[Bug middle-end/50040] [4.5/4.6/4.7 Regression] missed warning: ‘x?=.=?UTF-8?Q?y’ is used uninitialized in this function

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50040

--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-11 14:28:39 UTC ---
Author: rguenth
Date: Thu Aug 11 14:28:36 2011
New Revision: 177667

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=177667
Log:
2011-08-11  Richard Guenther  <rguenther@suse.de>

    PR middle-end/50040
    * gimplify.c (gimplify_modify_expr_complex_part): Mark the
    load of the other piece with TREE_NO_WARNING.
    * tree-flow.h (warn_uninit): Adjust prototype.
    * tree-ssa.c (warn_uninit): Take uninitialized SSA name,
    the base variable and the expression that is used separately.
    Properly query all TREE_NO_WARNING flags.
    (struct walk_data): Remove.
    (warn_uninitialized_var): Likewise.
    (warn_uninitialized_vars): Do not walk gimple pieces but simply
    look at all SSA uses of the statement.  Handle unused memory
    separately.
    * tree-ssa-uninit.c (warn_uninitialized_phi): Adjust.

    * g++.dg/warn/unit-1.C: Un-XFAIL.
    * gcc.dg/uninit-I.c: Likewise.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimplify.c
    trunk/gcc/testsuite/g++.dg/warn/unit-1.C
    trunk/gcc/testsuite/gcc.dg/uninit-I.c
    trunk/gcc/tree-flow.h
    trunk/gcc/tree-ssa-uninit.c
    trunk/gcc/tree-ssa.c