Author: Younan Zhang Date: 2024-11-08T14:04:57+08:00 New Revision: 37b4df434d2cf82feb3672eeeb469e54ee8f7ff2
URL: https://github.com/llvm/llvm-project/commit/37b4df434d2cf82feb3672eeeb469e54ee8f7ff2 DIFF: https://github.com/llvm/llvm-project/commit/37b4df434d2cf82feb3672eeeb469e54ee8f7ff2.diff LOG: [Clang] Remove the wrong assumption when rebuilding SizeOfPackExprs for constraint normalization (#115120) In 463a4f150, we assumed that all the template argument packs are of size 1 when normalizing a constraint expression because I mistakenly thought those packs were obtained from their injected template parameters. This was wrong because we might be checking constraints when instantiating a friend declaration within a class template specialization, where the parent class template is specialized with non-dependent template arguments. In that sense, we shouldn't assume any pack size nor expand anything in such a scenario. Moreover, there are no intermediate (substituted but unexpanded) AST nodes for template template parameters, so we have to special-case their transformations by looking into the instantiation scope instead of extracting anything from template arguments. Fixes #115098 Added: Modified: clang/include/clang/AST/ExprCXX.h clang/lib/Sema/SemaTemplateInstantiate.cpp clang/test/SemaTemplate/concepts-out-of-line-def.cpp Removed: ################################################################################ diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h index 57ab94bcb2010f..696a574833dad2 100644 --- a/clang/include/clang/AST/ExprCXX.h +++ b/clang/include/clang/AST/ExprCXX.h @@ -4326,6 +4326,8 @@ class SizeOfPackExpr final /// Retrieve the parameter pack. NamedDecl *getPack() const { return Pack; } + void setPack(NamedDecl *NewPack) { Pack = NewPack; } + /// Retrieve the length of the parameter pack. /// /// This routine may only be invoked when the expression is not diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp index b1b92c0333c976..9e76b60fd509c7 100644 --- a/clang/lib/Sema/SemaTemplateInstantiate.cpp +++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp @@ -1749,31 +1749,21 @@ namespace { return inherited::TransformLambdaBody(E, Body); } - ExprResult RebuildSizeOfPackExpr(SourceLocation OperatorLoc, - NamedDecl *Pack, SourceLocation PackLoc, - SourceLocation RParenLoc, - std::optional<unsigned> Length, - ArrayRef<TemplateArgument> PartialArgs) { - if (SemaRef.CodeSynthesisContexts.back().Kind != - Sema::CodeSynthesisContext::ConstraintNormalization) - return inherited::RebuildSizeOfPackExpr(OperatorLoc, Pack, PackLoc, - RParenLoc, Length, PartialArgs); - -#ifndef NDEBUG - for (auto *Iter = TemplateArgs.begin(); Iter != TemplateArgs.end(); - ++Iter) - for (const TemplateArgument &TA : Iter->Args) - assert(TA.getKind() != TemplateArgument::Pack || TA.pack_size() == 1); -#endif - Sema::ArgumentPackSubstitutionIndexRAII SubstIndex( - SemaRef, /*NewSubstitutionIndex=*/0); - Decl *NewPack = TransformDecl(PackLoc, Pack); - if (!NewPack) - return ExprError(); - - return inherited::RebuildSizeOfPackExpr(OperatorLoc, - cast<NamedDecl>(NewPack), PackLoc, - RParenLoc, Length, PartialArgs); + ExprResult TransformSizeOfPackExpr(SizeOfPackExpr *E) { + ExprResult Transformed = inherited::TransformSizeOfPackExpr(E); + if (!Transformed.isUsable()) + return Transformed; + auto *TransformedExpr = cast<SizeOfPackExpr>(Transformed.get()); + if (SemaRef.CodeSynthesisContexts.back().Kind == + Sema::CodeSynthesisContext::ConstraintNormalization && + TransformedExpr->getPack() == E->getPack()) { + Decl *NewPack = + TransformDecl(E->getPackLoc(), TransformedExpr->getPack()); + if (!NewPack) + return ExprError(); + TransformedExpr->setPack(cast<NamedDecl>(NewPack)); + } + return TransformedExpr; } ExprResult TransformRequiresExpr(RequiresExpr *E) { @@ -1899,6 +1889,15 @@ Decl *TemplateInstantiator::TransformDecl(SourceLocation Loc, Decl *D) { TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getPosition()); if (TTP->isParameterPack()) { + // We might not have an index for pack expansion when normalizing + // constraint expressions. In that case, resort to instantiation scopes + // for the transformed declarations. + if (SemaRef.ArgumentPackSubstitutionIndex == -1 && + SemaRef.CodeSynthesisContexts.back().Kind == + Sema::CodeSynthesisContext::ConstraintNormalization) { + return SemaRef.FindInstantiatedDecl(Loc, cast<NamedDecl>(D), + TemplateArgs); + } assert(Arg.getKind() == TemplateArgument::Pack && "Missing argument pack"); Arg = getPackSubstitutedTemplateArgument(getSema(), Arg); diff --git a/clang/test/SemaTemplate/concepts-out-of-line-def.cpp b/clang/test/SemaTemplate/concepts-out-of-line-def.cpp index dd518d283c83c8..7cb5cfc10b9a7b 100644 --- a/clang/test/SemaTemplate/concepts-out-of-line-def.cpp +++ b/clang/test/SemaTemplate/concepts-out-of-line-def.cpp @@ -703,6 +703,25 @@ C v; } // namespace GH93099 +namespace GH115098 { + +template <typename... Ts> struct c { + template <typename T> + requires(sizeof...(Ts) > 0) + friend bool operator==(c, c); +}; + +template <typename... Ts> struct d { + template <typename T> + requires(sizeof...(Ts) > 0) + friend bool operator==(d, d); +}; + +template struct c<int>; +template struct d<int, int>; + +} // namespace GH115098 + namespace GH114685 { template <typename T> struct ptr { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
