e0590a305655b6da3c5903875b3f2080f47a57c7
   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 = 400;
  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;
  33static int diff_no_prefix;
  34static int diff_dirstat_permille_default = 30;
  35static struct diff_options default_diff_options;
  36
  37static char diff_colors[][COLOR_MAXLEN] = {
  38        GIT_COLOR_RESET,
  39        GIT_COLOR_NORMAL,       /* PLAIN */
  40        GIT_COLOR_BOLD,         /* METAINFO */
  41        GIT_COLOR_CYAN,         /* FRAGINFO */
  42        GIT_COLOR_RED,          /* OLD */
  43        GIT_COLOR_GREEN,        /* NEW */
  44        GIT_COLOR_YELLOW,       /* COMMIT */
  45        GIT_COLOR_BG_RED,       /* WHITESPACE */
  46        GIT_COLOR_NORMAL,       /* FUNCINFO */
  47};
  48
  49static int parse_diff_color_slot(const char *var, int ofs)
  50{
  51        if (!strcasecmp(var+ofs, "plain"))
  52                return DIFF_PLAIN;
  53        if (!strcasecmp(var+ofs, "meta"))
  54                return DIFF_METAINFO;
  55        if (!strcasecmp(var+ofs, "frag"))
  56                return DIFF_FRAGINFO;
  57        if (!strcasecmp(var+ofs, "old"))
  58                return DIFF_FILE_OLD;
  59        if (!strcasecmp(var+ofs, "new"))
  60                return DIFF_FILE_NEW;
  61        if (!strcasecmp(var+ofs, "commit"))
  62                return DIFF_COMMIT;
  63        if (!strcasecmp(var+ofs, "whitespace"))
  64                return DIFF_WHITESPACE;
  65        if (!strcasecmp(var+ofs, "func"))
  66                return DIFF_FUNCINFO;
  67        return -1;
  68}
  69
  70static int parse_dirstat_params(struct diff_options *options, const char *params,
  71                                struct strbuf *errmsg)
  72{
  73        const char *p = params;
  74        int p_len, ret = 0;
  75
  76        while (*p) {
  77                p_len = strchrnul(p, ',') - p;
  78                if (!memcmp(p, "changes", p_len)) {
  79                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  81                } else if (!memcmp(p, "lines", p_len)) {
  82                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  83                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  84                } else if (!memcmp(p, "files", p_len)) {
  85                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  86                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  87                } else if (!memcmp(p, "noncumulative", p_len)) {
  88                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  89                } else if (!memcmp(p, "cumulative", p_len)) {
  90                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  91                } else if (isdigit(*p)) {
  92                        char *end;
  93                        int permille = strtoul(p, &end, 10) * 10;
  94                        if (*end == '.' && isdigit(*++end)) {
  95                                /* only use first digit */
  96                                permille += *end - '0';
  97                                /* .. and ignore any further digits */
  98                                while (isdigit(*++end))
  99                                        ; /* nothing */
 100                        }
 101                        if (end - p == p_len)
 102                                options->dirstat_permille = permille;
 103                        else {
 104                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 105                                            p_len, p);
 106                                ret++;
 107                        }
 108                } else {
 109                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 110                                    p_len, p);
 111                        ret++;
 112                }
 113
 114                p += p_len;
 115
 116                if (*p)
 117                        p++; /* more parameters, swallow separator */
 118        }
 119        return ret;
 120}
 121
 122static int git_config_rename(const char *var, const char *value)
 123{
 124        if (!value)
 125                return DIFF_DETECT_RENAME;
 126        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 127                return  DIFF_DETECT_COPY;
 128        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 129}
 130
 131/*
 132 * These are to give UI layer defaults.
 133 * The core-level commands such as git-diff-files should
 134 * never be affected by the setting of diff.renames
 135 * the user happens to have in the configuration file.
 136 */
 137int git_diff_ui_config(const char *var, const char *value, void *cb)
 138{
 139        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 140                diff_use_color_default = git_config_colorbool(var, value);
 141                return 0;
 142        }
 143        if (!strcmp(var, "diff.renames")) {
 144                diff_detect_rename_default = git_config_rename(var, value);
 145                return 0;
 146        }
 147        if (!strcmp(var, "diff.autorefreshindex")) {
 148                diff_auto_refresh_index = git_config_bool(var, value);
 149                return 0;
 150        }
 151        if (!strcmp(var, "diff.mnemonicprefix")) {
 152                diff_mnemonic_prefix = git_config_bool(var, value);
 153                return 0;
 154        }
 155        if (!strcmp(var, "diff.noprefix")) {
 156                diff_no_prefix = git_config_bool(var, value);
 157                return 0;
 158        }
 159        if (!strcmp(var, "diff.external"))
 160                return git_config_string(&external_diff_cmd_cfg, var, value);
 161        if (!strcmp(var, "diff.wordregex"))
 162                return git_config_string(&diff_word_regex_cfg, var, value);
 163
 164        if (!strcmp(var, "diff.ignoresubmodules"))
 165                handle_ignore_submodules_arg(&default_diff_options, value);
 166
 167        if (git_color_config(var, value, cb) < 0)
 168                return -1;
 169
 170        return git_diff_basic_config(var, value, cb);
 171}
 172
 173int git_diff_basic_config(const char *var, const char *value, void *cb)
 174{
 175        if (!strcmp(var, "diff.renamelimit")) {
 176                diff_rename_limit_default = git_config_int(var, value);
 177                return 0;
 178        }
 179
 180        switch (userdiff_config(var, value)) {
 181                case 0: break;
 182                case -1: return -1;
 183                default: return 0;
 184        }
 185
 186        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 187                int slot = parse_diff_color_slot(var, 11);
 188                if (slot < 0)
 189                        return 0;
 190                if (!value)
 191                        return config_error_nonbool(var);
 192                color_parse(value, var, diff_colors[slot]);
 193                return 0;
 194        }
 195
 196        /* like GNU diff's --suppress-blank-empty option  */
 197        if (!strcmp(var, "diff.suppressblankempty") ||
 198                        /* for backwards compatibility */
 199                        !strcmp(var, "diff.suppress-blank-empty")) {
 200                diff_suppress_blank_empty = git_config_bool(var, value);
 201                return 0;
 202        }
 203
 204        if (!strcmp(var, "diff.dirstat")) {
 205                struct strbuf errmsg = STRBUF_INIT;
 206                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 207                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 208                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 209                                errmsg.buf);
 210                strbuf_release(&errmsg);
 211                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 212                return 0;
 213        }
 214
 215        if (!prefixcmp(var, "submodule."))
 216                return parse_submodule_config_option(var, value);
 217
 218        return git_default_config(var, value, cb);
 219}
 220
 221static char *quote_two(const char *one, const char *two)
 222{
 223        int need_one = quote_c_style(one, NULL, NULL, 1);
 224        int need_two = quote_c_style(two, NULL, NULL, 1);
 225        struct strbuf res = STRBUF_INIT;
 226
 227        if (need_one + need_two) {
 228                strbuf_addch(&res, '"');
 229                quote_c_style(one, &res, NULL, 1);
 230                quote_c_style(two, &res, NULL, 1);
 231                strbuf_addch(&res, '"');
 232        } else {
 233                strbuf_addstr(&res, one);
 234                strbuf_addstr(&res, two);
 235        }
 236        return strbuf_detach(&res, NULL);
 237}
 238
 239static const char *external_diff(void)
 240{
 241        static const char *external_diff_cmd = NULL;
 242        static int done_preparing = 0;
 243
 244        if (done_preparing)
 245                return external_diff_cmd;
 246        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 247        if (!external_diff_cmd)
 248                external_diff_cmd = external_diff_cmd_cfg;
 249        done_preparing = 1;
 250        return external_diff_cmd;
 251}
 252
 253static struct diff_tempfile {
 254        const char *name; /* filename external diff should read from */
 255        char hex[41];
 256        char mode[10];
 257        char tmp_path[PATH_MAX];
 258} diff_temp[2];
 259
 260typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 261
 262struct emit_callback {
 263        int color_diff;
 264        unsigned ws_rule;
 265        int blank_at_eof_in_preimage;
 266        int blank_at_eof_in_postimage;
 267        int lno_in_preimage;
 268        int lno_in_postimage;
 269        sane_truncate_fn truncate;
 270        const char **label_path;
 271        struct diff_words_data *diff_words;
 272        struct diff_options *opt;
 273        int *found_changesp;
 274        struct strbuf *header;
 275};
 276
 277static int count_lines(const char *data, int size)
 278{
 279        int count, ch, completely_empty = 1, nl_just_seen = 0;
 280        count = 0;
 281        while (0 < size--) {
 282                ch = *data++;
 283                if (ch == '\n') {
 284                        count++;
 285                        nl_just_seen = 1;
 286                        completely_empty = 0;
 287                }
 288                else {
 289                        nl_just_seen = 0;
 290                        completely_empty = 0;
 291                }
 292        }
 293        if (completely_empty)
 294                return 0;
 295        if (!nl_just_seen)
 296                count++; /* no trailing newline */
 297        return count;
 298}
 299
 300static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 301{
 302        if (!DIFF_FILE_VALID(one)) {
 303                mf->ptr = (char *)""; /* does not matter */
 304                mf->size = 0;
 305                return 0;
 306        }
 307        else if (diff_populate_filespec(one, 0))
 308                return -1;
 309
 310        mf->ptr = one->data;
 311        mf->size = one->size;
 312        return 0;
 313}
 314
 315/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 316static unsigned long diff_filespec_size(struct diff_filespec *one)
 317{
 318        if (!DIFF_FILE_VALID(one))
 319                return 0;
 320        diff_populate_filespec(one, 1);
 321        return one->size;
 322}
 323
 324static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 325{
 326        char *ptr = mf->ptr;
 327        long size = mf->size;
 328        int cnt = 0;
 329
 330        if (!size)
 331                return cnt;
 332        ptr += size - 1; /* pointing at the very end */
 333        if (*ptr != '\n')
 334                ; /* incomplete line */
 335        else
 336                ptr--; /* skip the last LF */
 337        while (mf->ptr < ptr) {
 338                char *prev_eol;
 339                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 340                        if (*prev_eol == '\n')
 341                                break;
 342                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 343                        break;
 344                cnt++;
 345                ptr = prev_eol - 1;
 346        }
 347        return cnt;
 348}
 349
 350static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 351                               struct emit_callback *ecbdata)
 352{
 353        int l1, l2, at;
 354        unsigned ws_rule = ecbdata->ws_rule;
 355        l1 = count_trailing_blank(mf1, ws_rule);
 356        l2 = count_trailing_blank(mf2, ws_rule);
 357        if (l2 <= l1) {
 358                ecbdata->blank_at_eof_in_preimage = 0;
 359                ecbdata->blank_at_eof_in_postimage = 0;
 360                return;
 361        }
 362        at = count_lines(mf1->ptr, mf1->size);
 363        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 364
 365        at = count_lines(mf2->ptr, mf2->size);
 366        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 367}
 368
 369static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 370                        int first, const char *line, int len)
 371{
 372        int has_trailing_newline, has_trailing_carriage_return;
 373        int nofirst;
 374        FILE *file = o->file;
 375
 376        if (o->output_prefix) {
 377                struct strbuf *msg = NULL;
 378                msg = o->output_prefix(o, o->output_prefix_data);
 379                assert(msg);
 380                fwrite(msg->buf, msg->len, 1, file);
 381        }
 382
 383        if (len == 0) {
 384                has_trailing_newline = (first == '\n');
 385                has_trailing_carriage_return = (!has_trailing_newline &&
 386                                                (first == '\r'));
 387                nofirst = has_trailing_newline || has_trailing_carriage_return;
 388        } else {
 389                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 390                if (has_trailing_newline)
 391                        len--;
 392                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 393                if (has_trailing_carriage_return)
 394                        len--;
 395                nofirst = 0;
 396        }
 397
 398        if (len || !nofirst) {
 399                fputs(set, file);
 400                if (!nofirst)
 401                        fputc(first, file);
 402                fwrite(line, len, 1, file);
 403                fputs(reset, file);
 404        }
 405        if (has_trailing_carriage_return)
 406                fputc('\r', file);
 407        if (has_trailing_newline)
 408                fputc('\n', file);
 409}
 410
 411static void emit_line(struct diff_options *o, const char *set, const char *reset,
 412                      const char *line, int len)
 413{
 414        emit_line_0(o, set, reset, line[0], line+1, len-1);
 415}
 416
 417static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 418{
 419        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 420              ecbdata->blank_at_eof_in_preimage &&
 421              ecbdata->blank_at_eof_in_postimage &&
 422              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 423              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 424                return 0;
 425        return ws_blank_line(line, len, ecbdata->ws_rule);
 426}
 427
 428static void emit_add_line(const char *reset,
 429                          struct emit_callback *ecbdata,
 430                          const char *line, int len)
 431{
 432        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 433        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 434
 435        if (!*ws)
 436                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 437        else if (new_blank_line_at_eof(ecbdata, line, len))
 438                /* Blank line at EOF - paint '+' as well */
 439                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 440        else {
 441                /* Emit just the prefix, then the rest. */
 442                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 443                ws_check_emit(line, len, ecbdata->ws_rule,
 444                              ecbdata->opt->file, set, reset, ws);
 445        }
 446}
 447
 448static void emit_hunk_header(struct emit_callback *ecbdata,
 449                             const char *line, int len)
 450{
 451        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 452        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 453        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 454        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 455        static const char atat[2] = { '@', '@' };
 456        const char *cp, *ep;
 457        struct strbuf msgbuf = STRBUF_INIT;
 458        int org_len = len;
 459        int i = 1;
 460
 461        /*
 462         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 463         * it always is at least 10 bytes long.
 464         */
 465        if (len < 10 ||
 466            memcmp(line, atat, 2) ||
 467            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 468                emit_line(ecbdata->opt, plain, reset, line, len);
 469                return;
 470        }
 471        ep += 2; /* skip over @@ */
 472
 473        /* The hunk header in fraginfo color */
 474        strbuf_add(&msgbuf, frag, strlen(frag));
 475        strbuf_add(&msgbuf, line, ep - line);
 476        strbuf_add(&msgbuf, reset, strlen(reset));
 477
 478        /*
 479         * trailing "\r\n"
 480         */
 481        for ( ; i < 3; i++)
 482                if (line[len - i] == '\r' || line[len - i] == '\n')
 483                        len--;
 484
 485        /* blank before the func header */
 486        for (cp = ep; ep - line < len; ep++)
 487                if (*ep != ' ' && *ep != '\t')
 488                        break;
 489        if (ep != cp) {
 490                strbuf_add(&msgbuf, plain, strlen(plain));
 491                strbuf_add(&msgbuf, cp, ep - cp);
 492                strbuf_add(&msgbuf, reset, strlen(reset));
 493        }
 494
 495        if (ep < line + len) {
 496                strbuf_add(&msgbuf, func, strlen(func));
 497                strbuf_add(&msgbuf, ep, line + len - ep);
 498                strbuf_add(&msgbuf, reset, strlen(reset));
 499        }
 500
 501        strbuf_add(&msgbuf, line + len, org_len - len);
 502        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 503        strbuf_release(&msgbuf);
 504}
 505
 506static struct diff_tempfile *claim_diff_tempfile(void) {
 507        int i;
 508        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 509                if (!diff_temp[i].name)
 510                        return diff_temp + i;
 511        die("BUG: diff is failing to clean up its tempfiles");
 512}
 513
 514static int remove_tempfile_installed;
 515
 516static void remove_tempfile(void)
 517{
 518        int i;
 519        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 520                if (diff_temp[i].name == diff_temp[i].tmp_path)
 521                        unlink_or_warn(diff_temp[i].name);
 522                diff_temp[i].name = NULL;
 523        }
 524}
 525
 526static void remove_tempfile_on_signal(int signo)
 527{
 528        remove_tempfile();
 529        sigchain_pop(signo);
 530        raise(signo);
 531}
 532
 533static void print_line_count(FILE *file, int count)
 534{
 535        switch (count) {
 536        case 0:
 537                fprintf(file, "0,0");
 538                break;
 539        case 1:
 540                fprintf(file, "1");
 541                break;
 542        default:
 543                fprintf(file, "1,%d", count);
 544                break;
 545        }
 546}
 547
 548static void emit_rewrite_lines(struct emit_callback *ecb,
 549                               int prefix, const char *data, int size)
 550{
 551        const char *endp = NULL;
 552        static const char *nneof = " No newline at end of file\n";
 553        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 554        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 555
 556        while (0 < size) {
 557                int len;
 558
 559                endp = memchr(data, '\n', size);
 560                len = endp ? (endp - data + 1) : size;
 561                if (prefix != '+') {
 562                        ecb->lno_in_preimage++;
 563                        emit_line_0(ecb->opt, old, reset, '-',
 564                                    data, len);
 565                } else {
 566                        ecb->lno_in_postimage++;
 567                        emit_add_line(reset, ecb, data, len);
 568                }
 569                size -= len;
 570                data += len;
 571        }
 572        if (!endp) {
 573                const char *plain = diff_get_color(ecb->color_diff,
 574                                                   DIFF_PLAIN);
 575                emit_line_0(ecb->opt, plain, reset, '\\',
 576                            nneof, strlen(nneof));
 577        }
 578}
 579
 580static void emit_rewrite_diff(const char *name_a,
 581                              const char *name_b,
 582                              struct diff_filespec *one,
 583                              struct diff_filespec *two,
 584                              struct userdiff_driver *textconv_one,
 585                              struct userdiff_driver *textconv_two,
 586                              struct diff_options *o)
 587{
 588        int lc_a, lc_b;
 589        const char *name_a_tab, *name_b_tab;
 590        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 591        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 592        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 593        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 594        const char *a_prefix, *b_prefix;
 595        char *data_one, *data_two;
 596        size_t size_one, size_two;
 597        struct emit_callback ecbdata;
 598        char *line_prefix = "";
 599        struct strbuf *msgbuf;
 600
 601        if (o && o->output_prefix) {
 602                msgbuf = o->output_prefix(o, o->output_prefix_data);
 603                line_prefix = msgbuf->buf;
 604        }
 605
 606        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 607                a_prefix = o->b_prefix;
 608                b_prefix = o->a_prefix;
 609        } else {
 610                a_prefix = o->a_prefix;
 611                b_prefix = o->b_prefix;
 612        }
 613
 614        name_a += (*name_a == '/');
 615        name_b += (*name_b == '/');
 616        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 617        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 618
 619        strbuf_reset(&a_name);
 620        strbuf_reset(&b_name);
 621        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 622        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 623
 624        size_one = fill_textconv(textconv_one, one, &data_one);
 625        size_two = fill_textconv(textconv_two, two, &data_two);
 626
 627        memset(&ecbdata, 0, sizeof(ecbdata));
 628        ecbdata.color_diff = want_color(o->use_color);
 629        ecbdata.found_changesp = &o->found_changes;
 630        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 631        ecbdata.opt = o;
 632        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 633                mmfile_t mf1, mf2;
 634                mf1.ptr = (char *)data_one;
 635                mf2.ptr = (char *)data_two;
 636                mf1.size = size_one;
 637                mf2.size = size_two;
 638                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 639        }
 640        ecbdata.lno_in_preimage = 1;
 641        ecbdata.lno_in_postimage = 1;
 642
 643        lc_a = count_lines(data_one, size_one);
 644        lc_b = count_lines(data_two, size_two);
 645        fprintf(o->file,
 646                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 647                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 648                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 649                line_prefix, fraginfo);
 650        if (!o->irreversible_delete)
 651                print_line_count(o->file, lc_a);
 652        else
 653                fprintf(o->file, "?,?");
 654        fprintf(o->file, " +");
 655        print_line_count(o->file, lc_b);
 656        fprintf(o->file, " @@%s\n", reset);
 657        if (lc_a && !o->irreversible_delete)
 658                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 659        if (lc_b)
 660                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 661        if (textconv_one)
 662                free((char *)data_one);
 663        if (textconv_two)
 664                free((char *)data_two);
 665}
 666
 667struct diff_words_buffer {
 668        mmfile_t text;
 669        long alloc;
 670        struct diff_words_orig {
 671                const char *begin, *end;
 672        } *orig;
 673        int orig_nr, orig_alloc;
 674};
 675
 676static void diff_words_append(char *line, unsigned long len,
 677                struct diff_words_buffer *buffer)
 678{
 679        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 680        line++;
 681        len--;
 682        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 683        buffer->text.size += len;
 684        buffer->text.ptr[buffer->text.size] = '\0';
 685}
 686
 687struct diff_words_style_elem {
 688        const char *prefix;
 689        const char *suffix;
 690        const char *color; /* NULL; filled in by the setup code if
 691                            * color is enabled */
 692};
 693
 694struct diff_words_style {
 695        enum diff_words_type type;
 696        struct diff_words_style_elem new, old, ctx;
 697        const char *newline;
 698};
 699
 700static struct diff_words_style diff_words_styles[] = {
 701        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 702        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 703        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 704};
 705
 706struct diff_words_data {
 707        struct diff_words_buffer minus, plus;
 708        const char *current_plus;
 709        int last_minus;
 710        struct diff_options *opt;
 711        regex_t *word_regex;
 712        enum diff_words_type type;
 713        struct diff_words_style *style;
 714};
 715
 716static int fn_out_diff_words_write_helper(FILE *fp,
 717                                          struct diff_words_style_elem *st_el,
 718                                          const char *newline,
 719                                          size_t count, const char *buf,
 720                                          const char *line_prefix)
 721{
 722        int print = 0;
 723
 724        while (count) {
 725                char *p = memchr(buf, '\n', count);
 726                if (print)
 727                        fputs(line_prefix, fp);
 728                if (p != buf) {
 729                        if (st_el->color && fputs(st_el->color, fp) < 0)
 730                                return -1;
 731                        if (fputs(st_el->prefix, fp) < 0 ||
 732                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 733                            fputs(st_el->suffix, fp) < 0)
 734                                return -1;
 735                        if (st_el->color && *st_el->color
 736                            && fputs(GIT_COLOR_RESET, fp) < 0)
 737                                return -1;
 738                }
 739                if (!p)
 740                        return 0;
 741                if (fputs(newline, fp) < 0)
 742                        return -1;
 743                count -= p + 1 - buf;
 744                buf = p + 1;
 745                print = 1;
 746        }
 747        return 0;
 748}
 749
 750/*
 751 * '--color-words' algorithm can be described as:
 752 *
 753 *   1. collect a the minus/plus lines of a diff hunk, divided into
 754 *      minus-lines and plus-lines;
 755 *
 756 *   2. break both minus-lines and plus-lines into words and
 757 *      place them into two mmfile_t with one word for each line;
 758 *
 759 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 760 *
 761 * And for the common parts of the both file, we output the plus side text.
 762 * diff_words->current_plus is used to trace the current position of the plus file
 763 * which printed. diff_words->last_minus is used to trace the last minus word
 764 * printed.
 765 *
 766 * For '--graph' to work with '--color-words', we need to output the graph prefix
 767 * on each line of color words output. Generally, there are two conditions on
 768 * which we should output the prefix.
 769 *
 770 *   1. diff_words->last_minus == 0 &&
 771 *      diff_words->current_plus == diff_words->plus.text.ptr
 772 *
 773 *      that is: the plus text must start as a new line, and if there is no minus
 774 *      word printed, a graph prefix must be printed.
 775 *
 776 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 777 *      *(diff_words->current_plus - 1) == '\n'
 778 *
 779 *      that is: a graph prefix must be printed following a '\n'
 780 */
 781static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 782{
 783        if ((diff_words->last_minus == 0 &&
 784                diff_words->current_plus == diff_words->plus.text.ptr) ||
 785                (diff_words->current_plus > diff_words->plus.text.ptr &&
 786                *(diff_words->current_plus - 1) == '\n')) {
 787                return 1;
 788        } else {
 789                return 0;
 790        }
 791}
 792
 793static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 794{
 795        struct diff_words_data *diff_words = priv;
 796        struct diff_words_style *style = diff_words->style;
 797        int minus_first, minus_len, plus_first, plus_len;
 798        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 799        struct diff_options *opt = diff_words->opt;
 800        struct strbuf *msgbuf;
 801        char *line_prefix = "";
 802
 803        if (line[0] != '@' || parse_hunk_header(line, len,
 804                        &minus_first, &minus_len, &plus_first, &plus_len))
 805                return;
 806
 807        assert(opt);
 808        if (opt->output_prefix) {
 809                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 810                line_prefix = msgbuf->buf;
 811        }
 812
 813        /* POSIX requires that first be decremented by one if len == 0... */
 814        if (minus_len) {
 815                minus_begin = diff_words->minus.orig[minus_first].begin;
 816                minus_end =
 817                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 818        } else
 819                minus_begin = minus_end =
 820                        diff_words->minus.orig[minus_first].end;
 821
 822        if (plus_len) {
 823                plus_begin = diff_words->plus.orig[plus_first].begin;
 824                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 825        } else
 826                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 827
 828        if (color_words_output_graph_prefix(diff_words)) {
 829                fputs(line_prefix, diff_words->opt->file);
 830        }
 831        if (diff_words->current_plus != plus_begin) {
 832                fn_out_diff_words_write_helper(diff_words->opt->file,
 833                                &style->ctx, style->newline,
 834                                plus_begin - diff_words->current_plus,
 835                                diff_words->current_plus, line_prefix);
 836                if (*(plus_begin - 1) == '\n')
 837                        fputs(line_prefix, diff_words->opt->file);
 838        }
 839        if (minus_begin != minus_end) {
 840                fn_out_diff_words_write_helper(diff_words->opt->file,
 841                                &style->old, style->newline,
 842                                minus_end - minus_begin, minus_begin,
 843                                line_prefix);
 844        }
 845        if (plus_begin != plus_end) {
 846                fn_out_diff_words_write_helper(diff_words->opt->file,
 847                                &style->new, style->newline,
 848                                plus_end - plus_begin, plus_begin,
 849                                line_prefix);
 850        }
 851
 852        diff_words->current_plus = plus_end;
 853        diff_words->last_minus = minus_first;
 854}
 855
 856/* This function starts looking at *begin, and returns 0 iff a word was found. */
 857static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 858                int *begin, int *end)
 859{
 860        if (word_regex && *begin < buffer->size) {
 861                regmatch_t match[1];
 862                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 863                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 864                                        '\n', match[0].rm_eo - match[0].rm_so);
 865                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 866                        *begin += match[0].rm_so;
 867                        return *begin >= *end;
 868                }
 869                return -1;
 870        }
 871
 872        /* find the next word */
 873        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 874                (*begin)++;
 875        if (*begin >= buffer->size)
 876                return -1;
 877
 878        /* find the end of the word */
 879        *end = *begin + 1;
 880        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 881                (*end)++;
 882
 883        return 0;
 884}
 885
 886/*
 887 * This function splits the words in buffer->text, stores the list with
 888 * newline separator into out, and saves the offsets of the original words
 889 * in buffer->orig.
 890 */
 891static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 892                regex_t *word_regex)
 893{
 894        int i, j;
 895        long alloc = 0;
 896
 897        out->size = 0;
 898        out->ptr = NULL;
 899
 900        /* fake an empty "0th" word */
 901        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 902        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 903        buffer->orig_nr = 1;
 904
 905        for (i = 0; i < buffer->text.size; i++) {
 906                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 907                        return;
 908
 909                /* store original boundaries */
 910                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 911                                buffer->orig_alloc);
 912                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 913                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 914                buffer->orig_nr++;
 915
 916                /* store one word */
 917                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 918                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 919                out->ptr[out->size + j - i] = '\n';
 920                out->size += j - i + 1;
 921
 922                i = j - 1;
 923        }
 924}
 925
 926/* this executes the word diff on the accumulated buffers */
 927static void diff_words_show(struct diff_words_data *diff_words)
 928{
 929        xpparam_t xpp;
 930        xdemitconf_t xecfg;
 931        mmfile_t minus, plus;
 932        struct diff_words_style *style = diff_words->style;
 933
 934        struct diff_options *opt = diff_words->opt;
 935        struct strbuf *msgbuf;
 936        char *line_prefix = "";
 937
 938        assert(opt);
 939        if (opt->output_prefix) {
 940                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 941                line_prefix = msgbuf->buf;
 942        }
 943
 944        /* special case: only removal */
 945        if (!diff_words->plus.text.size) {
 946                fputs(line_prefix, diff_words->opt->file);
 947                fn_out_diff_words_write_helper(diff_words->opt->file,
 948                        &style->old, style->newline,
 949                        diff_words->minus.text.size,
 950                        diff_words->minus.text.ptr, line_prefix);
 951                diff_words->minus.text.size = 0;
 952                return;
 953        }
 954
 955        diff_words->current_plus = diff_words->plus.text.ptr;
 956        diff_words->last_minus = 0;
 957
 958        memset(&xpp, 0, sizeof(xpp));
 959        memset(&xecfg, 0, sizeof(xecfg));
 960        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 961        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 962        xpp.flags = 0;
 963        /* as only the hunk header will be parsed, we need a 0-context */
 964        xecfg.ctxlen = 0;
 965        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 966                      &xpp, &xecfg);
 967        free(minus.ptr);
 968        free(plus.ptr);
 969        if (diff_words->current_plus != diff_words->plus.text.ptr +
 970                        diff_words->plus.text.size) {
 971                if (color_words_output_graph_prefix(diff_words))
 972                        fputs(line_prefix, diff_words->opt->file);
 973                fn_out_diff_words_write_helper(diff_words->opt->file,
 974                        &style->ctx, style->newline,
 975                        diff_words->plus.text.ptr + diff_words->plus.text.size
 976                        - diff_words->current_plus, diff_words->current_plus,
 977                        line_prefix);
 978        }
 979        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 980}
 981
 982/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 983static void diff_words_flush(struct emit_callback *ecbdata)
 984{
 985        if (ecbdata->diff_words->minus.text.size ||
 986            ecbdata->diff_words->plus.text.size)
 987                diff_words_show(ecbdata->diff_words);
 988}
 989
 990static void free_diff_words_data(struct emit_callback *ecbdata)
 991{
 992        if (ecbdata->diff_words) {
 993                diff_words_flush(ecbdata);
 994                free (ecbdata->diff_words->minus.text.ptr);
 995                free (ecbdata->diff_words->minus.orig);
 996                free (ecbdata->diff_words->plus.text.ptr);
 997                free (ecbdata->diff_words->plus.orig);
 998                if (ecbdata->diff_words->word_regex) {
 999                        regfree(ecbdata->diff_words->word_regex);
1000                        free(ecbdata->diff_words->word_regex);
1001                }
1002                free(ecbdata->diff_words);
1003                ecbdata->diff_words = NULL;
1004        }
1005}
1006
1007const char *diff_get_color(int diff_use_color, enum color_diff ix)
1008{
1009        if (want_color(diff_use_color))
1010                return diff_colors[ix];
1011        return "";
1012}
1013
1014static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1015{
1016        const char *cp;
1017        unsigned long allot;
1018        size_t l = len;
1019
1020        if (ecb->truncate)
1021                return ecb->truncate(line, len);
1022        cp = line;
1023        allot = l;
1024        while (0 < l) {
1025                (void) utf8_width(&cp, &l);
1026                if (!cp)
1027                        break; /* truncated in the middle? */
1028        }
1029        return allot - l;
1030}
1031
1032static void find_lno(const char *line, struct emit_callback *ecbdata)
1033{
1034        const char *p;
1035        ecbdata->lno_in_preimage = 0;
1036        ecbdata->lno_in_postimage = 0;
1037        p = strchr(line, '-');
1038        if (!p)
1039                return; /* cannot happen */
1040        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1041        p = strchr(p, '+');
1042        if (!p)
1043                return; /* cannot happen */
1044        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1045}
1046
1047static void fn_out_consume(void *priv, char *line, unsigned long len)
1048{
1049        struct emit_callback *ecbdata = priv;
1050        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1051        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1052        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1053        struct diff_options *o = ecbdata->opt;
1054        char *line_prefix = "";
1055        struct strbuf *msgbuf;
1056
1057        if (o && o->output_prefix) {
1058                msgbuf = o->output_prefix(o, o->output_prefix_data);
1059                line_prefix = msgbuf->buf;
1060        }
1061
1062        if (ecbdata->header) {
1063                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1064                strbuf_reset(ecbdata->header);
1065                ecbdata->header = NULL;
1066        }
1067        *(ecbdata->found_changesp) = 1;
1068
1069        if (ecbdata->label_path[0]) {
1070                const char *name_a_tab, *name_b_tab;
1071
1072                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1073                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1074
1075                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1076                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1077                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1078                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1079                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1080        }
1081
1082        if (diff_suppress_blank_empty
1083            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1084                line[0] = '\n';
1085                len = 1;
1086        }
1087
1088        if (line[0] == '@') {
1089                if (ecbdata->diff_words)
1090                        diff_words_flush(ecbdata);
1091                len = sane_truncate_line(ecbdata, line, len);
1092                find_lno(line, ecbdata);
1093                emit_hunk_header(ecbdata, line, len);
1094                if (line[len-1] != '\n')
1095                        putc('\n', ecbdata->opt->file);
1096                return;
1097        }
1098
1099        if (len < 1) {
1100                emit_line(ecbdata->opt, reset, reset, line, len);
1101                if (ecbdata->diff_words
1102                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1103                        fputs("~\n", ecbdata->opt->file);
1104                return;
1105        }
1106
1107        if (ecbdata->diff_words) {
1108                if (line[0] == '-') {
1109                        diff_words_append(line, len,
1110                                          &ecbdata->diff_words->minus);
1111                        return;
1112                } else if (line[0] == '+') {
1113                        diff_words_append(line, len,
1114                                          &ecbdata->diff_words->plus);
1115                        return;
1116                } else if (!prefixcmp(line, "\\ ")) {
1117                        /*
1118                         * Eat the "no newline at eof" marker as if we
1119                         * saw a "+" or "-" line with nothing on it,
1120                         * and return without diff_words_flush() to
1121                         * defer processing. If this is the end of
1122                         * preimage, more "+" lines may come after it.
1123                         */
1124                        return;
1125                }
1126                diff_words_flush(ecbdata);
1127                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1128                        emit_line(ecbdata->opt, plain, reset, line, len);
1129                        fputs("~\n", ecbdata->opt->file);
1130                } else {
1131                        /*
1132                         * Skip the prefix character, if any.  With
1133                         * diff_suppress_blank_empty, there may be
1134                         * none.
1135                         */
1136                        if (line[0] != '\n') {
1137                              line++;
1138                              len--;
1139                        }
1140                        emit_line(ecbdata->opt, plain, reset, line, len);
1141                }
1142                return;
1143        }
1144
1145        if (line[0] != '+') {
1146                const char *color =
1147                        diff_get_color(ecbdata->color_diff,
1148                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1149                ecbdata->lno_in_preimage++;
1150                if (line[0] == ' ')
1151                        ecbdata->lno_in_postimage++;
1152                emit_line(ecbdata->opt, color, reset, line, len);
1153        } else {
1154                ecbdata->lno_in_postimage++;
1155                emit_add_line(reset, ecbdata, line + 1, len - 1);
1156        }
1157}
1158
1159static char *pprint_rename(const char *a, const char *b)
1160{
1161        const char *old = a;
1162        const char *new = b;
1163        struct strbuf name = STRBUF_INIT;
1164        int pfx_length, sfx_length;
1165        int len_a = strlen(a);
1166        int len_b = strlen(b);
1167        int a_midlen, b_midlen;
1168        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1169        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1170
1171        if (qlen_a || qlen_b) {
1172                quote_c_style(a, &name, NULL, 0);
1173                strbuf_addstr(&name, " => ");
1174                quote_c_style(b, &name, NULL, 0);
1175                return strbuf_detach(&name, NULL);
1176        }
1177
1178        /* Find common prefix */
1179        pfx_length = 0;
1180        while (*old && *new && *old == *new) {
1181                if (*old == '/')
1182                        pfx_length = old - a + 1;
1183                old++;
1184                new++;
1185        }
1186
1187        /* Find common suffix */
1188        old = a + len_a;
1189        new = b + len_b;
1190        sfx_length = 0;
1191        while (a <= old && b <= new && *old == *new) {
1192                if (*old == '/')
1193                        sfx_length = len_a - (old - a);
1194                old--;
1195                new--;
1196        }
1197
1198        /*
1199         * pfx{mid-a => mid-b}sfx
1200         * {pfx-a => pfx-b}sfx
1201         * pfx{sfx-a => sfx-b}
1202         * name-a => name-b
1203         */
1204        a_midlen = len_a - pfx_length - sfx_length;
1205        b_midlen = len_b - pfx_length - sfx_length;
1206        if (a_midlen < 0)
1207                a_midlen = 0;
1208        if (b_midlen < 0)
1209                b_midlen = 0;
1210
1211        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1212        if (pfx_length + sfx_length) {
1213                strbuf_add(&name, a, pfx_length);
1214                strbuf_addch(&name, '{');
1215        }
1216        strbuf_add(&name, a + pfx_length, a_midlen);
1217        strbuf_addstr(&name, " => ");
1218        strbuf_add(&name, b + pfx_length, b_midlen);
1219        if (pfx_length + sfx_length) {
1220                strbuf_addch(&name, '}');
1221                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1222        }
1223        return strbuf_detach(&name, NULL);
1224}
1225
1226struct diffstat_t {
1227        int nr;
1228        int alloc;
1229        struct diffstat_file {
1230                char *from_name;
1231                char *name;
1232                char *print_name;
1233                unsigned is_unmerged:1;
1234                unsigned is_binary:1;
1235                unsigned is_renamed:1;
1236                uintmax_t added, deleted;
1237        } **files;
1238};
1239
1240static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1241                                          const char *name_a,
1242                                          const char *name_b)
1243{
1244        struct diffstat_file *x;
1245        x = xcalloc(sizeof (*x), 1);
1246        if (diffstat->nr == diffstat->alloc) {
1247                diffstat->alloc = alloc_nr(diffstat->alloc);
1248                diffstat->files = xrealloc(diffstat->files,
1249                                diffstat->alloc * sizeof(x));
1250        }
1251        diffstat->files[diffstat->nr++] = x;
1252        if (name_b) {
1253                x->from_name = xstrdup(name_a);
1254                x->name = xstrdup(name_b);
1255                x->is_renamed = 1;
1256        }
1257        else {
1258                x->from_name = NULL;
1259                x->name = xstrdup(name_a);
1260        }
1261        return x;
1262}
1263
1264static void diffstat_consume(void *priv, char *line, unsigned long len)
1265{
1266        struct diffstat_t *diffstat = priv;
1267        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1268
1269        if (line[0] == '+')
1270                x->added++;
1271        else if (line[0] == '-')
1272                x->deleted++;
1273}
1274
1275const char mime_boundary_leader[] = "------------";
1276
1277static int scale_linear(int it, int width, int max_change)
1278{
1279        if (!it)
1280                return 0;
1281        /*
1282         * make sure that at least one '-' or '+' is printed if
1283         * there is any change to this path. The easiest way is to
1284         * scale linearly as if the alloted width is one column shorter
1285         * than it is, and then add 1 to the result.
1286         */
1287        return 1 + (it * (width - 1) / max_change);
1288}
1289
1290static void show_name(FILE *file,
1291                      const char *prefix, const char *name, int len)
1292{
1293        fprintf(file, " %s%-*s |", prefix, len, name);
1294}
1295
1296static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1297{
1298        if (cnt <= 0)
1299                return;
1300        fprintf(file, "%s", set);
1301        while (cnt--)
1302                putc(ch, file);
1303        fprintf(file, "%s", reset);
1304}
1305
1306static void fill_print_name(struct diffstat_file *file)
1307{
1308        char *pname;
1309
1310        if (file->print_name)
1311                return;
1312
1313        if (!file->is_renamed) {
1314                struct strbuf buf = STRBUF_INIT;
1315                if (quote_c_style(file->name, &buf, NULL, 0)) {
1316                        pname = strbuf_detach(&buf, NULL);
1317                } else {
1318                        pname = file->name;
1319                        strbuf_release(&buf);
1320                }
1321        } else {
1322                pname = pprint_rename(file->from_name, file->name);
1323        }
1324        file->print_name = pname;
1325}
1326
1327static void show_stats(struct diffstat_t *data, struct diff_options *options)
1328{
1329        int i, len, add, del, adds = 0, dels = 0;
1330        uintmax_t max_change = 0, max_len = 0;
1331        int total_files = data->nr;
1332        int width, name_width, count;
1333        const char *reset, *add_c, *del_c;
1334        const char *line_prefix = "";
1335        int extra_shown = 0;
1336        struct strbuf *msg = NULL;
1337
1338        if (data->nr == 0)
1339                return;
1340
1341        if (options->output_prefix) {
1342                msg = options->output_prefix(options, options->output_prefix_data);
1343                line_prefix = msg->buf;
1344        }
1345
1346        width = options->stat_width ? options->stat_width : 80;
1347        name_width = options->stat_name_width ? options->stat_name_width : 50;
1348        count = options->stat_count ? options->stat_count : data->nr;
1349
1350        /* Sanity: give at least 5 columns to the graph,
1351         * but leave at least 10 columns for the name.
1352         */
1353        if (width < 25)
1354                width = 25;
1355        if (name_width < 10)
1356                name_width = 10;
1357        else if (width < name_width + 15)
1358                name_width = width - 15;
1359
1360        /* Find the longest filename and max number of changes */
1361        reset = diff_get_color_opt(options, DIFF_RESET);
1362        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1363        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1364
1365        for (i = 0; (i < count) && (i < data->nr); i++) {
1366                struct diffstat_file *file = data->files[i];
1367                uintmax_t change = file->added + file->deleted;
1368                if (!data->files[i]->is_renamed &&
1369                         (change == 0)) {
1370                        count++; /* not shown == room for one more */
1371                        continue;
1372                }
1373                fill_print_name(file);
1374                len = strlen(file->print_name);
1375                if (max_len < len)
1376                        max_len = len;
1377
1378                if (file->is_binary || file->is_unmerged)
1379                        continue;
1380                if (max_change < change)
1381                        max_change = change;
1382        }
1383        count = i; /* min(count, data->nr) */
1384
1385        /* Compute the width of the graph part;
1386         * 10 is for one blank at the beginning of the line plus
1387         * " | count " between the name and the graph.
1388         *
1389         * From here on, name_width is the width of the name area,
1390         * and width is the width of the graph area.
1391         */
1392        name_width = (name_width < max_len) ? name_width : max_len;
1393        if (width < (name_width + 10) + max_change)
1394                width = width - (name_width + 10);
1395        else
1396                width = max_change;
1397
1398        for (i = 0; i < count; i++) {
1399                const char *prefix = "";
1400                char *name = data->files[i]->print_name;
1401                uintmax_t added = data->files[i]->added;
1402                uintmax_t deleted = data->files[i]->deleted;
1403                int name_len;
1404
1405                if (!data->files[i]->is_renamed &&
1406                         (added + deleted == 0)) {
1407                        total_files--;
1408                        continue;
1409                }
1410                /*
1411                 * "scale" the filename
1412                 */
1413                len = name_width;
1414                name_len = strlen(name);
1415                if (name_width < name_len) {
1416                        char *slash;
1417                        prefix = "...";
1418                        len -= 3;
1419                        name += name_len - len;
1420                        slash = strchr(name, '/');
1421                        if (slash)
1422                                name = slash;
1423                }
1424
1425                if (data->files[i]->is_binary) {
1426                        fprintf(options->file, "%s", line_prefix);
1427                        show_name(options->file, prefix, name, len);
1428                        fprintf(options->file, "  Bin ");
1429                        fprintf(options->file, "%s%"PRIuMAX"%s",
1430                                del_c, deleted, reset);
1431                        fprintf(options->file, " -> ");
1432                        fprintf(options->file, "%s%"PRIuMAX"%s",
1433                                add_c, added, reset);
1434                        fprintf(options->file, " bytes");
1435                        fprintf(options->file, "\n");
1436                        continue;
1437                }
1438                else if (data->files[i]->is_unmerged) {
1439                        fprintf(options->file, "%s", line_prefix);
1440                        show_name(options->file, prefix, name, len);
1441                        fprintf(options->file, "  Unmerged\n");
1442                        continue;
1443                }
1444
1445                /*
1446                 * scale the add/delete
1447                 */
1448                add = added;
1449                del = deleted;
1450                adds += add;
1451                dels += del;
1452
1453                if (width <= max_change) {
1454                        int total = add + del;
1455
1456                        total = scale_linear(add + del, width, max_change);
1457                        if (total < 2 && add && del)
1458                                /* width >= 2 due to the sanity check */
1459                                total = 2;
1460                        if (add < del) {
1461                                add = scale_linear(add, width, max_change);
1462                                del = total - add;
1463                        } else {
1464                                del = scale_linear(del, width, max_change);
1465                                add = total - del;
1466                        }
1467                }
1468                fprintf(options->file, "%s", line_prefix);
1469                show_name(options->file, prefix, name, len);
1470                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1471                                added + deleted ? " " : "");
1472                show_graph(options->file, '+', add, add_c, reset);
1473                show_graph(options->file, '-', del, del_c, reset);
1474                fprintf(options->file, "\n");
1475        }
1476        for (i = count; i < data->nr; i++) {
1477                uintmax_t added = data->files[i]->added;
1478                uintmax_t deleted = data->files[i]->deleted;
1479                if (!data->files[i]->is_renamed &&
1480                         (added + deleted == 0)) {
1481                        total_files--;
1482                        continue;
1483                }
1484                adds += added;
1485                dels += deleted;
1486                if (!extra_shown)
1487                        fprintf(options->file, "%s ...\n", line_prefix);
1488                extra_shown = 1;
1489        }
1490        fprintf(options->file, "%s", line_prefix);
1491        fprintf(options->file,
1492               " %d files changed, %d insertions(+), %d deletions(-)\n",
1493               total_files, adds, dels);
1494}
1495
1496static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1497{
1498        int i, adds = 0, dels = 0, total_files = data->nr;
1499
1500        if (data->nr == 0)
1501                return;
1502
1503        for (i = 0; i < data->nr; i++) {
1504                if (!data->files[i]->is_binary &&
1505                    !data->files[i]->is_unmerged) {
1506                        int added = data->files[i]->added;
1507                        int deleted= data->files[i]->deleted;
1508                        if (!data->files[i]->is_renamed &&
1509                            (added + deleted == 0)) {
1510                                total_files--;
1511                        } else {
1512                                adds += added;
1513                                dels += deleted;
1514                        }
1515                }
1516        }
1517        if (options->output_prefix) {
1518                struct strbuf *msg = NULL;
1519                msg = options->output_prefix(options,
1520                                options->output_prefix_data);
1521                fprintf(options->file, "%s", msg->buf);
1522        }
1523        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1524               total_files, adds, dels);
1525}
1526
1527static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1528{
1529        int i;
1530
1531        if (data->nr == 0)
1532                return;
1533
1534        for (i = 0; i < data->nr; i++) {
1535                struct diffstat_file *file = data->files[i];
1536
1537                if (options->output_prefix) {
1538                        struct strbuf *msg = NULL;
1539                        msg = options->output_prefix(options,
1540                                        options->output_prefix_data);
1541                        fprintf(options->file, "%s", msg->buf);
1542                }
1543
1544                if (file->is_binary)
1545                        fprintf(options->file, "-\t-\t");
1546                else
1547                        fprintf(options->file,
1548                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1549                                file->added, file->deleted);
1550                if (options->line_termination) {
1551                        fill_print_name(file);
1552                        if (!file->is_renamed)
1553                                write_name_quoted(file->name, options->file,
1554                                                  options->line_termination);
1555                        else {
1556                                fputs(file->print_name, options->file);
1557                                putc(options->line_termination, options->file);
1558                        }
1559                } else {
1560                        if (file->is_renamed) {
1561                                putc('\0', options->file);
1562                                write_name_quoted(file->from_name, options->file, '\0');
1563                        }
1564                        write_name_quoted(file->name, options->file, '\0');
1565                }
1566        }
1567}
1568
1569struct dirstat_file {
1570        const char *name;
1571        unsigned long changed;
1572};
1573
1574struct dirstat_dir {
1575        struct dirstat_file *files;
1576        int alloc, nr, permille, cumulative;
1577};
1578
1579static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1580                unsigned long changed, const char *base, int baselen)
1581{
1582        unsigned long this_dir = 0;
1583        unsigned int sources = 0;
1584        const char *line_prefix = "";
1585        struct strbuf *msg = NULL;
1586
1587        if (opt->output_prefix) {
1588                msg = opt->output_prefix(opt, opt->output_prefix_data);
1589                line_prefix = msg->buf;
1590        }
1591
1592        while (dir->nr) {
1593                struct dirstat_file *f = dir->files;
1594                int namelen = strlen(f->name);
1595                unsigned long this;
1596                char *slash;
1597
1598                if (namelen < baselen)
1599                        break;
1600                if (memcmp(f->name, base, baselen))
1601                        break;
1602                slash = strchr(f->name + baselen, '/');
1603                if (slash) {
1604                        int newbaselen = slash + 1 - f->name;
1605                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1606                        sources++;
1607                } else {
1608                        this = f->changed;
1609                        dir->files++;
1610                        dir->nr--;
1611                        sources += 2;
1612                }
1613                this_dir += this;
1614        }
1615
1616        /*
1617         * We don't report dirstat's for
1618         *  - the top level
1619         *  - or cases where everything came from a single directory
1620         *    under this directory (sources == 1).
1621         */
1622        if (baselen && sources != 1) {
1623                if (this_dir) {
1624                        int permille = this_dir * 1000 / changed;
1625                        if (permille >= dir->permille) {
1626                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1627                                        permille / 10, permille % 10, baselen, base);
1628                                if (!dir->cumulative)
1629                                        return 0;
1630                        }
1631                }
1632        }
1633        return this_dir;
1634}
1635
1636static int dirstat_compare(const void *_a, const void *_b)
1637{
1638        const struct dirstat_file *a = _a;
1639        const struct dirstat_file *b = _b;
1640        return strcmp(a->name, b->name);
1641}
1642
1643static void show_dirstat(struct diff_options *options)
1644{
1645        int i;
1646        unsigned long changed;
1647        struct dirstat_dir dir;
1648        struct diff_queue_struct *q = &diff_queued_diff;
1649
1650        dir.files = NULL;
1651        dir.alloc = 0;
1652        dir.nr = 0;
1653        dir.permille = options->dirstat_permille;
1654        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1655
1656        changed = 0;
1657        for (i = 0; i < q->nr; i++) {
1658                struct diff_filepair *p = q->queue[i];
1659                const char *name;
1660                unsigned long copied, added, damage;
1661                int content_changed;
1662
1663                name = p->two->path ? p->two->path : p->one->path;
1664
1665                if (p->one->sha1_valid && p->two->sha1_valid)
1666                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1667                else
1668                        content_changed = 1;
1669
1670                if (!content_changed) {
1671                        /*
1672                         * The SHA1 has not changed, so pre-/post-content is
1673                         * identical. We can therefore skip looking at the
1674                         * file contents altogether.
1675                         */
1676                        damage = 0;
1677                        goto found_damage;
1678                }
1679
1680                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1681                        /*
1682                         * In --dirstat-by-file mode, we don't really need to
1683                         * look at the actual file contents at all.
1684                         * The fact that the SHA1 changed is enough for us to
1685                         * add this file to the list of results
1686                         * (with each file contributing equal damage).
1687                         */
1688                        damage = 1;
1689                        goto found_damage;
1690                }
1691
1692                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1693                        diff_populate_filespec(p->one, 0);
1694                        diff_populate_filespec(p->two, 0);
1695                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1696                                               &copied, &added);
1697                        diff_free_filespec_data(p->one);
1698                        diff_free_filespec_data(p->two);
1699                } else if (DIFF_FILE_VALID(p->one)) {
1700                        diff_populate_filespec(p->one, 1);
1701                        copied = added = 0;
1702                        diff_free_filespec_data(p->one);
1703                } else if (DIFF_FILE_VALID(p->two)) {
1704                        diff_populate_filespec(p->two, 1);
1705                        copied = 0;
1706                        added = p->two->size;
1707                        diff_free_filespec_data(p->two);
1708                } else
1709                        continue;
1710
1711                /*
1712                 * Original minus copied is the removed material,
1713                 * added is the new material.  They are both damages
1714                 * made to the preimage.
1715                 * If the resulting damage is zero, we know that
1716                 * diffcore_count_changes() considers the two entries to
1717                 * be identical, but since content_changed is true, we
1718                 * know that there must have been _some_ kind of change,
1719                 * so we force all entries to have damage > 0.
1720                 */
1721                damage = (p->one->size - copied) + added;
1722                if (!damage)
1723                        damage = 1;
1724
1725found_damage:
1726                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1727                dir.files[dir.nr].name = name;
1728                dir.files[dir.nr].changed = damage;
1729                changed += damage;
1730                dir.nr++;
1731        }
1732
1733        /* This can happen even with many files, if everything was renames */
1734        if (!changed)
1735                return;
1736
1737        /* Show all directories with more than x% of the changes */
1738        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1739        gather_dirstat(options, &dir, changed, "", 0);
1740}
1741
1742static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1743{
1744        int i;
1745        unsigned long changed;
1746        struct dirstat_dir dir;
1747
1748        if (data->nr == 0)
1749                return;
1750
1751        dir.files = NULL;
1752        dir.alloc = 0;
1753        dir.nr = 0;
1754        dir.permille = options->dirstat_permille;
1755        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1756
1757        changed = 0;
1758        for (i = 0; i < data->nr; i++) {
1759                struct diffstat_file *file = data->files[i];
1760                unsigned long damage = file->added + file->deleted;
1761                if (file->is_binary)
1762                        /*
1763                         * binary files counts bytes, not lines. Must find some
1764                         * way to normalize binary bytes vs. textual lines.
1765                         * The following heuristic assumes that there are 64
1766                         * bytes per "line".
1767                         * This is stupid and ugly, but very cheap...
1768                         */
1769                        damage = (damage + 63) / 64;
1770                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1771                dir.files[dir.nr].name = file->name;
1772                dir.files[dir.nr].changed = damage;
1773                changed += damage;
1774                dir.nr++;
1775        }
1776
1777        /* This can happen even with many files, if everything was renames */
1778        if (!changed)
1779                return;
1780
1781        /* Show all directories with more than x% of the changes */
1782        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1783        gather_dirstat(options, &dir, changed, "", 0);
1784}
1785
1786static void free_diffstat_info(struct diffstat_t *diffstat)
1787{
1788        int i;
1789        for (i = 0; i < diffstat->nr; i++) {
1790                struct diffstat_file *f = diffstat->files[i];
1791                if (f->name != f->print_name)
1792                        free(f->print_name);
1793                free(f->name);
1794                free(f->from_name);
1795                free(f);
1796        }
1797        free(diffstat->files);
1798}
1799
1800struct checkdiff_t {
1801        const char *filename;
1802        int lineno;
1803        int conflict_marker_size;
1804        struct diff_options *o;
1805        unsigned ws_rule;
1806        unsigned status;
1807};
1808
1809static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1810{
1811        char firstchar;
1812        int cnt;
1813
1814        if (len < marker_size + 1)
1815                return 0;
1816        firstchar = line[0];
1817        switch (firstchar) {
1818        case '=': case '>': case '<': case '|':
1819                break;
1820        default:
1821                return 0;
1822        }
1823        for (cnt = 1; cnt < marker_size; cnt++)
1824                if (line[cnt] != firstchar)
1825                        return 0;
1826        /* line[1] thru line[marker_size-1] are same as firstchar */
1827        if (len < marker_size + 1 || !isspace(line[marker_size]))
1828                return 0;
1829        return 1;
1830}
1831
1832static void checkdiff_consume(void *priv, char *line, unsigned long len)
1833{
1834        struct checkdiff_t *data = priv;
1835        int marker_size = data->conflict_marker_size;
1836        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1837        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1838        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1839        char *err;
1840        char *line_prefix = "";
1841        struct strbuf *msgbuf;
1842
1843        assert(data->o);
1844        if (data->o->output_prefix) {
1845                msgbuf = data->o->output_prefix(data->o,
1846                        data->o->output_prefix_data);
1847                line_prefix = msgbuf->buf;
1848        }
1849
1850        if (line[0] == '+') {
1851                unsigned bad;
1852                data->lineno++;
1853                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1854                        data->status |= 1;
1855                        fprintf(data->o->file,
1856                                "%s%s:%d: leftover conflict marker\n",
1857                                line_prefix, data->filename, data->lineno);
1858                }
1859                bad = ws_check(line + 1, len - 1, data->ws_rule);
1860                if (!bad)
1861                        return;
1862                data->status |= bad;
1863                err = whitespace_error_string(bad);
1864                fprintf(data->o->file, "%s%s:%d: %s.\n",
1865                        line_prefix, data->filename, data->lineno, err);
1866                free(err);
1867                emit_line(data->o, set, reset, line, 1);
1868                ws_check_emit(line + 1, len - 1, data->ws_rule,
1869                              data->o->file, set, reset, ws);
1870        } else if (line[0] == ' ') {
1871                data->lineno++;
1872        } else if (line[0] == '@') {
1873                char *plus = strchr(line, '+');
1874                if (plus)
1875                        data->lineno = strtol(plus, NULL, 10) - 1;
1876                else
1877                        die("invalid diff");
1878        }
1879}
1880
1881static unsigned char *deflate_it(char *data,
1882                                 unsigned long size,
1883                                 unsigned long *result_size)
1884{
1885        int bound;
1886        unsigned char *deflated;
1887        git_zstream stream;
1888
1889        memset(&stream, 0, sizeof(stream));
1890        git_deflate_init(&stream, zlib_compression_level);
1891        bound = git_deflate_bound(&stream, size);
1892        deflated = xmalloc(bound);
1893        stream.next_out = deflated;
1894        stream.avail_out = bound;
1895
1896        stream.next_in = (unsigned char *)data;
1897        stream.avail_in = size;
1898        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1899                ; /* nothing */
1900        git_deflate_end(&stream);
1901        *result_size = stream.total_out;
1902        return deflated;
1903}
1904
1905static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1906{
1907        void *cp;
1908        void *delta;
1909        void *deflated;
1910        void *data;
1911        unsigned long orig_size;
1912        unsigned long delta_size;
1913        unsigned long deflate_size;
1914        unsigned long data_size;
1915
1916        /* We could do deflated delta, or we could do just deflated two,
1917         * whichever is smaller.
1918         */
1919        delta = NULL;
1920        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1921        if (one->size && two->size) {
1922                delta = diff_delta(one->ptr, one->size,
1923                                   two->ptr, two->size,
1924                                   &delta_size, deflate_size);
1925                if (delta) {
1926                        void *to_free = delta;
1927                        orig_size = delta_size;
1928                        delta = deflate_it(delta, delta_size, &delta_size);
1929                        free(to_free);
1930                }
1931        }
1932
1933        if (delta && delta_size < deflate_size) {
1934                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1935                free(deflated);
1936                data = delta;
1937                data_size = delta_size;
1938        }
1939        else {
1940                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1941                free(delta);
1942                data = deflated;
1943                data_size = deflate_size;
1944        }
1945
1946        /* emit data encoded in base85 */
1947        cp = data;
1948        while (data_size) {
1949                int bytes = (52 < data_size) ? 52 : data_size;
1950                char line[70];
1951                data_size -= bytes;
1952                if (bytes <= 26)
1953                        line[0] = bytes + 'A' - 1;
1954                else
1955                        line[0] = bytes - 26 + 'a' - 1;
1956                encode_85(line + 1, cp, bytes);
1957                cp = (char *) cp + bytes;
1958                fprintf(file, "%s", prefix);
1959                fputs(line, file);
1960                fputc('\n', file);
1961        }
1962        fprintf(file, "%s\n", prefix);
1963        free(data);
1964}
1965
1966static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1967{
1968        fprintf(file, "%sGIT binary patch\n", prefix);
1969        emit_binary_diff_body(file, one, two, prefix);
1970        emit_binary_diff_body(file, two, one, prefix);
1971}
1972
1973static void diff_filespec_load_driver(struct diff_filespec *one)
1974{
1975        /* Use already-loaded driver */
1976        if (one->driver)
1977                return;
1978
1979        if (S_ISREG(one->mode))
1980                one->driver = userdiff_find_by_path(one->path);
1981
1982        /* Fallback to default settings */
1983        if (!one->driver)
1984                one->driver = userdiff_find_by_name("default");
1985}
1986
1987int diff_filespec_is_binary(struct diff_filespec *one)
1988{
1989        if (one->is_binary == -1) {
1990                diff_filespec_load_driver(one);
1991                if (one->driver->binary != -1)
1992                        one->is_binary = one->driver->binary;
1993                else {
1994                        if (!one->data && DIFF_FILE_VALID(one))
1995                                diff_populate_filespec(one, 0);
1996                        if (one->data)
1997                                one->is_binary = buffer_is_binary(one->data,
1998                                                one->size);
1999                        if (one->is_binary == -1)
2000                                one->is_binary = 0;
2001                }
2002        }
2003        return one->is_binary;
2004}
2005
2006static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2007{
2008        diff_filespec_load_driver(one);
2009        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2010}
2011
2012static const char *userdiff_word_regex(struct diff_filespec *one)
2013{
2014        diff_filespec_load_driver(one);
2015        return one->driver->word_regex;
2016}
2017
2018void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2019{
2020        if (!options->a_prefix)
2021                options->a_prefix = a;
2022        if (!options->b_prefix)
2023                options->b_prefix = b;
2024}
2025
2026struct userdiff_driver *get_textconv(struct diff_filespec *one)
2027{
2028        if (!DIFF_FILE_VALID(one))
2029                return NULL;
2030
2031        diff_filespec_load_driver(one);
2032        return userdiff_get_textconv(one->driver);
2033}
2034
2035static void builtin_diff(const char *name_a,
2036                         const char *name_b,
2037                         struct diff_filespec *one,
2038                         struct diff_filespec *two,
2039                         const char *xfrm_msg,
2040                         int must_show_header,
2041                         struct diff_options *o,
2042                         int complete_rewrite)
2043{
2044        mmfile_t mf1, mf2;
2045        const char *lbl[2];
2046        char *a_one, *b_two;
2047        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2048        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2049        const char *a_prefix, *b_prefix;
2050        struct userdiff_driver *textconv_one = NULL;
2051        struct userdiff_driver *textconv_two = NULL;
2052        struct strbuf header = STRBUF_INIT;
2053        struct strbuf *msgbuf;
2054        char *line_prefix = "";
2055
2056        if (o->output_prefix) {
2057                msgbuf = o->output_prefix(o, o->output_prefix_data);
2058                line_prefix = msgbuf->buf;
2059        }
2060
2061        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2062                        (!one->mode || S_ISGITLINK(one->mode)) &&
2063                        (!two->mode || S_ISGITLINK(two->mode))) {
2064                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2065                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2066                show_submodule_summary(o->file, one ? one->path : two->path,
2067                                one->sha1, two->sha1, two->dirty_submodule,
2068                                del, add, reset);
2069                return;
2070        }
2071
2072        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2073                textconv_one = get_textconv(one);
2074                textconv_two = get_textconv(two);
2075        }
2076
2077        diff_set_mnemonic_prefix(o, "a/", "b/");
2078        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2079                a_prefix = o->b_prefix;
2080                b_prefix = o->a_prefix;
2081        } else {
2082                a_prefix = o->a_prefix;
2083                b_prefix = o->b_prefix;
2084        }
2085
2086        /* Never use a non-valid filename anywhere if at all possible */
2087        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2088        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2089
2090        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2091        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2092        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2093        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2094        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2095        if (lbl[0][0] == '/') {
2096                /* /dev/null */
2097                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2098                if (xfrm_msg)
2099                        strbuf_addstr(&header, xfrm_msg);
2100                must_show_header = 1;
2101        }
2102        else if (lbl[1][0] == '/') {
2103                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2104                if (xfrm_msg)
2105                        strbuf_addstr(&header, xfrm_msg);
2106                must_show_header = 1;
2107        }
2108        else {
2109                if (one->mode != two->mode) {
2110                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2111                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2112                        must_show_header = 1;
2113                }
2114                if (xfrm_msg)
2115                        strbuf_addstr(&header, xfrm_msg);
2116
2117                /*
2118                 * we do not run diff between different kind
2119                 * of objects.
2120                 */
2121                if ((one->mode ^ two->mode) & S_IFMT)
2122                        goto free_ab_and_return;
2123                if (complete_rewrite &&
2124                    (textconv_one || !diff_filespec_is_binary(one)) &&
2125                    (textconv_two || !diff_filespec_is_binary(two))) {
2126                        fprintf(o->file, "%s", header.buf);
2127                        strbuf_reset(&header);
2128                        emit_rewrite_diff(name_a, name_b, one, two,
2129                                                textconv_one, textconv_two, o);
2130                        o->found_changes = 1;
2131                        goto free_ab_and_return;
2132                }
2133        }
2134
2135        if (o->irreversible_delete && lbl[1][0] == '/') {
2136                fprintf(o->file, "%s", header.buf);
2137                strbuf_reset(&header);
2138                goto free_ab_and_return;
2139        } else if (!DIFF_OPT_TST(o, TEXT) &&
2140            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2141              (!textconv_two && diff_filespec_is_binary(two)) )) {
2142                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2143                        die("unable to read files to diff");
2144                /* Quite common confusing case */
2145                if (mf1.size == mf2.size &&
2146                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2147                        if (must_show_header)
2148                                fprintf(o->file, "%s", header.buf);
2149                        goto free_ab_and_return;
2150                }
2151                fprintf(o->file, "%s", header.buf);
2152                strbuf_reset(&header);
2153                if (DIFF_OPT_TST(o, BINARY))
2154                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2155                else
2156                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2157                                line_prefix, lbl[0], lbl[1]);
2158                o->found_changes = 1;
2159        } else {
2160                /* Crazy xdl interfaces.. */
2161                const char *diffopts = getenv("GIT_DIFF_OPTS");
2162                xpparam_t xpp;
2163                xdemitconf_t xecfg;
2164                struct emit_callback ecbdata;
2165                const struct userdiff_funcname *pe;
2166
2167                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2168                        fprintf(o->file, "%s", header.buf);
2169                        strbuf_reset(&header);
2170                }
2171
2172                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2173                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2174
2175                pe = diff_funcname_pattern(one);
2176                if (!pe)
2177                        pe = diff_funcname_pattern(two);
2178
2179                memset(&xpp, 0, sizeof(xpp));
2180                memset(&xecfg, 0, sizeof(xecfg));
2181                memset(&ecbdata, 0, sizeof(ecbdata));
2182                ecbdata.label_path = lbl;
2183                ecbdata.color_diff = want_color(o->use_color);
2184                ecbdata.found_changesp = &o->found_changes;
2185                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2186                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2187                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2188                ecbdata.opt = o;
2189                ecbdata.header = header.len ? &header : NULL;
2190                xpp.flags = o->xdl_opts;
2191                xecfg.ctxlen = o->context;
2192                xecfg.interhunkctxlen = o->interhunkcontext;
2193                xecfg.flags = XDL_EMIT_FUNCNAMES;
2194                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2195                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2196                if (pe)
2197                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2198                if (!diffopts)
2199                        ;
2200                else if (!prefixcmp(diffopts, "--unified="))
2201                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2202                else if (!prefixcmp(diffopts, "-u"))
2203                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2204                if (o->word_diff) {
2205                        int i;
2206
2207                        ecbdata.diff_words =
2208                                xcalloc(1, sizeof(struct diff_words_data));
2209                        ecbdata.diff_words->type = o->word_diff;
2210                        ecbdata.diff_words->opt = o;
2211                        if (!o->word_regex)
2212                                o->word_regex = userdiff_word_regex(one);
2213                        if (!o->word_regex)
2214                                o->word_regex = userdiff_word_regex(two);
2215                        if (!o->word_regex)
2216                                o->word_regex = diff_word_regex_cfg;
2217                        if (o->word_regex) {
2218                                ecbdata.diff_words->word_regex = (regex_t *)
2219                                        xmalloc(sizeof(regex_t));
2220                                if (regcomp(ecbdata.diff_words->word_regex,
2221                                                o->word_regex,
2222                                                REG_EXTENDED | REG_NEWLINE))
2223                                        die ("Invalid regular expression: %s",
2224                                                        o->word_regex);
2225                        }
2226                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2227                                if (o->word_diff == diff_words_styles[i].type) {
2228                                        ecbdata.diff_words->style =
2229                                                &diff_words_styles[i];
2230                                        break;
2231                                }
2232                        }
2233                        if (want_color(o->use_color)) {
2234                                struct diff_words_style *st = ecbdata.diff_words->style;
2235                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2236                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2237                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2238                        }
2239                }
2240                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2241                              &xpp, &xecfg);
2242                if (o->word_diff)
2243                        free_diff_words_data(&ecbdata);
2244                if (textconv_one)
2245                        free(mf1.ptr);
2246                if (textconv_two)
2247                        free(mf2.ptr);
2248                xdiff_clear_find_func(&xecfg);
2249        }
2250
2251 free_ab_and_return:
2252        strbuf_release(&header);
2253        diff_free_filespec_data(one);
2254        diff_free_filespec_data(two);
2255        free(a_one);
2256        free(b_two);
2257        return;
2258}
2259
2260static void builtin_diffstat(const char *name_a, const char *name_b,
2261                             struct diff_filespec *one,
2262                             struct diff_filespec *two,
2263                             struct diffstat_t *diffstat,
2264                             struct diff_options *o,
2265                             int complete_rewrite)
2266{
2267        mmfile_t mf1, mf2;
2268        struct diffstat_file *data;
2269
2270        data = diffstat_add(diffstat, name_a, name_b);
2271
2272        if (!one || !two) {
2273                data->is_unmerged = 1;
2274                return;
2275        }
2276
2277        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2278                data->is_binary = 1;
2279                data->added = diff_filespec_size(two);
2280                data->deleted = diff_filespec_size(one);
2281        }
2282
2283        else if (complete_rewrite) {
2284                diff_populate_filespec(one, 0);
2285                diff_populate_filespec(two, 0);
2286                data->deleted = count_lines(one->data, one->size);
2287                data->added = count_lines(two->data, two->size);
2288        }
2289
2290        else {
2291                /* Crazy xdl interfaces.. */
2292                xpparam_t xpp;
2293                xdemitconf_t xecfg;
2294
2295                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2296                        die("unable to read files to diff");
2297
2298                memset(&xpp, 0, sizeof(xpp));
2299                memset(&xecfg, 0, sizeof(xecfg));
2300                xpp.flags = o->xdl_opts;
2301                xecfg.ctxlen = o->context;
2302                xecfg.interhunkctxlen = o->interhunkcontext;
2303                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2304                              &xpp, &xecfg);
2305        }
2306
2307        diff_free_filespec_data(one);
2308        diff_free_filespec_data(two);
2309}
2310
2311static void builtin_checkdiff(const char *name_a, const char *name_b,
2312                              const char *attr_path,
2313                              struct diff_filespec *one,
2314                              struct diff_filespec *two,
2315                              struct diff_options *o)
2316{
2317        mmfile_t mf1, mf2;
2318        struct checkdiff_t data;
2319
2320        if (!two)
2321                return;
2322
2323        memset(&data, 0, sizeof(data));
2324        data.filename = name_b ? name_b : name_a;
2325        data.lineno = 0;
2326        data.o = o;
2327        data.ws_rule = whitespace_rule(attr_path);
2328        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2329
2330        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2331                die("unable to read files to diff");
2332
2333        /*
2334         * All the other codepaths check both sides, but not checking
2335         * the "old" side here is deliberate.  We are checking the newly
2336         * introduced changes, and as long as the "new" side is text, we
2337         * can and should check what it introduces.
2338         */
2339        if (diff_filespec_is_binary(two))
2340                goto free_and_return;
2341        else {
2342                /* Crazy xdl interfaces.. */
2343                xpparam_t xpp;
2344                xdemitconf_t xecfg;
2345
2346                memset(&xpp, 0, sizeof(xpp));
2347                memset(&xecfg, 0, sizeof(xecfg));
2348                xecfg.ctxlen = 1; /* at least one context line */
2349                xpp.flags = 0;
2350                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2351                              &xpp, &xecfg);
2352
2353                if (data.ws_rule & WS_BLANK_AT_EOF) {
2354                        struct emit_callback ecbdata;
2355                        int blank_at_eof;
2356
2357                        ecbdata.ws_rule = data.ws_rule;
2358                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2359                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2360
2361                        if (blank_at_eof) {
2362                                static char *err;
2363                                if (!err)
2364                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2365                                fprintf(o->file, "%s:%d: %s.\n",
2366                                        data.filename, blank_at_eof, err);
2367                                data.status = 1; /* report errors */
2368                        }
2369                }
2370        }
2371 free_and_return:
2372        diff_free_filespec_data(one);
2373        diff_free_filespec_data(two);
2374        if (data.status)
2375                DIFF_OPT_SET(o, CHECK_FAILED);
2376}
2377
2378struct diff_filespec *alloc_filespec(const char *path)
2379{
2380        int namelen = strlen(path);
2381        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2382
2383        memset(spec, 0, sizeof(*spec));
2384        spec->path = (char *)(spec + 1);
2385        memcpy(spec->path, path, namelen+1);
2386        spec->count = 1;
2387        spec->is_binary = -1;
2388        return spec;
2389}
2390
2391void free_filespec(struct diff_filespec *spec)
2392{
2393        if (!--spec->count) {
2394                diff_free_filespec_data(spec);
2395                free(spec);
2396        }
2397}
2398
2399void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2400                   unsigned short mode)
2401{
2402        if (mode) {
2403                spec->mode = canon_mode(mode);
2404                hashcpy(spec->sha1, sha1);
2405                spec->sha1_valid = !is_null_sha1(sha1);
2406        }
2407}
2408
2409/*
2410 * Given a name and sha1 pair, if the index tells us the file in
2411 * the work tree has that object contents, return true, so that
2412 * prepare_temp_file() does not have to inflate and extract.
2413 */
2414static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2415{
2416        struct cache_entry *ce;
2417        struct stat st;
2418        int pos, len;
2419
2420        /*
2421         * We do not read the cache ourselves here, because the
2422         * benchmark with my previous version that always reads cache
2423         * shows that it makes things worse for diff-tree comparing
2424         * two linux-2.6 kernel trees in an already checked out work
2425         * tree.  This is because most diff-tree comparisons deal with
2426         * only a small number of files, while reading the cache is
2427         * expensive for a large project, and its cost outweighs the
2428         * savings we get by not inflating the object to a temporary
2429         * file.  Practically, this code only helps when we are used
2430         * by diff-cache --cached, which does read the cache before
2431         * calling us.
2432         */
2433        if (!active_cache)
2434                return 0;
2435
2436        /* We want to avoid the working directory if our caller
2437         * doesn't need the data in a normal file, this system
2438         * is rather slow with its stat/open/mmap/close syscalls,
2439         * and the object is contained in a pack file.  The pack
2440         * is probably already open and will be faster to obtain
2441         * the data through than the working directory.  Loose
2442         * objects however would tend to be slower as they need
2443         * to be individually opened and inflated.
2444         */
2445        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2446                return 0;
2447
2448        len = strlen(name);
2449        pos = cache_name_pos(name, len);
2450        if (pos < 0)
2451                return 0;
2452        ce = active_cache[pos];
2453
2454        /*
2455         * This is not the sha1 we are looking for, or
2456         * unreusable because it is not a regular file.
2457         */
2458        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2459                return 0;
2460
2461        /*
2462         * If ce is marked as "assume unchanged", there is no
2463         * guarantee that work tree matches what we are looking for.
2464         */
2465        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2466                return 0;
2467
2468        /*
2469         * If ce matches the file in the work tree, we can reuse it.
2470         */
2471        if (ce_uptodate(ce) ||
2472            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2473                return 1;
2474
2475        return 0;
2476}
2477
2478static int populate_from_stdin(struct diff_filespec *s)
2479{
2480        struct strbuf buf = STRBUF_INIT;
2481        size_t size = 0;
2482
2483        if (strbuf_read(&buf, 0, 0) < 0)
2484                return error("error while reading from stdin %s",
2485                                     strerror(errno));
2486
2487        s->should_munmap = 0;
2488        s->data = strbuf_detach(&buf, &size);
2489        s->size = size;
2490        s->should_free = 1;
2491        return 0;
2492}
2493
2494static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2495{
2496        int len;
2497        char *data = xmalloc(100), *dirty = "";
2498
2499        /* Are we looking at the work tree? */
2500        if (s->dirty_submodule)
2501                dirty = "-dirty";
2502
2503        len = snprintf(data, 100,
2504                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2505        s->data = data;
2506        s->size = len;
2507        s->should_free = 1;
2508        if (size_only) {
2509                s->data = NULL;
2510                free(data);
2511        }
2512        return 0;
2513}
2514
2515/*
2516 * While doing rename detection and pickaxe operation, we may need to
2517 * grab the data for the blob (or file) for our own in-core comparison.
2518 * diff_filespec has data and size fields for this purpose.
2519 */
2520int diff_populate_filespec(struct diff_filespec *s, int size_only)
2521{
2522        int err = 0;
2523        if (!DIFF_FILE_VALID(s))
2524                die("internal error: asking to populate invalid file.");
2525        if (S_ISDIR(s->mode))
2526                return -1;
2527
2528        if (s->data)
2529                return 0;
2530
2531        if (size_only && 0 < s->size)
2532                return 0;
2533
2534        if (S_ISGITLINK(s->mode))
2535                return diff_populate_gitlink(s, size_only);
2536
2537        if (!s->sha1_valid ||
2538            reuse_worktree_file(s->path, s->sha1, 0)) {
2539                struct strbuf buf = STRBUF_INIT;
2540                struct stat st;
2541                int fd;
2542
2543                if (!strcmp(s->path, "-"))
2544                        return populate_from_stdin(s);
2545
2546                if (lstat(s->path, &st) < 0) {
2547                        if (errno == ENOENT) {
2548                        err_empty:
2549                                err = -1;
2550                        empty:
2551                                s->data = (char *)"";
2552                                s->size = 0;
2553                                return err;
2554                        }
2555                }
2556                s->size = xsize_t(st.st_size);
2557                if (!s->size)
2558                        goto empty;
2559                if (S_ISLNK(st.st_mode)) {
2560                        struct strbuf sb = STRBUF_INIT;
2561
2562                        if (strbuf_readlink(&sb, s->path, s->size))
2563                                goto err_empty;
2564                        s->size = sb.len;
2565                        s->data = strbuf_detach(&sb, NULL);
2566                        s->should_free = 1;
2567                        return 0;
2568                }
2569                if (size_only)
2570                        return 0;
2571                fd = open(s->path, O_RDONLY);
2572                if (fd < 0)
2573                        goto err_empty;
2574                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2575                close(fd);
2576                s->should_munmap = 1;
2577
2578                /*
2579                 * Convert from working tree format to canonical git format
2580                 */
2581                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2582                        size_t size = 0;
2583                        munmap(s->data, s->size);
2584                        s->should_munmap = 0;
2585                        s->data = strbuf_detach(&buf, &size);
2586                        s->size = size;
2587                        s->should_free = 1;
2588                }
2589        }
2590        else {
2591                enum object_type type;
2592                if (size_only) {
2593                        type = sha1_object_info(s->sha1, &s->size);
2594                        if (type < 0)
2595                                die("unable to read %s", sha1_to_hex(s->sha1));
2596                } else {
2597                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2598                        if (!s->data)
2599                                die("unable to read %s", sha1_to_hex(s->sha1));
2600                        s->should_free = 1;
2601                }
2602        }
2603        return 0;
2604}
2605
2606void diff_free_filespec_blob(struct diff_filespec *s)
2607{
2608        if (s->should_free)
2609                free(s->data);
2610        else if (s->should_munmap)
2611                munmap(s->data, s->size);
2612
2613        if (s->should_free || s->should_munmap) {
2614                s->should_free = s->should_munmap = 0;
2615                s->data = NULL;
2616        }
2617}
2618
2619void diff_free_filespec_data(struct diff_filespec *s)
2620{
2621        diff_free_filespec_blob(s);
2622        free(s->cnt_data);
2623        s->cnt_data = NULL;
2624}
2625
2626static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2627                           void *blob,
2628                           unsigned long size,
2629                           const unsigned char *sha1,
2630                           int mode)
2631{
2632        int fd;
2633        struct strbuf buf = STRBUF_INIT;
2634        struct strbuf template = STRBUF_INIT;
2635        char *path_dup = xstrdup(path);
2636        const char *base = basename(path_dup);
2637
2638        /* Generate "XXXXXX_basename.ext" */
2639        strbuf_addstr(&template, "XXXXXX_");
2640        strbuf_addstr(&template, base);
2641
2642        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2643                        strlen(base) + 1);
2644        if (fd < 0)
2645                die_errno("unable to create temp-file");
2646        if (convert_to_working_tree(path,
2647                        (const char *)blob, (size_t)size, &buf)) {
2648                blob = buf.buf;
2649                size = buf.len;
2650        }
2651        if (write_in_full(fd, blob, size) != size)
2652                die_errno("unable to write temp-file");
2653        close(fd);
2654        temp->name = temp->tmp_path;
2655        strcpy(temp->hex, sha1_to_hex(sha1));
2656        temp->hex[40] = 0;
2657        sprintf(temp->mode, "%06o", mode);
2658        strbuf_release(&buf);
2659        strbuf_release(&template);
2660        free(path_dup);
2661}
2662
2663static struct diff_tempfile *prepare_temp_file(const char *name,
2664                struct diff_filespec *one)
2665{
2666        struct diff_tempfile *temp = claim_diff_tempfile();
2667
2668        if (!DIFF_FILE_VALID(one)) {
2669        not_a_valid_file:
2670                /* A '-' entry produces this for file-2, and
2671                 * a '+' entry produces this for file-1.
2672                 */
2673                temp->name = "/dev/null";
2674                strcpy(temp->hex, ".");
2675                strcpy(temp->mode, ".");
2676                return temp;
2677        }
2678
2679        if (!remove_tempfile_installed) {
2680                atexit(remove_tempfile);
2681                sigchain_push_common(remove_tempfile_on_signal);
2682                remove_tempfile_installed = 1;
2683        }
2684
2685        if (!one->sha1_valid ||
2686            reuse_worktree_file(name, one->sha1, 1)) {
2687                struct stat st;
2688                if (lstat(name, &st) < 0) {
2689                        if (errno == ENOENT)
2690                                goto not_a_valid_file;
2691                        die_errno("stat(%s)", name);
2692                }
2693                if (S_ISLNK(st.st_mode)) {
2694                        struct strbuf sb = STRBUF_INIT;
2695                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2696                                die_errno("readlink(%s)", name);
2697                        prep_temp_blob(name, temp, sb.buf, sb.len,
2698                                       (one->sha1_valid ?
2699                                        one->sha1 : null_sha1),
2700                                       (one->sha1_valid ?
2701                                        one->mode : S_IFLNK));
2702                        strbuf_release(&sb);
2703                }
2704                else {
2705                        /* we can borrow from the file in the work tree */
2706                        temp->name = name;
2707                        if (!one->sha1_valid)
2708                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2709                        else
2710                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2711                        /* Even though we may sometimes borrow the
2712                         * contents from the work tree, we always want
2713                         * one->mode.  mode is trustworthy even when
2714                         * !(one->sha1_valid), as long as
2715                         * DIFF_FILE_VALID(one).
2716                         */
2717                        sprintf(temp->mode, "%06o", one->mode);
2718                }
2719                return temp;
2720        }
2721        else {
2722                if (diff_populate_filespec(one, 0))
2723                        die("cannot read data blob for %s", one->path);
2724                prep_temp_blob(name, temp, one->data, one->size,
2725                               one->sha1, one->mode);
2726        }
2727        return temp;
2728}
2729
2730/* An external diff command takes:
2731 *
2732 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2733 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2734 *
2735 */
2736static void run_external_diff(const char *pgm,
2737                              const char *name,
2738                              const char *other,
2739                              struct diff_filespec *one,
2740                              struct diff_filespec *two,
2741                              const char *xfrm_msg,
2742                              int complete_rewrite)
2743{
2744        const char *spawn_arg[10];
2745        int retval;
2746        const char **arg = &spawn_arg[0];
2747
2748        if (one && two) {
2749                struct diff_tempfile *temp_one, *temp_two;
2750                const char *othername = (other ? other : name);
2751                temp_one = prepare_temp_file(name, one);
2752                temp_two = prepare_temp_file(othername, two);
2753                *arg++ = pgm;
2754                *arg++ = name;
2755                *arg++ = temp_one->name;
2756                *arg++ = temp_one->hex;
2757                *arg++ = temp_one->mode;
2758                *arg++ = temp_two->name;
2759                *arg++ = temp_two->hex;
2760                *arg++ = temp_two->mode;
2761                if (other) {
2762                        *arg++ = other;
2763                        *arg++ = xfrm_msg;
2764                }
2765        } else {
2766                *arg++ = pgm;
2767                *arg++ = name;
2768        }
2769        *arg = NULL;
2770        fflush(NULL);
2771        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2772        remove_tempfile();
2773        if (retval) {
2774                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2775                exit(1);
2776        }
2777}
2778
2779static int similarity_index(struct diff_filepair *p)
2780{
2781        return p->score * 100 / MAX_SCORE;
2782}
2783
2784static void fill_metainfo(struct strbuf *msg,
2785                          const char *name,
2786                          const char *other,
2787                          struct diff_filespec *one,
2788                          struct diff_filespec *two,
2789                          struct diff_options *o,
2790                          struct diff_filepair *p,
2791                          int *must_show_header,
2792                          int use_color)
2793{
2794        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2795        const char *reset = diff_get_color(use_color, DIFF_RESET);
2796        struct strbuf *msgbuf;
2797        char *line_prefix = "";
2798
2799        *must_show_header = 1;
2800        if (o->output_prefix) {
2801                msgbuf = o->output_prefix(o, o->output_prefix_data);
2802                line_prefix = msgbuf->buf;
2803        }
2804        strbuf_init(msg, PATH_MAX * 2 + 300);
2805        switch (p->status) {
2806        case DIFF_STATUS_COPIED:
2807                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2808                            line_prefix, set, similarity_index(p));
2809                strbuf_addf(msg, "%s\n%s%scopy from ",
2810                            reset,  line_prefix, set);
2811                quote_c_style(name, msg, NULL, 0);
2812                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2813                quote_c_style(other, msg, NULL, 0);
2814                strbuf_addf(msg, "%s\n", reset);
2815                break;
2816        case DIFF_STATUS_RENAMED:
2817                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2818                            line_prefix, set, similarity_index(p));
2819                strbuf_addf(msg, "%s\n%s%srename from ",
2820                            reset, line_prefix, set);
2821                quote_c_style(name, msg, NULL, 0);
2822                strbuf_addf(msg, "%s\n%s%srename to ",
2823                            reset, line_prefix, set);
2824                quote_c_style(other, msg, NULL, 0);
2825                strbuf_addf(msg, "%s\n", reset);
2826                break;
2827        case DIFF_STATUS_MODIFIED:
2828                if (p->score) {
2829                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2830                                    line_prefix,
2831                                    set, similarity_index(p), reset);
2832                        break;
2833                }
2834                /* fallthru */
2835        default:
2836                *must_show_header = 0;
2837        }
2838        if (one && two && hashcmp(one->sha1, two->sha1)) {
2839                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2840
2841                if (DIFF_OPT_TST(o, BINARY)) {
2842                        mmfile_t mf;
2843                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2844                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2845                                abbrev = 40;
2846                }
2847                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2848                            find_unique_abbrev(one->sha1, abbrev));
2849                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2850                if (one->mode == two->mode)
2851                        strbuf_addf(msg, " %06o", one->mode);
2852                strbuf_addf(msg, "%s\n", reset);
2853        }
2854}
2855
2856static void run_diff_cmd(const char *pgm,
2857                         const char *name,
2858                         const char *other,
2859                         const char *attr_path,
2860                         struct diff_filespec *one,
2861                         struct diff_filespec *two,
2862                         struct strbuf *msg,
2863                         struct diff_options *o,
2864                         struct diff_filepair *p)
2865{
2866        const char *xfrm_msg = NULL;
2867        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2868        int must_show_header = 0;
2869
2870        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2871                pgm = NULL;
2872        else {
2873                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2874                if (drv && drv->external)
2875                        pgm = drv->external;
2876        }
2877
2878        if (msg) {
2879                /*
2880                 * don't use colors when the header is intended for an
2881                 * external diff driver
2882                 */
2883                fill_metainfo(msg, name, other, one, two, o, p,
2884                              &must_show_header,
2885                              want_color(o->use_color) && !pgm);
2886                xfrm_msg = msg->len ? msg->buf : NULL;
2887        }
2888
2889        if (pgm) {
2890                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2891                                  complete_rewrite);
2892                return;
2893        }
2894        if (one && two)
2895                builtin_diff(name, other ? other : name,
2896                             one, two, xfrm_msg, must_show_header,
2897                             o, complete_rewrite);
2898        else
2899                fprintf(o->file, "* Unmerged path %s\n", name);
2900}
2901
2902static void diff_fill_sha1_info(struct diff_filespec *one)
2903{
2904        if (DIFF_FILE_VALID(one)) {
2905                if (!one->sha1_valid) {
2906                        struct stat st;
2907                        if (!strcmp(one->path, "-")) {
2908                                hashcpy(one->sha1, null_sha1);
2909                                return;
2910                        }
2911                        if (lstat(one->path, &st) < 0)
2912                                die_errno("stat '%s'", one->path);
2913                        if (index_path(one->sha1, one->path, &st, 0))
2914                                die("cannot hash %s", one->path);
2915                }
2916        }
2917        else
2918                hashclr(one->sha1);
2919}
2920
2921static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2922{
2923        /* Strip the prefix but do not molest /dev/null and absolute paths */
2924        if (*namep && **namep != '/') {
2925                *namep += prefix_length;
2926                if (**namep == '/')
2927                        ++*namep;
2928        }
2929        if (*otherp && **otherp != '/') {
2930                *otherp += prefix_length;
2931                if (**otherp == '/')
2932                        ++*otherp;
2933        }
2934}
2935
2936static void run_diff(struct diff_filepair *p, struct diff_options *o)
2937{
2938        const char *pgm = external_diff();
2939        struct strbuf msg;
2940        struct diff_filespec *one = p->one;
2941        struct diff_filespec *two = p->two;
2942        const char *name;
2943        const char *other;
2944        const char *attr_path;
2945
2946        name  = p->one->path;
2947        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2948        attr_path = name;
2949        if (o->prefix_length)
2950                strip_prefix(o->prefix_length, &name, &other);
2951
2952        if (DIFF_PAIR_UNMERGED(p)) {
2953                run_diff_cmd(pgm, name, NULL, attr_path,
2954                             NULL, NULL, NULL, o, p);
2955                return;
2956        }
2957
2958        diff_fill_sha1_info(one);
2959        diff_fill_sha1_info(two);
2960
2961        if (!pgm &&
2962            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2963            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2964                /*
2965                 * a filepair that changes between file and symlink
2966                 * needs to be split into deletion and creation.
2967                 */
2968                struct diff_filespec *null = alloc_filespec(two->path);
2969                run_diff_cmd(NULL, name, other, attr_path,
2970                             one, null, &msg, o, p);
2971                free(null);
2972                strbuf_release(&msg);
2973
2974                null = alloc_filespec(one->path);
2975                run_diff_cmd(NULL, name, other, attr_path,
2976                             null, two, &msg, o, p);
2977                free(null);
2978        }
2979        else
2980                run_diff_cmd(pgm, name, other, attr_path,
2981                             one, two, &msg, o, p);
2982
2983        strbuf_release(&msg);
2984}
2985
2986static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2987                         struct diffstat_t *diffstat)
2988{
2989        const char *name;
2990        const char *other;
2991        int complete_rewrite = 0;
2992
2993        if (DIFF_PAIR_UNMERGED(p)) {
2994                /* unmerged */
2995                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2996                return;
2997        }
2998
2999        name = p->one->path;
3000        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3001
3002        if (o->prefix_length)
3003                strip_prefix(o->prefix_length, &name, &other);
3004
3005        diff_fill_sha1_info(p->one);
3006        diff_fill_sha1_info(p->two);
3007
3008        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3009                complete_rewrite = 1;
3010        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3011}
3012
3013static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3014{
3015        const char *name;
3016        const char *other;
3017        const char *attr_path;
3018
3019        if (DIFF_PAIR_UNMERGED(p)) {
3020                /* unmerged */
3021                return;
3022        }
3023
3024        name = p->one->path;
3025        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3026        attr_path = other ? other : name;
3027
3028        if (o->prefix_length)
3029                strip_prefix(o->prefix_length, &name, &other);
3030
3031        diff_fill_sha1_info(p->one);
3032        diff_fill_sha1_info(p->two);
3033
3034        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3035}
3036
3037void diff_setup(struct diff_options *options)
3038{
3039        memcpy(options, &default_diff_options, sizeof(*options));
3040
3041        options->file = stdout;
3042
3043        options->line_termination = '\n';
3044        options->break_opt = -1;
3045        options->rename_limit = -1;
3046        options->dirstat_permille = diff_dirstat_permille_default;
3047        options->context = 3;
3048
3049        options->change = diff_change;
3050        options->add_remove = diff_addremove;
3051        options->use_color = diff_use_color_default;
3052        options->detect_rename = diff_detect_rename_default;
3053
3054        if (diff_no_prefix) {
3055                options->a_prefix = options->b_prefix = "";
3056        } else if (!diff_mnemonic_prefix) {
3057                options->a_prefix = "a/";
3058                options->b_prefix = "b/";
3059        }
3060}
3061
3062int diff_setup_done(struct diff_options *options)
3063{
3064        int count = 0;
3065
3066        if (options->output_format & DIFF_FORMAT_NAME)
3067                count++;
3068        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3069                count++;
3070        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3071                count++;
3072        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3073                count++;
3074        if (count > 1)
3075                die("--name-only, --name-status, --check and -s are mutually exclusive");
3076
3077        /*
3078         * Most of the time we can say "there are changes"
3079         * only by checking if there are changed paths, but
3080         * --ignore-whitespace* options force us to look
3081         * inside contents.
3082         */
3083
3084        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3085            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3086            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3087                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3088        else
3089                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3090
3091        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3092                options->detect_rename = DIFF_DETECT_COPY;
3093
3094        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3095                options->prefix = NULL;
3096        if (options->prefix)
3097                options->prefix_length = strlen(options->prefix);
3098        else
3099                options->prefix_length = 0;
3100
3101        if (options->output_format & (DIFF_FORMAT_NAME |
3102                                      DIFF_FORMAT_NAME_STATUS |
3103                                      DIFF_FORMAT_CHECKDIFF |
3104                                      DIFF_FORMAT_NO_OUTPUT))
3105                options->output_format &= ~(DIFF_FORMAT_RAW |
3106                                            DIFF_FORMAT_NUMSTAT |
3107                                            DIFF_FORMAT_DIFFSTAT |
3108                                            DIFF_FORMAT_SHORTSTAT |
3109                                            DIFF_FORMAT_DIRSTAT |
3110                                            DIFF_FORMAT_SUMMARY |
3111                                            DIFF_FORMAT_PATCH);
3112
3113        /*
3114         * These cases always need recursive; we do not drop caller-supplied
3115         * recursive bits for other formats here.
3116         */
3117        if (options->output_format & (DIFF_FORMAT_PATCH |
3118                                      DIFF_FORMAT_NUMSTAT |
3119                                      DIFF_FORMAT_DIFFSTAT |
3120                                      DIFF_FORMAT_SHORTSTAT |
3121                                      DIFF_FORMAT_DIRSTAT |
3122                                      DIFF_FORMAT_SUMMARY |
3123                                      DIFF_FORMAT_CHECKDIFF))
3124                DIFF_OPT_SET(options, RECURSIVE);
3125        /*
3126         * Also pickaxe would not work very well if you do not say recursive
3127         */
3128        if (options->pickaxe)
3129                DIFF_OPT_SET(options, RECURSIVE);
3130        /*
3131         * When patches are generated, submodules diffed against the work tree
3132         * must be checked for dirtiness too so it can be shown in the output
3133         */
3134        if (options->output_format & DIFF_FORMAT_PATCH)
3135                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3136
3137        if (options->detect_rename && options->rename_limit < 0)
3138                options->rename_limit = diff_rename_limit_default;
3139        if (options->setup & DIFF_SETUP_USE_CACHE) {
3140                if (!active_cache)
3141                        /* read-cache does not die even when it fails
3142                         * so it is safe for us to do this here.  Also
3143                         * it does not smudge active_cache or active_nr
3144                         * when it fails, so we do not have to worry about
3145                         * cleaning it up ourselves either.
3146                         */
3147                        read_cache();
3148        }
3149        if (options->abbrev <= 0 || 40 < options->abbrev)
3150                options->abbrev = 40; /* full */
3151
3152        /*
3153         * It does not make sense to show the first hit we happened
3154         * to have found.  It does not make sense not to return with
3155         * exit code in such a case either.
3156         */
3157        if (DIFF_OPT_TST(options, QUICK)) {
3158                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3159                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3160        }
3161
3162        return 0;
3163}
3164
3165static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3166{
3167        char c, *eq;
3168        int len;
3169
3170        if (*arg != '-')
3171                return 0;
3172        c = *++arg;
3173        if (!c)
3174                return 0;
3175        if (c == arg_short) {
3176                c = *++arg;
3177                if (!c)
3178                        return 1;
3179                if (val && isdigit(c)) {
3180                        char *end;
3181                        int n = strtoul(arg, &end, 10);
3182                        if (*end)
3183                                return 0;
3184                        *val = n;
3185                        return 1;
3186                }
3187                return 0;
3188        }
3189        if (c != '-')
3190                return 0;
3191        arg++;
3192        eq = strchr(arg, '=');
3193        if (eq)
3194                len = eq - arg;
3195        else
3196                len = strlen(arg);
3197        if (!len || strncmp(arg, arg_long, len))
3198                return 0;
3199        if (eq) {
3200                int n;
3201                char *end;
3202                if (!isdigit(*++eq))
3203                        return 0;
3204                n = strtoul(eq, &end, 10);
3205                if (*end)
3206                        return 0;
3207                *val = n;
3208        }
3209        return 1;
3210}
3211
3212static int diff_scoreopt_parse(const char *opt);
3213
3214static inline int short_opt(char opt, const char **argv,
3215                            const char **optarg)
3216{
3217        const char *arg = argv[0];
3218        if (arg[0] != '-' || arg[1] != opt)
3219                return 0;
3220        if (arg[2] != '\0') {
3221                *optarg = arg + 2;
3222                return 1;
3223        }
3224        if (!argv[1])
3225                die("Option '%c' requires a value", opt);
3226        *optarg = argv[1];
3227        return 2;
3228}
3229
3230int parse_long_opt(const char *opt, const char **argv,
3231                   const char **optarg)
3232{
3233        const char *arg = argv[0];
3234        if (arg[0] != '-' || arg[1] != '-')
3235                return 0;
3236        arg += strlen("--");
3237        if (prefixcmp(arg, opt))
3238                return 0;
3239        arg += strlen(opt);
3240        if (*arg == '=') { /* sticked form: --option=value */
3241                *optarg = arg + 1;
3242                return 1;
3243        }
3244        if (*arg != '\0')
3245                return 0;
3246        /* separate form: --option value */
3247        if (!argv[1])
3248                die("Option '--%s' requires a value", opt);
3249        *optarg = argv[1];
3250        return 2;
3251}
3252
3253static int stat_opt(struct diff_options *options, const char **av)
3254{
3255        const char *arg = av[0];
3256        char *end;
3257        int width = options->stat_width;
3258        int name_width = options->stat_name_width;
3259        int count = options->stat_count;
3260        int argcount = 1;
3261
3262        arg += strlen("--stat");
3263        end = (char *)arg;
3264
3265        switch (*arg) {
3266        case '-':
3267                if (!prefixcmp(arg, "-width")) {
3268                        arg += strlen("-width");
3269                        if (*arg == '=')
3270                                width = strtoul(arg + 1, &end, 10);
3271                        else if (!*arg && !av[1])
3272                                die("Option '--stat-width' requires a value");
3273                        else if (!*arg) {
3274                                width = strtoul(av[1], &end, 10);
3275                                argcount = 2;
3276                        }
3277                } else if (!prefixcmp(arg, "-name-width")) {
3278                        arg += strlen("-name-width");
3279                        if (*arg == '=')
3280                                name_width = strtoul(arg + 1, &end, 10);
3281                        else if (!*arg && !av[1])
3282                                die("Option '--stat-name-width' requires a value");
3283                        else if (!*arg) {
3284                                name_width = strtoul(av[1], &end, 10);
3285                                argcount = 2;
3286                        }
3287                } else if (!prefixcmp(arg, "-count")) {
3288                        arg += strlen("-count");
3289                        if (*arg == '=')
3290                                count = strtoul(arg + 1, &end, 10);
3291                        else if (!*arg && !av[1])
3292                                die("Option '--stat-count' requires a value");
3293                        else if (!*arg) {
3294                                count = strtoul(av[1], &end, 10);
3295                                argcount = 2;
3296                        }
3297                }
3298                break;
3299        case '=':
3300                width = strtoul(arg+1, &end, 10);
3301                if (*end == ',')
3302                        name_width = strtoul(end+1, &end, 10);
3303                if (*end == ',')
3304                        count = strtoul(end+1, &end, 10);
3305        }
3306
3307        /* Important! This checks all the error cases! */
3308        if (*end)
3309                return 0;
3310        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3311        options->stat_name_width = name_width;
3312        options->stat_width = width;
3313        options->stat_count = count;
3314        return argcount;
3315}
3316
3317static int parse_dirstat_opt(struct diff_options *options, const char *params)
3318{
3319        struct strbuf errmsg = STRBUF_INIT;
3320        if (parse_dirstat_params(options, params, &errmsg))
3321                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3322                    errmsg.buf);
3323        strbuf_release(&errmsg);
3324        /*
3325         * The caller knows a dirstat-related option is given from the command
3326         * line; allow it to say "return this_function();"
3327         */
3328        options->output_format |= DIFF_FORMAT_DIRSTAT;
3329        return 1;
3330}
3331
3332int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3333{
3334        const char *arg = av[0];
3335        const char *optarg;
3336        int argcount;
3337
3338        /* Output format options */
3339        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3340                options->output_format |= DIFF_FORMAT_PATCH;
3341        else if (opt_arg(arg, 'U', "unified", &options->context))
3342                options->output_format |= DIFF_FORMAT_PATCH;
3343        else if (!strcmp(arg, "--raw"))
3344                options->output_format |= DIFF_FORMAT_RAW;
3345        else if (!strcmp(arg, "--patch-with-raw"))
3346                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3347        else if (!strcmp(arg, "--numstat"))
3348                options->output_format |= DIFF_FORMAT_NUMSTAT;
3349        else if (!strcmp(arg, "--shortstat"))
3350                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3351        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3352                return parse_dirstat_opt(options, "");
3353        else if (!prefixcmp(arg, "-X"))
3354                return parse_dirstat_opt(options, arg + 2);
3355        else if (!prefixcmp(arg, "--dirstat="))
3356                return parse_dirstat_opt(options, arg + 10);
3357        else if (!strcmp(arg, "--cumulative"))
3358                return parse_dirstat_opt(options, "cumulative");
3359        else if (!strcmp(arg, "--dirstat-by-file"))
3360                return parse_dirstat_opt(options, "files");
3361        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3362                parse_dirstat_opt(options, "files");
3363                return parse_dirstat_opt(options, arg + 18);
3364        }
3365        else if (!strcmp(arg, "--check"))
3366                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3367        else if (!strcmp(arg, "--summary"))
3368                options->output_format |= DIFF_FORMAT_SUMMARY;
3369        else if (!strcmp(arg, "--patch-with-stat"))
3370                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3371        else if (!strcmp(arg, "--name-only"))
3372                options->output_format |= DIFF_FORMAT_NAME;
3373        else if (!strcmp(arg, "--name-status"))
3374                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3375        else if (!strcmp(arg, "-s"))
3376                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3377        else if (!prefixcmp(arg, "--stat"))
3378                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3379                return stat_opt(options, av);
3380
3381        /* renames options */
3382        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3383                 !strcmp(arg, "--break-rewrites")) {
3384                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3385                        return error("invalid argument to -B: %s", arg+2);
3386        }
3387        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3388                 !strcmp(arg, "--find-renames")) {
3389                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3390                        return error("invalid argument to -M: %s", arg+2);
3391                options->detect_rename = DIFF_DETECT_RENAME;
3392        }
3393        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3394                options->irreversible_delete = 1;
3395        }
3396        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3397                 !strcmp(arg, "--find-copies")) {
3398                if (options->detect_rename == DIFF_DETECT_COPY)
3399                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3400                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3401                        return error("invalid argument to -C: %s", arg+2);
3402                options->detect_rename = DIFF_DETECT_COPY;
3403        }
3404        else if (!strcmp(arg, "--no-renames"))
3405                options->detect_rename = 0;
3406        else if (!strcmp(arg, "--relative"))
3407                DIFF_OPT_SET(options, RELATIVE_NAME);
3408        else if (!prefixcmp(arg, "--relative=")) {
3409                DIFF_OPT_SET(options, RELATIVE_NAME);
3410                options->prefix = arg + 11;
3411        }
3412
3413        /* xdiff options */
3414        else if (!strcmp(arg, "--minimal"))
3415                DIFF_XDL_SET(options, NEED_MINIMAL);
3416        else if (!strcmp(arg, "--no-minimal"))
3417                DIFF_XDL_CLR(options, NEED_MINIMAL);
3418        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3419                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3420        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3421                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3422        else if (!strcmp(arg, "--ignore-space-at-eol"))
3423                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3424        else if (!strcmp(arg, "--patience"))
3425                DIFF_XDL_SET(options, PATIENCE_DIFF);
3426        else if (!strcmp(arg, "--histogram"))
3427                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3428
3429        /* flags options */
3430        else if (!strcmp(arg, "--binary")) {
3431                options->output_format |= DIFF_FORMAT_PATCH;
3432                DIFF_OPT_SET(options, BINARY);
3433        }
3434        else if (!strcmp(arg, "--full-index"))
3435                DIFF_OPT_SET(options, FULL_INDEX);
3436        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3437                DIFF_OPT_SET(options, TEXT);
3438        else if (!strcmp(arg, "-R"))
3439                DIFF_OPT_SET(options, REVERSE_DIFF);
3440        else if (!strcmp(arg, "--find-copies-harder"))
3441                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3442        else if (!strcmp(arg, "--follow"))
3443                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3444        else if (!strcmp(arg, "--color"))
3445                options->use_color = 1;
3446        else if (!prefixcmp(arg, "--color=")) {
3447                int value = git_config_colorbool(NULL, arg+8);
3448                if (value < 0)
3449                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3450                options->use_color = value;
3451        }
3452        else if (!strcmp(arg, "--no-color"))
3453                options->use_color = 0;
3454        else if (!strcmp(arg, "--color-words")) {
3455                options->use_color = 1;
3456                options->word_diff = DIFF_WORDS_COLOR;
3457        }
3458        else if (!prefixcmp(arg, "--color-words=")) {
3459                options->use_color = 1;
3460                options->word_diff = DIFF_WORDS_COLOR;
3461                options->word_regex = arg + 14;
3462        }
3463        else if (!strcmp(arg, "--word-diff")) {
3464                if (options->word_diff == DIFF_WORDS_NONE)
3465                        options->word_diff = DIFF_WORDS_PLAIN;
3466        }
3467        else if (!prefixcmp(arg, "--word-diff=")) {
3468                const char *type = arg + 12;
3469                if (!strcmp(type, "plain"))
3470                        options->word_diff = DIFF_WORDS_PLAIN;
3471                else if (!strcmp(type, "color")) {
3472                        options->use_color = 1;
3473                        options->word_diff = DIFF_WORDS_COLOR;
3474                }
3475                else if (!strcmp(type, "porcelain"))
3476                        options->word_diff = DIFF_WORDS_PORCELAIN;
3477                else if (!strcmp(type, "none"))
3478                        options->word_diff = DIFF_WORDS_NONE;
3479                else
3480                        die("bad --word-diff argument: %s", type);
3481        }
3482        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3483                if (options->word_diff == DIFF_WORDS_NONE)
3484                        options->word_diff = DIFF_WORDS_PLAIN;
3485                options->word_regex = optarg;
3486                return argcount;
3487        }
3488        else if (!strcmp(arg, "--exit-code"))
3489                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3490        else if (!strcmp(arg, "--quiet"))
3491                DIFF_OPT_SET(options, QUICK);
3492        else if (!strcmp(arg, "--ext-diff"))
3493                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3494        else if (!strcmp(arg, "--no-ext-diff"))
3495                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3496        else if (!strcmp(arg, "--textconv"))
3497                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3498        else if (!strcmp(arg, "--no-textconv"))
3499                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3500        else if (!strcmp(arg, "--ignore-submodules")) {
3501                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3502                handle_ignore_submodules_arg(options, "all");
3503        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3504                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3505                handle_ignore_submodules_arg(options, arg + 20);
3506        } else if (!strcmp(arg, "--submodule"))
3507                DIFF_OPT_SET(options, SUBMODULE_LOG);
3508        else if (!prefixcmp(arg, "--submodule=")) {
3509                if (!strcmp(arg + 12, "log"))
3510                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3511        }
3512
3513        /* misc options */
3514        else if (!strcmp(arg, "-z"))
3515                options->line_termination = 0;
3516        else if ((argcount = short_opt('l', av, &optarg))) {
3517                options->rename_limit = strtoul(optarg, NULL, 10);
3518                return argcount;
3519        }
3520        else if ((argcount = short_opt('S', av, &optarg))) {
3521                options->pickaxe = optarg;
3522                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3523                return argcount;
3524        } else if ((argcount = short_opt('G', av, &optarg))) {
3525                options->pickaxe = optarg;
3526                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3527                return argcount;
3528        }
3529        else if (!strcmp(arg, "--pickaxe-all"))
3530                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3531        else if (!strcmp(arg, "--pickaxe-regex"))
3532                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3533        else if ((argcount = short_opt('O', av, &optarg))) {
3534                options->orderfile = optarg;
3535                return argcount;
3536        }
3537        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3538                options->filter = optarg;
3539                return argcount;
3540        }
3541        else if (!strcmp(arg, "--abbrev"))
3542                options->abbrev = DEFAULT_ABBREV;
3543        else if (!prefixcmp(arg, "--abbrev=")) {
3544                options->abbrev = strtoul(arg + 9, NULL, 10);
3545                if (options->abbrev < MINIMUM_ABBREV)
3546                        options->abbrev = MINIMUM_ABBREV;
3547                else if (40 < options->abbrev)
3548                        options->abbrev = 40;
3549        }
3550        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3551                options->a_prefix = optarg;
3552                return argcount;
3553        }
3554        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3555                options->b_prefix = optarg;
3556                return argcount;
3557        }
3558        else if (!strcmp(arg, "--no-prefix"))
3559                options->a_prefix = options->b_prefix = "";
3560        else if (opt_arg(arg, '\0', "inter-hunk-context",
3561                         &options->interhunkcontext))
3562                ;
3563        else if (!strcmp(arg, "-W"))
3564                DIFF_OPT_SET(options, FUNCCONTEXT);
3565        else if (!strcmp(arg, "--function-context"))
3566                DIFF_OPT_SET(options, FUNCCONTEXT);
3567        else if (!strcmp(arg, "--no-function-context"))
3568                DIFF_OPT_CLR(options, FUNCCONTEXT);
3569        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3570                options->file = fopen(optarg, "w");
3571                if (!options->file)
3572                        die_errno("Could not open '%s'", optarg);
3573                options->close_file = 1;
3574                return argcount;
3575        } else
3576                return 0;
3577        return 1;
3578}
3579
3580int parse_rename_score(const char **cp_p)
3581{
3582        unsigned long num, scale;
3583        int ch, dot;
3584        const char *cp = *cp_p;
3585
3586        num = 0;
3587        scale = 1;
3588        dot = 0;
3589        for (;;) {
3590                ch = *cp;
3591                if ( !dot && ch == '.' ) {
3592                        scale = 1;
3593                        dot = 1;
3594                } else if ( ch == '%' ) {
3595                        scale = dot ? scale*100 : 100;
3596                        cp++;   /* % is always at the end */
3597                        break;
3598                } else if ( ch >= '0' && ch <= '9' ) {
3599                        if ( scale < 100000 ) {
3600                                scale *= 10;
3601                                num = (num*10) + (ch-'0');
3602                        }
3603                } else {
3604                        break;
3605                }
3606                cp++;
3607        }
3608        *cp_p = cp;
3609
3610        /* user says num divided by scale and we say internally that
3611         * is MAX_SCORE * num / scale.
3612         */
3613        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3614}
3615
3616static int diff_scoreopt_parse(const char *opt)
3617{
3618        int opt1, opt2, cmd;
3619
3620        if (*opt++ != '-')
3621                return -1;
3622        cmd = *opt++;
3623        if (cmd == '-') {
3624                /* convert the long-form arguments into short-form versions */
3625                if (!prefixcmp(opt, "break-rewrites")) {
3626                        opt += strlen("break-rewrites");
3627                        if (*opt == 0 || *opt++ == '=')
3628                                cmd = 'B';
3629                } else if (!prefixcmp(opt, "find-copies")) {
3630                        opt += strlen("find-copies");
3631                        if (*opt == 0 || *opt++ == '=')
3632                                cmd = 'C';
3633                } else if (!prefixcmp(opt, "find-renames")) {
3634                        opt += strlen("find-renames");
3635                        if (*opt == 0 || *opt++ == '=')
3636                                cmd = 'M';
3637                }
3638        }
3639        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3640                return -1; /* that is not a -M, -C nor -B option */
3641
3642        opt1 = parse_rename_score(&opt);
3643        if (cmd != 'B')
3644                opt2 = 0;
3645        else {
3646                if (*opt == 0)
3647                        opt2 = 0;
3648                else if (*opt != '/')
3649                        return -1; /* we expect -B80/99 or -B80 */
3650                else {
3651                        opt++;
3652                        opt2 = parse_rename_score(&opt);
3653                }
3654        }
3655        if (*opt != 0)
3656                return -1;
3657        return opt1 | (opt2 << 16);
3658}
3659
3660struct diff_queue_struct diff_queued_diff;
3661
3662void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3663{
3664        if (queue->alloc <= queue->nr) {
3665                queue->alloc = alloc_nr(queue->alloc);
3666                queue->queue = xrealloc(queue->queue,
3667                                        sizeof(dp) * queue->alloc);
3668        }
3669        queue->queue[queue->nr++] = dp;
3670}
3671
3672struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3673                                 struct diff_filespec *one,
3674                                 struct diff_filespec *two)
3675{
3676        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3677        dp->one = one;
3678        dp->two = two;
3679        if (queue)
3680                diff_q(queue, dp);
3681        return dp;
3682}
3683
3684void diff_free_filepair(struct diff_filepair *p)
3685{
3686        free_filespec(p->one);
3687        free_filespec(p->two);
3688        free(p);
3689}
3690
3691/* This is different from find_unique_abbrev() in that
3692 * it stuffs the result with dots for alignment.
3693 */
3694const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3695{
3696        int abblen;
3697        const char *abbrev;
3698        if (len == 40)
3699                return sha1_to_hex(sha1);
3700
3701        abbrev = find_unique_abbrev(sha1, len);
3702        abblen = strlen(abbrev);
3703        if (abblen < 37) {
3704                static char hex[41];
3705                if (len < abblen && abblen <= len + 2)
3706                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3707                else
3708                        sprintf(hex, "%s...", abbrev);
3709                return hex;
3710        }
3711        return sha1_to_hex(sha1);
3712}
3713
3714static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3715{
3716        int line_termination = opt->line_termination;
3717        int inter_name_termination = line_termination ? '\t' : '\0';
3718        if (opt->output_prefix) {
3719                struct strbuf *msg = NULL;
3720                msg = opt->output_prefix(opt, opt->output_prefix_data);
3721                fprintf(opt->file, "%s", msg->buf);
3722        }
3723
3724        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3725                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3726                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3727                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3728        }
3729        if (p->score) {
3730                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3731                        inter_name_termination);
3732        } else {
3733                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3734        }
3735
3736        if (p->status == DIFF_STATUS_COPIED ||
3737            p->status == DIFF_STATUS_RENAMED) {
3738                const char *name_a, *name_b;
3739                name_a = p->one->path;
3740                name_b = p->two->path;
3741                strip_prefix(opt->prefix_length, &name_a, &name_b);
3742                write_name_quoted(name_a, opt->file, inter_name_termination);
3743                write_name_quoted(name_b, opt->file, line_termination);
3744        } else {
3745                const char *name_a, *name_b;
3746                name_a = p->one->mode ? p->one->path : p->two->path;
3747                name_b = NULL;
3748                strip_prefix(opt->prefix_length, &name_a, &name_b);
3749                write_name_quoted(name_a, opt->file, line_termination);
3750        }
3751}
3752
3753int diff_unmodified_pair(struct diff_filepair *p)
3754{
3755        /* This function is written stricter than necessary to support
3756         * the currently implemented transformers, but the idea is to
3757         * let transformers to produce diff_filepairs any way they want,
3758         * and filter and clean them up here before producing the output.
3759         */
3760        struct diff_filespec *one = p->one, *two = p->two;
3761
3762        if (DIFF_PAIR_UNMERGED(p))
3763                return 0; /* unmerged is interesting */
3764
3765        /* deletion, addition, mode or type change
3766         * and rename are all interesting.
3767         */
3768        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3769            DIFF_PAIR_MODE_CHANGED(p) ||
3770            strcmp(one->path, two->path))
3771                return 0;
3772
3773        /* both are valid and point at the same path.  that is, we are
3774         * dealing with a change.
3775         */
3776        if (one->sha1_valid && two->sha1_valid &&
3777            !hashcmp(one->sha1, two->sha1) &&
3778            !one->dirty_submodule && !two->dirty_submodule)
3779                return 1; /* no change */
3780        if (!one->sha1_valid && !two->sha1_valid)
3781                return 1; /* both look at the same file on the filesystem. */
3782        return 0;
3783}
3784
3785static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3786{
3787        if (diff_unmodified_pair(p))
3788                return;
3789
3790        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3791            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3792                return; /* no tree diffs in patch format */
3793
3794        run_diff(p, o);
3795}
3796
3797static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3798                            struct diffstat_t *diffstat)
3799{
3800        if (diff_unmodified_pair(p))
3801                return;
3802
3803        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3804            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3805                return; /* no useful stat for tree diffs */
3806
3807        run_diffstat(p, o, diffstat);
3808}
3809
3810static void diff_flush_checkdiff(struct diff_filepair *p,
3811                struct diff_options *o)
3812{
3813        if (diff_unmodified_pair(p))
3814                return;
3815
3816        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3817            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3818                return; /* nothing to check in tree diffs */
3819
3820        run_checkdiff(p, o);
3821}
3822
3823int diff_queue_is_empty(void)
3824{
3825        struct diff_queue_struct *q = &diff_queued_diff;
3826        int i;
3827        for (i = 0; i < q->nr; i++)
3828                if (!diff_unmodified_pair(q->queue[i]))
3829                        return 0;
3830        return 1;
3831}
3832
3833#if DIFF_DEBUG
3834void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3835{
3836        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3837                x, one ? one : "",
3838                s->path,
3839                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3840                s->mode,
3841                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3842        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3843                x, one ? one : "",
3844                s->size, s->xfrm_flags);
3845}
3846
3847void diff_debug_filepair(const struct diff_filepair *p, int i)
3848{
3849        diff_debug_filespec(p->one, i, "one");
3850        diff_debug_filespec(p->two, i, "two");
3851        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3852                p->score, p->status ? p->status : '?',
3853                p->one->rename_used, p->broken_pair);
3854}
3855
3856void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3857{
3858        int i;
3859        if (msg)
3860                fprintf(stderr, "%s\n", msg);
3861        fprintf(stderr, "q->nr = %d\n", q->nr);
3862        for (i = 0; i < q->nr; i++) {
3863                struct diff_filepair *p = q->queue[i];
3864                diff_debug_filepair(p, i);
3865        }
3866}
3867#endif
3868
3869static void diff_resolve_rename_copy(void)
3870{
3871        int i;
3872        struct diff_filepair *p;
3873        struct diff_queue_struct *q = &diff_queued_diff;
3874
3875        diff_debug_queue("resolve-rename-copy", q);
3876
3877        for (i = 0; i < q->nr; i++) {
3878                p = q->queue[i];
3879                p->status = 0; /* undecided */
3880                if (DIFF_PAIR_UNMERGED(p))
3881                        p->status = DIFF_STATUS_UNMERGED;
3882                else if (!DIFF_FILE_VALID(p->one))
3883                        p->status = DIFF_STATUS_ADDED;
3884                else if (!DIFF_FILE_VALID(p->two))
3885                        p->status = DIFF_STATUS_DELETED;
3886                else if (DIFF_PAIR_TYPE_CHANGED(p))
3887                        p->status = DIFF_STATUS_TYPE_CHANGED;
3888
3889                /* from this point on, we are dealing with a pair
3890                 * whose both sides are valid and of the same type, i.e.
3891                 * either in-place edit or rename/copy edit.
3892                 */
3893                else if (DIFF_PAIR_RENAME(p)) {
3894                        /*
3895                         * A rename might have re-connected a broken
3896                         * pair up, causing the pathnames to be the
3897                         * same again. If so, that's not a rename at
3898                         * all, just a modification..
3899                         *
3900                         * Otherwise, see if this source was used for
3901                         * multiple renames, in which case we decrement
3902                         * the count, and call it a copy.
3903                         */
3904                        if (!strcmp(p->one->path, p->two->path))
3905                                p->status = DIFF_STATUS_MODIFIED;
3906                        else if (--p->one->rename_used > 0)
3907                                p->status = DIFF_STATUS_COPIED;
3908                        else
3909                                p->status = DIFF_STATUS_RENAMED;
3910                }
3911                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3912                         p->one->mode != p->two->mode ||
3913                         p->one->dirty_submodule ||
3914                         p->two->dirty_submodule ||
3915                         is_null_sha1(p->one->sha1))
3916                        p->status = DIFF_STATUS_MODIFIED;
3917                else {
3918                        /* This is a "no-change" entry and should not
3919                         * happen anymore, but prepare for broken callers.
3920                         */
3921                        error("feeding unmodified %s to diffcore",
3922                              p->one->path);
3923                        p->status = DIFF_STATUS_UNKNOWN;
3924                }
3925        }
3926        diff_debug_queue("resolve-rename-copy done", q);
3927}
3928
3929static int check_pair_status(struct diff_filepair *p)
3930{
3931        switch (p->status) {
3932        case DIFF_STATUS_UNKNOWN:
3933                return 0;
3934        case 0:
3935                die("internal error in diff-resolve-rename-copy");
3936        default:
3937                return 1;
3938        }
3939}
3940
3941static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3942{
3943        int fmt = opt->output_format;
3944
3945        if (fmt & DIFF_FORMAT_CHECKDIFF)
3946                diff_flush_checkdiff(p, opt);
3947        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3948                diff_flush_raw(p, opt);
3949        else if (fmt & DIFF_FORMAT_NAME) {
3950                const char *name_a, *name_b;
3951                name_a = p->two->path;
3952                name_b = NULL;
3953                strip_prefix(opt->prefix_length, &name_a, &name_b);
3954                write_name_quoted(name_a, opt->file, opt->line_termination);
3955        }
3956}
3957
3958static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3959{
3960        if (fs->mode)
3961                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3962        else
3963                fprintf(file, " %s ", newdelete);
3964        write_name_quoted(fs->path, file, '\n');
3965}
3966
3967
3968static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3969                const char *line_prefix)
3970{
3971        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3972                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3973                        p->two->mode, show_name ? ' ' : '\n');
3974                if (show_name) {
3975                        write_name_quoted(p->two->path, file, '\n');
3976                }
3977        }
3978}
3979
3980static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3981                        const char *line_prefix)
3982{
3983        char *names = pprint_rename(p->one->path, p->two->path);
3984
3985        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3986        free(names);
3987        show_mode_change(file, p, 0, line_prefix);
3988}
3989
3990static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3991{
3992        FILE *file = opt->file;
3993        char *line_prefix = "";
3994
3995        if (opt->output_prefix) {
3996                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3997                line_prefix = buf->buf;
3998        }
3999
4000        switch(p->status) {
4001        case DIFF_STATUS_DELETED:
4002                fputs(line_prefix, file);
4003                show_file_mode_name(file, "delete", p->one);
4004                break;
4005        case DIFF_STATUS_ADDED:
4006                fputs(line_prefix, file);
4007                show_file_mode_name(file, "create", p->two);
4008                break;
4009        case DIFF_STATUS_COPIED:
4010                fputs(line_prefix, file);
4011                show_rename_copy(file, "copy", p, line_prefix);
4012                break;
4013        case DIFF_STATUS_RENAMED:
4014                fputs(line_prefix, file);
4015                show_rename_copy(file, "rename", p, line_prefix);
4016                break;
4017        default:
4018                if (p->score) {
4019                        fprintf(file, "%s rewrite ", line_prefix);
4020                        write_name_quoted(p->two->path, file, ' ');
4021                        fprintf(file, "(%d%%)\n", similarity_index(p));
4022                }
4023                show_mode_change(file, p, !p->score, line_prefix);
4024                break;
4025        }
4026}
4027
4028struct patch_id_t {
4029        git_SHA_CTX *ctx;
4030        int patchlen;
4031};
4032
4033static int remove_space(char *line, int len)
4034{
4035        int i;
4036        char *dst = line;
4037        unsigned char c;
4038
4039        for (i = 0; i < len; i++)
4040                if (!isspace((c = line[i])))
4041                        *dst++ = c;
4042
4043        return dst - line;
4044}
4045
4046static void patch_id_consume(void *priv, char *line, unsigned long len)
4047{
4048        struct patch_id_t *data = priv;
4049        int new_len;
4050
4051        /* Ignore line numbers when computing the SHA1 of the patch */
4052        if (!prefixcmp(line, "@@ -"))
4053                return;
4054
4055        new_len = remove_space(line, len);
4056
4057        git_SHA1_Update(data->ctx, line, new_len);
4058        data->patchlen += new_len;
4059}
4060
4061/* returns 0 upon success, and writes result into sha1 */
4062static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4063{
4064        struct diff_queue_struct *q = &diff_queued_diff;
4065        int i;
4066        git_SHA_CTX ctx;
4067        struct patch_id_t data;
4068        char buffer[PATH_MAX * 4 + 20];
4069
4070        git_SHA1_Init(&ctx);
4071        memset(&data, 0, sizeof(struct patch_id_t));
4072        data.ctx = &ctx;
4073
4074        for (i = 0; i < q->nr; i++) {
4075                xpparam_t xpp;
4076                xdemitconf_t xecfg;
4077                mmfile_t mf1, mf2;
4078                struct diff_filepair *p = q->queue[i];
4079                int len1, len2;
4080
4081                memset(&xpp, 0, sizeof(xpp));
4082                memset(&xecfg, 0, sizeof(xecfg));
4083                if (p->status == 0)
4084                        return error("internal diff status error");
4085                if (p->status == DIFF_STATUS_UNKNOWN)
4086                        continue;
4087                if (diff_unmodified_pair(p))
4088                        continue;
4089                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4090                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4091                        continue;
4092                if (DIFF_PAIR_UNMERGED(p))
4093                        continue;
4094
4095                diff_fill_sha1_info(p->one);
4096                diff_fill_sha1_info(p->two);
4097                if (fill_mmfile(&mf1, p->one) < 0 ||
4098                                fill_mmfile(&mf2, p->two) < 0)
4099                        return error("unable to read files to diff");
4100
4101                len1 = remove_space(p->one->path, strlen(p->one->path));
4102                len2 = remove_space(p->two->path, strlen(p->two->path));
4103                if (p->one->mode == 0)
4104                        len1 = snprintf(buffer, sizeof(buffer),
4105                                        "diff--gita/%.*sb/%.*s"
4106                                        "newfilemode%06o"
4107                                        "---/dev/null"
4108                                        "+++b/%.*s",
4109                                        len1, p->one->path,
4110                                        len2, p->two->path,
4111                                        p->two->mode,
4112                                        len2, p->two->path);
4113                else if (p->two->mode == 0)
4114                        len1 = snprintf(buffer, sizeof(buffer),
4115                                        "diff--gita/%.*sb/%.*s"
4116                                        "deletedfilemode%06o"
4117                                        "---a/%.*s"
4118                                        "+++/dev/null",
4119                                        len1, p->one->path,
4120                                        len2, p->two->path,
4121                                        p->one->mode,
4122                                        len1, p->one->path);
4123                else
4124                        len1 = snprintf(buffer, sizeof(buffer),
4125                                        "diff--gita/%.*sb/%.*s"
4126                                        "---a/%.*s"
4127                                        "+++b/%.*s",
4128                                        len1, p->one->path,
4129                                        len2, p->two->path,
4130                                        len1, p->one->path,
4131                                        len2, p->two->path);
4132                git_SHA1_Update(&ctx, buffer, len1);
4133
4134                if (diff_filespec_is_binary(p->one) ||
4135                    diff_filespec_is_binary(p->two)) {
4136                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4137                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4138                        continue;
4139                }
4140
4141                xpp.flags = 0;
4142                xecfg.ctxlen = 3;
4143                xecfg.flags = 0;
4144                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4145                              &xpp, &xecfg);
4146        }
4147
4148        git_SHA1_Final(sha1, &ctx);
4149        return 0;
4150}
4151
4152int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4153{
4154        struct diff_queue_struct *q = &diff_queued_diff;
4155        int i;
4156        int result = diff_get_patch_id(options, sha1);
4157
4158        for (i = 0; i < q->nr; i++)
4159                diff_free_filepair(q->queue[i]);
4160
4161        free(q->queue);
4162        DIFF_QUEUE_CLEAR(q);
4163
4164        return result;
4165}
4166
4167static int is_summary_empty(const struct diff_queue_struct *q)
4168{
4169        int i;
4170
4171        for (i = 0; i < q->nr; i++) {
4172                const struct diff_filepair *p = q->queue[i];
4173
4174                switch (p->status) {
4175                case DIFF_STATUS_DELETED:
4176                case DIFF_STATUS_ADDED:
4177                case DIFF_STATUS_COPIED:
4178                case DIFF_STATUS_RENAMED:
4179                        return 0;
4180                default:
4181                        if (p->score)
4182                                return 0;
4183                        if (p->one->mode && p->two->mode &&
4184                            p->one->mode != p->two->mode)
4185                                return 0;
4186                        break;
4187                }
4188        }
4189        return 1;
4190}
4191
4192static const char rename_limit_warning[] =
4193"inexact rename detection was skipped due to too many files.";
4194
4195static const char degrade_cc_to_c_warning[] =
4196"only found copies from modified paths due to too many files.";
4197
4198static const char rename_limit_advice[] =
4199"you may want to set your %s variable to at least "
4200"%d and retry the command.";
4201
4202void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4203{
4204        if (degraded_cc)
4205                warning(degrade_cc_to_c_warning);
4206        else if (needed)
4207                warning(rename_limit_warning);
4208        else
4209                return;
4210        if (0 < needed && needed < 32767)
4211                warning(rename_limit_advice, varname, needed);
4212}
4213
4214void diff_flush(struct diff_options *options)
4215{
4216        struct diff_queue_struct *q = &diff_queued_diff;
4217        int i, output_format = options->output_format;
4218        int separator = 0;
4219        int dirstat_by_line = 0;
4220
4221        /*
4222         * Order: raw, stat, summary, patch
4223         * or:    name/name-status/checkdiff (other bits clear)
4224         */
4225        if (!q->nr)
4226                goto free_queue;
4227
4228        if (output_format & (DIFF_FORMAT_RAW |
4229                             DIFF_FORMAT_NAME |
4230                             DIFF_FORMAT_NAME_STATUS |
4231                             DIFF_FORMAT_CHECKDIFF)) {
4232                for (i = 0; i < q->nr; i++) {
4233                        struct diff_filepair *p = q->queue[i];
4234                        if (check_pair_status(p))
4235                                flush_one_pair(p, options);
4236                }
4237                separator++;
4238        }
4239
4240        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4241                dirstat_by_line = 1;
4242
4243        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4244            dirstat_by_line) {
4245                struct diffstat_t diffstat;
4246
4247                memset(&diffstat, 0, sizeof(struct diffstat_t));
4248                for (i = 0; i < q->nr; i++) {
4249                        struct diff_filepair *p = q->queue[i];
4250                        if (check_pair_status(p))
4251                                diff_flush_stat(p, options, &diffstat);
4252                }
4253                if (output_format & DIFF_FORMAT_NUMSTAT)
4254                        show_numstat(&diffstat, options);
4255                if (output_format & DIFF_FORMAT_DIFFSTAT)
4256                        show_stats(&diffstat, options);
4257                if (output_format & DIFF_FORMAT_SHORTSTAT)
4258                        show_shortstats(&diffstat, options);
4259                if (output_format & DIFF_FORMAT_DIRSTAT)
4260                        show_dirstat_by_line(&diffstat, options);
4261                free_diffstat_info(&diffstat);
4262                separator++;
4263        }
4264        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4265                show_dirstat(options);
4266
4267        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4268                for (i = 0; i < q->nr; i++) {
4269                        diff_summary(options, q->queue[i]);
4270                }
4271                separator++;
4272        }
4273
4274        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4275            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4276            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4277                /*
4278                 * run diff_flush_patch for the exit status. setting
4279                 * options->file to /dev/null should be safe, becaue we
4280                 * aren't supposed to produce any output anyway.
4281                 */
4282                if (options->close_file)
4283                        fclose(options->file);
4284                options->file = fopen("/dev/null", "w");
4285                if (!options->file)
4286                        die_errno("Could not open /dev/null");
4287                options->close_file = 1;
4288                for (i = 0; i < q->nr; i++) {
4289                        struct diff_filepair *p = q->queue[i];
4290                        if (check_pair_status(p))
4291                                diff_flush_patch(p, options);
4292                        if (options->found_changes)
4293                                break;
4294                }
4295        }
4296
4297        if (output_format & DIFF_FORMAT_PATCH) {
4298                if (separator) {
4299                        putc(options->line_termination, options->file);
4300                        if (options->stat_sep) {
4301                                /* attach patch instead of inline */
4302                                fputs(options->stat_sep, options->file);
4303                        }
4304                }
4305
4306                for (i = 0; i < q->nr; i++) {
4307                        struct diff_filepair *p = q->queue[i];
4308                        if (check_pair_status(p))
4309                                diff_flush_patch(p, options);
4310                }
4311        }
4312
4313        if (output_format & DIFF_FORMAT_CALLBACK)
4314                options->format_callback(q, options, options->format_callback_data);
4315
4316        for (i = 0; i < q->nr; i++)
4317                diff_free_filepair(q->queue[i]);
4318free_queue:
4319        free(q->queue);
4320        DIFF_QUEUE_CLEAR(q);
4321        if (options->close_file)
4322                fclose(options->file);
4323
4324        /*
4325         * Report the content-level differences with HAS_CHANGES;
4326         * diff_addremove/diff_change does not set the bit when
4327         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4328         */
4329        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4330                if (options->found_changes)
4331                        DIFF_OPT_SET(options, HAS_CHANGES);
4332                else
4333                        DIFF_OPT_CLR(options, HAS_CHANGES);
4334        }
4335}
4336
4337static void diffcore_apply_filter(const char *filter)
4338{
4339        int i;
4340        struct diff_queue_struct *q = &diff_queued_diff;
4341        struct diff_queue_struct outq;
4342        DIFF_QUEUE_CLEAR(&outq);
4343
4344        if (!filter)
4345                return;
4346
4347        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4348                int found;
4349                for (i = found = 0; !found && i < q->nr; i++) {
4350                        struct diff_filepair *p = q->queue[i];
4351                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4352                             ((p->score &&
4353                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4354                              (!p->score &&
4355                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4356                            ((p->status != DIFF_STATUS_MODIFIED) &&
4357                             strchr(filter, p->status)))
4358                                found++;
4359                }
4360                if (found)
4361                        return;
4362
4363                /* otherwise we will clear the whole queue
4364                 * by copying the empty outq at the end of this
4365                 * function, but first clear the current entries
4366                 * in the queue.
4367                 */
4368                for (i = 0; i < q->nr; i++)
4369                        diff_free_filepair(q->queue[i]);
4370        }
4371        else {
4372                /* Only the matching ones */
4373                for (i = 0; i < q->nr; i++) {
4374                        struct diff_filepair *p = q->queue[i];
4375
4376                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4377                             ((p->score &&
4378                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4379                              (!p->score &&
4380                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4381                            ((p->status != DIFF_STATUS_MODIFIED) &&
4382                             strchr(filter, p->status)))
4383                                diff_q(&outq, p);
4384                        else
4385                                diff_free_filepair(p);
4386                }
4387        }
4388        free(q->queue);
4389        *q = outq;
4390}
4391
4392/* Check whether two filespecs with the same mode and size are identical */
4393static int diff_filespec_is_identical(struct diff_filespec *one,
4394                                      struct diff_filespec *two)
4395{
4396        if (S_ISGITLINK(one->mode))
4397                return 0;
4398        if (diff_populate_filespec(one, 0))
4399                return 0;
4400        if (diff_populate_filespec(two, 0))
4401                return 0;
4402        return !memcmp(one->data, two->data, one->size);
4403}
4404
4405static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4406{
4407        int i;
4408        struct diff_queue_struct *q = &diff_queued_diff;
4409        struct diff_queue_struct outq;
4410        DIFF_QUEUE_CLEAR(&outq);
4411
4412        for (i = 0; i < q->nr; i++) {
4413                struct diff_filepair *p = q->queue[i];
4414
4415                /*
4416                 * 1. Entries that come from stat info dirtiness
4417                 *    always have both sides (iow, not create/delete),
4418                 *    one side of the object name is unknown, with
4419                 *    the same mode and size.  Keep the ones that
4420                 *    do not match these criteria.  They have real
4421                 *    differences.
4422                 *
4423                 * 2. At this point, the file is known to be modified,
4424                 *    with the same mode and size, and the object
4425                 *    name of one side is unknown.  Need to inspect
4426                 *    the identical contents.
4427                 */
4428                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4429                    !DIFF_FILE_VALID(p->two) ||
4430                    (p->one->sha1_valid && p->two->sha1_valid) ||
4431                    (p->one->mode != p->two->mode) ||
4432                    diff_populate_filespec(p->one, 1) ||
4433                    diff_populate_filespec(p->two, 1) ||
4434                    (p->one->size != p->two->size) ||
4435                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4436                        diff_q(&outq, p);
4437                else {
4438                        /*
4439                         * The caller can subtract 1 from skip_stat_unmatch
4440                         * to determine how many paths were dirty only
4441                         * due to stat info mismatch.
4442                         */
4443                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4444                                diffopt->skip_stat_unmatch++;
4445                        diff_free_filepair(p);
4446                }
4447        }
4448        free(q->queue);
4449        *q = outq;
4450}
4451
4452static int diffnamecmp(const void *a_, const void *b_)
4453{
4454        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4455        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4456        const char *name_a, *name_b;
4457
4458        name_a = a->one ? a->one->path : a->two->path;
4459        name_b = b->one ? b->one->path : b->two->path;
4460        return strcmp(name_a, name_b);
4461}
4462
4463void diffcore_fix_diff_index(struct diff_options *options)
4464{
4465        struct diff_queue_struct *q = &diff_queued_diff;
4466        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4467}
4468
4469void diffcore_std(struct diff_options *options)
4470{
4471        if (options->skip_stat_unmatch)
4472                diffcore_skip_stat_unmatch(options);
4473        if (!options->found_follow) {
4474                /* See try_to_follow_renames() in tree-diff.c */
4475                if (options->break_opt != -1)
4476                        diffcore_break(options->break_opt);
4477                if (options->detect_rename)
4478                        diffcore_rename(options);
4479                if (options->break_opt != -1)
4480                        diffcore_merge_broken();
4481        }
4482        if (options->pickaxe)
4483                diffcore_pickaxe(options);
4484        if (options->orderfile)
4485                diffcore_order(options->orderfile);
4486        if (!options->found_follow)
4487                /* See try_to_follow_renames() in tree-diff.c */
4488                diff_resolve_rename_copy();
4489        diffcore_apply_filter(options->filter);
4490
4491        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4492                DIFF_OPT_SET(options, HAS_CHANGES);
4493        else
4494                DIFF_OPT_CLR(options, HAS_CHANGES);
4495
4496        options->found_follow = 0;
4497}
4498
4499int diff_result_code(struct diff_options *opt, int status)
4500{
4501        int result = 0;
4502
4503        diff_warn_rename_limit("diff.renamelimit",
4504                               opt->needed_rename_limit,
4505                               opt->degraded_cc_to_c);
4506        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4507            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4508                return status;
4509        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4510            DIFF_OPT_TST(opt, HAS_CHANGES))
4511                result |= 01;
4512        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4513            DIFF_OPT_TST(opt, CHECK_FAILED))
4514                result |= 02;
4515        return result;
4516}
4517
4518int diff_can_quit_early(struct diff_options *opt)
4519{
4520        return (DIFF_OPT_TST(opt, QUICK) &&
4521                !opt->filter &&
4522                DIFF_OPT_TST(opt, HAS_CHANGES));
4523}
4524
4525/*
4526 * Shall changes to this submodule be ignored?
4527 *
4528 * Submodule changes can be configured to be ignored separately for each path,
4529 * but that configuration can be overridden from the command line.
4530 */
4531static int is_submodule_ignored(const char *path, struct diff_options *options)
4532{
4533        int ignored = 0;
4534        unsigned orig_flags = options->flags;
4535        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4536                set_diffopt_flags_from_submodule_config(options, path);
4537        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4538                ignored = 1;
4539        options->flags = orig_flags;
4540        return ignored;
4541}
4542
4543void diff_addremove(struct diff_options *options,
4544                    int addremove, unsigned mode,
4545                    const unsigned char *sha1,
4546                    const char *concatpath, unsigned dirty_submodule)
4547{
4548        struct diff_filespec *one, *two;
4549
4550        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4551                return;
4552
4553        /* This may look odd, but it is a preparation for
4554         * feeding "there are unchanged files which should
4555         * not produce diffs, but when you are doing copy
4556         * detection you would need them, so here they are"
4557         * entries to the diff-core.  They will be prefixed
4558         * with something like '=' or '*' (I haven't decided
4559         * which but should not make any difference).
4560         * Feeding the same new and old to diff_change()
4561         * also has the same effect.
4562         * Before the final output happens, they are pruned after
4563         * merged into rename/copy pairs as appropriate.
4564         */
4565        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4566                addremove = (addremove == '+' ? '-' :
4567                             addremove == '-' ? '+' : addremove);
4568
4569        if (options->prefix &&
4570            strncmp(concatpath, options->prefix, options->prefix_length))
4571                return;
4572
4573        one = alloc_filespec(concatpath);
4574        two = alloc_filespec(concatpath);
4575
4576        if (addremove != '+')
4577                fill_filespec(one, sha1, mode);
4578        if (addremove != '-') {
4579                fill_filespec(two, sha1, mode);
4580                two->dirty_submodule = dirty_submodule;
4581        }
4582
4583        diff_queue(&diff_queued_diff, one, two);
4584        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4585                DIFF_OPT_SET(options, HAS_CHANGES);
4586}
4587
4588void diff_change(struct diff_options *options,
4589                 unsigned old_mode, unsigned new_mode,
4590                 const unsigned char *old_sha1,
4591                 const unsigned char *new_sha1,
4592                 const char *concatpath,
4593                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4594{
4595        struct diff_filespec *one, *two;
4596
4597        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4598            is_submodule_ignored(concatpath, options))
4599                return;
4600
4601        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4602                unsigned tmp;
4603                const unsigned char *tmp_c;
4604                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4605                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4606                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4607                        new_dirty_submodule = tmp;
4608        }
4609
4610        if (options->prefix &&
4611            strncmp(concatpath, options->prefix, options->prefix_length))
4612                return;
4613
4614        one = alloc_filespec(concatpath);
4615        two = alloc_filespec(concatpath);
4616        fill_filespec(one, old_sha1, old_mode);
4617        fill_filespec(two, new_sha1, new_mode);
4618        one->dirty_submodule = old_dirty_submodule;
4619        two->dirty_submodule = new_dirty_submodule;
4620
4621        diff_queue(&diff_queued_diff, one, two);
4622        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4623                DIFF_OPT_SET(options, HAS_CHANGES);
4624}
4625
4626struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4627{
4628        struct diff_filepair *pair;
4629        struct diff_filespec *one, *two;
4630
4631        if (options->prefix &&
4632            strncmp(path, options->prefix, options->prefix_length))
4633                return NULL;
4634
4635        one = alloc_filespec(path);
4636        two = alloc_filespec(path);
4637        pair = diff_queue(&diff_queued_diff, one, two);
4638        pair->is_unmerged = 1;
4639        return pair;
4640}
4641
4642static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4643                size_t *outsize)
4644{
4645        struct diff_tempfile *temp;
4646        const char *argv[3];
4647        const char **arg = argv;
4648        struct child_process child;
4649        struct strbuf buf = STRBUF_INIT;
4650        int err = 0;
4651
4652        temp = prepare_temp_file(spec->path, spec);
4653        *arg++ = pgm;
4654        *arg++ = temp->name;
4655        *arg = NULL;
4656
4657        memset(&child, 0, sizeof(child));
4658        child.use_shell = 1;
4659        child.argv = argv;
4660        child.out = -1;
4661        if (start_command(&child)) {
4662                remove_tempfile();
4663                return NULL;
4664        }
4665
4666        if (strbuf_read(&buf, child.out, 0) < 0)
4667                err = error("error reading from textconv command '%s'", pgm);
4668        close(child.out);
4669
4670        if (finish_command(&child) || err) {
4671                strbuf_release(&buf);
4672                remove_tempfile();
4673                return NULL;
4674        }
4675        remove_tempfile();
4676
4677        return strbuf_detach(&buf, outsize);
4678}
4679
4680size_t fill_textconv(struct userdiff_driver *driver,
4681                     struct diff_filespec *df,
4682                     char **outbuf)
4683{
4684        size_t size;
4685
4686        if (!driver || !driver->textconv) {
4687                if (!DIFF_FILE_VALID(df)) {
4688                        *outbuf = "";
4689                        return 0;
4690                }
4691                if (diff_populate_filespec(df, 0))
4692                        die("unable to read files to diff");
4693                *outbuf = df->data;
4694                return df->size;
4695        }
4696
4697        if (driver->textconv_cache && df->sha1_valid) {
4698                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4699                                          &size);
4700                if (*outbuf)
4701                        return size;
4702        }
4703
4704        *outbuf = run_textconv(driver->textconv, df, &size);
4705        if (!*outbuf)
4706                die("unable to read files to diff");
4707
4708        if (driver->textconv_cache && df->sha1_valid) {
4709                /* ignore errors, as we might be in a readonly repository */
4710                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4711                                size);
4712                /*
4713                 * we could save up changes and flush them all at the end,
4714                 * but we would need an extra call after all diffing is done.
4715                 * Since generating a cache entry is the slow path anyway,
4716                 * this extra overhead probably isn't a big deal.
4717                 */
4718                notes_cache_write(driver->textconv_cache);
4719        }
4720
4721        return size;
4722}