[Bug regression/39799] New: missing 'may be used uninitialized' warning

[alexvod at google dot com]

The following code:

inline int foo(int x)
{
  return x;
}
static void bar(int a, int *ptr)
{
  do
  {
    int b;
    if (b < 40)
    {
      ptr[0] = b;
    }
    b += 1;
    ptr++;
  }
  while (--a != 0);
}
void foobar(int a, int *ptr)
{
  bar(foo(a), ptr);
}

generates correct warning when compiled by gcc 4.2.4:
$ gcc -O3 -Wall -Werror -c 1.c
cc1: warnings being treated as errors
1.c: In function ‘foobar’:
1.c:9: warning: ‘b’ may be used uninitialized in this function
1.c:9: note: ‘b’ was declared here

But it compiles without any warning with gcc 4.4.0. The bug reproduces on gcc
4.3.1 as well.


-- 
           Summary: missing 'may be used uninitialized' warning
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: regression
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: alexvod at google dot com
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39799