https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82698
Bug ID: 82698
Summary: Spurious warning __builtin_memset at O3
Product: gcc
Version: 7.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ipa
Assignee: unassigned at gcc dot gnu.org
Reporter: paulg at chiark dot greenend.org.uk
CC: marxin at gcc dot gnu.org
Target Milestone: ---
With the following code fragment
#include <vector>
void foo(std::vector<int> & bar)
{
bar.resize(bar.size() - 1);
}
compiled with
g++ -c -O3 -Wall -Wextra test.cpp
the following is produced
cc1plus: warning: ‘void* __builtin_memset(void*, int, long unsigned int)’:
specified size 18446744073709551612 exceeds maximum object size
9223372036854775807 -Wstringop-overflow=]
Since the compiler cannot know if the user has arranged to never pass a
argument which would produce this problem this seems like overreach on the part
of the compiler.
