scripts/basic/fixdep.c - codeaurora/busybox - Gitiles

 /*
  * "Optimize" a list of dependencies as spit out by gcc -MD
  * for the kernel build
  * ===========================================================================
  *
  * Author       Kai Germaschewski
  * Copyright    2002 by Kai Germaschewski  <kai.germaschewski@gmx.de>
  *
  * This software may be used and distributed according to the terms
  * of the GNU General Public License, incorporated herein by reference.
  *
  *
  * Introduction:
  *
  * gcc produces a very nice and correct list of dependencies which
  * tells make when to remake a file.
  *
  * To use this list as-is however has the drawback that virtually
  * every file in the kernel includes <linux/config.h> which then again
  * includes <linux/autoconf.h>
  *
  * If the user re-runs make *config, linux/autoconf.h will be
  * regenerated.  make notices that and will rebuild every file which
  * includes autoconf.h, i.e. basically all files. This is extremely
  * annoying if the user just changed CONFIG_HIS_DRIVER from n to m.
  *
  * So we play the same trick that "mkdep" played before. We replace
  * the dependency on linux/autoconf.h by a dependency on every config
  * option which is mentioned in any of the listed prequisites.
  *
  * To be exact, split-include populates a tree in include/config/,
  * e.g. include/config/his/driver.h, which contains the #define/#undef
  * for the CONFIG_HIS_DRIVER option.
  *
  * 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,
  * so most likely only his driver ;-)
  *
  * The idea above dates, by the way, back to Michael E Chastain, AFAIK.
  *
  * So to get dependencies right, there are two issues:
  * o if any of the files the compiler read changed, we need to rebuild
  * o if the command line given to the compile the file changed, we
  *   better rebuild as well.
  *
  * The former is handled by using the -MD output, the later by saving
  * the command line used to compile the old object and comparing it
  * to the one we would now use.
  *
  * Again, also this idea is pretty old and has been discussed on
  * kbuild-devel a long time ago. I don't have a sensibly working
  * internet connection right now, so I rather don't mention names
  * without double checking.
  *
  * This code here has been based partially based on mkdep.c, which
  * says the following about its history:
  *
  *   Copyright abandoned, Michael Chastain, <mailto:mec@shout.net>.
  *   This is a C version of syncdep.pl by Werner Almesberger.
  *
  *
  * It is invoked as
  *
  *   fixdep <depfile> <target> <cmdline>
  *
  * and will read the dependency file <depfile>
  *
  * The transformed dependency snipped is written to stdout.
  *
  * It first generates a line
  *
  *   cmd_<target> = <cmdline>
  *
  * and then basically copies the .<target>.d file to stdout, in the
  * process filtering out the dependency on linux/autoconf.h and adding
  * dependencies on include/config/my/option.h for every
  * CONFIG_MY_OPTION encountered in any of the prequisites.
  *
  * 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
  * 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
  * we cannot miss a rebuild. Since people tend to not mention totally
  * unrelated CONFIG_ options all over the place, it's not an
  * efficiency problem either.
  *
  * (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 <stdlib.h>
 #include <stdio.h>
 #include <limits.h>
 #include <ctype.h>
 #include <arpa/inet.h>

 /* bbox: not needed
 #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;

 void usage(void)

 {
 	fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n");
 	exit(1);
 }

 /*
  * Print out the commandline prefixed with cmd_<target filename> :=
  */
 void print_cmdline(void)
 {
 	printf("cmd_%s := %s\n\n", target, cmdline);
 }

 char * str_config  = NULL;
 int    size_config = 0;
 int    len_config  = 0;

 /*
  * Grow the configuration string to a desired length.
  * Usually the first growth is plenty.
  */
 void grow_config(int len)
 {
 	while (len_config + len > size_config) {
 		if (size_config == 0)
 			size_config = 2048;
 		str_config = realloc(str_config, size_config *= 2);
 		if (str_config == NULL)
 			{ perror("fixdep:malloc"); exit(1); }
 	}
 }


 /*
  * Lookup a value in the configuration string.
  */
 int is_defined_config(const char * name, int len)
 {
 	const char * pconfig;
 	const char * plast = str_config + len_config - len;
 	for ( pconfig = str_config + 1; pconfig < plast; pconfig++ ) {
 		if (pconfig[ -1] == '\n'
 		&&  pconfig[len] == '\n'
 		&&  !memcmp(pconfig, name, len))
 			return 1;
 	}
 	return 0;
 }

 /*
  * Add a new value to the configuration string.
  */
 void define_config(const char * name, int len)
 {
 	grow_config(len + 1);

 	memcpy(str_config+len_config, name, len);
 	len_config += len;
 	str_config[len_config++] = '\n';
 }

 /*
  * Clear the set of configuration strings.
  */
 void clear_config(void)
 {
 	len_config = 0;
 	define_config("", 0);
 }

 /*
  * Record the use of a CONFIG_* word.
  */
 void use_config(char *m, int slen)
 {
 	char s[PATH_MAX];
 	char *p;

 	if (is_defined_config(m, slen))
 	    return;

 	define_config(m, slen);

 	memcpy(s, m, slen); s[slen] = 0;

 	for (p = s; p < s + slen; p++) {
 		if (*p == '_')
 			*p = '/';
 		else
 			*p = tolower((int)*p);
 	}
 	printf("    $(wildcard include/config/%s.h) \\\n", s);
 }

 void parse_config_file(char *map, size_t len)
 {
 	/* modified for bbox */
 	char *end_4 = map + len - 4; /* 4 == length of "USE_" */
 	char *end_7 = map + len - 7;
 	char *p = map;
 	char *q;
 	int off;

 	for (; p < end_4; p++) {
 		if (p < end_7 && p[6] == '_') {
 			if (!memcmp(p, "CONFIG", 6)) goto conf7;
 			if (!memcmp(p, "ENABLE", 6)) goto conf7;
 		}
 		/* We have at least 5 chars: for() has
 		 * "p < end-4", not "p <= end-4"
 		 * therefore we don't need to check p <= end-5 here */
 		if (p[4] == '_')
 			if (!memcmp(p, "SKIP", 4)) goto conf5;
 		/* Ehhh, gcc is too stupid to just compare it as 32bit int */
 		if (p[0] == 'U')
 			if (!memcmp(p, "USE_", 4)) goto conf4;
 		continue;

 	conf4:	off = 4;
 	conf5:	off = 5;
 	conf7:	off = 7;
 		p += off;
 		for (q = p; q < end_4+4; q++) {
 			if (!(isalnum(*q) || *q == '_'))
 				break;
 		}
 		use_config(p, q-p);
 	}
 }

 /* test is s ends in sub */
 int strrcmp(char *s, char *sub)
 {
 	int slen = strlen(s);
 	int sublen = strlen(sub);

 	if (sublen > slen)
 		return 1;

 	return memcmp(s + slen - sublen, sub, sublen);
 }

 void do_config_file(char *filename)
 {
 	struct stat st;
 	int fd;
 	void *map;

 	fd = open(filename, O_RDONLY);
 	if (fd < 0) {
 		fprintf(stderr, "fixdep: ");
 		perror(filename);
 		exit(2);
 	}
 	fstat(fd, &st);
 	if (st.st_size == 0) {
 		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_config_file(map, st.st_size);

 	munmap(map, st.st_size);

 	close(fd);
 }

 void parse_dep_file(void *map, size_t len)
 {
 	char *m = map;
 	char *end = m + len;
 	char *p;
 	char s[PATH_MAX];

 	p = memchr(m, ':', len);
 	if (!p) {
 		fprintf(stderr, "fixdep: parse error\n");
 		exit(1);
 	}
 	memcpy(s, m, p-m); s[p-m] = 0;
 	printf("deps_%s := \\\n", target);
 	m = p+1;

 	clear_config();

 	while (m < end) {
 		while (m < end && (*m == ' ' || *m == '\\' || *m == '\n'))
 			m++;
 		p = m;
 		while (p < end && *p != ' ') p++;
 		if (p == end) {
 			do p--; while (!isalnum(*p));
 			p++;
 		}
 		memcpy(s, m, p-m); s[p-m] = 0;
 		if (strrcmp(s, "include/autoconf.h") &&
 		    strrcmp(s, "arch/um/include/uml-config.h") &&
 		    strrcmp(s, ".ver")) {
 			printf("  %s \\\n", s);
 			do_config_file(s);
 		}
 		m = p + 1;
 	}
 	printf("\n%s: $(deps_%s)\n\n", target, target);
 	printf("$(deps_%s):\n", target);
 }

 void print_deps(void)
 {
 	struct stat st;
 	int fd;
 	void *map;

 	fd = open(depfile, O_RDONLY);
 	if (fd < 0) {
 		fprintf(stderr, "fixdep: ");
 		perror(depfile);
 		exit(2);
 	}
 	fstat(fd, &st);
 	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);
 }

 void traps(void)
 {
 /* bbox: not needed
 	static char test[] __attribute__((aligned(sizeof(int)))) = "CONF";

 	if (*(int *)test != INT_CONF) {
 		fprintf(stderr, "fixdep: sizeof(int) != 4 or wrong endianess? %#x\n",
 			*(int *)test);
 		exit(2);
 	}
 */
 }

 int main(int argc, char **argv)
 {
 	traps();

 	if (argc != 4)
 		usage();

 	depfile = argv[1];
 	target = argv[2];
 	cmdline = argv[3];

 	print_cmdline();
 	print_deps();

 	return 0;
 }
	/*
	* "Optimize" a list of dependencies as spit out by gcc -MD
	* for the kernel build
	* ===========================================================================
	*
	* Author Kai Germaschewski
	* Copyright 2002 by Kai Germaschewski <kai.germaschewski@gmx.de>
	*
	* This software may be used and distributed according to the terms
	* of the GNU General Public License, incorporated herein by reference.
	*
	*
	* Introduction:
	*
	* gcc produces a very nice and correct list of dependencies which
	* tells make when to remake a file.
	*
	* To use this list as-is however has the drawback that virtually
	* every file in the kernel includes <linux/config.h> which then again
	* includes <linux/autoconf.h>
	*
	* If the user re-runs make *config, linux/autoconf.h will be
	* regenerated. make notices that and will rebuild every file which
	* includes autoconf.h, i.e. basically all files. This is extremely
	* annoying if the user just changed CONFIG_HIS_DRIVER from n to m.
	*
	* So we play the same trick that "mkdep" played before. We replace
	* the dependency on linux/autoconf.h by a dependency on every config
	* option which is mentioned in any of the listed prequisites.
	*
	* To be exact, split-include populates a tree in include/config/,
	* e.g. include/config/his/driver.h, which contains the #define/#undef
	* for the CONFIG_HIS_DRIVER option.
	*
	* 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,
	* so most likely only his driver ;-)
	*
	* The idea above dates, by the way, back to Michael E Chastain, AFAIK.
	*
	* So to get dependencies right, there are two issues:
	* o if any of the files the compiler read changed, we need to rebuild
	* o if the command line given to the compile the file changed, we
	* better rebuild as well.
	*
	* The former is handled by using the -MD output, the later by saving
	* the command line used to compile the old object and comparing it
	* to the one we would now use.
	*
	* Again, also this idea is pretty old and has been discussed on
	* kbuild-devel a long time ago. I don't have a sensibly working
	* internet connection right now, so I rather don't mention names
	* without double checking.
	*
	* This code here has been based partially based on mkdep.c, which
	* says the following about its history:
	*
	* Copyright abandoned, Michael Chastain, <mailto:mec@shout.net>.
	* This is a C version of syncdep.pl by Werner Almesberger.
	*
	*
	* It is invoked as
	*
	* fixdep <depfile> <target> <cmdline>
	*
	* and will read the dependency file <depfile>
	*
	* The transformed dependency snipped is written to stdout.
	*
	* It first generates a line
	*
	* cmd_<target> = <cmdline>
	*
	* and then basically copies the .<target>.d file to stdout, in the
	* process filtering out the dependency on linux/autoconf.h and adding
	* dependencies on include/config/my/option.h for every
	* CONFIG_MY_OPTION encountered in any of the prequisites.
	*
	* 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
	* 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
	* we cannot miss a rebuild. Since people tend to not mention totally
	* unrelated CONFIG_ options all over the place, it's not an
	* efficiency problem either.
	*
	* (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 <stdlib.h>
	#include <stdio.h>
	#include <limits.h>
	#include <ctype.h>
	#include <arpa/inet.h>

	/* bbox: not needed
	#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;

	void usage(void)

	{
	fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n");
	exit(1);
	}

	/*
	* Print out the commandline prefixed with cmd_<target filename> :=
	*/
	void print_cmdline(void)
	{
	printf("cmd_%s := %s\n\n", target, cmdline);
	}

	char * str_config = NULL;
	int size_config = 0;
	int len_config = 0;

	/*
	* Grow the configuration string to a desired length.
	* Usually the first growth is plenty.
	*/
	void grow_config(int len)
	{
	while (len_config + len > size_config) {
	if (size_config == 0)
	size_config = 2048;
	str_config = realloc(str_config, size_config *= 2);
	if (str_config == NULL)
	{ perror("fixdep:malloc"); exit(1); }
	}
	}



	/*
	* Lookup a value in the configuration string.
	*/
	int is_defined_config(const char * name, int len)
	{
	const char * pconfig;
	const char * plast = str_config + len_config - len;
	for ( pconfig = str_config + 1; pconfig < plast; pconfig++ ) {
	if (pconfig[ -1] == '\n'
	&& pconfig[len] == '\n'
	&& !memcmp(pconfig, name, len))
	return 1;
	}
	return 0;
	}

	/*
	* Add a new value to the configuration string.
	*/
	void define_config(const char * name, int len)
	{
	grow_config(len + 1);

	memcpy(str_config+len_config, name, len);
	len_config += len;
	str_config[len_config++] = '\n';
	}

	/*
	* Clear the set of configuration strings.
	*/
	void clear_config(void)
	{
	len_config = 0;
	define_config("", 0);
	}

	/*
	* Record the use of a CONFIG_* word.
	*/
	void use_config(char *m, int slen)
	{
	char s[PATH_MAX];
	char *p;

	if (is_defined_config(m, slen))
	return;

	define_config(m, slen);

	memcpy(s, m, slen); s[slen] = 0;

	for (p = s; p < s + slen; p++) {
	if (*p == '_')
	*p = '/';
	else
	p = tolower((int)p);
	}
	printf(" $(wildcard include/config/%s.h) \\\n", s);
	}

	void parse_config_file(char *map, size_t len)
	{
	/* modified for bbox */
	char end_4 = map + len - 4; / 4 == length of "USE_" */
	char *end_7 = map + len - 7;
	char *p = map;
	char *q;
	int off;

	for (; p < end_4; p++) {
	if (p < end_7 && p[6] == '_') {
	if (!memcmp(p, "CONFIG", 6)) goto conf7;
	if (!memcmp(p, "ENABLE", 6)) goto conf7;
	}
	/* We have at least 5 chars: for() has
	* "p < end-4", not "p <= end-4"
	* therefore we don't need to check p <= end-5 here */
	if (p[4] == '_')
	if (!memcmp(p, "SKIP", 4)) goto conf5;
	/* Ehhh, gcc is too stupid to just compare it as 32bit int */
	if (p[0] == 'U')
	if (!memcmp(p, "USE_", 4)) goto conf4;
	continue;

	conf4: off = 4;
	conf5: off = 5;
	conf7: off = 7;
	p += off;
	for (q = p; q < end_4+4; q++) {
	if (!(isalnum(q) \|\| q == '_'))
	break;
	}
	use_config(p, q-p);
	}
	}

	/* test is s ends in sub */
	int strrcmp(char s, char sub)
	{
	int slen = strlen(s);
	int sublen = strlen(sub);

	if (sublen > slen)
	return 1;

	return memcmp(s + slen - sublen, sub, sublen);
	}

	void do_config_file(char *filename)
	{
	struct stat st;
	int fd;
	void *map;

	fd = open(filename, O_RDONLY);
	if (fd < 0) {
	fprintf(stderr, "fixdep: ");
	perror(filename);
	exit(2);
	}
	fstat(fd, &st);
	if (st.st_size == 0) {
	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_config_file(map, st.st_size);

	munmap(map, st.st_size);

	close(fd);
	}

	void parse_dep_file(void *map, size_t len)
	{
	char *m = map;
	char *end = m + len;
	char *p;
	char s[PATH_MAX];

	p = memchr(m, ':', len);
	if (!p) {
	fprintf(stderr, "fixdep: parse error\n");
	exit(1);
	}
	memcpy(s, m, p-m); s[p-m] = 0;
	printf("deps_%s := \\\n", target);
	m = p+1;

	clear_config();

	while (m < end) {
	while (m < end && (m == ' ' \|\| m == '\\' \|\| *m == '\n'))
	m++;
	p = m;
	while (p < end && *p != ' ') p++;
	if (p == end) {
	do p--; while (!isalnum(*p));
	p++;
	}
	memcpy(s, m, p-m); s[p-m] = 0;
	if (strrcmp(s, "include/autoconf.h") &&
	strrcmp(s, "arch/um/include/uml-config.h") &&
	strrcmp(s, ".ver")) {
	printf(" %s \\\n", s);
	do_config_file(s);
	}
	m = p + 1;
	}
	printf("\n%s: $(deps_%s)\n\n", target, target);
	printf("$(deps_%s):\n", target);
	}

	void print_deps(void)
	{
	struct stat st;
	int fd;
	void *map;

	fd = open(depfile, O_RDONLY);
	if (fd < 0) {
	fprintf(stderr, "fixdep: ");
	perror(depfile);
	exit(2);
	}
	fstat(fd, &st);
	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);
	}

	void traps(void)
	{
	/* bbox: not needed
	static char test[] __attribute__((aligned(sizeof(int)))) = "CONF";

	if ((int )test != INT_CONF) {
	fprintf(stderr, "fixdep: sizeof(int) != 4 or wrong endianess? %#x\n",
	(int )test);
	exit(2);
	}
	*/
	}

	int main(int argc, char **argv)
	{
	traps();

	if (argc != 4)
	usage();

	depfile = argv[1];
	target = argv[2];
	cmdline = argv[3];

	print_cmdline();
	print_deps();

	return 0;
	}