llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Younan Zhang (zyn0217) <details> <summary>Changes</summary> Thanks to the example provided by @<!-- -->MagentaTreehouse, I realized the assertion I added didn't cover all valid cases like, when inheriting from a class template specialization, the source of a synthesized template parameter might be an implicit specialization, whose inner function template is thus living at depth 0, for which we don’t want it to overflow too. --- Full diff: https://github.com/llvm/llvm-project/pull/132669.diff 2 Files Affected: - (modified) clang/lib/Sema/SemaTemplateDeductionGuide.cpp (+7-5) - (modified) clang/test/SemaTemplate/deduction-guide.cpp (+26) ``````````diff diff --git a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp index 9cfdb7596b660..e20130a33f368 100644 --- a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp +++ b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp @@ -376,12 +376,14 @@ struct ConvertConstructorToDeductionGuideTransform { if (NestedPattern) Args.addOuterRetainedLevels(NestedPattern->getTemplateDepth()); auto [Depth, Index] = getDepthAndIndex(Param); - // Depth can still be 0 if FTD belongs to an explicit class template - // specialization with an empty template parameter list. In that case, - // we don't want the NewDepth to overflow, and it should remain 0. + // Depth can be 0 if FTD belongs to a class template specialization with + // an empty template parameter list (i.e. either an explicit full + // specialization or an implicit specialization) In that case, we don't + // want the NewDepth to overflow, and it should remain 0. assert(Depth || - cast<ClassTemplateSpecializationDecl>(FTD->getDeclContext()) - ->isExplicitSpecialization()); + isa<ClassTemplateDecl *>( + cast<ClassTemplateSpecializationDecl>(FTD->getDeclContext()) + ->getSpecializedTemplateOrPartial())); NamedDecl *NewParam = transformTemplateParameter( SemaRef, DC, Param, Args, Index + Depth1IndexAdjustment, Depth ? Depth - 1 : 0); diff --git a/clang/test/SemaTemplate/deduction-guide.cpp b/clang/test/SemaTemplate/deduction-guide.cpp index ecd152abebd74..95e740a026550 100644 --- a/clang/test/SemaTemplate/deduction-guide.cpp +++ b/clang/test/SemaTemplate/deduction-guide.cpp @@ -723,3 +723,29 @@ void test() { NewDeleteAllocator abc(42); } // expected-error {{no viable constr // CHECK-NEXT: `-ParmVarDecl {{.+}} 'T' } // namespace GH128691 + +namespace GH132616_DeductionGuide { + +template <class T> struct A { + template <class U> + A(U); +}; + +template <typename> +struct B: A<int> { + using A::A; +}; + +template <class T> +B(T) -> B<T>; + +B b(24); + +// CHECK-LABEL: Dumping GH132616_DeductionGuide::<deduction guide for B>: +// CHECK-NEXT: FunctionTemplateDecl {{.+}} implicit <deduction guide for B> +// CHECK-NEXT: |-TemplateTypeParmDecl {{.+}} typename depth 0 index 0 +// CHECK-NEXT: |-TemplateTypeParmDecl {{.+}} class depth 0 index 1 U +// CHECK-NEXT: `-CXXDeductionGuideDecl {{.+}} implicit <deduction guide for B> 'auto (U) -> B<type-parameter-0-0>' +// CHECK-NEXT: `-ParmVarDecl {{.+}} 'U' + +} // namespace GH132616_DeductionGuide `````````` </details> https://github.com/llvm/llvm-project/pull/132669 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
