Author: Younan Zhang Date: 2025-01-22T16:08:19+08:00 New Revision: 69d0c4c1675c90cf99126210679a9c3ae0a8637e
URL: https://github.com/llvm/llvm-project/commit/69d0c4c1675c90cf99126210679a9c3ae0a8637e DIFF: https://github.com/llvm/llvm-project/commit/69d0c4c1675c90cf99126210679a9c3ae0a8637e.diff LOG: [Clang] SubstituteConstraintExpressionWithoutSatisfaction needs an unevaluated context (#123883) It turns out that the substitution for expression comparing also needs an unevaluated context, otherwise any reference to immediate functions might not be properly handled. As a fallout, this also guards the VLA transformation under unevaluated context with `InConditionallyConstantEvaluateContext` to avoid duplicate diagnostics. Fixes https://github.com/llvm/llvm-project/issues/123472 --------- Co-authored-by: cor3ntin <corentinja...@gmail.com> Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Parse/ParseExpr.cpp clang/lib/Sema/SemaConcept.cpp clang/lib/Sema/SemaExpr.cpp clang/test/SemaTemplate/concepts-out-of-line-def.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index f19be0446d3fec..6895fca41c3bd3 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -968,7 +968,7 @@ Bug Fixes to C++ Support constraints are applied. (#GH122134) - Fixed canonicalization of pack indexing types - Clang did not always recognized identical pack indexing. (#GH123033) - Fixed a nested lambda substitution issue for constraint evaluation. (#GH123441) - +- Fixed various false diagnostics related to the use of immediate functions. (#GH123472) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp index 8dd72db8f5b4a2..aa8b3870a188c6 100644 --- a/clang/lib/Parse/ParseExpr.cpp +++ b/clang/lib/Parse/ParseExpr.cpp @@ -248,6 +248,25 @@ ExprResult Parser::ParseArrayBoundExpression() { // If we parse the bound of a VLA... we parse a non-constant // constant-expression! Actions.ExprEvalContexts.back().InConditionallyConstantEvaluateContext = true; + // For a VLA type inside an unevaluated operator like: + // + // sizeof(typeof(*(int (*)[N])array)) + // + // N and array are supposed to be ODR-used. + // Initially when encountering `array`, it is deemed unevaluated and non-ODR + // used because that occurs before parsing the type cast. Therefore we use + // Sema::TransformToPotentiallyEvaluated() to rebuild the expression to ensure + // it's actually ODR-used. + // + // However, in other unevaluated contexts as in constraint substitution, it + // would end up rebuilding the type twice which is unnecessary. So we push up + // a flag to help distinguish these cases. + for (auto Iter = Actions.ExprEvalContexts.rbegin() + 1; + Iter != Actions.ExprEvalContexts.rend(); ++Iter) { + if (!Iter->isUnevaluated()) + break; + Iter->InConditionallyConstantEvaluateContext = true; + } return ParseConstantExpressionInExprEvalContext(NotTypeCast); } diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp index 6a40a59c977d78..8a77cbf8c9477b 100644 --- a/clang/lib/Sema/SemaConcept.cpp +++ b/clang/lib/Sema/SemaConcept.cpp @@ -1027,6 +1027,9 @@ static const Expr *SubstituteConstraintExpressionWithoutSatisfaction( ContextScope.emplace(S, const_cast<DeclContext *>(cast<DeclContext>(RD)), /*NewThisContext=*/false); } + EnterExpressionEvaluationContext UnevaluatedContext( + S, Sema::ExpressionEvaluationContext::Unevaluated, + Sema::ReuseLambdaContextDecl); ExprResult SubstConstr = S.SubstConstraintExprWithoutSatisfaction( const_cast<clang::Expr *>(ConstrExpr), MLTAL); if (SFINAE.hasErrorOccurred() || !SubstConstr.isUsable()) diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index ae40895980d90a..444640b27de1fe 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -4630,8 +4630,9 @@ ExprResult Sema::CreateUnaryExprOrTypeTraitExpr(TypeSourceInfo *TInfo, // Adds overload of TransformToPotentiallyEvaluated for TypeSourceInfo to // properly deal with VLAs in nested calls of sizeof and typeof. - if (isUnevaluatedContext() && ExprKind == UETT_SizeOf && - TInfo->getType()->isVariablyModifiedType()) + if (currentEvaluationContext().isUnevaluated() && + currentEvaluationContext().InConditionallyConstantEvaluateContext && + ExprKind == UETT_SizeOf && TInfo->getType()->isVariablyModifiedType()) TInfo = TransformToPotentiallyEvaluated(TInfo); // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. diff --git a/clang/test/SemaTemplate/concepts-out-of-line-def.cpp b/clang/test/SemaTemplate/concepts-out-of-line-def.cpp index 7cb5cfc10b9a7b..6c1a229a9fddab 100644 --- a/clang/test/SemaTemplate/concepts-out-of-line-def.cpp +++ b/clang/test/SemaTemplate/concepts-out-of-line-def.cpp @@ -737,3 +737,17 @@ ptr<U> make_item(auto &&args) ptr<char> p; } // namespace GH114685 + +namespace GH123472 { + +consteval bool fn() { return true; } + +struct S { + template <typename T> + static consteval void mfn() requires (bool(&fn)); +}; + +template <typename T> +consteval void S::mfn() requires (bool(&fn)) {} + +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
