llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Corentin Jabot (cor3ntin) <details> <summary>Changes</summary> This fixes the crash reported in #<!-- -->130604. It does not try to improve diagnostics or resolve CWG3003 (this will be explored separately). Fixes #<!-- -->130604 --- Full diff: https://github.com/llvm/llvm-project/pull/161488.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+1) - (modified) clang/lib/Sema/SemaTemplateDeductionGuide.cpp (+5-2) - (modified) clang/test/SemaCXX/cxx20-ctad-type-alias.cpp (+15) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index e8deae50e4cb0..4aedcddc1146d 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -433,6 +433,7 @@ Bug Fixes to C++ Support object type. (#GH151531) - Suppress ``-Wdouble-promotion`` when explicitly asked for with C++ list initialization (#GH33409). - Fix the result of `__builtin_is_implicit_lifetime` for types with a user-provided constructor. (#GH160610) +- Fix a crash when attempting to deduce a deduction guide from a non deducible template template parameter. (#130604) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp index 3d54d1eb4373a..4cad4a02c190f 100644 --- a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp +++ b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp @@ -1428,8 +1428,11 @@ void Sema::DeclareImplicitDeductionGuides(TemplateDecl *Template, DeclareImplicitDeductionGuidesForTypeAlias(*this, AliasTemplate, Loc); return; } - if (CXXRecordDecl *DefRecord = - cast<CXXRecordDecl>(Template->getTemplatedDecl())->getDefinition()) { + CXXRecordDecl *DefRecord = + llvm::dyn_cast_or_null<CXXRecordDecl>(Template->getTemplatedDecl()); + if (!DefRecord) + return; + if (DefRecord->getDefinition()) { if (TemplateDecl *DescribedTemplate = DefRecord->getDescribedClassTemplate()) Template = DescribedTemplate; diff --git a/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp b/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp index 2f1817d0ca7eb..fd1a5c01233d5 100644 --- a/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp +++ b/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp @@ -586,3 +586,18 @@ Baz a{}; static_assert(__is_same(decltype(a), A<A<int>>)); } // namespace GH133132 + +namespace GH130604 { +template <typename T> struct A { + A(T); +}; + +template <typename T, template <typename> class TT = A> using Alias = TT<T>; // #gh130604-alias +template <typename T> using Alias2 = Alias<T>; + +Alias2 a(42); +// expected-error@-1 {{no viable constructor or deduction guide for deduction of template arguments of 'Alias2'}} +Alias b(42); +// expected-error@-1 {{alias template 'Alias' requires template arguments; argument deduction only allowed for class templates or alias template}} +// expected-note@#gh130604-alias {{template is declared here}} +} `````````` </details> https://github.com/llvm/llvm-project/pull/161488 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
