Here's the reproduction recipe:
/* bug.c */
#include <stdint.h>
#include <stdio.h>
struct squash {
uintptr_t bug;
};
static const struct squash bug = {(uintptr_t)(void *)"4321"};
int main()
{
printf("bug.bug = 0x%llx\n", (unsigned long long)bug.bug);
return 0;
}
#!/bin/sh
# bug.sh
PS4= && set -vx
${CC:-tcc} -o bug -Wall bug.c && ./bug "$@"
$ CC=gcc ./bug.sh
${CC:-tcc} -o bug -Wall bug.c && ./bug "$@"
gcc -o bug -Wall bug.c
./bug
bug.bug = 0x5606e048b004
$ CC=clang ./bug.sh
${CC:-tcc} -o bug -Wall bug.c && ./bug "$@"
clang -o bug -Wall bug.c
./bug
bug.bug = 0x556d5b578016
$ CC=pcc ./bug.sh
${CC:-tcc} -o bug -Wall bug.c && ./bug "$@"
pcc -o bug -Wall bug.c
./bug
bug.bug = 0x402022
tcc version 0.9.27 mob:909d58dd 2022-12-20T07:34:41+01:00 (x86_64 Linux)
$ ./bug.sh
${CC:-tcc} -o bug -Wall bug.c && ./bug "$@"
tcc -o bug -Wall bug.c
./bug
bug.bug = 0x31323334
# 0x31323334 is just the four ASCII values for '1' '2' '3' '4'
# and obviously wrong, it should be the address of the "4321" string
I tested out gcc and it allows these:
char var[] = "";
unsigned char var[] = "";
signed char var[] = "";
#include <stddef.h>
wchar_t var[] = L"";
int var[] = L"";
On the system I tested, wchar_t is apparently an int.
Any other type for the "[]" array and gcc spits an error.
--Kyle
P.S. If someone can provide a pointer to where to look in the sources
to fix this, I'll take a stab at it, but not being familiar with the
tcc sources at all, I'm posting this bug instead.