[Bug c/11370] New: -Wunreachable-code gives false complaints

[Bug c/11370] New: -Wunreachable-code gives false complaints

[debian-gcc at lists dot debian dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370

           Summary: -Wunreachable-code gives false complaints
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: debian-gcc at lists dot debian dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i386-linux
  GCC host triplet: i386-linux
GCC target triplet: i386-linux

[forwarded from http://bugs.debian.org/196600]

rechecked with HEAD.

  Gcc complains that a declaration "will never be executed" for a
code path that executes, as shown below.
If I:
 . remove the exit line
 . change "int ix;" to "int ix = 0;"
or
 . move the declaration to line 2 or after line 3
the complaint go away.

$ cat -n test.c
#include <stdio.h>

int main(int argc, char *argv[]) { /* line 3 */
  if (argc != 1) exit(1);

  {
    int ix;                     /* line 7 */
    ix = printf("hello\n");
    printf("%d\n", ix);
  }

  return 0;
}

$ gcc-3.3 -Wunreachable-code test.c; ./a.out 
test.c: In function `main':
test.c:7: warning: will never be executed
hello
6

[Bug c/11370] [3.3/3.4 Regression] -Wunreachable-code gives false complaints

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |diagnostic
   Last reconfirmed|0000-00-00 00:00:00         |2003-06-29 13:39:29
               date|                            |
            Summary|-Wunreachable-code gives    |[3.3/3.4 Regression] -
                   |false complaints            |Wunreachable-code gives
                   |                            |false complaints
   Target Milestone|3.4                         |3.3.1


------- Additional Comments From pinskia at physics dot uc dot edu  2003-06-29 13:39 -------
I can confirm this bug on the mainline (20030629) and in 3.3.1 (20030616).  I also 
happens in 3.2.2 and 3.2.3 but does not in 3.0.4 (2.95.3 does not have the option), so this 
is a regression.
Note this only happens with -march=i386 (with -march=i686 the warning does not 
happen).

[Bug c/11370] [3.3/3.4 Regression] -Wunreachable-code gives false complaints

[roger at eyesopen dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370


roger at eyesopen dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |roger at eyesopen dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED

[Bug c/11370] [3.3/3.4 Regression] -Wunreachable-code gives false complaints

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370



------- Additional Comments From pinskia at physics dot uc dot edu  2003-07-06 14:32 -------
*** Bug 11445 has been marked as a duplicate of this bug. ***

[Bug c/11370] [3.3/3.4 Regression] -Wunreachable-code gives false complaints

[cvs-commit at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370



------- Additional Comments From cvs-commit at gcc dot gnu dot org  2003-07-09 01:17 -------
Subject: Bug 11370

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	sayle@gcc.gnu.org	2003-07-09 01:17:28

Modified files:
	gcc            : ChangeLog calls.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg: Wunreachable-6.c Wunreachable-7.c 

Log message:
	PR c/11370
	* calls.c (emit_call_1): Don't bother popping the arguments off of
	the stack after a noreturn function call;  The adjustment is dead.
	(expand_call): Likewise.
	
	* gcc.dg/Wunreachable-6.c: New testcase.
	* gcc.dg/Wunreachable-7.c: New testcase.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.412&r2=2.413
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/calls.c.diff?cvsroot=gcc&r1=1.284&r2=1.285
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.2852&r2=1.2853
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/Wunreachable-6.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/Wunreachable-7.c.diff?cvsroot=gcc&r1=NONE&r2=1.1

[Bug c/11370] [3.3/3.4 Regression] -Wunreachable-code gives false complaints

[steven at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370


steven at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sayle at gcc dot gnu dot org


------- Additional Comments From steven at gcc dot gnu dot org  2003-07-10 20:58 -------
Roger, does this bug still need fixing somewhere or should it be closed?

[Bug c/11370] [3.3 Regression] -Wunreachable-code gives false complaints

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[3.3/3.4 Regression] -      |[3.3 Regression] -
                   |Wunreachable-code gives     |Wunreachable-code gives
                   |false complaints            |false complaints


------- Additional Comments From pinskia at physics dot uc dot edu  2003-07-11 14:59 -------
This is a 3.3 regression only now. It has been fixed on the mainline.

[Bug c/11370] [3.3 Regression] -Wunreachable-code gives false complaints

[mmitchel at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370


mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.3.1                       |3.3.2


------- Additional Comments From mmitchel at gcc dot gnu dot org  2003-07-11 22:50 -------
Postponed until GCC 3.3.2.

[Bug other/11370] [3.3 Regression] -Wunreachable-code gives false complaints

[cvs-commit at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370



------- Additional Comments From cvs-commit at gcc dot gnu dot org  2003-08-09 03:50 -------
Subject: Bug 11370

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_3-branch
Changes by:	sayle@gcc.gnu.org	2003-08-09 03:50:05

Modified files:
	gcc            : ChangeLog calls.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg: Wunreachable-6.c Wunreachable-7.c 

Log message:
	PR c/11370
	* calls.c (emit_call_1): Don't bother popping the arguments off of
	the stack after a noreturn function call;  The adjustment is dead.
	(expand_call): Likewise.
	
	* gcc.dg/Wunreachable-6.c: New testcase.
	* gcc.dg/Wunreachable-7.c: New testcase.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.16114.2.699&r2=1.16114.2.700
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/calls.c.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.244.2.9&r2=1.244.2.10
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.2261.2.249&r2=1.2261.2.250
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/Wunreachable-6.c.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=NONE&r2=1.1.10.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/Wunreachable-7.c.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=NONE&r2=1.1.10.1

[Bug other/11370] [3.3 Regression] -Wunreachable-code gives false complaints

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370


pinskia at gcc dot gnu dot org changed:

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


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-08-09 03:57 -------
Fixed for 3.3.2.