Author: Younan Zhang Date: 2024-03-16T12:56:11+08:00 New Revision: 3e69e5a15782a5776a3245170aeb5d97ef746fa5
URL: https://github.com/llvm/llvm-project/commit/3e69e5a15782a5776a3245170aeb5d97ef746fa5 DIFF: https://github.com/llvm/llvm-project/commit/3e69e5a15782a5776a3245170aeb5d97ef746fa5.diff LOG: [Concepts] Add Decls from the outer scope of the current lambda for conversion function constraints (#83420) This fixes the case shown by https://github.com/llvm/llvm-project/issues/64808#issuecomment-1929131611. Similar to https://github.com/llvm/llvm-project/commit/f9caa12328b265b77221fe7a310d4504673d814a, we have some calls to constraint checking for a lambda's conversion function while determining the conversion sequence. This patch addresses the problem where the requires-expression within such a lambda references to a Decl outside of the lambda by adding these Decls to the current instantiation scope. I'm abusing the flag `ForOverloadResolution` of CheckFunctionConstraints, which is actually meant to consider the Decls from parent DeclContexts. --------- Co-authored-by: cor3ntin <corentinja...@gmail.com> Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaConcept.cpp clang/test/SemaTemplate/concepts.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 1ae35e6881d2f8..93cc5291e2391f 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -387,6 +387,8 @@ Bug Fixes to C++ Support Fixes (#GH80997) - Fix an issue where missing set friend declaration in template class instantiation. Fixes (#GH84368). +- Fixed a crash while checking constraints of a trailing requires-expression of a lambda, that the + expression references to an entity declared outside of the lambda. (#GH64808) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp index a8e387e35fb4c9..1c546e9f5894f0 100644 --- a/clang/lib/Sema/SemaConcept.cpp +++ b/clang/lib/Sema/SemaConcept.cpp @@ -692,11 +692,15 @@ bool Sema::CheckFunctionConstraints(const FunctionDecl *FD, // A lambda conversion operator has the same constraints as the call operator // and constraints checking relies on whether we are in a lambda call operator // (and may refer to its parameters), so check the call operator instead. + // Note that the declarations outside of the lambda should also be + // considered. Turning on the 'ForOverloadResolution' flag results in the + // LocalInstantiationScope not looking into its parents, but we can still + // access Decls from the parents while building a lambda RAII scope later. if (const auto *MD = dyn_cast<CXXConversionDecl>(FD); MD && isLambdaConversionOperator(const_cast<CXXConversionDecl *>(MD))) return CheckFunctionConstraints(MD->getParent()->getLambdaCallOperator(), Satisfaction, UsageLoc, - ForOverloadResolution); + /*ShouldAddDeclsFromParentScope=*/true); DeclContext *CtxToSave = const_cast<FunctionDecl *>(FD); diff --git a/clang/test/SemaTemplate/concepts.cpp b/clang/test/SemaTemplate/concepts.cpp index bac209a28da912..b7ea0d003a52d7 100644 --- a/clang/test/SemaTemplate/concepts.cpp +++ b/clang/test/SemaTemplate/concepts.cpp @@ -1085,3 +1085,32 @@ template void Struct<void>::bar<>(); template int Struct<void>::field<1, 2>; } + +namespace GH64808 { + +template <class T> struct basic_sender { + T func; + basic_sender(T) : func(T()) {} +}; + +auto a = basic_sender{[](auto... __captures) { + return []() // #note-a-1 + requires((__captures, ...), false) // #note-a-2 + {}; +}()}; + +auto b = basic_sender{[](auto... __captures) { + return []() + requires([](int, double) { return true; }(decltype(__captures)()...)) + {}; +}(1, 2.33)}; + +void foo() { + a.func(); + // expected-error@-1{{no matching function for call}} + // expected-note@#note-a-1{{constraints not satisfied}} + // expected-note@#note-a-2{{evaluated to false}} + b.func(); +} + +} // namespace GH64808 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
