e2f910ad14a2836440ebcae5cdebde6395923e61
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33
  34static char diff_colors[][COLOR_MAXLEN] = {
  35        GIT_COLOR_RESET,
  36        GIT_COLOR_NORMAL,       /* PLAIN */
  37        GIT_COLOR_BOLD,         /* METAINFO */
  38        GIT_COLOR_CYAN,         /* FRAGINFO */
  39        GIT_COLOR_RED,          /* OLD */
  40        GIT_COLOR_GREEN,        /* NEW */
  41        GIT_COLOR_YELLOW,       /* COMMIT */
  42        GIT_COLOR_BG_RED,       /* WHITESPACE */
  43        GIT_COLOR_NORMAL,       /* FUNCINFO */
  44};
  45
  46static void diff_filespec_load_driver(struct diff_filespec *one);
  47static size_t fill_textconv(struct userdiff_driver *driver,
  48                            struct diff_filespec *df, char **outbuf);
  49
  50static int parse_diff_color_slot(const char *var, int ofs)
  51{
  52        if (!strcasecmp(var+ofs, "plain"))
  53                return DIFF_PLAIN;
  54        if (!strcasecmp(var+ofs, "meta"))
  55                return DIFF_METAINFO;
  56        if (!strcasecmp(var+ofs, "frag"))
  57                return DIFF_FRAGINFO;
  58        if (!strcasecmp(var+ofs, "old"))
  59                return DIFF_FILE_OLD;
  60        if (!strcasecmp(var+ofs, "new"))
  61                return DIFF_FILE_NEW;
  62        if (!strcasecmp(var+ofs, "commit"))
  63                return DIFF_COMMIT;
  64        if (!strcasecmp(var+ofs, "whitespace"))
  65                return DIFF_WHITESPACE;
  66        if (!strcasecmp(var+ofs, "func"))
  67                return DIFF_FUNCINFO;
  68        return -1;
  69}
  70
  71static int git_config_rename(const char *var, const char *value)
  72{
  73        if (!value)
  74                return DIFF_DETECT_RENAME;
  75        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  76                return  DIFF_DETECT_COPY;
  77        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  78}
  79
  80/*
  81 * These are to give UI layer defaults.
  82 * The core-level commands such as git-diff-files should
  83 * never be affected by the setting of diff.renames
  84 * the user happens to have in the configuration file.
  85 */
  86int git_diff_ui_config(const char *var, const char *value, void *cb)
  87{
  88        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  89                diff_use_color_default = git_config_colorbool(var, value, -1);
  90                return 0;
  91        }
  92        if (!strcmp(var, "diff.renames")) {
  93                diff_detect_rename_default = git_config_rename(var, value);
  94                return 0;
  95        }
  96        if (!strcmp(var, "diff.autorefreshindex")) {
  97                diff_auto_refresh_index = git_config_bool(var, value);
  98                return 0;
  99        }
 100        if (!strcmp(var, "diff.mnemonicprefix")) {
 101                diff_mnemonic_prefix = git_config_bool(var, value);
 102                return 0;
 103        }
 104        if (!strcmp(var, "diff.external"))
 105                return git_config_string(&external_diff_cmd_cfg, var, value);
 106        if (!strcmp(var, "diff.wordregex"))
 107                return git_config_string(&diff_word_regex_cfg, var, value);
 108
 109        return git_diff_basic_config(var, value, cb);
 110}
 111
 112int git_diff_basic_config(const char *var, const char *value, void *cb)
 113{
 114        if (!strcmp(var, "diff.renamelimit")) {
 115                diff_rename_limit_default = git_config_int(var, value);
 116                return 0;
 117        }
 118
 119        switch (userdiff_config(var, value)) {
 120                case 0: break;
 121                case -1: return -1;
 122                default: return 0;
 123        }
 124
 125        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 126                int slot = parse_diff_color_slot(var, 11);
 127                if (slot < 0)
 128                        return 0;
 129                if (!value)
 130                        return config_error_nonbool(var);
 131                color_parse(value, var, diff_colors[slot]);
 132                return 0;
 133        }
 134
 135        /* like GNU diff's --suppress-blank-empty option  */
 136        if (!strcmp(var, "diff.suppressblankempty") ||
 137                        /* for backwards compatibility */
 138                        !strcmp(var, "diff.suppress-blank-empty")) {
 139                diff_suppress_blank_empty = git_config_bool(var, value);
 140                return 0;
 141        }
 142
 143        return git_color_default_config(var, value, cb);
 144}
 145
 146static char *quote_two(const char *one, const char *two)
 147{
 148        int need_one = quote_c_style(one, NULL, NULL, 1);
 149        int need_two = quote_c_style(two, NULL, NULL, 1);
 150        struct strbuf res = STRBUF_INIT;
 151
 152        if (need_one + need_two) {
 153                strbuf_addch(&res, '"');
 154                quote_c_style(one, &res, NULL, 1);
 155                quote_c_style(two, &res, NULL, 1);
 156                strbuf_addch(&res, '"');
 157        } else {
 158                strbuf_addstr(&res, one);
 159                strbuf_addstr(&res, two);
 160        }
 161        return strbuf_detach(&res, NULL);
 162}
 163
 164static const char *external_diff(void)
 165{
 166        static const char *external_diff_cmd = NULL;
 167        static int done_preparing = 0;
 168
 169        if (done_preparing)
 170                return external_diff_cmd;
 171        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 172        if (!external_diff_cmd)
 173                external_diff_cmd = external_diff_cmd_cfg;
 174        done_preparing = 1;
 175        return external_diff_cmd;
 176}
 177
 178static struct diff_tempfile {
 179        const char *name; /* filename external diff should read from */
 180        char hex[41];
 181        char mode[10];
 182        char tmp_path[PATH_MAX];
 183} diff_temp[2];
 184
 185typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 186
 187struct emit_callback {
 188        int color_diff;
 189        unsigned ws_rule;
 190        int blank_at_eof_in_preimage;
 191        int blank_at_eof_in_postimage;
 192        int lno_in_preimage;
 193        int lno_in_postimage;
 194        sane_truncate_fn truncate;
 195        const char **label_path;
 196        struct diff_words_data *diff_words;
 197        struct diff_options *opt;
 198        int *found_changesp;
 199        struct strbuf *header;
 200};
 201
 202static int count_lines(const char *data, int size)
 203{
 204        int count, ch, completely_empty = 1, nl_just_seen = 0;
 205        count = 0;
 206        while (0 < size--) {
 207                ch = *data++;
 208                if (ch == '\n') {
 209                        count++;
 210                        nl_just_seen = 1;
 211                        completely_empty = 0;
 212                }
 213                else {
 214                        nl_just_seen = 0;
 215                        completely_empty = 0;
 216                }
 217        }
 218        if (completely_empty)
 219                return 0;
 220        if (!nl_just_seen)
 221                count++; /* no trailing newline */
 222        return count;
 223}
 224
 225static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 226{
 227        if (!DIFF_FILE_VALID(one)) {
 228                mf->ptr = (char *)""; /* does not matter */
 229                mf->size = 0;
 230                return 0;
 231        }
 232        else if (diff_populate_filespec(one, 0))
 233                return -1;
 234
 235        mf->ptr = one->data;
 236        mf->size = one->size;
 237        return 0;
 238}
 239
 240static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 241{
 242        char *ptr = mf->ptr;
 243        long size = mf->size;
 244        int cnt = 0;
 245
 246        if (!size)
 247                return cnt;
 248        ptr += size - 1; /* pointing at the very end */
 249        if (*ptr != '\n')
 250                ; /* incomplete line */
 251        else
 252                ptr--; /* skip the last LF */
 253        while (mf->ptr < ptr) {
 254                char *prev_eol;
 255                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 256                        if (*prev_eol == '\n')
 257                                break;
 258                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 259                        break;
 260                cnt++;
 261                ptr = prev_eol - 1;
 262        }
 263        return cnt;
 264}
 265
 266static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 267                               struct emit_callback *ecbdata)
 268{
 269        int l1, l2, at;
 270        unsigned ws_rule = ecbdata->ws_rule;
 271        l1 = count_trailing_blank(mf1, ws_rule);
 272        l2 = count_trailing_blank(mf2, ws_rule);
 273        if (l2 <= l1) {
 274                ecbdata->blank_at_eof_in_preimage = 0;
 275                ecbdata->blank_at_eof_in_postimage = 0;
 276                return;
 277        }
 278        at = count_lines(mf1->ptr, mf1->size);
 279        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 280
 281        at = count_lines(mf2->ptr, mf2->size);
 282        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 283}
 284
 285static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 286                        int first, const char *line, int len)
 287{
 288        int has_trailing_newline, has_trailing_carriage_return;
 289        int nofirst;
 290        FILE *file = o->file;
 291
 292        if (o->output_prefix) {
 293                struct strbuf *msg = NULL;
 294                msg = o->output_prefix(o, o->output_prefix_data);
 295                assert(msg);
 296                fwrite(msg->buf, msg->len, 1, file);
 297        }
 298
 299        if (len == 0) {
 300                has_trailing_newline = (first == '\n');
 301                has_trailing_carriage_return = (!has_trailing_newline &&
 302                                                (first == '\r'));
 303                nofirst = has_trailing_newline || has_trailing_carriage_return;
 304        } else {
 305                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 306                if (has_trailing_newline)
 307                        len--;
 308                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 309                if (has_trailing_carriage_return)
 310                        len--;
 311                nofirst = 0;
 312        }
 313
 314        if (len || !nofirst) {
 315                fputs(set, file);
 316                if (!nofirst)
 317                        fputc(first, file);
 318                fwrite(line, len, 1, file);
 319                fputs(reset, file);
 320        }
 321        if (has_trailing_carriage_return)
 322                fputc('\r', file);
 323        if (has_trailing_newline)
 324                fputc('\n', file);
 325}
 326
 327static void emit_line(struct diff_options *o, const char *set, const char *reset,
 328                      const char *line, int len)
 329{
 330        emit_line_0(o, set, reset, line[0], line+1, len-1);
 331}
 332
 333static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 334{
 335        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 336              ecbdata->blank_at_eof_in_preimage &&
 337              ecbdata->blank_at_eof_in_postimage &&
 338              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 339              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 340                return 0;
 341        return ws_blank_line(line, len, ecbdata->ws_rule);
 342}
 343
 344static void emit_add_line(const char *reset,
 345                          struct emit_callback *ecbdata,
 346                          const char *line, int len)
 347{
 348        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 349        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 350
 351        if (!*ws)
 352                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 353        else if (new_blank_line_at_eof(ecbdata, line, len))
 354                /* Blank line at EOF - paint '+' as well */
 355                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 356        else {
 357                /* Emit just the prefix, then the rest. */
 358                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 359                ws_check_emit(line, len, ecbdata->ws_rule,
 360                              ecbdata->opt->file, set, reset, ws);
 361        }
 362}
 363
 364static void emit_hunk_header(struct emit_callback *ecbdata,
 365                             const char *line, int len)
 366{
 367        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 368        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 369        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 370        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 371        static const char atat[2] = { '@', '@' };
 372        const char *cp, *ep;
 373
 374        /*
 375         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 376         * it always is at least 10 bytes long.
 377         */
 378        if (len < 10 ||
 379            memcmp(line, atat, 2) ||
 380            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 381                emit_line(ecbdata->opt, plain, reset, line, len);
 382                return;
 383        }
 384        ep += 2; /* skip over @@ */
 385
 386        /* The hunk header in fraginfo color */
 387        emit_line(ecbdata->opt, frag, reset, line, ep - line);
 388
 389        /* blank before the func header */
 390        for (cp = ep; ep - line < len; ep++)
 391                if (*ep != ' ' && *ep != '\t')
 392                        break;
 393        if (ep != cp)
 394                emit_line(ecbdata->opt, plain, reset, cp, ep - cp);
 395
 396        if (ep < line + len)
 397                emit_line(ecbdata->opt, func, reset, ep, line + len - ep);
 398}
 399
 400static struct diff_tempfile *claim_diff_tempfile(void) {
 401        int i;
 402        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 403                if (!diff_temp[i].name)
 404                        return diff_temp + i;
 405        die("BUG: diff is failing to clean up its tempfiles");
 406}
 407
 408static int remove_tempfile_installed;
 409
 410static void remove_tempfile(void)
 411{
 412        int i;
 413        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 414                if (diff_temp[i].name == diff_temp[i].tmp_path)
 415                        unlink_or_warn(diff_temp[i].name);
 416                diff_temp[i].name = NULL;
 417        }
 418}
 419
 420static void remove_tempfile_on_signal(int signo)
 421{
 422        remove_tempfile();
 423        sigchain_pop(signo);
 424        raise(signo);
 425}
 426
 427static void print_line_count(FILE *file, int count)
 428{
 429        switch (count) {
 430        case 0:
 431                fprintf(file, "0,0");
 432                break;
 433        case 1:
 434                fprintf(file, "1");
 435                break;
 436        default:
 437                fprintf(file, "1,%d", count);
 438                break;
 439        }
 440}
 441
 442static void emit_rewrite_lines(struct emit_callback *ecb,
 443                               int prefix, const char *data, int size)
 444{
 445        const char *endp = NULL;
 446        static const char *nneof = " No newline at end of file\n";
 447        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 448        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 449
 450        while (0 < size) {
 451                int len;
 452
 453                endp = memchr(data, '\n', size);
 454                len = endp ? (endp - data + 1) : size;
 455                if (prefix != '+') {
 456                        ecb->lno_in_preimage++;
 457                        emit_line_0(ecb->opt, old, reset, '-',
 458                                    data, len);
 459                } else {
 460                        ecb->lno_in_postimage++;
 461                        emit_add_line(reset, ecb, data, len);
 462                }
 463                size -= len;
 464                data += len;
 465        }
 466        if (!endp) {
 467                const char *plain = diff_get_color(ecb->color_diff,
 468                                                   DIFF_PLAIN);
 469                emit_line_0(ecb->opt, plain, reset, '\\',
 470                            nneof, strlen(nneof));
 471        }
 472}
 473
 474static void emit_rewrite_diff(const char *name_a,
 475                              const char *name_b,
 476                              struct diff_filespec *one,
 477                              struct diff_filespec *two,
 478                              struct userdiff_driver *textconv_one,
 479                              struct userdiff_driver *textconv_two,
 480                              struct diff_options *o)
 481{
 482        int lc_a, lc_b;
 483        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 484        const char *name_a_tab, *name_b_tab;
 485        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 486        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 487        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 488        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 489        const char *a_prefix, *b_prefix;
 490        char *data_one, *data_two;
 491        size_t size_one, size_two;
 492        struct emit_callback ecbdata;
 493
 494        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 495                a_prefix = o->b_prefix;
 496                b_prefix = o->a_prefix;
 497        } else {
 498                a_prefix = o->a_prefix;
 499                b_prefix = o->b_prefix;
 500        }
 501
 502        name_a += (*name_a == '/');
 503        name_b += (*name_b == '/');
 504        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 505        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 506
 507        strbuf_reset(&a_name);
 508        strbuf_reset(&b_name);
 509        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 510        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 511
 512        size_one = fill_textconv(textconv_one, one, &data_one);
 513        size_two = fill_textconv(textconv_two, two, &data_two);
 514
 515        memset(&ecbdata, 0, sizeof(ecbdata));
 516        ecbdata.color_diff = color_diff;
 517        ecbdata.found_changesp = &o->found_changes;
 518        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 519        ecbdata.opt = o;
 520        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 521                mmfile_t mf1, mf2;
 522                mf1.ptr = (char *)data_one;
 523                mf2.ptr = (char *)data_two;
 524                mf1.size = size_one;
 525                mf2.size = size_two;
 526                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 527        }
 528        ecbdata.lno_in_preimage = 1;
 529        ecbdata.lno_in_postimage = 1;
 530
 531        lc_a = count_lines(data_one, size_one);
 532        lc_b = count_lines(data_two, size_two);
 533        fprintf(o->file,
 534                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 535                metainfo, a_name.buf, name_a_tab, reset,
 536                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 537        print_line_count(o->file, lc_a);
 538        fprintf(o->file, " +");
 539        print_line_count(o->file, lc_b);
 540        fprintf(o->file, " @@%s\n", reset);
 541        if (lc_a)
 542                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 543        if (lc_b)
 544                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 545        if (textconv_one)
 546                free((char *)data_one);
 547        if (textconv_two)
 548                free((char *)data_two);
 549}
 550
 551struct diff_words_buffer {
 552        mmfile_t text;
 553        long alloc;
 554        struct diff_words_orig {
 555                const char *begin, *end;
 556        } *orig;
 557        int orig_nr, orig_alloc;
 558};
 559
 560static void diff_words_append(char *line, unsigned long len,
 561                struct diff_words_buffer *buffer)
 562{
 563        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 564        line++;
 565        len--;
 566        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 567        buffer->text.size += len;
 568        buffer->text.ptr[buffer->text.size] = '\0';
 569}
 570
 571struct diff_words_style_elem
 572{
 573        const char *prefix;
 574        const char *suffix;
 575        const char *color; /* NULL; filled in by the setup code if
 576                            * color is enabled */
 577};
 578
 579struct diff_words_style
 580{
 581        enum diff_words_type type;
 582        struct diff_words_style_elem new, old, ctx;
 583        const char *newline;
 584};
 585
 586struct diff_words_style diff_words_styles[] = {
 587        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 588        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 589        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 590};
 591
 592struct diff_words_data {
 593        struct diff_words_buffer minus, plus;
 594        const char *current_plus;
 595        FILE *file;
 596        regex_t *word_regex;
 597        enum diff_words_type type;
 598        struct diff_words_style *style;
 599};
 600
 601static int fn_out_diff_words_write_helper(FILE *fp,
 602                                          struct diff_words_style_elem *st_el,
 603                                          const char *newline,
 604                                          size_t count, const char *buf)
 605{
 606        while (count) {
 607                char *p = memchr(buf, '\n', count);
 608                if (p != buf) {
 609                        if (st_el->color && fputs(st_el->color, fp) < 0)
 610                                return -1;
 611                        if (fputs(st_el->prefix, fp) < 0 ||
 612                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 613                            fputs(st_el->suffix, fp) < 0)
 614                                return -1;
 615                        if (st_el->color && *st_el->color
 616                            && fputs(GIT_COLOR_RESET, fp) < 0)
 617                                return -1;
 618                }
 619                if (!p)
 620                        return 0;
 621                if (fputs(newline, fp) < 0)
 622                        return -1;
 623                count -= p + 1 - buf;
 624                buf = p + 1;
 625        }
 626        return 0;
 627}
 628
 629static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 630{
 631        struct diff_words_data *diff_words = priv;
 632        struct diff_words_style *style = diff_words->style;
 633        int minus_first, minus_len, plus_first, plus_len;
 634        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 635
 636        if (line[0] != '@' || parse_hunk_header(line, len,
 637                        &minus_first, &minus_len, &plus_first, &plus_len))
 638                return;
 639
 640        /* POSIX requires that first be decremented by one if len == 0... */
 641        if (minus_len) {
 642                minus_begin = diff_words->minus.orig[minus_first].begin;
 643                minus_end =
 644                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 645        } else
 646                minus_begin = minus_end =
 647                        diff_words->minus.orig[minus_first].end;
 648
 649        if (plus_len) {
 650                plus_begin = diff_words->plus.orig[plus_first].begin;
 651                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 652        } else
 653                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 654
 655        if (diff_words->current_plus != plus_begin)
 656                fn_out_diff_words_write_helper(diff_words->file,
 657                                &style->ctx, style->newline,
 658                                plus_begin - diff_words->current_plus,
 659                                diff_words->current_plus);
 660        if (minus_begin != minus_end)
 661                fn_out_diff_words_write_helper(diff_words->file,
 662                                &style->old, style->newline,
 663                                minus_end - minus_begin, minus_begin);
 664        if (plus_begin != plus_end)
 665                fn_out_diff_words_write_helper(diff_words->file,
 666                                &style->new, style->newline,
 667                                plus_end - plus_begin, plus_begin);
 668
 669        diff_words->current_plus = plus_end;
 670}
 671
 672/* This function starts looking at *begin, and returns 0 iff a word was found. */
 673static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 674                int *begin, int *end)
 675{
 676        if (word_regex && *begin < buffer->size) {
 677                regmatch_t match[1];
 678                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 679                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 680                                        '\n', match[0].rm_eo - match[0].rm_so);
 681                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 682                        *begin += match[0].rm_so;
 683                        return *begin >= *end;
 684                }
 685                return -1;
 686        }
 687
 688        /* find the next word */
 689        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 690                (*begin)++;
 691        if (*begin >= buffer->size)
 692                return -1;
 693
 694        /* find the end of the word */
 695        *end = *begin + 1;
 696        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 697                (*end)++;
 698
 699        return 0;
 700}
 701
 702/*
 703 * This function splits the words in buffer->text, stores the list with
 704 * newline separator into out, and saves the offsets of the original words
 705 * in buffer->orig.
 706 */
 707static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 708                regex_t *word_regex)
 709{
 710        int i, j;
 711        long alloc = 0;
 712
 713        out->size = 0;
 714        out->ptr = NULL;
 715
 716        /* fake an empty "0th" word */
 717        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 718        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 719        buffer->orig_nr = 1;
 720
 721        for (i = 0; i < buffer->text.size; i++) {
 722                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 723                        return;
 724
 725                /* store original boundaries */
 726                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 727                                buffer->orig_alloc);
 728                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 729                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 730                buffer->orig_nr++;
 731
 732                /* store one word */
 733                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 734                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 735                out->ptr[out->size + j - i] = '\n';
 736                out->size += j - i + 1;
 737
 738                i = j - 1;
 739        }
 740}
 741
 742/* this executes the word diff on the accumulated buffers */
 743static void diff_words_show(struct diff_words_data *diff_words)
 744{
 745        xpparam_t xpp;
 746        xdemitconf_t xecfg;
 747        mmfile_t minus, plus;
 748        struct diff_words_style *style = diff_words->style;
 749
 750        /* special case: only removal */
 751        if (!diff_words->plus.text.size) {
 752                fn_out_diff_words_write_helper(diff_words->file,
 753                        &style->old, style->newline,
 754                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 755                diff_words->minus.text.size = 0;
 756                return;
 757        }
 758
 759        diff_words->current_plus = diff_words->plus.text.ptr;
 760
 761        memset(&xpp, 0, sizeof(xpp));
 762        memset(&xecfg, 0, sizeof(xecfg));
 763        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 764        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 765        xpp.flags = XDF_NEED_MINIMAL;
 766        /* as only the hunk header will be parsed, we need a 0-context */
 767        xecfg.ctxlen = 0;
 768        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 769                      &xpp, &xecfg);
 770        free(minus.ptr);
 771        free(plus.ptr);
 772        if (diff_words->current_plus != diff_words->plus.text.ptr +
 773                        diff_words->plus.text.size)
 774                fn_out_diff_words_write_helper(diff_words->file,
 775                        &style->ctx, style->newline,
 776                        diff_words->plus.text.ptr + diff_words->plus.text.size
 777                        - diff_words->current_plus, diff_words->current_plus);
 778        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 779}
 780
 781/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 782static void diff_words_flush(struct emit_callback *ecbdata)
 783{
 784        if (ecbdata->diff_words->minus.text.size ||
 785            ecbdata->diff_words->plus.text.size)
 786                diff_words_show(ecbdata->diff_words);
 787}
 788
 789static void free_diff_words_data(struct emit_callback *ecbdata)
 790{
 791        if (ecbdata->diff_words) {
 792                diff_words_flush(ecbdata);
 793                free (ecbdata->diff_words->minus.text.ptr);
 794                free (ecbdata->diff_words->minus.orig);
 795                free (ecbdata->diff_words->plus.text.ptr);
 796                free (ecbdata->diff_words->plus.orig);
 797                free(ecbdata->diff_words->word_regex);
 798                free(ecbdata->diff_words);
 799                ecbdata->diff_words = NULL;
 800        }
 801}
 802
 803const char *diff_get_color(int diff_use_color, enum color_diff ix)
 804{
 805        if (diff_use_color)
 806                return diff_colors[ix];
 807        return "";
 808}
 809
 810static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 811{
 812        const char *cp;
 813        unsigned long allot;
 814        size_t l = len;
 815
 816        if (ecb->truncate)
 817                return ecb->truncate(line, len);
 818        cp = line;
 819        allot = l;
 820        while (0 < l) {
 821                (void) utf8_width(&cp, &l);
 822                if (!cp)
 823                        break; /* truncated in the middle? */
 824        }
 825        return allot - l;
 826}
 827
 828static void find_lno(const char *line, struct emit_callback *ecbdata)
 829{
 830        const char *p;
 831        ecbdata->lno_in_preimage = 0;
 832        ecbdata->lno_in_postimage = 0;
 833        p = strchr(line, '-');
 834        if (!p)
 835                return; /* cannot happen */
 836        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 837        p = strchr(p, '+');
 838        if (!p)
 839                return; /* cannot happen */
 840        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 841}
 842
 843static void fn_out_consume(void *priv, char *line, unsigned long len)
 844{
 845        struct emit_callback *ecbdata = priv;
 846        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 847        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 848        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 849
 850        if (ecbdata->header) {
 851                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 852                strbuf_reset(ecbdata->header);
 853                ecbdata->header = NULL;
 854        }
 855        *(ecbdata->found_changesp) = 1;
 856
 857        if (ecbdata->label_path[0]) {
 858                const char *name_a_tab, *name_b_tab;
 859
 860                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 861                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 862
 863                fprintf(ecbdata->opt->file, "%s--- %s%s%s\n",
 864                        meta, ecbdata->label_path[0], reset, name_a_tab);
 865                fprintf(ecbdata->opt->file, "%s+++ %s%s%s\n",
 866                        meta, ecbdata->label_path[1], reset, name_b_tab);
 867                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 868        }
 869
 870        if (diff_suppress_blank_empty
 871            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 872                line[0] = '\n';
 873                len = 1;
 874        }
 875
 876        if (line[0] == '@') {
 877                if (ecbdata->diff_words)
 878                        diff_words_flush(ecbdata);
 879                len = sane_truncate_line(ecbdata, line, len);
 880                find_lno(line, ecbdata);
 881                emit_hunk_header(ecbdata, line, len);
 882                if (line[len-1] != '\n')
 883                        putc('\n', ecbdata->opt->file);
 884                return;
 885        }
 886
 887        if (len < 1) {
 888                emit_line(ecbdata->opt, reset, reset, line, len);
 889                if (ecbdata->diff_words
 890                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
 891                        fputs("~\n", ecbdata->opt->file);
 892                return;
 893        }
 894
 895        if (ecbdata->diff_words) {
 896                if (line[0] == '-') {
 897                        diff_words_append(line, len,
 898                                          &ecbdata->diff_words->minus);
 899                        return;
 900                } else if (line[0] == '+') {
 901                        diff_words_append(line, len,
 902                                          &ecbdata->diff_words->plus);
 903                        return;
 904                }
 905                diff_words_flush(ecbdata);
 906                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
 907                        emit_line(ecbdata->opt, plain, reset, line, len);
 908                        fputs("~\n", ecbdata->opt->file);
 909                } else {
 910                        /* don't print the prefix character */
 911                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
 912                }
 913                return;
 914        }
 915
 916        if (line[0] != '+') {
 917                const char *color =
 918                        diff_get_color(ecbdata->color_diff,
 919                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
 920                ecbdata->lno_in_preimage++;
 921                if (line[0] == ' ')
 922                        ecbdata->lno_in_postimage++;
 923                emit_line(ecbdata->opt, color, reset, line, len);
 924        } else {
 925                ecbdata->lno_in_postimage++;
 926                emit_add_line(reset, ecbdata, line + 1, len - 1);
 927        }
 928}
 929
 930static char *pprint_rename(const char *a, const char *b)
 931{
 932        const char *old = a;
 933        const char *new = b;
 934        struct strbuf name = STRBUF_INIT;
 935        int pfx_length, sfx_length;
 936        int len_a = strlen(a);
 937        int len_b = strlen(b);
 938        int a_midlen, b_midlen;
 939        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 940        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 941
 942        if (qlen_a || qlen_b) {
 943                quote_c_style(a, &name, NULL, 0);
 944                strbuf_addstr(&name, " => ");
 945                quote_c_style(b, &name, NULL, 0);
 946                return strbuf_detach(&name, NULL);
 947        }
 948
 949        /* Find common prefix */
 950        pfx_length = 0;
 951        while (*old && *new && *old == *new) {
 952                if (*old == '/')
 953                        pfx_length = old - a + 1;
 954                old++;
 955                new++;
 956        }
 957
 958        /* Find common suffix */
 959        old = a + len_a;
 960        new = b + len_b;
 961        sfx_length = 0;
 962        while (a <= old && b <= new && *old == *new) {
 963                if (*old == '/')
 964                        sfx_length = len_a - (old - a);
 965                old--;
 966                new--;
 967        }
 968
 969        /*
 970         * pfx{mid-a => mid-b}sfx
 971         * {pfx-a => pfx-b}sfx
 972         * pfx{sfx-a => sfx-b}
 973         * name-a => name-b
 974         */
 975        a_midlen = len_a - pfx_length - sfx_length;
 976        b_midlen = len_b - pfx_length - sfx_length;
 977        if (a_midlen < 0)
 978                a_midlen = 0;
 979        if (b_midlen < 0)
 980                b_midlen = 0;
 981
 982        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 983        if (pfx_length + sfx_length) {
 984                strbuf_add(&name, a, pfx_length);
 985                strbuf_addch(&name, '{');
 986        }
 987        strbuf_add(&name, a + pfx_length, a_midlen);
 988        strbuf_addstr(&name, " => ");
 989        strbuf_add(&name, b + pfx_length, b_midlen);
 990        if (pfx_length + sfx_length) {
 991                strbuf_addch(&name, '}');
 992                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 993        }
 994        return strbuf_detach(&name, NULL);
 995}
 996
 997struct diffstat_t {
 998        int nr;
 999        int alloc;
1000        struct diffstat_file {
1001                char *from_name;
1002                char *name;
1003                char *print_name;
1004                unsigned is_unmerged:1;
1005                unsigned is_binary:1;
1006                unsigned is_renamed:1;
1007                uintmax_t added, deleted;
1008        } **files;
1009};
1010
1011static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1012                                          const char *name_a,
1013                                          const char *name_b)
1014{
1015        struct diffstat_file *x;
1016        x = xcalloc(sizeof (*x), 1);
1017        if (diffstat->nr == diffstat->alloc) {
1018                diffstat->alloc = alloc_nr(diffstat->alloc);
1019                diffstat->files = xrealloc(diffstat->files,
1020                                diffstat->alloc * sizeof(x));
1021        }
1022        diffstat->files[diffstat->nr++] = x;
1023        if (name_b) {
1024                x->from_name = xstrdup(name_a);
1025                x->name = xstrdup(name_b);
1026                x->is_renamed = 1;
1027        }
1028        else {
1029                x->from_name = NULL;
1030                x->name = xstrdup(name_a);
1031        }
1032        return x;
1033}
1034
1035static void diffstat_consume(void *priv, char *line, unsigned long len)
1036{
1037        struct diffstat_t *diffstat = priv;
1038        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1039
1040        if (line[0] == '+')
1041                x->added++;
1042        else if (line[0] == '-')
1043                x->deleted++;
1044}
1045
1046const char mime_boundary_leader[] = "------------";
1047
1048static int scale_linear(int it, int width, int max_change)
1049{
1050        /*
1051         * make sure that at least one '-' is printed if there were deletions,
1052         * and likewise for '+'.
1053         */
1054        if (max_change < 2)
1055                return it;
1056        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1057}
1058
1059static void show_name(FILE *file,
1060                      const char *prefix, const char *name, int len)
1061{
1062        fprintf(file, " %s%-*s |", prefix, len, name);
1063}
1064
1065static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1066{
1067        if (cnt <= 0)
1068                return;
1069        fprintf(file, "%s", set);
1070        while (cnt--)
1071                putc(ch, file);
1072        fprintf(file, "%s", reset);
1073}
1074
1075static void fill_print_name(struct diffstat_file *file)
1076{
1077        char *pname;
1078
1079        if (file->print_name)
1080                return;
1081
1082        if (!file->is_renamed) {
1083                struct strbuf buf = STRBUF_INIT;
1084                if (quote_c_style(file->name, &buf, NULL, 0)) {
1085                        pname = strbuf_detach(&buf, NULL);
1086                } else {
1087                        pname = file->name;
1088                        strbuf_release(&buf);
1089                }
1090        } else {
1091                pname = pprint_rename(file->from_name, file->name);
1092        }
1093        file->print_name = pname;
1094}
1095
1096static void show_stats(struct diffstat_t *data, struct diff_options *options)
1097{
1098        int i, len, add, del, adds = 0, dels = 0;
1099        uintmax_t max_change = 0, max_len = 0;
1100        int total_files = data->nr;
1101        int width, name_width;
1102        const char *reset, *set, *add_c, *del_c;
1103
1104        if (data->nr == 0)
1105                return;
1106
1107        width = options->stat_width ? options->stat_width : 80;
1108        name_width = options->stat_name_width ? options->stat_name_width : 50;
1109
1110        /* Sanity: give at least 5 columns to the graph,
1111         * but leave at least 10 columns for the name.
1112         */
1113        if (width < 25)
1114                width = 25;
1115        if (name_width < 10)
1116                name_width = 10;
1117        else if (width < name_width + 15)
1118                name_width = width - 15;
1119
1120        /* Find the longest filename and max number of changes */
1121        reset = diff_get_color_opt(options, DIFF_RESET);
1122        set   = diff_get_color_opt(options, DIFF_PLAIN);
1123        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1124        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1125
1126        for (i = 0; i < data->nr; i++) {
1127                struct diffstat_file *file = data->files[i];
1128                uintmax_t change = file->added + file->deleted;
1129                fill_print_name(file);
1130                len = strlen(file->print_name);
1131                if (max_len < len)
1132                        max_len = len;
1133
1134                if (file->is_binary || file->is_unmerged)
1135                        continue;
1136                if (max_change < change)
1137                        max_change = change;
1138        }
1139
1140        /* Compute the width of the graph part;
1141         * 10 is for one blank at the beginning of the line plus
1142         * " | count " between the name and the graph.
1143         *
1144         * From here on, name_width is the width of the name area,
1145         * and width is the width of the graph area.
1146         */
1147        name_width = (name_width < max_len) ? name_width : max_len;
1148        if (width < (name_width + 10) + max_change)
1149                width = width - (name_width + 10);
1150        else
1151                width = max_change;
1152
1153        for (i = 0; i < data->nr; i++) {
1154                const char *prefix = "";
1155                char *name = data->files[i]->print_name;
1156                uintmax_t added = data->files[i]->added;
1157                uintmax_t deleted = data->files[i]->deleted;
1158                int name_len;
1159
1160                /*
1161                 * "scale" the filename
1162                 */
1163                len = name_width;
1164                name_len = strlen(name);
1165                if (name_width < name_len) {
1166                        char *slash;
1167                        prefix = "...";
1168                        len -= 3;
1169                        name += name_len - len;
1170                        slash = strchr(name, '/');
1171                        if (slash)
1172                                name = slash;
1173                }
1174
1175                if (data->files[i]->is_binary) {
1176                        show_name(options->file, prefix, name, len);
1177                        fprintf(options->file, "  Bin ");
1178                        fprintf(options->file, "%s%"PRIuMAX"%s",
1179                                del_c, deleted, reset);
1180                        fprintf(options->file, " -> ");
1181                        fprintf(options->file, "%s%"PRIuMAX"%s",
1182                                add_c, added, reset);
1183                        fprintf(options->file, " bytes");
1184                        fprintf(options->file, "\n");
1185                        continue;
1186                }
1187                else if (data->files[i]->is_unmerged) {
1188                        show_name(options->file, prefix, name, len);
1189                        fprintf(options->file, "  Unmerged\n");
1190                        continue;
1191                }
1192                else if (!data->files[i]->is_renamed &&
1193                         (added + deleted == 0)) {
1194                        total_files--;
1195                        continue;
1196                }
1197
1198                /*
1199                 * scale the add/delete
1200                 */
1201                add = added;
1202                del = deleted;
1203                adds += add;
1204                dels += del;
1205
1206                if (width <= max_change) {
1207                        add = scale_linear(add, width, max_change);
1208                        del = scale_linear(del, width, max_change);
1209                }
1210                show_name(options->file, prefix, name, len);
1211                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1212                                added + deleted ? " " : "");
1213                show_graph(options->file, '+', add, add_c, reset);
1214                show_graph(options->file, '-', del, del_c, reset);
1215                fprintf(options->file, "\n");
1216        }
1217        fprintf(options->file,
1218               " %d files changed, %d insertions(+), %d deletions(-)\n",
1219               total_files, adds, dels);
1220}
1221
1222static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1223{
1224        int i, adds = 0, dels = 0, total_files = data->nr;
1225
1226        if (data->nr == 0)
1227                return;
1228
1229        for (i = 0; i < data->nr; i++) {
1230                if (!data->files[i]->is_binary &&
1231                    !data->files[i]->is_unmerged) {
1232                        int added = data->files[i]->added;
1233                        int deleted= data->files[i]->deleted;
1234                        if (!data->files[i]->is_renamed &&
1235                            (added + deleted == 0)) {
1236                                total_files--;
1237                        } else {
1238                                adds += added;
1239                                dels += deleted;
1240                        }
1241                }
1242        }
1243        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1244               total_files, adds, dels);
1245}
1246
1247static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1248{
1249        int i;
1250
1251        if (data->nr == 0)
1252                return;
1253
1254        for (i = 0; i < data->nr; i++) {
1255                struct diffstat_file *file = data->files[i];
1256
1257                if (file->is_binary)
1258                        fprintf(options->file, "-\t-\t");
1259                else
1260                        fprintf(options->file,
1261                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1262                                file->added, file->deleted);
1263                if (options->line_termination) {
1264                        fill_print_name(file);
1265                        if (!file->is_renamed)
1266                                write_name_quoted(file->name, options->file,
1267                                                  options->line_termination);
1268                        else {
1269                                fputs(file->print_name, options->file);
1270                                putc(options->line_termination, options->file);
1271                        }
1272                } else {
1273                        if (file->is_renamed) {
1274                                putc('\0', options->file);
1275                                write_name_quoted(file->from_name, options->file, '\0');
1276                        }
1277                        write_name_quoted(file->name, options->file, '\0');
1278                }
1279        }
1280}
1281
1282struct dirstat_file {
1283        const char *name;
1284        unsigned long changed;
1285};
1286
1287struct dirstat_dir {
1288        struct dirstat_file *files;
1289        int alloc, nr, percent, cumulative;
1290};
1291
1292static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1293{
1294        unsigned long this_dir = 0;
1295        unsigned int sources = 0;
1296
1297        while (dir->nr) {
1298                struct dirstat_file *f = dir->files;
1299                int namelen = strlen(f->name);
1300                unsigned long this;
1301                char *slash;
1302
1303                if (namelen < baselen)
1304                        break;
1305                if (memcmp(f->name, base, baselen))
1306                        break;
1307                slash = strchr(f->name + baselen, '/');
1308                if (slash) {
1309                        int newbaselen = slash + 1 - f->name;
1310                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1311                        sources++;
1312                } else {
1313                        this = f->changed;
1314                        dir->files++;
1315                        dir->nr--;
1316                        sources += 2;
1317                }
1318                this_dir += this;
1319        }
1320
1321        /*
1322         * We don't report dirstat's for
1323         *  - the top level
1324         *  - or cases where everything came from a single directory
1325         *    under this directory (sources == 1).
1326         */
1327        if (baselen && sources != 1) {
1328                int permille = this_dir * 1000 / changed;
1329                if (permille) {
1330                        int percent = permille / 10;
1331                        if (percent >= dir->percent) {
1332                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1333                                if (!dir->cumulative)
1334                                        return 0;
1335                        }
1336                }
1337        }
1338        return this_dir;
1339}
1340
1341static int dirstat_compare(const void *_a, const void *_b)
1342{
1343        const struct dirstat_file *a = _a;
1344        const struct dirstat_file *b = _b;
1345        return strcmp(a->name, b->name);
1346}
1347
1348static void show_dirstat(struct diff_options *options)
1349{
1350        int i;
1351        unsigned long changed;
1352        struct dirstat_dir dir;
1353        struct diff_queue_struct *q = &diff_queued_diff;
1354
1355        dir.files = NULL;
1356        dir.alloc = 0;
1357        dir.nr = 0;
1358        dir.percent = options->dirstat_percent;
1359        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1360
1361        changed = 0;
1362        for (i = 0; i < q->nr; i++) {
1363                struct diff_filepair *p = q->queue[i];
1364                const char *name;
1365                unsigned long copied, added, damage;
1366
1367                name = p->one->path ? p->one->path : p->two->path;
1368
1369                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1370                        diff_populate_filespec(p->one, 0);
1371                        diff_populate_filespec(p->two, 0);
1372                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1373                                               &copied, &added);
1374                        diff_free_filespec_data(p->one);
1375                        diff_free_filespec_data(p->two);
1376                } else if (DIFF_FILE_VALID(p->one)) {
1377                        diff_populate_filespec(p->one, 1);
1378                        copied = added = 0;
1379                        diff_free_filespec_data(p->one);
1380                } else if (DIFF_FILE_VALID(p->two)) {
1381                        diff_populate_filespec(p->two, 1);
1382                        copied = 0;
1383                        added = p->two->size;
1384                        diff_free_filespec_data(p->two);
1385                } else
1386                        continue;
1387
1388                /*
1389                 * Original minus copied is the removed material,
1390                 * added is the new material.  They are both damages
1391                 * made to the preimage. In --dirstat-by-file mode, count
1392                 * damaged files, not damaged lines. This is done by
1393                 * counting only a single damaged line per file.
1394                 */
1395                damage = (p->one->size - copied) + added;
1396                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1397                        damage = 1;
1398
1399                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1400                dir.files[dir.nr].name = name;
1401                dir.files[dir.nr].changed = damage;
1402                changed += damage;
1403                dir.nr++;
1404        }
1405
1406        /* This can happen even with many files, if everything was renames */
1407        if (!changed)
1408                return;
1409
1410        /* Show all directories with more than x% of the changes */
1411        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1412        gather_dirstat(options->file, &dir, changed, "", 0);
1413}
1414
1415static void free_diffstat_info(struct diffstat_t *diffstat)
1416{
1417        int i;
1418        for (i = 0; i < diffstat->nr; i++) {
1419                struct diffstat_file *f = diffstat->files[i];
1420                if (f->name != f->print_name)
1421                        free(f->print_name);
1422                free(f->name);
1423                free(f->from_name);
1424                free(f);
1425        }
1426        free(diffstat->files);
1427}
1428
1429struct checkdiff_t {
1430        const char *filename;
1431        int lineno;
1432        int conflict_marker_size;
1433        struct diff_options *o;
1434        unsigned ws_rule;
1435        unsigned status;
1436};
1437
1438static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1439{
1440        char firstchar;
1441        int cnt;
1442
1443        if (len < marker_size + 1)
1444                return 0;
1445        firstchar = line[0];
1446        switch (firstchar) {
1447        case '=': case '>': case '<': case '|':
1448                break;
1449        default:
1450                return 0;
1451        }
1452        for (cnt = 1; cnt < marker_size; cnt++)
1453                if (line[cnt] != firstchar)
1454                        return 0;
1455        /* line[1] thru line[marker_size-1] are same as firstchar */
1456        if (len < marker_size + 1 || !isspace(line[marker_size]))
1457                return 0;
1458        return 1;
1459}
1460
1461static void checkdiff_consume(void *priv, char *line, unsigned long len)
1462{
1463        struct checkdiff_t *data = priv;
1464        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1465        int marker_size = data->conflict_marker_size;
1466        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1467        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1468        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1469        char *err;
1470
1471        if (line[0] == '+') {
1472                unsigned bad;
1473                data->lineno++;
1474                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1475                        data->status |= 1;
1476                        fprintf(data->o->file,
1477                                "%s:%d: leftover conflict marker\n",
1478                                data->filename, data->lineno);
1479                }
1480                bad = ws_check(line + 1, len - 1, data->ws_rule);
1481                if (!bad)
1482                        return;
1483                data->status |= bad;
1484                err = whitespace_error_string(bad);
1485                fprintf(data->o->file, "%s:%d: %s.\n",
1486                        data->filename, data->lineno, err);
1487                free(err);
1488                emit_line(data->o, set, reset, line, 1);
1489                ws_check_emit(line + 1, len - 1, data->ws_rule,
1490                              data->o->file, set, reset, ws);
1491        } else if (line[0] == ' ') {
1492                data->lineno++;
1493        } else if (line[0] == '@') {
1494                char *plus = strchr(line, '+');
1495                if (plus)
1496                        data->lineno = strtol(plus, NULL, 10) - 1;
1497                else
1498                        die("invalid diff");
1499        }
1500}
1501
1502static unsigned char *deflate_it(char *data,
1503                                 unsigned long size,
1504                                 unsigned long *result_size)
1505{
1506        int bound;
1507        unsigned char *deflated;
1508        z_stream stream;
1509
1510        memset(&stream, 0, sizeof(stream));
1511        deflateInit(&stream, zlib_compression_level);
1512        bound = deflateBound(&stream, size);
1513        deflated = xmalloc(bound);
1514        stream.next_out = deflated;
1515        stream.avail_out = bound;
1516
1517        stream.next_in = (unsigned char *)data;
1518        stream.avail_in = size;
1519        while (deflate(&stream, Z_FINISH) == Z_OK)
1520                ; /* nothing */
1521        deflateEnd(&stream);
1522        *result_size = stream.total_out;
1523        return deflated;
1524}
1525
1526static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1527{
1528        void *cp;
1529        void *delta;
1530        void *deflated;
1531        void *data;
1532        unsigned long orig_size;
1533        unsigned long delta_size;
1534        unsigned long deflate_size;
1535        unsigned long data_size;
1536
1537        /* We could do deflated delta, or we could do just deflated two,
1538         * whichever is smaller.
1539         */
1540        delta = NULL;
1541        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1542        if (one->size && two->size) {
1543                delta = diff_delta(one->ptr, one->size,
1544                                   two->ptr, two->size,
1545                                   &delta_size, deflate_size);
1546                if (delta) {
1547                        void *to_free = delta;
1548                        orig_size = delta_size;
1549                        delta = deflate_it(delta, delta_size, &delta_size);
1550                        free(to_free);
1551                }
1552        }
1553
1554        if (delta && delta_size < deflate_size) {
1555                fprintf(file, "delta %lu\n", orig_size);
1556                free(deflated);
1557                data = delta;
1558                data_size = delta_size;
1559        }
1560        else {
1561                fprintf(file, "literal %lu\n", two->size);
1562                free(delta);
1563                data = deflated;
1564                data_size = deflate_size;
1565        }
1566
1567        /* emit data encoded in base85 */
1568        cp = data;
1569        while (data_size) {
1570                int bytes = (52 < data_size) ? 52 : data_size;
1571                char line[70];
1572                data_size -= bytes;
1573                if (bytes <= 26)
1574                        line[0] = bytes + 'A' - 1;
1575                else
1576                        line[0] = bytes - 26 + 'a' - 1;
1577                encode_85(line + 1, cp, bytes);
1578                cp = (char *) cp + bytes;
1579                fputs(line, file);
1580                fputc('\n', file);
1581        }
1582        fprintf(file, "\n");
1583        free(data);
1584}
1585
1586static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1587{
1588        fprintf(file, "GIT binary patch\n");
1589        emit_binary_diff_body(file, one, two);
1590        emit_binary_diff_body(file, two, one);
1591}
1592
1593static void diff_filespec_load_driver(struct diff_filespec *one)
1594{
1595        if (!one->driver)
1596                one->driver = userdiff_find_by_path(one->path);
1597        if (!one->driver)
1598                one->driver = userdiff_find_by_name("default");
1599}
1600
1601int diff_filespec_is_binary(struct diff_filespec *one)
1602{
1603        if (one->is_binary == -1) {
1604                diff_filespec_load_driver(one);
1605                if (one->driver->binary != -1)
1606                        one->is_binary = one->driver->binary;
1607                else {
1608                        if (!one->data && DIFF_FILE_VALID(one))
1609                                diff_populate_filespec(one, 0);
1610                        if (one->data)
1611                                one->is_binary = buffer_is_binary(one->data,
1612                                                one->size);
1613                        if (one->is_binary == -1)
1614                                one->is_binary = 0;
1615                }
1616        }
1617        return one->is_binary;
1618}
1619
1620static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1621{
1622        diff_filespec_load_driver(one);
1623        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1624}
1625
1626static const char *userdiff_word_regex(struct diff_filespec *one)
1627{
1628        diff_filespec_load_driver(one);
1629        return one->driver->word_regex;
1630}
1631
1632void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1633{
1634        if (!options->a_prefix)
1635                options->a_prefix = a;
1636        if (!options->b_prefix)
1637                options->b_prefix = b;
1638}
1639
1640static struct userdiff_driver *get_textconv(struct diff_filespec *one)
1641{
1642        if (!DIFF_FILE_VALID(one))
1643                return NULL;
1644        if (!S_ISREG(one->mode))
1645                return NULL;
1646        diff_filespec_load_driver(one);
1647        if (!one->driver->textconv)
1648                return NULL;
1649
1650        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1651                struct notes_cache *c = xmalloc(sizeof(*c));
1652                struct strbuf name = STRBUF_INIT;
1653
1654                strbuf_addf(&name, "textconv/%s", one->driver->name);
1655                notes_cache_init(c, name.buf, one->driver->textconv);
1656                one->driver->textconv_cache = c;
1657        }
1658
1659        return one->driver;
1660}
1661
1662static void builtin_diff(const char *name_a,
1663                         const char *name_b,
1664                         struct diff_filespec *one,
1665                         struct diff_filespec *two,
1666                         const char *xfrm_msg,
1667                         struct diff_options *o,
1668                         int complete_rewrite)
1669{
1670        mmfile_t mf1, mf2;
1671        const char *lbl[2];
1672        char *a_one, *b_two;
1673        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1674        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1675        const char *a_prefix, *b_prefix;
1676        struct userdiff_driver *textconv_one = NULL;
1677        struct userdiff_driver *textconv_two = NULL;
1678        struct strbuf header = STRBUF_INIT;
1679
1680        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1681                        (!one->mode || S_ISGITLINK(one->mode)) &&
1682                        (!two->mode || S_ISGITLINK(two->mode))) {
1683                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1684                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1685                show_submodule_summary(o->file, one ? one->path : two->path,
1686                                one->sha1, two->sha1, two->dirty_submodule,
1687                                del, add, reset);
1688                return;
1689        }
1690
1691        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1692                textconv_one = get_textconv(one);
1693                textconv_two = get_textconv(two);
1694        }
1695
1696        diff_set_mnemonic_prefix(o, "a/", "b/");
1697        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1698                a_prefix = o->b_prefix;
1699                b_prefix = o->a_prefix;
1700        } else {
1701                a_prefix = o->a_prefix;
1702                b_prefix = o->b_prefix;
1703        }
1704
1705        /* Never use a non-valid filename anywhere if at all possible */
1706        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1707        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1708
1709        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1710        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1711        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1712        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1713        strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1714        if (lbl[0][0] == '/') {
1715                /* /dev/null */
1716                strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
1717                if (xfrm_msg && xfrm_msg[0])
1718                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1719        }
1720        else if (lbl[1][0] == '/') {
1721                strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1722                if (xfrm_msg && xfrm_msg[0])
1723                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1724        }
1725        else {
1726                if (one->mode != two->mode) {
1727                        strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
1728                        strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
1729                }
1730                if (xfrm_msg && xfrm_msg[0])
1731                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1732
1733                /*
1734                 * we do not run diff between different kind
1735                 * of objects.
1736                 */
1737                if ((one->mode ^ two->mode) & S_IFMT)
1738                        goto free_ab_and_return;
1739                if (complete_rewrite &&
1740                    (textconv_one || !diff_filespec_is_binary(one)) &&
1741                    (textconv_two || !diff_filespec_is_binary(two))) {
1742                        fprintf(o->file, "%s", header.buf);
1743                        strbuf_reset(&header);
1744                        emit_rewrite_diff(name_a, name_b, one, two,
1745                                                textconv_one, textconv_two, o);
1746                        o->found_changes = 1;
1747                        goto free_ab_and_return;
1748                }
1749        }
1750
1751        if (!DIFF_OPT_TST(o, TEXT) &&
1752            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1753              (!textconv_two && diff_filespec_is_binary(two)) )) {
1754                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1755                        die("unable to read files to diff");
1756                /* Quite common confusing case */
1757                if (mf1.size == mf2.size &&
1758                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1759                        goto free_ab_and_return;
1760                fprintf(o->file, "%s", header.buf);
1761                strbuf_reset(&header);
1762                if (DIFF_OPT_TST(o, BINARY))
1763                        emit_binary_diff(o->file, &mf1, &mf2);
1764                else
1765                        fprintf(o->file, "Binary files %s and %s differ\n",
1766                                lbl[0], lbl[1]);
1767                o->found_changes = 1;
1768        }
1769        else {
1770                /* Crazy xdl interfaces.. */
1771                const char *diffopts = getenv("GIT_DIFF_OPTS");
1772                xpparam_t xpp;
1773                xdemitconf_t xecfg;
1774                struct emit_callback ecbdata;
1775                const struct userdiff_funcname *pe;
1776
1777                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1778                        fprintf(o->file, "%s", header.buf);
1779                        strbuf_reset(&header);
1780                }
1781
1782                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1783                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1784
1785                pe = diff_funcname_pattern(one);
1786                if (!pe)
1787                        pe = diff_funcname_pattern(two);
1788
1789                memset(&xpp, 0, sizeof(xpp));
1790                memset(&xecfg, 0, sizeof(xecfg));
1791                memset(&ecbdata, 0, sizeof(ecbdata));
1792                ecbdata.label_path = lbl;
1793                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1794                ecbdata.found_changesp = &o->found_changes;
1795                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1796                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1797                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1798                ecbdata.opt = o;
1799                ecbdata.header = header.len ? &header : NULL;
1800                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1801                xecfg.ctxlen = o->context;
1802                xecfg.interhunkctxlen = o->interhunkcontext;
1803                xecfg.flags = XDL_EMIT_FUNCNAMES;
1804                if (pe)
1805                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1806                if (!diffopts)
1807                        ;
1808                else if (!prefixcmp(diffopts, "--unified="))
1809                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1810                else if (!prefixcmp(diffopts, "-u"))
1811                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1812                if (o->word_diff) {
1813                        int i;
1814
1815                        ecbdata.diff_words =
1816                                xcalloc(1, sizeof(struct diff_words_data));
1817                        ecbdata.diff_words->file = o->file;
1818                        ecbdata.diff_words->type = o->word_diff;
1819                        if (!o->word_regex)
1820                                o->word_regex = userdiff_word_regex(one);
1821                        if (!o->word_regex)
1822                                o->word_regex = userdiff_word_regex(two);
1823                        if (!o->word_regex)
1824                                o->word_regex = diff_word_regex_cfg;
1825                        if (o->word_regex) {
1826                                ecbdata.diff_words->word_regex = (regex_t *)
1827                                        xmalloc(sizeof(regex_t));
1828                                if (regcomp(ecbdata.diff_words->word_regex,
1829                                                o->word_regex,
1830                                                REG_EXTENDED | REG_NEWLINE))
1831                                        die ("Invalid regular expression: %s",
1832                                                        o->word_regex);
1833                        }
1834                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1835                                if (o->word_diff == diff_words_styles[i].type) {
1836                                        ecbdata.diff_words->style =
1837                                                &diff_words_styles[i];
1838                                        break;
1839                                }
1840                        }
1841                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
1842                                struct diff_words_style *st = ecbdata.diff_words->style;
1843                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1844                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1845                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1846                        }
1847                }
1848                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1849                              &xpp, &xecfg);
1850                if (o->word_diff)
1851                        free_diff_words_data(&ecbdata);
1852                if (textconv_one)
1853                        free(mf1.ptr);
1854                if (textconv_two)
1855                        free(mf2.ptr);
1856                xdiff_clear_find_func(&xecfg);
1857        }
1858
1859 free_ab_and_return:
1860        strbuf_release(&header);
1861        diff_free_filespec_data(one);
1862        diff_free_filespec_data(two);
1863        free(a_one);
1864        free(b_two);
1865        return;
1866}
1867
1868static void builtin_diffstat(const char *name_a, const char *name_b,
1869                             struct diff_filespec *one,
1870                             struct diff_filespec *two,
1871                             struct diffstat_t *diffstat,
1872                             struct diff_options *o,
1873                             int complete_rewrite)
1874{
1875        mmfile_t mf1, mf2;
1876        struct diffstat_file *data;
1877
1878        data = diffstat_add(diffstat, name_a, name_b);
1879
1880        if (!one || !two) {
1881                data->is_unmerged = 1;
1882                return;
1883        }
1884        if (complete_rewrite) {
1885                diff_populate_filespec(one, 0);
1886                diff_populate_filespec(two, 0);
1887                data->deleted = count_lines(one->data, one->size);
1888                data->added = count_lines(two->data, two->size);
1889                goto free_and_return;
1890        }
1891        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1892                die("unable to read files to diff");
1893
1894        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1895                data->is_binary = 1;
1896                data->added = mf2.size;
1897                data->deleted = mf1.size;
1898        } else {
1899                /* Crazy xdl interfaces.. */
1900                xpparam_t xpp;
1901                xdemitconf_t xecfg;
1902
1903                memset(&xpp, 0, sizeof(xpp));
1904                memset(&xecfg, 0, sizeof(xecfg));
1905                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1906                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1907                              &xpp, &xecfg);
1908        }
1909
1910 free_and_return:
1911        diff_free_filespec_data(one);
1912        diff_free_filespec_data(two);
1913}
1914
1915static void builtin_checkdiff(const char *name_a, const char *name_b,
1916                              const char *attr_path,
1917                              struct diff_filespec *one,
1918                              struct diff_filespec *two,
1919                              struct diff_options *o)
1920{
1921        mmfile_t mf1, mf2;
1922        struct checkdiff_t data;
1923
1924        if (!two)
1925                return;
1926
1927        memset(&data, 0, sizeof(data));
1928        data.filename = name_b ? name_b : name_a;
1929        data.lineno = 0;
1930        data.o = o;
1931        data.ws_rule = whitespace_rule(attr_path);
1932        data.conflict_marker_size = ll_merge_marker_size(attr_path);
1933
1934        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1935                die("unable to read files to diff");
1936
1937        /*
1938         * All the other codepaths check both sides, but not checking
1939         * the "old" side here is deliberate.  We are checking the newly
1940         * introduced changes, and as long as the "new" side is text, we
1941         * can and should check what it introduces.
1942         */
1943        if (diff_filespec_is_binary(two))
1944                goto free_and_return;
1945        else {
1946                /* Crazy xdl interfaces.. */
1947                xpparam_t xpp;
1948                xdemitconf_t xecfg;
1949
1950                memset(&xpp, 0, sizeof(xpp));
1951                memset(&xecfg, 0, sizeof(xecfg));
1952                xecfg.ctxlen = 1; /* at least one context line */
1953                xpp.flags = XDF_NEED_MINIMAL;
1954                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1955                              &xpp, &xecfg);
1956
1957                if (data.ws_rule & WS_BLANK_AT_EOF) {
1958                        struct emit_callback ecbdata;
1959                        int blank_at_eof;
1960
1961                        ecbdata.ws_rule = data.ws_rule;
1962                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1963                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1964
1965                        if (blank_at_eof) {
1966                                static char *err;
1967                                if (!err)
1968                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
1969                                fprintf(o->file, "%s:%d: %s.\n",
1970                                        data.filename, blank_at_eof, err);
1971                                data.status = 1; /* report errors */
1972                        }
1973                }
1974        }
1975 free_and_return:
1976        diff_free_filespec_data(one);
1977        diff_free_filespec_data(two);
1978        if (data.status)
1979                DIFF_OPT_SET(o, CHECK_FAILED);
1980}
1981
1982struct diff_filespec *alloc_filespec(const char *path)
1983{
1984        int namelen = strlen(path);
1985        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1986
1987        memset(spec, 0, sizeof(*spec));
1988        spec->path = (char *)(spec + 1);
1989        memcpy(spec->path, path, namelen+1);
1990        spec->count = 1;
1991        spec->is_binary = -1;
1992        return spec;
1993}
1994
1995void free_filespec(struct diff_filespec *spec)
1996{
1997        if (!--spec->count) {
1998                diff_free_filespec_data(spec);
1999                free(spec);
2000        }
2001}
2002
2003void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2004                   unsigned short mode)
2005{
2006        if (mode) {
2007                spec->mode = canon_mode(mode);
2008                hashcpy(spec->sha1, sha1);
2009                spec->sha1_valid = !is_null_sha1(sha1);
2010        }
2011}
2012
2013/*
2014 * Given a name and sha1 pair, if the index tells us the file in
2015 * the work tree has that object contents, return true, so that
2016 * prepare_temp_file() does not have to inflate and extract.
2017 */
2018static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2019{
2020        struct cache_entry *ce;
2021        struct stat st;
2022        int pos, len;
2023
2024        /*
2025         * We do not read the cache ourselves here, because the
2026         * benchmark with my previous version that always reads cache
2027         * shows that it makes things worse for diff-tree comparing
2028         * two linux-2.6 kernel trees in an already checked out work
2029         * tree.  This is because most diff-tree comparisons deal with
2030         * only a small number of files, while reading the cache is
2031         * expensive for a large project, and its cost outweighs the
2032         * savings we get by not inflating the object to a temporary
2033         * file.  Practically, this code only helps when we are used
2034         * by diff-cache --cached, which does read the cache before
2035         * calling us.
2036         */
2037        if (!active_cache)
2038                return 0;
2039
2040        /* We want to avoid the working directory if our caller
2041         * doesn't need the data in a normal file, this system
2042         * is rather slow with its stat/open/mmap/close syscalls,
2043         * and the object is contained in a pack file.  The pack
2044         * is probably already open and will be faster to obtain
2045         * the data through than the working directory.  Loose
2046         * objects however would tend to be slower as they need
2047         * to be individually opened and inflated.
2048         */
2049        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2050                return 0;
2051
2052        len = strlen(name);
2053        pos = cache_name_pos(name, len);
2054        if (pos < 0)
2055                return 0;
2056        ce = active_cache[pos];
2057
2058        /*
2059         * This is not the sha1 we are looking for, or
2060         * unreusable because it is not a regular file.
2061         */
2062        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2063                return 0;
2064
2065        /*
2066         * If ce is marked as "assume unchanged", there is no
2067         * guarantee that work tree matches what we are looking for.
2068         */
2069        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2070                return 0;
2071
2072        /*
2073         * If ce matches the file in the work tree, we can reuse it.
2074         */
2075        if (ce_uptodate(ce) ||
2076            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2077                return 1;
2078
2079        return 0;
2080}
2081
2082static int populate_from_stdin(struct diff_filespec *s)
2083{
2084        struct strbuf buf = STRBUF_INIT;
2085        size_t size = 0;
2086
2087        if (strbuf_read(&buf, 0, 0) < 0)
2088                return error("error while reading from stdin %s",
2089                                     strerror(errno));
2090
2091        s->should_munmap = 0;
2092        s->data = strbuf_detach(&buf, &size);
2093        s->size = size;
2094        s->should_free = 1;
2095        return 0;
2096}
2097
2098static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2099{
2100        int len;
2101        char *data = xmalloc(100), *dirty = "";
2102
2103        /* Are we looking at the work tree? */
2104        if (s->dirty_submodule)
2105                dirty = "-dirty";
2106
2107        len = snprintf(data, 100,
2108                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2109        s->data = data;
2110        s->size = len;
2111        s->should_free = 1;
2112        if (size_only) {
2113                s->data = NULL;
2114                free(data);
2115        }
2116        return 0;
2117}
2118
2119/*
2120 * While doing rename detection and pickaxe operation, we may need to
2121 * grab the data for the blob (or file) for our own in-core comparison.
2122 * diff_filespec has data and size fields for this purpose.
2123 */
2124int diff_populate_filespec(struct diff_filespec *s, int size_only)
2125{
2126        int err = 0;
2127        if (!DIFF_FILE_VALID(s))
2128                die("internal error: asking to populate invalid file.");
2129        if (S_ISDIR(s->mode))
2130                return -1;
2131
2132        if (s->data)
2133                return 0;
2134
2135        if (size_only && 0 < s->size)
2136                return 0;
2137
2138        if (S_ISGITLINK(s->mode))
2139                return diff_populate_gitlink(s, size_only);
2140
2141        if (!s->sha1_valid ||
2142            reuse_worktree_file(s->path, s->sha1, 0)) {
2143                struct strbuf buf = STRBUF_INIT;
2144                struct stat st;
2145                int fd;
2146
2147                if (!strcmp(s->path, "-"))
2148                        return populate_from_stdin(s);
2149
2150                if (lstat(s->path, &st) < 0) {
2151                        if (errno == ENOENT) {
2152                        err_empty:
2153                                err = -1;
2154                        empty:
2155                                s->data = (char *)"";
2156                                s->size = 0;
2157                                return err;
2158                        }
2159                }
2160                s->size = xsize_t(st.st_size);
2161                if (!s->size)
2162                        goto empty;
2163                if (S_ISLNK(st.st_mode)) {
2164                        struct strbuf sb = STRBUF_INIT;
2165
2166                        if (strbuf_readlink(&sb, s->path, s->size))
2167                                goto err_empty;
2168                        s->size = sb.len;
2169                        s->data = strbuf_detach(&sb, NULL);
2170                        s->should_free = 1;
2171                        return 0;
2172                }
2173                if (size_only)
2174                        return 0;
2175                fd = open(s->path, O_RDONLY);
2176                if (fd < 0)
2177                        goto err_empty;
2178                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2179                close(fd);
2180                s->should_munmap = 1;
2181
2182                /*
2183                 * Convert from working tree format to canonical git format
2184                 */
2185                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2186                        size_t size = 0;
2187                        munmap(s->data, s->size);
2188                        s->should_munmap = 0;
2189                        s->data = strbuf_detach(&buf, &size);
2190                        s->size = size;
2191                        s->should_free = 1;
2192                }
2193        }
2194        else {
2195                enum object_type type;
2196                if (size_only)
2197                        type = sha1_object_info(s->sha1, &s->size);
2198                else {
2199                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2200                        s->should_free = 1;
2201                }
2202        }
2203        return 0;
2204}
2205
2206void diff_free_filespec_blob(struct diff_filespec *s)
2207{
2208        if (s->should_free)
2209                free(s->data);
2210        else if (s->should_munmap)
2211                munmap(s->data, s->size);
2212
2213        if (s->should_free || s->should_munmap) {
2214                s->should_free = s->should_munmap = 0;
2215                s->data = NULL;
2216        }
2217}
2218
2219void diff_free_filespec_data(struct diff_filespec *s)
2220{
2221        diff_free_filespec_blob(s);
2222        free(s->cnt_data);
2223        s->cnt_data = NULL;
2224}
2225
2226static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2227                           void *blob,
2228                           unsigned long size,
2229                           const unsigned char *sha1,
2230                           int mode)
2231{
2232        int fd;
2233        struct strbuf buf = STRBUF_INIT;
2234        struct strbuf template = STRBUF_INIT;
2235        char *path_dup = xstrdup(path);
2236        const char *base = basename(path_dup);
2237
2238        /* Generate "XXXXXX_basename.ext" */
2239        strbuf_addstr(&template, "XXXXXX_");
2240        strbuf_addstr(&template, base);
2241
2242        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2243                        strlen(base) + 1);
2244        if (fd < 0)
2245                die_errno("unable to create temp-file");
2246        if (convert_to_working_tree(path,
2247                        (const char *)blob, (size_t)size, &buf)) {
2248                blob = buf.buf;
2249                size = buf.len;
2250        }
2251        if (write_in_full(fd, blob, size) != size)
2252                die_errno("unable to write temp-file");
2253        close(fd);
2254        temp->name = temp->tmp_path;
2255        strcpy(temp->hex, sha1_to_hex(sha1));
2256        temp->hex[40] = 0;
2257        sprintf(temp->mode, "%06o", mode);
2258        strbuf_release(&buf);
2259        strbuf_release(&template);
2260        free(path_dup);
2261}
2262
2263static struct diff_tempfile *prepare_temp_file(const char *name,
2264                struct diff_filespec *one)
2265{
2266        struct diff_tempfile *temp = claim_diff_tempfile();
2267
2268        if (!DIFF_FILE_VALID(one)) {
2269        not_a_valid_file:
2270                /* A '-' entry produces this for file-2, and
2271                 * a '+' entry produces this for file-1.
2272                 */
2273                temp->name = "/dev/null";
2274                strcpy(temp->hex, ".");
2275                strcpy(temp->mode, ".");
2276                return temp;
2277        }
2278
2279        if (!remove_tempfile_installed) {
2280                atexit(remove_tempfile);
2281                sigchain_push_common(remove_tempfile_on_signal);
2282                remove_tempfile_installed = 1;
2283        }
2284
2285        if (!one->sha1_valid ||
2286            reuse_worktree_file(name, one->sha1, 1)) {
2287                struct stat st;
2288                if (lstat(name, &st) < 0) {
2289                        if (errno == ENOENT)
2290                                goto not_a_valid_file;
2291                        die_errno("stat(%s)", name);
2292                }
2293                if (S_ISLNK(st.st_mode)) {
2294                        struct strbuf sb = STRBUF_INIT;
2295                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2296                                die_errno("readlink(%s)", name);
2297                        prep_temp_blob(name, temp, sb.buf, sb.len,
2298                                       (one->sha1_valid ?
2299                                        one->sha1 : null_sha1),
2300                                       (one->sha1_valid ?
2301                                        one->mode : S_IFLNK));
2302                        strbuf_release(&sb);
2303                }
2304                else {
2305                        /* we can borrow from the file in the work tree */
2306                        temp->name = name;
2307                        if (!one->sha1_valid)
2308                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2309                        else
2310                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2311                        /* Even though we may sometimes borrow the
2312                         * contents from the work tree, we always want
2313                         * one->mode.  mode is trustworthy even when
2314                         * !(one->sha1_valid), as long as
2315                         * DIFF_FILE_VALID(one).
2316                         */
2317                        sprintf(temp->mode, "%06o", one->mode);
2318                }
2319                return temp;
2320        }
2321        else {
2322                if (diff_populate_filespec(one, 0))
2323                        die("cannot read data blob for %s", one->path);
2324                prep_temp_blob(name, temp, one->data, one->size,
2325                               one->sha1, one->mode);
2326        }
2327        return temp;
2328}
2329
2330/* An external diff command takes:
2331 *
2332 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2333 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2334 *
2335 */
2336static void run_external_diff(const char *pgm,
2337                              const char *name,
2338                              const char *other,
2339                              struct diff_filespec *one,
2340                              struct diff_filespec *two,
2341                              const char *xfrm_msg,
2342                              int complete_rewrite)
2343{
2344        const char *spawn_arg[10];
2345        int retval;
2346        const char **arg = &spawn_arg[0];
2347
2348        if (one && two) {
2349                struct diff_tempfile *temp_one, *temp_two;
2350                const char *othername = (other ? other : name);
2351                temp_one = prepare_temp_file(name, one);
2352                temp_two = prepare_temp_file(othername, two);
2353                *arg++ = pgm;
2354                *arg++ = name;
2355                *arg++ = temp_one->name;
2356                *arg++ = temp_one->hex;
2357                *arg++ = temp_one->mode;
2358                *arg++ = temp_two->name;
2359                *arg++ = temp_two->hex;
2360                *arg++ = temp_two->mode;
2361                if (other) {
2362                        *arg++ = other;
2363                        *arg++ = xfrm_msg;
2364                }
2365        } else {
2366                *arg++ = pgm;
2367                *arg++ = name;
2368        }
2369        *arg = NULL;
2370        fflush(NULL);
2371        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2372        remove_tempfile();
2373        if (retval) {
2374                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2375                exit(1);
2376        }
2377}
2378
2379static int similarity_index(struct diff_filepair *p)
2380{
2381        return p->score * 100 / MAX_SCORE;
2382}
2383
2384static void fill_metainfo(struct strbuf *msg,
2385                          const char *name,
2386                          const char *other,
2387                          struct diff_filespec *one,
2388                          struct diff_filespec *two,
2389                          struct diff_options *o,
2390                          struct diff_filepair *p)
2391{
2392        strbuf_init(msg, PATH_MAX * 2 + 300);
2393        switch (p->status) {
2394        case DIFF_STATUS_COPIED:
2395                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2396                strbuf_addstr(msg, "\ncopy from ");
2397                quote_c_style(name, msg, NULL, 0);
2398                strbuf_addstr(msg, "\ncopy to ");
2399                quote_c_style(other, msg, NULL, 0);
2400                strbuf_addch(msg, '\n');
2401                break;
2402        case DIFF_STATUS_RENAMED:
2403                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2404                strbuf_addstr(msg, "\nrename from ");
2405                quote_c_style(name, msg, NULL, 0);
2406                strbuf_addstr(msg, "\nrename to ");
2407                quote_c_style(other, msg, NULL, 0);
2408                strbuf_addch(msg, '\n');
2409                break;
2410        case DIFF_STATUS_MODIFIED:
2411                if (p->score) {
2412                        strbuf_addf(msg, "dissimilarity index %d%%\n",
2413                                    similarity_index(p));
2414                        break;
2415                }
2416                /* fallthru */
2417        default:
2418                /* nothing */
2419                ;
2420        }
2421        if (one && two && hashcmp(one->sha1, two->sha1)) {
2422                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2423
2424                if (DIFF_OPT_TST(o, BINARY)) {
2425                        mmfile_t mf;
2426                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2427                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2428                                abbrev = 40;
2429                }
2430                strbuf_addf(msg, "index %.*s..%.*s",
2431                            abbrev, sha1_to_hex(one->sha1),
2432                            abbrev, sha1_to_hex(two->sha1));
2433                if (one->mode == two->mode)
2434                        strbuf_addf(msg, " %06o", one->mode);
2435                strbuf_addch(msg, '\n');
2436        }
2437        if (msg->len)
2438                strbuf_setlen(msg, msg->len - 1);
2439}
2440
2441static void run_diff_cmd(const char *pgm,
2442                         const char *name,
2443                         const char *other,
2444                         const char *attr_path,
2445                         struct diff_filespec *one,
2446                         struct diff_filespec *two,
2447                         struct strbuf *msg,
2448                         struct diff_options *o,
2449                         struct diff_filepair *p)
2450{
2451        const char *xfrm_msg = NULL;
2452        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2453
2454        if (msg) {
2455                fill_metainfo(msg, name, other, one, two, o, p);
2456                xfrm_msg = msg->len ? msg->buf : NULL;
2457        }
2458
2459        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2460                pgm = NULL;
2461        else {
2462                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2463                if (drv && drv->external)
2464                        pgm = drv->external;
2465        }
2466
2467        if (pgm) {
2468                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2469                                  complete_rewrite);
2470                return;
2471        }
2472        if (one && two)
2473                builtin_diff(name, other ? other : name,
2474                             one, two, xfrm_msg, o, complete_rewrite);
2475        else
2476                fprintf(o->file, "* Unmerged path %s\n", name);
2477}
2478
2479static void diff_fill_sha1_info(struct diff_filespec *one)
2480{
2481        if (DIFF_FILE_VALID(one)) {
2482                if (!one->sha1_valid) {
2483                        struct stat st;
2484                        if (!strcmp(one->path, "-")) {
2485                                hashcpy(one->sha1, null_sha1);
2486                                return;
2487                        }
2488                        if (lstat(one->path, &st) < 0)
2489                                die_errno("stat '%s'", one->path);
2490                        if (index_path(one->sha1, one->path, &st, 0))
2491                                die("cannot hash %s", one->path);
2492                }
2493        }
2494        else
2495                hashclr(one->sha1);
2496}
2497
2498static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2499{
2500        /* Strip the prefix but do not molest /dev/null and absolute paths */
2501        if (*namep && **namep != '/')
2502                *namep += prefix_length;
2503        if (*otherp && **otherp != '/')
2504                *otherp += prefix_length;
2505}
2506
2507static void run_diff(struct diff_filepair *p, struct diff_options *o)
2508{
2509        const char *pgm = external_diff();
2510        struct strbuf msg;
2511        struct diff_filespec *one = p->one;
2512        struct diff_filespec *two = p->two;
2513        const char *name;
2514        const char *other;
2515        const char *attr_path;
2516
2517        name  = p->one->path;
2518        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2519        attr_path = name;
2520        if (o->prefix_length)
2521                strip_prefix(o->prefix_length, &name, &other);
2522
2523        if (DIFF_PAIR_UNMERGED(p)) {
2524                run_diff_cmd(pgm, name, NULL, attr_path,
2525                             NULL, NULL, NULL, o, p);
2526                return;
2527        }
2528
2529        diff_fill_sha1_info(one);
2530        diff_fill_sha1_info(two);
2531
2532        if (!pgm &&
2533            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2534            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2535                /*
2536                 * a filepair that changes between file and symlink
2537                 * needs to be split into deletion and creation.
2538                 */
2539                struct diff_filespec *null = alloc_filespec(two->path);
2540                run_diff_cmd(NULL, name, other, attr_path,
2541                             one, null, &msg, o, p);
2542                free(null);
2543                strbuf_release(&msg);
2544
2545                null = alloc_filespec(one->path);
2546                run_diff_cmd(NULL, name, other, attr_path,
2547                             null, two, &msg, o, p);
2548                free(null);
2549        }
2550        else
2551                run_diff_cmd(pgm, name, other, attr_path,
2552                             one, two, &msg, o, p);
2553
2554        strbuf_release(&msg);
2555}
2556
2557static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2558                         struct diffstat_t *diffstat)
2559{
2560        const char *name;
2561        const char *other;
2562        int complete_rewrite = 0;
2563
2564        if (DIFF_PAIR_UNMERGED(p)) {
2565                /* unmerged */
2566                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2567                return;
2568        }
2569
2570        name = p->one->path;
2571        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2572
2573        if (o->prefix_length)
2574                strip_prefix(o->prefix_length, &name, &other);
2575
2576        diff_fill_sha1_info(p->one);
2577        diff_fill_sha1_info(p->two);
2578
2579        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2580                complete_rewrite = 1;
2581        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2582}
2583
2584static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2585{
2586        const char *name;
2587        const char *other;
2588        const char *attr_path;
2589
2590        if (DIFF_PAIR_UNMERGED(p)) {
2591                /* unmerged */
2592                return;
2593        }
2594
2595        name = p->one->path;
2596        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2597        attr_path = other ? other : name;
2598
2599        if (o->prefix_length)
2600                strip_prefix(o->prefix_length, &name, &other);
2601
2602        diff_fill_sha1_info(p->one);
2603        diff_fill_sha1_info(p->two);
2604
2605        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2606}
2607
2608void diff_setup(struct diff_options *options)
2609{
2610        memset(options, 0, sizeof(*options));
2611        memset(&diff_queued_diff, 0, sizeof(diff_queued_diff));
2612
2613        options->file = stdout;
2614
2615        options->line_termination = '\n';
2616        options->break_opt = -1;
2617        options->rename_limit = -1;
2618        options->dirstat_percent = 3;
2619        options->context = 3;
2620
2621        options->change = diff_change;
2622        options->add_remove = diff_addremove;
2623        if (diff_use_color_default > 0)
2624                DIFF_OPT_SET(options, COLOR_DIFF);
2625        options->detect_rename = diff_detect_rename_default;
2626
2627        if (!diff_mnemonic_prefix) {
2628                options->a_prefix = "a/";
2629                options->b_prefix = "b/";
2630        }
2631}
2632
2633int diff_setup_done(struct diff_options *options)
2634{
2635        int count = 0;
2636
2637        if (options->output_format & DIFF_FORMAT_NAME)
2638                count++;
2639        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2640                count++;
2641        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2642                count++;
2643        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2644                count++;
2645        if (count > 1)
2646                die("--name-only, --name-status, --check and -s are mutually exclusive");
2647
2648        /*
2649         * Most of the time we can say "there are changes"
2650         * only by checking if there are changed paths, but
2651         * --ignore-whitespace* options force us to look
2652         * inside contents.
2653         */
2654
2655        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2656            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2657            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2658                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2659        else
2660                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2661
2662        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2663                options->detect_rename = DIFF_DETECT_COPY;
2664
2665        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2666                options->prefix = NULL;
2667        if (options->prefix)
2668                options->prefix_length = strlen(options->prefix);
2669        else
2670                options->prefix_length = 0;
2671
2672        if (options->output_format & (DIFF_FORMAT_NAME |
2673                                      DIFF_FORMAT_NAME_STATUS |
2674                                      DIFF_FORMAT_CHECKDIFF |
2675                                      DIFF_FORMAT_NO_OUTPUT))
2676                options->output_format &= ~(DIFF_FORMAT_RAW |
2677                                            DIFF_FORMAT_NUMSTAT |
2678                                            DIFF_FORMAT_DIFFSTAT |
2679                                            DIFF_FORMAT_SHORTSTAT |
2680                                            DIFF_FORMAT_DIRSTAT |
2681                                            DIFF_FORMAT_SUMMARY |
2682                                            DIFF_FORMAT_PATCH);
2683
2684        /*
2685         * These cases always need recursive; we do not drop caller-supplied
2686         * recursive bits for other formats here.
2687         */
2688        if (options->output_format & (DIFF_FORMAT_PATCH |
2689                                      DIFF_FORMAT_NUMSTAT |
2690                                      DIFF_FORMAT_DIFFSTAT |
2691                                      DIFF_FORMAT_SHORTSTAT |
2692                                      DIFF_FORMAT_DIRSTAT |
2693                                      DIFF_FORMAT_SUMMARY |
2694                                      DIFF_FORMAT_CHECKDIFF))
2695                DIFF_OPT_SET(options, RECURSIVE);
2696        /*
2697         * Also pickaxe would not work very well if you do not say recursive
2698         */
2699        if (options->pickaxe)
2700                DIFF_OPT_SET(options, RECURSIVE);
2701        /*
2702         * When patches are generated, submodules diffed against the work tree
2703         * must be checked for dirtiness too so it can be shown in the output
2704         */
2705        if (options->output_format & DIFF_FORMAT_PATCH)
2706                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2707
2708        if (options->detect_rename && options->rename_limit < 0)
2709                options->rename_limit = diff_rename_limit_default;
2710        if (options->setup & DIFF_SETUP_USE_CACHE) {
2711                if (!active_cache)
2712                        /* read-cache does not die even when it fails
2713                         * so it is safe for us to do this here.  Also
2714                         * it does not smudge active_cache or active_nr
2715                         * when it fails, so we do not have to worry about
2716                         * cleaning it up ourselves either.
2717                         */
2718                        read_cache();
2719        }
2720        if (options->abbrev <= 0 || 40 < options->abbrev)
2721                options->abbrev = 40; /* full */
2722
2723        /*
2724         * It does not make sense to show the first hit we happened
2725         * to have found.  It does not make sense not to return with
2726         * exit code in such a case either.
2727         */
2728        if (DIFF_OPT_TST(options, QUICK)) {
2729                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2730                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2731        }
2732
2733        return 0;
2734}
2735
2736static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2737{
2738        char c, *eq;
2739        int len;
2740
2741        if (*arg != '-')
2742                return 0;
2743        c = *++arg;
2744        if (!c)
2745                return 0;
2746        if (c == arg_short) {
2747                c = *++arg;
2748                if (!c)
2749                        return 1;
2750                if (val && isdigit(c)) {
2751                        char *end;
2752                        int n = strtoul(arg, &end, 10);
2753                        if (*end)
2754                                return 0;
2755                        *val = n;
2756                        return 1;
2757                }
2758                return 0;
2759        }
2760        if (c != '-')
2761                return 0;
2762        arg++;
2763        eq = strchr(arg, '=');
2764        if (eq)
2765                len = eq - arg;
2766        else
2767                len = strlen(arg);
2768        if (!len || strncmp(arg, arg_long, len))
2769                return 0;
2770        if (eq) {
2771                int n;
2772                char *end;
2773                if (!isdigit(*++eq))
2774                        return 0;
2775                n = strtoul(eq, &end, 10);
2776                if (*end)
2777                        return 0;
2778                *val = n;
2779        }
2780        return 1;
2781}
2782
2783static int diff_scoreopt_parse(const char *opt);
2784
2785int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2786{
2787        const char *arg = av[0];
2788
2789        /* Output format options */
2790        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
2791                options->output_format |= DIFF_FORMAT_PATCH;
2792        else if (opt_arg(arg, 'U', "unified", &options->context))
2793                options->output_format |= DIFF_FORMAT_PATCH;
2794        else if (!strcmp(arg, "--raw"))
2795                options->output_format |= DIFF_FORMAT_RAW;
2796        else if (!strcmp(arg, "--patch-with-raw"))
2797                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2798        else if (!strcmp(arg, "--numstat"))
2799                options->output_format |= DIFF_FORMAT_NUMSTAT;
2800        else if (!strcmp(arg, "--shortstat"))
2801                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2802        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2803                options->output_format |= DIFF_FORMAT_DIRSTAT;
2804        else if (!strcmp(arg, "--cumulative")) {
2805                options->output_format |= DIFF_FORMAT_DIRSTAT;
2806                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2807        } else if (opt_arg(arg, 0, "dirstat-by-file",
2808                           &options->dirstat_percent)) {
2809                options->output_format |= DIFF_FORMAT_DIRSTAT;
2810                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2811        }
2812        else if (!strcmp(arg, "--check"))
2813                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2814        else if (!strcmp(arg, "--summary"))
2815                options->output_format |= DIFF_FORMAT_SUMMARY;
2816        else if (!strcmp(arg, "--patch-with-stat"))
2817                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2818        else if (!strcmp(arg, "--name-only"))
2819                options->output_format |= DIFF_FORMAT_NAME;
2820        else if (!strcmp(arg, "--name-status"))
2821                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2822        else if (!strcmp(arg, "-s"))
2823                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2824        else if (!prefixcmp(arg, "--stat")) {
2825                char *end;
2826                int width = options->stat_width;
2827                int name_width = options->stat_name_width;
2828                arg += 6;
2829                end = (char *)arg;
2830
2831                switch (*arg) {
2832                case '-':
2833                        if (!prefixcmp(arg, "-width="))
2834                                width = strtoul(arg + 7, &end, 10);
2835                        else if (!prefixcmp(arg, "-name-width="))
2836                                name_width = strtoul(arg + 12, &end, 10);
2837                        break;
2838                case '=':
2839                        width = strtoul(arg+1, &end, 10);
2840                        if (*end == ',')
2841                                name_width = strtoul(end+1, &end, 10);
2842                }
2843
2844                /* Important! This checks all the error cases! */
2845                if (*end)
2846                        return 0;
2847                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2848                options->stat_name_width = name_width;
2849                options->stat_width = width;
2850        }
2851
2852        /* renames options */
2853        else if (!prefixcmp(arg, "-B")) {
2854                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2855                        return -1;
2856        }
2857        else if (!prefixcmp(arg, "-M")) {
2858                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2859                        return -1;
2860                options->detect_rename = DIFF_DETECT_RENAME;
2861        }
2862        else if (!prefixcmp(arg, "-C")) {
2863                if (options->detect_rename == DIFF_DETECT_COPY)
2864                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2865                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2866                        return -1;
2867                options->detect_rename = DIFF_DETECT_COPY;
2868        }
2869        else if (!strcmp(arg, "--no-renames"))
2870                options->detect_rename = 0;
2871        else if (!strcmp(arg, "--relative"))
2872                DIFF_OPT_SET(options, RELATIVE_NAME);
2873        else if (!prefixcmp(arg, "--relative=")) {
2874                DIFF_OPT_SET(options, RELATIVE_NAME);
2875                options->prefix = arg + 11;
2876        }
2877
2878        /* xdiff options */
2879        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2880                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2881        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2882                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2883        else if (!strcmp(arg, "--ignore-space-at-eol"))
2884                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2885        else if (!strcmp(arg, "--patience"))
2886                DIFF_XDL_SET(options, PATIENCE_DIFF);
2887
2888        /* flags options */
2889        else if (!strcmp(arg, "--binary")) {
2890                options->output_format |= DIFF_FORMAT_PATCH;
2891                DIFF_OPT_SET(options, BINARY);
2892        }
2893        else if (!strcmp(arg, "--full-index"))
2894                DIFF_OPT_SET(options, FULL_INDEX);
2895        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2896                DIFF_OPT_SET(options, TEXT);
2897        else if (!strcmp(arg, "-R"))
2898                DIFF_OPT_SET(options, REVERSE_DIFF);
2899        else if (!strcmp(arg, "--find-copies-harder"))
2900                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2901        else if (!strcmp(arg, "--follow"))
2902                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2903        else if (!strcmp(arg, "--color"))
2904                DIFF_OPT_SET(options, COLOR_DIFF);
2905        else if (!prefixcmp(arg, "--color=")) {
2906                int value = git_config_colorbool(NULL, arg+8, -1);
2907                if (value == 0)
2908                        DIFF_OPT_CLR(options, COLOR_DIFF);
2909                else if (value > 0)
2910                        DIFF_OPT_SET(options, COLOR_DIFF);
2911                else
2912                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
2913        }
2914        else if (!strcmp(arg, "--no-color"))
2915                DIFF_OPT_CLR(options, COLOR_DIFF);
2916        else if (!strcmp(arg, "--color-words")) {
2917                DIFF_OPT_SET(options, COLOR_DIFF);
2918                options->word_diff = DIFF_WORDS_COLOR;
2919        }
2920        else if (!prefixcmp(arg, "--color-words=")) {
2921                DIFF_OPT_SET(options, COLOR_DIFF);
2922                options->word_diff = DIFF_WORDS_COLOR;
2923                options->word_regex = arg + 14;
2924        }
2925        else if (!strcmp(arg, "--word-diff")) {
2926                if (options->word_diff == DIFF_WORDS_NONE)
2927                        options->word_diff = DIFF_WORDS_PLAIN;
2928        }
2929        else if (!prefixcmp(arg, "--word-diff=")) {
2930                const char *type = arg + 12;
2931                if (!strcmp(type, "plain"))
2932                        options->word_diff = DIFF_WORDS_PLAIN;
2933                else if (!strcmp(type, "color")) {
2934                        DIFF_OPT_SET(options, COLOR_DIFF);
2935                        options->word_diff = DIFF_WORDS_COLOR;
2936                }
2937                else if (!strcmp(type, "porcelain"))
2938                        options->word_diff = DIFF_WORDS_PORCELAIN;
2939                else if (!strcmp(type, "none"))
2940                        options->word_diff = DIFF_WORDS_NONE;
2941                else
2942                        die("bad --word-diff argument: %s", type);
2943        }
2944        else if (!prefixcmp(arg, "--word-diff-regex=")) {
2945                if (options->word_diff == DIFF_WORDS_NONE)
2946                        options->word_diff = DIFF_WORDS_PLAIN;
2947                options->word_regex = arg + 18;
2948        }
2949        else if (!strcmp(arg, "--exit-code"))
2950                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2951        else if (!strcmp(arg, "--quiet"))
2952                DIFF_OPT_SET(options, QUICK);
2953        else if (!strcmp(arg, "--ext-diff"))
2954                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2955        else if (!strcmp(arg, "--no-ext-diff"))
2956                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2957        else if (!strcmp(arg, "--textconv"))
2958                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2959        else if (!strcmp(arg, "--no-textconv"))
2960                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2961        else if (!strcmp(arg, "--ignore-submodules"))
2962                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2963        else if (!strcmp(arg, "--submodule"))
2964                DIFF_OPT_SET(options, SUBMODULE_LOG);
2965        else if (!prefixcmp(arg, "--submodule=")) {
2966                if (!strcmp(arg + 12, "log"))
2967                        DIFF_OPT_SET(options, SUBMODULE_LOG);
2968        }
2969
2970        /* misc options */
2971        else if (!strcmp(arg, "-z"))
2972                options->line_termination = 0;
2973        else if (!prefixcmp(arg, "-l"))
2974                options->rename_limit = strtoul(arg+2, NULL, 10);
2975        else if (!prefixcmp(arg, "-S"))
2976                options->pickaxe = arg + 2;
2977        else if (!strcmp(arg, "--pickaxe-all"))
2978                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2979        else if (!strcmp(arg, "--pickaxe-regex"))
2980                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2981        else if (!prefixcmp(arg, "-O"))
2982                options->orderfile = arg + 2;
2983        else if (!prefixcmp(arg, "--diff-filter="))
2984                options->filter = arg + 14;
2985        else if (!strcmp(arg, "--abbrev"))
2986                options->abbrev = DEFAULT_ABBREV;
2987        else if (!prefixcmp(arg, "--abbrev=")) {
2988                options->abbrev = strtoul(arg + 9, NULL, 10);
2989                if (options->abbrev < MINIMUM_ABBREV)
2990                        options->abbrev = MINIMUM_ABBREV;
2991                else if (40 < options->abbrev)
2992                        options->abbrev = 40;
2993        }
2994        else if (!prefixcmp(arg, "--src-prefix="))
2995                options->a_prefix = arg + 13;
2996        else if (!prefixcmp(arg, "--dst-prefix="))
2997                options->b_prefix = arg + 13;
2998        else if (!strcmp(arg, "--no-prefix"))
2999                options->a_prefix = options->b_prefix = "";
3000        else if (opt_arg(arg, '\0', "inter-hunk-context",
3001                         &options->interhunkcontext))
3002                ;
3003        else if (!prefixcmp(arg, "--output=")) {
3004                options->file = fopen(arg + strlen("--output="), "w");
3005                if (!options->file)
3006                        die_errno("Could not open '%s'", arg + strlen("--output="));
3007                options->close_file = 1;
3008        } else
3009                return 0;
3010        return 1;
3011}
3012
3013static int parse_num(const char **cp_p)
3014{
3015        unsigned long num, scale;
3016        int ch, dot;
3017        const char *cp = *cp_p;
3018
3019        num = 0;
3020        scale = 1;
3021        dot = 0;
3022        for (;;) {
3023                ch = *cp;
3024                if ( !dot && ch == '.' ) {
3025                        scale = 1;
3026                        dot = 1;
3027                } else if ( ch == '%' ) {
3028                        scale = dot ? scale*100 : 100;
3029                        cp++;   /* % is always at the end */
3030                        break;
3031                } else if ( ch >= '0' && ch <= '9' ) {
3032                        if ( scale < 100000 ) {
3033                                scale *= 10;
3034                                num = (num*10) + (ch-'0');
3035                        }
3036                } else {
3037                        break;
3038                }
3039                cp++;
3040        }
3041        *cp_p = cp;
3042
3043        /* user says num divided by scale and we say internally that
3044         * is MAX_SCORE * num / scale.
3045         */
3046        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3047}
3048
3049static int diff_scoreopt_parse(const char *opt)
3050{
3051        int opt1, opt2, cmd;
3052
3053        if (*opt++ != '-')
3054                return -1;
3055        cmd = *opt++;
3056        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3057                return -1; /* that is not a -M, -C nor -B option */
3058
3059        opt1 = parse_num(&opt);
3060        if (cmd != 'B')
3061                opt2 = 0;
3062        else {
3063                if (*opt == 0)
3064                        opt2 = 0;
3065                else if (*opt != '/')
3066                        return -1; /* we expect -B80/99 or -B80 */
3067                else {
3068                        opt++;
3069                        opt2 = parse_num(&opt);
3070                }
3071        }
3072        if (*opt != 0)
3073                return -1;
3074        return opt1 | (opt2 << 16);
3075}
3076
3077struct diff_queue_struct diff_queued_diff;
3078
3079void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3080{
3081        if (queue->alloc <= queue->nr) {
3082                queue->alloc = alloc_nr(queue->alloc);
3083                queue->queue = xrealloc(queue->queue,
3084                                        sizeof(dp) * queue->alloc);
3085        }
3086        queue->queue[queue->nr++] = dp;
3087}
3088
3089struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3090                                 struct diff_filespec *one,
3091                                 struct diff_filespec *two)
3092{
3093        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3094        dp->one = one;
3095        dp->two = two;
3096        if (queue)
3097                diff_q(queue, dp);
3098        return dp;
3099}
3100
3101void diff_free_filepair(struct diff_filepair *p)
3102{
3103        free_filespec(p->one);
3104        free_filespec(p->two);
3105        free(p);
3106}
3107
3108/* This is different from find_unique_abbrev() in that
3109 * it stuffs the result with dots for alignment.
3110 */
3111const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3112{
3113        int abblen;
3114        const char *abbrev;
3115        if (len == 40)
3116                return sha1_to_hex(sha1);
3117
3118        abbrev = find_unique_abbrev(sha1, len);
3119        abblen = strlen(abbrev);
3120        if (abblen < 37) {
3121                static char hex[41];
3122                if (len < abblen && abblen <= len + 2)
3123                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3124                else
3125                        sprintf(hex, "%s...", abbrev);
3126                return hex;
3127        }
3128        return sha1_to_hex(sha1);
3129}
3130
3131static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3132{
3133        int line_termination = opt->line_termination;
3134        int inter_name_termination = line_termination ? '\t' : '\0';
3135
3136        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3137                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3138                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3139                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3140        }
3141        if (p->score) {
3142                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3143                        inter_name_termination);
3144        } else {
3145                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3146        }
3147
3148        if (p->status == DIFF_STATUS_COPIED ||
3149            p->status == DIFF_STATUS_RENAMED) {
3150                const char *name_a, *name_b;
3151                name_a = p->one->path;
3152                name_b = p->two->path;
3153                strip_prefix(opt->prefix_length, &name_a, &name_b);
3154                write_name_quoted(name_a, opt->file, inter_name_termination);
3155                write_name_quoted(name_b, opt->file, line_termination);
3156        } else {
3157                const char *name_a, *name_b;
3158                name_a = p->one->mode ? p->one->path : p->two->path;
3159                name_b = NULL;
3160                strip_prefix(opt->prefix_length, &name_a, &name_b);
3161                write_name_quoted(name_a, opt->file, line_termination);
3162        }
3163}
3164
3165int diff_unmodified_pair(struct diff_filepair *p)
3166{
3167        /* This function is written stricter than necessary to support
3168         * the currently implemented transformers, but the idea is to
3169         * let transformers to produce diff_filepairs any way they want,
3170         * and filter and clean them up here before producing the output.
3171         */
3172        struct diff_filespec *one = p->one, *two = p->two;
3173
3174        if (DIFF_PAIR_UNMERGED(p))
3175                return 0; /* unmerged is interesting */
3176
3177        /* deletion, addition, mode or type change
3178         * and rename are all interesting.
3179         */
3180        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3181            DIFF_PAIR_MODE_CHANGED(p) ||
3182            strcmp(one->path, two->path))
3183                return 0;
3184
3185        /* both are valid and point at the same path.  that is, we are
3186         * dealing with a change.
3187         */
3188        if (one->sha1_valid && two->sha1_valid &&
3189            !hashcmp(one->sha1, two->sha1) &&
3190            !one->dirty_submodule && !two->dirty_submodule)
3191                return 1; /* no change */
3192        if (!one->sha1_valid && !two->sha1_valid)
3193                return 1; /* both look at the same file on the filesystem. */
3194        return 0;
3195}
3196
3197static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3198{
3199        if (diff_unmodified_pair(p))
3200                return;
3201
3202        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3203            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3204                return; /* no tree diffs in patch format */
3205
3206        run_diff(p, o);
3207}
3208
3209static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3210                            struct diffstat_t *diffstat)
3211{
3212        if (diff_unmodified_pair(p))
3213                return;
3214
3215        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3216            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3217                return; /* no tree diffs in patch format */
3218
3219        run_diffstat(p, o, diffstat);
3220}
3221
3222static void diff_flush_checkdiff(struct diff_filepair *p,
3223                struct diff_options *o)
3224{
3225        if (diff_unmodified_pair(p))
3226                return;
3227
3228        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3229            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3230                return; /* no tree diffs in patch format */
3231
3232        run_checkdiff(p, o);
3233}
3234
3235int diff_queue_is_empty(void)
3236{
3237        struct diff_queue_struct *q = &diff_queued_diff;
3238        int i;
3239        for (i = 0; i < q->nr; i++)
3240                if (!diff_unmodified_pair(q->queue[i]))
3241                        return 0;
3242        return 1;
3243}
3244
3245#if DIFF_DEBUG
3246void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3247{
3248        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3249                x, one ? one : "",
3250                s->path,
3251                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3252                s->mode,
3253                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3254        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3255                x, one ? one : "",
3256                s->size, s->xfrm_flags);
3257}
3258
3259void diff_debug_filepair(const struct diff_filepair *p, int i)
3260{
3261        diff_debug_filespec(p->one, i, "one");
3262        diff_debug_filespec(p->two, i, "two");
3263        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3264                p->score, p->status ? p->status : '?',
3265                p->one->rename_used, p->broken_pair);
3266}
3267
3268void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3269{
3270        int i;
3271        if (msg)
3272                fprintf(stderr, "%s\n", msg);
3273        fprintf(stderr, "q->nr = %d\n", q->nr);
3274        for (i = 0; i < q->nr; i++) {
3275                struct diff_filepair *p = q->queue[i];
3276                diff_debug_filepair(p, i);
3277        }
3278}
3279#endif
3280
3281static void diff_resolve_rename_copy(void)
3282{
3283        int i;
3284        struct diff_filepair *p;
3285        struct diff_queue_struct *q = &diff_queued_diff;
3286
3287        diff_debug_queue("resolve-rename-copy", q);
3288
3289        for (i = 0; i < q->nr; i++) {
3290                p = q->queue[i];
3291                p->status = 0; /* undecided */
3292                if (DIFF_PAIR_UNMERGED(p))
3293                        p->status = DIFF_STATUS_UNMERGED;
3294                else if (!DIFF_FILE_VALID(p->one))
3295                        p->status = DIFF_STATUS_ADDED;
3296                else if (!DIFF_FILE_VALID(p->two))
3297                        p->status = DIFF_STATUS_DELETED;
3298                else if (DIFF_PAIR_TYPE_CHANGED(p))
3299                        p->status = DIFF_STATUS_TYPE_CHANGED;
3300
3301                /* from this point on, we are dealing with a pair
3302                 * whose both sides are valid and of the same type, i.e.
3303                 * either in-place edit or rename/copy edit.
3304                 */
3305                else if (DIFF_PAIR_RENAME(p)) {
3306                        /*
3307                         * A rename might have re-connected a broken
3308                         * pair up, causing the pathnames to be the
3309                         * same again. If so, that's not a rename at
3310                         * all, just a modification..
3311                         *
3312                         * Otherwise, see if this source was used for
3313                         * multiple renames, in which case we decrement
3314                         * the count, and call it a copy.
3315                         */
3316                        if (!strcmp(p->one->path, p->two->path))
3317                                p->status = DIFF_STATUS_MODIFIED;
3318                        else if (--p->one->rename_used > 0)
3319                                p->status = DIFF_STATUS_COPIED;
3320                        else
3321                                p->status = DIFF_STATUS_RENAMED;
3322                }
3323                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3324                         p->one->mode != p->two->mode ||
3325                         p->one->dirty_submodule ||
3326                         p->two->dirty_submodule ||
3327                         is_null_sha1(p->one->sha1))
3328                        p->status = DIFF_STATUS_MODIFIED;
3329                else {
3330                        /* This is a "no-change" entry and should not
3331                         * happen anymore, but prepare for broken callers.
3332                         */
3333                        error("feeding unmodified %s to diffcore",
3334                              p->one->path);
3335                        p->status = DIFF_STATUS_UNKNOWN;
3336                }
3337        }
3338        diff_debug_queue("resolve-rename-copy done", q);
3339}
3340
3341static int check_pair_status(struct diff_filepair *p)
3342{
3343        switch (p->status) {
3344        case DIFF_STATUS_UNKNOWN:
3345                return 0;
3346        case 0:
3347                die("internal error in diff-resolve-rename-copy");
3348        default:
3349                return 1;
3350        }
3351}
3352
3353static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3354{
3355        int fmt = opt->output_format;
3356
3357        if (fmt & DIFF_FORMAT_CHECKDIFF)
3358                diff_flush_checkdiff(p, opt);
3359        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3360                diff_flush_raw(p, opt);
3361        else if (fmt & DIFF_FORMAT_NAME) {
3362                const char *name_a, *name_b;
3363                name_a = p->two->path;
3364                name_b = NULL;
3365                strip_prefix(opt->prefix_length, &name_a, &name_b);
3366                write_name_quoted(name_a, opt->file, opt->line_termination);
3367        }
3368}
3369
3370static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3371{
3372        if (fs->mode)
3373                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3374        else
3375                fprintf(file, " %s ", newdelete);
3376        write_name_quoted(fs->path, file, '\n');
3377}
3378
3379
3380static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3381{
3382        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3383                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3384                        show_name ? ' ' : '\n');
3385                if (show_name) {
3386                        write_name_quoted(p->two->path, file, '\n');
3387                }
3388        }
3389}
3390
3391static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3392{
3393        char *names = pprint_rename(p->one->path, p->two->path);
3394
3395        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3396        free(names);
3397        show_mode_change(file, p, 0);
3398}
3399
3400static void diff_summary(FILE *file, struct diff_filepair *p)
3401{
3402        switch(p->status) {
3403        case DIFF_STATUS_DELETED:
3404                show_file_mode_name(file, "delete", p->one);
3405                break;
3406        case DIFF_STATUS_ADDED:
3407                show_file_mode_name(file, "create", p->two);
3408                break;
3409        case DIFF_STATUS_COPIED:
3410                show_rename_copy(file, "copy", p);
3411                break;
3412        case DIFF_STATUS_RENAMED:
3413                show_rename_copy(file, "rename", p);
3414                break;
3415        default:
3416                if (p->score) {
3417                        fputs(" rewrite ", file);
3418                        write_name_quoted(p->two->path, file, ' ');
3419                        fprintf(file, "(%d%%)\n", similarity_index(p));
3420                }
3421                show_mode_change(file, p, !p->score);
3422                break;
3423        }
3424}
3425
3426struct patch_id_t {
3427        git_SHA_CTX *ctx;
3428        int patchlen;
3429};
3430
3431static int remove_space(char *line, int len)
3432{
3433        int i;
3434        char *dst = line;
3435        unsigned char c;
3436
3437        for (i = 0; i < len; i++)
3438                if (!isspace((c = line[i])))
3439                        *dst++ = c;
3440
3441        return dst - line;
3442}
3443
3444static void patch_id_consume(void *priv, char *line, unsigned long len)
3445{
3446        struct patch_id_t *data = priv;
3447        int new_len;
3448
3449        /* Ignore line numbers when computing the SHA1 of the patch */
3450        if (!prefixcmp(line, "@@ -"))
3451                return;
3452
3453        new_len = remove_space(line, len);
3454
3455        git_SHA1_Update(data->ctx, line, new_len);
3456        data->patchlen += new_len;
3457}
3458
3459/* returns 0 upon success, and writes result into sha1 */
3460static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3461{
3462        struct diff_queue_struct *q = &diff_queued_diff;
3463        int i;
3464        git_SHA_CTX ctx;
3465        struct patch_id_t data;
3466        char buffer[PATH_MAX * 4 + 20];
3467
3468        git_SHA1_Init(&ctx);
3469        memset(&data, 0, sizeof(struct patch_id_t));
3470        data.ctx = &ctx;
3471
3472        for (i = 0; i < q->nr; i++) {
3473                xpparam_t xpp;
3474                xdemitconf_t xecfg;
3475                mmfile_t mf1, mf2;
3476                struct diff_filepair *p = q->queue[i];
3477                int len1, len2;
3478
3479                memset(&xpp, 0, sizeof(xpp));
3480                memset(&xecfg, 0, sizeof(xecfg));
3481                if (p->status == 0)
3482                        return error("internal diff status error");
3483                if (p->status == DIFF_STATUS_UNKNOWN)
3484                        continue;
3485                if (diff_unmodified_pair(p))
3486                        continue;
3487                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3488                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3489                        continue;
3490                if (DIFF_PAIR_UNMERGED(p))
3491                        continue;
3492
3493                diff_fill_sha1_info(p->one);
3494                diff_fill_sha1_info(p->two);
3495                if (fill_mmfile(&mf1, p->one) < 0 ||
3496                                fill_mmfile(&mf2, p->two) < 0)
3497                        return error("unable to read files to diff");
3498
3499                len1 = remove_space(p->one->path, strlen(p->one->path));
3500                len2 = remove_space(p->two->path, strlen(p->two->path));
3501                if (p->one->mode == 0)
3502                        len1 = snprintf(buffer, sizeof(buffer),
3503                                        "diff--gita/%.*sb/%.*s"
3504                                        "newfilemode%06o"
3505                                        "---/dev/null"
3506                                        "+++b/%.*s",
3507                                        len1, p->one->path,
3508                                        len2, p->two->path,
3509                                        p->two->mode,
3510                                        len2, p->two->path);
3511                else if (p->two->mode == 0)
3512                        len1 = snprintf(buffer, sizeof(buffer),
3513                                        "diff--gita/%.*sb/%.*s"
3514                                        "deletedfilemode%06o"
3515                                        "---a/%.*s"
3516                                        "+++/dev/null",
3517                                        len1, p->one->path,
3518                                        len2, p->two->path,
3519                                        p->one->mode,
3520                                        len1, p->one->path);
3521                else
3522                        len1 = snprintf(buffer, sizeof(buffer),
3523                                        "diff--gita/%.*sb/%.*s"
3524                                        "---a/%.*s"
3525                                        "+++b/%.*s",
3526                                        len1, p->one->path,
3527                                        len2, p->two->path,
3528                                        len1, p->one->path,
3529                                        len2, p->two->path);
3530                git_SHA1_Update(&ctx, buffer, len1);
3531
3532                xpp.flags = XDF_NEED_MINIMAL;
3533                xecfg.ctxlen = 3;
3534                xecfg.flags = XDL_EMIT_FUNCNAMES;
3535                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3536                              &xpp, &xecfg);
3537        }
3538
3539        git_SHA1_Final(sha1, &ctx);
3540        return 0;
3541}
3542
3543int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3544{
3545        struct diff_queue_struct *q = &diff_queued_diff;
3546        int i;
3547        int result = diff_get_patch_id(options, sha1);
3548
3549        for (i = 0; i < q->nr; i++)
3550                diff_free_filepair(q->queue[i]);
3551
3552        free(q->queue);
3553        DIFF_QUEUE_CLEAR(q);
3554
3555        return result;
3556}
3557
3558static int is_summary_empty(const struct diff_queue_struct *q)
3559{
3560        int i;
3561
3562        for (i = 0; i < q->nr; i++) {
3563                const struct diff_filepair *p = q->queue[i];
3564
3565                switch (p->status) {
3566                case DIFF_STATUS_DELETED:
3567                case DIFF_STATUS_ADDED:
3568                case DIFF_STATUS_COPIED:
3569                case DIFF_STATUS_RENAMED:
3570                        return 0;
3571                default:
3572                        if (p->score)
3573                                return 0;
3574                        if (p->one->mode && p->two->mode &&
3575                            p->one->mode != p->two->mode)
3576                                return 0;
3577                        break;
3578                }
3579        }
3580        return 1;
3581}
3582
3583void diff_flush(struct diff_options *options)
3584{
3585        struct diff_queue_struct *q = &diff_queued_diff;
3586        int i, output_format = options->output_format;
3587        int separator = 0;
3588
3589        /*
3590         * Order: raw, stat, summary, patch
3591         * or:    name/name-status/checkdiff (other bits clear)
3592         */
3593        if (!q->nr)
3594                goto free_queue;
3595
3596        if (output_format & (DIFF_FORMAT_RAW |
3597                             DIFF_FORMAT_NAME |
3598                             DIFF_FORMAT_NAME_STATUS |
3599                             DIFF_FORMAT_CHECKDIFF)) {
3600                for (i = 0; i < q->nr; i++) {
3601                        struct diff_filepair *p = q->queue[i];
3602                        if (check_pair_status(p))
3603                                flush_one_pair(p, options);
3604                }
3605                separator++;
3606        }
3607
3608        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3609                struct diffstat_t diffstat;
3610
3611                memset(&diffstat, 0, sizeof(struct diffstat_t));
3612                for (i = 0; i < q->nr; i++) {
3613                        struct diff_filepair *p = q->queue[i];
3614                        if (check_pair_status(p))
3615                                diff_flush_stat(p, options, &diffstat);
3616                }
3617                if (output_format & DIFF_FORMAT_NUMSTAT)
3618                        show_numstat(&diffstat, options);
3619                if (output_format & DIFF_FORMAT_DIFFSTAT)
3620                        show_stats(&diffstat, options);
3621                if (output_format & DIFF_FORMAT_SHORTSTAT)
3622                        show_shortstats(&diffstat, options);
3623                free_diffstat_info(&diffstat);
3624                separator++;
3625        }
3626        if (output_format & DIFF_FORMAT_DIRSTAT)
3627                show_dirstat(options);
3628
3629        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3630                for (i = 0; i < q->nr; i++)
3631                        diff_summary(options->file, q->queue[i]);
3632                separator++;
3633        }
3634
3635        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3636            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3637            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3638                /*
3639                 * run diff_flush_patch for the exit status. setting
3640                 * options->file to /dev/null should be safe, becaue we
3641                 * aren't supposed to produce any output anyway.
3642                 */
3643                if (options->close_file)
3644                        fclose(options->file);
3645                options->file = fopen("/dev/null", "w");
3646                if (!options->file)
3647                        die_errno("Could not open /dev/null");
3648                options->close_file = 1;
3649                for (i = 0; i < q->nr; i++) {
3650                        struct diff_filepair *p = q->queue[i];
3651                        if (check_pair_status(p))
3652                                diff_flush_patch(p, options);
3653                        if (options->found_changes)
3654                                break;
3655                }
3656        }
3657
3658        if (output_format & DIFF_FORMAT_PATCH) {
3659                if (separator) {
3660                        putc(options->line_termination, options->file);
3661                        if (options->stat_sep) {
3662                                /* attach patch instead of inline */
3663                                fputs(options->stat_sep, options->file);
3664                        }
3665                }
3666
3667                for (i = 0; i < q->nr; i++) {
3668                        struct diff_filepair *p = q->queue[i];
3669                        if (check_pair_status(p))
3670                                diff_flush_patch(p, options);
3671                }
3672        }
3673
3674        if (output_format & DIFF_FORMAT_CALLBACK)
3675                options->format_callback(q, options, options->format_callback_data);
3676
3677        for (i = 0; i < q->nr; i++)
3678                diff_free_filepair(q->queue[i]);
3679free_queue:
3680        free(q->queue);
3681        DIFF_QUEUE_CLEAR(q);
3682        if (options->close_file)
3683                fclose(options->file);
3684
3685        /*
3686         * Report the content-level differences with HAS_CHANGES;
3687         * diff_addremove/diff_change does not set the bit when
3688         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3689         */
3690        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3691                if (options->found_changes)
3692                        DIFF_OPT_SET(options, HAS_CHANGES);
3693                else
3694                        DIFF_OPT_CLR(options, HAS_CHANGES);
3695        }
3696}
3697
3698static void diffcore_apply_filter(const char *filter)
3699{
3700        int i;
3701        struct diff_queue_struct *q = &diff_queued_diff;
3702        struct diff_queue_struct outq;
3703        DIFF_QUEUE_CLEAR(&outq);
3704
3705        if (!filter)
3706                return;
3707
3708        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3709                int found;
3710                for (i = found = 0; !found && i < q->nr; i++) {
3711                        struct diff_filepair *p = q->queue[i];
3712                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3713                             ((p->score &&
3714                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3715                              (!p->score &&
3716                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3717                            ((p->status != DIFF_STATUS_MODIFIED) &&
3718                             strchr(filter, p->status)))
3719                                found++;
3720                }
3721                if (found)
3722                        return;
3723
3724                /* otherwise we will clear the whole queue
3725                 * by copying the empty outq at the end of this
3726                 * function, but first clear the current entries
3727                 * in the queue.
3728                 */
3729                for (i = 0; i < q->nr; i++)
3730                        diff_free_filepair(q->queue[i]);
3731        }
3732        else {
3733                /* Only the matching ones */
3734                for (i = 0; i < q->nr; i++) {
3735                        struct diff_filepair *p = q->queue[i];
3736
3737                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3738                             ((p->score &&
3739                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3740                              (!p->score &&
3741                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3742                            ((p->status != DIFF_STATUS_MODIFIED) &&
3743                             strchr(filter, p->status)))
3744                                diff_q(&outq, p);
3745                        else
3746                                diff_free_filepair(p);
3747                }
3748        }
3749        free(q->queue);
3750        *q = outq;
3751}
3752
3753/* Check whether two filespecs with the same mode and size are identical */
3754static int diff_filespec_is_identical(struct diff_filespec *one,
3755                                      struct diff_filespec *two)
3756{
3757        if (S_ISGITLINK(one->mode))
3758                return 0;
3759        if (diff_populate_filespec(one, 0))
3760                return 0;
3761        if (diff_populate_filespec(two, 0))
3762                return 0;
3763        return !memcmp(one->data, two->data, one->size);
3764}
3765
3766static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3767{
3768        int i;
3769        struct diff_queue_struct *q = &diff_queued_diff;
3770        struct diff_queue_struct outq;
3771        DIFF_QUEUE_CLEAR(&outq);
3772
3773        for (i = 0; i < q->nr; i++) {
3774                struct diff_filepair *p = q->queue[i];
3775
3776                /*
3777                 * 1. Entries that come from stat info dirtiness
3778                 *    always have both sides (iow, not create/delete),
3779                 *    one side of the object name is unknown, with
3780                 *    the same mode and size.  Keep the ones that
3781                 *    do not match these criteria.  They have real
3782                 *    differences.
3783                 *
3784                 * 2. At this point, the file is known to be modified,
3785                 *    with the same mode and size, and the object
3786                 *    name of one side is unknown.  Need to inspect
3787                 *    the identical contents.
3788                 */
3789                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3790                    !DIFF_FILE_VALID(p->two) ||
3791                    (p->one->sha1_valid && p->two->sha1_valid) ||
3792                    (p->one->mode != p->two->mode) ||
3793                    diff_populate_filespec(p->one, 1) ||
3794                    diff_populate_filespec(p->two, 1) ||
3795                    (p->one->size != p->two->size) ||
3796                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3797                        diff_q(&outq, p);
3798                else {
3799                        /*
3800                         * The caller can subtract 1 from skip_stat_unmatch
3801                         * to determine how many paths were dirty only
3802                         * due to stat info mismatch.
3803                         */
3804                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3805                                diffopt->skip_stat_unmatch++;
3806                        diff_free_filepair(p);
3807                }
3808        }
3809        free(q->queue);
3810        *q = outq;
3811}
3812
3813static int diffnamecmp(const void *a_, const void *b_)
3814{
3815        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
3816        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
3817        const char *name_a, *name_b;
3818
3819        name_a = a->one ? a->one->path : a->two->path;
3820        name_b = b->one ? b->one->path : b->two->path;
3821        return strcmp(name_a, name_b);
3822}
3823
3824void diffcore_fix_diff_index(struct diff_options *options)
3825{
3826        struct diff_queue_struct *q = &diff_queued_diff;
3827        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
3828}
3829
3830void diffcore_std(struct diff_options *options)
3831{
3832        /* We never run this function more than one time, because the
3833         * rename/copy detection logic can only run once.
3834         */
3835        if (diff_queued_diff.run)
3836                return;
3837
3838        if (options->skip_stat_unmatch)
3839                diffcore_skip_stat_unmatch(options);
3840        if (options->break_opt != -1)
3841                diffcore_break(options->break_opt);
3842        if (options->detect_rename)
3843                diffcore_rename(options);
3844        if (options->break_opt != -1)
3845                diffcore_merge_broken();
3846        if (options->pickaxe)
3847                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3848        if (options->orderfile)
3849                diffcore_order(options->orderfile);
3850        diff_resolve_rename_copy();
3851        diffcore_apply_filter(options->filter);
3852
3853        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3854                DIFF_OPT_SET(options, HAS_CHANGES);
3855        else
3856                DIFF_OPT_CLR(options, HAS_CHANGES);
3857
3858        diff_queued_diff.run = 1;
3859}
3860
3861int diff_result_code(struct diff_options *opt, int status)
3862{
3863        int result = 0;
3864        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3865            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3866                return status;
3867        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3868            DIFF_OPT_TST(opt, HAS_CHANGES))
3869                result |= 01;
3870        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3871            DIFF_OPT_TST(opt, CHECK_FAILED))
3872                result |= 02;
3873        return result;
3874}
3875
3876void diff_addremove(struct diff_options *options,
3877                    int addremove, unsigned mode,
3878                    const unsigned char *sha1,
3879                    const char *concatpath, unsigned dirty_submodule)
3880{
3881        struct diff_filespec *one, *two;
3882
3883        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3884                return;
3885
3886        /* This may look odd, but it is a preparation for
3887         * feeding "there are unchanged files which should
3888         * not produce diffs, but when you are doing copy
3889         * detection you would need them, so here they are"
3890         * entries to the diff-core.  They will be prefixed
3891         * with something like '=' or '*' (I haven't decided
3892         * which but should not make any difference).
3893         * Feeding the same new and old to diff_change()
3894         * also has the same effect.
3895         * Before the final output happens, they are pruned after
3896         * merged into rename/copy pairs as appropriate.
3897         */
3898        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3899                addremove = (addremove == '+' ? '-' :
3900                             addremove == '-' ? '+' : addremove);
3901
3902        if (options->prefix &&
3903            strncmp(concatpath, options->prefix, options->prefix_length))
3904                return;
3905
3906        one = alloc_filespec(concatpath);
3907        two = alloc_filespec(concatpath);
3908
3909        if (addremove != '+')
3910                fill_filespec(one, sha1, mode);
3911        if (addremove != '-') {
3912                fill_filespec(two, sha1, mode);
3913                two->dirty_submodule = dirty_submodule;
3914        }
3915
3916        diff_queue(&diff_queued_diff, one, two);
3917        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3918                DIFF_OPT_SET(options, HAS_CHANGES);
3919}
3920
3921void diff_change(struct diff_options *options,
3922                 unsigned old_mode, unsigned new_mode,
3923                 const unsigned char *old_sha1,
3924                 const unsigned char *new_sha1,
3925                 const char *concatpath,
3926                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
3927{
3928        struct diff_filespec *one, *two;
3929
3930        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3931                        && S_ISGITLINK(new_mode))
3932                return;
3933
3934        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3935                unsigned tmp;
3936                const unsigned char *tmp_c;
3937                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3938                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3939                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
3940                        new_dirty_submodule = tmp;
3941        }
3942
3943        if (options->prefix &&
3944            strncmp(concatpath, options->prefix, options->prefix_length))
3945                return;
3946
3947        one = alloc_filespec(concatpath);
3948        two = alloc_filespec(concatpath);
3949        fill_filespec(one, old_sha1, old_mode);
3950        fill_filespec(two, new_sha1, new_mode);
3951        one->dirty_submodule = old_dirty_submodule;
3952        two->dirty_submodule = new_dirty_submodule;
3953
3954        diff_queue(&diff_queued_diff, one, two);
3955        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3956                DIFF_OPT_SET(options, HAS_CHANGES);
3957}
3958
3959void diff_unmerge(struct diff_options *options,
3960                  const char *path,
3961                  unsigned mode, const unsigned char *sha1)
3962{
3963        struct diff_filespec *one, *two;
3964
3965        if (options->prefix &&
3966            strncmp(path, options->prefix, options->prefix_length))
3967                return;
3968
3969        one = alloc_filespec(path);
3970        two = alloc_filespec(path);
3971        fill_filespec(one, sha1, mode);
3972        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3973}
3974
3975static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3976                size_t *outsize)
3977{
3978        struct diff_tempfile *temp;
3979        const char *argv[3];
3980        const char **arg = argv;
3981        struct child_process child;
3982        struct strbuf buf = STRBUF_INIT;
3983        int err = 0;
3984
3985        temp = prepare_temp_file(spec->path, spec);
3986        *arg++ = pgm;
3987        *arg++ = temp->name;
3988        *arg = NULL;
3989
3990        memset(&child, 0, sizeof(child));
3991        child.use_shell = 1;
3992        child.argv = argv;
3993        child.out = -1;
3994        if (start_command(&child)) {
3995                remove_tempfile();
3996                return NULL;
3997        }
3998
3999        if (strbuf_read(&buf, child.out, 0) < 0)
4000                err = error("error reading from textconv command '%s'", pgm);
4001        close(child.out);
4002
4003        if (finish_command(&child) || err) {
4004                strbuf_release(&buf);
4005                remove_tempfile();
4006                return NULL;
4007        }
4008        remove_tempfile();
4009
4010        return strbuf_detach(&buf, outsize);
4011}
4012
4013static size_t fill_textconv(struct userdiff_driver *driver,
4014                            struct diff_filespec *df,
4015                            char **outbuf)
4016{
4017        size_t size;
4018
4019        if (!driver || !driver->textconv) {
4020                if (!DIFF_FILE_VALID(df)) {
4021                        *outbuf = "";
4022                        return 0;
4023                }
4024                if (diff_populate_filespec(df, 0))
4025                        die("unable to read files to diff");
4026                *outbuf = df->data;
4027                return df->size;
4028        }
4029
4030        if (driver->textconv_cache) {
4031                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4032                                          &size);
4033                if (*outbuf)
4034                        return size;
4035        }
4036
4037        *outbuf = run_textconv(driver->textconv, df, &size);
4038        if (!*outbuf)
4039                die("unable to read files to diff");
4040
4041        if (driver->textconv_cache) {
4042                /* ignore errors, as we might be in a readonly repository */
4043                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4044                                size);
4045                /*
4046                 * we could save up changes and flush them all at the end,
4047                 * but we would need an extra call after all diffing is done.
4048                 * Since generating a cache entry is the slow path anyway,
4049                 * this extra overhead probably isn't a big deal.
4050                 */
4051                notes_cache_write(driver->textconv_cache);
4052        }
4053
4054        return size;
4055}