diff.c 9.59 KB
Newer Older
1
/*
2
 * libgit2 "diff" example - shows how to use the diff API
3
 *
4 5 6 7 8 9 10 11 12
 * 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/>.
13 14 15 16
 */

#include "common.h"

17
/**
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
 * This example demonstrates the use of the libgit2 diff APIs to
 * create `git_diff` objects and display them, emulating a number of
 * core Git `diff` command line options.
 *
 * This covers on a portion of the core Git diff options and doesn't
 * have particularly good error handling, but it should show most of
 * the core libgit2 diff APIs, including various types of diffs and
 * how to do renaming detection and patch formatting.
 */

static const char *colors[] = {
	"\033[m", /* reset */
	"\033[1m", /* bold */
	"\033[31m", /* red */
	"\033[32m", /* green */
	"\033[36m" /* cyan */
};
35

36
enum {
37 38 39 40 41
	OUTPUT_DIFF = (1 << 0),
	OUTPUT_STAT = (1 << 1),
	OUTPUT_SHORTSTAT = (1 << 2),
	OUTPUT_NUMSTAT = (1 << 3),
	OUTPUT_SUMMARY = (1 << 4)
42 43 44 45 46 47 48 49
};

enum {
	CACHE_NORMAL = 0,
	CACHE_ONLY = 1,
	CACHE_NONE = 2
};

50
/** The 'opts' struct captures all the various parsed command line options. */
51 52 53 54
struct opts {
	git_diff_options diffopts;
	git_diff_find_options findopts;
	int color;
55 56
	int cache;
	int output;
57 58 59 60 61 62
	git_diff_format_t format;
	const char *treeish1;
	const char *treeish2;
	const char *dir;
};

63
/** These functions are implemented at the end */
64
static void usage(const char *message, const char *arg);
65
static void parse_opts(struct opts *o, int argc, char *argv[]);
66 67
static int color_printer(
	const git_diff_delta*, const git_diff_hunk*, const git_diff_line*, void*);
68
static void diff_print_stats(git_diff *diff, struct opts *o);
69

70
int main(int argc, char *argv[])
71
{
72 73 74 75 76
	git_repository *repo = NULL;
	git_tree *t1 = NULL, *t2 = NULL;
	git_diff *diff;
	struct opts o = {
		GIT_DIFF_OPTIONS_INIT, GIT_DIFF_FIND_OPTIONS_INIT,
77
		-1, 0, 0, GIT_DIFF_FORMAT_PATCH, NULL, NULL, "."
78 79
	};

80
	git_libgit2_init();
81 82 83 84 85 86

	parse_opts(&o, argc, argv);

	check_lg2(git_repository_open_ext(&repo, o.dir, 0, NULL),
		"Could not open repository", o.dir);

87 88 89
	/**
	 * Possible argument patterns:
	 *
90 91 92
	 *  * &lt;sha1&gt; &lt;sha2&gt;
	 *  * &lt;sha1&gt; --cached
	 *  * &lt;sha1&gt;
93
	 *  * --cached
94
	 *  * --nocache (don't use index data in diff at all)
95
	 *  * nothing
96
	 *
97
	 * Currently ranged arguments like &lt;sha1&gt;..&lt;sha2&gt; and &lt;sha1&gt;...&lt;sha2&gt;
98 99 100 101 102 103 104 105 106 107 108 109
	 * are not supported in this example
	 */

	if (o.treeish1)
		treeish_to_tree(&t1, repo, o.treeish1);
	if (o.treeish2)
		treeish_to_tree(&t2, repo, o.treeish2);

	if (t1 && t2)
		check_lg2(
			git_diff_tree_to_tree(&diff, repo, t1, t2, &o.diffopts),
			"diff trees", NULL);
110 111 112 113 114 115 116 117 118 119 120 121 122
	else if (o.cache != CACHE_NORMAL) {
		if (!t1)
			treeish_to_tree(&t1, repo, "HEAD");

		if (o.cache == CACHE_NONE)
			check_lg2(
				git_diff_tree_to_workdir(&diff, repo, t1, &o.diffopts),
				"diff tree to working directory", NULL);
		else
			check_lg2(
				git_diff_tree_to_index(&diff, repo, t1, NULL, &o.diffopts),
				"diff tree to index", NULL);
	}
123 124 125 126 127 128 129 130 131
	else if (t1)
		check_lg2(
			git_diff_tree_to_workdir_with_index(&diff, repo, t1, &o.diffopts),
			"diff tree to working directory", NULL);
	else
		check_lg2(
			git_diff_index_to_workdir(&diff, repo, NULL, &o.diffopts),
			"diff index to working directory", NULL);

132
	/** Apply rename and copy detection if requested. */
133 134 135 136 137 138

	if ((o.findopts.flags & GIT_DIFF_FIND_ALL) != 0)
		check_lg2(
			git_diff_find_similar(diff, &o.findopts),
			"finding renames and copies", NULL);

139
	/** Generate simple output using libgit2 display helper. */
140

141 142 143 144
	if (!o.output)
		o.output = OUTPUT_DIFF;

	if (o.output != OUTPUT_DIFF)
145 146
		diff_print_stats(diff, &o);

147
	if ((o.output & OUTPUT_DIFF) != 0) {
148 149
		if (o.color >= 0)
			fputs(colors[0], stdout);
150

151 152 153
		check_lg2(
			git_diff_print(diff, o.format, color_printer, &o.color),
			"displaying diff", NULL);
154

155 156 157
		if (o.color >= 0)
			fputs(colors[0], stdout);
	}
158

159
	/** Cleanup before exiting. */
160 161 162 163 164 165

	git_diff_free(diff);
	git_tree_free(t1);
	git_tree_free(t2);
	git_repository_free(repo);

166
	git_libgit2_shutdown();
167 168

	return 0;
169 170
}

171 172 173 174 175 176 177 178 179
static void usage(const char *message, const char *arg)
{
	if (message && arg)
		fprintf(stderr, "%s: %s\n", message, arg);
	else if (message)
		fprintf(stderr, "%s\n", message);
	fprintf(stderr, "usage: diff [<tree-oid> [<tree-oid>]]\n");
	exit(1);
}
180

181
/** This implements very rudimentary colorized output. */
182
static int color_printer(
183
	const git_diff_delta *delta,
184 185
	const git_diff_hunk *hunk,
	const git_diff_line *line,
186
	void *data)
187 188 189
{
	int *last_color = data, color = 0;

190
	(void)delta; (void)hunk;
191

192
	if (*last_color >= 0) {
193 194 195
		switch (line->origin) {
		case GIT_DIFF_LINE_ADDITION:  color = 3; break;
		case GIT_DIFF_LINE_DELETION:  color = 2; break;
196 197
		case GIT_DIFF_LINE_ADD_EOFNL: color = 3; break;
		case GIT_DIFF_LINE_DEL_EOFNL: color = 2; break;
198 199 200
		case GIT_DIFF_LINE_FILE_HDR:  color = 1; break;
		case GIT_DIFF_LINE_HUNK_HDR:  color = 4; break;
		default: break;
201
		}
202

203 204 205 206 207 208 209 210
		if (color != *last_color) {
			if (*last_color == 1 || color == 1)
				fputs(colors[0], stdout);
			fputs(colors[color], stdout);
			*last_color = color;
		}
	}

211
	return diff_output(delta, hunk, line, stdout);
212 213
}

214
/** Parse arguments as copied from git-diff. */
215
static void parse_opts(struct opts *o, int argc, char *argv[])
216
{
217
	struct args_info args = ARGS_INFO_INIT;
218

219

220 221
	for (args.pos = 1; args.pos < argc; ++args.pos) {
		const char *a = argv[args.pos];
222 223

		if (a[0] != '-') {
224 225 226 227
			if (o->treeish1 == NULL)
				o->treeish1 = a;
			else if (o->treeish2 == NULL)
				o->treeish2 = a;
228 229 230 231
			else
				usage("Only one or two tree identifiers can be provided", NULL);
		}
		else if (!strcmp(a, "-p") || !strcmp(a, "-u") ||
232 233
				 !strcmp(a, "--patch")) {
			o->output |= OUTPUT_DIFF;
234
			o->format = GIT_DIFF_FORMAT_PATCH;
235
		}
236
		else if (!strcmp(a, "--cached"))
237 238 239 240
			o->cache = CACHE_ONLY;
		else if (!strcmp(a, "--nocache"))
			o->cache = CACHE_NONE;
		else if (!strcmp(a, "--name-only") || !strcmp(a, "--format=name"))
241
			o->format = GIT_DIFF_FORMAT_NAME_ONLY;
242 243
		else if (!strcmp(a, "--name-status") ||
				!strcmp(a, "--format=name-status"))
244
			o->format = GIT_DIFF_FORMAT_NAME_STATUS;
245
		else if (!strcmp(a, "--raw") || !strcmp(a, "--format=raw"))
246
			o->format = GIT_DIFF_FORMAT_RAW;
247 248 249 250
		else if (!strcmp(a, "--format=diff-index")) {
			o->format = GIT_DIFF_FORMAT_RAW;
			o->diffopts.id_abbrev = 40;
		}
251
		else if (!strcmp(a, "--color"))
252
			o->color = 0;
253
		else if (!strcmp(a, "--no-color"))
254
			o->color = -1;
255
		else if (!strcmp(a, "-R"))
256
			o->diffopts.flags |= GIT_DIFF_REVERSE;
257
		else if (!strcmp(a, "-a") || !strcmp(a, "--text"))
258
			o->diffopts.flags |= GIT_DIFF_FORCE_TEXT;
259
		else if (!strcmp(a, "--ignore-space-at-eol"))
260
			o->diffopts.flags |= GIT_DIFF_IGNORE_WHITESPACE_EOL;
261
		else if (!strcmp(a, "-b") || !strcmp(a, "--ignore-space-change"))
262
			o->diffopts.flags |= GIT_DIFF_IGNORE_WHITESPACE_CHANGE;
263
		else if (!strcmp(a, "-w") || !strcmp(a, "--ignore-all-space"))
264
			o->diffopts.flags |= GIT_DIFF_IGNORE_WHITESPACE;
265
		else if (!strcmp(a, "--ignored"))
266
			o->diffopts.flags |= GIT_DIFF_INCLUDE_IGNORED;
267
		else if (!strcmp(a, "--untracked"))
268
			o->diffopts.flags |= GIT_DIFF_INCLUDE_UNTRACKED;
269 270 271 272
		else if (!strcmp(a, "--patience"))
			o->diffopts.flags |= GIT_DIFF_PATIENCE;
		else if (!strcmp(a, "--minimal"))
			o->diffopts.flags |= GIT_DIFF_MINIMAL;
273
		else if (!strcmp(a, "--stat"))
274
			o->output |= OUTPUT_STAT;
275
		else if (!strcmp(a, "--numstat"))
276
			o->output |= OUTPUT_NUMSTAT;
277
		else if (!strcmp(a, "--shortstat"))
278 279 280
			o->output |= OUTPUT_SHORTSTAT;
		else if (!strcmp(a, "--summary"))
			o->output |= OUTPUT_SUMMARY;
281 282 283 284 285 286 287 288 289 290
		else if (match_uint16_arg(
				&o->findopts.rename_threshold, &args, "-M") ||
			match_uint16_arg(
				&o->findopts.rename_threshold, &args, "--find-renames"))
			o->findopts.flags |= GIT_DIFF_FIND_RENAMES;
		else if (match_uint16_arg(
				&o->findopts.copy_threshold, &args, "-C") ||
			match_uint16_arg(
				&o->findopts.copy_threshold, &args, "--find-copies"))
			o->findopts.flags |= GIT_DIFF_FIND_COPIES;
Russell Belfer committed
291
		else if (!strcmp(a, "--find-copies-harder"))
292 293
			o->findopts.flags |= GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED;
		else if (is_prefixed(a, "-B") || is_prefixed(a, "--break-rewrites"))
Russell Belfer committed
294
			/* TODO: parse thresholds */
295 296 297 298 299 300 301
			o->findopts.flags |= GIT_DIFF_FIND_REWRITES;
		else if (!match_uint16_arg(
				&o->diffopts.context_lines, &args, "-U") &&
			!match_uint16_arg(
				&o->diffopts.context_lines, &args, "--unified") &&
			!match_uint16_arg(
				&o->diffopts.interhunk_lines, &args, "--inter-hunk-context") &&
302 303
			!match_uint16_arg(
				&o->diffopts.id_abbrev, &args, "--abbrev") &&
304 305 306 307
			!match_str_arg(&o->diffopts.old_prefix, &args, "--src-prefix") &&
			!match_str_arg(&o->diffopts.new_prefix, &args, "--dst-prefix") &&
			!match_str_arg(&o->dir, &args, "--git-dir"))
			usage("Unknown command line argument", a);
308
	}
309
}
310

311
/** Display diff output with "--stat", "--numstat", or "--shortstat" */
312
static void diff_print_stats(git_diff *diff, struct opts *o)
313
{
314 315 316
	git_diff_stats *stats;
	git_buf b = GIT_BUF_INIT_CONST(NULL, 0);
	git_diff_stats_format_t format = 0;
317

318 319
	check_lg2(
		git_diff_get_stats(&stats, diff), "generating stats for diff", NULL);
320

321 322 323 324 325 326 327 328
	if (o->output & OUTPUT_STAT)
		format |= GIT_DIFF_STATS_FULL;
	if (o->output & OUTPUT_SHORTSTAT)
		format |= GIT_DIFF_STATS_SHORT;
	if (o->output & OUTPUT_NUMSTAT)
		format |= GIT_DIFF_STATS_NUMBER;
	if (o->output & OUTPUT_SUMMARY)
		format |= GIT_DIFF_STATS_INCLUDE_SUMMARY;
329

330 331
	check_lg2(
		git_diff_stats_to_buf(&b, stats, format, 80), "formatting stats", NULL);
332

333
	fputs(b.ptr, stdout);
334

335 336
	git_buf_free(&b);
	git_diff_stats_free(stats);
337
}