Author: Younan Zhang Date: 2024-06-01T16:16:15+08:00 New Revision: 16397e8ec7ffbee2907dfec698356f67672086e8
URL: https://github.com/llvm/llvm-project/commit/16397e8ec7ffbee2907dfec698356f67672086e8 DIFF: https://github.com/llvm/llvm-project/commit/16397e8ec7ffbee2907dfec698356f67672086e8.diff LOG: [Clang][Sema] Push an evaluation context for type constraints (#93945) This helps getTemplateInstantiationArgs() to properly recover template arguments of an enclosing concept Decl. Fixes https://github.com/llvm/llvm-project/issues/93821 Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaTemplate.cpp clang/lib/Sema/SemaTemplateDeduction.cpp clang/test/SemaTemplate/concepts-lambda.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 22b4dc172c840..0c700d23257bf 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -822,6 +822,7 @@ Bug Fixes to C++ Support - Fix a regression introduced in Clang 18 causing incorrect overload resolution in the presence of functions only diff erering by their constraints when only one of these function was variadic. - Fix a crash when a variable is captured by a block nested inside a lambda. (Fixes #GH93625). +- Fixed a type constraint substitution issue involving a generic lambda expression. (#GH93821) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 3e3ed77de710e..40a759ea330de 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -5660,7 +5660,7 @@ Sema::CheckConceptTemplateId(const CXXScopeSpec &SS, LocalInstantiationScope Scope(*this); EnterExpressionEvaluationContext EECtx{ - *this, ExpressionEvaluationContext::ConstantEvaluated, CSD}; + *this, ExpressionEvaluationContext::Unevaluated, CSD}; if (!AreArgsDependent && CheckConstraintSatisfaction( diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp index 8ec49fcf553d0..1011db2d2830d 100644 --- a/clang/lib/Sema/SemaTemplateDeduction.cpp +++ b/clang/lib/Sema/SemaTemplateDeduction.cpp @@ -5134,6 +5134,20 @@ static bool CheckDeducedPlaceholderConstraints(Sema &S, const AutoType &Type, return true; MultiLevelTemplateArgumentList MLTAL(Concept, CanonicalConverted, /*Final=*/false); + // Build up an EvaluationContext with an ImplicitConceptSpecializationDecl so + // that the template arguments of the constraint can be preserved. For + // example: + // + // template <class T> + // concept C = []<D U = void>() { return true; }(); + // + // We need the argument for T while evaluating type constraint D in + // building the CallExpr to the lambda. + EnterExpressionEvaluationContext EECtx( + S, Sema::ExpressionEvaluationContext::Unevaluated, + ImplicitConceptSpecializationDecl::Create( + S.getASTContext(), Concept->getDeclContext(), Concept->getLocation(), + CanonicalConverted)); if (S.CheckConstraintSatisfaction(Concept, {Concept->getConstraintExpr()}, MLTAL, TypeLoc.getLocalSourceRange(), Satisfaction)) diff --git a/clang/test/SemaTemplate/concepts-lambda.cpp b/clang/test/SemaTemplate/concepts-lambda.cpp index fac790d09f9cf..280be71284f97 100644 --- a/clang/test/SemaTemplate/concepts-lambda.cpp +++ b/clang/test/SemaTemplate/concepts-lambda.cpp @@ -225,3 +225,15 @@ void foo() { }(x); } } // namespace GH73418 + +namespace GH93821 { + +template <class> +concept C = true; + +template <class...> +concept D = []<C T = int>() { return true; }(); + +D auto x = 0; + +} // namespace GH93821 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
