llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: cor3ntin (cor3ntin) <details> <summary>Changes</summary> If the pattern of a pack indexing type did not contain a pack, we would still construct a pack indexing type (to improve error messages) but we would fail to make the type as dependent, leading to infinite recursion when trying to extract a canonical type. --- Full diff: https://github.com/llvm/llvm-project/pull/80652.diff 2 Files Affected: - (modified) clang/lib/AST/Type.cpp (+6) - (modified) clang/test/SemaCXX/cxx2c-pack-indexing.cpp (+15) ``````````diff diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp index 11ca02be13ab4..c68254a459ccc 100644 --- a/clang/lib/AST/Type.cpp +++ b/clang/lib/AST/Type.cpp @@ -3854,6 +3854,12 @@ PackIndexingType::computeDependence(QualType Pattern, Expr *IndexExpr, if (!(IndexD & TypeDependence::UnexpandedPack)) TD &= ~TypeDependence::UnexpandedPack; + + // If the pattern does not contain an unexpended pack, + // the type is still dependent, and invalid + if (!Pattern->containsUnexpandedParameterPack()) + TD |= TypeDependence::Error | TypeDependence::DependentInstantiation; + return TD; } diff --git a/clang/test/SemaCXX/cxx2c-pack-indexing.cpp b/clang/test/SemaCXX/cxx2c-pack-indexing.cpp index bd75c1180a1c1..625a56031598b 100644 --- a/clang/test/SemaCXX/cxx2c-pack-indexing.cpp +++ b/clang/test/SemaCXX/cxx2c-pack-indexing.cpp @@ -11,6 +11,21 @@ void not_pack() { Tp...[0] c; // expected-error{{'Tp' does not refer to the name of a parameter pack}} } +template <typename T, auto V, template<typename> typename Tp> +void not_pack_arrays() { + NotAPack...[0] a[1]; // expected-error{{'NotAPack' does not refer to the name of a parameter pack}} + T...[0] b[1]; // expected-error{{'T' does not refer to the name of a parameter pack}} + Tp...[0] c[1]; // expected-error{{'Tp' does not refer to the name of a parameter pack}} +} + +template <typename T> +struct TTP; + +void test_errors() { + not_pack<int, 0, TTP>(); + not_pack_arrays<int, 0, TTP>(); +} + namespace invalid_indexes { int non_constant_index(); // expected-note 2{{declared here}} `````````` </details> https://github.com/llvm/llvm-project/pull/80652 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
