[git commit] syslogd,logger: code shrink for musl

Denys Vlasenko vda.linux at googlemail.com
Wed Aug 16 13:05:36 UTC 2017


commit: https://git.busybox.net/busybox/commit/?id=cf686ae3b401c68b64ff997b68b7972881dbf80e
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

function                                             old     new   delta
syslogd_main                                        1252    1910    +658
logger_main                                          277     393    +116
timestamp_and_log                                    434     542    +108
static.__compound_literal                              -     104    +104
parse_fac_prio_20                                    137       -    -137
pencode                                              167       -    -167
parse_syslogdcfg                                     715       -    -715
------------------------------------------------------------------------------
(add/remove: 1/3 grow/shrink: 3/0 up/down: 986/-1019)         Total: -33 bytes
   text	   data	    bss	    dec	    hex	filename
 912506	    563	   6132	 919201	  e06a1	busybox_old
 912364	    563	   6132	 919059	  e0613	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 sysklogd/logger.c             |  4 ++--
 sysklogd/syslogd.c            |  8 ++++----
 sysklogd/syslogd_and_logger.c | 11 +++++++++++
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/sysklogd/logger.c b/sysklogd/logger.c
index 359ac3a..1e0384c 100644
--- a/sysklogd/logger.c
+++ b/sysklogd/logger.c
@@ -77,14 +77,14 @@ static int pencode(char *s)
 		;
 	if (*s) {
 		*s = '\0';
-		fac = decode(save, facilitynames);
+		fac = decode(save, bb_facilitynames);
 		if (fac < 0)
 			bb_error_msg_and_die("unknown %s name: %s", "facility", save);
 		*s++ = '.';
 	} else {
 		s = save;
 	}
-	lev = decode(s, prioritynames);
+	lev = decode(s, bb_prioritynames);
 	if (lev < 0)
 		bb_error_msg_and_die("unknown %s name: %s", "priority", save);
 	return ((lev & LOG_PRIMASK) | (fac & LOG_FACMASK));
diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index 2b85234..4265f4f 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -447,7 +447,7 @@ static void parse_syslogdcfg(const char *file)
 				primap = 0xff; /* all 8 log levels enabled */
 			else {
 				uint8_t priority;
-				code = find_by_name(t, prioritynames);
+				code = find_by_name(t, bb_prioritynames);
 				if (!code)
 					goto cfgerr;
 				primap = 0;
@@ -480,7 +480,7 @@ static void parse_syslogdcfg(const char *file)
 					next_facility = strchr(t, ',');
 					if (next_facility)
 						*next_facility++ = '\0';
-					code = find_by_name(t, facilitynames);
+					code = find_by_name(t, bb_facilitynames);
 					if (!code)
 						goto cfgerr;
 					/* "mark" is not a real facility, skip it */
@@ -797,9 +797,9 @@ static void parse_fac_prio_20(int pri, char *res20)
 {
 	const CODE *c_pri, *c_fac;
 
-	c_fac = find_by_val(LOG_FAC(pri) << 3, facilitynames);
+	c_fac = find_by_val(LOG_FAC(pri) << 3, bb_facilitynames);
 	if (c_fac) {
-		c_pri = find_by_val(LOG_PRI(pri), prioritynames);
+		c_pri = find_by_val(LOG_PRI(pri), bb_prioritynames);
 		if (c_pri) {
 			snprintf(res20, 20, "%s.%s", c_fac->c_name, c_pri->c_name);
 			return;
diff --git a/sysklogd/syslogd_and_logger.c b/sysklogd/syslogd_and_logger.c
index 6458a93..6d06a71 100644
--- a/sysklogd/syslogd_and_logger.c
+++ b/sysklogd/syslogd_and_logger.c
@@ -43,6 +43,17 @@ typedef struct _code {
  */
 #endif
 
+/* musl decided to be funny and it implements these as giant defines
+ * of the form: ((CODE *)(const CODE []){ ... })
+ * Which works, but causes _every_ function using them
+ * to have a copy on stack (at least with gcc-6.3.0).
+ * If we reference them just once, this saves 150 bytes.
+ * The pointers themselves are optimized out
+ * (no size change on uclibc).
+ */
+static const CODE *const bb_prioritynames = prioritynames;
+static const CODE *const bb_facilitynames = facilitynames;
+
 #if ENABLE_SYSLOGD
 #include "syslogd.c"
 #endif


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