Slight optimization and cleanup in trace()
* strace.c (trace): Do not recalculate "cflag ? &ru : NULL"
again and again. Do not clear errno unnecessarily.
Consistently check wait errors as pid < 0, not pid == -1.
Indent ifdefs for better readability.
Remove comments after endif if ifdef/endif block is really tiny.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
diff --git a/strace.c b/strace.c
index df10a72..dd179c9 100644
--- a/strace.c
+++ b/strace.c
@@ -2351,9 +2351,10 @@
struct tcb *tcp;
#ifdef LINUX
struct rusage ru;
-#ifdef __WALL
+ struct rusage *rup = cflag ? &ru : NULL;
+# ifdef __WALL
static int wait4_options = __WALL;
-#endif
+# endif
#endif /* LINUX */
while (nprocs != 0) {
@@ -2362,35 +2363,32 @@
if (interactive)
sigprocmask(SIG_SETMASK, &empty_set, NULL);
#ifdef LINUX
-#ifdef __WALL
- pid = wait4(-1, &status, wait4_options, cflag ? &ru : NULL);
+# ifdef __WALL
+ pid = wait4(-1, &status, wait4_options, rup);
if (pid < 0 && (wait4_options & __WALL) && errno == EINVAL) {
/* this kernel does not support __WALL */
wait4_options &= ~__WALL;
- errno = 0;
- pid = wait4(-1, &status, wait4_options,
- cflag ? &ru : NULL);
+ pid = wait4(-1, &status, wait4_options, rup);
}
if (pid < 0 && !(wait4_options & __WALL) && errno == ECHILD) {
/* most likely a "cloned" process */
- pid = wait4(-1, &status, __WCLONE,
- cflag ? &ru : NULL);
- if (pid == -1) {
+ pid = wait4(-1, &status, __WCLONE, rup);
+ if (pid < 0) {
perror_msg("wait4(__WCLONE) failed");
}
}
-#else
- pid = wait4(-1, &status, 0, cflag ? &ru : NULL);
-#endif /* __WALL */
+# else
+ pid = wait4(-1, &status, 0, rup);
+# endif /* __WALL */
#endif /* LINUX */
#ifdef SUNOS4
pid = wait(&status);
-#endif /* SUNOS4 */
+#endif
wait_errno = errno;
if (interactive)
sigprocmask(SIG_BLOCK, &blocked_set, NULL);
- if (pid == -1) {
+ if (pid < 0) {
switch (wait_errno) {
case EINTR:
continue;