Further optimize applet tables; prettify build output

text    data     bss     dec     hex filename
 775923     929    9100  785952   bfe20 busybox_old
 775565     929    9100  785594   bfcba busybox_unstripped

applets/Kbuild

@@ -14,20 +14,20 @@ always:= $(hostprogs-y)
 
 # Generated files need additional love
 
-quiet_cmd_gen_usage_compressed = GEN     include/usage_compressed.h
-      cmd_gen_usage_compressed = $(srctree)/applets/usage_compressed include/usage_compressed.h applets
-
 HOSTCFLAGS_usage.o = -I$(srctree)/include
 
-applets/applets.o:          include/usage_compressed.h include/applet_tables.h
+applets/applets.o: include/usage_compressed.h include/applet_tables.h
 
-applets/usage:              .config $(srctree)/applets/usage_compressed
+applets/usage:     .config $(srctree)/applets/usage_compressed
+
+quiet_cmd_gen_usage_compressed = GEN     include/usage_compressed.h
+      cmd_gen_usage_compressed = $(srctree)/applets/usage_compressed include/usage_compressed.h applets
 
 include/usage_compressed.h: applets/usage $(srctree)/applets/usage_compressed
 	$(call cmd,gen_usage_compressed)
 
-# Two-stage file creation, to avoid having target file still created
+quiet_cmd_gen_applet_tables = GEN     include/applet_tables.h
-# in case applet_tables fails
+      cmd_gen_applet_tables = applets/applet_tables include/applet_tables.h
+
 include/applet_tables.h: applets/applet_tables
-	applets/applet_tables >include/applet_tables.h.tmp
+	$(call cmd,gen_applet_tables)
-	mv include/applet_tables.h.tmp include/applet_tables.h

applets/applet_tables.c

@@ -50,45 +50,66 @@ int main(int argc, char **argv)
 
 	qsort(applets, NUM_APPLETS, sizeof(applets[0]), cmp_name);
 
-	/* Keep in sync with include/busybox.h! */
-
-	puts("const char applet_names[] ALIGN1 =");
 	ofs = 0;
-	i = 0;
 	for (i = 0; i < NUM_APPLETS; i++) {
 		offset[i] = ofs;
 		ofs += strlen(applets[i].name) + 1;
+	}
+	/* We reuse 4 high-order bits of offset array for other purposes,
+	 * so if they are indeed needed, refuse to proceed */
+	if (ofs > 0xfff)
+		return 1;
+	if (!argv[1])
+		return 1;
+
+	i = open(argv[1], O_WRONLY | O_TRUNC | O_CREAT, 0666);
+	if (i < 0)
+		return 1;
+	dup2(i, 1);		
+
+	/* Keep in sync with include/busybox.h! */
+
+	puts("/* This is a generated file, don't edit */");
+
+	puts("const char applet_names[] ALIGN1 =");
+	for (i = 0; i < NUM_APPLETS; i++) {
 		printf("\"%s\" \"\\0\"\n", applets[i].name);
 	}
 	puts(";");
 
-	puts("int (*const applet_mains[])(int argc, char **argv) = {");
+	puts("int (*const applet_main[])(int argc, char **argv) = {");
 	for (i = 0; i < NUM_APPLETS; i++) {
 		printf("%s_main,\n", applets[i].main);
 	}
 	puts("};");
 
-#if ENABLE_FEATURE_INSTALLER || ENABLE_FEATURE_PREFER_APPLETS
-	puts("const uint32_t applet_nameofs[] = {");
-#else
 	puts("const uint16_t applet_nameofs[] ALIGN2 = {");
-#endif
 	for (i = 0; i < NUM_APPLETS; i++) {
-		printf("0x%08x,\n",
+		printf("0x%04x,\n",
 			offset[i]
+#if ENABLE_FEATURE_PREFER_APPLETS
+			+ (applets[i].nofork << 12)
+			+ (applets[i].noexec << 13)
+#endif
 #if ENABLE_FEATURE_SUID
 			+ (applets[i].need_suid   << 14) /* 2 bits */
-#endif
-#if ENABLE_FEATURE_INSTALLER
-			+ (applets[i].install_loc << 16) /* 3 bits */
-#endif
-#if ENABLE_FEATURE_PREFER_APPLETS
-			+ (applets[i].nofork << 19)
-			+ (applets[i].noexec << 20)
 #endif
 		);
 	}
 	puts("};");
 
+#if ENABLE_FEATURE_INSTALLER
+	puts("const uint8_t applet_install_loc[] ALIGN1 = {");
+	i = 0;
+	while (i < NUM_APPLETS) {
+		int v = applets[i].install_loc; /* 3 bits */
+		if (++i < NUM_APPLETS)
+			v |= applets[i].install_loc << 4; /* 3 bits */
+		printf("0x%02x,\n", v);
+		i++;
+	}
+	puts("};");
+#endif
+
 	return 0;
 }

include/busybox.h

@@ -28,28 +28,31 @@ typedef enum bb_suid_t {
 /* Defined in appletlib.c (by including generated applet_tables.h) */
 /* Keep in sync with applets/applet_tables.c! */
 extern const char applet_names[];
-extern int (*const applet_mains[])(int argc, char **argv);
+extern int (*const applet_main[])(int argc, char **argv);
-
-#if ENABLE_FEATURE_INSTALLER || ENABLE_FEATURE_PREFER_APPLETS
-extern const uint32_t applet_nameofs[];
-#else
 extern const uint16_t applet_nameofs[];
-#endif
+extern const uint8_t applet_install_loc[];
 
-#if ENABLE_FEATURE_SUID
+#if ENABLE_FEATURE_SUID || ENABLE_FEATURE_PREFER_APPLETS
-#define APPLET_NAME(i) (applet_names + (applet_nameofs[i] & 0x3fff))
+#define APPLET_NAME(i) (applet_names + (applet_nameofs[i] & 0x0fff))
-#define APPLET_SUID(i) ((applet_nameofs[i] >> 14) & 0x3)
 #else
-#define APPLET_NAME(i) (applet_names + (applet_nameofs[i] & 0xffff))
+#define APPLET_NAME(i) (applet_names + applet_nameofs[i])
-#endif
-
-#if ENABLE_FEATURE_INSTALLER
-#define APPLET_INSTALL_LOC(i) ((applet_nameofs[i] >> 16) & 0x7)
 #endif
 
 #if ENABLE_FEATURE_PREFER_APPLETS
-#define APPLET_IS_NOFORK(i) (applet_nameofs[i] & (1 << 19))
+#define APPLET_IS_NOFORK(i) (applet_nameofs[i] & (1 << 12))
-#define APPLET_IS_NOEXEC(i) (applet_nameofs[i] & (1 << 20))
+#define APPLET_IS_NOEXEC(i) (applet_nameofs[i] & (1 << 13))
+#endif
+
+#if ENABLE_FEATURE_SUID
+#define APPLET_SUID(i) ((applet_nameofs[i] >> 14) & 0x3)
+#endif
+
+#if ENABLE_FEATURE_INSTALLER
+#define APPLET_INSTALL_LOC(i) ({ \
+	unsigned v = (i); \
+	if (v & 1) v = applet_install_loc[v/2] >> 4; \
+	else v = applet_install_loc[v/2] & 0xf; \
+	v; })
 #endif
 
 

libbb/appletlib.c

@@ -101,19 +101,17 @@ void bb_show_usage(void)
 }
 
 
+/* NB: any char pointer will work as well, not necessarily applet_names */
 static int applet_name_compare(const void *name, const void *v)
 {
 	int i = (const char *)v - applet_names;
 	return strcmp(name, APPLET_NAME(i));
 }
-
 int find_applet_by_name(const char *name)
 {
-	const char *p;
 	/* Do a binary search to find the applet entry given the name. */
-
+	const char *p;
-	/* NB: any char pointer will work as well, not necessarily applet_names */
+	p = bsearch(name, applet_names, ARRAY_SIZE(applet_main), 1, applet_name_compare);
-	p = bsearch(name, applet_names, ARRAY_SIZE(applet_mains), 1, applet_name_compare);
 	if (!p)
 		return -1;
 	return p - applet_names;
@@ -543,10 +541,12 @@ static void install_links(const char *busybox, int use_symbolic_links)
 	if (use_symbolic_links)
 		lf = symlink;
 
-	for (i = 0; i < ARRAY_SIZE(applet_mains); i++) {
+	for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
 		fpc = concat_path_file(
 				install_dir[APPLET_INSTALL_LOC(i)],
 				APPLET_NAME(i));
+		// debug: bb_error_msg("%slinking %s to busybox",
+		//		use_symbolic_links ? "sym" : "", fpc);
 		rc = lf(busybox, fpc);
 		if (rc != 0 && errno != EEXIST) {
 			bb_simple_perror_msg(fpc);
@@ -644,7 +644,7 @@ void run_applet_no_and_exit(int applet_no, char **argv)
 		bb_show_usage();
 	if (ENABLE_FEATURE_SUID)
 		check_suid(applet_no);
-	exit(applet_mains[applet_no](argc, argv));
+	exit(applet_main[applet_no](argc, argv));
 }
 
 void run_applet_and_exit(const char *name, char **argv)

libbb/vfork_daemon_rexec.c

@@ -143,7 +143,7 @@ int run_nofork_applet_prime(struct nofork_save_area *old, int applet_no, char **
 		char *tmp_argv[argc+1];
 		memcpy(tmp_argv, argv, (argc+1) * sizeof(tmp_argv[0]));
 		/* Finally we can call NOFORK applet's main() */
-		rc = applet_mains[applet_no](argc, tmp_argv);
+		rc = applet_main[applet_no](argc, tmp_argv);
 	} else { /* xfunc died in NOFORK applet */
 		/* in case they meant to return 0... */
 		if (rc == -2222)