https://github.com/cor3ntin created
https://github.com/llvm/llvm-project/pull/80652
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.
>From 15e7279b71764342de5073da88854356e0d8dea2 Mon Sep 17 00:00:00 2001
From: Corentin Jabot <corentinja...@gmail.com>
Date: Mon, 5 Feb 2024 10:30:06 +0100
Subject: [PATCH] [Clang] Fix crash when recovering from an invalid pack
indexing type.
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.
---
clang/lib/AST/Type.cpp | 6 ++++++
clang/test/SemaCXX/cxx2c-pack-indexing.cpp | 15 +++++++++++++++
2 files changed, 21 insertions(+)
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}}
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
