diff.con commit Submodules: Use "ignore" settings from .gitmodules too for diff and status (302ad7a)
   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;
  33static int diff_no_prefix;
  34
  35static char diff_colors[][COLOR_MAXLEN] = {
  36        GIT_COLOR_RESET,
  37        GIT_COLOR_NORMAL,       /* PLAIN */
  38        GIT_COLOR_BOLD,         /* METAINFO */
  39        GIT_COLOR_CYAN,         /* FRAGINFO */
  40        GIT_COLOR_RED,          /* OLD */
  41        GIT_COLOR_GREEN,        /* NEW */
  42        GIT_COLOR_YELLOW,       /* COMMIT */
  43        GIT_COLOR_BG_RED,       /* WHITESPACE */
  44        GIT_COLOR_NORMAL,       /* FUNCINFO */
  45};
  46
  47static int parse_diff_color_slot(const char *var, int ofs)
  48{
  49        if (!strcasecmp(var+ofs, "plain"))
  50                return DIFF_PLAIN;
  51        if (!strcasecmp(var+ofs, "meta"))
  52                return DIFF_METAINFO;
  53        if (!strcasecmp(var+ofs, "frag"))
  54                return DIFF_FRAGINFO;
  55        if (!strcasecmp(var+ofs, "old"))
  56                return DIFF_FILE_OLD;
  57        if (!strcasecmp(var+ofs, "new"))
  58                return DIFF_FILE_NEW;
  59        if (!strcasecmp(var+ofs, "commit"))
  60                return DIFF_COMMIT;
  61        if (!strcasecmp(var+ofs, "whitespace"))
  62                return DIFF_WHITESPACE;
  63        if (!strcasecmp(var+ofs, "func"))
  64                return DIFF_FUNCINFO;
  65        return -1;
  66}
  67
  68static int git_config_rename(const char *var, const char *value)
  69{
  70        if (!value)
  71                return DIFF_DETECT_RENAME;
  72        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  73                return  DIFF_DETECT_COPY;
  74        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  75}
  76
  77/*
  78 * These are to give UI layer defaults.
  79 * The core-level commands such as git-diff-files should
  80 * never be affected by the setting of diff.renames
  81 * the user happens to have in the configuration file.
  82 */
  83int git_diff_ui_config(const char *var, const char *value, void *cb)
  84{
  85        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  86                diff_use_color_default = git_config_colorbool(var, value, -1);
  87                return 0;
  88        }
  89        if (!strcmp(var, "diff.renames")) {
  90                diff_detect_rename_default = git_config_rename(var, value);
  91                return 0;
  92        }
  93        if (!strcmp(var, "diff.autorefreshindex")) {
  94                diff_auto_refresh_index = git_config_bool(var, value);
  95                return 0;
  96        }
  97        if (!strcmp(var, "diff.mnemonicprefix")) {
  98                diff_mnemonic_prefix = git_config_bool(var, value);
  99                return 0;
 100        }
 101        if (!strcmp(var, "diff.noprefix")) {
 102                diff_no_prefix = git_config_bool(var, value);
 103                return 0;
 104        }
 105        if (!strcmp(var, "diff.external"))
 106                return git_config_string(&external_diff_cmd_cfg, var, value);
 107        if (!strcmp(var, "diff.wordregex"))
 108                return git_config_string(&diff_word_regex_cfg, var, value);
 109
 110        return git_diff_basic_config(var, value, cb);
 111}
 112
 113int git_diff_basic_config(const char *var, const char *value, void *cb)
 114{
 115        if (!strcmp(var, "diff.renamelimit")) {
 116                diff_rename_limit_default = git_config_int(var, value);
 117                return 0;
 118        }
 119
 120        switch (userdiff_config(var, value)) {
 121                case 0: break;
 122                case -1: return -1;
 123                default: return 0;
 124        }
 125
 126        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 127                int slot = parse_diff_color_slot(var, 11);
 128                if (slot < 0)
 129                        return 0;
 130                if (!value)
 131                        return config_error_nonbool(var);
 132                color_parse(value, var, diff_colors[slot]);
 133                return 0;
 134        }
 135
 136        /* like GNU diff's --suppress-blank-empty option  */
 137        if (!strcmp(var, "diff.suppressblankempty") ||
 138                        /* for backwards compatibility */
 139                        !strcmp(var, "diff.suppress-blank-empty")) {
 140                diff_suppress_blank_empty = git_config_bool(var, value);
 141                return 0;
 142        }
 143
 144        if (!prefixcmp(var, "submodule."))
 145                return parse_submodule_config_option(var, value);
 146
 147        return git_color_default_config(var, value, cb);
 148}
 149
 150static char *quote_two(const char *one, const char *two)
 151{
 152        int need_one = quote_c_style(one, NULL, NULL, 1);
 153        int need_two = quote_c_style(two, NULL, NULL, 1);
 154        struct strbuf res = STRBUF_INIT;
 155
 156        if (need_one + need_two) {
 157                strbuf_addch(&res, '"');
 158                quote_c_style(one, &res, NULL, 1);
 159                quote_c_style(two, &res, NULL, 1);
 160                strbuf_addch(&res, '"');
 161        } else {
 162                strbuf_addstr(&res, one);
 163                strbuf_addstr(&res, two);
 164        }
 165        return strbuf_detach(&res, NULL);
 166}
 167
 168static const char *external_diff(void)
 169{
 170        static const char *external_diff_cmd = NULL;
 171        static int done_preparing = 0;
 172
 173        if (done_preparing)
 174                return external_diff_cmd;
 175        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 176        if (!external_diff_cmd)
 177                external_diff_cmd = external_diff_cmd_cfg;
 178        done_preparing = 1;
 179        return external_diff_cmd;
 180}
 181
 182static struct diff_tempfile {
 183        const char *name; /* filename external diff should read from */
 184        char hex[41];
 185        char mode[10];
 186        char tmp_path[PATH_MAX];
 187} diff_temp[2];
 188
 189typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 190
 191struct emit_callback {
 192        int color_diff;
 193        unsigned ws_rule;
 194        int blank_at_eof_in_preimage;
 195        int blank_at_eof_in_postimage;
 196        int lno_in_preimage;
 197        int lno_in_postimage;
 198        sane_truncate_fn truncate;
 199        const char **label_path;
 200        struct diff_words_data *diff_words;
 201        struct diff_options *opt;
 202        int *found_changesp;
 203        struct strbuf *header;
 204};
 205
 206static int count_lines(const char *data, int size)
 207{
 208        int count, ch, completely_empty = 1, nl_just_seen = 0;
 209        count = 0;
 210        while (0 < size--) {
 211                ch = *data++;
 212                if (ch == '\n') {
 213                        count++;
 214                        nl_just_seen = 1;
 215                        completely_empty = 0;
 216                }
 217                else {
 218                        nl_just_seen = 0;
 219                        completely_empty = 0;
 220                }
 221        }
 222        if (completely_empty)
 223                return 0;
 224        if (!nl_just_seen)
 225                count++; /* no trailing newline */
 226        return count;
 227}
 228
 229static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 230{
 231        if (!DIFF_FILE_VALID(one)) {
 232                mf->ptr = (char *)""; /* does not matter */
 233                mf->size = 0;
 234                return 0;
 235        }
 236        else if (diff_populate_filespec(one, 0))
 237                return -1;
 238
 239        mf->ptr = one->data;
 240        mf->size = one->size;
 241        return 0;
 242}
 243
 244static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 245{
 246        char *ptr = mf->ptr;
 247        long size = mf->size;
 248        int cnt = 0;
 249
 250        if (!size)
 251                return cnt;
 252        ptr += size - 1; /* pointing at the very end */
 253        if (*ptr != '\n')
 254                ; /* incomplete line */
 255        else
 256                ptr--; /* skip the last LF */
 257        while (mf->ptr < ptr) {
 258                char *prev_eol;
 259                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 260                        if (*prev_eol == '\n')
 261                                break;
 262                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 263                        break;
 264                cnt++;
 265                ptr = prev_eol - 1;
 266        }
 267        return cnt;
 268}
 269
 270static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 271                               struct emit_callback *ecbdata)
 272{
 273        int l1, l2, at;
 274        unsigned ws_rule = ecbdata->ws_rule;
 275        l1 = count_trailing_blank(mf1, ws_rule);
 276        l2 = count_trailing_blank(mf2, ws_rule);
 277        if (l2 <= l1) {
 278                ecbdata->blank_at_eof_in_preimage = 0;
 279                ecbdata->blank_at_eof_in_postimage = 0;
 280                return;
 281        }
 282        at = count_lines(mf1->ptr, mf1->size);
 283        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 284
 285        at = count_lines(mf2->ptr, mf2->size);
 286        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 287}
 288
 289static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 290                        int first, const char *line, int len)
 291{
 292        int has_trailing_newline, has_trailing_carriage_return;
 293        int nofirst;
 294        FILE *file = o->file;
 295
 296        if (o->output_prefix) {
 297                struct strbuf *msg = NULL;
 298                msg = o->output_prefix(o, o->output_prefix_data);
 299                assert(msg);
 300                fwrite(msg->buf, msg->len, 1, file);
 301        }
 302
 303        if (len == 0) {
 304                has_trailing_newline = (first == '\n');
 305                has_trailing_carriage_return = (!has_trailing_newline &&
 306                                                (first == '\r'));
 307                nofirst = has_trailing_newline || has_trailing_carriage_return;
 308        } else {
 309                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 310                if (has_trailing_newline)
 311                        len--;
 312                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 313                if (has_trailing_carriage_return)
 314                        len--;
 315                nofirst = 0;
 316        }
 317
 318        if (len || !nofirst) {
 319                fputs(set, file);
 320                if (!nofirst)
 321                        fputc(first, file);
 322                fwrite(line, len, 1, file);
 323                fputs(reset, file);
 324        }
 325        if (has_trailing_carriage_return)
 326                fputc('\r', file);
 327        if (has_trailing_newline)
 328                fputc('\n', file);
 329}
 330
 331static void emit_line(struct diff_options *o, const char *set, const char *reset,
 332                      const char *line, int len)
 333{
 334        emit_line_0(o, set, reset, line[0], line+1, len-1);
 335}
 336
 337static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 338{
 339        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 340              ecbdata->blank_at_eof_in_preimage &&
 341              ecbdata->blank_at_eof_in_postimage &&
 342              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 343              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 344                return 0;
 345        return ws_blank_line(line, len, ecbdata->ws_rule);
 346}
 347
 348static void emit_add_line(const char *reset,
 349                          struct emit_callback *ecbdata,
 350                          const char *line, int len)
 351{
 352        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 353        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 354
 355        if (!*ws)
 356                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 357        else if (new_blank_line_at_eof(ecbdata, line, len))
 358                /* Blank line at EOF - paint '+' as well */
 359                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 360        else {
 361                /* Emit just the prefix, then the rest. */
 362                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 363                ws_check_emit(line, len, ecbdata->ws_rule,
 364                              ecbdata->opt->file, set, reset, ws);
 365        }
 366}
 367
 368static void emit_hunk_header(struct emit_callback *ecbdata,
 369                             const char *line, int len)
 370{
 371        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 372        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 373        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 374        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 375        static const char atat[2] = { '@', '@' };
 376        const char *cp, *ep;
 377        struct strbuf msgbuf = STRBUF_INIT;
 378        int org_len = len;
 379        int i = 1;
 380
 381        /*
 382         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 383         * it always is at least 10 bytes long.
 384         */
 385        if (len < 10 ||
 386            memcmp(line, atat, 2) ||
 387            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 388                emit_line(ecbdata->opt, plain, reset, line, len);
 389                return;
 390        }
 391        ep += 2; /* skip over @@ */
 392
 393        /* The hunk header in fraginfo color */
 394        strbuf_add(&msgbuf, frag, strlen(frag));
 395        strbuf_add(&msgbuf, line, ep - line);
 396        strbuf_add(&msgbuf, reset, strlen(reset));
 397
 398        /*
 399         * trailing "\r\n"
 400         */
 401        for ( ; i < 3; i++)
 402                if (line[len - i] == '\r' || line[len - i] == '\n')
 403                        len--;
 404
 405        /* blank before the func header */
 406        for (cp = ep; ep - line < len; ep++)
 407                if (*ep != ' ' && *ep != '\t')
 408                        break;
 409        if (ep != cp) {
 410                strbuf_add(&msgbuf, plain, strlen(plain));
 411                strbuf_add(&msgbuf, cp, ep - cp);
 412                strbuf_add(&msgbuf, reset, strlen(reset));
 413        }
 414
 415        if (ep < line + len) {
 416                strbuf_add(&msgbuf, func, strlen(func));
 417                strbuf_add(&msgbuf, ep, line + len - ep);
 418                strbuf_add(&msgbuf, reset, strlen(reset));
 419        }
 420
 421        strbuf_add(&msgbuf, line + len, org_len - len);
 422        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 423        strbuf_release(&msgbuf);
 424}
 425
 426static struct diff_tempfile *claim_diff_tempfile(void) {
 427        int i;
 428        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 429                if (!diff_temp[i].name)
 430                        return diff_temp + i;
 431        die("BUG: diff is failing to clean up its tempfiles");
 432}
 433
 434static int remove_tempfile_installed;
 435
 436static void remove_tempfile(void)
 437{
 438        int i;
 439        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 440                if (diff_temp[i].name == diff_temp[i].tmp_path)
 441                        unlink_or_warn(diff_temp[i].name);
 442                diff_temp[i].name = NULL;
 443        }
 444}
 445
 446static void remove_tempfile_on_signal(int signo)
 447{
 448        remove_tempfile();
 449        sigchain_pop(signo);
 450        raise(signo);
 451}
 452
 453static void print_line_count(FILE *file, int count)
 454{
 455        switch (count) {
 456        case 0:
 457                fprintf(file, "0,0");
 458                break;
 459        case 1:
 460                fprintf(file, "1");
 461                break;
 462        default:
 463                fprintf(file, "1,%d", count);
 464                break;
 465        }
 466}
 467
 468static void emit_rewrite_lines(struct emit_callback *ecb,
 469                               int prefix, const char *data, int size)
 470{
 471        const char *endp = NULL;
 472        static const char *nneof = " No newline at end of file\n";
 473        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 474        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 475
 476        while (0 < size) {
 477                int len;
 478
 479                endp = memchr(data, '\n', size);
 480                len = endp ? (endp - data + 1) : size;
 481                if (prefix != '+') {
 482                        ecb->lno_in_preimage++;
 483                        emit_line_0(ecb->opt, old, reset, '-',
 484                                    data, len);
 485                } else {
 486                        ecb->lno_in_postimage++;
 487                        emit_add_line(reset, ecb, data, len);
 488                }
 489                size -= len;
 490                data += len;
 491        }
 492        if (!endp) {
 493                const char *plain = diff_get_color(ecb->color_diff,
 494                                                   DIFF_PLAIN);
 495                emit_line_0(ecb->opt, plain, reset, '\\',
 496                            nneof, strlen(nneof));
 497        }
 498}
 499
 500static void emit_rewrite_diff(const char *name_a,
 501                              const char *name_b,
 502                              struct diff_filespec *one,
 503                              struct diff_filespec *two,
 504                              struct userdiff_driver *textconv_one,
 505                              struct userdiff_driver *textconv_two,
 506                              struct diff_options *o)
 507{
 508        int lc_a, lc_b;
 509        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 510        const char *name_a_tab, *name_b_tab;
 511        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 512        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 513        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 514        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 515        const char *a_prefix, *b_prefix;
 516        char *data_one, *data_two;
 517        size_t size_one, size_two;
 518        struct emit_callback ecbdata;
 519        char *line_prefix = "";
 520        struct strbuf *msgbuf;
 521
 522        if (o && o->output_prefix) {
 523                msgbuf = o->output_prefix(o, o->output_prefix_data);
 524                line_prefix = msgbuf->buf;
 525        }
 526
 527        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 528                a_prefix = o->b_prefix;
 529                b_prefix = o->a_prefix;
 530        } else {
 531                a_prefix = o->a_prefix;
 532                b_prefix = o->b_prefix;
 533        }
 534
 535        name_a += (*name_a == '/');
 536        name_b += (*name_b == '/');
 537        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 538        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 539
 540        strbuf_reset(&a_name);
 541        strbuf_reset(&b_name);
 542        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 543        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 544
 545        size_one = fill_textconv(textconv_one, one, &data_one);
 546        size_two = fill_textconv(textconv_two, two, &data_two);
 547
 548        memset(&ecbdata, 0, sizeof(ecbdata));
 549        ecbdata.color_diff = color_diff;
 550        ecbdata.found_changesp = &o->found_changes;
 551        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 552        ecbdata.opt = o;
 553        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 554                mmfile_t mf1, mf2;
 555                mf1.ptr = (char *)data_one;
 556                mf2.ptr = (char *)data_two;
 557                mf1.size = size_one;
 558                mf2.size = size_two;
 559                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 560        }
 561        ecbdata.lno_in_preimage = 1;
 562        ecbdata.lno_in_postimage = 1;
 563
 564        lc_a = count_lines(data_one, size_one);
 565        lc_b = count_lines(data_two, size_two);
 566        fprintf(o->file,
 567                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 568                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 569                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 570                line_prefix, fraginfo);
 571        print_line_count(o->file, lc_a);
 572        fprintf(o->file, " +");
 573        print_line_count(o->file, lc_b);
 574        fprintf(o->file, " @@%s\n", reset);
 575        if (lc_a)
 576                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 577        if (lc_b)
 578                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 579        if (textconv_one)
 580                free((char *)data_one);
 581        if (textconv_two)
 582                free((char *)data_two);
 583}
 584
 585struct diff_words_buffer {
 586        mmfile_t text;
 587        long alloc;
 588        struct diff_words_orig {
 589                const char *begin, *end;
 590        } *orig;
 591        int orig_nr, orig_alloc;
 592};
 593
 594static void diff_words_append(char *line, unsigned long len,
 595                struct diff_words_buffer *buffer)
 596{
 597        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 598        line++;
 599        len--;
 600        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 601        buffer->text.size += len;
 602        buffer->text.ptr[buffer->text.size] = '\0';
 603}
 604
 605struct diff_words_style_elem
 606{
 607        const char *prefix;
 608        const char *suffix;
 609        const char *color; /* NULL; filled in by the setup code if
 610                            * color is enabled */
 611};
 612
 613struct diff_words_style
 614{
 615        enum diff_words_type type;
 616        struct diff_words_style_elem new, old, ctx;
 617        const char *newline;
 618};
 619
 620struct diff_words_style diff_words_styles[] = {
 621        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 622        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 623        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 624};
 625
 626struct diff_words_data {
 627        struct diff_words_buffer minus, plus;
 628        const char *current_plus;
 629        int last_minus;
 630        struct diff_options *opt;
 631        regex_t *word_regex;
 632        enum diff_words_type type;
 633        struct diff_words_style *style;
 634};
 635
 636static int fn_out_diff_words_write_helper(FILE *fp,
 637                                          struct diff_words_style_elem *st_el,
 638                                          const char *newline,
 639                                          size_t count, const char *buf,
 640                                          const char *line_prefix)
 641{
 642        int print = 0;
 643
 644        while (count) {
 645                char *p = memchr(buf, '\n', count);
 646                if (print)
 647                        fputs(line_prefix, fp);
 648                if (p != buf) {
 649                        if (st_el->color && fputs(st_el->color, fp) < 0)
 650                                return -1;
 651                        if (fputs(st_el->prefix, fp) < 0 ||
 652                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 653                            fputs(st_el->suffix, fp) < 0)
 654                                return -1;
 655                        if (st_el->color && *st_el->color
 656                            && fputs(GIT_COLOR_RESET, fp) < 0)
 657                                return -1;
 658                }
 659                if (!p)
 660                        return 0;
 661                if (fputs(newline, fp) < 0)
 662                        return -1;
 663                count -= p + 1 - buf;
 664                buf = p + 1;
 665                print = 1;
 666        }
 667        return 0;
 668}
 669
 670/*
 671 * '--color-words' algorithm can be described as:
 672 *
 673 *   1. collect a the minus/plus lines of a diff hunk, divided into
 674 *      minus-lines and plus-lines;
 675 *
 676 *   2. break both minus-lines and plus-lines into words and
 677 *      place them into two mmfile_t with one word for each line;
 678 *
 679 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 680 *
 681 * And for the common parts of the both file, we output the plus side text.
 682 * diff_words->current_plus is used to trace the current position of the plus file
 683 * which printed. diff_words->last_minus is used to trace the last minus word
 684 * printed.
 685 *
 686 * For '--graph' to work with '--color-words', we need to output the graph prefix
 687 * on each line of color words output. Generally, there are two conditions on
 688 * which we should output the prefix.
 689 *
 690 *   1. diff_words->last_minus == 0 &&
 691 *      diff_words->current_plus == diff_words->plus.text.ptr
 692 *
 693 *      that is: the plus text must start as a new line, and if there is no minus
 694 *      word printed, a graph prefix must be printed.
 695 *
 696 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 697 *      *(diff_words->current_plus - 1) == '\n'
 698 *
 699 *      that is: a graph prefix must be printed following a '\n'
 700 */
 701static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 702{
 703        if ((diff_words->last_minus == 0 &&
 704                diff_words->current_plus == diff_words->plus.text.ptr) ||
 705                (diff_words->current_plus > diff_words->plus.text.ptr &&
 706                *(diff_words->current_plus - 1) == '\n')) {
 707                return 1;
 708        } else {
 709                return 0;
 710        }
 711}
 712
 713static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 714{
 715        struct diff_words_data *diff_words = priv;
 716        struct diff_words_style *style = diff_words->style;
 717        int minus_first, minus_len, plus_first, plus_len;
 718        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 719        struct diff_options *opt = diff_words->opt;
 720        struct strbuf *msgbuf;
 721        char *line_prefix = "";
 722
 723        if (line[0] != '@' || parse_hunk_header(line, len,
 724                        &minus_first, &minus_len, &plus_first, &plus_len))
 725                return;
 726
 727        assert(opt);
 728        if (opt->output_prefix) {
 729                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 730                line_prefix = msgbuf->buf;
 731        }
 732
 733        /* POSIX requires that first be decremented by one if len == 0... */
 734        if (minus_len) {
 735                minus_begin = diff_words->minus.orig[minus_first].begin;
 736                minus_end =
 737                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 738        } else
 739                minus_begin = minus_end =
 740                        diff_words->minus.orig[minus_first].end;
 741
 742        if (plus_len) {
 743                plus_begin = diff_words->plus.orig[plus_first].begin;
 744                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 745        } else
 746                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 747
 748        if (color_words_output_graph_prefix(diff_words)) {
 749                fputs(line_prefix, diff_words->opt->file);
 750        }
 751        if (diff_words->current_plus != plus_begin) {
 752                fn_out_diff_words_write_helper(diff_words->opt->file,
 753                                &style->ctx, style->newline,
 754                                plus_begin - diff_words->current_plus,
 755                                diff_words->current_plus, line_prefix);
 756                if (*(plus_begin - 1) == '\n')
 757                        fputs(line_prefix, diff_words->opt->file);
 758        }
 759        if (minus_begin != minus_end) {
 760                fn_out_diff_words_write_helper(diff_words->opt->file,
 761                                &style->old, style->newline,
 762                                minus_end - minus_begin, minus_begin,
 763                                line_prefix);
 764        }
 765        if (plus_begin != plus_end) {
 766                fn_out_diff_words_write_helper(diff_words->opt->file,
 767                                &style->new, style->newline,
 768                                plus_end - plus_begin, plus_begin,
 769                                line_prefix);
 770        }
 771
 772        diff_words->current_plus = plus_end;
 773        diff_words->last_minus = minus_first;
 774}
 775
 776/* This function starts looking at *begin, and returns 0 iff a word was found. */
 777static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 778                int *begin, int *end)
 779{
 780        if (word_regex && *begin < buffer->size) {
 781                regmatch_t match[1];
 782                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 783                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 784                                        '\n', match[0].rm_eo - match[0].rm_so);
 785                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 786                        *begin += match[0].rm_so;
 787                        return *begin >= *end;
 788                }
 789                return -1;
 790        }
 791
 792        /* find the next word */
 793        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 794                (*begin)++;
 795        if (*begin >= buffer->size)
 796                return -1;
 797
 798        /* find the end of the word */
 799        *end = *begin + 1;
 800        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 801                (*end)++;
 802
 803        return 0;
 804}
 805
 806/*
 807 * This function splits the words in buffer->text, stores the list with
 808 * newline separator into out, and saves the offsets of the original words
 809 * in buffer->orig.
 810 */
 811static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 812                regex_t *word_regex)
 813{
 814        int i, j;
 815        long alloc = 0;
 816
 817        out->size = 0;
 818        out->ptr = NULL;
 819
 820        /* fake an empty "0th" word */
 821        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 822        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 823        buffer->orig_nr = 1;
 824
 825        for (i = 0; i < buffer->text.size; i++) {
 826                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 827                        return;
 828
 829                /* store original boundaries */
 830                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 831                                buffer->orig_alloc);
 832                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 833                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 834                buffer->orig_nr++;
 835
 836                /* store one word */
 837                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 838                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 839                out->ptr[out->size + j - i] = '\n';
 840                out->size += j - i + 1;
 841
 842                i = j - 1;
 843        }
 844}
 845
 846/* this executes the word diff on the accumulated buffers */
 847static void diff_words_show(struct diff_words_data *diff_words)
 848{
 849        xpparam_t xpp;
 850        xdemitconf_t xecfg;
 851        mmfile_t minus, plus;
 852        struct diff_words_style *style = diff_words->style;
 853
 854        struct diff_options *opt = diff_words->opt;
 855        struct strbuf *msgbuf;
 856        char *line_prefix = "";
 857
 858        assert(opt);
 859        if (opt->output_prefix) {
 860                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 861                line_prefix = msgbuf->buf;
 862        }
 863
 864        /* special case: only removal */
 865        if (!diff_words->plus.text.size) {
 866                fputs(line_prefix, diff_words->opt->file);
 867                fn_out_diff_words_write_helper(diff_words->opt->file,
 868                        &style->old, style->newline,
 869                        diff_words->minus.text.size,
 870                        diff_words->minus.text.ptr, line_prefix);
 871                diff_words->minus.text.size = 0;
 872                return;
 873        }
 874
 875        diff_words->current_plus = diff_words->plus.text.ptr;
 876        diff_words->last_minus = 0;
 877
 878        memset(&xpp, 0, sizeof(xpp));
 879        memset(&xecfg, 0, sizeof(xecfg));
 880        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 881        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 882        xpp.flags = 0;
 883        /* as only the hunk header will be parsed, we need a 0-context */
 884        xecfg.ctxlen = 0;
 885        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 886                      &xpp, &xecfg);
 887        free(minus.ptr);
 888        free(plus.ptr);
 889        if (diff_words->current_plus != diff_words->plus.text.ptr +
 890                        diff_words->plus.text.size) {
 891                if (color_words_output_graph_prefix(diff_words))
 892                        fputs(line_prefix, diff_words->opt->file);
 893                fn_out_diff_words_write_helper(diff_words->opt->file,
 894                        &style->ctx, style->newline,
 895                        diff_words->plus.text.ptr + diff_words->plus.text.size
 896                        - diff_words->current_plus, diff_words->current_plus,
 897                        line_prefix);
 898        }
 899        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 900}
 901
 902/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 903static void diff_words_flush(struct emit_callback *ecbdata)
 904{
 905        if (ecbdata->diff_words->minus.text.size ||
 906            ecbdata->diff_words->plus.text.size)
 907                diff_words_show(ecbdata->diff_words);
 908}
 909
 910static void free_diff_words_data(struct emit_callback *ecbdata)
 911{
 912        if (ecbdata->diff_words) {
 913                diff_words_flush(ecbdata);
 914                free (ecbdata->diff_words->minus.text.ptr);
 915                free (ecbdata->diff_words->minus.orig);
 916                free (ecbdata->diff_words->plus.text.ptr);
 917                free (ecbdata->diff_words->plus.orig);
 918                free(ecbdata->diff_words->word_regex);
 919                free(ecbdata->diff_words);
 920                ecbdata->diff_words = NULL;
 921        }
 922}
 923
 924const char *diff_get_color(int diff_use_color, enum color_diff ix)
 925{
 926        if (diff_use_color)
 927                return diff_colors[ix];
 928        return "";
 929}
 930
 931static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 932{
 933        const char *cp;
 934        unsigned long allot;
 935        size_t l = len;
 936
 937        if (ecb->truncate)
 938                return ecb->truncate(line, len);
 939        cp = line;
 940        allot = l;
 941        while (0 < l) {
 942                (void) utf8_width(&cp, &l);
 943                if (!cp)
 944                        break; /* truncated in the middle? */
 945        }
 946        return allot - l;
 947}
 948
 949static void find_lno(const char *line, struct emit_callback *ecbdata)
 950{
 951        const char *p;
 952        ecbdata->lno_in_preimage = 0;
 953        ecbdata->lno_in_postimage = 0;
 954        p = strchr(line, '-');
 955        if (!p)
 956                return; /* cannot happen */
 957        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 958        p = strchr(p, '+');
 959        if (!p)
 960                return; /* cannot happen */
 961        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 962}
 963
 964static void fn_out_consume(void *priv, char *line, unsigned long len)
 965{
 966        struct emit_callback *ecbdata = priv;
 967        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 968        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 969        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 970        struct diff_options *o = ecbdata->opt;
 971        char *line_prefix = "";
 972        struct strbuf *msgbuf;
 973
 974        if (o && o->output_prefix) {
 975                msgbuf = o->output_prefix(o, o->output_prefix_data);
 976                line_prefix = msgbuf->buf;
 977        }
 978
 979        if (ecbdata->header) {
 980                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 981                strbuf_reset(ecbdata->header);
 982                ecbdata->header = NULL;
 983        }
 984        *(ecbdata->found_changesp) = 1;
 985
 986        if (ecbdata->label_path[0]) {
 987                const char *name_a_tab, *name_b_tab;
 988
 989                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 990                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 991
 992                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
 993                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
 994                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
 995                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
 996                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 997        }
 998
 999        if (diff_suppress_blank_empty
1000            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1001                line[0] = '\n';
1002                len = 1;
1003        }
1004
1005        if (line[0] == '@') {
1006                if (ecbdata->diff_words)
1007                        diff_words_flush(ecbdata);
1008                len = sane_truncate_line(ecbdata, line, len);
1009                find_lno(line, ecbdata);
1010                emit_hunk_header(ecbdata, line, len);
1011                if (line[len-1] != '\n')
1012                        putc('\n', ecbdata->opt->file);
1013                return;
1014        }
1015
1016        if (len < 1) {
1017                emit_line(ecbdata->opt, reset, reset, line, len);
1018                if (ecbdata->diff_words
1019                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1020                        fputs("~\n", ecbdata->opt->file);
1021                return;
1022        }
1023
1024        if (ecbdata->diff_words) {
1025                if (line[0] == '-') {
1026                        diff_words_append(line, len,
1027                                          &ecbdata->diff_words->minus);
1028                        return;
1029                } else if (line[0] == '+') {
1030                        diff_words_append(line, len,
1031                                          &ecbdata->diff_words->plus);
1032                        return;
1033                }
1034                diff_words_flush(ecbdata);
1035                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1036                        emit_line(ecbdata->opt, plain, reset, line, len);
1037                        fputs("~\n", ecbdata->opt->file);
1038                } else {
1039                        /* don't print the prefix character */
1040                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1041                }
1042                return;
1043        }
1044
1045        if (line[0] != '+') {
1046                const char *color =
1047                        diff_get_color(ecbdata->color_diff,
1048                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1049                ecbdata->lno_in_preimage++;
1050                if (line[0] == ' ')
1051                        ecbdata->lno_in_postimage++;
1052                emit_line(ecbdata->opt, color, reset, line, len);
1053        } else {
1054                ecbdata->lno_in_postimage++;
1055                emit_add_line(reset, ecbdata, line + 1, len - 1);
1056        }
1057}
1058
1059static char *pprint_rename(const char *a, const char *b)
1060{
1061        const char *old = a;
1062        const char *new = b;
1063        struct strbuf name = STRBUF_INIT;
1064        int pfx_length, sfx_length;
1065        int len_a = strlen(a);
1066        int len_b = strlen(b);
1067        int a_midlen, b_midlen;
1068        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1069        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1070
1071        if (qlen_a || qlen_b) {
1072                quote_c_style(a, &name, NULL, 0);
1073                strbuf_addstr(&name, " => ");
1074                quote_c_style(b, &name, NULL, 0);
1075                return strbuf_detach(&name, NULL);
1076        }
1077
1078        /* Find common prefix */
1079        pfx_length = 0;
1080        while (*old && *new && *old == *new) {
1081                if (*old == '/')
1082                        pfx_length = old - a + 1;
1083                old++;
1084                new++;
1085        }
1086
1087        /* Find common suffix */
1088        old = a + len_a;
1089        new = b + len_b;
1090        sfx_length = 0;
1091        while (a <= old && b <= new && *old == *new) {
1092                if (*old == '/')
1093                        sfx_length = len_a - (old - a);
1094                old--;
1095                new--;
1096        }
1097
1098        /*
1099         * pfx{mid-a => mid-b}sfx
1100         * {pfx-a => pfx-b}sfx
1101         * pfx{sfx-a => sfx-b}
1102         * name-a => name-b
1103         */
1104        a_midlen = len_a - pfx_length - sfx_length;
1105        b_midlen = len_b - pfx_length - sfx_length;
1106        if (a_midlen < 0)
1107                a_midlen = 0;
1108        if (b_midlen < 0)
1109                b_midlen = 0;
1110
1111        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1112        if (pfx_length + sfx_length) {
1113                strbuf_add(&name, a, pfx_length);
1114                strbuf_addch(&name, '{');
1115        }
1116        strbuf_add(&name, a + pfx_length, a_midlen);
1117        strbuf_addstr(&name, " => ");
1118        strbuf_add(&name, b + pfx_length, b_midlen);
1119        if (pfx_length + sfx_length) {
1120                strbuf_addch(&name, '}');
1121                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1122        }
1123        return strbuf_detach(&name, NULL);
1124}
1125
1126struct diffstat_t {
1127        int nr;
1128        int alloc;
1129        struct diffstat_file {
1130                char *from_name;
1131                char *name;
1132                char *print_name;
1133                unsigned is_unmerged:1;
1134                unsigned is_binary:1;
1135                unsigned is_renamed:1;
1136                uintmax_t added, deleted;
1137        } **files;
1138};
1139
1140static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1141                                          const char *name_a,
1142                                          const char *name_b)
1143{
1144        struct diffstat_file *x;
1145        x = xcalloc(sizeof (*x), 1);
1146        if (diffstat->nr == diffstat->alloc) {
1147                diffstat->alloc = alloc_nr(diffstat->alloc);
1148                diffstat->files = xrealloc(diffstat->files,
1149                                diffstat->alloc * sizeof(x));
1150        }
1151        diffstat->files[diffstat->nr++] = x;
1152        if (name_b) {
1153                x->from_name = xstrdup(name_a);
1154                x->name = xstrdup(name_b);
1155                x->is_renamed = 1;
1156        }
1157        else {
1158                x->from_name = NULL;
1159                x->name = xstrdup(name_a);
1160        }
1161        return x;
1162}
1163
1164static void diffstat_consume(void *priv, char *line, unsigned long len)
1165{
1166        struct diffstat_t *diffstat = priv;
1167        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1168
1169        if (line[0] == '+')
1170                x->added++;
1171        else if (line[0] == '-')
1172                x->deleted++;
1173}
1174
1175const char mime_boundary_leader[] = "------------";
1176
1177static int scale_linear(int it, int width, int max_change)
1178{
1179        /*
1180         * make sure that at least one '-' is printed if there were deletions,
1181         * and likewise for '+'.
1182         */
1183        if (max_change < 2)
1184                return it;
1185        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1186}
1187
1188static void show_name(FILE *file,
1189                      const char *prefix, const char *name, int len)
1190{
1191        fprintf(file, " %s%-*s |", prefix, len, name);
1192}
1193
1194static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1195{
1196        if (cnt <= 0)
1197                return;
1198        fprintf(file, "%s", set);
1199        while (cnt--)
1200                putc(ch, file);
1201        fprintf(file, "%s", reset);
1202}
1203
1204static void fill_print_name(struct diffstat_file *file)
1205{
1206        char *pname;
1207
1208        if (file->print_name)
1209                return;
1210
1211        if (!file->is_renamed) {
1212                struct strbuf buf = STRBUF_INIT;
1213                if (quote_c_style(file->name, &buf, NULL, 0)) {
1214                        pname = strbuf_detach(&buf, NULL);
1215                } else {
1216                        pname = file->name;
1217                        strbuf_release(&buf);
1218                }
1219        } else {
1220                pname = pprint_rename(file->from_name, file->name);
1221        }
1222        file->print_name = pname;
1223}
1224
1225static void show_stats(struct diffstat_t *data, struct diff_options *options)
1226{
1227        int i, len, add, del, adds = 0, dels = 0;
1228        uintmax_t max_change = 0, max_len = 0;
1229        int total_files = data->nr;
1230        int width, name_width;
1231        const char *reset, *set, *add_c, *del_c;
1232        const char *line_prefix = "";
1233        struct strbuf *msg = NULL;
1234
1235        if (data->nr == 0)
1236                return;
1237
1238        if (options->output_prefix) {
1239                msg = options->output_prefix(options, options->output_prefix_data);
1240                line_prefix = msg->buf;
1241        }
1242
1243        width = options->stat_width ? options->stat_width : 80;
1244        name_width = options->stat_name_width ? options->stat_name_width : 50;
1245
1246        /* Sanity: give at least 5 columns to the graph,
1247         * but leave at least 10 columns for the name.
1248         */
1249        if (width < 25)
1250                width = 25;
1251        if (name_width < 10)
1252                name_width = 10;
1253        else if (width < name_width + 15)
1254                name_width = width - 15;
1255
1256        /* Find the longest filename and max number of changes */
1257        reset = diff_get_color_opt(options, DIFF_RESET);
1258        set   = diff_get_color_opt(options, DIFF_PLAIN);
1259        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1260        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1261
1262        for (i = 0; i < data->nr; i++) {
1263                struct diffstat_file *file = data->files[i];
1264                uintmax_t change = file->added + file->deleted;
1265                fill_print_name(file);
1266                len = strlen(file->print_name);
1267                if (max_len < len)
1268                        max_len = len;
1269
1270                if (file->is_binary || file->is_unmerged)
1271                        continue;
1272                if (max_change < change)
1273                        max_change = change;
1274        }
1275
1276        /* Compute the width of the graph part;
1277         * 10 is for one blank at the beginning of the line plus
1278         * " | count " between the name and the graph.
1279         *
1280         * From here on, name_width is the width of the name area,
1281         * and width is the width of the graph area.
1282         */
1283        name_width = (name_width < max_len) ? name_width : max_len;
1284        if (width < (name_width + 10) + max_change)
1285                width = width - (name_width + 10);
1286        else
1287                width = max_change;
1288
1289        for (i = 0; i < data->nr; i++) {
1290                const char *prefix = "";
1291                char *name = data->files[i]->print_name;
1292                uintmax_t added = data->files[i]->added;
1293                uintmax_t deleted = data->files[i]->deleted;
1294                int name_len;
1295
1296                /*
1297                 * "scale" the filename
1298                 */
1299                len = name_width;
1300                name_len = strlen(name);
1301                if (name_width < name_len) {
1302                        char *slash;
1303                        prefix = "...";
1304                        len -= 3;
1305                        name += name_len - len;
1306                        slash = strchr(name, '/');
1307                        if (slash)
1308                                name = slash;
1309                }
1310
1311                if (data->files[i]->is_binary) {
1312                        fprintf(options->file, "%s", line_prefix);
1313                        show_name(options->file, prefix, name, len);
1314                        fprintf(options->file, "  Bin ");
1315                        fprintf(options->file, "%s%"PRIuMAX"%s",
1316                                del_c, deleted, reset);
1317                        fprintf(options->file, " -> ");
1318                        fprintf(options->file, "%s%"PRIuMAX"%s",
1319                                add_c, added, reset);
1320                        fprintf(options->file, " bytes");
1321                        fprintf(options->file, "\n");
1322                        continue;
1323                }
1324                else if (data->files[i]->is_unmerged) {
1325                        fprintf(options->file, "%s", line_prefix);
1326                        show_name(options->file, prefix, name, len);
1327                        fprintf(options->file, "  Unmerged\n");
1328                        continue;
1329                }
1330                else if (!data->files[i]->is_renamed &&
1331                         (added + deleted == 0)) {
1332                        total_files--;
1333                        continue;
1334                }
1335
1336                /*
1337                 * scale the add/delete
1338                 */
1339                add = added;
1340                del = deleted;
1341                adds += add;
1342                dels += del;
1343
1344                if (width <= max_change) {
1345                        add = scale_linear(add, width, max_change);
1346                        del = scale_linear(del, width, max_change);
1347                }
1348                fprintf(options->file, "%s", line_prefix);
1349                show_name(options->file, prefix, name, len);
1350                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1351                                added + deleted ? " " : "");
1352                show_graph(options->file, '+', add, add_c, reset);
1353                show_graph(options->file, '-', del, del_c, reset);
1354                fprintf(options->file, "\n");
1355        }
1356        fprintf(options->file, "%s", line_prefix);
1357        fprintf(options->file,
1358               " %d files changed, %d insertions(+), %d deletions(-)\n",
1359               total_files, adds, dels);
1360}
1361
1362static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1363{
1364        int i, adds = 0, dels = 0, total_files = data->nr;
1365
1366        if (data->nr == 0)
1367                return;
1368
1369        for (i = 0; i < data->nr; i++) {
1370                if (!data->files[i]->is_binary &&
1371                    !data->files[i]->is_unmerged) {
1372                        int added = data->files[i]->added;
1373                        int deleted= data->files[i]->deleted;
1374                        if (!data->files[i]->is_renamed &&
1375                            (added + deleted == 0)) {
1376                                total_files--;
1377                        } else {
1378                                adds += added;
1379                                dels += deleted;
1380                        }
1381                }
1382        }
1383        if (options->output_prefix) {
1384                struct strbuf *msg = NULL;
1385                msg = options->output_prefix(options,
1386                                options->output_prefix_data);
1387                fprintf(options->file, "%s", msg->buf);
1388        }
1389        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1390               total_files, adds, dels);
1391}
1392
1393static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1394{
1395        int i;
1396
1397        if (data->nr == 0)
1398                return;
1399
1400        for (i = 0; i < data->nr; i++) {
1401                struct diffstat_file *file = data->files[i];
1402
1403                if (options->output_prefix) {
1404                        struct strbuf *msg = NULL;
1405                        msg = options->output_prefix(options,
1406                                        options->output_prefix_data);
1407                        fprintf(options->file, "%s", msg->buf);
1408                }
1409
1410                if (file->is_binary)
1411                        fprintf(options->file, "-\t-\t");
1412                else
1413                        fprintf(options->file,
1414                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1415                                file->added, file->deleted);
1416                if (options->line_termination) {
1417                        fill_print_name(file);
1418                        if (!file->is_renamed)
1419                                write_name_quoted(file->name, options->file,
1420                                                  options->line_termination);
1421                        else {
1422                                fputs(file->print_name, options->file);
1423                                putc(options->line_termination, options->file);
1424                        }
1425                } else {
1426                        if (file->is_renamed) {
1427                                putc('\0', options->file);
1428                                write_name_quoted(file->from_name, options->file, '\0');
1429                        }
1430                        write_name_quoted(file->name, options->file, '\0');
1431                }
1432        }
1433}
1434
1435struct dirstat_file {
1436        const char *name;
1437        unsigned long changed;
1438};
1439
1440struct dirstat_dir {
1441        struct dirstat_file *files;
1442        int alloc, nr, percent, cumulative;
1443};
1444
1445static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1446                unsigned long changed, const char *base, int baselen)
1447{
1448        unsigned long this_dir = 0;
1449        unsigned int sources = 0;
1450        const char *line_prefix = "";
1451        struct strbuf *msg = NULL;
1452
1453        if (opt->output_prefix) {
1454                msg = opt->output_prefix(opt, opt->output_prefix_data);
1455                line_prefix = msg->buf;
1456        }
1457
1458        while (dir->nr) {
1459                struct dirstat_file *f = dir->files;
1460                int namelen = strlen(f->name);
1461                unsigned long this;
1462                char *slash;
1463
1464                if (namelen < baselen)
1465                        break;
1466                if (memcmp(f->name, base, baselen))
1467                        break;
1468                slash = strchr(f->name + baselen, '/');
1469                if (slash) {
1470                        int newbaselen = slash + 1 - f->name;
1471                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1472                        sources++;
1473                } else {
1474                        this = f->changed;
1475                        dir->files++;
1476                        dir->nr--;
1477                        sources += 2;
1478                }
1479                this_dir += this;
1480        }
1481
1482        /*
1483         * We don't report dirstat's for
1484         *  - the top level
1485         *  - or cases where everything came from a single directory
1486         *    under this directory (sources == 1).
1487         */
1488        if (baselen && sources != 1) {
1489                int permille = this_dir * 1000 / changed;
1490                if (permille) {
1491                        int percent = permille / 10;
1492                        if (percent >= dir->percent) {
1493                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1494                                        percent, permille % 10, baselen, base);
1495                                if (!dir->cumulative)
1496                                        return 0;
1497                        }
1498                }
1499        }
1500        return this_dir;
1501}
1502
1503static int dirstat_compare(const void *_a, const void *_b)
1504{
1505        const struct dirstat_file *a = _a;
1506        const struct dirstat_file *b = _b;
1507        return strcmp(a->name, b->name);
1508}
1509
1510static void show_dirstat(struct diff_options *options)
1511{
1512        int i;
1513        unsigned long changed;
1514        struct dirstat_dir dir;
1515        struct diff_queue_struct *q = &diff_queued_diff;
1516
1517        dir.files = NULL;
1518        dir.alloc = 0;
1519        dir.nr = 0;
1520        dir.percent = options->dirstat_percent;
1521        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1522
1523        changed = 0;
1524        for (i = 0; i < q->nr; i++) {
1525                struct diff_filepair *p = q->queue[i];
1526                const char *name;
1527                unsigned long copied, added, damage;
1528
1529                name = p->one->path ? p->one->path : p->two->path;
1530
1531                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1532                        diff_populate_filespec(p->one, 0);
1533                        diff_populate_filespec(p->two, 0);
1534                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1535                                               &copied, &added);
1536                        diff_free_filespec_data(p->one);
1537                        diff_free_filespec_data(p->two);
1538                } else if (DIFF_FILE_VALID(p->one)) {
1539                        diff_populate_filespec(p->one, 1);
1540                        copied = added = 0;
1541                        diff_free_filespec_data(p->one);
1542                } else if (DIFF_FILE_VALID(p->two)) {
1543                        diff_populate_filespec(p->two, 1);
1544                        copied = 0;
1545                        added = p->two->size;
1546                        diff_free_filespec_data(p->two);
1547                } else
1548                        continue;
1549
1550                /*
1551                 * Original minus copied is the removed material,
1552                 * added is the new material.  They are both damages
1553                 * made to the preimage. In --dirstat-by-file mode, count
1554                 * damaged files, not damaged lines. This is done by
1555                 * counting only a single damaged line per file.
1556                 */
1557                damage = (p->one->size - copied) + added;
1558                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1559                        damage = 1;
1560
1561                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1562                dir.files[dir.nr].name = name;
1563                dir.files[dir.nr].changed = damage;
1564                changed += damage;
1565                dir.nr++;
1566        }
1567
1568        /* This can happen even with many files, if everything was renames */
1569        if (!changed)
1570                return;
1571
1572        /* Show all directories with more than x% of the changes */
1573        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1574        gather_dirstat(options, &dir, changed, "", 0);
1575}
1576
1577static void free_diffstat_info(struct diffstat_t *diffstat)
1578{
1579        int i;
1580        for (i = 0; i < diffstat->nr; i++) {
1581                struct diffstat_file *f = diffstat->files[i];
1582                if (f->name != f->print_name)
1583                        free(f->print_name);
1584                free(f->name);
1585                free(f->from_name);
1586                free(f);
1587        }
1588        free(diffstat->files);
1589}
1590
1591struct checkdiff_t {
1592        const char *filename;
1593        int lineno;
1594        int conflict_marker_size;
1595        struct diff_options *o;
1596        unsigned ws_rule;
1597        unsigned status;
1598};
1599
1600static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1601{
1602        char firstchar;
1603        int cnt;
1604
1605        if (len < marker_size + 1)
1606                return 0;
1607        firstchar = line[0];
1608        switch (firstchar) {
1609        case '=': case '>': case '<': case '|':
1610                break;
1611        default:
1612                return 0;
1613        }
1614        for (cnt = 1; cnt < marker_size; cnt++)
1615                if (line[cnt] != firstchar)
1616                        return 0;
1617        /* line[1] thru line[marker_size-1] are same as firstchar */
1618        if (len < marker_size + 1 || !isspace(line[marker_size]))
1619                return 0;
1620        return 1;
1621}
1622
1623static void checkdiff_consume(void *priv, char *line, unsigned long len)
1624{
1625        struct checkdiff_t *data = priv;
1626        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1627        int marker_size = data->conflict_marker_size;
1628        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1629        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1630        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1631        char *err;
1632        char *line_prefix = "";
1633        struct strbuf *msgbuf;
1634
1635        assert(data->o);
1636        if (data->o->output_prefix) {
1637                msgbuf = data->o->output_prefix(data->o,
1638                        data->o->output_prefix_data);
1639                line_prefix = msgbuf->buf;
1640        }
1641
1642        if (line[0] == '+') {
1643                unsigned bad;
1644                data->lineno++;
1645                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1646                        data->status |= 1;
1647                        fprintf(data->o->file,
1648                                "%s%s:%d: leftover conflict marker\n",
1649                                line_prefix, data->filename, data->lineno);
1650                }
1651                bad = ws_check(line + 1, len - 1, data->ws_rule);
1652                if (!bad)
1653                        return;
1654                data->status |= bad;
1655                err = whitespace_error_string(bad);
1656                fprintf(data->o->file, "%s%s:%d: %s.\n",
1657                        line_prefix, data->filename, data->lineno, err);
1658                free(err);
1659                emit_line(data->o, set, reset, line, 1);
1660                ws_check_emit(line + 1, len - 1, data->ws_rule,
1661                              data->o->file, set, reset, ws);
1662        } else if (line[0] == ' ') {
1663                data->lineno++;
1664        } else if (line[0] == '@') {
1665                char *plus = strchr(line, '+');
1666                if (plus)
1667                        data->lineno = strtol(plus, NULL, 10) - 1;
1668                else
1669                        die("invalid diff");
1670        }
1671}
1672
1673static unsigned char *deflate_it(char *data,
1674                                 unsigned long size,
1675                                 unsigned long *result_size)
1676{
1677        int bound;
1678        unsigned char *deflated;
1679        z_stream stream;
1680
1681        memset(&stream, 0, sizeof(stream));
1682        deflateInit(&stream, zlib_compression_level);
1683        bound = deflateBound(&stream, size);
1684        deflated = xmalloc(bound);
1685        stream.next_out = deflated;
1686        stream.avail_out = bound;
1687
1688        stream.next_in = (unsigned char *)data;
1689        stream.avail_in = size;
1690        while (deflate(&stream, Z_FINISH) == Z_OK)
1691                ; /* nothing */
1692        deflateEnd(&stream);
1693        *result_size = stream.total_out;
1694        return deflated;
1695}
1696
1697static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1698{
1699        void *cp;
1700        void *delta;
1701        void *deflated;
1702        void *data;
1703        unsigned long orig_size;
1704        unsigned long delta_size;
1705        unsigned long deflate_size;
1706        unsigned long data_size;
1707
1708        /* We could do deflated delta, or we could do just deflated two,
1709         * whichever is smaller.
1710         */
1711        delta = NULL;
1712        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1713        if (one->size && two->size) {
1714                delta = diff_delta(one->ptr, one->size,
1715                                   two->ptr, two->size,
1716                                   &delta_size, deflate_size);
1717                if (delta) {
1718                        void *to_free = delta;
1719                        orig_size = delta_size;
1720                        delta = deflate_it(delta, delta_size, &delta_size);
1721                        free(to_free);
1722                }
1723        }
1724
1725        if (delta && delta_size < deflate_size) {
1726                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1727                free(deflated);
1728                data = delta;
1729                data_size = delta_size;
1730        }
1731        else {
1732                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1733                free(delta);
1734                data = deflated;
1735                data_size = deflate_size;
1736        }
1737
1738        /* emit data encoded in base85 */
1739        cp = data;
1740        while (data_size) {
1741                int bytes = (52 < data_size) ? 52 : data_size;
1742                char line[70];
1743                data_size -= bytes;
1744                if (bytes <= 26)
1745                        line[0] = bytes + 'A' - 1;
1746                else
1747                        line[0] = bytes - 26 + 'a' - 1;
1748                encode_85(line + 1, cp, bytes);
1749                cp = (char *) cp + bytes;
1750                fprintf(file, "%s", prefix);
1751                fputs(line, file);
1752                fputc('\n', file);
1753        }
1754        fprintf(file, "%s\n", prefix);
1755        free(data);
1756}
1757
1758static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1759{
1760        fprintf(file, "%sGIT binary patch\n", prefix);
1761        emit_binary_diff_body(file, one, two, prefix);
1762        emit_binary_diff_body(file, two, one, prefix);
1763}
1764
1765static void diff_filespec_load_driver(struct diff_filespec *one)
1766{
1767        if (!one->driver)
1768                one->driver = userdiff_find_by_path(one->path);
1769        if (!one->driver)
1770                one->driver = userdiff_find_by_name("default");
1771}
1772
1773int diff_filespec_is_binary(struct diff_filespec *one)
1774{
1775        if (one->is_binary == -1) {
1776                diff_filespec_load_driver(one);
1777                if (one->driver->binary != -1)
1778                        one->is_binary = one->driver->binary;
1779                else {
1780                        if (!one->data && DIFF_FILE_VALID(one))
1781                                diff_populate_filespec(one, 0);
1782                        if (one->data)
1783                                one->is_binary = buffer_is_binary(one->data,
1784                                                one->size);
1785                        if (one->is_binary == -1)
1786                                one->is_binary = 0;
1787                }
1788        }
1789        return one->is_binary;
1790}
1791
1792static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1793{
1794        diff_filespec_load_driver(one);
1795        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1796}
1797
1798static const char *userdiff_word_regex(struct diff_filespec *one)
1799{
1800        diff_filespec_load_driver(one);
1801        return one->driver->word_regex;
1802}
1803
1804void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1805{
1806        if (!options->a_prefix)
1807                options->a_prefix = a;
1808        if (!options->b_prefix)
1809                options->b_prefix = b;
1810}
1811
1812struct userdiff_driver *get_textconv(struct diff_filespec *one)
1813{
1814        if (!DIFF_FILE_VALID(one))
1815                return NULL;
1816        if (!S_ISREG(one->mode))
1817                return NULL;
1818        diff_filespec_load_driver(one);
1819        if (!one->driver->textconv)
1820                return NULL;
1821
1822        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1823                struct notes_cache *c = xmalloc(sizeof(*c));
1824                struct strbuf name = STRBUF_INIT;
1825
1826                strbuf_addf(&name, "textconv/%s", one->driver->name);
1827                notes_cache_init(c, name.buf, one->driver->textconv);
1828                one->driver->textconv_cache = c;
1829        }
1830
1831        return one->driver;
1832}
1833
1834static void builtin_diff(const char *name_a,
1835                         const char *name_b,
1836                         struct diff_filespec *one,
1837                         struct diff_filespec *two,
1838                         const char *xfrm_msg,
1839                         int must_show_header,
1840                         struct diff_options *o,
1841                         int complete_rewrite)
1842{
1843        mmfile_t mf1, mf2;
1844        const char *lbl[2];
1845        char *a_one, *b_two;
1846        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1847        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1848        const char *a_prefix, *b_prefix;
1849        struct userdiff_driver *textconv_one = NULL;
1850        struct userdiff_driver *textconv_two = NULL;
1851        struct strbuf header = STRBUF_INIT;
1852        struct strbuf *msgbuf;
1853        char *line_prefix = "";
1854
1855        if (o->output_prefix) {
1856                msgbuf = o->output_prefix(o, o->output_prefix_data);
1857                line_prefix = msgbuf->buf;
1858        }
1859
1860        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1861                        (!one->mode || S_ISGITLINK(one->mode)) &&
1862                        (!two->mode || S_ISGITLINK(two->mode))) {
1863                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1864                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1865                show_submodule_summary(o->file, one ? one->path : two->path,
1866                                one->sha1, two->sha1, two->dirty_submodule,
1867                                del, add, reset);
1868                return;
1869        }
1870
1871        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1872                textconv_one = get_textconv(one);
1873                textconv_two = get_textconv(two);
1874        }
1875
1876        diff_set_mnemonic_prefix(o, "a/", "b/");
1877        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1878                a_prefix = o->b_prefix;
1879                b_prefix = o->a_prefix;
1880        } else {
1881                a_prefix = o->a_prefix;
1882                b_prefix = o->b_prefix;
1883        }
1884
1885        /* Never use a non-valid filename anywhere if at all possible */
1886        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1887        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1888
1889        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1890        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1891        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1892        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1893        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1894        if (lbl[0][0] == '/') {
1895                /* /dev/null */
1896                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1897                if (xfrm_msg)
1898                        strbuf_addstr(&header, xfrm_msg);
1899                must_show_header = 1;
1900        }
1901        else if (lbl[1][0] == '/') {
1902                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1903                if (xfrm_msg)
1904                        strbuf_addstr(&header, xfrm_msg);
1905                must_show_header = 1;
1906        }
1907        else {
1908                if (one->mode != two->mode) {
1909                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1910                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1911                        must_show_header = 1;
1912                }
1913                if (xfrm_msg)
1914                        strbuf_addstr(&header, xfrm_msg);
1915
1916                /*
1917                 * we do not run diff between different kind
1918                 * of objects.
1919                 */
1920                if ((one->mode ^ two->mode) & S_IFMT)
1921                        goto free_ab_and_return;
1922                if (complete_rewrite &&
1923                    (textconv_one || !diff_filespec_is_binary(one)) &&
1924                    (textconv_two || !diff_filespec_is_binary(two))) {
1925                        fprintf(o->file, "%s", header.buf);
1926                        strbuf_reset(&header);
1927                        emit_rewrite_diff(name_a, name_b, one, two,
1928                                                textconv_one, textconv_two, o);
1929                        o->found_changes = 1;
1930                        goto free_ab_and_return;
1931                }
1932        }
1933
1934        if (!DIFF_OPT_TST(o, TEXT) &&
1935            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1936              (!textconv_two && diff_filespec_is_binary(two)) )) {
1937                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1938                        die("unable to read files to diff");
1939                /* Quite common confusing case */
1940                if (mf1.size == mf2.size &&
1941                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1942                        if (must_show_header)
1943                                fprintf(o->file, "%s", header.buf);
1944                        goto free_ab_and_return;
1945                }
1946                fprintf(o->file, "%s", header.buf);
1947                strbuf_reset(&header);
1948                if (DIFF_OPT_TST(o, BINARY))
1949                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1950                else
1951                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1952                                line_prefix, lbl[0], lbl[1]);
1953                o->found_changes = 1;
1954        }
1955        else {
1956                /* Crazy xdl interfaces.. */
1957                const char *diffopts = getenv("GIT_DIFF_OPTS");
1958                xpparam_t xpp;
1959                xdemitconf_t xecfg;
1960                struct emit_callback ecbdata;
1961                const struct userdiff_funcname *pe;
1962
1963                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1964                        fprintf(o->file, "%s", header.buf);
1965                        strbuf_reset(&header);
1966                }
1967
1968                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1969                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1970
1971                pe = diff_funcname_pattern(one);
1972                if (!pe)
1973                        pe = diff_funcname_pattern(two);
1974
1975                memset(&xpp, 0, sizeof(xpp));
1976                memset(&xecfg, 0, sizeof(xecfg));
1977                memset(&ecbdata, 0, sizeof(ecbdata));
1978                ecbdata.label_path = lbl;
1979                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1980                ecbdata.found_changesp = &o->found_changes;
1981                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1982                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1983                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1984                ecbdata.opt = o;
1985                ecbdata.header = header.len ? &header : NULL;
1986                xpp.flags = o->xdl_opts;
1987                xecfg.ctxlen = o->context;
1988                xecfg.interhunkctxlen = o->interhunkcontext;
1989                xecfg.flags = XDL_EMIT_FUNCNAMES;
1990                if (pe)
1991                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1992                if (!diffopts)
1993                        ;
1994                else if (!prefixcmp(diffopts, "--unified="))
1995                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1996                else if (!prefixcmp(diffopts, "-u"))
1997                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1998                if (o->word_diff) {
1999                        int i;
2000
2001                        ecbdata.diff_words =
2002                                xcalloc(1, sizeof(struct diff_words_data));
2003                        ecbdata.diff_words->type = o->word_diff;
2004                        ecbdata.diff_words->opt = o;
2005                        if (!o->word_regex)
2006                                o->word_regex = userdiff_word_regex(one);
2007                        if (!o->word_regex)
2008                                o->word_regex = userdiff_word_regex(two);
2009                        if (!o->word_regex)
2010                                o->word_regex = diff_word_regex_cfg;
2011                        if (o->word_regex) {
2012                                ecbdata.diff_words->word_regex = (regex_t *)
2013                                        xmalloc(sizeof(regex_t));
2014                                if (regcomp(ecbdata.diff_words->word_regex,
2015                                                o->word_regex,
2016                                                REG_EXTENDED | REG_NEWLINE))
2017                                        die ("Invalid regular expression: %s",
2018                                                        o->word_regex);
2019                        }
2020                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2021                                if (o->word_diff == diff_words_styles[i].type) {
2022                                        ecbdata.diff_words->style =
2023                                                &diff_words_styles[i];
2024                                        break;
2025                                }
2026                        }
2027                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2028                                struct diff_words_style *st = ecbdata.diff_words->style;
2029                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2030                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2031                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2032                        }
2033                }
2034                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2035                              &xpp, &xecfg);
2036                if (o->word_diff)
2037                        free_diff_words_data(&ecbdata);
2038                if (textconv_one)
2039                        free(mf1.ptr);
2040                if (textconv_two)
2041                        free(mf2.ptr);
2042                xdiff_clear_find_func(&xecfg);
2043        }
2044
2045 free_ab_and_return:
2046        strbuf_release(&header);
2047        diff_free_filespec_data(one);
2048        diff_free_filespec_data(two);
2049        free(a_one);
2050        free(b_two);
2051        return;
2052}
2053
2054static void builtin_diffstat(const char *name_a, const char *name_b,
2055                             struct diff_filespec *one,
2056                             struct diff_filespec *two,
2057                             struct diffstat_t *diffstat,
2058                             struct diff_options *o,
2059                             int complete_rewrite)
2060{
2061        mmfile_t mf1, mf2;
2062        struct diffstat_file *data;
2063
2064        data = diffstat_add(diffstat, name_a, name_b);
2065
2066        if (!one || !two) {
2067                data->is_unmerged = 1;
2068                return;
2069        }
2070        if (complete_rewrite) {
2071                diff_populate_filespec(one, 0);
2072                diff_populate_filespec(two, 0);
2073                data->deleted = count_lines(one->data, one->size);
2074                data->added = count_lines(two->data, two->size);
2075                goto free_and_return;
2076        }
2077        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2078                die("unable to read files to diff");
2079
2080        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2081                data->is_binary = 1;
2082                data->added = mf2.size;
2083                data->deleted = mf1.size;
2084        } else {
2085                /* Crazy xdl interfaces.. */
2086                xpparam_t xpp;
2087                xdemitconf_t xecfg;
2088
2089                memset(&xpp, 0, sizeof(xpp));
2090                memset(&xecfg, 0, sizeof(xecfg));
2091                xpp.flags = o->xdl_opts;
2092                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2093                              &xpp, &xecfg);
2094        }
2095
2096 free_and_return:
2097        diff_free_filespec_data(one);
2098        diff_free_filespec_data(two);
2099}
2100
2101static void builtin_checkdiff(const char *name_a, const char *name_b,
2102                              const char *attr_path,
2103                              struct diff_filespec *one,
2104                              struct diff_filespec *two,
2105                              struct diff_options *o)
2106{
2107        mmfile_t mf1, mf2;
2108        struct checkdiff_t data;
2109
2110        if (!two)
2111                return;
2112
2113        memset(&data, 0, sizeof(data));
2114        data.filename = name_b ? name_b : name_a;
2115        data.lineno = 0;
2116        data.o = o;
2117        data.ws_rule = whitespace_rule(attr_path);
2118        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2119
2120        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2121                die("unable to read files to diff");
2122
2123        /*
2124         * All the other codepaths check both sides, but not checking
2125         * the "old" side here is deliberate.  We are checking the newly
2126         * introduced changes, and as long as the "new" side is text, we
2127         * can and should check what it introduces.
2128         */
2129        if (diff_filespec_is_binary(two))
2130                goto free_and_return;
2131        else {
2132                /* Crazy xdl interfaces.. */
2133                xpparam_t xpp;
2134                xdemitconf_t xecfg;
2135
2136                memset(&xpp, 0, sizeof(xpp));
2137                memset(&xecfg, 0, sizeof(xecfg));
2138                xecfg.ctxlen = 1; /* at least one context line */
2139                xpp.flags = 0;
2140                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2141                              &xpp, &xecfg);
2142
2143                if (data.ws_rule & WS_BLANK_AT_EOF) {
2144                        struct emit_callback ecbdata;
2145                        int blank_at_eof;
2146
2147                        ecbdata.ws_rule = data.ws_rule;
2148                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2149                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
2150
2151                        if (blank_at_eof) {
2152                                static char *err;
2153                                if (!err)
2154                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2155                                fprintf(o->file, "%s:%d: %s.\n",
2156                                        data.filename, blank_at_eof, err);
2157                                data.status = 1; /* report errors */
2158                        }
2159                }
2160        }
2161 free_and_return:
2162        diff_free_filespec_data(one);
2163        diff_free_filespec_data(two);
2164        if (data.status)
2165                DIFF_OPT_SET(o, CHECK_FAILED);
2166}
2167
2168struct diff_filespec *alloc_filespec(const char *path)
2169{
2170        int namelen = strlen(path);
2171        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2172
2173        memset(spec, 0, sizeof(*spec));
2174        spec->path = (char *)(spec + 1);
2175        memcpy(spec->path, path, namelen+1);
2176        spec->count = 1;
2177        spec->is_binary = -1;
2178        return spec;
2179}
2180
2181void free_filespec(struct diff_filespec *spec)
2182{
2183        if (!--spec->count) {
2184                diff_free_filespec_data(spec);
2185                free(spec);
2186        }
2187}
2188
2189void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2190                   unsigned short mode)
2191{
2192        if (mode) {
2193                spec->mode = canon_mode(mode);
2194                hashcpy(spec->sha1, sha1);
2195                spec->sha1_valid = !is_null_sha1(sha1);
2196        }
2197}
2198
2199/*
2200 * Given a name and sha1 pair, if the index tells us the file in
2201 * the work tree has that object contents, return true, so that
2202 * prepare_temp_file() does not have to inflate and extract.
2203 */
2204static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2205{
2206        struct cache_entry *ce;
2207        struct stat st;
2208        int pos, len;
2209
2210        /*
2211         * We do not read the cache ourselves here, because the
2212         * benchmark with my previous version that always reads cache
2213         * shows that it makes things worse for diff-tree comparing
2214         * two linux-2.6 kernel trees in an already checked out work
2215         * tree.  This is because most diff-tree comparisons deal with
2216         * only a small number of files, while reading the cache is
2217         * expensive for a large project, and its cost outweighs the
2218         * savings we get by not inflating the object to a temporary
2219         * file.  Practically, this code only helps when we are used
2220         * by diff-cache --cached, which does read the cache before
2221         * calling us.
2222         */
2223        if (!active_cache)
2224                return 0;
2225
2226        /* We want to avoid the working directory if our caller
2227         * doesn't need the data in a normal file, this system
2228         * is rather slow with its stat/open/mmap/close syscalls,
2229         * and the object is contained in a pack file.  The pack
2230         * is probably already open and will be faster to obtain
2231         * the data through than the working directory.  Loose
2232         * objects however would tend to be slower as they need
2233         * to be individually opened and inflated.
2234         */
2235        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2236                return 0;
2237
2238        len = strlen(name);
2239        pos = cache_name_pos(name, len);
2240        if (pos < 0)
2241                return 0;
2242        ce = active_cache[pos];
2243
2244        /*
2245         * This is not the sha1 we are looking for, or
2246         * unreusable because it is not a regular file.
2247         */
2248        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2249                return 0;
2250
2251        /*
2252         * If ce is marked as "assume unchanged", there is no
2253         * guarantee that work tree matches what we are looking for.
2254         */
2255        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2256                return 0;
2257
2258        /*
2259         * If ce matches the file in the work tree, we can reuse it.
2260         */
2261        if (ce_uptodate(ce) ||
2262            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2263                return 1;
2264
2265        return 0;
2266}
2267
2268static int populate_from_stdin(struct diff_filespec *s)
2269{
2270        struct strbuf buf = STRBUF_INIT;
2271        size_t size = 0;
2272
2273        if (strbuf_read(&buf, 0, 0) < 0)
2274                return error("error while reading from stdin %s",
2275                                     strerror(errno));
2276
2277        s->should_munmap = 0;
2278        s->data = strbuf_detach(&buf, &size);
2279        s->size = size;
2280        s->should_free = 1;
2281        return 0;
2282}
2283
2284static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2285{
2286        int len;
2287        char *data = xmalloc(100), *dirty = "";
2288
2289        /* Are we looking at the work tree? */
2290        if (s->dirty_submodule)
2291                dirty = "-dirty";
2292
2293        len = snprintf(data, 100,
2294                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2295        s->data = data;
2296        s->size = len;
2297        s->should_free = 1;
2298        if (size_only) {
2299                s->data = NULL;
2300                free(data);
2301        }
2302        return 0;
2303}
2304
2305/*
2306 * While doing rename detection and pickaxe operation, we may need to
2307 * grab the data for the blob (or file) for our own in-core comparison.
2308 * diff_filespec has data and size fields for this purpose.
2309 */
2310int diff_populate_filespec(struct diff_filespec *s, int size_only)
2311{
2312        int err = 0;
2313        if (!DIFF_FILE_VALID(s))
2314                die("internal error: asking to populate invalid file.");
2315        if (S_ISDIR(s->mode))
2316                return -1;
2317
2318        if (s->data)
2319                return 0;
2320
2321        if (size_only && 0 < s->size)
2322                return 0;
2323
2324        if (S_ISGITLINK(s->mode))
2325                return diff_populate_gitlink(s, size_only);
2326
2327        if (!s->sha1_valid ||
2328            reuse_worktree_file(s->path, s->sha1, 0)) {
2329                struct strbuf buf = STRBUF_INIT;
2330                struct stat st;
2331                int fd;
2332
2333                if (!strcmp(s->path, "-"))
2334                        return populate_from_stdin(s);
2335
2336                if (lstat(s->path, &st) < 0) {
2337                        if (errno == ENOENT) {
2338                        err_empty:
2339                                err = -1;
2340                        empty:
2341                                s->data = (char *)"";
2342                                s->size = 0;
2343                                return err;
2344                        }
2345                }
2346                s->size = xsize_t(st.st_size);
2347                if (!s->size)
2348                        goto empty;
2349                if (S_ISLNK(st.st_mode)) {
2350                        struct strbuf sb = STRBUF_INIT;
2351
2352                        if (strbuf_readlink(&sb, s->path, s->size))
2353                                goto err_empty;
2354                        s->size = sb.len;
2355                        s->data = strbuf_detach(&sb, NULL);
2356                        s->should_free = 1;
2357                        return 0;
2358                }
2359                if (size_only)
2360                        return 0;
2361                fd = open(s->path, O_RDONLY);
2362                if (fd < 0)
2363                        goto err_empty;
2364                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2365                close(fd);
2366                s->should_munmap = 1;
2367
2368                /*
2369                 * Convert from working tree format to canonical git format
2370                 */
2371                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2372                        size_t size = 0;
2373                        munmap(s->data, s->size);
2374                        s->should_munmap = 0;
2375                        s->data = strbuf_detach(&buf, &size);
2376                        s->size = size;
2377                        s->should_free = 1;
2378                }
2379        }
2380        else {
2381                enum object_type type;
2382                if (size_only)
2383                        type = sha1_object_info(s->sha1, &s->size);
2384                else {
2385                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2386                        s->should_free = 1;
2387                }
2388        }
2389        return 0;
2390}
2391
2392void diff_free_filespec_blob(struct diff_filespec *s)
2393{
2394        if (s->should_free)
2395                free(s->data);
2396        else if (s->should_munmap)
2397                munmap(s->data, s->size);
2398
2399        if (s->should_free || s->should_munmap) {
2400                s->should_free = s->should_munmap = 0;
2401                s->data = NULL;
2402        }
2403}
2404
2405void diff_free_filespec_data(struct diff_filespec *s)
2406{
2407        diff_free_filespec_blob(s);
2408        free(s->cnt_data);
2409        s->cnt_data = NULL;
2410}
2411
2412static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2413                           void *blob,
2414                           unsigned long size,
2415                           const unsigned char *sha1,
2416                           int mode)
2417{
2418        int fd;
2419        struct strbuf buf = STRBUF_INIT;
2420        struct strbuf template = STRBUF_INIT;
2421        char *path_dup = xstrdup(path);
2422        const char *base = basename(path_dup);
2423
2424        /* Generate "XXXXXX_basename.ext" */
2425        strbuf_addstr(&template, "XXXXXX_");
2426        strbuf_addstr(&template, base);
2427
2428        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2429                        strlen(base) + 1);
2430        if (fd < 0)
2431                die_errno("unable to create temp-file");
2432        if (convert_to_working_tree(path,
2433                        (const char *)blob, (size_t)size, &buf)) {
2434                blob = buf.buf;
2435                size = buf.len;
2436        }
2437        if (write_in_full(fd, blob, size) != size)
2438                die_errno("unable to write temp-file");
2439        close(fd);
2440        temp->name = temp->tmp_path;
2441        strcpy(temp->hex, sha1_to_hex(sha1));
2442        temp->hex[40] = 0;
2443        sprintf(temp->mode, "%06o", mode);
2444        strbuf_release(&buf);
2445        strbuf_release(&template);
2446        free(path_dup);
2447}
2448
2449static struct diff_tempfile *prepare_temp_file(const char *name,
2450                struct diff_filespec *one)
2451{
2452        struct diff_tempfile *temp = claim_diff_tempfile();
2453
2454        if (!DIFF_FILE_VALID(one)) {
2455        not_a_valid_file:
2456                /* A '-' entry produces this for file-2, and
2457                 * a '+' entry produces this for file-1.
2458                 */
2459                temp->name = "/dev/null";
2460                strcpy(temp->hex, ".");
2461                strcpy(temp->mode, ".");
2462                return temp;
2463        }
2464
2465        if (!remove_tempfile_installed) {
2466                atexit(remove_tempfile);
2467                sigchain_push_common(remove_tempfile_on_signal);
2468                remove_tempfile_installed = 1;
2469        }
2470
2471        if (!one->sha1_valid ||
2472            reuse_worktree_file(name, one->sha1, 1)) {
2473                struct stat st;
2474                if (lstat(name, &st) < 0) {
2475                        if (errno == ENOENT)
2476                                goto not_a_valid_file;
2477                        die_errno("stat(%s)", name);
2478                }
2479                if (S_ISLNK(st.st_mode)) {
2480                        struct strbuf sb = STRBUF_INIT;
2481                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2482                                die_errno("readlink(%s)", name);
2483                        prep_temp_blob(name, temp, sb.buf, sb.len,
2484                                       (one->sha1_valid ?
2485                                        one->sha1 : null_sha1),
2486                                       (one->sha1_valid ?
2487                                        one->mode : S_IFLNK));
2488                        strbuf_release(&sb);
2489                }
2490                else {
2491                        /* we can borrow from the file in the work tree */
2492                        temp->name = name;
2493                        if (!one->sha1_valid)
2494                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2495                        else
2496                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2497                        /* Even though we may sometimes borrow the
2498                         * contents from the work tree, we always want
2499                         * one->mode.  mode is trustworthy even when
2500                         * !(one->sha1_valid), as long as
2501                         * DIFF_FILE_VALID(one).
2502                         */
2503                        sprintf(temp->mode, "%06o", one->mode);
2504                }
2505                return temp;
2506        }
2507        else {
2508                if (diff_populate_filespec(one, 0))
2509                        die("cannot read data blob for %s", one->path);
2510                prep_temp_blob(name, temp, one->data, one->size,
2511                               one->sha1, one->mode);
2512        }
2513        return temp;
2514}
2515
2516/* An external diff command takes:
2517 *
2518 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2519 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2520 *
2521 */
2522static void run_external_diff(const char *pgm,
2523                              const char *name,
2524                              const char *other,
2525                              struct diff_filespec *one,
2526                              struct diff_filespec *two,
2527                              const char *xfrm_msg,
2528                              int complete_rewrite)
2529{
2530        const char *spawn_arg[10];
2531        int retval;
2532        const char **arg = &spawn_arg[0];
2533
2534        if (one && two) {
2535                struct diff_tempfile *temp_one, *temp_two;
2536                const char *othername = (other ? other : name);
2537                temp_one = prepare_temp_file(name, one);
2538                temp_two = prepare_temp_file(othername, two);
2539                *arg++ = pgm;
2540                *arg++ = name;
2541                *arg++ = temp_one->name;
2542                *arg++ = temp_one->hex;
2543                *arg++ = temp_one->mode;
2544                *arg++ = temp_two->name;
2545                *arg++ = temp_two->hex;
2546                *arg++ = temp_two->mode;
2547                if (other) {
2548                        *arg++ = other;
2549                        *arg++ = xfrm_msg;
2550                }
2551        } else {
2552                *arg++ = pgm;
2553                *arg++ = name;
2554        }
2555        *arg = NULL;
2556        fflush(NULL);
2557        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2558        remove_tempfile();
2559        if (retval) {
2560                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2561                exit(1);
2562        }
2563}
2564
2565static int similarity_index(struct diff_filepair *p)
2566{
2567        return p->score * 100 / MAX_SCORE;
2568}
2569
2570static void fill_metainfo(struct strbuf *msg,
2571                          const char *name,
2572                          const char *other,
2573                          struct diff_filespec *one,
2574                          struct diff_filespec *two,
2575                          struct diff_options *o,
2576                          struct diff_filepair *p,
2577                          int *must_show_header,
2578                          int use_color)
2579{
2580        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2581        const char *reset = diff_get_color(use_color, DIFF_RESET);
2582        struct strbuf *msgbuf;
2583        char *line_prefix = "";
2584
2585        *must_show_header = 1;
2586        if (o->output_prefix) {
2587                msgbuf = o->output_prefix(o, o->output_prefix_data);
2588                line_prefix = msgbuf->buf;
2589        }
2590        strbuf_init(msg, PATH_MAX * 2 + 300);
2591        switch (p->status) {
2592        case DIFF_STATUS_COPIED:
2593                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2594                            line_prefix, set, similarity_index(p));
2595                strbuf_addf(msg, "%s\n%s%scopy from ",
2596                            reset,  line_prefix, set);
2597                quote_c_style(name, msg, NULL, 0);
2598                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2599                quote_c_style(other, msg, NULL, 0);
2600                strbuf_addf(msg, "%s\n", reset);
2601                break;
2602        case DIFF_STATUS_RENAMED:
2603                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2604                            line_prefix, set, similarity_index(p));
2605                strbuf_addf(msg, "%s\n%s%srename from ",
2606                            reset, line_prefix, set);
2607                quote_c_style(name, msg, NULL, 0);
2608                strbuf_addf(msg, "%s\n%s%srename to ",
2609                            reset, line_prefix, set);
2610                quote_c_style(other, msg, NULL, 0);
2611                strbuf_addf(msg, "%s\n", reset);
2612                break;
2613        case DIFF_STATUS_MODIFIED:
2614                if (p->score) {
2615                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2616                                    line_prefix,
2617                                    set, similarity_index(p), reset);
2618                        break;
2619                }
2620                /* fallthru */
2621        default:
2622                *must_show_header = 0;
2623        }
2624        if (one && two && hashcmp(one->sha1, two->sha1)) {
2625                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2626
2627                if (DIFF_OPT_TST(o, BINARY)) {
2628                        mmfile_t mf;
2629                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2630                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2631                                abbrev = 40;
2632                }
2633                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2634                            find_unique_abbrev(one->sha1, abbrev));
2635                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2636                if (one->mode == two->mode)
2637                        strbuf_addf(msg, " %06o", one->mode);
2638                strbuf_addf(msg, "%s\n", reset);
2639        }
2640}
2641
2642static void run_diff_cmd(const char *pgm,
2643                         const char *name,
2644                         const char *other,
2645                         const char *attr_path,
2646                         struct diff_filespec *one,
2647                         struct diff_filespec *two,
2648                         struct strbuf *msg,
2649                         struct diff_options *o,
2650                         struct diff_filepair *p)
2651{
2652        const char *xfrm_msg = NULL;
2653        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2654        int must_show_header = 0;
2655
2656        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2657                pgm = NULL;
2658        else {
2659                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2660                if (drv && drv->external)
2661                        pgm = drv->external;
2662        }
2663
2664        if (msg) {
2665                /*
2666                 * don't use colors when the header is intended for an
2667                 * external diff driver
2668                 */
2669                fill_metainfo(msg, name, other, one, two, o, p,
2670                              &must_show_header,
2671                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2672                xfrm_msg = msg->len ? msg->buf : NULL;
2673        }
2674
2675        if (pgm) {
2676                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2677                                  complete_rewrite);
2678                return;
2679        }
2680        if (one && two)
2681                builtin_diff(name, other ? other : name,
2682                             one, two, xfrm_msg, must_show_header,
2683                             o, complete_rewrite);
2684        else
2685                fprintf(o->file, "* Unmerged path %s\n", name);
2686}
2687
2688static void diff_fill_sha1_info(struct diff_filespec *one)
2689{
2690        if (DIFF_FILE_VALID(one)) {
2691                if (!one->sha1_valid) {
2692                        struct stat st;
2693                        if (!strcmp(one->path, "-")) {
2694                                hashcpy(one->sha1, null_sha1);
2695                                return;
2696                        }
2697                        if (lstat(one->path, &st) < 0)
2698                                die_errno("stat '%s'", one->path);
2699                        if (index_path(one->sha1, one->path, &st, 0))
2700                                die("cannot hash %s", one->path);
2701                }
2702        }
2703        else
2704                hashclr(one->sha1);
2705}
2706
2707static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2708{
2709        /* Strip the prefix but do not molest /dev/null and absolute paths */
2710        if (*namep && **namep != '/')
2711                *namep += prefix_length;
2712        if (*otherp && **otherp != '/')
2713                *otherp += prefix_length;
2714}
2715
2716static void run_diff(struct diff_filepair *p, struct diff_options *o)
2717{
2718        const char *pgm = external_diff();
2719        struct strbuf msg;
2720        struct diff_filespec *one = p->one;
2721        struct diff_filespec *two = p->two;
2722        const char *name;
2723        const char *other;
2724        const char *attr_path;
2725
2726        name  = p->one->path;
2727        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2728        attr_path = name;
2729        if (o->prefix_length)
2730                strip_prefix(o->prefix_length, &name, &other);
2731
2732        if (DIFF_PAIR_UNMERGED(p)) {
2733                run_diff_cmd(pgm, name, NULL, attr_path,
2734                             NULL, NULL, NULL, o, p);
2735                return;
2736        }
2737
2738        diff_fill_sha1_info(one);
2739        diff_fill_sha1_info(two);
2740
2741        if (!pgm &&
2742            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2743            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2744                /*
2745                 * a filepair that changes between file and symlink
2746                 * needs to be split into deletion and creation.
2747                 */
2748                struct diff_filespec *null = alloc_filespec(two->path);
2749                run_diff_cmd(NULL, name, other, attr_path,
2750                             one, null, &msg, o, p);
2751                free(null);
2752                strbuf_release(&msg);
2753
2754                null = alloc_filespec(one->path);
2755                run_diff_cmd(NULL, name, other, attr_path,
2756                             null, two, &msg, o, p);
2757                free(null);
2758        }
2759        else
2760                run_diff_cmd(pgm, name, other, attr_path,
2761                             one, two, &msg, o, p);
2762
2763        strbuf_release(&msg);
2764}
2765
2766static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2767                         struct diffstat_t *diffstat)
2768{
2769        const char *name;
2770        const char *other;
2771        int complete_rewrite = 0;
2772
2773        if (DIFF_PAIR_UNMERGED(p)) {
2774                /* unmerged */
2775                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2776                return;
2777        }
2778
2779        name = p->one->path;
2780        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2781
2782        if (o->prefix_length)
2783                strip_prefix(o->prefix_length, &name, &other);
2784
2785        diff_fill_sha1_info(p->one);
2786        diff_fill_sha1_info(p->two);
2787
2788        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2789                complete_rewrite = 1;
2790        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2791}
2792
2793static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2794{
2795        const char *name;
2796        const char *other;
2797        const char *attr_path;
2798
2799        if (DIFF_PAIR_UNMERGED(p)) {
2800                /* unmerged */
2801                return;
2802        }
2803
2804        name = p->one->path;
2805        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2806        attr_path = other ? other : name;
2807
2808        if (o->prefix_length)
2809                strip_prefix(o->prefix_length, &name, &other);
2810
2811        diff_fill_sha1_info(p->one);
2812        diff_fill_sha1_info(p->two);
2813
2814        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2815}
2816
2817void diff_setup(struct diff_options *options)
2818{
2819        memset(options, 0, sizeof(*options));
2820        memset(&diff_queued_diff, 0, sizeof(diff_queued_diff));
2821
2822        options->file = stdout;
2823
2824        options->line_termination = '\n';
2825        options->break_opt = -1;
2826        options->rename_limit = -1;
2827        options->dirstat_percent = 3;
2828        options->context = 3;
2829
2830        options->change = diff_change;
2831        options->add_remove = diff_addremove;
2832        if (diff_use_color_default > 0)
2833                DIFF_OPT_SET(options, COLOR_DIFF);
2834        options->detect_rename = diff_detect_rename_default;
2835
2836        if (diff_no_prefix) {
2837                options->a_prefix = options->b_prefix = "";
2838        } else if (!diff_mnemonic_prefix) {
2839                options->a_prefix = "a/";
2840                options->b_prefix = "b/";
2841        }
2842}
2843
2844int diff_setup_done(struct diff_options *options)
2845{
2846        int count = 0;
2847
2848        if (options->output_format & DIFF_FORMAT_NAME)
2849                count++;
2850        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2851                count++;
2852        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2853                count++;
2854        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2855                count++;
2856        if (count > 1)
2857                die("--name-only, --name-status, --check and -s are mutually exclusive");
2858
2859        /*
2860         * Most of the time we can say "there are changes"
2861         * only by checking if there are changed paths, but
2862         * --ignore-whitespace* options force us to look
2863         * inside contents.
2864         */
2865
2866        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2867            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2868            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2869                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2870        else
2871                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2872
2873        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2874                options->detect_rename = DIFF_DETECT_COPY;
2875
2876        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2877                options->prefix = NULL;
2878        if (options->prefix)
2879                options->prefix_length = strlen(options->prefix);
2880        else
2881                options->prefix_length = 0;
2882
2883        if (options->output_format & (DIFF_FORMAT_NAME |
2884                                      DIFF_FORMAT_NAME_STATUS |
2885                                      DIFF_FORMAT_CHECKDIFF |
2886                                      DIFF_FORMAT_NO_OUTPUT))
2887                options->output_format &= ~(DIFF_FORMAT_RAW |
2888                                            DIFF_FORMAT_NUMSTAT |
2889                                            DIFF_FORMAT_DIFFSTAT |
2890                                            DIFF_FORMAT_SHORTSTAT |
2891                                            DIFF_FORMAT_DIRSTAT |
2892                                            DIFF_FORMAT_SUMMARY |
2893                                            DIFF_FORMAT_PATCH);
2894
2895        /*
2896         * These cases always need recursive; we do not drop caller-supplied
2897         * recursive bits for other formats here.
2898         */
2899        if (options->output_format & (DIFF_FORMAT_PATCH |
2900                                      DIFF_FORMAT_NUMSTAT |
2901                                      DIFF_FORMAT_DIFFSTAT |
2902                                      DIFF_FORMAT_SHORTSTAT |
2903                                      DIFF_FORMAT_DIRSTAT |
2904                                      DIFF_FORMAT_SUMMARY |
2905                                      DIFF_FORMAT_CHECKDIFF))
2906                DIFF_OPT_SET(options, RECURSIVE);
2907        /*
2908         * Also pickaxe would not work very well if you do not say recursive
2909         */
2910        if (options->pickaxe)
2911                DIFF_OPT_SET(options, RECURSIVE);
2912        /*
2913         * When patches are generated, submodules diffed against the work tree
2914         * must be checked for dirtiness too so it can be shown in the output
2915         */
2916        if (options->output_format & DIFF_FORMAT_PATCH)
2917                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2918
2919        if (options->detect_rename && options->rename_limit < 0)
2920                options->rename_limit = diff_rename_limit_default;
2921        if (options->setup & DIFF_SETUP_USE_CACHE) {
2922                if (!active_cache)
2923                        /* read-cache does not die even when it fails
2924                         * so it is safe for us to do this here.  Also
2925                         * it does not smudge active_cache or active_nr
2926                         * when it fails, so we do not have to worry about
2927                         * cleaning it up ourselves either.
2928                         */
2929                        read_cache();
2930        }
2931        if (options->abbrev <= 0 || 40 < options->abbrev)
2932                options->abbrev = 40; /* full */
2933
2934        /*
2935         * It does not make sense to show the first hit we happened
2936         * to have found.  It does not make sense not to return with
2937         * exit code in such a case either.
2938         */
2939        if (DIFF_OPT_TST(options, QUICK)) {
2940                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2941                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2942        }
2943
2944        return 0;
2945}
2946
2947static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2948{
2949        char c, *eq;
2950        int len;
2951
2952        if (*arg != '-')
2953                return 0;
2954        c = *++arg;
2955        if (!c)
2956                return 0;
2957        if (c == arg_short) {
2958                c = *++arg;
2959                if (!c)
2960                        return 1;
2961                if (val && isdigit(c)) {
2962                        char *end;
2963                        int n = strtoul(arg, &end, 10);
2964                        if (*end)
2965                                return 0;
2966                        *val = n;
2967                        return 1;
2968                }
2969                return 0;
2970        }
2971        if (c != '-')
2972                return 0;
2973        arg++;
2974        eq = strchr(arg, '=');
2975        if (eq)
2976                len = eq - arg;
2977        else
2978                len = strlen(arg);
2979        if (!len || strncmp(arg, arg_long, len))
2980                return 0;
2981        if (eq) {
2982                int n;
2983                char *end;
2984                if (!isdigit(*++eq))
2985                        return 0;
2986                n = strtoul(eq, &end, 10);
2987                if (*end)
2988                        return 0;
2989                *val = n;
2990        }
2991        return 1;
2992}
2993
2994static int diff_scoreopt_parse(const char *opt);
2995
2996int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2997{
2998        const char *arg = av[0];
2999
3000        /* Output format options */
3001        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3002                options->output_format |= DIFF_FORMAT_PATCH;
3003        else if (opt_arg(arg, 'U', "unified", &options->context))
3004                options->output_format |= DIFF_FORMAT_PATCH;
3005        else if (!strcmp(arg, "--raw"))
3006                options->output_format |= DIFF_FORMAT_RAW;
3007        else if (!strcmp(arg, "--patch-with-raw"))
3008                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3009        else if (!strcmp(arg, "--numstat"))
3010                options->output_format |= DIFF_FORMAT_NUMSTAT;
3011        else if (!strcmp(arg, "--shortstat"))
3012                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3013        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3014                options->output_format |= DIFF_FORMAT_DIRSTAT;
3015        else if (!strcmp(arg, "--cumulative")) {
3016                options->output_format |= DIFF_FORMAT_DIRSTAT;
3017                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3018        } else if (opt_arg(arg, 0, "dirstat-by-file",
3019                           &options->dirstat_percent)) {
3020                options->output_format |= DIFF_FORMAT_DIRSTAT;
3021                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3022        }
3023        else if (!strcmp(arg, "--check"))
3024                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3025        else if (!strcmp(arg, "--summary"))
3026                options->output_format |= DIFF_FORMAT_SUMMARY;
3027        else if (!strcmp(arg, "--patch-with-stat"))
3028                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3029        else if (!strcmp(arg, "--name-only"))
3030                options->output_format |= DIFF_FORMAT_NAME;
3031        else if (!strcmp(arg, "--name-status"))
3032                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3033        else if (!strcmp(arg, "-s"))
3034                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3035        else if (!prefixcmp(arg, "--stat")) {
3036                char *end;
3037                int width = options->stat_width;
3038                int name_width = options->stat_name_width;
3039                arg += 6;
3040                end = (char *)arg;
3041
3042                switch (*arg) {
3043                case '-':
3044                        if (!prefixcmp(arg, "-width="))
3045                                width = strtoul(arg + 7, &end, 10);
3046                        else if (!prefixcmp(arg, "-name-width="))
3047                                name_width = strtoul(arg + 12, &end, 10);
3048                        break;
3049                case '=':
3050                        width = strtoul(arg+1, &end, 10);
3051                        if (*end == ',')
3052                                name_width = strtoul(end+1, &end, 10);
3053                }
3054
3055                /* Important! This checks all the error cases! */
3056                if (*end)
3057                        return 0;
3058                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3059                options->stat_name_width = name_width;
3060                options->stat_width = width;
3061        }
3062
3063        /* renames options */
3064        else if (!prefixcmp(arg, "-B")) {
3065                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3066                        return -1;
3067        }
3068        else if (!prefixcmp(arg, "-M")) {
3069                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3070                        return -1;
3071                options->detect_rename = DIFF_DETECT_RENAME;
3072        }
3073        else if (!prefixcmp(arg, "-C")) {
3074                if (options->detect_rename == DIFF_DETECT_COPY)
3075                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3076                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3077                        return -1;
3078                options->detect_rename = DIFF_DETECT_COPY;
3079        }
3080        else if (!strcmp(arg, "--no-renames"))
3081                options->detect_rename = 0;
3082        else if (!strcmp(arg, "--relative"))
3083                DIFF_OPT_SET(options, RELATIVE_NAME);
3084        else if (!prefixcmp(arg, "--relative=")) {
3085                DIFF_OPT_SET(options, RELATIVE_NAME);
3086                options->prefix = arg + 11;
3087        }
3088
3089        /* xdiff options */
3090        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3091                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3092        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3093                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3094        else if (!strcmp(arg, "--ignore-space-at-eol"))
3095                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3096        else if (!strcmp(arg, "--patience"))
3097                DIFF_XDL_SET(options, PATIENCE_DIFF);
3098
3099        /* flags options */
3100        else if (!strcmp(arg, "--binary")) {
3101                options->output_format |= DIFF_FORMAT_PATCH;
3102                DIFF_OPT_SET(options, BINARY);
3103        }
3104        else if (!strcmp(arg, "--full-index"))
3105                DIFF_OPT_SET(options, FULL_INDEX);
3106        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3107                DIFF_OPT_SET(options, TEXT);
3108        else if (!strcmp(arg, "-R"))
3109                DIFF_OPT_SET(options, REVERSE_DIFF);
3110        else if (!strcmp(arg, "--find-copies-harder"))
3111                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3112        else if (!strcmp(arg, "--follow"))
3113                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3114        else if (!strcmp(arg, "--color"))
3115                DIFF_OPT_SET(options, COLOR_DIFF);
3116        else if (!prefixcmp(arg, "--color=")) {
3117                int value = git_config_colorbool(NULL, arg+8, -1);
3118                if (value == 0)
3119                        DIFF_OPT_CLR(options, COLOR_DIFF);
3120                else if (value > 0)
3121                        DIFF_OPT_SET(options, COLOR_DIFF);
3122                else
3123                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3124        }
3125        else if (!strcmp(arg, "--no-color"))
3126                DIFF_OPT_CLR(options, COLOR_DIFF);
3127        else if (!strcmp(arg, "--color-words")) {
3128                DIFF_OPT_SET(options, COLOR_DIFF);
3129                options->word_diff = DIFF_WORDS_COLOR;
3130        }
3131        else if (!prefixcmp(arg, "--color-words=")) {
3132                DIFF_OPT_SET(options, COLOR_DIFF);
3133                options->word_diff = DIFF_WORDS_COLOR;
3134                options->word_regex = arg + 14;
3135        }
3136        else if (!strcmp(arg, "--word-diff")) {
3137                if (options->word_diff == DIFF_WORDS_NONE)
3138                        options->word_diff = DIFF_WORDS_PLAIN;
3139        }
3140        else if (!prefixcmp(arg, "--word-diff=")) {
3141                const char *type = arg + 12;
3142                if (!strcmp(type, "plain"))
3143                        options->word_diff = DIFF_WORDS_PLAIN;
3144                else if (!strcmp(type, "color")) {
3145                        DIFF_OPT_SET(options, COLOR_DIFF);
3146                        options->word_diff = DIFF_WORDS_COLOR;
3147                }
3148                else if (!strcmp(type, "porcelain"))
3149                        options->word_diff = DIFF_WORDS_PORCELAIN;
3150                else if (!strcmp(type, "none"))
3151                        options->word_diff = DIFF_WORDS_NONE;
3152                else
3153                        die("bad --word-diff argument: %s", type);
3154        }
3155        else if (!prefixcmp(arg, "--word-diff-regex=")) {
3156                if (options->word_diff == DIFF_WORDS_NONE)
3157                        options->word_diff = DIFF_WORDS_PLAIN;
3158                options->word_regex = arg + 18;
3159        }
3160        else if (!strcmp(arg, "--exit-code"))
3161                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3162        else if (!strcmp(arg, "--quiet"))
3163                DIFF_OPT_SET(options, QUICK);
3164        else if (!strcmp(arg, "--ext-diff"))
3165                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3166        else if (!strcmp(arg, "--no-ext-diff"))
3167                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3168        else if (!strcmp(arg, "--textconv"))
3169                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3170        else if (!strcmp(arg, "--no-textconv"))
3171                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3172        else if (!strcmp(arg, "--ignore-submodules")) {
3173                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3174                handle_ignore_submodules_arg(options, "all");
3175        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3176                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3177                handle_ignore_submodules_arg(options, arg + 20);
3178        } else if (!strcmp(arg, "--submodule"))
3179                DIFF_OPT_SET(options, SUBMODULE_LOG);
3180        else if (!prefixcmp(arg, "--submodule=")) {
3181                if (!strcmp(arg + 12, "log"))
3182                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3183        }
3184
3185        /* misc options */
3186        else if (!strcmp(arg, "-z"))
3187                options->line_termination = 0;
3188        else if (!prefixcmp(arg, "-l"))
3189                options->rename_limit = strtoul(arg+2, NULL, 10);
3190        else if (!prefixcmp(arg, "-S"))
3191                options->pickaxe = arg + 2;
3192        else if (!strcmp(arg, "--pickaxe-all"))
3193                options->pickaxe_opts = DIFF_PICKAXE_ALL;
3194        else if (!strcmp(arg, "--pickaxe-regex"))
3195                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
3196        else if (!prefixcmp(arg, "-O"))
3197                options->orderfile = arg + 2;
3198        else if (!prefixcmp(arg, "--diff-filter="))
3199                options->filter = arg + 14;
3200        else if (!strcmp(arg, "--abbrev"))
3201                options->abbrev = DEFAULT_ABBREV;
3202        else if (!prefixcmp(arg, "--abbrev=")) {
3203                options->abbrev = strtoul(arg + 9, NULL, 10);
3204                if (options->abbrev < MINIMUM_ABBREV)
3205                        options->abbrev = MINIMUM_ABBREV;
3206                else if (40 < options->abbrev)
3207                        options->abbrev = 40;
3208        }
3209        else if (!prefixcmp(arg, "--src-prefix="))
3210                options->a_prefix = arg + 13;
3211        else if (!prefixcmp(arg, "--dst-prefix="))
3212                options->b_prefix = arg + 13;
3213        else if (!strcmp(arg, "--no-prefix"))
3214                options->a_prefix = options->b_prefix = "";
3215        else if (opt_arg(arg, '\0', "inter-hunk-context",
3216                         &options->interhunkcontext))
3217                ;
3218        else if (!prefixcmp(arg, "--output=")) {
3219                options->file = fopen(arg + strlen("--output="), "w");
3220                if (!options->file)
3221                        die_errno("Could not open '%s'", arg + strlen("--output="));
3222                options->close_file = 1;
3223        } else
3224                return 0;
3225        return 1;
3226}
3227
3228static int parse_num(const char **cp_p)
3229{
3230        unsigned long num, scale;
3231        int ch, dot;
3232        const char *cp = *cp_p;
3233
3234        num = 0;
3235        scale = 1;
3236        dot = 0;
3237        for (;;) {
3238                ch = *cp;
3239                if ( !dot && ch == '.' ) {
3240                        scale = 1;
3241                        dot = 1;
3242                } else if ( ch == '%' ) {
3243                        scale = dot ? scale*100 : 100;
3244                        cp++;   /* % is always at the end */
3245                        break;
3246                } else if ( ch >= '0' && ch <= '9' ) {
3247                        if ( scale < 100000 ) {
3248                                scale *= 10;
3249                                num = (num*10) + (ch-'0');
3250                        }
3251                } else {
3252                        break;
3253                }
3254                cp++;
3255        }
3256        *cp_p = cp;
3257
3258        /* user says num divided by scale and we say internally that
3259         * is MAX_SCORE * num / scale.
3260         */
3261        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3262}
3263
3264static int diff_scoreopt_parse(const char *opt)
3265{
3266        int opt1, opt2, cmd;
3267
3268        if (*opt++ != '-')
3269                return -1;
3270        cmd = *opt++;
3271        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3272                return -1; /* that is not a -M, -C nor -B option */
3273
3274        opt1 = parse_num(&opt);
3275        if (cmd != 'B')
3276                opt2 = 0;
3277        else {
3278                if (*opt == 0)
3279                        opt2 = 0;
3280                else if (*opt != '/')
3281                        return -1; /* we expect -B80/99 or -B80 */
3282                else {
3283                        opt++;
3284                        opt2 = parse_num(&opt);
3285                }
3286        }
3287        if (*opt != 0)
3288                return -1;
3289        return opt1 | (opt2 << 16);
3290}
3291
3292struct diff_queue_struct diff_queued_diff;
3293
3294void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3295{
3296        if (queue->alloc <= queue->nr) {
3297                queue->alloc = alloc_nr(queue->alloc);
3298                queue->queue = xrealloc(queue->queue,
3299                                        sizeof(dp) * queue->alloc);
3300        }
3301        queue->queue[queue->nr++] = dp;
3302}
3303
3304struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3305                                 struct diff_filespec *one,
3306                                 struct diff_filespec *two)
3307{
3308        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3309        dp->one = one;
3310        dp->two = two;
3311        if (queue)
3312                diff_q(queue, dp);
3313        return dp;
3314}
3315
3316void diff_free_filepair(struct diff_filepair *p)
3317{
3318        free_filespec(p->one);
3319        free_filespec(p->two);
3320        free(p);
3321}
3322
3323/* This is different from find_unique_abbrev() in that
3324 * it stuffs the result with dots for alignment.
3325 */
3326const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3327{
3328        int abblen;
3329        const char *abbrev;
3330        if (len == 40)
3331                return sha1_to_hex(sha1);
3332
3333        abbrev = find_unique_abbrev(sha1, len);
3334        abblen = strlen(abbrev);
3335        if (abblen < 37) {
3336                static char hex[41];
3337                if (len < abblen && abblen <= len + 2)
3338                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3339                else
3340                        sprintf(hex, "%s...", abbrev);
3341                return hex;
3342        }
3343        return sha1_to_hex(sha1);
3344}
3345
3346static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3347{
3348        int line_termination = opt->line_termination;
3349        int inter_name_termination = line_termination ? '\t' : '\0';
3350        if (opt->output_prefix) {
3351                struct strbuf *msg = NULL;
3352                msg = opt->output_prefix(opt, opt->output_prefix_data);
3353                fprintf(opt->file, "%s", msg->buf);
3354        }
3355
3356        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3357                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3358                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3359                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3360        }
3361        if (p->score) {
3362                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3363                        inter_name_termination);
3364        } else {
3365                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3366        }
3367
3368        if (p->status == DIFF_STATUS_COPIED ||
3369            p->status == DIFF_STATUS_RENAMED) {
3370                const char *name_a, *name_b;
3371                name_a = p->one->path;
3372                name_b = p->two->path;
3373                strip_prefix(opt->prefix_length, &name_a, &name_b);
3374                write_name_quoted(name_a, opt->file, inter_name_termination);
3375                write_name_quoted(name_b, opt->file, line_termination);
3376        } else {
3377                const char *name_a, *name_b;
3378                name_a = p->one->mode ? p->one->path : p->two->path;
3379                name_b = NULL;
3380                strip_prefix(opt->prefix_length, &name_a, &name_b);
3381                write_name_quoted(name_a, opt->file, line_termination);
3382        }
3383}
3384
3385int diff_unmodified_pair(struct diff_filepair *p)
3386{
3387        /* This function is written stricter than necessary to support
3388         * the currently implemented transformers, but the idea is to
3389         * let transformers to produce diff_filepairs any way they want,
3390         * and filter and clean them up here before producing the output.
3391         */
3392        struct diff_filespec *one = p->one, *two = p->two;
3393
3394        if (DIFF_PAIR_UNMERGED(p))
3395                return 0; /* unmerged is interesting */
3396
3397        /* deletion, addition, mode or type change
3398         * and rename are all interesting.
3399         */
3400        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3401            DIFF_PAIR_MODE_CHANGED(p) ||
3402            strcmp(one->path, two->path))
3403                return 0;
3404
3405        /* both are valid and point at the same path.  that is, we are
3406         * dealing with a change.
3407         */
3408        if (one->sha1_valid && two->sha1_valid &&
3409            !hashcmp(one->sha1, two->sha1) &&
3410            !one->dirty_submodule && !two->dirty_submodule)
3411                return 1; /* no change */
3412        if (!one->sha1_valid && !two->sha1_valid)
3413                return 1; /* both look at the same file on the filesystem. */
3414        return 0;
3415}
3416
3417static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3418{
3419        if (diff_unmodified_pair(p))
3420                return;
3421
3422        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3423            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3424                return; /* no tree diffs in patch format */
3425
3426        run_diff(p, o);
3427}
3428
3429static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3430                            struct diffstat_t *diffstat)
3431{
3432        if (diff_unmodified_pair(p))
3433                return;
3434
3435        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3436            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3437                return; /* no tree diffs in patch format */
3438
3439        run_diffstat(p, o, diffstat);
3440}
3441
3442static void diff_flush_checkdiff(struct diff_filepair *p,
3443                struct diff_options *o)
3444{
3445        if (diff_unmodified_pair(p))
3446                return;
3447
3448        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3449            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3450                return; /* no tree diffs in patch format */
3451
3452        run_checkdiff(p, o);
3453}
3454
3455int diff_queue_is_empty(void)
3456{
3457        struct diff_queue_struct *q = &diff_queued_diff;
3458        int i;
3459        for (i = 0; i < q->nr; i++)
3460                if (!diff_unmodified_pair(q->queue[i]))
3461                        return 0;
3462        return 1;
3463}
3464
3465#if DIFF_DEBUG
3466void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3467{
3468        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3469                x, one ? one : "",
3470                s->path,
3471                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3472                s->mode,
3473                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3474        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3475                x, one ? one : "",
3476                s->size, s->xfrm_flags);
3477}
3478
3479void diff_debug_filepair(const struct diff_filepair *p, int i)
3480{
3481        diff_debug_filespec(p->one, i, "one");
3482        diff_debug_filespec(p->two, i, "two");
3483        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3484                p->score, p->status ? p->status : '?',
3485                p->one->rename_used, p->broken_pair);
3486}
3487
3488void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3489{
3490        int i;
3491        if (msg)
3492                fprintf(stderr, "%s\n", msg);
3493        fprintf(stderr, "q->nr = %d\n", q->nr);
3494        for (i = 0; i < q->nr; i++) {
3495                struct diff_filepair *p = q->queue[i];
3496                diff_debug_filepair(p, i);
3497        }
3498}
3499#endif
3500
3501static void diff_resolve_rename_copy(void)
3502{
3503        int i;
3504        struct diff_filepair *p;
3505        struct diff_queue_struct *q = &diff_queued_diff;
3506
3507        diff_debug_queue("resolve-rename-copy", q);
3508
3509        for (i = 0; i < q->nr; i++) {
3510                p = q->queue[i];
3511                p->status = 0; /* undecided */
3512                if (DIFF_PAIR_UNMERGED(p))
3513                        p->status = DIFF_STATUS_UNMERGED;
3514                else if (!DIFF_FILE_VALID(p->one))
3515                        p->status = DIFF_STATUS_ADDED;
3516                else if (!DIFF_FILE_VALID(p->two))
3517                        p->status = DIFF_STATUS_DELETED;
3518                else if (DIFF_PAIR_TYPE_CHANGED(p))
3519                        p->status = DIFF_STATUS_TYPE_CHANGED;
3520
3521                /* from this point on, we are dealing with a pair
3522                 * whose both sides are valid and of the same type, i.e.
3523                 * either in-place edit or rename/copy edit.
3524                 */
3525                else if (DIFF_PAIR_RENAME(p)) {
3526                        /*
3527                         * A rename might have re-connected a broken
3528                         * pair up, causing the pathnames to be the
3529                         * same again. If so, that's not a rename at
3530                         * all, just a modification..
3531                         *
3532                         * Otherwise, see if this source was used for
3533                         * multiple renames, in which case we decrement
3534                         * the count, and call it a copy.
3535                         */
3536                        if (!strcmp(p->one->path, p->two->path))
3537                                p->status = DIFF_STATUS_MODIFIED;
3538                        else if (--p->one->rename_used > 0)
3539                                p->status = DIFF_STATUS_COPIED;
3540                        else
3541                                p->status = DIFF_STATUS_RENAMED;
3542                }
3543                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3544                         p->one->mode != p->two->mode ||
3545                         p->one->dirty_submodule ||
3546                         p->two->dirty_submodule ||
3547                         is_null_sha1(p->one->sha1))
3548                        p->status = DIFF_STATUS_MODIFIED;
3549                else {
3550                        /* This is a "no-change" entry and should not
3551                         * happen anymore, but prepare for broken callers.
3552                         */
3553                        error("feeding unmodified %s to diffcore",
3554                              p->one->path);
3555                        p->status = DIFF_STATUS_UNKNOWN;
3556                }
3557        }
3558        diff_debug_queue("resolve-rename-copy done", q);
3559}
3560
3561static int check_pair_status(struct diff_filepair *p)
3562{
3563        switch (p->status) {
3564        case DIFF_STATUS_UNKNOWN:
3565                return 0;
3566        case 0:
3567                die("internal error in diff-resolve-rename-copy");
3568        default:
3569                return 1;
3570        }
3571}
3572
3573static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3574{
3575        int fmt = opt->output_format;
3576
3577        if (fmt & DIFF_FORMAT_CHECKDIFF)
3578                diff_flush_checkdiff(p, opt);
3579        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3580                diff_flush_raw(p, opt);
3581        else if (fmt & DIFF_FORMAT_NAME) {
3582                const char *name_a, *name_b;
3583                name_a = p->two->path;
3584                name_b = NULL;
3585                strip_prefix(opt->prefix_length, &name_a, &name_b);
3586                write_name_quoted(name_a, opt->file, opt->line_termination);
3587        }
3588}
3589
3590static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3591{
3592        if (fs->mode)
3593                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3594        else
3595                fprintf(file, " %s ", newdelete);
3596        write_name_quoted(fs->path, file, '\n');
3597}
3598
3599
3600static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3601                const char *line_prefix)
3602{
3603        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3604                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3605                        p->two->mode, show_name ? ' ' : '\n');
3606                if (show_name) {
3607                        write_name_quoted(p->two->path, file, '\n');
3608                }
3609        }
3610}
3611
3612static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3613                        const char *line_prefix)
3614{
3615        char *names = pprint_rename(p->one->path, p->two->path);
3616
3617        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3618        free(names);
3619        show_mode_change(file, p, 0, line_prefix);
3620}
3621
3622static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3623{
3624        FILE *file = opt->file;
3625        char *line_prefix = "";
3626
3627        if (opt->output_prefix) {
3628                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3629                line_prefix = buf->buf;
3630        }
3631
3632        switch(p->status) {
3633        case DIFF_STATUS_DELETED:
3634                fputs(line_prefix, file);
3635                show_file_mode_name(file, "delete", p->one);
3636                break;
3637        case DIFF_STATUS_ADDED:
3638                fputs(line_prefix, file);
3639                show_file_mode_name(file, "create", p->two);
3640                break;
3641        case DIFF_STATUS_COPIED:
3642                fputs(line_prefix, file);
3643                show_rename_copy(file, "copy", p, line_prefix);
3644                break;
3645        case DIFF_STATUS_RENAMED:
3646                fputs(line_prefix, file);
3647                show_rename_copy(file, "rename", p, line_prefix);
3648                break;
3649        default:
3650                if (p->score) {
3651                        fprintf(file, "%s rewrite ", line_prefix);
3652                        write_name_quoted(p->two->path, file, ' ');
3653                        fprintf(file, "(%d%%)\n", similarity_index(p));
3654                }
3655                show_mode_change(file, p, !p->score, line_prefix);
3656                break;
3657        }
3658}
3659
3660struct patch_id_t {
3661        git_SHA_CTX *ctx;
3662        int patchlen;
3663};
3664
3665static int remove_space(char *line, int len)
3666{
3667        int i;
3668        char *dst = line;
3669        unsigned char c;
3670
3671        for (i = 0; i < len; i++)
3672                if (!isspace((c = line[i])))
3673                        *dst++ = c;
3674
3675        return dst - line;
3676}
3677
3678static void patch_id_consume(void *priv, char *line, unsigned long len)
3679{
3680        struct patch_id_t *data = priv;
3681        int new_len;
3682
3683        /* Ignore line numbers when computing the SHA1 of the patch */
3684        if (!prefixcmp(line, "@@ -"))
3685                return;
3686
3687        new_len = remove_space(line, len);
3688
3689        git_SHA1_Update(data->ctx, line, new_len);
3690        data->patchlen += new_len;
3691}
3692
3693/* returns 0 upon success, and writes result into sha1 */
3694static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3695{
3696        struct diff_queue_struct *q = &diff_queued_diff;
3697        int i;
3698        git_SHA_CTX ctx;
3699        struct patch_id_t data;
3700        char buffer[PATH_MAX * 4 + 20];
3701
3702        git_SHA1_Init(&ctx);
3703        memset(&data, 0, sizeof(struct patch_id_t));
3704        data.ctx = &ctx;
3705
3706        for (i = 0; i < q->nr; i++) {
3707                xpparam_t xpp;
3708                xdemitconf_t xecfg;
3709                mmfile_t mf1, mf2;
3710                struct diff_filepair *p = q->queue[i];
3711                int len1, len2;
3712
3713                memset(&xpp, 0, sizeof(xpp));
3714                memset(&xecfg, 0, sizeof(xecfg));
3715                if (p->status == 0)
3716                        return error("internal diff status error");
3717                if (p->status == DIFF_STATUS_UNKNOWN)
3718                        continue;
3719                if (diff_unmodified_pair(p))
3720                        continue;
3721                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3722                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3723                        continue;
3724                if (DIFF_PAIR_UNMERGED(p))
3725                        continue;
3726
3727                diff_fill_sha1_info(p->one);
3728                diff_fill_sha1_info(p->two);
3729                if (fill_mmfile(&mf1, p->one) < 0 ||
3730                                fill_mmfile(&mf2, p->two) < 0)
3731                        return error("unable to read files to diff");
3732
3733                len1 = remove_space(p->one->path, strlen(p->one->path));
3734                len2 = remove_space(p->two->path, strlen(p->two->path));
3735                if (p->one->mode == 0)
3736                        len1 = snprintf(buffer, sizeof(buffer),
3737                                        "diff--gita/%.*sb/%.*s"
3738                                        "newfilemode%06o"
3739                                        "---/dev/null"
3740                                        "+++b/%.*s",
3741                                        len1, p->one->path,
3742                                        len2, p->two->path,
3743                                        p->two->mode,
3744                                        len2, p->two->path);
3745                else if (p->two->mode == 0)
3746                        len1 = snprintf(buffer, sizeof(buffer),
3747                                        "diff--gita/%.*sb/%.*s"
3748                                        "deletedfilemode%06o"
3749                                        "---a/%.*s"
3750                                        "+++/dev/null",
3751                                        len1, p->one->path,
3752                                        len2, p->two->path,
3753                                        p->one->mode,
3754                                        len1, p->one->path);
3755                else
3756                        len1 = snprintf(buffer, sizeof(buffer),
3757                                        "diff--gita/%.*sb/%.*s"
3758                                        "---a/%.*s"
3759                                        "+++b/%.*s",
3760                                        len1, p->one->path,
3761                                        len2, p->two->path,
3762                                        len1, p->one->path,
3763                                        len2, p->two->path);
3764                git_SHA1_Update(&ctx, buffer, len1);
3765
3766                xpp.flags = 0;
3767                xecfg.ctxlen = 3;
3768                xecfg.flags = XDL_EMIT_FUNCNAMES;
3769                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3770                              &xpp, &xecfg);
3771        }
3772
3773        git_SHA1_Final(sha1, &ctx);
3774        return 0;
3775}
3776
3777int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3778{
3779        struct diff_queue_struct *q = &diff_queued_diff;
3780        int i;
3781        int result = diff_get_patch_id(options, sha1);
3782
3783        for (i = 0; i < q->nr; i++)
3784                diff_free_filepair(q->queue[i]);
3785
3786        free(q->queue);
3787        DIFF_QUEUE_CLEAR(q);
3788
3789        return result;
3790}
3791
3792static int is_summary_empty(const struct diff_queue_struct *q)
3793{
3794        int i;
3795
3796        for (i = 0; i < q->nr; i++) {
3797                const struct diff_filepair *p = q->queue[i];
3798
3799                switch (p->status) {
3800                case DIFF_STATUS_DELETED:
3801                case DIFF_STATUS_ADDED:
3802                case DIFF_STATUS_COPIED:
3803                case DIFF_STATUS_RENAMED:
3804                        return 0;
3805                default:
3806                        if (p->score)
3807                                return 0;
3808                        if (p->one->mode && p->two->mode &&
3809                            p->one->mode != p->two->mode)
3810                                return 0;
3811                        break;
3812                }
3813        }
3814        return 1;
3815}
3816
3817void diff_flush(struct diff_options *options)
3818{
3819        struct diff_queue_struct *q = &diff_queued_diff;
3820        int i, output_format = options->output_format;
3821        int separator = 0;
3822
3823        /*
3824         * Order: raw, stat, summary, patch
3825         * or:    name/name-status/checkdiff (other bits clear)
3826         */
3827        if (!q->nr)
3828                goto free_queue;
3829
3830        if (output_format & (DIFF_FORMAT_RAW |
3831                             DIFF_FORMAT_NAME |
3832                             DIFF_FORMAT_NAME_STATUS |
3833                             DIFF_FORMAT_CHECKDIFF)) {
3834                for (i = 0; i < q->nr; i++) {
3835                        struct diff_filepair *p = q->queue[i];
3836                        if (check_pair_status(p))
3837                                flush_one_pair(p, options);
3838                }
3839                separator++;
3840        }
3841
3842        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3843                struct diffstat_t diffstat;
3844
3845                memset(&diffstat, 0, sizeof(struct diffstat_t));
3846                for (i = 0; i < q->nr; i++) {
3847                        struct diff_filepair *p = q->queue[i];
3848                        if (check_pair_status(p))
3849                                diff_flush_stat(p, options, &diffstat);
3850                }
3851                if (output_format & DIFF_FORMAT_NUMSTAT)
3852                        show_numstat(&diffstat, options);
3853                if (output_format & DIFF_FORMAT_DIFFSTAT)
3854                        show_stats(&diffstat, options);
3855                if (output_format & DIFF_FORMAT_SHORTSTAT)
3856                        show_shortstats(&diffstat, options);
3857                free_diffstat_info(&diffstat);
3858                separator++;
3859        }
3860        if (output_format & DIFF_FORMAT_DIRSTAT)
3861                show_dirstat(options);
3862
3863        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3864                for (i = 0; i < q->nr; i++) {
3865                        diff_summary(options, q->queue[i]);
3866                }
3867                separator++;
3868        }
3869
3870        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3871            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3872            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3873                /*
3874                 * run diff_flush_patch for the exit status. setting
3875                 * options->file to /dev/null should be safe, becaue we
3876                 * aren't supposed to produce any output anyway.
3877                 */
3878                if (options->close_file)
3879                        fclose(options->file);
3880                options->file = fopen("/dev/null", "w");
3881                if (!options->file)
3882                        die_errno("Could not open /dev/null");
3883                options->close_file = 1;
3884                for (i = 0; i < q->nr; i++) {
3885                        struct diff_filepair *p = q->queue[i];
3886                        if (check_pair_status(p))
3887                                diff_flush_patch(p, options);
3888                        if (options->found_changes)
3889                                break;
3890                }
3891        }
3892
3893        if (output_format & DIFF_FORMAT_PATCH) {
3894                if (separator) {
3895                        putc(options->line_termination, options->file);
3896                        if (options->stat_sep) {
3897                                /* attach patch instead of inline */
3898                                fputs(options->stat_sep, options->file);
3899                        }
3900                }
3901
3902                for (i = 0; i < q->nr; i++) {
3903                        struct diff_filepair *p = q->queue[i];
3904                        if (check_pair_status(p))
3905                                diff_flush_patch(p, options);
3906                }
3907        }
3908
3909        if (output_format & DIFF_FORMAT_CALLBACK)
3910                options->format_callback(q, options, options->format_callback_data);
3911
3912        for (i = 0; i < q->nr; i++)
3913                diff_free_filepair(q->queue[i]);
3914free_queue:
3915        free(q->queue);
3916        DIFF_QUEUE_CLEAR(q);
3917        if (options->close_file)
3918                fclose(options->file);
3919
3920        /*
3921         * Report the content-level differences with HAS_CHANGES;
3922         * diff_addremove/diff_change does not set the bit when
3923         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3924         */
3925        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3926                if (options->found_changes)
3927                        DIFF_OPT_SET(options, HAS_CHANGES);
3928                else
3929                        DIFF_OPT_CLR(options, HAS_CHANGES);
3930        }
3931}
3932
3933static void diffcore_apply_filter(const char *filter)
3934{
3935        int i;
3936        struct diff_queue_struct *q = &diff_queued_diff;
3937        struct diff_queue_struct outq;
3938        DIFF_QUEUE_CLEAR(&outq);
3939
3940        if (!filter)
3941                return;
3942
3943        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3944                int found;
3945                for (i = found = 0; !found && i < q->nr; i++) {
3946                        struct diff_filepair *p = q->queue[i];
3947                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3948                             ((p->score &&
3949                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3950                              (!p->score &&
3951                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3952                            ((p->status != DIFF_STATUS_MODIFIED) &&
3953                             strchr(filter, p->status)))
3954                                found++;
3955                }
3956                if (found)
3957                        return;
3958
3959                /* otherwise we will clear the whole queue
3960                 * by copying the empty outq at the end of this
3961                 * function, but first clear the current entries
3962                 * in the queue.
3963                 */
3964                for (i = 0; i < q->nr; i++)
3965                        diff_free_filepair(q->queue[i]);
3966        }
3967        else {
3968                /* Only the matching ones */
3969                for (i = 0; i < q->nr; i++) {
3970                        struct diff_filepair *p = q->queue[i];
3971
3972                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3973                             ((p->score &&
3974                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3975                              (!p->score &&
3976                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3977                            ((p->status != DIFF_STATUS_MODIFIED) &&
3978                             strchr(filter, p->status)))
3979                                diff_q(&outq, p);
3980                        else
3981                                diff_free_filepair(p);
3982                }
3983        }
3984        free(q->queue);
3985        *q = outq;
3986}
3987
3988/* Check whether two filespecs with the same mode and size are identical */
3989static int diff_filespec_is_identical(struct diff_filespec *one,
3990                                      struct diff_filespec *two)
3991{
3992        if (S_ISGITLINK(one->mode))
3993                return 0;
3994        if (diff_populate_filespec(one, 0))
3995                return 0;
3996        if (diff_populate_filespec(two, 0))
3997                return 0;
3998        return !memcmp(one->data, two->data, one->size);
3999}
4000
4001static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4002{
4003        int i;
4004        struct diff_queue_struct *q = &diff_queued_diff;
4005        struct diff_queue_struct outq;
4006        DIFF_QUEUE_CLEAR(&outq);
4007
4008        for (i = 0; i < q->nr; i++) {
4009                struct diff_filepair *p = q->queue[i];
4010
4011                /*
4012                 * 1. Entries that come from stat info dirtiness
4013                 *    always have both sides (iow, not create/delete),
4014                 *    one side of the object name is unknown, with
4015                 *    the same mode and size.  Keep the ones that
4016                 *    do not match these criteria.  They have real
4017                 *    differences.
4018                 *
4019                 * 2. At this point, the file is known to be modified,
4020                 *    with the same mode and size, and the object
4021                 *    name of one side is unknown.  Need to inspect
4022                 *    the identical contents.
4023                 */
4024                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4025                    !DIFF_FILE_VALID(p->two) ||
4026                    (p->one->sha1_valid && p->two->sha1_valid) ||
4027                    (p->one->mode != p->two->mode) ||
4028                    diff_populate_filespec(p->one, 1) ||
4029                    diff_populate_filespec(p->two, 1) ||
4030                    (p->one->size != p->two->size) ||
4031                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4032                        diff_q(&outq, p);
4033                else {
4034                        /*
4035                         * The caller can subtract 1 from skip_stat_unmatch
4036                         * to determine how many paths were dirty only
4037                         * due to stat info mismatch.
4038                         */
4039                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4040                                diffopt->skip_stat_unmatch++;
4041                        diff_free_filepair(p);
4042                }
4043        }
4044        free(q->queue);
4045        *q = outq;
4046}
4047
4048static int diffnamecmp(const void *a_, const void *b_)
4049{
4050        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4051        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4052        const char *name_a, *name_b;
4053
4054        name_a = a->one ? a->one->path : a->two->path;
4055        name_b = b->one ? b->one->path : b->two->path;
4056        return strcmp(name_a, name_b);
4057}
4058
4059void diffcore_fix_diff_index(struct diff_options *options)
4060{
4061        struct diff_queue_struct *q = &diff_queued_diff;
4062        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4063}
4064
4065void diffcore_std(struct diff_options *options)
4066{
4067        /* We never run this function more than one time, because the
4068         * rename/copy detection logic can only run once.
4069         */
4070        if (diff_queued_diff.run)
4071                return;
4072
4073        if (options->skip_stat_unmatch)
4074                diffcore_skip_stat_unmatch(options);
4075        if (options->break_opt != -1)
4076                diffcore_break(options->break_opt);
4077        if (options->detect_rename)
4078                diffcore_rename(options);
4079        if (options->break_opt != -1)
4080                diffcore_merge_broken();
4081        if (options->pickaxe)
4082                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
4083        if (options->orderfile)
4084                diffcore_order(options->orderfile);
4085        diff_resolve_rename_copy();
4086        diffcore_apply_filter(options->filter);
4087
4088        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4089                DIFF_OPT_SET(options, HAS_CHANGES);
4090        else
4091                DIFF_OPT_CLR(options, HAS_CHANGES);
4092
4093        diff_queued_diff.run = 1;
4094}
4095
4096int diff_result_code(struct diff_options *opt, int status)
4097{
4098        int result = 0;
4099        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4100            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4101                return status;
4102        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4103            DIFF_OPT_TST(opt, HAS_CHANGES))
4104                result |= 01;
4105        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4106            DIFF_OPT_TST(opt, CHECK_FAILED))
4107                result |= 02;
4108        return result;
4109}
4110
4111/*
4112 * Shall changes to this submodule be ignored?
4113 *
4114 * Submodule changes can be configured to be ignored separately for each path,
4115 * but that configuration can be overridden from the command line.
4116 */
4117static int is_submodule_ignored(const char *path, struct diff_options *options)
4118{
4119        int ignored = 0;
4120        unsigned orig_flags = options->flags;
4121        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4122                set_diffopt_flags_from_submodule_config(options, path);
4123        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4124                ignored = 1;
4125        options->flags = orig_flags;
4126        return ignored;
4127}
4128
4129void diff_addremove(struct diff_options *options,
4130                    int addremove, unsigned mode,
4131                    const unsigned char *sha1,
4132                    const char *concatpath, unsigned dirty_submodule)
4133{
4134        struct diff_filespec *one, *two;
4135
4136        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4137                return;
4138
4139        /* This may look odd, but it is a preparation for
4140         * feeding "there are unchanged files which should
4141         * not produce diffs, but when you are doing copy
4142         * detection you would need them, so here they are"
4143         * entries to the diff-core.  They will be prefixed
4144         * with something like '=' or '*' (I haven't decided
4145         * which but should not make any difference).
4146         * Feeding the same new and old to diff_change()
4147         * also has the same effect.
4148         * Before the final output happens, they are pruned after
4149         * merged into rename/copy pairs as appropriate.
4150         */
4151        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4152                addremove = (addremove == '+' ? '-' :
4153                             addremove == '-' ? '+' : addremove);
4154
4155        if (options->prefix &&
4156            strncmp(concatpath, options->prefix, options->prefix_length))
4157                return;
4158
4159        one = alloc_filespec(concatpath);
4160        two = alloc_filespec(concatpath);
4161
4162        if (addremove != '+')
4163                fill_filespec(one, sha1, mode);
4164        if (addremove != '-') {
4165                fill_filespec(two, sha1, mode);
4166                two->dirty_submodule = dirty_submodule;
4167        }
4168
4169        diff_queue(&diff_queued_diff, one, two);
4170        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4171                DIFF_OPT_SET(options, HAS_CHANGES);
4172}
4173
4174void diff_change(struct diff_options *options,
4175                 unsigned old_mode, unsigned new_mode,
4176                 const unsigned char *old_sha1,
4177                 const unsigned char *new_sha1,
4178                 const char *concatpath,
4179                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4180{
4181        struct diff_filespec *one, *two;
4182
4183        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4184            is_submodule_ignored(concatpath, options))
4185                return;
4186
4187        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4188                unsigned tmp;
4189                const unsigned char *tmp_c;
4190                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4191                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4192                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4193                        new_dirty_submodule = tmp;
4194        }
4195
4196        if (options->prefix &&
4197            strncmp(concatpath, options->prefix, options->prefix_length))
4198                return;
4199
4200        one = alloc_filespec(concatpath);
4201        two = alloc_filespec(concatpath);
4202        fill_filespec(one, old_sha1, old_mode);
4203        fill_filespec(two, new_sha1, new_mode);
4204        one->dirty_submodule = old_dirty_submodule;
4205        two->dirty_submodule = new_dirty_submodule;
4206
4207        diff_queue(&diff_queued_diff, one, two);
4208        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4209                DIFF_OPT_SET(options, HAS_CHANGES);
4210}
4211
4212void diff_unmerge(struct diff_options *options,
4213                  const char *path,
4214                  unsigned mode, const unsigned char *sha1)
4215{
4216        struct diff_filespec *one, *two;
4217
4218        if (options->prefix &&
4219            strncmp(path, options->prefix, options->prefix_length))
4220                return;
4221
4222        one = alloc_filespec(path);
4223        two = alloc_filespec(path);
4224        fill_filespec(one, sha1, mode);
4225        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4226}
4227
4228static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4229                size_t *outsize)
4230{
4231        struct diff_tempfile *temp;
4232        const char *argv[3];
4233        const char **arg = argv;
4234        struct child_process child;
4235        struct strbuf buf = STRBUF_INIT;
4236        int err = 0;
4237
4238        temp = prepare_temp_file(spec->path, spec);
4239        *arg++ = pgm;
4240        *arg++ = temp->name;
4241        *arg = NULL;
4242
4243        memset(&child, 0, sizeof(child));
4244        child.use_shell = 1;
4245        child.argv = argv;
4246        child.out = -1;
4247        if (start_command(&child)) {
4248                remove_tempfile();
4249                return NULL;
4250        }
4251
4252        if (strbuf_read(&buf, child.out, 0) < 0)
4253                err = error("error reading from textconv command '%s'", pgm);
4254        close(child.out);
4255
4256        if (finish_command(&child) || err) {
4257                strbuf_release(&buf);
4258                remove_tempfile();
4259                return NULL;
4260        }
4261        remove_tempfile();
4262
4263        return strbuf_detach(&buf, outsize);
4264}
4265
4266size_t fill_textconv(struct userdiff_driver *driver,
4267                     struct diff_filespec *df,
4268                     char **outbuf)
4269{
4270        size_t size;
4271
4272        if (!driver || !driver->textconv) {
4273                if (!DIFF_FILE_VALID(df)) {
4274                        *outbuf = "";
4275                        return 0;
4276                }
4277                if (diff_populate_filespec(df, 0))
4278                        die("unable to read files to diff");
4279                *outbuf = df->data;
4280                return df->size;
4281        }
4282
4283        if (driver->textconv_cache) {
4284                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4285                                          &size);
4286                if (*outbuf)
4287                        return size;
4288        }
4289
4290        *outbuf = run_textconv(driver->textconv, df, &size);
4291        if (!*outbuf)
4292                die("unable to read files to diff");
4293
4294        if (driver->textconv_cache) {
4295                /* ignore errors, as we might be in a readonly repository */
4296                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4297                                size);
4298                /*
4299                 * we could save up changes and flush them all at the end,
4300                 * but we would need an extra call after all diffing is done.
4301                 * Since generating a cache entry is the slow path anyway,
4302                 * this extra overhead probably isn't a big deal.
4303                 */
4304                notes_cache_write(driver->textconv_cache);
4305        }
4306
4307        return size;
4308}