https://github.com/zyn0217 created https://github.com/llvm/llvm-project/pull/90195
Fixes https://github.com/llvm/llvm-project/issues/88925 >From f708694fc2686684589dca7b8f3738a117fc047e Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Fri, 26 Apr 2024 19:06:57 +0800 Subject: [PATCH] [Sema] Avoid an undesired pack expansion while transforming PackIndexingType --- clang/lib/Sema/TreeTransform.h | 3 +++ clang/test/SemaCXX/cxx2c-pack-indexing.cpp | 19 +++++++++++++++++++ 2 files changed, 22 insertions(+) diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h index 9404be5a46f3f7..abc4a16c004a9f 100644 --- a/clang/lib/Sema/TreeTransform.h +++ b/clang/lib/Sema/TreeTransform.h @@ -6649,6 +6649,9 @@ TreeTransform<Derived>::TransformPackIndexingType(TypeLocBuilder &TLB, } } + // We may be doing this in the context of expanding the Pattern. Forget that + // because it has been handled above. + Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(getSema(), -1); QualType Result = getDerived().TransformType(TLB, TL.getPatternLoc()); QualType Out = getDerived().RebuildPackIndexingType( diff --git a/clang/test/SemaCXX/cxx2c-pack-indexing.cpp b/clang/test/SemaCXX/cxx2c-pack-indexing.cpp index 606715e6aacffd..2fd0dbfed294a5 100644 --- a/clang/test/SemaCXX/cxx2c-pack-indexing.cpp +++ b/clang/test/SemaCXX/cxx2c-pack-indexing.cpp @@ -160,3 +160,22 @@ namespace GH88929 { using E = P...[0]; // expected-error {{unknown type name 'P'}} \ // expected-error {{expected ';' after alias declaration}} } + +namespace GH88925 { +template <typename...> struct S {}; + +template <int...> struct sequence {}; + +template <typename... Args, int... indices> auto f(sequence<indices...>) { + return S<Args...[indices]...>(); // #use +} + +void g() { + static_assert(__is_same(decltype(f<int>(sequence<0, 0>())), S<int, int>)); + static_assert(__is_same(decltype(f<int, long>(sequence<0, 0>())), S<int, int>)); + static_assert(__is_same(decltype(f<int, long>(sequence<0, 1>())), S<int, long>)); + f<int, long>(sequence<3>()); + // expected-error@#use {{invalid index 3 for pack 'Args' of size 2}}} + // expected-note-re@-2 {{function template specialization '{{.*}}' requested here}} +} +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
