erichkeane updated this revision to Diff 490120.
erichkeane added a reviewer: libc++.
erichkeane added a comment.
Add module map fix, add nit from Shafik.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D141954/new/
https://reviews.llvm.org/D141954
Files:
clang/docs/ReleaseNotes.rst
clang/lib/Sema/SemaConcept.cpp
clang/test/CXX/temp/temp.constr/temp.constr.atomic/constrant-satisfaction-conversions.cpp
libcxx/include/module.modulemap.in
Index: libcxx/include/module.modulemap.in
===================================================================
--- libcxx/include/module.modulemap.in
+++ libcxx/include/module.modulemap.in
@@ -747,7 +747,10 @@
module assignable { private header "__concepts/assignable.h" }
module boolean_testable { private header "__concepts/boolean_testable.h" }
module class_or_enum { private header "__concepts/class_or_enum.h" }
- module common_reference_with { private header "__concepts/common_reference_with.h" }
+ module common_reference_with {
+ private header "__concepts/common_reference_with.h"
+ export type_traits.common_reference
+ }
module common_with { private header "__concepts/common_with.h" }
module constructible { private header "__concepts/constructible.h" }
module convertible_to { private header "__concepts/convertible_to.h" }
Index: clang/test/CXX/temp/temp.constr/temp.constr.atomic/constrant-satisfaction-conversions.cpp
===================================================================
--- /dev/null
+++ clang/test/CXX/temp/temp.constr/temp.constr.atomic/constrant-satisfaction-conversions.cpp
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -std=c++20 -x c++ -verify %s
+
+template<typename T> concept C =
+sizeof(T) == 4 && !true; // requires atomic constraints sizeof(T) == 4 and !true
+
+template<typename T> struct S {
+ constexpr operator bool() const { return true; }
+};
+
+// expected-error@+3{{atomic constraint must be of type 'bool' (found 'S<int>')}}
+// expected-note@#FINST{{while checking constraint satisfaction}}
+// expected-note@#FINST{{in instantiation of function template specialization}}
+template<typename T> requires (S<T>{})
+void f(T);
+void f(int);
+
+// Ensure this applies to operator && as well.
+// expected-error@+3{{atomic constraint must be of type 'bool' (found 'S<int>')}}
+// expected-note@#F2INST{{while checking constraint satisfaction}}
+// expected-note@#F2INST{{in instantiation of function template specialization}}
+template<typename T> requires (S<T>{} && true)
+void f2(T);
+void f2(int);
+
+void g() {
+ f(0); // #FINST
+ f2(0); // #F2INST
+}
Index: clang/lib/Sema/SemaConcept.cpp
===================================================================
--- clang/lib/Sema/SemaConcept.cpp
+++ clang/lib/Sema/SemaConcept.cpp
@@ -329,14 +329,7 @@
Sema::SFINAETrap Trap(S);
SubstitutedExpression =
S.SubstConstraintExpr(const_cast<Expr *>(AtomicExpr), MLTAL);
- // Substitution might have stripped off a contextual conversion to
- // bool if this is the operand of an '&&' or '||'. For example, we
- // might lose an lvalue-to-rvalue conversion here. If so, put it back
- // before we try to evaluate.
- if (SubstitutedExpression.isUsable() &&
- !SubstitutedExpression.isInvalid())
- SubstitutedExpression =
- S.PerformContextuallyConvertToBool(SubstitutedExpression.get());
+
if (SubstitutedExpression.isInvalid() || Trap.hasErrorOccurred()) {
// C++2a [temp.constr.atomic]p1
// ...If substitution results in an invalid type or expression, the
@@ -370,8 +363,24 @@
}
}
+ // [temp.constr.atomic]p3: To determine if an atomic constraint is
+ // satisfied, the parameter mapping and template arguments are first
+ // substituted into its expression. If substitution results in an
+ // invalid type or expression, the constraint is not satisfied.
+ // Otherwise, the lvalue-to-rvalue conversion is performed if necessary,
+ // and E shall be a constant expression of type bool.
+ //
+ // Perform the L to R Value conversion if necessary. We do so for all
+ // non-PRValue categories, else we fail to extend the lifetime of
+ // temporaries, and that fails the constant expression check.
+ if (!SubstitutedExpression.get()->isPRValue())
+ SubstitutedExpression = ImplicitCastExpr::Create(
+ S.Context, SubstitutedExpression.get()->getType(),
+ CK_LValueToRValue, SubstitutedExpression.get(),
+ /*BasePath=*/nullptr, VK_PRValue, FPOptionsOverride());
+
if (!S.CheckConstraintExpression(SubstitutedExpression.get()))
- return ExprError();
+ return ExprError(); // convert to bool here?
return SubstitutedExpression;
});
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -754,6 +754,9 @@
and `P1975R0: <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1975r0.html>`_,
which allows parenthesized aggregate-initialization.
+- Fixed an issue with concept requirement evaluation, where we incorrectly allowed implicit
+ conversions to bool for a requirement. This fixes `GH54524 <https://github.com/llvm/llvm-project/issues/54524>`_.
+
C++2b Feature Support
^^^^^^^^^^^^^^^^^^^^^
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