[mirror_ubuntu-bionic-kernel.git] / scripts / basic / fixdep.c

/*
 * "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.
 *
 * kconfig populates a tree in include/config/ with an empty file
 * for each config symbol and when the configuration is updated
 * the files representing changed config options are touched
 * which then let make pick up the changes and the files that use
 * 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,
 * 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>

#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)
{
	int *end = (int *) (map + len);
	/* start at +1, so that p can never be < map */
	int *m   = (int *) map + 1;
	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;

	found:
		if (!memcmp(q - 7, "_MODULE", 7))
			q -= 7;
		if( (q-p-7) < 0 )
			continue;
		use_config(p+7, q-p-7);
	}
}

/* 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 = strchr(m, ':');
	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/linux/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)
{
	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;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* "Optimize" a list of dependencies as spit out by gcc -MD
	3	* for the kernel build
	4	* ===========================================================================
	5	*
	6	* Author Kai Germaschewski
	7	* Copyright 2002 by Kai Germaschewski <kai.germaschewski@gmx.de>
	8	*
	9	* This software may be used and distributed according to the terms
	10	* of the GNU General Public License, incorporated herein by reference.
	11	*
	12	*
	13	* Introduction:
	14	*
	15	* gcc produces a very nice and correct list of dependencies which
	16	* tells make when to remake a file.
	17	*
	18	* To use this list as-is however has the drawback that virtually
	19	* every file in the kernel includes <linux/config.h> which then again
	20	* includes <linux/autoconf.h>
	21	*
	22	* If the user re-runs make *config, linux/autoconf.h will be
	23	* regenerated. make notices that and will rebuild every file which
	24	* includes autoconf.h, i.e. basically all files. This is extremely
	25	* annoying if the user just changed CONFIG_HIS_DRIVER from n to m.
	26	*
	27	* So we play the same trick that "mkdep" played before. We replace
	28	* the dependency on linux/autoconf.h by a dependency on every config
	29	* option which is mentioned in any of the listed prequisites.
	30	*
c21b1e4d JB	31	* kconfig populates a tree in include/config/ with an empty file
	32	* for each config symbol and when the configuration is updated
	33	* the files representing changed config options are touched
	34	* which then let make pick up the changes and the files that use
	35	* the config symbols are rebuilt.
1da177e4 LT	36	*
	37	* So if the user changes his CONFIG_HIS_DRIVER option, only the objects
	38	* which depend on "include/linux/config/his/driver.h" will be rebuilt,
	39	* so most likely only his driver ;-)
	40	*
	41	* The idea above dates, by the way, back to Michael E Chastain, AFAIK.
	42	*
	43	* So to get dependencies right, there are two issues:
	44	* o if any of the files the compiler read changed, we need to rebuild
	45	* o if the command line given to the compile the file changed, we
	46	* better rebuild as well.
	47	*
	48	* The former is handled by using the -MD output, the later by saving
	49	* the command line used to compile the old object and comparing it
	50	* to the one we would now use.
	51	*
	52	* Again, also this idea is pretty old and has been discussed on
	53	* kbuild-devel a long time ago. I don't have a sensibly working
	54	* internet connection right now, so I rather don't mention names
	55	* without double checking.
	56	*
	57	* This code here has been based partially based on mkdep.c, which
	58	* says the following about its history:
	59	*
	60	* Copyright abandoned, Michael Chastain, <mailto:mec@shout.net>.
	61	* This is a C version of syncdep.pl by Werner Almesberger.
	62	*
	63	*
	64	* It is invoked as
	65	*
	66	* fixdep <depfile> <target> <cmdline>
	67	*
	68	* and will read the dependency file <depfile>
	69	*
	70	* The transformed dependency snipped is written to stdout.
	71	*
	72	* It first generates a line
	73	*
	74	* cmd_<target> = <cmdline>
	75	*
	76	* and then basically copies the .<target>.d file to stdout, in the
	77	* process filtering out the dependency on linux/autoconf.h and adding
	78	* dependencies on include/config/my/option.h for every
	79	* CONFIG_MY_OPTION encountered in any of the prequisites.
	80	*
	81	* It will also filter out all the dependencies on *.ver. We need
	82	* to make sure that the generated version checksum are globally up
	83	* to date before even starting the recursive build, so it's too late
	84	* at this point anyway.
	85	*
	86	* The algorithm to grep for "CONFIG_..." is bit unusual, but should
	87	* be fast ;-) We don't even try to really parse the header files, but
	88	* merely grep, i.e. if CONFIG_FOO is mentioned in a comment, it will
	89	* be picked up as well. It's not a problem with respect to
	90	* correctness, since that can only give too many dependencies, thus
	91	* we cannot miss a rebuild. Since people tend to not mention totally
	92	* unrelated CONFIG_ options all over the place, it's not an
	93	* efficiency problem either.
	94	*
	95	* (Note: it'd be easy to port over the complete mkdep state machine,
	96	* but I don't think the added complexity is worth it)
	97	*/
	98	/*
	99	* Note 2: if somebody writes HELLO_CONFIG_BOOM in a file, it will depend onto
100	* CONFIG_BOOM. This could seem a bug (not too hard to fix), but please do not
101	* fix it! Some UserModeLinux files (look at arch/um/) call CONFIG_BOOM as
102	* UML_CONFIG_BOOM, to avoid conflicts with /usr/include/linux/autoconf.h,
103	* through arch/um/include/uml-config.h; this fixdep "bug" makes sure that
104	* those files will have correct dependencies.
105	*/
106
107	#include <sys/types.h>
108	#include <sys/stat.h>
109	#include <sys/mman.h>
110	#include <unistd.h>
111	#include <fcntl.h>
112	#include <string.h>
113	#include <stdlib.h>
114	#include <stdio.h>
115	#include <limits.h>
116	#include <ctype.h>
117	#include <arpa/inet.h>
118
119	#define INT_CONF ntohl(0x434f4e46)
120	#define INT_ONFI ntohl(0x4f4e4649)
121	#define INT_NFIG ntohl(0x4e464947)
122	#define INT_FIG_ ntohl(0x4649475f)
123
124	char *target;
125	char *depfile;
126	char *cmdline;
127
128	void usage(void)
129
130	{
131	fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n");
132	exit(1);
133	}
134
4d99f93b SR	135	/*
4d99f93b SR	136	* Print out the commandline prefixed with cmd_<target filename> :=
6176aa9a	137	*/
1da177e4 LT	138	void print_cmdline(void)
1da177e4 LT	139	{
6176aa9a	140	printf("cmd_%s := %s\n\n", target, cmdline);
1da177e4 LT	141	}
	142
	143	char * str_config = NULL;
	144	int size_config = 0;
	145	int len_config = 0;
	146
	147	/*
	148	* Grow the configuration string to a desired length.
	149	* Usually the first growth is plenty.
	150	*/
	151	void grow_config(int len)
	152	{
	153	while (len_config + len > size_config) {
	154	if (size_config == 0)
	155	size_config = 2048;
	156	str_config = realloc(str_config, size_config *= 2);
	157	if (str_config == NULL)
	158	{ perror("fixdep:malloc"); exit(1); }
	159	}
	160	}
	161
	162
	163
	164	/*
	165	* Lookup a value in the configuration string.
	166	*/
	167	int is_defined_config(const char * name, int len)
	168	{
	169	const char * pconfig;
	170	const char * plast = str_config + len_config - len;
	171	for ( pconfig = str_config + 1; pconfig < plast; pconfig++ ) {
	172	if (pconfig[ -1] == '\n'
	173	&& pconfig[len] == '\n'
	174	&& !memcmp(pconfig, name, len))
	175	return 1;
	176	}
	177	return 0;
	178	}
	179
	180	/*
	181	* Add a new value to the configuration string.
	182	*/
	183	void define_config(const char * name, int len)
	184	{
	185	grow_config(len + 1);
	186
	187	memcpy(str_config+len_config, name, len);
	188	len_config += len;
	189	str_config[len_config++] = '\n';
	190	}
	191
	192	/*
	193	* Clear the set of configuration strings.
	194	*/
	195	void clear_config(void)
	196	{
	197	len_config = 0;
	198	define_config("", 0);
	199	}
	200
	201	/*
	202	* Record the use of a CONFIG_* word.
	203	*/
	204	void use_config(char *m, int slen)
205	{
206	char s[PATH_MAX];
207	char *p;
208
209	if (is_defined_config(m, slen))
210	return;
211
212	define_config(m, slen);
213
214	memcpy(s, m, slen); s[slen] = 0;
215
216	for (p = s; p < s + slen; p++) {
217	if (*p == '_')
218	*p = '/';
219	else
48b9d03c	220	p = tolower((int)p);
1da177e4 LT	221	}
	222	printf(" $(wildcard include/config/%s.h) \\\n", s);
	223	}
	224
48b9d03c	225	void parse_config_file(char *map, size_t len)
1da177e4 LT	226	{
	227	int end = (int ) (map + len);
	228	/* start at +1, so that p can never be < map */
	229	int m = (int ) map + 1;
48b9d03c	230	char p, q;
1da177e4 LT	231
1da177e4 LT	232	for (; m < end; m++) {
48b9d03c M	233	if (m == INT_CONF) { p = (char ) m ; goto conf; }
	234	if (m == INT_ONFI) { p = (char ) m-1; goto conf; }
	235	if (m == INT_NFIG) { p = (char ) m-2; goto conf; }
	236	if (m == INT_FIG_) { p = (char ) m-3; goto conf; }
1da177e4 LT	237	continue;
	238	conf:
	239	if (p > map + len - 7)
	240	continue;
	241	if (memcmp(p, "CONFIG_", 7))
	242	continue;
	243	for (q = p + 7; q < map + len; q++) {
	244	if (!(isalnum(q) \|\| q == '_'))
	245	goto found;
	246	}
	247	continue;
	248
	249	found:
c21b1e4d JB	250	if (!memcmp(q - 7, "_MODULE", 7))
c21b1e4d JB	251	q -= 7;
04c58f81 AG	252	if( (q-p-7) < 0 )
04c58f81 AG	253	continue;
1da177e4 LT	254	use_config(p+7, q-p-7);
	255	}
	256	}
	257
	258	/* test is s ends in sub */
	259	int strrcmp(char s, char sub)
	260	{
	261	int slen = strlen(s);
	262	int sublen = strlen(sub);
	263
	264	if (sublen > slen)
	265	return 1;
	266
	267	return memcmp(s + slen - sublen, sub, sublen);
	268	}
	269
	270	void do_config_file(char *filename)
	271	{
	272	struct stat st;
	273	int fd;
	274	void *map;
	275
	276	fd = open(filename, O_RDONLY);
	277	if (fd < 0) {
	278	fprintf(stderr, "fixdep: ");
	279	perror(filename);
	280	exit(2);
	281	}
	282	fstat(fd, &st);
	283	if (st.st_size == 0) {
	284	close(fd);
	285	return;
	286	}
	287	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
	288	if ((long) map == -1) {
	289	perror("fixdep: mmap");
	290	close(fd);
	291	return;
	292	}
	293
	294	parse_config_file(map, st.st_size);
	295
	296	munmap(map, st.st_size);
	297
	298	close(fd);
	299	}
	300
	301	void parse_dep_file(void *map, size_t len)
	302	{
48b9d03c M	303	char *m = map;
	304	char *end = m + len;
	305	char *p;
1da177e4 LT	306	char s[PATH_MAX];
	307
	308	p = strchr(m, ':');
	309	if (!p) {
	310	fprintf(stderr, "fixdep: parse error\n");
	311	exit(1);
	312	}
	313	memcpy(s, m, p-m); s[p-m] = 0;
	314	printf("deps_%s := \\\n", target);
	315	m = p+1;
	316
	317	clear_config();
	318
	319	while (m < end) {
	320	while (m < end && (m == ' ' \|\| m == '\\' \|\| *m == '\n'))
	321	m++;
	322	p = m;
	323	while (p < end && *p != ' ') p++;
	324	if (p == end) {
	325	do p--; while (!isalnum(*p));
	326	p++;
	327	}
	328	memcpy(s, m, p-m); s[p-m] = 0;
	329	if (strrcmp(s, "include/linux/autoconf.h") &&
	330	strrcmp(s, "arch/um/include/uml-config.h") &&
	331	strrcmp(s, ".ver")) {
	332	printf(" %s \\\n", s);
	333	do_config_file(s);
	334	}
	335	m = p + 1;
	336	}
	337	printf("\n%s: $(deps_%s)\n\n", target, target);
	338	printf("$(deps_%s):\n", target);
	339	}
	340
	341	void print_deps(void)
	342	{
	343	struct stat st;
	344	int fd;
	345	void *map;
	346
	347	fd = open(depfile, O_RDONLY);
	348	if (fd < 0) {
	349	fprintf(stderr, "fixdep: ");
	350	perror(depfile);
	351	exit(2);
	352	}
	353	fstat(fd, &st);
	354	if (st.st_size == 0) {
	355	fprintf(stderr,"fixdep: %s is empty\n",depfile);
	356	close(fd);
	357	return;
	358	}
	359	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
	360	if ((long) map == -1) {
	361	perror("fixdep: mmap");
	362	close(fd);
	363	return;
	364	}
	365
	366	parse_dep_file(map, st.st_size);
	367
	368	munmap(map, st.st_size);
	369
370	close(fd);
371	}
372
373	void traps(void)
374	{
375	static char test[] __attribute__((aligned(sizeof(int)))) = "CONF";
376
377	if ((int )test != INT_CONF) {
378	fprintf(stderr, "fixdep: sizeof(int) != 4 or wrong endianess? %#x\n",
379	(int )test);
380	exit(2);
381	}
382	}
383
384	int main(int argc, char *argv[])
385	{
386	traps();
387
388	if (argc != 4)
389	usage();
390
391	depfile = argv[1];
392	target = argv[2];
393	cmdline = argv[3];
394
395	print_cmdline();
396	print_deps();
397
398	return 0;
399	}