built-in diff.

This starts to replace the shell script version of "git diff".

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 332 insertions, 0 deletions

diff --git a/builtin-diff.c b/builtin-diff.c
new file mode 100644
index 0000000000..196821294e
--- /dev/null
+++ b/builtin-diff.c
@@ -0,0 +1,332 @@
+/*
+ * Builtin "git diff"
+ *
+ * Copyright (c) 2006 Junio C Hamano
+ */
+#include "cache.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"
+
+/* NEEDSWORK: struct object has place for name but we _do_
+ * know mode when we extracted the blob out of a tree, which
+ * we currently lose.
+ */
+struct blobinfo {
+	unsigned char sha1[20];
+	const char *name;
+};
+
+static const char builtin_diff_usage[] =
+"diff <options> <rev>{0,2} -- <path>*";
+
+static int builtin_diff_files(struct rev_info *revs,
+			      int argc, const char **argv)
+{
+	int silent = 0;
+	while (1 < argc) {
+		const char *arg = argv[1];
+		if (!strcmp(arg, "--base"))
+			revs->max_count = 1;
+		else if (!strcmp(arg, "--ours"))
+			revs->max_count = 2;
+		else if (!strcmp(arg, "--theirs"))
+			revs->max_count = 3;
+		else if (!strcmp(arg, "-q"))
+			silent = 1;
+		else if (!strcmp(arg, "--raw"))
+			revs->diffopt.output_format = DIFF_FORMAT_RAW;
+		else
+			usage(builtin_diff_usage);
+		argv++; argc--;
+	}
+	/*
+	 * Make sure there are NO revision (i.e. pending object) parameter,
+	 * rev.max_count is reasonable (0 <= n <= 3),
+	 * there is no other revision filtering parameters.
+	 */
+	if (revs->pending_objects ||
+	    revs->min_age != -1 ||
+	    revs->max_age != -1)
+		usage(builtin_diff_usage);
+	/*
+	 * Backward compatibility wart - "diff-files -s" used to
+	 * defeat the common diff option "-s" which asked for
+	 * DIFF_FORMAT_NO_OUTPUT.
+	 */
+	if (revs->diffopt.output_format == DIFF_FORMAT_NO_OUTPUT)
+		revs->diffopt.output_format = DIFF_FORMAT_RAW;
+	return run_diff_files(revs, silent);
+}
+
+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 (memcmp(null_sha1, old_sha1, 20) &&
+	    memcmp(null_sha1, new_sha1, 20) &&
+	    !memcmp(old_sha1, new_sha1, 20))
+		return;
+
+	if (opt->reverse_diff) {
+		unsigned tmp;
+		const
+			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;
+	}
+	one = alloc_filespec(old_name);
+	two = alloc_filespec(new_name);
+	fill_filespec(one, old_sha1, old_mode);
+	fill_filespec(two, new_sha1, new_mode);
+
+	/* NEEDSWORK: shouldn't this part of diffopt??? */
+	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;
+
+	while (1 < argc) {
+		const char *arg = argv[1];
+		if (!strcmp(arg, "--raw"))
+			revs->diffopt.output_format = DIFF_FORMAT_RAW;
+		else
+			usage(builtin_diff_usage);
+		argv++; argc--;
+	}
+	if (lstat(path, &st))
+		die("'%s': %s", path, strerror(errno));
+	if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
+		die("'%s': not a regular file or symlink", path);
+	stuff_change(&revs->diffopt,
+		     canon_mode(st.st_mode), canon_mode(st.st_mode),
+		     blob[0].sha1, null_sha1,
+		     blob[0].name, 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)
+{
+	/* Blobs */
+	unsigned mode = canon_mode(S_IFREG | 0644);
+
+	while (1 < argc) {
+		const char *arg = argv[1];
+		if (!strcmp(arg, "--raw"))
+			revs->diffopt.output_format = DIFF_FORMAT_RAW;
+		else
+			usage(builtin_diff_usage);
+		argv++; argc--;
+	}
+	stuff_change(&revs->diffopt,
+		     mode, mode,
+		     blob[0].sha1, blob[1].sha1,
+		     blob[1].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"))
+			cached = 1;
+		else if (!strcmp(arg, "--raw"))
+			revs->diffopt.output_format = DIFF_FORMAT_RAW;
+		else
+			usage(builtin_diff_usage);
+		argv++; argc--;
+	}
+	/*
+	 * Make sure there is one revision (i.e. pending object),
+	 * and there is no revision filtering parameters.
+	 */
+	if (!revs->pending_objects || revs->pending_objects->next ||
+	    revs->max_count != -1 || revs->min_age != -1 ||
+	    revs->max_age != -1)
+		usage(builtin_diff_usage);
+	return run_diff_index(revs, cached);
+}
+
+static int builtin_diff_tree(struct rev_info *revs,
+			     int argc, const char **argv,
+			     struct object_list *ent)
+{
+	/* We saw two trees, ent[0] and ent[1].
+	 * unless ent[0] is unintesting, they are swapped
+	 */
+	const unsigned char *(sha1[2]);
+	int swap = 1;
+	while (1 < argc) {
+		const char *arg = argv[1];
+		if (!strcmp(arg, "--raw"))
+			revs->diffopt.output_format = DIFF_FORMAT_RAW;
+		else
+			usage(builtin_diff_usage);
+		argv++; argc--;
+	}
+	if (ent[0].item->flags & UNINTERESTING)
+		swap = 0;
+	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 void add_head(struct rev_info *revs)
+{
+	unsigned char sha1[20];
+	struct object *obj;
+	if (get_sha1("HEAD", sha1))
+		return;
+	obj = parse_object(sha1);
+	if (!obj)
+		return;
+	add_object(obj, &revs->pending_objects, NULL, "HEAD");
+}
+
+int cmd_diff(int argc, const char **argv, char **envp)
+{
+	struct rev_info rev;
+	struct object_list *list, ent[2];
+	int ents = 0, blobs = 0, paths = 0;
+	const char *path = NULL;
+	struct blobinfo blob[2];
+
+	/*
+	 * 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)
+	 *
+	 * Other cases are errors.
+	 */
+	
+	git_config(git_diff_config);
+	init_revisions(&rev);
+	rev.diffopt.output_format = DIFF_FORMAT_PATCH;
+
+	argc = setup_revisions(argc, argv, &rev, NULL);
+	/* Do we have --cached and not have a pending object, then
+	 * default to HEAD by hand.  Eek.
+	 */
+	if (!rev.pending_objects) {
+		int i;
+		for (i = 1; i < argc; i++) {
+			const char *arg = argv[i];
+			if (!strcmp(arg, "--"))
+				break;
+			else if (!strcmp(arg, "--cached")) {
+				add_head(&rev);
+				break;
+			}
+		}
+	}
+
+	for (list = rev.pending_objects; list; list = list->next) {
+		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 (!strcmp(obj->type, commit_type))
+			obj = &((struct commit *)obj)->tree->object;
+		if (!strcmp(obj->type, tree_type)) {
+			if (2 <= ents)
+				die("more than two trees given: '%s'", name);
+			obj->flags |= flags;
+			ent[ents].item = obj;
+			ent[ents].name = name;
+			ents++;
+			continue;
+		}
+		if (!strcmp(obj->type, blob_type)) {
+			if (2 <= blobs)
+				die("more than two blobs given: '%s'", name);
+			memcpy(blob[blobs].sha1, obj->sha1, 20);
+			blob[blobs].name = name;
+			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:
+			return builtin_diff_files(&rev, argc, argv);
+			break;
+		case 1:
+			if (paths != 1)
+				usage(builtin_diff_usage);
+			return builtin_diff_b_f(&rev, argc, argv, blob, path);
+			break;
+		case 2:
+			return builtin_diff_blobs(&rev, argc, argv, blob);
+			break;
+		default:
+			usage(builtin_diff_usage);
+		}
+	}
+	else if (blobs)
+		usage(builtin_diff_usage);
+	else if (ents == 1)
+		return builtin_diff_index(&rev, argc, argv);
+	else if (ents == 2)
+		return builtin_diff_tree(&rev, argc, argv, ent);
+	usage(builtin_diff_usage);
+}