This updates the build procedure so that a mark-up in the form
of:
SP "FEATURE<" feature-name ">" SP
is picked up from the sources, in order to help keeping
supported_features[] array automatically in sync.
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
---
Junio C Hamano <gitster@xxxxxxxxx> writes:
> So, first of all, I would want the list of features in
> supported_features[] to come from a separate file, whose sole
> purpose is to have that list. I would even suggest making it an
> generated file, which depends on the source files (not
> necessarily limited to C files), and built from within the build
> procedure.
> ...
> Assuming if this --list-features is a viable approach in the
> long run, my gut feeling of relative order of things is:
>
> (1) We prepare rock-solid runtime with an _EMPTY_ feature array
> in 'master'.
>
> (2) We add automated feature array management in 'master', as
> outlined above.
>
> (3) Merge the above two to 'next'.
>
> (4) Update all existing topics, including the ones that are
> already in 'next', with the feature mark-up in comment
> (i.e. "FEATURE[[[feature-name]]]").
>
> After (3) happens, any new topics that introduce a new feature
> should be accompanied with the feature mark-up.
So here is a PoC for step (2). It loses more lines than it
adds, primarily because we can lose is_feature_name_sane(); it
is done at the build time now.
.gitignore | 1 +
Makefile | 12 +++++++++++-
builtin-blame.c | 1 +
generate-features.sh | 9 +++++++++
help.c | 48 +++++++++++++-----------------------------------
5 files changed, 35 insertions(+), 36 deletions(-)
create mode 100755 generate-features.sh
diff --git a/.gitignore b/.gitignore
index e8b060c..64ee08b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -169,3 +169,4 @@ config.status
config.mak.autogen
config.mak.append
configure
+features.h
diff --git a/Makefile b/Makefile
index c09dfaf..d8d1ddc 100644
--- a/Makefile
+++ b/Makefile
@@ -262,6 +262,13 @@ BUILT_INS = \
git-fsck-objects$X git-cherry-pick$X \
$(patsubst builtin-%.o,git-%$X,$(BUILTIN_OBJS))
+# what are the source files
+SOURCE_FILES = $(sort \
+ $(SCRIPT_SH) $(SCRIPT_PERL) $(SCRIPT_PYTHON) \
+ $(patsubst git-%$X,%.c,$(PROGRAMS)) \
+ $(LIB_H) \
+ $(patsubst %.o,%.c,$(LIB_OBJS) $(BUILTIN_OBJS)))
+
# what 'all' will build and 'install' will install, in gitexecdir
ALL_PROGRAMS = $(PROGRAMS) $(SCRIPTS)
@@ -755,7 +762,10 @@ git$X: git.o $(BUILTIN_OBJS) $(GITLIBS)
$(ALL_CFLAGS) -o $@ $(filter %.c,$^) git.o \
$(BUILTIN_OBJS) $(ALL_LDFLAGS) $(LIBS)
-help.o: common-cmds.h
+features.h: $(SOURCE_FILES) generate-features.sh
+ $(QUIET_GEN)./generate-features.sh $(SOURCE_FILES) > $@+ && mv $@+ $@
+
+help.o: common-cmds.h features.h
git-merge-subtree$X: git-merge-recursive$X
$(QUIET_BUILT_IN)rm -f $@ && ln git-merge-recursive$X $@
diff --git a/builtin-blame.c b/builtin-blame.c
index f7e2c13..c84d96a 100644
--- a/builtin-blame.c
+++ b/builtin-blame.c
@@ -2162,6 +2162,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
else if (!strcmp("-s", arg))
output_option |= OUTPUT_NO_AUTHOR;
else if (!strcmp("-w", arg))
+ /* FEATURE<blame-ignore-whitespace> */
xdl_opts |= XDF_IGNORE_WHITESPACE;
else if (!strcmp("-S", arg) && ++i < argc)
revs_file = argv[i];
diff --git a/generate-features.sh b/generate-features.sh
new file mode 100755
index 0000000..674c5fe
--- /dev/null
+++ b/generate-features.sh
@@ -0,0 +1,9 @@
+#!/bin/sh
+#
+# New features that Porcelains may care about can be marked in the
+# source code with FEATURE<feature name>. This script is driven
+# by Makefile to pick them out and sort them to prepare features.h
+# file, which is included by help.c.
+
+sed -n -e 's|.* FEATURE<\([a-z0-9][-a-z0-9]*[a-z0-9]\)> .*/| "\1",|p' "$@" |
+sort -u
diff --git a/help.c b/help.c
index d050cbf..b0887ea 100644
--- a/help.c
+++ b/help.c
@@ -9,9 +9,10 @@
#include "common-cmds.h"
#include <sys/ioctl.h>
+/* FEATURE<list-features> */
+
static const char *supported_features[] = {
- "blame-ignore-whitespace",
- "list-features",
+#include "features.h"
};
/* most GUI terminals set COLUMNS (although some don't export it) */
@@ -195,51 +196,28 @@ void help_unknown_cmd(const char *cmd)
exit(1);
}
-static int is_feature_name_sane(const char *a)
+static void list_features(void)
{
- if (!*a || *a == '-')
- return 0;
- for (; *a; a++) {
- if (! ((*a >= 'a' && *a <= 'z')
- || (*a >= '0' && *a <= '9')
- || *a == '-'))
- return 0;
- }
- return 1;
+ unsigned cnt = ARRAY_SIZE(supported_features);
+ unsigned i;
+
+ for (i = 0; i < cnt; i++)
+ printf("%s\n", supported_features[i]);
}
static int cmp_feature(const void *a_, const void *b_)
{
const char *a = *((const char **)a_);
const char *b = *((const char **)b_);
- return strcmp(a, b);
-}
-static void list_features()
-{
- unsigned cnt = ARRAY_SIZE(supported_features);
- unsigned i;
-
- qsort(supported_features, cnt,
- sizeof(supported_features[0]), cmp_feature);
- for (i = 0; i < cnt; i++) {
- const char *f = supported_features[i];
- if (!is_feature_name_sane(f))
- die("feature name \"%s\" is bogus", f);
- printf("%s\n", f);
- }
+ return strcmp(a, b);
}
static int supports_feature(const char *the_feature)
{
- unsigned cnt = ARRAY_SIZE(supported_features);
- unsigned i;
-
- for (i = 0; i < cnt; i++) {
- if (!strcmp(supported_features[i], the_feature))
- return 0;
- }
- return 1;
+ return !bsearch(&the_feature, supported_features,
+ (size_t) ARRAY_SIZE(supported_features),
+ sizeof(const char *), cmp_feature);
}
static const char version_usage[] =
--
1.5.2.2.1050.g51a8b
-
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
