range-diff.con commit conditional markdown preprocessing (c8b1cd9)
   1#include "cache.h"
   2#include "range-diff.h"
   3#include "string-list.h"
   4#include "run-command.h"
   5#include "argv-array.h"
   6#include "hashmap.h"
   7#include "xdiff-interface.h"
   8#include "linear-assignment.h"
   9#include "diffcore.h"
  10#include "commit.h"
  11#include "pretty.h"
  12#include "userdiff.h"
  13#include "apply.h"
  14
  15struct patch_util {
  16        /* For the search for an exact match */
  17        struct hashmap_entry e;
  18        const char *diff, *patch;
  19
  20        int i, shown;
  21        int diffsize;
  22        size_t diff_offset;
  23        /* the index of the matching item in the other branch, or -1 */
  24        int matching;
  25        struct object_id oid;
  26};
  27
  28static size_t find_end_of_line(char *buffer, unsigned long size)
  29{
  30        char *eol = memchr(buffer, '\n', size);
  31
  32        if (!eol)
  33                return size;
  34
  35        *eol = '\0';
  36        return eol + 1 - buffer;
  37}
  38
  39/*
  40 * Reads the patches into a string list, with the `util` field being populated
  41 * as struct object_id (will need to be free()d).
  42 */
  43static int read_patches(const char *range, struct string_list *list)
  44{
  45        struct child_process cp = CHILD_PROCESS_INIT;
  46        struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
  47        struct patch_util *util = NULL;
  48        int in_header = 1;
  49        char *line, *current_filename = NULL;
  50        int offset, len;
  51        size_t size;
  52
  53        argv_array_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
  54                        "--reverse", "--date-order", "--decorate=no",
  55                        /*
  56                         * Choose indicators that are not used anywhere
  57                         * else in diffs, but still look reasonable
  58                         * (e.g. will not be confusing when debugging)
  59                         */
  60                        "--output-indicator-new=>",
  61                        "--output-indicator-old=<",
  62                        "--output-indicator-context=#",
  63                        "--no-abbrev-commit", range,
  64                        NULL);
  65        cp.out = -1;
  66        cp.no_stdin = 1;
  67        cp.git_cmd = 1;
  68
  69        if (start_command(&cp))
  70                return error_errno(_("could not start `log`"));
  71        if (strbuf_read(&contents, cp.out, 0) < 0) {
  72                error_errno(_("could not read `log` output"));
  73                finish_command(&cp);
  74                return -1;
  75        }
  76
  77        line = contents.buf;
  78        size = contents.len;
  79        for (offset = 0; size > 0; offset += len, size -= len, line += len) {
  80                const char *p;
  81
  82                len = find_end_of_line(line, size);
  83                line[len - 1] = '\0';
  84                if (skip_prefix(line, "commit ", &p)) {
  85                        if (util) {
  86                                string_list_append(list, buf.buf)->util = util;
  87                                strbuf_reset(&buf);
  88                        }
  89                        util = xcalloc(sizeof(*util), 1);
  90                        if (get_oid(p, &util->oid)) {
  91                                error(_("could not parse commit '%s'"), p);
  92                                free(util);
  93                                string_list_clear(list, 1);
  94                                strbuf_release(&buf);
  95                                strbuf_release(&contents);
  96                                finish_command(&cp);
  97                                return -1;
  98                        }
  99                        util->matching = -1;
 100                        in_header = 1;
 101                        continue;
 102                }
 103
 104                if (starts_with(line, "diff --git")) {
 105                        struct patch patch = { 0 };
 106                        struct strbuf root = STRBUF_INIT;
 107                        int linenr = 0;
 108
 109                        in_header = 0;
 110                        strbuf_addch(&buf, '\n');
 111                        if (!util->diff_offset)
 112                                util->diff_offset = buf.len;
 113                        line[len - 1] = '\n';
 114                        len = parse_git_diff_header(&root, &linenr, 1, line,
 115                                                    len, size, &patch);
 116                        if (len < 0)
 117                                die(_("could not parse git header '%.*s'"), (int)len, line);
 118                        strbuf_addstr(&buf, " ## ");
 119                        if (patch.is_new > 0)
 120                                strbuf_addf(&buf, "%s (new)", patch.new_name);
 121                        else if (patch.is_delete > 0)
 122                                strbuf_addf(&buf, "%s (deleted)", patch.old_name);
 123                        else if (patch.is_rename)
 124                                strbuf_addf(&buf, "%s => %s", patch.old_name, patch.new_name);
 125                        else
 126                                strbuf_addstr(&buf, patch.new_name);
 127
 128                        free(current_filename);
 129                        if (patch.is_delete > 0)
 130                                current_filename = xstrdup(patch.old_name);
 131                        else
 132                                current_filename = xstrdup(patch.new_name);
 133
 134                        if (patch.new_mode && patch.old_mode &&
 135                            patch.old_mode != patch.new_mode)
 136                                strbuf_addf(&buf, " (mode change %06o => %06o)",
 137                                            patch.old_mode, patch.new_mode);
 138
 139                        strbuf_addstr(&buf, " ##");
 140                } else if (in_header) {
 141                        if (starts_with(line, "Author: ")) {
 142                                strbuf_addstr(&buf, " ## Metadata ##\n");
 143                                strbuf_addstr(&buf, line);
 144                                strbuf_addstr(&buf, "\n\n");
 145                                strbuf_addstr(&buf, " ## Commit message ##\n");
 146                        } else if (starts_with(line, "    ")) {
 147                                p = line + len - 2;
 148                                while (isspace(*p) && p >= line)
 149                                        p--;
 150                                strbuf_add(&buf, line, p - line + 1);
 151                                strbuf_addch(&buf, '\n');
 152                        }
 153                        continue;
 154                } else if (skip_prefix(line, "@@ ", &p)) {
 155                        p = strstr(p, "@@");
 156                        strbuf_addstr(&buf, "@@");
 157                        if (current_filename && p[2])
 158                                strbuf_addf(&buf, " %s:", current_filename);
 159                        if (p)
 160                                strbuf_addstr(&buf, p + 2);
 161                } else if (!line[0])
 162                        /*
 163                         * A completely blank (not ' \n', which is context)
 164                         * line is not valid in a diff.  We skip it
 165                         * silently, because this neatly handles the blank
 166                         * separator line between commits in git-log
 167                         * output.
 168                         */
 169                        continue;
 170                else if (line[0] == '>') {
 171                        strbuf_addch(&buf, '+');
 172                        strbuf_addstr(&buf, line + 1);
 173                } else if (line[0] == '<') {
 174                        strbuf_addch(&buf, '-');
 175                        strbuf_addstr(&buf, line + 1);
 176                } else if (line[0] == '#') {
 177                        strbuf_addch(&buf, ' ');
 178                        strbuf_addstr(&buf, line + 1);
 179                } else {
 180                        strbuf_addch(&buf, ' ');
 181                        strbuf_addstr(&buf, line);
 182                }
 183
 184                strbuf_addch(&buf, '\n');
 185                util->diffsize++;
 186        }
 187        strbuf_release(&contents);
 188
 189        if (util)
 190                string_list_append(list, buf.buf)->util = util;
 191        strbuf_release(&buf);
 192        free(current_filename);
 193
 194        if (finish_command(&cp))
 195                return -1;
 196
 197        return 0;
 198}
 199
 200static int patch_util_cmp(const void *dummy, const struct patch_util *a,
 201                          const struct patch_util *b, const char *keydata)
 202{
 203        return strcmp(a->diff, keydata ? keydata : b->diff);
 204}
 205
 206static void find_exact_matches(struct string_list *a, struct string_list *b)
 207{
 208        struct hashmap map;
 209        int i;
 210
 211        hashmap_init(&map, (hashmap_cmp_fn)patch_util_cmp, NULL, 0);
 212
 213        /* First, add the patches of a to a hash map */
 214        for (i = 0; i < a->nr; i++) {
 215                struct patch_util *util = a->items[i].util;
 216
 217                util->i = i;
 218                util->patch = a->items[i].string;
 219                util->diff = util->patch + util->diff_offset;
 220                hashmap_entry_init(util, strhash(util->diff));
 221                hashmap_add(&map, util);
 222        }
 223
 224        /* Now try to find exact matches in b */
 225        for (i = 0; i < b->nr; i++) {
 226                struct patch_util *util = b->items[i].util, *other;
 227
 228                util->i = i;
 229                util->patch = b->items[i].string;
 230                util->diff = util->patch + util->diff_offset;
 231                hashmap_entry_init(util, strhash(util->diff));
 232                other = hashmap_remove(&map, util, NULL);
 233                if (other) {
 234                        if (other->matching >= 0)
 235                                BUG("already assigned!");
 236
 237                        other->matching = i;
 238                        util->matching = other->i;
 239                }
 240        }
 241
 242        hashmap_free(&map, 0);
 243}
 244
 245static void diffsize_consume(void *data, char *line, unsigned long len)
 246{
 247        (*(int *)data)++;
 248}
 249
 250static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
 251                          const char *funcline, long funclen)
 252{
 253        diffsize_consume(data, NULL, 0);
 254}
 255
 256static int diffsize(const char *a, const char *b)
 257{
 258        xpparam_t pp = { 0 };
 259        xdemitconf_t cfg = { 0 };
 260        mmfile_t mf1, mf2;
 261        int count = 0;
 262
 263        mf1.ptr = (char *)a;
 264        mf1.size = strlen(a);
 265        mf2.ptr = (char *)b;
 266        mf2.size = strlen(b);
 267
 268        cfg.ctxlen = 3;
 269        if (!xdi_diff_outf(&mf1, &mf2,
 270                           diffsize_hunk, diffsize_consume, &count,
 271                           &pp, &cfg))
 272                return count;
 273
 274        error(_("failed to generate diff"));
 275        return COST_MAX;
 276}
 277
 278static void get_correspondences(struct string_list *a, struct string_list *b,
 279                                int creation_factor)
 280{
 281        int n = a->nr + b->nr;
 282        int *cost, c, *a2b, *b2a;
 283        int i, j;
 284
 285        ALLOC_ARRAY(cost, st_mult(n, n));
 286        ALLOC_ARRAY(a2b, n);
 287        ALLOC_ARRAY(b2a, n);
 288
 289        for (i = 0; i < a->nr; i++) {
 290                struct patch_util *a_util = a->items[i].util;
 291
 292                for (j = 0; j < b->nr; j++) {
 293                        struct patch_util *b_util = b->items[j].util;
 294
 295                        if (a_util->matching == j)
 296                                c = 0;
 297                        else if (a_util->matching < 0 && b_util->matching < 0)
 298                                c = diffsize(a_util->diff, b_util->diff);
 299                        else
 300                                c = COST_MAX;
 301                        cost[i + n * j] = c;
 302                }
 303
 304                c = a_util->matching < 0 ?
 305                        a_util->diffsize * creation_factor / 100 : COST_MAX;
 306                for (j = b->nr; j < n; j++)
 307                        cost[i + n * j] = c;
 308        }
 309
 310        for (j = 0; j < b->nr; j++) {
 311                struct patch_util *util = b->items[j].util;
 312
 313                c = util->matching < 0 ?
 314                        util->diffsize * creation_factor / 100 : COST_MAX;
 315                for (i = a->nr; i < n; i++)
 316                        cost[i + n * j] = c;
 317        }
 318
 319        for (i = a->nr; i < n; i++)
 320                for (j = b->nr; j < n; j++)
 321                        cost[i + n * j] = 0;
 322
 323        compute_assignment(n, n, cost, a2b, b2a);
 324
 325        for (i = 0; i < a->nr; i++)
 326                if (a2b[i] >= 0 && a2b[i] < b->nr) {
 327                        struct patch_util *a_util = a->items[i].util;
 328                        struct patch_util *b_util = b->items[a2b[i]].util;
 329
 330                        a_util->matching = a2b[i];
 331                        b_util->matching = i;
 332                }
 333
 334        free(cost);
 335        free(a2b);
 336        free(b2a);
 337}
 338
 339static void output_pair_header(struct diff_options *diffopt,
 340                               int patch_no_width,
 341                               struct strbuf *buf,
 342                               struct strbuf *dashes,
 343                               struct patch_util *a_util,
 344                               struct patch_util *b_util)
 345{
 346        struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
 347        struct commit *commit;
 348        char status;
 349        const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
 350        const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
 351        const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
 352        const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
 353        const char *color;
 354
 355        if (!dashes->len)
 356                strbuf_addchars(dashes, '-',
 357                                strlen(find_unique_abbrev(oid,
 358                                                          DEFAULT_ABBREV)));
 359
 360        if (!b_util) {
 361                color = color_old;
 362                status = '<';
 363        } else if (!a_util) {
 364                color = color_new;
 365                status = '>';
 366        } else if (strcmp(a_util->patch, b_util->patch)) {
 367                color = color_commit;
 368                status = '!';
 369        } else {
 370                color = color_commit;
 371                status = '=';
 372        }
 373
 374        strbuf_reset(buf);
 375        strbuf_addstr(buf, status == '!' ? color_old : color);
 376        if (!a_util)
 377                strbuf_addf(buf, "%*s:  %s ", patch_no_width, "-", dashes->buf);
 378        else
 379                strbuf_addf(buf, "%*d:  %s ", patch_no_width, a_util->i + 1,
 380                            find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
 381
 382        if (status == '!')
 383                strbuf_addf(buf, "%s%s", color_reset, color);
 384        strbuf_addch(buf, status);
 385        if (status == '!')
 386                strbuf_addf(buf, "%s%s", color_reset, color_new);
 387
 388        if (!b_util)
 389                strbuf_addf(buf, " %*s:  %s", patch_no_width, "-", dashes->buf);
 390        else
 391                strbuf_addf(buf, " %*d:  %s", patch_no_width, b_util->i + 1,
 392                            find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
 393
 394        commit = lookup_commit_reference(the_repository, oid);
 395        if (commit) {
 396                if (status == '!')
 397                        strbuf_addf(buf, "%s%s", color_reset, color);
 398
 399                strbuf_addch(buf, ' ');
 400                pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
 401        }
 402        strbuf_addf(buf, "%s\n", color_reset);
 403
 404        fwrite(buf->buf, buf->len, 1, diffopt->file);
 405}
 406
 407static struct userdiff_driver section_headers = {
 408        .funcname = { "^ ## (.*) ##$\n"
 409                      "^.?@@ (.*)$", REG_EXTENDED }
 410};
 411
 412static struct diff_filespec *get_filespec(const char *name, const char *p)
 413{
 414        struct diff_filespec *spec = alloc_filespec(name);
 415
 416        fill_filespec(spec, &null_oid, 0, 0100644);
 417        spec->data = (char *)p;
 418        spec->size = strlen(p);
 419        spec->should_munmap = 0;
 420        spec->is_stdin = 1;
 421        spec->driver = &section_headers;
 422
 423        return spec;
 424}
 425
 426static void patch_diff(const char *a, const char *b,
 427                       struct diff_options *diffopt)
 428{
 429        diff_queue(&diff_queued_diff,
 430                   get_filespec("a", a), get_filespec("b", b));
 431
 432        diffcore_std(diffopt);
 433        diff_flush(diffopt);
 434}
 435
 436static void output(struct string_list *a, struct string_list *b,
 437                   struct diff_options *diffopt)
 438{
 439        struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
 440        int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
 441        int i = 0, j = 0;
 442
 443        /*
 444         * We assume the user is really more interested in the second argument
 445         * ("newer" version). To that end, we print the output in the order of
 446         * the RHS (the `b` parameter). To put the LHS (the `a` parameter)
 447         * commits that are no longer in the RHS into a good place, we place
 448         * them once we have shown all of their predecessors in the LHS.
 449         */
 450
 451        while (i < a->nr || j < b->nr) {
 452                struct patch_util *a_util, *b_util;
 453                a_util = i < a->nr ? a->items[i].util : NULL;
 454                b_util = j < b->nr ? b->items[j].util : NULL;
 455
 456                /* Skip all the already-shown commits from the LHS. */
 457                while (i < a->nr && a_util->shown)
 458                        a_util = ++i < a->nr ? a->items[i].util : NULL;
 459
 460                /* Show unmatched LHS commit whose predecessors were shown. */
 461                if (i < a->nr && a_util->matching < 0) {
 462                        output_pair_header(diffopt, patch_no_width,
 463                                           &buf, &dashes, a_util, NULL);
 464                        i++;
 465                        continue;
 466                }
 467
 468                /* Show unmatched RHS commits. */
 469                while (j < b->nr && b_util->matching < 0) {
 470                        output_pair_header(diffopt, patch_no_width,
 471                                           &buf, &dashes, NULL, b_util);
 472                        b_util = ++j < b->nr ? b->items[j].util : NULL;
 473                }
 474
 475                /* Show matching LHS/RHS pair. */
 476                if (j < b->nr) {
 477                        a_util = a->items[b_util->matching].util;
 478                        output_pair_header(diffopt, patch_no_width,
 479                                           &buf, &dashes, a_util, b_util);
 480                        if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
 481                                patch_diff(a->items[b_util->matching].string,
 482                                           b->items[j].string, diffopt);
 483                        a_util->shown = 1;
 484                        j++;
 485                }
 486        }
 487        strbuf_release(&buf);
 488        strbuf_release(&dashes);
 489}
 490
 491static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
 492{
 493        return data;
 494}
 495
 496int show_range_diff(const char *range1, const char *range2,
 497                    int creation_factor, int dual_color,
 498                    struct diff_options *diffopt)
 499{
 500        int res = 0;
 501
 502        struct string_list branch1 = STRING_LIST_INIT_DUP;
 503        struct string_list branch2 = STRING_LIST_INIT_DUP;
 504
 505        if (read_patches(range1, &branch1))
 506                res = error(_("could not parse log for '%s'"), range1);
 507        if (!res && read_patches(range2, &branch2))
 508                res = error(_("could not parse log for '%s'"), range2);
 509
 510        if (!res) {
 511                struct diff_options opts;
 512                struct strbuf indent = STRBUF_INIT;
 513
 514                if (diffopt)
 515                        memcpy(&opts, diffopt, sizeof(opts));
 516                else
 517                        diff_setup(&opts);
 518
 519                if (!opts.output_format)
 520                        opts.output_format = DIFF_FORMAT_PATCH;
 521                opts.flags.suppress_diff_headers = 1;
 522                opts.flags.dual_color_diffed_diffs = dual_color;
 523                opts.flags.suppress_hunk_header_line_count = 1;
 524                opts.output_prefix = output_prefix_cb;
 525                strbuf_addstr(&indent, "    ");
 526                opts.output_prefix_data = &indent;
 527                diff_setup_done(&opts);
 528
 529                find_exact_matches(&branch1, &branch2);
 530                get_correspondences(&branch1, &branch2, creation_factor);
 531                output(&branch1, &branch2, &opts);
 532
 533                strbuf_release(&indent);
 534        }
 535
 536        string_list_clear(&branch1, 1);
 537        string_list_clear(&branch2, 1);
 538
 539        return res;
 540}