allow C code to suppress warnings about ignored return values

2 files changed, 17 insertions, 3 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index aee41f57ac2..a65fc5730df 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,16 @@
+2011-02-03  Paul Eggert  <eggert@cs.ucla.edu>
+
+        allow C code to suppress warnings about ignored return values
+
+        We need to go through the code and for each such warning, either
+        fix the code to pay attention to the returned value, or tell GCC
+        that we really do want to ignore the returned value.  Here is one
+        example of how to do the latter.
+        * sysdep.c: Include <ignore-value.h>.
+        (sys_subshell): Suppress an undesirable warning about not checking
+        the returned value of 'write', as there's nothing useful one can
+        do with that returned value.
+
 2011-02-03  Jan Djärv  <jan.h.d@swipnet.se>
 
         * xterm.c (x_connection_closed): Remove all calls that calls
diff --git a/src/sysdep.c b/src/sysdep.c
index 5f82d2d534c..53b7f39171e 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -31,6 +31,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #endif /* HAVE_LIMITS_H */
 #include <unistd.h>
 
+#include <ignore-value.h>
+
 #include "lisp.h"
 #include "sysselect.h"
 #include "blockinput.h"
@@ -263,7 +265,7 @@ void
 init_baud_rate (int fd)
 {
   int emacs_ospeed;
- 
+
   if (noninteractive)
     emacs_ospeed = 0;
   else
@@ -578,7 +580,7 @@ sys_subshell (void)
         write (1, "Can't execute subshell", 22);
 #else   /* not WINDOWSNT */
       execlp (sh, sh, (char *) 0);
-      write (1, "Can't execute subshell", 22);
+      ignore_value (write (1, "Can't execute subshell", 22));
       _exit (1);
 #endif  /* not WINDOWSNT */
 #endif /* not MSDOS */
@@ -3058,4 +3060,3 @@ system_process_attributes (Lisp_Object pid)
 }
 
 #endif  /* !defined (WINDOWSNT) */
-