Ignore return values harder

In various places where we intentionally ignore the return values of system
calls and standard library routines, this changes the way in which we do so,
to avoid compiler warnings when building on Ubuntu 12.10, with gcc 4.7.2 and
eglibc 2.15-0ubuntu20.1.

Change-Id: I41f806a686d68b02aec2847886bd5d787cbff3d3
Reviewed-on: http://gerrit.openafs.org/9980
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>

diff --git a/src/aklog/aklog.c b/src/aklog/aklog.c
index f7b13132041c2a9e80191f74ce5a7d6fe0412f1b..c098d8424afcd09299a61556b8a710d328095651 100644 (file)
--- a/src/aklog/aklog.c
+++ b/src/aklog/aklog.c
@@ -1094,8 +1094,11 @@ auth_to_cell(krb5_context context, const char *config,
         * this routine, it will not add the token. It is not clear what
         * is going on here! So we will do the following operation.
         * On AIX 5, it causes the parent program to die, so we won't.
+        * We don't care about the return value, but need to collect it
+        * to avoid compiler warnings.
         */
-       write(2,"",0); /* dummy write */
+       if (write(2,"",0) < 0) /* dummy write */
+           ; /* don't care */
 #endif
        token_setPag(token, afssetpag);
        status = ktc_SetTokenEx(token);

diff --git a/src/butm/file_tm.c b/src/butm/file_tm.c
index d53dd4c4faaa2bdee7281aa0d13360773b0dad82..d25da70472bf98cf21522646e60776cbbeaa7cbe 100644 (file)
--- a/src/butm/file_tm.c
+++ b/src/butm/file_tm.c
@@ -204,8 +204,13 @@ ForkIoctl(usd_handle_t fd, int op, int count)
        /* do the ioctl call */
        ioctl_rc = USD_IOCTL(fd, USD_IOCTL_TAPEOPERATION, (void *)&tapeop);
 
-       /* send the return code back to the parent */
-       write(pipefd[1], &ioctl_rc, sizeof(int));
+       /*
+        * Send the return code back to the parent.
+        * If this fails, there's nothing we can do, but we must test
+        * it in order to avoid complier warnings on some platforms.
+        */
+       if (write(pipefd[1], &ioctl_rc, sizeof(int)) < 0)
+           ; /* don't care */
 
        exit(0);
     } else {                   /* parent process */
@@ -327,8 +332,13 @@ ForkOpen(char *device)
            USD_CLOSE(fd);
        }
 
-       /* send the return code back to the parent */
-       write(pipefd[1], &open_rc, sizeof(open_rc));
+       /*
+        * Send the return code back to the parent.
+        * If this fails, there's nothing we can do, but we must test
+        * it in order to avoid complier warnings on some platforms.
+        */
+       if (write(pipefd[1], &open_rc, sizeof(open_rc)) < 0)
+           ; /* don't care */
 
        exit(0);
     } else {                   /* parent process */
@@ -452,15 +462,26 @@ ForkClose(usd_handle_t fd)
            }
        }
 
-       /* the parent writes the control pipe after it closes the device */
-       read(ctlpipe[0], &close_rc, sizeof(int));
+       /*
+        * The parent writes the control pipe after it closes the device.
+        * We don't actually care about the read; we're just using it to
+        * block until the parent is ready.  But we must do something
+        * with the result, to avoid complier warnings on some platforms.
+        */
+       if (read(ctlpipe[0], &close_rc, sizeof(int)) < 0)
+           ; /* don't care */
        close(ctlpipe[0]);
 
        /* do the close */
        close_rc = USD_CLOSE(fd);
 
-       /* send the return code back to the parent */
-       write(pipefd[1], &close_rc, sizeof(int));
+       /*
+        * Send the return code back to the parent.
+        * If this fails, there's nothing we can do, but we must test
+        * it in order to avoid complier warnings on some platforms.
+        */
+       if (write(pipefd[1], &close_rc, sizeof(int)) < 0)
+           ; /* don't care */
 
        exit(0);
     } else {                   /* parent process */

diff --git a/src/rx/rx_trace.c b/src/rx/rx_trace.c
index d60e92896b0719ea53109e0e65173f2a9007d91a..94dc117140e3851dd1d746fb3abf2ab54bd2b8f2 100644 (file)
--- a/src/rx/rx_trace.c
+++ b/src/rx/rx_trace.c
@@ -55,9 +55,13 @@ struct rx_trace {
 void
 rxi_flushtrace(void)
 {
-    if (rxi_logfd >= 0)
-       write(rxi_logfd, rxi_tracebuf, rxi_tracepos);
+    afs_uint32 len = rxi_tracepos;
+
     rxi_tracepos = 0;
+    if (rxi_logfd < 0)
+       return;
+    if (write(rxi_logfd, rxi_tracebuf, len) < 0)
+       ; /* don't care */
 }
 
 void

diff --git a/src/util/serverLog.c b/src/util/serverLog.c
index 877f488f8bd37fbc46d7315d1ace22e269478a4b..64f081d6e7c1111288c3d60ec2f9804b8408d239 100644 (file)
--- a/src/util/serverLog.c
+++ b/src/util/serverLog.c
@@ -81,8 +81,10 @@ void
 WriteLogBuffer(char *buf, afs_uint32 len)
 {
     LOCK_SERVERLOG();
-    if (serverLogFD > 0)
-       (void)write(serverLogFD, buf, len);
+    if (serverLogFD > 0) {
+       if (write(serverLogFD, buf, len) < 0)
+           ; /* don't care */
+    }
     UNLOCK_SERVERLOG();
 }
 
@@ -125,8 +127,10 @@ vFSLog(const char *format, va_list args)
        syslog(LOG_INFO, "%s", info);
     } else
 #endif
-    if (serverLogFD > 0)
-       (void)write(serverLogFD, tbuffer, len);
+    if (serverLogFD > 0) {
+       if (write(serverLogFD, tbuffer, len) < 0)
+           ; /* don't care */
+    }
     UNLOCK_SERVERLOG();
 
 #if !defined(AFS_PTHREAD_ENV) && !defined(AFS_NT40_ENV)
@@ -340,13 +344,15 @@ OpenLog(const char *fileName)
        return -1;
     }
     /* redirect stdout and stderr so random printf's don't write to data */
-    (void)freopen(fileName, "a", stdout);
-    (void)freopen(fileName, "a", stderr);
+    if (freopen(fileName, "a", stdout) == NULL)
+       ; /* don't care */
+    if (freopen(fileName, "a", stderr) != NULL) {
 #ifdef HAVE_SETVBUF
-    setvbuf(stderr, NULL, _IONBF, 0);
+       setvbuf(stderr, NULL, _IONBF, 0);
 #else
-    setbuf(stderr, NULL);
+       setbuf(stderr, NULL);
 #endif
+    }
 
 #if defined(AFS_PTHREAD_ENV)
     opr_Verify(pthread_mutex_init(&serverLogMutex, NULL) == 0);
@@ -384,17 +390,19 @@ ReOpenLog(const char *fileName)
        close(serverLogFD);
     serverLogFD = open(fileName, O_WRONLY | O_APPEND | O_CREAT | (isfifo?O_NONBLOCK:0), 0666);
     if (serverLogFD > 0) {
-       (void)freopen(fileName, "a", stdout);
-       (void)freopen(fileName, "a", stderr);
+       if (freopen(fileName, "a", stdout) == NULL)
+           ; /* don't care */
+       if (freopen(fileName, "a", stderr) != NULL) {
 #ifdef HAVE_SETVBUF
 #ifdef SETVBUF_REVERSED
-       setvbuf(stderr, _IONBF, NULL, 0);
+           setvbuf(stderr, _IONBF, NULL, 0);
 #else
-       setvbuf(stderr, NULL, _IONBF, 0);
+           setvbuf(stderr, NULL, _IONBF, 0);
 #endif
 #else
-       setbuf(stderr, NULL);
+           setbuf(stderr, NULL);
 #endif
+       }
 
     }
     UNLOCK_SERVERLOG();

diff --git a/src/viced/viced.c b/src/viced/viced.c
index 7cc7aaad1995a9c0daaa6694cefb209d4b6a7a76..e529f69afd42b69f97378ebd8d90c98b8851ea39 100644 (file)
--- a/src/viced/viced.c
+++ b/src/viced/viced.c
@@ -1912,7 +1912,8 @@ main(int argc, char *argv[])
     if (SawLock)
        plock(PROCLOCK);
 #elif !defined(AFS_NT40_ENV)
-    nice(-5);                  /* TODO: */
+    if (nice(-5) < 0)
+       ; /* don't care */
 #endif
     DInit(buffs);
 #ifdef AFS_DEMAND_ATTACH_FS

diff --git a/src/vol/vol-salvage.c b/src/vol/vol-salvage.c
index 547a5ca7558ab6aefa73567a622cdae2e2033f5b..f961d9c57212781b3de87ccc1ae0fea4e7cd5122 100644 (file)
--- a/src/vol/vol-salvage.c
+++ b/src/vol/vol-salvage.c
@@ -4874,7 +4874,8 @@ TimeStampLogFile(char * log_path)
 
     /* try to link the logfile to a timestamped filename */
     /* if it fails, oh well, nothing we can do */
-    link(log_path, stampSlvgLog);
+    if (link(log_path, stampSlvgLog))
+       ; /* oh well */
 }
 #endif
 

diff --git a/src/volser/vsprocs.c b/src/volser/vsprocs.c
index ac7fcf487b2ea7027a7faae155dd8f1ca914eeca..2735f78d93363621c1bb9b6cb1632db9201f629c 100644 (file)
--- a/src/volser/vsprocs.c
+++ b/src/volser/vsprocs.c
@@ -1562,8 +1562,10 @@ UV_MoveVolume2(afs_uint32 afromvol, afs_uint32 afromserver, afs_int32 afrompart,
        fprintf(STDOUT, "First test point - operation not started.\n");
        fprintf(STDOUT, "...test here (y, n)? ");
        fflush(STDOUT);
-       fscanf(stdin, "%c", &in);
-       fscanf(stdin, "%c", &lf);       /* toss away */
+       if (fscanf(stdin, "%c", &in) < 1)
+           in = 0;
+       if (fscanf(stdin, "%c", &lf) < 0)       /* toss away */
+           ; /* don't care */
        if (in == 'y') {
            fprintf(STDOUT, "type control-c\n");
            while (1) {
@@ -1918,8 +1920,10 @@ UV_MoveVolume2(afs_uint32 afromvol, afs_uint32 afromserver, afs_int32 afrompart,
                "Second test point - operation in progress but not complete.\n");
        fprintf(STDOUT, "...test here (y, n)? ");
        fflush(STDOUT);
-       fscanf(stdin, "%c", &in);
-       fscanf(stdin, "%c", &lf);       /* toss away */
+       if (fscanf(stdin, "%c", &in) < 1)
+           in = 0;
+       if (fscanf(stdin, "%c", &lf) < 0)       /* toss away */
+           ; /* don't care */
        if (in == 'y') {
            fprintf(STDOUT, "type control-c\n");
            while (1) {
@@ -1951,8 +1955,10 @@ UV_MoveVolume2(afs_uint32 afromvol, afs_uint32 afromserver, afs_int32 afrompart,
                "Third test point - operation complete but no cleanup.\n");
        fprintf(STDOUT, "...test here (y, n)? ");
        fflush(STDOUT);
-       fscanf(stdin, "%c", &in);
-       fscanf(stdin, "%c", &lf);       /* toss away */
+       if (fscanf(stdin, "%c", &in) < 1)
+           in = 0;
+       if (fscanf(stdin, "%c", &lf) < 0)       /* toss away */
+           ; /* don't care */
        if (in == 'y') {
            fprintf(STDOUT, "type control-c\n");
            while (1) {
@@ -2034,8 +2040,10 @@ UV_MoveVolume2(afs_uint32 afromvol, afs_uint32 afromserver, afs_int32 afrompart,
        fprintf(STDOUT, "Fourth test point - operation complete.\n");
        fprintf(STDOUT, "...test here (y, n)? ");
        fflush(STDOUT);
-       fscanf(stdin, "%c", &in);
-       fscanf(stdin, "%c", &lf);       /* toss away */
+       if (fscanf(stdin, "%c", &in) < 1)
+           in = 0;
+       if (fscanf(stdin, "%c", &lf) < 0)       /* toss away */
+           ; /* don't care */
        if (in == 'y') {
            fprintf(STDOUT, "type control-c\n");
            while (1) {