| Message ID | 20221231064203.1623793-6-masahiroy@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kbuild: fix dep-file processing for rust | expand |
On Sat, Dec 31, 2022 at 7:42 AM Masahiro Yamada <masahiroy@kernel.org> wrote: > > To skip the second parsing, this commit adds a hash table for parsed > files, just like we did for CONFIG options. Acked-by: Miguel Ojeda <ojeda@kernel.org> Tested-by: Miguel Ojeda <ojeda@kernel.org> Cheers, Miguel
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> On Sat Dec 31, 2022 at 7:42 AM CET, Masahiro Yamada wrote: > The dep files (*.d files) emitted by C compilers usually contain the > deduplicated list of included files. > > There is an exceptional case; if a header is included by the -include > command line option, and also by #include directive, it appears twice > in the *.d file. > > For example, the top Makefile specifies the command line option, > -include $(srctree)/include/linux/kconfig.h. You do not need to > add #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 including <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> > --- > > scripts/basic/fixdep.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c > index b20777b888d7..cc8f6d34c2ca 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) > { > @@ -361,6 +361,10 @@ 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; > @@ -368,7 +372,8 @@ 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; > } > -- > 2.34.1
diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c index b20777b888d7..cc8f6d34c2ca 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) { @@ -361,6 +361,10 @@ 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; @@ -368,7 +372,8 @@ 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; }
The dep files (*.d files) emitted by C compilers usually contain the deduplicated list of included files. There is an exceptional case; if a header is included by the -include command line option, and also by #include directive, it appears twice in the *.d file. For example, the top Makefile specifies the command line option, -include $(srctree)/include/linux/kconfig.h. You do not need to add #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 including <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> --- scripts/basic/fixdep.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)