1 files changed, 50 insertions, 22 deletions

diff --git a/builtin/grep.c b/builtin/grep.c
index 10a1f65310..871afaa3c7 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -533,18 +533,18 @@ static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int
 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 		     struct tree_desc *tree, struct strbuf *base, int tn_len)
 {
-	int hit = 0, matched = 0;
+	int hit = 0, match = 0;
 	struct name_entry entry;
 	int old_baselen = base->len;
 
 	while (tree_entry(tree, &entry)) {
 		int te_len = tree_entry_len(entry.path, entry.sha1);
 
-		if (matched != 2) {
-			matched = tree_entry_interesting(&entry, base, tn_len, pathspec);
-			if (matched == -1)
-				break; /* no more matches */
-			if (!matched)
+		if (match != 2) {
+			match = tree_entry_interesting(&entry, base, tn_len, pathspec);
+			if (match < 0)
+				break;
+			if (match == 0)
 				continue;
 		}
 
@@ -753,6 +753,15 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 	int i;
 	int dummy;
 	int use_index = 1;
+	enum {
+		pattern_type_unspecified = 0,
+		pattern_type_bre,
+		pattern_type_ere,
+		pattern_type_fixed,
+		pattern_type_pcre,
+	};
+	int pattern_type = pattern_type_unspecified;
+
 	struct option options[] = {
 		OPT_BOOLEAN(0, "cached", &cached,
 			"search in index instead of in the work tree"),
@@ -774,13 +783,18 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			"descend at most <depth> levels", PARSE_OPT_NONEG,
 			NULL, 1 },
 		OPT_GROUP(""),
-		OPT_BIT('E', "extended-regexp", &opt.regflags,
-			"use extended POSIX regular expressions", REG_EXTENDED),
-		OPT_NEGBIT('G', "basic-regexp", &opt.regflags,
-			"use basic POSIX regular expressions (default)",
-			REG_EXTENDED),
-		OPT_BOOLEAN('F', "fixed-strings", &opt.fixed,
-			"interpret patterns as fixed strings"),
+		OPT_SET_INT('E', "extended-regexp", &pattern_type,
+			    "use extended POSIX regular expressions",
+			    pattern_type_ere),
+		OPT_SET_INT('G', "basic-regexp", &pattern_type,
+			    "use basic POSIX regular expressions (default)",
+			    pattern_type_bre),
+		OPT_SET_INT('F', "fixed-strings", &pattern_type,
+			    "interpret patterns as fixed strings",
+			    pattern_type_fixed),
+		OPT_SET_INT('P', "perl-regexp", &pattern_type,
+			    "use Perl-compatible regular expressions",
+			    pattern_type_pcre),
 		OPT_GROUP(""),
 		OPT_BOOLEAN('n', "line-number", &opt.linenum, "show line numbers"),
 		OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
@@ -886,6 +900,28 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			     PARSE_OPT_KEEP_DASHDASH |
 			     PARSE_OPT_STOP_AT_NON_OPTION |
 			     PARSE_OPT_NO_INTERNAL_HELP);
+	switch (pattern_type) {
+	case pattern_type_fixed:
+		opt.fixed = 1;
+		opt.pcre = 0;
+		break;
+	case pattern_type_bre:
+		opt.fixed = 0;
+		opt.pcre = 0;
+		opt.regflags &= ~REG_EXTENDED;
+		break;
+	case pattern_type_ere:
+		opt.fixed = 0;
+		opt.pcre = 0;
+		opt.regflags |= REG_EXTENDED;
+		break;
+	case pattern_type_pcre:
+		opt.fixed = 0;
+		opt.pcre = 1;
+		break;
+	default:
+		break; /* nothing */
+	}
 
 	if (use_index && !startup_info->have_repository)
 		/* die the same way as if we did it at the beginning */
@@ -925,8 +961,6 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 		die(_("no pattern given."));
 	if (!opt.fixed && opt.ignore_case)
 		opt.regflags |= REG_ICASE;
-	if ((opt.regflags != REG_NEWLINE) && opt.fixed)
-		die(_("cannot mix --fixed-strings and regexp"));
 
 #ifndef NO_PTHREADS
 	if (online_cpus() == 1 || !grep_threads_ok(&opt))
@@ -969,13 +1003,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			verify_filename(prefix, argv[j]);
 	}
 
-	if (i < argc)
-		paths = get_pathspec(prefix, argv + i);
-	else if (prefix) {
-		paths = xcalloc(2, sizeof(const char *));
-		paths[0] = prefix;
-		paths[1] = NULL;
-	}
+	paths = get_pathspec(prefix, argv + i);
 	init_pathspec(&pathspec, paths);
 	pathspec.max_depth = opt.max_depth;
 	pathspec.recursive = 1;