[Bug c++/32256] New: pragma system_header doesn't suppress warnings in tree-cfg

[Bug c++/32256] New: pragma system_header doesn't suppress warnings in tree-cfg

[pcarlini at suse dot de]

Hi, this header (header.h):

#pragma GCC system_header
int noreturn() { }

included by (file.cc):

#include "header.h"
void ok() { }

Leads to:

paolo:~/Work> g++ -Wall -c file.cc
header.h: In function 'int noreturn()':
header.h:2: warning: control reaches end of non-void function

Note, this problem doesn't happen if file.cc is compiled as C, thus the problem
apparently is the C++ front-end not setting TREE_NO_WARNING on the decl or
something similar...


-- 
           Summary: pragma system_header doesn't suppress warnings in tree-
                    cfg
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pcarlini at suse dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] pragma system_header doesn't suppress warnings in tree-cfg

[pcarlini at suse dot de]

------- Comment #1 from pcarlini at suse dot de  2007-06-08 16:53 -------
In fact, the problem is of the same type of that in C++/30500: in C++ only when
execute_warn_function_return begins in_system_header is zero (in C is 1 and all
the warnings are suppressed because diagnostic_report_warnings_p is false)


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.0/4.1/4.2/4.3 regression] pragma system_header doesn't suppress warnings in tree-cfg

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
   Target Milestone|---                         |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.0/4.1/4.2/4.3 regression] pragma system_header doesn't suppress warnings in tree-cfg

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.0/4.1/4.2/4.3 regression] pragma system_header doesn't suppress warnings in tree-cfg

[tromey at gcc dot gnu dot org]

------- Comment #2 from tromey at gcc dot gnu dot org  2007-11-02 20:43 -------
You can reproduce this in C by using -funit-at-a-time.
IMO this is a general bug in unit-at-a-time.

Perhaps cgraph_analyze_function or something similar should set
in_system_header.  Maybe set_cfun.


-- 

tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-11-02 20:43:14
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.0/4.1/4.2/4.3 regression] pragma system_header doesn't suppress warnings in tree-cfg

[pcarlini at suse dot de]

------- Comment #3 from pcarlini at suse dot de  2007-11-02 20:53 -------
Thanks Tom, your help is appreciated. Note we have also c++/32368: shall we
recategorize both as middle-end bugs then?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.0/4.1/4.2/4.3 regression] pragma system_header doesn't suppress warnings in tree-cfg

[tromey at gcc dot gnu dot org]

------- Comment #4 from tromey at gcc dot gnu dot org  2007-11-02 21:02 -------
Recategorizing is fine by me -- though I wouldn't consider my opinion
authoritative :)

FWIW I have a patch to set_cfun that appears to fix both these bugs.
I'll bootstrap and test it and see what people think.


-- 

tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |tromey at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2007-11-02 20:43:14         |2007-11-02 21:02:27
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.0/4.1/4.2/4.3 regression] pragma system_header doesn't suppress warnings in tree-cfg

[pcarlini at suse dot de]

------- Comment #5 from pcarlini at suse dot de  2007-11-02 21:12 -------
Cool. Then maybe recategorizing is now just a waste of time ;)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.0/4.1/4.2/4.3 regression] pragma system_header doesn't suppress warnings in tree-cfg

[tromey at gcc dot gnu dot org]

------- Comment #6 from tromey at gcc dot gnu dot org  2007-11-06 15:57 -------
Subject: Bug 32256

Author: tromey
Date: Tue Nov  6 15:57:02 2007
New Revision: 129936

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=129936
Log:
gcc
        PR c++/32256, PR c++/32368:
        * function.c (saved_in_system_header): New global.
        (push_cfun): Save in_system_header.
        (pop_cfun): Restore in_system_header.
        (push_struct_function): Save in_system_header.
gcc/testsuite
        PR c++/32368:
        * g++.dg/warn/pragma-system_header3.h: New.
        * g++.dg/warn/pragma-system_header3.C: New.

        PR c++/32256:
        * g++.dg/warn/pragma-system_header4.C: New.
        * g++.dg/warn/pragma-system_header4.h: New.

Added:
    trunk/gcc/testsuite/g++.dg/warn/pragma-system_header3.C
    trunk/gcc/testsuite/g++.dg/warn/pragma-system_header3.h
    trunk/gcc/testsuite/g++.dg/warn/pragma-system_header4.C
    trunk/gcc/testsuite/g++.dg/warn/pragma-system_header4.h
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/function.c
    trunk/gcc/testsuite/ChangeLog


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.0/4.1/4.2 regression] pragma system_header doesn't suppress warnings in tree-cfg

[tromey at gcc dot gnu dot org]

------- Comment #7 from tromey at gcc dot gnu dot org  2007-11-06 16:01 -------
Fixed on trunk.


-- 

tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|3.4.4                       |3.4.4 4.3.0
            Summary|[4.0/4.1/4.2/4.3 regression]|[4.0/4.1/4.2 regression]
                   |pragma system_header doesn't|pragma system_header doesn't
                   |suppress warnings in tree-  |suppress warnings in tree-
                   |cfg                         |cfg
   Target Milestone|4.1.3                       |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.0/4.1/4.2 regression] pragma system_header doesn't suppress warnings in tree-cfg

[pcarlini at suse dot de]

------- Comment #8 from pcarlini at suse dot de  2007-11-06 17:24 -------
Thanks a lot, Tom!


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256

[Bug c++/32256] [4.2 Regression] pragma system_header doesn't suppress warnings in tree-cfg

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
      Known to fail|4.0.3                       |4.0.4 4.1.3 4.2.3
            Summary|[4.0/4.1/4.2 regression]    |[4.2 Regression] pragma
                   |pragma system_header doesn't|system_header doesn't
                   |suppress warnings in tree-  |suppress warnings in tree-
                   |cfg                         |cfg
   Target Milestone|4.3.0                       |4.2.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32256