Improve code readability by avoiding assignments inside if()

* desc.c (decode_select): Move assignment out of if() condition.
* file.c (sprinttime): Likewise.
(sys_getdirentries): Likewise.
* io.c (sys_ioctl): Likewise.
* strace.c (test_ptrace_setoptions_followfork): Likewise.
(main): Likewise.
(proc_open): Likewise.
(detach): Likewise.
(proc_poll): Likewise.
(trace): Likewise.
* syscall.c (qualify): Likewise.
(sys_indir): Likewise.
* test/procpollable.c (main): Likewise.
* test/sfd.c (main): Likewise.
* time.c (printtv_bitness): Likewise.
(sprinttv): Likewise.
(print_timespec): Likewise.
(void sprint_timespec): Likewise.
(printitv_bitness): Likewise.
* util.c (dumpstr): Likewise.
(umovestr): Likewise.
(fixvfork): Likewise.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

9 files changed, 78 insertions, 42 deletions

diff --git a/desc.c b/desc.c
index 00bf37b..4276a81 100644
--- a/desc.c
+++ b/desc.c
@@ -538,7 +538,8 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
 		if (syserror(tcp))
 			return 0;
 
-		if ((nfds = tcp->u_rval) == 0) {
+		nfds = tcp->u_rval;
+		if (nfds == 0) {
 			tcp->auxstr = "Timeout";
 			return RVAL_STR;
 		}
diff --git a/file.c b/file.c
index 38bf976..5d5a0fe 100644
--- a/file.c
+++ b/file.c
@@ -738,7 +738,8 @@ sprinttime(time_t t)
 		strcpy(buf, "0");
 		return buf;
 	}
-	if ((tmp = localtime(&t)))
+	tmp = localtime(&t);
+	if (tmp)
 		snprintf(buf, sizeof buf, "%02d/%02d/%02d-%02d:%02d:%02d",
 			tmp->tm_year + 1900, tmp->tm_mon + 1, tmp->tm_mday,
 			tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
@@ -2590,7 +2591,8 @@ sys_getdirentries(struct tcb *tcp)
 		return 0;
 	}
 	len = tcp->u_rval;
-	if ((buf = malloc(len)) == NULL) {
+	buf = malloc(len);
+	if (buf == NULL) {
 		tprintf("%#lx, %lu, %#lx", tcp->u_arg[1], tcp->u_arg[2], tcp->u_arg[3]);
 		fprintf(stderr, "out of memory\n");
 		return 0;
diff --git a/io.c b/io.c
index 7f2f243..e3cad66 100644
--- a/io.c
+++ b/io.c
@@ -434,8 +434,8 @@ sys_ioctl(struct tcb *tcp)
 		ioctl_decode(tcp, tcp->u_arg[1], tcp->u_arg[2]);
 	}
 	else {
-		int ret;
-		if (!(ret = ioctl_decode(tcp, tcp->u_arg[1], tcp->u_arg[2])))
+		int ret = ioctl_decode(tcp, tcp->u_arg[1], tcp->u_arg[2]);
+		if (!ret)
 			tprintf(", %#lx", tcp->u_arg[2]);
 		else
 			return ret - 1;
diff --git a/strace.c b/strace.c
index bfa9a0d..84bcddb 100644
--- a/strace.c
+++ b/strace.c
@@ -744,9 +744,10 @@ test_ptrace_setoptions_followfork(void)
 					  PTRACE_O_TRACEFORK |
 					  PTRACE_O_TRACEVFORK;
 
-	if ((pid = fork()) < 0)
+	pid = fork();
+	if (pid < 0)
 		perror_msg_and_die("fork");
-	else if (pid == 0) {
+	if (pid == 0) {
 		pid = getpid();
 		if (ptrace(PTRACE_TRACEME, 0, 0, 0) < 0)
 			perror_msg_and_die("%s: PTRACE_TRACEME doesn't work",
@@ -1043,7 +1044,8 @@ main(int argc, char *argv[])
 			set_overhead(atoi(optarg));
 			break;
 		case 'p':
-			if ((pid = atoi(optarg)) <= 0) {
+			pid = atoi(optarg);
+			if (pid <= 0) {
 				error_msg("Invalid process id: '%s'", optarg);
 				break;
 			}
@@ -1105,7 +1107,8 @@ main(int argc, char *argv[])
 		if (getuid() != 0 || geteuid() != 0) {
 			error_msg_and_die("You must be root to use the -u option");
 		}
-		if ((pent = getpwnam(username)) == NULL) {
+		pent = getpwnam(username);
+		if (pent == NULL) {
 			error_msg_and_die("Cannot find user '%s'", username);
 		}
 		run_uid = pent->pw_uid;
@@ -1284,19 +1287,22 @@ proc_open(struct tcb *tcp, int attaching)
 #ifdef HAVE_MP_PROCFS
 	/* Open the process pseudo-files in /proc. */
 	sprintf(proc, "/proc/%d/ctl", tcp->pid);
-	if ((tcp->pfd = open(proc, O_WRONLY|O_EXCL)) < 0) {
+	tcp->pfd = open(proc, O_WRONLY|O_EXCL);
+	if (tcp->pfd < 0) {
 		perror("strace: open(\"/proc/...\", ...)");
 		return -1;
 	}
 	set_cloexec_flag(tcp->pfd);
 	sprintf(proc, "/proc/%d/status", tcp->pid);
-	if ((tcp->pfd_stat = open(proc, O_RDONLY|O_EXCL)) < 0) {
+	tcp->pfd_stat = open(proc, O_RDONLY|O_EXCL);
+	if (tcp->pfd_stat < 0) {
 		perror("strace: open(\"/proc/...\", ...)");
 		return -1;
 	}
 	set_cloexec_flag(tcp->pfd_stat);
 	sprintf(proc, "/proc/%d/as", tcp->pid);
-	if ((tcp->pfd_as = open(proc, O_RDONLY|O_EXCL)) < 0) {
+	tcp->pfd_as = open(proc, O_RDONLY|O_EXCL);
+	if (tcp->pfd_as < 0) {
 		perror("strace: open(\"/proc/...\", ...)");
 		return -1;
 	}
@@ -1318,13 +1324,15 @@ proc_open(struct tcb *tcp, int attaching)
 #endif
 #ifdef FREEBSD
 	sprintf(proc, "/proc/%d/regs", tcp->pid);
-	if ((tcp->pfd_reg = open(proc, O_RDONLY)) < 0) {
+	tcp->pfd_reg = open(proc, O_RDONLY);
+	if (tcp->pfd_reg < 0) {
 		perror("strace: open(\"/proc/.../regs\", ...)");
 		return -1;
 	}
 	if (cflag) {
 		sprintf(proc, "/proc/%d/status", tcp->pid);
-		if ((tcp->pfd_status = open(proc, O_RDONLY)) < 0) {
+		tcp->pfd_status = open(proc, O_RDONLY);
+		if (tcp->pfd_status < 0) {
 			perror("strace: open(\"/proc/.../status\", ...)");
 			return -1;
 		}
@@ -1662,7 +1670,8 @@ detach(struct tcb *tcp, int sig)
 	 * detached process would be left stopped (process state T).
 	 */
 	catch_sigstop = (tcp->flags & TCB_STARTUP);
-	if ((error = ptrace(PTRACE_DETACH, tcp->pid, (char *) 1, sig)) == 0) {
+	error = ptrace(PTRACE_DETACH, tcp->pid, (char *) 1, sig);
+	if (error == 0) {
 		/* On a clear day, you can see forever. */
 	}
 	else if (errno != ESRCH) {
@@ -1887,7 +1896,8 @@ proc_poll(struct pollfd *pollv, int nfds, int timeout)
 	int n;
 	struct proc_pollfd pollinfo;
 
-	if ((n = read(proc_poll_pipe[0], &pollinfo, sizeof(pollinfo))) < 0)
+	n = read(proc_poll_pipe[0], &pollinfo, sizeof(pollinfo));
+	if (n < 0)
 		return n;
 	if (n != sizeof(struct proc_pollfd)) {
 		error_msg_and_die("panic: short read: %d", n);
@@ -2072,7 +2082,8 @@ trace(void)
 				in_syscall = NULL;
 				pv.fd = tcp->pfd;
 				pv.events = POLLWANT;
-				if ((what = poll(&pv, 1, 1)) < 0) {
+				what = poll(&pv, 1, 1);
+				if (what < 0) {
 					if (interrupted)
 						return 0;
 					continue;
@@ -2102,7 +2113,8 @@ trace(void)
 		}
 
 		/* Look up `pfd' in our table. */
-		if ((tcp = pfd2tcb(pfd)) == NULL) {
+		tcp = pfd2tcb(pfd);
+		if (tcp == NULL) {
 			error_msg_and_die("unknown pfd: %u", pfd);
 		}
 #ifdef POLL_HACK
@@ -2175,7 +2187,8 @@ trace(void)
 			char buf[1024];
 			int len;
 
-			if ((len = pread(tcp->pfd_status, buf, sizeof(buf) - 1, 0)) > 0) {
+			len = pread(tcp->pfd_status, buf, sizeof(buf) - 1, 0);
+			if (len > 0) {
 				buf[len] = '\0';
 				sscanf(buf,
 				       "%*s %*d %*d %*d %*d %*d,%*d %*s %*d,%*d %*d,%*d %ld,%ld",
@@ -2374,7 +2387,8 @@ trace()
 		}
 
 		/* Look up `pid' in our table. */
-		if ((tcp = pid2tcb(pid)) == NULL) {
+		tcp = pid2tcb(pid);
+		if (tcp == NULL) {
 #ifdef LINUX
 			if (followfork) {
 				/* This is needed to go with the CLONE_PTRACE
diff --git a/syscall.c b/syscall.c
index e22e391..cbe9f12 100644
--- a/syscall.c
+++ b/syscall.c
@@ -470,7 +470,8 @@ qualify(const char *s)
 	for (i = 0; i < MAX_QUALS; i++) {
 		qualify_one(i, opt->bitflag, !not, -1);
 	}
-	if (!(copy = strdup(s))) {
+	copy = strdup(s);
+	if (!copy) {
 		fprintf(stderr, "out of memory\n");
 		exit(1);
 	}
@@ -2775,7 +2776,8 @@ sys_indir(struct tcb *tcp)
 	int i, scno, nargs;
 
 	if (entering(tcp)) {
-		if ((scno = tcp->u_arg[0]) > nsyscalls) {
+		scno = tcp->u_arg[0];
+		if (scno > nsyscalls) {
 			fprintf(stderr, "Bogus syscall: %u\n", scno);
 			return 0;
 		}
diff --git a/test/procpollable.c b/test/procpollable.c
index a841af1..7bc5efa 100644
--- a/test/procpollable.c
+++ b/test/procpollable.c
@@ -12,14 +12,16 @@ int main(int argc, char *argv[])
 	FILE *pfp;
 	struct pollfd pfd;
 
-	if ((pid = fork()) == 0) {
+	pid = fork();
+	if (pid == 0) {
 		pause();
 		exit(0);
 	}
 
 	sprintf(proc, "/proc/%d", pid);
 
-	if ((pfp = fopen(proc, "r+")) == NULL)
+	pfp = fopen(proc, "r+");
+	if (pfp == NULL)
 		goto fail;
 
 	if (ioctl(fileno(pfp), PIOCSTOP, NULL) < 0)
diff --git a/test/sfd.c b/test/sfd.c
index b5ff847..815da80 100644
--- a/test/sfd.c
+++ b/test/sfd.c
@@ -13,7 +13,8 @@ int main(int argc, char *argv[])
 
 	sprintf(sname, "/proc/%d/stat", pid);
 
-	if ((sfd = open(sname, O_RDONLY)) == -1) {
+	sfd = open(sname, O_RDONLY);
+	if (sfd == -1) {
 		perror(sname);
 		return 1;
 	}
diff --git a/time.c b/time.c
index 257d04b..a4599f7 100644
--- a/time.c
+++ b/time.c
@@ -81,7 +81,8 @@ printtv_bitness(struct tcb *tcp, long addr, enum bitness_t bitness, int special)
 		{
 			struct timeval32 tv;
 
-			if ((rc = umove(tcp, addr, &tv)) >= 0) {
+			rc = umove(tcp, addr, &tv);
+			if (rc >= 0) {
 				if (special && tv.tv_sec == 0 &&
 				    tv.tv_usec == UTIME_NOW)
 					tprintf("UTIME_NOW");
@@ -94,7 +95,8 @@ printtv_bitness(struct tcb *tcp, long addr, enum bitness_t bitness, int special)
 		} else {
 			struct timeval tv;
 
-			if ((rc = umove(tcp, addr, &tv)) >= 0) {
+			rc = umove(tcp, addr, &tv);
+			if (rc >= 0) {
 				if (special && tv.tv_sec == 0 &&
 				    tv.tv_usec == UTIME_NOW)
 					tprintf("UTIME_NOW");
@@ -128,13 +130,15 @@ sprinttv(struct tcb *tcp, long addr, enum bitness_t bitness, char *buf)
 		{
 			struct timeval32 tv;
 
-			if ((rc = umove(tcp, addr, &tv)) >= 0)
+			rc = umove(tcp, addr, &tv);
+			if (rc >= 0)
 				sprintf(buf, "{%u, %u}",
 					tv.tv_sec, tv.tv_usec);
 		} else {
 			struct timeval tv;
 
-			if ((rc = umove(tcp, addr, &tv)) >= 0)
+			rc = umove(tcp, addr, &tv);
+			if (rc >= 0)
 				sprintf(buf, "{%lu, %lu}",
 					(unsigned long) tv.tv_sec,
 					(unsigned long) tv.tv_usec);
@@ -157,7 +161,8 @@ void print_timespec(struct tcb *tcp, long addr)
 		if (personality_wordsize[current_personality] == 4) {
 			struct timeval32 tv;
 
-			if ((rc = umove(tcp, addr, &tv)) >= 0)
+			rc = umove(tcp, addr, &tv);
+			if (rc >= 0)
 				tprintf("{%u, %u}",
 					tv.tv_sec, tv.tv_usec);
 		} else
@@ -165,7 +170,8 @@ void print_timespec(struct tcb *tcp, long addr)
 		{
 			struct timespec ts;
 
-			if ((rc = umove(tcp, addr, &ts)) >= 0)
+			rc = umove(tcp, addr, &ts);
+			if (rc >= 0)
 				tprintf("{%lu, %lu}",
 					(unsigned long) ts.tv_sec,
 					(unsigned long) ts.tv_nsec);
@@ -188,7 +194,8 @@ void sprint_timespec(char *buf, struct tcb *tcp, long addr)
 		if (personality_wordsize[current_personality] == 4) {
 			struct timeval32 tv;
 
-			if ((rc = umove(tcp, addr, &tv)) >= 0)
+			rc = umove(tcp, addr, &tv);
+			if (rc >= 0)
 				sprintf(buf, "{%u, %u}",
 					tv.tv_sec, tv.tv_usec);
 		} else
@@ -196,7 +203,8 @@ void sprint_timespec(char *buf, struct tcb *tcp, long addr)
 		{
 			struct timespec ts;
 
-			if ((rc = umove(tcp, addr, &ts)) >= 0)
+			rc = umove(tcp, addr, &ts);
+			if (rc >= 0)
 				sprintf(buf, "{%lu, %lu}",
 					(unsigned long) ts.tv_sec,
 					(unsigned long) ts.tv_nsec);
@@ -349,7 +357,8 @@ printitv_bitness(struct tcb *tcp, long addr, enum bitness_t bitness)
 				struct timeval32 it_interval, it_value;
 			} itv;
 
-			if ((rc = umove(tcp, addr, &itv)) >= 0) {
+			rc = umove(tcp, addr, &itv);
+			if (rc >= 0) {
 				tprintf("{it_interval=");
 				tprint_timeval32(tcp, &itv.it_interval);
 				tprintf(", it_value=");
@@ -359,7 +368,8 @@ printitv_bitness(struct tcb *tcp, long addr, enum bitness_t bitness)
 		} else {
 			struct itimerval itv;
 
-			if ((rc = umove(tcp, addr, &itv)) >= 0) {
+			rc = umove(tcp, addr, &itv);
+			if (rc >= 0) {
 				tprintf("{it_interval=");
 				tprint_timeval(tcp, &itv.it_interval);
 				tprintf(", it_value=");
diff --git a/util.c b/util.c
index bfa2856..9ccc5c9 100644
--- a/util.c
+++ b/util.c
@@ -687,9 +687,9 @@ dumpstr(struct tcb *tcp, long addr, int len)
 	int i, j;
 
 	if (strsize < len) {
-		if (str)
-			free(str);
-		if ((str = malloc(len)) == NULL) {
+		free(str);
+		str = malloc(len);
+		if (str == NULL) {
 			fprintf(stderr, "out of memory\n");
 			return;
 		}
@@ -848,10 +848,13 @@ umovestr(struct tcb *tcp, long addr, int len, char *laddr)
 	lseek(fd, addr, SEEK_SET);
 
 	while (left) {
-		if (move > left) move = left;
-		if ((move = read(fd, laddr, move)) <= 0)
+		if (move > left)
+			move = left;
+		move = read(fd, laddr, move);
+		if (move <= 0)
 			return left != len ? 0 : -1;
-		if (memchr(laddr, 0, move)) break;
+		if (memchr(laddr, 0, move))
+			break;
 		left -= move;
 		laddr += move;
 		addr += move;
@@ -1703,7 +1706,8 @@ fixvfork(struct tcb *tcp)
 		fprintf(stderr, "Cannot read link_dynamic_2\n");
 		return -1;
 	}
-	if ((strtab = malloc((unsigned)ld.ld_symb_size)) == NULL) {
+	strtab = malloc((unsigned)ld.ld_symb_size);
+	if (strtab == NULL) {
 		fprintf(stderr, "out of memory\n");
 		return -1;
 	}