f1800a54d482d94d04f872f62d6d8ae0121ab8cb
   1/*
   2 * Builtin "git grep"
   3 *
   4 * Copyright (c) 2006 Junio C Hamano
   5 */
   6#include "cache.h"
   7#include "blob.h"
   8#include "tree.h"
   9#include "commit.h"
  10#include "tag.h"
  11#include "tree-walk.h"
  12#include "builtin.h"
  13#include <regex.h>
  14#include <fnmatch.h>
  15
  16/*
  17 * git grep pathspecs are somewhat different from diff-tree pathspecs;
  18 * pathname wildcards are allowed.
  19 */
  20static int pathspec_matches(const char **paths, const char *name)
  21{
  22        int namelen, i;
  23        if (!paths || !*paths)
  24                return 1;
  25        namelen = strlen(name);
  26        for (i = 0; paths[i]; i++) {
  27                const char *match = paths[i];
  28                int matchlen = strlen(match);
  29                const char *slash, *cp;
  30
  31                if ((matchlen <= namelen) &&
  32                    !strncmp(name, match, matchlen) &&
  33                    (match[matchlen-1] == '/' ||
  34                     name[matchlen] == '\0' || name[matchlen] == '/'))
  35                        return 1;
  36                if (!fnmatch(match, name, 0))
  37                        return 1;
  38                if (name[namelen-1] != '/')
  39                        continue;
  40
  41                /* We are being asked if the name directory is worth
  42                 * descending into.
  43                 *
  44                 * Find the longest leading directory name that does
  45                 * not have metacharacter in the pathspec; the name
  46                 * we are looking at must overlap with that directory.
  47                 */
  48                for (cp = match, slash = NULL; cp - match < matchlen; cp++) {
  49                        char ch = *cp;
  50                        if (ch == '/')
  51                                slash = cp;
  52                        if (ch == '*' || ch == '[')
  53                                break;
  54                }
  55                if (!slash)
  56                        slash = match; /* toplevel */
  57                else
  58                        slash++;
  59                if (namelen <= slash - match) {
  60                        /* Looking at "Documentation/" and
  61                         * the pattern says "Documentation/howto/", or
  62                         * "Documentation/diff*.txt".
  63                         */
  64                        if (!memcmp(match, name, namelen))
  65                                return 1;
  66                }
  67                else {
  68                        /* Looking at "Documentation/howto/" and
  69                         * the pattern says "Documentation/h*".
  70                         */
  71                        if (!memcmp(match, name, slash - match))
  72                                return 1;
  73                }
  74        }
  75        return 0;
  76}
  77
  78struct grep_pat {
  79        struct grep_pat *next;
  80        const char *pattern;
  81        regex_t regexp;
  82};
  83
  84struct grep_opt {
  85        struct grep_pat *pattern_list;
  86        struct grep_pat **pattern_tail;
  87        regex_t regexp;
  88        unsigned linenum:1;
  89        unsigned invert:1;
  90        unsigned name_only:1;
  91        unsigned count:1;
  92        int regflags;
  93        unsigned pre_context;
  94        unsigned post_context;
  95};
  96
  97static void add_pattern(struct grep_opt *opt, const char *pat)
  98{
  99        struct grep_pat *p = xcalloc(1, sizeof(*p));
 100        p->pattern = pat;
 101        *opt->pattern_tail = p;
 102        opt->pattern_tail = &p->next;
 103        p->next = NULL;
 104}
 105
 106static void compile_patterns(struct grep_opt *opt)
 107{
 108        struct grep_pat *p;
 109        for (p = opt->pattern_list; p; p = p->next) {
 110                int err = regcomp(&p->regexp, p->pattern, opt->regflags);
 111                if (err) {
 112                        char errbuf[1024];
 113                        regerror(err, &p->regexp, errbuf, 1024);
 114                        regfree(&p->regexp);
 115                        die("'%s': %s", p->pattern, errbuf);
 116                }
 117        }
 118}
 119
 120static char *end_of_line(char *cp, unsigned long *left)
 121{
 122        unsigned long l = *left;
 123        while (l && *cp != '\n') {
 124                l--;
 125                cp++;
 126        }
 127        *left = l;
 128        return cp;
 129}
 130
 131static void show_line(struct grep_opt *opt, const char *bol, const char *eol,
 132                      const char *name, unsigned lno, char sign)
 133{
 134        printf("%s%c", name, sign);
 135        if (opt->linenum)
 136                printf("%d%c", lno, sign);
 137        printf("%.*s\n", (int)(eol-bol), bol);
 138}
 139
 140static int grep_buffer(struct grep_opt *opt, const char *name,
 141                       char *buf, unsigned long size)
 142{
 143        char *bol = buf;
 144        unsigned long left = size;
 145        unsigned lno = 1;
 146        struct pre_context_line {
 147                char *bol;
 148                char *eol;
 149        } *prev = NULL, *pcl;
 150        unsigned last_hit = 0;
 151        unsigned last_shown = 0;
 152        const char *hunk_mark = "";
 153        unsigned count = 0;
 154
 155        if (opt->pre_context)
 156                prev = xcalloc(opt->pre_context, sizeof(*prev));
 157        if (opt->pre_context || opt->post_context)
 158                hunk_mark = "--\n";
 159
 160        while (left) {
 161                regmatch_t pmatch[10];
 162                char *eol, ch;
 163                int hit = 0;
 164                struct grep_pat *p;
 165
 166                eol = end_of_line(bol, &left);
 167                ch = *eol;
 168                *eol = 0;
 169
 170                for (p = opt->pattern_list; p; p = p->next) {
 171                        regex_t *exp = &p->regexp;
 172                        hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
 173                                       pmatch, 0);
 174                        if (hit)
 175                                break;
 176                }
 177                /* "grep -v -e foo -e bla" should list lines
 178                 * that do not have either, so inversion should
 179                 * be done outside.
 180                 */
 181                if (opt->invert)
 182                        hit = !hit;
 183                if (hit) {
 184                        count++;
 185                        if (opt->name_only) {
 186                                printf("%s\n", name);
 187                                return 1;
 188                        }
 189                        /* Hit at this line.  If we haven't shown the
 190                         * pre-context lines, we would need to show them.
 191                         * When asked to do "count", this still show
 192                         * the context which is nonsense, but the user
 193                         * deserves to get that ;-).
 194                         */
 195                        if (opt->pre_context) {
 196                                unsigned from;
 197                                if (opt->pre_context < lno)
 198                                        from = lno - opt->pre_context;
 199                                else
 200                                        from = 1;
 201                                if (from <= last_shown)
 202                                        from = last_shown + 1;
 203                                if (last_shown && from != last_shown + 1)
 204                                        printf(hunk_mark);
 205                                while (from < lno) {
 206                                        pcl = &prev[lno-from-1];
 207                                        show_line(opt, pcl->bol, pcl->eol,
 208                                                  name, from, '-');
 209                                        from++;
 210                                }
 211                                last_shown = lno-1;
 212                        }
 213                        if (last_shown && lno != last_shown + 1)
 214                                printf(hunk_mark);
 215                        if (!opt->count)
 216                                show_line(opt, bol, eol, name, lno, ':');
 217                        last_shown = last_hit = lno;
 218                }
 219                else if (last_hit &&
 220                         lno <= last_hit + opt->post_context) {
 221                        /* If the last hit is within the post context,
 222                         * we need to show this line.
 223                         */
 224                        if (last_shown && lno != last_shown + 1)
 225                                printf(hunk_mark);
 226                        show_line(opt, bol, eol, name, lno, '-');
 227                        last_shown = lno;
 228                }
 229                if (opt->pre_context) {
 230                        memmove(prev+1, prev,
 231                                (opt->pre_context-1) * sizeof(*prev));
 232                        prev->bol = bol;
 233                        prev->eol = eol;
 234                }
 235                *eol = ch;
 236                bol = eol + 1;
 237                left--;
 238                lno++;
 239        }
 240        /* NEEDSWORK:
 241         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
 242         * which feels mostly useless but sometimes useful.  Maybe
 243         * make it another option?  For now suppress them.
 244         */
 245        if (opt->count && count)
 246                printf("%s:%u\n", name, count);
 247        return !!last_hit;
 248}
 249
 250static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name)
 251{
 252        unsigned long size;
 253        char *data;
 254        char type[20];
 255        int hit;
 256        data = read_sha1_file(sha1, type, &size);
 257        if (!data) {
 258                error("'%s': unable to read %s", name, sha1_to_hex(sha1));
 259                return 0;
 260        }
 261        hit = grep_buffer(opt, name, data, size);
 262        free(data);
 263        return hit;
 264}
 265
 266static int grep_file(struct grep_opt *opt, const char *filename)
 267{
 268        struct stat st;
 269        int i;
 270        char *data;
 271        if (lstat(filename, &st) < 0) {
 272        err_ret:
 273                if (errno != ENOENT)
 274                        error("'%s': %s", filename, strerror(errno));
 275                return 0;
 276        }
 277        if (!st.st_size)
 278                return 0; /* empty file -- no grep hit */
 279        if (!S_ISREG(st.st_mode))
 280                return 0;
 281        i = open(filename, O_RDONLY);
 282        if (i < 0)
 283                goto err_ret;
 284        data = xmalloc(st.st_size + 1);
 285        if (st.st_size != xread(i, data, st.st_size)) {
 286                error("'%s': short read %s", filename, strerror(errno));
 287                close(i);
 288                free(data);
 289                return 0;
 290        }
 291        close(i);
 292        i = grep_buffer(opt, filename, data, st.st_size);
 293        free(data);
 294        return i;
 295}
 296
 297static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
 298{
 299        int hit = 0;
 300        int nr;
 301        read_cache();
 302
 303        for (nr = 0; nr < active_nr; nr++) {
 304                struct cache_entry *ce = active_cache[nr];
 305                if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
 306                        continue;
 307                if (!pathspec_matches(paths, ce->name))
 308                        continue;
 309                if (cached)
 310                        hit |= grep_sha1(opt, ce->sha1, ce->name);
 311                else
 312                        hit |= grep_file(opt, ce->name);
 313        }
 314        return hit;
 315}
 316
 317static int grep_tree(struct grep_opt *opt, const char **paths,
 318                     struct tree_desc *tree,
 319                     const char *tree_name, const char *base)
 320{
 321        unsigned mode;
 322        int len;
 323        int hit = 0;
 324        const char *path;
 325        const unsigned char *sha1;
 326        char *down;
 327        char *path_buf = xmalloc(PATH_MAX + strlen(tree_name) + 100);
 328
 329        if (tree_name[0]) {
 330                int offset = sprintf(path_buf, "%s:", tree_name);
 331                down = path_buf + offset;
 332                strcat(down, base);
 333        }
 334        else {
 335                down = path_buf;
 336                strcpy(down, base);
 337        }
 338        len = strlen(path_buf);
 339
 340        while (tree->size) {
 341                int pathlen;
 342                sha1 = tree_entry_extract(tree, &path, &mode);
 343                pathlen = strlen(path);
 344                strcpy(path_buf + len, path);
 345
 346                if (S_ISDIR(mode))
 347                        /* Match "abc/" against pathspec to
 348                         * decide if we want to descend into "abc"
 349                         * directory.
 350                         */
 351                        strcpy(path_buf + len + pathlen, "/");
 352
 353                if (!pathspec_matches(paths, down))
 354                        ;
 355                else if (S_ISREG(mode))
 356                        hit |= grep_sha1(opt, sha1, path_buf);
 357                else if (S_ISDIR(mode)) {
 358                        char type[20];
 359                        struct tree_desc sub;
 360                        void *data;
 361                        data = read_sha1_file(sha1, type, &sub.size);
 362                        if (!data)
 363                                die("unable to read tree (%s)",
 364                                    sha1_to_hex(sha1));
 365                        sub.buf = data;
 366                        hit |= grep_tree(opt, paths, &sub, tree_name, down);
 367                        free(data);
 368                }
 369                update_tree_entry(tree);
 370        }
 371        return hit;
 372}
 373
 374static int grep_object(struct grep_opt *opt, const char **paths,
 375                       struct object *obj, const char *name)
 376{
 377        if (!strcmp(obj->type, blob_type))
 378                return grep_sha1(opt, obj->sha1, name);
 379        if (!strcmp(obj->type, commit_type) ||
 380            !strcmp(obj->type, tree_type)) {
 381                struct tree_desc tree;
 382                void *data;
 383                int hit;
 384                data = read_object_with_reference(obj->sha1, tree_type,
 385                                                  &tree.size, NULL);
 386                if (!data)
 387                        die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 388                tree.buf = data;
 389                hit = grep_tree(opt, paths, &tree, name, "");
 390                free(data);
 391                return hit;
 392        }
 393        die("unable to grep from object of type %s", obj->type);
 394}
 395
 396static const char builtin_grep_usage[] =
 397"git-grep <option>* <rev>* [-e] <pattern> [<path>...]";
 398
 399int cmd_grep(int argc, const char **argv, char **envp)
 400{
 401        int hit = 0;
 402        int no_more_flags = 0;
 403        int seen_noncommit = 0;
 404        int cached = 0;
 405        struct grep_opt opt;
 406        struct object_list *list, **tail, *object_list = NULL;
 407        const char *prefix = setup_git_directory();
 408        const char **paths = NULL;
 409
 410        memset(&opt, 0, sizeof(opt));
 411        opt.pattern_tail = &opt.pattern_list;
 412        opt.regflags = REG_NEWLINE;
 413
 414        /*
 415         * No point using rev_info, really.
 416         */
 417        while (1 < argc) {
 418                const char *arg = argv[1];
 419                argc--; argv++;
 420                if (!strcmp("--cached", arg)) {
 421                        cached = 1;
 422                        continue;
 423                }
 424                if (!strcmp("-i", arg) ||
 425                    !strcmp("--ignore-case", arg)) {
 426                        opt.regflags |= REG_ICASE;
 427                        continue;
 428                }
 429                if (!strcmp("-v", arg) ||
 430                    !strcmp("--invert-match", arg)) {
 431                        opt.invert = 1;
 432                        continue;
 433                }
 434                if (!strcmp("-E", arg) ||
 435                    !strcmp("--extended-regexp", arg)) {
 436                        opt.regflags |= REG_EXTENDED;
 437                        continue;
 438                }
 439                if (!strcmp("-G", arg) ||
 440                    !strcmp("--basic-regexp", arg)) {
 441                        opt.regflags &= ~REG_EXTENDED;
 442                        continue;
 443                }
 444                if (!strcmp("-n", arg)) {
 445                        opt.linenum = 1;
 446                        continue;
 447                }
 448                if (!strcmp("-H", arg)) {
 449                        /* We always show the pathname, so this
 450                         * is a noop.
 451                         */
 452                        continue;
 453                }
 454                if (!strcmp("-l", arg) ||
 455                    !strcmp("--files-with-matches", arg)) {
 456                        opt.name_only = 1;
 457                        continue;
 458                }
 459                if (!strcmp("-c", arg) ||
 460                    !strcmp("--count", arg)) {
 461                        opt.count = 1;
 462                        continue;
 463                }
 464                if (!strncmp("-A", arg, 2) ||
 465                    !strncmp("-B", arg, 2) ||
 466                    !strncmp("-C", arg, 2) ||
 467                    (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
 468                        unsigned num;
 469                        const char *scan;
 470                        switch (arg[1]) {
 471                        case 'A': case 'B': case 'C':
 472                                if (!arg[2]) {
 473                                        if (argc <= 1)
 474                                                usage(builtin_grep_usage);
 475                                        scan = *++argv;
 476                                        argc--;
 477                                }
 478                                else
 479                                        scan = arg + 2;
 480                                break;
 481                        default:
 482                                scan = arg + 1;
 483                                break;
 484                        }
 485                        if (sscanf(scan, "%u", &num) != 1)
 486                                usage(builtin_grep_usage);
 487                        switch (arg[1]) {
 488                        case 'A':
 489                                opt.post_context = num;
 490                                break;
 491                        default:
 492                        case 'C':
 493                                opt.post_context = num;
 494                        case 'B':
 495                                opt.pre_context = num;
 496                                break;
 497                        }
 498                        continue;
 499                }
 500                if (!strcmp("-e", arg)) {
 501                        if (1 < argc) {
 502                                add_pattern(&opt, argv[1]);
 503                                argv++;
 504                                argc--;
 505                                continue;
 506                        }
 507                        usage(builtin_grep_usage);
 508                }
 509                if (!strcmp("--", arg)) {
 510                        no_more_flags = 1;
 511                        continue;
 512                }
 513                /* Either unrecognized option or a single pattern */
 514                if (!no_more_flags && *arg == '-')
 515                        usage(builtin_grep_usage);
 516                if (!opt.pattern_list) {
 517                        add_pattern(&opt, arg);
 518                        break;
 519                }
 520                else {
 521                        /* We are looking at the first path or rev;
 522                         * it is found at argv[0] after leaving the
 523                         * loop.
 524                         */
 525                        argc++; argv--;
 526                        break;
 527                }
 528        }
 529        if (!opt.pattern_list)
 530                die("no pattern given.");
 531        compile_patterns(&opt);
 532        tail = &object_list;
 533        while (1 < argc) {
 534                struct object *object;
 535                struct object_list *elem;
 536                const char *arg = argv[1];
 537                unsigned char sha1[20];
 538                if (get_sha1(arg, sha1) < 0)
 539                        break;
 540                object = parse_object(sha1);
 541                if (!object)
 542                        die("bad object %s", arg);
 543                elem = object_list_insert(object, tail);
 544                elem->name = arg;
 545                tail = &elem->next;
 546                argc--; argv++;
 547        }
 548        if (1 < argc)
 549                paths = get_pathspec(prefix, argv + 1);
 550        else if (prefix) {
 551                paths = xcalloc(2, sizeof(const char *));
 552                paths[0] = prefix;
 553                paths[1] = NULL;
 554        }
 555
 556        if (!object_list)
 557                return !grep_cache(&opt, paths, cached);
 558        /*
 559         * Do not walk "grep -e foo master next pu -- Documentation/"
 560         * but do walk "grep -e foo master..next -- Documentation/".
 561         * Ranged request mixed with a blob or tree object, like
 562         * "grep -e foo v1.0.0:Documentation/ master..next"
 563         * so detect that and complain.
 564         */
 565        for (list = object_list; list; list = list->next) {
 566                struct object *real_obj;
 567                real_obj = deref_tag(list->item, NULL, 0);
 568                if (strcmp(real_obj->type, commit_type))
 569                        seen_noncommit = 1;
 570        }
 571        if (cached)
 572                die("both --cached and revisions given.");
 573
 574        for (list = object_list; list; list = list->next) {
 575                struct object *real_obj;
 576                real_obj = deref_tag(list->item, NULL, 0);
 577                if (grep_object(&opt, paths, real_obj, list->name))
 578                        hit = 1;
 579        }
 580        return !hit;
 581}