[PATCH] diff overhaul

This cleans up the way calls are made into the diff core from diff-tree
family and diff-helper.  Earlier, these programs had "if
(generating_patch)" sprinkled all over the place, but those ugliness are
gone and handled uniformly from the diff core, even when not generating
patch format.

This also allowed diff-cache and diff-files to acquire -R
(reverse) option to generate diff in reverse.  Users of
diff-tree can swap two trees easily so I did not add -R there.

[ Linus' note: I'll add -R to "diff-tree" too, since a "commit
  diff" doesn't have another tree to switch around: the other
  tree is always the parent(s) of the commit ]

Also -M<digits-as-mantissa> suggestion made by Linus has been
implemented.

Documentation updates are also included.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Documentation/git-diff-cache.txt

@@ -9,7 +9,7 @@ git-diff-cache - Compares content and mode of blobs between the cache and reposi
 
 SYNOPSIS
 --------
-'git-diff-cache' [-p] [-r] [-z] [-m] [-M] [--cached] <tree-ish>
+'git-diff-cache' [-p] [-r] [-z] [-m] [-M] [-R] [--cached] <tree-ish>
 
 DESCRIPTION
 -----------
@@ -36,6 +36,9 @@ OPTIONS
 -M::
 	Detect renames; implies -p.
 
+-R::
+	Output diff in reverse.
+
 --cached::
 	do not consider the on-disk file at all
 

Documentation/git-diff-files.txt

@@ -9,7 +9,7 @@ git-diff-files - Compares files in the working tree and the cache
 
 SYNOPSIS
 --------
-'git-diff-files' [-p] [-q] [-r] [-z] [-M] [<pattern>...]
+'git-diff-files' [-p] [-q] [-r] [-z] [-M] [-R] [<pattern>...]
 
 DESCRIPTION
 -----------
@@ -26,6 +26,9 @@ OPTIONS
 -q::
 	Remain silent even on nonexisting files
 
+-R::
+	Output diff in reverse.
+
 -M::
 	Detect renames; implies -p.
 

diff-cache.c

@@ -6,15 +6,13 @@ static int generate_patch = 0;
 static int match_nonexisting = 0;
 static int line_termination = '\n';
 static int detect_rename = 0;
+static int reverse_diff = 0;
+static int diff_score_opt = 0;
 
 /* A file entry went away or appeared */
 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
 {
-	if (generate_patch)
-		diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
-	else
-		printf("%s%06o\tblob\t%s\t%s%c", prefix, ntohl(mode),
-		       sha1_to_hex(sha1), ce->name, line_termination);
+	diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
 }
 
 static int get_stat_data(struct cache_entry *ce, unsigned char **sha1p, unsigned int *modep)
@@ -64,7 +62,6 @@ static int show_modified(struct cache_entry *old,
 {
 	unsigned int mode, oldmode;
 	unsigned char *sha1;
-	char old_sha1_hex[60];
 
 	if (get_stat_data(new, &sha1, &mode) < 0) {
 		if (report_missing)
@@ -79,15 +76,8 @@ static int show_modified(struct cache_entry *old,
 	mode = ntohl(mode);
 	oldmode = ntohl(oldmode);
 
-	if (generate_patch)
-		diff_change(oldmode, mode,
-			    old->sha1, sha1, old->name, NULL);
-	else {
-		strcpy(old_sha1_hex, sha1_to_hex(old->sha1));
-		printf("*%06o->%06o\tblob\t%s->%s\t%s%c", oldmode, mode,
-		       old_sha1_hex, sha1_to_hex(sha1),
-		       old->name, line_termination);
-	}
+	diff_change(oldmode, mode,
+		    old->sha1, sha1, old->name, NULL);
 	return 0;
 }
 
@@ -127,10 +117,7 @@ static int diff_cache(struct cache_entry **ac, int entries)
 				break;
 			/* fallthru */
 		case 3:
-			if (generate_patch)
-				diff_unmerge(ce->name);
-			else
-				printf("U %s%c", ce->name, line_termination);
+			diff_unmerge(ce->name);
 			break;
 
 		default:
@@ -166,7 +153,7 @@ static void mark_merge_entries(void)
 }
 
 static char *diff_cache_usage =
-"git-diff-cache [-p] [-r] [-z] [-m] [-M] [--cached] <tree-ish>";
+"git-diff-cache [-p] [-r] [-z] [-m] [-M] [-R] [--cached] <tree-ish>";
 
 int main(int argc, char **argv)
 {
@@ -188,14 +175,19 @@ int main(int argc, char **argv)
 			generate_patch = 1;
 			continue;
 		}
-		if (!strcmp(arg, "-M")) {
+		if (!strncmp(arg, "-M", 2)) {
 			generate_patch = detect_rename = 1;
+			diff_score_opt = diff_scoreopt_parse(arg);
 			continue;
 		}
 		if (!strcmp(arg, "-z")) {
 			line_termination = '\0';
 			continue;
 		}
+		if (!strcmp(arg, "-R")) {
+			reverse_diff = 1;
+			continue;
+		}
 		if (!strcmp(arg, "-m")) {
 			match_nonexisting = 1;
 			continue;
@@ -210,8 +202,9 @@ int main(int argc, char **argv)
 	if (argc != 2 || get_sha1(argv[1], tree_sha1))
 		usage(diff_cache_usage);
 
-	if (generate_patch)
-		diff_setup(detect_rename, 0, 0, 0, 0);
+	diff_setup(detect_rename, diff_score_opt, reverse_diff,
+		   (generate_patch ? -1 : line_termination),
+		   0, 0);
 
 	mark_merge_entries();
 
@@ -222,7 +215,6 @@ int main(int argc, char **argv)
 		die("unable to read tree object %s", argv[1]);
 
 	ret = diff_cache(active_cache, active_nr);
-	if (generate_patch)
-		diff_flush();
+	diff_flush();
 	return ret;
 }

diff-files.c

@@ -7,11 +7,13 @@
 #include "diff.h"
 
 static const char *diff_files_usage =
-"git-diff-files [-p] [-q] [-r] [-z] [-M] [paths...]";
+"git-diff-files [-p] [-q] [-r] [-z] [-M] [-R] [paths...]";
 
 static int generate_patch = 0;
 static int line_termination = '\n';
 static int detect_rename = 0;
+static int reverse_diff = 0;
+static int diff_score_opt = 0;
 static int silent = 0;
 
 static int matches_pathspec(struct cache_entry *ce, char **spec, int cnt)
@@ -31,36 +33,19 @@ static int matches_pathspec(struct cache_entry *ce, char **spec, int cnt)
 
 static void show_unmerge(const char *path)
 {
-	if (generate_patch)
-		diff_unmerge(path);
-	else
-		printf("U %s%c", path, line_termination);
+	diff_unmerge(path);
 }
 
 static void show_file(int pfx, struct cache_entry *ce)
 {
-	if (generate_patch)
-		diff_addremove(pfx, ntohl(ce->ce_mode), ce->sha1,
-			       ce->name, NULL);
-	else
-		printf("%c%06o\t%s\t%s\t%s%c",
-		       pfx, ntohl(ce->ce_mode), "blob",
-		       sha1_to_hex(ce->sha1), ce->name, line_termination);
+	diff_addremove(pfx, ntohl(ce->ce_mode), ce->sha1, ce->name, NULL);
 }
 
 static void show_modified(int oldmode, int mode,
 			  const unsigned char *old_sha1, const unsigned char *sha1,
 			  char *path)
 {
-	char old_sha1_hex[41];
-	strcpy(old_sha1_hex, sha1_to_hex(old_sha1));
-
-	if (generate_patch)
-		diff_change(oldmode, mode, old_sha1, sha1, path, NULL);
-	else
-		printf("*%06o->%06o\tblob\t%s->%s\t%s%c",
-		       oldmode, mode, old_sha1_hex, sha1_to_hex(sha1), path,
-		       line_termination);
+	diff_change(oldmode, mode, old_sha1, sha1, path, NULL);
 }
 
 int main(int argc, char **argv)
@@ -80,7 +65,10 @@ int main(int argc, char **argv)
 			; /* no-op */
 		else if (!strcmp(argv[1], "-z"))
 			line_termination = 0;
-		else if (!strcmp(argv[1], "-M")) {
+		else if (!strcmp(argv[1], "-R"))
+			reverse_diff = 1;
+		else if (!strncmp(argv[1], "-M", 2)) {
+			diff_score_opt = diff_scoreopt_parse(argv[1]);
 			detect_rename = generate_patch = 1;
 		}
 		else
@@ -96,8 +84,9 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
-	if (generate_patch)
-		diff_setup(detect_rename, 0, 0, 0, 0);		
+	diff_setup(detect_rename, diff_score_opt, reverse_diff,
+		   (generate_patch ? -1 : line_termination),
+		   0, 0);
 
 	for (i = 0; i < entries; i++) {
 		struct stat st;
@@ -117,12 +106,12 @@ int main(int argc, char **argv)
 			i--; /* compensate for loop control increments */
 			continue;
 		}
- 
+
 		if (lstat(ce->name, &st) < 0) {
 			if (errno != ENOENT) {
 				perror(ce->name);
 				continue;
-			}	
+			}
 			if (silent)
 				continue;
 			show_file('-', ce);
@@ -139,7 +128,6 @@ int main(int argc, char **argv)
 		show_modified(oldmode, mode, ce->sha1, null_sha1,
 			      ce->name);
 	}
-	if (generate_patch)
-		diff_flush();
+	diff_flush();
 	return 0;
 }

diff-helper.c

@@ -7,6 +7,7 @@
 #include "diff.h"
 
 static int detect_rename = 0;
+static int diff_score_opt = 0;
 
 static int parse_oneside_change(const char *cp, int *mode,
 				unsigned char *sha1, char *path)
@@ -19,15 +20,15 @@ static int parse_oneside_change(const char *cp, int *mode,
 		cp++;
 	}
 	*mode = m;
-	if (strncmp(cp, "\tblob\t", 6))
+	if (strncmp(cp, "\tblob\t", 6) && strncmp(cp, " blob ", 6))
 		return -1;
 	cp += 6;
 	if (get_sha1_hex(cp, sha1))
 		return -1;
 	cp += 40;
-	if (*cp++ != '\t')
+	if ((*cp != '\t') && *cp != ' ')
 		return -1;
-	strcpy(path, cp);
+	strcpy(path, ++cp);
 	return 0;
 }
 
@@ -63,7 +64,7 @@ static int parse_diff_raw_output(const char *buf)
 			new_mode = (new_mode << 3) | (ch - '0');
 			cp++;
 		}
-		if (strncmp(cp, "\tblob\t", 6))
+		if (strncmp(cp, "\tblob\t", 6) && strncmp(cp, " blob ", 6))
 			return -1;
 		cp += 6;
 		if (get_sha1_hex(cp, old_sha1))
@@ -75,9 +76,9 @@ static int parse_diff_raw_output(const char *buf)
 		if (get_sha1_hex(cp, new_sha1))
 			return -1;
 		cp += 40;
-		if (*cp++ != '\t')
+		if ((*cp != '\t') && *cp != ' ')
 			return -1;
-		strcpy(path, cp);
+		strcpy(path, ++cp);
 		diff_change(old_mode, new_mode, old_sha1, new_sha1, path, 0);
 		break;
 	default:
@@ -101,15 +102,17 @@ int main(int ac, const char **av) {
 			reverse = 1;
 		else if (av[1][1] == 'z')
 			line_termination = 0;
-		else if (av[1][1] == 'M')
+		else if (av[1][1] == 'M') {
 			detect_rename = 1;
+			diff_score_opt = diff_scoreopt_parse(av[1]);
+		}
 		else
 			usage(diff_helper_usage);
 		ac--; av++;
 	}
 	/* the remaining parameters are paths patterns */
 
-	diff_setup(detect_rename, 0, reverse, av+1, ac-1);
+	diff_setup(detect_rename, diff_score_opt, reverse, -1, av+1, ac-1);
 
 	while (1) {
 		int status;