From: Denys Vlasenko <vda.linux@googlemail.com>
Date: Tue, 24 Jan 2012 10:37:03 +0000 (+0100)
Subject: Slightly more compact handling of argv[]
X-Git-Tag: v4.7~198
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=837399af4ffefec55f9693022dc6d8608da442cf;p=strace

Slightly more compact handling of argv[]

   text	   data	    bss	    dec	    hex	filename
 238274	    672	  20484	 259430	  3f566	strace.before
 238226	    672	  20484	 259382	  3f536	strace

* strace.c (main): Slightly more compact handling of argv[]

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---

diff --git a/strace.c b/strace.c
index 835003ef..745294dd 100644
--- a/strace.c
+++ b/strace.c
@@ -1119,6 +1119,8 @@ main(int argc, char *argv[])
 			break;
 		}
 	}
+	argv += optind;
+	/* argc -= optind; - no need, argc is not used below */
 
 	acolumn_spaces = malloc(acolumn + 1);
 	if (!acolumn_spaces)
@@ -1126,7 +1128,8 @@ main(int argc, char *argv[])
 	memset(acolumn_spaces, ' ', acolumn);
 	acolumn_spaces[acolumn] = '\0';
 
-	if ((optind == argc) == !pflag_seen)
+	/* Must have PROG [ARGS], or -p PID. Not both. */
+	if (!argv[0] == !pflag_seen)
 		usage(stderr, 1);
 
 	if (pflag_seen && daemonized_tracer) {
@@ -1187,25 +1190,25 @@ main(int argc, char *argv[])
 			die_out_of_memory();
 		setvbuf(outf, buf, _IOLBF, BUFSIZ);
 	}
-	if (outfname && optind < argc) {
+	if (outfname && argv[0]) {
 		interactive = 0;
 		qflag = 1;
 	}
 
 	/* Valid states here:
-	   optind < argc	pflag_seen	outfname	interactive
-	   1			0		0		1
-	   0			1		0		1
-	   1			0		1		0
-	   0			1		1		1
+	   argv[0]	pflag_seen	outfname	interactive
+	   yes		0		0		1
+	   no		1		0		1
+	   yes		0		1		0
+	   no		1		1		1
 	 */
 
 	/* STARTUP_CHILD must be called before the signal handlers get
 	   installed below as they are inherited into the spawned process.
 	   Also we do not need to be protected by them as during interruption
 	   in the STARTUP_CHILD mode we kill the spawned process anyway.  */
-	if (!pflag_seen)
-		startup_child(&argv[optind]);
+	if (argv[0])
+		startup_child(argv);
 
 	sigemptyset(&empty_set);
 	sigemptyset(&blocked_set);
@@ -1214,6 +1217,10 @@ main(int argc, char *argv[])
 	sa.sa_flags = 0;
 	sigaction(SIGTTOU, &sa, NULL);
 	sigaction(SIGTTIN, &sa, NULL);
+	/* In interactive mode (if no -o OUTFILE, or -p PID is used),
+	 * fatal signals are blocked across syscall waits, and acted on
+	 * in between. In non-interactive mode, signals are ignored.
+	 */
 	if (interactive) {
 		sigaddset(&blocked_set, SIGHUP);
 		sigaddset(&blocked_set, SIGINT);