Merge branch 'nd/ls-files-sparse-fix'
[gitweb.git] / builtin-grep.c
index 3f12ba382690699d96580c3ddb1a61c79520e694..da854fa94f5cc159ea93156ba4c87973ee15cae9 100644 (file)
 #include "tag.h"
 #include "tree-walk.h"
 #include "builtin.h"
+#include "parse-options.h"
+#include "userdiff.h"
 #include "grep.h"
+#include "quote.h"
+#include "dir.h"
 
-#ifndef NO_EXTERNAL_GREP
-#ifdef __unix__
-#define NO_EXTERNAL_GREP 0
-#else
-#define NO_EXTERNAL_GREP 1
-#endif
-#endif
+static char const * const grep_usage[] = {
+       "git grep [options] [-e] <pattern> [<rev>...] [[--] path...]",
+       NULL
+};
 
-static int builtin_grep;
+static int grep_config(const char *var, const char *value, void *cb)
+{
+       struct grep_opt *opt = cb;
+
+       switch (userdiff_config(var, value)) {
+       case 0: break;
+       case -1: return -1;
+       default: return 0;
+       }
+
+       if (!strcmp(var, "color.grep")) {
+               opt->color = git_config_colorbool(var, value, -1);
+               return 0;
+       }
+       if (!strcmp(var, "color.grep.match")) {
+               if (!value)
+                       return config_error_nonbool(var);
+               color_parse(value, var, opt->color_match);
+               return 0;
+       }
+       return git_color_default_config(var, value, cb);
+}
+
+/*
+ * Return non-zero if max_depth is negative or path has no more then max_depth
+ * slashes.
+ */
+static int accept_subdir(const char *path, int max_depth)
+{
+       if (max_depth < 0)
+               return 1;
+
+       while ((path = strchr(path, '/')) != NULL) {
+               max_depth--;
+               if (max_depth < 0)
+                       return 0;
+               path++;
+       }
+       return 1;
+}
+
+/*
+ * Return non-zero if name is a subdirectory of match and is not too deep.
+ */
+static int is_subdir(const char *name, int namelen,
+               const char *match, int matchlen, int max_depth)
+{
+       if (matchlen > namelen || strncmp(name, match, matchlen))
+               return 0;
+
+       if (name[matchlen] == '\0') /* exact match */
+               return 1;
+
+       if (!matchlen || match[matchlen-1] == '/' || name[matchlen] == '/')
+               return accept_subdir(name + matchlen + 1, max_depth);
+
+       return 0;
+}
 
 /*
  * git grep pathspecs are somewhat different from diff-tree pathspecs;
  * pathname wildcards are allowed.
  */
-static int pathspec_matches(const char **paths, const char *name)
+static int pathspec_matches(const char **paths, const char *name, int max_depth)
 {
        int namelen, i;
        if (!paths || !*paths)
-               return 1;
+               return accept_subdir(name, max_depth);
        namelen = strlen(name);
        for (i = 0; paths[i]; i++) {
                const char *match = paths[i];
                int matchlen = strlen(match);
                const char *cp, *meta;
 
-               if (!matchlen ||
-                   ((matchlen <= namelen) &&
-                    !strncmp(name, match, matchlen) &&
-                    (match[matchlen-1] == '/' ||
-                     name[matchlen] == '\0' || name[matchlen] == '/')))
+               if (is_subdir(name, namelen, match, matchlen, max_depth))
                        return 1;
                if (!fnmatch(match, name, 0))
                        return 1;
@@ -95,8 +149,8 @@ static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char
        unsigned long size;
        char *data;
        enum object_type type;
-       char *to_free = NULL;
        int hit;
+       struct strbuf pathbuf = STRBUF_INIT;
 
        data = read_sha1_file(sha1, &type, &size);
        if (!data) {
@@ -104,26 +158,13 @@ static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char
                return 0;
        }
        if (opt->relative && opt->prefix_length) {
-               static char name_buf[PATH_MAX];
-               char *cp;
-               int name_len = strlen(name) - opt->prefix_length + 1;
-
-               if (!tree_name_len)
-                       name += opt->prefix_length;
-               else {
-                       if (ARRAY_SIZE(name_buf) <= name_len)
-                               cp = to_free = xmalloc(name_len);
-                       else
-                               cp = name_buf;
-                       memcpy(cp, name, tree_name_len);
-                       strcpy(cp + tree_name_len,
-                              name + tree_name_len + opt->prefix_length);
-                       name = cp;
-               }
+               quote_path_relative(name + tree_name_len, -1, &pathbuf, opt->prefix);
+               strbuf_insert(&pathbuf, 0, name, tree_name_len);
+               name = pathbuf.buf;
        }
        hit = grep_buffer(opt, name, data, size);
+       strbuf_release(&pathbuf);
        free(data);
-       free(to_free);
        return hit;
 }
 
@@ -133,6 +174,7 @@ static int grep_file(struct grep_opt *opt, const char *filename)
        int i;
        char *data;
        size_t sz;
+       struct strbuf buf = STRBUF_INIT;
 
        if (lstat(filename, &st) < 0) {
        err_ret:
@@ -140,8 +182,6 @@ static int grep_file(struct grep_opt *opt, const char *filename)
                        error("'%s': %s", filename, strerror(errno));
                return 0;
        }
-       if (!st.st_size)
-               return 0; /* empty file -- no grep hit */
        if (!S_ISREG(st.st_mode))
                return 0;
        sz = xsize_t(st.st_size);
@@ -156,262 +196,33 @@ static int grep_file(struct grep_opt *opt, const char *filename)
                return 0;
        }
        close(i);
+       data[sz] = 0;
        if (opt->relative && opt->prefix_length)
-               filename += opt->prefix_length;
+               filename = quote_path_relative(filename, -1, &buf, opt->prefix);
        i = grep_buffer(opt, filename, data, sz);
+       strbuf_release(&buf);
        free(data);
        return i;
 }
 
-#if !NO_EXTERNAL_GREP
-static int exec_grep(int argc, const char **argv)
-{
-       pid_t pid;
-       int status;
-
-       argv[argc] = NULL;
-       pid = fork();
-       if (pid < 0)
-               return pid;
-       if (!pid) {
-               execvp("grep", (char **) argv);
-               exit(255);
-       }
-       while (waitpid(pid, &status, 0) < 0) {
-               if (errno == EINTR)
-                       continue;
-               return -1;
-       }
-       if (WIFEXITED(status)) {
-               if (!WEXITSTATUS(status))
-                       return 1;
-               return 0;
-       }
-       return -1;
-}
-
-#define MAXARGS 1000
-#define ARGBUF 4096
-#define push_arg(a) do { \
-       if (nr < MAXARGS) argv[nr++] = (a); \
-       else die("maximum number of args exceeded"); \
-       } while (0)
-
-/*
- * If you send a singleton filename to grep, it does not give
- * the name of the file.  GNU grep has "-H" but we would want
- * that behaviour in a portable way.
- *
- * So we keep two pathnames in argv buffer unsent to grep in
- * the main loop if we need to do more than one grep.
- */
-static int flush_grep(struct grep_opt *opt,
-                     int argc, int arg0, const char **argv, int *kept)
-{
-       int status;
-       int count = argc - arg0;
-       const char *kept_0 = NULL;
-
-       if (count <= 2) {
-               /*
-                * Because we keep at least 2 paths in the call from
-                * the main loop (i.e. kept != NULL), and MAXARGS is
-                * far greater than 2, this usually is a call to
-                * conclude the grep.  However, the user could attempt
-                * to overflow the argv buffer by giving too many
-                * options to leave very small number of real
-                * arguments even for the call in the main loop.
-                */
-               if (kept)
-                       die("insanely many options to grep");
-
-               /*
-                * If we have two or more paths, we do not have to do
-                * anything special, but we need to push /dev/null to
-                * get "-H" behaviour of GNU grep portably but when we
-                * are not doing "-l" nor "-L" nor "-c".
-                */
-               if (count == 1 &&
-                   !opt->name_only &&
-                   !opt->unmatch_name_only &&
-                   !opt->count) {
-                       argv[argc++] = "/dev/null";
-                       argv[argc] = NULL;
-               }
-       }
-
-       else if (kept) {
-               /*
-                * Called because we found many paths and haven't finished
-                * iterating over the cache yet.  We keep two paths
-                * for the concluding call.  argv[argc-2] and argv[argc-1]
-                * has the last two paths, so save the first one away,
-                * replace it with NULL while sending the list to grep,
-                * and recover them after we are done.
-                */
-               *kept = 2;
-               kept_0 = argv[argc-2];
-               argv[argc-2] = NULL;
-               argc -= 2;
-       }
-
-       status = exec_grep(argc, argv);
-
-       if (kept_0) {
-               /*
-                * Then recover them.  Now the last arg is beyond the
-                * terminating NULL which is at argc, and the second
-                * from the last is what we saved away in kept_0
-                */
-               argv[arg0++] = kept_0;
-               argv[arg0] = argv[argc+1];
-       }
-       return status;
-}
-
-static int external_grep(struct grep_opt *opt, const char **paths, int cached)
-{
-       int i, nr, argc, hit, len, status;
-       const char *argv[MAXARGS+1];
-       char randarg[ARGBUF];
-       char *argptr = randarg;
-       struct grep_pat *p;
-
-       if (opt->extended || (opt->relative && opt->prefix_length))
-               return -1;
-       len = nr = 0;
-       push_arg("grep");
-       if (opt->fixed)
-               push_arg("-F");
-       if (opt->linenum)
-               push_arg("-n");
-       if (!opt->pathname)
-               push_arg("-h");
-       if (opt->regflags & REG_EXTENDED)
-               push_arg("-E");
-       if (opt->regflags & REG_ICASE)
-               push_arg("-i");
-       if (opt->binary == GREP_BINARY_NOMATCH)
-               push_arg("-I");
-       if (opt->word_regexp)
-               push_arg("-w");
-       if (opt->name_only)
-               push_arg("-l");
-       if (opt->unmatch_name_only)
-               push_arg("-L");
-       if (opt->null_following_name)
-               /* in GNU grep git's "-z" translates to "-Z" */
-               push_arg("-Z");
-       if (opt->count)
-               push_arg("-c");
-       if (opt->post_context || opt->pre_context) {
-               if (opt->post_context != opt->pre_context) {
-                       if (opt->pre_context) {
-                               push_arg("-B");
-                               len += snprintf(argptr, sizeof(randarg)-len,
-                                               "%u", opt->pre_context) + 1;
-                               if (sizeof(randarg) <= len)
-                                       die("maximum length of args exceeded");
-                               push_arg(argptr);
-                               argptr += len;
-                       }
-                       if (opt->post_context) {
-                               push_arg("-A");
-                               len += snprintf(argptr, sizeof(randarg)-len,
-                                               "%u", opt->post_context) + 1;
-                               if (sizeof(randarg) <= len)
-                                       die("maximum length of args exceeded");
-                               push_arg(argptr);
-                               argptr += len;
-                       }
-               }
-               else {
-                       push_arg("-C");
-                       len += snprintf(argptr, sizeof(randarg)-len,
-                                       "%u", opt->post_context) + 1;
-                       if (sizeof(randarg) <= len)
-                               die("maximum length of args exceeded");
-                       push_arg(argptr);
-                       argptr += len;
-               }
-       }
-       for (p = opt->pattern_list; p; p = p->next) {
-               push_arg("-e");
-               push_arg(p->pattern);
-       }
-
-       hit = 0;
-       argc = nr;
-       for (i = 0; i < active_nr; i++) {
-               struct cache_entry *ce = active_cache[i];
-               char *name;
-               int kept;
-               if (!S_ISREG(ce->ce_mode))
-                       continue;
-               if (!pathspec_matches(paths, ce->name))
-                       continue;
-               name = ce->name;
-               if (name[0] == '-') {
-                       int len = ce_namelen(ce);
-                       name = xmalloc(len + 3);
-                       memcpy(name, "./", 2);
-                       memcpy(name + 2, ce->name, len + 1);
-               }
-               argv[argc++] = name;
-               if (MAXARGS <= argc) {
-                       status = flush_grep(opt, argc, nr, argv, &kept);
-                       if (0 < status)
-                               hit = 1;
-                       argc = nr + kept;
-               }
-               if (ce_stage(ce)) {
-                       do {
-                               i++;
-                       } while (i < active_nr &&
-                                !strcmp(ce->name, active_cache[i]->name));
-                       i--; /* compensate for loop control */
-               }
-       }
-       if (argc > nr) {
-               status = flush_grep(opt, argc, nr, argv, NULL);
-               if (0 < status)
-                       hit = 1;
-       }
-       return hit;
-}
-#endif
-
 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
 {
        int hit = 0;
        int nr;
        read_cache();
 
-#if !NO_EXTERNAL_GREP
-       /*
-        * Use the external "grep" command for the case where
-        * we grep through the checked-out files. It tends to
-        * be a lot more optimized
-        */
-       if (!cached && !builtin_grep) {
-               hit = external_grep(opt, paths, cached);
-               if (hit >= 0)
-                       return hit;
-       }
-#endif
-
        for (nr = 0; nr < active_nr; nr++) {
                struct cache_entry *ce = active_cache[nr];
                if (!S_ISREG(ce->ce_mode))
                        continue;
-               if (!pathspec_matches(paths, ce->name))
+               if (!pathspec_matches(paths, ce->name, opt->max_depth))
                        continue;
                /*
                 * If CE_VALID is on, we assume worktree file and its cache entry
                 * are identical, even if worktree file has been modified, so use
                 * cache version instead
                 */
-               if (cached || (ce->ce_flags & CE_VALID)) {
+               if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
                        if (ce_stage(ce))
                                continue;
                        hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
@@ -464,7 +275,7 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
                        strbuf_addch(&pathbuf, '/');
 
                down = pathbuf.buf + tn_len;
-               if (!pathspec_matches(paths, down))
+               if (!pathspec_matches(paths, down, opt->max_depth))
                        ;
                else if (S_ISREG(entry.mode))
                        hit |= grep_sha1(opt, entry.sha1, pathbuf.buf, tn_len);
@@ -509,32 +320,224 @@ static int grep_object(struct grep_opt *opt, const char **paths,
        die("unable to grep from object of type %s", typename(obj->type));
 }
 
-static const char builtin_grep_usage[] =
-"git grep <option>* [-e] <pattern> <rev>* [[--] <path>...]";
+static int grep_directory(struct grep_opt *opt, const char **paths)
+{
+       struct dir_struct dir;
+       int i, hit = 0;
+
+       memset(&dir, 0, sizeof(dir));
+       setup_standard_excludes(&dir);
+
+       fill_directory(&dir, paths);
+       for (i = 0; i < dir.nr; i++)
+               hit |= grep_file(opt, dir.entries[i]->name);
+       free_grep_patterns(opt);
+       return hit;
+}
+
+static int context_callback(const struct option *opt, const char *arg,
+                           int unset)
+{
+       struct grep_opt *grep_opt = opt->value;
+       int value;
+       const char *endp;
+
+       if (unset) {
+               grep_opt->pre_context = grep_opt->post_context = 0;
+               return 0;
+       }
+       value = strtol(arg, (char **)&endp, 10);
+       if (*endp) {
+               return error("switch `%c' expects a numerical value",
+                            opt->short_name);
+       }
+       grep_opt->pre_context = grep_opt->post_context = value;
+       return 0;
+}
+
+static int file_callback(const struct option *opt, const char *arg, int unset)
+{
+       struct grep_opt *grep_opt = opt->value;
+       FILE *patterns;
+       int lno = 0;
+       struct strbuf sb = STRBUF_INIT;
+
+       patterns = fopen(arg, "r");
+       if (!patterns)
+               die_errno("cannot open '%s'", arg);
+       while (strbuf_getline(&sb, patterns, '\n') == 0) {
+               /* ignore empty line like grep does */
+               if (sb.len == 0)
+                       continue;
+               append_grep_pattern(grep_opt, strbuf_detach(&sb, NULL), arg,
+                                   ++lno, GREP_PATTERN);
+       }
+       fclose(patterns);
+       strbuf_release(&sb);
+       return 0;
+}
+
+static int not_callback(const struct option *opt, const char *arg, int unset)
+{
+       struct grep_opt *grep_opt = opt->value;
+       append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
+       return 0;
+}
+
+static int and_callback(const struct option *opt, const char *arg, int unset)
+{
+       struct grep_opt *grep_opt = opt->value;
+       append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
+       return 0;
+}
+
+static int open_callback(const struct option *opt, const char *arg, int unset)
+{
+       struct grep_opt *grep_opt = opt->value;
+       append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
+       return 0;
+}
+
+static int close_callback(const struct option *opt, const char *arg, int unset)
+{
+       struct grep_opt *grep_opt = opt->value;
+       append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
+       return 0;
+}
+
+static int pattern_callback(const struct option *opt, const char *arg,
+                           int unset)
+{
+       struct grep_opt *grep_opt = opt->value;
+       append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
+       return 0;
+}
 
-static const char emsg_invalid_context_len[] =
-"%s: invalid context length argument";
-static const char emsg_missing_context_len[] =
-"missing context length argument";
-static const char emsg_missing_argument[] =
-"option requires an argument -%s";
+static int help_callback(const struct option *opt, const char *arg, int unset)
+{
+       return -1;
+}
 
 int cmd_grep(int argc, const char **argv, const char *prefix)
 {
        int hit = 0;
        int cached = 0;
        int seen_dashdash = 0;
+       int external_grep_allowed__ignored;
        struct grep_opt opt;
        struct object_array list = { 0, 0, NULL };
        const char **paths = NULL;
        int i;
+       int dummy;
+       int nongit = 0, use_index = 1;
+       struct option options[] = {
+               OPT_BOOLEAN(0, "cached", &cached,
+                       "search in index instead of in the work tree"),
+               OPT_BOOLEAN(0, "index", &use_index,
+                       "--no-index finds in contents not managed by git"),
+               OPT_GROUP(""),
+               OPT_BOOLEAN('v', "invert-match", &opt.invert,
+                       "show non-matching lines"),
+               OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
+                       "case insensitive matching"),
+               OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
+                       "match patterns only at word boundaries"),
+               OPT_SET_INT('a', "text", &opt.binary,
+                       "process binary files as text", GREP_BINARY_TEXT),
+               OPT_SET_INT('I', NULL, &opt.binary,
+                       "don't match patterns in binary files",
+                       GREP_BINARY_NOMATCH),
+               { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
+                       "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_GROUP(""),
+               OPT_BOOLEAN('n', NULL, &opt.linenum, "show line numbers"),
+               OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
+               OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
+               OPT_NEGBIT(0, "full-name", &opt.relative,
+                       "show filenames relative to top directory", 1),
+               OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
+                       "show only filenames instead of matching lines"),
+               OPT_BOOLEAN(0, "name-only", &opt.name_only,
+                       "synonym for --files-with-matches"),
+               OPT_BOOLEAN('L', "files-without-match",
+                       &opt.unmatch_name_only,
+                       "show only the names of files without match"),
+               OPT_BOOLEAN('z', "null", &opt.null_following_name,
+                       "print NUL after filenames"),
+               OPT_BOOLEAN('c', "count", &opt.count,
+                       "show the number of matches instead of matching lines"),
+               OPT_SET_INT(0, "color", &opt.color, "highlight matches", 1),
+               OPT_GROUP(""),
+               OPT_CALLBACK('C', NULL, &opt, "n",
+                       "show <n> context lines before and after matches",
+                       context_callback),
+               OPT_INTEGER('B', NULL, &opt.pre_context,
+                       "show <n> context lines before matches"),
+               OPT_INTEGER('A', NULL, &opt.post_context,
+                       "show <n> context lines after matches"),
+               OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
+                       context_callback),
+               OPT_BOOLEAN('p', "show-function", &opt.funcname,
+                       "show a line with the function name before matches"),
+               OPT_GROUP(""),
+               OPT_CALLBACK('f', NULL, &opt, "file",
+                       "read patterns from file", file_callback),
+               { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
+                       "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
+               { OPTION_CALLBACK, 0, "and", &opt, NULL,
+                 "combine patterns specified with -e",
+                 PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
+               OPT_BOOLEAN(0, "or", &dummy, ""),
+               { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
+                 PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
+               { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
+                 PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
+                 open_callback },
+               { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
+                 PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
+                 close_callback },
+               OPT_BOOLEAN(0, "all-match", &opt.all_match,
+                       "show only matches from files that match all patterns"),
+               OPT_GROUP(""),
+               OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
+                           "allow calling of grep(1) (ignored by this build)"),
+               { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
+                 PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
+               OPT_END()
+       };
+
+       prefix = setup_git_directory_gently(&nongit);
+
+       /*
+        * 'git grep -h', unlike 'git grep -h <pattern>', is a request
+        * to show usage information and exit.
+        */
+       if (argc == 2 && !strcmp(argv[1], "-h"))
+               usage_with_options(grep_usage, options);
 
        memset(&opt, 0, sizeof(opt));
+       opt.prefix = prefix;
        opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
        opt.relative = 1;
        opt.pathname = 1;
        opt.pattern_tail = &opt.pattern_list;
        opt.regflags = REG_NEWLINE;
+       opt.max_depth = -1;
+
+       strcpy(opt.color_match, GIT_COLOR_RED GIT_COLOR_BOLD);
+       opt.color = -1;
+       git_config(grep_config, &opt);
+       if (opt.color == -1)
+               opt.color = git_use_color_default;
 
        /*
         * If there is no -- then the paths must exist in the working
@@ -546,225 +549,33 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
         * unrecognized non option is the beginning of the refs list
         * that continues up to the -- (if exists), and then paths.
         */
-
-       while (1 < argc) {
-               const char *arg = argv[1];
-               argc--; argv++;
-               if (!strcmp("--cached", arg)) {
-                       cached = 1;
-                       continue;
-               }
-               if (!strcmp("--no-ext-grep", arg)) {
-                       builtin_grep = 1;
-                       continue;
-               }
-               if (!strcmp("-a", arg) ||
-                   !strcmp("--text", arg)) {
-                       opt.binary = GREP_BINARY_TEXT;
-                       continue;
-               }
-               if (!strcmp("-i", arg) ||
-                   !strcmp("--ignore-case", arg)) {
-                       opt.regflags |= REG_ICASE;
-                       continue;
-               }
-               if (!strcmp("-I", arg)) {
-                       opt.binary = GREP_BINARY_NOMATCH;
-                       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("-F", arg) ||
-                   !strcmp("--fixed-strings", arg)) {
-                       opt.fixed = 1;
-                       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)) {
-                       opt.pathname = 0;
-                       continue;
-               }
-               if (!strcmp("-H", arg)) {
-                       opt.pathname = 1;
-                       continue;
-               }
-               if (!strcmp("-l", arg) ||
-                   !strcmp("--name-only", arg) ||
-                   !strcmp("--files-with-matches", arg)) {
-                       opt.name_only = 1;
-                       continue;
-               }
-               if (!strcmp("-L", arg) ||
-                   !strcmp("--files-without-match", arg)) {
-                       opt.unmatch_name_only = 1;
-                       continue;
-               }
-               if (!strcmp("-z", arg) ||
-                   !strcmp("--null", arg)) {
-                       opt.null_following_name = 1;
-                       continue;
-               }
-               if (!strcmp("-c", arg) ||
-                   !strcmp("--count", arg)) {
-                       opt.count = 1;
-                       continue;
-               }
-               if (!strcmp("-w", arg) ||
-                   !strcmp("--word-regexp", arg)) {
-                       opt.word_regexp = 1;
-                       continue;
-               }
-               if (!prefixcmp(arg, "-A") ||
-                   !prefixcmp(arg, "-B") ||
-                   !prefixcmp(arg, "-C") ||
-                   (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
-                       unsigned num;
-                       const char *scan;
-                       switch (arg[1]) {
-                       case 'A': case 'B': case 'C':
-                               if (!arg[2]) {
-                                       if (argc <= 1)
-                                               die(emsg_missing_context_len);
-                                       scan = *++argv;
-                                       argc--;
-                               }
-                               else
-                                       scan = arg + 2;
-                               break;
-                       default:
-                               scan = arg + 1;
-                               break;
-                       }
-                       if (strtoul_ui(scan, 10, &num))
-                               die(emsg_invalid_context_len, scan);
-                       switch (arg[1]) {
-                       case 'A':
-                               opt.post_context = num;
-                               break;
-                       default:
-                       case 'C':
-                               opt.post_context = num;
-                       case 'B':
-                               opt.pre_context = num;
-                               break;
-                       }
-                       continue;
-               }
-               if (!strcmp("-f", arg)) {
-                       FILE *patterns;
-                       int lno = 0;
-                       char buf[1024];
-                       if (argc <= 1)
-                               die(emsg_missing_argument, arg);
-                       patterns = fopen(argv[1], "r");
-                       if (!patterns)
-                               die("'%s': %s", argv[1], strerror(errno));
-                       while (fgets(buf, sizeof(buf), patterns)) {
-                               int len = strlen(buf);
-                               if (len && buf[len-1] == '\n')
-                                       buf[len-1] = 0;
-                               /* ignore empty line like grep does */
-                               if (!buf[0])
-                                       continue;
-                               append_grep_pattern(&opt, xstrdup(buf),
-                                                   argv[1], ++lno,
-                                                   GREP_PATTERN);
-                       }
-                       fclose(patterns);
-                       argv++;
-                       argc--;
-                       continue;
-               }
-               if (!strcmp("--not", arg)) {
-                       append_grep_pattern(&opt, arg, "command line", 0,
-                                           GREP_NOT);
-                       continue;
-               }
-               if (!strcmp("--and", arg)) {
-                       append_grep_pattern(&opt, arg, "command line", 0,
-                                           GREP_AND);
-                       continue;
-               }
-               if (!strcmp("--or", arg))
-                       continue; /* no-op */
-               if (!strcmp("(", arg)) {
-                       append_grep_pattern(&opt, arg, "command line", 0,
-                                           GREP_OPEN_PAREN);
-                       continue;
-               }
-               if (!strcmp(")", arg)) {
-                       append_grep_pattern(&opt, arg, "command line", 0,
-                                           GREP_CLOSE_PAREN);
-                       continue;
-               }
-               if (!strcmp("--all-match", arg)) {
-                       opt.all_match = 1;
-                       continue;
-               }
-               if (!strcmp("-e", arg)) {
-                       if (1 < argc) {
-                               append_grep_pattern(&opt, argv[1],
-                                                   "-e option", 0,
-                                                   GREP_PATTERN);
-                               argv++;
-                               argc--;
-                               continue;
-                       }
-                       die(emsg_missing_argument, arg);
-               }
-               if (!strcmp("--full-name", arg)) {
-                       opt.relative = 0;
-                       continue;
-               }
-               if (!strcmp("--", arg)) {
-                       /* later processing wants to have this at argv[1] */
-                       argv--;
-                       argc++;
-                       break;
-               }
-               if (*arg == '-')
-                       usage(builtin_grep_usage);
-
-               /* First unrecognized non-option token */
-               if (!opt.pattern_list) {
-                       append_grep_pattern(&opt, arg, "command line", 0,
-                                           GREP_PATTERN);
-                       break;
-               }
-               else {
-                       /* We are looking at the first path or rev;
-                        * it is found at argv[1] after leaving the
-                        * loop.
-                        */
-                       argc++; argv--;
-                       break;
-               }
+       argc = parse_options(argc, argv, prefix, options, grep_usage,
+                            PARSE_OPT_KEEP_DASHDASH |
+                            PARSE_OPT_STOP_AT_NON_OPTION |
+                            PARSE_OPT_NO_INTERNAL_HELP);
+
+       if (use_index && nongit)
+               /* die the same way as if we did it at the beginning */
+               setup_git_directory();
+
+       /* First unrecognized non-option token */
+       if (argc > 0 && !opt.pattern_list) {
+               append_grep_pattern(&opt, argv[0], "command line", 0,
+                                   GREP_PATTERN);
+               argv++;
+               argc--;
        }
 
        if (!opt.pattern_list)
                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");
        compile_grep_patterns(&opt);
 
        /* Check revs and then paths */
-       for (i = 1; i < argc; i++) {
+       for (i = 0; i < argc; i++) {
                const char *arg = argv[i];
                unsigned char sha1[20];
                /* Is it a rev? */
@@ -789,21 +600,22 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                        verify_filename(prefix, argv[j]);
        }
 
-       if (i < argc) {
+       if (i < argc)
                paths = get_pathspec(prefix, argv + i);
-               if (opt.prefix_length && opt.relative) {
-                       /* Make sure we do not get outside of paths */
-                       for (i = 0; paths[i]; i++)
-                               if (strncmp(prefix, paths[i], opt.prefix_length))
-                                       die("git grep: cannot generate relative filenames containing '..'");
-               }
-       }
        else if (prefix) {
                paths = xcalloc(2, sizeof(const char *));
                paths[0] = prefix;
                paths[1] = NULL;
        }
 
+       if (!use_index) {
+               if (cached)
+                       die("--cached cannot be used with --no-index.");
+               if (list.nr)
+                       die("--no-index cannot be used with revs.");
+               return !grep_directory(&opt, paths);
+       }
+
        if (!list.nr) {
                if (!cached)
                        setup_work_tree();