fixdep: Do not record dependency on the source file itself

The dependency is already expressed by the Makefiles, storing it in the
.cmd file breaks build if a .c file is replaced by .S or vice versa,
because the .cmd file contains

foo/bar.o: foo/bar.c ...

foo/bar.c ... :

so the foo/bar.c -> foo/bar.o rule triggers even if there is no
foo/bar.c anymore.

Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 11 insertions, 1 deletions

diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
index c9a16abacab4..6c94c6ce2925 100644
--- a/scripts/basic/fixdep.c
+++ b/scripts/basic/fixdep.c
@@ -315,6 +315,7 @@ static void parse_dep_file(void *map, size_t len)
         char *end = m + len;
         char *p;
         char s[PATH_MAX];
+        int first;
 
         p = strchr(m, ':');
         if (!p) {
@@ -327,6 +328,7 @@ static void parse_dep_file(void *map, size_t len)
 
         clear_config();
 
+        first = 1;
         while (m < end) {
                 while (m < end && (*m == ' ' || *m == '\\' || *m == '\n'))
                         m++;
@@ -340,9 +342,17 @@ static void parse_dep_file(void *map, size_t len)
                 if (strrcmp(s, "include/generated/autoconf.h") &&
                     strrcmp(s, "arch/um/include/uml-config.h") &&
                     strrcmp(s, ".ver")) {
-                        printf("  %s \\\n", s);
+                        /*
+                         * Do not output the first dependency (the
+                         * source file), so that kbuild is not confused
+                         * if a .c file is rewritten into .S or vice
+                         * versa.
+                         */
+                        if (!first)
+                                printf("  %s \\\n", s);
                         do_config_file(s);
                 }
+                first = 0;
                 m = p + 1;
         }
         printf("\n%s: $(deps_%s)\n\n", target, target);