[Bug c++/36814] G++ won't warn about an uninitialized value

[manu at gcc dot gnu dot org]

------- Comment #5 from manu at gcc dot gnu dot org  2008-08-18 18:56 -------
possible_bug.cc:1: error: `cMyClass' has not been declared
possible_bug.cc: In function `bool Init()':
possible_bug.cc:5: error: `some_function' was not declared in this scope
possible_bug.cc:5: warning: unused variable 'some_function'

Anyway, I guess the following reproduces the original problem:

bool some_function(void);

bool Init()
{
    bool retval;

    if (some_function())
    {
        // If the `goto' is executed, 'return retval;' will use the
        // uninitialized value of 'retval'.
        goto error;
    }

    retval = true;
error:
    return retval;
}


which is converted to:

bool Init() ()
{
  boolD.2365 retvalD.2430;
  boolD.2365 retval.0D.2432;

  # BLOCK 2
  # PRED: ENTRY (fallthru,exec)
  [pr36814.C : 7] retval.0D.2432_2 = some_functionD.2427 ();
  [pr36814.C : 7] retval.0D.2432_3 = retval.0D.2432_2;
  [pr36814.C : 7] if (retval.0D.2432_3 != 0)
    goto <bb 4> (error);
  else
    goto <bb 3>;
  # SUCC: 4 (true,exec) 3 (false,exec)

  # BLOCK 3
  # PRED: 2 (false,exec)
  [pr36814.C : 14] retvalD.2430_5 = 1;
  # SUCC: 4 (fallthru,exec)

  # BLOCK 4, starting at line 0
  # PRED: 2 (true,exec) 3 (fallthru,exec)
  # retvalD.2430_1 = PHI <retvalD.2430_4(D)(2), 1(3)>
errorL.1:
  return 1;
  # SUCC: EXIT

}

by the first CCP pass. So this is CCP again.

*** This bug has been marked as a duplicate of 18501 ***


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36814