depmod: generate "new-style" modules.dep with relative paths.

function                                             old     new   delta
parse_module                                         384     379      -5
depmod_main                                          590     559     -31
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-36)             Total: -36 bytes

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

modutils/depmod.c

@@ -28,16 +28,6 @@ typedef struct module_info {
 	struct module_info *dnext, *dprev;
 } module_info;
 
-enum {
-	ARG_a = (1<<0), /* All modules, ignore mods in argv */
-	ARG_A = (1<<1), /* Only emit .ko that are newer than modules.dep file */
-	ARG_b = (1<<2), /* base directory when modules are in staging area */
-	ARG_e = (1<<3), /* with -F, print unresolved symbols */
-	ARG_F = (1<<4), /* System.map that contains the symbols */
-	ARG_n = (1<<5), /* dry-run, print to stdout only */
-	ARG_r = (1<<6)  /* Compat dummy. Linux Makefile uses it */
-};
-
 static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARAM,
 				  void *data, int depth UNUSED_PARAM)
 {
@@ -58,7 +48,7 @@ static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARA
 	*first = info;
 
 	info->dnext = info->dprev = info;
-	info->name = xasprintf("/%s", fname);
+	info->name = xstrdup(fname + 2); /* skip "./" */
 	info->modname = xstrdup(filename2modname(fname, modname));
 	for (ptr = image; ptr < image + len - 10; ptr++) {
 		if (strncmp(ptr, "depends=", 8) == 0) {
@@ -134,10 +124,44 @@ static void xfreopen_write(const char *file, FILE *f)
 		bb_perror_msg_and_die("can't open '%s'", file);
 }
 
+/* Usage:
+ * [-aAenv] [-C FILE or DIR] [-b BASE] [-F System.map] [VERSION] [MODFILES]...
+ *	-a --all
+ *		Probe all modules. Default if no MODFILES.
+ *	-A --quick
+ *		Check modules.dep's mtime against module files' mtimes.
+ *	-b --basedir BASE
+ *		Use $BASE/lib/modules/VERSION
+ *	-C --config FILE or DIR
+ *		Path to /etc/depmod.conf or /etc/depmod.d/
+ *	-e --errsyms
+ *		When combined with the -F option, this reports any symbols which
+ *		which are not supplied by other modules or kernel.
+ *	-F --filesyms System.map
+ *	-n --dry-run
+ *		Print modules.dep etc to standard output
+ *	-v --verbose
+ *		Print to stdout all the symbols each module depends on
+ *		and the module's file name which provides that symbol.
+ *	-r	No-op
+ *
+ * So far we only support: [-rn] [-b BASE] [VERSION] [MODFILES]...
+ * -aAeF are accepted but ignored. -vC are not accepted.
+ */
+enum {
+	//OPT_a = (1 << 0), /* All modules, ignore mods in argv */
+	//OPT_A = (1 << 1), /* Only emit .ko that are newer than modules.dep file */
+	OPT_b = (1 << 2), /* base directory when modules are in staging area */
+	//OPT_e = (1 << 3), /* with -F, print unresolved symbols */
+	//OPT_F = (1 << 4), /* System.map that contains the symbols */
+	OPT_n = (1 << 5), /* dry-run, print to stdout only */
+	OPT_r = (1 << 6)  /* Compat dummy. Linux Makefile uses it */
+};
+
 int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int depmod_main(int argc UNUSED_PARAM, char **argv)
 {
-	module_info *modules = NULL, *m, *dep;
+	module_info *modules, *m, *dep;
 	const char *moddir_base = "/";
 	char *moddir, *version;
 	struct utsname uts;
@@ -152,36 +176,30 @@ int depmod_main(int argc UNUSED_PARAM, char **argv)
 	/* If a version is provided, then that kernel version's module directory
 	 * is used, rather than the current kernel version (as returned by
 	 * "uname -r").  */
-	if (*argv && sscanf(*argv, "%d.%d.%d", &tmp, &tmp, &tmp) == 3) {
+	if (*argv && sscanf(*argv, "%u.%u.%u", &tmp, &tmp, &tmp) == 3) {
 		version = *argv++;
 	} else {
 		uname(&uts);
 		version = uts.release;
 	}
 	moddir = concat_path_file(&CONFIG_DEFAULT_MODULES_DIR[1], version);
-
-	/* Scan modules */
-	if (*argv) {
-		char *modfile;
-		struct stat sb;
-		do {
-			modfile = concat_path_file(moddir, *argv);
-			xstat(modfile, &sb);
-			parse_module(modfile, &sb, &modules, 0);
-			free(modfile);
-		} while (*(++argv));
-	} else {
-		recursive_action(moddir, ACTION_RECURSE,
-				 parse_module, NULL, &modules, 0);
-	}
-
-	/* Prepare for writing out the dep files */
 	xchdir(moddir);
 	if (ENABLE_FEATURE_CLEAN_UP)
 		free(moddir);
 
+	/* Scan modules */
+	modules = NULL;
+	if (*argv) {
+		do {
+			parse_module(*argv, /*sb (unused):*/ NULL, &modules, 0);
+		} while (*++argv);
+	} else {
+		recursive_action(".", ACTION_RECURSE,
+				 parse_module, NULL, &modules, 0);
+	}
+
 	/* Generate dependency and alias files */
-	if (!(option_mask32 & ARG_n))
+	if (!(option_mask32 & OPT_n))
 		xfreopen_write(CONFIG_DEFAULT_DEPMOD_FILE, stdout);
 	for (m = modules; m != NULL; m = m->next) {
 		printf("%s:", m->name);
@@ -200,7 +218,7 @@ int depmod_main(int argc UNUSED_PARAM, char **argv)
 	}
 
 #if ENABLE_FEATURE_MODUTILS_ALIAS
-	if (!(option_mask32 & ARG_n))
+	if (!(option_mask32 & OPT_n))
 		xfreopen_write("modules.alias", stdout);
 	for (m = modules; m != NULL; m = m->next) {
 		const char *fname = bb_basename(m->name);
@@ -218,7 +236,7 @@ int depmod_main(int argc UNUSED_PARAM, char **argv)
 	}
 #endif
 #if ENABLE_FEATURE_MODUTILS_SYMBOLS
-	if (!(option_mask32 & ARG_n))
+	if (!(option_mask32 & OPT_n))
 		xfreopen_write("modules.symbols", stdout);
 	for (m = modules; m != NULL; m = m->next) {
 		const char *fname = bb_basename(m->name);