diff.con commit Merge branch 'jc/maint-commit-ignore-i-t-a' (44a1020)
   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        /*
1280         * make sure that at least one '-' is printed if there were deletions,
1281         * and likewise for '+'.
1282         */
1283        if (max_change < 2)
1284                return it;
1285        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1286}
1287
1288static void show_name(FILE *file,
1289                      const char *prefix, const char *name, int len)
1290{
1291        fprintf(file, " %s%-*s |", prefix, len, name);
1292}
1293
1294static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1295{
1296        if (cnt <= 0)
1297                return;
1298        fprintf(file, "%s", set);
1299        while (cnt--)
1300                putc(ch, file);
1301        fprintf(file, "%s", reset);
1302}
1303
1304static void fill_print_name(struct diffstat_file *file)
1305{
1306        char *pname;
1307
1308        if (file->print_name)
1309                return;
1310
1311        if (!file->is_renamed) {
1312                struct strbuf buf = STRBUF_INIT;
1313                if (quote_c_style(file->name, &buf, NULL, 0)) {
1314                        pname = strbuf_detach(&buf, NULL);
1315                } else {
1316                        pname = file->name;
1317                        strbuf_release(&buf);
1318                }
1319        } else {
1320                pname = pprint_rename(file->from_name, file->name);
1321        }
1322        file->print_name = pname;
1323}
1324
1325static void show_stats(struct diffstat_t *data, struct diff_options *options)
1326{
1327        int i, len, add, del, adds = 0, dels = 0;
1328        uintmax_t max_change = 0, max_len = 0;
1329        int total_files = data->nr;
1330        int width, name_width, count;
1331        const char *reset, *add_c, *del_c;
1332        const char *line_prefix = "";
1333        int extra_shown = 0;
1334        struct strbuf *msg = NULL;
1335
1336        if (data->nr == 0)
1337                return;
1338
1339        if (options->output_prefix) {
1340                msg = options->output_prefix(options, options->output_prefix_data);
1341                line_prefix = msg->buf;
1342        }
1343
1344        width = options->stat_width ? options->stat_width : 80;
1345        name_width = options->stat_name_width ? options->stat_name_width : 50;
1346        count = options->stat_count ? options->stat_count : data->nr;
1347
1348        /* Sanity: give at least 5 columns to the graph,
1349         * but leave at least 10 columns for the name.
1350         */
1351        if (width < 25)
1352                width = 25;
1353        if (name_width < 10)
1354                name_width = 10;
1355        else if (width < name_width + 15)
1356                name_width = width - 15;
1357
1358        /* Find the longest filename and max number of changes */
1359        reset = diff_get_color_opt(options, DIFF_RESET);
1360        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1361        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1362
1363        for (i = 0; (i < count) && (i < data->nr); i++) {
1364                struct diffstat_file *file = data->files[i];
1365                uintmax_t change = file->added + file->deleted;
1366                if (!data->files[i]->is_renamed &&
1367                         (change == 0)) {
1368                        count++; /* not shown == room for one more */
1369                        continue;
1370                }
1371                fill_print_name(file);
1372                len = strlen(file->print_name);
1373                if (max_len < len)
1374                        max_len = len;
1375
1376                if (file->is_binary || file->is_unmerged)
1377                        continue;
1378                if (max_change < change)
1379                        max_change = change;
1380        }
1381        count = i; /* min(count, data->nr) */
1382
1383        /* Compute the width of the graph part;
1384         * 10 is for one blank at the beginning of the line plus
1385         * " | count " between the name and the graph.
1386         *
1387         * From here on, name_width is the width of the name area,
1388         * and width is the width of the graph area.
1389         */
1390        name_width = (name_width < max_len) ? name_width : max_len;
1391        if (width < (name_width + 10) + max_change)
1392                width = width - (name_width + 10);
1393        else
1394                width = max_change;
1395
1396        for (i = 0; i < count; i++) {
1397                const char *prefix = "";
1398                char *name = data->files[i]->print_name;
1399                uintmax_t added = data->files[i]->added;
1400                uintmax_t deleted = data->files[i]->deleted;
1401                int name_len;
1402
1403                if (!data->files[i]->is_renamed &&
1404                         (added + deleted == 0)) {
1405                        total_files--;
1406                        continue;
1407                }
1408                /*
1409                 * "scale" the filename
1410                 */
1411                len = name_width;
1412                name_len = strlen(name);
1413                if (name_width < name_len) {
1414                        char *slash;
1415                        prefix = "...";
1416                        len -= 3;
1417                        name += name_len - len;
1418                        slash = strchr(name, '/');
1419                        if (slash)
1420                                name = slash;
1421                }
1422
1423                if (data->files[i]->is_binary) {
1424                        fprintf(options->file, "%s", line_prefix);
1425                        show_name(options->file, prefix, name, len);
1426                        fprintf(options->file, "  Bin ");
1427                        fprintf(options->file, "%s%"PRIuMAX"%s",
1428                                del_c, deleted, reset);
1429                        fprintf(options->file, " -> ");
1430                        fprintf(options->file, "%s%"PRIuMAX"%s",
1431                                add_c, added, reset);
1432                        fprintf(options->file, " bytes");
1433                        fprintf(options->file, "\n");
1434                        continue;
1435                }
1436                else if (data->files[i]->is_unmerged) {
1437                        fprintf(options->file, "%s", line_prefix);
1438                        show_name(options->file, prefix, name, len);
1439                        fprintf(options->file, "  Unmerged\n");
1440                        continue;
1441                }
1442
1443                /*
1444                 * scale the add/delete
1445                 */
1446                add = added;
1447                del = deleted;
1448                adds += add;
1449                dels += del;
1450
1451                if (width <= max_change) {
1452                        add = scale_linear(add, width, max_change);
1453                        del = scale_linear(del, width, max_change);
1454                }
1455                fprintf(options->file, "%s", line_prefix);
1456                show_name(options->file, prefix, name, len);
1457                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1458                                added + deleted ? " " : "");
1459                show_graph(options->file, '+', add, add_c, reset);
1460                show_graph(options->file, '-', del, del_c, reset);
1461                fprintf(options->file, "\n");
1462        }
1463        for (i = count; i < data->nr; i++) {
1464                uintmax_t added = data->files[i]->added;
1465                uintmax_t deleted = data->files[i]->deleted;
1466                if (!data->files[i]->is_renamed &&
1467                         (added + deleted == 0)) {
1468                        total_files--;
1469                        continue;
1470                }
1471                adds += added;
1472                dels += deleted;
1473                if (!extra_shown)
1474                        fprintf(options->file, "%s ...\n", line_prefix);
1475                extra_shown = 1;
1476        }
1477        fprintf(options->file, "%s", line_prefix);
1478        fprintf(options->file,
1479               " %d files changed, %d insertions(+), %d deletions(-)\n",
1480               total_files, adds, dels);
1481}
1482
1483static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1484{
1485        int i, adds = 0, dels = 0, total_files = data->nr;
1486
1487        if (data->nr == 0)
1488                return;
1489
1490        for (i = 0; i < data->nr; i++) {
1491                if (!data->files[i]->is_binary &&
1492                    !data->files[i]->is_unmerged) {
1493                        int added = data->files[i]->added;
1494                        int deleted= data->files[i]->deleted;
1495                        if (!data->files[i]->is_renamed &&
1496                            (added + deleted == 0)) {
1497                                total_files--;
1498                        } else {
1499                                adds += added;
1500                                dels += deleted;
1501                        }
1502                }
1503        }
1504        if (options->output_prefix) {
1505                struct strbuf *msg = NULL;
1506                msg = options->output_prefix(options,
1507                                options->output_prefix_data);
1508                fprintf(options->file, "%s", msg->buf);
1509        }
1510        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1511               total_files, adds, dels);
1512}
1513
1514static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1515{
1516        int i;
1517
1518        if (data->nr == 0)
1519                return;
1520
1521        for (i = 0; i < data->nr; i++) {
1522                struct diffstat_file *file = data->files[i];
1523
1524                if (options->output_prefix) {
1525                        struct strbuf *msg = NULL;
1526                        msg = options->output_prefix(options,
1527                                        options->output_prefix_data);
1528                        fprintf(options->file, "%s", msg->buf);
1529                }
1530
1531                if (file->is_binary)
1532                        fprintf(options->file, "-\t-\t");
1533                else
1534                        fprintf(options->file,
1535                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1536                                file->added, file->deleted);
1537                if (options->line_termination) {
1538                        fill_print_name(file);
1539                        if (!file->is_renamed)
1540                                write_name_quoted(file->name, options->file,
1541                                                  options->line_termination);
1542                        else {
1543                                fputs(file->print_name, options->file);
1544                                putc(options->line_termination, options->file);
1545                        }
1546                } else {
1547                        if (file->is_renamed) {
1548                                putc('\0', options->file);
1549                                write_name_quoted(file->from_name, options->file, '\0');
1550                        }
1551                        write_name_quoted(file->name, options->file, '\0');
1552                }
1553        }
1554}
1555
1556struct dirstat_file {
1557        const char *name;
1558        unsigned long changed;
1559};
1560
1561struct dirstat_dir {
1562        struct dirstat_file *files;
1563        int alloc, nr, permille, cumulative;
1564};
1565
1566static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1567                unsigned long changed, const char *base, int baselen)
1568{
1569        unsigned long this_dir = 0;
1570        unsigned int sources = 0;
1571        const char *line_prefix = "";
1572        struct strbuf *msg = NULL;
1573
1574        if (opt->output_prefix) {
1575                msg = opt->output_prefix(opt, opt->output_prefix_data);
1576                line_prefix = msg->buf;
1577        }
1578
1579        while (dir->nr) {
1580                struct dirstat_file *f = dir->files;
1581                int namelen = strlen(f->name);
1582                unsigned long this;
1583                char *slash;
1584
1585                if (namelen < baselen)
1586                        break;
1587                if (memcmp(f->name, base, baselen))
1588                        break;
1589                slash = strchr(f->name + baselen, '/');
1590                if (slash) {
1591                        int newbaselen = slash + 1 - f->name;
1592                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1593                        sources++;
1594                } else {
1595                        this = f->changed;
1596                        dir->files++;
1597                        dir->nr--;
1598                        sources += 2;
1599                }
1600                this_dir += this;
1601        }
1602
1603        /*
1604         * We don't report dirstat's for
1605         *  - the top level
1606         *  - or cases where everything came from a single directory
1607         *    under this directory (sources == 1).
1608         */
1609        if (baselen && sources != 1) {
1610                if (this_dir) {
1611                        int permille = this_dir * 1000 / changed;
1612                        if (permille >= dir->permille) {
1613                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1614                                        permille / 10, permille % 10, baselen, base);
1615                                if (!dir->cumulative)
1616                                        return 0;
1617                        }
1618                }
1619        }
1620        return this_dir;
1621}
1622
1623static int dirstat_compare(const void *_a, const void *_b)
1624{
1625        const struct dirstat_file *a = _a;
1626        const struct dirstat_file *b = _b;
1627        return strcmp(a->name, b->name);
1628}
1629
1630static void show_dirstat(struct diff_options *options)
1631{
1632        int i;
1633        unsigned long changed;
1634        struct dirstat_dir dir;
1635        struct diff_queue_struct *q = &diff_queued_diff;
1636
1637        dir.files = NULL;
1638        dir.alloc = 0;
1639        dir.nr = 0;
1640        dir.permille = options->dirstat_permille;
1641        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1642
1643        changed = 0;
1644        for (i = 0; i < q->nr; i++) {
1645                struct diff_filepair *p = q->queue[i];
1646                const char *name;
1647                unsigned long copied, added, damage;
1648                int content_changed;
1649
1650                name = p->two->path ? p->two->path : p->one->path;
1651
1652                if (p->one->sha1_valid && p->two->sha1_valid)
1653                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1654                else
1655                        content_changed = 1;
1656
1657                if (!content_changed) {
1658                        /*
1659                         * The SHA1 has not changed, so pre-/post-content is
1660                         * identical. We can therefore skip looking at the
1661                         * file contents altogether.
1662                         */
1663                        damage = 0;
1664                        goto found_damage;
1665                }
1666
1667                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1668                        /*
1669                         * In --dirstat-by-file mode, we don't really need to
1670                         * look at the actual file contents at all.
1671                         * The fact that the SHA1 changed is enough for us to
1672                         * add this file to the list of results
1673                         * (with each file contributing equal damage).
1674                         */
1675                        damage = 1;
1676                        goto found_damage;
1677                }
1678
1679                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1680                        diff_populate_filespec(p->one, 0);
1681                        diff_populate_filespec(p->two, 0);
1682                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1683                                               &copied, &added);
1684                        diff_free_filespec_data(p->one);
1685                        diff_free_filespec_data(p->two);
1686                } else if (DIFF_FILE_VALID(p->one)) {
1687                        diff_populate_filespec(p->one, 1);
1688                        copied = added = 0;
1689                        diff_free_filespec_data(p->one);
1690                } else if (DIFF_FILE_VALID(p->two)) {
1691                        diff_populate_filespec(p->two, 1);
1692                        copied = 0;
1693                        added = p->two->size;
1694                        diff_free_filespec_data(p->two);
1695                } else
1696                        continue;
1697
1698                /*
1699                 * Original minus copied is the removed material,
1700                 * added is the new material.  They are both damages
1701                 * made to the preimage.
1702                 * If the resulting damage is zero, we know that
1703                 * diffcore_count_changes() considers the two entries to
1704                 * be identical, but since content_changed is true, we
1705                 * know that there must have been _some_ kind of change,
1706                 * so we force all entries to have damage > 0.
1707                 */
1708                damage = (p->one->size - copied) + added;
1709                if (!damage)
1710                        damage = 1;
1711
1712found_damage:
1713                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1714                dir.files[dir.nr].name = name;
1715                dir.files[dir.nr].changed = damage;
1716                changed += damage;
1717                dir.nr++;
1718        }
1719
1720        /* This can happen even with many files, if everything was renames */
1721        if (!changed)
1722                return;
1723
1724        /* Show all directories with more than x% of the changes */
1725        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1726        gather_dirstat(options, &dir, changed, "", 0);
1727}
1728
1729static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1730{
1731        int i;
1732        unsigned long changed;
1733        struct dirstat_dir dir;
1734
1735        if (data->nr == 0)
1736                return;
1737
1738        dir.files = NULL;
1739        dir.alloc = 0;
1740        dir.nr = 0;
1741        dir.permille = options->dirstat_permille;
1742        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1743
1744        changed = 0;
1745        for (i = 0; i < data->nr; i++) {
1746                struct diffstat_file *file = data->files[i];
1747                unsigned long damage = file->added + file->deleted;
1748                if (file->is_binary)
1749                        /*
1750                         * binary files counts bytes, not lines. Must find some
1751                         * way to normalize binary bytes vs. textual lines.
1752                         * The following heuristic assumes that there are 64
1753                         * bytes per "line".
1754                         * This is stupid and ugly, but very cheap...
1755                         */
1756                        damage = (damage + 63) / 64;
1757                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1758                dir.files[dir.nr].name = file->name;
1759                dir.files[dir.nr].changed = damage;
1760                changed += damage;
1761                dir.nr++;
1762        }
1763
1764        /* This can happen even with many files, if everything was renames */
1765        if (!changed)
1766                return;
1767
1768        /* Show all directories with more than x% of the changes */
1769        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1770        gather_dirstat(options, &dir, changed, "", 0);
1771}
1772
1773static void free_diffstat_info(struct diffstat_t *diffstat)
1774{
1775        int i;
1776        for (i = 0; i < diffstat->nr; i++) {
1777                struct diffstat_file *f = diffstat->files[i];
1778                if (f->name != f->print_name)
1779                        free(f->print_name);
1780                free(f->name);
1781                free(f->from_name);
1782                free(f);
1783        }
1784        free(diffstat->files);
1785}
1786
1787struct checkdiff_t {
1788        const char *filename;
1789        int lineno;
1790        int conflict_marker_size;
1791        struct diff_options *o;
1792        unsigned ws_rule;
1793        unsigned status;
1794};
1795
1796static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1797{
1798        char firstchar;
1799        int cnt;
1800
1801        if (len < marker_size + 1)
1802                return 0;
1803        firstchar = line[0];
1804        switch (firstchar) {
1805        case '=': case '>': case '<': case '|':
1806                break;
1807        default:
1808                return 0;
1809        }
1810        for (cnt = 1; cnt < marker_size; cnt++)
1811                if (line[cnt] != firstchar)
1812                        return 0;
1813        /* line[1] thru line[marker_size-1] are same as firstchar */
1814        if (len < marker_size + 1 || !isspace(line[marker_size]))
1815                return 0;
1816        return 1;
1817}
1818
1819static void checkdiff_consume(void *priv, char *line, unsigned long len)
1820{
1821        struct checkdiff_t *data = priv;
1822        int marker_size = data->conflict_marker_size;
1823        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1824        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1825        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1826        char *err;
1827        char *line_prefix = "";
1828        struct strbuf *msgbuf;
1829
1830        assert(data->o);
1831        if (data->o->output_prefix) {
1832                msgbuf = data->o->output_prefix(data->o,
1833                        data->o->output_prefix_data);
1834                line_prefix = msgbuf->buf;
1835        }
1836
1837        if (line[0] == '+') {
1838                unsigned bad;
1839                data->lineno++;
1840                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1841                        data->status |= 1;
1842                        fprintf(data->o->file,
1843                                "%s%s:%d: leftover conflict marker\n",
1844                                line_prefix, data->filename, data->lineno);
1845                }
1846                bad = ws_check(line + 1, len - 1, data->ws_rule);
1847                if (!bad)
1848                        return;
1849                data->status |= bad;
1850                err = whitespace_error_string(bad);
1851                fprintf(data->o->file, "%s%s:%d: %s.\n",
1852                        line_prefix, data->filename, data->lineno, err);
1853                free(err);
1854                emit_line(data->o, set, reset, line, 1);
1855                ws_check_emit(line + 1, len - 1, data->ws_rule,
1856                              data->o->file, set, reset, ws);
1857        } else if (line[0] == ' ') {
1858                data->lineno++;
1859        } else if (line[0] == '@') {
1860                char *plus = strchr(line, '+');
1861                if (plus)
1862                        data->lineno = strtol(plus, NULL, 10) - 1;
1863                else
1864                        die("invalid diff");
1865        }
1866}
1867
1868static unsigned char *deflate_it(char *data,
1869                                 unsigned long size,
1870                                 unsigned long *result_size)
1871{
1872        int bound;
1873        unsigned char *deflated;
1874        git_zstream stream;
1875
1876        memset(&stream, 0, sizeof(stream));
1877        git_deflate_init(&stream, zlib_compression_level);
1878        bound = git_deflate_bound(&stream, size);
1879        deflated = xmalloc(bound);
1880        stream.next_out = deflated;
1881        stream.avail_out = bound;
1882
1883        stream.next_in = (unsigned char *)data;
1884        stream.avail_in = size;
1885        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1886                ; /* nothing */
1887        git_deflate_end(&stream);
1888        *result_size = stream.total_out;
1889        return deflated;
1890}
1891
1892static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1893{
1894        void *cp;
1895        void *delta;
1896        void *deflated;
1897        void *data;
1898        unsigned long orig_size;
1899        unsigned long delta_size;
1900        unsigned long deflate_size;
1901        unsigned long data_size;
1902
1903        /* We could do deflated delta, or we could do just deflated two,
1904         * whichever is smaller.
1905         */
1906        delta = NULL;
1907        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1908        if (one->size && two->size) {
1909                delta = diff_delta(one->ptr, one->size,
1910                                   two->ptr, two->size,
1911                                   &delta_size, deflate_size);
1912                if (delta) {
1913                        void *to_free = delta;
1914                        orig_size = delta_size;
1915                        delta = deflate_it(delta, delta_size, &delta_size);
1916                        free(to_free);
1917                }
1918        }
1919
1920        if (delta && delta_size < deflate_size) {
1921                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1922                free(deflated);
1923                data = delta;
1924                data_size = delta_size;
1925        }
1926        else {
1927                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1928                free(delta);
1929                data = deflated;
1930                data_size = deflate_size;
1931        }
1932
1933        /* emit data encoded in base85 */
1934        cp = data;
1935        while (data_size) {
1936                int bytes = (52 < data_size) ? 52 : data_size;
1937                char line[70];
1938                data_size -= bytes;
1939                if (bytes <= 26)
1940                        line[0] = bytes + 'A' - 1;
1941                else
1942                        line[0] = bytes - 26 + 'a' - 1;
1943                encode_85(line + 1, cp, bytes);
1944                cp = (char *) cp + bytes;
1945                fprintf(file, "%s", prefix);
1946                fputs(line, file);
1947                fputc('\n', file);
1948        }
1949        fprintf(file, "%s\n", prefix);
1950        free(data);
1951}
1952
1953static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1954{
1955        fprintf(file, "%sGIT binary patch\n", prefix);
1956        emit_binary_diff_body(file, one, two, prefix);
1957        emit_binary_diff_body(file, two, one, prefix);
1958}
1959
1960static void diff_filespec_load_driver(struct diff_filespec *one)
1961{
1962        /* Use already-loaded driver */
1963        if (one->driver)
1964                return;
1965
1966        if (S_ISREG(one->mode))
1967                one->driver = userdiff_find_by_path(one->path);
1968
1969        /* Fallback to default settings */
1970        if (!one->driver)
1971                one->driver = userdiff_find_by_name("default");
1972}
1973
1974int diff_filespec_is_binary(struct diff_filespec *one)
1975{
1976        if (one->is_binary == -1) {
1977                diff_filespec_load_driver(one);
1978                if (one->driver->binary != -1)
1979                        one->is_binary = one->driver->binary;
1980                else {
1981                        if (!one->data && DIFF_FILE_VALID(one))
1982                                diff_populate_filespec(one, 0);
1983                        if (one->data)
1984                                one->is_binary = buffer_is_binary(one->data,
1985                                                one->size);
1986                        if (one->is_binary == -1)
1987                                one->is_binary = 0;
1988                }
1989        }
1990        return one->is_binary;
1991}
1992
1993static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1994{
1995        diff_filespec_load_driver(one);
1996        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1997}
1998
1999static const char *userdiff_word_regex(struct diff_filespec *one)
2000{
2001        diff_filespec_load_driver(one);
2002        return one->driver->word_regex;
2003}
2004
2005void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2006{
2007        if (!options->a_prefix)
2008                options->a_prefix = a;
2009        if (!options->b_prefix)
2010                options->b_prefix = b;
2011}
2012
2013struct userdiff_driver *get_textconv(struct diff_filespec *one)
2014{
2015        if (!DIFF_FILE_VALID(one))
2016                return NULL;
2017
2018        diff_filespec_load_driver(one);
2019        return userdiff_get_textconv(one->driver);
2020}
2021
2022static void builtin_diff(const char *name_a,
2023                         const char *name_b,
2024                         struct diff_filespec *one,
2025                         struct diff_filespec *two,
2026                         const char *xfrm_msg,
2027                         int must_show_header,
2028                         struct diff_options *o,
2029                         int complete_rewrite)
2030{
2031        mmfile_t mf1, mf2;
2032        const char *lbl[2];
2033        char *a_one, *b_two;
2034        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2035        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2036        const char *a_prefix, *b_prefix;
2037        struct userdiff_driver *textconv_one = NULL;
2038        struct userdiff_driver *textconv_two = NULL;
2039        struct strbuf header = STRBUF_INIT;
2040        struct strbuf *msgbuf;
2041        char *line_prefix = "";
2042
2043        if (o->output_prefix) {
2044                msgbuf = o->output_prefix(o, o->output_prefix_data);
2045                line_prefix = msgbuf->buf;
2046        }
2047
2048        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2049                        (!one->mode || S_ISGITLINK(one->mode)) &&
2050                        (!two->mode || S_ISGITLINK(two->mode))) {
2051                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2052                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2053                show_submodule_summary(o->file, one ? one->path : two->path,
2054                                one->sha1, two->sha1, two->dirty_submodule,
2055                                del, add, reset);
2056                return;
2057        }
2058
2059        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2060                textconv_one = get_textconv(one);
2061                textconv_two = get_textconv(two);
2062        }
2063
2064        diff_set_mnemonic_prefix(o, "a/", "b/");
2065        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2066                a_prefix = o->b_prefix;
2067                b_prefix = o->a_prefix;
2068        } else {
2069                a_prefix = o->a_prefix;
2070                b_prefix = o->b_prefix;
2071        }
2072
2073        /* Never use a non-valid filename anywhere if at all possible */
2074        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2075        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2076
2077        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2078        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2079        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2080        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2081        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2082        if (lbl[0][0] == '/') {
2083                /* /dev/null */
2084                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2085                if (xfrm_msg)
2086                        strbuf_addstr(&header, xfrm_msg);
2087                must_show_header = 1;
2088        }
2089        else if (lbl[1][0] == '/') {
2090                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2091                if (xfrm_msg)
2092                        strbuf_addstr(&header, xfrm_msg);
2093                must_show_header = 1;
2094        }
2095        else {
2096                if (one->mode != two->mode) {
2097                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2098                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2099                        must_show_header = 1;
2100                }
2101                if (xfrm_msg)
2102                        strbuf_addstr(&header, xfrm_msg);
2103
2104                /*
2105                 * we do not run diff between different kind
2106                 * of objects.
2107                 */
2108                if ((one->mode ^ two->mode) & S_IFMT)
2109                        goto free_ab_and_return;
2110                if (complete_rewrite &&
2111                    (textconv_one || !diff_filespec_is_binary(one)) &&
2112                    (textconv_two || !diff_filespec_is_binary(two))) {
2113                        fprintf(o->file, "%s", header.buf);
2114                        strbuf_reset(&header);
2115                        emit_rewrite_diff(name_a, name_b, one, two,
2116                                                textconv_one, textconv_two, o);
2117                        o->found_changes = 1;
2118                        goto free_ab_and_return;
2119                }
2120        }
2121
2122        if (o->irreversible_delete && lbl[1][0] == '/') {
2123                fprintf(o->file, "%s", header.buf);
2124                strbuf_reset(&header);
2125                goto free_ab_and_return;
2126        } else if (!DIFF_OPT_TST(o, TEXT) &&
2127            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2128              (!textconv_two && diff_filespec_is_binary(two)) )) {
2129                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2130                        die("unable to read files to diff");
2131                /* Quite common confusing case */
2132                if (mf1.size == mf2.size &&
2133                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2134                        if (must_show_header)
2135                                fprintf(o->file, "%s", header.buf);
2136                        goto free_ab_and_return;
2137                }
2138                fprintf(o->file, "%s", header.buf);
2139                strbuf_reset(&header);
2140                if (DIFF_OPT_TST(o, BINARY))
2141                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2142                else
2143                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2144                                line_prefix, lbl[0], lbl[1]);
2145                o->found_changes = 1;
2146        } else {
2147                /* Crazy xdl interfaces.. */
2148                const char *diffopts = getenv("GIT_DIFF_OPTS");
2149                xpparam_t xpp;
2150                xdemitconf_t xecfg;
2151                struct emit_callback ecbdata;
2152                const struct userdiff_funcname *pe;
2153
2154                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2155                        fprintf(o->file, "%s", header.buf);
2156                        strbuf_reset(&header);
2157                }
2158
2159                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2160                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2161
2162                pe = diff_funcname_pattern(one);
2163                if (!pe)
2164                        pe = diff_funcname_pattern(two);
2165
2166                memset(&xpp, 0, sizeof(xpp));
2167                memset(&xecfg, 0, sizeof(xecfg));
2168                memset(&ecbdata, 0, sizeof(ecbdata));
2169                ecbdata.label_path = lbl;
2170                ecbdata.color_diff = want_color(o->use_color);
2171                ecbdata.found_changesp = &o->found_changes;
2172                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2173                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2174                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2175                ecbdata.opt = o;
2176                ecbdata.header = header.len ? &header : NULL;
2177                xpp.flags = o->xdl_opts;
2178                xecfg.ctxlen = o->context;
2179                xecfg.interhunkctxlen = o->interhunkcontext;
2180                xecfg.flags = XDL_EMIT_FUNCNAMES;
2181                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2182                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2183                if (pe)
2184                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2185                if (!diffopts)
2186                        ;
2187                else if (!prefixcmp(diffopts, "--unified="))
2188                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2189                else if (!prefixcmp(diffopts, "-u"))
2190                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2191                if (o->word_diff) {
2192                        int i;
2193
2194                        ecbdata.diff_words =
2195                                xcalloc(1, sizeof(struct diff_words_data));
2196                        ecbdata.diff_words->type = o->word_diff;
2197                        ecbdata.diff_words->opt = o;
2198                        if (!o->word_regex)
2199                                o->word_regex = userdiff_word_regex(one);
2200                        if (!o->word_regex)
2201                                o->word_regex = userdiff_word_regex(two);
2202                        if (!o->word_regex)
2203                                o->word_regex = diff_word_regex_cfg;
2204                        if (o->word_regex) {
2205                                ecbdata.diff_words->word_regex = (regex_t *)
2206                                        xmalloc(sizeof(regex_t));
2207                                if (regcomp(ecbdata.diff_words->word_regex,
2208                                                o->word_regex,
2209                                                REG_EXTENDED | REG_NEWLINE))
2210                                        die ("Invalid regular expression: %s",
2211                                                        o->word_regex);
2212                        }
2213                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2214                                if (o->word_diff == diff_words_styles[i].type) {
2215                                        ecbdata.diff_words->style =
2216                                                &diff_words_styles[i];
2217                                        break;
2218                                }
2219                        }
2220                        if (want_color(o->use_color)) {
2221                                struct diff_words_style *st = ecbdata.diff_words->style;
2222                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2223                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2224                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2225                        }
2226                }
2227                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2228                              &xpp, &xecfg);
2229                if (o->word_diff)
2230                        free_diff_words_data(&ecbdata);
2231                if (textconv_one)
2232                        free(mf1.ptr);
2233                if (textconv_two)
2234                        free(mf2.ptr);
2235                xdiff_clear_find_func(&xecfg);
2236        }
2237
2238 free_ab_and_return:
2239        strbuf_release(&header);
2240        diff_free_filespec_data(one);
2241        diff_free_filespec_data(two);
2242        free(a_one);
2243        free(b_two);
2244        return;
2245}
2246
2247static void builtin_diffstat(const char *name_a, const char *name_b,
2248                             struct diff_filespec *one,
2249                             struct diff_filespec *two,
2250                             struct diffstat_t *diffstat,
2251                             struct diff_options *o,
2252                             int complete_rewrite)
2253{
2254        mmfile_t mf1, mf2;
2255        struct diffstat_file *data;
2256
2257        data = diffstat_add(diffstat, name_a, name_b);
2258
2259        if (!one || !two) {
2260                data->is_unmerged = 1;
2261                return;
2262        }
2263
2264        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2265                data->is_binary = 1;
2266                data->added = diff_filespec_size(two);
2267                data->deleted = diff_filespec_size(one);
2268        }
2269
2270        else if (complete_rewrite) {
2271                diff_populate_filespec(one, 0);
2272                diff_populate_filespec(two, 0);
2273                data->deleted = count_lines(one->data, one->size);
2274                data->added = count_lines(two->data, two->size);
2275        }
2276
2277        else {
2278                /* Crazy xdl interfaces.. */
2279                xpparam_t xpp;
2280                xdemitconf_t xecfg;
2281
2282                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2283                        die("unable to read files to diff");
2284
2285                memset(&xpp, 0, sizeof(xpp));
2286                memset(&xecfg, 0, sizeof(xecfg));
2287                xpp.flags = o->xdl_opts;
2288                xecfg.ctxlen = o->context;
2289                xecfg.interhunkctxlen = o->interhunkcontext;
2290                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2291                              &xpp, &xecfg);
2292        }
2293
2294        diff_free_filespec_data(one);
2295        diff_free_filespec_data(two);
2296}
2297
2298static void builtin_checkdiff(const char *name_a, const char *name_b,
2299                              const char *attr_path,
2300                              struct diff_filespec *one,
2301                              struct diff_filespec *two,
2302                              struct diff_options *o)
2303{
2304        mmfile_t mf1, mf2;
2305        struct checkdiff_t data;
2306
2307        if (!two)
2308                return;
2309
2310        memset(&data, 0, sizeof(data));
2311        data.filename = name_b ? name_b : name_a;
2312        data.lineno = 0;
2313        data.o = o;
2314        data.ws_rule = whitespace_rule(attr_path);
2315        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2316
2317        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2318                die("unable to read files to diff");
2319
2320        /*
2321         * All the other codepaths check both sides, but not checking
2322         * the "old" side here is deliberate.  We are checking the newly
2323         * introduced changes, and as long as the "new" side is text, we
2324         * can and should check what it introduces.
2325         */
2326        if (diff_filespec_is_binary(two))
2327                goto free_and_return;
2328        else {
2329                /* Crazy xdl interfaces.. */
2330                xpparam_t xpp;
2331                xdemitconf_t xecfg;
2332
2333                memset(&xpp, 0, sizeof(xpp));
2334                memset(&xecfg, 0, sizeof(xecfg));
2335                xecfg.ctxlen = 1; /* at least one context line */
2336                xpp.flags = 0;
2337                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2338                              &xpp, &xecfg);
2339
2340                if (data.ws_rule & WS_BLANK_AT_EOF) {
2341                        struct emit_callback ecbdata;
2342                        int blank_at_eof;
2343
2344                        ecbdata.ws_rule = data.ws_rule;
2345                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2346                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2347
2348                        if (blank_at_eof) {
2349                                static char *err;
2350                                if (!err)
2351                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2352                                fprintf(o->file, "%s:%d: %s.\n",
2353                                        data.filename, blank_at_eof, err);
2354                                data.status = 1; /* report errors */
2355                        }
2356                }
2357        }
2358 free_and_return:
2359        diff_free_filespec_data(one);
2360        diff_free_filespec_data(two);
2361        if (data.status)
2362                DIFF_OPT_SET(o, CHECK_FAILED);
2363}
2364
2365struct diff_filespec *alloc_filespec(const char *path)
2366{
2367        int namelen = strlen(path);
2368        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2369
2370        memset(spec, 0, sizeof(*spec));
2371        spec->path = (char *)(spec + 1);
2372        memcpy(spec->path, path, namelen+1);
2373        spec->count = 1;
2374        spec->is_binary = -1;
2375        return spec;
2376}
2377
2378void free_filespec(struct diff_filespec *spec)
2379{
2380        if (!--spec->count) {
2381                diff_free_filespec_data(spec);
2382                free(spec);
2383        }
2384}
2385
2386void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2387                   unsigned short mode)
2388{
2389        if (mode) {
2390                spec->mode = canon_mode(mode);
2391                hashcpy(spec->sha1, sha1);
2392                spec->sha1_valid = !is_null_sha1(sha1);
2393        }
2394}
2395
2396/*
2397 * Given a name and sha1 pair, if the index tells us the file in
2398 * the work tree has that object contents, return true, so that
2399 * prepare_temp_file() does not have to inflate and extract.
2400 */
2401static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2402{
2403        struct cache_entry *ce;
2404        struct stat st;
2405        int pos, len;
2406
2407        /*
2408         * We do not read the cache ourselves here, because the
2409         * benchmark with my previous version that always reads cache
2410         * shows that it makes things worse for diff-tree comparing
2411         * two linux-2.6 kernel trees in an already checked out work
2412         * tree.  This is because most diff-tree comparisons deal with
2413         * only a small number of files, while reading the cache is
2414         * expensive for a large project, and its cost outweighs the
2415         * savings we get by not inflating the object to a temporary
2416         * file.  Practically, this code only helps when we are used
2417         * by diff-cache --cached, which does read the cache before
2418         * calling us.
2419         */
2420        if (!active_cache)
2421                return 0;
2422
2423        /* We want to avoid the working directory if our caller
2424         * doesn't need the data in a normal file, this system
2425         * is rather slow with its stat/open/mmap/close syscalls,
2426         * and the object is contained in a pack file.  The pack
2427         * is probably already open and will be faster to obtain
2428         * the data through than the working directory.  Loose
2429         * objects however would tend to be slower as they need
2430         * to be individually opened and inflated.
2431         */
2432        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2433                return 0;
2434
2435        len = strlen(name);
2436        pos = cache_name_pos(name, len);
2437        if (pos < 0)
2438                return 0;
2439        ce = active_cache[pos];
2440
2441        /*
2442         * This is not the sha1 we are looking for, or
2443         * unreusable because it is not a regular file.
2444         */
2445        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2446                return 0;
2447
2448        /*
2449         * If ce is marked as "assume unchanged", there is no
2450         * guarantee that work tree matches what we are looking for.
2451         */
2452        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2453                return 0;
2454
2455        /*
2456         * If ce matches the file in the work tree, we can reuse it.
2457         */
2458        if (ce_uptodate(ce) ||
2459            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2460                return 1;
2461
2462        return 0;
2463}
2464
2465static int populate_from_stdin(struct diff_filespec *s)
2466{
2467        struct strbuf buf = STRBUF_INIT;
2468        size_t size = 0;
2469
2470        if (strbuf_read(&buf, 0, 0) < 0)
2471                return error("error while reading from stdin %s",
2472                                     strerror(errno));
2473
2474        s->should_munmap = 0;
2475        s->data = strbuf_detach(&buf, &size);
2476        s->size = size;
2477        s->should_free = 1;
2478        return 0;
2479}
2480
2481static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2482{
2483        int len;
2484        char *data = xmalloc(100), *dirty = "";
2485
2486        /* Are we looking at the work tree? */
2487        if (s->dirty_submodule)
2488                dirty = "-dirty";
2489
2490        len = snprintf(data, 100,
2491                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2492        s->data = data;
2493        s->size = len;
2494        s->should_free = 1;
2495        if (size_only) {
2496                s->data = NULL;
2497                free(data);
2498        }
2499        return 0;
2500}
2501
2502/*
2503 * While doing rename detection and pickaxe operation, we may need to
2504 * grab the data for the blob (or file) for our own in-core comparison.
2505 * diff_filespec has data and size fields for this purpose.
2506 */
2507int diff_populate_filespec(struct diff_filespec *s, int size_only)
2508{
2509        int err = 0;
2510        if (!DIFF_FILE_VALID(s))
2511                die("internal error: asking to populate invalid file.");
2512        if (S_ISDIR(s->mode))
2513                return -1;
2514
2515        if (s->data)
2516                return 0;
2517
2518        if (size_only && 0 < s->size)
2519                return 0;
2520
2521        if (S_ISGITLINK(s->mode))
2522                return diff_populate_gitlink(s, size_only);
2523
2524        if (!s->sha1_valid ||
2525            reuse_worktree_file(s->path, s->sha1, 0)) {
2526                struct strbuf buf = STRBUF_INIT;
2527                struct stat st;
2528                int fd;
2529
2530                if (!strcmp(s->path, "-"))
2531                        return populate_from_stdin(s);
2532
2533                if (lstat(s->path, &st) < 0) {
2534                        if (errno == ENOENT) {
2535                        err_empty:
2536                                err = -1;
2537                        empty:
2538                                s->data = (char *)"";
2539                                s->size = 0;
2540                                return err;
2541                        }
2542                }
2543                s->size = xsize_t(st.st_size);
2544                if (!s->size)
2545                        goto empty;
2546                if (S_ISLNK(st.st_mode)) {
2547                        struct strbuf sb = STRBUF_INIT;
2548
2549                        if (strbuf_readlink(&sb, s->path, s->size))
2550                                goto err_empty;
2551                        s->size = sb.len;
2552                        s->data = strbuf_detach(&sb, NULL);
2553                        s->should_free = 1;
2554                        return 0;
2555                }
2556                if (size_only)
2557                        return 0;
2558                fd = open(s->path, O_RDONLY);
2559                if (fd < 0)
2560                        goto err_empty;
2561                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2562                close(fd);
2563                s->should_munmap = 1;
2564
2565                /*
2566                 * Convert from working tree format to canonical git format
2567                 */
2568                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2569                        size_t size = 0;
2570                        munmap(s->data, s->size);
2571                        s->should_munmap = 0;
2572                        s->data = strbuf_detach(&buf, &size);
2573                        s->size = size;
2574                        s->should_free = 1;
2575                }
2576        }
2577        else {
2578                enum object_type type;
2579                if (size_only) {
2580                        type = sha1_object_info(s->sha1, &s->size);
2581                        if (type < 0)
2582                                die("unable to read %s", sha1_to_hex(s->sha1));
2583                } else {
2584                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2585                        if (!s->data)
2586                                die("unable to read %s", sha1_to_hex(s->sha1));
2587                        s->should_free = 1;
2588                }
2589        }
2590        return 0;
2591}
2592
2593void diff_free_filespec_blob(struct diff_filespec *s)
2594{
2595        if (s->should_free)
2596                free(s->data);
2597        else if (s->should_munmap)
2598                munmap(s->data, s->size);
2599
2600        if (s->should_free || s->should_munmap) {
2601                s->should_free = s->should_munmap = 0;
2602                s->data = NULL;
2603        }
2604}
2605
2606void diff_free_filespec_data(struct diff_filespec *s)
2607{
2608        diff_free_filespec_blob(s);
2609        free(s->cnt_data);
2610        s->cnt_data = NULL;
2611}
2612
2613static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2614                           void *blob,
2615                           unsigned long size,
2616                           const unsigned char *sha1,
2617                           int mode)
2618{
2619        int fd;
2620        struct strbuf buf = STRBUF_INIT;
2621        struct strbuf template = STRBUF_INIT;
2622        char *path_dup = xstrdup(path);
2623        const char *base = basename(path_dup);
2624
2625        /* Generate "XXXXXX_basename.ext" */
2626        strbuf_addstr(&template, "XXXXXX_");
2627        strbuf_addstr(&template, base);
2628
2629        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2630                        strlen(base) + 1);
2631        if (fd < 0)
2632                die_errno("unable to create temp-file");
2633        if (convert_to_working_tree(path,
2634                        (const char *)blob, (size_t)size, &buf)) {
2635                blob = buf.buf;
2636                size = buf.len;
2637        }
2638        if (write_in_full(fd, blob, size) != size)
2639                die_errno("unable to write temp-file");
2640        close(fd);
2641        temp->name = temp->tmp_path;
2642        strcpy(temp->hex, sha1_to_hex(sha1));
2643        temp->hex[40] = 0;
2644        sprintf(temp->mode, "%06o", mode);
2645        strbuf_release(&buf);
2646        strbuf_release(&template);
2647        free(path_dup);
2648}
2649
2650static struct diff_tempfile *prepare_temp_file(const char *name,
2651                struct diff_filespec *one)
2652{
2653        struct diff_tempfile *temp = claim_diff_tempfile();
2654
2655        if (!DIFF_FILE_VALID(one)) {
2656        not_a_valid_file:
2657                /* A '-' entry produces this for file-2, and
2658                 * a '+' entry produces this for file-1.
2659                 */
2660                temp->name = "/dev/null";
2661                strcpy(temp->hex, ".");
2662                strcpy(temp->mode, ".");
2663                return temp;
2664        }
2665
2666        if (!remove_tempfile_installed) {
2667                atexit(remove_tempfile);
2668                sigchain_push_common(remove_tempfile_on_signal);
2669                remove_tempfile_installed = 1;
2670        }
2671
2672        if (!one->sha1_valid ||
2673            reuse_worktree_file(name, one->sha1, 1)) {
2674                struct stat st;
2675                if (lstat(name, &st) < 0) {
2676                        if (errno == ENOENT)
2677                                goto not_a_valid_file;
2678                        die_errno("stat(%s)", name);
2679                }
2680                if (S_ISLNK(st.st_mode)) {
2681                        struct strbuf sb = STRBUF_INIT;
2682                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2683                                die_errno("readlink(%s)", name);
2684                        prep_temp_blob(name, temp, sb.buf, sb.len,
2685                                       (one->sha1_valid ?
2686                                        one->sha1 : null_sha1),
2687                                       (one->sha1_valid ?
2688                                        one->mode : S_IFLNK));
2689                        strbuf_release(&sb);
2690                }
2691                else {
2692                        /* we can borrow from the file in the work tree */
2693                        temp->name = name;
2694                        if (!one->sha1_valid)
2695                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2696                        else
2697                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2698                        /* Even though we may sometimes borrow the
2699                         * contents from the work tree, we always want
2700                         * one->mode.  mode is trustworthy even when
2701                         * !(one->sha1_valid), as long as
2702                         * DIFF_FILE_VALID(one).
2703                         */
2704                        sprintf(temp->mode, "%06o", one->mode);
2705                }
2706                return temp;
2707        }
2708        else {
2709                if (diff_populate_filespec(one, 0))
2710                        die("cannot read data blob for %s", one->path);
2711                prep_temp_blob(name, temp, one->data, one->size,
2712                               one->sha1, one->mode);
2713        }
2714        return temp;
2715}
2716
2717/* An external diff command takes:
2718 *
2719 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2720 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2721 *
2722 */
2723static void run_external_diff(const char *pgm,
2724                              const char *name,
2725                              const char *other,
2726                              struct diff_filespec *one,
2727                              struct diff_filespec *two,
2728                              const char *xfrm_msg,
2729                              int complete_rewrite)
2730{
2731        const char *spawn_arg[10];
2732        int retval;
2733        const char **arg = &spawn_arg[0];
2734
2735        if (one && two) {
2736                struct diff_tempfile *temp_one, *temp_two;
2737                const char *othername = (other ? other : name);
2738                temp_one = prepare_temp_file(name, one);
2739                temp_two = prepare_temp_file(othername, two);
2740                *arg++ = pgm;
2741                *arg++ = name;
2742                *arg++ = temp_one->name;
2743                *arg++ = temp_one->hex;
2744                *arg++ = temp_one->mode;
2745                *arg++ = temp_two->name;
2746                *arg++ = temp_two->hex;
2747                *arg++ = temp_two->mode;
2748                if (other) {
2749                        *arg++ = other;
2750                        *arg++ = xfrm_msg;
2751                }
2752        } else {
2753                *arg++ = pgm;
2754                *arg++ = name;
2755        }
2756        *arg = NULL;
2757        fflush(NULL);
2758        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2759        remove_tempfile();
2760        if (retval) {
2761                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2762                exit(1);
2763        }
2764}
2765
2766static int similarity_index(struct diff_filepair *p)
2767{
2768        return p->score * 100 / MAX_SCORE;
2769}
2770
2771static void fill_metainfo(struct strbuf *msg,
2772                          const char *name,
2773                          const char *other,
2774                          struct diff_filespec *one,
2775                          struct diff_filespec *two,
2776                          struct diff_options *o,
2777                          struct diff_filepair *p,
2778                          int *must_show_header,
2779                          int use_color)
2780{
2781        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2782        const char *reset = diff_get_color(use_color, DIFF_RESET);
2783        struct strbuf *msgbuf;
2784        char *line_prefix = "";
2785
2786        *must_show_header = 1;
2787        if (o->output_prefix) {
2788                msgbuf = o->output_prefix(o, o->output_prefix_data);
2789                line_prefix = msgbuf->buf;
2790        }
2791        strbuf_init(msg, PATH_MAX * 2 + 300);
2792        switch (p->status) {
2793        case DIFF_STATUS_COPIED:
2794                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2795                            line_prefix, set, similarity_index(p));
2796                strbuf_addf(msg, "%s\n%s%scopy from ",
2797                            reset,  line_prefix, set);
2798                quote_c_style(name, msg, NULL, 0);
2799                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2800                quote_c_style(other, msg, NULL, 0);
2801                strbuf_addf(msg, "%s\n", reset);
2802                break;
2803        case DIFF_STATUS_RENAMED:
2804                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2805                            line_prefix, set, similarity_index(p));
2806                strbuf_addf(msg, "%s\n%s%srename from ",
2807                            reset, line_prefix, set);
2808                quote_c_style(name, msg, NULL, 0);
2809                strbuf_addf(msg, "%s\n%s%srename to ",
2810                            reset, line_prefix, set);
2811                quote_c_style(other, msg, NULL, 0);
2812                strbuf_addf(msg, "%s\n", reset);
2813                break;
2814        case DIFF_STATUS_MODIFIED:
2815                if (p->score) {
2816                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2817                                    line_prefix,
2818                                    set, similarity_index(p), reset);
2819                        break;
2820                }
2821                /* fallthru */
2822        default:
2823                *must_show_header = 0;
2824        }
2825        if (one && two && hashcmp(one->sha1, two->sha1)) {
2826                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2827
2828                if (DIFF_OPT_TST(o, BINARY)) {
2829                        mmfile_t mf;
2830                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2831                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2832                                abbrev = 40;
2833                }
2834                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2835                            find_unique_abbrev(one->sha1, abbrev));
2836                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2837                if (one->mode == two->mode)
2838                        strbuf_addf(msg, " %06o", one->mode);
2839                strbuf_addf(msg, "%s\n", reset);
2840        }
2841}
2842
2843static void run_diff_cmd(const char *pgm,
2844                         const char *name,
2845                         const char *other,
2846                         const char *attr_path,
2847                         struct diff_filespec *one,
2848                         struct diff_filespec *two,
2849                         struct strbuf *msg,
2850                         struct diff_options *o,
2851                         struct diff_filepair *p)
2852{
2853        const char *xfrm_msg = NULL;
2854        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2855        int must_show_header = 0;
2856
2857        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2858                pgm = NULL;
2859        else {
2860                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2861                if (drv && drv->external)
2862                        pgm = drv->external;
2863        }
2864
2865        if (msg) {
2866                /*
2867                 * don't use colors when the header is intended for an
2868                 * external diff driver
2869                 */
2870                fill_metainfo(msg, name, other, one, two, o, p,
2871                              &must_show_header,
2872                              want_color(o->use_color) && !pgm);
2873                xfrm_msg = msg->len ? msg->buf : NULL;
2874        }
2875
2876        if (pgm) {
2877                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2878                                  complete_rewrite);
2879                return;
2880        }
2881        if (one && two)
2882                builtin_diff(name, other ? other : name,
2883                             one, two, xfrm_msg, must_show_header,
2884                             o, complete_rewrite);
2885        else
2886                fprintf(o->file, "* Unmerged path %s\n", name);
2887}
2888
2889static void diff_fill_sha1_info(struct diff_filespec *one)
2890{
2891        if (DIFF_FILE_VALID(one)) {
2892                if (!one->sha1_valid) {
2893                        struct stat st;
2894                        if (!strcmp(one->path, "-")) {
2895                                hashcpy(one->sha1, null_sha1);
2896                                return;
2897                        }
2898                        if (lstat(one->path, &st) < 0)
2899                                die_errno("stat '%s'", one->path);
2900                        if (index_path(one->sha1, one->path, &st, 0))
2901                                die("cannot hash %s", one->path);
2902                }
2903        }
2904        else
2905                hashclr(one->sha1);
2906}
2907
2908static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2909{
2910        /* Strip the prefix but do not molest /dev/null and absolute paths */
2911        if (*namep && **namep != '/') {
2912                *namep += prefix_length;
2913                if (**namep == '/')
2914                        ++*namep;
2915        }
2916        if (*otherp && **otherp != '/') {
2917                *otherp += prefix_length;
2918                if (**otherp == '/')
2919                        ++*otherp;
2920        }
2921}
2922
2923static void run_diff(struct diff_filepair *p, struct diff_options *o)
2924{
2925        const char *pgm = external_diff();
2926        struct strbuf msg;
2927        struct diff_filespec *one = p->one;
2928        struct diff_filespec *two = p->two;
2929        const char *name;
2930        const char *other;
2931        const char *attr_path;
2932
2933        name  = p->one->path;
2934        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2935        attr_path = name;
2936        if (o->prefix_length)
2937                strip_prefix(o->prefix_length, &name, &other);
2938
2939        if (DIFF_PAIR_UNMERGED(p)) {
2940                run_diff_cmd(pgm, name, NULL, attr_path,
2941                             NULL, NULL, NULL, o, p);
2942                return;
2943        }
2944
2945        diff_fill_sha1_info(one);
2946        diff_fill_sha1_info(two);
2947
2948        if (!pgm &&
2949            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2950            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2951                /*
2952                 * a filepair that changes between file and symlink
2953                 * needs to be split into deletion and creation.
2954                 */
2955                struct diff_filespec *null = alloc_filespec(two->path);
2956                run_diff_cmd(NULL, name, other, attr_path,
2957                             one, null, &msg, o, p);
2958                free(null);
2959                strbuf_release(&msg);
2960
2961                null = alloc_filespec(one->path);
2962                run_diff_cmd(NULL, name, other, attr_path,
2963                             null, two, &msg, o, p);
2964                free(null);
2965        }
2966        else
2967                run_diff_cmd(pgm, name, other, attr_path,
2968                             one, two, &msg, o, p);
2969
2970        strbuf_release(&msg);
2971}
2972
2973static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2974                         struct diffstat_t *diffstat)
2975{
2976        const char *name;
2977        const char *other;
2978        int complete_rewrite = 0;
2979
2980        if (DIFF_PAIR_UNMERGED(p)) {
2981                /* unmerged */
2982                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2983                return;
2984        }
2985
2986        name = p->one->path;
2987        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2988
2989        if (o->prefix_length)
2990                strip_prefix(o->prefix_length, &name, &other);
2991
2992        diff_fill_sha1_info(p->one);
2993        diff_fill_sha1_info(p->two);
2994
2995        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2996                complete_rewrite = 1;
2997        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2998}
2999
3000static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3001{
3002        const char *name;
3003        const char *other;
3004        const char *attr_path;
3005
3006        if (DIFF_PAIR_UNMERGED(p)) {
3007                /* unmerged */
3008                return;
3009        }
3010
3011        name = p->one->path;
3012        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3013        attr_path = other ? other : name;
3014
3015        if (o->prefix_length)
3016                strip_prefix(o->prefix_length, &name, &other);
3017
3018        diff_fill_sha1_info(p->one);
3019        diff_fill_sha1_info(p->two);
3020
3021        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3022}
3023
3024void diff_setup(struct diff_options *options)
3025{
3026        memcpy(options, &default_diff_options, sizeof(*options));
3027
3028        options->file = stdout;
3029
3030        options->line_termination = '\n';
3031        options->break_opt = -1;
3032        options->rename_limit = -1;
3033        options->dirstat_permille = diff_dirstat_permille_default;
3034        options->context = 3;
3035
3036        options->change = diff_change;
3037        options->add_remove = diff_addremove;
3038        options->use_color = diff_use_color_default;
3039        options->detect_rename = diff_detect_rename_default;
3040
3041        if (diff_no_prefix) {
3042                options->a_prefix = options->b_prefix = "";
3043        } else if (!diff_mnemonic_prefix) {
3044                options->a_prefix = "a/";
3045                options->b_prefix = "b/";
3046        }
3047}
3048
3049int diff_setup_done(struct diff_options *options)
3050{
3051        int count = 0;
3052
3053        if (options->output_format & DIFF_FORMAT_NAME)
3054                count++;
3055        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3056                count++;
3057        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3058                count++;
3059        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3060                count++;
3061        if (count > 1)
3062                die("--name-only, --name-status, --check and -s are mutually exclusive");
3063
3064        /*
3065         * Most of the time we can say "there are changes"
3066         * only by checking if there are changed paths, but
3067         * --ignore-whitespace* options force us to look
3068         * inside contents.
3069         */
3070
3071        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3072            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3073            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3074                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3075        else
3076                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3077
3078        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3079                options->detect_rename = DIFF_DETECT_COPY;
3080
3081        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3082                options->prefix = NULL;
3083        if (options->prefix)
3084                options->prefix_length = strlen(options->prefix);
3085        else
3086                options->prefix_length = 0;
3087
3088        if (options->output_format & (DIFF_FORMAT_NAME |
3089                                      DIFF_FORMAT_NAME_STATUS |
3090                                      DIFF_FORMAT_CHECKDIFF |
3091                                      DIFF_FORMAT_NO_OUTPUT))
3092                options->output_format &= ~(DIFF_FORMAT_RAW |
3093                                            DIFF_FORMAT_NUMSTAT |
3094                                            DIFF_FORMAT_DIFFSTAT |
3095                                            DIFF_FORMAT_SHORTSTAT |
3096                                            DIFF_FORMAT_DIRSTAT |
3097                                            DIFF_FORMAT_SUMMARY |
3098                                            DIFF_FORMAT_PATCH);
3099
3100        /*
3101         * These cases always need recursive; we do not drop caller-supplied
3102         * recursive bits for other formats here.
3103         */
3104        if (options->output_format & (DIFF_FORMAT_PATCH |
3105                                      DIFF_FORMAT_NUMSTAT |
3106                                      DIFF_FORMAT_DIFFSTAT |
3107                                      DIFF_FORMAT_SHORTSTAT |
3108                                      DIFF_FORMAT_DIRSTAT |
3109                                      DIFF_FORMAT_SUMMARY |
3110                                      DIFF_FORMAT_CHECKDIFF))
3111                DIFF_OPT_SET(options, RECURSIVE);
3112        /*
3113         * Also pickaxe would not work very well if you do not say recursive
3114         */
3115        if (options->pickaxe)
3116                DIFF_OPT_SET(options, RECURSIVE);
3117        /*
3118         * When patches are generated, submodules diffed against the work tree
3119         * must be checked for dirtiness too so it can be shown in the output
3120         */
3121        if (options->output_format & DIFF_FORMAT_PATCH)
3122                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3123
3124        if (options->detect_rename && options->rename_limit < 0)
3125                options->rename_limit = diff_rename_limit_default;
3126        if (options->setup & DIFF_SETUP_USE_CACHE) {
3127                if (!active_cache)
3128                        /* read-cache does not die even when it fails
3129                         * so it is safe for us to do this here.  Also
3130                         * it does not smudge active_cache or active_nr
3131                         * when it fails, so we do not have to worry about
3132                         * cleaning it up ourselves either.
3133                         */
3134                        read_cache();
3135        }
3136        if (options->abbrev <= 0 || 40 < options->abbrev)
3137                options->abbrev = 40; /* full */
3138
3139        /*
3140         * It does not make sense to show the first hit we happened
3141         * to have found.  It does not make sense not to return with
3142         * exit code in such a case either.
3143         */
3144        if (DIFF_OPT_TST(options, QUICK)) {
3145                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3146                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3147        }
3148
3149        return 0;
3150}
3151
3152static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3153{
3154        char c, *eq;
3155        int len;
3156
3157        if (*arg != '-')
3158                return 0;
3159        c = *++arg;
3160        if (!c)
3161                return 0;
3162        if (c == arg_short) {
3163                c = *++arg;
3164                if (!c)
3165                        return 1;
3166                if (val && isdigit(c)) {
3167                        char *end;
3168                        int n = strtoul(arg, &end, 10);
3169                        if (*end)
3170                                return 0;
3171                        *val = n;
3172                        return 1;
3173                }
3174                return 0;
3175        }
3176        if (c != '-')
3177                return 0;
3178        arg++;
3179        eq = strchr(arg, '=');
3180        if (eq)
3181                len = eq - arg;
3182        else
3183                len = strlen(arg);
3184        if (!len || strncmp(arg, arg_long, len))
3185                return 0;
3186        if (eq) {
3187                int n;
3188                char *end;
3189                if (!isdigit(*++eq))
3190                        return 0;
3191                n = strtoul(eq, &end, 10);
3192                if (*end)
3193                        return 0;
3194                *val = n;
3195        }
3196        return 1;
3197}
3198
3199static int diff_scoreopt_parse(const char *opt);
3200
3201static inline int short_opt(char opt, const char **argv,
3202                            const char **optarg)
3203{
3204        const char *arg = argv[0];
3205        if (arg[0] != '-' || arg[1] != opt)
3206                return 0;
3207        if (arg[2] != '\0') {
3208                *optarg = arg + 2;
3209                return 1;
3210        }
3211        if (!argv[1])
3212                die("Option '%c' requires a value", opt);
3213        *optarg = argv[1];
3214        return 2;
3215}
3216
3217int parse_long_opt(const char *opt, const char **argv,
3218                   const char **optarg)
3219{
3220        const char *arg = argv[0];
3221        if (arg[0] != '-' || arg[1] != '-')
3222                return 0;
3223        arg += strlen("--");
3224        if (prefixcmp(arg, opt))
3225                return 0;
3226        arg += strlen(opt);
3227        if (*arg == '=') { /* sticked form: --option=value */
3228                *optarg = arg + 1;
3229                return 1;
3230        }
3231        if (*arg != '\0')
3232                return 0;
3233        /* separate form: --option value */
3234        if (!argv[1])
3235                die("Option '--%s' requires a value", opt);
3236        *optarg = argv[1];
3237        return 2;
3238}
3239
3240static int stat_opt(struct diff_options *options, const char **av)
3241{
3242        const char *arg = av[0];
3243        char *end;
3244        int width = options->stat_width;
3245        int name_width = options->stat_name_width;
3246        int count = options->stat_count;
3247        int argcount = 1;
3248
3249        arg += strlen("--stat");
3250        end = (char *)arg;
3251
3252        switch (*arg) {
3253        case '-':
3254                if (!prefixcmp(arg, "-width")) {
3255                        arg += strlen("-width");
3256                        if (*arg == '=')
3257                                width = strtoul(arg + 1, &end, 10);
3258                        else if (!*arg && !av[1])
3259                                die("Option '--stat-width' requires a value");
3260                        else if (!*arg) {
3261                                width = strtoul(av[1], &end, 10);
3262                                argcount = 2;
3263                        }
3264                } else if (!prefixcmp(arg, "-name-width")) {
3265                        arg += strlen("-name-width");
3266                        if (*arg == '=')
3267                                name_width = strtoul(arg + 1, &end, 10);
3268                        else if (!*arg && !av[1])
3269                                die("Option '--stat-name-width' requires a value");
3270                        else if (!*arg) {
3271                                name_width = strtoul(av[1], &end, 10);
3272                                argcount = 2;
3273                        }
3274                } else if (!prefixcmp(arg, "-count")) {
3275                        arg += strlen("-count");
3276                        if (*arg == '=')
3277                                count = strtoul(arg + 1, &end, 10);
3278                        else if (!*arg && !av[1])
3279                                die("Option '--stat-count' requires a value");
3280                        else if (!*arg) {
3281                                count = strtoul(av[1], &end, 10);
3282                                argcount = 2;
3283                        }
3284                }
3285                break;
3286        case '=':
3287                width = strtoul(arg+1, &end, 10);
3288                if (*end == ',')
3289                        name_width = strtoul(end+1, &end, 10);
3290                if (*end == ',')
3291                        count = strtoul(end+1, &end, 10);
3292        }
3293
3294        /* Important! This checks all the error cases! */
3295        if (*end)
3296                return 0;
3297        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3298        options->stat_name_width = name_width;
3299        options->stat_width = width;
3300        options->stat_count = count;
3301        return argcount;
3302}
3303
3304static int parse_dirstat_opt(struct diff_options *options, const char *params)
3305{
3306        struct strbuf errmsg = STRBUF_INIT;
3307        if (parse_dirstat_params(options, params, &errmsg))
3308                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3309                    errmsg.buf);
3310        strbuf_release(&errmsg);
3311        /*
3312         * The caller knows a dirstat-related option is given from the command
3313         * line; allow it to say "return this_function();"
3314         */
3315        options->output_format |= DIFF_FORMAT_DIRSTAT;
3316        return 1;
3317}
3318
3319int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3320{
3321        const char *arg = av[0];
3322        const char *optarg;
3323        int argcount;
3324
3325        /* Output format options */
3326        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3327                options->output_format |= DIFF_FORMAT_PATCH;
3328        else if (opt_arg(arg, 'U', "unified", &options->context))
3329                options->output_format |= DIFF_FORMAT_PATCH;
3330        else if (!strcmp(arg, "--raw"))
3331                options->output_format |= DIFF_FORMAT_RAW;
3332        else if (!strcmp(arg, "--patch-with-raw"))
3333                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3334        else if (!strcmp(arg, "--numstat"))
3335                options->output_format |= DIFF_FORMAT_NUMSTAT;
3336        else if (!strcmp(arg, "--shortstat"))
3337                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3338        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3339                return parse_dirstat_opt(options, "");
3340        else if (!prefixcmp(arg, "-X"))
3341                return parse_dirstat_opt(options, arg + 2);
3342        else if (!prefixcmp(arg, "--dirstat="))
3343                return parse_dirstat_opt(options, arg + 10);
3344        else if (!strcmp(arg, "--cumulative"))
3345                return parse_dirstat_opt(options, "cumulative");
3346        else if (!strcmp(arg, "--dirstat-by-file"))
3347                return parse_dirstat_opt(options, "files");
3348        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3349                parse_dirstat_opt(options, "files");
3350                return parse_dirstat_opt(options, arg + 18);
3351        }
3352        else if (!strcmp(arg, "--check"))
3353                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3354        else if (!strcmp(arg, "--summary"))
3355                options->output_format |= DIFF_FORMAT_SUMMARY;
3356        else if (!strcmp(arg, "--patch-with-stat"))
3357                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3358        else if (!strcmp(arg, "--name-only"))
3359                options->output_format |= DIFF_FORMAT_NAME;
3360        else if (!strcmp(arg, "--name-status"))
3361                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3362        else if (!strcmp(arg, "-s"))
3363                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3364        else if (!prefixcmp(arg, "--stat"))
3365                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3366                return stat_opt(options, av);
3367
3368        /* renames options */
3369        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3370                 !strcmp(arg, "--break-rewrites")) {
3371                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3372                        return error("invalid argument to -B: %s", arg+2);
3373        }
3374        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3375                 !strcmp(arg, "--find-renames")) {
3376                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3377                        return error("invalid argument to -M: %s", arg+2);
3378                options->detect_rename = DIFF_DETECT_RENAME;
3379        }
3380        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3381                options->irreversible_delete = 1;
3382        }
3383        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3384                 !strcmp(arg, "--find-copies")) {
3385                if (options->detect_rename == DIFF_DETECT_COPY)
3386                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3387                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3388                        return error("invalid argument to -C: %s", arg+2);
3389                options->detect_rename = DIFF_DETECT_COPY;
3390        }
3391        else if (!strcmp(arg, "--no-renames"))
3392                options->detect_rename = 0;
3393        else if (!strcmp(arg, "--relative"))
3394                DIFF_OPT_SET(options, RELATIVE_NAME);
3395        else if (!prefixcmp(arg, "--relative=")) {
3396                DIFF_OPT_SET(options, RELATIVE_NAME);
3397                options->prefix = arg + 11;
3398        }
3399
3400        /* xdiff options */
3401        else if (!strcmp(arg, "--minimal"))
3402                DIFF_XDL_SET(options, NEED_MINIMAL);
3403        else if (!strcmp(arg, "--no-minimal"))
3404                DIFF_XDL_CLR(options, NEED_MINIMAL);
3405        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3406                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3407        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3408                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3409        else if (!strcmp(arg, "--ignore-space-at-eol"))
3410                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3411        else if (!strcmp(arg, "--patience"))
3412                DIFF_XDL_SET(options, PATIENCE_DIFF);
3413        else if (!strcmp(arg, "--histogram"))
3414                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3415
3416        /* flags options */
3417        else if (!strcmp(arg, "--binary")) {
3418                options->output_format |= DIFF_FORMAT_PATCH;
3419                DIFF_OPT_SET(options, BINARY);
3420        }
3421        else if (!strcmp(arg, "--full-index"))
3422                DIFF_OPT_SET(options, FULL_INDEX);
3423        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3424                DIFF_OPT_SET(options, TEXT);
3425        else if (!strcmp(arg, "-R"))
3426                DIFF_OPT_SET(options, REVERSE_DIFF);
3427        else if (!strcmp(arg, "--find-copies-harder"))
3428                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3429        else if (!strcmp(arg, "--follow"))
3430                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3431        else if (!strcmp(arg, "--color"))
3432                options->use_color = 1;
3433        else if (!prefixcmp(arg, "--color=")) {
3434                int value = git_config_colorbool(NULL, arg+8);
3435                if (value < 0)
3436                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3437                options->use_color = value;
3438        }
3439        else if (!strcmp(arg, "--no-color"))
3440                options->use_color = 0;
3441        else if (!strcmp(arg, "--color-words")) {
3442                options->use_color = 1;
3443                options->word_diff = DIFF_WORDS_COLOR;
3444        }
3445        else if (!prefixcmp(arg, "--color-words=")) {
3446                options->use_color = 1;
3447                options->word_diff = DIFF_WORDS_COLOR;
3448                options->word_regex = arg + 14;
3449        }
3450        else if (!strcmp(arg, "--word-diff")) {
3451                if (options->word_diff == DIFF_WORDS_NONE)
3452                        options->word_diff = DIFF_WORDS_PLAIN;
3453        }
3454        else if (!prefixcmp(arg, "--word-diff=")) {
3455                const char *type = arg + 12;
3456                if (!strcmp(type, "plain"))
3457                        options->word_diff = DIFF_WORDS_PLAIN;
3458                else if (!strcmp(type, "color")) {
3459                        options->use_color = 1;
3460                        options->word_diff = DIFF_WORDS_COLOR;
3461                }
3462                else if (!strcmp(type, "porcelain"))
3463                        options->word_diff = DIFF_WORDS_PORCELAIN;
3464                else if (!strcmp(type, "none"))
3465                        options->word_diff = DIFF_WORDS_NONE;
3466                else
3467                        die("bad --word-diff argument: %s", type);
3468        }
3469        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3470                if (options->word_diff == DIFF_WORDS_NONE)
3471                        options->word_diff = DIFF_WORDS_PLAIN;
3472                options->word_regex = optarg;
3473                return argcount;
3474        }
3475        else if (!strcmp(arg, "--exit-code"))
3476                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3477        else if (!strcmp(arg, "--quiet"))
3478                DIFF_OPT_SET(options, QUICK);
3479        else if (!strcmp(arg, "--ext-diff"))
3480                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3481        else if (!strcmp(arg, "--no-ext-diff"))
3482                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3483        else if (!strcmp(arg, "--textconv"))
3484                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3485        else if (!strcmp(arg, "--no-textconv"))
3486                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3487        else if (!strcmp(arg, "--ignore-submodules")) {
3488                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3489                handle_ignore_submodules_arg(options, "all");
3490        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3491                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3492                handle_ignore_submodules_arg(options, arg + 20);
3493        } else if (!strcmp(arg, "--submodule"))
3494                DIFF_OPT_SET(options, SUBMODULE_LOG);
3495        else if (!prefixcmp(arg, "--submodule=")) {
3496                if (!strcmp(arg + 12, "log"))
3497                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3498        }
3499
3500        /* misc options */
3501        else if (!strcmp(arg, "-z"))
3502                options->line_termination = 0;
3503        else if ((argcount = short_opt('l', av, &optarg))) {
3504                options->rename_limit = strtoul(optarg, NULL, 10);
3505                return argcount;
3506        }
3507        else if ((argcount = short_opt('S', av, &optarg))) {
3508                options->pickaxe = optarg;
3509                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3510                return argcount;
3511        } else if ((argcount = short_opt('G', av, &optarg))) {
3512                options->pickaxe = optarg;
3513                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3514                return argcount;
3515        }
3516        else if (!strcmp(arg, "--pickaxe-all"))
3517                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3518        else if (!strcmp(arg, "--pickaxe-regex"))
3519                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3520        else if ((argcount = short_opt('O', av, &optarg))) {
3521                options->orderfile = optarg;
3522                return argcount;
3523        }
3524        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3525                options->filter = optarg;
3526                return argcount;
3527        }
3528        else if (!strcmp(arg, "--abbrev"))
3529                options->abbrev = DEFAULT_ABBREV;
3530        else if (!prefixcmp(arg, "--abbrev=")) {
3531                options->abbrev = strtoul(arg + 9, NULL, 10);
3532                if (options->abbrev < MINIMUM_ABBREV)
3533                        options->abbrev = MINIMUM_ABBREV;
3534                else if (40 < options->abbrev)
3535                        options->abbrev = 40;
3536        }
3537        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3538                options->a_prefix = optarg;
3539                return argcount;
3540        }
3541        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3542                options->b_prefix = optarg;
3543                return argcount;
3544        }
3545        else if (!strcmp(arg, "--no-prefix"))
3546                options->a_prefix = options->b_prefix = "";
3547        else if (opt_arg(arg, '\0', "inter-hunk-context",
3548                         &options->interhunkcontext))
3549                ;
3550        else if (!strcmp(arg, "-W"))
3551                DIFF_OPT_SET(options, FUNCCONTEXT);
3552        else if (!strcmp(arg, "--function-context"))
3553                DIFF_OPT_SET(options, FUNCCONTEXT);
3554        else if (!strcmp(arg, "--no-function-context"))
3555                DIFF_OPT_CLR(options, FUNCCONTEXT);
3556        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3557                options->file = fopen(optarg, "w");
3558                if (!options->file)
3559                        die_errno("Could not open '%s'", optarg);
3560                options->close_file = 1;
3561                return argcount;
3562        } else
3563                return 0;
3564        return 1;
3565}
3566
3567int parse_rename_score(const char **cp_p)
3568{
3569        unsigned long num, scale;
3570        int ch, dot;
3571        const char *cp = *cp_p;
3572
3573        num = 0;
3574        scale = 1;
3575        dot = 0;
3576        for (;;) {
3577                ch = *cp;
3578                if ( !dot && ch == '.' ) {
3579                        scale = 1;
3580                        dot = 1;
3581                } else if ( ch == '%' ) {
3582                        scale = dot ? scale*100 : 100;
3583                        cp++;   /* % is always at the end */
3584                        break;
3585                } else if ( ch >= '0' && ch <= '9' ) {
3586                        if ( scale < 100000 ) {
3587                                scale *= 10;
3588                                num = (num*10) + (ch-'0');
3589                        }
3590                } else {
3591                        break;
3592                }
3593                cp++;
3594        }
3595        *cp_p = cp;
3596
3597        /* user says num divided by scale and we say internally that
3598         * is MAX_SCORE * num / scale.
3599         */
3600        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3601}
3602
3603static int diff_scoreopt_parse(const char *opt)
3604{
3605        int opt1, opt2, cmd;
3606
3607        if (*opt++ != '-')
3608                return -1;
3609        cmd = *opt++;
3610        if (cmd == '-') {
3611                /* convert the long-form arguments into short-form versions */
3612                if (!prefixcmp(opt, "break-rewrites")) {
3613                        opt += strlen("break-rewrites");
3614                        if (*opt == 0 || *opt++ == '=')
3615                                cmd = 'B';
3616                } else if (!prefixcmp(opt, "find-copies")) {
3617                        opt += strlen("find-copies");
3618                        if (*opt == 0 || *opt++ == '=')
3619                                cmd = 'C';
3620                } else if (!prefixcmp(opt, "find-renames")) {
3621                        opt += strlen("find-renames");
3622                        if (*opt == 0 || *opt++ == '=')
3623                                cmd = 'M';
3624                }
3625        }
3626        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3627                return -1; /* that is not a -M, -C nor -B option */
3628
3629        opt1 = parse_rename_score(&opt);
3630        if (cmd != 'B')
3631                opt2 = 0;
3632        else {
3633                if (*opt == 0)
3634                        opt2 = 0;
3635                else if (*opt != '/')
3636                        return -1; /* we expect -B80/99 or -B80 */
3637                else {
3638                        opt++;
3639                        opt2 = parse_rename_score(&opt);
3640                }
3641        }
3642        if (*opt != 0)
3643                return -1;
3644        return opt1 | (opt2 << 16);
3645}
3646
3647struct diff_queue_struct diff_queued_diff;
3648
3649void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3650{
3651        if (queue->alloc <= queue->nr) {
3652                queue->alloc = alloc_nr(queue->alloc);
3653                queue->queue = xrealloc(queue->queue,
3654                                        sizeof(dp) * queue->alloc);
3655        }
3656        queue->queue[queue->nr++] = dp;
3657}
3658
3659struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3660                                 struct diff_filespec *one,
3661                                 struct diff_filespec *two)
3662{
3663        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3664        dp->one = one;
3665        dp->two = two;
3666        if (queue)
3667                diff_q(queue, dp);
3668        return dp;
3669}
3670
3671void diff_free_filepair(struct diff_filepair *p)
3672{
3673        free_filespec(p->one);
3674        free_filespec(p->two);
3675        free(p);
3676}
3677
3678/* This is different from find_unique_abbrev() in that
3679 * it stuffs the result with dots for alignment.
3680 */
3681const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3682{
3683        int abblen;
3684        const char *abbrev;
3685        if (len == 40)
3686                return sha1_to_hex(sha1);
3687
3688        abbrev = find_unique_abbrev(sha1, len);
3689        abblen = strlen(abbrev);
3690        if (abblen < 37) {
3691                static char hex[41];
3692                if (len < abblen && abblen <= len + 2)
3693                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3694                else
3695                        sprintf(hex, "%s...", abbrev);
3696                return hex;
3697        }
3698        return sha1_to_hex(sha1);
3699}
3700
3701static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3702{
3703        int line_termination = opt->line_termination;
3704        int inter_name_termination = line_termination ? '\t' : '\0';
3705        if (opt->output_prefix) {
3706                struct strbuf *msg = NULL;
3707                msg = opt->output_prefix(opt, opt->output_prefix_data);
3708                fprintf(opt->file, "%s", msg->buf);
3709        }
3710
3711        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3712                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3713                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3714                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3715        }
3716        if (p->score) {
3717                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3718                        inter_name_termination);
3719        } else {
3720                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3721        }
3722
3723        if (p->status == DIFF_STATUS_COPIED ||
3724            p->status == DIFF_STATUS_RENAMED) {
3725                const char *name_a, *name_b;
3726                name_a = p->one->path;
3727                name_b = p->two->path;
3728                strip_prefix(opt->prefix_length, &name_a, &name_b);
3729                write_name_quoted(name_a, opt->file, inter_name_termination);
3730                write_name_quoted(name_b, opt->file, line_termination);
3731        } else {
3732                const char *name_a, *name_b;
3733                name_a = p->one->mode ? p->one->path : p->two->path;
3734                name_b = NULL;
3735                strip_prefix(opt->prefix_length, &name_a, &name_b);
3736                write_name_quoted(name_a, opt->file, line_termination);
3737        }
3738}
3739
3740int diff_unmodified_pair(struct diff_filepair *p)
3741{
3742        /* This function is written stricter than necessary to support
3743         * the currently implemented transformers, but the idea is to
3744         * let transformers to produce diff_filepairs any way they want,
3745         * and filter and clean them up here before producing the output.
3746         */
3747        struct diff_filespec *one = p->one, *two = p->two;
3748
3749        if (DIFF_PAIR_UNMERGED(p))
3750                return 0; /* unmerged is interesting */
3751
3752        /* deletion, addition, mode or type change
3753         * and rename are all interesting.
3754         */
3755        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3756            DIFF_PAIR_MODE_CHANGED(p) ||
3757            strcmp(one->path, two->path))
3758                return 0;
3759
3760        /* both are valid and point at the same path.  that is, we are
3761         * dealing with a change.
3762         */
3763        if (one->sha1_valid && two->sha1_valid &&
3764            !hashcmp(one->sha1, two->sha1) &&
3765            !one->dirty_submodule && !two->dirty_submodule)
3766                return 1; /* no change */
3767        if (!one->sha1_valid && !two->sha1_valid)
3768                return 1; /* both look at the same file on the filesystem. */
3769        return 0;
3770}
3771
3772static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3773{
3774        if (diff_unmodified_pair(p))
3775                return;
3776
3777        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3778            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3779                return; /* no tree diffs in patch format */
3780
3781        run_diff(p, o);
3782}
3783
3784static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3785                            struct diffstat_t *diffstat)
3786{
3787        if (diff_unmodified_pair(p))
3788                return;
3789
3790        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3791            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3792                return; /* no useful stat for tree diffs */
3793
3794        run_diffstat(p, o, diffstat);
3795}
3796
3797static void diff_flush_checkdiff(struct diff_filepair *p,
3798                struct diff_options *o)
3799{
3800        if (diff_unmodified_pair(p))
3801                return;
3802
3803        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3804            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3805                return; /* nothing to check in tree diffs */
3806
3807        run_checkdiff(p, o);
3808}
3809
3810int diff_queue_is_empty(void)
3811{
3812        struct diff_queue_struct *q = &diff_queued_diff;
3813        int i;
3814        for (i = 0; i < q->nr; i++)
3815                if (!diff_unmodified_pair(q->queue[i]))
3816                        return 0;
3817        return 1;
3818}
3819
3820#if DIFF_DEBUG
3821void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3822{
3823        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3824                x, one ? one : "",
3825                s->path,
3826                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3827                s->mode,
3828                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3829        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3830                x, one ? one : "",
3831                s->size, s->xfrm_flags);
3832}
3833
3834void diff_debug_filepair(const struct diff_filepair *p, int i)
3835{
3836        diff_debug_filespec(p->one, i, "one");
3837        diff_debug_filespec(p->two, i, "two");
3838        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3839                p->score, p->status ? p->status : '?',
3840                p->one->rename_used, p->broken_pair);
3841}
3842
3843void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3844{
3845        int i;
3846        if (msg)
3847                fprintf(stderr, "%s\n", msg);
3848        fprintf(stderr, "q->nr = %d\n", q->nr);
3849        for (i = 0; i < q->nr; i++) {
3850                struct diff_filepair *p = q->queue[i];
3851                diff_debug_filepair(p, i);
3852        }
3853}
3854#endif
3855
3856static void diff_resolve_rename_copy(void)
3857{
3858        int i;
3859        struct diff_filepair *p;
3860        struct diff_queue_struct *q = &diff_queued_diff;
3861
3862        diff_debug_queue("resolve-rename-copy", q);
3863
3864        for (i = 0; i < q->nr; i++) {
3865                p = q->queue[i];
3866                p->status = 0; /* undecided */
3867                if (DIFF_PAIR_UNMERGED(p))
3868                        p->status = DIFF_STATUS_UNMERGED;
3869                else if (!DIFF_FILE_VALID(p->one))
3870                        p->status = DIFF_STATUS_ADDED;
3871                else if (!DIFF_FILE_VALID(p->two))
3872                        p->status = DIFF_STATUS_DELETED;
3873                else if (DIFF_PAIR_TYPE_CHANGED(p))
3874                        p->status = DIFF_STATUS_TYPE_CHANGED;
3875
3876                /* from this point on, we are dealing with a pair
3877                 * whose both sides are valid and of the same type, i.e.
3878                 * either in-place edit or rename/copy edit.
3879                 */
3880                else if (DIFF_PAIR_RENAME(p)) {
3881                        /*
3882                         * A rename might have re-connected a broken
3883                         * pair up, causing the pathnames to be the
3884                         * same again. If so, that's not a rename at
3885                         * all, just a modification..
3886                         *
3887                         * Otherwise, see if this source was used for
3888                         * multiple renames, in which case we decrement
3889                         * the count, and call it a copy.
3890                         */
3891                        if (!strcmp(p->one->path, p->two->path))
3892                                p->status = DIFF_STATUS_MODIFIED;
3893                        else if (--p->one->rename_used > 0)
3894                                p->status = DIFF_STATUS_COPIED;
3895                        else
3896                                p->status = DIFF_STATUS_RENAMED;
3897                }
3898                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3899                         p->one->mode != p->two->mode ||
3900                         p->one->dirty_submodule ||
3901                         p->two->dirty_submodule ||
3902                         is_null_sha1(p->one->sha1))
3903                        p->status = DIFF_STATUS_MODIFIED;
3904                else {
3905                        /* This is a "no-change" entry and should not
3906                         * happen anymore, but prepare for broken callers.
3907                         */
3908                        error("feeding unmodified %s to diffcore",
3909                              p->one->path);
3910                        p->status = DIFF_STATUS_UNKNOWN;
3911                }
3912        }
3913        diff_debug_queue("resolve-rename-copy done", q);
3914}
3915
3916static int check_pair_status(struct diff_filepair *p)
3917{
3918        switch (p->status) {
3919        case DIFF_STATUS_UNKNOWN:
3920                return 0;
3921        case 0:
3922                die("internal error in diff-resolve-rename-copy");
3923        default:
3924                return 1;
3925        }
3926}
3927
3928static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3929{
3930        int fmt = opt->output_format;
3931
3932        if (fmt & DIFF_FORMAT_CHECKDIFF)
3933                diff_flush_checkdiff(p, opt);
3934        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3935                diff_flush_raw(p, opt);
3936        else if (fmt & DIFF_FORMAT_NAME) {
3937                const char *name_a, *name_b;
3938                name_a = p->two->path;
3939                name_b = NULL;
3940                strip_prefix(opt->prefix_length, &name_a, &name_b);
3941                write_name_quoted(name_a, opt->file, opt->line_termination);
3942        }
3943}
3944
3945static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3946{
3947        if (fs->mode)
3948                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3949        else
3950                fprintf(file, " %s ", newdelete);
3951        write_name_quoted(fs->path, file, '\n');
3952}
3953
3954
3955static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3956                const char *line_prefix)
3957{
3958        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3959                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3960                        p->two->mode, show_name ? ' ' : '\n');
3961                if (show_name) {
3962                        write_name_quoted(p->two->path, file, '\n');
3963                }
3964        }
3965}
3966
3967static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3968                        const char *line_prefix)
3969{
3970        char *names = pprint_rename(p->one->path, p->two->path);
3971
3972        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3973        free(names);
3974        show_mode_change(file, p, 0, line_prefix);
3975}
3976
3977static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3978{
3979        FILE *file = opt->file;
3980        char *line_prefix = "";
3981
3982        if (opt->output_prefix) {
3983                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3984                line_prefix = buf->buf;
3985        }
3986
3987        switch(p->status) {
3988        case DIFF_STATUS_DELETED:
3989                fputs(line_prefix, file);
3990                show_file_mode_name(file, "delete", p->one);
3991                break;
3992        case DIFF_STATUS_ADDED:
3993                fputs(line_prefix, file);
3994                show_file_mode_name(file, "create", p->two);
3995                break;
3996        case DIFF_STATUS_COPIED:
3997                fputs(line_prefix, file);
3998                show_rename_copy(file, "copy", p, line_prefix);
3999                break;
4000        case DIFF_STATUS_RENAMED:
4001                fputs(line_prefix, file);
4002                show_rename_copy(file, "rename", p, line_prefix);
4003                break;
4004        default:
4005                if (p->score) {
4006                        fprintf(file, "%s rewrite ", line_prefix);
4007                        write_name_quoted(p->two->path, file, ' ');
4008                        fprintf(file, "(%d%%)\n", similarity_index(p));
4009                }
4010                show_mode_change(file, p, !p->score, line_prefix);
4011                break;
4012        }
4013}
4014
4015struct patch_id_t {
4016        git_SHA_CTX *ctx;
4017        int patchlen;
4018};
4019
4020static int remove_space(char *line, int len)
4021{
4022        int i;
4023        char *dst = line;
4024        unsigned char c;
4025
4026        for (i = 0; i < len; i++)
4027                if (!isspace((c = line[i])))
4028                        *dst++ = c;
4029
4030        return dst - line;
4031}
4032
4033static void patch_id_consume(void *priv, char *line, unsigned long len)
4034{
4035        struct patch_id_t *data = priv;
4036        int new_len;
4037
4038        /* Ignore line numbers when computing the SHA1 of the patch */
4039        if (!prefixcmp(line, "@@ -"))
4040                return;
4041
4042        new_len = remove_space(line, len);
4043
4044        git_SHA1_Update(data->ctx, line, new_len);
4045        data->patchlen += new_len;
4046}
4047
4048/* returns 0 upon success, and writes result into sha1 */
4049static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4050{
4051        struct diff_queue_struct *q = &diff_queued_diff;
4052        int i;
4053        git_SHA_CTX ctx;
4054        struct patch_id_t data;
4055        char buffer[PATH_MAX * 4 + 20];
4056
4057        git_SHA1_Init(&ctx);
4058        memset(&data, 0, sizeof(struct patch_id_t));
4059        data.ctx = &ctx;
4060
4061        for (i = 0; i < q->nr; i++) {
4062                xpparam_t xpp;
4063                xdemitconf_t xecfg;
4064                mmfile_t mf1, mf2;
4065                struct diff_filepair *p = q->queue[i];
4066                int len1, len2;
4067
4068                memset(&xpp, 0, sizeof(xpp));
4069                memset(&xecfg, 0, sizeof(xecfg));
4070                if (p->status == 0)
4071                        return error("internal diff status error");
4072                if (p->status == DIFF_STATUS_UNKNOWN)
4073                        continue;
4074                if (diff_unmodified_pair(p))
4075                        continue;
4076                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4077                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4078                        continue;
4079                if (DIFF_PAIR_UNMERGED(p))
4080                        continue;
4081
4082                diff_fill_sha1_info(p->one);
4083                diff_fill_sha1_info(p->two);
4084                if (fill_mmfile(&mf1, p->one) < 0 ||
4085                                fill_mmfile(&mf2, p->two) < 0)
4086                        return error("unable to read files to diff");
4087
4088                len1 = remove_space(p->one->path, strlen(p->one->path));
4089                len2 = remove_space(p->two->path, strlen(p->two->path));
4090                if (p->one->mode == 0)
4091                        len1 = snprintf(buffer, sizeof(buffer),
4092                                        "diff--gita/%.*sb/%.*s"
4093                                        "newfilemode%06o"
4094                                        "---/dev/null"
4095                                        "+++b/%.*s",
4096                                        len1, p->one->path,
4097                                        len2, p->two->path,
4098                                        p->two->mode,
4099                                        len2, p->two->path);
4100                else if (p->two->mode == 0)
4101                        len1 = snprintf(buffer, sizeof(buffer),
4102                                        "diff--gita/%.*sb/%.*s"
4103                                        "deletedfilemode%06o"
4104                                        "---a/%.*s"
4105                                        "+++/dev/null",
4106                                        len1, p->one->path,
4107                                        len2, p->two->path,
4108                                        p->one->mode,
4109                                        len1, p->one->path);
4110                else
4111                        len1 = snprintf(buffer, sizeof(buffer),
4112                                        "diff--gita/%.*sb/%.*s"
4113                                        "---a/%.*s"
4114                                        "+++b/%.*s",
4115                                        len1, p->one->path,
4116                                        len2, p->two->path,
4117                                        len1, p->one->path,
4118                                        len2, p->two->path);
4119                git_SHA1_Update(&ctx, buffer, len1);
4120
4121                if (diff_filespec_is_binary(p->one) ||
4122                    diff_filespec_is_binary(p->two)) {
4123                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4124                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4125                        continue;
4126                }
4127
4128                xpp.flags = 0;
4129                xecfg.ctxlen = 3;
4130                xecfg.flags = 0;
4131                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4132                              &xpp, &xecfg);
4133        }
4134
4135        git_SHA1_Final(sha1, &ctx);
4136        return 0;
4137}
4138
4139int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4140{
4141        struct diff_queue_struct *q = &diff_queued_diff;
4142        int i;
4143        int result = diff_get_patch_id(options, sha1);
4144
4145        for (i = 0; i < q->nr; i++)
4146                diff_free_filepair(q->queue[i]);
4147
4148        free(q->queue);
4149        DIFF_QUEUE_CLEAR(q);
4150
4151        return result;
4152}
4153
4154static int is_summary_empty(const struct diff_queue_struct *q)
4155{
4156        int i;
4157
4158        for (i = 0; i < q->nr; i++) {
4159                const struct diff_filepair *p = q->queue[i];
4160
4161                switch (p->status) {
4162                case DIFF_STATUS_DELETED:
4163                case DIFF_STATUS_ADDED:
4164                case DIFF_STATUS_COPIED:
4165                case DIFF_STATUS_RENAMED:
4166                        return 0;
4167                default:
4168                        if (p->score)
4169                                return 0;
4170                        if (p->one->mode && p->two->mode &&
4171                            p->one->mode != p->two->mode)
4172                                return 0;
4173                        break;
4174                }
4175        }
4176        return 1;
4177}
4178
4179static const char rename_limit_warning[] =
4180"inexact rename detection was skipped due to too many files.";
4181
4182static const char degrade_cc_to_c_warning[] =
4183"only found copies from modified paths due to too many files.";
4184
4185static const char rename_limit_advice[] =
4186"you may want to set your %s variable to at least "
4187"%d and retry the command.";
4188
4189void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4190{
4191        if (degraded_cc)
4192                warning(degrade_cc_to_c_warning);
4193        else if (needed)
4194                warning(rename_limit_warning);
4195        else
4196                return;
4197        if (0 < needed && needed < 32767)
4198                warning(rename_limit_advice, varname, needed);
4199}
4200
4201void diff_flush(struct diff_options *options)
4202{
4203        struct diff_queue_struct *q = &diff_queued_diff;
4204        int i, output_format = options->output_format;
4205        int separator = 0;
4206        int dirstat_by_line = 0;
4207
4208        /*
4209         * Order: raw, stat, summary, patch
4210         * or:    name/name-status/checkdiff (other bits clear)
4211         */
4212        if (!q->nr)
4213                goto free_queue;
4214
4215        if (output_format & (DIFF_FORMAT_RAW |
4216                             DIFF_FORMAT_NAME |
4217                             DIFF_FORMAT_NAME_STATUS |
4218                             DIFF_FORMAT_CHECKDIFF)) {
4219                for (i = 0; i < q->nr; i++) {
4220                        struct diff_filepair *p = q->queue[i];
4221                        if (check_pair_status(p))
4222                                flush_one_pair(p, options);
4223                }
4224                separator++;
4225        }
4226
4227        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4228                dirstat_by_line = 1;
4229
4230        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4231            dirstat_by_line) {
4232                struct diffstat_t diffstat;
4233
4234                memset(&diffstat, 0, sizeof(struct diffstat_t));
4235                for (i = 0; i < q->nr; i++) {
4236                        struct diff_filepair *p = q->queue[i];
4237                        if (check_pair_status(p))
4238                                diff_flush_stat(p, options, &diffstat);
4239                }
4240                if (output_format & DIFF_FORMAT_NUMSTAT)
4241                        show_numstat(&diffstat, options);
4242                if (output_format & DIFF_FORMAT_DIFFSTAT)
4243                        show_stats(&diffstat, options);
4244                if (output_format & DIFF_FORMAT_SHORTSTAT)
4245                        show_shortstats(&diffstat, options);
4246                if (output_format & DIFF_FORMAT_DIRSTAT)
4247                        show_dirstat_by_line(&diffstat, options);
4248                free_diffstat_info(&diffstat);
4249                separator++;
4250        }
4251        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4252                show_dirstat(options);
4253
4254        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4255                for (i = 0; i < q->nr; i++) {
4256                        diff_summary(options, q->queue[i]);
4257                }
4258                separator++;
4259        }
4260
4261        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4262            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4263            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4264                /*
4265                 * run diff_flush_patch for the exit status. setting
4266                 * options->file to /dev/null should be safe, becaue we
4267                 * aren't supposed to produce any output anyway.
4268                 */
4269                if (options->close_file)
4270                        fclose(options->file);
4271                options->file = fopen("/dev/null", "w");
4272                if (!options->file)
4273                        die_errno("Could not open /dev/null");
4274                options->close_file = 1;
4275                for (i = 0; i < q->nr; i++) {
4276                        struct diff_filepair *p = q->queue[i];
4277                        if (check_pair_status(p))
4278                                diff_flush_patch(p, options);
4279                        if (options->found_changes)
4280                                break;
4281                }
4282        }
4283
4284        if (output_format & DIFF_FORMAT_PATCH) {
4285                if (separator) {
4286                        putc(options->line_termination, options->file);
4287                        if (options->stat_sep) {
4288                                /* attach patch instead of inline */
4289                                fputs(options->stat_sep, options->file);
4290                        }
4291                }
4292
4293                for (i = 0; i < q->nr; i++) {
4294                        struct diff_filepair *p = q->queue[i];
4295                        if (check_pair_status(p))
4296                                diff_flush_patch(p, options);
4297                }
4298        }
4299
4300        if (output_format & DIFF_FORMAT_CALLBACK)
4301                options->format_callback(q, options, options->format_callback_data);
4302
4303        for (i = 0; i < q->nr; i++)
4304                diff_free_filepair(q->queue[i]);
4305free_queue:
4306        free(q->queue);
4307        DIFF_QUEUE_CLEAR(q);
4308        if (options->close_file)
4309                fclose(options->file);
4310
4311        /*
4312         * Report the content-level differences with HAS_CHANGES;
4313         * diff_addremove/diff_change does not set the bit when
4314         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4315         */
4316        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4317                if (options->found_changes)
4318                        DIFF_OPT_SET(options, HAS_CHANGES);
4319                else
4320                        DIFF_OPT_CLR(options, HAS_CHANGES);
4321        }
4322}
4323
4324static void diffcore_apply_filter(const char *filter)
4325{
4326        int i;
4327        struct diff_queue_struct *q = &diff_queued_diff;
4328        struct diff_queue_struct outq;
4329        DIFF_QUEUE_CLEAR(&outq);
4330
4331        if (!filter)
4332                return;
4333
4334        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4335                int found;
4336                for (i = found = 0; !found && i < q->nr; i++) {
4337                        struct diff_filepair *p = q->queue[i];
4338                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4339                             ((p->score &&
4340                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4341                              (!p->score &&
4342                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4343                            ((p->status != DIFF_STATUS_MODIFIED) &&
4344                             strchr(filter, p->status)))
4345                                found++;
4346                }
4347                if (found)
4348                        return;
4349
4350                /* otherwise we will clear the whole queue
4351                 * by copying the empty outq at the end of this
4352                 * function, but first clear the current entries
4353                 * in the queue.
4354                 */
4355                for (i = 0; i < q->nr; i++)
4356                        diff_free_filepair(q->queue[i]);
4357        }
4358        else {
4359                /* Only the matching ones */
4360                for (i = 0; i < q->nr; i++) {
4361                        struct diff_filepair *p = q->queue[i];
4362
4363                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4364                             ((p->score &&
4365                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4366                              (!p->score &&
4367                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4368                            ((p->status != DIFF_STATUS_MODIFIED) &&
4369                             strchr(filter, p->status)))
4370                                diff_q(&outq, p);
4371                        else
4372                                diff_free_filepair(p);
4373                }
4374        }
4375        free(q->queue);
4376        *q = outq;
4377}
4378
4379/* Check whether two filespecs with the same mode and size are identical */
4380static int diff_filespec_is_identical(struct diff_filespec *one,
4381                                      struct diff_filespec *two)
4382{
4383        if (S_ISGITLINK(one->mode))
4384                return 0;
4385        if (diff_populate_filespec(one, 0))
4386                return 0;
4387        if (diff_populate_filespec(two, 0))
4388                return 0;
4389        return !memcmp(one->data, two->data, one->size);
4390}
4391
4392static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4393{
4394        int i;
4395        struct diff_queue_struct *q = &diff_queued_diff;
4396        struct diff_queue_struct outq;
4397        DIFF_QUEUE_CLEAR(&outq);
4398
4399        for (i = 0; i < q->nr; i++) {
4400                struct diff_filepair *p = q->queue[i];
4401
4402                /*
4403                 * 1. Entries that come from stat info dirtiness
4404                 *    always have both sides (iow, not create/delete),
4405                 *    one side of the object name is unknown, with
4406                 *    the same mode and size.  Keep the ones that
4407                 *    do not match these criteria.  They have real
4408                 *    differences.
4409                 *
4410                 * 2. At this point, the file is known to be modified,
4411                 *    with the same mode and size, and the object
4412                 *    name of one side is unknown.  Need to inspect
4413                 *    the identical contents.
4414                 */
4415                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4416                    !DIFF_FILE_VALID(p->two) ||
4417                    (p->one->sha1_valid && p->two->sha1_valid) ||
4418                    (p->one->mode != p->two->mode) ||
4419                    diff_populate_filespec(p->one, 1) ||
4420                    diff_populate_filespec(p->two, 1) ||
4421                    (p->one->size != p->two->size) ||
4422                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4423                        diff_q(&outq, p);
4424                else {
4425                        /*
4426                         * The caller can subtract 1 from skip_stat_unmatch
4427                         * to determine how many paths were dirty only
4428                         * due to stat info mismatch.
4429                         */
4430                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4431                                diffopt->skip_stat_unmatch++;
4432                        diff_free_filepair(p);
4433                }
4434        }
4435        free(q->queue);
4436        *q = outq;
4437}
4438
4439static int diffnamecmp(const void *a_, const void *b_)
4440{
4441        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4442        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4443        const char *name_a, *name_b;
4444
4445        name_a = a->one ? a->one->path : a->two->path;
4446        name_b = b->one ? b->one->path : b->two->path;
4447        return strcmp(name_a, name_b);
4448}
4449
4450void diffcore_fix_diff_index(struct diff_options *options)
4451{
4452        struct diff_queue_struct *q = &diff_queued_diff;
4453        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4454}
4455
4456void diffcore_std(struct diff_options *options)
4457{
4458        if (options->skip_stat_unmatch)
4459                diffcore_skip_stat_unmatch(options);
4460        if (!options->found_follow) {
4461                /* See try_to_follow_renames() in tree-diff.c */
4462                if (options->break_opt != -1)
4463                        diffcore_break(options->break_opt);
4464                if (options->detect_rename)
4465                        diffcore_rename(options);
4466                if (options->break_opt != -1)
4467                        diffcore_merge_broken();
4468        }
4469        if (options->pickaxe)
4470                diffcore_pickaxe(options);
4471        if (options->orderfile)
4472                diffcore_order(options->orderfile);
4473        if (!options->found_follow)
4474                /* See try_to_follow_renames() in tree-diff.c */
4475                diff_resolve_rename_copy();
4476        diffcore_apply_filter(options->filter);
4477
4478        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4479                DIFF_OPT_SET(options, HAS_CHANGES);
4480        else
4481                DIFF_OPT_CLR(options, HAS_CHANGES);
4482
4483        options->found_follow = 0;
4484}
4485
4486int diff_result_code(struct diff_options *opt, int status)
4487{
4488        int result = 0;
4489
4490        diff_warn_rename_limit("diff.renamelimit",
4491                               opt->needed_rename_limit,
4492                               opt->degraded_cc_to_c);
4493        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4494            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4495                return status;
4496        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4497            DIFF_OPT_TST(opt, HAS_CHANGES))
4498                result |= 01;
4499        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4500            DIFF_OPT_TST(opt, CHECK_FAILED))
4501                result |= 02;
4502        return result;
4503}
4504
4505int diff_can_quit_early(struct diff_options *opt)
4506{
4507        return (DIFF_OPT_TST(opt, QUICK) &&
4508                !opt->filter &&
4509                DIFF_OPT_TST(opt, HAS_CHANGES));
4510}
4511
4512/*
4513 * Shall changes to this submodule be ignored?
4514 *
4515 * Submodule changes can be configured to be ignored separately for each path,
4516 * but that configuration can be overridden from the command line.
4517 */
4518static int is_submodule_ignored(const char *path, struct diff_options *options)
4519{
4520        int ignored = 0;
4521        unsigned orig_flags = options->flags;
4522        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4523                set_diffopt_flags_from_submodule_config(options, path);
4524        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4525                ignored = 1;
4526        options->flags = orig_flags;
4527        return ignored;
4528}
4529
4530void diff_addremove(struct diff_options *options,
4531                    int addremove, unsigned mode,
4532                    const unsigned char *sha1,
4533                    const char *concatpath, unsigned dirty_submodule)
4534{
4535        struct diff_filespec *one, *two;
4536
4537        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4538                return;
4539
4540        /* This may look odd, but it is a preparation for
4541         * feeding "there are unchanged files which should
4542         * not produce diffs, but when you are doing copy
4543         * detection you would need them, so here they are"
4544         * entries to the diff-core.  They will be prefixed
4545         * with something like '=' or '*' (I haven't decided
4546         * which but should not make any difference).
4547         * Feeding the same new and old to diff_change()
4548         * also has the same effect.
4549         * Before the final output happens, they are pruned after
4550         * merged into rename/copy pairs as appropriate.
4551         */
4552        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4553                addremove = (addremove == '+' ? '-' :
4554                             addremove == '-' ? '+' : addremove);
4555
4556        if (options->prefix &&
4557            strncmp(concatpath, options->prefix, options->prefix_length))
4558                return;
4559
4560        one = alloc_filespec(concatpath);
4561        two = alloc_filespec(concatpath);
4562
4563        if (addremove != '+')
4564                fill_filespec(one, sha1, mode);
4565        if (addremove != '-') {
4566                fill_filespec(two, sha1, mode);
4567                two->dirty_submodule = dirty_submodule;
4568        }
4569
4570        diff_queue(&diff_queued_diff, one, two);
4571        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4572                DIFF_OPT_SET(options, HAS_CHANGES);
4573}
4574
4575void diff_change(struct diff_options *options,
4576                 unsigned old_mode, unsigned new_mode,
4577                 const unsigned char *old_sha1,
4578                 const unsigned char *new_sha1,
4579                 const char *concatpath,
4580                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4581{
4582        struct diff_filespec *one, *two;
4583
4584        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4585            is_submodule_ignored(concatpath, options))
4586                return;
4587
4588        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4589                unsigned tmp;
4590                const unsigned char *tmp_c;
4591                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4592                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4593                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4594                        new_dirty_submodule = tmp;
4595        }
4596
4597        if (options->prefix &&
4598            strncmp(concatpath, options->prefix, options->prefix_length))
4599                return;
4600
4601        one = alloc_filespec(concatpath);
4602        two = alloc_filespec(concatpath);
4603        fill_filespec(one, old_sha1, old_mode);
4604        fill_filespec(two, new_sha1, new_mode);
4605        one->dirty_submodule = old_dirty_submodule;
4606        two->dirty_submodule = new_dirty_submodule;
4607
4608        diff_queue(&diff_queued_diff, one, two);
4609        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4610                DIFF_OPT_SET(options, HAS_CHANGES);
4611}
4612
4613struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4614{
4615        struct diff_filepair *pair;
4616        struct diff_filespec *one, *two;
4617
4618        if (options->prefix &&
4619            strncmp(path, options->prefix, options->prefix_length))
4620                return NULL;
4621
4622        one = alloc_filespec(path);
4623        two = alloc_filespec(path);
4624        pair = diff_queue(&diff_queued_diff, one, two);
4625        pair->is_unmerged = 1;
4626        return pair;
4627}
4628
4629static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4630                size_t *outsize)
4631{
4632        struct diff_tempfile *temp;
4633        const char *argv[3];
4634        const char **arg = argv;
4635        struct child_process child;
4636        struct strbuf buf = STRBUF_INIT;
4637        int err = 0;
4638
4639        temp = prepare_temp_file(spec->path, spec);
4640        *arg++ = pgm;
4641        *arg++ = temp->name;
4642        *arg = NULL;
4643
4644        memset(&child, 0, sizeof(child));
4645        child.use_shell = 1;
4646        child.argv = argv;
4647        child.out = -1;
4648        if (start_command(&child)) {
4649                remove_tempfile();
4650                return NULL;
4651        }
4652
4653        if (strbuf_read(&buf, child.out, 0) < 0)
4654                err = error("error reading from textconv command '%s'", pgm);
4655        close(child.out);
4656
4657        if (finish_command(&child) || err) {
4658                strbuf_release(&buf);
4659                remove_tempfile();
4660                return NULL;
4661        }
4662        remove_tempfile();
4663
4664        return strbuf_detach(&buf, outsize);
4665}
4666
4667size_t fill_textconv(struct userdiff_driver *driver,
4668                     struct diff_filespec *df,
4669                     char **outbuf)
4670{
4671        size_t size;
4672
4673        if (!driver || !driver->textconv) {
4674                if (!DIFF_FILE_VALID(df)) {
4675                        *outbuf = "";
4676                        return 0;
4677                }
4678                if (diff_populate_filespec(df, 0))
4679                        die("unable to read files to diff");
4680                *outbuf = df->data;
4681                return df->size;
4682        }
4683
4684        if (driver->textconv_cache && df->sha1_valid) {
4685                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4686                                          &size);
4687                if (*outbuf)
4688                        return size;
4689        }
4690
4691        *outbuf = run_textconv(driver->textconv, df, &size);
4692        if (!*outbuf)
4693                die("unable to read files to diff");
4694
4695        if (driver->textconv_cache && df->sha1_valid) {
4696                /* ignore errors, as we might be in a readonly repository */
4697                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4698                                size);
4699                /*
4700                 * we could save up changes and flush them all at the end,
4701                 * but we would need an extra call after all diffing is done.
4702                 * Since generating a cache entry is the slow path anyway,
4703                 * this extra overhead probably isn't a big deal.
4704                 */
4705                notes_cache_write(driver->textconv_cache);
4706        }
4707
4708        return size;
4709}