https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83671
Bug ID: 83671
Summary: Fix for false positive reported by -Wstringop-overflow
does not work with inlining
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: bugzi...@poradnik-webmastera.com
Target Milestone: ---
Fix for bug 83373 does not work well with inlining:
[code]
#include <stdint.h>
#include <string.h>
char dest[20];
char src[10];
__attribute((nonnull(1, 2)))
inline char* my_strcpy(char* __restrict__ dst, const char* __restrict__ src,
size_t size)
{
size_t len = strlen(src);
if (len < size)
memcpy(dst, src, len + 1);
else
{
memcpy(dst, src, size - 1);
dst[size - 1] = '\0';
}
return dst;
}
inline void func1()
{
my_strcpy(dest, src, sizeof(dest));
}
void func2()
{
func1();
}
[/code]
[out]
$ g++ -c -o test.o test.cc -Wall -Wstringop-overflow=2 -O1
In function ‘char* my_strcpy(char*, const char*, size_t)’,
inlined from ‘void func2()’ at test.cc:23:14:
test.cc:15:15: warning: ‘void* memcpy(void*, const void*, size_t)’ forming
offset [11, 19] is out of the bounds [0, 10] of object ‘src’ with type ‘char
[10]’ [-Warray-bounds]
memcpy(dst, src, size - 1);
~~~~~~^~~~~~~~~~~~~~~~~~~~
test.cc: In function ‘void func2()’:
test.cc:5:6: note: ‘src’ declared here
char src[10];
^~~
In function ‘char* my_strcpy(char*, const char*, size_t)’,
inlined from ‘void func2()’ at test.cc:23:14:
test.cc:15:15: warning: ‘void* memcpy(void*, const void*, size_t)’ reading 19
bytes from a region of size 10 [-Wstringop-overflow=]
memcpy(dst, src, size - 1);
~~~~~~^~~~~~~~~~~~~~~~~~~~
$ gcc --version
gcc (GCC) 8.0.0 20171231 (experimental)
[/out]
