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authorMasahiro Yamada <masahiroy@kernel.org>2023-01-07 18:18:19 +0900
committerMasahiro Yamada <masahiroy@kernel.org>2023-01-22 23:43:33 +0900
commitfaa91c472be8ffa3121c9db803d3e529d48e246a (patch)
tree6caf27d9379f743b9d974896dbe864ba1569c47c
parent871d657385466d380133e457fc86672bedf14cd9 (diff)
fixdep: avoid parsing the same file over again
The dep files (*.d files) emitted by C compilers usually contain the deduplicated list of included files. One exceptional case is when a header is included by the -include command line option, and also by #include directive. For example, the top Makefile adds the command line option, "-include $(srctree)/include/linux/kconfig.h". You do not need to include <linux/kconfig.h> in every source file. In fact, include/linux/kconfig.h is listed twice in many .*.cmd files due to include/linux/xarray.h having "#include <linux/kconfig.h>". I did not fix that since it is a small redundancy. However, this is more annoying for rustc. rustc emits the dependency for each emission type. For example, cmd_rustc_library emits dep-info, obj, and metadata. So, the emitted *.d file contains the dependency for those 3 targets, which makes fixdep parse the same file 3 times. $ grep rust/alloc/raw_vec.rs rust/.alloc.o.cmd rust/alloc/raw_vec.rs \ rust/alloc/raw_vec.rs \ rust/alloc/raw_vec.rs \ To skip the second parsing, this commit adds a hash table for parsed files, just like we did for CONFIG options. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Miguel Ojeda <ojeda@kernel.org> Tested-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
-rw-r--r--scripts/basic/fixdep.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
index 74f90a0deeb9..e22e689de61e 100644
--- a/scripts/basic/fixdep.c
+++ b/scripts/basic/fixdep.c
@@ -113,7 +113,7 @@ struct item {
};
#define HASHSZ 256
-static struct item *config_hashtab[HASHSZ];
+static struct item *config_hashtab[HASHSZ], *file_hashtab[HASHSZ];
static unsigned int strhash(const char *str, unsigned int sz)
{
@@ -365,6 +365,10 @@ static void parse_dep_file(char *p, const char *target)
* name, which will be the original one, and ignore any
* other source names, which will be intermediate
* temporary files.
+ *
+ * rustc emits the same dependency list for each
+ * emission type. It is enough to list the source name
+ * just once.
*/
if (!saw_any_target) {
saw_any_target = true;
@@ -372,7 +376,8 @@ static void parse_dep_file(char *p, const char *target)
printf("deps_%s := \\\n", target);
need_parse = true;
}
- } else if (!is_ignored_file(p, q - p)) {
+ } else if (!is_ignored_file(p, q - p) &&
+ !in_hashtable(p, q - p, file_hashtab)) {
printf(" %s \\\n", p);
need_parse = true;
}