this pull request.

LGTM

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread Younan Zhang via cfe-commits 

zyn0217 wrote:

@cor3ntin Thanks! I have updated the test to reflect the nested `requires` 
cases. PTAL?

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread Younan Zhang via cfe-commits 


@@ -13649,10 +13649,29 @@ 
TreeTransform::TransformLambdaExpr(LambdaExpr *E) {
   // use evaluation contexts to distinguish the function parameter case.
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
+  DeclContext *DC = getSema().CurContext;
+  // A RequiresExprBodyDecl is not interesting for dependencies.
+  // For the following case,
+  //
+  // template 
+  // concept C = requires { [] {}; };
+  //
+  // template 
+  // struct Widget;
+  //
+  // template 
+  // struct Widget {};
+  //
+  // While we are here in substitution for Widget, the parent of DC would be
+  // the template specialization itself. Thus, the lambda expression
+  // will be deemed as dependent even if we have non-dependent template
+  // arguments.
+  // (A ClassTemplateSpecializationDecl is always a dependent context.)
+  if (DC->getDeclKind() == Decl::Kind::RequiresExprBody)
+DC = DC->getParent();

zyn0217 wrote:

Oops, this should be a `while` loop, I think

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 updated 
https://github.com/llvm/llvm-project/pull/83997

>From 69414d7352b170f6fcff22c6f5dfa91cc76b0b58 Mon Sep 17 00:00:00 2001
From: Younan Zhang 
Date: Tue, 5 Mar 2024 19:56:59 +0800
Subject: [PATCH 1/3] gh56556

---
 clang/lib/Sema/TreeTransform.h | 6 --
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 7389a48fe56fcc..c96ffcb97a7591 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -13649,10 +13649,12 @@ 
TreeTransform::TransformLambdaExpr(LambdaExpr *E) {
   // use evaluation contexts to distinguish the function parameter case.
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
+  DeclContext *DC = getSema().CurContext;
+  if (DC->getDeclKind() == Decl::Kind::RequiresExprBody)
+DC = DC->getParent();
   if ((getSema().isUnevaluatedContext() ||
getSema().isConstantEvaluatedContext()) &&
-  (getSema().CurContext->isFileContext() ||
-   !getSema().CurContext->getParent()->isDependentContext()))
+  (DC->isFileContext() || !DC->getParent()->isDependentContext()))
 DependencyKind = CXXRecordDecl::LDK_NeverDependent;
 
   CXXRecordDecl *OldClass = E->getLambdaClass();

>From b905083e5d5186ad08ac3d553be3e8f47dabc1b6 Mon Sep 17 00:00:00 2001
From: Younan Zhang 
Date: Wed, 6 Mar 2024 13:46:43 +0800
Subject: [PATCH 2/3] Tests & release notes

---
 clang/docs/ReleaseNotes.rst |  2 +
 clang/lib/Sema/TreeTransform.h  | 17 +++
 clang/test/SemaTemplate/concepts-lambda.cpp | 52 +
 3 files changed, 71 insertions(+)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index d4e6bcf661da1a..141099fb68a200 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -302,6 +302,8 @@ Bug Fixes to C++ Support
   our attention by an attempt to fix in (#GH77703). Fixes (#GH83385).
 - Fix evaluation of some immediate calls in default arguments.
   Fixes (#GH80630)
+- Fixed an issue where the ``RequiresExprBody`` was involved in the lambda 
dependency
+  calculation. (#GH56556), (#GH82849).
 
 Bug Fixes to AST Handling
 ^
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index c96ffcb97a7591..84348e13567e71 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -13650,6 +13650,23 @@ TreeTransform::TransformLambdaExpr(LambdaExpr 
*E) {
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
   DeclContext *DC = getSema().CurContext;
+  // A RequiresExprBodyDecl is not interesting for dependencies.
+  // For the following case,
+  //
+  // template 
+  // concept C = requires { [] {}; };
+  //
+  // template 
+  // struct Widget;
+  //
+  // template 
+  // struct Widget {};
+  //
+  // While we are here in substitution for Widget, the parent of DC would be
+  // the template specialization itself. Thus, the lambda expression
+  // will be deemed as dependent even if we have non-dependent template
+  // arguments.
+  // (A ClassTemplateSpecializationDecl is always a dependent context.)
   if (DC->getDeclKind() == Decl::Kind::RequiresExprBody)
 DC = DC->getParent();
   if ((getSema().isUnevaluatedContext() ||
diff --git a/clang/test/SemaTemplate/concepts-lambda.cpp 
b/clang/test/SemaTemplate/concepts-lambda.cpp
index 0b7580f91043c7..ef04cad4eef98b 100644
--- a/clang/test/SemaTemplate/concepts-lambda.cpp
+++ b/clang/test/SemaTemplate/concepts-lambda.cpp
@@ -90,6 +90,58 @@ struct Foo {
 
 static_assert(ConstructibleWithN);
 
+namespace GH56556 {
+
+template 
+inline constexpr It declare ();
+
+template  typename Template>
+concept D = requires {
+   { []  (Template &) {}(declare()) };
+};
+
+template 
+struct B {};
+
+template 
+struct Adapter;
+
+template  T>
+struct Adapter {};
+
+template struct Adapter>;
+
+} // namespace GH56556
+
+namespace GH82849 {
+
+template 
+concept C = requires(T t) {
+  [](T) {}(t);
+};
+
+template 
+struct Widget;
+
+template 
+struct Widget {
+  static F create(F from) {
+return from;
+  }
+};
+
+template 
+bool foo() {
+  return C;
+}
+
+void bar() {
+  // https://github.com/llvm/llvm-project/issues/49570#issuecomment-1664966972
+  Widget::create(0);
+}
+
+} // namespace GH82849
+
 }
 
 // GH60642 reported an assert being hit, make sure we don't assert.

>From 6b36f74b6aede38766674c99a803c86becacd01d Mon Sep 17 00:00:00 2001
From: Younan Zhang 
Date: Wed, 6 Mar 2024 18:56:53 +0800
Subject: [PATCH 3/3] Address Corentin's comments

---
 clang/lib/Sema/TreeTransform.h  | 6 +++---
 clang/test/SemaTemplate/concepts-lambda.cpp | 8 +++-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 84348e13567e71..409aee73d960eb 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/Tr

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread via cfe-commits 


@@ -13649,10 +13649,29 @@ 
TreeTransform::TransformLambdaExpr(LambdaExpr *E) {
   // use evaluation contexts to distinguish the function parameter case.
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
+  DeclContext *DC = getSema().CurContext;
+  // A RequiresExprBodyDecl is not interesting for dependencies.
+  // For the following case,
+  //
+  // template 
+  // concept C = requires { [] {}; };
+  //
+  // template 
+  // struct Widget;
+  //
+  // template 
+  // struct Widget {};
+  //
+  // While we are here in substitution for Widget, the parent of DC would be
+  // the template specialization itself. Thus, the lambda expression
+  // will be deemed as dependent even if we have non-dependent template
+  // arguments.

cor3ntin wrote:

```suggestion
  // will be deemed as dependent even if there is are no dependent template
  // arguments.
```

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread via cfe-commits 


@@ -13649,10 +13649,29 @@ 
TreeTransform::TransformLambdaExpr(LambdaExpr *E) {
   // use evaluation contexts to distinguish the function parameter case.
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
+  DeclContext *DC = getSema().CurContext;
+  // A RequiresExprBodyDecl is not interesting for dependencies.
+  // For the following case,
+  //
+  // template 
+  // concept C = requires { [] {}; };
+  //
+  // template 
+  // struct Widget;
+  //
+  // template 
+  // struct Widget {};
+  //
+  // While we are here in substitution for Widget, the parent of DC would be
+  // the template specialization itself. Thus, the lambda expression
+  // will be deemed as dependent even if we have non-dependent template
+  // arguments.
+  // (A ClassTemplateSpecializationDecl is always a dependent context.)
+  if (DC->getDeclKind() == Decl::Kind::RequiresExprBody)
+DC = DC->getParent();

cor3ntin wrote:

Do we get into the same issue if there are multiple nested `requires`?

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-06 Thread via cfe-commits 


@@ -13649,10 +13649,29 @@ 
TreeTransform::TransformLambdaExpr(LambdaExpr *E) {
   // use evaluation contexts to distinguish the function parameter case.
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
+  DeclContext *DC = getSema().CurContext;
+  // A RequiresExprBodyDecl is not interesting for dependencies.
+  // For the following case,
+  //
+  // template 
+  // concept C = requires { [] {}; };
+  //
+  // template 
+  // struct Widget;
+  //
+  // template 
+  // struct Widget {};
+  //
+  // While we are here in substitution for Widget, the parent of DC would be

cor3ntin wrote:

```suggestion
  // While we are substituting Widget, the parent of DC would be
```

https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-05 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 edited 
https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-05 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 edited 
https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-05 Thread via cfe-commits 

llvmbot wrote:




@llvm/pr-subscribers-clang

Author: Younan Zhang (zyn0217)


Changes

The dependency of a lambda inside of a `RequiresExprBodyDecl` was previously 
affected by its parent, e.g., `ClassTemplateSpecializationDecl`. This made the 
lambda always dependent regardless of the template arguments we had, which 
caused some crashes on the constraint evaluation later.

This fixes https://github.com/llvm/llvm-project/issues/56556, 
https://github.com/llvm/llvm-project/issues/82849 and a case demonstrated by 
https://github.com/llvm/llvm-project/issues/49570#issuecomment-1664966972.

---
Full diff: https://github.com/llvm/llvm-project/pull/83997.diff


3 Files Affected:

- (modified) clang/docs/ReleaseNotes.rst (+2) 
- (modified) clang/lib/Sema/TreeTransform.h (+21-2) 
- (modified) clang/test/SemaTemplate/concepts-lambda.cpp (+52) 


``diff
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 5e0352a7eaf6cd..9c64cd2b5f6a10 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -311,6 +311,8 @@ Bug Fixes to C++ Support
   Fixes (#GH80630)
 - Fix a crash when an explicit template argument list is used with a name for 
which lookup
   finds a non-template function and a dependent using declarator.
+- Fixed an issue where the ``RequiresExprBody`` was involved in the lambda 
dependency
+  calculation. (#GH56556), (#GH82849).
 
 Bug Fixes to AST Handling
 ^
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 7389a48fe56fcc..84348e13567e71 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -13649,10 +13649,29 @@ 
TreeTransform::TransformLambdaExpr(LambdaExpr *E) {
   // use evaluation contexts to distinguish the function parameter case.
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
+  DeclContext *DC = getSema().CurContext;
+  // A RequiresExprBodyDecl is not interesting for dependencies.
+  // For the following case,
+  //
+  // template 
+  // concept C = requires { [] {}; };
+  //
+  // template 
+  // struct Widget;
+  //
+  // template 
+  // struct Widget {};
+  //
+  // While we are here in substitution for Widget, the parent of DC would be
+  // the template specialization itself. Thus, the lambda expression
+  // will be deemed as dependent even if we have non-dependent template
+  // arguments.
+  // (A ClassTemplateSpecializationDecl is always a dependent context.)
+  if (DC->getDeclKind() == Decl::Kind::RequiresExprBody)
+DC = DC->getParent();
   if ((getSema().isUnevaluatedContext() ||
getSema().isConstantEvaluatedContext()) &&
-  (getSema().CurContext->isFileContext() ||
-   !getSema().CurContext->getParent()->isDependentContext()))
+  (DC->isFileContext() || !DC->getParent()->isDependentContext()))
 DependencyKind = CXXRecordDecl::LDK_NeverDependent;
 
   CXXRecordDecl *OldClass = E->getLambdaClass();
diff --git a/clang/test/SemaTemplate/concepts-lambda.cpp 
b/clang/test/SemaTemplate/concepts-lambda.cpp
index 0b7580f91043c7..ef04cad4eef98b 100644
--- a/clang/test/SemaTemplate/concepts-lambda.cpp
+++ b/clang/test/SemaTemplate/concepts-lambda.cpp
@@ -90,6 +90,58 @@ struct Foo {
 
 static_assert(ConstructibleWithN);
 
+namespace GH56556 {
+
+template 
+inline constexpr It declare ();
+
+template  typename Template>
+concept D = requires {
+   { []  (Template &) {}(declare()) };
+};
+
+template 
+struct B {};
+
+template 
+struct Adapter;
+
+template  T>
+struct Adapter {};
+
+template struct Adapter>;
+
+} // namespace GH56556
+
+namespace GH82849 {
+
+template 
+concept C = requires(T t) {
+  [](T) {}(t);
+};
+
+template 
+struct Widget;
+
+template 
+struct Widget {
+  static F create(F from) {
+return from;
+  }
+};
+
+template 
+bool foo() {
+  return C;
+}
+
+void bar() {
+  // https://github.com/llvm/llvm-project/issues/49570#issuecomment-1664966972
+  Widget::create(0);
+}
+
+} // namespace GH82849
+
 }
 
 // GH60642 reported an assert being hit, make sure we don't assert.

``




https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-05 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 ready_for_review 
https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-05 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 updated 
https://github.com/llvm/llvm-project/pull/83997

>From 69414d7352b170f6fcff22c6f5dfa91cc76b0b58 Mon Sep 17 00:00:00 2001
From: Younan Zhang 
Date: Tue, 5 Mar 2024 19:56:59 +0800
Subject: [PATCH 1/2] gh56556

---
 clang/lib/Sema/TreeTransform.h | 6 --
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 7389a48fe56fcc..c96ffcb97a7591 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -13649,10 +13649,12 @@ 
TreeTransform::TransformLambdaExpr(LambdaExpr *E) {
   // use evaluation contexts to distinguish the function parameter case.
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
+  DeclContext *DC = getSema().CurContext;
+  if (DC->getDeclKind() == Decl::Kind::RequiresExprBody)
+DC = DC->getParent();
   if ((getSema().isUnevaluatedContext() ||
getSema().isConstantEvaluatedContext()) &&
-  (getSema().CurContext->isFileContext() ||
-   !getSema().CurContext->getParent()->isDependentContext()))
+  (DC->isFileContext() || !DC->getParent()->isDependentContext()))
 DependencyKind = CXXRecordDecl::LDK_NeverDependent;
 
   CXXRecordDecl *OldClass = E->getLambdaClass();

>From b905083e5d5186ad08ac3d553be3e8f47dabc1b6 Mon Sep 17 00:00:00 2001
From: Younan Zhang 
Date: Wed, 6 Mar 2024 13:46:43 +0800
Subject: [PATCH 2/2] Tests & release notes

---
 clang/docs/ReleaseNotes.rst |  2 +
 clang/lib/Sema/TreeTransform.h  | 17 +++
 clang/test/SemaTemplate/concepts-lambda.cpp | 52 +
 3 files changed, 71 insertions(+)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index d4e6bcf661da1a..141099fb68a200 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -302,6 +302,8 @@ Bug Fixes to C++ Support
   our attention by an attempt to fix in (#GH77703). Fixes (#GH83385).
 - Fix evaluation of some immediate calls in default arguments.
   Fixes (#GH80630)
+- Fixed an issue where the ``RequiresExprBody`` was involved in the lambda 
dependency
+  calculation. (#GH56556), (#GH82849).
 
 Bug Fixes to AST Handling
 ^
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index c96ffcb97a7591..84348e13567e71 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -13650,6 +13650,23 @@ TreeTransform::TransformLambdaExpr(LambdaExpr 
*E) {
   CXXRecordDecl::LambdaDependencyKind DependencyKind =
   CXXRecordDecl::LDK_Unknown;
   DeclContext *DC = getSema().CurContext;
+  // A RequiresExprBodyDecl is not interesting for dependencies.
+  // For the following case,
+  //
+  // template 
+  // concept C = requires { [] {}; };
+  //
+  // template 
+  // struct Widget;
+  //
+  // template 
+  // struct Widget {};
+  //
+  // While we are here in substitution for Widget, the parent of DC would be
+  // the template specialization itself. Thus, the lambda expression
+  // will be deemed as dependent even if we have non-dependent template
+  // arguments.
+  // (A ClassTemplateSpecializationDecl is always a dependent context.)
   if (DC->getDeclKind() == Decl::Kind::RequiresExprBody)
 DC = DC->getParent();
   if ((getSema().isUnevaluatedContext() ||
diff --git a/clang/test/SemaTemplate/concepts-lambda.cpp 
b/clang/test/SemaTemplate/concepts-lambda.cpp
index 0b7580f91043c7..ef04cad4eef98b 100644
--- a/clang/test/SemaTemplate/concepts-lambda.cpp
+++ b/clang/test/SemaTemplate/concepts-lambda.cpp
@@ -90,6 +90,58 @@ struct Foo {
 
 static_assert(ConstructibleWithN);
 
+namespace GH56556 {
+
+template 
+inline constexpr It declare ();
+
+template  typename Template>
+concept D = requires {
+   { []  (Template &) {}(declare()) };
+};
+
+template 
+struct B {};
+
+template 
+struct Adapter;
+
+template  T>
+struct Adapter {};
+
+template struct Adapter>;
+
+} // namespace GH56556
+
+namespace GH82849 {
+
+template 
+concept C = requires(T t) {
+  [](T) {}(t);
+};
+
+template 
+struct Widget;
+
+template 
+struct Widget {
+  static F create(F from) {
+return from;
+  }
+};
+
+template 
+bool foo() {
+  return C;
+}
+
+void bar() {
+  // https://github.com/llvm/llvm-project/issues/49570#issuecomment-1664966972
+  Widget::create(0);
+}
+
+} // namespace GH82849
+
 }
 
 // GH60642 reported an assert being hit, make sure we don't assert.

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

[clang] [clang][Sema] Skip the RequiresExprBodyDecls for lambda dependencies (PR #83997)

2024-03-05 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 edited 
https://github.com/llvm/llvm-project/pull/83997
___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits