Release 4.17 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 autoconf.h.
 *
 * If the user re-runs make *config, 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 autoconf.h by a dependency on every config
 * 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
 * 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/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 autoconf.h and adding
 * dependencies on include/config/my/option.h 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.
 *
 * 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)
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>



static void usage(void)
{
	fprintf(stderr, "Usage: fixdep [-e] <depfile> <target> <cmdline>\n");
	fprintf(stderr, " -e  insert extra dependencies given on stdin\n");
	exit(1);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kai Germaschewski
18
66.67%
1
33.33%
Nico Pitre
8
29.63%
1
33.33%
Trevor Keith
1
3.70%
1
33.33%
Total
27
100.00%
3
100.00%

/*
 * Print out a dependency path from a symbol name
 */


static void print_dep(const char *m, int slen, const char *dir)
{
	int c, i;

	printf("    $(wildcard %s/", dir);
	for (i = 0; i < slen; i++) {
		c = m[i];
		if (c == '_')
			c = '/';
		else
			c = tolower(c);
		putchar(c);
	}
	printf(".h) \\\n");
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nico Pitre
72
88.89%
1
50.00%
Masahiro Yamada
9
11.11%
1
50.00%
Total
81
100.00%
2
100.00%



static void do_extra_deps(void)
{
	char buf[80];

	while (fgets(buf, sizeof(buf), stdin)) {
		int len = strlen(buf);

		if (len < 2 || buf[len - 1] != '\n') {
			fprintf(stderr, "fixdep: bad data on stdin\n");
			exit(1);
		}
		print_dep(buf, len - 1, "include/ksym");
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nico Pitre
75
96.15%
1
50.00%
Masahiro Yamada
3
3.85%
1
50.00%
Total
78
100.00%
2
100.00%


struct item {
	
struct item	*next;
	
unsigned int	len;
	
unsigned int	hash;
	
char		name[0];
};


#define HASHSZ 256

static struct item *hashtab[HASHSZ];



static unsigned int strhash(const char *str, unsigned int sz)
{
	/* fnv32 hash */
	unsigned int i, hash = 2166136261U;

	for (i = 0; i < sz; i++)
		hash = (hash ^ str[i]) * 0x01000193;
	return hash;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric Dumazet
45
83.33%
1
33.33%
Kai Germaschewski
8
14.81%
1
33.33%
Trevor Keith
1
1.85%
1
33.33%
Total
54
100.00%
3
100.00%

/*
 * 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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kai Germaschewski
44
57.14%
1
33.33%
Eric Dumazet
32
41.56%
1
33.33%
Trevor Keith
1
1.30%
1
33.33%
Total
77
100.00%
3
100.00%

/*
 * Add a new value to the configuration string.
 */


static void define_config(const char *name, int len, unsigned int hash)
{
	struct item *aux = malloc(sizeof(*aux) + len);

	if (!aux) {
		perror("fixdep:malloc");
		exit(1);
	}
	memcpy(aux->name, name, len);
	aux->len = len;
	aux->hash = hash;
	aux->next = hashtab[hash % HASHSZ];
	hashtab[hash % HASHSZ] = aux;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric Dumazet
61
64.89%
1
33.33%
Kai Germaschewski
32
34.04%
1
33.33%
Trevor Keith
1
1.06%
1
33.33%
Total
94
100.00%
3
100.00%

/*
 * Record the use of a CONFIG_* word.
 */


static void use_config(const char *m, int slen)
{
	unsigned int hash = strhash(m, slen);

	if (is_defined_config(m, slen, hash))
	    return;

	define_config(m, slen, hash);
	print_dep(m, slen, "include/config");
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kai Germaschewski
33
60.00%
1
20.00%
Eric Dumazet
16
29.09%
1
20.00%
Masahiro Yamada
3
5.45%
1
20.00%
Nico Pitre
2
3.64%
1
20.00%
Trevor Keith
1
1.82%
1
20.00%
Total
55
100.00%
5
100.00%

/* test if s ends in sub */


static int str_ends_with(const char *s, int slen, const char *sub)
{
	int sublen = strlen(sub);

	if (sublen > slen)
		return 0;

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

Contributors
Person
Tokens
Prop
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CommitProp
Masahiro Yamada
51
100.00%
1
100.00%
Total
51
100.00%
1
100.00%



static void parse_config_file(const char *p)
{
	const char *q, *r;
	const char *start = p;

	while ((p = strstr(p, "CONFIG_"))) {
		if (p > start && (isalnum(p[-1]) || p[-1] == '_')) {
			p += 7;
			continue;
		}
		p += 7;
		q = p;
		while (*q && (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;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kai Germaschewski
49
33.79%
2
20.00%
Rasmus Villemoes
39
26.90%
1
10.00%
Alexey Dobriyan
30
20.69%
1
10.00%
Jan Beulich
12
8.28%
1
10.00%
Masahiro Yamada
8
5.52%
2
20.00%
Andy Green
4
2.76%
1
10.00%
Eric Dumazet
2
1.38%
1
10.00%
Trevor Keith
1
0.69%
1
10.00%
Total
145
100.00%
10
100.00%



static void *read_file(const char *filename)
{
	struct stat st;
	int fd;
	char *buf;

	fd = open(filename, O_RDONLY);
	if (fd < 0) {
		fprintf(stderr, "fixdep: error opening file: ");
		perror(filename);
		exit(2);
	}
	if (fstat(fd, &st) < 0) {
		fprintf(stderr, "fixdep: error fstat'ing file: ");
		perror(filename);
		exit(2);
	}
	buf = malloc(st.st_size + 1);
	if (!buf) {
		perror("fixdep: malloc");
		exit(2);
	}
	if (read(fd, buf, st.st_size) != st.st_size) {
		perror("fixdep: read");
		exit(2);
	}
	buf[st.st_size] = '\0';
	close(fd);

	return buf;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kai Germaschewski
94
58.02%
3
33.33%
Alexey Dobriyan
28
17.28%
1
11.11%
Tom Rini
22
13.58%
1
11.11%
Masahiro Yamada
12
7.41%
1
11.11%
Lukas Bulwahn
4
2.47%
1
11.11%
Trevor Keith
1
0.62%
1
11.11%
Eric Dumazet
1
0.62%
1
11.11%
Total
162
100.00%
9
100.00%

/* Ignore certain dependencies */


static int is_ignored_file(const char *s, int len)
{
	return str_ends_with(s, len, "include/generated/autoconf.h") ||
	       str_ends_with(s, len, "include/generated/autoksyms.h") ||
	       str_ends_with(s, len, ".ver");
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Masahiro Yamada
42
100.00%
1
100.00%
Total
42
100.00%
1
100.00%

/*
 * Important: The below generated source_foo.o and deps_foo.o variable
 * assignments are parsed not only by make, but also by the rather simple
 * parser in scripts/mod/sumversion.c.
 */


static void parse_dep_file(char *m, const char *target, int insert_extra_deps)
{
	char *p;
	int is_last, is_target;
	int saw_any_target = 0;
	int is_first_dep = 0;
	void *buf;

	while (1) {
		/* Skip any "white space" */
		while (*m == ' ' || *m == '\\' || *m == '\n')
			m++;

		if (!*m)
			break;

		/* Find next "white space" */
		p = m;
		while (*p && *p != ' ' && *p != '\\' && *p != '\n')
			p++;
		is_last = (*p == '\0');
		/* 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 if (!is_ignored_file(m, p - m)) {
			*p = '\0';

			/*
                         * 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.
                         */
			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, m);
					printf("deps_%s := \\\n", target);
				}
				is_first_dep = 0;
			} else {
				printf("  %s \\\n", m);
			}

			buf = read_file(m);
			parse_config_file(buf);
			free(buf);
		}

		if (is_last)
			break;

		/*
                 * Start searching for next token immediately after the first
                 * "whitespace" character that follows this token.
                 */
		m = p + 1;
	}

	if (!saw_any_target) {
		fprintf(stderr, "fixdep: parse error; no targets found\n");
		exit(1);
	}

	if (insert_extra_deps)
		do_extra_deps();

	printf("\n%s: $(deps_%s)\n\n", target, target);
	printf("$(deps_%s):\n", target);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kai Germaschewski
99
35.61%
3
23.08%
Stephen Warren
77
27.70%
1
7.69%
Masahiro Yamada
75
26.98%
5
38.46%
Michal Marek
23
8.27%
2
15.38%
Nico Pitre
3
1.08%
1
7.69%
Trevor Keith
1
0.36%
1
7.69%
Total
278
100.00%
13
100.00%



int main(int argc, char *argv[])
{
	const char *depfile, *target, *cmdline;
	int insert_extra_deps = 0;
	void *buf;

	if (argc == 5 && !strcmp(argv[1], "-e")) {
		insert_extra_deps = 1;
		argv++;
	} else if (argc != 4)
		usage();

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

	printf("cmd_%s := %s\n\n", target, cmdline);

	buf = read_file(depfile);
	parse_dep_file(buf, target, insert_extra_deps);
	free(buf);

	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Kai Germaschewski
48
39.02%
3
42.86%
Masahiro Yamada
48
39.02%
3
42.86%
Nico Pitre
27
21.95%
1
14.29%
Total
123
100.00%
7
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Kai Germaschewski
458
34.28%
8
27.59%
Masahiro Yamada
253
18.94%
8
27.59%
Nico Pitre
188
14.07%
1
3.45%
Eric Dumazet
188
14.07%
1
3.45%
Stephen Warren
77
5.76%
1
3.45%
Alexey Dobriyan
58
4.34%
1
3.45%
Rasmus Villemoes
39
2.92%
1
3.45%
Michal Marek
24
1.80%
2
6.90%
Tom Rini
22
1.65%
1
3.45%
Jan Beulich
12
0.90%
1
3.45%
Trevor Keith
8
0.60%
1
3.45%
Lukas Bulwahn
4
0.30%
1
3.45%
Andy Green
4
0.30%
1
3.45%
Cao jin
1
0.07%
1
3.45%
Total
1336
100.00%
29
100.00%
Directory: scripts/basic

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