diff.con commit Merge branch 'py/submodule' (37bd6c5)
   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 = 100;
  23int diff_use_color_default = -1;
  24static const char *external_diff_cmd_cfg;
  25int diff_auto_refresh_index = 1;
  26
  27static char diff_colors[][COLOR_MAXLEN] = {
  28        "\033[m",       /* reset */
  29        "",             /* PLAIN (normal) */
  30        "\033[1m",      /* METAINFO (bold) */
  31        "\033[36m",     /* FRAGINFO (cyan) */
  32        "\033[31m",     /* OLD (red) */
  33        "\033[32m",     /* NEW (green) */
  34        "\033[33m",     /* COMMIT (yellow) */
  35        "\033[41m",     /* WHITESPACE (red background) */
  36};
  37
  38static int parse_diff_color_slot(const char *var, int ofs)
  39{
  40        if (!strcasecmp(var+ofs, "plain"))
  41                return DIFF_PLAIN;
  42        if (!strcasecmp(var+ofs, "meta"))
  43                return DIFF_METAINFO;
  44        if (!strcasecmp(var+ofs, "frag"))
  45                return DIFF_FRAGINFO;
  46        if (!strcasecmp(var+ofs, "old"))
  47                return DIFF_FILE_OLD;
  48        if (!strcasecmp(var+ofs, "new"))
  49                return DIFF_FILE_NEW;
  50        if (!strcasecmp(var+ofs, "commit"))
  51                return DIFF_COMMIT;
  52        if (!strcasecmp(var+ofs, "whitespace"))
  53                return DIFF_WHITESPACE;
  54        die("bad config variable '%s'", var);
  55}
  56
  57static struct ll_diff_driver {
  58        const char *name;
  59        struct ll_diff_driver *next;
  60        const char *cmd;
  61} *user_diff, **user_diff_tail;
  62
  63/*
  64 * Currently there is only "diff.<drivername>.command" variable;
  65 * because there are "diff.color.<slot>" variables, we are parsing
  66 * this in a bit convoluted way to allow low level diff driver
  67 * called "color".
  68 */
  69static int parse_lldiff_command(const char *var, const char *ep, const char *value)
  70{
  71        const char *name;
  72        int namelen;
  73        struct ll_diff_driver *drv;
  74
  75        name = var + 5;
  76        namelen = ep - name;
  77        for (drv = user_diff; drv; drv = drv->next)
  78                if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
  79                        break;
  80        if (!drv) {
  81                drv = xcalloc(1, sizeof(struct ll_diff_driver));
  82                drv->name = xmemdupz(name, namelen);
  83                if (!user_diff_tail)
  84                        user_diff_tail = &user_diff;
  85                *user_diff_tail = drv;
  86                user_diff_tail = &(drv->next);
  87        }
  88
  89        return git_config_string(&(drv->cmd), var, value);
  90}
  91
  92/*
  93 * 'diff.<what>.funcname' attribute can be specified in the configuration
  94 * to define a customized regexp to find the beginning of a function to
  95 * be used for hunk header lines of "diff -p" style output.
  96 */
  97static struct funcname_pattern {
  98        char *name;
  99        char *pattern;
 100        struct funcname_pattern *next;
 101} *funcname_pattern_list;
 102
 103static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
 104{
 105        const char *name;
 106        int namelen;
 107        struct funcname_pattern *pp;
 108
 109        name = var + 5; /* "diff." */
 110        namelen = ep - name;
 111
 112        for (pp = funcname_pattern_list; pp; pp = pp->next)
 113                if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
 114                        break;
 115        if (!pp) {
 116                pp = xcalloc(1, sizeof(*pp));
 117                pp->name = xmemdupz(name, namelen);
 118                pp->next = funcname_pattern_list;
 119                funcname_pattern_list = pp;
 120        }
 121        free(pp->pattern);
 122        pp->pattern = xstrdup(value);
 123        return 0;
 124}
 125
 126/*
 127 * These are to give UI layer defaults.
 128 * The core-level commands such as git-diff-files should
 129 * never be affected by the setting of diff.renames
 130 * the user happens to have in the configuration file.
 131 */
 132int git_diff_ui_config(const char *var, const char *value)
 133{
 134        if (!strcmp(var, "diff.renamelimit")) {
 135                diff_rename_limit_default = git_config_int(var, value);
 136                return 0;
 137        }
 138        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 139                diff_use_color_default = git_config_colorbool(var, value, -1);
 140                return 0;
 141        }
 142        if (!strcmp(var, "diff.renames")) {
 143                if (!value)
 144                        diff_detect_rename_default = DIFF_DETECT_RENAME;
 145                else if (!strcasecmp(value, "copies") ||
 146                         !strcasecmp(value, "copy"))
 147                        diff_detect_rename_default = DIFF_DETECT_COPY;
 148                else if (git_config_bool(var,value))
 149                        diff_detect_rename_default = DIFF_DETECT_RENAME;
 150                return 0;
 151        }
 152        if (!strcmp(var, "diff.autorefreshindex")) {
 153                diff_auto_refresh_index = git_config_bool(var, value);
 154                return 0;
 155        }
 156        if (!strcmp(var, "diff.external")) {
 157                if (!value)
 158                        return config_error_nonbool(var);
 159                external_diff_cmd_cfg = xstrdup(value);
 160                return 0;
 161        }
 162        if (!prefixcmp(var, "diff.")) {
 163                const char *ep = strrchr(var, '.');
 164
 165                if (ep != var + 4 && !strcmp(ep, ".command"))
 166                        return parse_lldiff_command(var, ep, value);
 167        }
 168
 169        return git_diff_basic_config(var, value);
 170}
 171
 172int git_diff_basic_config(const char *var, const char *value)
 173{
 174        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 175                int slot = parse_diff_color_slot(var, 11);
 176                if (!value)
 177                        return config_error_nonbool(var);
 178                color_parse(value, var, diff_colors[slot]);
 179                return 0;
 180        }
 181
 182        if (!prefixcmp(var, "diff.")) {
 183                const char *ep = strrchr(var, '.');
 184                if (ep != var + 4) {
 185                        if (!strcmp(ep, ".funcname")) {
 186                                if (!value)
 187                                        return config_error_nonbool(var);
 188                                return parse_funcname_pattern(var, ep, value);
 189                        }
 190                }
 191        }
 192
 193        return git_color_default_config(var, value);
 194}
 195
 196static char *quote_two(const char *one, const char *two)
 197{
 198        int need_one = quote_c_style(one, NULL, NULL, 1);
 199        int need_two = quote_c_style(two, NULL, NULL, 1);
 200        struct strbuf res;
 201
 202        strbuf_init(&res, 0);
 203        if (need_one + need_two) {
 204                strbuf_addch(&res, '"');
 205                quote_c_style(one, &res, NULL, 1);
 206                quote_c_style(two, &res, NULL, 1);
 207                strbuf_addch(&res, '"');
 208        } else {
 209                strbuf_addstr(&res, one);
 210                strbuf_addstr(&res, two);
 211        }
 212        return strbuf_detach(&res, NULL);
 213}
 214
 215static const char *external_diff(void)
 216{
 217        static const char *external_diff_cmd = NULL;
 218        static int done_preparing = 0;
 219
 220        if (done_preparing)
 221                return external_diff_cmd;
 222        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 223        if (!external_diff_cmd)
 224                external_diff_cmd = external_diff_cmd_cfg;
 225        done_preparing = 1;
 226        return external_diff_cmd;
 227}
 228
 229static struct diff_tempfile {
 230        const char *name; /* filename external diff should read from */
 231        char hex[41];
 232        char mode[10];
 233        char tmp_path[PATH_MAX];
 234} diff_temp[2];
 235
 236static int count_lines(const char *data, int size)
 237{
 238        int count, ch, completely_empty = 1, nl_just_seen = 0;
 239        count = 0;
 240        while (0 < size--) {
 241                ch = *data++;
 242                if (ch == '\n') {
 243                        count++;
 244                        nl_just_seen = 1;
 245                        completely_empty = 0;
 246                }
 247                else {
 248                        nl_just_seen = 0;
 249                        completely_empty = 0;
 250                }
 251        }
 252        if (completely_empty)
 253                return 0;
 254        if (!nl_just_seen)
 255                count++; /* no trailing newline */
 256        return count;
 257}
 258
 259static void print_line_count(FILE *file, int count)
 260{
 261        switch (count) {
 262        case 0:
 263                fprintf(file, "0,0");
 264                break;
 265        case 1:
 266                fprintf(file, "1");
 267                break;
 268        default:
 269                fprintf(file, "1,%d", count);
 270                break;
 271        }
 272}
 273
 274static void copy_file_with_prefix(FILE *file,
 275                                  int prefix, const char *data, int size,
 276                                  const char *set, const char *reset)
 277{
 278        int ch, nl_just_seen = 1;
 279        while (0 < size--) {
 280                ch = *data++;
 281                if (nl_just_seen) {
 282                        fputs(set, file);
 283                        putc(prefix, file);
 284                }
 285                if (ch == '\n') {
 286                        nl_just_seen = 1;
 287                        fputs(reset, file);
 288                } else
 289                        nl_just_seen = 0;
 290                putc(ch, file);
 291        }
 292        if (!nl_just_seen)
 293                fprintf(file, "%s\n\\ No newline at end of file\n", reset);
 294}
 295
 296static void emit_rewrite_diff(const char *name_a,
 297                              const char *name_b,
 298                              struct diff_filespec *one,
 299                              struct diff_filespec *two,
 300                              struct diff_options *o)
 301{
 302        int lc_a, lc_b;
 303        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 304        const char *name_a_tab, *name_b_tab;
 305        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 306        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 307        const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
 308        const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
 309        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 310        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 311
 312        name_a += (*name_a == '/');
 313        name_b += (*name_b == '/');
 314        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 315        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 316
 317        strbuf_reset(&a_name);
 318        strbuf_reset(&b_name);
 319        quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
 320        quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
 321
 322        diff_populate_filespec(one, 0);
 323        diff_populate_filespec(two, 0);
 324        lc_a = count_lines(one->data, one->size);
 325        lc_b = count_lines(two->data, two->size);
 326        fprintf(o->file,
 327                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 328                metainfo, a_name.buf, name_a_tab, reset,
 329                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 330        print_line_count(o->file, lc_a);
 331        fprintf(o->file, " +");
 332        print_line_count(o->file, lc_b);
 333        fprintf(o->file, " @@%s\n", reset);
 334        if (lc_a)
 335                copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
 336        if (lc_b)
 337                copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
 338}
 339
 340static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 341{
 342        if (!DIFF_FILE_VALID(one)) {
 343                mf->ptr = (char *)""; /* does not matter */
 344                mf->size = 0;
 345                return 0;
 346        }
 347        else if (diff_populate_filespec(one, 0))
 348                return -1;
 349        mf->ptr = one->data;
 350        mf->size = one->size;
 351        return 0;
 352}
 353
 354struct diff_words_buffer {
 355        mmfile_t text;
 356        long alloc;
 357        long current; /* output pointer */
 358        int suppressed_newline;
 359};
 360
 361static void diff_words_append(char *line, unsigned long len,
 362                struct diff_words_buffer *buffer)
 363{
 364        if (buffer->text.size + len > buffer->alloc) {
 365                buffer->alloc = (buffer->text.size + len) * 3 / 2;
 366                buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
 367        }
 368        line++;
 369        len--;
 370        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 371        buffer->text.size += len;
 372}
 373
 374struct diff_words_data {
 375        struct xdiff_emit_state xm;
 376        struct diff_words_buffer minus, plus;
 377        FILE *file;
 378};
 379
 380static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
 381                int suppress_newline)
 382{
 383        const char *ptr;
 384        int eol = 0;
 385
 386        if (len == 0)
 387                return;
 388
 389        ptr  = buffer->text.ptr + buffer->current;
 390        buffer->current += len;
 391
 392        if (ptr[len - 1] == '\n') {
 393                eol = 1;
 394                len--;
 395        }
 396
 397        fputs(diff_get_color(1, color), file);
 398        fwrite(ptr, len, 1, file);
 399        fputs(diff_get_color(1, DIFF_RESET), file);
 400
 401        if (eol) {
 402                if (suppress_newline)
 403                        buffer->suppressed_newline = 1;
 404                else
 405                        putc('\n', file);
 406        }
 407}
 408
 409static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 410{
 411        struct diff_words_data *diff_words = priv;
 412
 413        if (diff_words->minus.suppressed_newline) {
 414                if (line[0] != '+')
 415                        putc('\n', diff_words->file);
 416                diff_words->minus.suppressed_newline = 0;
 417        }
 418
 419        len--;
 420        switch (line[0]) {
 421                case '-':
 422                        print_word(diff_words->file,
 423                                   &diff_words->minus, len, DIFF_FILE_OLD, 1);
 424                        break;
 425                case '+':
 426                        print_word(diff_words->file,
 427                                   &diff_words->plus, len, DIFF_FILE_NEW, 0);
 428                        break;
 429                case ' ':
 430                        print_word(diff_words->file,
 431                                   &diff_words->plus, len, DIFF_PLAIN, 0);
 432                        diff_words->minus.current += len;
 433                        break;
 434        }
 435}
 436
 437/* this executes the word diff on the accumulated buffers */
 438static void diff_words_show(struct diff_words_data *diff_words)
 439{
 440        xpparam_t xpp;
 441        xdemitconf_t xecfg;
 442        xdemitcb_t ecb;
 443        mmfile_t minus, plus;
 444        int i;
 445
 446        memset(&xecfg, 0, sizeof(xecfg));
 447        minus.size = diff_words->minus.text.size;
 448        minus.ptr = xmalloc(minus.size);
 449        memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
 450        for (i = 0; i < minus.size; i++)
 451                if (isspace(minus.ptr[i]))
 452                        minus.ptr[i] = '\n';
 453        diff_words->minus.current = 0;
 454
 455        plus.size = diff_words->plus.text.size;
 456        plus.ptr = xmalloc(plus.size);
 457        memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
 458        for (i = 0; i < plus.size; i++)
 459                if (isspace(plus.ptr[i]))
 460                        plus.ptr[i] = '\n';
 461        diff_words->plus.current = 0;
 462
 463        xpp.flags = XDF_NEED_MINIMAL;
 464        xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 465        ecb.outf = xdiff_outf;
 466        ecb.priv = diff_words;
 467        diff_words->xm.consume = fn_out_diff_words_aux;
 468        xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 469
 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        struct xdiff_emit_state xm;
 484        int nparents, color_diff;
 485        unsigned ws_rule;
 486        sane_truncate_fn truncate;
 487        const char **label_path;
 488        struct diff_words_data *diff_words;
 489        int *found_changesp;
 490        FILE *file;
 491};
 492
 493static void free_diff_words_data(struct emit_callback *ecbdata)
 494{
 495        if (ecbdata->diff_words) {
 496                /* flush buffers */
 497                if (ecbdata->diff_words->minus.text.size ||
 498                                ecbdata->diff_words->plus.text.size)
 499                        diff_words_show(ecbdata->diff_words);
 500
 501                free (ecbdata->diff_words->minus.text.ptr);
 502                free (ecbdata->diff_words->plus.text.ptr);
 503                free(ecbdata->diff_words);
 504                ecbdata->diff_words = NULL;
 505        }
 506}
 507
 508const char *diff_get_color(int diff_use_color, enum color_diff ix)
 509{
 510        if (diff_use_color)
 511                return diff_colors[ix];
 512        return "";
 513}
 514
 515static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
 516{
 517        fputs(set, file);
 518        fwrite(line, len, 1, file);
 519        fputs(reset, file);
 520}
 521
 522static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
 523{
 524        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 525        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 526
 527        if (!*ws)
 528                emit_line(ecbdata->file, set, reset, line, len);
 529        else {
 530                /* Emit just the prefix, then the rest. */
 531                emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
 532                (void)check_and_emit_line(line + ecbdata->nparents,
 533                    len - ecbdata->nparents, ecbdata->ws_rule,
 534                    ecbdata->file, set, reset, ws);
 535        }
 536}
 537
 538static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 539{
 540        const char *cp;
 541        unsigned long allot;
 542        size_t l = len;
 543
 544        if (ecb->truncate)
 545                return ecb->truncate(line, len);
 546        cp = line;
 547        allot = l;
 548        while (0 < l) {
 549                (void) utf8_width(&cp, &l);
 550                if (!cp)
 551                        break; /* truncated in the middle? */
 552        }
 553        return allot - l;
 554}
 555
 556static void fn_out_consume(void *priv, char *line, unsigned long len)
 557{
 558        int i;
 559        int color;
 560        struct emit_callback *ecbdata = priv;
 561        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 562        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 563        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 564
 565        *(ecbdata->found_changesp) = 1;
 566
 567        if (ecbdata->label_path[0]) {
 568                const char *name_a_tab, *name_b_tab;
 569
 570                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 571                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 572
 573                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 574                        meta, ecbdata->label_path[0], reset, name_a_tab);
 575                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 576                        meta, ecbdata->label_path[1], reset, name_b_tab);
 577                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 578        }
 579
 580        /* This is not really necessary for now because
 581         * this codepath only deals with two-way diffs.
 582         */
 583        for (i = 0; i < len && line[i] == '@'; i++)
 584                ;
 585        if (2 <= i && i < len && line[i] == ' ') {
 586                ecbdata->nparents = i - 1;
 587                len = sane_truncate_line(ecbdata, line, len);
 588                emit_line(ecbdata->file,
 589                          diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
 590                          reset, line, len);
 591                if (line[len-1] != '\n')
 592                        putc('\n', ecbdata->file);
 593                return;
 594        }
 595
 596        if (len < ecbdata->nparents) {
 597                emit_line(ecbdata->file, reset, reset, line, len);
 598                return;
 599        }
 600
 601        color = DIFF_PLAIN;
 602        if (ecbdata->diff_words && ecbdata->nparents != 1)
 603                /* fall back to normal diff */
 604                free_diff_words_data(ecbdata);
 605        if (ecbdata->diff_words) {
 606                if (line[0] == '-') {
 607                        diff_words_append(line, len,
 608                                          &ecbdata->diff_words->minus);
 609                        return;
 610                } else if (line[0] == '+') {
 611                        diff_words_append(line, len,
 612                                          &ecbdata->diff_words->plus);
 613                        return;
 614                }
 615                if (ecbdata->diff_words->minus.text.size ||
 616                    ecbdata->diff_words->plus.text.size)
 617                        diff_words_show(ecbdata->diff_words);
 618                line++;
 619                len--;
 620                emit_line(ecbdata->file, plain, reset, line, len);
 621                return;
 622        }
 623        for (i = 0; i < ecbdata->nparents && len; i++) {
 624                if (line[i] == '-')
 625                        color = DIFF_FILE_OLD;
 626                else if (line[i] == '+')
 627                        color = DIFF_FILE_NEW;
 628        }
 629
 630        if (color != DIFF_FILE_NEW) {
 631                emit_line(ecbdata->file,
 632                          diff_get_color(ecbdata->color_diff, color),
 633                          reset, line, len);
 634                return;
 635        }
 636        emit_add_line(reset, ecbdata, line, len);
 637}
 638
 639static char *pprint_rename(const char *a, const char *b)
 640{
 641        const char *old = a;
 642        const char *new = b;
 643        struct strbuf name;
 644        int pfx_length, sfx_length;
 645        int len_a = strlen(a);
 646        int len_b = strlen(b);
 647        int a_midlen, b_midlen;
 648        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 649        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 650
 651        strbuf_init(&name, 0);
 652        if (qlen_a || qlen_b) {
 653                quote_c_style(a, &name, NULL, 0);
 654                strbuf_addstr(&name, " => ");
 655                quote_c_style(b, &name, NULL, 0);
 656                return strbuf_detach(&name, NULL);
 657        }
 658
 659        /* Find common prefix */
 660        pfx_length = 0;
 661        while (*old && *new && *old == *new) {
 662                if (*old == '/')
 663                        pfx_length = old - a + 1;
 664                old++;
 665                new++;
 666        }
 667
 668        /* Find common suffix */
 669        old = a + len_a;
 670        new = b + len_b;
 671        sfx_length = 0;
 672        while (a <= old && b <= new && *old == *new) {
 673                if (*old == '/')
 674                        sfx_length = len_a - (old - a);
 675                old--;
 676                new--;
 677        }
 678
 679        /*
 680         * pfx{mid-a => mid-b}sfx
 681         * {pfx-a => pfx-b}sfx
 682         * pfx{sfx-a => sfx-b}
 683         * name-a => name-b
 684         */
 685        a_midlen = len_a - pfx_length - sfx_length;
 686        b_midlen = len_b - pfx_length - sfx_length;
 687        if (a_midlen < 0)
 688                a_midlen = 0;
 689        if (b_midlen < 0)
 690                b_midlen = 0;
 691
 692        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 693        if (pfx_length + sfx_length) {
 694                strbuf_add(&name, a, pfx_length);
 695                strbuf_addch(&name, '{');
 696        }
 697        strbuf_add(&name, a + pfx_length, a_midlen);
 698        strbuf_addstr(&name, " => ");
 699        strbuf_add(&name, b + pfx_length, b_midlen);
 700        if (pfx_length + sfx_length) {
 701                strbuf_addch(&name, '}');
 702                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 703        }
 704        return strbuf_detach(&name, NULL);
 705}
 706
 707struct diffstat_t {
 708        struct xdiff_emit_state xm;
 709
 710        int nr;
 711        int alloc;
 712        struct diffstat_file {
 713                char *from_name;
 714                char *name;
 715                char *print_name;
 716                unsigned is_unmerged:1;
 717                unsigned is_binary:1;
 718                unsigned is_renamed:1;
 719                unsigned int added, deleted;
 720        } **files;
 721};
 722
 723static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 724                                          const char *name_a,
 725                                          const char *name_b)
 726{
 727        struct diffstat_file *x;
 728        x = xcalloc(sizeof (*x), 1);
 729        if (diffstat->nr == diffstat->alloc) {
 730                diffstat->alloc = alloc_nr(diffstat->alloc);
 731                diffstat->files = xrealloc(diffstat->files,
 732                                diffstat->alloc * sizeof(x));
 733        }
 734        diffstat->files[diffstat->nr++] = x;
 735        if (name_b) {
 736                x->from_name = xstrdup(name_a);
 737                x->name = xstrdup(name_b);
 738                x->is_renamed = 1;
 739        }
 740        else {
 741                x->from_name = NULL;
 742                x->name = xstrdup(name_a);
 743        }
 744        return x;
 745}
 746
 747static void diffstat_consume(void *priv, char *line, unsigned long len)
 748{
 749        struct diffstat_t *diffstat = priv;
 750        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 751
 752        if (line[0] == '+')
 753                x->added++;
 754        else if (line[0] == '-')
 755                x->deleted++;
 756}
 757
 758const char mime_boundary_leader[] = "------------";
 759
 760static int scale_linear(int it, int width, int max_change)
 761{
 762        /*
 763         * make sure that at least one '-' is printed if there were deletions,
 764         * and likewise for '+'.
 765         */
 766        if (max_change < 2)
 767                return it;
 768        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 769}
 770
 771static void show_name(FILE *file,
 772                      const char *prefix, const char *name, int len,
 773                      const char *reset, const char *set)
 774{
 775        fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
 776}
 777
 778static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
 779{
 780        if (cnt <= 0)
 781                return;
 782        fprintf(file, "%s", set);
 783        while (cnt--)
 784                putc(ch, file);
 785        fprintf(file, "%s", reset);
 786}
 787
 788static void fill_print_name(struct diffstat_file *file)
 789{
 790        char *pname;
 791
 792        if (file->print_name)
 793                return;
 794
 795        if (!file->is_renamed) {
 796                struct strbuf buf;
 797                strbuf_init(&buf, 0);
 798                if (quote_c_style(file->name, &buf, NULL, 0)) {
 799                        pname = strbuf_detach(&buf, NULL);
 800                } else {
 801                        pname = file->name;
 802                        strbuf_release(&buf);
 803                }
 804        } else {
 805                pname = pprint_rename(file->from_name, file->name);
 806        }
 807        file->print_name = pname;
 808}
 809
 810static void show_stats(struct diffstat_t* data, struct diff_options *options)
 811{
 812        int i, len, add, del, total, adds = 0, dels = 0;
 813        int max_change = 0, max_len = 0;
 814        int total_files = data->nr;
 815        int width, name_width;
 816        const char *reset, *set, *add_c, *del_c;
 817
 818        if (data->nr == 0)
 819                return;
 820
 821        width = options->stat_width ? options->stat_width : 80;
 822        name_width = options->stat_name_width ? options->stat_name_width : 50;
 823
 824        /* Sanity: give at least 5 columns to the graph,
 825         * but leave at least 10 columns for the name.
 826         */
 827        if (width < name_width + 15) {
 828                if (name_width <= 25)
 829                        width = name_width + 15;
 830                else
 831                        name_width = width - 15;
 832        }
 833
 834        /* Find the longest filename and max number of changes */
 835        reset = diff_get_color_opt(options, DIFF_RESET);
 836        set   = diff_get_color_opt(options, DIFF_PLAIN);
 837        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
 838        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
 839
 840        for (i = 0; i < data->nr; i++) {
 841                struct diffstat_file *file = data->files[i];
 842                int change = file->added + file->deleted;
 843                fill_print_name(file);
 844                len = strlen(file->print_name);
 845                if (max_len < len)
 846                        max_len = len;
 847
 848                if (file->is_binary || file->is_unmerged)
 849                        continue;
 850                if (max_change < change)
 851                        max_change = change;
 852        }
 853
 854        /* Compute the width of the graph part;
 855         * 10 is for one blank at the beginning of the line plus
 856         * " | count " between the name and the graph.
 857         *
 858         * From here on, name_width is the width of the name area,
 859         * and width is the width of the graph area.
 860         */
 861        name_width = (name_width < max_len) ? name_width : max_len;
 862        if (width < (name_width + 10) + max_change)
 863                width = width - (name_width + 10);
 864        else
 865                width = max_change;
 866
 867        for (i = 0; i < data->nr; i++) {
 868                const char *prefix = "";
 869                char *name = data->files[i]->print_name;
 870                int added = data->files[i]->added;
 871                int deleted = data->files[i]->deleted;
 872                int name_len;
 873
 874                /*
 875                 * "scale" the filename
 876                 */
 877                len = name_width;
 878                name_len = strlen(name);
 879                if (name_width < name_len) {
 880                        char *slash;
 881                        prefix = "...";
 882                        len -= 3;
 883                        name += name_len - len;
 884                        slash = strchr(name, '/');
 885                        if (slash)
 886                                name = slash;
 887                }
 888
 889                if (data->files[i]->is_binary) {
 890                        show_name(options->file, prefix, name, len, reset, set);
 891                        fprintf(options->file, "  Bin ");
 892                        fprintf(options->file, "%s%d%s", del_c, deleted, reset);
 893                        fprintf(options->file, " -> ");
 894                        fprintf(options->file, "%s%d%s", add_c, added, reset);
 895                        fprintf(options->file, " bytes");
 896                        fprintf(options->file, "\n");
 897                        continue;
 898                }
 899                else if (data->files[i]->is_unmerged) {
 900                        show_name(options->file, prefix, name, len, reset, set);
 901                        fprintf(options->file, "  Unmerged\n");
 902                        continue;
 903                }
 904                else if (!data->files[i]->is_renamed &&
 905                         (added + deleted == 0)) {
 906                        total_files--;
 907                        continue;
 908                }
 909
 910                /*
 911                 * scale the add/delete
 912                 */
 913                add = added;
 914                del = deleted;
 915                total = add + del;
 916                adds += add;
 917                dels += del;
 918
 919                if (width <= max_change) {
 920                        add = scale_linear(add, width, max_change);
 921                        del = scale_linear(del, width, max_change);
 922                        total = add + del;
 923                }
 924                show_name(options->file, prefix, name, len, reset, set);
 925                fprintf(options->file, "%5d ", added + deleted);
 926                show_graph(options->file, '+', add, add_c, reset);
 927                show_graph(options->file, '-', del, del_c, reset);
 928                fprintf(options->file, "\n");
 929        }
 930        fprintf(options->file,
 931               "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 932               set, total_files, adds, dels, reset);
 933}
 934
 935static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
 936{
 937        int i, adds = 0, dels = 0, total_files = data->nr;
 938
 939        if (data->nr == 0)
 940                return;
 941
 942        for (i = 0; i < data->nr; i++) {
 943                if (!data->files[i]->is_binary &&
 944                    !data->files[i]->is_unmerged) {
 945                        int added = data->files[i]->added;
 946                        int deleted= data->files[i]->deleted;
 947                        if (!data->files[i]->is_renamed &&
 948                            (added + deleted == 0)) {
 949                                total_files--;
 950                        } else {
 951                                adds += added;
 952                                dels += deleted;
 953                        }
 954                }
 955        }
 956        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
 957               total_files, adds, dels);
 958}
 959
 960static void show_numstat(struct diffstat_t* data, struct diff_options *options)
 961{
 962        int i;
 963
 964        if (data->nr == 0)
 965                return;
 966
 967        for (i = 0; i < data->nr; i++) {
 968                struct diffstat_file *file = data->files[i];
 969
 970                if (file->is_binary)
 971                        fprintf(options->file, "-\t-\t");
 972                else
 973                        fprintf(options->file,
 974                                "%d\t%d\t", file->added, file->deleted);
 975                if (options->line_termination) {
 976                        fill_print_name(file);
 977                        if (!file->is_renamed)
 978                                write_name_quoted(file->name, options->file,
 979                                                  options->line_termination);
 980                        else {
 981                                fputs(file->print_name, options->file);
 982                                putc(options->line_termination, options->file);
 983                        }
 984                } else {
 985                        if (file->is_renamed) {
 986                                putc('\0', options->file);
 987                                write_name_quoted(file->from_name, options->file, '\0');
 988                        }
 989                        write_name_quoted(file->name, options->file, '\0');
 990                }
 991        }
 992}
 993
 994struct diffstat_dir {
 995        struct diffstat_file **files;
 996        int nr, percent, cumulative;
 997};
 998
 999static long gather_dirstat(FILE *file, struct diffstat_dir *dir, unsigned long changed, const char *base, int baselen)
1000{
1001        unsigned long this_dir = 0;
1002        unsigned int sources = 0;
1003
1004        while (dir->nr) {
1005                struct diffstat_file *f = *dir->files;
1006                int namelen = strlen(f->name);
1007                unsigned long this;
1008                char *slash;
1009
1010                if (namelen < baselen)
1011                        break;
1012                if (memcmp(f->name, base, baselen))
1013                        break;
1014                slash = strchr(f->name + baselen, '/');
1015                if (slash) {
1016                        int newbaselen = slash + 1 - f->name;
1017                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1018                        sources++;
1019                } else {
1020                        if (f->is_unmerged || f->is_binary)
1021                                this = 0;
1022                        else
1023                                this = f->added + f->deleted;
1024                        dir->files++;
1025                        dir->nr--;
1026                        sources += 2;
1027                }
1028                this_dir += this;
1029        }
1030
1031        /*
1032         * We don't report dirstat's for
1033         *  - the top level
1034         *  - or cases where everything came from a single directory
1035         *    under this directory (sources == 1).
1036         */
1037        if (baselen && sources != 1) {
1038                int permille = this_dir * 1000 / changed;
1039                if (permille) {
1040                        int percent = permille / 10;
1041                        if (percent >= dir->percent) {
1042                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1043                                if (!dir->cumulative)
1044                                        return 0;
1045                        }
1046                }
1047        }
1048        return this_dir;
1049}
1050
1051static void show_dirstat(struct diffstat_t *data, struct diff_options *options)
1052{
1053        int i;
1054        unsigned long changed;
1055        struct diffstat_dir dir;
1056
1057        /* Calculate total changes */
1058        changed = 0;
1059        for (i = 0; i < data->nr; i++) {
1060                if (data->files[i]->is_binary || data->files[i]->is_unmerged)
1061                        continue;
1062                changed += data->files[i]->added;
1063                changed += data->files[i]->deleted;
1064        }
1065
1066        /* This can happen even with many files, if everything was renames */
1067        if (!changed)
1068                return;
1069
1070        /* Show all directories with more than x% of the changes */
1071        dir.files = data->files;
1072        dir.nr = data->nr;
1073        dir.percent = options->dirstat_percent;
1074        dir.cumulative = options->output_format & DIFF_FORMAT_CUMULATIVE;
1075        gather_dirstat(options->file, &dir, changed, "", 0);
1076}
1077
1078static void free_diffstat_info(struct diffstat_t *diffstat)
1079{
1080        int i;
1081        for (i = 0; i < diffstat->nr; i++) {
1082                struct diffstat_file *f = diffstat->files[i];
1083                if (f->name != f->print_name)
1084                        free(f->print_name);
1085                free(f->name);
1086                free(f->from_name);
1087                free(f);
1088        }
1089        free(diffstat->files);
1090}
1091
1092struct checkdiff_t {
1093        struct xdiff_emit_state xm;
1094        const char *filename;
1095        int lineno, color_diff;
1096        unsigned ws_rule;
1097        unsigned status;
1098        FILE *file;
1099};
1100
1101static void checkdiff_consume(void *priv, char *line, unsigned long len)
1102{
1103        struct checkdiff_t *data = priv;
1104        const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
1105        const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
1106        const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
1107        char *err;
1108
1109        if (line[0] == '+') {
1110                data->lineno++;
1111                data->status = check_and_emit_line(line + 1, len - 1,
1112                    data->ws_rule, NULL, NULL, NULL, NULL);
1113                if (!data->status)
1114                        return;
1115                err = whitespace_error_string(data->status);
1116                fprintf(data->file, "%s:%d: %s.\n", data->filename, data->lineno, err);
1117                free(err);
1118                emit_line(data->file, set, reset, line, 1);
1119                (void)check_and_emit_line(line + 1, len - 1, data->ws_rule,
1120                    data->file, set, reset, ws);
1121        } else if (line[0] == ' ')
1122                data->lineno++;
1123        else if (line[0] == '@') {
1124                char *plus = strchr(line, '+');
1125                if (plus)
1126                        data->lineno = strtol(plus, NULL, 10) - 1;
1127                else
1128                        die("invalid diff");
1129        }
1130}
1131
1132static unsigned char *deflate_it(char *data,
1133                                 unsigned long size,
1134                                 unsigned long *result_size)
1135{
1136        int bound;
1137        unsigned char *deflated;
1138        z_stream stream;
1139
1140        memset(&stream, 0, sizeof(stream));
1141        deflateInit(&stream, zlib_compression_level);
1142        bound = deflateBound(&stream, size);
1143        deflated = xmalloc(bound);
1144        stream.next_out = deflated;
1145        stream.avail_out = bound;
1146
1147        stream.next_in = (unsigned char *)data;
1148        stream.avail_in = size;
1149        while (deflate(&stream, Z_FINISH) == Z_OK)
1150                ; /* nothing */
1151        deflateEnd(&stream);
1152        *result_size = stream.total_out;
1153        return deflated;
1154}
1155
1156static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1157{
1158        void *cp;
1159        void *delta;
1160        void *deflated;
1161        void *data;
1162        unsigned long orig_size;
1163        unsigned long delta_size;
1164        unsigned long deflate_size;
1165        unsigned long data_size;
1166
1167        /* We could do deflated delta, or we could do just deflated two,
1168         * whichever is smaller.
1169         */
1170        delta = NULL;
1171        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1172        if (one->size && two->size) {
1173                delta = diff_delta(one->ptr, one->size,
1174                                   two->ptr, two->size,
1175                                   &delta_size, deflate_size);
1176                if (delta) {
1177                        void *to_free = delta;
1178                        orig_size = delta_size;
1179                        delta = deflate_it(delta, delta_size, &delta_size);
1180                        free(to_free);
1181                }
1182        }
1183
1184        if (delta && delta_size < deflate_size) {
1185                fprintf(file, "delta %lu\n", orig_size);
1186                free(deflated);
1187                data = delta;
1188                data_size = delta_size;
1189        }
1190        else {
1191                fprintf(file, "literal %lu\n", two->size);
1192                free(delta);
1193                data = deflated;
1194                data_size = deflate_size;
1195        }
1196
1197        /* emit data encoded in base85 */
1198        cp = data;
1199        while (data_size) {
1200                int bytes = (52 < data_size) ? 52 : data_size;
1201                char line[70];
1202                data_size -= bytes;
1203                if (bytes <= 26)
1204                        line[0] = bytes + 'A' - 1;
1205                else
1206                        line[0] = bytes - 26 + 'a' - 1;
1207                encode_85(line + 1, cp, bytes);
1208                cp = (char *) cp + bytes;
1209                fputs(line, file);
1210                fputc('\n', file);
1211        }
1212        fprintf(file, "\n");
1213        free(data);
1214}
1215
1216static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1217{
1218        fprintf(file, "GIT binary patch\n");
1219        emit_binary_diff_body(file, one, two);
1220        emit_binary_diff_body(file, two, one);
1221}
1222
1223static void setup_diff_attr_check(struct git_attr_check *check)
1224{
1225        static struct git_attr *attr_diff;
1226
1227        if (!attr_diff) {
1228                attr_diff = git_attr("diff", 4);
1229        }
1230        check[0].attr = attr_diff;
1231}
1232
1233static void diff_filespec_check_attr(struct diff_filespec *one)
1234{
1235        struct git_attr_check attr_diff_check;
1236        int check_from_data = 0;
1237
1238        if (one->checked_attr)
1239                return;
1240
1241        setup_diff_attr_check(&attr_diff_check);
1242        one->is_binary = 0;
1243        one->funcname_pattern_ident = NULL;
1244
1245        if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1246                const char *value;
1247
1248                /* binaryness */
1249                value = attr_diff_check.value;
1250                if (ATTR_TRUE(value))
1251                        ;
1252                else if (ATTR_FALSE(value))
1253                        one->is_binary = 1;
1254                else
1255                        check_from_data = 1;
1256
1257                /* funcname pattern ident */
1258                if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1259                        ;
1260                else
1261                        one->funcname_pattern_ident = value;
1262        }
1263
1264        if (check_from_data) {
1265                if (!one->data && DIFF_FILE_VALID(one))
1266                        diff_populate_filespec(one, 0);
1267
1268                if (one->data)
1269                        one->is_binary = buffer_is_binary(one->data, one->size);
1270        }
1271}
1272
1273int diff_filespec_is_binary(struct diff_filespec *one)
1274{
1275        diff_filespec_check_attr(one);
1276        return one->is_binary;
1277}
1278
1279static const char *funcname_pattern(const char *ident)
1280{
1281        struct funcname_pattern *pp;
1282
1283        for (pp = funcname_pattern_list; pp; pp = pp->next)
1284                if (!strcmp(ident, pp->name))
1285                        return pp->pattern;
1286        return NULL;
1287}
1288
1289static struct builtin_funcname_pattern {
1290        const char *name;
1291        const char *pattern;
1292} builtin_funcname_pattern[] = {
1293        { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1294                        "new\\|return\\|switch\\|throw\\|while\\)\n"
1295                        "^[     ]*\\(\\([       ]*"
1296                        "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1297                        "[      ]*([^;]*\\)$" },
1298        { "tex", "^\\(\\\\\\(sub\\)*section{.*\\)$" },
1299};
1300
1301static const char *diff_funcname_pattern(struct diff_filespec *one)
1302{
1303        const char *ident, *pattern;
1304        int i;
1305
1306        diff_filespec_check_attr(one);
1307        ident = one->funcname_pattern_ident;
1308
1309        if (!ident)
1310                /*
1311                 * If the config file has "funcname.default" defined, that
1312                 * regexp is used; otherwise NULL is returned and xemit uses
1313                 * the built-in default.
1314                 */
1315                return funcname_pattern("default");
1316
1317        /* Look up custom "funcname.$ident" regexp from config. */
1318        pattern = funcname_pattern(ident);
1319        if (pattern)
1320                return pattern;
1321
1322        /*
1323         * And define built-in fallback patterns here.  Note that
1324         * these can be overridden by the user's config settings.
1325         */
1326        for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1327                if (!strcmp(ident, builtin_funcname_pattern[i].name))
1328                        return builtin_funcname_pattern[i].pattern;
1329
1330        return NULL;
1331}
1332
1333static void builtin_diff(const char *name_a,
1334                         const char *name_b,
1335                         struct diff_filespec *one,
1336                         struct diff_filespec *two,
1337                         const char *xfrm_msg,
1338                         struct diff_options *o,
1339                         int complete_rewrite)
1340{
1341        mmfile_t mf1, mf2;
1342        const char *lbl[2];
1343        char *a_one, *b_two;
1344        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1345        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1346
1347        a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1348        b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1349        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1350        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1351        fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1352        if (lbl[0][0] == '/') {
1353                /* /dev/null */
1354                fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1355                if (xfrm_msg && xfrm_msg[0])
1356                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1357        }
1358        else if (lbl[1][0] == '/') {
1359                fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1360                if (xfrm_msg && xfrm_msg[0])
1361                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1362        }
1363        else {
1364                if (one->mode != two->mode) {
1365                        fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1366                        fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1367                }
1368                if (xfrm_msg && xfrm_msg[0])
1369                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1370                /*
1371                 * we do not run diff between different kind
1372                 * of objects.
1373                 */
1374                if ((one->mode ^ two->mode) & S_IFMT)
1375                        goto free_ab_and_return;
1376                if (complete_rewrite) {
1377                        emit_rewrite_diff(name_a, name_b, one, two, o);
1378                        o->found_changes = 1;
1379                        goto free_ab_and_return;
1380                }
1381        }
1382
1383        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1384                die("unable to read files to diff");
1385
1386        if (!DIFF_OPT_TST(o, TEXT) &&
1387            (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1388                /* Quite common confusing case */
1389                if (mf1.size == mf2.size &&
1390                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1391                        goto free_ab_and_return;
1392                if (DIFF_OPT_TST(o, BINARY))
1393                        emit_binary_diff(o->file, &mf1, &mf2);
1394                else
1395                        fprintf(o->file, "Binary files %s and %s differ\n",
1396                                lbl[0], lbl[1]);
1397                o->found_changes = 1;
1398        }
1399        else {
1400                /* Crazy xdl interfaces.. */
1401                const char *diffopts = getenv("GIT_DIFF_OPTS");
1402                xpparam_t xpp;
1403                xdemitconf_t xecfg;
1404                xdemitcb_t ecb;
1405                struct emit_callback ecbdata;
1406                const char *funcname_pattern;
1407
1408                funcname_pattern = diff_funcname_pattern(one);
1409                if (!funcname_pattern)
1410                        funcname_pattern = diff_funcname_pattern(two);
1411
1412                memset(&xecfg, 0, sizeof(xecfg));
1413                memset(&ecbdata, 0, sizeof(ecbdata));
1414                ecbdata.label_path = lbl;
1415                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1416                ecbdata.found_changesp = &o->found_changes;
1417                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1418                ecbdata.file = o->file;
1419                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1420                xecfg.ctxlen = o->context;
1421                xecfg.flags = XDL_EMIT_FUNCNAMES;
1422                if (funcname_pattern)
1423                        xdiff_set_find_func(&xecfg, funcname_pattern);
1424                if (!diffopts)
1425                        ;
1426                else if (!prefixcmp(diffopts, "--unified="))
1427                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1428                else if (!prefixcmp(diffopts, "-u"))
1429                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1430                ecb.outf = xdiff_outf;
1431                ecb.priv = &ecbdata;
1432                ecbdata.xm.consume = fn_out_consume;
1433                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1434                        ecbdata.diff_words =
1435                                xcalloc(1, sizeof(struct diff_words_data));
1436                        ecbdata.diff_words->file = o->file;
1437                }
1438                xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1439                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1440                        free_diff_words_data(&ecbdata);
1441        }
1442
1443 free_ab_and_return:
1444        diff_free_filespec_data(one);
1445        diff_free_filespec_data(two);
1446        free(a_one);
1447        free(b_two);
1448        return;
1449}
1450
1451static void builtin_diffstat(const char *name_a, const char *name_b,
1452                             struct diff_filespec *one,
1453                             struct diff_filespec *two,
1454                             struct diffstat_t *diffstat,
1455                             struct diff_options *o,
1456                             int complete_rewrite)
1457{
1458        mmfile_t mf1, mf2;
1459        struct diffstat_file *data;
1460
1461        data = diffstat_add(diffstat, name_a, name_b);
1462
1463        if (!one || !two) {
1464                data->is_unmerged = 1;
1465                return;
1466        }
1467        if (complete_rewrite) {
1468                diff_populate_filespec(one, 0);
1469                diff_populate_filespec(two, 0);
1470                data->deleted = count_lines(one->data, one->size);
1471                data->added = count_lines(two->data, two->size);
1472                goto free_and_return;
1473        }
1474        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1475                die("unable to read files to diff");
1476
1477        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1478                data->is_binary = 1;
1479                data->added = mf2.size;
1480                data->deleted = mf1.size;
1481        } else {
1482                /* Crazy xdl interfaces.. */
1483                xpparam_t xpp;
1484                xdemitconf_t xecfg;
1485                xdemitcb_t ecb;
1486
1487                memset(&xecfg, 0, sizeof(xecfg));
1488                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1489                ecb.outf = xdiff_outf;
1490                ecb.priv = diffstat;
1491                xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1492        }
1493
1494 free_and_return:
1495        diff_free_filespec_data(one);
1496        diff_free_filespec_data(two);
1497}
1498
1499static void builtin_checkdiff(const char *name_a, const char *name_b,
1500                              const char *attr_path,
1501                             struct diff_filespec *one,
1502                             struct diff_filespec *two, struct diff_options *o)
1503{
1504        mmfile_t mf1, mf2;
1505        struct checkdiff_t data;
1506
1507        if (!two)
1508                return;
1509
1510        memset(&data, 0, sizeof(data));
1511        data.xm.consume = checkdiff_consume;
1512        data.filename = name_b ? name_b : name_a;
1513        data.lineno = 0;
1514        data.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1515        data.ws_rule = whitespace_rule(attr_path);
1516        data.file = o->file;
1517
1518        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1519                die("unable to read files to diff");
1520
1521        if (diff_filespec_is_binary(two))
1522                goto free_and_return;
1523        else {
1524                /* Crazy xdl interfaces.. */
1525                xpparam_t xpp;
1526                xdemitconf_t xecfg;
1527                xdemitcb_t ecb;
1528
1529                memset(&xecfg, 0, sizeof(xecfg));
1530                xpp.flags = XDF_NEED_MINIMAL;
1531                ecb.outf = xdiff_outf;
1532                ecb.priv = &data;
1533                xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1534        }
1535 free_and_return:
1536        diff_free_filespec_data(one);
1537        diff_free_filespec_data(two);
1538        if (data.status)
1539                DIFF_OPT_SET(o, CHECK_FAILED);
1540}
1541
1542struct diff_filespec *alloc_filespec(const char *path)
1543{
1544        int namelen = strlen(path);
1545        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1546
1547        memset(spec, 0, sizeof(*spec));
1548        spec->path = (char *)(spec + 1);
1549        memcpy(spec->path, path, namelen+1);
1550        spec->count = 1;
1551        return spec;
1552}
1553
1554void free_filespec(struct diff_filespec *spec)
1555{
1556        if (!--spec->count) {
1557                diff_free_filespec_data(spec);
1558                free(spec);
1559        }
1560}
1561
1562void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1563                   unsigned short mode)
1564{
1565        if (mode) {
1566                spec->mode = canon_mode(mode);
1567                hashcpy(spec->sha1, sha1);
1568                spec->sha1_valid = !is_null_sha1(sha1);
1569        }
1570}
1571
1572/*
1573 * Given a name and sha1 pair, if the index tells us the file in
1574 * the work tree has that object contents, return true, so that
1575 * prepare_temp_file() does not have to inflate and extract.
1576 */
1577static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1578{
1579        struct cache_entry *ce;
1580        struct stat st;
1581        int pos, len;
1582
1583        /* We do not read the cache ourselves here, because the
1584         * benchmark with my previous version that always reads cache
1585         * shows that it makes things worse for diff-tree comparing
1586         * two linux-2.6 kernel trees in an already checked out work
1587         * tree.  This is because most diff-tree comparisons deal with
1588         * only a small number of files, while reading the cache is
1589         * expensive for a large project, and its cost outweighs the
1590         * savings we get by not inflating the object to a temporary
1591         * file.  Practically, this code only helps when we are used
1592         * by diff-cache --cached, which does read the cache before
1593         * calling us.
1594         */
1595        if (!active_cache)
1596                return 0;
1597
1598        /* We want to avoid the working directory if our caller
1599         * doesn't need the data in a normal file, this system
1600         * is rather slow with its stat/open/mmap/close syscalls,
1601         * and the object is contained in a pack file.  The pack
1602         * is probably already open and will be faster to obtain
1603         * the data through than the working directory.  Loose
1604         * objects however would tend to be slower as they need
1605         * to be individually opened and inflated.
1606         */
1607        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1608                return 0;
1609
1610        len = strlen(name);
1611        pos = cache_name_pos(name, len);
1612        if (pos < 0)
1613                return 0;
1614        ce = active_cache[pos];
1615
1616        /*
1617         * This is not the sha1 we are looking for, or
1618         * unreusable because it is not a regular file.
1619         */
1620        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1621                return 0;
1622
1623        /*
1624         * If ce matches the file in the work tree, we can reuse it.
1625         */
1626        if (ce_uptodate(ce) ||
1627            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1628                return 1;
1629
1630        return 0;
1631}
1632
1633static int populate_from_stdin(struct diff_filespec *s)
1634{
1635        struct strbuf buf;
1636        size_t size = 0;
1637
1638        strbuf_init(&buf, 0);
1639        if (strbuf_read(&buf, 0, 0) < 0)
1640                return error("error while reading from stdin %s",
1641                                     strerror(errno));
1642
1643        s->should_munmap = 0;
1644        s->data = strbuf_detach(&buf, &size);
1645        s->size = size;
1646        s->should_free = 1;
1647        return 0;
1648}
1649
1650static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1651{
1652        int len;
1653        char *data = xmalloc(100);
1654        len = snprintf(data, 100,
1655                "Subproject commit %s\n", sha1_to_hex(s->sha1));
1656        s->data = data;
1657        s->size = len;
1658        s->should_free = 1;
1659        if (size_only) {
1660                s->data = NULL;
1661                free(data);
1662        }
1663        return 0;
1664}
1665
1666/*
1667 * While doing rename detection and pickaxe operation, we may need to
1668 * grab the data for the blob (or file) for our own in-core comparison.
1669 * diff_filespec has data and size fields for this purpose.
1670 */
1671int diff_populate_filespec(struct diff_filespec *s, int size_only)
1672{
1673        int err = 0;
1674        if (!DIFF_FILE_VALID(s))
1675                die("internal error: asking to populate invalid file.");
1676        if (S_ISDIR(s->mode))
1677                return -1;
1678
1679        if (s->data)
1680                return 0;
1681
1682        if (size_only && 0 < s->size)
1683                return 0;
1684
1685        if (S_ISGITLINK(s->mode))
1686                return diff_populate_gitlink(s, size_only);
1687
1688        if (!s->sha1_valid ||
1689            reuse_worktree_file(s->path, s->sha1, 0)) {
1690                struct strbuf buf;
1691                struct stat st;
1692                int fd;
1693
1694                if (!strcmp(s->path, "-"))
1695                        return populate_from_stdin(s);
1696
1697                if (lstat(s->path, &st) < 0) {
1698                        if (errno == ENOENT) {
1699                        err_empty:
1700                                err = -1;
1701                        empty:
1702                                s->data = (char *)"";
1703                                s->size = 0;
1704                                return err;
1705                        }
1706                }
1707                s->size = xsize_t(st.st_size);
1708                if (!s->size)
1709                        goto empty;
1710                if (size_only)
1711                        return 0;
1712                if (S_ISLNK(st.st_mode)) {
1713                        int ret;
1714                        s->data = xmalloc(s->size);
1715                        s->should_free = 1;
1716                        ret = readlink(s->path, s->data, s->size);
1717                        if (ret < 0) {
1718                                free(s->data);
1719                                goto err_empty;
1720                        }
1721                        return 0;
1722                }
1723                fd = open(s->path, O_RDONLY);
1724                if (fd < 0)
1725                        goto err_empty;
1726                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1727                close(fd);
1728                s->should_munmap = 1;
1729
1730                /*
1731                 * Convert from working tree format to canonical git format
1732                 */
1733                strbuf_init(&buf, 0);
1734                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1735                        size_t size = 0;
1736                        munmap(s->data, s->size);
1737                        s->should_munmap = 0;
1738                        s->data = strbuf_detach(&buf, &size);
1739                        s->size = size;
1740                        s->should_free = 1;
1741                }
1742        }
1743        else {
1744                enum object_type type;
1745                if (size_only)
1746                        type = sha1_object_info(s->sha1, &s->size);
1747                else {
1748                        s->data = read_sha1_file(s->sha1, &type, &s->size);
1749                        s->should_free = 1;
1750                }
1751        }
1752        return 0;
1753}
1754
1755void diff_free_filespec_blob(struct diff_filespec *s)
1756{
1757        if (s->should_free)
1758                free(s->data);
1759        else if (s->should_munmap)
1760                munmap(s->data, s->size);
1761
1762        if (s->should_free || s->should_munmap) {
1763                s->should_free = s->should_munmap = 0;
1764                s->data = NULL;
1765        }
1766}
1767
1768void diff_free_filespec_data(struct diff_filespec *s)
1769{
1770        diff_free_filespec_blob(s);
1771        free(s->cnt_data);
1772        s->cnt_data = NULL;
1773}
1774
1775static void prep_temp_blob(struct diff_tempfile *temp,
1776                           void *blob,
1777                           unsigned long size,
1778                           const unsigned char *sha1,
1779                           int mode)
1780{
1781        int fd;
1782
1783        fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1784        if (fd < 0)
1785                die("unable to create temp-file: %s", strerror(errno));
1786        if (write_in_full(fd, blob, size) != size)
1787                die("unable to write temp-file");
1788        close(fd);
1789        temp->name = temp->tmp_path;
1790        strcpy(temp->hex, sha1_to_hex(sha1));
1791        temp->hex[40] = 0;
1792        sprintf(temp->mode, "%06o", mode);
1793}
1794
1795static void prepare_temp_file(const char *name,
1796                              struct diff_tempfile *temp,
1797                              struct diff_filespec *one)
1798{
1799        if (!DIFF_FILE_VALID(one)) {
1800        not_a_valid_file:
1801                /* A '-' entry produces this for file-2, and
1802                 * a '+' entry produces this for file-1.
1803                 */
1804                temp->name = "/dev/null";
1805                strcpy(temp->hex, ".");
1806                strcpy(temp->mode, ".");
1807                return;
1808        }
1809
1810        if (!one->sha1_valid ||
1811            reuse_worktree_file(name, one->sha1, 1)) {
1812                struct stat st;
1813                if (lstat(name, &st) < 0) {
1814                        if (errno == ENOENT)
1815                                goto not_a_valid_file;
1816                        die("stat(%s): %s", name, strerror(errno));
1817                }
1818                if (S_ISLNK(st.st_mode)) {
1819                        int ret;
1820                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1821                        size_t sz = xsize_t(st.st_size);
1822                        if (sizeof(buf) <= st.st_size)
1823                                die("symlink too long: %s", name);
1824                        ret = readlink(name, buf, sz);
1825                        if (ret < 0)
1826                                die("readlink(%s)", name);
1827                        prep_temp_blob(temp, buf, sz,
1828                                       (one->sha1_valid ?
1829                                        one->sha1 : null_sha1),
1830                                       (one->sha1_valid ?
1831                                        one->mode : S_IFLNK));
1832                }
1833                else {
1834                        /* we can borrow from the file in the work tree */
1835                        temp->name = name;
1836                        if (!one->sha1_valid)
1837                                strcpy(temp->hex, sha1_to_hex(null_sha1));
1838                        else
1839                                strcpy(temp->hex, sha1_to_hex(one->sha1));
1840                        /* Even though we may sometimes borrow the
1841                         * contents from the work tree, we always want
1842                         * one->mode.  mode is trustworthy even when
1843                         * !(one->sha1_valid), as long as
1844                         * DIFF_FILE_VALID(one).
1845                         */
1846                        sprintf(temp->mode, "%06o", one->mode);
1847                }
1848                return;
1849        }
1850        else {
1851                if (diff_populate_filespec(one, 0))
1852                        die("cannot read data blob for %s", one->path);
1853                prep_temp_blob(temp, one->data, one->size,
1854                               one->sha1, one->mode);
1855        }
1856}
1857
1858static void remove_tempfile(void)
1859{
1860        int i;
1861
1862        for (i = 0; i < 2; i++)
1863                if (diff_temp[i].name == diff_temp[i].tmp_path) {
1864                        unlink(diff_temp[i].name);
1865                        diff_temp[i].name = NULL;
1866                }
1867}
1868
1869static void remove_tempfile_on_signal(int signo)
1870{
1871        remove_tempfile();
1872        signal(SIGINT, SIG_DFL);
1873        raise(signo);
1874}
1875
1876/* An external diff command takes:
1877 *
1878 * diff-cmd name infile1 infile1-sha1 infile1-mode \
1879 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1880 *
1881 */
1882static void run_external_diff(const char *pgm,
1883                              const char *name,
1884                              const char *other,
1885                              struct diff_filespec *one,
1886                              struct diff_filespec *two,
1887                              const char *xfrm_msg,
1888                              int complete_rewrite)
1889{
1890        const char *spawn_arg[10];
1891        struct diff_tempfile *temp = diff_temp;
1892        int retval;
1893        static int atexit_asked = 0;
1894        const char *othername;
1895        const char **arg = &spawn_arg[0];
1896
1897        othername = (other? other : name);
1898        if (one && two) {
1899                prepare_temp_file(name, &temp[0], one);
1900                prepare_temp_file(othername, &temp[1], two);
1901                if (! atexit_asked &&
1902                    (temp[0].name == temp[0].tmp_path ||
1903                     temp[1].name == temp[1].tmp_path)) {
1904                        atexit_asked = 1;
1905                        atexit(remove_tempfile);
1906                }
1907                signal(SIGINT, remove_tempfile_on_signal);
1908        }
1909
1910        if (one && two) {
1911                *arg++ = pgm;
1912                *arg++ = name;
1913                *arg++ = temp[0].name;
1914                *arg++ = temp[0].hex;
1915                *arg++ = temp[0].mode;
1916                *arg++ = temp[1].name;
1917                *arg++ = temp[1].hex;
1918                *arg++ = temp[1].mode;
1919                if (other) {
1920                        *arg++ = other;
1921                        *arg++ = xfrm_msg;
1922                }
1923        } else {
1924                *arg++ = pgm;
1925                *arg++ = name;
1926        }
1927        *arg = NULL;
1928        fflush(NULL);
1929        retval = run_command_v_opt(spawn_arg, 0);
1930        remove_tempfile();
1931        if (retval) {
1932                fprintf(stderr, "external diff died, stopping at %s.\n", name);
1933                exit(1);
1934        }
1935}
1936
1937static const char *external_diff_attr(const char *name)
1938{
1939        struct git_attr_check attr_diff_check;
1940
1941        if (!name)
1942                return NULL;
1943
1944        setup_diff_attr_check(&attr_diff_check);
1945        if (!git_checkattr(name, 1, &attr_diff_check)) {
1946                const char *value = attr_diff_check.value;
1947                if (!ATTR_TRUE(value) &&
1948                    !ATTR_FALSE(value) &&
1949                    !ATTR_UNSET(value)) {
1950                        struct ll_diff_driver *drv;
1951
1952                        for (drv = user_diff; drv; drv = drv->next)
1953                                if (!strcmp(drv->name, value))
1954                                        return drv->cmd;
1955                }
1956        }
1957        return NULL;
1958}
1959
1960static void run_diff_cmd(const char *pgm,
1961                         const char *name,
1962                         const char *other,
1963                         const char *attr_path,
1964                         struct diff_filespec *one,
1965                         struct diff_filespec *two,
1966                         const char *xfrm_msg,
1967                         struct diff_options *o,
1968                         int complete_rewrite)
1969{
1970        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
1971                pgm = NULL;
1972        else {
1973                const char *cmd = external_diff_attr(attr_path);
1974                if (cmd)
1975                        pgm = cmd;
1976        }
1977
1978        if (pgm) {
1979                run_external_diff(pgm, name, other, one, two, xfrm_msg,
1980                                  complete_rewrite);
1981                return;
1982        }
1983        if (one && two)
1984                builtin_diff(name, other ? other : name,
1985                             one, two, xfrm_msg, o, complete_rewrite);
1986        else
1987                fprintf(o->file, "* Unmerged path %s\n", name);
1988}
1989
1990static void diff_fill_sha1_info(struct diff_filespec *one)
1991{
1992        if (DIFF_FILE_VALID(one)) {
1993                if (!one->sha1_valid) {
1994                        struct stat st;
1995                        if (!strcmp(one->path, "-")) {
1996                                hashcpy(one->sha1, null_sha1);
1997                                return;
1998                        }
1999                        if (lstat(one->path, &st) < 0)
2000                                die("stat %s", one->path);
2001                        if (index_path(one->sha1, one->path, &st, 0))
2002                                die("cannot hash %s\n", one->path);
2003                }
2004        }
2005        else
2006                hashclr(one->sha1);
2007}
2008
2009static int similarity_index(struct diff_filepair *p)
2010{
2011        return p->score * 100 / MAX_SCORE;
2012}
2013
2014static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2015{
2016        /* Strip the prefix but do not molest /dev/null and absolute paths */
2017        if (*namep && **namep != '/')
2018                *namep += prefix_length;
2019        if (*otherp && **otherp != '/')
2020                *otherp += prefix_length;
2021}
2022
2023static void run_diff(struct diff_filepair *p, struct diff_options *o)
2024{
2025        const char *pgm = external_diff();
2026        struct strbuf msg;
2027        char *xfrm_msg;
2028        struct diff_filespec *one = p->one;
2029        struct diff_filespec *two = p->two;
2030        const char *name;
2031        const char *other;
2032        const char *attr_path;
2033        int complete_rewrite = 0;
2034
2035        name  = p->one->path;
2036        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2037        attr_path = name;
2038        if (o->prefix_length)
2039                strip_prefix(o->prefix_length, &name, &other);
2040
2041        if (DIFF_PAIR_UNMERGED(p)) {
2042                run_diff_cmd(pgm, name, NULL, attr_path,
2043                             NULL, NULL, NULL, o, 0);
2044                return;
2045        }
2046
2047        diff_fill_sha1_info(one);
2048        diff_fill_sha1_info(two);
2049
2050        strbuf_init(&msg, PATH_MAX * 2 + 300);
2051        switch (p->status) {
2052        case DIFF_STATUS_COPIED:
2053                strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2054                strbuf_addstr(&msg, "\ncopy from ");
2055                quote_c_style(name, &msg, NULL, 0);
2056                strbuf_addstr(&msg, "\ncopy to ");
2057                quote_c_style(other, &msg, NULL, 0);
2058                strbuf_addch(&msg, '\n');
2059                break;
2060        case DIFF_STATUS_RENAMED:
2061                strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2062                strbuf_addstr(&msg, "\nrename from ");
2063                quote_c_style(name, &msg, NULL, 0);
2064                strbuf_addstr(&msg, "\nrename to ");
2065                quote_c_style(other, &msg, NULL, 0);
2066                strbuf_addch(&msg, '\n');
2067                break;
2068        case DIFF_STATUS_MODIFIED:
2069                if (p->score) {
2070                        strbuf_addf(&msg, "dissimilarity index %d%%\n",
2071                                        similarity_index(p));
2072                        complete_rewrite = 1;
2073                        break;
2074                }
2075                /* fallthru */
2076        default:
2077                /* nothing */
2078                ;
2079        }
2080
2081        if (hashcmp(one->sha1, two->sha1)) {
2082                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2083
2084                if (DIFF_OPT_TST(o, BINARY)) {
2085                        mmfile_t mf;
2086                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2087                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2088                                abbrev = 40;
2089                }
2090                strbuf_addf(&msg, "index %.*s..%.*s",
2091                                abbrev, sha1_to_hex(one->sha1),
2092                                abbrev, sha1_to_hex(two->sha1));
2093                if (one->mode == two->mode)
2094                        strbuf_addf(&msg, " %06o", one->mode);
2095                strbuf_addch(&msg, '\n');
2096        }
2097
2098        if (msg.len)
2099                strbuf_setlen(&msg, msg.len - 1);
2100        xfrm_msg = msg.len ? msg.buf : NULL;
2101
2102        if (!pgm &&
2103            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2104            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2105                /* a filepair that changes between file and symlink
2106                 * needs to be split into deletion and creation.
2107                 */
2108                struct diff_filespec *null = alloc_filespec(two->path);
2109                run_diff_cmd(NULL, name, other, attr_path,
2110                             one, null, xfrm_msg, o, 0);
2111                free(null);
2112                null = alloc_filespec(one->path);
2113                run_diff_cmd(NULL, name, other, attr_path,
2114                             null, two, xfrm_msg, o, 0);
2115                free(null);
2116        }
2117        else
2118                run_diff_cmd(pgm, name, other, attr_path,
2119                             one, two, xfrm_msg, o, complete_rewrite);
2120
2121        strbuf_release(&msg);
2122}
2123
2124static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2125                         struct diffstat_t *diffstat)
2126{
2127        const char *name;
2128        const char *other;
2129        int complete_rewrite = 0;
2130
2131        if (DIFF_PAIR_UNMERGED(p)) {
2132                /* unmerged */
2133                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2134                return;
2135        }
2136
2137        name = p->one->path;
2138        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2139
2140        if (o->prefix_length)
2141                strip_prefix(o->prefix_length, &name, &other);
2142
2143        diff_fill_sha1_info(p->one);
2144        diff_fill_sha1_info(p->two);
2145
2146        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2147                complete_rewrite = 1;
2148        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2149}
2150
2151static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2152{
2153        const char *name;
2154        const char *other;
2155        const char *attr_path;
2156
2157        if (DIFF_PAIR_UNMERGED(p)) {
2158                /* unmerged */
2159                return;
2160        }
2161
2162        name = p->one->path;
2163        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2164        attr_path = other ? other : name;
2165
2166        if (o->prefix_length)
2167                strip_prefix(o->prefix_length, &name, &other);
2168
2169        diff_fill_sha1_info(p->one);
2170        diff_fill_sha1_info(p->two);
2171
2172        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2173}
2174
2175void diff_setup(struct diff_options *options)
2176{
2177        memset(options, 0, sizeof(*options));
2178
2179        options->file = stdout;
2180
2181        options->line_termination = '\n';
2182        options->break_opt = -1;
2183        options->rename_limit = -1;
2184        options->dirstat_percent = 3;
2185        options->context = 3;
2186        options->msg_sep = "";
2187
2188        options->change = diff_change;
2189        options->add_remove = diff_addremove;
2190        if (diff_use_color_default > 0)
2191                DIFF_OPT_SET(options, COLOR_DIFF);
2192        else
2193                DIFF_OPT_CLR(options, COLOR_DIFF);
2194        options->detect_rename = diff_detect_rename_default;
2195
2196        options->a_prefix = "a/";
2197        options->b_prefix = "b/";
2198}
2199
2200int diff_setup_done(struct diff_options *options)
2201{
2202        int count = 0;
2203
2204        if (options->output_format & DIFF_FORMAT_NAME)
2205                count++;
2206        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2207                count++;
2208        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2209                count++;
2210        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2211                count++;
2212        if (count > 1)
2213                die("--name-only, --name-status, --check and -s are mutually exclusive");
2214
2215        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2216                options->detect_rename = DIFF_DETECT_COPY;
2217
2218        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2219                options->prefix = NULL;
2220        if (options->prefix)
2221                options->prefix_length = strlen(options->prefix);
2222        else
2223                options->prefix_length = 0;
2224
2225        if (options->output_format & (DIFF_FORMAT_NAME |
2226                                      DIFF_FORMAT_NAME_STATUS |
2227                                      DIFF_FORMAT_CHECKDIFF |
2228                                      DIFF_FORMAT_NO_OUTPUT))
2229                options->output_format &= ~(DIFF_FORMAT_RAW |
2230                                            DIFF_FORMAT_NUMSTAT |
2231                                            DIFF_FORMAT_DIFFSTAT |
2232                                            DIFF_FORMAT_SHORTSTAT |
2233                                            DIFF_FORMAT_DIRSTAT |
2234                                            DIFF_FORMAT_SUMMARY |
2235                                            DIFF_FORMAT_PATCH);
2236
2237        /*
2238         * These cases always need recursive; we do not drop caller-supplied
2239         * recursive bits for other formats here.
2240         */
2241        if (options->output_format & (DIFF_FORMAT_PATCH |
2242                                      DIFF_FORMAT_NUMSTAT |
2243                                      DIFF_FORMAT_DIFFSTAT |
2244                                      DIFF_FORMAT_SHORTSTAT |
2245                                      DIFF_FORMAT_DIRSTAT |
2246                                      DIFF_FORMAT_SUMMARY |
2247                                      DIFF_FORMAT_CHECKDIFF))
2248                DIFF_OPT_SET(options, RECURSIVE);
2249        /*
2250         * Also pickaxe would not work very well if you do not say recursive
2251         */
2252        if (options->pickaxe)
2253                DIFF_OPT_SET(options, RECURSIVE);
2254
2255        if (options->detect_rename && options->rename_limit < 0)
2256                options->rename_limit = diff_rename_limit_default;
2257        if (options->setup & DIFF_SETUP_USE_CACHE) {
2258                if (!active_cache)
2259                        /* read-cache does not die even when it fails
2260                         * so it is safe for us to do this here.  Also
2261                         * it does not smudge active_cache or active_nr
2262                         * when it fails, so we do not have to worry about
2263                         * cleaning it up ourselves either.
2264                         */
2265                        read_cache();
2266        }
2267        if (options->abbrev <= 0 || 40 < options->abbrev)
2268                options->abbrev = 40; /* full */
2269
2270        /*
2271         * It does not make sense to show the first hit we happened
2272         * to have found.  It does not make sense not to return with
2273         * exit code in such a case either.
2274         */
2275        if (DIFF_OPT_TST(options, QUIET)) {
2276                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2277                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2278        }
2279
2280        /*
2281         * If we postprocess in diffcore, we cannot simply return
2282         * upon the first hit.  We need to run diff as usual.
2283         */
2284        if (options->pickaxe || options->filter)
2285                DIFF_OPT_CLR(options, QUIET);
2286
2287        return 0;
2288}
2289
2290static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2291{
2292        char c, *eq;
2293        int len;
2294
2295        if (*arg != '-')
2296                return 0;
2297        c = *++arg;
2298        if (!c)
2299                return 0;
2300        if (c == arg_short) {
2301                c = *++arg;
2302                if (!c)
2303                        return 1;
2304                if (val && isdigit(c)) {
2305                        char *end;
2306                        int n = strtoul(arg, &end, 10);
2307                        if (*end)
2308                                return 0;
2309                        *val = n;
2310                        return 1;
2311                }
2312                return 0;
2313        }
2314        if (c != '-')
2315                return 0;
2316        arg++;
2317        eq = strchr(arg, '=');
2318        if (eq)
2319                len = eq - arg;
2320        else
2321                len = strlen(arg);
2322        if (!len || strncmp(arg, arg_long, len))
2323                return 0;
2324        if (eq) {
2325                int n;
2326                char *end;
2327                if (!isdigit(*++eq))
2328                        return 0;
2329                n = strtoul(eq, &end, 10);
2330                if (*end)
2331                        return 0;
2332                *val = n;
2333        }
2334        return 1;
2335}
2336
2337static int diff_scoreopt_parse(const char *opt);
2338
2339int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2340{
2341        const char *arg = av[0];
2342
2343        /* Output format options */
2344        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2345                options->output_format |= DIFF_FORMAT_PATCH;
2346        else if (opt_arg(arg, 'U', "unified", &options->context))
2347                options->output_format |= DIFF_FORMAT_PATCH;
2348        else if (!strcmp(arg, "--raw"))
2349                options->output_format |= DIFF_FORMAT_RAW;
2350        else if (!strcmp(arg, "--patch-with-raw"))
2351                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2352        else if (!strcmp(arg, "--numstat"))
2353                options->output_format |= DIFF_FORMAT_NUMSTAT;
2354        else if (!strcmp(arg, "--shortstat"))
2355                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2356        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2357                options->output_format |= DIFF_FORMAT_DIRSTAT;
2358        else if (!strcmp(arg, "--cumulative"))
2359                options->output_format |= DIFF_FORMAT_CUMULATIVE;
2360        else if (!strcmp(arg, "--check"))
2361                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2362        else if (!strcmp(arg, "--summary"))
2363                options->output_format |= DIFF_FORMAT_SUMMARY;
2364        else if (!strcmp(arg, "--patch-with-stat"))
2365                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2366        else if (!strcmp(arg, "--name-only"))
2367                options->output_format |= DIFF_FORMAT_NAME;
2368        else if (!strcmp(arg, "--name-status"))
2369                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2370        else if (!strcmp(arg, "-s"))
2371                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2372        else if (!prefixcmp(arg, "--stat")) {
2373                char *end;
2374                int width = options->stat_width;
2375                int name_width = options->stat_name_width;
2376                arg += 6;
2377                end = (char *)arg;
2378
2379                switch (*arg) {
2380                case '-':
2381                        if (!prefixcmp(arg, "-width="))
2382                                width = strtoul(arg + 7, &end, 10);
2383                        else if (!prefixcmp(arg, "-name-width="))
2384                                name_width = strtoul(arg + 12, &end, 10);
2385                        break;
2386                case '=':
2387                        width = strtoul(arg+1, &end, 10);
2388                        if (*end == ',')
2389                                name_width = strtoul(end+1, &end, 10);
2390                }
2391
2392                /* Important! This checks all the error cases! */
2393                if (*end)
2394                        return 0;
2395                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2396                options->stat_name_width = name_width;
2397                options->stat_width = width;
2398        }
2399
2400        /* renames options */
2401        else if (!prefixcmp(arg, "-B")) {
2402                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2403                        return -1;
2404        }
2405        else if (!prefixcmp(arg, "-M")) {
2406                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2407                        return -1;
2408                options->detect_rename = DIFF_DETECT_RENAME;
2409        }
2410        else if (!prefixcmp(arg, "-C")) {
2411                if (options->detect_rename == DIFF_DETECT_COPY)
2412                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2413                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2414                        return -1;
2415                options->detect_rename = DIFF_DETECT_COPY;
2416        }
2417        else if (!strcmp(arg, "--no-renames"))
2418                options->detect_rename = 0;
2419        else if (!strcmp(arg, "--relative"))
2420                DIFF_OPT_SET(options, RELATIVE_NAME);
2421        else if (!prefixcmp(arg, "--relative=")) {
2422                DIFF_OPT_SET(options, RELATIVE_NAME);
2423                options->prefix = arg + 11;
2424        }
2425
2426        /* xdiff options */
2427        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2428                options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2429        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2430                options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2431        else if (!strcmp(arg, "--ignore-space-at-eol"))
2432                options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2433
2434        /* flags options */
2435        else if (!strcmp(arg, "--binary")) {
2436                options->output_format |= DIFF_FORMAT_PATCH;
2437                DIFF_OPT_SET(options, BINARY);
2438        }
2439        else if (!strcmp(arg, "--full-index"))
2440                DIFF_OPT_SET(options, FULL_INDEX);
2441        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2442                DIFF_OPT_SET(options, TEXT);
2443        else if (!strcmp(arg, "-R"))
2444                DIFF_OPT_SET(options, REVERSE_DIFF);
2445        else if (!strcmp(arg, "--find-copies-harder"))
2446                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2447        else if (!strcmp(arg, "--follow"))
2448                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2449        else if (!strcmp(arg, "--color"))
2450                DIFF_OPT_SET(options, COLOR_DIFF);
2451        else if (!strcmp(arg, "--no-color"))
2452                DIFF_OPT_CLR(options, COLOR_DIFF);
2453        else if (!strcmp(arg, "--color-words"))
2454                options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2455        else if (!strcmp(arg, "--exit-code"))
2456                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2457        else if (!strcmp(arg, "--quiet"))
2458                DIFF_OPT_SET(options, QUIET);
2459        else if (!strcmp(arg, "--ext-diff"))
2460                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2461        else if (!strcmp(arg, "--no-ext-diff"))
2462                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2463
2464        /* misc options */
2465        else if (!strcmp(arg, "-z"))
2466                options->line_termination = 0;
2467        else if (!prefixcmp(arg, "-l"))
2468                options->rename_limit = strtoul(arg+2, NULL, 10);
2469        else if (!prefixcmp(arg, "-S"))
2470                options->pickaxe = arg + 2;
2471        else if (!strcmp(arg, "--pickaxe-all"))
2472                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2473        else if (!strcmp(arg, "--pickaxe-regex"))
2474                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2475        else if (!prefixcmp(arg, "-O"))
2476                options->orderfile = arg + 2;
2477        else if (!prefixcmp(arg, "--diff-filter="))
2478                options->filter = arg + 14;
2479        else if (!strcmp(arg, "--abbrev"))
2480                options->abbrev = DEFAULT_ABBREV;
2481        else if (!prefixcmp(arg, "--abbrev=")) {
2482                options->abbrev = strtoul(arg + 9, NULL, 10);
2483                if (options->abbrev < MINIMUM_ABBREV)
2484                        options->abbrev = MINIMUM_ABBREV;
2485                else if (40 < options->abbrev)
2486                        options->abbrev = 40;
2487        }
2488        else if (!prefixcmp(arg, "--src-prefix="))
2489                options->a_prefix = arg + 13;
2490        else if (!prefixcmp(arg, "--dst-prefix="))
2491                options->b_prefix = arg + 13;
2492        else if (!strcmp(arg, "--no-prefix"))
2493                options->a_prefix = options->b_prefix = "";
2494        else if (!prefixcmp(arg, "--output=")) {
2495                options->file = fopen(arg + strlen("--output="), "w");
2496                options->close_file = 1;
2497        } else
2498                return 0;
2499        return 1;
2500}
2501
2502static int parse_num(const char **cp_p)
2503{
2504        unsigned long num, scale;
2505        int ch, dot;
2506        const char *cp = *cp_p;
2507
2508        num = 0;
2509        scale = 1;
2510        dot = 0;
2511        for(;;) {
2512                ch = *cp;
2513                if ( !dot && ch == '.' ) {
2514                        scale = 1;
2515                        dot = 1;
2516                } else if ( ch == '%' ) {
2517                        scale = dot ? scale*100 : 100;
2518                        cp++;   /* % is always at the end */
2519                        break;
2520                } else if ( ch >= '0' && ch <= '9' ) {
2521                        if ( scale < 100000 ) {
2522                                scale *= 10;
2523                                num = (num*10) + (ch-'0');
2524                        }
2525                } else {
2526                        break;
2527                }
2528                cp++;
2529        }
2530        *cp_p = cp;
2531
2532        /* user says num divided by scale and we say internally that
2533         * is MAX_SCORE * num / scale.
2534         */
2535        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2536}
2537
2538static int diff_scoreopt_parse(const char *opt)
2539{
2540        int opt1, opt2, cmd;
2541
2542        if (*opt++ != '-')
2543                return -1;
2544        cmd = *opt++;
2545        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2546                return -1; /* that is not a -M, -C nor -B option */
2547
2548        opt1 = parse_num(&opt);
2549        if (cmd != 'B')
2550                opt2 = 0;
2551        else {
2552                if (*opt == 0)
2553                        opt2 = 0;
2554                else if (*opt != '/')
2555                        return -1; /* we expect -B80/99 or -B80 */
2556                else {
2557                        opt++;
2558                        opt2 = parse_num(&opt);
2559                }
2560        }
2561        if (*opt != 0)
2562                return -1;
2563        return opt1 | (opt2 << 16);
2564}
2565
2566struct diff_queue_struct diff_queued_diff;
2567
2568void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2569{
2570        if (queue->alloc <= queue->nr) {
2571                queue->alloc = alloc_nr(queue->alloc);
2572                queue->queue = xrealloc(queue->queue,
2573                                        sizeof(dp) * queue->alloc);
2574        }
2575        queue->queue[queue->nr++] = dp;
2576}
2577
2578struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2579                                 struct diff_filespec *one,
2580                                 struct diff_filespec *two)
2581{
2582        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2583        dp->one = one;
2584        dp->two = two;
2585        if (queue)
2586                diff_q(queue, dp);
2587        return dp;
2588}
2589
2590void diff_free_filepair(struct diff_filepair *p)
2591{
2592        free_filespec(p->one);
2593        free_filespec(p->two);
2594        free(p);
2595}
2596
2597/* This is different from find_unique_abbrev() in that
2598 * it stuffs the result with dots for alignment.
2599 */
2600const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2601{
2602        int abblen;
2603        const char *abbrev;
2604        if (len == 40)
2605                return sha1_to_hex(sha1);
2606
2607        abbrev = find_unique_abbrev(sha1, len);
2608        abblen = strlen(abbrev);
2609        if (abblen < 37) {
2610                static char hex[41];
2611                if (len < abblen && abblen <= len + 2)
2612                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2613                else
2614                        sprintf(hex, "%s...", abbrev);
2615                return hex;
2616        }
2617        return sha1_to_hex(sha1);
2618}
2619
2620static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2621{
2622        int line_termination = opt->line_termination;
2623        int inter_name_termination = line_termination ? '\t' : '\0';
2624
2625        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2626                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2627                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2628                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2629        }
2630        if (p->score) {
2631                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2632                        inter_name_termination);
2633        } else {
2634                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2635        }
2636
2637        if (p->status == DIFF_STATUS_COPIED ||
2638            p->status == DIFF_STATUS_RENAMED) {
2639                const char *name_a, *name_b;
2640                name_a = p->one->path;
2641                name_b = p->two->path;
2642                strip_prefix(opt->prefix_length, &name_a, &name_b);
2643                write_name_quoted(name_a, opt->file, inter_name_termination);
2644                write_name_quoted(name_b, opt->file, line_termination);
2645        } else {
2646                const char *name_a, *name_b;
2647                name_a = p->one->mode ? p->one->path : p->two->path;
2648                name_b = NULL;
2649                strip_prefix(opt->prefix_length, &name_a, &name_b);
2650                write_name_quoted(name_a, opt->file, line_termination);
2651        }
2652}
2653
2654int diff_unmodified_pair(struct diff_filepair *p)
2655{
2656        /* This function is written stricter than necessary to support
2657         * the currently implemented transformers, but the idea is to
2658         * let transformers to produce diff_filepairs any way they want,
2659         * and filter and clean them up here before producing the output.
2660         */
2661        struct diff_filespec *one = p->one, *two = p->two;
2662
2663        if (DIFF_PAIR_UNMERGED(p))
2664                return 0; /* unmerged is interesting */
2665
2666        /* deletion, addition, mode or type change
2667         * and rename are all interesting.
2668         */
2669        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2670            DIFF_PAIR_MODE_CHANGED(p) ||
2671            strcmp(one->path, two->path))
2672                return 0;
2673
2674        /* both are valid and point at the same path.  that is, we are
2675         * dealing with a change.
2676         */
2677        if (one->sha1_valid && two->sha1_valid &&
2678            !hashcmp(one->sha1, two->sha1))
2679                return 1; /* no change */
2680        if (!one->sha1_valid && !two->sha1_valid)
2681                return 1; /* both look at the same file on the filesystem. */
2682        return 0;
2683}
2684
2685static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2686{
2687        if (diff_unmodified_pair(p))
2688                return;
2689
2690        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2691            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2692                return; /* no tree diffs in patch format */
2693
2694        run_diff(p, o);
2695}
2696
2697static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2698                            struct diffstat_t *diffstat)
2699{
2700        if (diff_unmodified_pair(p))
2701                return;
2702
2703        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2704            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2705                return; /* no tree diffs in patch format */
2706
2707        run_diffstat(p, o, diffstat);
2708}
2709
2710static void diff_flush_checkdiff(struct diff_filepair *p,
2711                struct diff_options *o)
2712{
2713        if (diff_unmodified_pair(p))
2714                return;
2715
2716        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2717            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2718                return; /* no tree diffs in patch format */
2719
2720        run_checkdiff(p, o);
2721}
2722
2723int diff_queue_is_empty(void)
2724{
2725        struct diff_queue_struct *q = &diff_queued_diff;
2726        int i;
2727        for (i = 0; i < q->nr; i++)
2728                if (!diff_unmodified_pair(q->queue[i]))
2729                        return 0;
2730        return 1;
2731}
2732
2733#if DIFF_DEBUG
2734void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2735{
2736        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2737                x, one ? one : "",
2738                s->path,
2739                DIFF_FILE_VALID(s) ? "valid" : "invalid",
2740                s->mode,
2741                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2742        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2743                x, one ? one : "",
2744                s->size, s->xfrm_flags);
2745}
2746
2747void diff_debug_filepair(const struct diff_filepair *p, int i)
2748{
2749        diff_debug_filespec(p->one, i, "one");
2750        diff_debug_filespec(p->two, i, "two");
2751        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2752                p->score, p->status ? p->status : '?',
2753                p->one->rename_used, p->broken_pair);
2754}
2755
2756void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2757{
2758        int i;
2759        if (msg)
2760                fprintf(stderr, "%s\n", msg);
2761        fprintf(stderr, "q->nr = %d\n", q->nr);
2762        for (i = 0; i < q->nr; i++) {
2763                struct diff_filepair *p = q->queue[i];
2764                diff_debug_filepair(p, i);
2765        }
2766}
2767#endif
2768
2769static void diff_resolve_rename_copy(void)
2770{
2771        int i;
2772        struct diff_filepair *p;
2773        struct diff_queue_struct *q = &diff_queued_diff;
2774
2775        diff_debug_queue("resolve-rename-copy", q);
2776
2777        for (i = 0; i < q->nr; i++) {
2778                p = q->queue[i];
2779                p->status = 0; /* undecided */
2780                if (DIFF_PAIR_UNMERGED(p))
2781                        p->status = DIFF_STATUS_UNMERGED;
2782                else if (!DIFF_FILE_VALID(p->one))
2783                        p->status = DIFF_STATUS_ADDED;
2784                else if (!DIFF_FILE_VALID(p->two))
2785                        p->status = DIFF_STATUS_DELETED;
2786                else if (DIFF_PAIR_TYPE_CHANGED(p))
2787                        p->status = DIFF_STATUS_TYPE_CHANGED;
2788
2789                /* from this point on, we are dealing with a pair
2790                 * whose both sides are valid and of the same type, i.e.
2791                 * either in-place edit or rename/copy edit.
2792                 */
2793                else if (DIFF_PAIR_RENAME(p)) {
2794                        /*
2795                         * A rename might have re-connected a broken
2796                         * pair up, causing the pathnames to be the
2797                         * same again. If so, that's not a rename at
2798                         * all, just a modification..
2799                         *
2800                         * Otherwise, see if this source was used for
2801                         * multiple renames, in which case we decrement
2802                         * the count, and call it a copy.
2803                         */
2804                        if (!strcmp(p->one->path, p->two->path))
2805                                p->status = DIFF_STATUS_MODIFIED;
2806                        else if (--p->one->rename_used > 0)
2807                                p->status = DIFF_STATUS_COPIED;
2808                        else
2809                                p->status = DIFF_STATUS_RENAMED;
2810                }
2811                else if (hashcmp(p->one->sha1, p->two->sha1) ||
2812                         p->one->mode != p->two->mode ||
2813                         is_null_sha1(p->one->sha1))
2814                        p->status = DIFF_STATUS_MODIFIED;
2815                else {
2816                        /* This is a "no-change" entry and should not
2817                         * happen anymore, but prepare for broken callers.
2818                         */
2819                        error("feeding unmodified %s to diffcore",
2820                              p->one->path);
2821                        p->status = DIFF_STATUS_UNKNOWN;
2822                }
2823        }
2824        diff_debug_queue("resolve-rename-copy done", q);
2825}
2826
2827static int check_pair_status(struct diff_filepair *p)
2828{
2829        switch (p->status) {
2830        case DIFF_STATUS_UNKNOWN:
2831                return 0;
2832        case 0:
2833                die("internal error in diff-resolve-rename-copy");
2834        default:
2835                return 1;
2836        }
2837}
2838
2839static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2840{
2841        int fmt = opt->output_format;
2842
2843        if (fmt & DIFF_FORMAT_CHECKDIFF)
2844                diff_flush_checkdiff(p, opt);
2845        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2846                diff_flush_raw(p, opt);
2847        else if (fmt & DIFF_FORMAT_NAME) {
2848                const char *name_a, *name_b;
2849                name_a = p->two->path;
2850                name_b = NULL;
2851                strip_prefix(opt->prefix_length, &name_a, &name_b);
2852                write_name_quoted(name_a, opt->file, opt->line_termination);
2853        }
2854}
2855
2856static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2857{
2858        if (fs->mode)
2859                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2860        else
2861                fprintf(file, " %s ", newdelete);
2862        write_name_quoted(fs->path, file, '\n');
2863}
2864
2865
2866static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2867{
2868        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2869                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2870                        show_name ? ' ' : '\n');
2871                if (show_name) {
2872                        write_name_quoted(p->two->path, file, '\n');
2873                }
2874        }
2875}
2876
2877static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
2878{
2879        char *names = pprint_rename(p->one->path, p->two->path);
2880
2881        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2882        free(names);
2883        show_mode_change(file, p, 0);
2884}
2885
2886static void diff_summary(FILE *file, struct diff_filepair *p)
2887{
2888        switch(p->status) {
2889        case DIFF_STATUS_DELETED:
2890                show_file_mode_name(file, "delete", p->one);
2891                break;
2892        case DIFF_STATUS_ADDED:
2893                show_file_mode_name(file, "create", p->two);
2894                break;
2895        case DIFF_STATUS_COPIED:
2896                show_rename_copy(file, "copy", p);
2897                break;
2898        case DIFF_STATUS_RENAMED:
2899                show_rename_copy(file, "rename", p);
2900                break;
2901        default:
2902                if (p->score) {
2903                        fputs(" rewrite ", file);
2904                        write_name_quoted(p->two->path, file, ' ');
2905                        fprintf(file, "(%d%%)\n", similarity_index(p));
2906                }
2907                show_mode_change(file, p, !p->score);
2908                break;
2909        }
2910}
2911
2912struct patch_id_t {
2913        struct xdiff_emit_state xm;
2914        SHA_CTX *ctx;
2915        int patchlen;
2916};
2917
2918static int remove_space(char *line, int len)
2919{
2920        int i;
2921        char *dst = line;
2922        unsigned char c;
2923
2924        for (i = 0; i < len; i++)
2925                if (!isspace((c = line[i])))
2926                        *dst++ = c;
2927
2928        return dst - line;
2929}
2930
2931static void patch_id_consume(void *priv, char *line, unsigned long len)
2932{
2933        struct patch_id_t *data = priv;
2934        int new_len;
2935
2936        /* Ignore line numbers when computing the SHA1 of the patch */
2937        if (!prefixcmp(line, "@@ -"))
2938                return;
2939
2940        new_len = remove_space(line, len);
2941
2942        SHA1_Update(data->ctx, line, new_len);
2943        data->patchlen += new_len;
2944}
2945
2946/* returns 0 upon success, and writes result into sha1 */
2947static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2948{
2949        struct diff_queue_struct *q = &diff_queued_diff;
2950        int i;
2951        SHA_CTX ctx;
2952        struct patch_id_t data;
2953        char buffer[PATH_MAX * 4 + 20];
2954
2955        SHA1_Init(&ctx);
2956        memset(&data, 0, sizeof(struct patch_id_t));
2957        data.ctx = &ctx;
2958        data.xm.consume = patch_id_consume;
2959
2960        for (i = 0; i < q->nr; i++) {
2961                xpparam_t xpp;
2962                xdemitconf_t xecfg;
2963                xdemitcb_t ecb;
2964                mmfile_t mf1, mf2;
2965                struct diff_filepair *p = q->queue[i];
2966                int len1, len2;
2967
2968                memset(&xecfg, 0, sizeof(xecfg));
2969                if (p->status == 0)
2970                        return error("internal diff status error");
2971                if (p->status == DIFF_STATUS_UNKNOWN)
2972                        continue;
2973                if (diff_unmodified_pair(p))
2974                        continue;
2975                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2976                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2977                        continue;
2978                if (DIFF_PAIR_UNMERGED(p))
2979                        continue;
2980
2981                diff_fill_sha1_info(p->one);
2982                diff_fill_sha1_info(p->two);
2983                if (fill_mmfile(&mf1, p->one) < 0 ||
2984                                fill_mmfile(&mf2, p->two) < 0)
2985                        return error("unable to read files to diff");
2986
2987                len1 = remove_space(p->one->path, strlen(p->one->path));
2988                len2 = remove_space(p->two->path, strlen(p->two->path));
2989                if (p->one->mode == 0)
2990                        len1 = snprintf(buffer, sizeof(buffer),
2991                                        "diff--gita/%.*sb/%.*s"
2992                                        "newfilemode%06o"
2993                                        "---/dev/null"
2994                                        "+++b/%.*s",
2995                                        len1, p->one->path,
2996                                        len2, p->two->path,
2997                                        p->two->mode,
2998                                        len2, p->two->path);
2999                else if (p->two->mode == 0)
3000                        len1 = snprintf(buffer, sizeof(buffer),
3001                                        "diff--gita/%.*sb/%.*s"
3002                                        "deletedfilemode%06o"
3003                                        "---a/%.*s"
3004                                        "+++/dev/null",
3005                                        len1, p->one->path,
3006                                        len2, p->two->path,
3007                                        p->one->mode,
3008                                        len1, p->one->path);
3009                else
3010                        len1 = snprintf(buffer, sizeof(buffer),
3011                                        "diff--gita/%.*sb/%.*s"
3012                                        "---a/%.*s"
3013                                        "+++b/%.*s",
3014                                        len1, p->one->path,
3015                                        len2, p->two->path,
3016                                        len1, p->one->path,
3017                                        len2, p->two->path);
3018                SHA1_Update(&ctx, buffer, len1);
3019
3020                xpp.flags = XDF_NEED_MINIMAL;
3021                xecfg.ctxlen = 3;
3022                xecfg.flags = XDL_EMIT_FUNCNAMES;
3023                ecb.outf = xdiff_outf;
3024                ecb.priv = &data;
3025                xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
3026        }
3027
3028        SHA1_Final(sha1, &ctx);
3029        return 0;
3030}
3031
3032int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3033{
3034        struct diff_queue_struct *q = &diff_queued_diff;
3035        int i;
3036        int result = diff_get_patch_id(options, sha1);
3037
3038        for (i = 0; i < q->nr; i++)
3039                diff_free_filepair(q->queue[i]);
3040
3041        free(q->queue);
3042        q->queue = NULL;
3043        q->nr = q->alloc = 0;
3044
3045        return result;
3046}
3047
3048static int is_summary_empty(const struct diff_queue_struct *q)
3049{
3050        int i;
3051
3052        for (i = 0; i < q->nr; i++) {
3053                const struct diff_filepair *p = q->queue[i];
3054
3055                switch (p->status) {
3056                case DIFF_STATUS_DELETED:
3057                case DIFF_STATUS_ADDED:
3058                case DIFF_STATUS_COPIED:
3059                case DIFF_STATUS_RENAMED:
3060                        return 0;
3061                default:
3062                        if (p->score)
3063                                return 0;
3064                        if (p->one->mode && p->two->mode &&
3065                            p->one->mode != p->two->mode)
3066                                return 0;
3067                        break;
3068                }
3069        }
3070        return 1;
3071}
3072
3073void diff_flush(struct diff_options *options)
3074{
3075        struct diff_queue_struct *q = &diff_queued_diff;
3076        int i, output_format = options->output_format;
3077        int separator = 0;
3078
3079        /*
3080         * Order: raw, stat, summary, patch
3081         * or:    name/name-status/checkdiff (other bits clear)
3082         */
3083        if (!q->nr)
3084                goto free_queue;
3085
3086        if (output_format & (DIFF_FORMAT_RAW |
3087                             DIFF_FORMAT_NAME |
3088                             DIFF_FORMAT_NAME_STATUS |
3089                             DIFF_FORMAT_CHECKDIFF)) {
3090                for (i = 0; i < q->nr; i++) {
3091                        struct diff_filepair *p = q->queue[i];
3092                        if (check_pair_status(p))
3093                                flush_one_pair(p, options);
3094                }
3095                separator++;
3096        }
3097
3098        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIRSTAT)) {
3099                struct diffstat_t diffstat;
3100
3101                memset(&diffstat, 0, sizeof(struct diffstat_t));
3102                diffstat.xm.consume = diffstat_consume;
3103                for (i = 0; i < q->nr; i++) {
3104                        struct diff_filepair *p = q->queue[i];
3105                        if (check_pair_status(p))
3106                                diff_flush_stat(p, options, &diffstat);
3107                }
3108                if (output_format & DIFF_FORMAT_DIRSTAT)
3109                        show_dirstat(&diffstat, options);
3110                if (output_format & DIFF_FORMAT_NUMSTAT)
3111                        show_numstat(&diffstat, options);
3112                if (output_format & DIFF_FORMAT_DIFFSTAT)
3113                        show_stats(&diffstat, options);
3114                if (output_format & DIFF_FORMAT_SHORTSTAT)
3115                        show_shortstats(&diffstat, options);
3116                free_diffstat_info(&diffstat);
3117                separator++;
3118        }
3119
3120        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3121                for (i = 0; i < q->nr; i++)
3122                        diff_summary(options->file, q->queue[i]);
3123                separator++;
3124        }
3125
3126        if (output_format & DIFF_FORMAT_PATCH) {
3127                if (separator) {
3128                        if (options->stat_sep) {
3129                                /* attach patch instead of inline */
3130                                fputs(options->stat_sep, options->file);
3131                        } else {
3132                                putc(options->line_termination, options->file);
3133                        }
3134                }
3135
3136                for (i = 0; i < q->nr; i++) {
3137                        struct diff_filepair *p = q->queue[i];
3138                        if (check_pair_status(p))
3139                                diff_flush_patch(p, options);
3140                }
3141        }
3142
3143        if (output_format & DIFF_FORMAT_CALLBACK)
3144                options->format_callback(q, options, options->format_callback_data);
3145
3146        for (i = 0; i < q->nr; i++)
3147                diff_free_filepair(q->queue[i]);
3148free_queue:
3149        free(q->queue);
3150        q->queue = NULL;
3151        q->nr = q->alloc = 0;
3152        if (options->close_file)
3153                fclose(options->file);
3154}
3155
3156static void diffcore_apply_filter(const char *filter)
3157{
3158        int i;
3159        struct diff_queue_struct *q = &diff_queued_diff;
3160        struct diff_queue_struct outq;
3161        outq.queue = NULL;
3162        outq.nr = outq.alloc = 0;
3163
3164        if (!filter)
3165                return;
3166
3167        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3168                int found;
3169                for (i = found = 0; !found && i < q->nr; i++) {
3170                        struct diff_filepair *p = q->queue[i];
3171                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3172                             ((p->score &&
3173                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3174                              (!p->score &&
3175                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3176                            ((p->status != DIFF_STATUS_MODIFIED) &&
3177                             strchr(filter, p->status)))
3178                                found++;
3179                }
3180                if (found)
3181                        return;
3182
3183                /* otherwise we will clear the whole queue
3184                 * by copying the empty outq at the end of this
3185                 * function, but first clear the current entries
3186                 * in the queue.
3187                 */
3188                for (i = 0; i < q->nr; i++)
3189                        diff_free_filepair(q->queue[i]);
3190        }
3191        else {
3192                /* Only the matching ones */
3193                for (i = 0; i < q->nr; i++) {
3194                        struct diff_filepair *p = q->queue[i];
3195
3196                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3197                             ((p->score &&
3198                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3199                              (!p->score &&
3200                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3201                            ((p->status != DIFF_STATUS_MODIFIED) &&
3202                             strchr(filter, p->status)))
3203                                diff_q(&outq, p);
3204                        else
3205                                diff_free_filepair(p);
3206                }
3207        }
3208        free(q->queue);
3209        *q = outq;
3210}
3211
3212/* Check whether two filespecs with the same mode and size are identical */
3213static int diff_filespec_is_identical(struct diff_filespec *one,
3214                                      struct diff_filespec *two)
3215{
3216        if (S_ISGITLINK(one->mode))
3217                return 0;
3218        if (diff_populate_filespec(one, 0))
3219                return 0;
3220        if (diff_populate_filespec(two, 0))
3221                return 0;
3222        return !memcmp(one->data, two->data, one->size);
3223}
3224
3225static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3226{
3227        int i;
3228        struct diff_queue_struct *q = &diff_queued_diff;
3229        struct diff_queue_struct outq;
3230        outq.queue = NULL;
3231        outq.nr = outq.alloc = 0;
3232
3233        for (i = 0; i < q->nr; i++) {
3234                struct diff_filepair *p = q->queue[i];
3235
3236                /*
3237                 * 1. Entries that come from stat info dirtyness
3238                 *    always have both sides (iow, not create/delete),
3239                 *    one side of the object name is unknown, with
3240                 *    the same mode and size.  Keep the ones that
3241                 *    do not match these criteria.  They have real
3242                 *    differences.
3243                 *
3244                 * 2. At this point, the file is known to be modified,
3245                 *    with the same mode and size, and the object
3246                 *    name of one side is unknown.  Need to inspect
3247                 *    the identical contents.
3248                 */
3249                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3250                    !DIFF_FILE_VALID(p->two) ||
3251                    (p->one->sha1_valid && p->two->sha1_valid) ||
3252                    (p->one->mode != p->two->mode) ||
3253                    diff_populate_filespec(p->one, 1) ||
3254                    diff_populate_filespec(p->two, 1) ||
3255                    (p->one->size != p->two->size) ||
3256                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3257                        diff_q(&outq, p);
3258                else {
3259                        /*
3260                         * The caller can subtract 1 from skip_stat_unmatch
3261                         * to determine how many paths were dirty only
3262                         * due to stat info mismatch.
3263                         */
3264                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3265                                diffopt->skip_stat_unmatch++;
3266                        diff_free_filepair(p);
3267                }
3268        }
3269        free(q->queue);
3270        *q = outq;
3271}
3272
3273void diffcore_std(struct diff_options *options)
3274{
3275        if (DIFF_OPT_TST(options, QUIET))
3276                return;
3277
3278        if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3279                diffcore_skip_stat_unmatch(options);
3280        if (options->break_opt != -1)
3281                diffcore_break(options->break_opt);
3282        if (options->detect_rename)
3283                diffcore_rename(options);
3284        if (options->break_opt != -1)
3285                diffcore_merge_broken();
3286        if (options->pickaxe)
3287                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3288        if (options->orderfile)
3289                diffcore_order(options->orderfile);
3290        diff_resolve_rename_copy();
3291        diffcore_apply_filter(options->filter);
3292
3293        if (diff_queued_diff.nr)
3294                DIFF_OPT_SET(options, HAS_CHANGES);
3295        else
3296                DIFF_OPT_CLR(options, HAS_CHANGES);
3297}
3298
3299int diff_result_code(struct diff_options *opt, int status)
3300{
3301        int result = 0;
3302        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3303            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3304                return status;
3305        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3306            DIFF_OPT_TST(opt, HAS_CHANGES))
3307                result |= 01;
3308        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3309            DIFF_OPT_TST(opt, CHECK_FAILED))
3310                result |= 02;
3311        return result;
3312}
3313
3314void diff_addremove(struct diff_options *options,
3315                    int addremove, unsigned mode,
3316                    const unsigned char *sha1,
3317                    const char *base, const char *path)
3318{
3319        char concatpath[PATH_MAX];
3320        struct diff_filespec *one, *two;
3321
3322        /* This may look odd, but it is a preparation for
3323         * feeding "there are unchanged files which should
3324         * not produce diffs, but when you are doing copy
3325         * detection you would need them, so here they are"
3326         * entries to the diff-core.  They will be prefixed
3327         * with something like '=' or '*' (I haven't decided
3328         * which but should not make any difference).
3329         * Feeding the same new and old to diff_change()
3330         * also has the same effect.
3331         * Before the final output happens, they are pruned after
3332         * merged into rename/copy pairs as appropriate.
3333         */
3334        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3335                addremove = (addremove == '+' ? '-' :
3336                             addremove == '-' ? '+' : addremove);
3337
3338        if (!path) path = "";
3339        sprintf(concatpath, "%s%s", base, path);
3340
3341        if (options->prefix &&
3342            strncmp(concatpath, options->prefix, options->prefix_length))
3343                return;
3344
3345        one = alloc_filespec(concatpath);
3346        two = alloc_filespec(concatpath);
3347
3348        if (addremove != '+')
3349                fill_filespec(one, sha1, mode);
3350        if (addremove != '-')
3351                fill_filespec(two, sha1, mode);
3352
3353        diff_queue(&diff_queued_diff, one, two);
3354        DIFF_OPT_SET(options, HAS_CHANGES);
3355}
3356
3357void diff_change(struct diff_options *options,
3358                 unsigned old_mode, unsigned new_mode,
3359                 const unsigned char *old_sha1,
3360                 const unsigned char *new_sha1,
3361                 const char *base, const char *path)
3362{
3363        char concatpath[PATH_MAX];
3364        struct diff_filespec *one, *two;
3365
3366        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3367                unsigned tmp;
3368                const unsigned char *tmp_c;
3369                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3370                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3371        }
3372        if (!path) path = "";
3373        sprintf(concatpath, "%s%s", base, path);
3374
3375        if (options->prefix &&
3376            strncmp(concatpath, options->prefix, options->prefix_length))
3377                return;
3378
3379        one = alloc_filespec(concatpath);
3380        two = alloc_filespec(concatpath);
3381        fill_filespec(one, old_sha1, old_mode);
3382        fill_filespec(two, new_sha1, new_mode);
3383
3384        diff_queue(&diff_queued_diff, one, two);
3385        DIFF_OPT_SET(options, HAS_CHANGES);
3386}
3387
3388void diff_unmerge(struct diff_options *options,
3389                  const char *path,
3390                  unsigned mode, const unsigned char *sha1)
3391{
3392        struct diff_filespec *one, *two;
3393
3394        if (options->prefix &&
3395            strncmp(path, options->prefix, options->prefix_length))
3396                return;
3397
3398        one = alloc_filespec(path);
3399        two = alloc_filespec(path);
3400        fill_filespec(one, sha1, mode);
3401        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3402}