Any variable that has the same name with standard/builtin function name will be
accepted by free parameter.
example of code,
>>>
#include <stdlib.h>
int main(int argc, char *argv[])
{
free(rand);
return 0;
}
<<<
This sample code will success on compile,
$ gcc -Wall -g -O0 free-bug.c
but error on run,
$ ./a.out
*** glibc detected *** ./a.out: free(): invalid pointer: 0x08048364 ***
======= Backtrace: =========
/lib/libc.so.6[0xb7ee94b6]
/lib/libc.so.6(cfree+0x89)[0xb7eeb179]
./a.out[0x8048421]
/lib/libc.so.6(__libc_start_main+0xe0)[0xb7e98fe0]
./a.out[0x80483a1]
======= Memory map: ========
08048000-08049000 r-xp 00000000 08:03 7946378
/home/rv77ax/doc/sandbox/c/a.out
08049000-0804a000 r--p 00000000 08:03 7946378
/home/rv77ax/doc/sandbox/c/a.out
0804a000-0804b000 rw-p 00001000 08:03 7946378
/home/rv77ax/doc/sandbox/c/a.out
0804b000-0806c000 rw-p 0804b000 00:00 0 [heap]
b7e76000-b7e80000 r-xp 00000000 08:01 817696 /lib/libgcc_s.so.1
b7e80000-b7e82000 rw-p 00009000 08:01 817696 /lib/libgcc_s.so.1
b7e82000-b7e83000 rw-p b7e82000 00:00 0
b7e83000-b7fb0000 r-xp 00000000 08:01 817612 /lib/libc-2.6.1.so
b7fb0000-b7fb1000 r--p 0012c000 08:01 817612 /lib/libc-2.6.1.so
b7fb1000-b7fb3000 rw-p 0012d000 08:01 817612 /lib/libc-2.6.1.so
b7fb3000-b7fb6000 rw-p b7fb3000 00:00 0
b7fcb000-b7fcc000 rw-p b7fcb000 00:00 0
b7fcc000-b7fe6000 r-xp 00000000 08:01 819693 /lib/ld-2.6.1.so
b7fe6000-b7fe8000 rw-p 0001a000 08:01 819693 /lib/ld-2.6.1.so
bfd0a000-bfd20000 rw-p bfd0a000 00:00 0 [stack]
ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
Aborted
--
Summary: free() accept argument that has the same name with
standard/builtin function
Product: gcc
Version: 4.2.1
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: m dot shulhan at gmail dot com
GCC build triplet: -Wall -g -O0
GCC host triplet: i586-suse-linux
GCC target triplet: i586-suse-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38575
