🚀 go-pugleaf

Hi,

This is not a bug report, just a suggestion for a new warning.
When a structure is initialized from a bracketed list {.., .., ..},
if fewer initializers are given than structure elements, the remaining
elements are initialized to 0.

It would be nice if gcc would allow to check when this occurs, through
a special warning option (not implied in -Wall).

When programming with structures of function pointers, missing function
pointers at the end are especially nasty, because they cause a core dump
and gdb is not able to give a stack backtrace.
Example:

================================= foo.c ===================================
#include <stdlib.h>

struct vtable {
	void* (* _malloc) (size_t);
	void (* _free) (void*);
	void* (* _realloc) (void*, size_t);
};

struct vtable mtable = {
	malloc,
	free
};

int main ()
{
	void* p = mtable._malloc(10);
	p = mtable._realloc(p,20);
	return 0;
}
===========================================================================

$ gcc -v
Reading specs from /usr/lib/gcc-lib/i486-linux/2.7.2/specs
gcc version 2.7.2

$ gcc -O -g -Wall foo.c             or      $ gcc -O -g -Wall -x c++ foo.c
$ ./a.out
Segmentation fault (core dumped)
$ gdb a.out
(gdb) run
Starting program: /home/bruno/a.out 
Program received signal SIGSEGV, Segmentation fault.
0x0 in ?? ()
(gdb) where
#0  0x0 in ?? ()


----------------------------------------------------------------------------
Bruno Haible                            net: <haible@ilog.fr>
ILOG S.A.                               tel: +33 1 4908 3585
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