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-rw-r--r--tools/build/fixdep.c170
1 files changed, 170 insertions, 0 deletions
diff --git a/tools/build/fixdep.c b/tools/build/fixdep.c
new file mode 100644
index 000000000..2501fea7a
--- /dev/null
+++ b/tools/build/fixdep.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * "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, has_target = 0;
+ 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;
+ has_target = 1;
+ } else if (has_target) {
+ /* 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;
+}