diff: add an internal option to dual-color diffs of diffs

[thirdparty/git.git] / builtin / range-diff.c

#include "cache.h"
#include "builtin.h"
#include "parse-options.h"
#include "range-diff.h"
#include "config.h"

static const char * const builtin_range_diff_usage[] = {
N_("git range-diff [<options>] <old-base>..<old-tip> <new-base>..<new-tip>"),
N_("git range-diff [<options>] <old-tip>...<new-tip>"),
N_("git range-diff [<options>] <base> <old-tip> <new-tip>"),
NULL
};

static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
{
	return data;
}

int cmd_range_diff(int argc, const char **argv, const char *prefix)
{
	int creation_factor = 60;
	struct diff_options diffopt = { NULL };
	struct option options[] = {
		OPT_INTEGER(0, "creation-factor", &creation_factor,
			    N_("Percentage by which creation is weighted")),
		OPT_END()
	};
	int i, j, res = 0;
	struct strbuf four_spaces = STRBUF_INIT;
	struct strbuf range1 = STRBUF_INIT, range2 = STRBUF_INIT;

	git_config(git_diff_ui_config, NULL);

	diff_setup(&diffopt);
	diffopt.output_format = DIFF_FORMAT_PATCH;
	diffopt.flags.suppress_diff_headers = 1;
	diffopt.output_prefix = output_prefix_cb;
	strbuf_addstr(&four_spaces, "    ");
	diffopt.output_prefix_data = &four_spaces;

	argc = parse_options(argc, argv, NULL, options,
			     builtin_range_diff_usage, PARSE_OPT_KEEP_UNKNOWN |
			     PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_ARGV0);

	for (i = j = 1; i < argc && strcmp("--", argv[i]); ) {
		int c = diff_opt_parse(&diffopt, argv + i, argc - i, prefix);

		if (!c)
			argv[j++] = argv[i++];
		else
			i += c;
	}
	while (i < argc)
		argv[j++] = argv[i++];
	argc = j;
	diff_setup_done(&diffopt);

	/* Make sure that there are no unparsed options */
	argc = parse_options(argc, argv, NULL,
			     options + ARRAY_SIZE(options) - 1, /* OPT_END */
			     builtin_range_diff_usage, 0);

	if (argc == 2) {
		if (!strstr(argv[0], ".."))
			die(_("no .. in range: '%s'"), argv[0]);
		strbuf_addstr(&range1, argv[0]);

		if (!strstr(argv[1], ".."))
			die(_("no .. in range: '%s'"), argv[1]);
		strbuf_addstr(&range2, argv[1]);
	} else if (argc == 3) {
		strbuf_addf(&range1, "%s..%s", argv[0], argv[1]);
		strbuf_addf(&range2, "%s..%s", argv[0], argv[2]);
	} else if (argc == 1) {
		const char *b = strstr(argv[0], "..."), *a = argv[0];
		int a_len;

		if (!b) {
			error(_("single arg format must be symmetric range"));
			usage_with_options(builtin_range_diff_usage, options);
		}

		a_len = (int)(b - a);
		if (!a_len) {
			a = "HEAD";
			a_len = strlen(a);
		}
		b += 3;
		if (!*b)
			b = "HEAD";
		strbuf_addf(&range1, "%s..%.*s", b, a_len, a);
		strbuf_addf(&range2, "%.*s..%s", a_len, a, b);
	} else {
		error(_("need two commit ranges"));
		usage_with_options(builtin_range_diff_usage, options);
	}

	res = show_range_diff(range1.buf, range2.buf, creation_factor,
			      &diffopt);

	strbuf_release(&range1);
	strbuf_release(&range2);
	strbuf_release(&four_spaces);

	return res;
}