From 16afbd9c9c4282d56062cef95e6eccfdcf3efe03 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Mon, 18 Mar 2024 13:00:17 +0000
Subject: [PATCH] libstdc++: Begin lifetime of storage in std::vector<bool>
[PR114367]
This doesn't cause a problem with GCC, but Clang correctly diagnoses a
bug in the code. The objects in the allocated storage need to begin
their lifetime before we start using them.
This change uses the allocator's construct function instead of using
std::construct_at directly, in order to support fancy pointers.
libstdc++-v3/ChangeLog:
PR libstdc++/114367
* include/bits/stl_bvector.h (_M_allocate): Use allocator's
construct function to begin lifetime of words.
---
libstdc++-v3/include/bits/stl_bvector.h | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/libstdc++-v3/include/bits/stl_bvector.h b/libstdc++-v3/include/bits/stl_bvector.h
index 2c8b892b07a4..a3343d95b368 100644
--- a/libstdc++-v3/include/bits/stl_bvector.h
+++ b/libstdc++-v3/include/bits/stl_bvector.h
@@ -674,13 +674,13 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
_M_allocate(size_t __n)
{
_Bit_pointer __p = _Bit_alloc_traits::allocate(_M_impl, _S_nword(__n));
-#if __cpp_lib_is_constant_evaluated
+#if __cpp_lib_is_constant_evaluated && __cpp_constexpr_dynamic_alloc
if (std::is_constant_evaluated())
- {
- __n = _S_nword(__n);
- for (size_t __i = 0; __i < __n; ++__i)
- __p[__i] = 0ul;
- }
+ {
+ __n = _S_nword(__n);
+ for (size_t __i = 0; __i < __n; ++__i)
+ std::construct_at(std::to_address(__p) + __i);
+ }
#endif
return __p;
}
--
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