1 files changed, 425 insertions, 0 deletions

diff --git a/builtin-diff.c b/builtin-diff.c
new file mode 100644
index 0000000000..ffcdd055ca
--- /dev/null
+++ b/builtin-diff.c
@@ -0,0 +1,425 @@
+/*
+ * Builtin "git diff"
+ *
+ * Copyright (c) 2006 Junio C Hamano
+ */
+#include "cache.h"
+#include "color.h"
+#include "commit.h"
+#include "blob.h"
+#include "tag.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "revision.h"
+#include "log-tree.h"
+#include "builtin.h"
+
+struct blobinfo {
+	unsigned char sha1[20];
+	const char *name;
+	unsigned mode;
+};
+
+static const char builtin_diff_usage[] =
+"git diff <options> <rev>{0,2} -- <path>*";
+
+static void stuff_change(struct diff_options *opt,
+			 unsigned old_mode, unsigned new_mode,
+			 const unsigned char *old_sha1,
+			 const unsigned char *new_sha1,
+			 const char *old_name,
+			 const char *new_name)
+{
+	struct diff_filespec *one, *two;
+
+	if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
+	    !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
+		return;
+
+	if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
+		unsigned tmp;
+		const unsigned char *tmp_u;
+		const char *tmp_c;
+		tmp = old_mode; old_mode = new_mode; new_mode = tmp;
+		tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
+		tmp_c = old_name; old_name = new_name; new_name = tmp_c;
+	}
+
+	if (opt->prefix &&
+	    (strncmp(old_name, opt->prefix, opt->prefix_length) ||
+	     strncmp(new_name, opt->prefix, opt->prefix_length)))
+		return;
+
+	one = alloc_filespec(old_name);
+	two = alloc_filespec(new_name);
+	fill_filespec(one, old_sha1, old_mode);
+	fill_filespec(two, new_sha1, new_mode);
+
+	diff_queue(&diff_queued_diff, one, two);
+}
+
+static int builtin_diff_b_f(struct rev_info *revs,
+			    int argc, const char **argv,
+			    struct blobinfo *blob,
+			    const char *path)
+{
+	/* Blob vs file in the working tree*/
+	struct stat st;
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	if (lstat(path, &st))
+		die_errno("failed to stat '%s'", path);
+	if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
+		die("'%s': not a regular file or symlink", path);
+
+	diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
+
+	if (blob[0].mode == S_IFINVALID)
+		blob[0].mode = canon_mode(st.st_mode);
+
+	stuff_change(&revs->diffopt,
+		     blob[0].mode, canon_mode(st.st_mode),
+		     blob[0].sha1, null_sha1,
+		     path, path);
+	diffcore_std(&revs->diffopt);
+	diff_flush(&revs->diffopt);
+	return 0;
+}
+
+static int builtin_diff_blobs(struct rev_info *revs,
+			      int argc, const char **argv,
+			      struct blobinfo *blob)
+{
+	unsigned mode = canon_mode(S_IFREG | 0644);
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	if (blob[0].mode == S_IFINVALID)
+		blob[0].mode = mode;
+
+	if (blob[1].mode == S_IFINVALID)
+		blob[1].mode = mode;
+
+	stuff_change(&revs->diffopt,
+		     blob[0].mode, blob[1].mode,
+		     blob[0].sha1, blob[1].sha1,
+		     blob[0].name, blob[1].name);
+	diffcore_std(&revs->diffopt);
+	diff_flush(&revs->diffopt);
+	return 0;
+}
+
+static int builtin_diff_index(struct rev_info *revs,
+			      int argc, const char **argv)
+{
+	int cached = 0;
+	while (1 < argc) {
+		const char *arg = argv[1];
+		if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
+			cached = 1;
+		else
+			usage(builtin_diff_usage);
+		argv++; argc--;
+	}
+	if (!cached)
+		setup_work_tree();
+	/*
+	 * Make sure there is one revision (i.e. pending object),
+	 * and there is no revision filtering parameters.
+	 */
+	if (revs->pending.nr != 1 ||
+	    revs->max_count != -1 || revs->min_age != -1 ||
+	    revs->max_age != -1)
+		usage(builtin_diff_usage);
+	if (read_cache_preload(revs->diffopt.paths) < 0) {
+		perror("read_cache_preload");
+		return -1;
+	}
+	return run_diff_index(revs, cached);
+}
+
+static int builtin_diff_tree(struct rev_info *revs,
+			     int argc, const char **argv,
+			     struct object_array_entry *ent)
+{
+	const unsigned char *(sha1[2]);
+	int swap = 0;
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	/* We saw two trees, ent[0] and ent[1].
+	 * if ent[1] is uninteresting, they are swapped
+	 */
+	if (ent[1].item->flags & UNINTERESTING)
+		swap = 1;
+	sha1[swap] = ent[0].item->sha1;
+	sha1[1-swap] = ent[1].item->sha1;
+	diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
+	log_tree_diff_flush(revs);
+	return 0;
+}
+
+static int builtin_diff_combined(struct rev_info *revs,
+				 int argc, const char **argv,
+				 struct object_array_entry *ent,
+				 int ents)
+{
+	const unsigned char (*parent)[20];
+	int i;
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	if (!revs->dense_combined_merges && !revs->combine_merges)
+		revs->dense_combined_merges = revs->combine_merges = 1;
+	parent = xmalloc(ents * sizeof(*parent));
+	for (i = 0; i < ents; i++)
+		hashcpy((unsigned char *)(parent + i), ent[i].item->sha1);
+	diff_tree_combined(parent[0], parent + 1, ents - 1,
+			   revs->dense_combined_merges, revs);
+	return 0;
+}
+
+static void refresh_index_quietly(void)
+{
+	struct lock_file *lock_file;
+	int fd;
+
+	lock_file = xcalloc(1, sizeof(struct lock_file));
+	fd = hold_locked_index(lock_file, 0);
+	if (fd < 0)
+		return;
+	discard_cache();
+	read_cache();
+	refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
+
+	if (active_cache_changed &&
+	    !write_cache(fd, active_cache, active_nr))
+		commit_locked_index(lock_file);
+
+	rollback_lock_file(lock_file);
+}
+
+static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
+{
+	int result;
+	unsigned int options = 0;
+
+	while (1 < argc && argv[1][0] == '-') {
+		if (!strcmp(argv[1], "--base"))
+			revs->max_count = 1;
+		else if (!strcmp(argv[1], "--ours"))
+			revs->max_count = 2;
+		else if (!strcmp(argv[1], "--theirs"))
+			revs->max_count = 3;
+		else if (!strcmp(argv[1], "-q"))
+			options |= DIFF_SILENT_ON_REMOVED;
+		else if (!strcmp(argv[1], "-h"))
+			usage(builtin_diff_usage);
+		else
+			return error("invalid option: %s", argv[1]);
+		argv++; argc--;
+	}
+
+	/*
+	 * "diff --base" should not combine merges because it was not
+	 * asked to.  "diff -c" should not densify (if the user wants
+	 * dense one, --cc can be explicitly asked for, or just rely
+	 * on the default).
+	 */
+	if (revs->max_count == -1 && !revs->combine_merges &&
+	    (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
+		revs->combine_merges = revs->dense_combined_merges = 1;
+
+	setup_work_tree();
+	if (read_cache_preload(revs->diffopt.paths) < 0) {
+		perror("read_cache_preload");
+		return -1;
+	}
+	result = run_diff_files(revs, options);
+	return diff_result_code(&revs->diffopt, result);
+}
+
+int cmd_diff(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	struct rev_info rev;
+	struct object_array_entry ent[100];
+	int ents = 0, blobs = 0, paths = 0;
+	const char *path = NULL;
+	struct blobinfo blob[2];
+	int nongit;
+	int result = 0;
+
+	/*
+	 * We could get N tree-ish in the rev.pending_objects list.
+	 * Also there could be M blobs there, and P pathspecs.
+	 *
+	 * N=0, M=0:
+	 *	cache vs files (diff-files)
+	 * N=0, M=2:
+	 *      compare two random blobs.  P must be zero.
+	 * N=0, M=1, P=1:
+	 *	compare a blob with a working tree file.
+	 *
+	 * N=1, M=0:
+	 *      tree vs cache (diff-index --cached)
+	 *
+	 * N=2, M=0:
+	 *      tree vs tree (diff-tree)
+	 *
+	 * N=0, M=0, P=2:
+	 *      compare two filesystem entities (aka --no-index).
+	 *
+	 * Other cases are errors.
+	 */
+
+	prefix = setup_git_directory_gently(&nongit);
+	git_config(git_diff_ui_config, NULL);
+
+	if (diff_use_color_default == -1)
+		diff_use_color_default = git_use_color_default;
+
+	init_revisions(&rev, prefix);
+
+	/* If this is a no-index diff, just run it and exit there. */
+	diff_no_index(&rev, argc, argv, nongit, prefix);
+
+	/* Otherwise, we are doing the usual "git" diff */
+	rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
+
+	/* Default to let external and textconv be used */
+	DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
+	DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
+
+	if (nongit)
+		die("Not a git repository");
+	argc = setup_revisions(argc, argv, &rev, NULL);
+	if (!rev.diffopt.output_format) {
+		rev.diffopt.output_format = DIFF_FORMAT_PATCH;
+		if (diff_setup_done(&rev.diffopt) < 0)
+			die("diff_setup_done failed");
+	}
+
+	DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
+
+	/*
+	 * If the user asked for our exit code then don't start a
+	 * pager or we would end up reporting its exit code instead.
+	 */
+	if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
+	    check_pager_config("diff") != 0)
+		setup_pager();
+
+	/*
+	 * Do we have --cached and not have a pending object, then
+	 * default to HEAD by hand.  Eek.
+	 */
+	if (!rev.pending.nr) {
+		int i;
+		for (i = 1; i < argc; i++) {
+			const char *arg = argv[i];
+			if (!strcmp(arg, "--"))
+				break;
+			else if (!strcmp(arg, "--cached") ||
+				 !strcmp(arg, "--staged")) {
+				add_head_to_pending(&rev);
+				if (!rev.pending.nr)
+					die("No HEAD commit to compare with (yet)");
+				break;
+			}
+		}
+	}
+
+	for (i = 0; i < rev.pending.nr; i++) {
+		struct object_array_entry *list = rev.pending.objects+i;
+		struct object *obj = list->item;
+		const char *name = list->name;
+		int flags = (obj->flags & UNINTERESTING);
+		if (!obj->parsed)
+			obj = parse_object(obj->sha1);
+		obj = deref_tag(obj, NULL, 0);
+		if (!obj)
+			die("invalid object '%s' given.", name);
+		if (obj->type == OBJ_COMMIT)
+			obj = &((struct commit *)obj)->tree->object;
+		if (obj->type == OBJ_TREE) {
+			if (ARRAY_SIZE(ent) <= ents)
+				die("more than %d trees given: '%s'",
+				    (int) ARRAY_SIZE(ent), name);
+			obj->flags |= flags;
+			ent[ents].item = obj;
+			ent[ents].name = name;
+			ents++;
+			continue;
+		}
+		if (obj->type == OBJ_BLOB) {
+			if (2 <= blobs)
+				die("more than two blobs given: '%s'", name);
+			hashcpy(blob[blobs].sha1, obj->sha1);
+			blob[blobs].name = name;
+			blob[blobs].mode = list->mode;
+			blobs++;
+			continue;
+
+		}
+		die("unhandled object '%s' given.", name);
+	}
+	if (rev.prune_data) {
+		const char **pathspec = rev.prune_data;
+		while (*pathspec) {
+			if (!path)
+				path = *pathspec;
+			paths++;
+			pathspec++;
+		}
+	}
+
+	/*
+	 * Now, do the arguments look reasonable?
+	 */
+	if (!ents) {
+		switch (blobs) {
+		case 0:
+			result = builtin_diff_files(&rev, argc, argv);
+			break;
+		case 1:
+			if (paths != 1)
+				usage(builtin_diff_usage);
+			result = builtin_diff_b_f(&rev, argc, argv, blob, path);
+			break;
+		case 2:
+			if (paths)
+				usage(builtin_diff_usage);
+			result = builtin_diff_blobs(&rev, argc, argv, blob);
+			break;
+		default:
+			usage(builtin_diff_usage);
+		}
+	}
+	else if (blobs)
+		usage(builtin_diff_usage);
+	else if (ents == 1)
+		result = builtin_diff_index(&rev, argc, argv);
+	else if (ents == 2)
+		result = builtin_diff_tree(&rev, argc, argv, ent);
+	else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
+		/* diff A...B where there is one sane merge base between
+		 * A and B.  We have ent[0] == merge-base, ent[1] == A,
+		 * and ent[2] == B.  Show diff between the base and B.
+		 */
+		ent[1] = ent[2];
+		result = builtin_diff_tree(&rev, argc, argv, ent);
+	}
+	else
+		result = builtin_diff_combined(&rev, argc, argv,
+					     ent, ents);
+	result = diff_result_code(&rev.diffopt, result);
+	if (1 < rev.diffopt.skip_stat_unmatch)
+		refresh_index_quietly();
+	return result;
+}