Make git-describe a builtin.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Makefile

@@ -204,7 +204,7 @@ PROGRAMS = \
 	git-update-server-info$X \
 	git-upload-pack$X git-verify-pack$X \
 	git-pack-redundant$X git-var$X \
-	git-describe$X git-merge-tree$X git-imap-send$X \
+	git-merge-tree$X git-imap-send$X \
 	git-merge-recursive$X \
 	$(EXTRA_PROGRAMS)
 
@@ -275,6 +275,7 @@ BUILTIN_OBJS = \
 	builtin-check-ref-format.o \
 	builtin-commit-tree.o \
 	builtin-count-objects.o \
+	builtin-describe.o \
 	builtin-diff.o \
 	builtin-diff-files.o \
 	builtin-diff-index.o \

builtin-describe.c

@@ -2,6 +2,7 @@
 #include "commit.h"
 #include "tag.h"
 #include "refs.h"
+#include "builtin.h"
 
 #define SEEN (1u << 0)
 
@@ -139,7 +140,7 @@ static void describe(const char *arg, int last_one)
 	die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 }
 
-int main(int argc, char **argv)
+int cmd_describe(int argc, const char **argv, const char *prefix)
 {
 	int i;
 
@@ -161,7 +162,6 @@ int main(int argc, char **argv)
 			usage(describe_usage);
 	}
 
-	setup_git_directory();
 	save_commit_buffer = 0;
 
 	if (argc <= i)

builtin.h

@@ -25,6 +25,7 @@ extern int cmd_check_ref_format(int argc, const char **argv, const char *prefix)
 extern int cmd_cherry(int argc, const char **argv, const char *prefix);
 extern int cmd_commit_tree(int argc, const char **argv, const char *prefix);
 extern int cmd_count_objects(int argc, const char **argv, const char *prefix);
+extern int cmd_describe(int argc, const char **argv, const char *prefix);
 extern int cmd_diff_files(int argc, const char **argv, const char *prefix);
 extern int cmd_diff_index(int argc, const char **argv, const char *prefix);
 extern int cmd_diff(int argc, const char **argv, const char *prefix);

git.c

@@ -220,6 +220,7 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
 		{ "cherry", cmd_cherry, RUN_SETUP },
 		{ "commit-tree", cmd_commit_tree, RUN_SETUP },
 		{ "count-objects", cmd_count_objects, RUN_SETUP },
+		{ "describe", cmd_describe, RUN_SETUP },
 		{ "diff", cmd_diff, RUN_SETUP | USE_PAGER },
 		{ "diff-files", cmd_diff_files, RUN_SETUP },
 		{ "diff-index", cmd_diff_index, RUN_SETUP },