[Bug c/20318] RFE: add attribute to specify that a function never returns NULL

[glisse at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20318

--- Comment #10 from Marc Glisse <glisse at gcc dot gnu.org> ---
Author: glisse
Date: Wed Oct  9 13:03:13 2013
New Revision: 203316

URL: http://gcc.gnu.org/viewcvs?rev=203316&root=gcc&view=rev
Log:
2013-10-09  Marc Glisse  <marc.glisse@inria.fr>

    PR tree-optimization/20318
gcc/c-family/
    * c-common.c (handle_returns_nonnull_attribute): New function.
    (c_common_attribute_table): Add returns_nonnull.

gcc/
    * doc/extend.texi (returns_nonnull): New function attribute.
    * fold-const.c (tree_expr_nonzero_warnv_p): Look for returns_nonnull
    attribute.
    * tree-vrp.c (gimple_stmt_nonzero_warnv_p): Likewise.
    (stmt_interesting_for_vrp): Accept all GIMPLE_CALL.

gcc/testsuite/
    * c-c++-common/pr20318.c: New file.
    * gcc.dg/tree-ssa/pr20318.c: New file.

Added:
    trunk/gcc/testsuite/c-c++-common/pr20318.c   (with props)
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr20318.c   (with props)
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-family/ChangeLog
    trunk/gcc/c-family/c-common.c
    trunk/gcc/doc/extend.texi
    trunk/gcc/fold-const.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vrp.c

Propchange: trunk/gcc/testsuite/c-c++-common/pr20318.c
            ('svn:eol-style' added)

Propchange: trunk/gcc/testsuite/c-c++-common/pr20318.c
            ('svn:keywords' added)

Propchange: trunk/gcc/testsuite/gcc.dg/tree-ssa/pr20318.c
            ('svn:eol-style' added)

Propchange: trunk/gcc/testsuite/gcc.dg/tree-ssa/pr20318.c
            ('svn:keywords' added)