diff.con commit diff --stat: use the full terminal width (af9fedc)
   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        if (options->stat_width == -1)
1347                width = term_columns();
1348        else
1349                width = options->stat_width ? options->stat_width : 80;
1350        name_width = options->stat_name_width ? options->stat_name_width : 50;
1351        count = options->stat_count ? options->stat_count : data->nr;
1352
1353        /* Sanity: give at least 5 columns to the graph,
1354         * but leave at least 10 columns for the name.
1355         */
1356        if (width < 25)
1357                width = 25;
1358        if (name_width < 10)
1359                name_width = 10;
1360        else if (width < name_width + 15)
1361                name_width = width - 15;
1362
1363        /* Find the longest filename and max number of changes */
1364        reset = diff_get_color_opt(options, DIFF_RESET);
1365        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1366        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1367
1368        for (i = 0; (i < count) && (i < data->nr); i++) {
1369                struct diffstat_file *file = data->files[i];
1370                uintmax_t change = file->added + file->deleted;
1371                if (!data->files[i]->is_renamed &&
1372                         (change == 0)) {
1373                        count++; /* not shown == room for one more */
1374                        continue;
1375                }
1376                fill_print_name(file);
1377                len = strlen(file->print_name);
1378                if (max_len < len)
1379                        max_len = len;
1380
1381                if (file->is_binary || file->is_unmerged)
1382                        continue;
1383                if (max_change < change)
1384                        max_change = change;
1385        }
1386        count = i; /* min(count, data->nr) */
1387
1388        /* Compute the width of the graph part;
1389         * 10 is for one blank at the beginning of the line plus
1390         * " | count " between the name and the graph.
1391         *
1392         * From here on, name_width is the width of the name area,
1393         * and width is the width of the graph area.
1394         */
1395        name_width = (name_width < max_len) ? name_width : max_len;
1396        if (width < (name_width + 10) + max_change)
1397                width = width - (name_width + 10);
1398        else
1399                width = max_change;
1400
1401        for (i = 0; i < count; i++) {
1402                const char *prefix = "";
1403                char *name = data->files[i]->print_name;
1404                uintmax_t added = data->files[i]->added;
1405                uintmax_t deleted = data->files[i]->deleted;
1406                int name_len;
1407
1408                if (!data->files[i]->is_renamed &&
1409                         (added + deleted == 0)) {
1410                        total_files--;
1411                        continue;
1412                }
1413                /*
1414                 * "scale" the filename
1415                 */
1416                len = name_width;
1417                name_len = strlen(name);
1418                if (name_width < name_len) {
1419                        char *slash;
1420                        prefix = "...";
1421                        len -= 3;
1422                        name += name_len - len;
1423                        slash = strchr(name, '/');
1424                        if (slash)
1425                                name = slash;
1426                }
1427
1428                if (data->files[i]->is_binary) {
1429                        fprintf(options->file, "%s", line_prefix);
1430                        show_name(options->file, prefix, name, len);
1431                        fprintf(options->file, "  Bin ");
1432                        fprintf(options->file, "%s%"PRIuMAX"%s",
1433                                del_c, deleted, reset);
1434                        fprintf(options->file, " -> ");
1435                        fprintf(options->file, "%s%"PRIuMAX"%s",
1436                                add_c, added, reset);
1437                        fprintf(options->file, " bytes");
1438                        fprintf(options->file, "\n");
1439                        continue;
1440                }
1441                else if (data->files[i]->is_unmerged) {
1442                        fprintf(options->file, "%s", line_prefix);
1443                        show_name(options->file, prefix, name, len);
1444                        fprintf(options->file, "  Unmerged\n");
1445                        continue;
1446                }
1447
1448                /*
1449                 * scale the add/delete
1450                 */
1451                add = added;
1452                del = deleted;
1453                adds += add;
1454                dels += del;
1455
1456                if (width <= max_change) {
1457                        int total = add + del;
1458
1459                        total = scale_linear(add + del, width, max_change);
1460                        if (total < 2 && add && del)
1461                                /* width >= 2 due to the sanity check */
1462                                total = 2;
1463                        if (add < del) {
1464                                add = scale_linear(add, width, max_change);
1465                                del = total - add;
1466                        } else {
1467                                del = scale_linear(del, width, max_change);
1468                                add = total - del;
1469                        }
1470                }
1471                fprintf(options->file, "%s", line_prefix);
1472                show_name(options->file, prefix, name, len);
1473                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1474                                added + deleted ? " " : "");
1475                show_graph(options->file, '+', add, add_c, reset);
1476                show_graph(options->file, '-', del, del_c, reset);
1477                fprintf(options->file, "\n");
1478        }
1479        for (i = count; i < data->nr; i++) {
1480                uintmax_t added = data->files[i]->added;
1481                uintmax_t deleted = data->files[i]->deleted;
1482                if (!data->files[i]->is_renamed &&
1483                         (added + deleted == 0)) {
1484                        total_files--;
1485                        continue;
1486                }
1487                adds += added;
1488                dels += deleted;
1489                if (!extra_shown)
1490                        fprintf(options->file, "%s ...\n", line_prefix);
1491                extra_shown = 1;
1492        }
1493        fprintf(options->file, "%s", line_prefix);
1494        fprintf(options->file,
1495               " %d files changed, %d insertions(+), %d deletions(-)\n",
1496               total_files, adds, dels);
1497}
1498
1499static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1500{
1501        int i, adds = 0, dels = 0, total_files = data->nr;
1502
1503        if (data->nr == 0)
1504                return;
1505
1506        for (i = 0; i < data->nr; i++) {
1507                if (!data->files[i]->is_binary &&
1508                    !data->files[i]->is_unmerged) {
1509                        int added = data->files[i]->added;
1510                        int deleted= data->files[i]->deleted;
1511                        if (!data->files[i]->is_renamed &&
1512                            (added + deleted == 0)) {
1513                                total_files--;
1514                        } else {
1515                                adds += added;
1516                                dels += deleted;
1517                        }
1518                }
1519        }
1520        if (options->output_prefix) {
1521                struct strbuf *msg = NULL;
1522                msg = options->output_prefix(options,
1523                                options->output_prefix_data);
1524                fprintf(options->file, "%s", msg->buf);
1525        }
1526        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1527               total_files, adds, dels);
1528}
1529
1530static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1531{
1532        int i;
1533
1534        if (data->nr == 0)
1535                return;
1536
1537        for (i = 0; i < data->nr; i++) {
1538                struct diffstat_file *file = data->files[i];
1539
1540                if (options->output_prefix) {
1541                        struct strbuf *msg = NULL;
1542                        msg = options->output_prefix(options,
1543                                        options->output_prefix_data);
1544                        fprintf(options->file, "%s", msg->buf);
1545                }
1546
1547                if (file->is_binary)
1548                        fprintf(options->file, "-\t-\t");
1549                else
1550                        fprintf(options->file,
1551                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1552                                file->added, file->deleted);
1553                if (options->line_termination) {
1554                        fill_print_name(file);
1555                        if (!file->is_renamed)
1556                                write_name_quoted(file->name, options->file,
1557                                                  options->line_termination);
1558                        else {
1559                                fputs(file->print_name, options->file);
1560                                putc(options->line_termination, options->file);
1561                        }
1562                } else {
1563                        if (file->is_renamed) {
1564                                putc('\0', options->file);
1565                                write_name_quoted(file->from_name, options->file, '\0');
1566                        }
1567                        write_name_quoted(file->name, options->file, '\0');
1568                }
1569        }
1570}
1571
1572struct dirstat_file {
1573        const char *name;
1574        unsigned long changed;
1575};
1576
1577struct dirstat_dir {
1578        struct dirstat_file *files;
1579        int alloc, nr, permille, cumulative;
1580};
1581
1582static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1583                unsigned long changed, const char *base, int baselen)
1584{
1585        unsigned long this_dir = 0;
1586        unsigned int sources = 0;
1587        const char *line_prefix = "";
1588        struct strbuf *msg = NULL;
1589
1590        if (opt->output_prefix) {
1591                msg = opt->output_prefix(opt, opt->output_prefix_data);
1592                line_prefix = msg->buf;
1593        }
1594
1595        while (dir->nr) {
1596                struct dirstat_file *f = dir->files;
1597                int namelen = strlen(f->name);
1598                unsigned long this;
1599                char *slash;
1600
1601                if (namelen < baselen)
1602                        break;
1603                if (memcmp(f->name, base, baselen))
1604                        break;
1605                slash = strchr(f->name + baselen, '/');
1606                if (slash) {
1607                        int newbaselen = slash + 1 - f->name;
1608                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1609                        sources++;
1610                } else {
1611                        this = f->changed;
1612                        dir->files++;
1613                        dir->nr--;
1614                        sources += 2;
1615                }
1616                this_dir += this;
1617        }
1618
1619        /*
1620         * We don't report dirstat's for
1621         *  - the top level
1622         *  - or cases where everything came from a single directory
1623         *    under this directory (sources == 1).
1624         */
1625        if (baselen && sources != 1) {
1626                if (this_dir) {
1627                        int permille = this_dir * 1000 / changed;
1628                        if (permille >= dir->permille) {
1629                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1630                                        permille / 10, permille % 10, baselen, base);
1631                                if (!dir->cumulative)
1632                                        return 0;
1633                        }
1634                }
1635        }
1636        return this_dir;
1637}
1638
1639static int dirstat_compare(const void *_a, const void *_b)
1640{
1641        const struct dirstat_file *a = _a;
1642        const struct dirstat_file *b = _b;
1643        return strcmp(a->name, b->name);
1644}
1645
1646static void show_dirstat(struct diff_options *options)
1647{
1648        int i;
1649        unsigned long changed;
1650        struct dirstat_dir dir;
1651        struct diff_queue_struct *q = &diff_queued_diff;
1652
1653        dir.files = NULL;
1654        dir.alloc = 0;
1655        dir.nr = 0;
1656        dir.permille = options->dirstat_permille;
1657        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1658
1659        changed = 0;
1660        for (i = 0; i < q->nr; i++) {
1661                struct diff_filepair *p = q->queue[i];
1662                const char *name;
1663                unsigned long copied, added, damage;
1664                int content_changed;
1665
1666                name = p->two->path ? p->two->path : p->one->path;
1667
1668                if (p->one->sha1_valid && p->two->sha1_valid)
1669                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1670                else
1671                        content_changed = 1;
1672
1673                if (!content_changed) {
1674                        /*
1675                         * The SHA1 has not changed, so pre-/post-content is
1676                         * identical. We can therefore skip looking at the
1677                         * file contents altogether.
1678                         */
1679                        damage = 0;
1680                        goto found_damage;
1681                }
1682
1683                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1684                        /*
1685                         * In --dirstat-by-file mode, we don't really need to
1686                         * look at the actual file contents at all.
1687                         * The fact that the SHA1 changed is enough for us to
1688                         * add this file to the list of results
1689                         * (with each file contributing equal damage).
1690                         */
1691                        damage = 1;
1692                        goto found_damage;
1693                }
1694
1695                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1696                        diff_populate_filespec(p->one, 0);
1697                        diff_populate_filespec(p->two, 0);
1698                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1699                                               &copied, &added);
1700                        diff_free_filespec_data(p->one);
1701                        diff_free_filespec_data(p->two);
1702                } else if (DIFF_FILE_VALID(p->one)) {
1703                        diff_populate_filespec(p->one, 1);
1704                        copied = added = 0;
1705                        diff_free_filespec_data(p->one);
1706                } else if (DIFF_FILE_VALID(p->two)) {
1707                        diff_populate_filespec(p->two, 1);
1708                        copied = 0;
1709                        added = p->two->size;
1710                        diff_free_filespec_data(p->two);
1711                } else
1712                        continue;
1713
1714                /*
1715                 * Original minus copied is the removed material,
1716                 * added is the new material.  They are both damages
1717                 * made to the preimage.
1718                 * If the resulting damage is zero, we know that
1719                 * diffcore_count_changes() considers the two entries to
1720                 * be identical, but since content_changed is true, we
1721                 * know that there must have been _some_ kind of change,
1722                 * so we force all entries to have damage > 0.
1723                 */
1724                damage = (p->one->size - copied) + added;
1725                if (!damage)
1726                        damage = 1;
1727
1728found_damage:
1729                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1730                dir.files[dir.nr].name = name;
1731                dir.files[dir.nr].changed = damage;
1732                changed += damage;
1733                dir.nr++;
1734        }
1735
1736        /* This can happen even with many files, if everything was renames */
1737        if (!changed)
1738                return;
1739
1740        /* Show all directories with more than x% of the changes */
1741        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1742        gather_dirstat(options, &dir, changed, "", 0);
1743}
1744
1745static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1746{
1747        int i;
1748        unsigned long changed;
1749        struct dirstat_dir dir;
1750
1751        if (data->nr == 0)
1752                return;
1753
1754        dir.files = NULL;
1755        dir.alloc = 0;
1756        dir.nr = 0;
1757        dir.permille = options->dirstat_permille;
1758        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1759
1760        changed = 0;
1761        for (i = 0; i < data->nr; i++) {
1762                struct diffstat_file *file = data->files[i];
1763                unsigned long damage = file->added + file->deleted;
1764                if (file->is_binary)
1765                        /*
1766                         * binary files counts bytes, not lines. Must find some
1767                         * way to normalize binary bytes vs. textual lines.
1768                         * The following heuristic assumes that there are 64
1769                         * bytes per "line".
1770                         * This is stupid and ugly, but very cheap...
1771                         */
1772                        damage = (damage + 63) / 64;
1773                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1774                dir.files[dir.nr].name = file->name;
1775                dir.files[dir.nr].changed = damage;
1776                changed += damage;
1777                dir.nr++;
1778        }
1779
1780        /* This can happen even with many files, if everything was renames */
1781        if (!changed)
1782                return;
1783
1784        /* Show all directories with more than x% of the changes */
1785        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1786        gather_dirstat(options, &dir, changed, "", 0);
1787}
1788
1789static void free_diffstat_info(struct diffstat_t *diffstat)
1790{
1791        int i;
1792        for (i = 0; i < diffstat->nr; i++) {
1793                struct diffstat_file *f = diffstat->files[i];
1794                if (f->name != f->print_name)
1795                        free(f->print_name);
1796                free(f->name);
1797                free(f->from_name);
1798                free(f);
1799        }
1800        free(diffstat->files);
1801}
1802
1803struct checkdiff_t {
1804        const char *filename;
1805        int lineno;
1806        int conflict_marker_size;
1807        struct diff_options *o;
1808        unsigned ws_rule;
1809        unsigned status;
1810};
1811
1812static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1813{
1814        char firstchar;
1815        int cnt;
1816
1817        if (len < marker_size + 1)
1818                return 0;
1819        firstchar = line[0];
1820        switch (firstchar) {
1821        case '=': case '>': case '<': case '|':
1822                break;
1823        default:
1824                return 0;
1825        }
1826        for (cnt = 1; cnt < marker_size; cnt++)
1827                if (line[cnt] != firstchar)
1828                        return 0;
1829        /* line[1] thru line[marker_size-1] are same as firstchar */
1830        if (len < marker_size + 1 || !isspace(line[marker_size]))
1831                return 0;
1832        return 1;
1833}
1834
1835static void checkdiff_consume(void *priv, char *line, unsigned long len)
1836{
1837        struct checkdiff_t *data = priv;
1838        int marker_size = data->conflict_marker_size;
1839        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1840        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1841        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1842        char *err;
1843        char *line_prefix = "";
1844        struct strbuf *msgbuf;
1845
1846        assert(data->o);
1847        if (data->o->output_prefix) {
1848                msgbuf = data->o->output_prefix(data->o,
1849                        data->o->output_prefix_data);
1850                line_prefix = msgbuf->buf;
1851        }
1852
1853        if (line[0] == '+') {
1854                unsigned bad;
1855                data->lineno++;
1856                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1857                        data->status |= 1;
1858                        fprintf(data->o->file,
1859                                "%s%s:%d: leftover conflict marker\n",
1860                                line_prefix, data->filename, data->lineno);
1861                }
1862                bad = ws_check(line + 1, len - 1, data->ws_rule);
1863                if (!bad)
1864                        return;
1865                data->status |= bad;
1866                err = whitespace_error_string(bad);
1867                fprintf(data->o->file, "%s%s:%d: %s.\n",
1868                        line_prefix, data->filename, data->lineno, err);
1869                free(err);
1870                emit_line(data->o, set, reset, line, 1);
1871                ws_check_emit(line + 1, len - 1, data->ws_rule,
1872                              data->o->file, set, reset, ws);
1873        } else if (line[0] == ' ') {
1874                data->lineno++;
1875        } else if (line[0] == '@') {
1876                char *plus = strchr(line, '+');
1877                if (plus)
1878                        data->lineno = strtol(plus, NULL, 10) - 1;
1879                else
1880                        die("invalid diff");
1881        }
1882}
1883
1884static unsigned char *deflate_it(char *data,
1885                                 unsigned long size,
1886                                 unsigned long *result_size)
1887{
1888        int bound;
1889        unsigned char *deflated;
1890        git_zstream stream;
1891
1892        memset(&stream, 0, sizeof(stream));
1893        git_deflate_init(&stream, zlib_compression_level);
1894        bound = git_deflate_bound(&stream, size);
1895        deflated = xmalloc(bound);
1896        stream.next_out = deflated;
1897        stream.avail_out = bound;
1898
1899        stream.next_in = (unsigned char *)data;
1900        stream.avail_in = size;
1901        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1902                ; /* nothing */
1903        git_deflate_end(&stream);
1904        *result_size = stream.total_out;
1905        return deflated;
1906}
1907
1908static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1909{
1910        void *cp;
1911        void *delta;
1912        void *deflated;
1913        void *data;
1914        unsigned long orig_size;
1915        unsigned long delta_size;
1916        unsigned long deflate_size;
1917        unsigned long data_size;
1918
1919        /* We could do deflated delta, or we could do just deflated two,
1920         * whichever is smaller.
1921         */
1922        delta = NULL;
1923        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1924        if (one->size && two->size) {
1925                delta = diff_delta(one->ptr, one->size,
1926                                   two->ptr, two->size,
1927                                   &delta_size, deflate_size);
1928                if (delta) {
1929                        void *to_free = delta;
1930                        orig_size = delta_size;
1931                        delta = deflate_it(delta, delta_size, &delta_size);
1932                        free(to_free);
1933                }
1934        }
1935
1936        if (delta && delta_size < deflate_size) {
1937                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1938                free(deflated);
1939                data = delta;
1940                data_size = delta_size;
1941        }
1942        else {
1943                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1944                free(delta);
1945                data = deflated;
1946                data_size = deflate_size;
1947        }
1948
1949        /* emit data encoded in base85 */
1950        cp = data;
1951        while (data_size) {
1952                int bytes = (52 < data_size) ? 52 : data_size;
1953                char line[70];
1954                data_size -= bytes;
1955                if (bytes <= 26)
1956                        line[0] = bytes + 'A' - 1;
1957                else
1958                        line[0] = bytes - 26 + 'a' - 1;
1959                encode_85(line + 1, cp, bytes);
1960                cp = (char *) cp + bytes;
1961                fprintf(file, "%s", prefix);
1962                fputs(line, file);
1963                fputc('\n', file);
1964        }
1965        fprintf(file, "%s\n", prefix);
1966        free(data);
1967}
1968
1969static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1970{
1971        fprintf(file, "%sGIT binary patch\n", prefix);
1972        emit_binary_diff_body(file, one, two, prefix);
1973        emit_binary_diff_body(file, two, one, prefix);
1974}
1975
1976static void diff_filespec_load_driver(struct diff_filespec *one)
1977{
1978        /* Use already-loaded driver */
1979        if (one->driver)
1980                return;
1981
1982        if (S_ISREG(one->mode))
1983                one->driver = userdiff_find_by_path(one->path);
1984
1985        /* Fallback to default settings */
1986        if (!one->driver)
1987                one->driver = userdiff_find_by_name("default");
1988}
1989
1990int diff_filespec_is_binary(struct diff_filespec *one)
1991{
1992        if (one->is_binary == -1) {
1993                diff_filespec_load_driver(one);
1994                if (one->driver->binary != -1)
1995                        one->is_binary = one->driver->binary;
1996                else {
1997                        if (!one->data && DIFF_FILE_VALID(one))
1998                                diff_populate_filespec(one, 0);
1999                        if (one->data)
2000                                one->is_binary = buffer_is_binary(one->data,
2001                                                one->size);
2002                        if (one->is_binary == -1)
2003                                one->is_binary = 0;
2004                }
2005        }
2006        return one->is_binary;
2007}
2008
2009static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2010{
2011        diff_filespec_load_driver(one);
2012        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2013}
2014
2015static const char *userdiff_word_regex(struct diff_filespec *one)
2016{
2017        diff_filespec_load_driver(one);
2018        return one->driver->word_regex;
2019}
2020
2021void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2022{
2023        if (!options->a_prefix)
2024                options->a_prefix = a;
2025        if (!options->b_prefix)
2026                options->b_prefix = b;
2027}
2028
2029struct userdiff_driver *get_textconv(struct diff_filespec *one)
2030{
2031        if (!DIFF_FILE_VALID(one))
2032                return NULL;
2033
2034        diff_filespec_load_driver(one);
2035        return userdiff_get_textconv(one->driver);
2036}
2037
2038static void builtin_diff(const char *name_a,
2039                         const char *name_b,
2040                         struct diff_filespec *one,
2041                         struct diff_filespec *two,
2042                         const char *xfrm_msg,
2043                         int must_show_header,
2044                         struct diff_options *o,
2045                         int complete_rewrite)
2046{
2047        mmfile_t mf1, mf2;
2048        const char *lbl[2];
2049        char *a_one, *b_two;
2050        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2051        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2052        const char *a_prefix, *b_prefix;
2053        struct userdiff_driver *textconv_one = NULL;
2054        struct userdiff_driver *textconv_two = NULL;
2055        struct strbuf header = STRBUF_INIT;
2056        struct strbuf *msgbuf;
2057        char *line_prefix = "";
2058
2059        if (o->output_prefix) {
2060                msgbuf = o->output_prefix(o, o->output_prefix_data);
2061                line_prefix = msgbuf->buf;
2062        }
2063
2064        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2065                        (!one->mode || S_ISGITLINK(one->mode)) &&
2066                        (!two->mode || S_ISGITLINK(two->mode))) {
2067                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2068                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2069                show_submodule_summary(o->file, one ? one->path : two->path,
2070                                one->sha1, two->sha1, two->dirty_submodule,
2071                                del, add, reset);
2072                return;
2073        }
2074
2075        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2076                textconv_one = get_textconv(one);
2077                textconv_two = get_textconv(two);
2078        }
2079
2080        diff_set_mnemonic_prefix(o, "a/", "b/");
2081        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2082                a_prefix = o->b_prefix;
2083                b_prefix = o->a_prefix;
2084        } else {
2085                a_prefix = o->a_prefix;
2086                b_prefix = o->b_prefix;
2087        }
2088
2089        /* Never use a non-valid filename anywhere if at all possible */
2090        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2091        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2092
2093        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2094        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2095        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2096        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2097        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2098        if (lbl[0][0] == '/') {
2099                /* /dev/null */
2100                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2101                if (xfrm_msg)
2102                        strbuf_addstr(&header, xfrm_msg);
2103                must_show_header = 1;
2104        }
2105        else if (lbl[1][0] == '/') {
2106                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2107                if (xfrm_msg)
2108                        strbuf_addstr(&header, xfrm_msg);
2109                must_show_header = 1;
2110        }
2111        else {
2112                if (one->mode != two->mode) {
2113                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2114                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2115                        must_show_header = 1;
2116                }
2117                if (xfrm_msg)
2118                        strbuf_addstr(&header, xfrm_msg);
2119
2120                /*
2121                 * we do not run diff between different kind
2122                 * of objects.
2123                 */
2124                if ((one->mode ^ two->mode) & S_IFMT)
2125                        goto free_ab_and_return;
2126                if (complete_rewrite &&
2127                    (textconv_one || !diff_filespec_is_binary(one)) &&
2128                    (textconv_two || !diff_filespec_is_binary(two))) {
2129                        fprintf(o->file, "%s", header.buf);
2130                        strbuf_reset(&header);
2131                        emit_rewrite_diff(name_a, name_b, one, two,
2132                                                textconv_one, textconv_two, o);
2133                        o->found_changes = 1;
2134                        goto free_ab_and_return;
2135                }
2136        }
2137
2138        if (o->irreversible_delete && lbl[1][0] == '/') {
2139                fprintf(o->file, "%s", header.buf);
2140                strbuf_reset(&header);
2141                goto free_ab_and_return;
2142        } else if (!DIFF_OPT_TST(o, TEXT) &&
2143            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2144              (!textconv_two && diff_filespec_is_binary(two)) )) {
2145                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2146                        die("unable to read files to diff");
2147                /* Quite common confusing case */
2148                if (mf1.size == mf2.size &&
2149                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2150                        if (must_show_header)
2151                                fprintf(o->file, "%s", header.buf);
2152                        goto free_ab_and_return;
2153                }
2154                fprintf(o->file, "%s", header.buf);
2155                strbuf_reset(&header);
2156                if (DIFF_OPT_TST(o, BINARY))
2157                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2158                else
2159                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2160                                line_prefix, lbl[0], lbl[1]);
2161                o->found_changes = 1;
2162        } else {
2163                /* Crazy xdl interfaces.. */
2164                const char *diffopts = getenv("GIT_DIFF_OPTS");
2165                xpparam_t xpp;
2166                xdemitconf_t xecfg;
2167                struct emit_callback ecbdata;
2168                const struct userdiff_funcname *pe;
2169
2170                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2171                        fprintf(o->file, "%s", header.buf);
2172                        strbuf_reset(&header);
2173                }
2174
2175                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2176                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2177
2178                pe = diff_funcname_pattern(one);
2179                if (!pe)
2180                        pe = diff_funcname_pattern(two);
2181
2182                memset(&xpp, 0, sizeof(xpp));
2183                memset(&xecfg, 0, sizeof(xecfg));
2184                memset(&ecbdata, 0, sizeof(ecbdata));
2185                ecbdata.label_path = lbl;
2186                ecbdata.color_diff = want_color(o->use_color);
2187                ecbdata.found_changesp = &o->found_changes;
2188                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2189                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2190                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2191                ecbdata.opt = o;
2192                ecbdata.header = header.len ? &header : NULL;
2193                xpp.flags = o->xdl_opts;
2194                xecfg.ctxlen = o->context;
2195                xecfg.interhunkctxlen = o->interhunkcontext;
2196                xecfg.flags = XDL_EMIT_FUNCNAMES;
2197                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2198                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2199                if (pe)
2200                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2201                if (!diffopts)
2202                        ;
2203                else if (!prefixcmp(diffopts, "--unified="))
2204                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2205                else if (!prefixcmp(diffopts, "-u"))
2206                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2207                if (o->word_diff) {
2208                        int i;
2209
2210                        ecbdata.diff_words =
2211                                xcalloc(1, sizeof(struct diff_words_data));
2212                        ecbdata.diff_words->type = o->word_diff;
2213                        ecbdata.diff_words->opt = o;
2214                        if (!o->word_regex)
2215                                o->word_regex = userdiff_word_regex(one);
2216                        if (!o->word_regex)
2217                                o->word_regex = userdiff_word_regex(two);
2218                        if (!o->word_regex)
2219                                o->word_regex = diff_word_regex_cfg;
2220                        if (o->word_regex) {
2221                                ecbdata.diff_words->word_regex = (regex_t *)
2222                                        xmalloc(sizeof(regex_t));
2223                                if (regcomp(ecbdata.diff_words->word_regex,
2224                                                o->word_regex,
2225                                                REG_EXTENDED | REG_NEWLINE))
2226                                        die ("Invalid regular expression: %s",
2227                                                        o->word_regex);
2228                        }
2229                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2230                                if (o->word_diff == diff_words_styles[i].type) {
2231                                        ecbdata.diff_words->style =
2232                                                &diff_words_styles[i];
2233                                        break;
2234                                }
2235                        }
2236                        if (want_color(o->use_color)) {
2237                                struct diff_words_style *st = ecbdata.diff_words->style;
2238                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2239                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2240                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2241                        }
2242                }
2243                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2244                              &xpp, &xecfg);
2245                if (o->word_diff)
2246                        free_diff_words_data(&ecbdata);
2247                if (textconv_one)
2248                        free(mf1.ptr);
2249                if (textconv_two)
2250                        free(mf2.ptr);
2251                xdiff_clear_find_func(&xecfg);
2252        }
2253
2254 free_ab_and_return:
2255        strbuf_release(&header);
2256        diff_free_filespec_data(one);
2257        diff_free_filespec_data(two);
2258        free(a_one);
2259        free(b_two);
2260        return;
2261}
2262
2263static void builtin_diffstat(const char *name_a, const char *name_b,
2264                             struct diff_filespec *one,
2265                             struct diff_filespec *two,
2266                             struct diffstat_t *diffstat,
2267                             struct diff_options *o,
2268                             int complete_rewrite)
2269{
2270        mmfile_t mf1, mf2;
2271        struct diffstat_file *data;
2272
2273        data = diffstat_add(diffstat, name_a, name_b);
2274
2275        if (!one || !two) {
2276                data->is_unmerged = 1;
2277                return;
2278        }
2279
2280        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2281                data->is_binary = 1;
2282                data->added = diff_filespec_size(two);
2283                data->deleted = diff_filespec_size(one);
2284        }
2285
2286        else if (complete_rewrite) {
2287                diff_populate_filespec(one, 0);
2288                diff_populate_filespec(two, 0);
2289                data->deleted = count_lines(one->data, one->size);
2290                data->added = count_lines(two->data, two->size);
2291        }
2292
2293        else {
2294                /* Crazy xdl interfaces.. */
2295                xpparam_t xpp;
2296                xdemitconf_t xecfg;
2297
2298                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2299                        die("unable to read files to diff");
2300
2301                memset(&xpp, 0, sizeof(xpp));
2302                memset(&xecfg, 0, sizeof(xecfg));
2303                xpp.flags = o->xdl_opts;
2304                xecfg.ctxlen = o->context;
2305                xecfg.interhunkctxlen = o->interhunkcontext;
2306                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2307                              &xpp, &xecfg);
2308        }
2309
2310        diff_free_filespec_data(one);
2311        diff_free_filespec_data(two);
2312}
2313
2314static void builtin_checkdiff(const char *name_a, const char *name_b,
2315                              const char *attr_path,
2316                              struct diff_filespec *one,
2317                              struct diff_filespec *two,
2318                              struct diff_options *o)
2319{
2320        mmfile_t mf1, mf2;
2321        struct checkdiff_t data;
2322
2323        if (!two)
2324                return;
2325
2326        memset(&data, 0, sizeof(data));
2327        data.filename = name_b ? name_b : name_a;
2328        data.lineno = 0;
2329        data.o = o;
2330        data.ws_rule = whitespace_rule(attr_path);
2331        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2332
2333        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2334                die("unable to read files to diff");
2335
2336        /*
2337         * All the other codepaths check both sides, but not checking
2338         * the "old" side here is deliberate.  We are checking the newly
2339         * introduced changes, and as long as the "new" side is text, we
2340         * can and should check what it introduces.
2341         */
2342        if (diff_filespec_is_binary(two))
2343                goto free_and_return;
2344        else {
2345                /* Crazy xdl interfaces.. */
2346                xpparam_t xpp;
2347                xdemitconf_t xecfg;
2348
2349                memset(&xpp, 0, sizeof(xpp));
2350                memset(&xecfg, 0, sizeof(xecfg));
2351                xecfg.ctxlen = 1; /* at least one context line */
2352                xpp.flags = 0;
2353                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2354                              &xpp, &xecfg);
2355
2356                if (data.ws_rule & WS_BLANK_AT_EOF) {
2357                        struct emit_callback ecbdata;
2358                        int blank_at_eof;
2359
2360                        ecbdata.ws_rule = data.ws_rule;
2361                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2362                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2363
2364                        if (blank_at_eof) {
2365                                static char *err;
2366                                if (!err)
2367                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2368                                fprintf(o->file, "%s:%d: %s.\n",
2369                                        data.filename, blank_at_eof, err);
2370                                data.status = 1; /* report errors */
2371                        }
2372                }
2373        }
2374 free_and_return:
2375        diff_free_filespec_data(one);
2376        diff_free_filespec_data(two);
2377        if (data.status)
2378                DIFF_OPT_SET(o, CHECK_FAILED);
2379}
2380
2381struct diff_filespec *alloc_filespec(const char *path)
2382{
2383        int namelen = strlen(path);
2384        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2385
2386        memset(spec, 0, sizeof(*spec));
2387        spec->path = (char *)(spec + 1);
2388        memcpy(spec->path, path, namelen+1);
2389        spec->count = 1;
2390        spec->is_binary = -1;
2391        return spec;
2392}
2393
2394void free_filespec(struct diff_filespec *spec)
2395{
2396        if (!--spec->count) {
2397                diff_free_filespec_data(spec);
2398                free(spec);
2399        }
2400}
2401
2402void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2403                   unsigned short mode)
2404{
2405        if (mode) {
2406                spec->mode = canon_mode(mode);
2407                hashcpy(spec->sha1, sha1);
2408                spec->sha1_valid = !is_null_sha1(sha1);
2409        }
2410}
2411
2412/*
2413 * Given a name and sha1 pair, if the index tells us the file in
2414 * the work tree has that object contents, return true, so that
2415 * prepare_temp_file() does not have to inflate and extract.
2416 */
2417static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2418{
2419        struct cache_entry *ce;
2420        struct stat st;
2421        int pos, len;
2422
2423        /*
2424         * We do not read the cache ourselves here, because the
2425         * benchmark with my previous version that always reads cache
2426         * shows that it makes things worse for diff-tree comparing
2427         * two linux-2.6 kernel trees in an already checked out work
2428         * tree.  This is because most diff-tree comparisons deal with
2429         * only a small number of files, while reading the cache is
2430         * expensive for a large project, and its cost outweighs the
2431         * savings we get by not inflating the object to a temporary
2432         * file.  Practically, this code only helps when we are used
2433         * by diff-cache --cached, which does read the cache before
2434         * calling us.
2435         */
2436        if (!active_cache)
2437                return 0;
2438
2439        /* We want to avoid the working directory if our caller
2440         * doesn't need the data in a normal file, this system
2441         * is rather slow with its stat/open/mmap/close syscalls,
2442         * and the object is contained in a pack file.  The pack
2443         * is probably already open and will be faster to obtain
2444         * the data through than the working directory.  Loose
2445         * objects however would tend to be slower as they need
2446         * to be individually opened and inflated.
2447         */
2448        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2449                return 0;
2450
2451        len = strlen(name);
2452        pos = cache_name_pos(name, len);
2453        if (pos < 0)
2454                return 0;
2455        ce = active_cache[pos];
2456
2457        /*
2458         * This is not the sha1 we are looking for, or
2459         * unreusable because it is not a regular file.
2460         */
2461        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2462                return 0;
2463
2464        /*
2465         * If ce is marked as "assume unchanged", there is no
2466         * guarantee that work tree matches what we are looking for.
2467         */
2468        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2469                return 0;
2470
2471        /*
2472         * If ce matches the file in the work tree, we can reuse it.
2473         */
2474        if (ce_uptodate(ce) ||
2475            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2476                return 1;
2477
2478        return 0;
2479}
2480
2481static int populate_from_stdin(struct diff_filespec *s)
2482{
2483        struct strbuf buf = STRBUF_INIT;
2484        size_t size = 0;
2485
2486        if (strbuf_read(&buf, 0, 0) < 0)
2487                return error("error while reading from stdin %s",
2488                                     strerror(errno));
2489
2490        s->should_munmap = 0;
2491        s->data = strbuf_detach(&buf, &size);
2492        s->size = size;
2493        s->should_free = 1;
2494        return 0;
2495}
2496
2497static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2498{
2499        int len;
2500        char *data = xmalloc(100), *dirty = "";
2501
2502        /* Are we looking at the work tree? */
2503        if (s->dirty_submodule)
2504                dirty = "-dirty";
2505
2506        len = snprintf(data, 100,
2507                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2508        s->data = data;
2509        s->size = len;
2510        s->should_free = 1;
2511        if (size_only) {
2512                s->data = NULL;
2513                free(data);
2514        }
2515        return 0;
2516}
2517
2518/*
2519 * While doing rename detection and pickaxe operation, we may need to
2520 * grab the data for the blob (or file) for our own in-core comparison.
2521 * diff_filespec has data and size fields for this purpose.
2522 */
2523int diff_populate_filespec(struct diff_filespec *s, int size_only)
2524{
2525        int err = 0;
2526        if (!DIFF_FILE_VALID(s))
2527                die("internal error: asking to populate invalid file.");
2528        if (S_ISDIR(s->mode))
2529                return -1;
2530
2531        if (s->data)
2532                return 0;
2533
2534        if (size_only && 0 < s->size)
2535                return 0;
2536
2537        if (S_ISGITLINK(s->mode))
2538                return diff_populate_gitlink(s, size_only);
2539
2540        if (!s->sha1_valid ||
2541            reuse_worktree_file(s->path, s->sha1, 0)) {
2542                struct strbuf buf = STRBUF_INIT;
2543                struct stat st;
2544                int fd;
2545
2546                if (!strcmp(s->path, "-"))
2547                        return populate_from_stdin(s);
2548
2549                if (lstat(s->path, &st) < 0) {
2550                        if (errno == ENOENT) {
2551                        err_empty:
2552                                err = -1;
2553                        empty:
2554                                s->data = (char *)"";
2555                                s->size = 0;
2556                                return err;
2557                        }
2558                }
2559                s->size = xsize_t(st.st_size);
2560                if (!s->size)
2561                        goto empty;
2562                if (S_ISLNK(st.st_mode)) {
2563                        struct strbuf sb = STRBUF_INIT;
2564
2565                        if (strbuf_readlink(&sb, s->path, s->size))
2566                                goto err_empty;
2567                        s->size = sb.len;
2568                        s->data = strbuf_detach(&sb, NULL);
2569                        s->should_free = 1;
2570                        return 0;
2571                }
2572                if (size_only)
2573                        return 0;
2574                fd = open(s->path, O_RDONLY);
2575                if (fd < 0)
2576                        goto err_empty;
2577                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2578                close(fd);
2579                s->should_munmap = 1;
2580
2581                /*
2582                 * Convert from working tree format to canonical git format
2583                 */
2584                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2585                        size_t size = 0;
2586                        munmap(s->data, s->size);
2587                        s->should_munmap = 0;
2588                        s->data = strbuf_detach(&buf, &size);
2589                        s->size = size;
2590                        s->should_free = 1;
2591                }
2592        }
2593        else {
2594                enum object_type type;
2595                if (size_only) {
2596                        type = sha1_object_info(s->sha1, &s->size);
2597                        if (type < 0)
2598                                die("unable to read %s", sha1_to_hex(s->sha1));
2599                } else {
2600                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2601                        if (!s->data)
2602                                die("unable to read %s", sha1_to_hex(s->sha1));
2603                        s->should_free = 1;
2604                }
2605        }
2606        return 0;
2607}
2608
2609void diff_free_filespec_blob(struct diff_filespec *s)
2610{
2611        if (s->should_free)
2612                free(s->data);
2613        else if (s->should_munmap)
2614                munmap(s->data, s->size);
2615
2616        if (s->should_free || s->should_munmap) {
2617                s->should_free = s->should_munmap = 0;
2618                s->data = NULL;
2619        }
2620}
2621
2622void diff_free_filespec_data(struct diff_filespec *s)
2623{
2624        diff_free_filespec_blob(s);
2625        free(s->cnt_data);
2626        s->cnt_data = NULL;
2627}
2628
2629static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2630                           void *blob,
2631                           unsigned long size,
2632                           const unsigned char *sha1,
2633                           int mode)
2634{
2635        int fd;
2636        struct strbuf buf = STRBUF_INIT;
2637        struct strbuf template = STRBUF_INIT;
2638        char *path_dup = xstrdup(path);
2639        const char *base = basename(path_dup);
2640
2641        /* Generate "XXXXXX_basename.ext" */
2642        strbuf_addstr(&template, "XXXXXX_");
2643        strbuf_addstr(&template, base);
2644
2645        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2646                        strlen(base) + 1);
2647        if (fd < 0)
2648                die_errno("unable to create temp-file");
2649        if (convert_to_working_tree(path,
2650                        (const char *)blob, (size_t)size, &buf)) {
2651                blob = buf.buf;
2652                size = buf.len;
2653        }
2654        if (write_in_full(fd, blob, size) != size)
2655                die_errno("unable to write temp-file");
2656        close(fd);
2657        temp->name = temp->tmp_path;
2658        strcpy(temp->hex, sha1_to_hex(sha1));
2659        temp->hex[40] = 0;
2660        sprintf(temp->mode, "%06o", mode);
2661        strbuf_release(&buf);
2662        strbuf_release(&template);
2663        free(path_dup);
2664}
2665
2666static struct diff_tempfile *prepare_temp_file(const char *name,
2667                struct diff_filespec *one)
2668{
2669        struct diff_tempfile *temp = claim_diff_tempfile();
2670
2671        if (!DIFF_FILE_VALID(one)) {
2672        not_a_valid_file:
2673                /* A '-' entry produces this for file-2, and
2674                 * a '+' entry produces this for file-1.
2675                 */
2676                temp->name = "/dev/null";
2677                strcpy(temp->hex, ".");
2678                strcpy(temp->mode, ".");
2679                return temp;
2680        }
2681
2682        if (!remove_tempfile_installed) {
2683                atexit(remove_tempfile);
2684                sigchain_push_common(remove_tempfile_on_signal);
2685                remove_tempfile_installed = 1;
2686        }
2687
2688        if (!one->sha1_valid ||
2689            reuse_worktree_file(name, one->sha1, 1)) {
2690                struct stat st;
2691                if (lstat(name, &st) < 0) {
2692                        if (errno == ENOENT)
2693                                goto not_a_valid_file;
2694                        die_errno("stat(%s)", name);
2695                }
2696                if (S_ISLNK(st.st_mode)) {
2697                        struct strbuf sb = STRBUF_INIT;
2698                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2699                                die_errno("readlink(%s)", name);
2700                        prep_temp_blob(name, temp, sb.buf, sb.len,
2701                                       (one->sha1_valid ?
2702                                        one->sha1 : null_sha1),
2703                                       (one->sha1_valid ?
2704                                        one->mode : S_IFLNK));
2705                        strbuf_release(&sb);
2706                }
2707                else {
2708                        /* we can borrow from the file in the work tree */
2709                        temp->name = name;
2710                        if (!one->sha1_valid)
2711                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2712                        else
2713                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2714                        /* Even though we may sometimes borrow the
2715                         * contents from the work tree, we always want
2716                         * one->mode.  mode is trustworthy even when
2717                         * !(one->sha1_valid), as long as
2718                         * DIFF_FILE_VALID(one).
2719                         */
2720                        sprintf(temp->mode, "%06o", one->mode);
2721                }
2722                return temp;
2723        }
2724        else {
2725                if (diff_populate_filespec(one, 0))
2726                        die("cannot read data blob for %s", one->path);
2727                prep_temp_blob(name, temp, one->data, one->size,
2728                               one->sha1, one->mode);
2729        }
2730        return temp;
2731}
2732
2733/* An external diff command takes:
2734 *
2735 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2736 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2737 *
2738 */
2739static void run_external_diff(const char *pgm,
2740                              const char *name,
2741                              const char *other,
2742                              struct diff_filespec *one,
2743                              struct diff_filespec *two,
2744                              const char *xfrm_msg,
2745                              int complete_rewrite)
2746{
2747        const char *spawn_arg[10];
2748        int retval;
2749        const char **arg = &spawn_arg[0];
2750
2751        if (one && two) {
2752                struct diff_tempfile *temp_one, *temp_two;
2753                const char *othername = (other ? other : name);
2754                temp_one = prepare_temp_file(name, one);
2755                temp_two = prepare_temp_file(othername, two);
2756                *arg++ = pgm;
2757                *arg++ = name;
2758                *arg++ = temp_one->name;
2759                *arg++ = temp_one->hex;
2760                *arg++ = temp_one->mode;
2761                *arg++ = temp_two->name;
2762                *arg++ = temp_two->hex;
2763                *arg++ = temp_two->mode;
2764                if (other) {
2765                        *arg++ = other;
2766                        *arg++ = xfrm_msg;
2767                }
2768        } else {
2769                *arg++ = pgm;
2770                *arg++ = name;
2771        }
2772        *arg = NULL;
2773        fflush(NULL);
2774        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2775        remove_tempfile();
2776        if (retval) {
2777                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2778                exit(1);
2779        }
2780}
2781
2782static int similarity_index(struct diff_filepair *p)
2783{
2784        return p->score * 100 / MAX_SCORE;
2785}
2786
2787static void fill_metainfo(struct strbuf *msg,
2788                          const char *name,
2789                          const char *other,
2790                          struct diff_filespec *one,
2791                          struct diff_filespec *two,
2792                          struct diff_options *o,
2793                          struct diff_filepair *p,
2794                          int *must_show_header,
2795                          int use_color)
2796{
2797        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2798        const char *reset = diff_get_color(use_color, DIFF_RESET);
2799        struct strbuf *msgbuf;
2800        char *line_prefix = "";
2801
2802        *must_show_header = 1;
2803        if (o->output_prefix) {
2804                msgbuf = o->output_prefix(o, o->output_prefix_data);
2805                line_prefix = msgbuf->buf;
2806        }
2807        strbuf_init(msg, PATH_MAX * 2 + 300);
2808        switch (p->status) {
2809        case DIFF_STATUS_COPIED:
2810                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2811                            line_prefix, set, similarity_index(p));
2812                strbuf_addf(msg, "%s\n%s%scopy from ",
2813                            reset,  line_prefix, set);
2814                quote_c_style(name, msg, NULL, 0);
2815                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2816                quote_c_style(other, msg, NULL, 0);
2817                strbuf_addf(msg, "%s\n", reset);
2818                break;
2819        case DIFF_STATUS_RENAMED:
2820                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2821                            line_prefix, set, similarity_index(p));
2822                strbuf_addf(msg, "%s\n%s%srename from ",
2823                            reset, line_prefix, set);
2824                quote_c_style(name, msg, NULL, 0);
2825                strbuf_addf(msg, "%s\n%s%srename to ",
2826                            reset, line_prefix, set);
2827                quote_c_style(other, msg, NULL, 0);
2828                strbuf_addf(msg, "%s\n", reset);
2829                break;
2830        case DIFF_STATUS_MODIFIED:
2831                if (p->score) {
2832                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2833                                    line_prefix,
2834                                    set, similarity_index(p), reset);
2835                        break;
2836                }
2837                /* fallthru */
2838        default:
2839                *must_show_header = 0;
2840        }
2841        if (one && two && hashcmp(one->sha1, two->sha1)) {
2842                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2843
2844                if (DIFF_OPT_TST(o, BINARY)) {
2845                        mmfile_t mf;
2846                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2847                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2848                                abbrev = 40;
2849                }
2850                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2851                            find_unique_abbrev(one->sha1, abbrev));
2852                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2853                if (one->mode == two->mode)
2854                        strbuf_addf(msg, " %06o", one->mode);
2855                strbuf_addf(msg, "%s\n", reset);
2856        }
2857}
2858
2859static void run_diff_cmd(const char *pgm,
2860                         const char *name,
2861                         const char *other,
2862                         const char *attr_path,
2863                         struct diff_filespec *one,
2864                         struct diff_filespec *two,
2865                         struct strbuf *msg,
2866                         struct diff_options *o,
2867                         struct diff_filepair *p)
2868{
2869        const char *xfrm_msg = NULL;
2870        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2871        int must_show_header = 0;
2872
2873        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2874                pgm = NULL;
2875        else {
2876                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2877                if (drv && drv->external)
2878                        pgm = drv->external;
2879        }
2880
2881        if (msg) {
2882                /*
2883                 * don't use colors when the header is intended for an
2884                 * external diff driver
2885                 */
2886                fill_metainfo(msg, name, other, one, two, o, p,
2887                              &must_show_header,
2888                              want_color(o->use_color) && !pgm);
2889                xfrm_msg = msg->len ? msg->buf : NULL;
2890        }
2891
2892        if (pgm) {
2893                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2894                                  complete_rewrite);
2895                return;
2896        }
2897        if (one && two)
2898                builtin_diff(name, other ? other : name,
2899                             one, two, xfrm_msg, must_show_header,
2900                             o, complete_rewrite);
2901        else
2902                fprintf(o->file, "* Unmerged path %s\n", name);
2903}
2904
2905static void diff_fill_sha1_info(struct diff_filespec *one)
2906{
2907        if (DIFF_FILE_VALID(one)) {
2908                if (!one->sha1_valid) {
2909                        struct stat st;
2910                        if (!strcmp(one->path, "-")) {
2911                                hashcpy(one->sha1, null_sha1);
2912                                return;
2913                        }
2914                        if (lstat(one->path, &st) < 0)
2915                                die_errno("stat '%s'", one->path);
2916                        if (index_path(one->sha1, one->path, &st, 0))
2917                                die("cannot hash %s", one->path);
2918                }
2919        }
2920        else
2921                hashclr(one->sha1);
2922}
2923
2924static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2925{
2926        /* Strip the prefix but do not molest /dev/null and absolute paths */
2927        if (*namep && **namep != '/') {
2928                *namep += prefix_length;
2929                if (**namep == '/')
2930                        ++*namep;
2931        }
2932        if (*otherp && **otherp != '/') {
2933                *otherp += prefix_length;
2934                if (**otherp == '/')
2935                        ++*otherp;
2936        }
2937}
2938
2939static void run_diff(struct diff_filepair *p, struct diff_options *o)
2940{
2941        const char *pgm = external_diff();
2942        struct strbuf msg;
2943        struct diff_filespec *one = p->one;
2944        struct diff_filespec *two = p->two;
2945        const char *name;
2946        const char *other;
2947        const char *attr_path;
2948
2949        name  = p->one->path;
2950        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2951        attr_path = name;
2952        if (o->prefix_length)
2953                strip_prefix(o->prefix_length, &name, &other);
2954
2955        if (DIFF_PAIR_UNMERGED(p)) {
2956                run_diff_cmd(pgm, name, NULL, attr_path,
2957                             NULL, NULL, NULL, o, p);
2958                return;
2959        }
2960
2961        diff_fill_sha1_info(one);
2962        diff_fill_sha1_info(two);
2963
2964        if (!pgm &&
2965            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2966            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2967                /*
2968                 * a filepair that changes between file and symlink
2969                 * needs to be split into deletion and creation.
2970                 */
2971                struct diff_filespec *null = alloc_filespec(two->path);
2972                run_diff_cmd(NULL, name, other, attr_path,
2973                             one, null, &msg, o, p);
2974                free(null);
2975                strbuf_release(&msg);
2976
2977                null = alloc_filespec(one->path);
2978                run_diff_cmd(NULL, name, other, attr_path,
2979                             null, two, &msg, o, p);
2980                free(null);
2981        }
2982        else
2983                run_diff_cmd(pgm, name, other, attr_path,
2984                             one, two, &msg, o, p);
2985
2986        strbuf_release(&msg);
2987}
2988
2989static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2990                         struct diffstat_t *diffstat)
2991{
2992        const char *name;
2993        const char *other;
2994        int complete_rewrite = 0;
2995
2996        if (DIFF_PAIR_UNMERGED(p)) {
2997                /* unmerged */
2998                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2999                return;
3000        }
3001
3002        name = p->one->path;
3003        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3004
3005        if (o->prefix_length)
3006                strip_prefix(o->prefix_length, &name, &other);
3007
3008        diff_fill_sha1_info(p->one);
3009        diff_fill_sha1_info(p->two);
3010
3011        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3012                complete_rewrite = 1;
3013        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3014}
3015
3016static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3017{
3018        const char *name;
3019        const char *other;
3020        const char *attr_path;
3021
3022        if (DIFF_PAIR_UNMERGED(p)) {
3023                /* unmerged */
3024                return;
3025        }
3026
3027        name = p->one->path;
3028        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3029        attr_path = other ? other : name;
3030
3031        if (o->prefix_length)
3032                strip_prefix(o->prefix_length, &name, &other);
3033
3034        diff_fill_sha1_info(p->one);
3035        diff_fill_sha1_info(p->two);
3036
3037        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3038}
3039
3040void diff_setup(struct diff_options *options)
3041{
3042        memcpy(options, &default_diff_options, sizeof(*options));
3043
3044        options->file = stdout;
3045
3046        options->line_termination = '\n';
3047        options->break_opt = -1;
3048        options->rename_limit = -1;
3049        options->dirstat_permille = diff_dirstat_permille_default;
3050        options->context = 3;
3051
3052        options->change = diff_change;
3053        options->add_remove = diff_addremove;
3054        options->use_color = diff_use_color_default;
3055        options->detect_rename = diff_detect_rename_default;
3056
3057        if (diff_no_prefix) {
3058                options->a_prefix = options->b_prefix = "";
3059        } else if (!diff_mnemonic_prefix) {
3060                options->a_prefix = "a/";
3061                options->b_prefix = "b/";
3062        }
3063}
3064
3065int diff_setup_done(struct diff_options *options)
3066{
3067        int count = 0;
3068
3069        if (options->output_format & DIFF_FORMAT_NAME)
3070                count++;
3071        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3072                count++;
3073        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3074                count++;
3075        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3076                count++;
3077        if (count > 1)
3078                die("--name-only, --name-status, --check and -s are mutually exclusive");
3079
3080        /*
3081         * Most of the time we can say "there are changes"
3082         * only by checking if there are changed paths, but
3083         * --ignore-whitespace* options force us to look
3084         * inside contents.
3085         */
3086
3087        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3088            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3089            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3090                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3091        else
3092                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3093
3094        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3095                options->detect_rename = DIFF_DETECT_COPY;
3096
3097        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3098                options->prefix = NULL;
3099        if (options->prefix)
3100                options->prefix_length = strlen(options->prefix);
3101        else
3102                options->prefix_length = 0;
3103
3104        if (options->output_format & (DIFF_FORMAT_NAME |
3105                                      DIFF_FORMAT_NAME_STATUS |
3106                                      DIFF_FORMAT_CHECKDIFF |
3107                                      DIFF_FORMAT_NO_OUTPUT))
3108                options->output_format &= ~(DIFF_FORMAT_RAW |
3109                                            DIFF_FORMAT_NUMSTAT |
3110                                            DIFF_FORMAT_DIFFSTAT |
3111                                            DIFF_FORMAT_SHORTSTAT |
3112                                            DIFF_FORMAT_DIRSTAT |
3113                                            DIFF_FORMAT_SUMMARY |
3114                                            DIFF_FORMAT_PATCH);
3115
3116        /*
3117         * These cases always need recursive; we do not drop caller-supplied
3118         * recursive bits for other formats here.
3119         */
3120        if (options->output_format & (DIFF_FORMAT_PATCH |
3121                                      DIFF_FORMAT_NUMSTAT |
3122                                      DIFF_FORMAT_DIFFSTAT |
3123                                      DIFF_FORMAT_SHORTSTAT |
3124                                      DIFF_FORMAT_DIRSTAT |
3125                                      DIFF_FORMAT_SUMMARY |
3126                                      DIFF_FORMAT_CHECKDIFF))
3127                DIFF_OPT_SET(options, RECURSIVE);
3128        /*
3129         * Also pickaxe would not work very well if you do not say recursive
3130         */
3131        if (options->pickaxe)
3132                DIFF_OPT_SET(options, RECURSIVE);
3133        /*
3134         * When patches are generated, submodules diffed against the work tree
3135         * must be checked for dirtiness too so it can be shown in the output
3136         */
3137        if (options->output_format & DIFF_FORMAT_PATCH)
3138                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3139
3140        if (options->detect_rename && options->rename_limit < 0)
3141                options->rename_limit = diff_rename_limit_default;
3142        if (options->setup & DIFF_SETUP_USE_CACHE) {
3143                if (!active_cache)
3144                        /* read-cache does not die even when it fails
3145                         * so it is safe for us to do this here.  Also
3146                         * it does not smudge active_cache or active_nr
3147                         * when it fails, so we do not have to worry about
3148                         * cleaning it up ourselves either.
3149                         */
3150                        read_cache();
3151        }
3152        if (options->abbrev <= 0 || 40 < options->abbrev)
3153                options->abbrev = 40; /* full */
3154
3155        /*
3156         * It does not make sense to show the first hit we happened
3157         * to have found.  It does not make sense not to return with
3158         * exit code in such a case either.
3159         */
3160        if (DIFF_OPT_TST(options, QUICK)) {
3161                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3162                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3163        }
3164
3165        return 0;
3166}
3167
3168static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3169{
3170        char c, *eq;
3171        int len;
3172
3173        if (*arg != '-')
3174                return 0;
3175        c = *++arg;
3176        if (!c)
3177                return 0;
3178        if (c == arg_short) {
3179                c = *++arg;
3180                if (!c)
3181                        return 1;
3182                if (val && isdigit(c)) {
3183                        char *end;
3184                        int n = strtoul(arg, &end, 10);
3185                        if (*end)
3186                                return 0;
3187                        *val = n;
3188                        return 1;
3189                }
3190                return 0;
3191        }
3192        if (c != '-')
3193                return 0;
3194        arg++;
3195        eq = strchr(arg, '=');
3196        if (eq)
3197                len = eq - arg;
3198        else
3199                len = strlen(arg);
3200        if (!len || strncmp(arg, arg_long, len))
3201                return 0;
3202        if (eq) {
3203                int n;
3204                char *end;
3205                if (!isdigit(*++eq))
3206                        return 0;
3207                n = strtoul(eq, &end, 10);
3208                if (*end)
3209                        return 0;
3210                *val = n;
3211        }
3212        return 1;
3213}
3214
3215static int diff_scoreopt_parse(const char *opt);
3216
3217static inline int short_opt(char opt, const char **argv,
3218                            const char **optarg)
3219{
3220        const char *arg = argv[0];
3221        if (arg[0] != '-' || arg[1] != opt)
3222                return 0;
3223        if (arg[2] != '\0') {
3224                *optarg = arg + 2;
3225                return 1;
3226        }
3227        if (!argv[1])
3228                die("Option '%c' requires a value", opt);
3229        *optarg = argv[1];
3230        return 2;
3231}
3232
3233int parse_long_opt(const char *opt, const char **argv,
3234                   const char **optarg)
3235{
3236        const char *arg = argv[0];
3237        if (arg[0] != '-' || arg[1] != '-')
3238                return 0;
3239        arg += strlen("--");
3240        if (prefixcmp(arg, opt))
3241                return 0;
3242        arg += strlen(opt);
3243        if (*arg == '=') { /* sticked form: --option=value */
3244                *optarg = arg + 1;
3245                return 1;
3246        }
3247        if (*arg != '\0')
3248                return 0;
3249        /* separate form: --option value */
3250        if (!argv[1])
3251                die("Option '--%s' requires a value", opt);
3252        *optarg = argv[1];
3253        return 2;
3254}
3255
3256static int stat_opt(struct diff_options *options, const char **av)
3257{
3258        const char *arg = av[0];
3259        char *end;
3260        int width = options->stat_width;
3261        int name_width = options->stat_name_width;
3262        int count = options->stat_count;
3263        int argcount = 1;
3264
3265        arg += strlen("--stat");
3266        end = (char *)arg;
3267
3268        switch (*arg) {
3269        case '-':
3270                if (!prefixcmp(arg, "-width")) {
3271                        arg += strlen("-width");
3272                        if (*arg == '=')
3273                                width = strtoul(arg + 1, &end, 10);
3274                        else if (!*arg && !av[1])
3275                                die("Option '--stat-width' requires a value");
3276                        else if (!*arg) {
3277                                width = strtoul(av[1], &end, 10);
3278                                argcount = 2;
3279                        }
3280                } else if (!prefixcmp(arg, "-name-width")) {
3281                        arg += strlen("-name-width");
3282                        if (*arg == '=')
3283                                name_width = strtoul(arg + 1, &end, 10);
3284                        else if (!*arg && !av[1])
3285                                die("Option '--stat-name-width' requires a value");
3286                        else if (!*arg) {
3287                                name_width = strtoul(av[1], &end, 10);
3288                                argcount = 2;
3289                        }
3290                } else if (!prefixcmp(arg, "-count")) {
3291                        arg += strlen("-count");
3292                        if (*arg == '=')
3293                                count = strtoul(arg + 1, &end, 10);
3294                        else if (!*arg && !av[1])
3295                                die("Option '--stat-count' requires a value");
3296                        else if (!*arg) {
3297                                count = strtoul(av[1], &end, 10);
3298                                argcount = 2;
3299                        }
3300                }
3301                break;
3302        case '=':
3303                width = strtoul(arg+1, &end, 10);
3304                if (*end == ',')
3305                        name_width = strtoul(end+1, &end, 10);
3306                if (*end == ',')
3307                        count = strtoul(end+1, &end, 10);
3308        }
3309
3310        /* Important! This checks all the error cases! */
3311        if (*end)
3312                return 0;
3313        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3314        options->stat_name_width = name_width;
3315        options->stat_width = width;
3316        options->stat_count = count;
3317        return argcount;
3318}
3319
3320static int parse_dirstat_opt(struct diff_options *options, const char *params)
3321{
3322        struct strbuf errmsg = STRBUF_INIT;
3323        if (parse_dirstat_params(options, params, &errmsg))
3324                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3325                    errmsg.buf);
3326        strbuf_release(&errmsg);
3327        /*
3328         * The caller knows a dirstat-related option is given from the command
3329         * line; allow it to say "return this_function();"
3330         */
3331        options->output_format |= DIFF_FORMAT_DIRSTAT;
3332        return 1;
3333}
3334
3335int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3336{
3337        const char *arg = av[0];
3338        const char *optarg;
3339        int argcount;
3340
3341        /* Output format options */
3342        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3343                options->output_format |= DIFF_FORMAT_PATCH;
3344        else if (opt_arg(arg, 'U', "unified", &options->context))
3345                options->output_format |= DIFF_FORMAT_PATCH;
3346        else if (!strcmp(arg, "--raw"))
3347                options->output_format |= DIFF_FORMAT_RAW;
3348        else if (!strcmp(arg, "--patch-with-raw"))
3349                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3350        else if (!strcmp(arg, "--numstat"))
3351                options->output_format |= DIFF_FORMAT_NUMSTAT;
3352        else if (!strcmp(arg, "--shortstat"))
3353                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3354        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3355                return parse_dirstat_opt(options, "");
3356        else if (!prefixcmp(arg, "-X"))
3357                return parse_dirstat_opt(options, arg + 2);
3358        else if (!prefixcmp(arg, "--dirstat="))
3359                return parse_dirstat_opt(options, arg + 10);
3360        else if (!strcmp(arg, "--cumulative"))
3361                return parse_dirstat_opt(options, "cumulative");
3362        else if (!strcmp(arg, "--dirstat-by-file"))
3363                return parse_dirstat_opt(options, "files");
3364        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3365                parse_dirstat_opt(options, "files");
3366                return parse_dirstat_opt(options, arg + 18);
3367        }
3368        else if (!strcmp(arg, "--check"))
3369                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3370        else if (!strcmp(arg, "--summary"))
3371                options->output_format |= DIFF_FORMAT_SUMMARY;
3372        else if (!strcmp(arg, "--patch-with-stat"))
3373                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3374        else if (!strcmp(arg, "--name-only"))
3375                options->output_format |= DIFF_FORMAT_NAME;
3376        else if (!strcmp(arg, "--name-status"))
3377                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3378        else if (!strcmp(arg, "-s"))
3379                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3380        else if (!prefixcmp(arg, "--stat"))
3381                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3382                return stat_opt(options, av);
3383
3384        /* renames options */
3385        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3386                 !strcmp(arg, "--break-rewrites")) {
3387                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3388                        return error("invalid argument to -B: %s", arg+2);
3389        }
3390        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3391                 !strcmp(arg, "--find-renames")) {
3392                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3393                        return error("invalid argument to -M: %s", arg+2);
3394                options->detect_rename = DIFF_DETECT_RENAME;
3395        }
3396        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3397                options->irreversible_delete = 1;
3398        }
3399        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3400                 !strcmp(arg, "--find-copies")) {
3401                if (options->detect_rename == DIFF_DETECT_COPY)
3402                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3403                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3404                        return error("invalid argument to -C: %s", arg+2);
3405                options->detect_rename = DIFF_DETECT_COPY;
3406        }
3407        else if (!strcmp(arg, "--no-renames"))
3408                options->detect_rename = 0;
3409        else if (!strcmp(arg, "--relative"))
3410                DIFF_OPT_SET(options, RELATIVE_NAME);
3411        else if (!prefixcmp(arg, "--relative=")) {
3412                DIFF_OPT_SET(options, RELATIVE_NAME);
3413                options->prefix = arg + 11;
3414        }
3415
3416        /* xdiff options */
3417        else if (!strcmp(arg, "--minimal"))
3418                DIFF_XDL_SET(options, NEED_MINIMAL);
3419        else if (!strcmp(arg, "--no-minimal"))
3420                DIFF_XDL_CLR(options, NEED_MINIMAL);
3421        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3422                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3423        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3424                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3425        else if (!strcmp(arg, "--ignore-space-at-eol"))
3426                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3427        else if (!strcmp(arg, "--patience"))
3428                DIFF_XDL_SET(options, PATIENCE_DIFF);
3429        else if (!strcmp(arg, "--histogram"))
3430                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3431
3432        /* flags options */
3433        else if (!strcmp(arg, "--binary")) {
3434                options->output_format |= DIFF_FORMAT_PATCH;
3435                DIFF_OPT_SET(options, BINARY);
3436        }
3437        else if (!strcmp(arg, "--full-index"))
3438                DIFF_OPT_SET(options, FULL_INDEX);
3439        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3440                DIFF_OPT_SET(options, TEXT);
3441        else if (!strcmp(arg, "-R"))
3442                DIFF_OPT_SET(options, REVERSE_DIFF);
3443        else if (!strcmp(arg, "--find-copies-harder"))
3444                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3445        else if (!strcmp(arg, "--follow"))
3446                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3447        else if (!strcmp(arg, "--color"))
3448                options->use_color = 1;
3449        else if (!prefixcmp(arg, "--color=")) {
3450                int value = git_config_colorbool(NULL, arg+8);
3451                if (value < 0)
3452                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3453                options->use_color = value;
3454        }
3455        else if (!strcmp(arg, "--no-color"))
3456                options->use_color = 0;
3457        else if (!strcmp(arg, "--color-words")) {
3458                options->use_color = 1;
3459                options->word_diff = DIFF_WORDS_COLOR;
3460        }
3461        else if (!prefixcmp(arg, "--color-words=")) {
3462                options->use_color = 1;
3463                options->word_diff = DIFF_WORDS_COLOR;
3464                options->word_regex = arg + 14;
3465        }
3466        else if (!strcmp(arg, "--word-diff")) {
3467                if (options->word_diff == DIFF_WORDS_NONE)
3468                        options->word_diff = DIFF_WORDS_PLAIN;
3469        }
3470        else if (!prefixcmp(arg, "--word-diff=")) {
3471                const char *type = arg + 12;
3472                if (!strcmp(type, "plain"))
3473                        options->word_diff = DIFF_WORDS_PLAIN;
3474                else if (!strcmp(type, "color")) {
3475                        options->use_color = 1;
3476                        options->word_diff = DIFF_WORDS_COLOR;
3477                }
3478                else if (!strcmp(type, "porcelain"))
3479                        options->word_diff = DIFF_WORDS_PORCELAIN;
3480                else if (!strcmp(type, "none"))
3481                        options->word_diff = DIFF_WORDS_NONE;
3482                else
3483                        die("bad --word-diff argument: %s", type);
3484        }
3485        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3486                if (options->word_diff == DIFF_WORDS_NONE)
3487                        options->word_diff = DIFF_WORDS_PLAIN;
3488                options->word_regex = optarg;
3489                return argcount;
3490        }
3491        else if (!strcmp(arg, "--exit-code"))
3492                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3493        else if (!strcmp(arg, "--quiet"))
3494                DIFF_OPT_SET(options, QUICK);
3495        else if (!strcmp(arg, "--ext-diff"))
3496                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3497        else if (!strcmp(arg, "--no-ext-diff"))
3498                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3499        else if (!strcmp(arg, "--textconv"))
3500                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3501        else if (!strcmp(arg, "--no-textconv"))
3502                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3503        else if (!strcmp(arg, "--ignore-submodules")) {
3504                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3505                handle_ignore_submodules_arg(options, "all");
3506        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3507                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3508                handle_ignore_submodules_arg(options, arg + 20);
3509        } else if (!strcmp(arg, "--submodule"))
3510                DIFF_OPT_SET(options, SUBMODULE_LOG);
3511        else if (!prefixcmp(arg, "--submodule=")) {
3512                if (!strcmp(arg + 12, "log"))
3513                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3514        }
3515
3516        /* misc options */
3517        else if (!strcmp(arg, "-z"))
3518                options->line_termination = 0;
3519        else if ((argcount = short_opt('l', av, &optarg))) {
3520                options->rename_limit = strtoul(optarg, NULL, 10);
3521                return argcount;
3522        }
3523        else if ((argcount = short_opt('S', av, &optarg))) {
3524                options->pickaxe = optarg;
3525                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3526                return argcount;
3527        } else if ((argcount = short_opt('G', av, &optarg))) {
3528                options->pickaxe = optarg;
3529                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3530                return argcount;
3531        }
3532        else if (!strcmp(arg, "--pickaxe-all"))
3533                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3534        else if (!strcmp(arg, "--pickaxe-regex"))
3535                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3536        else if ((argcount = short_opt('O', av, &optarg))) {
3537                options->orderfile = optarg;
3538                return argcount;
3539        }
3540        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3541                options->filter = optarg;
3542                return argcount;
3543        }
3544        else if (!strcmp(arg, "--abbrev"))
3545                options->abbrev = DEFAULT_ABBREV;
3546        else if (!prefixcmp(arg, "--abbrev=")) {
3547                options->abbrev = strtoul(arg + 9, NULL, 10);
3548                if (options->abbrev < MINIMUM_ABBREV)
3549                        options->abbrev = MINIMUM_ABBREV;
3550                else if (40 < options->abbrev)
3551                        options->abbrev = 40;
3552        }
3553        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3554                options->a_prefix = optarg;
3555                return argcount;
3556        }
3557        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3558                options->b_prefix = optarg;
3559                return argcount;
3560        }
3561        else if (!strcmp(arg, "--no-prefix"))
3562                options->a_prefix = options->b_prefix = "";
3563        else if (opt_arg(arg, '\0', "inter-hunk-context",
3564                         &options->interhunkcontext))
3565                ;
3566        else if (!strcmp(arg, "-W"))
3567                DIFF_OPT_SET(options, FUNCCONTEXT);
3568        else if (!strcmp(arg, "--function-context"))
3569                DIFF_OPT_SET(options, FUNCCONTEXT);
3570        else if (!strcmp(arg, "--no-function-context"))
3571                DIFF_OPT_CLR(options, FUNCCONTEXT);
3572        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3573                options->file = fopen(optarg, "w");
3574                if (!options->file)
3575                        die_errno("Could not open '%s'", optarg);
3576                options->close_file = 1;
3577                return argcount;
3578        } else
3579                return 0;
3580        return 1;
3581}
3582
3583int parse_rename_score(const char **cp_p)
3584{
3585        unsigned long num, scale;
3586        int ch, dot;
3587        const char *cp = *cp_p;
3588
3589        num = 0;
3590        scale = 1;
3591        dot = 0;
3592        for (;;) {
3593                ch = *cp;
3594                if ( !dot && ch == '.' ) {
3595                        scale = 1;
3596                        dot = 1;
3597                } else if ( ch == '%' ) {
3598                        scale = dot ? scale*100 : 100;
3599                        cp++;   /* % is always at the end */
3600                        break;
3601                } else if ( ch >= '0' && ch <= '9' ) {
3602                        if ( scale < 100000 ) {
3603                                scale *= 10;
3604                                num = (num*10) + (ch-'0');
3605                        }
3606                } else {
3607                        break;
3608                }
3609                cp++;
3610        }
3611        *cp_p = cp;
3612
3613        /* user says num divided by scale and we say internally that
3614         * is MAX_SCORE * num / scale.
3615         */
3616        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3617}
3618
3619static int diff_scoreopt_parse(const char *opt)
3620{
3621        int opt1, opt2, cmd;
3622
3623        if (*opt++ != '-')
3624                return -1;
3625        cmd = *opt++;
3626        if (cmd == '-') {
3627                /* convert the long-form arguments into short-form versions */
3628                if (!prefixcmp(opt, "break-rewrites")) {
3629                        opt += strlen("break-rewrites");
3630                        if (*opt == 0 || *opt++ == '=')
3631                                cmd = 'B';
3632                } else if (!prefixcmp(opt, "find-copies")) {
3633                        opt += strlen("find-copies");
3634                        if (*opt == 0 || *opt++ == '=')
3635                                cmd = 'C';
3636                } else if (!prefixcmp(opt, "find-renames")) {
3637                        opt += strlen("find-renames");
3638                        if (*opt == 0 || *opt++ == '=')
3639                                cmd = 'M';
3640                }
3641        }
3642        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3643                return -1; /* that is not a -M, -C nor -B option */
3644
3645        opt1 = parse_rename_score(&opt);
3646        if (cmd != 'B')
3647                opt2 = 0;
3648        else {
3649                if (*opt == 0)
3650                        opt2 = 0;
3651                else if (*opt != '/')
3652                        return -1; /* we expect -B80/99 or -B80 */
3653                else {
3654                        opt++;
3655                        opt2 = parse_rename_score(&opt);
3656                }
3657        }
3658        if (*opt != 0)
3659                return -1;
3660        return opt1 | (opt2 << 16);
3661}
3662
3663struct diff_queue_struct diff_queued_diff;
3664
3665void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3666{
3667        if (queue->alloc <= queue->nr) {
3668                queue->alloc = alloc_nr(queue->alloc);
3669                queue->queue = xrealloc(queue->queue,
3670                                        sizeof(dp) * queue->alloc);
3671        }
3672        queue->queue[queue->nr++] = dp;
3673}
3674
3675struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3676                                 struct diff_filespec *one,
3677                                 struct diff_filespec *two)
3678{
3679        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3680        dp->one = one;
3681        dp->two = two;
3682        if (queue)
3683                diff_q(queue, dp);
3684        return dp;
3685}
3686
3687void diff_free_filepair(struct diff_filepair *p)
3688{
3689        free_filespec(p->one);
3690        free_filespec(p->two);
3691        free(p);
3692}
3693
3694/* This is different from find_unique_abbrev() in that
3695 * it stuffs the result with dots for alignment.
3696 */
3697const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3698{
3699        int abblen;
3700        const char *abbrev;
3701        if (len == 40)
3702                return sha1_to_hex(sha1);
3703
3704        abbrev = find_unique_abbrev(sha1, len);
3705        abblen = strlen(abbrev);
3706        if (abblen < 37) {
3707                static char hex[41];
3708                if (len < abblen && abblen <= len + 2)
3709                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3710                else
3711                        sprintf(hex, "%s...", abbrev);
3712                return hex;
3713        }
3714        return sha1_to_hex(sha1);
3715}
3716
3717static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3718{
3719        int line_termination = opt->line_termination;
3720        int inter_name_termination = line_termination ? '\t' : '\0';
3721        if (opt->output_prefix) {
3722                struct strbuf *msg = NULL;
3723                msg = opt->output_prefix(opt, opt->output_prefix_data);
3724                fprintf(opt->file, "%s", msg->buf);
3725        }
3726
3727        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3728                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3729                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3730                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3731        }
3732        if (p->score) {
3733                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3734                        inter_name_termination);
3735        } else {
3736                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3737        }
3738
3739        if (p->status == DIFF_STATUS_COPIED ||
3740            p->status == DIFF_STATUS_RENAMED) {
3741                const char *name_a, *name_b;
3742                name_a = p->one->path;
3743                name_b = p->two->path;
3744                strip_prefix(opt->prefix_length, &name_a, &name_b);
3745                write_name_quoted(name_a, opt->file, inter_name_termination);
3746                write_name_quoted(name_b, opt->file, line_termination);
3747        } else {
3748                const char *name_a, *name_b;
3749                name_a = p->one->mode ? p->one->path : p->two->path;
3750                name_b = NULL;
3751                strip_prefix(opt->prefix_length, &name_a, &name_b);
3752                write_name_quoted(name_a, opt->file, line_termination);
3753        }
3754}
3755
3756int diff_unmodified_pair(struct diff_filepair *p)
3757{
3758        /* This function is written stricter than necessary to support
3759         * the currently implemented transformers, but the idea is to
3760         * let transformers to produce diff_filepairs any way they want,
3761         * and filter and clean them up here before producing the output.
3762         */
3763        struct diff_filespec *one = p->one, *two = p->two;
3764
3765        if (DIFF_PAIR_UNMERGED(p))
3766                return 0; /* unmerged is interesting */
3767
3768        /* deletion, addition, mode or type change
3769         * and rename are all interesting.
3770         */
3771        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3772            DIFF_PAIR_MODE_CHANGED(p) ||
3773            strcmp(one->path, two->path))
3774                return 0;
3775
3776        /* both are valid and point at the same path.  that is, we are
3777         * dealing with a change.
3778         */
3779        if (one->sha1_valid && two->sha1_valid &&
3780            !hashcmp(one->sha1, two->sha1) &&
3781            !one->dirty_submodule && !two->dirty_submodule)
3782                return 1; /* no change */
3783        if (!one->sha1_valid && !two->sha1_valid)
3784                return 1; /* both look at the same file on the filesystem. */
3785        return 0;
3786}
3787
3788static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3789{
3790        if (diff_unmodified_pair(p))
3791                return;
3792
3793        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3794            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3795                return; /* no tree diffs in patch format */
3796
3797        run_diff(p, o);
3798}
3799
3800static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3801                            struct diffstat_t *diffstat)
3802{
3803        if (diff_unmodified_pair(p))
3804                return;
3805
3806        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3807            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3808                return; /* no useful stat for tree diffs */
3809
3810        run_diffstat(p, o, diffstat);
3811}
3812
3813static void diff_flush_checkdiff(struct diff_filepair *p,
3814                struct diff_options *o)
3815{
3816        if (diff_unmodified_pair(p))
3817                return;
3818
3819        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3820            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3821                return; /* nothing to check in tree diffs */
3822
3823        run_checkdiff(p, o);
3824}
3825
3826int diff_queue_is_empty(void)
3827{
3828        struct diff_queue_struct *q = &diff_queued_diff;
3829        int i;
3830        for (i = 0; i < q->nr; i++)
3831                if (!diff_unmodified_pair(q->queue[i]))
3832                        return 0;
3833        return 1;
3834}
3835
3836#if DIFF_DEBUG
3837void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3838{
3839        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3840                x, one ? one : "",
3841                s->path,
3842                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3843                s->mode,
3844                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3845        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3846                x, one ? one : "",
3847                s->size, s->xfrm_flags);
3848}
3849
3850void diff_debug_filepair(const struct diff_filepair *p, int i)
3851{
3852        diff_debug_filespec(p->one, i, "one");
3853        diff_debug_filespec(p->two, i, "two");
3854        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3855                p->score, p->status ? p->status : '?',
3856                p->one->rename_used, p->broken_pair);
3857}
3858
3859void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3860{
3861        int i;
3862        if (msg)
3863                fprintf(stderr, "%s\n", msg);
3864        fprintf(stderr, "q->nr = %d\n", q->nr);
3865        for (i = 0; i < q->nr; i++) {
3866                struct diff_filepair *p = q->queue[i];
3867                diff_debug_filepair(p, i);
3868        }
3869}
3870#endif
3871
3872static void diff_resolve_rename_copy(void)
3873{
3874        int i;
3875        struct diff_filepair *p;
3876        struct diff_queue_struct *q = &diff_queued_diff;
3877
3878        diff_debug_queue("resolve-rename-copy", q);
3879
3880        for (i = 0; i < q->nr; i++) {
3881                p = q->queue[i];
3882                p->status = 0; /* undecided */
3883                if (DIFF_PAIR_UNMERGED(p))
3884                        p->status = DIFF_STATUS_UNMERGED;
3885                else if (!DIFF_FILE_VALID(p->one))
3886                        p->status = DIFF_STATUS_ADDED;
3887                else if (!DIFF_FILE_VALID(p->two))
3888                        p->status = DIFF_STATUS_DELETED;
3889                else if (DIFF_PAIR_TYPE_CHANGED(p))
3890                        p->status = DIFF_STATUS_TYPE_CHANGED;
3891
3892                /* from this point on, we are dealing with a pair
3893                 * whose both sides are valid and of the same type, i.e.
3894                 * either in-place edit or rename/copy edit.
3895                 */
3896                else if (DIFF_PAIR_RENAME(p)) {
3897                        /*
3898                         * A rename might have re-connected a broken
3899                         * pair up, causing the pathnames to be the
3900                         * same again. If so, that's not a rename at
3901                         * all, just a modification..
3902                         *
3903                         * Otherwise, see if this source was used for
3904                         * multiple renames, in which case we decrement
3905                         * the count, and call it a copy.
3906                         */
3907                        if (!strcmp(p->one->path, p->two->path))
3908                                p->status = DIFF_STATUS_MODIFIED;
3909                        else if (--p->one->rename_used > 0)
3910                                p->status = DIFF_STATUS_COPIED;
3911                        else
3912                                p->status = DIFF_STATUS_RENAMED;
3913                }
3914                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3915                         p->one->mode != p->two->mode ||
3916                         p->one->dirty_submodule ||
3917                         p->two->dirty_submodule ||
3918                         is_null_sha1(p->one->sha1))
3919                        p->status = DIFF_STATUS_MODIFIED;
3920                else {
3921                        /* This is a "no-change" entry and should not
3922                         * happen anymore, but prepare for broken callers.
3923                         */
3924                        error("feeding unmodified %s to diffcore",
3925                              p->one->path);
3926                        p->status = DIFF_STATUS_UNKNOWN;
3927                }
3928        }
3929        diff_debug_queue("resolve-rename-copy done", q);
3930}
3931
3932static int check_pair_status(struct diff_filepair *p)
3933{
3934        switch (p->status) {
3935        case DIFF_STATUS_UNKNOWN:
3936                return 0;
3937        case 0:
3938                die("internal error in diff-resolve-rename-copy");
3939        default:
3940                return 1;
3941        }
3942}
3943
3944static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3945{
3946        int fmt = opt->output_format;
3947
3948        if (fmt & DIFF_FORMAT_CHECKDIFF)
3949                diff_flush_checkdiff(p, opt);
3950        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3951                diff_flush_raw(p, opt);
3952        else if (fmt & DIFF_FORMAT_NAME) {
3953                const char *name_a, *name_b;
3954                name_a = p->two->path;
3955                name_b = NULL;
3956                strip_prefix(opt->prefix_length, &name_a, &name_b);
3957                write_name_quoted(name_a, opt->file, opt->line_termination);
3958        }
3959}
3960
3961static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3962{
3963        if (fs->mode)
3964                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3965        else
3966                fprintf(file, " %s ", newdelete);
3967        write_name_quoted(fs->path, file, '\n');
3968}
3969
3970
3971static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3972                const char *line_prefix)
3973{
3974        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3975                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3976                        p->two->mode, show_name ? ' ' : '\n');
3977                if (show_name) {
3978                        write_name_quoted(p->two->path, file, '\n');
3979                }
3980        }
3981}
3982
3983static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3984                        const char *line_prefix)
3985{
3986        char *names = pprint_rename(p->one->path, p->two->path);
3987
3988        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3989        free(names);
3990        show_mode_change(file, p, 0, line_prefix);
3991}
3992
3993static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3994{
3995        FILE *file = opt->file;
3996        char *line_prefix = "";
3997
3998        if (opt->output_prefix) {
3999                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4000                line_prefix = buf->buf;
4001        }
4002
4003        switch(p->status) {
4004        case DIFF_STATUS_DELETED:
4005                fputs(line_prefix, file);
4006                show_file_mode_name(file, "delete", p->one);
4007                break;
4008        case DIFF_STATUS_ADDED:
4009                fputs(line_prefix, file);
4010                show_file_mode_name(file, "create", p->two);
4011                break;
4012        case DIFF_STATUS_COPIED:
4013                fputs(line_prefix, file);
4014                show_rename_copy(file, "copy", p, line_prefix);
4015                break;
4016        case DIFF_STATUS_RENAMED:
4017                fputs(line_prefix, file);
4018                show_rename_copy(file, "rename", p, line_prefix);
4019                break;
4020        default:
4021                if (p->score) {
4022                        fprintf(file, "%s rewrite ", line_prefix);
4023                        write_name_quoted(p->two->path, file, ' ');
4024                        fprintf(file, "(%d%%)\n", similarity_index(p));
4025                }
4026                show_mode_change(file, p, !p->score, line_prefix);
4027                break;
4028        }
4029}
4030
4031struct patch_id_t {
4032        git_SHA_CTX *ctx;
4033        int patchlen;
4034};
4035
4036static int remove_space(char *line, int len)
4037{
4038        int i;
4039        char *dst = line;
4040        unsigned char c;
4041
4042        for (i = 0; i < len; i++)
4043                if (!isspace((c = line[i])))
4044                        *dst++ = c;
4045
4046        return dst - line;
4047}
4048
4049static void patch_id_consume(void *priv, char *line, unsigned long len)
4050{
4051        struct patch_id_t *data = priv;
4052        int new_len;
4053
4054        /* Ignore line numbers when computing the SHA1 of the patch */
4055        if (!prefixcmp(line, "@@ -"))
4056                return;
4057
4058        new_len = remove_space(line, len);
4059
4060        git_SHA1_Update(data->ctx, line, new_len);
4061        data->patchlen += new_len;
4062}
4063
4064/* returns 0 upon success, and writes result into sha1 */
4065static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4066{
4067        struct diff_queue_struct *q = &diff_queued_diff;
4068        int i;
4069        git_SHA_CTX ctx;
4070        struct patch_id_t data;
4071        char buffer[PATH_MAX * 4 + 20];
4072
4073        git_SHA1_Init(&ctx);
4074        memset(&data, 0, sizeof(struct patch_id_t));
4075        data.ctx = &ctx;
4076
4077        for (i = 0; i < q->nr; i++) {
4078                xpparam_t xpp;
4079                xdemitconf_t xecfg;
4080                mmfile_t mf1, mf2;
4081                struct diff_filepair *p = q->queue[i];
4082                int len1, len2;
4083
4084                memset(&xpp, 0, sizeof(xpp));
4085                memset(&xecfg, 0, sizeof(xecfg));
4086                if (p->status == 0)
4087                        return error("internal diff status error");
4088                if (p->status == DIFF_STATUS_UNKNOWN)
4089                        continue;
4090                if (diff_unmodified_pair(p))
4091                        continue;
4092                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4093                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4094                        continue;
4095                if (DIFF_PAIR_UNMERGED(p))
4096                        continue;
4097
4098                diff_fill_sha1_info(p->one);
4099                diff_fill_sha1_info(p->two);
4100                if (fill_mmfile(&mf1, p->one) < 0 ||
4101                                fill_mmfile(&mf2, p->two) < 0)
4102                        return error("unable to read files to diff");
4103
4104                len1 = remove_space(p->one->path, strlen(p->one->path));
4105                len2 = remove_space(p->two->path, strlen(p->two->path));
4106                if (p->one->mode == 0)
4107                        len1 = snprintf(buffer, sizeof(buffer),
4108                                        "diff--gita/%.*sb/%.*s"
4109                                        "newfilemode%06o"
4110                                        "---/dev/null"
4111                                        "+++b/%.*s",
4112                                        len1, p->one->path,
4113                                        len2, p->two->path,
4114                                        p->two->mode,
4115                                        len2, p->two->path);
4116                else if (p->two->mode == 0)
4117                        len1 = snprintf(buffer, sizeof(buffer),
4118                                        "diff--gita/%.*sb/%.*s"
4119                                        "deletedfilemode%06o"
4120                                        "---a/%.*s"
4121                                        "+++/dev/null",
4122                                        len1, p->one->path,
4123                                        len2, p->two->path,
4124                                        p->one->mode,
4125                                        len1, p->one->path);
4126                else
4127                        len1 = snprintf(buffer, sizeof(buffer),
4128                                        "diff--gita/%.*sb/%.*s"
4129                                        "---a/%.*s"
4130                                        "+++b/%.*s",
4131                                        len1, p->one->path,
4132                                        len2, p->two->path,
4133                                        len1, p->one->path,
4134                                        len2, p->two->path);
4135                git_SHA1_Update(&ctx, buffer, len1);
4136
4137                if (diff_filespec_is_binary(p->one) ||
4138                    diff_filespec_is_binary(p->two)) {
4139                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4140                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4141                        continue;
4142                }
4143
4144                xpp.flags = 0;
4145                xecfg.ctxlen = 3;
4146                xecfg.flags = 0;
4147                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4148                              &xpp, &xecfg);
4149        }
4150
4151        git_SHA1_Final(sha1, &ctx);
4152        return 0;
4153}
4154
4155int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4156{
4157        struct diff_queue_struct *q = &diff_queued_diff;
4158        int i;
4159        int result = diff_get_patch_id(options, sha1);
4160
4161        for (i = 0; i < q->nr; i++)
4162                diff_free_filepair(q->queue[i]);
4163
4164        free(q->queue);
4165        DIFF_QUEUE_CLEAR(q);
4166
4167        return result;
4168}
4169
4170static int is_summary_empty(const struct diff_queue_struct *q)
4171{
4172        int i;
4173
4174        for (i = 0; i < q->nr; i++) {
4175                const struct diff_filepair *p = q->queue[i];
4176
4177                switch (p->status) {
4178                case DIFF_STATUS_DELETED:
4179                case DIFF_STATUS_ADDED:
4180                case DIFF_STATUS_COPIED:
4181                case DIFF_STATUS_RENAMED:
4182                        return 0;
4183                default:
4184                        if (p->score)
4185                                return 0;
4186                        if (p->one->mode && p->two->mode &&
4187                            p->one->mode != p->two->mode)
4188                                return 0;
4189                        break;
4190                }
4191        }
4192        return 1;
4193}
4194
4195static const char rename_limit_warning[] =
4196"inexact rename detection was skipped due to too many files.";
4197
4198static const char degrade_cc_to_c_warning[] =
4199"only found copies from modified paths due to too many files.";
4200
4201static const char rename_limit_advice[] =
4202"you may want to set your %s variable to at least "
4203"%d and retry the command.";
4204
4205void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4206{
4207        if (degraded_cc)
4208                warning(degrade_cc_to_c_warning);
4209        else if (needed)
4210                warning(rename_limit_warning);
4211        else
4212                return;
4213        if (0 < needed && needed < 32767)
4214                warning(rename_limit_advice, varname, needed);
4215}
4216
4217void diff_flush(struct diff_options *options)
4218{
4219        struct diff_queue_struct *q = &diff_queued_diff;
4220        int i, output_format = options->output_format;
4221        int separator = 0;
4222        int dirstat_by_line = 0;
4223
4224        /*
4225         * Order: raw, stat, summary, patch
4226         * or:    name/name-status/checkdiff (other bits clear)
4227         */
4228        if (!q->nr)
4229                goto free_queue;
4230
4231        if (output_format & (DIFF_FORMAT_RAW |
4232                             DIFF_FORMAT_NAME |
4233                             DIFF_FORMAT_NAME_STATUS |
4234                             DIFF_FORMAT_CHECKDIFF)) {
4235                for (i = 0; i < q->nr; i++) {
4236                        struct diff_filepair *p = q->queue[i];
4237                        if (check_pair_status(p))
4238                                flush_one_pair(p, options);
4239                }
4240                separator++;
4241        }
4242
4243        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4244                dirstat_by_line = 1;
4245
4246        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4247            dirstat_by_line) {
4248                struct diffstat_t diffstat;
4249
4250                memset(&diffstat, 0, sizeof(struct diffstat_t));
4251                for (i = 0; i < q->nr; i++) {
4252                        struct diff_filepair *p = q->queue[i];
4253                        if (check_pair_status(p))
4254                                diff_flush_stat(p, options, &diffstat);
4255                }
4256                if (output_format & DIFF_FORMAT_NUMSTAT)
4257                        show_numstat(&diffstat, options);
4258                if (output_format & DIFF_FORMAT_DIFFSTAT)
4259                        show_stats(&diffstat, options);
4260                if (output_format & DIFF_FORMAT_SHORTSTAT)
4261                        show_shortstats(&diffstat, options);
4262                if (output_format & DIFF_FORMAT_DIRSTAT)
4263                        show_dirstat_by_line(&diffstat, options);
4264                free_diffstat_info(&diffstat);
4265                separator++;
4266        }
4267        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4268                show_dirstat(options);
4269
4270        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4271                for (i = 0; i < q->nr; i++) {
4272                        diff_summary(options, q->queue[i]);
4273                }
4274                separator++;
4275        }
4276
4277        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4278            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4279            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4280                /*
4281                 * run diff_flush_patch for the exit status. setting
4282                 * options->file to /dev/null should be safe, becaue we
4283                 * aren't supposed to produce any output anyway.
4284                 */
4285                if (options->close_file)
4286                        fclose(options->file);
4287                options->file = fopen("/dev/null", "w");
4288                if (!options->file)
4289                        die_errno("Could not open /dev/null");
4290                options->close_file = 1;
4291                for (i = 0; i < q->nr; i++) {
4292                        struct diff_filepair *p = q->queue[i];
4293                        if (check_pair_status(p))
4294                                diff_flush_patch(p, options);
4295                        if (options->found_changes)
4296                                break;
4297                }
4298        }
4299
4300        if (output_format & DIFF_FORMAT_PATCH) {
4301                if (separator) {
4302                        putc(options->line_termination, options->file);
4303                        if (options->stat_sep) {
4304                                /* attach patch instead of inline */
4305                                fputs(options->stat_sep, options->file);
4306                        }
4307                }
4308
4309                for (i = 0; i < q->nr; i++) {
4310                        struct diff_filepair *p = q->queue[i];
4311                        if (check_pair_status(p))
4312                                diff_flush_patch(p, options);
4313                }
4314        }
4315
4316        if (output_format & DIFF_FORMAT_CALLBACK)
4317                options->format_callback(q, options, options->format_callback_data);
4318
4319        for (i = 0; i < q->nr; i++)
4320                diff_free_filepair(q->queue[i]);
4321free_queue:
4322        free(q->queue);
4323        DIFF_QUEUE_CLEAR(q);
4324        if (options->close_file)
4325                fclose(options->file);
4326
4327        /*
4328         * Report the content-level differences with HAS_CHANGES;
4329         * diff_addremove/diff_change does not set the bit when
4330         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4331         */
4332        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4333                if (options->found_changes)
4334                        DIFF_OPT_SET(options, HAS_CHANGES);
4335                else
4336                        DIFF_OPT_CLR(options, HAS_CHANGES);
4337        }
4338}
4339
4340static void diffcore_apply_filter(const char *filter)
4341{
4342        int i;
4343        struct diff_queue_struct *q = &diff_queued_diff;
4344        struct diff_queue_struct outq;
4345        DIFF_QUEUE_CLEAR(&outq);
4346
4347        if (!filter)
4348                return;
4349
4350        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4351                int found;
4352                for (i = found = 0; !found && i < q->nr; i++) {
4353                        struct diff_filepair *p = q->queue[i];
4354                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4355                             ((p->score &&
4356                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4357                              (!p->score &&
4358                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4359                            ((p->status != DIFF_STATUS_MODIFIED) &&
4360                             strchr(filter, p->status)))
4361                                found++;
4362                }
4363                if (found)
4364                        return;
4365
4366                /* otherwise we will clear the whole queue
4367                 * by copying the empty outq at the end of this
4368                 * function, but first clear the current entries
4369                 * in the queue.
4370                 */
4371                for (i = 0; i < q->nr; i++)
4372                        diff_free_filepair(q->queue[i]);
4373        }
4374        else {
4375                /* Only the matching ones */
4376                for (i = 0; i < q->nr; i++) {
4377                        struct diff_filepair *p = q->queue[i];
4378
4379                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4380                             ((p->score &&
4381                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4382                              (!p->score &&
4383                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4384                            ((p->status != DIFF_STATUS_MODIFIED) &&
4385                             strchr(filter, p->status)))
4386                                diff_q(&outq, p);
4387                        else
4388                                diff_free_filepair(p);
4389                }
4390        }
4391        free(q->queue);
4392        *q = outq;
4393}
4394
4395/* Check whether two filespecs with the same mode and size are identical */
4396static int diff_filespec_is_identical(struct diff_filespec *one,
4397                                      struct diff_filespec *two)
4398{
4399        if (S_ISGITLINK(one->mode))
4400                return 0;
4401        if (diff_populate_filespec(one, 0))
4402                return 0;
4403        if (diff_populate_filespec(two, 0))
4404                return 0;
4405        return !memcmp(one->data, two->data, one->size);
4406}
4407
4408static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4409{
4410        int i;
4411        struct diff_queue_struct *q = &diff_queued_diff;
4412        struct diff_queue_struct outq;
4413        DIFF_QUEUE_CLEAR(&outq);
4414
4415        for (i = 0; i < q->nr; i++) {
4416                struct diff_filepair *p = q->queue[i];
4417
4418                /*
4419                 * 1. Entries that come from stat info dirtiness
4420                 *    always have both sides (iow, not create/delete),
4421                 *    one side of the object name is unknown, with
4422                 *    the same mode and size.  Keep the ones that
4423                 *    do not match these criteria.  They have real
4424                 *    differences.
4425                 *
4426                 * 2. At this point, the file is known to be modified,
4427                 *    with the same mode and size, and the object
4428                 *    name of one side is unknown.  Need to inspect
4429                 *    the identical contents.
4430                 */
4431                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4432                    !DIFF_FILE_VALID(p->two) ||
4433                    (p->one->sha1_valid && p->two->sha1_valid) ||
4434                    (p->one->mode != p->two->mode) ||
4435                    diff_populate_filespec(p->one, 1) ||
4436                    diff_populate_filespec(p->two, 1) ||
4437                    (p->one->size != p->two->size) ||
4438                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4439                        diff_q(&outq, p);
4440                else {
4441                        /*
4442                         * The caller can subtract 1 from skip_stat_unmatch
4443                         * to determine how many paths were dirty only
4444                         * due to stat info mismatch.
4445                         */
4446                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4447                                diffopt->skip_stat_unmatch++;
4448                        diff_free_filepair(p);
4449                }
4450        }
4451        free(q->queue);
4452        *q = outq;
4453}
4454
4455static int diffnamecmp(const void *a_, const void *b_)
4456{
4457        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4458        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4459        const char *name_a, *name_b;
4460
4461        name_a = a->one ? a->one->path : a->two->path;
4462        name_b = b->one ? b->one->path : b->two->path;
4463        return strcmp(name_a, name_b);
4464}
4465
4466void diffcore_fix_diff_index(struct diff_options *options)
4467{
4468        struct diff_queue_struct *q = &diff_queued_diff;
4469        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4470}
4471
4472void diffcore_std(struct diff_options *options)
4473{
4474        if (options->skip_stat_unmatch)
4475                diffcore_skip_stat_unmatch(options);
4476        if (!options->found_follow) {
4477                /* See try_to_follow_renames() in tree-diff.c */
4478                if (options->break_opt != -1)
4479                        diffcore_break(options->break_opt);
4480                if (options->detect_rename)
4481                        diffcore_rename(options);
4482                if (options->break_opt != -1)
4483                        diffcore_merge_broken();
4484        }
4485        if (options->pickaxe)
4486                diffcore_pickaxe(options);
4487        if (options->orderfile)
4488                diffcore_order(options->orderfile);
4489        if (!options->found_follow)
4490                /* See try_to_follow_renames() in tree-diff.c */
4491                diff_resolve_rename_copy();
4492        diffcore_apply_filter(options->filter);
4493
4494        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4495                DIFF_OPT_SET(options, HAS_CHANGES);
4496        else
4497                DIFF_OPT_CLR(options, HAS_CHANGES);
4498
4499        options->found_follow = 0;
4500}
4501
4502int diff_result_code(struct diff_options *opt, int status)
4503{
4504        int result = 0;
4505
4506        diff_warn_rename_limit("diff.renamelimit",
4507                               opt->needed_rename_limit,
4508                               opt->degraded_cc_to_c);
4509        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4510            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4511                return status;
4512        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4513            DIFF_OPT_TST(opt, HAS_CHANGES))
4514                result |= 01;
4515        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4516            DIFF_OPT_TST(opt, CHECK_FAILED))
4517                result |= 02;
4518        return result;
4519}
4520
4521int diff_can_quit_early(struct diff_options *opt)
4522{
4523        return (DIFF_OPT_TST(opt, QUICK) &&
4524                !opt->filter &&
4525                DIFF_OPT_TST(opt, HAS_CHANGES));
4526}
4527
4528/*
4529 * Shall changes to this submodule be ignored?
4530 *
4531 * Submodule changes can be configured to be ignored separately for each path,
4532 * but that configuration can be overridden from the command line.
4533 */
4534static int is_submodule_ignored(const char *path, struct diff_options *options)
4535{
4536        int ignored = 0;
4537        unsigned orig_flags = options->flags;
4538        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4539                set_diffopt_flags_from_submodule_config(options, path);
4540        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4541                ignored = 1;
4542        options->flags = orig_flags;
4543        return ignored;
4544}
4545
4546void diff_addremove(struct diff_options *options,
4547                    int addremove, unsigned mode,
4548                    const unsigned char *sha1,
4549                    const char *concatpath, unsigned dirty_submodule)
4550{
4551        struct diff_filespec *one, *two;
4552
4553        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4554                return;
4555
4556        /* This may look odd, but it is a preparation for
4557         * feeding "there are unchanged files which should
4558         * not produce diffs, but when you are doing copy
4559         * detection you would need them, so here they are"
4560         * entries to the diff-core.  They will be prefixed
4561         * with something like '=' or '*' (I haven't decided
4562         * which but should not make any difference).
4563         * Feeding the same new and old to diff_change()
4564         * also has the same effect.
4565         * Before the final output happens, they are pruned after
4566         * merged into rename/copy pairs as appropriate.
4567         */
4568        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4569                addremove = (addremove == '+' ? '-' :
4570                             addremove == '-' ? '+' : addremove);
4571
4572        if (options->prefix &&
4573            strncmp(concatpath, options->prefix, options->prefix_length))
4574                return;
4575
4576        one = alloc_filespec(concatpath);
4577        two = alloc_filespec(concatpath);
4578
4579        if (addremove != '+')
4580                fill_filespec(one, sha1, mode);
4581        if (addremove != '-') {
4582                fill_filespec(two, sha1, mode);
4583                two->dirty_submodule = dirty_submodule;
4584        }
4585
4586        diff_queue(&diff_queued_diff, one, two);
4587        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4588                DIFF_OPT_SET(options, HAS_CHANGES);
4589}
4590
4591void diff_change(struct diff_options *options,
4592                 unsigned old_mode, unsigned new_mode,
4593                 const unsigned char *old_sha1,
4594                 const unsigned char *new_sha1,
4595                 const char *concatpath,
4596                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4597{
4598        struct diff_filespec *one, *two;
4599
4600        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4601            is_submodule_ignored(concatpath, options))
4602                return;
4603
4604        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4605                unsigned tmp;
4606                const unsigned char *tmp_c;
4607                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4608                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4609                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4610                        new_dirty_submodule = tmp;
4611        }
4612
4613        if (options->prefix &&
4614            strncmp(concatpath, options->prefix, options->prefix_length))
4615                return;
4616
4617        one = alloc_filespec(concatpath);
4618        two = alloc_filespec(concatpath);
4619        fill_filespec(one, old_sha1, old_mode);
4620        fill_filespec(two, new_sha1, new_mode);
4621        one->dirty_submodule = old_dirty_submodule;
4622        two->dirty_submodule = new_dirty_submodule;
4623
4624        diff_queue(&diff_queued_diff, one, two);
4625        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4626                DIFF_OPT_SET(options, HAS_CHANGES);
4627}
4628
4629struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4630{
4631        struct diff_filepair *pair;
4632        struct diff_filespec *one, *two;
4633
4634        if (options->prefix &&
4635            strncmp(path, options->prefix, options->prefix_length))
4636                return NULL;
4637
4638        one = alloc_filespec(path);
4639        two = alloc_filespec(path);
4640        pair = diff_queue(&diff_queued_diff, one, two);
4641        pair->is_unmerged = 1;
4642        return pair;
4643}
4644
4645static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4646                size_t *outsize)
4647{
4648        struct diff_tempfile *temp;
4649        const char *argv[3];
4650        const char **arg = argv;
4651        struct child_process child;
4652        struct strbuf buf = STRBUF_INIT;
4653        int err = 0;
4654
4655        temp = prepare_temp_file(spec->path, spec);
4656        *arg++ = pgm;
4657        *arg++ = temp->name;
4658        *arg = NULL;
4659
4660        memset(&child, 0, sizeof(child));
4661        child.use_shell = 1;
4662        child.argv = argv;
4663        child.out = -1;
4664        if (start_command(&child)) {
4665                remove_tempfile();
4666                return NULL;
4667        }
4668
4669        if (strbuf_read(&buf, child.out, 0) < 0)
4670                err = error("error reading from textconv command '%s'", pgm);
4671        close(child.out);
4672
4673        if (finish_command(&child) || err) {
4674                strbuf_release(&buf);
4675                remove_tempfile();
4676                return NULL;
4677        }
4678        remove_tempfile();
4679
4680        return strbuf_detach(&buf, outsize);
4681}
4682
4683size_t fill_textconv(struct userdiff_driver *driver,
4684                     struct diff_filespec *df,
4685                     char **outbuf)
4686{
4687        size_t size;
4688
4689        if (!driver || !driver->textconv) {
4690                if (!DIFF_FILE_VALID(df)) {
4691                        *outbuf = "";
4692                        return 0;
4693                }
4694                if (diff_populate_filespec(df, 0))
4695                        die("unable to read files to diff");
4696                *outbuf = df->data;
4697                return df->size;
4698        }
4699
4700        if (driver->textconv_cache && df->sha1_valid) {
4701                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4702                                          &size);
4703                if (*outbuf)
4704                        return size;
4705        }
4706
4707        *outbuf = run_textconv(driver->textconv, df, &size);
4708        if (!*outbuf)
4709                die("unable to read files to diff");
4710
4711        if (driver->textconv_cache && df->sha1_valid) {
4712                /* ignore errors, as we might be in a readonly repository */
4713                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4714                                size);
4715                /*
4716                 * we could save up changes and flush them all at the end,
4717                 * but we would need an extra call after all diffing is done.
4718                 * Since generating a cache entry is the slow path anyway,
4719                 * this extra overhead probably isn't a big deal.
4720                 */
4721                notes_cache_write(driver->textconv_cache);
4722        }
4723
4724        return size;
4725}