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/*
* libgit2 "describe" example - shows how to describe commits
*
* Written by the libgit2 contributors
*
* To the extent possible under law, the author(s) have dedicated all copyright
* and related and neighboring rights to this software to the public domain
* worldwide. This software is distributed without any warranty.
*
* You should have received a copy of the CC0 Public Domain Dedication along
* with this software. If not, see
* <http://creativecommons.org/publicdomain/zero/1.0/>.
*/
#include "common.h"
#include <assert.h>
/**
* The following example partially reimplements the `git describe` command
* and some of its options.
*
* These commands should work:
* - Describe HEAD with default options (`describe`)
* - Describe specified revision (`describe master~2`)
* - Describe specified revisions (`describe master~2 HEAD~3`)
* - Describe HEAD with dirty state suffix (`describe --dirty=*`)
* - Describe consider all refs (`describe --all master`)
* - Describe consider lightweight tags (`describe --tags temp-tag`)
* - Describe show non-default abbreviated size (`describe --abbrev=10`)
* - Describe always output the long format if matches a tag (`describe --long v1.0`)
* - Describe consider only tags of specified pattern (`describe --match v*-release`)
* - Describe show the fallback result (`describe --always`)
* - Describe follow only the first parent commit (`describe --first-parent`)
*
* The command line parsing logic is simplified and doesn't handle
* all of the use cases.
*/
/** describe_options represents the parsed command line options */
typedef struct {
const char **commits;
size_t commit_count;
git_describe_options describe_options;
git_describe_format_options format_options;
} describe_options;
typedef struct args_info args_info;
static void *xrealloc(void *oldp, size_t newsz)
{
void *p = realloc(oldp, newsz);
if (p == NULL) {
fprintf(stderr, "Cannot allocate memory, exiting.\n");
exit(1);
}
return p;
}
static void opts_add_commit(describe_options *opts, const char *commit)
{
size_t sz;
assert(opts != NULL);
sz = ++opts->commit_count * sizeof(opts->commits[0]);
opts->commits = xrealloc(opts->commits, sz);
opts->commits[opts->commit_count - 1] = commit;
}
static void do_describe_single(git_repository *repo, describe_options *opts, const char *rev)
{
git_object *commit;
git_describe_result *describe_result;
git_buf buf = { 0 };
if (rev) {
check_lg2(git_revparse_single(&commit, repo, rev),
"Failed to lookup rev", rev);
check_lg2(git_describe_commit(&describe_result, commit, &opts->describe_options),
"Failed to describe rev", rev);
}
else
check_lg2(git_describe_workdir(&describe_result, repo, &opts->describe_options),
"Failed to describe workdir", NULL);
check_lg2(git_describe_format(&buf, describe_result, &opts->format_options),
"Failed to format describe rev", rev);
printf("%s\n", buf.ptr);
}
static void do_describe(git_repository *repo, describe_options *opts)
{
if (opts->commit_count == 0)
do_describe_single(repo, opts, NULL);
else
{
size_t i;
for (i = 0; i < opts->commit_count; i++)
do_describe_single(repo, opts, opts->commits[i]);
}
}
static void print_usage(void)
{
fprintf(stderr, "usage: see `git help describe`\n");
exit(1);
}
/** Parse command line arguments */
static void parse_options(describe_options *opts, int argc, char **argv)
{
args_info args = ARGS_INFO_INIT;
for (args.pos = 1; args.pos < argc; ++args.pos) {
const char *curr = argv[args.pos];
if (curr[0] != '-') {
opts_add_commit(opts, curr);
} else if (!strcmp(curr, "--all")) {
opts->describe_options.describe_strategy = GIT_DESCRIBE_ALL;
} else if (!strcmp(curr, "--tags")) {
opts->describe_options.describe_strategy = GIT_DESCRIBE_TAGS;
} else if (!strcmp(curr, "--exact-match")) {
opts->describe_options.max_candidates_tags = 0;
} else if (!strcmp(curr, "--long")) {
opts->format_options.always_use_long_format = 1;
} else if (!strcmp(curr, "--always")) {
opts->describe_options.show_commit_oid_as_fallback = 1;
} else if (!strcmp(curr, "--first-parent")) {
opts->describe_options.only_follow_first_parent = 1;
} else if (optional_str_arg(&opts->format_options.dirty_suffix, &args, "--dirty", "-dirty")) {
} else if (match_int_arg((int *)&opts->format_options.abbreviated_size, &args, "--abbrev", 0)) {
} else if (match_int_arg((int *)&opts->describe_options.max_candidates_tags, &args, "--candidates", 0)) {
} else if (match_str_arg(&opts->describe_options.pattern, &args, "--match")) {
}
}
if (opts->commit_count > 0) {
if (opts->format_options.dirty_suffix)
fatal("--dirty is incompatible with commit-ishes", NULL);
}
else {
if (!opts->format_options.dirty_suffix || !opts->format_options.dirty_suffix[0]) {
opts_add_commit(opts, "HEAD");
}
}
}
/** Initialize describe_options struct */
static void describe_options_init(describe_options *opts)
{
memset(opts, 0, sizeof(*opts));
opts->commits = NULL;
opts->commit_count = 0;
git_describe_init_options(&opts->describe_options, GIT_DESCRIBE_OPTIONS_VERSION);
git_describe_init_format_options(&opts->format_options, GIT_DESCRIBE_FORMAT_OPTIONS_VERSION);
}
int main(int argc, char **argv)
{
git_repository *repo;
describe_options opts;
git_libgit2_init();
check_lg2(git_repository_open_ext(&repo, ".", 0, NULL),
"Could not open repository", NULL);
describe_options_init(&opts);
parse_options(&opts, argc, argv);
do_describe(repo, &opts);
git_repository_free(repo);
git_libgit2_shutdown();
return 0;
}
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