diff.con commit diff --stat: show bars of same length for paths with same amount of changes (2eeeef2)
   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                }
1117                diff_words_flush(ecbdata);
1118                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1119                        emit_line(ecbdata->opt, plain, reset, line, len);
1120                        fputs("~\n", ecbdata->opt->file);
1121                } else {
1122                        /*
1123                         * Skip the prefix character, if any.  With
1124                         * diff_suppress_blank_empty, there may be
1125                         * none.
1126                         */
1127                        if (line[0] != '\n') {
1128                              line++;
1129                              len--;
1130                        }
1131                        emit_line(ecbdata->opt, plain, reset, line, len);
1132                }
1133                return;
1134        }
1135
1136        if (line[0] != '+') {
1137                const char *color =
1138                        diff_get_color(ecbdata->color_diff,
1139                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1140                ecbdata->lno_in_preimage++;
1141                if (line[0] == ' ')
1142                        ecbdata->lno_in_postimage++;
1143                emit_line(ecbdata->opt, color, reset, line, len);
1144        } else {
1145                ecbdata->lno_in_postimage++;
1146                emit_add_line(reset, ecbdata, line + 1, len - 1);
1147        }
1148}
1149
1150static char *pprint_rename(const char *a, const char *b)
1151{
1152        const char *old = a;
1153        const char *new = b;
1154        struct strbuf name = STRBUF_INIT;
1155        int pfx_length, sfx_length;
1156        int len_a = strlen(a);
1157        int len_b = strlen(b);
1158        int a_midlen, b_midlen;
1159        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1160        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1161
1162        if (qlen_a || qlen_b) {
1163                quote_c_style(a, &name, NULL, 0);
1164                strbuf_addstr(&name, " => ");
1165                quote_c_style(b, &name, NULL, 0);
1166                return strbuf_detach(&name, NULL);
1167        }
1168
1169        /* Find common prefix */
1170        pfx_length = 0;
1171        while (*old && *new && *old == *new) {
1172                if (*old == '/')
1173                        pfx_length = old - a + 1;
1174                old++;
1175                new++;
1176        }
1177
1178        /* Find common suffix */
1179        old = a + len_a;
1180        new = b + len_b;
1181        sfx_length = 0;
1182        while (a <= old && b <= new && *old == *new) {
1183                if (*old == '/')
1184                        sfx_length = len_a - (old - a);
1185                old--;
1186                new--;
1187        }
1188
1189        /*
1190         * pfx{mid-a => mid-b}sfx
1191         * {pfx-a => pfx-b}sfx
1192         * pfx{sfx-a => sfx-b}
1193         * name-a => name-b
1194         */
1195        a_midlen = len_a - pfx_length - sfx_length;
1196        b_midlen = len_b - pfx_length - sfx_length;
1197        if (a_midlen < 0)
1198                a_midlen = 0;
1199        if (b_midlen < 0)
1200                b_midlen = 0;
1201
1202        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1203        if (pfx_length + sfx_length) {
1204                strbuf_add(&name, a, pfx_length);
1205                strbuf_addch(&name, '{');
1206        }
1207        strbuf_add(&name, a + pfx_length, a_midlen);
1208        strbuf_addstr(&name, " => ");
1209        strbuf_add(&name, b + pfx_length, b_midlen);
1210        if (pfx_length + sfx_length) {
1211                strbuf_addch(&name, '}');
1212                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1213        }
1214        return strbuf_detach(&name, NULL);
1215}
1216
1217struct diffstat_t {
1218        int nr;
1219        int alloc;
1220        struct diffstat_file {
1221                char *from_name;
1222                char *name;
1223                char *print_name;
1224                unsigned is_unmerged:1;
1225                unsigned is_binary:1;
1226                unsigned is_renamed:1;
1227                uintmax_t added, deleted;
1228        } **files;
1229};
1230
1231static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1232                                          const char *name_a,
1233                                          const char *name_b)
1234{
1235        struct diffstat_file *x;
1236        x = xcalloc(sizeof (*x), 1);
1237        if (diffstat->nr == diffstat->alloc) {
1238                diffstat->alloc = alloc_nr(diffstat->alloc);
1239                diffstat->files = xrealloc(diffstat->files,
1240                                diffstat->alloc * sizeof(x));
1241        }
1242        diffstat->files[diffstat->nr++] = x;
1243        if (name_b) {
1244                x->from_name = xstrdup(name_a);
1245                x->name = xstrdup(name_b);
1246                x->is_renamed = 1;
1247        }
1248        else {
1249                x->from_name = NULL;
1250                x->name = xstrdup(name_a);
1251        }
1252        return x;
1253}
1254
1255static void diffstat_consume(void *priv, char *line, unsigned long len)
1256{
1257        struct diffstat_t *diffstat = priv;
1258        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1259
1260        if (line[0] == '+')
1261                x->added++;
1262        else if (line[0] == '-')
1263                x->deleted++;
1264}
1265
1266const char mime_boundary_leader[] = "------------";
1267
1268static int scale_linear(int it, int width, int max_change)
1269{
1270        if (!it)
1271                return 0;
1272        /*
1273         * make sure that at least one '-' or '+' is printed if
1274         * there is any change to this path. The easiest way is to
1275         * scale linearly as if the alloted width is one column shorter
1276         * than it is, and then add 1 to the result.
1277         */
1278        return 1 + (it * (width - 1) / max_change);
1279}
1280
1281static void show_name(FILE *file,
1282                      const char *prefix, const char *name, int len)
1283{
1284        fprintf(file, " %s%-*s |", prefix, len, name);
1285}
1286
1287static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1288{
1289        if (cnt <= 0)
1290                return;
1291        fprintf(file, "%s", set);
1292        while (cnt--)
1293                putc(ch, file);
1294        fprintf(file, "%s", reset);
1295}
1296
1297static void fill_print_name(struct diffstat_file *file)
1298{
1299        char *pname;
1300
1301        if (file->print_name)
1302                return;
1303
1304        if (!file->is_renamed) {
1305                struct strbuf buf = STRBUF_INIT;
1306                if (quote_c_style(file->name, &buf, NULL, 0)) {
1307                        pname = strbuf_detach(&buf, NULL);
1308                } else {
1309                        pname = file->name;
1310                        strbuf_release(&buf);
1311                }
1312        } else {
1313                pname = pprint_rename(file->from_name, file->name);
1314        }
1315        file->print_name = pname;
1316}
1317
1318static void show_stats(struct diffstat_t *data, struct diff_options *options)
1319{
1320        int i, len, add, del, adds = 0, dels = 0;
1321        uintmax_t max_change = 0, max_len = 0;
1322        int total_files = data->nr;
1323        int width, name_width, count;
1324        const char *reset, *add_c, *del_c;
1325        const char *line_prefix = "";
1326        int extra_shown = 0;
1327        struct strbuf *msg = NULL;
1328
1329        if (data->nr == 0)
1330                return;
1331
1332        if (options->output_prefix) {
1333                msg = options->output_prefix(options, options->output_prefix_data);
1334                line_prefix = msg->buf;
1335        }
1336
1337        width = options->stat_width ? options->stat_width : 80;
1338        name_width = options->stat_name_width ? options->stat_name_width : 50;
1339        count = options->stat_count ? options->stat_count : data->nr;
1340
1341        /* Sanity: give at least 5 columns to the graph,
1342         * but leave at least 10 columns for the name.
1343         */
1344        if (width < 25)
1345                width = 25;
1346        if (name_width < 10)
1347                name_width = 10;
1348        else if (width < name_width + 15)
1349                name_width = width - 15;
1350
1351        /* Find the longest filename and max number of changes */
1352        reset = diff_get_color_opt(options, DIFF_RESET);
1353        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1354        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1355
1356        for (i = 0; (i < count) && (i < data->nr); i++) {
1357                struct diffstat_file *file = data->files[i];
1358                uintmax_t change = file->added + file->deleted;
1359                if (!data->files[i]->is_renamed &&
1360                         (change == 0)) {
1361                        count++; /* not shown == room for one more */
1362                        continue;
1363                }
1364                fill_print_name(file);
1365                len = strlen(file->print_name);
1366                if (max_len < len)
1367                        max_len = len;
1368
1369                if (file->is_binary || file->is_unmerged)
1370                        continue;
1371                if (max_change < change)
1372                        max_change = change;
1373        }
1374        count = i; /* min(count, data->nr) */
1375
1376        /* Compute the width of the graph part;
1377         * 10 is for one blank at the beginning of the line plus
1378         * " | count " between the name and the graph.
1379         *
1380         * From here on, name_width is the width of the name area,
1381         * and width is the width of the graph area.
1382         */
1383        name_width = (name_width < max_len) ? name_width : max_len;
1384        if (width < (name_width + 10) + max_change)
1385                width = width - (name_width + 10);
1386        else
1387                width = max_change;
1388
1389        for (i = 0; i < count; i++) {
1390                const char *prefix = "";
1391                char *name = data->files[i]->print_name;
1392                uintmax_t added = data->files[i]->added;
1393                uintmax_t deleted = data->files[i]->deleted;
1394                int name_len;
1395
1396                if (!data->files[i]->is_renamed &&
1397                         (added + deleted == 0)) {
1398                        total_files--;
1399                        continue;
1400                }
1401                /*
1402                 * "scale" the filename
1403                 */
1404                len = name_width;
1405                name_len = strlen(name);
1406                if (name_width < name_len) {
1407                        char *slash;
1408                        prefix = "...";
1409                        len -= 3;
1410                        name += name_len - len;
1411                        slash = strchr(name, '/');
1412                        if (slash)
1413                                name = slash;
1414                }
1415
1416                if (data->files[i]->is_binary) {
1417                        fprintf(options->file, "%s", line_prefix);
1418                        show_name(options->file, prefix, name, len);
1419                        fprintf(options->file, "  Bin ");
1420                        fprintf(options->file, "%s%"PRIuMAX"%s",
1421                                del_c, deleted, reset);
1422                        fprintf(options->file, " -> ");
1423                        fprintf(options->file, "%s%"PRIuMAX"%s",
1424                                add_c, added, reset);
1425                        fprintf(options->file, " bytes");
1426                        fprintf(options->file, "\n");
1427                        continue;
1428                }
1429                else if (data->files[i]->is_unmerged) {
1430                        fprintf(options->file, "%s", line_prefix);
1431                        show_name(options->file, prefix, name, len);
1432                        fprintf(options->file, "  Unmerged\n");
1433                        continue;
1434                }
1435
1436                /*
1437                 * scale the add/delete
1438                 */
1439                add = added;
1440                del = deleted;
1441                adds += add;
1442                dels += del;
1443
1444                if (width <= max_change) {
1445                        int total = add + del;
1446
1447                        total = scale_linear(add + del, width, max_change);
1448                        if (total < 2 && add && del)
1449                                /* width >= 2 due to the sanity check */
1450                                total = 2;
1451                        if (add < del) {
1452                                add = scale_linear(add, width, max_change);
1453                                del = total - add;
1454                        } else {
1455                                del = scale_linear(del, width, max_change);
1456                                add = total - del;
1457                        }
1458                }
1459                fprintf(options->file, "%s", line_prefix);
1460                show_name(options->file, prefix, name, len);
1461                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1462                                added + deleted ? " " : "");
1463                show_graph(options->file, '+', add, add_c, reset);
1464                show_graph(options->file, '-', del, del_c, reset);
1465                fprintf(options->file, "\n");
1466        }
1467        for (i = count; i < data->nr; i++) {
1468                uintmax_t added = data->files[i]->added;
1469                uintmax_t deleted = data->files[i]->deleted;
1470                if (!data->files[i]->is_renamed &&
1471                         (added + deleted == 0)) {
1472                        total_files--;
1473                        continue;
1474                }
1475                adds += added;
1476                dels += deleted;
1477                if (!extra_shown)
1478                        fprintf(options->file, "%s ...\n", line_prefix);
1479                extra_shown = 1;
1480        }
1481        fprintf(options->file, "%s", line_prefix);
1482        fprintf(options->file,
1483               " %d files changed, %d insertions(+), %d deletions(-)\n",
1484               total_files, adds, dels);
1485}
1486
1487static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1488{
1489        int i, adds = 0, dels = 0, total_files = data->nr;
1490
1491        if (data->nr == 0)
1492                return;
1493
1494        for (i = 0; i < data->nr; i++) {
1495                if (!data->files[i]->is_binary &&
1496                    !data->files[i]->is_unmerged) {
1497                        int added = data->files[i]->added;
1498                        int deleted= data->files[i]->deleted;
1499                        if (!data->files[i]->is_renamed &&
1500                            (added + deleted == 0)) {
1501                                total_files--;
1502                        } else {
1503                                adds += added;
1504                                dels += deleted;
1505                        }
1506                }
1507        }
1508        if (options->output_prefix) {
1509                struct strbuf *msg = NULL;
1510                msg = options->output_prefix(options,
1511                                options->output_prefix_data);
1512                fprintf(options->file, "%s", msg->buf);
1513        }
1514        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1515               total_files, adds, dels);
1516}
1517
1518static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1519{
1520        int i;
1521
1522        if (data->nr == 0)
1523                return;
1524
1525        for (i = 0; i < data->nr; i++) {
1526                struct diffstat_file *file = data->files[i];
1527
1528                if (options->output_prefix) {
1529                        struct strbuf *msg = NULL;
1530                        msg = options->output_prefix(options,
1531                                        options->output_prefix_data);
1532                        fprintf(options->file, "%s", msg->buf);
1533                }
1534
1535                if (file->is_binary)
1536                        fprintf(options->file, "-\t-\t");
1537                else
1538                        fprintf(options->file,
1539                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1540                                file->added, file->deleted);
1541                if (options->line_termination) {
1542                        fill_print_name(file);
1543                        if (!file->is_renamed)
1544                                write_name_quoted(file->name, options->file,
1545                                                  options->line_termination);
1546                        else {
1547                                fputs(file->print_name, options->file);
1548                                putc(options->line_termination, options->file);
1549                        }
1550                } else {
1551                        if (file->is_renamed) {
1552                                putc('\0', options->file);
1553                                write_name_quoted(file->from_name, options->file, '\0');
1554                        }
1555                        write_name_quoted(file->name, options->file, '\0');
1556                }
1557        }
1558}
1559
1560struct dirstat_file {
1561        const char *name;
1562        unsigned long changed;
1563};
1564
1565struct dirstat_dir {
1566        struct dirstat_file *files;
1567        int alloc, nr, permille, cumulative;
1568};
1569
1570static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1571                unsigned long changed, const char *base, int baselen)
1572{
1573        unsigned long this_dir = 0;
1574        unsigned int sources = 0;
1575        const char *line_prefix = "";
1576        struct strbuf *msg = NULL;
1577
1578        if (opt->output_prefix) {
1579                msg = opt->output_prefix(opt, opt->output_prefix_data);
1580                line_prefix = msg->buf;
1581        }
1582
1583        while (dir->nr) {
1584                struct dirstat_file *f = dir->files;
1585                int namelen = strlen(f->name);
1586                unsigned long this;
1587                char *slash;
1588
1589                if (namelen < baselen)
1590                        break;
1591                if (memcmp(f->name, base, baselen))
1592                        break;
1593                slash = strchr(f->name + baselen, '/');
1594                if (slash) {
1595                        int newbaselen = slash + 1 - f->name;
1596                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1597                        sources++;
1598                } else {
1599                        this = f->changed;
1600                        dir->files++;
1601                        dir->nr--;
1602                        sources += 2;
1603                }
1604                this_dir += this;
1605        }
1606
1607        /*
1608         * We don't report dirstat's for
1609         *  - the top level
1610         *  - or cases where everything came from a single directory
1611         *    under this directory (sources == 1).
1612         */
1613        if (baselen && sources != 1) {
1614                if (this_dir) {
1615                        int permille = this_dir * 1000 / changed;
1616                        if (permille >= dir->permille) {
1617                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1618                                        permille / 10, permille % 10, baselen, base);
1619                                if (!dir->cumulative)
1620                                        return 0;
1621                        }
1622                }
1623        }
1624        return this_dir;
1625}
1626
1627static int dirstat_compare(const void *_a, const void *_b)
1628{
1629        const struct dirstat_file *a = _a;
1630        const struct dirstat_file *b = _b;
1631        return strcmp(a->name, b->name);
1632}
1633
1634static void show_dirstat(struct diff_options *options)
1635{
1636        int i;
1637        unsigned long changed;
1638        struct dirstat_dir dir;
1639        struct diff_queue_struct *q = &diff_queued_diff;
1640
1641        dir.files = NULL;
1642        dir.alloc = 0;
1643        dir.nr = 0;
1644        dir.permille = options->dirstat_permille;
1645        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1646
1647        changed = 0;
1648        for (i = 0; i < q->nr; i++) {
1649                struct diff_filepair *p = q->queue[i];
1650                const char *name;
1651                unsigned long copied, added, damage;
1652                int content_changed;
1653
1654                name = p->two->path ? p->two->path : p->one->path;
1655
1656                if (p->one->sha1_valid && p->two->sha1_valid)
1657                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1658                else
1659                        content_changed = 1;
1660
1661                if (!content_changed) {
1662                        /*
1663                         * The SHA1 has not changed, so pre-/post-content is
1664                         * identical. We can therefore skip looking at the
1665                         * file contents altogether.
1666                         */
1667                        damage = 0;
1668                        goto found_damage;
1669                }
1670
1671                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1672                        /*
1673                         * In --dirstat-by-file mode, we don't really need to
1674                         * look at the actual file contents at all.
1675                         * The fact that the SHA1 changed is enough for us to
1676                         * add this file to the list of results
1677                         * (with each file contributing equal damage).
1678                         */
1679                        damage = 1;
1680                        goto found_damage;
1681                }
1682
1683                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1684                        diff_populate_filespec(p->one, 0);
1685                        diff_populate_filespec(p->two, 0);
1686                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1687                                               &copied, &added);
1688                        diff_free_filespec_data(p->one);
1689                        diff_free_filespec_data(p->two);
1690                } else if (DIFF_FILE_VALID(p->one)) {
1691                        diff_populate_filespec(p->one, 1);
1692                        copied = added = 0;
1693                        diff_free_filespec_data(p->one);
1694                } else if (DIFF_FILE_VALID(p->two)) {
1695                        diff_populate_filespec(p->two, 1);
1696                        copied = 0;
1697                        added = p->two->size;
1698                        diff_free_filespec_data(p->two);
1699                } else
1700                        continue;
1701
1702                /*
1703                 * Original minus copied is the removed material,
1704                 * added is the new material.  They are both damages
1705                 * made to the preimage.
1706                 * If the resulting damage is zero, we know that
1707                 * diffcore_count_changes() considers the two entries to
1708                 * be identical, but since content_changed is true, we
1709                 * know that there must have been _some_ kind of change,
1710                 * so we force all entries to have damage > 0.
1711                 */
1712                damage = (p->one->size - copied) + added;
1713                if (!damage)
1714                        damage = 1;
1715
1716found_damage:
1717                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1718                dir.files[dir.nr].name = name;
1719                dir.files[dir.nr].changed = damage;
1720                changed += damage;
1721                dir.nr++;
1722        }
1723
1724        /* This can happen even with many files, if everything was renames */
1725        if (!changed)
1726                return;
1727
1728        /* Show all directories with more than x% of the changes */
1729        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1730        gather_dirstat(options, &dir, changed, "", 0);
1731}
1732
1733static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1734{
1735        int i;
1736        unsigned long changed;
1737        struct dirstat_dir dir;
1738
1739        if (data->nr == 0)
1740                return;
1741
1742        dir.files = NULL;
1743        dir.alloc = 0;
1744        dir.nr = 0;
1745        dir.permille = options->dirstat_permille;
1746        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1747
1748        changed = 0;
1749        for (i = 0; i < data->nr; i++) {
1750                struct diffstat_file *file = data->files[i];
1751                unsigned long damage = file->added + file->deleted;
1752                if (file->is_binary)
1753                        /*
1754                         * binary files counts bytes, not lines. Must find some
1755                         * way to normalize binary bytes vs. textual lines.
1756                         * The following heuristic assumes that there are 64
1757                         * bytes per "line".
1758                         * This is stupid and ugly, but very cheap...
1759                         */
1760                        damage = (damage + 63) / 64;
1761                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1762                dir.files[dir.nr].name = file->name;
1763                dir.files[dir.nr].changed = damage;
1764                changed += damage;
1765                dir.nr++;
1766        }
1767
1768        /* This can happen even with many files, if everything was renames */
1769        if (!changed)
1770                return;
1771
1772        /* Show all directories with more than x% of the changes */
1773        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1774        gather_dirstat(options, &dir, changed, "", 0);
1775}
1776
1777static void free_diffstat_info(struct diffstat_t *diffstat)
1778{
1779        int i;
1780        for (i = 0; i < diffstat->nr; i++) {
1781                struct diffstat_file *f = diffstat->files[i];
1782                if (f->name != f->print_name)
1783                        free(f->print_name);
1784                free(f->name);
1785                free(f->from_name);
1786                free(f);
1787        }
1788        free(diffstat->files);
1789}
1790
1791struct checkdiff_t {
1792        const char *filename;
1793        int lineno;
1794        int conflict_marker_size;
1795        struct diff_options *o;
1796        unsigned ws_rule;
1797        unsigned status;
1798};
1799
1800static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1801{
1802        char firstchar;
1803        int cnt;
1804
1805        if (len < marker_size + 1)
1806                return 0;
1807        firstchar = line[0];
1808        switch (firstchar) {
1809        case '=': case '>': case '<': case '|':
1810                break;
1811        default:
1812                return 0;
1813        }
1814        for (cnt = 1; cnt < marker_size; cnt++)
1815                if (line[cnt] != firstchar)
1816                        return 0;
1817        /* line[1] thru line[marker_size-1] are same as firstchar */
1818        if (len < marker_size + 1 || !isspace(line[marker_size]))
1819                return 0;
1820        return 1;
1821}
1822
1823static void checkdiff_consume(void *priv, char *line, unsigned long len)
1824{
1825        struct checkdiff_t *data = priv;
1826        int marker_size = data->conflict_marker_size;
1827        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1828        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1829        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1830        char *err;
1831        char *line_prefix = "";
1832        struct strbuf *msgbuf;
1833
1834        assert(data->o);
1835        if (data->o->output_prefix) {
1836                msgbuf = data->o->output_prefix(data->o,
1837                        data->o->output_prefix_data);
1838                line_prefix = msgbuf->buf;
1839        }
1840
1841        if (line[0] == '+') {
1842                unsigned bad;
1843                data->lineno++;
1844                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1845                        data->status |= 1;
1846                        fprintf(data->o->file,
1847                                "%s%s:%d: leftover conflict marker\n",
1848                                line_prefix, data->filename, data->lineno);
1849                }
1850                bad = ws_check(line + 1, len - 1, data->ws_rule);
1851                if (!bad)
1852                        return;
1853                data->status |= bad;
1854                err = whitespace_error_string(bad);
1855                fprintf(data->o->file, "%s%s:%d: %s.\n",
1856                        line_prefix, data->filename, data->lineno, err);
1857                free(err);
1858                emit_line(data->o, set, reset, line, 1);
1859                ws_check_emit(line + 1, len - 1, data->ws_rule,
1860                              data->o->file, set, reset, ws);
1861        } else if (line[0] == ' ') {
1862                data->lineno++;
1863        } else if (line[0] == '@') {
1864                char *plus = strchr(line, '+');
1865                if (plus)
1866                        data->lineno = strtol(plus, NULL, 10) - 1;
1867                else
1868                        die("invalid diff");
1869        }
1870}
1871
1872static unsigned char *deflate_it(char *data,
1873                                 unsigned long size,
1874                                 unsigned long *result_size)
1875{
1876        int bound;
1877        unsigned char *deflated;
1878        git_zstream stream;
1879
1880        memset(&stream, 0, sizeof(stream));
1881        git_deflate_init(&stream, zlib_compression_level);
1882        bound = git_deflate_bound(&stream, size);
1883        deflated = xmalloc(bound);
1884        stream.next_out = deflated;
1885        stream.avail_out = bound;
1886
1887        stream.next_in = (unsigned char *)data;
1888        stream.avail_in = size;
1889        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1890                ; /* nothing */
1891        git_deflate_end(&stream);
1892        *result_size = stream.total_out;
1893        return deflated;
1894}
1895
1896static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1897{
1898        void *cp;
1899        void *delta;
1900        void *deflated;
1901        void *data;
1902        unsigned long orig_size;
1903        unsigned long delta_size;
1904        unsigned long deflate_size;
1905        unsigned long data_size;
1906
1907        /* We could do deflated delta, or we could do just deflated two,
1908         * whichever is smaller.
1909         */
1910        delta = NULL;
1911        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1912        if (one->size && two->size) {
1913                delta = diff_delta(one->ptr, one->size,
1914                                   two->ptr, two->size,
1915                                   &delta_size, deflate_size);
1916                if (delta) {
1917                        void *to_free = delta;
1918                        orig_size = delta_size;
1919                        delta = deflate_it(delta, delta_size, &delta_size);
1920                        free(to_free);
1921                }
1922        }
1923
1924        if (delta && delta_size < deflate_size) {
1925                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1926                free(deflated);
1927                data = delta;
1928                data_size = delta_size;
1929        }
1930        else {
1931                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1932                free(delta);
1933                data = deflated;
1934                data_size = deflate_size;
1935        }
1936
1937        /* emit data encoded in base85 */
1938        cp = data;
1939        while (data_size) {
1940                int bytes = (52 < data_size) ? 52 : data_size;
1941                char line[70];
1942                data_size -= bytes;
1943                if (bytes <= 26)
1944                        line[0] = bytes + 'A' - 1;
1945                else
1946                        line[0] = bytes - 26 + 'a' - 1;
1947                encode_85(line + 1, cp, bytes);
1948                cp = (char *) cp + bytes;
1949                fprintf(file, "%s", prefix);
1950                fputs(line, file);
1951                fputc('\n', file);
1952        }
1953        fprintf(file, "%s\n", prefix);
1954        free(data);
1955}
1956
1957static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1958{
1959        fprintf(file, "%sGIT binary patch\n", prefix);
1960        emit_binary_diff_body(file, one, two, prefix);
1961        emit_binary_diff_body(file, two, one, prefix);
1962}
1963
1964static void diff_filespec_load_driver(struct diff_filespec *one)
1965{
1966        /* Use already-loaded driver */
1967        if (one->driver)
1968                return;
1969
1970        if (S_ISREG(one->mode))
1971                one->driver = userdiff_find_by_path(one->path);
1972
1973        /* Fallback to default settings */
1974        if (!one->driver)
1975                one->driver = userdiff_find_by_name("default");
1976}
1977
1978int diff_filespec_is_binary(struct diff_filespec *one)
1979{
1980        if (one->is_binary == -1) {
1981                diff_filespec_load_driver(one);
1982                if (one->driver->binary != -1)
1983                        one->is_binary = one->driver->binary;
1984                else {
1985                        if (!one->data && DIFF_FILE_VALID(one))
1986                                diff_populate_filespec(one, 0);
1987                        if (one->data)
1988                                one->is_binary = buffer_is_binary(one->data,
1989                                                one->size);
1990                        if (one->is_binary == -1)
1991                                one->is_binary = 0;
1992                }
1993        }
1994        return one->is_binary;
1995}
1996
1997static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1998{
1999        diff_filespec_load_driver(one);
2000        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2001}
2002
2003static const char *userdiff_word_regex(struct diff_filespec *one)
2004{
2005        diff_filespec_load_driver(one);
2006        return one->driver->word_regex;
2007}
2008
2009void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2010{
2011        if (!options->a_prefix)
2012                options->a_prefix = a;
2013        if (!options->b_prefix)
2014                options->b_prefix = b;
2015}
2016
2017struct userdiff_driver *get_textconv(struct diff_filespec *one)
2018{
2019        if (!DIFF_FILE_VALID(one))
2020                return NULL;
2021
2022        diff_filespec_load_driver(one);
2023        return userdiff_get_textconv(one->driver);
2024}
2025
2026static void builtin_diff(const char *name_a,
2027                         const char *name_b,
2028                         struct diff_filespec *one,
2029                         struct diff_filespec *two,
2030                         const char *xfrm_msg,
2031                         int must_show_header,
2032                         struct diff_options *o,
2033                         int complete_rewrite)
2034{
2035        mmfile_t mf1, mf2;
2036        const char *lbl[2];
2037        char *a_one, *b_two;
2038        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2039        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2040        const char *a_prefix, *b_prefix;
2041        struct userdiff_driver *textconv_one = NULL;
2042        struct userdiff_driver *textconv_two = NULL;
2043        struct strbuf header = STRBUF_INIT;
2044        struct strbuf *msgbuf;
2045        char *line_prefix = "";
2046
2047        if (o->output_prefix) {
2048                msgbuf = o->output_prefix(o, o->output_prefix_data);
2049                line_prefix = msgbuf->buf;
2050        }
2051
2052        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2053                        (!one->mode || S_ISGITLINK(one->mode)) &&
2054                        (!two->mode || S_ISGITLINK(two->mode))) {
2055                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2056                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2057                show_submodule_summary(o->file, one ? one->path : two->path,
2058                                one->sha1, two->sha1, two->dirty_submodule,
2059                                del, add, reset);
2060                return;
2061        }
2062
2063        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2064                textconv_one = get_textconv(one);
2065                textconv_two = get_textconv(two);
2066        }
2067
2068        diff_set_mnemonic_prefix(o, "a/", "b/");
2069        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2070                a_prefix = o->b_prefix;
2071                b_prefix = o->a_prefix;
2072        } else {
2073                a_prefix = o->a_prefix;
2074                b_prefix = o->b_prefix;
2075        }
2076
2077        /* Never use a non-valid filename anywhere if at all possible */
2078        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2079        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2080
2081        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2082        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2083        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2084        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2085        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2086        if (lbl[0][0] == '/') {
2087                /* /dev/null */
2088                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2089                if (xfrm_msg)
2090                        strbuf_addstr(&header, xfrm_msg);
2091                must_show_header = 1;
2092        }
2093        else if (lbl[1][0] == '/') {
2094                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2095                if (xfrm_msg)
2096                        strbuf_addstr(&header, xfrm_msg);
2097                must_show_header = 1;
2098        }
2099        else {
2100                if (one->mode != two->mode) {
2101                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2102                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2103                        must_show_header = 1;
2104                }
2105                if (xfrm_msg)
2106                        strbuf_addstr(&header, xfrm_msg);
2107
2108                /*
2109                 * we do not run diff between different kind
2110                 * of objects.
2111                 */
2112                if ((one->mode ^ two->mode) & S_IFMT)
2113                        goto free_ab_and_return;
2114                if (complete_rewrite &&
2115                    (textconv_one || !diff_filespec_is_binary(one)) &&
2116                    (textconv_two || !diff_filespec_is_binary(two))) {
2117                        fprintf(o->file, "%s", header.buf);
2118                        strbuf_reset(&header);
2119                        emit_rewrite_diff(name_a, name_b, one, two,
2120                                                textconv_one, textconv_two, o);
2121                        o->found_changes = 1;
2122                        goto free_ab_and_return;
2123                }
2124        }
2125
2126        if (o->irreversible_delete && lbl[1][0] == '/') {
2127                fprintf(o->file, "%s", header.buf);
2128                strbuf_reset(&header);
2129                goto free_ab_and_return;
2130        } else if (!DIFF_OPT_TST(o, TEXT) &&
2131            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2132              (!textconv_two && diff_filespec_is_binary(two)) )) {
2133                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2134                        die("unable to read files to diff");
2135                /* Quite common confusing case */
2136                if (mf1.size == mf2.size &&
2137                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2138                        if (must_show_header)
2139                                fprintf(o->file, "%s", header.buf);
2140                        goto free_ab_and_return;
2141                }
2142                fprintf(o->file, "%s", header.buf);
2143                strbuf_reset(&header);
2144                if (DIFF_OPT_TST(o, BINARY))
2145                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2146                else
2147                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2148                                line_prefix, lbl[0], lbl[1]);
2149                o->found_changes = 1;
2150        } else {
2151                /* Crazy xdl interfaces.. */
2152                const char *diffopts = getenv("GIT_DIFF_OPTS");
2153                xpparam_t xpp;
2154                xdemitconf_t xecfg;
2155                struct emit_callback ecbdata;
2156                const struct userdiff_funcname *pe;
2157
2158                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2159                        fprintf(o->file, "%s", header.buf);
2160                        strbuf_reset(&header);
2161                }
2162
2163                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2164                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2165
2166                pe = diff_funcname_pattern(one);
2167                if (!pe)
2168                        pe = diff_funcname_pattern(two);
2169
2170                memset(&xpp, 0, sizeof(xpp));
2171                memset(&xecfg, 0, sizeof(xecfg));
2172                memset(&ecbdata, 0, sizeof(ecbdata));
2173                ecbdata.label_path = lbl;
2174                ecbdata.color_diff = want_color(o->use_color);
2175                ecbdata.found_changesp = &o->found_changes;
2176                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2177                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2178                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2179                ecbdata.opt = o;
2180                ecbdata.header = header.len ? &header : NULL;
2181                xpp.flags = o->xdl_opts;
2182                xecfg.ctxlen = o->context;
2183                xecfg.interhunkctxlen = o->interhunkcontext;
2184                xecfg.flags = XDL_EMIT_FUNCNAMES;
2185                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2186                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2187                if (pe)
2188                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2189                if (!diffopts)
2190                        ;
2191                else if (!prefixcmp(diffopts, "--unified="))
2192                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2193                else if (!prefixcmp(diffopts, "-u"))
2194                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2195                if (o->word_diff) {
2196                        int i;
2197
2198                        ecbdata.diff_words =
2199                                xcalloc(1, sizeof(struct diff_words_data));
2200                        ecbdata.diff_words->type = o->word_diff;
2201                        ecbdata.diff_words->opt = o;
2202                        if (!o->word_regex)
2203                                o->word_regex = userdiff_word_regex(one);
2204                        if (!o->word_regex)
2205                                o->word_regex = userdiff_word_regex(two);
2206                        if (!o->word_regex)
2207                                o->word_regex = diff_word_regex_cfg;
2208                        if (o->word_regex) {
2209                                ecbdata.diff_words->word_regex = (regex_t *)
2210                                        xmalloc(sizeof(regex_t));
2211                                if (regcomp(ecbdata.diff_words->word_regex,
2212                                                o->word_regex,
2213                                                REG_EXTENDED | REG_NEWLINE))
2214                                        die ("Invalid regular expression: %s",
2215                                                        o->word_regex);
2216                        }
2217                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2218                                if (o->word_diff == diff_words_styles[i].type) {
2219                                        ecbdata.diff_words->style =
2220                                                &diff_words_styles[i];
2221                                        break;
2222                                }
2223                        }
2224                        if (want_color(o->use_color)) {
2225                                struct diff_words_style *st = ecbdata.diff_words->style;
2226                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2227                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2228                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2229                        }
2230                }
2231                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2232                              &xpp, &xecfg);
2233                if (o->word_diff)
2234                        free_diff_words_data(&ecbdata);
2235                if (textconv_one)
2236                        free(mf1.ptr);
2237                if (textconv_two)
2238                        free(mf2.ptr);
2239                xdiff_clear_find_func(&xecfg);
2240        }
2241
2242 free_ab_and_return:
2243        strbuf_release(&header);
2244        diff_free_filespec_data(one);
2245        diff_free_filespec_data(two);
2246        free(a_one);
2247        free(b_two);
2248        return;
2249}
2250
2251static void builtin_diffstat(const char *name_a, const char *name_b,
2252                             struct diff_filespec *one,
2253                             struct diff_filespec *two,
2254                             struct diffstat_t *diffstat,
2255                             struct diff_options *o,
2256                             int complete_rewrite)
2257{
2258        mmfile_t mf1, mf2;
2259        struct diffstat_file *data;
2260
2261        data = diffstat_add(diffstat, name_a, name_b);
2262
2263        if (!one || !two) {
2264                data->is_unmerged = 1;
2265                return;
2266        }
2267
2268        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2269                data->is_binary = 1;
2270                data->added = diff_filespec_size(two);
2271                data->deleted = diff_filespec_size(one);
2272        }
2273
2274        else if (complete_rewrite) {
2275                diff_populate_filespec(one, 0);
2276                diff_populate_filespec(two, 0);
2277                data->deleted = count_lines(one->data, one->size);
2278                data->added = count_lines(two->data, two->size);
2279        }
2280
2281        else {
2282                /* Crazy xdl interfaces.. */
2283                xpparam_t xpp;
2284                xdemitconf_t xecfg;
2285
2286                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2287                        die("unable to read files to diff");
2288
2289                memset(&xpp, 0, sizeof(xpp));
2290                memset(&xecfg, 0, sizeof(xecfg));
2291                xpp.flags = o->xdl_opts;
2292                xecfg.ctxlen = o->context;
2293                xecfg.interhunkctxlen = o->interhunkcontext;
2294                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2295                              &xpp, &xecfg);
2296        }
2297
2298        diff_free_filespec_data(one);
2299        diff_free_filespec_data(two);
2300}
2301
2302static void builtin_checkdiff(const char *name_a, const char *name_b,
2303                              const char *attr_path,
2304                              struct diff_filespec *one,
2305                              struct diff_filespec *two,
2306                              struct diff_options *o)
2307{
2308        mmfile_t mf1, mf2;
2309        struct checkdiff_t data;
2310
2311        if (!two)
2312                return;
2313
2314        memset(&data, 0, sizeof(data));
2315        data.filename = name_b ? name_b : name_a;
2316        data.lineno = 0;
2317        data.o = o;
2318        data.ws_rule = whitespace_rule(attr_path);
2319        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2320
2321        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2322                die("unable to read files to diff");
2323
2324        /*
2325         * All the other codepaths check both sides, but not checking
2326         * the "old" side here is deliberate.  We are checking the newly
2327         * introduced changes, and as long as the "new" side is text, we
2328         * can and should check what it introduces.
2329         */
2330        if (diff_filespec_is_binary(two))
2331                goto free_and_return;
2332        else {
2333                /* Crazy xdl interfaces.. */
2334                xpparam_t xpp;
2335                xdemitconf_t xecfg;
2336
2337                memset(&xpp, 0, sizeof(xpp));
2338                memset(&xecfg, 0, sizeof(xecfg));
2339                xecfg.ctxlen = 1; /* at least one context line */
2340                xpp.flags = 0;
2341                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2342                              &xpp, &xecfg);
2343
2344                if (data.ws_rule & WS_BLANK_AT_EOF) {
2345                        struct emit_callback ecbdata;
2346                        int blank_at_eof;
2347
2348                        ecbdata.ws_rule = data.ws_rule;
2349                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2350                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2351
2352                        if (blank_at_eof) {
2353                                static char *err;
2354                                if (!err)
2355                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2356                                fprintf(o->file, "%s:%d: %s.\n",
2357                                        data.filename, blank_at_eof, err);
2358                                data.status = 1; /* report errors */
2359                        }
2360                }
2361        }
2362 free_and_return:
2363        diff_free_filespec_data(one);
2364        diff_free_filespec_data(two);
2365        if (data.status)
2366                DIFF_OPT_SET(o, CHECK_FAILED);
2367}
2368
2369struct diff_filespec *alloc_filespec(const char *path)
2370{
2371        int namelen = strlen(path);
2372        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2373
2374        memset(spec, 0, sizeof(*spec));
2375        spec->path = (char *)(spec + 1);
2376        memcpy(spec->path, path, namelen+1);
2377        spec->count = 1;
2378        spec->is_binary = -1;
2379        return spec;
2380}
2381
2382void free_filespec(struct diff_filespec *spec)
2383{
2384        if (!--spec->count) {
2385                diff_free_filespec_data(spec);
2386                free(spec);
2387        }
2388}
2389
2390void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2391                   unsigned short mode)
2392{
2393        if (mode) {
2394                spec->mode = canon_mode(mode);
2395                hashcpy(spec->sha1, sha1);
2396                spec->sha1_valid = !is_null_sha1(sha1);
2397        }
2398}
2399
2400/*
2401 * Given a name and sha1 pair, if the index tells us the file in
2402 * the work tree has that object contents, return true, so that
2403 * prepare_temp_file() does not have to inflate and extract.
2404 */
2405static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2406{
2407        struct cache_entry *ce;
2408        struct stat st;
2409        int pos, len;
2410
2411        /*
2412         * We do not read the cache ourselves here, because the
2413         * benchmark with my previous version that always reads cache
2414         * shows that it makes things worse for diff-tree comparing
2415         * two linux-2.6 kernel trees in an already checked out work
2416         * tree.  This is because most diff-tree comparisons deal with
2417         * only a small number of files, while reading the cache is
2418         * expensive for a large project, and its cost outweighs the
2419         * savings we get by not inflating the object to a temporary
2420         * file.  Practically, this code only helps when we are used
2421         * by diff-cache --cached, which does read the cache before
2422         * calling us.
2423         */
2424        if (!active_cache)
2425                return 0;
2426
2427        /* We want to avoid the working directory if our caller
2428         * doesn't need the data in a normal file, this system
2429         * is rather slow with its stat/open/mmap/close syscalls,
2430         * and the object is contained in a pack file.  The pack
2431         * is probably already open and will be faster to obtain
2432         * the data through than the working directory.  Loose
2433         * objects however would tend to be slower as they need
2434         * to be individually opened and inflated.
2435         */
2436        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2437                return 0;
2438
2439        len = strlen(name);
2440        pos = cache_name_pos(name, len);
2441        if (pos < 0)
2442                return 0;
2443        ce = active_cache[pos];
2444
2445        /*
2446         * This is not the sha1 we are looking for, or
2447         * unreusable because it is not a regular file.
2448         */
2449        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2450                return 0;
2451
2452        /*
2453         * If ce is marked as "assume unchanged", there is no
2454         * guarantee that work tree matches what we are looking for.
2455         */
2456        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2457                return 0;
2458
2459        /*
2460         * If ce matches the file in the work tree, we can reuse it.
2461         */
2462        if (ce_uptodate(ce) ||
2463            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2464                return 1;
2465
2466        return 0;
2467}
2468
2469static int populate_from_stdin(struct diff_filespec *s)
2470{
2471        struct strbuf buf = STRBUF_INIT;
2472        size_t size = 0;
2473
2474        if (strbuf_read(&buf, 0, 0) < 0)
2475                return error("error while reading from stdin %s",
2476                                     strerror(errno));
2477
2478        s->should_munmap = 0;
2479        s->data = strbuf_detach(&buf, &size);
2480        s->size = size;
2481        s->should_free = 1;
2482        return 0;
2483}
2484
2485static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2486{
2487        int len;
2488        char *data = xmalloc(100), *dirty = "";
2489
2490        /* Are we looking at the work tree? */
2491        if (s->dirty_submodule)
2492                dirty = "-dirty";
2493
2494        len = snprintf(data, 100,
2495                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2496        s->data = data;
2497        s->size = len;
2498        s->should_free = 1;
2499        if (size_only) {
2500                s->data = NULL;
2501                free(data);
2502        }
2503        return 0;
2504}
2505
2506/*
2507 * While doing rename detection and pickaxe operation, we may need to
2508 * grab the data for the blob (or file) for our own in-core comparison.
2509 * diff_filespec has data and size fields for this purpose.
2510 */
2511int diff_populate_filespec(struct diff_filespec *s, int size_only)
2512{
2513        int err = 0;
2514        if (!DIFF_FILE_VALID(s))
2515                die("internal error: asking to populate invalid file.");
2516        if (S_ISDIR(s->mode))
2517                return -1;
2518
2519        if (s->data)
2520                return 0;
2521
2522        if (size_only && 0 < s->size)
2523                return 0;
2524
2525        if (S_ISGITLINK(s->mode))
2526                return diff_populate_gitlink(s, size_only);
2527
2528        if (!s->sha1_valid ||
2529            reuse_worktree_file(s->path, s->sha1, 0)) {
2530                struct strbuf buf = STRBUF_INIT;
2531                struct stat st;
2532                int fd;
2533
2534                if (!strcmp(s->path, "-"))
2535                        return populate_from_stdin(s);
2536
2537                if (lstat(s->path, &st) < 0) {
2538                        if (errno == ENOENT) {
2539                        err_empty:
2540                                err = -1;
2541                        empty:
2542                                s->data = (char *)"";
2543                                s->size = 0;
2544                                return err;
2545                        }
2546                }
2547                s->size = xsize_t(st.st_size);
2548                if (!s->size)
2549                        goto empty;
2550                if (S_ISLNK(st.st_mode)) {
2551                        struct strbuf sb = STRBUF_INIT;
2552
2553                        if (strbuf_readlink(&sb, s->path, s->size))
2554                                goto err_empty;
2555                        s->size = sb.len;
2556                        s->data = strbuf_detach(&sb, NULL);
2557                        s->should_free = 1;
2558                        return 0;
2559                }
2560                if (size_only)
2561                        return 0;
2562                fd = open(s->path, O_RDONLY);
2563                if (fd < 0)
2564                        goto err_empty;
2565                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2566                close(fd);
2567                s->should_munmap = 1;
2568
2569                /*
2570                 * Convert from working tree format to canonical git format
2571                 */
2572                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2573                        size_t size = 0;
2574                        munmap(s->data, s->size);
2575                        s->should_munmap = 0;
2576                        s->data = strbuf_detach(&buf, &size);
2577                        s->size = size;
2578                        s->should_free = 1;
2579                }
2580        }
2581        else {
2582                enum object_type type;
2583                if (size_only) {
2584                        type = sha1_object_info(s->sha1, &s->size);
2585                        if (type < 0)
2586                                die("unable to read %s", sha1_to_hex(s->sha1));
2587                } else {
2588                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2589                        if (!s->data)
2590                                die("unable to read %s", sha1_to_hex(s->sha1));
2591                        s->should_free = 1;
2592                }
2593        }
2594        return 0;
2595}
2596
2597void diff_free_filespec_blob(struct diff_filespec *s)
2598{
2599        if (s->should_free)
2600                free(s->data);
2601        else if (s->should_munmap)
2602                munmap(s->data, s->size);
2603
2604        if (s->should_free || s->should_munmap) {
2605                s->should_free = s->should_munmap = 0;
2606                s->data = NULL;
2607        }
2608}
2609
2610void diff_free_filespec_data(struct diff_filespec *s)
2611{
2612        diff_free_filespec_blob(s);
2613        free(s->cnt_data);
2614        s->cnt_data = NULL;
2615}
2616
2617static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2618                           void *blob,
2619                           unsigned long size,
2620                           const unsigned char *sha1,
2621                           int mode)
2622{
2623        int fd;
2624        struct strbuf buf = STRBUF_INIT;
2625        struct strbuf template = STRBUF_INIT;
2626        char *path_dup = xstrdup(path);
2627        const char *base = basename(path_dup);
2628
2629        /* Generate "XXXXXX_basename.ext" */
2630        strbuf_addstr(&template, "XXXXXX_");
2631        strbuf_addstr(&template, base);
2632
2633        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2634                        strlen(base) + 1);
2635        if (fd < 0)
2636                die_errno("unable to create temp-file");
2637        if (convert_to_working_tree(path,
2638                        (const char *)blob, (size_t)size, &buf)) {
2639                blob = buf.buf;
2640                size = buf.len;
2641        }
2642        if (write_in_full(fd, blob, size) != size)
2643                die_errno("unable to write temp-file");
2644        close(fd);
2645        temp->name = temp->tmp_path;
2646        strcpy(temp->hex, sha1_to_hex(sha1));
2647        temp->hex[40] = 0;
2648        sprintf(temp->mode, "%06o", mode);
2649        strbuf_release(&buf);
2650        strbuf_release(&template);
2651        free(path_dup);
2652}
2653
2654static struct diff_tempfile *prepare_temp_file(const char *name,
2655                struct diff_filespec *one)
2656{
2657        struct diff_tempfile *temp = claim_diff_tempfile();
2658
2659        if (!DIFF_FILE_VALID(one)) {
2660        not_a_valid_file:
2661                /* A '-' entry produces this for file-2, and
2662                 * a '+' entry produces this for file-1.
2663                 */
2664                temp->name = "/dev/null";
2665                strcpy(temp->hex, ".");
2666                strcpy(temp->mode, ".");
2667                return temp;
2668        }
2669
2670        if (!remove_tempfile_installed) {
2671                atexit(remove_tempfile);
2672                sigchain_push_common(remove_tempfile_on_signal);
2673                remove_tempfile_installed = 1;
2674        }
2675
2676        if (!one->sha1_valid ||
2677            reuse_worktree_file(name, one->sha1, 1)) {
2678                struct stat st;
2679                if (lstat(name, &st) < 0) {
2680                        if (errno == ENOENT)
2681                                goto not_a_valid_file;
2682                        die_errno("stat(%s)", name);
2683                }
2684                if (S_ISLNK(st.st_mode)) {
2685                        struct strbuf sb = STRBUF_INIT;
2686                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2687                                die_errno("readlink(%s)", name);
2688                        prep_temp_blob(name, temp, sb.buf, sb.len,
2689                                       (one->sha1_valid ?
2690                                        one->sha1 : null_sha1),
2691                                       (one->sha1_valid ?
2692                                        one->mode : S_IFLNK));
2693                        strbuf_release(&sb);
2694                }
2695                else {
2696                        /* we can borrow from the file in the work tree */
2697                        temp->name = name;
2698                        if (!one->sha1_valid)
2699                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2700                        else
2701                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2702                        /* Even though we may sometimes borrow the
2703                         * contents from the work tree, we always want
2704                         * one->mode.  mode is trustworthy even when
2705                         * !(one->sha1_valid), as long as
2706                         * DIFF_FILE_VALID(one).
2707                         */
2708                        sprintf(temp->mode, "%06o", one->mode);
2709                }
2710                return temp;
2711        }
2712        else {
2713                if (diff_populate_filespec(one, 0))
2714                        die("cannot read data blob for %s", one->path);
2715                prep_temp_blob(name, temp, one->data, one->size,
2716                               one->sha1, one->mode);
2717        }
2718        return temp;
2719}
2720
2721/* An external diff command takes:
2722 *
2723 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2724 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2725 *
2726 */
2727static void run_external_diff(const char *pgm,
2728                              const char *name,
2729                              const char *other,
2730                              struct diff_filespec *one,
2731                              struct diff_filespec *two,
2732                              const char *xfrm_msg,
2733                              int complete_rewrite)
2734{
2735        const char *spawn_arg[10];
2736        int retval;
2737        const char **arg = &spawn_arg[0];
2738
2739        if (one && two) {
2740                struct diff_tempfile *temp_one, *temp_two;
2741                const char *othername = (other ? other : name);
2742                temp_one = prepare_temp_file(name, one);
2743                temp_two = prepare_temp_file(othername, two);
2744                *arg++ = pgm;
2745                *arg++ = name;
2746                *arg++ = temp_one->name;
2747                *arg++ = temp_one->hex;
2748                *arg++ = temp_one->mode;
2749                *arg++ = temp_two->name;
2750                *arg++ = temp_two->hex;
2751                *arg++ = temp_two->mode;
2752                if (other) {
2753                        *arg++ = other;
2754                        *arg++ = xfrm_msg;
2755                }
2756        } else {
2757                *arg++ = pgm;
2758                *arg++ = name;
2759        }
2760        *arg = NULL;
2761        fflush(NULL);
2762        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2763        remove_tempfile();
2764        if (retval) {
2765                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2766                exit(1);
2767        }
2768}
2769
2770static int similarity_index(struct diff_filepair *p)
2771{
2772        return p->score * 100 / MAX_SCORE;
2773}
2774
2775static void fill_metainfo(struct strbuf *msg,
2776                          const char *name,
2777                          const char *other,
2778                          struct diff_filespec *one,
2779                          struct diff_filespec *two,
2780                          struct diff_options *o,
2781                          struct diff_filepair *p,
2782                          int *must_show_header,
2783                          int use_color)
2784{
2785        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2786        const char *reset = diff_get_color(use_color, DIFF_RESET);
2787        struct strbuf *msgbuf;
2788        char *line_prefix = "";
2789
2790        *must_show_header = 1;
2791        if (o->output_prefix) {
2792                msgbuf = o->output_prefix(o, o->output_prefix_data);
2793                line_prefix = msgbuf->buf;
2794        }
2795        strbuf_init(msg, PATH_MAX * 2 + 300);
2796        switch (p->status) {
2797        case DIFF_STATUS_COPIED:
2798                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2799                            line_prefix, set, similarity_index(p));
2800                strbuf_addf(msg, "%s\n%s%scopy from ",
2801                            reset,  line_prefix, set);
2802                quote_c_style(name, msg, NULL, 0);
2803                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2804                quote_c_style(other, msg, NULL, 0);
2805                strbuf_addf(msg, "%s\n", reset);
2806                break;
2807        case DIFF_STATUS_RENAMED:
2808                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2809                            line_prefix, set, similarity_index(p));
2810                strbuf_addf(msg, "%s\n%s%srename from ",
2811                            reset, line_prefix, set);
2812                quote_c_style(name, msg, NULL, 0);
2813                strbuf_addf(msg, "%s\n%s%srename to ",
2814                            reset, line_prefix, set);
2815                quote_c_style(other, msg, NULL, 0);
2816                strbuf_addf(msg, "%s\n", reset);
2817                break;
2818        case DIFF_STATUS_MODIFIED:
2819                if (p->score) {
2820                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2821                                    line_prefix,
2822                                    set, similarity_index(p), reset);
2823                        break;
2824                }
2825                /* fallthru */
2826        default:
2827                *must_show_header = 0;
2828        }
2829        if (one && two && hashcmp(one->sha1, two->sha1)) {
2830                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2831
2832                if (DIFF_OPT_TST(o, BINARY)) {
2833                        mmfile_t mf;
2834                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2835                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2836                                abbrev = 40;
2837                }
2838                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2839                            find_unique_abbrev(one->sha1, abbrev));
2840                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2841                if (one->mode == two->mode)
2842                        strbuf_addf(msg, " %06o", one->mode);
2843                strbuf_addf(msg, "%s\n", reset);
2844        }
2845}
2846
2847static void run_diff_cmd(const char *pgm,
2848                         const char *name,
2849                         const char *other,
2850                         const char *attr_path,
2851                         struct diff_filespec *one,
2852                         struct diff_filespec *two,
2853                         struct strbuf *msg,
2854                         struct diff_options *o,
2855                         struct diff_filepair *p)
2856{
2857        const char *xfrm_msg = NULL;
2858        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2859        int must_show_header = 0;
2860
2861        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2862                pgm = NULL;
2863        else {
2864                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2865                if (drv && drv->external)
2866                        pgm = drv->external;
2867        }
2868
2869        if (msg) {
2870                /*
2871                 * don't use colors when the header is intended for an
2872                 * external diff driver
2873                 */
2874                fill_metainfo(msg, name, other, one, two, o, p,
2875                              &must_show_header,
2876                              want_color(o->use_color) && !pgm);
2877                xfrm_msg = msg->len ? msg->buf : NULL;
2878        }
2879
2880        if (pgm) {
2881                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2882                                  complete_rewrite);
2883                return;
2884        }
2885        if (one && two)
2886                builtin_diff(name, other ? other : name,
2887                             one, two, xfrm_msg, must_show_header,
2888                             o, complete_rewrite);
2889        else
2890                fprintf(o->file, "* Unmerged path %s\n", name);
2891}
2892
2893static void diff_fill_sha1_info(struct diff_filespec *one)
2894{
2895        if (DIFF_FILE_VALID(one)) {
2896                if (!one->sha1_valid) {
2897                        struct stat st;
2898                        if (!strcmp(one->path, "-")) {
2899                                hashcpy(one->sha1, null_sha1);
2900                                return;
2901                        }
2902                        if (lstat(one->path, &st) < 0)
2903                                die_errno("stat '%s'", one->path);
2904                        if (index_path(one->sha1, one->path, &st, 0))
2905                                die("cannot hash %s", one->path);
2906                }
2907        }
2908        else
2909                hashclr(one->sha1);
2910}
2911
2912static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2913{
2914        /* Strip the prefix but do not molest /dev/null and absolute paths */
2915        if (*namep && **namep != '/') {
2916                *namep += prefix_length;
2917                if (**namep == '/')
2918                        ++*namep;
2919        }
2920        if (*otherp && **otherp != '/') {
2921                *otherp += prefix_length;
2922                if (**otherp == '/')
2923                        ++*otherp;
2924        }
2925}
2926
2927static void run_diff(struct diff_filepair *p, struct diff_options *o)
2928{
2929        const char *pgm = external_diff();
2930        struct strbuf msg;
2931        struct diff_filespec *one = p->one;
2932        struct diff_filespec *two = p->two;
2933        const char *name;
2934        const char *other;
2935        const char *attr_path;
2936
2937        name  = p->one->path;
2938        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2939        attr_path = name;
2940        if (o->prefix_length)
2941                strip_prefix(o->prefix_length, &name, &other);
2942
2943        if (DIFF_PAIR_UNMERGED(p)) {
2944                run_diff_cmd(pgm, name, NULL, attr_path,
2945                             NULL, NULL, NULL, o, p);
2946                return;
2947        }
2948
2949        diff_fill_sha1_info(one);
2950        diff_fill_sha1_info(two);
2951
2952        if (!pgm &&
2953            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2954            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2955                /*
2956                 * a filepair that changes between file and symlink
2957                 * needs to be split into deletion and creation.
2958                 */
2959                struct diff_filespec *null = alloc_filespec(two->path);
2960                run_diff_cmd(NULL, name, other, attr_path,
2961                             one, null, &msg, o, p);
2962                free(null);
2963                strbuf_release(&msg);
2964
2965                null = alloc_filespec(one->path);
2966                run_diff_cmd(NULL, name, other, attr_path,
2967                             null, two, &msg, o, p);
2968                free(null);
2969        }
2970        else
2971                run_diff_cmd(pgm, name, other, attr_path,
2972                             one, two, &msg, o, p);
2973
2974        strbuf_release(&msg);
2975}
2976
2977static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2978                         struct diffstat_t *diffstat)
2979{
2980        const char *name;
2981        const char *other;
2982        int complete_rewrite = 0;
2983
2984        if (DIFF_PAIR_UNMERGED(p)) {
2985                /* unmerged */
2986                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2987                return;
2988        }
2989
2990        name = p->one->path;
2991        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2992
2993        if (o->prefix_length)
2994                strip_prefix(o->prefix_length, &name, &other);
2995
2996        diff_fill_sha1_info(p->one);
2997        diff_fill_sha1_info(p->two);
2998
2999        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3000                complete_rewrite = 1;
3001        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3002}
3003
3004static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3005{
3006        const char *name;
3007        const char *other;
3008        const char *attr_path;
3009
3010        if (DIFF_PAIR_UNMERGED(p)) {
3011                /* unmerged */
3012                return;
3013        }
3014
3015        name = p->one->path;
3016        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3017        attr_path = other ? other : name;
3018
3019        if (o->prefix_length)
3020                strip_prefix(o->prefix_length, &name, &other);
3021
3022        diff_fill_sha1_info(p->one);
3023        diff_fill_sha1_info(p->two);
3024
3025        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3026}
3027
3028void diff_setup(struct diff_options *options)
3029{
3030        memcpy(options, &default_diff_options, sizeof(*options));
3031
3032        options->file = stdout;
3033
3034        options->line_termination = '\n';
3035        options->break_opt = -1;
3036        options->rename_limit = -1;
3037        options->dirstat_permille = diff_dirstat_permille_default;
3038        options->context = 3;
3039
3040        options->change = diff_change;
3041        options->add_remove = diff_addremove;
3042        options->use_color = diff_use_color_default;
3043        options->detect_rename = diff_detect_rename_default;
3044
3045        if (diff_no_prefix) {
3046                options->a_prefix = options->b_prefix = "";
3047        } else if (!diff_mnemonic_prefix) {
3048                options->a_prefix = "a/";
3049                options->b_prefix = "b/";
3050        }
3051}
3052
3053int diff_setup_done(struct diff_options *options)
3054{
3055        int count = 0;
3056
3057        if (options->output_format & DIFF_FORMAT_NAME)
3058                count++;
3059        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3060                count++;
3061        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3062                count++;
3063        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3064                count++;
3065        if (count > 1)
3066                die("--name-only, --name-status, --check and -s are mutually exclusive");
3067
3068        /*
3069         * Most of the time we can say "there are changes"
3070         * only by checking if there are changed paths, but
3071         * --ignore-whitespace* options force us to look
3072         * inside contents.
3073         */
3074
3075        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3076            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3077            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3078                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3079        else
3080                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3081
3082        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3083                options->detect_rename = DIFF_DETECT_COPY;
3084
3085        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3086                options->prefix = NULL;
3087        if (options->prefix)
3088                options->prefix_length = strlen(options->prefix);
3089        else
3090                options->prefix_length = 0;
3091
3092        if (options->output_format & (DIFF_FORMAT_NAME |
3093                                      DIFF_FORMAT_NAME_STATUS |
3094                                      DIFF_FORMAT_CHECKDIFF |
3095                                      DIFF_FORMAT_NO_OUTPUT))
3096                options->output_format &= ~(DIFF_FORMAT_RAW |
3097                                            DIFF_FORMAT_NUMSTAT |
3098                                            DIFF_FORMAT_DIFFSTAT |
3099                                            DIFF_FORMAT_SHORTSTAT |
3100                                            DIFF_FORMAT_DIRSTAT |
3101                                            DIFF_FORMAT_SUMMARY |
3102                                            DIFF_FORMAT_PATCH);
3103
3104        /*
3105         * These cases always need recursive; we do not drop caller-supplied
3106         * recursive bits for other formats here.
3107         */
3108        if (options->output_format & (DIFF_FORMAT_PATCH |
3109                                      DIFF_FORMAT_NUMSTAT |
3110                                      DIFF_FORMAT_DIFFSTAT |
3111                                      DIFF_FORMAT_SHORTSTAT |
3112                                      DIFF_FORMAT_DIRSTAT |
3113                                      DIFF_FORMAT_SUMMARY |
3114                                      DIFF_FORMAT_CHECKDIFF))
3115                DIFF_OPT_SET(options, RECURSIVE);
3116        /*
3117         * Also pickaxe would not work very well if you do not say recursive
3118         */
3119        if (options->pickaxe)
3120                DIFF_OPT_SET(options, RECURSIVE);
3121        /*
3122         * When patches are generated, submodules diffed against the work tree
3123         * must be checked for dirtiness too so it can be shown in the output
3124         */
3125        if (options->output_format & DIFF_FORMAT_PATCH)
3126                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3127
3128        if (options->detect_rename && options->rename_limit < 0)
3129                options->rename_limit = diff_rename_limit_default;
3130        if (options->setup & DIFF_SETUP_USE_CACHE) {
3131                if (!active_cache)
3132                        /* read-cache does not die even when it fails
3133                         * so it is safe for us to do this here.  Also
3134                         * it does not smudge active_cache or active_nr
3135                         * when it fails, so we do not have to worry about
3136                         * cleaning it up ourselves either.
3137                         */
3138                        read_cache();
3139        }
3140        if (options->abbrev <= 0 || 40 < options->abbrev)
3141                options->abbrev = 40; /* full */
3142
3143        /*
3144         * It does not make sense to show the first hit we happened
3145         * to have found.  It does not make sense not to return with
3146         * exit code in such a case either.
3147         */
3148        if (DIFF_OPT_TST(options, QUICK)) {
3149                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3150                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3151        }
3152
3153        return 0;
3154}
3155
3156static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3157{
3158        char c, *eq;
3159        int len;
3160
3161        if (*arg != '-')
3162                return 0;
3163        c = *++arg;
3164        if (!c)
3165                return 0;
3166        if (c == arg_short) {
3167                c = *++arg;
3168                if (!c)
3169                        return 1;
3170                if (val && isdigit(c)) {
3171                        char *end;
3172                        int n = strtoul(arg, &end, 10);
3173                        if (*end)
3174                                return 0;
3175                        *val = n;
3176                        return 1;
3177                }
3178                return 0;
3179        }
3180        if (c != '-')
3181                return 0;
3182        arg++;
3183        eq = strchr(arg, '=');
3184        if (eq)
3185                len = eq - arg;
3186        else
3187                len = strlen(arg);
3188        if (!len || strncmp(arg, arg_long, len))
3189                return 0;
3190        if (eq) {
3191                int n;
3192                char *end;
3193                if (!isdigit(*++eq))
3194                        return 0;
3195                n = strtoul(eq, &end, 10);
3196                if (*end)
3197                        return 0;
3198                *val = n;
3199        }
3200        return 1;
3201}
3202
3203static int diff_scoreopt_parse(const char *opt);
3204
3205static inline int short_opt(char opt, const char **argv,
3206                            const char **optarg)
3207{
3208        const char *arg = argv[0];
3209        if (arg[0] != '-' || arg[1] != opt)
3210                return 0;
3211        if (arg[2] != '\0') {
3212                *optarg = arg + 2;
3213                return 1;
3214        }
3215        if (!argv[1])
3216                die("Option '%c' requires a value", opt);
3217        *optarg = argv[1];
3218        return 2;
3219}
3220
3221int parse_long_opt(const char *opt, const char **argv,
3222                   const char **optarg)
3223{
3224        const char *arg = argv[0];
3225        if (arg[0] != '-' || arg[1] != '-')
3226                return 0;
3227        arg += strlen("--");
3228        if (prefixcmp(arg, opt))
3229                return 0;
3230        arg += strlen(opt);
3231        if (*arg == '=') { /* sticked form: --option=value */
3232                *optarg = arg + 1;
3233                return 1;
3234        }
3235        if (*arg != '\0')
3236                return 0;
3237        /* separate form: --option value */
3238        if (!argv[1])
3239                die("Option '--%s' requires a value", opt);
3240        *optarg = argv[1];
3241        return 2;
3242}
3243
3244static int stat_opt(struct diff_options *options, const char **av)
3245{
3246        const char *arg = av[0];
3247        char *end;
3248        int width = options->stat_width;
3249        int name_width = options->stat_name_width;
3250        int count = options->stat_count;
3251        int argcount = 1;
3252
3253        arg += strlen("--stat");
3254        end = (char *)arg;
3255
3256        switch (*arg) {
3257        case '-':
3258                if (!prefixcmp(arg, "-width")) {
3259                        arg += strlen("-width");
3260                        if (*arg == '=')
3261                                width = strtoul(arg + 1, &end, 10);
3262                        else if (!*arg && !av[1])
3263                                die("Option '--stat-width' requires a value");
3264                        else if (!*arg) {
3265                                width = strtoul(av[1], &end, 10);
3266                                argcount = 2;
3267                        }
3268                } else if (!prefixcmp(arg, "-name-width")) {
3269                        arg += strlen("-name-width");
3270                        if (*arg == '=')
3271                                name_width = strtoul(arg + 1, &end, 10);
3272                        else if (!*arg && !av[1])
3273                                die("Option '--stat-name-width' requires a value");
3274                        else if (!*arg) {
3275                                name_width = strtoul(av[1], &end, 10);
3276                                argcount = 2;
3277                        }
3278                } else if (!prefixcmp(arg, "-count")) {
3279                        arg += strlen("-count");
3280                        if (*arg == '=')
3281                                count = strtoul(arg + 1, &end, 10);
3282                        else if (!*arg && !av[1])
3283                                die("Option '--stat-count' requires a value");
3284                        else if (!*arg) {
3285                                count = strtoul(av[1], &end, 10);
3286                                argcount = 2;
3287                        }
3288                }
3289                break;
3290        case '=':
3291                width = strtoul(arg+1, &end, 10);
3292                if (*end == ',')
3293                        name_width = strtoul(end+1, &end, 10);
3294                if (*end == ',')
3295                        count = strtoul(end+1, &end, 10);
3296        }
3297
3298        /* Important! This checks all the error cases! */
3299        if (*end)
3300                return 0;
3301        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3302        options->stat_name_width = name_width;
3303        options->stat_width = width;
3304        options->stat_count = count;
3305        return argcount;
3306}
3307
3308static int parse_dirstat_opt(struct diff_options *options, const char *params)
3309{
3310        struct strbuf errmsg = STRBUF_INIT;
3311        if (parse_dirstat_params(options, params, &errmsg))
3312                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3313                    errmsg.buf);
3314        strbuf_release(&errmsg);
3315        /*
3316         * The caller knows a dirstat-related option is given from the command
3317         * line; allow it to say "return this_function();"
3318         */
3319        options->output_format |= DIFF_FORMAT_DIRSTAT;
3320        return 1;
3321}
3322
3323int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3324{
3325        const char *arg = av[0];
3326        const char *optarg;
3327        int argcount;
3328
3329        /* Output format options */
3330        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3331                options->output_format |= DIFF_FORMAT_PATCH;
3332        else if (opt_arg(arg, 'U', "unified", &options->context))
3333                options->output_format |= DIFF_FORMAT_PATCH;
3334        else if (!strcmp(arg, "--raw"))
3335                options->output_format |= DIFF_FORMAT_RAW;
3336        else if (!strcmp(arg, "--patch-with-raw"))
3337                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3338        else if (!strcmp(arg, "--numstat"))
3339                options->output_format |= DIFF_FORMAT_NUMSTAT;
3340        else if (!strcmp(arg, "--shortstat"))
3341                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3342        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3343                return parse_dirstat_opt(options, "");
3344        else if (!prefixcmp(arg, "-X"))
3345                return parse_dirstat_opt(options, arg + 2);
3346        else if (!prefixcmp(arg, "--dirstat="))
3347                return parse_dirstat_opt(options, arg + 10);
3348        else if (!strcmp(arg, "--cumulative"))
3349                return parse_dirstat_opt(options, "cumulative");
3350        else if (!strcmp(arg, "--dirstat-by-file"))
3351                return parse_dirstat_opt(options, "files");
3352        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3353                parse_dirstat_opt(options, "files");
3354                return parse_dirstat_opt(options, arg + 18);
3355        }
3356        else if (!strcmp(arg, "--check"))
3357                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3358        else if (!strcmp(arg, "--summary"))
3359                options->output_format |= DIFF_FORMAT_SUMMARY;
3360        else if (!strcmp(arg, "--patch-with-stat"))
3361                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3362        else if (!strcmp(arg, "--name-only"))
3363                options->output_format |= DIFF_FORMAT_NAME;
3364        else if (!strcmp(arg, "--name-status"))
3365                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3366        else if (!strcmp(arg, "-s"))
3367                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3368        else if (!prefixcmp(arg, "--stat"))
3369                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3370                return stat_opt(options, av);
3371
3372        /* renames options */
3373        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3374                 !strcmp(arg, "--break-rewrites")) {
3375                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3376                        return error("invalid argument to -B: %s", arg+2);
3377        }
3378        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3379                 !strcmp(arg, "--find-renames")) {
3380                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3381                        return error("invalid argument to -M: %s", arg+2);
3382                options->detect_rename = DIFF_DETECT_RENAME;
3383        }
3384        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3385                options->irreversible_delete = 1;
3386        }
3387        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3388                 !strcmp(arg, "--find-copies")) {
3389                if (options->detect_rename == DIFF_DETECT_COPY)
3390                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3391                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3392                        return error("invalid argument to -C: %s", arg+2);
3393                options->detect_rename = DIFF_DETECT_COPY;
3394        }
3395        else if (!strcmp(arg, "--no-renames"))
3396                options->detect_rename = 0;
3397        else if (!strcmp(arg, "--relative"))
3398                DIFF_OPT_SET(options, RELATIVE_NAME);
3399        else if (!prefixcmp(arg, "--relative=")) {
3400                DIFF_OPT_SET(options, RELATIVE_NAME);
3401                options->prefix = arg + 11;
3402        }
3403
3404        /* xdiff options */
3405        else if (!strcmp(arg, "--minimal"))
3406                DIFF_XDL_SET(options, NEED_MINIMAL);
3407        else if (!strcmp(arg, "--no-minimal"))
3408                DIFF_XDL_CLR(options, NEED_MINIMAL);
3409        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3410                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3411        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3412                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3413        else if (!strcmp(arg, "--ignore-space-at-eol"))
3414                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3415        else if (!strcmp(arg, "--patience"))
3416                DIFF_XDL_SET(options, PATIENCE_DIFF);
3417        else if (!strcmp(arg, "--histogram"))
3418                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3419
3420        /* flags options */
3421        else if (!strcmp(arg, "--binary")) {
3422                options->output_format |= DIFF_FORMAT_PATCH;
3423                DIFF_OPT_SET(options, BINARY);
3424        }
3425        else if (!strcmp(arg, "--full-index"))
3426                DIFF_OPT_SET(options, FULL_INDEX);
3427        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3428                DIFF_OPT_SET(options, TEXT);
3429        else if (!strcmp(arg, "-R"))
3430                DIFF_OPT_SET(options, REVERSE_DIFF);
3431        else if (!strcmp(arg, "--find-copies-harder"))
3432                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3433        else if (!strcmp(arg, "--follow"))
3434                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3435        else if (!strcmp(arg, "--color"))
3436                options->use_color = 1;
3437        else if (!prefixcmp(arg, "--color=")) {
3438                int value = git_config_colorbool(NULL, arg+8);
3439                if (value < 0)
3440                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3441                options->use_color = value;
3442        }
3443        else if (!strcmp(arg, "--no-color"))
3444                options->use_color = 0;
3445        else if (!strcmp(arg, "--color-words")) {
3446                options->use_color = 1;
3447                options->word_diff = DIFF_WORDS_COLOR;
3448        }
3449        else if (!prefixcmp(arg, "--color-words=")) {
3450                options->use_color = 1;
3451                options->word_diff = DIFF_WORDS_COLOR;
3452                options->word_regex = arg + 14;
3453        }
3454        else if (!strcmp(arg, "--word-diff")) {
3455                if (options->word_diff == DIFF_WORDS_NONE)
3456                        options->word_diff = DIFF_WORDS_PLAIN;
3457        }
3458        else if (!prefixcmp(arg, "--word-diff=")) {
3459                const char *type = arg + 12;
3460                if (!strcmp(type, "plain"))
3461                        options->word_diff = DIFF_WORDS_PLAIN;
3462                else if (!strcmp(type, "color")) {
3463                        options->use_color = 1;
3464                        options->word_diff = DIFF_WORDS_COLOR;
3465                }
3466                else if (!strcmp(type, "porcelain"))
3467                        options->word_diff = DIFF_WORDS_PORCELAIN;
3468                else if (!strcmp(type, "none"))
3469                        options->word_diff = DIFF_WORDS_NONE;
3470                else
3471                        die("bad --word-diff argument: %s", type);
3472        }
3473        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3474                if (options->word_diff == DIFF_WORDS_NONE)
3475                        options->word_diff = DIFF_WORDS_PLAIN;
3476                options->word_regex = optarg;
3477                return argcount;
3478        }
3479        else if (!strcmp(arg, "--exit-code"))
3480                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3481        else if (!strcmp(arg, "--quiet"))
3482                DIFF_OPT_SET(options, QUICK);
3483        else if (!strcmp(arg, "--ext-diff"))
3484                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3485        else if (!strcmp(arg, "--no-ext-diff"))
3486                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3487        else if (!strcmp(arg, "--textconv"))
3488                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3489        else if (!strcmp(arg, "--no-textconv"))
3490                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3491        else if (!strcmp(arg, "--ignore-submodules")) {
3492                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3493                handle_ignore_submodules_arg(options, "all");
3494        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3495                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3496                handle_ignore_submodules_arg(options, arg + 20);
3497        } else if (!strcmp(arg, "--submodule"))
3498                DIFF_OPT_SET(options, SUBMODULE_LOG);
3499        else if (!prefixcmp(arg, "--submodule=")) {
3500                if (!strcmp(arg + 12, "log"))
3501                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3502        }
3503
3504        /* misc options */
3505        else if (!strcmp(arg, "-z"))
3506                options->line_termination = 0;
3507        else if ((argcount = short_opt('l', av, &optarg))) {
3508                options->rename_limit = strtoul(optarg, NULL, 10);
3509                return argcount;
3510        }
3511        else if ((argcount = short_opt('S', av, &optarg))) {
3512                options->pickaxe = optarg;
3513                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3514                return argcount;
3515        } else if ((argcount = short_opt('G', av, &optarg))) {
3516                options->pickaxe = optarg;
3517                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3518                return argcount;
3519        }
3520        else if (!strcmp(arg, "--pickaxe-all"))
3521                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3522        else if (!strcmp(arg, "--pickaxe-regex"))
3523                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3524        else if ((argcount = short_opt('O', av, &optarg))) {
3525                options->orderfile = optarg;
3526                return argcount;
3527        }
3528        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3529                options->filter = optarg;
3530                return argcount;
3531        }
3532        else if (!strcmp(arg, "--abbrev"))
3533                options->abbrev = DEFAULT_ABBREV;
3534        else if (!prefixcmp(arg, "--abbrev=")) {
3535                options->abbrev = strtoul(arg + 9, NULL, 10);
3536                if (options->abbrev < MINIMUM_ABBREV)
3537                        options->abbrev = MINIMUM_ABBREV;
3538                else if (40 < options->abbrev)
3539                        options->abbrev = 40;
3540        }
3541        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3542                options->a_prefix = optarg;
3543                return argcount;
3544        }
3545        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3546                options->b_prefix = optarg;
3547                return argcount;
3548        }
3549        else if (!strcmp(arg, "--no-prefix"))
3550                options->a_prefix = options->b_prefix = "";
3551        else if (opt_arg(arg, '\0', "inter-hunk-context",
3552                         &options->interhunkcontext))
3553                ;
3554        else if (!strcmp(arg, "-W"))
3555                DIFF_OPT_SET(options, FUNCCONTEXT);
3556        else if (!strcmp(arg, "--function-context"))
3557                DIFF_OPT_SET(options, FUNCCONTEXT);
3558        else if (!strcmp(arg, "--no-function-context"))
3559                DIFF_OPT_CLR(options, FUNCCONTEXT);
3560        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3561                options->file = fopen(optarg, "w");
3562                if (!options->file)
3563                        die_errno("Could not open '%s'", optarg);
3564                options->close_file = 1;
3565                return argcount;
3566        } else
3567                return 0;
3568        return 1;
3569}
3570
3571int parse_rename_score(const char **cp_p)
3572{
3573        unsigned long num, scale;
3574        int ch, dot;
3575        const char *cp = *cp_p;
3576
3577        num = 0;
3578        scale = 1;
3579        dot = 0;
3580        for (;;) {
3581                ch = *cp;
3582                if ( !dot && ch == '.' ) {
3583                        scale = 1;
3584                        dot = 1;
3585                } else if ( ch == '%' ) {
3586                        scale = dot ? scale*100 : 100;
3587                        cp++;   /* % is always at the end */
3588                        break;
3589                } else if ( ch >= '0' && ch <= '9' ) {
3590                        if ( scale < 100000 ) {
3591                                scale *= 10;
3592                                num = (num*10) + (ch-'0');
3593                        }
3594                } else {
3595                        break;
3596                }
3597                cp++;
3598        }
3599        *cp_p = cp;
3600
3601        /* user says num divided by scale and we say internally that
3602         * is MAX_SCORE * num / scale.
3603         */
3604        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3605}
3606
3607static int diff_scoreopt_parse(const char *opt)
3608{
3609        int opt1, opt2, cmd;
3610
3611        if (*opt++ != '-')
3612                return -1;
3613        cmd = *opt++;
3614        if (cmd == '-') {
3615                /* convert the long-form arguments into short-form versions */
3616                if (!prefixcmp(opt, "break-rewrites")) {
3617                        opt += strlen("break-rewrites");
3618                        if (*opt == 0 || *opt++ == '=')
3619                                cmd = 'B';
3620                } else if (!prefixcmp(opt, "find-copies")) {
3621                        opt += strlen("find-copies");
3622                        if (*opt == 0 || *opt++ == '=')
3623                                cmd = 'C';
3624                } else if (!prefixcmp(opt, "find-renames")) {
3625                        opt += strlen("find-renames");
3626                        if (*opt == 0 || *opt++ == '=')
3627                                cmd = 'M';
3628                }
3629        }
3630        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3631                return -1; /* that is not a -M, -C nor -B option */
3632
3633        opt1 = parse_rename_score(&opt);
3634        if (cmd != 'B')
3635                opt2 = 0;
3636        else {
3637                if (*opt == 0)
3638                        opt2 = 0;
3639                else if (*opt != '/')
3640                        return -1; /* we expect -B80/99 or -B80 */
3641                else {
3642                        opt++;
3643                        opt2 = parse_rename_score(&opt);
3644                }
3645        }
3646        if (*opt != 0)
3647                return -1;
3648        return opt1 | (opt2 << 16);
3649}
3650
3651struct diff_queue_struct diff_queued_diff;
3652
3653void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3654{
3655        if (queue->alloc <= queue->nr) {
3656                queue->alloc = alloc_nr(queue->alloc);
3657                queue->queue = xrealloc(queue->queue,
3658                                        sizeof(dp) * queue->alloc);
3659        }
3660        queue->queue[queue->nr++] = dp;
3661}
3662
3663struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3664                                 struct diff_filespec *one,
3665                                 struct diff_filespec *two)
3666{
3667        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3668        dp->one = one;
3669        dp->two = two;
3670        if (queue)
3671                diff_q(queue, dp);
3672        return dp;
3673}
3674
3675void diff_free_filepair(struct diff_filepair *p)
3676{
3677        free_filespec(p->one);
3678        free_filespec(p->two);
3679        free(p);
3680}
3681
3682/* This is different from find_unique_abbrev() in that
3683 * it stuffs the result with dots for alignment.
3684 */
3685const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3686{
3687        int abblen;
3688        const char *abbrev;
3689        if (len == 40)
3690                return sha1_to_hex(sha1);
3691
3692        abbrev = find_unique_abbrev(sha1, len);
3693        abblen = strlen(abbrev);
3694        if (abblen < 37) {
3695                static char hex[41];
3696                if (len < abblen && abblen <= len + 2)
3697                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3698                else
3699                        sprintf(hex, "%s...", abbrev);
3700                return hex;
3701        }
3702        return sha1_to_hex(sha1);
3703}
3704
3705static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3706{
3707        int line_termination = opt->line_termination;
3708        int inter_name_termination = line_termination ? '\t' : '\0';
3709        if (opt->output_prefix) {
3710                struct strbuf *msg = NULL;
3711                msg = opt->output_prefix(opt, opt->output_prefix_data);
3712                fprintf(opt->file, "%s", msg->buf);
3713        }
3714
3715        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3716                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3717                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3718                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3719        }
3720        if (p->score) {
3721                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3722                        inter_name_termination);
3723        } else {
3724                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3725        }
3726
3727        if (p->status == DIFF_STATUS_COPIED ||
3728            p->status == DIFF_STATUS_RENAMED) {
3729                const char *name_a, *name_b;
3730                name_a = p->one->path;
3731                name_b = p->two->path;
3732                strip_prefix(opt->prefix_length, &name_a, &name_b);
3733                write_name_quoted(name_a, opt->file, inter_name_termination);
3734                write_name_quoted(name_b, opt->file, line_termination);
3735        } else {
3736                const char *name_a, *name_b;
3737                name_a = p->one->mode ? p->one->path : p->two->path;
3738                name_b = NULL;
3739                strip_prefix(opt->prefix_length, &name_a, &name_b);
3740                write_name_quoted(name_a, opt->file, line_termination);
3741        }
3742}
3743
3744int diff_unmodified_pair(struct diff_filepair *p)
3745{
3746        /* This function is written stricter than necessary to support
3747         * the currently implemented transformers, but the idea is to
3748         * let transformers to produce diff_filepairs any way they want,
3749         * and filter and clean them up here before producing the output.
3750         */
3751        struct diff_filespec *one = p->one, *two = p->two;
3752
3753        if (DIFF_PAIR_UNMERGED(p))
3754                return 0; /* unmerged is interesting */
3755
3756        /* deletion, addition, mode or type change
3757         * and rename are all interesting.
3758         */
3759        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3760            DIFF_PAIR_MODE_CHANGED(p) ||
3761            strcmp(one->path, two->path))
3762                return 0;
3763
3764        /* both are valid and point at the same path.  that is, we are
3765         * dealing with a change.
3766         */
3767        if (one->sha1_valid && two->sha1_valid &&
3768            !hashcmp(one->sha1, two->sha1) &&
3769            !one->dirty_submodule && !two->dirty_submodule)
3770                return 1; /* no change */
3771        if (!one->sha1_valid && !two->sha1_valid)
3772                return 1; /* both look at the same file on the filesystem. */
3773        return 0;
3774}
3775
3776static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3777{
3778        if (diff_unmodified_pair(p))
3779                return;
3780
3781        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3782            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3783                return; /* no tree diffs in patch format */
3784
3785        run_diff(p, o);
3786}
3787
3788static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3789                            struct diffstat_t *diffstat)
3790{
3791        if (diff_unmodified_pair(p))
3792                return;
3793
3794        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3795            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3796                return; /* no useful stat for tree diffs */
3797
3798        run_diffstat(p, o, diffstat);
3799}
3800
3801static void diff_flush_checkdiff(struct diff_filepair *p,
3802                struct diff_options *o)
3803{
3804        if (diff_unmodified_pair(p))
3805                return;
3806
3807        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3808            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3809                return; /* nothing to check in tree diffs */
3810
3811        run_checkdiff(p, o);
3812}
3813
3814int diff_queue_is_empty(void)
3815{
3816        struct diff_queue_struct *q = &diff_queued_diff;
3817        int i;
3818        for (i = 0; i < q->nr; i++)
3819                if (!diff_unmodified_pair(q->queue[i]))
3820                        return 0;
3821        return 1;
3822}
3823
3824#if DIFF_DEBUG
3825void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3826{
3827        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3828                x, one ? one : "",
3829                s->path,
3830                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3831                s->mode,
3832                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3833        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3834                x, one ? one : "",
3835                s->size, s->xfrm_flags);
3836}
3837
3838void diff_debug_filepair(const struct diff_filepair *p, int i)
3839{
3840        diff_debug_filespec(p->one, i, "one");
3841        diff_debug_filespec(p->two, i, "two");
3842        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3843                p->score, p->status ? p->status : '?',
3844                p->one->rename_used, p->broken_pair);
3845}
3846
3847void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3848{
3849        int i;
3850        if (msg)
3851                fprintf(stderr, "%s\n", msg);
3852        fprintf(stderr, "q->nr = %d\n", q->nr);
3853        for (i = 0; i < q->nr; i++) {
3854                struct diff_filepair *p = q->queue[i];
3855                diff_debug_filepair(p, i);
3856        }
3857}
3858#endif
3859
3860static void diff_resolve_rename_copy(void)
3861{
3862        int i;
3863        struct diff_filepair *p;
3864        struct diff_queue_struct *q = &diff_queued_diff;
3865
3866        diff_debug_queue("resolve-rename-copy", q);
3867
3868        for (i = 0; i < q->nr; i++) {
3869                p = q->queue[i];
3870                p->status = 0; /* undecided */
3871                if (DIFF_PAIR_UNMERGED(p))
3872                        p->status = DIFF_STATUS_UNMERGED;
3873                else if (!DIFF_FILE_VALID(p->one))
3874                        p->status = DIFF_STATUS_ADDED;
3875                else if (!DIFF_FILE_VALID(p->two))
3876                        p->status = DIFF_STATUS_DELETED;
3877                else if (DIFF_PAIR_TYPE_CHANGED(p))
3878                        p->status = DIFF_STATUS_TYPE_CHANGED;
3879
3880                /* from this point on, we are dealing with a pair
3881                 * whose both sides are valid and of the same type, i.e.
3882                 * either in-place edit or rename/copy edit.
3883                 */
3884                else if (DIFF_PAIR_RENAME(p)) {
3885                        /*
3886                         * A rename might have re-connected a broken
3887                         * pair up, causing the pathnames to be the
3888                         * same again. If so, that's not a rename at
3889                         * all, just a modification..
3890                         *
3891                         * Otherwise, see if this source was used for
3892                         * multiple renames, in which case we decrement
3893                         * the count, and call it a copy.
3894                         */
3895                        if (!strcmp(p->one->path, p->two->path))
3896                                p->status = DIFF_STATUS_MODIFIED;
3897                        else if (--p->one->rename_used > 0)
3898                                p->status = DIFF_STATUS_COPIED;
3899                        else
3900                                p->status = DIFF_STATUS_RENAMED;
3901                }
3902                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3903                         p->one->mode != p->two->mode ||
3904                         p->one->dirty_submodule ||
3905                         p->two->dirty_submodule ||
3906                         is_null_sha1(p->one->sha1))
3907                        p->status = DIFF_STATUS_MODIFIED;
3908                else {
3909                        /* This is a "no-change" entry and should not
3910                         * happen anymore, but prepare for broken callers.
3911                         */
3912                        error("feeding unmodified %s to diffcore",
3913                              p->one->path);
3914                        p->status = DIFF_STATUS_UNKNOWN;
3915                }
3916        }
3917        diff_debug_queue("resolve-rename-copy done", q);
3918}
3919
3920static int check_pair_status(struct diff_filepair *p)
3921{
3922        switch (p->status) {
3923        case DIFF_STATUS_UNKNOWN:
3924                return 0;
3925        case 0:
3926                die("internal error in diff-resolve-rename-copy");
3927        default:
3928                return 1;
3929        }
3930}
3931
3932static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3933{
3934        int fmt = opt->output_format;
3935
3936        if (fmt & DIFF_FORMAT_CHECKDIFF)
3937                diff_flush_checkdiff(p, opt);
3938        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3939                diff_flush_raw(p, opt);
3940        else if (fmt & DIFF_FORMAT_NAME) {
3941                const char *name_a, *name_b;
3942                name_a = p->two->path;
3943                name_b = NULL;
3944                strip_prefix(opt->prefix_length, &name_a, &name_b);
3945                write_name_quoted(name_a, opt->file, opt->line_termination);
3946        }
3947}
3948
3949static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3950{
3951        if (fs->mode)
3952                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3953        else
3954                fprintf(file, " %s ", newdelete);
3955        write_name_quoted(fs->path, file, '\n');
3956}
3957
3958
3959static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3960                const char *line_prefix)
3961{
3962        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3963                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3964                        p->two->mode, show_name ? ' ' : '\n');
3965                if (show_name) {
3966                        write_name_quoted(p->two->path, file, '\n');
3967                }
3968        }
3969}
3970
3971static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3972                        const char *line_prefix)
3973{
3974        char *names = pprint_rename(p->one->path, p->two->path);
3975
3976        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3977        free(names);
3978        show_mode_change(file, p, 0, line_prefix);
3979}
3980
3981static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3982{
3983        FILE *file = opt->file;
3984        char *line_prefix = "";
3985
3986        if (opt->output_prefix) {
3987                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3988                line_prefix = buf->buf;
3989        }
3990
3991        switch(p->status) {
3992        case DIFF_STATUS_DELETED:
3993                fputs(line_prefix, file);
3994                show_file_mode_name(file, "delete", p->one);
3995                break;
3996        case DIFF_STATUS_ADDED:
3997                fputs(line_prefix, file);
3998                show_file_mode_name(file, "create", p->two);
3999                break;
4000        case DIFF_STATUS_COPIED:
4001                fputs(line_prefix, file);
4002                show_rename_copy(file, "copy", p, line_prefix);
4003                break;
4004        case DIFF_STATUS_RENAMED:
4005                fputs(line_prefix, file);
4006                show_rename_copy(file, "rename", p, line_prefix);
4007                break;
4008        default:
4009                if (p->score) {
4010                        fprintf(file, "%s rewrite ", line_prefix);
4011                        write_name_quoted(p->two->path, file, ' ');
4012                        fprintf(file, "(%d%%)\n", similarity_index(p));
4013                }
4014                show_mode_change(file, p, !p->score, line_prefix);
4015                break;
4016        }
4017}
4018
4019struct patch_id_t {
4020        git_SHA_CTX *ctx;
4021        int patchlen;
4022};
4023
4024static int remove_space(char *line, int len)
4025{
4026        int i;
4027        char *dst = line;
4028        unsigned char c;
4029
4030        for (i = 0; i < len; i++)
4031                if (!isspace((c = line[i])))
4032                        *dst++ = c;
4033
4034        return dst - line;
4035}
4036
4037static void patch_id_consume(void *priv, char *line, unsigned long len)
4038{
4039        struct patch_id_t *data = priv;
4040        int new_len;
4041
4042        /* Ignore line numbers when computing the SHA1 of the patch */
4043        if (!prefixcmp(line, "@@ -"))
4044                return;
4045
4046        new_len = remove_space(line, len);
4047
4048        git_SHA1_Update(data->ctx, line, new_len);
4049        data->patchlen += new_len;
4050}
4051
4052/* returns 0 upon success, and writes result into sha1 */
4053static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4054{
4055        struct diff_queue_struct *q = &diff_queued_diff;
4056        int i;
4057        git_SHA_CTX ctx;
4058        struct patch_id_t data;
4059        char buffer[PATH_MAX * 4 + 20];
4060
4061        git_SHA1_Init(&ctx);
4062        memset(&data, 0, sizeof(struct patch_id_t));
4063        data.ctx = &ctx;
4064
4065        for (i = 0; i < q->nr; i++) {
4066                xpparam_t xpp;
4067                xdemitconf_t xecfg;
4068                mmfile_t mf1, mf2;
4069                struct diff_filepair *p = q->queue[i];
4070                int len1, len2;
4071
4072                memset(&xpp, 0, sizeof(xpp));
4073                memset(&xecfg, 0, sizeof(xecfg));
4074                if (p->status == 0)
4075                        return error("internal diff status error");
4076                if (p->status == DIFF_STATUS_UNKNOWN)
4077                        continue;
4078                if (diff_unmodified_pair(p))
4079                        continue;
4080                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4081                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4082                        continue;
4083                if (DIFF_PAIR_UNMERGED(p))
4084                        continue;
4085
4086                diff_fill_sha1_info(p->one);
4087                diff_fill_sha1_info(p->two);
4088                if (fill_mmfile(&mf1, p->one) < 0 ||
4089                                fill_mmfile(&mf2, p->two) < 0)
4090                        return error("unable to read files to diff");
4091
4092                len1 = remove_space(p->one->path, strlen(p->one->path));
4093                len2 = remove_space(p->two->path, strlen(p->two->path));
4094                if (p->one->mode == 0)
4095                        len1 = snprintf(buffer, sizeof(buffer),
4096                                        "diff--gita/%.*sb/%.*s"
4097                                        "newfilemode%06o"
4098                                        "---/dev/null"
4099                                        "+++b/%.*s",
4100                                        len1, p->one->path,
4101                                        len2, p->two->path,
4102                                        p->two->mode,
4103                                        len2, p->two->path);
4104                else if (p->two->mode == 0)
4105                        len1 = snprintf(buffer, sizeof(buffer),
4106                                        "diff--gita/%.*sb/%.*s"
4107                                        "deletedfilemode%06o"
4108                                        "---a/%.*s"
4109                                        "+++/dev/null",
4110                                        len1, p->one->path,
4111                                        len2, p->two->path,
4112                                        p->one->mode,
4113                                        len1, p->one->path);
4114                else
4115                        len1 = snprintf(buffer, sizeof(buffer),
4116                                        "diff--gita/%.*sb/%.*s"
4117                                        "---a/%.*s"
4118                                        "+++b/%.*s",
4119                                        len1, p->one->path,
4120                                        len2, p->two->path,
4121                                        len1, p->one->path,
4122                                        len2, p->two->path);
4123                git_SHA1_Update(&ctx, buffer, len1);
4124
4125                if (diff_filespec_is_binary(p->one) ||
4126                    diff_filespec_is_binary(p->two)) {
4127                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4128                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4129                        continue;
4130                }
4131
4132                xpp.flags = 0;
4133                xecfg.ctxlen = 3;
4134                xecfg.flags = 0;
4135                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4136                              &xpp, &xecfg);
4137        }
4138
4139        git_SHA1_Final(sha1, &ctx);
4140        return 0;
4141}
4142
4143int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4144{
4145        struct diff_queue_struct *q = &diff_queued_diff;
4146        int i;
4147        int result = diff_get_patch_id(options, sha1);
4148
4149        for (i = 0; i < q->nr; i++)
4150                diff_free_filepair(q->queue[i]);
4151
4152        free(q->queue);
4153        DIFF_QUEUE_CLEAR(q);
4154
4155        return result;
4156}
4157
4158static int is_summary_empty(const struct diff_queue_struct *q)
4159{
4160        int i;
4161
4162        for (i = 0; i < q->nr; i++) {
4163                const struct diff_filepair *p = q->queue[i];
4164
4165                switch (p->status) {
4166                case DIFF_STATUS_DELETED:
4167                case DIFF_STATUS_ADDED:
4168                case DIFF_STATUS_COPIED:
4169                case DIFF_STATUS_RENAMED:
4170                        return 0;
4171                default:
4172                        if (p->score)
4173                                return 0;
4174                        if (p->one->mode && p->two->mode &&
4175                            p->one->mode != p->two->mode)
4176                                return 0;
4177                        break;
4178                }
4179        }
4180        return 1;
4181}
4182
4183static const char rename_limit_warning[] =
4184"inexact rename detection was skipped due to too many files.";
4185
4186static const char degrade_cc_to_c_warning[] =
4187"only found copies from modified paths due to too many files.";
4188
4189static const char rename_limit_advice[] =
4190"you may want to set your %s variable to at least "
4191"%d and retry the command.";
4192
4193void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4194{
4195        if (degraded_cc)
4196                warning(degrade_cc_to_c_warning);
4197        else if (needed)
4198                warning(rename_limit_warning);
4199        else
4200                return;
4201        if (0 < needed && needed < 32767)
4202                warning(rename_limit_advice, varname, needed);
4203}
4204
4205void diff_flush(struct diff_options *options)
4206{
4207        struct diff_queue_struct *q = &diff_queued_diff;
4208        int i, output_format = options->output_format;
4209        int separator = 0;
4210        int dirstat_by_line = 0;
4211
4212        /*
4213         * Order: raw, stat, summary, patch
4214         * or:    name/name-status/checkdiff (other bits clear)
4215         */
4216        if (!q->nr)
4217                goto free_queue;
4218
4219        if (output_format & (DIFF_FORMAT_RAW |
4220                             DIFF_FORMAT_NAME |
4221                             DIFF_FORMAT_NAME_STATUS |
4222                             DIFF_FORMAT_CHECKDIFF)) {
4223                for (i = 0; i < q->nr; i++) {
4224                        struct diff_filepair *p = q->queue[i];
4225                        if (check_pair_status(p))
4226                                flush_one_pair(p, options);
4227                }
4228                separator++;
4229        }
4230
4231        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4232                dirstat_by_line = 1;
4233
4234        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4235            dirstat_by_line) {
4236                struct diffstat_t diffstat;
4237
4238                memset(&diffstat, 0, sizeof(struct diffstat_t));
4239                for (i = 0; i < q->nr; i++) {
4240                        struct diff_filepair *p = q->queue[i];
4241                        if (check_pair_status(p))
4242                                diff_flush_stat(p, options, &diffstat);
4243                }
4244                if (output_format & DIFF_FORMAT_NUMSTAT)
4245                        show_numstat(&diffstat, options);
4246                if (output_format & DIFF_FORMAT_DIFFSTAT)
4247                        show_stats(&diffstat, options);
4248                if (output_format & DIFF_FORMAT_SHORTSTAT)
4249                        show_shortstats(&diffstat, options);
4250                if (output_format & DIFF_FORMAT_DIRSTAT)
4251                        show_dirstat_by_line(&diffstat, options);
4252                free_diffstat_info(&diffstat);
4253                separator++;
4254        }
4255        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4256                show_dirstat(options);
4257
4258        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4259                for (i = 0; i < q->nr; i++) {
4260                        diff_summary(options, q->queue[i]);
4261                }
4262                separator++;
4263        }
4264
4265        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4266            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4267            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4268                /*
4269                 * run diff_flush_patch for the exit status. setting
4270                 * options->file to /dev/null should be safe, becaue we
4271                 * aren't supposed to produce any output anyway.
4272                 */
4273                if (options->close_file)
4274                        fclose(options->file);
4275                options->file = fopen("/dev/null", "w");
4276                if (!options->file)
4277                        die_errno("Could not open /dev/null");
4278                options->close_file = 1;
4279                for (i = 0; i < q->nr; i++) {
4280                        struct diff_filepair *p = q->queue[i];
4281                        if (check_pair_status(p))
4282                                diff_flush_patch(p, options);
4283                        if (options->found_changes)
4284                                break;
4285                }
4286        }
4287
4288        if (output_format & DIFF_FORMAT_PATCH) {
4289                if (separator) {
4290                        putc(options->line_termination, options->file);
4291                        if (options->stat_sep) {
4292                                /* attach patch instead of inline */
4293                                fputs(options->stat_sep, options->file);
4294                        }
4295                }
4296
4297                for (i = 0; i < q->nr; i++) {
4298                        struct diff_filepair *p = q->queue[i];
4299                        if (check_pair_status(p))
4300                                diff_flush_patch(p, options);
4301                }
4302        }
4303
4304        if (output_format & DIFF_FORMAT_CALLBACK)
4305                options->format_callback(q, options, options->format_callback_data);
4306
4307        for (i = 0; i < q->nr; i++)
4308                diff_free_filepair(q->queue[i]);
4309free_queue:
4310        free(q->queue);
4311        DIFF_QUEUE_CLEAR(q);
4312        if (options->close_file)
4313                fclose(options->file);
4314
4315        /*
4316         * Report the content-level differences with HAS_CHANGES;
4317         * diff_addremove/diff_change does not set the bit when
4318         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4319         */
4320        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4321                if (options->found_changes)
4322                        DIFF_OPT_SET(options, HAS_CHANGES);
4323                else
4324                        DIFF_OPT_CLR(options, HAS_CHANGES);
4325        }
4326}
4327
4328static void diffcore_apply_filter(const char *filter)
4329{
4330        int i;
4331        struct diff_queue_struct *q = &diff_queued_diff;
4332        struct diff_queue_struct outq;
4333        DIFF_QUEUE_CLEAR(&outq);
4334
4335        if (!filter)
4336                return;
4337
4338        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4339                int found;
4340                for (i = found = 0; !found && i < q->nr; i++) {
4341                        struct diff_filepair *p = q->queue[i];
4342                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4343                             ((p->score &&
4344                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4345                              (!p->score &&
4346                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4347                            ((p->status != DIFF_STATUS_MODIFIED) &&
4348                             strchr(filter, p->status)))
4349                                found++;
4350                }
4351                if (found)
4352                        return;
4353
4354                /* otherwise we will clear the whole queue
4355                 * by copying the empty outq at the end of this
4356                 * function, but first clear the current entries
4357                 * in the queue.
4358                 */
4359                for (i = 0; i < q->nr; i++)
4360                        diff_free_filepair(q->queue[i]);
4361        }
4362        else {
4363                /* Only the matching ones */
4364                for (i = 0; i < q->nr; i++) {
4365                        struct diff_filepair *p = q->queue[i];
4366
4367                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4368                             ((p->score &&
4369                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4370                              (!p->score &&
4371                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4372                            ((p->status != DIFF_STATUS_MODIFIED) &&
4373                             strchr(filter, p->status)))
4374                                diff_q(&outq, p);
4375                        else
4376                                diff_free_filepair(p);
4377                }
4378        }
4379        free(q->queue);
4380        *q = outq;
4381}
4382
4383/* Check whether two filespecs with the same mode and size are identical */
4384static int diff_filespec_is_identical(struct diff_filespec *one,
4385                                      struct diff_filespec *two)
4386{
4387        if (S_ISGITLINK(one->mode))
4388                return 0;
4389        if (diff_populate_filespec(one, 0))
4390                return 0;
4391        if (diff_populate_filespec(two, 0))
4392                return 0;
4393        return !memcmp(one->data, two->data, one->size);
4394}
4395
4396static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4397{
4398        int i;
4399        struct diff_queue_struct *q = &diff_queued_diff;
4400        struct diff_queue_struct outq;
4401        DIFF_QUEUE_CLEAR(&outq);
4402
4403        for (i = 0; i < q->nr; i++) {
4404                struct diff_filepair *p = q->queue[i];
4405
4406                /*
4407                 * 1. Entries that come from stat info dirtiness
4408                 *    always have both sides (iow, not create/delete),
4409                 *    one side of the object name is unknown, with
4410                 *    the same mode and size.  Keep the ones that
4411                 *    do not match these criteria.  They have real
4412                 *    differences.
4413                 *
4414                 * 2. At this point, the file is known to be modified,
4415                 *    with the same mode and size, and the object
4416                 *    name of one side is unknown.  Need to inspect
4417                 *    the identical contents.
4418                 */
4419                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4420                    !DIFF_FILE_VALID(p->two) ||
4421                    (p->one->sha1_valid && p->two->sha1_valid) ||
4422                    (p->one->mode != p->two->mode) ||
4423                    diff_populate_filespec(p->one, 1) ||
4424                    diff_populate_filespec(p->two, 1) ||
4425                    (p->one->size != p->two->size) ||
4426                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4427                        diff_q(&outq, p);
4428                else {
4429                        /*
4430                         * The caller can subtract 1 from skip_stat_unmatch
4431                         * to determine how many paths were dirty only
4432                         * due to stat info mismatch.
4433                         */
4434                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4435                                diffopt->skip_stat_unmatch++;
4436                        diff_free_filepair(p);
4437                }
4438        }
4439        free(q->queue);
4440        *q = outq;
4441}
4442
4443static int diffnamecmp(const void *a_, const void *b_)
4444{
4445        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4446        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4447        const char *name_a, *name_b;
4448
4449        name_a = a->one ? a->one->path : a->two->path;
4450        name_b = b->one ? b->one->path : b->two->path;
4451        return strcmp(name_a, name_b);
4452}
4453
4454void diffcore_fix_diff_index(struct diff_options *options)
4455{
4456        struct diff_queue_struct *q = &diff_queued_diff;
4457        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4458}
4459
4460void diffcore_std(struct diff_options *options)
4461{
4462        if (options->skip_stat_unmatch)
4463                diffcore_skip_stat_unmatch(options);
4464        if (!options->found_follow) {
4465                /* See try_to_follow_renames() in tree-diff.c */
4466                if (options->break_opt != -1)
4467                        diffcore_break(options->break_opt);
4468                if (options->detect_rename)
4469                        diffcore_rename(options);
4470                if (options->break_opt != -1)
4471                        diffcore_merge_broken();
4472        }
4473        if (options->pickaxe)
4474                diffcore_pickaxe(options);
4475        if (options->orderfile)
4476                diffcore_order(options->orderfile);
4477        if (!options->found_follow)
4478                /* See try_to_follow_renames() in tree-diff.c */
4479                diff_resolve_rename_copy();
4480        diffcore_apply_filter(options->filter);
4481
4482        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4483                DIFF_OPT_SET(options, HAS_CHANGES);
4484        else
4485                DIFF_OPT_CLR(options, HAS_CHANGES);
4486
4487        options->found_follow = 0;
4488}
4489
4490int diff_result_code(struct diff_options *opt, int status)
4491{
4492        int result = 0;
4493
4494        diff_warn_rename_limit("diff.renamelimit",
4495                               opt->needed_rename_limit,
4496                               opt->degraded_cc_to_c);
4497        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4498            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4499                return status;
4500        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4501            DIFF_OPT_TST(opt, HAS_CHANGES))
4502                result |= 01;
4503        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4504            DIFF_OPT_TST(opt, CHECK_FAILED))
4505                result |= 02;
4506        return result;
4507}
4508
4509int diff_can_quit_early(struct diff_options *opt)
4510{
4511        return (DIFF_OPT_TST(opt, QUICK) &&
4512                !opt->filter &&
4513                DIFF_OPT_TST(opt, HAS_CHANGES));
4514}
4515
4516/*
4517 * Shall changes to this submodule be ignored?
4518 *
4519 * Submodule changes can be configured to be ignored separately for each path,
4520 * but that configuration can be overridden from the command line.
4521 */
4522static int is_submodule_ignored(const char *path, struct diff_options *options)
4523{
4524        int ignored = 0;
4525        unsigned orig_flags = options->flags;
4526        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4527                set_diffopt_flags_from_submodule_config(options, path);
4528        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4529                ignored = 1;
4530        options->flags = orig_flags;
4531        return ignored;
4532}
4533
4534void diff_addremove(struct diff_options *options,
4535                    int addremove, unsigned mode,
4536                    const unsigned char *sha1,
4537                    const char *concatpath, unsigned dirty_submodule)
4538{
4539        struct diff_filespec *one, *two;
4540
4541        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4542                return;
4543
4544        /* This may look odd, but it is a preparation for
4545         * feeding "there are unchanged files which should
4546         * not produce diffs, but when you are doing copy
4547         * detection you would need them, so here they are"
4548         * entries to the diff-core.  They will be prefixed
4549         * with something like '=' or '*' (I haven't decided
4550         * which but should not make any difference).
4551         * Feeding the same new and old to diff_change()
4552         * also has the same effect.
4553         * Before the final output happens, they are pruned after
4554         * merged into rename/copy pairs as appropriate.
4555         */
4556        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4557                addremove = (addremove == '+' ? '-' :
4558                             addremove == '-' ? '+' : addremove);
4559
4560        if (options->prefix &&
4561            strncmp(concatpath, options->prefix, options->prefix_length))
4562                return;
4563
4564        one = alloc_filespec(concatpath);
4565        two = alloc_filespec(concatpath);
4566
4567        if (addremove != '+')
4568                fill_filespec(one, sha1, mode);
4569        if (addremove != '-') {
4570                fill_filespec(two, sha1, mode);
4571                two->dirty_submodule = dirty_submodule;
4572        }
4573
4574        diff_queue(&diff_queued_diff, one, two);
4575        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4576                DIFF_OPT_SET(options, HAS_CHANGES);
4577}
4578
4579void diff_change(struct diff_options *options,
4580                 unsigned old_mode, unsigned new_mode,
4581                 const unsigned char *old_sha1,
4582                 const unsigned char *new_sha1,
4583                 const char *concatpath,
4584                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4585{
4586        struct diff_filespec *one, *two;
4587
4588        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4589            is_submodule_ignored(concatpath, options))
4590                return;
4591
4592        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4593                unsigned tmp;
4594                const unsigned char *tmp_c;
4595                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4596                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4597                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4598                        new_dirty_submodule = tmp;
4599        }
4600
4601        if (options->prefix &&
4602            strncmp(concatpath, options->prefix, options->prefix_length))
4603                return;
4604
4605        one = alloc_filespec(concatpath);
4606        two = alloc_filespec(concatpath);
4607        fill_filespec(one, old_sha1, old_mode);
4608        fill_filespec(two, new_sha1, new_mode);
4609        one->dirty_submodule = old_dirty_submodule;
4610        two->dirty_submodule = new_dirty_submodule;
4611
4612        diff_queue(&diff_queued_diff, one, two);
4613        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4614                DIFF_OPT_SET(options, HAS_CHANGES);
4615}
4616
4617struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4618{
4619        struct diff_filepair *pair;
4620        struct diff_filespec *one, *two;
4621
4622        if (options->prefix &&
4623            strncmp(path, options->prefix, options->prefix_length))
4624                return NULL;
4625
4626        one = alloc_filespec(path);
4627        two = alloc_filespec(path);
4628        pair = diff_queue(&diff_queued_diff, one, two);
4629        pair->is_unmerged = 1;
4630        return pair;
4631}
4632
4633static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4634                size_t *outsize)
4635{
4636        struct diff_tempfile *temp;
4637        const char *argv[3];
4638        const char **arg = argv;
4639        struct child_process child;
4640        struct strbuf buf = STRBUF_INIT;
4641        int err = 0;
4642
4643        temp = prepare_temp_file(spec->path, spec);
4644        *arg++ = pgm;
4645        *arg++ = temp->name;
4646        *arg = NULL;
4647
4648        memset(&child, 0, sizeof(child));
4649        child.use_shell = 1;
4650        child.argv = argv;
4651        child.out = -1;
4652        if (start_command(&child)) {
4653                remove_tempfile();
4654                return NULL;
4655        }
4656
4657        if (strbuf_read(&buf, child.out, 0) < 0)
4658                err = error("error reading from textconv command '%s'", pgm);
4659        close(child.out);
4660
4661        if (finish_command(&child) || err) {
4662                strbuf_release(&buf);
4663                remove_tempfile();
4664                return NULL;
4665        }
4666        remove_tempfile();
4667
4668        return strbuf_detach(&buf, outsize);
4669}
4670
4671size_t fill_textconv(struct userdiff_driver *driver,
4672                     struct diff_filespec *df,
4673                     char **outbuf)
4674{
4675        size_t size;
4676
4677        if (!driver || !driver->textconv) {
4678                if (!DIFF_FILE_VALID(df)) {
4679                        *outbuf = "";
4680                        return 0;
4681                }
4682                if (diff_populate_filespec(df, 0))
4683                        die("unable to read files to diff");
4684                *outbuf = df->data;
4685                return df->size;
4686        }
4687
4688        if (driver->textconv_cache && df->sha1_valid) {
4689                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4690                                          &size);
4691                if (*outbuf)
4692                        return size;
4693        }
4694
4695        *outbuf = run_textconv(driver->textconv, df, &size);
4696        if (!*outbuf)
4697                die("unable to read files to diff");
4698
4699        if (driver->textconv_cache && df->sha1_valid) {
4700                /* ignore errors, as we might be in a readonly repository */
4701                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4702                                size);
4703                /*
4704                 * we could save up changes and flush them all at the end,
4705                 * but we would need an extra call after all diffing is done.
4706                 * Since generating a cache entry is the slow path anyway,
4707                 * this extra overhead probably isn't a big deal.
4708                 */
4709                notes_cache_write(driver->textconv_cache);
4710        }
4711
4712        return size;
4713}