builtin-grep: do not use setup_revisions()

Grep may want to grok multiple revisions, but it does not make
much sense to walk revisions while doing so.  This stops calling
the code to parse parameters for the revision walker.  The
parameter parsing for the optional "-e" option becomes a lot
simpler with it as well.

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

builtin-grep.c

@@ -8,8 +8,7 @@
 #include "tree.h"
 #include "commit.h"
 #include "tag.h"
-#include "diff.h"
-#include "revision.h"
+#include "tree-walk.h"
 #include "builtin.h"
 #include <regex.h>
 #include <fnmatch.h>
@@ -18,15 +17,15 @@
  * git grep pathspecs are somewhat different from diff-tree pathspecs;
  * pathname wildcards are allowed.
  */
-static int pathspec_matches(struct diff_options *opt, const char *name)
+static int pathspec_matches(const char **paths, const char *name)
 {
 	int namelen, i;
-	if (!opt->nr_paths)
+	if (!paths || !*paths)
 		return 1;
 	namelen = strlen(name);
-	for (i = 0; i < opt->nr_paths; i++) {
-		const char *match = opt->paths[i];
-		int matchlen = opt->pathlens[i];
+	for (i = 0; paths[i]; i++) {
+		const char *match = paths[i];
+		int matchlen = strlen(match);
 		const char *slash, *cp;
 
 		if ((matchlen <= namelen) &&
@@ -241,7 +240,7 @@ static int grep_file(struct grep_opt *opt, const char *filename)
 	return i;
 }
 
-static int grep_cache(struct grep_opt *opt, struct rev_info *revs, int cached)
+static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
 {
 	int hit = 0;
 	int nr;
@@ -251,7 +250,7 @@ static int grep_cache(struct grep_opt *opt, struct rev_info *revs, int cached)
 		struct cache_entry *ce = active_cache[nr];
 		if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
 			continue;
-		if (!pathspec_matches(&revs->diffopt, ce->name))
+		if (!pathspec_matches(paths, ce->name))
 			continue;
 		if (cached)
 			hit |= grep_sha1(opt, ce->sha1, ce->name);
@@ -261,7 +260,7 @@ static int grep_cache(struct grep_opt *opt, struct rev_info *revs, int cached)
 	return hit;
 }
 
-static int grep_tree(struct grep_opt *opt, struct rev_info *revs,
+static int grep_tree(struct grep_opt *opt, const char **paths,
 		     struct tree_desc *tree,
 		     const char *tree_name, const char *base)
 {
@@ -297,7 +296,7 @@ static int grep_tree(struct grep_opt *opt, struct rev_info *revs,
 			 */
 			strcpy(path_buf + len + pathlen, "/");
 
-		if (!pathspec_matches(&revs->diffopt, down))
+		if (!pathspec_matches(paths, down))
 			;
 		else if (S_ISREG(mode))
 			hit |= grep_sha1(opt, sha1, path_buf);
@@ -310,7 +309,7 @@ static int grep_tree(struct grep_opt *opt, struct rev_info *revs,
 				die("unable to read tree (%s)",
 				    sha1_to_hex(sha1));
 			sub.buf = data;
-			hit |= grep_tree(opt, revs, &sub, tree_name, down);
+			hit |= grep_tree(opt, paths, &sub, tree_name, down);
 			free(data);
 		}
 		update_tree_entry(tree);
@@ -318,7 +317,7 @@ static int grep_tree(struct grep_opt *opt, struct rev_info *revs,
 	return hit;
 }
 
-static int grep_object(struct grep_opt *opt, struct rev_info *revs,
+static int grep_object(struct grep_opt *opt, const char **paths,
 		       struct object *obj, const char *name)
 {
 	if (!strcmp(obj->type, blob_type))
@@ -333,7 +332,7 @@ static int grep_object(struct grep_opt *opt, struct rev_info *revs,
 		if (!data)
 			die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 		tree.buf = data;
-		hit = grep_tree(opt, revs, &tree, name, "");
+		hit = grep_tree(opt, paths, &tree, name, "");
 		free(data);
 		return hit;
 	}
@@ -345,102 +344,119 @@ static const char builtin_grep_usage[] =
 
 int cmd_grep(int argc, const char **argv, char **envp)
 {
-	struct rev_info rev;
-	const char **dst, **src;
 	int err;
 	int hit = 0;
-	int no_more_arg = 0;
-	int seen_range = 0;
+	int no_more_flags = 0;
 	int seen_noncommit = 0;
 	int cached = 0;
 	struct grep_opt opt;
-	struct object_list *list;
+	struct object_list *list, **tail, *object_list = NULL;
+	const char *prefix = setup_git_directory();
+	const char **paths = NULL;
 
 	memset(&opt, 0, sizeof(opt));
 	opt.regflags = REG_NEWLINE;
 
 	/*
-	 * Interpret and remove the grep options upfront.  Sigh...
+	 * No point using rev_info, really.
 	 */
-	for (dst = src = &argv[1]; src < argc + argv; ) {
-		const char *arg = *src++;
-		if (!no_more_arg) {
-			if (!strcmp("--", arg)) {
-				no_more_arg = 1;
-				*dst++ = arg;
-				continue;
-			}
-			if (!strcmp("--cached", arg)) {
-				cached = 1;
-				continue;
-			}
-			if (!strcmp("-i", arg) ||
-			    !strcmp("--ignore-case", arg)) {
-				opt.regflags |= REG_ICASE;
-				continue;
-			}
-			if (!strcmp("-v", arg) ||
-			    !strcmp("--invert-match", arg)) {
-				opt.invert = 1;
-				continue;
-			}
-			if (!strcmp("-E", arg) ||
-			    !strcmp("--extended-regexp", arg)) {
-				opt.regflags |= REG_EXTENDED;
-				continue;
-			}
-			if (!strcmp("-G", arg) ||
-			    !strcmp("--basic-regexp", arg)) {
-				opt.regflags &= ~REG_EXTENDED;
-				continue;
-			}
-			if (!strcmp("-e", arg)) {
-				if (src < argc + argv) {
-					opt.pattern = *src++;
-					continue;
-				}
+	while (1 < argc) {
+		const char *arg = argv[1];
+		argc--; argv++;
+		if (!strcmp("--cached", arg)) {
+			cached = 1;
+			continue;
+		}
+		if (!strcmp("-i", arg) ||
+		    !strcmp("--ignore-case", arg)) {
+			opt.regflags |= REG_ICASE;
+			continue;
+		}
+		if (!strcmp("-v", arg) ||
+		    !strcmp("--invert-match", arg)) {
+			opt.invert = 1;
+			continue;
+		}
+		if (!strcmp("-E", arg) ||
+		    !strcmp("--extended-regexp", arg)) {
+			opt.regflags |= REG_EXTENDED;
+			continue;
+		}
+		if (!strcmp("-G", arg) ||
+		    !strcmp("--basic-regexp", arg)) {
+			opt.regflags &= ~REG_EXTENDED;
+			continue;
+		}
+		if (!strcmp("-n", arg)) {
+			opt.linenum = 1;
+			continue;
+		}
+		if (!strcmp("-H", arg)) {
+			/* We always show the pathname, so this
+			 * is a noop.
+			 */
+			continue;
+		}
+		if (!strcmp("-l", arg) ||
+		    !strcmp("--files-with-matches", arg)) {
+			opt.name_only = 1;
+			continue;
+		}
+		if (!strcmp("-A", arg) ||
+		    !strcmp("-B", arg) ||
+		    !strcmp("-C", arg)) {
+			unsigned num;
+			if (argc <= 1 ||
+			    sscanf(*++argv, "%u", &num) != 1)
 				usage(builtin_grep_usage);
+			argc--;
+			switch (arg[1]) {
+			case 'A':
+				opt.post_context = num;
+				break;
+			case 'C':
+				opt.post_context = num;
+			case 'B':
+				opt.pre_context = num;
+				break;
 			}
-			if (!strcmp("-n", arg)) {
-				opt.linenum = 1;
-				continue;
-			}
-			if (!strcmp("-H", arg)) {
-				/* We always show the pathname, so this
-				 * is a noop.
+			continue;
+		}
+		if (!strcmp("-e", arg)) {
+			if (1 < argc) {
+				/* We probably would want to do
+				 * -e pat1 -e pat2 as well later...
 				 */
+				if (opt.pattern)
+					die("more than one pattern?");
+				opt.pattern = *++argv;
+				argc--;
 				continue;
 			}
-			if (!strcmp("-l", arg) ||
-			    !strcmp("--files-with-matches", arg)) {
-				opt.name_only = 1;
-				continue;
-			}
-			if (!strcmp("-A", arg) ||
-			    !strcmp("-B", arg) ||
-			    !strcmp("-C", arg)) {
-				unsigned num;
-				if ((argc + argv <= src) ||
-				    sscanf(*src++, "%u", &num) != 1)
-					usage(builtin_grep_usage);
-				switch (arg[1]) {
-				case 'A':
-					opt.post_context = num;
-					break;
-				case 'C':
-					opt.post_context = num;
-				case 'B':
-					opt.pre_context = num;
-					break;
-				}
-				continue;
-			}
+			usage(builtin_grep_usage);
+		}
+		if (!strcmp("--", arg)) {
+			no_more_flags = 1;
+			continue;
+		}
+		/* Either unrecognized option or a single pattern */
+		if (!no_more_flags && *arg == '-')
+			usage(builtin_grep_usage);
+		if (!opt.pattern) {
+			opt.pattern = arg;
+			break;
+		}
+		else {
+			/* We are looking at the first path or rev;
+			 * it is found at argv[0] after leaving the
+			 * loop.
+			 */
+			argc++; argv--;
+			break;
 		}
-		*dst++ = arg;
 	}
 	if (!opt.pattern)
 		die("no pattern given.");
-
 	err = regcomp(&opt.regexp, opt.pattern, opt.regflags);
 	if (err) {
 		char errbuf[1024];
@@ -448,11 +464,32 @@ int cmd_grep(int argc, const char **argv, char **envp)
 		regfree(&opt.regexp);
 		die("'%s': %s", opt.pattern, errbuf);
 	}
+	tail = &object_list;
+	while (1 < argc) {
+		struct object *object;
+		struct object_list *elem;
+		const char *arg = argv[1];
+		unsigned char sha1[20];
+		if (get_sha1(arg, sha1) < 0)
+			break;
+		object = parse_object(sha1);
+		if (!object)
+			die("bad object %s", arg);
+		elem = object_list_insert(object, tail);
+		elem->name = arg;
+		tail = &elem->next;
+		argc--; argv++;
+	}
+	if (1 < argc)
+		paths = get_pathspec(prefix, argv + 1);
+	else if (prefix) {
+		paths = xcalloc(2, sizeof(const char *));
+		paths[0] = prefix;
+		paths[1] = NULL;
+	}
 
-	init_revisions(&rev);
-	*dst = NULL;
-	argc = setup_revisions(dst - argv, argv, &rev, NULL);
-
+	if (!object_list)
+		return !grep_cache(&opt, paths, cached);
 	/*
 	 * Do not walk "grep -e foo master next pu -- Documentation/"
 	 * but do walk "grep -e foo master..next -- Documentation/".
@@ -460,43 +497,19 @@ int cmd_grep(int argc, const char **argv, char **envp)
 	 * "grep -e foo v1.0.0:Documentation/ master..next"
 	 * so detect that and complain.
 	 */
-	for (list = rev.pending_objects; list; list = list->next) {
+	for (list = object_list; list; list = list->next) {
 		struct object *real_obj;
-		if (list->item->flags & UNINTERESTING)
-			seen_range = 1;
 		real_obj = deref_tag(list->item, NULL, 0);
 		if (strcmp(real_obj->type, commit_type))
 			seen_noncommit = 1;
 	}
-	if (!rev.pending_objects)
-		return !grep_cache(&opt, &rev, cached);
 	if (cached)
 		die("both --cached and revisions given.");
 
-	if (seen_range && seen_noncommit)
-		die("both A..B and non commit are given.");
-	if (seen_range) {
-		struct commit *commit;
-		prepare_revision_walk(&rev);
-		while ((commit = get_revision(&rev)) != NULL) {
-			unsigned char *sha1 = commit->object.sha1;
-			const char *n = find_unique_abbrev(sha1, rev.abbrev);
-			char rev_name[41];
-			strcpy(rev_name, n);
-			if (grep_object(&opt, &rev, &commit->object, rev_name))
-				hit = 1;
-			commit->buffer = NULL;
-		}
-		return !hit;
-	}
-
-	/* all of them are non-commit; do not walk, and
-	 * do not lose their names.
-	 */
-	for (list = rev.pending_objects; list; list = list->next) {
+	for (list = object_list; list; list = list->next) {
 		struct object *real_obj;
 		real_obj = deref_tag(list->item, NULL, 0);
-		if (grep_object(&opt, &rev, real_obj, list->name))
+		if (grep_object(&opt, paths, real_obj, list->name))
 			hit = 1;
 	}
 	return !hit;