I came across a the below peculiarity in gdb: the third argument to
regcomp(3) appears mangled in gdb's output when I set a breakpoint and
run it. Even though I pass 1 (i.e., REG_EXTENDED) to regcomp, gdb
says that -809753220 was passed.
I see this behavior on 3.9 and a now rather of date 4.0 snapshot (at
least a month or so old). Is this a bug in gdb, or is it some goofy
(but expected) behavior caused by the linker resolving?
Thanks.
$ cat gdb-bug.c
#include <regex.h>
int
main ()
{
regex_t r;
regcomp (&r, "foo", 1 /* REG_EXTENDED */);
return 0;
}
$ cc -o gdb-bug gdb-bug.c -W -Wall -g
$ gdb ./gdb-bug
GNU gdb 6.3
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-unknown-openbsd3.9"...
(gdb) break regcomp
Function "regcomp" not defined.
Make breakpoint pending on future shared library load? (y or [n]) y
Breakpoint 1 (regcomp) pending.
(gdb) run
Starting program: /tmp/gdb-bug
Breakpoint 2 at 0x8349314: file /usr/src/lib/libc/regex/regcomp.c, line 162.
Pending breakpoint "regcomp" resolved
Breakpoint 2, regcomp (preg=0xcfbc25d0, pattern=0x3c000001 "foo",
cflags=-809753220) at /usr/src/lib/libc/regex/regcomp.c:162
162 /usr/src/lib/libc/regex/regcomp.c: No such file or directory.
in /usr/src/lib/libc/regex/regcomp.c
(gdb) quit
The program is running. Exit anyway? (y or n) y
