tools build: Add fixdep dependency helper

fixdep-y := fixdep.o

ifeq ($(srctree),)

srctree := $(patsubst %/,%,$(dir $(shell pwd)))

srctree := $(patsubst %/,%,$(dir $(srctree)))

endif

include $(srctree)/tools//scripts/Makefile.include

define allow-override

  $(if $(or $(findstring environment,$(origin $(1))),\

            $(findstring command line,$(origin $(1)))),,\

    $(eval $(1) = $(2)))

endef

$(call allow-override,CC,$(CROSS_COMPILE)gcc)

$(call allow-override,LD,$(CROSS_COMPILE)ld)

ifeq ($(V),1)

  Q =

else

  Q = @

endif

export Q srctree CC LD

MAKEFLAGS := --no-print-directory

build     := -f $(srctree)/tools/build/Makefile.build dir=. obj

all: fixdep

clean:

	$(call QUIET_CLEAN, fixdep)

	$(Q)find . -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete

	$(Q)rm -f fixdep

$(OUTPUT)fixdep-in.o: FORCE

	$(Q)$(MAKE) $(build)=fixdep

$(OUTPUT)fixdep: $(OUTPUT)fixdep-in.o

	$(QUIET_LINK)$(CC) $(LDFLAGS) -o $@ $<

FORCE:

.PHONY: FORCE

/*

 * "Optimize" a list of dependencies as spit out by gcc -MD

 * for the build framework.

 *

 * Original author:

 *   Copyright    2002 by Kai Germaschewski  <kai.germaschewski@gmx.de>

 *

 * This code has been borrowed from kbuild's fixdep (scripts/basic/fixdep.c),

 * Please check it for detailed explanation. This fixdep borow only the

 * base transformation of dependecies without the CONFIG mangle.

 */

#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>

char *target;

char *depfile;

char *cmdline;

static void usage(void)

{

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

	exit(1);

}

/*

 * Print out the commandline prefixed with cmd_<target filename> :=

 */

static void print_cmdline(void)

{

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

}

/*

 * 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(void *map, size_t len)

{

	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;

	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')

			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;

			/*

			 * 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, s);

					printf("deps_%s := \\\n",

						target);

				}

				is_first_dep = 0;

			} else

				printf("  %s \\\n", s);

		}

		/*

		 * 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);

	}

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

	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);

}

int main(int argc, char **argv)

{

	if (argc != 4)

		usage();

	depfile = argv[1];

	target  = argv[2];

	cmdline = argv[3];

	print_cmdline();

	print_deps();

	return 0;

}