diff.con commit sha1_name: add get_sha1_with_context() (573285e)
   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#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33
  34static char diff_colors[][COLOR_MAXLEN] = {
  35        GIT_COLOR_RESET,
  36        GIT_COLOR_NORMAL,       /* PLAIN */
  37        GIT_COLOR_BOLD,         /* METAINFO */
  38        GIT_COLOR_CYAN,         /* FRAGINFO */
  39        GIT_COLOR_RED,          /* OLD */
  40        GIT_COLOR_GREEN,        /* NEW */
  41        GIT_COLOR_YELLOW,       /* COMMIT */
  42        GIT_COLOR_BG_RED,       /* WHITESPACE */
  43        GIT_COLOR_NORMAL,       /* FUNCINFO */
  44};
  45
  46static int parse_diff_color_slot(const char *var, int ofs)
  47{
  48        if (!strcasecmp(var+ofs, "plain"))
  49                return DIFF_PLAIN;
  50        if (!strcasecmp(var+ofs, "meta"))
  51                return DIFF_METAINFO;
  52        if (!strcasecmp(var+ofs, "frag"))
  53                return DIFF_FRAGINFO;
  54        if (!strcasecmp(var+ofs, "old"))
  55                return DIFF_FILE_OLD;
  56        if (!strcasecmp(var+ofs, "new"))
  57                return DIFF_FILE_NEW;
  58        if (!strcasecmp(var+ofs, "commit"))
  59                return DIFF_COMMIT;
  60        if (!strcasecmp(var+ofs, "whitespace"))
  61                return DIFF_WHITESPACE;
  62        if (!strcasecmp(var+ofs, "func"))
  63                return DIFF_FUNCINFO;
  64        return -1;
  65}
  66
  67static int git_config_rename(const char *var, const char *value)
  68{
  69        if (!value)
  70                return DIFF_DETECT_RENAME;
  71        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  72                return  DIFF_DETECT_COPY;
  73        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  74}
  75
  76/*
  77 * These are to give UI layer defaults.
  78 * The core-level commands such as git-diff-files should
  79 * never be affected by the setting of diff.renames
  80 * the user happens to have in the configuration file.
  81 */
  82int git_diff_ui_config(const char *var, const char *value, void *cb)
  83{
  84        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  85                diff_use_color_default = git_config_colorbool(var, value, -1);
  86                return 0;
  87        }
  88        if (!strcmp(var, "diff.renames")) {
  89                diff_detect_rename_default = git_config_rename(var, value);
  90                return 0;
  91        }
  92        if (!strcmp(var, "diff.autorefreshindex")) {
  93                diff_auto_refresh_index = git_config_bool(var, value);
  94                return 0;
  95        }
  96        if (!strcmp(var, "diff.mnemonicprefix")) {
  97                diff_mnemonic_prefix = git_config_bool(var, value);
  98                return 0;
  99        }
 100        if (!strcmp(var, "diff.external"))
 101                return git_config_string(&external_diff_cmd_cfg, var, value);
 102        if (!strcmp(var, "diff.wordregex"))
 103                return git_config_string(&diff_word_regex_cfg, var, value);
 104
 105        return git_diff_basic_config(var, value, cb);
 106}
 107
 108int git_diff_basic_config(const char *var, const char *value, void *cb)
 109{
 110        if (!strcmp(var, "diff.renamelimit")) {
 111                diff_rename_limit_default = git_config_int(var, value);
 112                return 0;
 113        }
 114
 115        switch (userdiff_config(var, value)) {
 116                case 0: break;
 117                case -1: return -1;
 118                default: return 0;
 119        }
 120
 121        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 122                int slot = parse_diff_color_slot(var, 11);
 123                if (slot < 0)
 124                        return 0;
 125                if (!value)
 126                        return config_error_nonbool(var);
 127                color_parse(value, var, diff_colors[slot]);
 128                return 0;
 129        }
 130
 131        /* like GNU diff's --suppress-blank-empty option  */
 132        if (!strcmp(var, "diff.suppressblankempty") ||
 133                        /* for backwards compatibility */
 134                        !strcmp(var, "diff.suppress-blank-empty")) {
 135                diff_suppress_blank_empty = git_config_bool(var, value);
 136                return 0;
 137        }
 138
 139        return git_color_default_config(var, value, cb);
 140}
 141
 142static char *quote_two(const char *one, const char *two)
 143{
 144        int need_one = quote_c_style(one, NULL, NULL, 1);
 145        int need_two = quote_c_style(two, NULL, NULL, 1);
 146        struct strbuf res = STRBUF_INIT;
 147
 148        if (need_one + need_two) {
 149                strbuf_addch(&res, '"');
 150                quote_c_style(one, &res, NULL, 1);
 151                quote_c_style(two, &res, NULL, 1);
 152                strbuf_addch(&res, '"');
 153        } else {
 154                strbuf_addstr(&res, one);
 155                strbuf_addstr(&res, two);
 156        }
 157        return strbuf_detach(&res, NULL);
 158}
 159
 160static const char *external_diff(void)
 161{
 162        static const char *external_diff_cmd = NULL;
 163        static int done_preparing = 0;
 164
 165        if (done_preparing)
 166                return external_diff_cmd;
 167        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 168        if (!external_diff_cmd)
 169                external_diff_cmd = external_diff_cmd_cfg;
 170        done_preparing = 1;
 171        return external_diff_cmd;
 172}
 173
 174static struct diff_tempfile {
 175        const char *name; /* filename external diff should read from */
 176        char hex[41];
 177        char mode[10];
 178        char tmp_path[PATH_MAX];
 179} diff_temp[2];
 180
 181typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 182
 183struct emit_callback {
 184        int color_diff;
 185        unsigned ws_rule;
 186        int blank_at_eof_in_preimage;
 187        int blank_at_eof_in_postimage;
 188        int lno_in_preimage;
 189        int lno_in_postimage;
 190        sane_truncate_fn truncate;
 191        const char **label_path;
 192        struct diff_words_data *diff_words;
 193        int *found_changesp;
 194        FILE *file;
 195        struct strbuf *header;
 196};
 197
 198static int count_lines(const char *data, int size)
 199{
 200        int count, ch, completely_empty = 1, nl_just_seen = 0;
 201        count = 0;
 202        while (0 < size--) {
 203                ch = *data++;
 204                if (ch == '\n') {
 205                        count++;
 206                        nl_just_seen = 1;
 207                        completely_empty = 0;
 208                }
 209                else {
 210                        nl_just_seen = 0;
 211                        completely_empty = 0;
 212                }
 213        }
 214        if (completely_empty)
 215                return 0;
 216        if (!nl_just_seen)
 217                count++; /* no trailing newline */
 218        return count;
 219}
 220
 221static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 222{
 223        if (!DIFF_FILE_VALID(one)) {
 224                mf->ptr = (char *)""; /* does not matter */
 225                mf->size = 0;
 226                return 0;
 227        }
 228        else if (diff_populate_filespec(one, 0))
 229                return -1;
 230
 231        mf->ptr = one->data;
 232        mf->size = one->size;
 233        return 0;
 234}
 235
 236static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 237{
 238        char *ptr = mf->ptr;
 239        long size = mf->size;
 240        int cnt = 0;
 241
 242        if (!size)
 243                return cnt;
 244        ptr += size - 1; /* pointing at the very end */
 245        if (*ptr != '\n')
 246                ; /* incomplete line */
 247        else
 248                ptr--; /* skip the last LF */
 249        while (mf->ptr < ptr) {
 250                char *prev_eol;
 251                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 252                        if (*prev_eol == '\n')
 253                                break;
 254                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 255                        break;
 256                cnt++;
 257                ptr = prev_eol - 1;
 258        }
 259        return cnt;
 260}
 261
 262static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 263                               struct emit_callback *ecbdata)
 264{
 265        int l1, l2, at;
 266        unsigned ws_rule = ecbdata->ws_rule;
 267        l1 = count_trailing_blank(mf1, ws_rule);
 268        l2 = count_trailing_blank(mf2, ws_rule);
 269        if (l2 <= l1) {
 270                ecbdata->blank_at_eof_in_preimage = 0;
 271                ecbdata->blank_at_eof_in_postimage = 0;
 272                return;
 273        }
 274        at = count_lines(mf1->ptr, mf1->size);
 275        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 276
 277        at = count_lines(mf2->ptr, mf2->size);
 278        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 279}
 280
 281static void emit_line_0(FILE *file, const char *set, const char *reset,
 282                        int first, const char *line, int len)
 283{
 284        int has_trailing_newline, has_trailing_carriage_return;
 285        int nofirst;
 286
 287        if (len == 0) {
 288                has_trailing_newline = (first == '\n');
 289                has_trailing_carriage_return = (!has_trailing_newline &&
 290                                                (first == '\r'));
 291                nofirst = has_trailing_newline || has_trailing_carriage_return;
 292        } else {
 293                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 294                if (has_trailing_newline)
 295                        len--;
 296                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 297                if (has_trailing_carriage_return)
 298                        len--;
 299                nofirst = 0;
 300        }
 301
 302        if (len || !nofirst) {
 303                fputs(set, file);
 304                if (!nofirst)
 305                        fputc(first, file);
 306                fwrite(line, len, 1, file);
 307                fputs(reset, file);
 308        }
 309        if (has_trailing_carriage_return)
 310                fputc('\r', file);
 311        if (has_trailing_newline)
 312                fputc('\n', file);
 313}
 314
 315static void emit_line(FILE *file, const char *set, const char *reset,
 316                      const char *line, int len)
 317{
 318        emit_line_0(file, set, reset, line[0], line+1, len-1);
 319}
 320
 321static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 322{
 323        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 324              ecbdata->blank_at_eof_in_preimage &&
 325              ecbdata->blank_at_eof_in_postimage &&
 326              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 327              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 328                return 0;
 329        return ws_blank_line(line, len, ecbdata->ws_rule);
 330}
 331
 332static void emit_add_line(const char *reset,
 333                          struct emit_callback *ecbdata,
 334                          const char *line, int len)
 335{
 336        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 337        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 338
 339        if (!*ws)
 340                emit_line_0(ecbdata->file, set, reset, '+', line, len);
 341        else if (new_blank_line_at_eof(ecbdata, line, len))
 342                /* Blank line at EOF - paint '+' as well */
 343                emit_line_0(ecbdata->file, ws, reset, '+', line, len);
 344        else {
 345                /* Emit just the prefix, then the rest. */
 346                emit_line_0(ecbdata->file, set, reset, '+', "", 0);
 347                ws_check_emit(line, len, ecbdata->ws_rule,
 348                              ecbdata->file, set, reset, ws);
 349        }
 350}
 351
 352static void emit_hunk_header(struct emit_callback *ecbdata,
 353                             const char *line, int len)
 354{
 355        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 356        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 357        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 358        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 359        static const char atat[2] = { '@', '@' };
 360        const char *cp, *ep;
 361
 362        /*
 363         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 364         * it always is at least 10 bytes long.
 365         */
 366        if (len < 10 ||
 367            memcmp(line, atat, 2) ||
 368            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 369                emit_line(ecbdata->file, plain, reset, line, len);
 370                return;
 371        }
 372        ep += 2; /* skip over @@ */
 373
 374        /* The hunk header in fraginfo color */
 375        emit_line(ecbdata->file, frag, reset, line, ep - line);
 376
 377        /* blank before the func header */
 378        for (cp = ep; ep - line < len; ep++)
 379                if (*ep != ' ' && *ep != '\t')
 380                        break;
 381        if (ep != cp)
 382                emit_line(ecbdata->file, plain, reset, cp, ep - cp);
 383
 384        if (ep < line + len)
 385                emit_line(ecbdata->file, func, reset, ep, line + len - ep);
 386}
 387
 388static struct diff_tempfile *claim_diff_tempfile(void) {
 389        int i;
 390        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 391                if (!diff_temp[i].name)
 392                        return diff_temp + i;
 393        die("BUG: diff is failing to clean up its tempfiles");
 394}
 395
 396static int remove_tempfile_installed;
 397
 398static void remove_tempfile(void)
 399{
 400        int i;
 401        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 402                if (diff_temp[i].name == diff_temp[i].tmp_path)
 403                        unlink_or_warn(diff_temp[i].name);
 404                diff_temp[i].name = NULL;
 405        }
 406}
 407
 408static void remove_tempfile_on_signal(int signo)
 409{
 410        remove_tempfile();
 411        sigchain_pop(signo);
 412        raise(signo);
 413}
 414
 415static void print_line_count(FILE *file, int count)
 416{
 417        switch (count) {
 418        case 0:
 419                fprintf(file, "0,0");
 420                break;
 421        case 1:
 422                fprintf(file, "1");
 423                break;
 424        default:
 425                fprintf(file, "1,%d", count);
 426                break;
 427        }
 428}
 429
 430static void emit_rewrite_lines(struct emit_callback *ecb,
 431                               int prefix, const char *data, int size)
 432{
 433        const char *endp = NULL;
 434        static const char *nneof = " No newline at end of file\n";
 435        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 436        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 437
 438        while (0 < size) {
 439                int len;
 440
 441                endp = memchr(data, '\n', size);
 442                len = endp ? (endp - data + 1) : size;
 443                if (prefix != '+') {
 444                        ecb->lno_in_preimage++;
 445                        emit_line_0(ecb->file, old, reset, '-',
 446                                    data, len);
 447                } else {
 448                        ecb->lno_in_postimage++;
 449                        emit_add_line(reset, ecb, data, len);
 450                }
 451                size -= len;
 452                data += len;
 453        }
 454        if (!endp) {
 455                const char *plain = diff_get_color(ecb->color_diff,
 456                                                   DIFF_PLAIN);
 457                emit_line_0(ecb->file, plain, reset, '\\',
 458                            nneof, strlen(nneof));
 459        }
 460}
 461
 462static void emit_rewrite_diff(const char *name_a,
 463                              const char *name_b,
 464                              struct diff_filespec *one,
 465                              struct diff_filespec *two,
 466                              struct userdiff_driver *textconv_one,
 467                              struct userdiff_driver *textconv_two,
 468                              struct diff_options *o)
 469{
 470        int lc_a, lc_b;
 471        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 472        const char *name_a_tab, *name_b_tab;
 473        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 474        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 475        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 476        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 477        const char *a_prefix, *b_prefix;
 478        char *data_one, *data_two;
 479        size_t size_one, size_two;
 480        struct emit_callback ecbdata;
 481
 482        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 483                a_prefix = o->b_prefix;
 484                b_prefix = o->a_prefix;
 485        } else {
 486                a_prefix = o->a_prefix;
 487                b_prefix = o->b_prefix;
 488        }
 489
 490        name_a += (*name_a == '/');
 491        name_b += (*name_b == '/');
 492        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 493        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 494
 495        strbuf_reset(&a_name);
 496        strbuf_reset(&b_name);
 497        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 498        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 499
 500        size_one = fill_textconv(textconv_one, one, &data_one);
 501        size_two = fill_textconv(textconv_two, two, &data_two);
 502
 503        memset(&ecbdata, 0, sizeof(ecbdata));
 504        ecbdata.color_diff = color_diff;
 505        ecbdata.found_changesp = &o->found_changes;
 506        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 507        ecbdata.file = o->file;
 508        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 509                mmfile_t mf1, mf2;
 510                mf1.ptr = (char *)data_one;
 511                mf2.ptr = (char *)data_two;
 512                mf1.size = size_one;
 513                mf2.size = size_two;
 514                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 515        }
 516        ecbdata.lno_in_preimage = 1;
 517        ecbdata.lno_in_postimage = 1;
 518
 519        lc_a = count_lines(data_one, size_one);
 520        lc_b = count_lines(data_two, size_two);
 521        fprintf(o->file,
 522                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 523                metainfo, a_name.buf, name_a_tab, reset,
 524                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 525        print_line_count(o->file, lc_a);
 526        fprintf(o->file, " +");
 527        print_line_count(o->file, lc_b);
 528        fprintf(o->file, " @@%s\n", reset);
 529        if (lc_a)
 530                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 531        if (lc_b)
 532                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 533        if (textconv_one)
 534                free((char *)data_one);
 535        if (textconv_two)
 536                free((char *)data_two);
 537}
 538
 539struct diff_words_buffer {
 540        mmfile_t text;
 541        long alloc;
 542        struct diff_words_orig {
 543                const char *begin, *end;
 544        } *orig;
 545        int orig_nr, orig_alloc;
 546};
 547
 548static void diff_words_append(char *line, unsigned long len,
 549                struct diff_words_buffer *buffer)
 550{
 551        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 552        line++;
 553        len--;
 554        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 555        buffer->text.size += len;
 556        buffer->text.ptr[buffer->text.size] = '\0';
 557}
 558
 559struct diff_words_style_elem
 560{
 561        const char *prefix;
 562        const char *suffix;
 563        const char *color; /* NULL; filled in by the setup code if
 564                            * color is enabled */
 565};
 566
 567struct diff_words_style
 568{
 569        enum diff_words_type type;
 570        struct diff_words_style_elem new, old, ctx;
 571        const char *newline;
 572};
 573
 574struct diff_words_style diff_words_styles[] = {
 575        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 576        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 577        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 578};
 579
 580struct diff_words_data {
 581        struct diff_words_buffer minus, plus;
 582        const char *current_plus;
 583        FILE *file;
 584        regex_t *word_regex;
 585        enum diff_words_type type;
 586        struct diff_words_style *style;
 587};
 588
 589static int fn_out_diff_words_write_helper(FILE *fp,
 590                                          struct diff_words_style_elem *st_el,
 591                                          const char *newline,
 592                                          size_t count, const char *buf)
 593{
 594        while (count) {
 595                char *p = memchr(buf, '\n', count);
 596                if (p != buf) {
 597                        if (st_el->color && fputs(st_el->color, fp) < 0)
 598                                return -1;
 599                        if (fputs(st_el->prefix, fp) < 0 ||
 600                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 601                            fputs(st_el->suffix, fp) < 0)
 602                                return -1;
 603                        if (st_el->color && *st_el->color
 604                            && fputs(GIT_COLOR_RESET, fp) < 0)
 605                                return -1;
 606                }
 607                if (!p)
 608                        return 0;
 609                if (fputs(newline, fp) < 0)
 610                        return -1;
 611                count -= p + 1 - buf;
 612                buf = p + 1;
 613        }
 614        return 0;
 615}
 616
 617static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 618{
 619        struct diff_words_data *diff_words = priv;
 620        struct diff_words_style *style = diff_words->style;
 621        int minus_first, minus_len, plus_first, plus_len;
 622        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 623
 624        if (line[0] != '@' || parse_hunk_header(line, len,
 625                        &minus_first, &minus_len, &plus_first, &plus_len))
 626                return;
 627
 628        /* POSIX requires that first be decremented by one if len == 0... */
 629        if (minus_len) {
 630                minus_begin = diff_words->minus.orig[minus_first].begin;
 631                minus_end =
 632                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 633        } else
 634                minus_begin = minus_end =
 635                        diff_words->minus.orig[minus_first].end;
 636
 637        if (plus_len) {
 638                plus_begin = diff_words->plus.orig[plus_first].begin;
 639                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 640        } else
 641                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 642
 643        if (diff_words->current_plus != plus_begin)
 644                fn_out_diff_words_write_helper(diff_words->file,
 645                                &style->ctx, style->newline,
 646                                plus_begin - diff_words->current_plus,
 647                                diff_words->current_plus);
 648        if (minus_begin != minus_end)
 649                fn_out_diff_words_write_helper(diff_words->file,
 650                                &style->old, style->newline,
 651                                minus_end - minus_begin, minus_begin);
 652        if (plus_begin != plus_end)
 653                fn_out_diff_words_write_helper(diff_words->file,
 654                                &style->new, style->newline,
 655                                plus_end - plus_begin, plus_begin);
 656
 657        diff_words->current_plus = plus_end;
 658}
 659
 660/* This function starts looking at *begin, and returns 0 iff a word was found. */
 661static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 662                int *begin, int *end)
 663{
 664        if (word_regex && *begin < buffer->size) {
 665                regmatch_t match[1];
 666                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 667                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 668                                        '\n', match[0].rm_eo - match[0].rm_so);
 669                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 670                        *begin += match[0].rm_so;
 671                        return *begin >= *end;
 672                }
 673                return -1;
 674        }
 675
 676        /* find the next word */
 677        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 678                (*begin)++;
 679        if (*begin >= buffer->size)
 680                return -1;
 681
 682        /* find the end of the word */
 683        *end = *begin + 1;
 684        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 685                (*end)++;
 686
 687        return 0;
 688}
 689
 690/*
 691 * This function splits the words in buffer->text, stores the list with
 692 * newline separator into out, and saves the offsets of the original words
 693 * in buffer->orig.
 694 */
 695static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 696                regex_t *word_regex)
 697{
 698        int i, j;
 699        long alloc = 0;
 700
 701        out->size = 0;
 702        out->ptr = NULL;
 703
 704        /* fake an empty "0th" word */
 705        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 706        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 707        buffer->orig_nr = 1;
 708
 709        for (i = 0; i < buffer->text.size; i++) {
 710                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 711                        return;
 712
 713                /* store original boundaries */
 714                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 715                                buffer->orig_alloc);
 716                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 717                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 718                buffer->orig_nr++;
 719
 720                /* store one word */
 721                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 722                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 723                out->ptr[out->size + j - i] = '\n';
 724                out->size += j - i + 1;
 725
 726                i = j - 1;
 727        }
 728}
 729
 730/* this executes the word diff on the accumulated buffers */
 731static void diff_words_show(struct diff_words_data *diff_words)
 732{
 733        xpparam_t xpp;
 734        xdemitconf_t xecfg;
 735        mmfile_t minus, plus;
 736        struct diff_words_style *style = diff_words->style;
 737
 738        /* special case: only removal */
 739        if (!diff_words->plus.text.size) {
 740                fn_out_diff_words_write_helper(diff_words->file,
 741                        &style->old, style->newline,
 742                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 743                diff_words->minus.text.size = 0;
 744                return;
 745        }
 746
 747        diff_words->current_plus = diff_words->plus.text.ptr;
 748
 749        memset(&xpp, 0, sizeof(xpp));
 750        memset(&xecfg, 0, sizeof(xecfg));
 751        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 752        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 753        xpp.flags = XDF_NEED_MINIMAL;
 754        /* as only the hunk header will be parsed, we need a 0-context */
 755        xecfg.ctxlen = 0;
 756        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 757                      &xpp, &xecfg);
 758        free(minus.ptr);
 759        free(plus.ptr);
 760        if (diff_words->current_plus != diff_words->plus.text.ptr +
 761                        diff_words->plus.text.size)
 762                fn_out_diff_words_write_helper(diff_words->file,
 763                        &style->ctx, style->newline,
 764                        diff_words->plus.text.ptr + diff_words->plus.text.size
 765                        - diff_words->current_plus, diff_words->current_plus);
 766        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 767}
 768
 769/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 770static void diff_words_flush(struct emit_callback *ecbdata)
 771{
 772        if (ecbdata->diff_words->minus.text.size ||
 773            ecbdata->diff_words->plus.text.size)
 774                diff_words_show(ecbdata->diff_words);
 775}
 776
 777static void free_diff_words_data(struct emit_callback *ecbdata)
 778{
 779        if (ecbdata->diff_words) {
 780                diff_words_flush(ecbdata);
 781                free (ecbdata->diff_words->minus.text.ptr);
 782                free (ecbdata->diff_words->minus.orig);
 783                free (ecbdata->diff_words->plus.text.ptr);
 784                free (ecbdata->diff_words->plus.orig);
 785                free(ecbdata->diff_words->word_regex);
 786                free(ecbdata->diff_words);
 787                ecbdata->diff_words = NULL;
 788        }
 789}
 790
 791const char *diff_get_color(int diff_use_color, enum color_diff ix)
 792{
 793        if (diff_use_color)
 794                return diff_colors[ix];
 795        return "";
 796}
 797
 798static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 799{
 800        const char *cp;
 801        unsigned long allot;
 802        size_t l = len;
 803
 804        if (ecb->truncate)
 805                return ecb->truncate(line, len);
 806        cp = line;
 807        allot = l;
 808        while (0 < l) {
 809                (void) utf8_width(&cp, &l);
 810                if (!cp)
 811                        break; /* truncated in the middle? */
 812        }
 813        return allot - l;
 814}
 815
 816static void find_lno(const char *line, struct emit_callback *ecbdata)
 817{
 818        const char *p;
 819        ecbdata->lno_in_preimage = 0;
 820        ecbdata->lno_in_postimage = 0;
 821        p = strchr(line, '-');
 822        if (!p)
 823                return; /* cannot happen */
 824        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 825        p = strchr(p, '+');
 826        if (!p)
 827                return; /* cannot happen */
 828        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 829}
 830
 831static void fn_out_consume(void *priv, char *line, unsigned long len)
 832{
 833        struct emit_callback *ecbdata = priv;
 834        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 835        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 836        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 837
 838        if (ecbdata->header) {
 839                fprintf(ecbdata->file, "%s", ecbdata->header->buf);
 840                strbuf_reset(ecbdata->header);
 841                ecbdata->header = NULL;
 842        }
 843        *(ecbdata->found_changesp) = 1;
 844
 845        if (ecbdata->label_path[0]) {
 846                const char *name_a_tab, *name_b_tab;
 847
 848                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 849                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 850
 851                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 852                        meta, ecbdata->label_path[0], reset, name_a_tab);
 853                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 854                        meta, ecbdata->label_path[1], reset, name_b_tab);
 855                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 856        }
 857
 858        if (diff_suppress_blank_empty
 859            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 860                line[0] = '\n';
 861                len = 1;
 862        }
 863
 864        if (line[0] == '@') {
 865                if (ecbdata->diff_words)
 866                        diff_words_flush(ecbdata);
 867                len = sane_truncate_line(ecbdata, line, len);
 868                find_lno(line, ecbdata);
 869                emit_hunk_header(ecbdata, line, len);
 870                if (line[len-1] != '\n')
 871                        putc('\n', ecbdata->file);
 872                return;
 873        }
 874
 875        if (len < 1) {
 876                emit_line(ecbdata->file, reset, reset, line, len);
 877                if (ecbdata->diff_words
 878                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
 879                        fputs("~\n", ecbdata->file);
 880                return;
 881        }
 882
 883        if (ecbdata->diff_words) {
 884                if (line[0] == '-') {
 885                        diff_words_append(line, len,
 886                                          &ecbdata->diff_words->minus);
 887                        return;
 888                } else if (line[0] == '+') {
 889                        diff_words_append(line, len,
 890                                          &ecbdata->diff_words->plus);
 891                        return;
 892                }
 893                diff_words_flush(ecbdata);
 894                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
 895                        emit_line(ecbdata->file, plain, reset, line, len);
 896                        fputs("~\n", ecbdata->file);
 897                } else {
 898                        /* don't print the prefix character */
 899                        emit_line(ecbdata->file, plain, reset, line+1, len-1);
 900                }
 901                return;
 902        }
 903
 904        if (line[0] != '+') {
 905                const char *color =
 906                        diff_get_color(ecbdata->color_diff,
 907                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
 908                ecbdata->lno_in_preimage++;
 909                if (line[0] == ' ')
 910                        ecbdata->lno_in_postimage++;
 911                emit_line(ecbdata->file, color, reset, line, len);
 912        } else {
 913                ecbdata->lno_in_postimage++;
 914                emit_add_line(reset, ecbdata, line + 1, len - 1);
 915        }
 916}
 917
 918static char *pprint_rename(const char *a, const char *b)
 919{
 920        const char *old = a;
 921        const char *new = b;
 922        struct strbuf name = STRBUF_INIT;
 923        int pfx_length, sfx_length;
 924        int len_a = strlen(a);
 925        int len_b = strlen(b);
 926        int a_midlen, b_midlen;
 927        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 928        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 929
 930        if (qlen_a || qlen_b) {
 931                quote_c_style(a, &name, NULL, 0);
 932                strbuf_addstr(&name, " => ");
 933                quote_c_style(b, &name, NULL, 0);
 934                return strbuf_detach(&name, NULL);
 935        }
 936
 937        /* Find common prefix */
 938        pfx_length = 0;
 939        while (*old && *new && *old == *new) {
 940                if (*old == '/')
 941                        pfx_length = old - a + 1;
 942                old++;
 943                new++;
 944        }
 945
 946        /* Find common suffix */
 947        old = a + len_a;
 948        new = b + len_b;
 949        sfx_length = 0;
 950        while (a <= old && b <= new && *old == *new) {
 951                if (*old == '/')
 952                        sfx_length = len_a - (old - a);
 953                old--;
 954                new--;
 955        }
 956
 957        /*
 958         * pfx{mid-a => mid-b}sfx
 959         * {pfx-a => pfx-b}sfx
 960         * pfx{sfx-a => sfx-b}
 961         * name-a => name-b
 962         */
 963        a_midlen = len_a - pfx_length - sfx_length;
 964        b_midlen = len_b - pfx_length - sfx_length;
 965        if (a_midlen < 0)
 966                a_midlen = 0;
 967        if (b_midlen < 0)
 968                b_midlen = 0;
 969
 970        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 971        if (pfx_length + sfx_length) {
 972                strbuf_add(&name, a, pfx_length);
 973                strbuf_addch(&name, '{');
 974        }
 975        strbuf_add(&name, a + pfx_length, a_midlen);
 976        strbuf_addstr(&name, " => ");
 977        strbuf_add(&name, b + pfx_length, b_midlen);
 978        if (pfx_length + sfx_length) {
 979                strbuf_addch(&name, '}');
 980                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 981        }
 982        return strbuf_detach(&name, NULL);
 983}
 984
 985struct diffstat_t {
 986        int nr;
 987        int alloc;
 988        struct diffstat_file {
 989                char *from_name;
 990                char *name;
 991                char *print_name;
 992                unsigned is_unmerged:1;
 993                unsigned is_binary:1;
 994                unsigned is_renamed:1;
 995                uintmax_t added, deleted;
 996        } **files;
 997};
 998
 999static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1000                                          const char *name_a,
1001                                          const char *name_b)
1002{
1003        struct diffstat_file *x;
1004        x = xcalloc(sizeof (*x), 1);
1005        if (diffstat->nr == diffstat->alloc) {
1006                diffstat->alloc = alloc_nr(diffstat->alloc);
1007                diffstat->files = xrealloc(diffstat->files,
1008                                diffstat->alloc * sizeof(x));
1009        }
1010        diffstat->files[diffstat->nr++] = x;
1011        if (name_b) {
1012                x->from_name = xstrdup(name_a);
1013                x->name = xstrdup(name_b);
1014                x->is_renamed = 1;
1015        }
1016        else {
1017                x->from_name = NULL;
1018                x->name = xstrdup(name_a);
1019        }
1020        return x;
1021}
1022
1023static void diffstat_consume(void *priv, char *line, unsigned long len)
1024{
1025        struct diffstat_t *diffstat = priv;
1026        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1027
1028        if (line[0] == '+')
1029                x->added++;
1030        else if (line[0] == '-')
1031                x->deleted++;
1032}
1033
1034const char mime_boundary_leader[] = "------------";
1035
1036static int scale_linear(int it, int width, int max_change)
1037{
1038        /*
1039         * make sure that at least one '-' is printed if there were deletions,
1040         * and likewise for '+'.
1041         */
1042        if (max_change < 2)
1043                return it;
1044        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1045}
1046
1047static void show_name(FILE *file,
1048                      const char *prefix, const char *name, int len)
1049{
1050        fprintf(file, " %s%-*s |", prefix, len, name);
1051}
1052
1053static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1054{
1055        if (cnt <= 0)
1056                return;
1057        fprintf(file, "%s", set);
1058        while (cnt--)
1059                putc(ch, file);
1060        fprintf(file, "%s", reset);
1061}
1062
1063static void fill_print_name(struct diffstat_file *file)
1064{
1065        char *pname;
1066
1067        if (file->print_name)
1068                return;
1069
1070        if (!file->is_renamed) {
1071                struct strbuf buf = STRBUF_INIT;
1072                if (quote_c_style(file->name, &buf, NULL, 0)) {
1073                        pname = strbuf_detach(&buf, NULL);
1074                } else {
1075                        pname = file->name;
1076                        strbuf_release(&buf);
1077                }
1078        } else {
1079                pname = pprint_rename(file->from_name, file->name);
1080        }
1081        file->print_name = pname;
1082}
1083
1084static void show_stats(struct diffstat_t *data, struct diff_options *options)
1085{
1086        int i, len, add, del, adds = 0, dels = 0;
1087        uintmax_t max_change = 0, max_len = 0;
1088        int total_files = data->nr;
1089        int width, name_width;
1090        const char *reset, *set, *add_c, *del_c;
1091
1092        if (data->nr == 0)
1093                return;
1094
1095        width = options->stat_width ? options->stat_width : 80;
1096        name_width = options->stat_name_width ? options->stat_name_width : 50;
1097
1098        /* Sanity: give at least 5 columns to the graph,
1099         * but leave at least 10 columns for the name.
1100         */
1101        if (width < 25)
1102                width = 25;
1103        if (name_width < 10)
1104                name_width = 10;
1105        else if (width < name_width + 15)
1106                name_width = width - 15;
1107
1108        /* Find the longest filename and max number of changes */
1109        reset = diff_get_color_opt(options, DIFF_RESET);
1110        set   = diff_get_color_opt(options, DIFF_PLAIN);
1111        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1112        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1113
1114        for (i = 0; i < data->nr; i++) {
1115                struct diffstat_file *file = data->files[i];
1116                uintmax_t change = file->added + file->deleted;
1117                fill_print_name(file);
1118                len = strlen(file->print_name);
1119                if (max_len < len)
1120                        max_len = len;
1121
1122                if (file->is_binary || file->is_unmerged)
1123                        continue;
1124                if (max_change < change)
1125                        max_change = change;
1126        }
1127
1128        /* Compute the width of the graph part;
1129         * 10 is for one blank at the beginning of the line plus
1130         * " | count " between the name and the graph.
1131         *
1132         * From here on, name_width is the width of the name area,
1133         * and width is the width of the graph area.
1134         */
1135        name_width = (name_width < max_len) ? name_width : max_len;
1136        if (width < (name_width + 10) + max_change)
1137                width = width - (name_width + 10);
1138        else
1139                width = max_change;
1140
1141        for (i = 0; i < data->nr; i++) {
1142                const char *prefix = "";
1143                char *name = data->files[i]->print_name;
1144                uintmax_t added = data->files[i]->added;
1145                uintmax_t deleted = data->files[i]->deleted;
1146                int name_len;
1147
1148                /*
1149                 * "scale" the filename
1150                 */
1151                len = name_width;
1152                name_len = strlen(name);
1153                if (name_width < name_len) {
1154                        char *slash;
1155                        prefix = "...";
1156                        len -= 3;
1157                        name += name_len - len;
1158                        slash = strchr(name, '/');
1159                        if (slash)
1160                                name = slash;
1161                }
1162
1163                if (data->files[i]->is_binary) {
1164                        show_name(options->file, prefix, name, len);
1165                        fprintf(options->file, "  Bin ");
1166                        fprintf(options->file, "%s%"PRIuMAX"%s",
1167                                del_c, deleted, reset);
1168                        fprintf(options->file, " -> ");
1169                        fprintf(options->file, "%s%"PRIuMAX"%s",
1170                                add_c, added, reset);
1171                        fprintf(options->file, " bytes");
1172                        fprintf(options->file, "\n");
1173                        continue;
1174                }
1175                else if (data->files[i]->is_unmerged) {
1176                        show_name(options->file, prefix, name, len);
1177                        fprintf(options->file, "  Unmerged\n");
1178                        continue;
1179                }
1180                else if (!data->files[i]->is_renamed &&
1181                         (added + deleted == 0)) {
1182                        total_files--;
1183                        continue;
1184                }
1185
1186                /*
1187                 * scale the add/delete
1188                 */
1189                add = added;
1190                del = deleted;
1191                adds += add;
1192                dels += del;
1193
1194                if (width <= max_change) {
1195                        add = scale_linear(add, width, max_change);
1196                        del = scale_linear(del, width, max_change);
1197                }
1198                show_name(options->file, prefix, name, len);
1199                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1200                                added + deleted ? " " : "");
1201                show_graph(options->file, '+', add, add_c, reset);
1202                show_graph(options->file, '-', del, del_c, reset);
1203                fprintf(options->file, "\n");
1204        }
1205        fprintf(options->file,
1206               " %d files changed, %d insertions(+), %d deletions(-)\n",
1207               total_files, adds, dels);
1208}
1209
1210static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1211{
1212        int i, adds = 0, dels = 0, total_files = data->nr;
1213
1214        if (data->nr == 0)
1215                return;
1216
1217        for (i = 0; i < data->nr; i++) {
1218                if (!data->files[i]->is_binary &&
1219                    !data->files[i]->is_unmerged) {
1220                        int added = data->files[i]->added;
1221                        int deleted= data->files[i]->deleted;
1222                        if (!data->files[i]->is_renamed &&
1223                            (added + deleted == 0)) {
1224                                total_files--;
1225                        } else {
1226                                adds += added;
1227                                dels += deleted;
1228                        }
1229                }
1230        }
1231        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1232               total_files, adds, dels);
1233}
1234
1235static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1236{
1237        int i;
1238
1239        if (data->nr == 0)
1240                return;
1241
1242        for (i = 0; i < data->nr; i++) {
1243                struct diffstat_file *file = data->files[i];
1244
1245                if (file->is_binary)
1246                        fprintf(options->file, "-\t-\t");
1247                else
1248                        fprintf(options->file,
1249                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1250                                file->added, file->deleted);
1251                if (options->line_termination) {
1252                        fill_print_name(file);
1253                        if (!file->is_renamed)
1254                                write_name_quoted(file->name, options->file,
1255                                                  options->line_termination);
1256                        else {
1257                                fputs(file->print_name, options->file);
1258                                putc(options->line_termination, options->file);
1259                        }
1260                } else {
1261                        if (file->is_renamed) {
1262                                putc('\0', options->file);
1263                                write_name_quoted(file->from_name, options->file, '\0');
1264                        }
1265                        write_name_quoted(file->name, options->file, '\0');
1266                }
1267        }
1268}
1269
1270struct dirstat_file {
1271        const char *name;
1272        unsigned long changed;
1273};
1274
1275struct dirstat_dir {
1276        struct dirstat_file *files;
1277        int alloc, nr, percent, cumulative;
1278};
1279
1280static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1281{
1282        unsigned long this_dir = 0;
1283        unsigned int sources = 0;
1284
1285        while (dir->nr) {
1286                struct dirstat_file *f = dir->files;
1287                int namelen = strlen(f->name);
1288                unsigned long this;
1289                char *slash;
1290
1291                if (namelen < baselen)
1292                        break;
1293                if (memcmp(f->name, base, baselen))
1294                        break;
1295                slash = strchr(f->name + baselen, '/');
1296                if (slash) {
1297                        int newbaselen = slash + 1 - f->name;
1298                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1299                        sources++;
1300                } else {
1301                        this = f->changed;
1302                        dir->files++;
1303                        dir->nr--;
1304                        sources += 2;
1305                }
1306                this_dir += this;
1307        }
1308
1309        /*
1310         * We don't report dirstat's for
1311         *  - the top level
1312         *  - or cases where everything came from a single directory
1313         *    under this directory (sources == 1).
1314         */
1315        if (baselen && sources != 1) {
1316                int permille = this_dir * 1000 / changed;
1317                if (permille) {
1318                        int percent = permille / 10;
1319                        if (percent >= dir->percent) {
1320                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1321                                if (!dir->cumulative)
1322                                        return 0;
1323                        }
1324                }
1325        }
1326        return this_dir;
1327}
1328
1329static int dirstat_compare(const void *_a, const void *_b)
1330{
1331        const struct dirstat_file *a = _a;
1332        const struct dirstat_file *b = _b;
1333        return strcmp(a->name, b->name);
1334}
1335
1336static void show_dirstat(struct diff_options *options)
1337{
1338        int i;
1339        unsigned long changed;
1340        struct dirstat_dir dir;
1341        struct diff_queue_struct *q = &diff_queued_diff;
1342
1343        dir.files = NULL;
1344        dir.alloc = 0;
1345        dir.nr = 0;
1346        dir.percent = options->dirstat_percent;
1347        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1348
1349        changed = 0;
1350        for (i = 0; i < q->nr; i++) {
1351                struct diff_filepair *p = q->queue[i];
1352                const char *name;
1353                unsigned long copied, added, damage;
1354
1355                name = p->one->path ? p->one->path : p->two->path;
1356
1357                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1358                        diff_populate_filespec(p->one, 0);
1359                        diff_populate_filespec(p->two, 0);
1360                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1361                                               &copied, &added);
1362                        diff_free_filespec_data(p->one);
1363                        diff_free_filespec_data(p->two);
1364                } else if (DIFF_FILE_VALID(p->one)) {
1365                        diff_populate_filespec(p->one, 1);
1366                        copied = added = 0;
1367                        diff_free_filespec_data(p->one);
1368                } else if (DIFF_FILE_VALID(p->two)) {
1369                        diff_populate_filespec(p->two, 1);
1370                        copied = 0;
1371                        added = p->two->size;
1372                        diff_free_filespec_data(p->two);
1373                } else
1374                        continue;
1375
1376                /*
1377                 * Original minus copied is the removed material,
1378                 * added is the new material.  They are both damages
1379                 * made to the preimage. In --dirstat-by-file mode, count
1380                 * damaged files, not damaged lines. This is done by
1381                 * counting only a single damaged line per file.
1382                 */
1383                damage = (p->one->size - copied) + added;
1384                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1385                        damage = 1;
1386
1387                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1388                dir.files[dir.nr].name = name;
1389                dir.files[dir.nr].changed = damage;
1390                changed += damage;
1391                dir.nr++;
1392        }
1393
1394        /* This can happen even with many files, if everything was renames */
1395        if (!changed)
1396                return;
1397
1398        /* Show all directories with more than x% of the changes */
1399        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1400        gather_dirstat(options->file, &dir, changed, "", 0);
1401}
1402
1403static void free_diffstat_info(struct diffstat_t *diffstat)
1404{
1405        int i;
1406        for (i = 0; i < diffstat->nr; i++) {
1407                struct diffstat_file *f = diffstat->files[i];
1408                if (f->name != f->print_name)
1409                        free(f->print_name);
1410                free(f->name);
1411                free(f->from_name);
1412                free(f);
1413        }
1414        free(diffstat->files);
1415}
1416
1417struct checkdiff_t {
1418        const char *filename;
1419        int lineno;
1420        int conflict_marker_size;
1421        struct diff_options *o;
1422        unsigned ws_rule;
1423        unsigned status;
1424};
1425
1426static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1427{
1428        char firstchar;
1429        int cnt;
1430
1431        if (len < marker_size + 1)
1432                return 0;
1433        firstchar = line[0];
1434        switch (firstchar) {
1435        case '=': case '>': case '<': case '|':
1436                break;
1437        default:
1438                return 0;
1439        }
1440        for (cnt = 1; cnt < marker_size; cnt++)
1441                if (line[cnt] != firstchar)
1442                        return 0;
1443        /* line[1] thru line[marker_size-1] are same as firstchar */
1444        if (len < marker_size + 1 || !isspace(line[marker_size]))
1445                return 0;
1446        return 1;
1447}
1448
1449static void checkdiff_consume(void *priv, char *line, unsigned long len)
1450{
1451        struct checkdiff_t *data = priv;
1452        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1453        int marker_size = data->conflict_marker_size;
1454        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1455        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1456        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1457        char *err;
1458
1459        if (line[0] == '+') {
1460                unsigned bad;
1461                data->lineno++;
1462                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1463                        data->status |= 1;
1464                        fprintf(data->o->file,
1465                                "%s:%d: leftover conflict marker\n",
1466                                data->filename, data->lineno);
1467                }
1468                bad = ws_check(line + 1, len - 1, data->ws_rule);
1469                if (!bad)
1470                        return;
1471                data->status |= bad;
1472                err = whitespace_error_string(bad);
1473                fprintf(data->o->file, "%s:%d: %s.\n",
1474                        data->filename, data->lineno, err);
1475                free(err);
1476                emit_line(data->o->file, set, reset, line, 1);
1477                ws_check_emit(line + 1, len - 1, data->ws_rule,
1478                              data->o->file, set, reset, ws);
1479        } else if (line[0] == ' ') {
1480                data->lineno++;
1481        } else if (line[0] == '@') {
1482                char *plus = strchr(line, '+');
1483                if (plus)
1484                        data->lineno = strtol(plus, NULL, 10) - 1;
1485                else
1486                        die("invalid diff");
1487        }
1488}
1489
1490static unsigned char *deflate_it(char *data,
1491                                 unsigned long size,
1492                                 unsigned long *result_size)
1493{
1494        int bound;
1495        unsigned char *deflated;
1496        z_stream stream;
1497
1498        memset(&stream, 0, sizeof(stream));
1499        deflateInit(&stream, zlib_compression_level);
1500        bound = deflateBound(&stream, size);
1501        deflated = xmalloc(bound);
1502        stream.next_out = deflated;
1503        stream.avail_out = bound;
1504
1505        stream.next_in = (unsigned char *)data;
1506        stream.avail_in = size;
1507        while (deflate(&stream, Z_FINISH) == Z_OK)
1508                ; /* nothing */
1509        deflateEnd(&stream);
1510        *result_size = stream.total_out;
1511        return deflated;
1512}
1513
1514static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1515{
1516        void *cp;
1517        void *delta;
1518        void *deflated;
1519        void *data;
1520        unsigned long orig_size;
1521        unsigned long delta_size;
1522        unsigned long deflate_size;
1523        unsigned long data_size;
1524
1525        /* We could do deflated delta, or we could do just deflated two,
1526         * whichever is smaller.
1527         */
1528        delta = NULL;
1529        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1530        if (one->size && two->size) {
1531                delta = diff_delta(one->ptr, one->size,
1532                                   two->ptr, two->size,
1533                                   &delta_size, deflate_size);
1534                if (delta) {
1535                        void *to_free = delta;
1536                        orig_size = delta_size;
1537                        delta = deflate_it(delta, delta_size, &delta_size);
1538                        free(to_free);
1539                }
1540        }
1541
1542        if (delta && delta_size < deflate_size) {
1543                fprintf(file, "delta %lu\n", orig_size);
1544                free(deflated);
1545                data = delta;
1546                data_size = delta_size;
1547        }
1548        else {
1549                fprintf(file, "literal %lu\n", two->size);
1550                free(delta);
1551                data = deflated;
1552                data_size = deflate_size;
1553        }
1554
1555        /* emit data encoded in base85 */
1556        cp = data;
1557        while (data_size) {
1558                int bytes = (52 < data_size) ? 52 : data_size;
1559                char line[70];
1560                data_size -= bytes;
1561                if (bytes <= 26)
1562                        line[0] = bytes + 'A' - 1;
1563                else
1564                        line[0] = bytes - 26 + 'a' - 1;
1565                encode_85(line + 1, cp, bytes);
1566                cp = (char *) cp + bytes;
1567                fputs(line, file);
1568                fputc('\n', file);
1569        }
1570        fprintf(file, "\n");
1571        free(data);
1572}
1573
1574static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1575{
1576        fprintf(file, "GIT binary patch\n");
1577        emit_binary_diff_body(file, one, two);
1578        emit_binary_diff_body(file, two, one);
1579}
1580
1581static void diff_filespec_load_driver(struct diff_filespec *one)
1582{
1583        if (!one->driver)
1584                one->driver = userdiff_find_by_path(one->path);
1585        if (!one->driver)
1586                one->driver = userdiff_find_by_name("default");
1587}
1588
1589int diff_filespec_is_binary(struct diff_filespec *one)
1590{
1591        if (one->is_binary == -1) {
1592                diff_filespec_load_driver(one);
1593                if (one->driver->binary != -1)
1594                        one->is_binary = one->driver->binary;
1595                else {
1596                        if (!one->data && DIFF_FILE_VALID(one))
1597                                diff_populate_filespec(one, 0);
1598                        if (one->data)
1599                                one->is_binary = buffer_is_binary(one->data,
1600                                                one->size);
1601                        if (one->is_binary == -1)
1602                                one->is_binary = 0;
1603                }
1604        }
1605        return one->is_binary;
1606}
1607
1608static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1609{
1610        diff_filespec_load_driver(one);
1611        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1612}
1613
1614static const char *userdiff_word_regex(struct diff_filespec *one)
1615{
1616        diff_filespec_load_driver(one);
1617        return one->driver->word_regex;
1618}
1619
1620void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1621{
1622        if (!options->a_prefix)
1623                options->a_prefix = a;
1624        if (!options->b_prefix)
1625                options->b_prefix = b;
1626}
1627
1628struct userdiff_driver *get_textconv(struct diff_filespec *one)
1629{
1630        if (!DIFF_FILE_VALID(one))
1631                return NULL;
1632        if (!S_ISREG(one->mode))
1633                return NULL;
1634        diff_filespec_load_driver(one);
1635        if (!one->driver->textconv)
1636                return NULL;
1637
1638        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1639                struct notes_cache *c = xmalloc(sizeof(*c));
1640                struct strbuf name = STRBUF_INIT;
1641
1642                strbuf_addf(&name, "textconv/%s", one->driver->name);
1643                notes_cache_init(c, name.buf, one->driver->textconv);
1644                one->driver->textconv_cache = c;
1645        }
1646
1647        return one->driver;
1648}
1649
1650static void builtin_diff(const char *name_a,
1651                         const char *name_b,
1652                         struct diff_filespec *one,
1653                         struct diff_filespec *two,
1654                         const char *xfrm_msg,
1655                         struct diff_options *o,
1656                         int complete_rewrite)
1657{
1658        mmfile_t mf1, mf2;
1659        const char *lbl[2];
1660        char *a_one, *b_two;
1661        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1662        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1663        const char *a_prefix, *b_prefix;
1664        struct userdiff_driver *textconv_one = NULL;
1665        struct userdiff_driver *textconv_two = NULL;
1666        struct strbuf header = STRBUF_INIT;
1667
1668        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1669                        (!one->mode || S_ISGITLINK(one->mode)) &&
1670                        (!two->mode || S_ISGITLINK(two->mode))) {
1671                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1672                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1673                show_submodule_summary(o->file, one ? one->path : two->path,
1674                                one->sha1, two->sha1, two->dirty_submodule,
1675                                del, add, reset);
1676                return;
1677        }
1678
1679        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1680                textconv_one = get_textconv(one);
1681                textconv_two = get_textconv(two);
1682        }
1683
1684        diff_set_mnemonic_prefix(o, "a/", "b/");
1685        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1686                a_prefix = o->b_prefix;
1687                b_prefix = o->a_prefix;
1688        } else {
1689                a_prefix = o->a_prefix;
1690                b_prefix = o->b_prefix;
1691        }
1692
1693        /* Never use a non-valid filename anywhere if at all possible */
1694        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1695        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1696
1697        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1698        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1699        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1700        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1701        strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1702        if (lbl[0][0] == '/') {
1703                /* /dev/null */
1704                strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
1705                if (xfrm_msg && xfrm_msg[0])
1706                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1707        }
1708        else if (lbl[1][0] == '/') {
1709                strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1710                if (xfrm_msg && xfrm_msg[0])
1711                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1712        }
1713        else {
1714                if (one->mode != two->mode) {
1715                        strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
1716                        strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
1717                }
1718                if (xfrm_msg && xfrm_msg[0])
1719                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1720
1721                /*
1722                 * we do not run diff between different kind
1723                 * of objects.
1724                 */
1725                if ((one->mode ^ two->mode) & S_IFMT)
1726                        goto free_ab_and_return;
1727                if (complete_rewrite &&
1728                    (textconv_one || !diff_filespec_is_binary(one)) &&
1729                    (textconv_two || !diff_filespec_is_binary(two))) {
1730                        fprintf(o->file, "%s", header.buf);
1731                        strbuf_reset(&header);
1732                        emit_rewrite_diff(name_a, name_b, one, two,
1733                                                textconv_one, textconv_two, o);
1734                        o->found_changes = 1;
1735                        goto free_ab_and_return;
1736                }
1737        }
1738
1739        if (!DIFF_OPT_TST(o, TEXT) &&
1740            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1741              (!textconv_two && diff_filespec_is_binary(two)) )) {
1742                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1743                        die("unable to read files to diff");
1744                /* Quite common confusing case */
1745                if (mf1.size == mf2.size &&
1746                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1747                        goto free_ab_and_return;
1748                fprintf(o->file, "%s", header.buf);
1749                strbuf_reset(&header);
1750                if (DIFF_OPT_TST(o, BINARY))
1751                        emit_binary_diff(o->file, &mf1, &mf2);
1752                else
1753                        fprintf(o->file, "Binary files %s and %s differ\n",
1754                                lbl[0], lbl[1]);
1755                o->found_changes = 1;
1756        }
1757        else {
1758                /* Crazy xdl interfaces.. */
1759                const char *diffopts = getenv("GIT_DIFF_OPTS");
1760                xpparam_t xpp;
1761                xdemitconf_t xecfg;
1762                struct emit_callback ecbdata;
1763                const struct userdiff_funcname *pe;
1764
1765                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1766                        fprintf(o->file, "%s", header.buf);
1767                        strbuf_reset(&header);
1768                }
1769
1770                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1771                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1772
1773                pe = diff_funcname_pattern(one);
1774                if (!pe)
1775                        pe = diff_funcname_pattern(two);
1776
1777                memset(&xpp, 0, sizeof(xpp));
1778                memset(&xecfg, 0, sizeof(xecfg));
1779                memset(&ecbdata, 0, sizeof(ecbdata));
1780                ecbdata.label_path = lbl;
1781                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1782                ecbdata.found_changesp = &o->found_changes;
1783                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1784                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1785                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1786                ecbdata.file = o->file;
1787                ecbdata.header = header.len ? &header : NULL;
1788                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1789                xecfg.ctxlen = o->context;
1790                xecfg.interhunkctxlen = o->interhunkcontext;
1791                xecfg.flags = XDL_EMIT_FUNCNAMES;
1792                if (pe)
1793                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1794                if (!diffopts)
1795                        ;
1796                else if (!prefixcmp(diffopts, "--unified="))
1797                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1798                else if (!prefixcmp(diffopts, "-u"))
1799                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1800                if (o->word_diff) {
1801                        int i;
1802
1803                        ecbdata.diff_words =
1804                                xcalloc(1, sizeof(struct diff_words_data));
1805                        ecbdata.diff_words->file = o->file;
1806                        ecbdata.diff_words->type = o->word_diff;
1807                        if (!o->word_regex)
1808                                o->word_regex = userdiff_word_regex(one);
1809                        if (!o->word_regex)
1810                                o->word_regex = userdiff_word_regex(two);
1811                        if (!o->word_regex)
1812                                o->word_regex = diff_word_regex_cfg;
1813                        if (o->word_regex) {
1814                                ecbdata.diff_words->word_regex = (regex_t *)
1815                                        xmalloc(sizeof(regex_t));
1816                                if (regcomp(ecbdata.diff_words->word_regex,
1817                                                o->word_regex,
1818                                                REG_EXTENDED | REG_NEWLINE))
1819                                        die ("Invalid regular expression: %s",
1820                                                        o->word_regex);
1821                        }
1822                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1823                                if (o->word_diff == diff_words_styles[i].type) {
1824                                        ecbdata.diff_words->style =
1825                                                &diff_words_styles[i];
1826                                        break;
1827                                }
1828                        }
1829                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
1830                                struct diff_words_style *st = ecbdata.diff_words->style;
1831                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1832                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1833                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1834                        }
1835                }
1836                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1837                              &xpp, &xecfg);
1838                if (o->word_diff)
1839                        free_diff_words_data(&ecbdata);
1840                if (textconv_one)
1841                        free(mf1.ptr);
1842                if (textconv_two)
1843                        free(mf2.ptr);
1844                xdiff_clear_find_func(&xecfg);
1845        }
1846
1847 free_ab_and_return:
1848        strbuf_release(&header);
1849        diff_free_filespec_data(one);
1850        diff_free_filespec_data(two);
1851        free(a_one);
1852        free(b_two);
1853        return;
1854}
1855
1856static void builtin_diffstat(const char *name_a, const char *name_b,
1857                             struct diff_filespec *one,
1858                             struct diff_filespec *two,
1859                             struct diffstat_t *diffstat,
1860                             struct diff_options *o,
1861                             int complete_rewrite)
1862{
1863        mmfile_t mf1, mf2;
1864        struct diffstat_file *data;
1865
1866        data = diffstat_add(diffstat, name_a, name_b);
1867
1868        if (!one || !two) {
1869                data->is_unmerged = 1;
1870                return;
1871        }
1872        if (complete_rewrite) {
1873                diff_populate_filespec(one, 0);
1874                diff_populate_filespec(two, 0);
1875                data->deleted = count_lines(one->data, one->size);
1876                data->added = count_lines(two->data, two->size);
1877                goto free_and_return;
1878        }
1879        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1880                die("unable to read files to diff");
1881
1882        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1883                data->is_binary = 1;
1884                data->added = mf2.size;
1885                data->deleted = mf1.size;
1886        } else {
1887                /* Crazy xdl interfaces.. */
1888                xpparam_t xpp;
1889                xdemitconf_t xecfg;
1890
1891                memset(&xpp, 0, sizeof(xpp));
1892                memset(&xecfg, 0, sizeof(xecfg));
1893                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1894                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1895                              &xpp, &xecfg);
1896        }
1897
1898 free_and_return:
1899        diff_free_filespec_data(one);
1900        diff_free_filespec_data(two);
1901}
1902
1903static void builtin_checkdiff(const char *name_a, const char *name_b,
1904                              const char *attr_path,
1905                              struct diff_filespec *one,
1906                              struct diff_filespec *two,
1907                              struct diff_options *o)
1908{
1909        mmfile_t mf1, mf2;
1910        struct checkdiff_t data;
1911
1912        if (!two)
1913                return;
1914
1915        memset(&data, 0, sizeof(data));
1916        data.filename = name_b ? name_b : name_a;
1917        data.lineno = 0;
1918        data.o = o;
1919        data.ws_rule = whitespace_rule(attr_path);
1920        data.conflict_marker_size = ll_merge_marker_size(attr_path);
1921
1922        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1923                die("unable to read files to diff");
1924
1925        /*
1926         * All the other codepaths check both sides, but not checking
1927         * the "old" side here is deliberate.  We are checking the newly
1928         * introduced changes, and as long as the "new" side is text, we
1929         * can and should check what it introduces.
1930         */
1931        if (diff_filespec_is_binary(two))
1932                goto free_and_return;
1933        else {
1934                /* Crazy xdl interfaces.. */
1935                xpparam_t xpp;
1936                xdemitconf_t xecfg;
1937
1938                memset(&xpp, 0, sizeof(xpp));
1939                memset(&xecfg, 0, sizeof(xecfg));
1940                xecfg.ctxlen = 1; /* at least one context line */
1941                xpp.flags = XDF_NEED_MINIMAL;
1942                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1943                              &xpp, &xecfg);
1944
1945                if (data.ws_rule & WS_BLANK_AT_EOF) {
1946                        struct emit_callback ecbdata;
1947                        int blank_at_eof;
1948
1949                        ecbdata.ws_rule = data.ws_rule;
1950                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1951                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1952
1953                        if (blank_at_eof) {
1954                                static char *err;
1955                                if (!err)
1956                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
1957                                fprintf(o->file, "%s:%d: %s.\n",
1958                                        data.filename, blank_at_eof, err);
1959                                data.status = 1; /* report errors */
1960                        }
1961                }
1962        }
1963 free_and_return:
1964        diff_free_filespec_data(one);
1965        diff_free_filespec_data(two);
1966        if (data.status)
1967                DIFF_OPT_SET(o, CHECK_FAILED);
1968}
1969
1970struct diff_filespec *alloc_filespec(const char *path)
1971{
1972        int namelen = strlen(path);
1973        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1974
1975        memset(spec, 0, sizeof(*spec));
1976        spec->path = (char *)(spec + 1);
1977        memcpy(spec->path, path, namelen+1);
1978        spec->count = 1;
1979        spec->is_binary = -1;
1980        return spec;
1981}
1982
1983void free_filespec(struct diff_filespec *spec)
1984{
1985        if (!--spec->count) {
1986                diff_free_filespec_data(spec);
1987                free(spec);
1988        }
1989}
1990
1991void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1992                   unsigned short mode)
1993{
1994        if (mode) {
1995                spec->mode = canon_mode(mode);
1996                hashcpy(spec->sha1, sha1);
1997                spec->sha1_valid = !is_null_sha1(sha1);
1998        }
1999}
2000
2001/*
2002 * Given a name and sha1 pair, if the index tells us the file in
2003 * the work tree has that object contents, return true, so that
2004 * prepare_temp_file() does not have to inflate and extract.
2005 */
2006static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2007{
2008        struct cache_entry *ce;
2009        struct stat st;
2010        int pos, len;
2011
2012        /*
2013         * We do not read the cache ourselves here, because the
2014         * benchmark with my previous version that always reads cache
2015         * shows that it makes things worse for diff-tree comparing
2016         * two linux-2.6 kernel trees in an already checked out work
2017         * tree.  This is because most diff-tree comparisons deal with
2018         * only a small number of files, while reading the cache is
2019         * expensive for a large project, and its cost outweighs the
2020         * savings we get by not inflating the object to a temporary
2021         * file.  Practically, this code only helps when we are used
2022         * by diff-cache --cached, which does read the cache before
2023         * calling us.
2024         */
2025        if (!active_cache)
2026                return 0;
2027
2028        /* We want to avoid the working directory if our caller
2029         * doesn't need the data in a normal file, this system
2030         * is rather slow with its stat/open/mmap/close syscalls,
2031         * and the object is contained in a pack file.  The pack
2032         * is probably already open and will be faster to obtain
2033         * the data through than the working directory.  Loose
2034         * objects however would tend to be slower as they need
2035         * to be individually opened and inflated.
2036         */
2037        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2038                return 0;
2039
2040        len = strlen(name);
2041        pos = cache_name_pos(name, len);
2042        if (pos < 0)
2043                return 0;
2044        ce = active_cache[pos];
2045
2046        /*
2047         * This is not the sha1 we are looking for, or
2048         * unreusable because it is not a regular file.
2049         */
2050        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2051                return 0;
2052
2053        /*
2054         * If ce is marked as "assume unchanged", there is no
2055         * guarantee that work tree matches what we are looking for.
2056         */
2057        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2058                return 0;
2059
2060        /*
2061         * If ce matches the file in the work tree, we can reuse it.
2062         */
2063        if (ce_uptodate(ce) ||
2064            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2065                return 1;
2066
2067        return 0;
2068}
2069
2070static int populate_from_stdin(struct diff_filespec *s)
2071{
2072        struct strbuf buf = STRBUF_INIT;
2073        size_t size = 0;
2074
2075        if (strbuf_read(&buf, 0, 0) < 0)
2076                return error("error while reading from stdin %s",
2077                                     strerror(errno));
2078
2079        s->should_munmap = 0;
2080        s->data = strbuf_detach(&buf, &size);
2081        s->size = size;
2082        s->should_free = 1;
2083        return 0;
2084}
2085
2086static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2087{
2088        int len;
2089        char *data = xmalloc(100), *dirty = "";
2090
2091        /* Are we looking at the work tree? */
2092        if (s->dirty_submodule)
2093                dirty = "-dirty";
2094
2095        len = snprintf(data, 100,
2096                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2097        s->data = data;
2098        s->size = len;
2099        s->should_free = 1;
2100        if (size_only) {
2101                s->data = NULL;
2102                free(data);
2103        }
2104        return 0;
2105}
2106
2107/*
2108 * While doing rename detection and pickaxe operation, we may need to
2109 * grab the data for the blob (or file) for our own in-core comparison.
2110 * diff_filespec has data and size fields for this purpose.
2111 */
2112int diff_populate_filespec(struct diff_filespec *s, int size_only)
2113{
2114        int err = 0;
2115        if (!DIFF_FILE_VALID(s))
2116                die("internal error: asking to populate invalid file.");
2117        if (S_ISDIR(s->mode))
2118                return -1;
2119
2120        if (s->data)
2121                return 0;
2122
2123        if (size_only && 0 < s->size)
2124                return 0;
2125
2126        if (S_ISGITLINK(s->mode))
2127                return diff_populate_gitlink(s, size_only);
2128
2129        if (!s->sha1_valid ||
2130            reuse_worktree_file(s->path, s->sha1, 0)) {
2131                struct strbuf buf = STRBUF_INIT;
2132                struct stat st;
2133                int fd;
2134
2135                if (!strcmp(s->path, "-"))
2136                        return populate_from_stdin(s);
2137
2138                if (lstat(s->path, &st) < 0) {
2139                        if (errno == ENOENT) {
2140                        err_empty:
2141                                err = -1;
2142                        empty:
2143                                s->data = (char *)"";
2144                                s->size = 0;
2145                                return err;
2146                        }
2147                }
2148                s->size = xsize_t(st.st_size);
2149                if (!s->size)
2150                        goto empty;
2151                if (S_ISLNK(st.st_mode)) {
2152                        struct strbuf sb = STRBUF_INIT;
2153
2154                        if (strbuf_readlink(&sb, s->path, s->size))
2155                                goto err_empty;
2156                        s->size = sb.len;
2157                        s->data = strbuf_detach(&sb, NULL);
2158                        s->should_free = 1;
2159                        return 0;
2160                }
2161                if (size_only)
2162                        return 0;
2163                fd = open(s->path, O_RDONLY);
2164                if (fd < 0)
2165                        goto err_empty;
2166                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2167                close(fd);
2168                s->should_munmap = 1;
2169
2170                /*
2171                 * Convert from working tree format to canonical git format
2172                 */
2173                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2174                        size_t size = 0;
2175                        munmap(s->data, s->size);
2176                        s->should_munmap = 0;
2177                        s->data = strbuf_detach(&buf, &size);
2178                        s->size = size;
2179                        s->should_free = 1;
2180                }
2181        }
2182        else {
2183                enum object_type type;
2184                if (size_only)
2185                        type = sha1_object_info(s->sha1, &s->size);
2186                else {
2187                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2188                        s->should_free = 1;
2189                }
2190        }
2191        return 0;
2192}
2193
2194void diff_free_filespec_blob(struct diff_filespec *s)
2195{
2196        if (s->should_free)
2197                free(s->data);
2198        else if (s->should_munmap)
2199                munmap(s->data, s->size);
2200
2201        if (s->should_free || s->should_munmap) {
2202                s->should_free = s->should_munmap = 0;
2203                s->data = NULL;
2204        }
2205}
2206
2207void diff_free_filespec_data(struct diff_filespec *s)
2208{
2209        diff_free_filespec_blob(s);
2210        free(s->cnt_data);
2211        s->cnt_data = NULL;
2212}
2213
2214static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2215                           void *blob,
2216                           unsigned long size,
2217                           const unsigned char *sha1,
2218                           int mode)
2219{
2220        int fd;
2221        struct strbuf buf = STRBUF_INIT;
2222        struct strbuf template = STRBUF_INIT;
2223        char *path_dup = xstrdup(path);
2224        const char *base = basename(path_dup);
2225
2226        /* Generate "XXXXXX_basename.ext" */
2227        strbuf_addstr(&template, "XXXXXX_");
2228        strbuf_addstr(&template, base);
2229
2230        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2231                        strlen(base) + 1);
2232        if (fd < 0)
2233                die_errno("unable to create temp-file");
2234        if (convert_to_working_tree(path,
2235                        (const char *)blob, (size_t)size, &buf)) {
2236                blob = buf.buf;
2237                size = buf.len;
2238        }
2239        if (write_in_full(fd, blob, size) != size)
2240                die_errno("unable to write temp-file");
2241        close(fd);
2242        temp->name = temp->tmp_path;
2243        strcpy(temp->hex, sha1_to_hex(sha1));
2244        temp->hex[40] = 0;
2245        sprintf(temp->mode, "%06o", mode);
2246        strbuf_release(&buf);
2247        strbuf_release(&template);
2248        free(path_dup);
2249}
2250
2251static struct diff_tempfile *prepare_temp_file(const char *name,
2252                struct diff_filespec *one)
2253{
2254        struct diff_tempfile *temp = claim_diff_tempfile();
2255
2256        if (!DIFF_FILE_VALID(one)) {
2257        not_a_valid_file:
2258                /* A '-' entry produces this for file-2, and
2259                 * a '+' entry produces this for file-1.
2260                 */
2261                temp->name = "/dev/null";
2262                strcpy(temp->hex, ".");
2263                strcpy(temp->mode, ".");
2264                return temp;
2265        }
2266
2267        if (!remove_tempfile_installed) {
2268                atexit(remove_tempfile);
2269                sigchain_push_common(remove_tempfile_on_signal);
2270                remove_tempfile_installed = 1;
2271        }
2272
2273        if (!one->sha1_valid ||
2274            reuse_worktree_file(name, one->sha1, 1)) {
2275                struct stat st;
2276                if (lstat(name, &st) < 0) {
2277                        if (errno == ENOENT)
2278                                goto not_a_valid_file;
2279                        die_errno("stat(%s)", name);
2280                }
2281                if (S_ISLNK(st.st_mode)) {
2282                        struct strbuf sb = STRBUF_INIT;
2283                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2284                                die_errno("readlink(%s)", name);
2285                        prep_temp_blob(name, temp, sb.buf, sb.len,
2286                                       (one->sha1_valid ?
2287                                        one->sha1 : null_sha1),
2288                                       (one->sha1_valid ?
2289                                        one->mode : S_IFLNK));
2290                        strbuf_release(&sb);
2291                }
2292                else {
2293                        /* we can borrow from the file in the work tree */
2294                        temp->name = name;
2295                        if (!one->sha1_valid)
2296                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2297                        else
2298                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2299                        /* Even though we may sometimes borrow the
2300                         * contents from the work tree, we always want
2301                         * one->mode.  mode is trustworthy even when
2302                         * !(one->sha1_valid), as long as
2303                         * DIFF_FILE_VALID(one).
2304                         */
2305                        sprintf(temp->mode, "%06o", one->mode);
2306                }
2307                return temp;
2308        }
2309        else {
2310                if (diff_populate_filespec(one, 0))
2311                        die("cannot read data blob for %s", one->path);
2312                prep_temp_blob(name, temp, one->data, one->size,
2313                               one->sha1, one->mode);
2314        }
2315        return temp;
2316}
2317
2318/* An external diff command takes:
2319 *
2320 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2321 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2322 *
2323 */
2324static void run_external_diff(const char *pgm,
2325                              const char *name,
2326                              const char *other,
2327                              struct diff_filespec *one,
2328                              struct diff_filespec *two,
2329                              const char *xfrm_msg,
2330                              int complete_rewrite)
2331{
2332        const char *spawn_arg[10];
2333        int retval;
2334        const char **arg = &spawn_arg[0];
2335
2336        if (one && two) {
2337                struct diff_tempfile *temp_one, *temp_two;
2338                const char *othername = (other ? other : name);
2339                temp_one = prepare_temp_file(name, one);
2340                temp_two = prepare_temp_file(othername, two);
2341                *arg++ = pgm;
2342                *arg++ = name;
2343                *arg++ = temp_one->name;
2344                *arg++ = temp_one->hex;
2345                *arg++ = temp_one->mode;
2346                *arg++ = temp_two->name;
2347                *arg++ = temp_two->hex;
2348                *arg++ = temp_two->mode;
2349                if (other) {
2350                        *arg++ = other;
2351                        *arg++ = xfrm_msg;
2352                }
2353        } else {
2354                *arg++ = pgm;
2355                *arg++ = name;
2356        }
2357        *arg = NULL;
2358        fflush(NULL);
2359        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2360        remove_tempfile();
2361        if (retval) {
2362                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2363                exit(1);
2364        }
2365}
2366
2367static int similarity_index(struct diff_filepair *p)
2368{
2369        return p->score * 100 / MAX_SCORE;
2370}
2371
2372static void fill_metainfo(struct strbuf *msg,
2373                          const char *name,
2374                          const char *other,
2375                          struct diff_filespec *one,
2376                          struct diff_filespec *two,
2377                          struct diff_options *o,
2378                          struct diff_filepair *p)
2379{
2380        strbuf_init(msg, PATH_MAX * 2 + 300);
2381        switch (p->status) {
2382        case DIFF_STATUS_COPIED:
2383                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2384                strbuf_addstr(msg, "\ncopy from ");
2385                quote_c_style(name, msg, NULL, 0);
2386                strbuf_addstr(msg, "\ncopy to ");
2387                quote_c_style(other, msg, NULL, 0);
2388                strbuf_addch(msg, '\n');
2389                break;
2390        case DIFF_STATUS_RENAMED:
2391                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2392                strbuf_addstr(msg, "\nrename from ");
2393                quote_c_style(name, msg, NULL, 0);
2394                strbuf_addstr(msg, "\nrename to ");
2395                quote_c_style(other, msg, NULL, 0);
2396                strbuf_addch(msg, '\n');
2397                break;
2398        case DIFF_STATUS_MODIFIED:
2399                if (p->score) {
2400                        strbuf_addf(msg, "dissimilarity index %d%%\n",
2401                                    similarity_index(p));
2402                        break;
2403                }
2404                /* fallthru */
2405        default:
2406                /* nothing */
2407                ;
2408        }
2409        if (one && two && hashcmp(one->sha1, two->sha1)) {
2410                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2411
2412                if (DIFF_OPT_TST(o, BINARY)) {
2413                        mmfile_t mf;
2414                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2415                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2416                                abbrev = 40;
2417                }
2418                strbuf_addf(msg, "index %.*s..%.*s",
2419                            abbrev, sha1_to_hex(one->sha1),
2420                            abbrev, sha1_to_hex(two->sha1));
2421                if (one->mode == two->mode)
2422                        strbuf_addf(msg, " %06o", one->mode);
2423                strbuf_addch(msg, '\n');
2424        }
2425        if (msg->len)
2426                strbuf_setlen(msg, msg->len - 1);
2427}
2428
2429static void run_diff_cmd(const char *pgm,
2430                         const char *name,
2431                         const char *other,
2432                         const char *attr_path,
2433                         struct diff_filespec *one,
2434                         struct diff_filespec *two,
2435                         struct strbuf *msg,
2436                         struct diff_options *o,
2437                         struct diff_filepair *p)
2438{
2439        const char *xfrm_msg = NULL;
2440        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2441
2442        if (msg) {
2443                fill_metainfo(msg, name, other, one, two, o, p);
2444                xfrm_msg = msg->len ? msg->buf : NULL;
2445        }
2446
2447        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2448                pgm = NULL;
2449        else {
2450                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2451                if (drv && drv->external)
2452                        pgm = drv->external;
2453        }
2454
2455        if (pgm) {
2456                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2457                                  complete_rewrite);
2458                return;
2459        }
2460        if (one && two)
2461                builtin_diff(name, other ? other : name,
2462                             one, two, xfrm_msg, o, complete_rewrite);
2463        else
2464                fprintf(o->file, "* Unmerged path %s\n", name);
2465}
2466
2467static void diff_fill_sha1_info(struct diff_filespec *one)
2468{
2469        if (DIFF_FILE_VALID(one)) {
2470                if (!one->sha1_valid) {
2471                        struct stat st;
2472                        if (!strcmp(one->path, "-")) {
2473                                hashcpy(one->sha1, null_sha1);
2474                                return;
2475                        }
2476                        if (lstat(one->path, &st) < 0)
2477                                die_errno("stat '%s'", one->path);
2478                        if (index_path(one->sha1, one->path, &st, 0))
2479                                die("cannot hash %s", one->path);
2480                }
2481        }
2482        else
2483                hashclr(one->sha1);
2484}
2485
2486static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2487{
2488        /* Strip the prefix but do not molest /dev/null and absolute paths */
2489        if (*namep && **namep != '/')
2490                *namep += prefix_length;
2491        if (*otherp && **otherp != '/')
2492                *otherp += prefix_length;
2493}
2494
2495static void run_diff(struct diff_filepair *p, struct diff_options *o)
2496{
2497        const char *pgm = external_diff();
2498        struct strbuf msg;
2499        struct diff_filespec *one = p->one;
2500        struct diff_filespec *two = p->two;
2501        const char *name;
2502        const char *other;
2503        const char *attr_path;
2504
2505        name  = p->one->path;
2506        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2507        attr_path = name;
2508        if (o->prefix_length)
2509                strip_prefix(o->prefix_length, &name, &other);
2510
2511        if (DIFF_PAIR_UNMERGED(p)) {
2512                run_diff_cmd(pgm, name, NULL, attr_path,
2513                             NULL, NULL, NULL, o, p);
2514                return;
2515        }
2516
2517        diff_fill_sha1_info(one);
2518        diff_fill_sha1_info(two);
2519
2520        if (!pgm &&
2521            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2522            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2523                /*
2524                 * a filepair that changes between file and symlink
2525                 * needs to be split into deletion and creation.
2526                 */
2527                struct diff_filespec *null = alloc_filespec(two->path);
2528                run_diff_cmd(NULL, name, other, attr_path,
2529                             one, null, &msg, o, p);
2530                free(null);
2531                strbuf_release(&msg);
2532
2533                null = alloc_filespec(one->path);
2534                run_diff_cmd(NULL, name, other, attr_path,
2535                             null, two, &msg, o, p);
2536                free(null);
2537        }
2538        else
2539                run_diff_cmd(pgm, name, other, attr_path,
2540                             one, two, &msg, o, p);
2541
2542        strbuf_release(&msg);
2543}
2544
2545static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2546                         struct diffstat_t *diffstat)
2547{
2548        const char *name;
2549        const char *other;
2550        int complete_rewrite = 0;
2551
2552        if (DIFF_PAIR_UNMERGED(p)) {
2553                /* unmerged */
2554                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2555                return;
2556        }
2557
2558        name = p->one->path;
2559        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2560
2561        if (o->prefix_length)
2562                strip_prefix(o->prefix_length, &name, &other);
2563
2564        diff_fill_sha1_info(p->one);
2565        diff_fill_sha1_info(p->two);
2566
2567        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2568                complete_rewrite = 1;
2569        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2570}
2571
2572static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2573{
2574        const char *name;
2575        const char *other;
2576        const char *attr_path;
2577
2578        if (DIFF_PAIR_UNMERGED(p)) {
2579                /* unmerged */
2580                return;
2581        }
2582
2583        name = p->one->path;
2584        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2585        attr_path = other ? other : name;
2586
2587        if (o->prefix_length)
2588                strip_prefix(o->prefix_length, &name, &other);
2589
2590        diff_fill_sha1_info(p->one);
2591        diff_fill_sha1_info(p->two);
2592
2593        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2594}
2595
2596void diff_setup(struct diff_options *options)
2597{
2598        memset(options, 0, sizeof(*options));
2599        memset(&diff_queued_diff, 0, sizeof(diff_queued_diff));
2600
2601        options->file = stdout;
2602
2603        options->line_termination = '\n';
2604        options->break_opt = -1;
2605        options->rename_limit = -1;
2606        options->dirstat_percent = 3;
2607        options->context = 3;
2608
2609        options->change = diff_change;
2610        options->add_remove = diff_addremove;
2611        if (diff_use_color_default > 0)
2612                DIFF_OPT_SET(options, COLOR_DIFF);
2613        options->detect_rename = diff_detect_rename_default;
2614
2615        if (!diff_mnemonic_prefix) {
2616                options->a_prefix = "a/";
2617                options->b_prefix = "b/";
2618        }
2619}
2620
2621int diff_setup_done(struct diff_options *options)
2622{
2623        int count = 0;
2624
2625        if (options->output_format & DIFF_FORMAT_NAME)
2626                count++;
2627        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2628                count++;
2629        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2630                count++;
2631        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2632                count++;
2633        if (count > 1)
2634                die("--name-only, --name-status, --check and -s are mutually exclusive");
2635
2636        /*
2637         * Most of the time we can say "there are changes"
2638         * only by checking if there are changed paths, but
2639         * --ignore-whitespace* options force us to look
2640         * inside contents.
2641         */
2642
2643        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2644            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2645            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2646                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2647        else
2648                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2649
2650        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2651                options->detect_rename = DIFF_DETECT_COPY;
2652
2653        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2654                options->prefix = NULL;
2655        if (options->prefix)
2656                options->prefix_length = strlen(options->prefix);
2657        else
2658                options->prefix_length = 0;
2659
2660        if (options->output_format & (DIFF_FORMAT_NAME |
2661                                      DIFF_FORMAT_NAME_STATUS |
2662                                      DIFF_FORMAT_CHECKDIFF |
2663                                      DIFF_FORMAT_NO_OUTPUT))
2664                options->output_format &= ~(DIFF_FORMAT_RAW |
2665                                            DIFF_FORMAT_NUMSTAT |
2666                                            DIFF_FORMAT_DIFFSTAT |
2667                                            DIFF_FORMAT_SHORTSTAT |
2668                                            DIFF_FORMAT_DIRSTAT |
2669                                            DIFF_FORMAT_SUMMARY |
2670                                            DIFF_FORMAT_PATCH);
2671
2672        /*
2673         * These cases always need recursive; we do not drop caller-supplied
2674         * recursive bits for other formats here.
2675         */
2676        if (options->output_format & (DIFF_FORMAT_PATCH |
2677                                      DIFF_FORMAT_NUMSTAT |
2678                                      DIFF_FORMAT_DIFFSTAT |
2679                                      DIFF_FORMAT_SHORTSTAT |
2680                                      DIFF_FORMAT_DIRSTAT |
2681                                      DIFF_FORMAT_SUMMARY |
2682                                      DIFF_FORMAT_CHECKDIFF))
2683                DIFF_OPT_SET(options, RECURSIVE);
2684        /*
2685         * Also pickaxe would not work very well if you do not say recursive
2686         */
2687        if (options->pickaxe)
2688                DIFF_OPT_SET(options, RECURSIVE);
2689        /*
2690         * When patches are generated, submodules diffed against the work tree
2691         * must be checked for dirtiness too so it can be shown in the output
2692         */
2693        if (options->output_format & DIFF_FORMAT_PATCH)
2694                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2695
2696        if (options->detect_rename && options->rename_limit < 0)
2697                options->rename_limit = diff_rename_limit_default;
2698        if (options->setup & DIFF_SETUP_USE_CACHE) {
2699                if (!active_cache)
2700                        /* read-cache does not die even when it fails
2701                         * so it is safe for us to do this here.  Also
2702                         * it does not smudge active_cache or active_nr
2703                         * when it fails, so we do not have to worry about
2704                         * cleaning it up ourselves either.
2705                         */
2706                        read_cache();
2707        }
2708        if (options->abbrev <= 0 || 40 < options->abbrev)
2709                options->abbrev = 40; /* full */
2710
2711        /*
2712         * It does not make sense to show the first hit we happened
2713         * to have found.  It does not make sense not to return with
2714         * exit code in such a case either.
2715         */
2716        if (DIFF_OPT_TST(options, QUICK)) {
2717                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2718                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2719        }
2720
2721        return 0;
2722}
2723
2724static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2725{
2726        char c, *eq;
2727        int len;
2728
2729        if (*arg != '-')
2730                return 0;
2731        c = *++arg;
2732        if (!c)
2733                return 0;
2734        if (c == arg_short) {
2735                c = *++arg;
2736                if (!c)
2737                        return 1;
2738                if (val && isdigit(c)) {
2739                        char *end;
2740                        int n = strtoul(arg, &end, 10);
2741                        if (*end)
2742                                return 0;
2743                        *val = n;
2744                        return 1;
2745                }
2746                return 0;
2747        }
2748        if (c != '-')
2749                return 0;
2750        arg++;
2751        eq = strchr(arg, '=');
2752        if (eq)
2753                len = eq - arg;
2754        else
2755                len = strlen(arg);
2756        if (!len || strncmp(arg, arg_long, len))
2757                return 0;
2758        if (eq) {
2759                int n;
2760                char *end;
2761                if (!isdigit(*++eq))
2762                        return 0;
2763                n = strtoul(eq, &end, 10);
2764                if (*end)
2765                        return 0;
2766                *val = n;
2767        }
2768        return 1;
2769}
2770
2771static int diff_scoreopt_parse(const char *opt);
2772
2773int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2774{
2775        const char *arg = av[0];
2776
2777        /* Output format options */
2778        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
2779                options->output_format |= DIFF_FORMAT_PATCH;
2780        else if (opt_arg(arg, 'U', "unified", &options->context))
2781                options->output_format |= DIFF_FORMAT_PATCH;
2782        else if (!strcmp(arg, "--raw"))
2783                options->output_format |= DIFF_FORMAT_RAW;
2784        else if (!strcmp(arg, "--patch-with-raw"))
2785                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2786        else if (!strcmp(arg, "--numstat"))
2787                options->output_format |= DIFF_FORMAT_NUMSTAT;
2788        else if (!strcmp(arg, "--shortstat"))
2789                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2790        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2791                options->output_format |= DIFF_FORMAT_DIRSTAT;
2792        else if (!strcmp(arg, "--cumulative")) {
2793                options->output_format |= DIFF_FORMAT_DIRSTAT;
2794                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2795        } else if (opt_arg(arg, 0, "dirstat-by-file",
2796                           &options->dirstat_percent)) {
2797                options->output_format |= DIFF_FORMAT_DIRSTAT;
2798                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2799        }
2800        else if (!strcmp(arg, "--check"))
2801                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2802        else if (!strcmp(arg, "--summary"))
2803                options->output_format |= DIFF_FORMAT_SUMMARY;
2804        else if (!strcmp(arg, "--patch-with-stat"))
2805                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2806        else if (!strcmp(arg, "--name-only"))
2807                options->output_format |= DIFF_FORMAT_NAME;
2808        else if (!strcmp(arg, "--name-status"))
2809                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2810        else if (!strcmp(arg, "-s"))
2811                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2812        else if (!prefixcmp(arg, "--stat")) {
2813                char *end;
2814                int width = options->stat_width;
2815                int name_width = options->stat_name_width;
2816                arg += 6;
2817                end = (char *)arg;
2818
2819                switch (*arg) {
2820                case '-':
2821                        if (!prefixcmp(arg, "-width="))
2822                                width = strtoul(arg + 7, &end, 10);
2823                        else if (!prefixcmp(arg, "-name-width="))
2824                                name_width = strtoul(arg + 12, &end, 10);
2825                        break;
2826                case '=':
2827                        width = strtoul(arg+1, &end, 10);
2828                        if (*end == ',')
2829                                name_width = strtoul(end+1, &end, 10);
2830                }
2831
2832                /* Important! This checks all the error cases! */
2833                if (*end)
2834                        return 0;
2835                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2836                options->stat_name_width = name_width;
2837                options->stat_width = width;
2838        }
2839
2840        /* renames options */
2841        else if (!prefixcmp(arg, "-B")) {
2842                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2843                        return -1;
2844        }
2845        else if (!prefixcmp(arg, "-M")) {
2846                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2847                        return -1;
2848                options->detect_rename = DIFF_DETECT_RENAME;
2849        }
2850        else if (!prefixcmp(arg, "-C")) {
2851                if (options->detect_rename == DIFF_DETECT_COPY)
2852                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2853                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2854                        return -1;
2855                options->detect_rename = DIFF_DETECT_COPY;
2856        }
2857        else if (!strcmp(arg, "--no-renames"))
2858                options->detect_rename = 0;
2859        else if (!strcmp(arg, "--relative"))
2860                DIFF_OPT_SET(options, RELATIVE_NAME);
2861        else if (!prefixcmp(arg, "--relative=")) {
2862                DIFF_OPT_SET(options, RELATIVE_NAME);
2863                options->prefix = arg + 11;
2864        }
2865
2866        /* xdiff options */
2867        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2868                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2869        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2870                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2871        else if (!strcmp(arg, "--ignore-space-at-eol"))
2872                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2873        else if (!strcmp(arg, "--patience"))
2874                DIFF_XDL_SET(options, PATIENCE_DIFF);
2875
2876        /* flags options */
2877        else if (!strcmp(arg, "--binary")) {
2878                options->output_format |= DIFF_FORMAT_PATCH;
2879                DIFF_OPT_SET(options, BINARY);
2880        }
2881        else if (!strcmp(arg, "--full-index"))
2882                DIFF_OPT_SET(options, FULL_INDEX);
2883        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2884                DIFF_OPT_SET(options, TEXT);
2885        else if (!strcmp(arg, "-R"))
2886                DIFF_OPT_SET(options, REVERSE_DIFF);
2887        else if (!strcmp(arg, "--find-copies-harder"))
2888                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2889        else if (!strcmp(arg, "--follow"))
2890                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2891        else if (!strcmp(arg, "--color"))
2892                DIFF_OPT_SET(options, COLOR_DIFF);
2893        else if (!prefixcmp(arg, "--color=")) {
2894                int value = git_config_colorbool(NULL, arg+8, -1);
2895                if (value == 0)
2896                        DIFF_OPT_CLR(options, COLOR_DIFF);
2897                else if (value > 0)
2898                        DIFF_OPT_SET(options, COLOR_DIFF);
2899                else
2900                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
2901        }
2902        else if (!strcmp(arg, "--no-color"))
2903                DIFF_OPT_CLR(options, COLOR_DIFF);
2904        else if (!strcmp(arg, "--color-words")) {
2905                DIFF_OPT_SET(options, COLOR_DIFF);
2906                options->word_diff = DIFF_WORDS_COLOR;
2907        }
2908        else if (!prefixcmp(arg, "--color-words=")) {
2909                DIFF_OPT_SET(options, COLOR_DIFF);
2910                options->word_diff = DIFF_WORDS_COLOR;
2911                options->word_regex = arg + 14;
2912        }
2913        else if (!strcmp(arg, "--word-diff")) {
2914                if (options->word_diff == DIFF_WORDS_NONE)
2915                        options->word_diff = DIFF_WORDS_PLAIN;
2916        }
2917        else if (!prefixcmp(arg, "--word-diff=")) {
2918                const char *type = arg + 12;
2919                if (!strcmp(type, "plain"))
2920                        options->word_diff = DIFF_WORDS_PLAIN;
2921                else if (!strcmp(type, "color")) {
2922                        DIFF_OPT_SET(options, COLOR_DIFF);
2923                        options->word_diff = DIFF_WORDS_COLOR;
2924                }
2925                else if (!strcmp(type, "porcelain"))
2926                        options->word_diff = DIFF_WORDS_PORCELAIN;
2927                else if (!strcmp(type, "none"))
2928                        options->word_diff = DIFF_WORDS_NONE;
2929                else
2930                        die("bad --word-diff argument: %s", type);
2931        }
2932        else if (!prefixcmp(arg, "--word-diff-regex=")) {
2933                if (options->word_diff == DIFF_WORDS_NONE)
2934                        options->word_diff = DIFF_WORDS_PLAIN;
2935                options->word_regex = arg + 18;
2936        }
2937        else if (!strcmp(arg, "--exit-code"))
2938                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2939        else if (!strcmp(arg, "--quiet"))
2940                DIFF_OPT_SET(options, QUICK);
2941        else if (!strcmp(arg, "--ext-diff"))
2942                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2943        else if (!strcmp(arg, "--no-ext-diff"))
2944                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2945        else if (!strcmp(arg, "--textconv"))
2946                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2947        else if (!strcmp(arg, "--no-textconv"))
2948                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2949        else if (!strcmp(arg, "--ignore-submodules"))
2950                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2951        else if (!strcmp(arg, "--submodule"))
2952                DIFF_OPT_SET(options, SUBMODULE_LOG);
2953        else if (!prefixcmp(arg, "--submodule=")) {
2954                if (!strcmp(arg + 12, "log"))
2955                        DIFF_OPT_SET(options, SUBMODULE_LOG);
2956        }
2957
2958        /* misc options */
2959        else if (!strcmp(arg, "-z"))
2960                options->line_termination = 0;
2961        else if (!prefixcmp(arg, "-l"))
2962                options->rename_limit = strtoul(arg+2, NULL, 10);
2963        else if (!prefixcmp(arg, "-S"))
2964                options->pickaxe = arg + 2;
2965        else if (!strcmp(arg, "--pickaxe-all"))
2966                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2967        else if (!strcmp(arg, "--pickaxe-regex"))
2968                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2969        else if (!prefixcmp(arg, "-O"))
2970                options->orderfile = arg + 2;
2971        else if (!prefixcmp(arg, "--diff-filter="))
2972                options->filter = arg + 14;
2973        else if (!strcmp(arg, "--abbrev"))
2974                options->abbrev = DEFAULT_ABBREV;
2975        else if (!prefixcmp(arg, "--abbrev=")) {
2976                options->abbrev = strtoul(arg + 9, NULL, 10);
2977                if (options->abbrev < MINIMUM_ABBREV)
2978                        options->abbrev = MINIMUM_ABBREV;
2979                else if (40 < options->abbrev)
2980                        options->abbrev = 40;
2981        }
2982        else if (!prefixcmp(arg, "--src-prefix="))
2983                options->a_prefix = arg + 13;
2984        else if (!prefixcmp(arg, "--dst-prefix="))
2985                options->b_prefix = arg + 13;
2986        else if (!strcmp(arg, "--no-prefix"))
2987                options->a_prefix = options->b_prefix = "";
2988        else if (opt_arg(arg, '\0', "inter-hunk-context",
2989                         &options->interhunkcontext))
2990                ;
2991        else if (!prefixcmp(arg, "--output=")) {
2992                options->file = fopen(arg + strlen("--output="), "w");
2993                if (!options->file)
2994                        die_errno("Could not open '%s'", arg + strlen("--output="));
2995                options->close_file = 1;
2996        } else
2997                return 0;
2998        return 1;
2999}
3000
3001static int parse_num(const char **cp_p)
3002{
3003        unsigned long num, scale;
3004        int ch, dot;
3005        const char *cp = *cp_p;
3006
3007        num = 0;
3008        scale = 1;
3009        dot = 0;
3010        for (;;) {
3011                ch = *cp;
3012                if ( !dot && ch == '.' ) {
3013                        scale = 1;
3014                        dot = 1;
3015                } else if ( ch == '%' ) {
3016                        scale = dot ? scale*100 : 100;
3017                        cp++;   /* % is always at the end */
3018                        break;
3019                } else if ( ch >= '0' && ch <= '9' ) {
3020                        if ( scale < 100000 ) {
3021                                scale *= 10;
3022                                num = (num*10) + (ch-'0');
3023                        }
3024                } else {
3025                        break;
3026                }
3027                cp++;
3028        }
3029        *cp_p = cp;
3030
3031        /* user says num divided by scale and we say internally that
3032         * is MAX_SCORE * num / scale.
3033         */
3034        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3035}
3036
3037static int diff_scoreopt_parse(const char *opt)
3038{
3039        int opt1, opt2, cmd;
3040
3041        if (*opt++ != '-')
3042                return -1;
3043        cmd = *opt++;
3044        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3045                return -1; /* that is not a -M, -C nor -B option */
3046
3047        opt1 = parse_num(&opt);
3048        if (cmd != 'B')
3049                opt2 = 0;
3050        else {
3051                if (*opt == 0)
3052                        opt2 = 0;
3053                else if (*opt != '/')
3054                        return -1; /* we expect -B80/99 or -B80 */
3055                else {
3056                        opt++;
3057                        opt2 = parse_num(&opt);
3058                }
3059        }
3060        if (*opt != 0)
3061                return -1;
3062        return opt1 | (opt2 << 16);
3063}
3064
3065struct diff_queue_struct diff_queued_diff;
3066
3067void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3068{
3069        if (queue->alloc <= queue->nr) {
3070                queue->alloc = alloc_nr(queue->alloc);
3071                queue->queue = xrealloc(queue->queue,
3072                                        sizeof(dp) * queue->alloc);
3073        }
3074        queue->queue[queue->nr++] = dp;
3075}
3076
3077struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3078                                 struct diff_filespec *one,
3079                                 struct diff_filespec *two)
3080{
3081        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3082        dp->one = one;
3083        dp->two = two;
3084        if (queue)
3085                diff_q(queue, dp);
3086        return dp;
3087}
3088
3089void diff_free_filepair(struct diff_filepair *p)
3090{
3091        free_filespec(p->one);
3092        free_filespec(p->two);
3093        free(p);
3094}
3095
3096/* This is different from find_unique_abbrev() in that
3097 * it stuffs the result with dots for alignment.
3098 */
3099const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3100{
3101        int abblen;
3102        const char *abbrev;
3103        if (len == 40)
3104                return sha1_to_hex(sha1);
3105
3106        abbrev = find_unique_abbrev(sha1, len);
3107        abblen = strlen(abbrev);
3108        if (abblen < 37) {
3109                static char hex[41];
3110                if (len < abblen && abblen <= len + 2)
3111                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3112                else
3113                        sprintf(hex, "%s...", abbrev);
3114                return hex;
3115        }
3116        return sha1_to_hex(sha1);
3117}
3118
3119static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3120{
3121        int line_termination = opt->line_termination;
3122        int inter_name_termination = line_termination ? '\t' : '\0';
3123
3124        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3125                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3126                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3127                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3128        }
3129        if (p->score) {
3130                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3131                        inter_name_termination);
3132        } else {
3133                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3134        }
3135
3136        if (p->status == DIFF_STATUS_COPIED ||
3137            p->status == DIFF_STATUS_RENAMED) {
3138                const char *name_a, *name_b;
3139                name_a = p->one->path;
3140                name_b = p->two->path;
3141                strip_prefix(opt->prefix_length, &name_a, &name_b);
3142                write_name_quoted(name_a, opt->file, inter_name_termination);
3143                write_name_quoted(name_b, opt->file, line_termination);
3144        } else {
3145                const char *name_a, *name_b;
3146                name_a = p->one->mode ? p->one->path : p->two->path;
3147                name_b = NULL;
3148                strip_prefix(opt->prefix_length, &name_a, &name_b);
3149                write_name_quoted(name_a, opt->file, line_termination);
3150        }
3151}
3152
3153int diff_unmodified_pair(struct diff_filepair *p)
3154{
3155        /* This function is written stricter than necessary to support
3156         * the currently implemented transformers, but the idea is to
3157         * let transformers to produce diff_filepairs any way they want,
3158         * and filter and clean them up here before producing the output.
3159         */
3160        struct diff_filespec *one = p->one, *two = p->two;
3161
3162        if (DIFF_PAIR_UNMERGED(p))
3163                return 0; /* unmerged is interesting */
3164
3165        /* deletion, addition, mode or type change
3166         * and rename are all interesting.
3167         */
3168        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3169            DIFF_PAIR_MODE_CHANGED(p) ||
3170            strcmp(one->path, two->path))
3171                return 0;
3172
3173        /* both are valid and point at the same path.  that is, we are
3174         * dealing with a change.
3175         */
3176        if (one->sha1_valid && two->sha1_valid &&
3177            !hashcmp(one->sha1, two->sha1) &&
3178            !one->dirty_submodule && !two->dirty_submodule)
3179                return 1; /* no change */
3180        if (!one->sha1_valid && !two->sha1_valid)
3181                return 1; /* both look at the same file on the filesystem. */
3182        return 0;
3183}
3184
3185static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3186{
3187        if (diff_unmodified_pair(p))
3188                return;
3189
3190        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3191            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3192                return; /* no tree diffs in patch format */
3193
3194        run_diff(p, o);
3195}
3196
3197static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3198                            struct diffstat_t *diffstat)
3199{
3200        if (diff_unmodified_pair(p))
3201                return;
3202
3203        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3204            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3205                return; /* no tree diffs in patch format */
3206
3207        run_diffstat(p, o, diffstat);
3208}
3209
3210static void diff_flush_checkdiff(struct diff_filepair *p,
3211                struct diff_options *o)
3212{
3213        if (diff_unmodified_pair(p))
3214                return;
3215
3216        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3217            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3218                return; /* no tree diffs in patch format */
3219
3220        run_checkdiff(p, o);
3221}
3222
3223int diff_queue_is_empty(void)
3224{
3225        struct diff_queue_struct *q = &diff_queued_diff;
3226        int i;
3227        for (i = 0; i < q->nr; i++)
3228                if (!diff_unmodified_pair(q->queue[i]))
3229                        return 0;
3230        return 1;
3231}
3232
3233#if DIFF_DEBUG
3234void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3235{
3236        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3237                x, one ? one : "",
3238                s->path,
3239                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3240                s->mode,
3241                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3242        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3243                x, one ? one : "",
3244                s->size, s->xfrm_flags);
3245}
3246
3247void diff_debug_filepair(const struct diff_filepair *p, int i)
3248{
3249        diff_debug_filespec(p->one, i, "one");
3250        diff_debug_filespec(p->two, i, "two");
3251        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3252                p->score, p->status ? p->status : '?',
3253                p->one->rename_used, p->broken_pair);
3254}
3255
3256void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3257{
3258        int i;
3259        if (msg)
3260                fprintf(stderr, "%s\n", msg);
3261        fprintf(stderr, "q->nr = %d\n", q->nr);
3262        for (i = 0; i < q->nr; i++) {
3263                struct diff_filepair *p = q->queue[i];
3264                diff_debug_filepair(p, i);
3265        }
3266}
3267#endif
3268
3269static void diff_resolve_rename_copy(void)
3270{
3271        int i;
3272        struct diff_filepair *p;
3273        struct diff_queue_struct *q = &diff_queued_diff;
3274
3275        diff_debug_queue("resolve-rename-copy", q);
3276
3277        for (i = 0; i < q->nr; i++) {
3278                p = q->queue[i];
3279                p->status = 0; /* undecided */
3280                if (DIFF_PAIR_UNMERGED(p))
3281                        p->status = DIFF_STATUS_UNMERGED;
3282                else if (!DIFF_FILE_VALID(p->one))
3283                        p->status = DIFF_STATUS_ADDED;
3284                else if (!DIFF_FILE_VALID(p->two))
3285                        p->status = DIFF_STATUS_DELETED;
3286                else if (DIFF_PAIR_TYPE_CHANGED(p))
3287                        p->status = DIFF_STATUS_TYPE_CHANGED;
3288
3289                /* from this point on, we are dealing with a pair
3290                 * whose both sides are valid and of the same type, i.e.
3291                 * either in-place edit or rename/copy edit.
3292                 */
3293                else if (DIFF_PAIR_RENAME(p)) {
3294                        /*
3295                         * A rename might have re-connected a broken
3296                         * pair up, causing the pathnames to be the
3297                         * same again. If so, that's not a rename at
3298                         * all, just a modification..
3299                         *
3300                         * Otherwise, see if this source was used for
3301                         * multiple renames, in which case we decrement
3302                         * the count, and call it a copy.
3303                         */
3304                        if (!strcmp(p->one->path, p->two->path))
3305                                p->status = DIFF_STATUS_MODIFIED;
3306                        else if (--p->one->rename_used > 0)
3307                                p->status = DIFF_STATUS_COPIED;
3308                        else
3309                                p->status = DIFF_STATUS_RENAMED;
3310                }
3311                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3312                         p->one->mode != p->two->mode ||
3313                         p->one->dirty_submodule ||
3314                         p->two->dirty_submodule ||
3315                         is_null_sha1(p->one->sha1))
3316                        p->status = DIFF_STATUS_MODIFIED;
3317                else {
3318                        /* This is a "no-change" entry and should not
3319                         * happen anymore, but prepare for broken callers.
3320                         */
3321                        error("feeding unmodified %s to diffcore",
3322                              p->one->path);
3323                        p->status = DIFF_STATUS_UNKNOWN;
3324                }
3325        }
3326        diff_debug_queue("resolve-rename-copy done", q);
3327}
3328
3329static int check_pair_status(struct diff_filepair *p)
3330{
3331        switch (p->status) {
3332        case DIFF_STATUS_UNKNOWN:
3333                return 0;
3334        case 0:
3335                die("internal error in diff-resolve-rename-copy");
3336        default:
3337                return 1;
3338        }
3339}
3340
3341static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3342{
3343        int fmt = opt->output_format;
3344
3345        if (fmt & DIFF_FORMAT_CHECKDIFF)
3346                diff_flush_checkdiff(p, opt);
3347        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3348                diff_flush_raw(p, opt);
3349        else if (fmt & DIFF_FORMAT_NAME) {
3350                const char *name_a, *name_b;
3351                name_a = p->two->path;
3352                name_b = NULL;
3353                strip_prefix(opt->prefix_length, &name_a, &name_b);
3354                write_name_quoted(name_a, opt->file, opt->line_termination);
3355        }
3356}
3357
3358static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3359{
3360        if (fs->mode)
3361                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3362        else
3363                fprintf(file, " %s ", newdelete);
3364        write_name_quoted(fs->path, file, '\n');
3365}
3366
3367
3368static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3369{
3370        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3371                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3372                        show_name ? ' ' : '\n');
3373                if (show_name) {
3374                        write_name_quoted(p->two->path, file, '\n');
3375                }
3376        }
3377}
3378
3379static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3380{
3381        char *names = pprint_rename(p->one->path, p->two->path);
3382
3383        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3384        free(names);
3385        show_mode_change(file, p, 0);
3386}
3387
3388static void diff_summary(FILE *file, struct diff_filepair *p)
3389{
3390        switch(p->status) {
3391        case DIFF_STATUS_DELETED:
3392                show_file_mode_name(file, "delete", p->one);
3393                break;
3394        case DIFF_STATUS_ADDED:
3395                show_file_mode_name(file, "create", p->two);
3396                break;
3397        case DIFF_STATUS_COPIED:
3398                show_rename_copy(file, "copy", p);
3399                break;
3400        case DIFF_STATUS_RENAMED:
3401                show_rename_copy(file, "rename", p);
3402                break;
3403        default:
3404                if (p->score) {
3405                        fputs(" rewrite ", file);
3406                        write_name_quoted(p->two->path, file, ' ');
3407                        fprintf(file, "(%d%%)\n", similarity_index(p));
3408                }
3409                show_mode_change(file, p, !p->score);
3410                break;
3411        }
3412}
3413
3414struct patch_id_t {
3415        git_SHA_CTX *ctx;
3416        int patchlen;
3417};
3418
3419static int remove_space(char *line, int len)
3420{
3421        int i;
3422        char *dst = line;
3423        unsigned char c;
3424
3425        for (i = 0; i < len; i++)
3426                if (!isspace((c = line[i])))
3427                        *dst++ = c;
3428
3429        return dst - line;
3430}
3431
3432static void patch_id_consume(void *priv, char *line, unsigned long len)
3433{
3434        struct patch_id_t *data = priv;
3435        int new_len;
3436
3437        /* Ignore line numbers when computing the SHA1 of the patch */
3438        if (!prefixcmp(line, "@@ -"))
3439                return;
3440
3441        new_len = remove_space(line, len);
3442
3443        git_SHA1_Update(data->ctx, line, new_len);
3444        data->patchlen += new_len;
3445}
3446
3447/* returns 0 upon success, and writes result into sha1 */
3448static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3449{
3450        struct diff_queue_struct *q = &diff_queued_diff;
3451        int i;
3452        git_SHA_CTX ctx;
3453        struct patch_id_t data;
3454        char buffer[PATH_MAX * 4 + 20];
3455
3456        git_SHA1_Init(&ctx);
3457        memset(&data, 0, sizeof(struct patch_id_t));
3458        data.ctx = &ctx;
3459
3460        for (i = 0; i < q->nr; i++) {
3461                xpparam_t xpp;
3462                xdemitconf_t xecfg;
3463                mmfile_t mf1, mf2;
3464                struct diff_filepair *p = q->queue[i];
3465                int len1, len2;
3466
3467                memset(&xpp, 0, sizeof(xpp));
3468                memset(&xecfg, 0, sizeof(xecfg));
3469                if (p->status == 0)
3470                        return error("internal diff status error");
3471                if (p->status == DIFF_STATUS_UNKNOWN)
3472                        continue;
3473                if (diff_unmodified_pair(p))
3474                        continue;
3475                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3476                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3477                        continue;
3478                if (DIFF_PAIR_UNMERGED(p))
3479                        continue;
3480
3481                diff_fill_sha1_info(p->one);
3482                diff_fill_sha1_info(p->two);
3483                if (fill_mmfile(&mf1, p->one) < 0 ||
3484                                fill_mmfile(&mf2, p->two) < 0)
3485                        return error("unable to read files to diff");
3486
3487                len1 = remove_space(p->one->path, strlen(p->one->path));
3488                len2 = remove_space(p->two->path, strlen(p->two->path));
3489                if (p->one->mode == 0)
3490                        len1 = snprintf(buffer, sizeof(buffer),
3491                                        "diff--gita/%.*sb/%.*s"
3492                                        "newfilemode%06o"
3493                                        "---/dev/null"
3494                                        "+++b/%.*s",
3495                                        len1, p->one->path,
3496                                        len2, p->two->path,
3497                                        p->two->mode,
3498                                        len2, p->two->path);
3499                else if (p->two->mode == 0)
3500                        len1 = snprintf(buffer, sizeof(buffer),
3501                                        "diff--gita/%.*sb/%.*s"
3502                                        "deletedfilemode%06o"
3503                                        "---a/%.*s"
3504                                        "+++/dev/null",
3505                                        len1, p->one->path,
3506                                        len2, p->two->path,
3507                                        p->one->mode,
3508                                        len1, p->one->path);
3509                else
3510                        len1 = snprintf(buffer, sizeof(buffer),
3511                                        "diff--gita/%.*sb/%.*s"
3512                                        "---a/%.*s"
3513                                        "+++b/%.*s",
3514                                        len1, p->one->path,
3515                                        len2, p->two->path,
3516                                        len1, p->one->path,
3517                                        len2, p->two->path);
3518                git_SHA1_Update(&ctx, buffer, len1);
3519
3520                xpp.flags = XDF_NEED_MINIMAL;
3521                xecfg.ctxlen = 3;
3522                xecfg.flags = XDL_EMIT_FUNCNAMES;
3523                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3524                              &xpp, &xecfg);
3525        }
3526
3527        git_SHA1_Final(sha1, &ctx);
3528        return 0;
3529}
3530
3531int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3532{
3533        struct diff_queue_struct *q = &diff_queued_diff;
3534        int i;
3535        int result = diff_get_patch_id(options, sha1);
3536
3537        for (i = 0; i < q->nr; i++)
3538                diff_free_filepair(q->queue[i]);
3539
3540        free(q->queue);
3541        DIFF_QUEUE_CLEAR(q);
3542
3543        return result;
3544}
3545
3546static int is_summary_empty(const struct diff_queue_struct *q)
3547{
3548        int i;
3549
3550        for (i = 0; i < q->nr; i++) {
3551                const struct diff_filepair *p = q->queue[i];
3552
3553                switch (p->status) {
3554                case DIFF_STATUS_DELETED:
3555                case DIFF_STATUS_ADDED:
3556                case DIFF_STATUS_COPIED:
3557                case DIFF_STATUS_RENAMED:
3558                        return 0;
3559                default:
3560                        if (p->score)
3561                                return 0;
3562                        if (p->one->mode && p->two->mode &&
3563                            p->one->mode != p->two->mode)
3564                                return 0;
3565                        break;
3566                }
3567        }
3568        return 1;
3569}
3570
3571void diff_flush(struct diff_options *options)
3572{
3573        struct diff_queue_struct *q = &diff_queued_diff;
3574        int i, output_format = options->output_format;
3575        int separator = 0;
3576
3577        /*
3578         * Order: raw, stat, summary, patch
3579         * or:    name/name-status/checkdiff (other bits clear)
3580         */
3581        if (!q->nr)
3582                goto free_queue;
3583
3584        if (output_format & (DIFF_FORMAT_RAW |
3585                             DIFF_FORMAT_NAME |
3586                             DIFF_FORMAT_NAME_STATUS |
3587                             DIFF_FORMAT_CHECKDIFF)) {
3588                for (i = 0; i < q->nr; i++) {
3589                        struct diff_filepair *p = q->queue[i];
3590                        if (check_pair_status(p))
3591                                flush_one_pair(p, options);
3592                }
3593                separator++;
3594        }
3595
3596        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3597                struct diffstat_t diffstat;
3598
3599                memset(&diffstat, 0, sizeof(struct diffstat_t));
3600                for (i = 0; i < q->nr; i++) {
3601                        struct diff_filepair *p = q->queue[i];
3602                        if (check_pair_status(p))
3603                                diff_flush_stat(p, options, &diffstat);
3604                }
3605                if (output_format & DIFF_FORMAT_NUMSTAT)
3606                        show_numstat(&diffstat, options);
3607                if (output_format & DIFF_FORMAT_DIFFSTAT)
3608                        show_stats(&diffstat, options);
3609                if (output_format & DIFF_FORMAT_SHORTSTAT)
3610                        show_shortstats(&diffstat, options);
3611                free_diffstat_info(&diffstat);
3612                separator++;
3613        }
3614        if (output_format & DIFF_FORMAT_DIRSTAT)
3615                show_dirstat(options);
3616
3617        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3618                for (i = 0; i < q->nr; i++)
3619                        diff_summary(options->file, q->queue[i]);
3620                separator++;
3621        }
3622
3623        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3624            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3625            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3626                /*
3627                 * run diff_flush_patch for the exit status. setting
3628                 * options->file to /dev/null should be safe, becaue we
3629                 * aren't supposed to produce any output anyway.
3630                 */
3631                if (options->close_file)
3632                        fclose(options->file);
3633                options->file = fopen("/dev/null", "w");
3634                if (!options->file)
3635                        die_errno("Could not open /dev/null");
3636                options->close_file = 1;
3637                for (i = 0; i < q->nr; i++) {
3638                        struct diff_filepair *p = q->queue[i];
3639                        if (check_pair_status(p))
3640                                diff_flush_patch(p, options);
3641                        if (options->found_changes)
3642                                break;
3643                }
3644        }
3645
3646        if (output_format & DIFF_FORMAT_PATCH) {
3647                if (separator) {
3648                        putc(options->line_termination, options->file);
3649                        if (options->stat_sep) {
3650                                /* attach patch instead of inline */
3651                                fputs(options->stat_sep, options->file);
3652                        }
3653                }
3654
3655                for (i = 0; i < q->nr; i++) {
3656                        struct diff_filepair *p = q->queue[i];
3657                        if (check_pair_status(p))
3658                                diff_flush_patch(p, options);
3659                }
3660        }
3661
3662        if (output_format & DIFF_FORMAT_CALLBACK)
3663                options->format_callback(q, options, options->format_callback_data);
3664
3665        for (i = 0; i < q->nr; i++)
3666                diff_free_filepair(q->queue[i]);
3667free_queue:
3668        free(q->queue);
3669        DIFF_QUEUE_CLEAR(q);
3670        if (options->close_file)
3671                fclose(options->file);
3672
3673        /*
3674         * Report the content-level differences with HAS_CHANGES;
3675         * diff_addremove/diff_change does not set the bit when
3676         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3677         */
3678        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3679                if (options->found_changes)
3680                        DIFF_OPT_SET(options, HAS_CHANGES);
3681                else
3682                        DIFF_OPT_CLR(options, HAS_CHANGES);
3683        }
3684}
3685
3686static void diffcore_apply_filter(const char *filter)
3687{
3688        int i;
3689        struct diff_queue_struct *q = &diff_queued_diff;
3690        struct diff_queue_struct outq;
3691        DIFF_QUEUE_CLEAR(&outq);
3692
3693        if (!filter)
3694                return;
3695
3696        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3697                int found;
3698                for (i = found = 0; !found && i < q->nr; i++) {
3699                        struct diff_filepair *p = q->queue[i];
3700                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3701                             ((p->score &&
3702                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3703                              (!p->score &&
3704                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3705                            ((p->status != DIFF_STATUS_MODIFIED) &&
3706                             strchr(filter, p->status)))
3707                                found++;
3708                }
3709                if (found)
3710                        return;
3711
3712                /* otherwise we will clear the whole queue
3713                 * by copying the empty outq at the end of this
3714                 * function, but first clear the current entries
3715                 * in the queue.
3716                 */
3717                for (i = 0; i < q->nr; i++)
3718                        diff_free_filepair(q->queue[i]);
3719        }
3720        else {
3721                /* Only the matching ones */
3722                for (i = 0; i < q->nr; i++) {
3723                        struct diff_filepair *p = q->queue[i];
3724
3725                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3726                             ((p->score &&
3727                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3728                              (!p->score &&
3729                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3730                            ((p->status != DIFF_STATUS_MODIFIED) &&
3731                             strchr(filter, p->status)))
3732                                diff_q(&outq, p);
3733                        else
3734                                diff_free_filepair(p);
3735                }
3736        }
3737        free(q->queue);
3738        *q = outq;
3739}
3740
3741/* Check whether two filespecs with the same mode and size are identical */
3742static int diff_filespec_is_identical(struct diff_filespec *one,
3743                                      struct diff_filespec *two)
3744{
3745        if (S_ISGITLINK(one->mode))
3746                return 0;
3747        if (diff_populate_filespec(one, 0))
3748                return 0;
3749        if (diff_populate_filespec(two, 0))
3750                return 0;
3751        return !memcmp(one->data, two->data, one->size);
3752}
3753
3754static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3755{
3756        int i;
3757        struct diff_queue_struct *q = &diff_queued_diff;
3758        struct diff_queue_struct outq;
3759        DIFF_QUEUE_CLEAR(&outq);
3760
3761        for (i = 0; i < q->nr; i++) {
3762                struct diff_filepair *p = q->queue[i];
3763
3764                /*
3765                 * 1. Entries that come from stat info dirtiness
3766                 *    always have both sides (iow, not create/delete),
3767                 *    one side of the object name is unknown, with
3768                 *    the same mode and size.  Keep the ones that
3769                 *    do not match these criteria.  They have real
3770                 *    differences.
3771                 *
3772                 * 2. At this point, the file is known to be modified,
3773                 *    with the same mode and size, and the object
3774                 *    name of one side is unknown.  Need to inspect
3775                 *    the identical contents.
3776                 */
3777                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3778                    !DIFF_FILE_VALID(p->two) ||
3779                    (p->one->sha1_valid && p->two->sha1_valid) ||
3780                    (p->one->mode != p->two->mode) ||
3781                    diff_populate_filespec(p->one, 1) ||
3782                    diff_populate_filespec(p->two, 1) ||
3783                    (p->one->size != p->two->size) ||
3784                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3785                        diff_q(&outq, p);
3786                else {
3787                        /*
3788                         * The caller can subtract 1 from skip_stat_unmatch
3789                         * to determine how many paths were dirty only
3790                         * due to stat info mismatch.
3791                         */
3792                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3793                                diffopt->skip_stat_unmatch++;
3794                        diff_free_filepair(p);
3795                }
3796        }
3797        free(q->queue);
3798        *q = outq;
3799}
3800
3801static int diffnamecmp(const void *a_, const void *b_)
3802{
3803        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
3804        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
3805        const char *name_a, *name_b;
3806
3807        name_a = a->one ? a->one->path : a->two->path;
3808        name_b = b->one ? b->one->path : b->two->path;
3809        return strcmp(name_a, name_b);
3810}
3811
3812void diffcore_fix_diff_index(struct diff_options *options)
3813{
3814        struct diff_queue_struct *q = &diff_queued_diff;
3815        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
3816}
3817
3818void diffcore_std(struct diff_options *options)
3819{
3820        /* We never run this function more than one time, because the
3821         * rename/copy detection logic can only run once.
3822         */
3823        if (diff_queued_diff.run)
3824                return;
3825
3826        if (options->skip_stat_unmatch)
3827                diffcore_skip_stat_unmatch(options);
3828        if (options->break_opt != -1)
3829                diffcore_break(options->break_opt);
3830        if (options->detect_rename)
3831                diffcore_rename(options);
3832        if (options->break_opt != -1)
3833                diffcore_merge_broken();
3834        if (options->pickaxe)
3835                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3836        if (options->orderfile)
3837                diffcore_order(options->orderfile);
3838        diff_resolve_rename_copy();
3839        diffcore_apply_filter(options->filter);
3840
3841        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3842                DIFF_OPT_SET(options, HAS_CHANGES);
3843        else
3844                DIFF_OPT_CLR(options, HAS_CHANGES);
3845
3846        diff_queued_diff.run = 1;
3847}
3848
3849int diff_result_code(struct diff_options *opt, int status)
3850{
3851        int result = 0;
3852        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3853            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3854                return status;
3855        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3856            DIFF_OPT_TST(opt, HAS_CHANGES))
3857                result |= 01;
3858        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3859            DIFF_OPT_TST(opt, CHECK_FAILED))
3860                result |= 02;
3861        return result;
3862}
3863
3864void diff_addremove(struct diff_options *options,
3865                    int addremove, unsigned mode,
3866                    const unsigned char *sha1,
3867                    const char *concatpath, unsigned dirty_submodule)
3868{
3869        struct diff_filespec *one, *two;
3870
3871        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3872                return;
3873
3874        /* This may look odd, but it is a preparation for
3875         * feeding "there are unchanged files which should
3876         * not produce diffs, but when you are doing copy
3877         * detection you would need them, so here they are"
3878         * entries to the diff-core.  They will be prefixed
3879         * with something like '=' or '*' (I haven't decided
3880         * which but should not make any difference).
3881         * Feeding the same new and old to diff_change()
3882         * also has the same effect.
3883         * Before the final output happens, they are pruned after
3884         * merged into rename/copy pairs as appropriate.
3885         */
3886        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3887                addremove = (addremove == '+' ? '-' :
3888                             addremove == '-' ? '+' : addremove);
3889
3890        if (options->prefix &&
3891            strncmp(concatpath, options->prefix, options->prefix_length))
3892                return;
3893
3894        one = alloc_filespec(concatpath);
3895        two = alloc_filespec(concatpath);
3896
3897        if (addremove != '+')
3898                fill_filespec(one, sha1, mode);
3899        if (addremove != '-') {
3900                fill_filespec(two, sha1, mode);
3901                two->dirty_submodule = dirty_submodule;
3902        }
3903
3904        diff_queue(&diff_queued_diff, one, two);
3905        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3906                DIFF_OPT_SET(options, HAS_CHANGES);
3907}
3908
3909void diff_change(struct diff_options *options,
3910                 unsigned old_mode, unsigned new_mode,
3911                 const unsigned char *old_sha1,
3912                 const unsigned char *new_sha1,
3913                 const char *concatpath,
3914                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
3915{
3916        struct diff_filespec *one, *two;
3917
3918        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3919                        && S_ISGITLINK(new_mode))
3920                return;
3921
3922        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3923                unsigned tmp;
3924                const unsigned char *tmp_c;
3925                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3926                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3927                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
3928                        new_dirty_submodule = tmp;
3929        }
3930
3931        if (options->prefix &&
3932            strncmp(concatpath, options->prefix, options->prefix_length))
3933                return;
3934
3935        one = alloc_filespec(concatpath);
3936        two = alloc_filespec(concatpath);
3937        fill_filespec(one, old_sha1, old_mode);
3938        fill_filespec(two, new_sha1, new_mode);
3939        one->dirty_submodule = old_dirty_submodule;
3940        two->dirty_submodule = new_dirty_submodule;
3941
3942        diff_queue(&diff_queued_diff, one, two);
3943        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3944                DIFF_OPT_SET(options, HAS_CHANGES);
3945}
3946
3947void diff_unmerge(struct diff_options *options,
3948                  const char *path,
3949                  unsigned mode, const unsigned char *sha1)
3950{
3951        struct diff_filespec *one, *two;
3952
3953        if (options->prefix &&
3954            strncmp(path, options->prefix, options->prefix_length))
3955                return;
3956
3957        one = alloc_filespec(path);
3958        two = alloc_filespec(path);
3959        fill_filespec(one, sha1, mode);
3960        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3961}
3962
3963static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3964                size_t *outsize)
3965{
3966        struct diff_tempfile *temp;
3967        const char *argv[3];
3968        const char **arg = argv;
3969        struct child_process child;
3970        struct strbuf buf = STRBUF_INIT;
3971        int err = 0;
3972
3973        temp = prepare_temp_file(spec->path, spec);
3974        *arg++ = pgm;
3975        *arg++ = temp->name;
3976        *arg = NULL;
3977
3978        memset(&child, 0, sizeof(child));
3979        child.use_shell = 1;
3980        child.argv = argv;
3981        child.out = -1;
3982        if (start_command(&child)) {
3983                remove_tempfile();
3984                return NULL;
3985        }
3986
3987        if (strbuf_read(&buf, child.out, 0) < 0)
3988                err = error("error reading from textconv command '%s'", pgm);
3989        close(child.out);
3990
3991        if (finish_command(&child) || err) {
3992                strbuf_release(&buf);
3993                remove_tempfile();
3994                return NULL;
3995        }
3996        remove_tempfile();
3997
3998        return strbuf_detach(&buf, outsize);
3999}
4000
4001size_t fill_textconv(struct userdiff_driver *driver,
4002                     struct diff_filespec *df,
4003                     char **outbuf)
4004{
4005        size_t size;
4006
4007        if (!driver || !driver->textconv) {
4008                if (!DIFF_FILE_VALID(df)) {
4009                        *outbuf = "";
4010                        return 0;
4011                }
4012                if (diff_populate_filespec(df, 0))
4013                        die("unable to read files to diff");
4014                *outbuf = df->data;
4015                return df->size;
4016        }
4017
4018        if (driver->textconv_cache) {
4019                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4020                                          &size);
4021                if (*outbuf)
4022                        return size;
4023        }
4024
4025        *outbuf = run_textconv(driver->textconv, df, &size);
4026        if (!*outbuf)
4027                die("unable to read files to diff");
4028
4029        if (driver->textconv_cache) {
4030                /* ignore errors, as we might be in a readonly repository */
4031                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4032                                size);
4033                /*
4034                 * we could save up changes and flush them all at the end,
4035                 * but we would need an extra call after all diffing is done.
4036                 * Since generating a cache entry is the slow path anyway,
4037                 * this extra overhead probably isn't a big deal.
4038                 */
4039                notes_cache_write(driver->textconv_cache);
4040        }
4041
4042        return size;
4043}