Add write_or_die(), a helper function
[gitweb.git] / builtin-grep.c
index 2e7986cecefc964f665b10d363569951c1f40293..0bd517b2649af37d9980f85e784f9a00c3263922 100644 (file)
@@ -82,17 +82,48 @@ static int pathspec_matches(const char **paths, const char *name)
        return 0;
 }
 
+enum grep_pat_token {
+       GREP_PATTERN,
+       GREP_AND,
+       GREP_OPEN_PAREN,
+       GREP_CLOSE_PAREN,
+       GREP_NOT,
+       GREP_OR,
+};
+
 struct grep_pat {
        struct grep_pat *next;
        const char *origin;
        int no;
+       enum grep_pat_token token;
        const char *pattern;
        regex_t regexp;
 };
 
+enum grep_expr_node {
+       GREP_NODE_ATOM,
+       GREP_NODE_NOT,
+       GREP_NODE_AND,
+       GREP_NODE_OR,
+};
+
+struct grep_expr {
+       enum grep_expr_node node;
+       union {
+               struct grep_pat *atom;
+               struct grep_expr *unary;
+               struct {
+                       struct grep_expr *left;
+                       struct grep_expr *right;
+               } binary;
+       } u;
+};
+
 struct grep_opt {
        struct grep_pat *pattern_list;
        struct grep_pat **pattern_tail;
+       struct grep_expr *pattern_expression;
+       int prefix_length;
        regex_t regexp;
        unsigned linenum:1;
        unsigned invert:1;
@@ -105,43 +136,168 @@ struct grep_opt {
 #define GREP_BINARY_NOMATCH    1
 #define GREP_BINARY_TEXT       2
        unsigned binary:2;
+       unsigned extended:1;
+       unsigned relative:1;
        int regflags;
        unsigned pre_context;
        unsigned post_context;
 };
 
 static void add_pattern(struct grep_opt *opt, const char *pat,
-                       const char *origin, int no)
+                       const char *origin, int no, enum grep_pat_token t)
 {
        struct grep_pat *p = xcalloc(1, sizeof(*p));
        p->pattern = pat;
        p->origin = origin;
        p->no = no;
+       p->token = t;
        *opt->pattern_tail = p;
        opt->pattern_tail = &p->next;
        p->next = NULL;
 }
 
+static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
+{
+       int err = regcomp(&p->regexp, p->pattern, opt->regflags);
+       if (err) {
+               char errbuf[1024];
+               char where[1024];
+               if (p->no)
+                       sprintf(where, "In '%s' at %d, ",
+                               p->origin, p->no);
+               else if (p->origin)
+                       sprintf(where, "%s, ", p->origin);
+               else
+                       where[0] = 0;
+               regerror(err, &p->regexp, errbuf, 1024);
+               regfree(&p->regexp);
+               die("%s'%s': %s", where, p->pattern, errbuf);
+       }
+}
+
+static struct grep_expr *compile_pattern_expr(struct grep_pat **);
+static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
+{
+       struct grep_pat *p;
+       struct grep_expr *x;
+
+       p = *list;
+       switch (p->token) {
+       case GREP_PATTERN: /* atom */
+               x = xcalloc(1, sizeof (struct grep_expr));
+               x->node = GREP_NODE_ATOM;
+               x->u.atom = p;
+               *list = p->next;
+               return x;
+       case GREP_OPEN_PAREN:
+               *list = p->next;
+               x = compile_pattern_expr(list);
+               if (!x)
+                       return NULL;
+               if (!*list || (*list)->token != GREP_CLOSE_PAREN)
+                       die("unmatched parenthesis");
+               *list = (*list)->next;
+               return x;
+       default:
+               return NULL;
+       }
+}
+
+static struct grep_expr *compile_pattern_not(struct grep_pat **list)
+{
+       struct grep_pat *p;
+       struct grep_expr *x;
+
+       p = *list;
+       switch (p->token) {
+       case GREP_NOT:
+               if (!p->next)
+                       die("--not not followed by pattern expression");
+               *list = p->next;
+               x = xcalloc(1, sizeof (struct grep_expr));
+               x->node = GREP_NODE_NOT;
+               x->u.unary = compile_pattern_not(list);
+               if (!x->u.unary)
+                       die("--not followed by non pattern expression");
+               return x;
+       default:
+               return compile_pattern_atom(list);
+       }
+}
+
+static struct grep_expr *compile_pattern_and(struct grep_pat **list)
+{
+       struct grep_pat *p;
+       struct grep_expr *x, *y, *z;
+
+       x = compile_pattern_not(list);
+       p = *list;
+       if (p && p->token == GREP_AND) {
+               if (!p->next)
+                       die("--and not followed by pattern expression");
+               *list = p->next;
+               y = compile_pattern_and(list);
+               if (!y)
+                       die("--and not followed by pattern expression");
+               z = xcalloc(1, sizeof (struct grep_expr));
+               z->node = GREP_NODE_AND;
+               z->u.binary.left = x;
+               z->u.binary.right = y;
+               return z;
+       }
+       return x;
+}
+
+static struct grep_expr *compile_pattern_or(struct grep_pat **list)
+{
+       struct grep_pat *p;
+       struct grep_expr *x, *y, *z;
+
+       x = compile_pattern_and(list);
+       p = *list;
+       if (x && p && p->token != GREP_CLOSE_PAREN) {
+               y = compile_pattern_or(list);
+               if (!y)
+                       die("not a pattern expression %s", p->pattern);
+               z = xcalloc(1, sizeof (struct grep_expr));
+               z->node = GREP_NODE_OR;
+               z->u.binary.left = x;
+               z->u.binary.right = y;
+               return z;
+       }
+       return x;
+}
+
+static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
+{
+       return compile_pattern_or(list);
+}
+
 static void compile_patterns(struct grep_opt *opt)
 {
        struct grep_pat *p;
+
+       /* First compile regexps */
        for (p = opt->pattern_list; p; p = p->next) {
-               int err = regcomp(&p->regexp, p->pattern, opt->regflags);
-               if (err) {
-                       char errbuf[1024];
-                       char where[1024];
-                       if (p->no)
-                               sprintf(where, "In '%s' at %d, ",
-                                       p->origin, p->no);
-                       else if (p->origin)
-                               sprintf(where, "%s, ", p->origin);
-                       else
-                               where[0] = 0;
-                       regerror(err, &p->regexp, errbuf, 1024);
-                       regfree(&p->regexp);
-                       die("%s'%s': %s", where, p->pattern, errbuf);
-               }
+               if (p->token == GREP_PATTERN)
+                       compile_regexp(p, opt);
+               else
+                       opt->extended = 1;
        }
+
+       if (!opt->extended)
+               return;
+
+       /* Then bundle them up in an expression.
+        * A classic recursive descent parser would do.
+        */
+       p = opt->pattern_list;
+       opt->pattern_expression = compile_pattern_expr(&p);
+#if DEBUG
+       dump_pattern_exp(opt->pattern_expression, 0);
+#endif
+       if (p)
+               die("incomplete pattern expression: %s", p->pattern);
 }
 
 static char *end_of_line(char *cp, unsigned long *left)
@@ -177,9 +333,7 @@ static int buffer_is_binary(const char *ptr, unsigned long size)
 {
        if (FIRST_FEW_BYTES < size)
                size = FIRST_FEW_BYTES;
-       if (memchr(ptr, 0, size))
-               return 1;
-       return 0;
+       return !!memchr(ptr, 0, size);
 }
 
 static int fixmatch(const char *pattern, char *line, regmatch_t *match)
@@ -196,6 +350,94 @@ static int fixmatch(const char *pattern, char *line, regmatch_t *match)
        }
 }
 
+static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol)
+{
+       int hit = 0;
+       int at_true_bol = 1;
+       regmatch_t pmatch[10];
+
+ again:
+       if (!opt->fixed) {
+               regex_t *exp = &p->regexp;
+               hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
+                              pmatch, 0);
+       }
+       else {
+               hit = !fixmatch(p->pattern, bol, pmatch);
+       }
+
+       if (hit && opt->word_regexp) {
+               if ((pmatch[0].rm_so < 0) ||
+                   (eol - bol) <= pmatch[0].rm_so ||
+                   (pmatch[0].rm_eo < 0) ||
+                   (eol - bol) < pmatch[0].rm_eo)
+                       die("regexp returned nonsense");
+
+               /* Match beginning must be either beginning of the
+                * line, or at word boundary (i.e. the last char must
+                * not be a word char).  Similarly, match end must be
+                * either end of the line, or at word boundary
+                * (i.e. the next char must not be a word char).
+                */
+               if ( ((pmatch[0].rm_so == 0 && at_true_bol) ||
+                     !word_char(bol[pmatch[0].rm_so-1])) &&
+                    ((pmatch[0].rm_eo == (eol-bol)) ||
+                     !word_char(bol[pmatch[0].rm_eo])) )
+                       ;
+               else
+                       hit = 0;
+
+               if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
+                       /* There could be more than one match on the
+                        * line, and the first match might not be
+                        * strict word match.  But later ones could be!
+                        */
+                       bol = pmatch[0].rm_so + bol + 1;
+                       at_true_bol = 0;
+                       goto again;
+               }
+       }
+       return hit;
+}
+
+static int match_expr_eval(struct grep_opt *opt,
+                          struct grep_expr *x,
+                          char *bol, char *eol)
+{
+       switch (x->node) {
+       case GREP_NODE_ATOM:
+               return match_one_pattern(opt, x->u.atom, bol, eol);
+               break;
+       case GREP_NODE_NOT:
+               return !match_expr_eval(opt, x->u.unary, bol, eol);
+       case GREP_NODE_AND:
+               return (match_expr_eval(opt, x->u.binary.left, bol, eol) &&
+                       match_expr_eval(opt, x->u.binary.right, bol, eol));
+       case GREP_NODE_OR:
+               return (match_expr_eval(opt, x->u.binary.left, bol, eol) ||
+                       match_expr_eval(opt, x->u.binary.right, bol, eol));
+       }
+       die("Unexpected node type (internal error) %d\n", x->node);
+}
+
+static int match_expr(struct grep_opt *opt, char *bol, char *eol)
+{
+       struct grep_expr *x = opt->pattern_expression;
+       return match_expr_eval(opt, x, bol, eol);
+}
+
+static int match_line(struct grep_opt *opt, char *bol, char *eol)
+{
+       struct grep_pat *p;
+       if (opt->extended)
+               return match_expr(opt, bol, eol);
+       for (p = opt->pattern_list; p; p = p->next) {
+               if (match_one_pattern(opt, p, bol, eol))
+                       return 1;
+       }
+       return 0;
+}
+
 static int grep_buffer(struct grep_opt *opt, const char *name,
                       char *buf, unsigned long size)
 {
@@ -231,46 +473,15 @@ static int grep_buffer(struct grep_opt *opt, const char *name,
                hunk_mark = "--\n";
 
        while (left) {
-               regmatch_t pmatch[10];
                char *eol, ch;
                int hit = 0;
-               struct grep_pat *p;
 
                eol = end_of_line(bol, &left);
                ch = *eol;
                *eol = 0;
 
-               for (p = opt->pattern_list; p; p = p->next) {
-                       if (!opt->fixed) {
-                               regex_t *exp = &p->regexp;
-                               hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
-                                              pmatch, 0);
-                       }
-                       else {
-                               hit = !fixmatch(p->pattern, bol, pmatch);
-                       }
+               hit = match_line(opt, bol, eol);
 
-                       if (hit && opt->word_regexp) {
-                               /* Match beginning must be either
-                                * beginning of the line, or at word
-                                * boundary (i.e. the last char must
-                                * not be alnum or underscore).
-                                */
-                               if ((pmatch[0].rm_so < 0) ||
-                                   (eol - bol) <= pmatch[0].rm_so ||
-                                   (pmatch[0].rm_eo < 0) ||
-                                   (eol - bol) < pmatch[0].rm_eo)
-                                       die("regexp returned nonsense");
-                               if (pmatch[0].rm_so != 0 &&
-                                   word_char(bol[pmatch[0].rm_so-1]))
-                                       hit = 0;
-                               if (pmatch[0].rm_eo != (eol-bol) &&
-                                   word_char(bol[pmatch[0].rm_eo]))
-                                       hit = 0;
-                       }
-                       if (hit)
-                               break;
-               }
                /* "grep -v -e foo -e bla" should list lines
                 * that do not have either, so inversion should
                 * be done outside.
@@ -364,19 +575,40 @@ static int grep_buffer(struct grep_opt *opt, const char *name,
        return !!last_hit;
 }
 
-static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name)
+static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
 {
        unsigned long size;
        char *data;
        char type[20];
+       char *to_free = NULL;
        int hit;
+
        data = read_sha1_file(sha1, type, &size);
        if (!data) {
                error("'%s': unable to read %s", name, sha1_to_hex(sha1));
                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;
+               }
+       }
        hit = grep_buffer(opt, name, data, size);
        free(data);
+       free(to_free);
        return hit;
 }
 
@@ -406,6 +638,8 @@ static int grep_file(struct grep_opt *opt, const char *filename)
                return 0;
        }
        close(i);
+       if (opt->relative && opt->prefix_length)
+               filename += opt->prefix_length;
        i = grep_buffer(opt, filename, data, st.st_size);
        free(data);
        return i;
@@ -446,12 +680,14 @@ static int exec_grep(int argc, const char **argv)
 
 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
 {
-       int i, nr, argc, hit, len;
+       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)
@@ -536,12 +772,17 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
                argv[argc++] = name;
                if (argc < MAXARGS)
                        continue;
-               hit += exec_grep(argc, argv);
+               status = exec_grep(argc, argv);
+               if (0 < status)
+                       hit = 1;
                argc = nr;
        }
-       if (argc > nr)
-               hit += exec_grep(argc, argv);
-       return 0;
+       if (argc > nr) {
+               status = exec_grep(argc, argv);
+               if (0 < status)
+                       hit = 1;
+       }
+       return hit;
 }
 
 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
@@ -570,7 +811,7 @@ static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
                if (!pathspec_matches(paths, ce->name))
                        continue;
                if (cached)
-                       hit |= grep_sha1(opt, ce->sha1, ce->name);
+                       hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
                else
                        hit |= grep_file(opt, ce->name);
        }
@@ -585,11 +826,12 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
        int hit = 0;
        struct name_entry entry;
        char *down;
-       char *path_buf = xmalloc(PATH_MAX + strlen(tree_name) + 100);
+       int tn_len = strlen(tree_name);
+       char *path_buf = xmalloc(PATH_MAX + tn_len + 100);
 
-       if (tree_name[0]) {
-               int offset = sprintf(path_buf, "%s:", tree_name);
-               down = path_buf + offset;
+       if (tn_len) {
+               tn_len = sprintf(path_buf, "%s:", tree_name);
+               down = path_buf + tn_len;
                strcat(down, base);
        }
        else {
@@ -611,7 +853,7 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
                if (!pathspec_matches(paths, down))
                        ;
                else if (S_ISREG(entry.mode))
-                       hit |= grep_sha1(opt, entry.sha1, path_buf);
+                       hit |= grep_sha1(opt, entry.sha1, path_buf, tn_len);
                else if (S_ISDIR(entry.mode)) {
                        char type[20];
                        struct tree_desc sub;
@@ -631,9 +873,9 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
 static int grep_object(struct grep_opt *opt, const char **paths,
                       struct object *obj, const char *name)
 {
-       if (obj->type == TYPE_BLOB)
-               return grep_sha1(opt, obj->sha1, name);
-       if (obj->type == TYPE_COMMIT || obj->type == TYPE_TREE) {
+       if (obj->type == OBJ_BLOB)
+               return grep_sha1(opt, obj->sha1, name, 0);
+       if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
                struct tree_desc tree;
                void *data;
                int hit;
@@ -652,18 +894,26 @@ static int grep_object(struct grep_opt *opt, const char **paths,
 static const char builtin_grep_usage[] =
 "git-grep <option>* <rev>* [-e] <pattern> [<path>...]";
 
-int cmd_grep(int argc, const char **argv, char **envp)
+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";
+
+int cmd_grep(int argc, const char **argv, const char *prefix)
 {
        int hit = 0;
        int cached = 0;
        int seen_dashdash = 0;
        struct grep_opt opt;
        struct object_array list = { 0, 0, NULL };
-       const char *prefix = setup_git_directory();
        const char **paths = NULL;
        int i;
 
        memset(&opt, 0, sizeof(opt));
+       opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
+       opt.relative = 1;
        opt.pattern_tail = &opt.pattern_list;
        opt.regflags = REG_NEWLINE;
 
@@ -674,7 +924,7 @@ int cmd_grep(int argc, const char **argv, char **envp)
         * pattern, but then what follows it must be zero or more
         * valid refs up to the -- (if exists), and then existing
         * paths.  If there is an explicit pattern, then the first
-        * unrecocnized non option is the beginning of the refs list
+        * unrecognized non option is the beginning of the refs list
         * that continues up to the -- (if exists), and then paths.
         */
 
@@ -759,7 +1009,7 @@ int cmd_grep(int argc, const char **argv, char **envp)
                        case 'A': case 'B': case 'C':
                                if (!arg[2]) {
                                        if (argc <= 1)
-                                               usage(builtin_grep_usage);
+                                               die(emsg_missing_context_len);
                                        scan = *++argv;
                                        argc--;
                                }
@@ -771,7 +1021,7 @@ int cmd_grep(int argc, const char **argv, char **envp)
                                break;
                        }
                        if (sscanf(scan, "%u", &num) != 1)
-                               usage(builtin_grep_usage);
+                               die(emsg_invalid_context_len, scan);
                        switch (arg[1]) {
                        case 'A':
                                opt.post_context = num;
@@ -790,7 +1040,7 @@ int cmd_grep(int argc, const char **argv, char **envp)
                        int lno = 0;
                        char buf[1024];
                        if (argc <= 1)
-                               usage(builtin_grep_usage);
+                               die(emsg_missing_argument, arg);
                        patterns = fopen(argv[1], "r");
                        if (!patterns)
                                die("'%s': %s", argv[1], strerror(errno));
@@ -801,30 +1051,59 @@ int cmd_grep(int argc, const char **argv, char **envp)
                                /* ignore empty line like grep does */
                                if (!buf[0])
                                        continue;
-                               add_pattern(&opt, strdup(buf), argv[1], ++lno);
+                               add_pattern(&opt, strdup(buf), argv[1], ++lno,
+                                           GREP_PATTERN);
                        }
                        fclose(patterns);
                        argv++;
                        argc--;
                        continue;
                }
+               if (!strcmp("--not", arg)) {
+                       add_pattern(&opt, arg, "command line", 0, GREP_NOT);
+                       continue;
+               }
+               if (!strcmp("--and", arg)) {
+                       add_pattern(&opt, arg, "command line", 0, GREP_AND);
+                       continue;
+               }
+               if (!strcmp("--or", arg))
+                       continue; /* no-op */
+               if (!strcmp("(", arg)) {
+                       add_pattern(&opt, arg, "command line", 0, GREP_OPEN_PAREN);
+                       continue;
+               }
+               if (!strcmp(")", arg)) {
+                       add_pattern(&opt, arg, "command line", 0, GREP_CLOSE_PAREN);
+                       continue;
+               }
                if (!strcmp("-e", arg)) {
                        if (1 < argc) {
-                               add_pattern(&opt, argv[1], "-e option", 0);
+                               add_pattern(&opt, argv[1], "-e option", 0,
+                                           GREP_PATTERN);
                                argv++;
                                argc--;
                                continue;
                        }
-                       usage(builtin_grep_usage);
+                       die(emsg_missing_argument, arg);
+               }
+               if (!strcmp("--full-name", arg)) {
+                       opt.relative = 0;
+                       continue;
                }
-               if (!strcmp("--", arg))
+               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) {
-                       add_pattern(&opt, arg, "command line", 0);
+                       add_pattern(&opt, arg, "command line", 0,
+                                   GREP_PATTERN);
                        break;
                }
                else {
@@ -870,8 +1149,15 @@ int cmd_grep(int argc, const char **argv, char **envp)
                        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;