[Bug c/36708] New: syntatic warning

[Bug c/36708] New: syntatic warning

[robert dot lore at opensyscon dot com dot au]

I think this code is syntactically correct, but can cause problems in
debugging. If you don't scrutinize the code too carefully you can waste time
here - code was a cut and paste from strcpy to integer assignment with
resultant comma not changed to assignment.

 // this code does nothing !
 f -> font_size, current_font_size;

 // this code does something
 f -> font_size= current_font_size;

should this produce a warning like "statement does nothing" ? its like an
unused variable warning, it is a courtesy thing..


-- 
           Summary: syntatic warning
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: trivial
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: robert dot lore at opensyscon dot com dot au
 GCC build triplet: same
  GCC host triplet: x86 linux (redhat) gcc
GCC target triplet: same


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36708

[Bug c/36708] syntatic warning

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2008-07-03 02:50 -------
-Wunused-value should warn about this ...


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36708

[Bug c/36708] syntatic warning

[manu at gcc dot gnu dot org]

------- Comment #2 from manu at gcc dot gnu dot org  2008-07-21 16:16 -------
We need a complete testcase. I tried to reproduce this but GCC 4.4 with -Wall
-Wextra -Wunused always says:

src/pr36708.c:5: warning: left-hand operand of comma expression has no effect
src/pr36708.c:5: warning: statement with no effect

So this may be already fixed or your testcase is special. What flags are you
using?


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manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |manu at gcc dot gnu dot org
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36708

[Bug c/36708] syntatic warning

[robert dot lore at opensyscon dot com dot au]

------- Comment #3 from robert dot lore at opensyscon dot com dot au  2008-07-22 05:56 -------
Subject: RE:  syntatic warning

I did not have the flags you nominated set.
Thanks for you assistance
Robert

-----Original Message-----
From: manu at gcc dot gnu dot org [mailto:gcc-bugzilla@gcc.gnu.org] 
Sent: Tuesday, 22 July 2008 2:17 AM
To: robert.lore@opensyscon.com.au
Subject: [Bug c/36708] syntatic warning



------- Comment #2 from manu at gcc dot gnu dot org  2008-07-21 16:16
-------
We need a complete testcase. I tried to reproduce this but GCC 4.4 with
-Wall
-Wextra -Wunused always says:

src/pr36708.c:5: warning: left-hand operand of comma expression has no
effect
src/pr36708.c:5: warning: statement with no effect

So this may be already fixed or your testcase is special. What flags are you
using?


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |manu at gcc dot gnu dot org
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36708

------- You are receiving this mail because: -------
You reported the bug, or are watching the reporter.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36708

[Bug c/36708] syntatic warning

[manu at gcc dot gnu dot org]

------- Comment #4 from manu at gcc dot gnu dot org  2008-07-22 07:20 -------
Closing as invalid then.


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36708