diff.con commit Update draft release notes for 1.6.1 (ec3a4ba)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14
  15#ifdef NO_FAST_WORKING_DIRECTORY
  16#define FAST_WORKING_DIRECTORY 0
  17#else
  18#define FAST_WORKING_DIRECTORY 1
  19#endif
  20
  21static int diff_detect_rename_default;
  22static int diff_rename_limit_default = 200;
  23static int diff_suppress_blank_empty;
  24int diff_use_color_default = -1;
  25static const char *external_diff_cmd_cfg;
  26int diff_auto_refresh_index = 1;
  27
  28static char diff_colors[][COLOR_MAXLEN] = {
  29        "\033[m",       /* reset */
  30        "",             /* PLAIN (normal) */
  31        "\033[1m",      /* METAINFO (bold) */
  32        "\033[36m",     /* FRAGINFO (cyan) */
  33        "\033[31m",     /* OLD (red) */
  34        "\033[32m",     /* NEW (green) */
  35        "\033[33m",     /* COMMIT (yellow) */
  36        "\033[41m",     /* WHITESPACE (red background) */
  37};
  38
  39static int parse_diff_color_slot(const char *var, int ofs)
  40{
  41        if (!strcasecmp(var+ofs, "plain"))
  42                return DIFF_PLAIN;
  43        if (!strcasecmp(var+ofs, "meta"))
  44                return DIFF_METAINFO;
  45        if (!strcasecmp(var+ofs, "frag"))
  46                return DIFF_FRAGINFO;
  47        if (!strcasecmp(var+ofs, "old"))
  48                return DIFF_FILE_OLD;
  49        if (!strcasecmp(var+ofs, "new"))
  50                return DIFF_FILE_NEW;
  51        if (!strcasecmp(var+ofs, "commit"))
  52                return DIFF_COMMIT;
  53        if (!strcasecmp(var+ofs, "whitespace"))
  54                return DIFF_WHITESPACE;
  55        die("bad config variable '%s'", var);
  56}
  57
  58static struct ll_diff_driver {
  59        const char *name;
  60        struct ll_diff_driver *next;
  61        const char *cmd;
  62} *user_diff, **user_diff_tail;
  63
  64/*
  65 * Currently there is only "diff.<drivername>.command" variable;
  66 * because there are "diff.color.<slot>" variables, we are parsing
  67 * this in a bit convoluted way to allow low level diff driver
  68 * called "color".
  69 */
  70static int parse_lldiff_command(const char *var, const char *ep, const char *value)
  71{
  72        const char *name;
  73        int namelen;
  74        struct ll_diff_driver *drv;
  75
  76        name = var + 5;
  77        namelen = ep - name;
  78        for (drv = user_diff; drv; drv = drv->next)
  79                if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
  80                        break;
  81        if (!drv) {
  82                drv = xcalloc(1, sizeof(struct ll_diff_driver));
  83                drv->name = xmemdupz(name, namelen);
  84                if (!user_diff_tail)
  85                        user_diff_tail = &user_diff;
  86                *user_diff_tail = drv;
  87                user_diff_tail = &(drv->next);
  88        }
  89
  90        return git_config_string(&(drv->cmd), var, value);
  91}
  92
  93/*
  94 * 'diff.<what>.funcname' attribute can be specified in the configuration
  95 * to define a customized regexp to find the beginning of a function to
  96 * be used for hunk header lines of "diff -p" style output.
  97 */
  98static struct funcname_pattern {
  99        char *name;
 100        char *pattern;
 101        struct funcname_pattern *next;
 102} *funcname_pattern_list;
 103
 104static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
 105{
 106        const char *name;
 107        int namelen;
 108        struct funcname_pattern *pp;
 109
 110        name = var + 5; /* "diff." */
 111        namelen = ep - name;
 112
 113        for (pp = funcname_pattern_list; pp; pp = pp->next)
 114                if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
 115                        break;
 116        if (!pp) {
 117                pp = xcalloc(1, sizeof(*pp));
 118                pp->name = xmemdupz(name, namelen);
 119                pp->next = funcname_pattern_list;
 120                funcname_pattern_list = pp;
 121        }
 122        free(pp->pattern);
 123        pp->pattern = xstrdup(value);
 124        return 0;
 125}
 126
 127/*
 128 * These are to give UI layer defaults.
 129 * The core-level commands such as git-diff-files should
 130 * never be affected by the setting of diff.renames
 131 * the user happens to have in the configuration file.
 132 */
 133int git_diff_ui_config(const char *var, const char *value, void *cb)
 134{
 135        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 136                diff_use_color_default = git_config_colorbool(var, value, -1);
 137                return 0;
 138        }
 139        if (!strcmp(var, "diff.renames")) {
 140                if (!value)
 141                        diff_detect_rename_default = DIFF_DETECT_RENAME;
 142                else if (!strcasecmp(value, "copies") ||
 143                         !strcasecmp(value, "copy"))
 144                        diff_detect_rename_default = DIFF_DETECT_COPY;
 145                else if (git_config_bool(var,value))
 146                        diff_detect_rename_default = DIFF_DETECT_RENAME;
 147                return 0;
 148        }
 149        if (!strcmp(var, "diff.autorefreshindex")) {
 150                diff_auto_refresh_index = git_config_bool(var, value);
 151                return 0;
 152        }
 153        if (!strcmp(var, "diff.external"))
 154                return git_config_string(&external_diff_cmd_cfg, var, value);
 155        if (!prefixcmp(var, "diff.")) {
 156                const char *ep = strrchr(var, '.');
 157
 158                if (ep != var + 4 && !strcmp(ep, ".command"))
 159                        return parse_lldiff_command(var, ep, value);
 160        }
 161
 162        return git_diff_basic_config(var, value, cb);
 163}
 164
 165int git_diff_basic_config(const char *var, const char *value, void *cb)
 166{
 167        if (!strcmp(var, "diff.renamelimit")) {
 168                diff_rename_limit_default = git_config_int(var, value);
 169                return 0;
 170        }
 171
 172        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 173                int slot = parse_diff_color_slot(var, 11);
 174                if (!value)
 175                        return config_error_nonbool(var);
 176                color_parse(value, var, diff_colors[slot]);
 177                return 0;
 178        }
 179
 180        /* like GNU diff's --suppress-blank-empty option  */
 181        if (!strcmp(var, "diff.suppress-blank-empty")) {
 182                diff_suppress_blank_empty = git_config_bool(var, value);
 183                return 0;
 184        }
 185
 186        if (!prefixcmp(var, "diff.")) {
 187                const char *ep = strrchr(var, '.');
 188                if (ep != var + 4) {
 189                        if (!strcmp(ep, ".funcname")) {
 190                                if (!value)
 191                                        return config_error_nonbool(var);
 192                                return parse_funcname_pattern(var, ep, value);
 193                        }
 194                }
 195        }
 196
 197        return git_color_default_config(var, value, cb);
 198}
 199
 200static char *quote_two(const char *one, const char *two)
 201{
 202        int need_one = quote_c_style(one, NULL, NULL, 1);
 203        int need_two = quote_c_style(two, NULL, NULL, 1);
 204        struct strbuf res;
 205
 206        strbuf_init(&res, 0);
 207        if (need_one + need_two) {
 208                strbuf_addch(&res, '"');
 209                quote_c_style(one, &res, NULL, 1);
 210                quote_c_style(two, &res, NULL, 1);
 211                strbuf_addch(&res, '"');
 212        } else {
 213                strbuf_addstr(&res, one);
 214                strbuf_addstr(&res, two);
 215        }
 216        return strbuf_detach(&res, NULL);
 217}
 218
 219static const char *external_diff(void)
 220{
 221        static const char *external_diff_cmd = NULL;
 222        static int done_preparing = 0;
 223
 224        if (done_preparing)
 225                return external_diff_cmd;
 226        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 227        if (!external_diff_cmd)
 228                external_diff_cmd = external_diff_cmd_cfg;
 229        done_preparing = 1;
 230        return external_diff_cmd;
 231}
 232
 233static struct diff_tempfile {
 234        const char *name; /* filename external diff should read from */
 235        char hex[41];
 236        char mode[10];
 237        char tmp_path[PATH_MAX];
 238} diff_temp[2];
 239
 240static int count_lines(const char *data, int size)
 241{
 242        int count, ch, completely_empty = 1, nl_just_seen = 0;
 243        count = 0;
 244        while (0 < size--) {
 245                ch = *data++;
 246                if (ch == '\n') {
 247                        count++;
 248                        nl_just_seen = 1;
 249                        completely_empty = 0;
 250                }
 251                else {
 252                        nl_just_seen = 0;
 253                        completely_empty = 0;
 254                }
 255        }
 256        if (completely_empty)
 257                return 0;
 258        if (!nl_just_seen)
 259                count++; /* no trailing newline */
 260        return count;
 261}
 262
 263static void print_line_count(FILE *file, int count)
 264{
 265        switch (count) {
 266        case 0:
 267                fprintf(file, "0,0");
 268                break;
 269        case 1:
 270                fprintf(file, "1");
 271                break;
 272        default:
 273                fprintf(file, "1,%d", count);
 274                break;
 275        }
 276}
 277
 278static void copy_file_with_prefix(FILE *file,
 279                                  int prefix, const char *data, int size,
 280                                  const char *set, const char *reset)
 281{
 282        int ch, nl_just_seen = 1;
 283        while (0 < size--) {
 284                ch = *data++;
 285                if (nl_just_seen) {
 286                        fputs(set, file);
 287                        putc(prefix, file);
 288                }
 289                if (ch == '\n') {
 290                        nl_just_seen = 1;
 291                        fputs(reset, file);
 292                } else
 293                        nl_just_seen = 0;
 294                putc(ch, file);
 295        }
 296        if (!nl_just_seen)
 297                fprintf(file, "%s\n\\ No newline at end of file\n", reset);
 298}
 299
 300static void emit_rewrite_diff(const char *name_a,
 301                              const char *name_b,
 302                              struct diff_filespec *one,
 303                              struct diff_filespec *two,
 304                              struct diff_options *o)
 305{
 306        int lc_a, lc_b;
 307        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 308        const char *name_a_tab, *name_b_tab;
 309        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 310        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 311        const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
 312        const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
 313        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 314        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 315
 316        name_a += (*name_a == '/');
 317        name_b += (*name_b == '/');
 318        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 319        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 320
 321        strbuf_reset(&a_name);
 322        strbuf_reset(&b_name);
 323        quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
 324        quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
 325
 326        diff_populate_filespec(one, 0);
 327        diff_populate_filespec(two, 0);
 328        lc_a = count_lines(one->data, one->size);
 329        lc_b = count_lines(two->data, two->size);
 330        fprintf(o->file,
 331                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 332                metainfo, a_name.buf, name_a_tab, reset,
 333                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 334        print_line_count(o->file, lc_a);
 335        fprintf(o->file, " +");
 336        print_line_count(o->file, lc_b);
 337        fprintf(o->file, " @@%s\n", reset);
 338        if (lc_a)
 339                copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
 340        if (lc_b)
 341                copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
 342}
 343
 344static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 345{
 346        if (!DIFF_FILE_VALID(one)) {
 347                mf->ptr = (char *)""; /* does not matter */
 348                mf->size = 0;
 349                return 0;
 350        }
 351        else if (diff_populate_filespec(one, 0))
 352                return -1;
 353        mf->ptr = one->data;
 354        mf->size = one->size;
 355        return 0;
 356}
 357
 358struct diff_words_buffer {
 359        mmfile_t text;
 360        long alloc;
 361        long current; /* output pointer */
 362        int suppressed_newline;
 363};
 364
 365static void diff_words_append(char *line, unsigned long len,
 366                struct diff_words_buffer *buffer)
 367{
 368        if (buffer->text.size + len > buffer->alloc) {
 369                buffer->alloc = (buffer->text.size + len) * 3 / 2;
 370                buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
 371        }
 372        line++;
 373        len--;
 374        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 375        buffer->text.size += len;
 376}
 377
 378struct diff_words_data {
 379        struct diff_words_buffer minus, plus;
 380        FILE *file;
 381};
 382
 383static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
 384                int suppress_newline)
 385{
 386        const char *ptr;
 387        int eol = 0;
 388
 389        if (len == 0)
 390                return;
 391
 392        ptr  = buffer->text.ptr + buffer->current;
 393        buffer->current += len;
 394
 395        if (ptr[len - 1] == '\n') {
 396                eol = 1;
 397                len--;
 398        }
 399
 400        fputs(diff_get_color(1, color), file);
 401        fwrite(ptr, len, 1, file);
 402        fputs(diff_get_color(1, DIFF_RESET), file);
 403
 404        if (eol) {
 405                if (suppress_newline)
 406                        buffer->suppressed_newline = 1;
 407                else
 408                        putc('\n', file);
 409        }
 410}
 411
 412static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 413{
 414        struct diff_words_data *diff_words = priv;
 415
 416        if (diff_words->minus.suppressed_newline) {
 417                if (line[0] != '+')
 418                        putc('\n', diff_words->file);
 419                diff_words->minus.suppressed_newline = 0;
 420        }
 421
 422        len--;
 423        switch (line[0]) {
 424                case '-':
 425                        print_word(diff_words->file,
 426                                   &diff_words->minus, len, DIFF_FILE_OLD, 1);
 427                        break;
 428                case '+':
 429                        print_word(diff_words->file,
 430                                   &diff_words->plus, len, DIFF_FILE_NEW, 0);
 431                        break;
 432                case ' ':
 433                        print_word(diff_words->file,
 434                                   &diff_words->plus, len, DIFF_PLAIN, 0);
 435                        diff_words->minus.current += len;
 436                        break;
 437        }
 438}
 439
 440/* this executes the word diff on the accumulated buffers */
 441static void diff_words_show(struct diff_words_data *diff_words)
 442{
 443        xpparam_t xpp;
 444        xdemitconf_t xecfg;
 445        xdemitcb_t ecb;
 446        mmfile_t minus, plus;
 447        int i;
 448
 449        memset(&xecfg, 0, sizeof(xecfg));
 450        minus.size = diff_words->minus.text.size;
 451        minus.ptr = xmalloc(minus.size);
 452        memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
 453        for (i = 0; i < minus.size; i++)
 454                if (isspace(minus.ptr[i]))
 455                        minus.ptr[i] = '\n';
 456        diff_words->minus.current = 0;
 457
 458        plus.size = diff_words->plus.text.size;
 459        plus.ptr = xmalloc(plus.size);
 460        memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
 461        for (i = 0; i < plus.size; i++)
 462                if (isspace(plus.ptr[i]))
 463                        plus.ptr[i] = '\n';
 464        diff_words->plus.current = 0;
 465
 466        xpp.flags = XDF_NEED_MINIMAL;
 467        xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 468        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 469                      &xpp, &xecfg, &ecb);
 470        free(minus.ptr);
 471        free(plus.ptr);
 472        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 473
 474        if (diff_words->minus.suppressed_newline) {
 475                putc('\n', diff_words->file);
 476                diff_words->minus.suppressed_newline = 0;
 477        }
 478}
 479
 480typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 481
 482struct emit_callback {
 483        int nparents, color_diff;
 484        unsigned ws_rule;
 485        sane_truncate_fn truncate;
 486        const char **label_path;
 487        struct diff_words_data *diff_words;
 488        int *found_changesp;
 489        FILE *file;
 490};
 491
 492static void free_diff_words_data(struct emit_callback *ecbdata)
 493{
 494        if (ecbdata->diff_words) {
 495                /* flush buffers */
 496                if (ecbdata->diff_words->minus.text.size ||
 497                                ecbdata->diff_words->plus.text.size)
 498                        diff_words_show(ecbdata->diff_words);
 499
 500                free (ecbdata->diff_words->minus.text.ptr);
 501                free (ecbdata->diff_words->plus.text.ptr);
 502                free(ecbdata->diff_words);
 503                ecbdata->diff_words = NULL;
 504        }
 505}
 506
 507const char *diff_get_color(int diff_use_color, enum color_diff ix)
 508{
 509        if (diff_use_color)
 510                return diff_colors[ix];
 511        return "";
 512}
 513
 514static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
 515{
 516        int has_trailing_newline = (len > 0 && line[len-1] == '\n');
 517        if (has_trailing_newline)
 518                len--;
 519
 520        fputs(set, file);
 521        fwrite(line, len, 1, file);
 522        fputs(reset, file);
 523        if (has_trailing_newline)
 524                fputc('\n', file);
 525}
 526
 527static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
 528{
 529        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 530        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 531
 532        if (!*ws)
 533                emit_line(ecbdata->file, set, reset, line, len);
 534        else {
 535                /* Emit just the prefix, then the rest. */
 536                emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
 537                ws_check_emit(line + ecbdata->nparents,
 538                              len - ecbdata->nparents, ecbdata->ws_rule,
 539                              ecbdata->file, set, reset, ws);
 540        }
 541}
 542
 543static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 544{
 545        const char *cp;
 546        unsigned long allot;
 547        size_t l = len;
 548
 549        if (ecb->truncate)
 550                return ecb->truncate(line, len);
 551        cp = line;
 552        allot = l;
 553        while (0 < l) {
 554                (void) utf8_width(&cp, &l);
 555                if (!cp)
 556                        break; /* truncated in the middle? */
 557        }
 558        return allot - l;
 559}
 560
 561static void fn_out_consume(void *priv, char *line, unsigned long len)
 562{
 563        int i;
 564        int color;
 565        struct emit_callback *ecbdata = priv;
 566        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 567        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 568        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 569
 570        *(ecbdata->found_changesp) = 1;
 571
 572        if (ecbdata->label_path[0]) {
 573                const char *name_a_tab, *name_b_tab;
 574
 575                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 576                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 577
 578                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 579                        meta, ecbdata->label_path[0], reset, name_a_tab);
 580                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 581                        meta, ecbdata->label_path[1], reset, name_b_tab);
 582                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 583        }
 584
 585        if (diff_suppress_blank_empty
 586            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 587                line[0] = '\n';
 588                len = 1;
 589        }
 590
 591        /* This is not really necessary for now because
 592         * this codepath only deals with two-way diffs.
 593         */
 594        for (i = 0; i < len && line[i] == '@'; i++)
 595                ;
 596        if (2 <= i && i < len && line[i] == ' ') {
 597                ecbdata->nparents = i - 1;
 598                len = sane_truncate_line(ecbdata, line, len);
 599                emit_line(ecbdata->file,
 600                          diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
 601                          reset, line, len);
 602                if (line[len-1] != '\n')
 603                        putc('\n', ecbdata->file);
 604                return;
 605        }
 606
 607        if (len < ecbdata->nparents) {
 608                emit_line(ecbdata->file, reset, reset, line, len);
 609                return;
 610        }
 611
 612        color = DIFF_PLAIN;
 613        if (ecbdata->diff_words && ecbdata->nparents != 1)
 614                /* fall back to normal diff */
 615                free_diff_words_data(ecbdata);
 616        if (ecbdata->diff_words) {
 617                if (line[0] == '-') {
 618                        diff_words_append(line, len,
 619                                          &ecbdata->diff_words->minus);
 620                        return;
 621                } else if (line[0] == '+') {
 622                        diff_words_append(line, len,
 623                                          &ecbdata->diff_words->plus);
 624                        return;
 625                }
 626                if (ecbdata->diff_words->minus.text.size ||
 627                    ecbdata->diff_words->plus.text.size)
 628                        diff_words_show(ecbdata->diff_words);
 629                line++;
 630                len--;
 631                emit_line(ecbdata->file, plain, reset, line, len);
 632                return;
 633        }
 634        for (i = 0; i < ecbdata->nparents && len; i++) {
 635                if (line[i] == '-')
 636                        color = DIFF_FILE_OLD;
 637                else if (line[i] == '+')
 638                        color = DIFF_FILE_NEW;
 639        }
 640
 641        if (color != DIFF_FILE_NEW) {
 642                emit_line(ecbdata->file,
 643                          diff_get_color(ecbdata->color_diff, color),
 644                          reset, line, len);
 645                return;
 646        }
 647        emit_add_line(reset, ecbdata, line, len);
 648}
 649
 650static char *pprint_rename(const char *a, const char *b)
 651{
 652        const char *old = a;
 653        const char *new = b;
 654        struct strbuf name;
 655        int pfx_length, sfx_length;
 656        int len_a = strlen(a);
 657        int len_b = strlen(b);
 658        int a_midlen, b_midlen;
 659        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 660        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 661
 662        strbuf_init(&name, 0);
 663        if (qlen_a || qlen_b) {
 664                quote_c_style(a, &name, NULL, 0);
 665                strbuf_addstr(&name, " => ");
 666                quote_c_style(b, &name, NULL, 0);
 667                return strbuf_detach(&name, NULL);
 668        }
 669
 670        /* Find common prefix */
 671        pfx_length = 0;
 672        while (*old && *new && *old == *new) {
 673                if (*old == '/')
 674                        pfx_length = old - a + 1;
 675                old++;
 676                new++;
 677        }
 678
 679        /* Find common suffix */
 680        old = a + len_a;
 681        new = b + len_b;
 682        sfx_length = 0;
 683        while (a <= old && b <= new && *old == *new) {
 684                if (*old == '/')
 685                        sfx_length = len_a - (old - a);
 686                old--;
 687                new--;
 688        }
 689
 690        /*
 691         * pfx{mid-a => mid-b}sfx
 692         * {pfx-a => pfx-b}sfx
 693         * pfx{sfx-a => sfx-b}
 694         * name-a => name-b
 695         */
 696        a_midlen = len_a - pfx_length - sfx_length;
 697        b_midlen = len_b - pfx_length - sfx_length;
 698        if (a_midlen < 0)
 699                a_midlen = 0;
 700        if (b_midlen < 0)
 701                b_midlen = 0;
 702
 703        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 704        if (pfx_length + sfx_length) {
 705                strbuf_add(&name, a, pfx_length);
 706                strbuf_addch(&name, '{');
 707        }
 708        strbuf_add(&name, a + pfx_length, a_midlen);
 709        strbuf_addstr(&name, " => ");
 710        strbuf_add(&name, b + pfx_length, b_midlen);
 711        if (pfx_length + sfx_length) {
 712                strbuf_addch(&name, '}');
 713                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 714        }
 715        return strbuf_detach(&name, NULL);
 716}
 717
 718struct diffstat_t {
 719        int nr;
 720        int alloc;
 721        struct diffstat_file {
 722                char *from_name;
 723                char *name;
 724                char *print_name;
 725                unsigned is_unmerged:1;
 726                unsigned is_binary:1;
 727                unsigned is_renamed:1;
 728                unsigned int added, deleted;
 729        } **files;
 730};
 731
 732static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 733                                          const char *name_a,
 734                                          const char *name_b)
 735{
 736        struct diffstat_file *x;
 737        x = xcalloc(sizeof (*x), 1);
 738        if (diffstat->nr == diffstat->alloc) {
 739                diffstat->alloc = alloc_nr(diffstat->alloc);
 740                diffstat->files = xrealloc(diffstat->files,
 741                                diffstat->alloc * sizeof(x));
 742        }
 743        diffstat->files[diffstat->nr++] = x;
 744        if (name_b) {
 745                x->from_name = xstrdup(name_a);
 746                x->name = xstrdup(name_b);
 747                x->is_renamed = 1;
 748        }
 749        else {
 750                x->from_name = NULL;
 751                x->name = xstrdup(name_a);
 752        }
 753        return x;
 754}
 755
 756static void diffstat_consume(void *priv, char *line, unsigned long len)
 757{
 758        struct diffstat_t *diffstat = priv;
 759        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 760
 761        if (line[0] == '+')
 762                x->added++;
 763        else if (line[0] == '-')
 764                x->deleted++;
 765}
 766
 767const char mime_boundary_leader[] = "------------";
 768
 769static int scale_linear(int it, int width, int max_change)
 770{
 771        /*
 772         * make sure that at least one '-' is printed if there were deletions,
 773         * and likewise for '+'.
 774         */
 775        if (max_change < 2)
 776                return it;
 777        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 778}
 779
 780static void show_name(FILE *file,
 781                      const char *prefix, const char *name, int len,
 782                      const char *reset, const char *set)
 783{
 784        fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
 785}
 786
 787static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
 788{
 789        if (cnt <= 0)
 790                return;
 791        fprintf(file, "%s", set);
 792        while (cnt--)
 793                putc(ch, file);
 794        fprintf(file, "%s", reset);
 795}
 796
 797static void fill_print_name(struct diffstat_file *file)
 798{
 799        char *pname;
 800
 801        if (file->print_name)
 802                return;
 803
 804        if (!file->is_renamed) {
 805                struct strbuf buf;
 806                strbuf_init(&buf, 0);
 807                if (quote_c_style(file->name, &buf, NULL, 0)) {
 808                        pname = strbuf_detach(&buf, NULL);
 809                } else {
 810                        pname = file->name;
 811                        strbuf_release(&buf);
 812                }
 813        } else {
 814                pname = pprint_rename(file->from_name, file->name);
 815        }
 816        file->print_name = pname;
 817}
 818
 819static void show_stats(struct diffstat_t* data, struct diff_options *options)
 820{
 821        int i, len, add, del, total, adds = 0, dels = 0;
 822        int max_change = 0, max_len = 0;
 823        int total_files = data->nr;
 824        int width, name_width;
 825        const char *reset, *set, *add_c, *del_c;
 826
 827        if (data->nr == 0)
 828                return;
 829
 830        width = options->stat_width ? options->stat_width : 80;
 831        name_width = options->stat_name_width ? options->stat_name_width : 50;
 832
 833        /* Sanity: give at least 5 columns to the graph,
 834         * but leave at least 10 columns for the name.
 835         */
 836        if (width < 25)
 837                width = 25;
 838        if (name_width < 10)
 839                name_width = 10;
 840        else if (width < name_width + 15)
 841                name_width = width - 15;
 842
 843        /* Find the longest filename and max number of changes */
 844        reset = diff_get_color_opt(options, DIFF_RESET);
 845        set   = diff_get_color_opt(options, DIFF_PLAIN);
 846        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
 847        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
 848
 849        for (i = 0; i < data->nr; i++) {
 850                struct diffstat_file *file = data->files[i];
 851                int change = file->added + file->deleted;
 852                fill_print_name(file);
 853                len = strlen(file->print_name);
 854                if (max_len < len)
 855                        max_len = len;
 856
 857                if (file->is_binary || file->is_unmerged)
 858                        continue;
 859                if (max_change < change)
 860                        max_change = change;
 861        }
 862
 863        /* Compute the width of the graph part;
 864         * 10 is for one blank at the beginning of the line plus
 865         * " | count " between the name and the graph.
 866         *
 867         * From here on, name_width is the width of the name area,
 868         * and width is the width of the graph area.
 869         */
 870        name_width = (name_width < max_len) ? name_width : max_len;
 871        if (width < (name_width + 10) + max_change)
 872                width = width - (name_width + 10);
 873        else
 874                width = max_change;
 875
 876        for (i = 0; i < data->nr; i++) {
 877                const char *prefix = "";
 878                char *name = data->files[i]->print_name;
 879                int added = data->files[i]->added;
 880                int deleted = data->files[i]->deleted;
 881                int name_len;
 882
 883                /*
 884                 * "scale" the filename
 885                 */
 886                len = name_width;
 887                name_len = strlen(name);
 888                if (name_width < name_len) {
 889                        char *slash;
 890                        prefix = "...";
 891                        len -= 3;
 892                        name += name_len - len;
 893                        slash = strchr(name, '/');
 894                        if (slash)
 895                                name = slash;
 896                }
 897
 898                if (data->files[i]->is_binary) {
 899                        show_name(options->file, prefix, name, len, reset, set);
 900                        fprintf(options->file, "  Bin ");
 901                        fprintf(options->file, "%s%d%s", del_c, deleted, reset);
 902                        fprintf(options->file, " -> ");
 903                        fprintf(options->file, "%s%d%s", add_c, added, reset);
 904                        fprintf(options->file, " bytes");
 905                        fprintf(options->file, "\n");
 906                        continue;
 907                }
 908                else if (data->files[i]->is_unmerged) {
 909                        show_name(options->file, prefix, name, len, reset, set);
 910                        fprintf(options->file, "  Unmerged\n");
 911                        continue;
 912                }
 913                else if (!data->files[i]->is_renamed &&
 914                         (added + deleted == 0)) {
 915                        total_files--;
 916                        continue;
 917                }
 918
 919                /*
 920                 * scale the add/delete
 921                 */
 922                add = added;
 923                del = deleted;
 924                total = add + del;
 925                adds += add;
 926                dels += del;
 927
 928                if (width <= max_change) {
 929                        add = scale_linear(add, width, max_change);
 930                        del = scale_linear(del, width, max_change);
 931                        total = add + del;
 932                }
 933                show_name(options->file, prefix, name, len, reset, set);
 934                fprintf(options->file, "%5d%s", added + deleted,
 935                                added + deleted ? " " : "");
 936                show_graph(options->file, '+', add, add_c, reset);
 937                show_graph(options->file, '-', del, del_c, reset);
 938                fprintf(options->file, "\n");
 939        }
 940        fprintf(options->file,
 941               "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 942               set, total_files, adds, dels, reset);
 943}
 944
 945static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
 946{
 947        int i, adds = 0, dels = 0, total_files = data->nr;
 948
 949        if (data->nr == 0)
 950                return;
 951
 952        for (i = 0; i < data->nr; i++) {
 953                if (!data->files[i]->is_binary &&
 954                    !data->files[i]->is_unmerged) {
 955                        int added = data->files[i]->added;
 956                        int deleted= data->files[i]->deleted;
 957                        if (!data->files[i]->is_renamed &&
 958                            (added + deleted == 0)) {
 959                                total_files--;
 960                        } else {
 961                                adds += added;
 962                                dels += deleted;
 963                        }
 964                }
 965        }
 966        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
 967               total_files, adds, dels);
 968}
 969
 970static void show_numstat(struct diffstat_t* data, struct diff_options *options)
 971{
 972        int i;
 973
 974        if (data->nr == 0)
 975                return;
 976
 977        for (i = 0; i < data->nr; i++) {
 978                struct diffstat_file *file = data->files[i];
 979
 980                if (file->is_binary)
 981                        fprintf(options->file, "-\t-\t");
 982                else
 983                        fprintf(options->file,
 984                                "%d\t%d\t", file->added, file->deleted);
 985                if (options->line_termination) {
 986                        fill_print_name(file);
 987                        if (!file->is_renamed)
 988                                write_name_quoted(file->name, options->file,
 989                                                  options->line_termination);
 990                        else {
 991                                fputs(file->print_name, options->file);
 992                                putc(options->line_termination, options->file);
 993                        }
 994                } else {
 995                        if (file->is_renamed) {
 996                                putc('\0', options->file);
 997                                write_name_quoted(file->from_name, options->file, '\0');
 998                        }
 999                        write_name_quoted(file->name, options->file, '\0');
1000                }
1001        }
1002}
1003
1004struct dirstat_file {
1005        const char *name;
1006        unsigned long changed;
1007};
1008
1009struct dirstat_dir {
1010        struct dirstat_file *files;
1011        int alloc, nr, percent, cumulative;
1012};
1013
1014static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1015{
1016        unsigned long this_dir = 0;
1017        unsigned int sources = 0;
1018
1019        while (dir->nr) {
1020                struct dirstat_file *f = dir->files;
1021                int namelen = strlen(f->name);
1022                unsigned long this;
1023                char *slash;
1024
1025                if (namelen < baselen)
1026                        break;
1027                if (memcmp(f->name, base, baselen))
1028                        break;
1029                slash = strchr(f->name + baselen, '/');
1030                if (slash) {
1031                        int newbaselen = slash + 1 - f->name;
1032                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1033                        sources++;
1034                } else {
1035                        this = f->changed;
1036                        dir->files++;
1037                        dir->nr--;
1038                        sources += 2;
1039                }
1040                this_dir += this;
1041        }
1042
1043        /*
1044         * We don't report dirstat's for
1045         *  - the top level
1046         *  - or cases where everything came from a single directory
1047         *    under this directory (sources == 1).
1048         */
1049        if (baselen && sources != 1) {
1050                int permille = this_dir * 1000 / changed;
1051                if (permille) {
1052                        int percent = permille / 10;
1053                        if (percent >= dir->percent) {
1054                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1055                                if (!dir->cumulative)
1056                                        return 0;
1057                        }
1058                }
1059        }
1060        return this_dir;
1061}
1062
1063static int dirstat_compare(const void *_a, const void *_b)
1064{
1065        const struct dirstat_file *a = _a;
1066        const struct dirstat_file *b = _b;
1067        return strcmp(a->name, b->name);
1068}
1069
1070static void show_dirstat(struct diff_options *options)
1071{
1072        int i;
1073        unsigned long changed;
1074        struct dirstat_dir dir;
1075        struct diff_queue_struct *q = &diff_queued_diff;
1076
1077        dir.files = NULL;
1078        dir.alloc = 0;
1079        dir.nr = 0;
1080        dir.percent = options->dirstat_percent;
1081        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1082
1083        changed = 0;
1084        for (i = 0; i < q->nr; i++) {
1085                struct diff_filepair *p = q->queue[i];
1086                const char *name;
1087                unsigned long copied, added, damage;
1088
1089                name = p->one->path ? p->one->path : p->two->path;
1090
1091                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1092                        diff_populate_filespec(p->one, 0);
1093                        diff_populate_filespec(p->two, 0);
1094                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1095                                               &copied, &added);
1096                        diff_free_filespec_data(p->one);
1097                        diff_free_filespec_data(p->two);
1098                } else if (DIFF_FILE_VALID(p->one)) {
1099                        diff_populate_filespec(p->one, 1);
1100                        copied = added = 0;
1101                        diff_free_filespec_data(p->one);
1102                } else if (DIFF_FILE_VALID(p->two)) {
1103                        diff_populate_filespec(p->two, 1);
1104                        copied = 0;
1105                        added = p->two->size;
1106                        diff_free_filespec_data(p->two);
1107                } else
1108                        continue;
1109
1110                /*
1111                 * Original minus copied is the removed material,
1112                 * added is the new material.  They are both damages
1113                 * made to the preimage.
1114                 */
1115                damage = (p->one->size - copied) + added;
1116
1117                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1118                dir.files[dir.nr].name = name;
1119                dir.files[dir.nr].changed = damage;
1120                changed += damage;
1121                dir.nr++;
1122        }
1123
1124        /* This can happen even with many files, if everything was renames */
1125        if (!changed)
1126                return;
1127
1128        /* Show all directories with more than x% of the changes */
1129        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1130        gather_dirstat(options->file, &dir, changed, "", 0);
1131}
1132
1133static void free_diffstat_info(struct diffstat_t *diffstat)
1134{
1135        int i;
1136        for (i = 0; i < diffstat->nr; i++) {
1137                struct diffstat_file *f = diffstat->files[i];
1138                if (f->name != f->print_name)
1139                        free(f->print_name);
1140                free(f->name);
1141                free(f->from_name);
1142                free(f);
1143        }
1144        free(diffstat->files);
1145}
1146
1147struct checkdiff_t {
1148        const char *filename;
1149        int lineno;
1150        struct diff_options *o;
1151        unsigned ws_rule;
1152        unsigned status;
1153        int trailing_blanks_start;
1154};
1155
1156static int is_conflict_marker(const char *line, unsigned long len)
1157{
1158        char firstchar;
1159        int cnt;
1160
1161        if (len < 8)
1162                return 0;
1163        firstchar = line[0];
1164        switch (firstchar) {
1165        case '=': case '>': case '<':
1166                break;
1167        default:
1168                return 0;
1169        }
1170        for (cnt = 1; cnt < 7; cnt++)
1171                if (line[cnt] != firstchar)
1172                        return 0;
1173        /* line[0] thru line[6] are same as firstchar */
1174        if (firstchar == '=') {
1175                /* divider between ours and theirs? */
1176                if (len != 8 || line[7] != '\n')
1177                        return 0;
1178        } else if (len < 8 || !isspace(line[7])) {
1179                /* not divider before ours nor after theirs */
1180                return 0;
1181        }
1182        return 1;
1183}
1184
1185static void checkdiff_consume(void *priv, char *line, unsigned long len)
1186{
1187        struct checkdiff_t *data = priv;
1188        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1189        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1190        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1191        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1192        char *err;
1193
1194        if (line[0] == '+') {
1195                unsigned bad;
1196                data->lineno++;
1197                if (!ws_blank_line(line + 1, len - 1, data->ws_rule))
1198                        data->trailing_blanks_start = 0;
1199                else if (!data->trailing_blanks_start)
1200                        data->trailing_blanks_start = data->lineno;
1201                if (is_conflict_marker(line + 1, len - 1)) {
1202                        data->status |= 1;
1203                        fprintf(data->o->file,
1204                                "%s:%d: leftover conflict marker\n",
1205                                data->filename, data->lineno);
1206                }
1207                bad = ws_check(line + 1, len - 1, data->ws_rule);
1208                if (!bad)
1209                        return;
1210                data->status |= bad;
1211                err = whitespace_error_string(bad);
1212                fprintf(data->o->file, "%s:%d: %s.\n",
1213                        data->filename, data->lineno, err);
1214                free(err);
1215                emit_line(data->o->file, set, reset, line, 1);
1216                ws_check_emit(line + 1, len - 1, data->ws_rule,
1217                              data->o->file, set, reset, ws);
1218        } else if (line[0] == ' ') {
1219                data->lineno++;
1220                data->trailing_blanks_start = 0;
1221        } else if (line[0] == '@') {
1222                char *plus = strchr(line, '+');
1223                if (plus)
1224                        data->lineno = strtol(plus, NULL, 10) - 1;
1225                else
1226                        die("invalid diff");
1227                data->trailing_blanks_start = 0;
1228        }
1229}
1230
1231static unsigned char *deflate_it(char *data,
1232                                 unsigned long size,
1233                                 unsigned long *result_size)
1234{
1235        int bound;
1236        unsigned char *deflated;
1237        z_stream stream;
1238
1239        memset(&stream, 0, sizeof(stream));
1240        deflateInit(&stream, zlib_compression_level);
1241        bound = deflateBound(&stream, size);
1242        deflated = xmalloc(bound);
1243        stream.next_out = deflated;
1244        stream.avail_out = bound;
1245
1246        stream.next_in = (unsigned char *)data;
1247        stream.avail_in = size;
1248        while (deflate(&stream, Z_FINISH) == Z_OK)
1249                ; /* nothing */
1250        deflateEnd(&stream);
1251        *result_size = stream.total_out;
1252        return deflated;
1253}
1254
1255static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1256{
1257        void *cp;
1258        void *delta;
1259        void *deflated;
1260        void *data;
1261        unsigned long orig_size;
1262        unsigned long delta_size;
1263        unsigned long deflate_size;
1264        unsigned long data_size;
1265
1266        /* We could do deflated delta, or we could do just deflated two,
1267         * whichever is smaller.
1268         */
1269        delta = NULL;
1270        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1271        if (one->size && two->size) {
1272                delta = diff_delta(one->ptr, one->size,
1273                                   two->ptr, two->size,
1274                                   &delta_size, deflate_size);
1275                if (delta) {
1276                        void *to_free = delta;
1277                        orig_size = delta_size;
1278                        delta = deflate_it(delta, delta_size, &delta_size);
1279                        free(to_free);
1280                }
1281        }
1282
1283        if (delta && delta_size < deflate_size) {
1284                fprintf(file, "delta %lu\n", orig_size);
1285                free(deflated);
1286                data = delta;
1287                data_size = delta_size;
1288        }
1289        else {
1290                fprintf(file, "literal %lu\n", two->size);
1291                free(delta);
1292                data = deflated;
1293                data_size = deflate_size;
1294        }
1295
1296        /* emit data encoded in base85 */
1297        cp = data;
1298        while (data_size) {
1299                int bytes = (52 < data_size) ? 52 : data_size;
1300                char line[70];
1301                data_size -= bytes;
1302                if (bytes <= 26)
1303                        line[0] = bytes + 'A' - 1;
1304                else
1305                        line[0] = bytes - 26 + 'a' - 1;
1306                encode_85(line + 1, cp, bytes);
1307                cp = (char *) cp + bytes;
1308                fputs(line, file);
1309                fputc('\n', file);
1310        }
1311        fprintf(file, "\n");
1312        free(data);
1313}
1314
1315static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1316{
1317        fprintf(file, "GIT binary patch\n");
1318        emit_binary_diff_body(file, one, two);
1319        emit_binary_diff_body(file, two, one);
1320}
1321
1322static void setup_diff_attr_check(struct git_attr_check *check)
1323{
1324        static struct git_attr *attr_diff;
1325
1326        if (!attr_diff) {
1327                attr_diff = git_attr("diff", 4);
1328        }
1329        check[0].attr = attr_diff;
1330}
1331
1332static void diff_filespec_check_attr(struct diff_filespec *one)
1333{
1334        struct git_attr_check attr_diff_check;
1335        int check_from_data = 0;
1336
1337        if (one->checked_attr)
1338                return;
1339
1340        setup_diff_attr_check(&attr_diff_check);
1341        one->is_binary = 0;
1342        one->funcname_pattern_ident = NULL;
1343
1344        if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1345                const char *value;
1346
1347                /* binaryness */
1348                value = attr_diff_check.value;
1349                if (ATTR_TRUE(value))
1350                        ;
1351                else if (ATTR_FALSE(value))
1352                        one->is_binary = 1;
1353                else
1354                        check_from_data = 1;
1355
1356                /* funcname pattern ident */
1357                if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1358                        ;
1359                else
1360                        one->funcname_pattern_ident = value;
1361        }
1362
1363        if (check_from_data) {
1364                if (!one->data && DIFF_FILE_VALID(one))
1365                        diff_populate_filespec(one, 0);
1366
1367                if (one->data)
1368                        one->is_binary = buffer_is_binary(one->data, one->size);
1369        }
1370}
1371
1372int diff_filespec_is_binary(struct diff_filespec *one)
1373{
1374        diff_filespec_check_attr(one);
1375        return one->is_binary;
1376}
1377
1378static const char *funcname_pattern(const char *ident)
1379{
1380        struct funcname_pattern *pp;
1381
1382        for (pp = funcname_pattern_list; pp; pp = pp->next)
1383                if (!strcmp(ident, pp->name))
1384                        return pp->pattern;
1385        return NULL;
1386}
1387
1388static struct builtin_funcname_pattern {
1389        const char *name;
1390        const char *pattern;
1391} builtin_funcname_pattern[] = {
1392        { "bibtex", "\\(@[a-zA-Z]\\{1,\\}[ \t]*{\\{0,1\\}[ \t]*[^ \t\"@',\\#}{~%]*\\).*$" },
1393        { "html", "^\\s*\\(<[Hh][1-6]\\s.*>.*\\)$" },
1394        { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1395                        "new\\|return\\|switch\\|throw\\|while\\)\n"
1396                        "^[     ]*\\(\\([       ]*"
1397                        "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1398                        "[      ]*([^;]*\\)$" },
1399        { "pascal", "^\\(\\(procedure\\|function\\|constructor\\|"
1400                        "destructor\\|interface\\|implementation\\|"
1401                        "initialization\\|finalization\\)[ \t]*.*\\)$"
1402                        "\\|"
1403                        "^\\(.*=[ \t]*\\(class\\|record\\).*\\)$"
1404                        },
1405        { "python", "^\\s*\\(\\(class\\|def\\)\\s.*\\)$" },
1406        { "ruby", "^\\s*\\(\\(class\\|module\\|def\\)\\s.*\\)$" },
1407        { "tex", "^\\(\\\\\\(\\(sub\\)*section\\|chapter\\|part\\)\\*\\{0,1\\}{.*\\)$" },
1408};
1409
1410static const char *diff_funcname_pattern(struct diff_filespec *one)
1411{
1412        const char *ident, *pattern;
1413        int i;
1414
1415        diff_filespec_check_attr(one);
1416        ident = one->funcname_pattern_ident;
1417
1418        if (!ident)
1419                /*
1420                 * If the config file has "funcname.default" defined, that
1421                 * regexp is used; otherwise NULL is returned and xemit uses
1422                 * the built-in default.
1423                 */
1424                return funcname_pattern("default");
1425
1426        /* Look up custom "funcname.$ident" regexp from config. */
1427        pattern = funcname_pattern(ident);
1428        if (pattern)
1429                return pattern;
1430
1431        /*
1432         * And define built-in fallback patterns here.  Note that
1433         * these can be overridden by the user's config settings.
1434         */
1435        for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1436                if (!strcmp(ident, builtin_funcname_pattern[i].name))
1437                        return builtin_funcname_pattern[i].pattern;
1438
1439        return NULL;
1440}
1441
1442static void builtin_diff(const char *name_a,
1443                         const char *name_b,
1444                         struct diff_filespec *one,
1445                         struct diff_filespec *two,
1446                         const char *xfrm_msg,
1447                         struct diff_options *o,
1448                         int complete_rewrite)
1449{
1450        mmfile_t mf1, mf2;
1451        const char *lbl[2];
1452        char *a_one, *b_two;
1453        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1454        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1455
1456        a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1457        b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1458        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1459        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1460        fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1461        if (lbl[0][0] == '/') {
1462                /* /dev/null */
1463                fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1464                if (xfrm_msg && xfrm_msg[0])
1465                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1466        }
1467        else if (lbl[1][0] == '/') {
1468                fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1469                if (xfrm_msg && xfrm_msg[0])
1470                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1471        }
1472        else {
1473                if (one->mode != two->mode) {
1474                        fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1475                        fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1476                }
1477                if (xfrm_msg && xfrm_msg[0])
1478                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1479                /*
1480                 * we do not run diff between different kind
1481                 * of objects.
1482                 */
1483                if ((one->mode ^ two->mode) & S_IFMT)
1484                        goto free_ab_and_return;
1485                if (complete_rewrite) {
1486                        emit_rewrite_diff(name_a, name_b, one, two, o);
1487                        o->found_changes = 1;
1488                        goto free_ab_and_return;
1489                }
1490        }
1491
1492        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1493                die("unable to read files to diff");
1494
1495        if (!DIFF_OPT_TST(o, TEXT) &&
1496            (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1497                /* Quite common confusing case */
1498                if (mf1.size == mf2.size &&
1499                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1500                        goto free_ab_and_return;
1501                if (DIFF_OPT_TST(o, BINARY))
1502                        emit_binary_diff(o->file, &mf1, &mf2);
1503                else
1504                        fprintf(o->file, "Binary files %s and %s differ\n",
1505                                lbl[0], lbl[1]);
1506                o->found_changes = 1;
1507        }
1508        else {
1509                /* Crazy xdl interfaces.. */
1510                const char *diffopts = getenv("GIT_DIFF_OPTS");
1511                xpparam_t xpp;
1512                xdemitconf_t xecfg;
1513                xdemitcb_t ecb;
1514                struct emit_callback ecbdata;
1515                const char *funcname_pattern;
1516
1517                funcname_pattern = diff_funcname_pattern(one);
1518                if (!funcname_pattern)
1519                        funcname_pattern = diff_funcname_pattern(two);
1520
1521                memset(&xecfg, 0, sizeof(xecfg));
1522                memset(&ecbdata, 0, sizeof(ecbdata));
1523                ecbdata.label_path = lbl;
1524                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1525                ecbdata.found_changesp = &o->found_changes;
1526                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1527                ecbdata.file = o->file;
1528                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1529                xecfg.ctxlen = o->context;
1530                xecfg.flags = XDL_EMIT_FUNCNAMES;
1531                if (funcname_pattern)
1532                        xdiff_set_find_func(&xecfg, funcname_pattern);
1533                if (!diffopts)
1534                        ;
1535                else if (!prefixcmp(diffopts, "--unified="))
1536                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1537                else if (!prefixcmp(diffopts, "-u"))
1538                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1539                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1540                        ecbdata.diff_words =
1541                                xcalloc(1, sizeof(struct diff_words_data));
1542                        ecbdata.diff_words->file = o->file;
1543                }
1544                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1545                              &xpp, &xecfg, &ecb);
1546                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1547                        free_diff_words_data(&ecbdata);
1548        }
1549
1550 free_ab_and_return:
1551        diff_free_filespec_data(one);
1552        diff_free_filespec_data(two);
1553        free(a_one);
1554        free(b_two);
1555        return;
1556}
1557
1558static void builtin_diffstat(const char *name_a, const char *name_b,
1559                             struct diff_filespec *one,
1560                             struct diff_filespec *two,
1561                             struct diffstat_t *diffstat,
1562                             struct diff_options *o,
1563                             int complete_rewrite)
1564{
1565        mmfile_t mf1, mf2;
1566        struct diffstat_file *data;
1567
1568        data = diffstat_add(diffstat, name_a, name_b);
1569
1570        if (!one || !two) {
1571                data->is_unmerged = 1;
1572                return;
1573        }
1574        if (complete_rewrite) {
1575                diff_populate_filespec(one, 0);
1576                diff_populate_filespec(two, 0);
1577                data->deleted = count_lines(one->data, one->size);
1578                data->added = count_lines(two->data, two->size);
1579                goto free_and_return;
1580        }
1581        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1582                die("unable to read files to diff");
1583
1584        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1585                data->is_binary = 1;
1586                data->added = mf2.size;
1587                data->deleted = mf1.size;
1588        } else {
1589                /* Crazy xdl interfaces.. */
1590                xpparam_t xpp;
1591                xdemitconf_t xecfg;
1592                xdemitcb_t ecb;
1593
1594                memset(&xecfg, 0, sizeof(xecfg));
1595                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1596                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1597                              &xpp, &xecfg, &ecb);
1598        }
1599
1600 free_and_return:
1601        diff_free_filespec_data(one);
1602        diff_free_filespec_data(two);
1603}
1604
1605static void builtin_checkdiff(const char *name_a, const char *name_b,
1606                              const char *attr_path,
1607                              struct diff_filespec *one,
1608                              struct diff_filespec *two,
1609                              struct diff_options *o)
1610{
1611        mmfile_t mf1, mf2;
1612        struct checkdiff_t data;
1613
1614        if (!two)
1615                return;
1616
1617        memset(&data, 0, sizeof(data));
1618        data.filename = name_b ? name_b : name_a;
1619        data.lineno = 0;
1620        data.o = o;
1621        data.ws_rule = whitespace_rule(attr_path);
1622
1623        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1624                die("unable to read files to diff");
1625
1626        /*
1627         * All the other codepaths check both sides, but not checking
1628         * the "old" side here is deliberate.  We are checking the newly
1629         * introduced changes, and as long as the "new" side is text, we
1630         * can and should check what it introduces.
1631         */
1632        if (diff_filespec_is_binary(two))
1633                goto free_and_return;
1634        else {
1635                /* Crazy xdl interfaces.. */
1636                xpparam_t xpp;
1637                xdemitconf_t xecfg;
1638                xdemitcb_t ecb;
1639
1640                memset(&xecfg, 0, sizeof(xecfg));
1641                xecfg.ctxlen = 1; /* at least one context line */
1642                xpp.flags = XDF_NEED_MINIMAL;
1643                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1644                              &xpp, &xecfg, &ecb);
1645
1646                if ((data.ws_rule & WS_TRAILING_SPACE) &&
1647                    data.trailing_blanks_start) {
1648                        fprintf(o->file, "%s:%d: ends with blank lines.\n",
1649                                data.filename, data.trailing_blanks_start);
1650                        data.status = 1; /* report errors */
1651                }
1652        }
1653 free_and_return:
1654        diff_free_filespec_data(one);
1655        diff_free_filespec_data(two);
1656        if (data.status)
1657                DIFF_OPT_SET(o, CHECK_FAILED);
1658}
1659
1660struct diff_filespec *alloc_filespec(const char *path)
1661{
1662        int namelen = strlen(path);
1663        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1664
1665        memset(spec, 0, sizeof(*spec));
1666        spec->path = (char *)(spec + 1);
1667        memcpy(spec->path, path, namelen+1);
1668        spec->count = 1;
1669        return spec;
1670}
1671
1672void free_filespec(struct diff_filespec *spec)
1673{
1674        if (!--spec->count) {
1675                diff_free_filespec_data(spec);
1676                free(spec);
1677        }
1678}
1679
1680void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1681                   unsigned short mode)
1682{
1683        if (mode) {
1684                spec->mode = canon_mode(mode);
1685                hashcpy(spec->sha1, sha1);
1686                spec->sha1_valid = !is_null_sha1(sha1);
1687        }
1688}
1689
1690/*
1691 * Given a name and sha1 pair, if the index tells us the file in
1692 * the work tree has that object contents, return true, so that
1693 * prepare_temp_file() does not have to inflate and extract.
1694 */
1695static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1696{
1697        struct cache_entry *ce;
1698        struct stat st;
1699        int pos, len;
1700
1701        /* We do not read the cache ourselves here, because the
1702         * benchmark with my previous version that always reads cache
1703         * shows that it makes things worse for diff-tree comparing
1704         * two linux-2.6 kernel trees in an already checked out work
1705         * tree.  This is because most diff-tree comparisons deal with
1706         * only a small number of files, while reading the cache is
1707         * expensive for a large project, and its cost outweighs the
1708         * savings we get by not inflating the object to a temporary
1709         * file.  Practically, this code only helps when we are used
1710         * by diff-cache --cached, which does read the cache before
1711         * calling us.
1712         */
1713        if (!active_cache)
1714                return 0;
1715
1716        /* We want to avoid the working directory if our caller
1717         * doesn't need the data in a normal file, this system
1718         * is rather slow with its stat/open/mmap/close syscalls,
1719         * and the object is contained in a pack file.  The pack
1720         * is probably already open and will be faster to obtain
1721         * the data through than the working directory.  Loose
1722         * objects however would tend to be slower as they need
1723         * to be individually opened and inflated.
1724         */
1725        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1726                return 0;
1727
1728        len = strlen(name);
1729        pos = cache_name_pos(name, len);
1730        if (pos < 0)
1731                return 0;
1732        ce = active_cache[pos];
1733
1734        /*
1735         * This is not the sha1 we are looking for, or
1736         * unreusable because it is not a regular file.
1737         */
1738        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1739                return 0;
1740
1741        /*
1742         * If ce matches the file in the work tree, we can reuse it.
1743         */
1744        if (ce_uptodate(ce) ||
1745            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1746                return 1;
1747
1748        return 0;
1749}
1750
1751static int populate_from_stdin(struct diff_filespec *s)
1752{
1753        struct strbuf buf;
1754        size_t size = 0;
1755
1756        strbuf_init(&buf, 0);
1757        if (strbuf_read(&buf, 0, 0) < 0)
1758                return error("error while reading from stdin %s",
1759                                     strerror(errno));
1760
1761        s->should_munmap = 0;
1762        s->data = strbuf_detach(&buf, &size);
1763        s->size = size;
1764        s->should_free = 1;
1765        return 0;
1766}
1767
1768static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1769{
1770        int len;
1771        char *data = xmalloc(100);
1772        len = snprintf(data, 100,
1773                "Subproject commit %s\n", sha1_to_hex(s->sha1));
1774        s->data = data;
1775        s->size = len;
1776        s->should_free = 1;
1777        if (size_only) {
1778                s->data = NULL;
1779                free(data);
1780        }
1781        return 0;
1782}
1783
1784/*
1785 * While doing rename detection and pickaxe operation, we may need to
1786 * grab the data for the blob (or file) for our own in-core comparison.
1787 * diff_filespec has data and size fields for this purpose.
1788 */
1789int diff_populate_filespec(struct diff_filespec *s, int size_only)
1790{
1791        int err = 0;
1792        if (!DIFF_FILE_VALID(s))
1793                die("internal error: asking to populate invalid file.");
1794        if (S_ISDIR(s->mode))
1795                return -1;
1796
1797        if (s->data)
1798                return 0;
1799
1800        if (size_only && 0 < s->size)
1801                return 0;
1802
1803        if (S_ISGITLINK(s->mode))
1804                return diff_populate_gitlink(s, size_only);
1805
1806        if (!s->sha1_valid ||
1807            reuse_worktree_file(s->path, s->sha1, 0)) {
1808                struct strbuf buf;
1809                struct stat st;
1810                int fd;
1811
1812                if (!strcmp(s->path, "-"))
1813                        return populate_from_stdin(s);
1814
1815                if (lstat(s->path, &st) < 0) {
1816                        if (errno == ENOENT) {
1817                        err_empty:
1818                                err = -1;
1819                        empty:
1820                                s->data = (char *)"";
1821                                s->size = 0;
1822                                return err;
1823                        }
1824                }
1825                s->size = xsize_t(st.st_size);
1826                if (!s->size)
1827                        goto empty;
1828                if (size_only)
1829                        return 0;
1830                if (S_ISLNK(st.st_mode)) {
1831                        int ret;
1832                        s->data = xmalloc(s->size);
1833                        s->should_free = 1;
1834                        ret = readlink(s->path, s->data, s->size);
1835                        if (ret < 0) {
1836                                free(s->data);
1837                                goto err_empty;
1838                        }
1839                        return 0;
1840                }
1841                fd = open(s->path, O_RDONLY);
1842                if (fd < 0)
1843                        goto err_empty;
1844                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1845                close(fd);
1846                s->should_munmap = 1;
1847
1848                /*
1849                 * Convert from working tree format to canonical git format
1850                 */
1851                strbuf_init(&buf, 0);
1852                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1853                        size_t size = 0;
1854                        munmap(s->data, s->size);
1855                        s->should_munmap = 0;
1856                        s->data = strbuf_detach(&buf, &size);
1857                        s->size = size;
1858                        s->should_free = 1;
1859                }
1860        }
1861        else {
1862                enum object_type type;
1863                if (size_only)
1864                        type = sha1_object_info(s->sha1, &s->size);
1865                else {
1866                        s->data = read_sha1_file(s->sha1, &type, &s->size);
1867                        s->should_free = 1;
1868                }
1869        }
1870        return 0;
1871}
1872
1873void diff_free_filespec_blob(struct diff_filespec *s)
1874{
1875        if (s->should_free)
1876                free(s->data);
1877        else if (s->should_munmap)
1878                munmap(s->data, s->size);
1879
1880        if (s->should_free || s->should_munmap) {
1881                s->should_free = s->should_munmap = 0;
1882                s->data = NULL;
1883        }
1884}
1885
1886void diff_free_filespec_data(struct diff_filespec *s)
1887{
1888        diff_free_filespec_blob(s);
1889        free(s->cnt_data);
1890        s->cnt_data = NULL;
1891}
1892
1893static void prep_temp_blob(struct diff_tempfile *temp,
1894                           void *blob,
1895                           unsigned long size,
1896                           const unsigned char *sha1,
1897                           int mode)
1898{
1899        int fd;
1900
1901        fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1902        if (fd < 0)
1903                die("unable to create temp-file: %s", strerror(errno));
1904        if (write_in_full(fd, blob, size) != size)
1905                die("unable to write temp-file");
1906        close(fd);
1907        temp->name = temp->tmp_path;
1908        strcpy(temp->hex, sha1_to_hex(sha1));
1909        temp->hex[40] = 0;
1910        sprintf(temp->mode, "%06o", mode);
1911}
1912
1913static void prepare_temp_file(const char *name,
1914                              struct diff_tempfile *temp,
1915                              struct diff_filespec *one)
1916{
1917        if (!DIFF_FILE_VALID(one)) {
1918        not_a_valid_file:
1919                /* A '-' entry produces this for file-2, and
1920                 * a '+' entry produces this for file-1.
1921                 */
1922                temp->name = "/dev/null";
1923                strcpy(temp->hex, ".");
1924                strcpy(temp->mode, ".");
1925                return;
1926        }
1927
1928        if (!one->sha1_valid ||
1929            reuse_worktree_file(name, one->sha1, 1)) {
1930                struct stat st;
1931                if (lstat(name, &st) < 0) {
1932                        if (errno == ENOENT)
1933                                goto not_a_valid_file;
1934                        die("stat(%s): %s", name, strerror(errno));
1935                }
1936                if (S_ISLNK(st.st_mode)) {
1937                        int ret;
1938                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1939                        size_t sz = xsize_t(st.st_size);
1940                        if (sizeof(buf) <= st.st_size)
1941                                die("symlink too long: %s", name);
1942                        ret = readlink(name, buf, sz);
1943                        if (ret < 0)
1944                                die("readlink(%s)", name);
1945                        prep_temp_blob(temp, buf, sz,
1946                                       (one->sha1_valid ?
1947                                        one->sha1 : null_sha1),
1948                                       (one->sha1_valid ?
1949                                        one->mode : S_IFLNK));
1950                }
1951                else {
1952                        /* we can borrow from the file in the work tree */
1953                        temp->name = name;
1954                        if (!one->sha1_valid)
1955                                strcpy(temp->hex, sha1_to_hex(null_sha1));
1956                        else
1957                                strcpy(temp->hex, sha1_to_hex(one->sha1));
1958                        /* Even though we may sometimes borrow the
1959                         * contents from the work tree, we always want
1960                         * one->mode.  mode is trustworthy even when
1961                         * !(one->sha1_valid), as long as
1962                         * DIFF_FILE_VALID(one).
1963                         */
1964                        sprintf(temp->mode, "%06o", one->mode);
1965                }
1966                return;
1967        }
1968        else {
1969                if (diff_populate_filespec(one, 0))
1970                        die("cannot read data blob for %s", one->path);
1971                prep_temp_blob(temp, one->data, one->size,
1972                               one->sha1, one->mode);
1973        }
1974}
1975
1976static void remove_tempfile(void)
1977{
1978        int i;
1979
1980        for (i = 0; i < 2; i++)
1981                if (diff_temp[i].name == diff_temp[i].tmp_path) {
1982                        unlink(diff_temp[i].name);
1983                        diff_temp[i].name = NULL;
1984                }
1985}
1986
1987static void remove_tempfile_on_signal(int signo)
1988{
1989        remove_tempfile();
1990        signal(SIGINT, SIG_DFL);
1991        raise(signo);
1992}
1993
1994/* An external diff command takes:
1995 *
1996 * diff-cmd name infile1 infile1-sha1 infile1-mode \
1997 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1998 *
1999 */
2000static void run_external_diff(const char *pgm,
2001                              const char *name,
2002                              const char *other,
2003                              struct diff_filespec *one,
2004                              struct diff_filespec *two,
2005                              const char *xfrm_msg,
2006                              int complete_rewrite)
2007{
2008        const char *spawn_arg[10];
2009        struct diff_tempfile *temp = diff_temp;
2010        int retval;
2011        static int atexit_asked = 0;
2012        const char *othername;
2013        const char **arg = &spawn_arg[0];
2014
2015        othername = (other? other : name);
2016        if (one && two) {
2017                prepare_temp_file(name, &temp[0], one);
2018                prepare_temp_file(othername, &temp[1], two);
2019                if (! atexit_asked &&
2020                    (temp[0].name == temp[0].tmp_path ||
2021                     temp[1].name == temp[1].tmp_path)) {
2022                        atexit_asked = 1;
2023                        atexit(remove_tempfile);
2024                }
2025                signal(SIGINT, remove_tempfile_on_signal);
2026        }
2027
2028        if (one && two) {
2029                *arg++ = pgm;
2030                *arg++ = name;
2031                *arg++ = temp[0].name;
2032                *arg++ = temp[0].hex;
2033                *arg++ = temp[0].mode;
2034                *arg++ = temp[1].name;
2035                *arg++ = temp[1].hex;
2036                *arg++ = temp[1].mode;
2037                if (other) {
2038                        *arg++ = other;
2039                        *arg++ = xfrm_msg;
2040                }
2041        } else {
2042                *arg++ = pgm;
2043                *arg++ = name;
2044        }
2045        *arg = NULL;
2046        fflush(NULL);
2047        retval = run_command_v_opt(spawn_arg, 0);
2048        remove_tempfile();
2049        if (retval) {
2050                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2051                exit(1);
2052        }
2053}
2054
2055static const char *external_diff_attr(const char *name)
2056{
2057        struct git_attr_check attr_diff_check;
2058
2059        if (!name)
2060                return NULL;
2061
2062        setup_diff_attr_check(&attr_diff_check);
2063        if (!git_checkattr(name, 1, &attr_diff_check)) {
2064                const char *value = attr_diff_check.value;
2065                if (!ATTR_TRUE(value) &&
2066                    !ATTR_FALSE(value) &&
2067                    !ATTR_UNSET(value)) {
2068                        struct ll_diff_driver *drv;
2069
2070                        for (drv = user_diff; drv; drv = drv->next)
2071                                if (!strcmp(drv->name, value))
2072                                        return drv->cmd;
2073                }
2074        }
2075        return NULL;
2076}
2077
2078static void run_diff_cmd(const char *pgm,
2079                         const char *name,
2080                         const char *other,
2081                         const char *attr_path,
2082                         struct diff_filespec *one,
2083                         struct diff_filespec *two,
2084                         const char *xfrm_msg,
2085                         struct diff_options *o,
2086                         int complete_rewrite)
2087{
2088        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2089                pgm = NULL;
2090        else {
2091                const char *cmd = external_diff_attr(attr_path);
2092                if (cmd)
2093                        pgm = cmd;
2094        }
2095
2096        if (pgm) {
2097                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2098                                  complete_rewrite);
2099                return;
2100        }
2101        if (one && two)
2102                builtin_diff(name, other ? other : name,
2103                             one, two, xfrm_msg, o, complete_rewrite);
2104        else
2105                fprintf(o->file, "* Unmerged path %s\n", name);
2106}
2107
2108static void diff_fill_sha1_info(struct diff_filespec *one)
2109{
2110        if (DIFF_FILE_VALID(one)) {
2111                if (!one->sha1_valid) {
2112                        struct stat st;
2113                        if (!strcmp(one->path, "-")) {
2114                                hashcpy(one->sha1, null_sha1);
2115                                return;
2116                        }
2117                        if (lstat(one->path, &st) < 0)
2118                                die("stat %s", one->path);
2119                        if (index_path(one->sha1, one->path, &st, 0))
2120                                die("cannot hash %s\n", one->path);
2121                }
2122        }
2123        else
2124                hashclr(one->sha1);
2125}
2126
2127static int similarity_index(struct diff_filepair *p)
2128{
2129        return p->score * 100 / MAX_SCORE;
2130}
2131
2132static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2133{
2134        /* Strip the prefix but do not molest /dev/null and absolute paths */
2135        if (*namep && **namep != '/')
2136                *namep += prefix_length;
2137        if (*otherp && **otherp != '/')
2138                *otherp += prefix_length;
2139}
2140
2141static void run_diff(struct diff_filepair *p, struct diff_options *o)
2142{
2143        const char *pgm = external_diff();
2144        struct strbuf msg;
2145        char *xfrm_msg;
2146        struct diff_filespec *one = p->one;
2147        struct diff_filespec *two = p->two;
2148        const char *name;
2149        const char *other;
2150        const char *attr_path;
2151        int complete_rewrite = 0;
2152
2153        name  = p->one->path;
2154        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2155        attr_path = name;
2156        if (o->prefix_length)
2157                strip_prefix(o->prefix_length, &name, &other);
2158
2159        if (DIFF_PAIR_UNMERGED(p)) {
2160                run_diff_cmd(pgm, name, NULL, attr_path,
2161                             NULL, NULL, NULL, o, 0);
2162                return;
2163        }
2164
2165        diff_fill_sha1_info(one);
2166        diff_fill_sha1_info(two);
2167
2168        strbuf_init(&msg, PATH_MAX * 2 + 300);
2169        switch (p->status) {
2170        case DIFF_STATUS_COPIED:
2171                strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2172                strbuf_addstr(&msg, "\ncopy from ");
2173                quote_c_style(name, &msg, NULL, 0);
2174                strbuf_addstr(&msg, "\ncopy to ");
2175                quote_c_style(other, &msg, NULL, 0);
2176                strbuf_addch(&msg, '\n');
2177                break;
2178        case DIFF_STATUS_RENAMED:
2179                strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2180                strbuf_addstr(&msg, "\nrename from ");
2181                quote_c_style(name, &msg, NULL, 0);
2182                strbuf_addstr(&msg, "\nrename to ");
2183                quote_c_style(other, &msg, NULL, 0);
2184                strbuf_addch(&msg, '\n');
2185                break;
2186        case DIFF_STATUS_MODIFIED:
2187                if (p->score) {
2188                        strbuf_addf(&msg, "dissimilarity index %d%%\n",
2189                                        similarity_index(p));
2190                        complete_rewrite = 1;
2191                        break;
2192                }
2193                /* fallthru */
2194        default:
2195                /* nothing */
2196                ;
2197        }
2198
2199        if (hashcmp(one->sha1, two->sha1)) {
2200                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2201
2202                if (DIFF_OPT_TST(o, BINARY)) {
2203                        mmfile_t mf;
2204                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2205                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2206                                abbrev = 40;
2207                }
2208                strbuf_addf(&msg, "index %.*s..%.*s",
2209                                abbrev, sha1_to_hex(one->sha1),
2210                                abbrev, sha1_to_hex(two->sha1));
2211                if (one->mode == two->mode)
2212                        strbuf_addf(&msg, " %06o", one->mode);
2213                strbuf_addch(&msg, '\n');
2214        }
2215
2216        if (msg.len)
2217                strbuf_setlen(&msg, msg.len - 1);
2218        xfrm_msg = msg.len ? msg.buf : NULL;
2219
2220        if (!pgm &&
2221            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2222            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2223                /* a filepair that changes between file and symlink
2224                 * needs to be split into deletion and creation.
2225                 */
2226                struct diff_filespec *null = alloc_filespec(two->path);
2227                run_diff_cmd(NULL, name, other, attr_path,
2228                             one, null, xfrm_msg, o, 0);
2229                free(null);
2230                null = alloc_filespec(one->path);
2231                run_diff_cmd(NULL, name, other, attr_path,
2232                             null, two, xfrm_msg, o, 0);
2233                free(null);
2234        }
2235        else
2236                run_diff_cmd(pgm, name, other, attr_path,
2237                             one, two, xfrm_msg, o, complete_rewrite);
2238
2239        strbuf_release(&msg);
2240}
2241
2242static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2243                         struct diffstat_t *diffstat)
2244{
2245        const char *name;
2246        const char *other;
2247        int complete_rewrite = 0;
2248
2249        if (DIFF_PAIR_UNMERGED(p)) {
2250                /* unmerged */
2251                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2252                return;
2253        }
2254
2255        name = p->one->path;
2256        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2257
2258        if (o->prefix_length)
2259                strip_prefix(o->prefix_length, &name, &other);
2260
2261        diff_fill_sha1_info(p->one);
2262        diff_fill_sha1_info(p->two);
2263
2264        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2265                complete_rewrite = 1;
2266        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2267}
2268
2269static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2270{
2271        const char *name;
2272        const char *other;
2273        const char *attr_path;
2274
2275        if (DIFF_PAIR_UNMERGED(p)) {
2276                /* unmerged */
2277                return;
2278        }
2279
2280        name = p->one->path;
2281        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2282        attr_path = other ? other : name;
2283
2284        if (o->prefix_length)
2285                strip_prefix(o->prefix_length, &name, &other);
2286
2287        diff_fill_sha1_info(p->one);
2288        diff_fill_sha1_info(p->two);
2289
2290        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2291}
2292
2293void diff_setup(struct diff_options *options)
2294{
2295        memset(options, 0, sizeof(*options));
2296
2297        options->file = stdout;
2298
2299        options->line_termination = '\n';
2300        options->break_opt = -1;
2301        options->rename_limit = -1;
2302        options->dirstat_percent = 3;
2303        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
2304        options->context = 3;
2305
2306        options->change = diff_change;
2307        options->add_remove = diff_addremove;
2308        if (diff_use_color_default > 0)
2309                DIFF_OPT_SET(options, COLOR_DIFF);
2310        else
2311                DIFF_OPT_CLR(options, COLOR_DIFF);
2312        options->detect_rename = diff_detect_rename_default;
2313
2314        options->a_prefix = "a/";
2315        options->b_prefix = "b/";
2316}
2317
2318int diff_setup_done(struct diff_options *options)
2319{
2320        int count = 0;
2321
2322        if (options->output_format & DIFF_FORMAT_NAME)
2323                count++;
2324        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2325                count++;
2326        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2327                count++;
2328        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2329                count++;
2330        if (count > 1)
2331                die("--name-only, --name-status, --check and -s are mutually exclusive");
2332
2333        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2334                options->detect_rename = DIFF_DETECT_COPY;
2335
2336        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2337                options->prefix = NULL;
2338        if (options->prefix)
2339                options->prefix_length = strlen(options->prefix);
2340        else
2341                options->prefix_length = 0;
2342
2343        if (options->output_format & (DIFF_FORMAT_NAME |
2344                                      DIFF_FORMAT_NAME_STATUS |
2345                                      DIFF_FORMAT_CHECKDIFF |
2346                                      DIFF_FORMAT_NO_OUTPUT))
2347                options->output_format &= ~(DIFF_FORMAT_RAW |
2348                                            DIFF_FORMAT_NUMSTAT |
2349                                            DIFF_FORMAT_DIFFSTAT |
2350                                            DIFF_FORMAT_SHORTSTAT |
2351                                            DIFF_FORMAT_DIRSTAT |
2352                                            DIFF_FORMAT_SUMMARY |
2353                                            DIFF_FORMAT_PATCH);
2354
2355        /*
2356         * These cases always need recursive; we do not drop caller-supplied
2357         * recursive bits for other formats here.
2358         */
2359        if (options->output_format & (DIFF_FORMAT_PATCH |
2360                                      DIFF_FORMAT_NUMSTAT |
2361                                      DIFF_FORMAT_DIFFSTAT |
2362                                      DIFF_FORMAT_SHORTSTAT |
2363                                      DIFF_FORMAT_DIRSTAT |
2364                                      DIFF_FORMAT_SUMMARY |
2365                                      DIFF_FORMAT_CHECKDIFF))
2366                DIFF_OPT_SET(options, RECURSIVE);
2367        /*
2368         * Also pickaxe would not work very well if you do not say recursive
2369         */
2370        if (options->pickaxe)
2371                DIFF_OPT_SET(options, RECURSIVE);
2372
2373        if (options->detect_rename && options->rename_limit < 0)
2374                options->rename_limit = diff_rename_limit_default;
2375        if (options->setup & DIFF_SETUP_USE_CACHE) {
2376                if (!active_cache)
2377                        /* read-cache does not die even when it fails
2378                         * so it is safe for us to do this here.  Also
2379                         * it does not smudge active_cache or active_nr
2380                         * when it fails, so we do not have to worry about
2381                         * cleaning it up ourselves either.
2382                         */
2383                        read_cache();
2384        }
2385        if (options->abbrev <= 0 || 40 < options->abbrev)
2386                options->abbrev = 40; /* full */
2387
2388        /*
2389         * It does not make sense to show the first hit we happened
2390         * to have found.  It does not make sense not to return with
2391         * exit code in such a case either.
2392         */
2393        if (DIFF_OPT_TST(options, QUIET)) {
2394                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2395                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2396        }
2397
2398        /*
2399         * If we postprocess in diffcore, we cannot simply return
2400         * upon the first hit.  We need to run diff as usual.
2401         */
2402        if (options->pickaxe || options->filter)
2403                DIFF_OPT_CLR(options, QUIET);
2404
2405        return 0;
2406}
2407
2408static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2409{
2410        char c, *eq;
2411        int len;
2412
2413        if (*arg != '-')
2414                return 0;
2415        c = *++arg;
2416        if (!c)
2417                return 0;
2418        if (c == arg_short) {
2419                c = *++arg;
2420                if (!c)
2421                        return 1;
2422                if (val && isdigit(c)) {
2423                        char *end;
2424                        int n = strtoul(arg, &end, 10);
2425                        if (*end)
2426                                return 0;
2427                        *val = n;
2428                        return 1;
2429                }
2430                return 0;
2431        }
2432        if (c != '-')
2433                return 0;
2434        arg++;
2435        eq = strchr(arg, '=');
2436        if (eq)
2437                len = eq - arg;
2438        else
2439                len = strlen(arg);
2440        if (!len || strncmp(arg, arg_long, len))
2441                return 0;
2442        if (eq) {
2443                int n;
2444                char *end;
2445                if (!isdigit(*++eq))
2446                        return 0;
2447                n = strtoul(eq, &end, 10);
2448                if (*end)
2449                        return 0;
2450                *val = n;
2451        }
2452        return 1;
2453}
2454
2455static int diff_scoreopt_parse(const char *opt);
2456
2457int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2458{
2459        const char *arg = av[0];
2460
2461        /* Output format options */
2462        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2463                options->output_format |= DIFF_FORMAT_PATCH;
2464        else if (opt_arg(arg, 'U', "unified", &options->context))
2465                options->output_format |= DIFF_FORMAT_PATCH;
2466        else if (!strcmp(arg, "--raw"))
2467                options->output_format |= DIFF_FORMAT_RAW;
2468        else if (!strcmp(arg, "--patch-with-raw"))
2469                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2470        else if (!strcmp(arg, "--numstat"))
2471                options->output_format |= DIFF_FORMAT_NUMSTAT;
2472        else if (!strcmp(arg, "--shortstat"))
2473                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2474        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2475                options->output_format |= DIFF_FORMAT_DIRSTAT;
2476        else if (!strcmp(arg, "--cumulative")) {
2477                options->output_format |= DIFF_FORMAT_DIRSTAT;
2478                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2479        }
2480        else if (!strcmp(arg, "--check"))
2481                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2482        else if (!strcmp(arg, "--summary"))
2483                options->output_format |= DIFF_FORMAT_SUMMARY;
2484        else if (!strcmp(arg, "--patch-with-stat"))
2485                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2486        else if (!strcmp(arg, "--name-only"))
2487                options->output_format |= DIFF_FORMAT_NAME;
2488        else if (!strcmp(arg, "--name-status"))
2489                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2490        else if (!strcmp(arg, "-s"))
2491                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2492        else if (!prefixcmp(arg, "--stat")) {
2493                char *end;
2494                int width = options->stat_width;
2495                int name_width = options->stat_name_width;
2496                arg += 6;
2497                end = (char *)arg;
2498
2499                switch (*arg) {
2500                case '-':
2501                        if (!prefixcmp(arg, "-width="))
2502                                width = strtoul(arg + 7, &end, 10);
2503                        else if (!prefixcmp(arg, "-name-width="))
2504                                name_width = strtoul(arg + 12, &end, 10);
2505                        break;
2506                case '=':
2507                        width = strtoul(arg+1, &end, 10);
2508                        if (*end == ',')
2509                                name_width = strtoul(end+1, &end, 10);
2510                }
2511
2512                /* Important! This checks all the error cases! */
2513                if (*end)
2514                        return 0;
2515                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2516                options->stat_name_width = name_width;
2517                options->stat_width = width;
2518        }
2519
2520        /* renames options */
2521        else if (!prefixcmp(arg, "-B")) {
2522                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2523                        return -1;
2524        }
2525        else if (!prefixcmp(arg, "-M")) {
2526                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2527                        return -1;
2528                options->detect_rename = DIFF_DETECT_RENAME;
2529        }
2530        else if (!prefixcmp(arg, "-C")) {
2531                if (options->detect_rename == DIFF_DETECT_COPY)
2532                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2533                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2534                        return -1;
2535                options->detect_rename = DIFF_DETECT_COPY;
2536        }
2537        else if (!strcmp(arg, "--no-renames"))
2538                options->detect_rename = 0;
2539        else if (!strcmp(arg, "--relative"))
2540                DIFF_OPT_SET(options, RELATIVE_NAME);
2541        else if (!prefixcmp(arg, "--relative=")) {
2542                DIFF_OPT_SET(options, RELATIVE_NAME);
2543                options->prefix = arg + 11;
2544        }
2545
2546        /* xdiff options */
2547        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2548                options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2549        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2550                options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2551        else if (!strcmp(arg, "--ignore-space-at-eol"))
2552                options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2553
2554        /* flags options */
2555        else if (!strcmp(arg, "--binary")) {
2556                options->output_format |= DIFF_FORMAT_PATCH;
2557                DIFF_OPT_SET(options, BINARY);
2558        }
2559        else if (!strcmp(arg, "--full-index"))
2560                DIFF_OPT_SET(options, FULL_INDEX);
2561        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2562                DIFF_OPT_SET(options, TEXT);
2563        else if (!strcmp(arg, "-R"))
2564                DIFF_OPT_SET(options, REVERSE_DIFF);
2565        else if (!strcmp(arg, "--find-copies-harder"))
2566                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2567        else if (!strcmp(arg, "--follow"))
2568                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2569        else if (!strcmp(arg, "--color"))
2570                DIFF_OPT_SET(options, COLOR_DIFF);
2571        else if (!strcmp(arg, "--no-color"))
2572                DIFF_OPT_CLR(options, COLOR_DIFF);
2573        else if (!strcmp(arg, "--color-words"))
2574                options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2575        else if (!strcmp(arg, "--exit-code"))
2576                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2577        else if (!strcmp(arg, "--quiet"))
2578                DIFF_OPT_SET(options, QUIET);
2579        else if (!strcmp(arg, "--ext-diff"))
2580                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2581        else if (!strcmp(arg, "--no-ext-diff"))
2582                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2583        else if (!strcmp(arg, "--ignore-submodules"))
2584                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2585
2586        /* misc options */
2587        else if (!strcmp(arg, "-z"))
2588                options->line_termination = 0;
2589        else if (!prefixcmp(arg, "-l"))
2590                options->rename_limit = strtoul(arg+2, NULL, 10);
2591        else if (!prefixcmp(arg, "-S"))
2592                options->pickaxe = arg + 2;
2593        else if (!strcmp(arg, "--pickaxe-all"))
2594                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2595        else if (!strcmp(arg, "--pickaxe-regex"))
2596                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2597        else if (!prefixcmp(arg, "-O"))
2598                options->orderfile = arg + 2;
2599        else if (!prefixcmp(arg, "--diff-filter="))
2600                options->filter = arg + 14;
2601        else if (!strcmp(arg, "--abbrev"))
2602                options->abbrev = DEFAULT_ABBREV;
2603        else if (!prefixcmp(arg, "--abbrev=")) {
2604                options->abbrev = strtoul(arg + 9, NULL, 10);
2605                if (options->abbrev < MINIMUM_ABBREV)
2606                        options->abbrev = MINIMUM_ABBREV;
2607                else if (40 < options->abbrev)
2608                        options->abbrev = 40;
2609        }
2610        else if (!prefixcmp(arg, "--src-prefix="))
2611                options->a_prefix = arg + 13;
2612        else if (!prefixcmp(arg, "--dst-prefix="))
2613                options->b_prefix = arg + 13;
2614        else if (!strcmp(arg, "--no-prefix"))
2615                options->a_prefix = options->b_prefix = "";
2616        else if (!prefixcmp(arg, "--output=")) {
2617                options->file = fopen(arg + strlen("--output="), "w");
2618                options->close_file = 1;
2619        } else
2620                return 0;
2621        return 1;
2622}
2623
2624static int parse_num(const char **cp_p)
2625{
2626        unsigned long num, scale;
2627        int ch, dot;
2628        const char *cp = *cp_p;
2629
2630        num = 0;
2631        scale = 1;
2632        dot = 0;
2633        for(;;) {
2634                ch = *cp;
2635                if ( !dot && ch == '.' ) {
2636                        scale = 1;
2637                        dot = 1;
2638                } else if ( ch == '%' ) {
2639                        scale = dot ? scale*100 : 100;
2640                        cp++;   /* % is always at the end */
2641                        break;
2642                } else if ( ch >= '0' && ch <= '9' ) {
2643                        if ( scale < 100000 ) {
2644                                scale *= 10;
2645                                num = (num*10) + (ch-'0');
2646                        }
2647                } else {
2648                        break;
2649                }
2650                cp++;
2651        }
2652        *cp_p = cp;
2653
2654        /* user says num divided by scale and we say internally that
2655         * is MAX_SCORE * num / scale.
2656         */
2657        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2658}
2659
2660static int diff_scoreopt_parse(const char *opt)
2661{
2662        int opt1, opt2, cmd;
2663
2664        if (*opt++ != '-')
2665                return -1;
2666        cmd = *opt++;
2667        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2668                return -1; /* that is not a -M, -C nor -B option */
2669
2670        opt1 = parse_num(&opt);
2671        if (cmd != 'B')
2672                opt2 = 0;
2673        else {
2674                if (*opt == 0)
2675                        opt2 = 0;
2676                else if (*opt != '/')
2677                        return -1; /* we expect -B80/99 or -B80 */
2678                else {
2679                        opt++;
2680                        opt2 = parse_num(&opt);
2681                }
2682        }
2683        if (*opt != 0)
2684                return -1;
2685        return opt1 | (opt2 << 16);
2686}
2687
2688struct diff_queue_struct diff_queued_diff;
2689
2690void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2691{
2692        if (queue->alloc <= queue->nr) {
2693                queue->alloc = alloc_nr(queue->alloc);
2694                queue->queue = xrealloc(queue->queue,
2695                                        sizeof(dp) * queue->alloc);
2696        }
2697        queue->queue[queue->nr++] = dp;
2698}
2699
2700struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2701                                 struct diff_filespec *one,
2702                                 struct diff_filespec *two)
2703{
2704        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2705        dp->one = one;
2706        dp->two = two;
2707        if (queue)
2708                diff_q(queue, dp);
2709        return dp;
2710}
2711
2712void diff_free_filepair(struct diff_filepair *p)
2713{
2714        free_filespec(p->one);
2715        free_filespec(p->two);
2716        free(p);
2717}
2718
2719/* This is different from find_unique_abbrev() in that
2720 * it stuffs the result with dots for alignment.
2721 */
2722const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2723{
2724        int abblen;
2725        const char *abbrev;
2726        if (len == 40)
2727                return sha1_to_hex(sha1);
2728
2729        abbrev = find_unique_abbrev(sha1, len);
2730        abblen = strlen(abbrev);
2731        if (abblen < 37) {
2732                static char hex[41];
2733                if (len < abblen && abblen <= len + 2)
2734                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2735                else
2736                        sprintf(hex, "%s...", abbrev);
2737                return hex;
2738        }
2739        return sha1_to_hex(sha1);
2740}
2741
2742static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2743{
2744        int line_termination = opt->line_termination;
2745        int inter_name_termination = line_termination ? '\t' : '\0';
2746
2747        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2748                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2749                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2750                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2751        }
2752        if (p->score) {
2753                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2754                        inter_name_termination);
2755        } else {
2756                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2757        }
2758
2759        if (p->status == DIFF_STATUS_COPIED ||
2760            p->status == DIFF_STATUS_RENAMED) {
2761                const char *name_a, *name_b;
2762                name_a = p->one->path;
2763                name_b = p->two->path;
2764                strip_prefix(opt->prefix_length, &name_a, &name_b);
2765                write_name_quoted(name_a, opt->file, inter_name_termination);
2766                write_name_quoted(name_b, opt->file, line_termination);
2767        } else {
2768                const char *name_a, *name_b;
2769                name_a = p->one->mode ? p->one->path : p->two->path;
2770                name_b = NULL;
2771                strip_prefix(opt->prefix_length, &name_a, &name_b);
2772                write_name_quoted(name_a, opt->file, line_termination);
2773        }
2774}
2775
2776int diff_unmodified_pair(struct diff_filepair *p)
2777{
2778        /* This function is written stricter than necessary to support
2779         * the currently implemented transformers, but the idea is to
2780         * let transformers to produce diff_filepairs any way they want,
2781         * and filter and clean them up here before producing the output.
2782         */
2783        struct diff_filespec *one = p->one, *two = p->two;
2784
2785        if (DIFF_PAIR_UNMERGED(p))
2786                return 0; /* unmerged is interesting */
2787
2788        /* deletion, addition, mode or type change
2789         * and rename are all interesting.
2790         */
2791        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2792            DIFF_PAIR_MODE_CHANGED(p) ||
2793            strcmp(one->path, two->path))
2794                return 0;
2795
2796        /* both are valid and point at the same path.  that is, we are
2797         * dealing with a change.
2798         */
2799        if (one->sha1_valid && two->sha1_valid &&
2800            !hashcmp(one->sha1, two->sha1))
2801                return 1; /* no change */
2802        if (!one->sha1_valid && !two->sha1_valid)
2803                return 1; /* both look at the same file on the filesystem. */
2804        return 0;
2805}
2806
2807static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2808{
2809        if (diff_unmodified_pair(p))
2810                return;
2811
2812        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2813            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2814                return; /* no tree diffs in patch format */
2815
2816        run_diff(p, o);
2817}
2818
2819static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2820                            struct diffstat_t *diffstat)
2821{
2822        if (diff_unmodified_pair(p))
2823                return;
2824
2825        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2826            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2827                return; /* no tree diffs in patch format */
2828
2829        run_diffstat(p, o, diffstat);
2830}
2831
2832static void diff_flush_checkdiff(struct diff_filepair *p,
2833                struct diff_options *o)
2834{
2835        if (diff_unmodified_pair(p))
2836                return;
2837
2838        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2839            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2840                return; /* no tree diffs in patch format */
2841
2842        run_checkdiff(p, o);
2843}
2844
2845int diff_queue_is_empty(void)
2846{
2847        struct diff_queue_struct *q = &diff_queued_diff;
2848        int i;
2849        for (i = 0; i < q->nr; i++)
2850                if (!diff_unmodified_pair(q->queue[i]))
2851                        return 0;
2852        return 1;
2853}
2854
2855#if DIFF_DEBUG
2856void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2857{
2858        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2859                x, one ? one : "",
2860                s->path,
2861                DIFF_FILE_VALID(s) ? "valid" : "invalid",
2862                s->mode,
2863                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2864        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2865                x, one ? one : "",
2866                s->size, s->xfrm_flags);
2867}
2868
2869void diff_debug_filepair(const struct diff_filepair *p, int i)
2870{
2871        diff_debug_filespec(p->one, i, "one");
2872        diff_debug_filespec(p->two, i, "two");
2873        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2874                p->score, p->status ? p->status : '?',
2875                p->one->rename_used, p->broken_pair);
2876}
2877
2878void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2879{
2880        int i;
2881        if (msg)
2882                fprintf(stderr, "%s\n", msg);
2883        fprintf(stderr, "q->nr = %d\n", q->nr);
2884        for (i = 0; i < q->nr; i++) {
2885                struct diff_filepair *p = q->queue[i];
2886                diff_debug_filepair(p, i);
2887        }
2888}
2889#endif
2890
2891static void diff_resolve_rename_copy(void)
2892{
2893        int i;
2894        struct diff_filepair *p;
2895        struct diff_queue_struct *q = &diff_queued_diff;
2896
2897        diff_debug_queue("resolve-rename-copy", q);
2898
2899        for (i = 0; i < q->nr; i++) {
2900                p = q->queue[i];
2901                p->status = 0; /* undecided */
2902                if (DIFF_PAIR_UNMERGED(p))
2903                        p->status = DIFF_STATUS_UNMERGED;
2904                else if (!DIFF_FILE_VALID(p->one))
2905                        p->status = DIFF_STATUS_ADDED;
2906                else if (!DIFF_FILE_VALID(p->two))
2907                        p->status = DIFF_STATUS_DELETED;
2908                else if (DIFF_PAIR_TYPE_CHANGED(p))
2909                        p->status = DIFF_STATUS_TYPE_CHANGED;
2910
2911                /* from this point on, we are dealing with a pair
2912                 * whose both sides are valid and of the same type, i.e.
2913                 * either in-place edit or rename/copy edit.
2914                 */
2915                else if (DIFF_PAIR_RENAME(p)) {
2916                        /*
2917                         * A rename might have re-connected a broken
2918                         * pair up, causing the pathnames to be the
2919                         * same again. If so, that's not a rename at
2920                         * all, just a modification..
2921                         *
2922                         * Otherwise, see if this source was used for
2923                         * multiple renames, in which case we decrement
2924                         * the count, and call it a copy.
2925                         */
2926                        if (!strcmp(p->one->path, p->two->path))
2927                                p->status = DIFF_STATUS_MODIFIED;
2928                        else if (--p->one->rename_used > 0)
2929                                p->status = DIFF_STATUS_COPIED;
2930                        else
2931                                p->status = DIFF_STATUS_RENAMED;
2932                }
2933                else if (hashcmp(p->one->sha1, p->two->sha1) ||
2934                         p->one->mode != p->two->mode ||
2935                         is_null_sha1(p->one->sha1))
2936                        p->status = DIFF_STATUS_MODIFIED;
2937                else {
2938                        /* This is a "no-change" entry and should not
2939                         * happen anymore, but prepare for broken callers.
2940                         */
2941                        error("feeding unmodified %s to diffcore",
2942                              p->one->path);
2943                        p->status = DIFF_STATUS_UNKNOWN;
2944                }
2945        }
2946        diff_debug_queue("resolve-rename-copy done", q);
2947}
2948
2949static int check_pair_status(struct diff_filepair *p)
2950{
2951        switch (p->status) {
2952        case DIFF_STATUS_UNKNOWN:
2953                return 0;
2954        case 0:
2955                die("internal error in diff-resolve-rename-copy");
2956        default:
2957                return 1;
2958        }
2959}
2960
2961static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2962{
2963        int fmt = opt->output_format;
2964
2965        if (fmt & DIFF_FORMAT_CHECKDIFF)
2966                diff_flush_checkdiff(p, opt);
2967        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2968                diff_flush_raw(p, opt);
2969        else if (fmt & DIFF_FORMAT_NAME) {
2970                const char *name_a, *name_b;
2971                name_a = p->two->path;
2972                name_b = NULL;
2973                strip_prefix(opt->prefix_length, &name_a, &name_b);
2974                write_name_quoted(name_a, opt->file, opt->line_termination);
2975        }
2976}
2977
2978static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2979{
2980        if (fs->mode)
2981                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2982        else
2983                fprintf(file, " %s ", newdelete);
2984        write_name_quoted(fs->path, file, '\n');
2985}
2986
2987
2988static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2989{
2990        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2991                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2992                        show_name ? ' ' : '\n');
2993                if (show_name) {
2994                        write_name_quoted(p->two->path, file, '\n');
2995                }
2996        }
2997}
2998
2999static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3000{
3001        char *names = pprint_rename(p->one->path, p->two->path);
3002
3003        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3004        free(names);
3005        show_mode_change(file, p, 0);
3006}
3007
3008static void diff_summary(FILE *file, struct diff_filepair *p)
3009{
3010        switch(p->status) {
3011        case DIFF_STATUS_DELETED:
3012                show_file_mode_name(file, "delete", p->one);
3013                break;
3014        case DIFF_STATUS_ADDED:
3015                show_file_mode_name(file, "create", p->two);
3016                break;
3017        case DIFF_STATUS_COPIED:
3018                show_rename_copy(file, "copy", p);
3019                break;
3020        case DIFF_STATUS_RENAMED:
3021                show_rename_copy(file, "rename", p);
3022                break;
3023        default:
3024                if (p->score) {
3025                        fputs(" rewrite ", file);
3026                        write_name_quoted(p->two->path, file, ' ');
3027                        fprintf(file, "(%d%%)\n", similarity_index(p));
3028                }
3029                show_mode_change(file, p, !p->score);
3030                break;
3031        }
3032}
3033
3034struct patch_id_t {
3035        SHA_CTX *ctx;
3036        int patchlen;
3037};
3038
3039static int remove_space(char *line, int len)
3040{
3041        int i;
3042        char *dst = line;
3043        unsigned char c;
3044
3045        for (i = 0; i < len; i++)
3046                if (!isspace((c = line[i])))
3047                        *dst++ = c;
3048
3049        return dst - line;
3050}
3051
3052static void patch_id_consume(void *priv, char *line, unsigned long len)
3053{
3054        struct patch_id_t *data = priv;
3055        int new_len;
3056
3057        /* Ignore line numbers when computing the SHA1 of the patch */
3058        if (!prefixcmp(line, "@@ -"))
3059                return;
3060
3061        new_len = remove_space(line, len);
3062
3063        SHA1_Update(data->ctx, line, new_len);
3064        data->patchlen += new_len;
3065}
3066
3067/* returns 0 upon success, and writes result into sha1 */
3068static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3069{
3070        struct diff_queue_struct *q = &diff_queued_diff;
3071        int i;
3072        SHA_CTX ctx;
3073        struct patch_id_t data;
3074        char buffer[PATH_MAX * 4 + 20];
3075
3076        SHA1_Init(&ctx);
3077        memset(&data, 0, sizeof(struct patch_id_t));
3078        data.ctx = &ctx;
3079
3080        for (i = 0; i < q->nr; i++) {
3081                xpparam_t xpp;
3082                xdemitconf_t xecfg;
3083                xdemitcb_t ecb;
3084                mmfile_t mf1, mf2;
3085                struct diff_filepair *p = q->queue[i];
3086                int len1, len2;
3087
3088                memset(&xecfg, 0, sizeof(xecfg));
3089                if (p->status == 0)
3090                        return error("internal diff status error");
3091                if (p->status == DIFF_STATUS_UNKNOWN)
3092                        continue;
3093                if (diff_unmodified_pair(p))
3094                        continue;
3095                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3096                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3097                        continue;
3098                if (DIFF_PAIR_UNMERGED(p))
3099                        continue;
3100
3101                diff_fill_sha1_info(p->one);
3102                diff_fill_sha1_info(p->two);
3103                if (fill_mmfile(&mf1, p->one) < 0 ||
3104                                fill_mmfile(&mf2, p->two) < 0)
3105                        return error("unable to read files to diff");
3106
3107                len1 = remove_space(p->one->path, strlen(p->one->path));
3108                len2 = remove_space(p->two->path, strlen(p->two->path));
3109                if (p->one->mode == 0)
3110                        len1 = snprintf(buffer, sizeof(buffer),
3111                                        "diff--gita/%.*sb/%.*s"
3112                                        "newfilemode%06o"
3113                                        "---/dev/null"
3114                                        "+++b/%.*s",
3115                                        len1, p->one->path,
3116                                        len2, p->two->path,
3117                                        p->two->mode,
3118                                        len2, p->two->path);
3119                else if (p->two->mode == 0)
3120                        len1 = snprintf(buffer, sizeof(buffer),
3121                                        "diff--gita/%.*sb/%.*s"
3122                                        "deletedfilemode%06o"
3123                                        "---a/%.*s"
3124                                        "+++/dev/null",
3125                                        len1, p->one->path,
3126                                        len2, p->two->path,
3127                                        p->one->mode,
3128                                        len1, p->one->path);
3129                else
3130                        len1 = snprintf(buffer, sizeof(buffer),
3131                                        "diff--gita/%.*sb/%.*s"
3132                                        "---a/%.*s"
3133                                        "+++b/%.*s",
3134                                        len1, p->one->path,
3135                                        len2, p->two->path,
3136                                        len1, p->one->path,
3137                                        len2, p->two->path);
3138                SHA1_Update(&ctx, buffer, len1);
3139
3140                xpp.flags = XDF_NEED_MINIMAL;
3141                xecfg.ctxlen = 3;
3142                xecfg.flags = XDL_EMIT_FUNCNAMES;
3143                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3144                              &xpp, &xecfg, &ecb);
3145        }
3146
3147        SHA1_Final(sha1, &ctx);
3148        return 0;
3149}
3150
3151int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3152{
3153        struct diff_queue_struct *q = &diff_queued_diff;
3154        int i;
3155        int result = diff_get_patch_id(options, sha1);
3156
3157        for (i = 0; i < q->nr; i++)
3158                diff_free_filepair(q->queue[i]);
3159
3160        free(q->queue);
3161        q->queue = NULL;
3162        q->nr = q->alloc = 0;
3163
3164        return result;
3165}
3166
3167static int is_summary_empty(const struct diff_queue_struct *q)
3168{
3169        int i;
3170
3171        for (i = 0; i < q->nr; i++) {
3172                const struct diff_filepair *p = q->queue[i];
3173
3174                switch (p->status) {
3175                case DIFF_STATUS_DELETED:
3176                case DIFF_STATUS_ADDED:
3177                case DIFF_STATUS_COPIED:
3178                case DIFF_STATUS_RENAMED:
3179                        return 0;
3180                default:
3181                        if (p->score)
3182                                return 0;
3183                        if (p->one->mode && p->two->mode &&
3184                            p->one->mode != p->two->mode)
3185                                return 0;
3186                        break;
3187                }
3188        }
3189        return 1;
3190}
3191
3192void diff_flush(struct diff_options *options)
3193{
3194        struct diff_queue_struct *q = &diff_queued_diff;
3195        int i, output_format = options->output_format;
3196        int separator = 0;
3197
3198        /*
3199         * Order: raw, stat, summary, patch
3200         * or:    name/name-status/checkdiff (other bits clear)
3201         */
3202        if (!q->nr)
3203                goto free_queue;
3204
3205        if (output_format & (DIFF_FORMAT_RAW |
3206                             DIFF_FORMAT_NAME |
3207                             DIFF_FORMAT_NAME_STATUS |
3208                             DIFF_FORMAT_CHECKDIFF)) {
3209                for (i = 0; i < q->nr; i++) {
3210                        struct diff_filepair *p = q->queue[i];
3211                        if (check_pair_status(p))
3212                                flush_one_pair(p, options);
3213                }
3214                separator++;
3215        }
3216
3217        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3218                struct diffstat_t diffstat;
3219
3220                memset(&diffstat, 0, sizeof(struct diffstat_t));
3221                for (i = 0; i < q->nr; i++) {
3222                        struct diff_filepair *p = q->queue[i];
3223                        if (check_pair_status(p))
3224                                diff_flush_stat(p, options, &diffstat);
3225                }
3226                if (output_format & DIFF_FORMAT_NUMSTAT)
3227                        show_numstat(&diffstat, options);
3228                if (output_format & DIFF_FORMAT_DIFFSTAT)
3229                        show_stats(&diffstat, options);
3230                if (output_format & DIFF_FORMAT_SHORTSTAT)
3231                        show_shortstats(&diffstat, options);
3232                free_diffstat_info(&diffstat);
3233                separator++;
3234        }
3235        if (output_format & DIFF_FORMAT_DIRSTAT)
3236                show_dirstat(options);
3237
3238        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3239                for (i = 0; i < q->nr; i++)
3240                        diff_summary(options->file, q->queue[i]);
3241                separator++;
3242        }
3243
3244        if (output_format & DIFF_FORMAT_PATCH) {
3245                if (separator) {
3246                        putc(options->line_termination, options->file);
3247                        if (options->stat_sep) {
3248                                /* attach patch instead of inline */
3249                                fputs(options->stat_sep, options->file);
3250                        }
3251                }
3252
3253                for (i = 0; i < q->nr; i++) {
3254                        struct diff_filepair *p = q->queue[i];
3255                        if (check_pair_status(p))
3256                                diff_flush_patch(p, options);
3257                }
3258        }
3259
3260        if (output_format & DIFF_FORMAT_CALLBACK)
3261                options->format_callback(q, options, options->format_callback_data);
3262
3263        for (i = 0; i < q->nr; i++)
3264                diff_free_filepair(q->queue[i]);
3265free_queue:
3266        free(q->queue);
3267        q->queue = NULL;
3268        q->nr = q->alloc = 0;
3269        if (options->close_file)
3270                fclose(options->file);
3271}
3272
3273static void diffcore_apply_filter(const char *filter)
3274{
3275        int i;
3276        struct diff_queue_struct *q = &diff_queued_diff;
3277        struct diff_queue_struct outq;
3278        outq.queue = NULL;
3279        outq.nr = outq.alloc = 0;
3280
3281        if (!filter)
3282                return;
3283
3284        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3285                int found;
3286                for (i = found = 0; !found && i < q->nr; i++) {
3287                        struct diff_filepair *p = q->queue[i];
3288                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3289                             ((p->score &&
3290                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3291                              (!p->score &&
3292                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3293                            ((p->status != DIFF_STATUS_MODIFIED) &&
3294                             strchr(filter, p->status)))
3295                                found++;
3296                }
3297                if (found)
3298                        return;
3299
3300                /* otherwise we will clear the whole queue
3301                 * by copying the empty outq at the end of this
3302                 * function, but first clear the current entries
3303                 * in the queue.
3304                 */
3305                for (i = 0; i < q->nr; i++)
3306                        diff_free_filepair(q->queue[i]);
3307        }
3308        else {
3309                /* Only the matching ones */
3310                for (i = 0; i < q->nr; i++) {
3311                        struct diff_filepair *p = q->queue[i];
3312
3313                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3314                             ((p->score &&
3315                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3316                              (!p->score &&
3317                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3318                            ((p->status != DIFF_STATUS_MODIFIED) &&
3319                             strchr(filter, p->status)))
3320                                diff_q(&outq, p);
3321                        else
3322                                diff_free_filepair(p);
3323                }
3324        }
3325        free(q->queue);
3326        *q = outq;
3327}
3328
3329/* Check whether two filespecs with the same mode and size are identical */
3330static int diff_filespec_is_identical(struct diff_filespec *one,
3331                                      struct diff_filespec *two)
3332{
3333        if (S_ISGITLINK(one->mode))
3334                return 0;
3335        if (diff_populate_filespec(one, 0))
3336                return 0;
3337        if (diff_populate_filespec(two, 0))
3338                return 0;
3339        return !memcmp(one->data, two->data, one->size);
3340}
3341
3342static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3343{
3344        int i;
3345        struct diff_queue_struct *q = &diff_queued_diff;
3346        struct diff_queue_struct outq;
3347        outq.queue = NULL;
3348        outq.nr = outq.alloc = 0;
3349
3350        for (i = 0; i < q->nr; i++) {
3351                struct diff_filepair *p = q->queue[i];
3352
3353                /*
3354                 * 1. Entries that come from stat info dirtyness
3355                 *    always have both sides (iow, not create/delete),
3356                 *    one side of the object name is unknown, with
3357                 *    the same mode and size.  Keep the ones that
3358                 *    do not match these criteria.  They have real
3359                 *    differences.
3360                 *
3361                 * 2. At this point, the file is known to be modified,
3362                 *    with the same mode and size, and the object
3363                 *    name of one side is unknown.  Need to inspect
3364                 *    the identical contents.
3365                 */
3366                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3367                    !DIFF_FILE_VALID(p->two) ||
3368                    (p->one->sha1_valid && p->two->sha1_valid) ||
3369                    (p->one->mode != p->two->mode) ||
3370                    diff_populate_filespec(p->one, 1) ||
3371                    diff_populate_filespec(p->two, 1) ||
3372                    (p->one->size != p->two->size) ||
3373                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3374                        diff_q(&outq, p);
3375                else {
3376                        /*
3377                         * The caller can subtract 1 from skip_stat_unmatch
3378                         * to determine how many paths were dirty only
3379                         * due to stat info mismatch.
3380                         */
3381                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3382                                diffopt->skip_stat_unmatch++;
3383                        diff_free_filepair(p);
3384                }
3385        }
3386        free(q->queue);
3387        *q = outq;
3388}
3389
3390void diffcore_std(struct diff_options *options)
3391{
3392        if (DIFF_OPT_TST(options, QUIET))
3393                return;
3394
3395        if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3396                diffcore_skip_stat_unmatch(options);
3397        if (options->break_opt != -1)
3398                diffcore_break(options->break_opt);
3399        if (options->detect_rename)
3400                diffcore_rename(options);
3401        if (options->break_opt != -1)
3402                diffcore_merge_broken();
3403        if (options->pickaxe)
3404                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3405        if (options->orderfile)
3406                diffcore_order(options->orderfile);
3407        diff_resolve_rename_copy();
3408        diffcore_apply_filter(options->filter);
3409
3410        if (diff_queued_diff.nr)
3411                DIFF_OPT_SET(options, HAS_CHANGES);
3412        else
3413                DIFF_OPT_CLR(options, HAS_CHANGES);
3414}
3415
3416int diff_result_code(struct diff_options *opt, int status)
3417{
3418        int result = 0;
3419        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3420            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3421                return status;
3422        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3423            DIFF_OPT_TST(opt, HAS_CHANGES))
3424                result |= 01;
3425        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3426            DIFF_OPT_TST(opt, CHECK_FAILED))
3427                result |= 02;
3428        return result;
3429}
3430
3431void diff_addremove(struct diff_options *options,
3432                    int addremove, unsigned mode,
3433                    const unsigned char *sha1,
3434                    const char *concatpath)
3435{
3436        struct diff_filespec *one, *two;
3437
3438        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3439                return;
3440
3441        /* This may look odd, but it is a preparation for
3442         * feeding "there are unchanged files which should
3443         * not produce diffs, but when you are doing copy
3444         * detection you would need them, so here they are"
3445         * entries to the diff-core.  They will be prefixed
3446         * with something like '=' or '*' (I haven't decided
3447         * which but should not make any difference).
3448         * Feeding the same new and old to diff_change()
3449         * also has the same effect.
3450         * Before the final output happens, they are pruned after
3451         * merged into rename/copy pairs as appropriate.
3452         */
3453        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3454                addremove = (addremove == '+' ? '-' :
3455                             addremove == '-' ? '+' : addremove);
3456
3457        if (options->prefix &&
3458            strncmp(concatpath, options->prefix, options->prefix_length))
3459                return;
3460
3461        one = alloc_filespec(concatpath);
3462        two = alloc_filespec(concatpath);
3463
3464        if (addremove != '+')
3465                fill_filespec(one, sha1, mode);
3466        if (addremove != '-')
3467                fill_filespec(two, sha1, mode);
3468
3469        diff_queue(&diff_queued_diff, one, two);
3470        DIFF_OPT_SET(options, HAS_CHANGES);
3471}
3472
3473void diff_change(struct diff_options *options,
3474                 unsigned old_mode, unsigned new_mode,
3475                 const unsigned char *old_sha1,
3476                 const unsigned char *new_sha1,
3477                 const char *concatpath)
3478{
3479        struct diff_filespec *one, *two;
3480
3481        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3482                        && S_ISGITLINK(new_mode))
3483                return;
3484
3485        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3486                unsigned tmp;
3487                const unsigned char *tmp_c;
3488                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3489                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3490        }
3491
3492        if (options->prefix &&
3493            strncmp(concatpath, options->prefix, options->prefix_length))
3494                return;
3495
3496        one = alloc_filespec(concatpath);
3497        two = alloc_filespec(concatpath);
3498        fill_filespec(one, old_sha1, old_mode);
3499        fill_filespec(two, new_sha1, new_mode);
3500
3501        diff_queue(&diff_queued_diff, one, two);
3502        DIFF_OPT_SET(options, HAS_CHANGES);
3503}
3504
3505void diff_unmerge(struct diff_options *options,
3506                  const char *path,
3507                  unsigned mode, const unsigned char *sha1)
3508{
3509        struct diff_filespec *one, *two;
3510
3511        if (options->prefix &&
3512            strncmp(path, options->prefix, options->prefix_length))
3513                return;
3514
3515        one = alloc_filespec(path);
3516        two = alloc_filespec(path);
3517        fill_filespec(one, sha1, mode);
3518        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3519}