llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Younan Zhang (zyn0217) <details> <summary>Changes</summary> This helps getTemplateInstantiationArgs to properly recover template arguments of an enclosing concept Decl. Fixes https://github.com/llvm/llvm-project/issues/93821 --- Full diff: https://github.com/llvm/llvm-project/pull/93945.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+1) - (modified) clang/lib/Sema/SemaTemplateDeduction.cpp (+14) - (modified) clang/test/SemaTemplate/concepts-lambda.cpp (+12) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 49ab222bec405..83eb285e9ca48 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -710,6 +710,7 @@ Bug Fixes to C++ Support - Correctly treat the compound statement of an ``if consteval`` as an immediate context. Fixes (#GH91509). - When partial ordering alias templates against template template parameters, allow pack expansions when the alias has a fixed-size parameter list. Fixes (#GH62529). +- Fixed a type constraint substitution issue involving a generic lambda expression. (#GH93821) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp index 853c0e1b50619..56529b4d852e7 100644 --- a/clang/lib/Sema/SemaTemplateDeduction.cpp +++ b/clang/lib/Sema/SemaTemplateDeduction.cpp @@ -5004,6 +5004,20 @@ 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::ConstantEvaluated, + 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 `````````` </details> https://github.com/llvm/llvm-project/pull/93945 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
