1 files changed, 233 insertions, 255 deletions

diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
index 078fe1d64e7d..cdd5da7e009b 100644
--- a/scripts/basic/fixdep.c
+++ b/scripts/basic/fixdep.c
@@ -25,7 +25,7 @@
  *
  * So we play the same trick that "mkdep" played before. We replace
  * the dependency on autoconf.h by a dependency on every config
- * option which is mentioned in any of the listed prequisites.
+ * option which is mentioned in any of the listed prerequisites.
  *
  * kconfig populates a tree in include/config/ with an empty file
  * for each config symbol and when the configuration is updated
@@ -34,7 +34,7 @@
  * the config symbols are rebuilt.
  *
  * So if the user changes his CONFIG_HIS_DRIVER option, only the objects
- * which depend on "include/linux/config/his/driver.h" will be rebuilt,
+ * which depend on "include/config/HIS_DRIVER" will be rebuilt,
  * so most likely only his driver ;-)
  *
  * The idea above dates, by the way, back to Michael E Chastain, AFAIK.
@@ -70,20 +70,14 @@
  *
  * It first generates a line
  *
- *   cmd_<target> = <cmdline>
+ *   savedcmd_<target> = <cmdline>
  *
  * and then basically copies the .<target>.d file to stdout, in the
  * process filtering out the dependency on autoconf.h and adding
- * dependencies on include/config/my/option.h for every
- * CONFIG_MY_OPTION encountered in any of the prequisites.
+ * dependencies on include/config/MY_OPTION for every
+ * CONFIG_MY_OPTION encountered in any of the prerequisites.
  *
- * It will also filter out all the dependencies on *.ver. We need
- * to make sure that the generated version checksum are globally up
- * to date before even starting the recursive build, so it's too late
- * at this point anyway.
- *
- * The algorithm to grep for "CONFIG_..." is bit unusual, but should
- * be fast ;-) We don't even try to really parse the header files, but
+ * We don't even try to really parse the header files, but
  * merely grep, i.e. if CONFIG_FOO is mentioned in a comment, it will
  * be picked up as well. It's not a problem with respect to
  * correctness, since that can only give too many dependencies, thus
@@ -94,35 +88,18 @@
  * (Note: it'd be easy to port over the complete mkdep state machine,
  *  but I don't think the added complexity is worth it)
  */
-/*
- * Note 2: if somebody writes HELLO_CONFIG_BOOM in a file, it will depend onto
- * CONFIG_BOOM. This could seem a bug (not too hard to fix), but please do not
- * fix it! Some UserModeLinux files (look at arch/um/) call CONFIG_BOOM as
- * UML_CONFIG_BOOM, to avoid conflicts with /usr/include/linux/autoconf.h,
- * through arch/um/include/uml-config.h; this fixdep "bug" makes sure that
- * those files will have correct dependencies.
- */
 
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <sys/mman.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <string.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
-#include <limits.h>
 #include <ctype.h>
-#include <arpa/inet.h>
-
-#define INT_CONF ntohl(0x434f4e46)
-#define INT_ONFI ntohl(0x4f4e4649)
-#define INT_NFIG ntohl(0x4e464947)
-#define INT_FIG_ ntohl(0x4649475f)
 
-char *target;
-char *depfile;
-char *cmdline;
+#include <xalloc.h>
 
 static void usage(void)
 {
@@ -130,23 +107,15 @@ static void usage(void)
 	exit(1);
 }
 
-/*
- * Print out the commandline prefixed with cmd_<target filename> :=
- */
-static void print_cmdline(void)
-{
-	printf("cmd_%s := %s\n\n", target, cmdline);
-}
-
 struct item {
 	struct item	*next;
 	unsigned int	len;
 	unsigned int	hash;
-	char		name[0];
+	char		name[];
 };
 
 #define HASHSZ 256
-static struct item *hashtab[HASHSZ];
+static struct item *config_hashtab[HASHSZ], *file_hashtab[HASHSZ];
 
 static unsigned int strhash(const char *str, unsigned int sz)
 {
@@ -159,31 +128,14 @@ static unsigned int strhash(const char *str, unsigned int sz)
 }
 
 /*
- * Lookup a value in the configuration string.
- */
-static int is_defined_config(const char *name, int len, unsigned int hash)
-{
-	struct item *aux;
-
-	for (aux = hashtab[hash % HASHSZ]; aux; aux = aux->next) {
-		if (aux->hash == hash && aux->len == len &&
-		    memcmp(aux->name, name, len) == 0)
-			return 1;
-	}
-	return 0;
-}
-
-/*
  * Add a new value to the configuration string.
  */
-static void define_config(const char *name, int len, unsigned int hash)
+static void add_to_hashtable(const char *name, int len, unsigned int hash,
+			     struct item *hashtab[])
 {
-	struct item *aux = malloc(sizeof(*aux) + len);
+	struct item *aux;
 
-	if (!aux) {
-		perror("fixdep:malloc");
-		exit(1);
-	}
+	aux = xmalloc(sizeof(*aux) + len);
 	memcpy(aux->name, name, len);
 	aux->len = len;
 	aux->hash = hash;
@@ -192,20 +144,23 @@ static void define_config(const char *name, int len, unsigned int hash)
 }
 
 /*
- * Clear the set of configuration strings.
+ * Lookup a string in the hash table. If found, just return true.
+ * If not, add it to the hashtable and return false.
  */
-static void clear_config(void)
+static bool in_hashtable(const char *name, int len, struct item *hashtab[])
 {
-	struct item *aux, *next;
-	unsigned int i;
+	struct item *aux;
+	unsigned int hash = strhash(name, len);
 
-	for (i = 0; i < HASHSZ; i++) {
-		for (aux = hashtab[i]; aux; aux = next) {
-			next = aux->next;
-			free(aux);
-		}
-		hashtab[i] = NULL;
+	for (aux = hashtab[hash % HASHSZ]; aux; aux = aux->next) {
+		if (aux->hash == hash && aux->len == len &&
+		    memcmp(aux->name, name, len) == 0)
+			return true;
 	}
+
+	add_to_hashtable(name, len, hash, hashtab);
+
+	return false;
 }
 
 /*
@@ -213,100 +168,89 @@ static void clear_config(void)
  */
 static void use_config(const char *m, int slen)
 {
-	unsigned int hash = strhash(m, slen);
-	int c, i;
-
-	if (is_defined_config(m, slen, hash))
-	    return;
-
-	define_config(m, slen, hash);
+	if (in_hashtable(m, slen, config_hashtab))
+		return;
 
-	printf("    $(wildcard include/config/");
-	for (i = 0; i < slen; i++) {
-		c = m[i];
-		if (c == '_')
-			c = '/';
-		else
-			c = tolower(c);
-		putchar(c);
-	}
-	printf(".h) \\\n");
+	/* Print out a dependency path from a symbol name. */
+	printf("    $(wildcard include/config/%.*s) \\\n", slen, m);
 }
 
-static void parse_config_file(const char *map, size_t len)
+/* test if s ends in sub */
+static int str_ends_with(const char *s, int slen, const char *sub)
 {
-	const int *end = (const int *) (map + len);
-	/* start at +1, so that p can never be < map */
-	const int *m   = (const int *) map + 1;
-	const char *p, *q;
-
-	for (; m < end; m++) {
-		if (*m == INT_CONF) { p = (char *) m  ; goto conf; }
-		if (*m == INT_ONFI) { p = (char *) m-1; goto conf; }
-		if (*m == INT_NFIG) { p = (char *) m-2; goto conf; }
-		if (*m == INT_FIG_) { p = (char *) m-3; goto conf; }
-		continue;
-	conf:
-		if (p > map + len - 7)
-			continue;
-		if (memcmp(p, "CONFIG_", 7))
-			continue;
-		for (q = p + 7; q < map + len; q++) {
-			if (!(isalnum(*q) || *q == '_'))
-				goto found;
-		}
-		continue;
+	int sublen = strlen(sub);
 
-	found:
-		if (!memcmp(q - 7, "_MODULE", 7))
-			q -= 7;
-		if( (q-p-7) < 0 )
-			continue;
-		use_config(p+7, q-p-7);
-	}
+	if (sublen > slen)
+		return 0;
+
+	return !memcmp(s + slen - sublen, sub, sublen);
 }
 
-/* test is s ends in sub */
-static int strrcmp(char *s, char *sub)
+static void parse_config_file(const char *p)
 {
-	int slen = strlen(s);
-	int sublen = strlen(sub);
-
-	if (sublen > slen)
-		return 1;
+	const char *q, *r;
+	const char *start = p;
 
-	return memcmp(s + slen - sublen, sub, sublen);
+	while ((p = strstr(p, "CONFIG_"))) {
+		if (p > start && (isalnum(p[-1]) || p[-1] == '_')) {
+			p += 7;
+			continue;
+		}
+		p += 7;
+		q = p;
+		while (isalnum(*q) || *q == '_')
+			q++;
+		if (str_ends_with(p, q - p, "_MODULE"))
+			r = q - 7;
+		else
+			r = q;
+		if (r > p)
+			use_config(p, r - p);
+		p = q;
+	}
 }
 
-static void do_config_file(const char *filename)
+static void *read_file(const char *filename)
 {
 	struct stat st;
 	int fd;
-	void *map;
+	char *buf;
 
 	fd = open(filename, O_RDONLY);
 	if (fd < 0) {
-		fprintf(stderr, "fixdep: error opening config file: ");
+		fprintf(stderr, "fixdep: error opening file: ");
 		perror(filename);
 		exit(2);
 	}
-	fstat(fd, &st);
-	if (st.st_size == 0) {
-		close(fd);
-		return;
+	if (fstat(fd, &st) < 0) {
+		fprintf(stderr, "fixdep: error fstat'ing file: ");
+		perror(filename);
+		exit(2);
 	}
-	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
-	if ((long) map == -1) {
-		perror("fixdep: mmap");
-		close(fd);
-		return;
+	buf = xmalloc(st.st_size + 1);
+	if (read(fd, buf, st.st_size) != st.st_size) {
+		perror("fixdep: read");
+		exit(2);
 	}
+	buf[st.st_size] = '\0';
+	close(fd);
 
-	parse_config_file(map, st.st_size);
+	return buf;
+}
 
-	munmap(map, st.st_size);
+/* Ignore certain dependencies */
+static int is_ignored_file(const char *s, int len)
+{
+	return str_ends_with(s, len, "include/generated/autoconf.h");
+}
 
-	close(fd);
+/* Do not parse these files */
+static int is_no_parse_file(const char *s, int len)
+{
+	/* rustc may list binary files in dep-info */
+	return str_ends_with(s, len, ".rlib") ||
+	       str_ends_with(s, len, ".rmeta") ||
+	       str_ends_with(s, len, ".so");
 }
 
 /*
@@ -314,77 +258,144 @@ static void do_config_file(const char *filename)
  * assignments are parsed not only by make, but also by the rather simple
  * parser in scripts/mod/sumversion.c.
  */
-static void parse_dep_file(void *map, size_t len)
+static void parse_dep_file(char *p, const char *target)
 {
-	char *m = map;
-	char *end = m + len;
-	char *p;
-	char s[PATH_MAX];
-	int is_target;
-	int saw_any_target = 0;
-	int is_first_dep = 0;
-
-	clear_config();
-
-	while (m < end) {
-		/* Skip any "white space" */
-		while (m < end && (*m == ' ' || *m == '\\' || *m == '\n'))
-			m++;
-		/* Find next "white space" */
-		p = m;
-		while (p < end && *p != ' ' && *p != '\\' && *p != '\n')
+	bool saw_any_target = false;
+	bool is_target = true;
+	bool is_source = false;
+	bool need_parse;
+	char *q, saved_c;
+
+	while (*p) {
+		/* handle some special characters first. */
+		switch (*p) {
+		case '#':
+			/*
+			 * skip comments.
+			 * rustc may emit comments to dep-info.
+			 */
 			p++;
-		/* Is the token we found a target name? */
-		is_target = (*(p-1) == ':');
-		/* Don't write any target names into the dependency file */
-		if (is_target) {
-			/* The /next/ file is the first dependency */
-			is_first_dep = 1;
-		} else {
-			/* Save this token/filename */
-			memcpy(s, m, p-m);
-			s[p - m] = 0;
-
-			/* Ignore certain dependencies */
-			if (strrcmp(s, "include/generated/autoconf.h") &&
-			    strrcmp(s, "arch/um/include/uml-config.h") &&
-			    strrcmp(s, "include/linux/kconfig.h") &&
-			    strrcmp(s, ".ver")) {
+			while (*p != '\0' && *p != '\n') {
+				/*
+				 * escaped newlines continue the comment across
+				 * multiple lines.
+				 */
+				if (*p == '\\')
+					p++;
+				p++;
+			}
+			continue;
+		case ' ':
+		case '\t':
+			/* skip whitespaces */
+			p++;
+			continue;
+		case '\\':
+			/*
+			 * backslash/newline combinations continue the
+			 * statement. Skip it just like a whitespace.
+			 */
+			if (*(p + 1) == '\n') {
+				p += 2;
+				continue;
+			}
+			break;
+		case '\n':
+			/*
+			 * Makefiles use a line-based syntax, where the newline
+			 * is the end of a statement. After seeing a newline,
+			 * we expect the next token is a target.
+			 */
+			p++;
+			is_target = true;
+			continue;
+		case ':':
+			/*
+			 * assume the first dependency after a colon as the
+			 * source file.
+			 */
+			p++;
+			is_target = false;
+			is_source = true;
+			continue;
+		}
+
+		/* find the end of the token */
+		q = p;
+		while (*q != ' ' && *q != '\t' && *q != '\n' && *q != '#' && *q != ':') {
+			if (*q == '\\') {
 				/*
-				 * Do not list the source file as dependency,
-				 * so that kbuild is not confused if a .c file
-				 * is rewritten into .S or vice versa. Storing
-				 * it in source_* is needed for modpost to
-				 * compute srcversions.
+				 * backslash/newline combinations work like as
+				 * a whitespace, so this is the end of token.
 				 */
-				if (is_first_dep) {
-					/*
-					 * If processing the concatenation of
-					 * multiple dependency files, only
-					 * process the first target name, which
-					 * will be the original source name,
-					 * and ignore any other target names,
-					 * which will be intermediate temporary
-					 * files.
-					 */
-					if (!saw_any_target) {
-						saw_any_target = 1;
-						printf("source_%s := %s\n\n",
-							target, s);
-						printf("deps_%s := \\\n",
-							target);
-					}
-					is_first_dep = 0;
-				} else
-					printf("  %s \\\n", s);
-				do_config_file(s);
+				if (*(q + 1) == '\n')
+					break;
+
+				/* escaped special characters */
+				if (*(q + 1) == '#' || *(q + 1) == ':') {
+					memmove(p + 1, p, q - p);
+					p++;
+				}
+
+				q++;
 			}
+
+			if (*q == '\0')
+				break;
+			q++;
+		}
+
+		/* Just discard the target */
+		if (is_target) {
+			p = q;
+			continue;
 		}
+
+		saved_c = *q;
+		*q = '\0';
+		need_parse = false;
+
 		/*
-		 * Start searching for next token immediately after the first
-		 * "whitespace" character that follows this token.
+		 * Do not list the source file as dependency, so that kbuild is
+		 * not confused if a .c file is rewritten into .S or vice versa.
+		 * Storing it in source_* is needed for modpost to compute
+		 * srcversions.
 		 */
-		m = p + 1;
+		if (is_source) {
+			/*
+			 * The DT build rule concatenates multiple dep files.
+			 * When processing them, only process the first source
+			 * name, which will be the original one, and ignore any
+			 * other source names, which will be intermediate
+			 * temporary files.
+			 *
+			 * rustc emits the same dependency list for each
+			 * emission type. It is enough to list the source name
+			 * just once.
+			 */
+			if (!saw_any_target) {
+				saw_any_target = true;
+				printf("source_%s := %s\n\n", target, p);
+				printf("deps_%s := \\\n", target);
+				need_parse = true;
+			}
+		} else if (!is_ignored_file(p, q - p) &&
+			   !in_hashtable(p, q - p, file_hashtab)) {
+			printf("  %s \\\n", p);
+			need_parse = true;
+		}
+
+		if (need_parse && !is_no_parse_file(p, q - p)) {
+			void *buf;
+
+			buf = read_file(p);
+			parse_config_file(buf);
+			free(buf);
+		}
+
+		is_source = false;
+		*q = saved_c;
+		p = q;
 	}
 
 	if (!saw_any_target) {
@@ -396,57 +407,10 @@ static void parse_dep_file(void *map, size_t len)
 	printf("$(deps_%s):\n", target);
 }
 
-static void print_deps(void)
-{
-	struct stat st;
-	int fd;
-	void *map;
-
-	fd = open(depfile, O_RDONLY);
-	if (fd < 0) {
-		fprintf(stderr, "fixdep: error opening depfile: ");
-		perror(depfile);
-		exit(2);
-	}
-	if (fstat(fd, &st) < 0) {
-                fprintf(stderr, "fixdep: error fstat'ing depfile: ");
-                perror(depfile);
-                exit(2);
-        }
-	if (st.st_size == 0) {
-		fprintf(stderr,"fixdep: %s is empty\n",depfile);
-		close(fd);
-		return;
-	}
-	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
-	if ((long) map == -1) {
-		perror("fixdep: mmap");
-		close(fd);
-		return;
-	}
-
-	parse_dep_file(map, st.st_size);
-
-	munmap(map, st.st_size);
-
-	close(fd);
-}
-
-static void traps(void)
-{
-	static char test[] __attribute__((aligned(sizeof(int)))) = "CONF";
-	int *p = (int *)test;
-
-	if (*p != INT_CONF) {
-		fprintf(stderr, "fixdep: sizeof(int) != 4 or wrong endianness? %#x\n",
-			*p);
-		exit(2);
-	}
-}
-
 int main(int argc, char *argv[])
 {
-	traps();
+	const char *depfile, *target, *cmdline;
+	void *buf;
 
 	if (argc != 4)
 		usage();
@@ -455,8 +419,22 @@ int main(int argc, char *argv[])
 	target = argv[2];
 	cmdline = argv[3];
 
-	print_cmdline();
-	print_deps();
+	printf("savedcmd_%s := %s\n\n", target, cmdline);
+
+	buf = read_file(depfile);
+	parse_dep_file(buf, target);
+	free(buf);
+
+	fflush(stdout);
+
+	/*
+	 * In the intended usage, the stdout is redirected to .*.cmd files.
+	 * Call ferror() to catch errors such as "No space left on device".
+	 */
+	if (ferror(stdout)) {
+		fprintf(stderr, "fixdep: not all data was written to the output\n");
+		exit(1);
+	}
 
 	return 0;
 }