[Bug c/19099] New: No warning for uninitialized local variable use

["gopalv82 at dotgnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

Code similar to the one below does not give a warning (though one is expected).

int foo()
{
  int x = x;
  return x;
}

Though this code in itself seems stupid - this is how it hid into my codebase 
(in a simplified example).

#include <stdio.h>

#define macro2(imm) \
	do {\
		int __value = (imm);\
		printf("macro2 got %d\n", __value);\
	}while(0)

#define macro3(imm) \
	do { \
		int __value = (imm);\
		printf("macro3 got %d\n", __value);\
	} while(0);
#define macro1(imm)\
	do {\
		int __value = (imm);\
		printf("macro1 got %d\n", __value);\
		macro2(__value);\
		macro3(__value);\
	}while(0)

int foobar()
{
	printf("foobar was called\n");
	return 42;
}
int main()
{
	macro1(foobar());
	return 0;
}

The expected output was 
"""
foobar was called 
macro1 got 42
macro2 got 42
macro3 got 42
"""

But I get
"""
gopal@sweden samples $ gcc -Wall -pedantic -ansi -O3 test.c
gopal@sweden samples $ ./a.out 
foobar was called
macro1 got 42
macro2 got 805441120
macro3 got 805441120
"""

The original code was spread accross 4 files. I think the code 
should generate a valid warning because the variable is as good
as being stack/register junk . 

Tested with "gcc (GCC) 3.4.1 20040803 (Gentoo Linux 3.4.1-r3, ssp-3.4-2,
pie-8.7.6.5)".

-- 
           Summary: No warning for uninitialized local variable use
           Product: gcc
           Version: 3.4.1
            Status: UNCONFIRMED
          Severity: minor
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: gopalv82 at dotgnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: powerpc-unknown-linux-gnu
  GCC host triplet: powerpc-unknown-linux-gnu
GCC target triplet: powerpc-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19099