[Bug c++/28656] duplicated null argument warning on memcpy()

[Bug c++/28656] duplicated null argument warning on memcpy()

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28656

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-07-19 13:12:15 UTC ---
Created attachment 27833
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27833
gcc48-pr28656.patch

Untested fix.

[Bug c++/28656] duplicated null argument warning on memcpy()

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28656

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-07-20 09:37:29 UTC ---
Author: jakub
Date: Fri Jul 20 09:37:25 2012
New Revision: 189707

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=189707
Log:
    PR c++/28656
    * tree-vrp.c (nonnull_arg_p): Handle all nonnull attributes instead
    of just the first one.

    * c-common.c (check_function_nonnull): Handle multiple nonnull
    attributes properly.

    * c-c++-common/pr28656.c: New test.

Added:
    trunk/gcc/testsuite/c-c++-common/pr28656.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-family/ChangeLog
    trunk/gcc/c-family/c-common.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vrp.c

[Bug c++/28656] duplicated null argument warning on memcpy()

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28656

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.8.0

--- Comment #8 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-08-22 20:45:25 UTC ---
I guess we can close this as fixed for 4.8.0.

[Bug c++/28656] duplicated null argument warning on memcpy()

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2006-10-13 21:14 -------
One question is the duplicated warning a regression and is it a C++ front-end
problem or also a C one too?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28656

[Bug c++/28656] duplicated null argument warning on memcpy()

[sebor at roguewave dot com]

------- Comment #4 from sebor at roguewave dot com  2006-10-13 21:09 -------
I opened bug 29465 with a request for the new warning.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28656

[Bug c++/28656] duplicated null argument warning on memcpy()

[sebor at roguewave dot com]

------- Comment #3 from sebor at roguewave dot com  2006-10-13 21:02 -------
You're right, I missed that. I confess I don't quite understand the rationale
for this in the standard and I'm not aware of any plaform that causes problems
for such calls but based on Doug Gwyn's response to my query the undefined
behavior is intentional. Go figure.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28656

[Bug c++/28656] duplicated null argument warning on memcpy()

[falk at debian dot org]

------- Comment #2 from falk at debian dot org  2006-10-13 12:43 -------
>From the standard:

  [...] n can have the value zero on a call to that function. Unless
  explicitly stated otherwise in the description of a particular
  function in this subclause, pointer arguments on such a call shall
  still have valid values.

So the warning is justified (but not giving it twice).

For the missing warning on the second memcpy, please file a second report since
this is a totally different problem (and would require some aliasing analysis
to detect).


-- 

falk at debian dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|unhelpful null argument     |duplicated null argument
                   |warning on memcpy()         |warning on memcpy()


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28656