[gcc r12-8985] libstdc++: Fix size passed to operator delete [PR108097]

[Jonathan Wakely]

https://gcc.gnu.org/g:e9d58614b0b8eebd64d568fa22cd31faaa5f8dce

commit r12-8985-ge9d58614b0b8eebd64d568fa22cd31faaa5f8dce
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Dec 14 11:58:05 2022 +0000

    libstdc++: Fix size passed to operator delete [PR108097]
    
    The number of elements gets stored in _M_capacity so use a separate
    variable for the number of bytes to allocate.
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/108097
            * include/std/stacktrace (basic_stracktrace::_Impl): Do not
            multiply N by sizeof(value_type) when allocating.
    
    (cherry picked from commit 881c6cabce5d0b27285ed41bd6dabdf48848cce7)

Diff:
---
 libstdc++-v3/include/std/stacktrace | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/std/stacktrace b/libstdc++-v3/include/std/stacktrace
index 8e6c79a2f4f..a067d629a16 100644
--- a/libstdc++-v3/include/std/stacktrace
+++ b/libstdc++-v3/include/std/stacktrace
@@ -600,8 +600,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	    {
 	      if constexpr (is_same_v<allocator_type, allocator<value_type>>)
 		{
-		  __n *= sizeof(value_type);
-		  void* const __p = _GLIBCXX_OPERATOR_NEW (__n, nothrow_t{});
+		  // For std::allocator we use nothrow-new directly so we
+		  // don't need to handle bad_alloc exceptions.
+		  size_t __nb = __n * sizeof(value_type);
+		  void* const __p = _GLIBCXX_OPERATOR_NEW (__nb, nothrow_t{});
 		  if (__p == nullptr) [[unlikely]]
 		    return nullptr;
 		  _M_frames = static_cast<pointer>(__p);