linux: turn on -Wextra

This is a followup to an earlier change (r38266) which did most of the
warning-related cleanup.  This one just flips the flag, and fixes some
new warnings that crept in during the window while the flag was off.

BUG=34160

Review URL: http://codereview.chromium.org/597023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@42688 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 16 insertions, 14 deletions

diff --git a/sandbox/linux/suid/linux_util.c b/sandbox/linux/suid/linux_util.c
index ded545b..c5af0d0 100644
--- a/sandbox/linux/suid/linux_util.c
+++ b/sandbox/linux/suid/linux_util.c
@@ -83,8 +83,9 @@ bool FindProcessHoldingSocket(pid_t* pid_out, ino_t socket_inode) {
       continue;
 
     while ((dent = readdir(fd))) {
-      if (snprintf(buf, sizeof(buf), "/proc/%lu/fd/%s", pid_ul,
-                   dent->d_name) >= sizeof(buf) - 1) {
+      int printed = snprintf(buf, sizeof(buf), "/proc/%lu/fd/%s", pid_ul,
+                             dent->d_name);
+      if (printed < 0 || printed >= (int)(sizeof(buf) - 1)) {
         continue;
       }
 
diff --git a/sandbox/linux/suid/process_util_linux.c b/sandbox/linux/suid/process_util_linux.c
index 9f40f39..7b31274 100644
--- a/sandbox/linux/suid/process_util_linux.c
+++ b/sandbox/linux/suid/process_util_linux.c
@@ -38,7 +38,7 @@ bool AdjustOOMScore(pid_t process, int score) {
 
   char buf[3];  // 0 <= |score| <= 15;
   snprintf(buf, sizeof(buf), "%d", score);
-  size_t len = strlen(buf);
+  ssize_t len = strlen(buf);
 
   ssize_t bytes_written = write(fd, buf, len);
   close(fd);
diff --git a/sandbox/linux/suid/sandbox.c b/sandbox/linux/suid/sandbox.c
index e4968c9..7389f03 100644
--- a/sandbox/linux/suid/sandbox.c
+++ b/sandbox/linux/suid/sandbox.c
@@ -90,13 +90,13 @@ static int CloneChrootHelperProcess() {
   char tempDirectoryTemplate[80] = "/tmp/chrome-sandbox-chroot-XXXXXX";
   struct statfs sfs;
   if (!statfs("/tmp", &sfs) &&
-      sfs.f_type != BTRFS_SUPER_MAGIC &&
-      sfs.f_type != EXT2_SUPER_MAGIC &&
-      sfs.f_type != EXT3_SUPER_MAGIC &&
-      sfs.f_type != EXT4_SUPER_MAGIC &&
-      sfs.f_type != REISERFS_SUPER_MAGIC &&
-      sfs.f_type != TMPFS_MAGIC &&
-      sfs.f_type != XFS_SUPER_MAGIC) {
+      (unsigned long)sfs.f_type != BTRFS_SUPER_MAGIC &&
+      (unsigned long)sfs.f_type != EXT2_SUPER_MAGIC &&
+      (unsigned long)sfs.f_type != EXT3_SUPER_MAGIC &&
+      (unsigned long)sfs.f_type != EXT4_SUPER_MAGIC &&
+      (unsigned long)sfs.f_type != REISERFS_SUPER_MAGIC &&
+      (unsigned long)sfs.f_type != TMPFS_MAGIC &&
+      (unsigned long)sfs.f_type != XFS_SUPER_MAGIC) {
     // If /dev/shm exists, it is supposed to be a tmpfs filesystem. While we
     // are not actually using it for shared memory, moving our temp directory
     // into a known tmpfs filesystem is preferable over using a potentially
@@ -137,7 +137,7 @@ static int CloneChrootHelperProcess() {
   char proc_self_fd_str[128];
   int printed = snprintf(proc_self_fd_str, sizeof(proc_self_fd_str),
                          "/proc/self/fd/%d", chroot_dir_fd);
-  if (printed < 0 || printed >= sizeof(proc_self_fd_str)) {
+  if (printed < 0 || printed >= (int)sizeof(proc_self_fd_str)) {
     fprintf(stderr, "Error in snprintf");
     return -1;
   }
@@ -246,7 +246,7 @@ static bool SpawnChrootHelper() {
   // number of the file descriptor.
   char desc_str[64];
   int printed = snprintf(desc_str, sizeof(desc_str), "%d", chroot_signal_fd);
-  if (printed < 0 || printed >= sizeof(desc_str)) {
+  if (printed < 0 || printed >= (int)sizeof(desc_str)) {
     fprintf(stderr, "Failed to snprintf\n");
     return false;
   }
@@ -379,9 +379,10 @@ int main(int argc, char **argv) {
   if (argc == 4 && (0 == strcmp(argv[1], kAdjustOOMScoreSwitch))) {
     char* endptr;
     long score;
-    pid_t pid = strtoul(argv[2], &endptr, 10);
-    if (pid == ULONG_MAX || *endptr)
+    unsigned long pid_ul = strtoul(argv[2], &endptr, 10);
+    if (pid_ul == ULONG_MAX || *endptr)
       return 1;
+    pid_t pid = pid_ul;
     score = strtol(argv[3], &endptr, 10);
     if (score == LONG_MAX || score == LONG_MIN || *endptr)
       return 1;