[Bug c/30729] New: [4.1/4.2/4.3 Regression] value computed is not used warning with unused result of va_arg

[Bug c/30729] New: [4.1/4.2/4.3 Regression] value computed is not used warning with unused result of va_arg

[pinskia at gcc dot gnu dot org]

#include <stdarg.h>

int f(int t, ...)
{
  va_list a;
  va_start (a, t);
  va_arg(a, int);
  int t1 = va_arg(a, int);
  va_end(a);
  return t1;
}


-----
We get a warning on the line which just contains va_arg(a, int);
Even though the value is not used, a is still incremented so the result is not
unused after all.

t.c:7: warning: value computed is not used


-- 
           Summary: [4.1/4.2/4.3 Regression] value computed is not used
                    warning with unused result of va_arg
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729

[Bug c/30729] [4.1/4.2/4.3 Regression] value computed is not used warning with unused result of va_arg

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729

[Bug c/30729] [4.1/4.2/4.3 Regression] value computed is not used warning with unused result of va_arg

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2007-02-09 22:10 -------
I have a fix, ignore VA_ARG_EXPR in warn_if_unused_value like the rest of the
modify epxressions.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |pinskia at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-02-09 22:10:12
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729

[Bug middle-end/30729] [4.1/4.2/4.3 Regression] value computed is not used warning with unused result of va_arg

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.2                       |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729

[Bug middle-end/30729] [4.1/4.2/4.3 Regression] value computed is not used warning with unused result of va_arg

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2007-02-16 01:19 -------
Subject: Bug 30729

Author: pinskia
Date: Fri Feb 16 01:19:23 2007
New Revision: 122027

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=122027
Log:
2007-02-15  Andrew Pinski  <andrew_pinski@playstation.sony.com>

        PR middle-end/30729
        * stmt.c (warn_if_unused_value): VA_ARG_EXPR has side
        effects unknown to this function, return early.

2007-02-15  Andrew Pinski  <andrew_pinski@playstation.sony.com>

        PR middle-end/30729
        * gcc.dg/Wunused-value-2.c: New testcase.


Added:
    trunk/gcc/testsuite/gcc.dg/Wunused-value-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/stmt.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729

[Bug middle-end/30729] [4.1/4.2 Regression] value computed is not used warning with unused result of va_arg

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2007-02-16 01:20 -------
Fixed on the trunk, will apply to the other branches later.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.1/4.2/4.3 Regression]    |[4.1/4.2 Regression] value
                   |value computed is not used  |computed is not used warning
                   |warning with unused result  |with unused result of va_arg
                   |of va_arg                   |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729

[Bug middle-end/30729] [4.1/4.2 Regression] value computed is not used warning with unused result of va_arg

[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=30729

[Bug middle-end/30729] [4.1/4.2 Regression] value computed is not used warning with unused result of va_arg

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2007-03-09 23:20 -------
Subject: Bug 30729

Author: pinskia
Date: Fri Mar  9 23:20:28 2007
New Revision: 122769

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=122769
Log:
2007-03-09  Andrew Pinski  <andrew_pinski@playstation.sony.com>

        PR middle-end/30729
        * stmt.c (warn_if_unused_value): VA_ARG_EXPR has side
        effects unknown to this function, return early.

2007-03-09  Andrew Pinski  <andrew_pinski@playstation.sony.com>

        PR middle-end/30729
        * gcc.dg/Wunused-value-2.c: New testcase.


Added:
    branches/gcc-4_2-branch/gcc/testsuite/gcc.dg/Wunused-value-2.c
      - copied unchanged from r122027,
trunk/gcc/testsuite/gcc.dg/Wunused-value-2.c
Modified:
    branches/gcc-4_2-branch/gcc/ChangeLog
    branches/gcc-4_2-branch/gcc/stmt.c
    branches/gcc-4_2-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729

[Bug middle-end/30729] [4.1 Regression] value computed is not used warning with unused result of va_arg

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2007-04-15 02:28 -------
Fixed.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729

[Bug middle-end/30729] [4.1 Regression] value computed is not used warning with unused result of va_arg

[pinskia at gcc dot gnu dot org]

------- Comment #6 from pinskia at gcc dot gnu dot org  2007-04-15 02:28 -------
Subject: Bug 30729

Author: pinskia
Date: Sun Apr 15 02:28:09 2007
New Revision: 123840

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=123840
Log:
2007-04-14  Andrew Pinski  <andrew_pinski@playstation.sony.com>

        PR middle-end/30729
        * stmt.c (warn_if_unused_value): VA_ARG_EXPR has side
        effects unknown to this function, return early.

2007-04-14  Andrew Pinski  <andrew_pinski@playstation.sony.com>

        PR middle-end/30729
        * gcc.dg/Wunused-value-2.c: New testcase.



Added:
    branches/gcc-4_1-branch/gcc/testsuite/gcc.dg/Wunused-value-2.c
      - copied unchanged from r122027,
trunk/gcc/testsuite/gcc.dg/Wunused-value-2.c
Modified:
    branches/gcc-4_1-branch/gcc/ChangeLog
    branches/gcc-4_1-branch/gcc/stmt.c
    branches/gcc-4_1-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729