diff.h

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #ifndef DIFF_H
   5 #define DIFF_H
   6
   7 #include "tree-walk.h"
   8 #include "pathspec.h"
   9 #include "object.h"
  10 #include "oidset.h"
  11
  12 /**
  13  * The diff API is for programs that compare two sets of files (e.g. two trees,
  14  * one tree and the index) and present the found difference in various ways.
  15  * The calling program is responsible for feeding the API pairs of files, one
  16  * from the "old" set and the corresponding one from "new" set, that are
  17  * different.
  18  * The library called through this API is called diffcore, and is responsible
  19  * for two things.
  20  *
  21  * - finding total rewrites (`-B`), renames (`-M`) and copies (`-C`), and
  22  * changes that touch a string (`-S`), as specified by the caller.
  23  *
  24  * - outputting the differences in various formats, as specified by the caller.
  25  *
  26  * Calling sequence
  27  * ----------------
  28  *
  29  * - Prepare `struct diff_options` to record the set of diff options, and then
  30  * call `repo_diff_setup()` to initialize this structure.  This sets up the
  31  * vanilla default.
  32  *
  33  * - Fill in the options structure to specify desired output format, rename
  34  * detection, etc.  `diff_opt_parse()` can be used to parse options given
  35  * from the command line in a way consistent with existing git-diff family
  36  * of programs.
  37  *
  38  * - Call `diff_setup_done()`; this inspects the options set up so far for
  39  * internal consistency and make necessary tweaking to it (e.g. if textual
  40  * patch output was asked, recursive behaviour is turned on); the callback
  41  * set_default in diff_options can be used to tweak this more.
  42  *
  43  * - As you find different pairs of files, call `diff_change()` to feed
  44  * modified files, `diff_addremove()` to feed created or deleted files, or
  45  * `diff_unmerge()` to feed a file whose state is 'unmerged' to the API.
  46  * These are thin wrappers to a lower-level `diff_queue()` function that is
  47  * flexible enough to record any of these kinds of changes.
  48  *
  49  * - Once you finish feeding the pairs of files, call `diffcore_std()`.
  50  * This will tell the diffcore library to go ahead and do its work.
  51  *
  52  * - Calling `diff_flush()` will produce the output.
  53  */
  54
  55 struct combine_diff_path;
  56 struct commit;
  57 struct diff_filespec;
  58 struct diff_options;
  59 struct diff_queue_struct;
  60 struct oid_array;
  61 struct option;
  62 struct repository;
  63 struct rev_info;
  64 struct strbuf;
  65 struct userdiff_driver;
  66
  67 typedef int (*pathchange_fn_t)(struct diff_options *options,
  68                  struct combine_diff_path *path);
  69
  70 typedef void (*change_fn_t)(struct diff_options *options,
  71                  unsigned old_mode, unsigned new_mode,
  72                  const struct object_id *old_oid,
  73                  const struct object_id *new_oid,
  74                  int old_oid_valid, int new_oid_valid,
  75                  const char *fullpath,
  76                  unsigned old_dirty_submodule, unsigned new_dirty_submodule);
  77
  78 typedef void (*add_remove_fn_t)(struct diff_options *options,
  79                     int addremove, unsigned mode,
  80                     const struct object_id *oid,
  81                     int oid_valid,
  82                     const char *fullpath, unsigned dirty_submodule);
  83
  84 typedef void (*diff_format_fn_t)(struct diff_queue_struct *q,
  85                 struct diff_options *options, void *data);
  86
  87 typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data);
  88
  89 #define DIFF_FORMAT_RAW         0x0001
  90 #define DIFF_FORMAT_DIFFSTAT    0x0002
  91 #define DIFF_FORMAT_NUMSTAT     0x0004
  92 #define DIFF_FORMAT_SUMMARY     0x0008
  93 #define DIFF_FORMAT_PATCH       0x0010
  94 #define DIFF_FORMAT_SHORTSTAT   0x0020
  95 #define DIFF_FORMAT_DIRSTAT     0x0040
  96
  97 /* These override all above */
  98 #define DIFF_FORMAT_NAME        0x0100
  99 #define DIFF_FORMAT_NAME_STATUS 0x0200
 100 #define DIFF_FORMAT_CHECKDIFF   0x0400
 101
 102 /* Same as output_format = 0 but we know that -s flag was given
 103  * and we should not give default value to output_format.
 104  */
 105 #define DIFF_FORMAT_NO_OUTPUT   0x0800
 106
 107 #define DIFF_FORMAT_CALLBACK    0x1000
 108
 109 #define DIFF_FLAGS_INIT { 0 }
 110 struct diff_flags {
 111
 112         /**
 113          * Tells if tree traversal done by tree-diff should recursively descend
 114          * into a tree object pair that are different in preimage and postimage set.
 115          */
 116         unsigned recursive;
 117         unsigned tree_in_recursive;
 118
 119         /* Affects the way how a file that is seemingly binary is treated. */
 120         unsigned binary;
 121         unsigned text;
 122
 123         /**
 124          * Tells the patch output format not to use abbreviated object names on the
 125          * "index" lines.
 126          */
 127         unsigned full_index;
 128
 129         /* Affects if diff-files shows removed files. */
 130         unsigned silent_on_remove;
 131
 132         /**
 133          * Tells the diffcore library that the caller is feeding unchanged
 134          * filepairs to allow copies from unmodified files be detected.
 135          */
 136         unsigned find_copies_harder;
 137
 138         unsigned follow_renames;
 139         unsigned rename_empty;
 140
 141         /* Internal; used for optimization to see if there is any change. */
 142         unsigned has_changes;
 143
 144         unsigned quick;
 145
 146         /**
 147          * Tells diff-files that the input is not tracked files but files in random
 148          * locations on the filesystem.
 149          */
 150         unsigned no_index;
 151
 152         /**
 153          * Tells output routine that it is Ok to call user specified patch output
 154          * routine.  Plumbing disables this to ensure stable output.
 155          */
 156         unsigned allow_external;
 157
 158         /**
 159          * For communication between the calling program and the options parser;
 160          * tell the calling program to signal the presence of difference using
 161          * program exit code.
 162          */
 163         unsigned exit_with_status;
 164
 165         /**
 166          * Tells the library that the calling program is feeding the filepairs
 167          * reversed; `one` is two, and `two` is one.
 168          */
 169         unsigned reverse_diff;
 170
 171         unsigned check_failed;
 172         unsigned relative_name;
 173         unsigned ignore_submodules;
 174         unsigned dirstat_cumulative;
 175         unsigned dirstat_by_file;
 176         unsigned allow_textconv;
 177         unsigned textconv_set_via_cmdline;
 178         unsigned diff_from_contents;
 179         unsigned dirty_submodules;
 180         unsigned ignore_untracked_in_submodules;
 181         unsigned ignore_dirty_submodules;
 182         unsigned override_submodule_config;
 183         unsigned dirstat_by_line;
 184         unsigned funccontext;
 185         unsigned default_follow_renames;
 186         unsigned stat_with_summary;
 187         unsigned suppress_diff_headers;
 188         unsigned dual_color_diffed_diffs;
 189         unsigned suppress_hunk_header_line_count;
 190 };
 191
 192 static inline void diff_flags_or(struct diff_flags *a,
 193                                  const struct diff_flags *b)
 194 {
 195         char *tmp_a = (char *)a;
 196         const char *tmp_b = (const char *)b;
 197         int i;
 198
 199         for (i = 0; i < sizeof(struct diff_flags); i++)
 200                 tmp_a[i] |= tmp_b[i];
 201 }
 202
 203 #define DIFF_XDL_TST(opts, flag)    ((opts)->xdl_opts & XDF_##flag)
 204 #define DIFF_XDL_SET(opts, flag)    ((opts)->xdl_opts |= XDF_##flag)
 205 #define DIFF_XDL_CLR(opts, flag)    ((opts)->xdl_opts &= ~XDF_##flag)
 206
 207 #define DIFF_WITH_ALG(opts, flag)   (((opts)->xdl_opts & ~XDF_DIFF_ALGORITHM_MASK) | XDF_##flag)
 208
 209 enum diff_words_type {
 210         DIFF_WORDS_NONE = 0,
 211         DIFF_WORDS_PORCELAIN,
 212         DIFF_WORDS_PLAIN,
 213         DIFF_WORDS_COLOR
 214 };
 215
 216 enum diff_submodule_format {
 217         DIFF_SUBMODULE_SHORT = 0,
 218         DIFF_SUBMODULE_LOG,
 219         DIFF_SUBMODULE_INLINE_DIFF
 220 };
 221
 222 /**
 223  * the set of options the calling program wants to affect the operation of
 224  * diffcore library with.
 225  */
 226 struct diff_options {
 227         const char *orderfile;
 228
 229         /**
 230          * A constant string (can and typically does contain newlines to look for
 231          * a block of text, not just a single line) to filter out the filepairs
 232          * that do not change the number of strings contained in its preimage and
 233          * postimage of the diff_queue.
 234          */
 235         const char *pickaxe;
 236
 237         const char *single_follow;
 238         const char *a_prefix, *b_prefix;
 239         const char *line_prefix;
 240         size_t line_prefix_length;
 241
 242         /**
 243          * collection of boolean options that affects the operation, but some do
 244          * not have anything to do with the diffcore library.
 245          */
 246         struct diff_flags flags;
 247
 248         /* diff-filter bits */
 249         unsigned int filter;
 250
 251         int use_color;
 252
 253         /* Number of context lines to generate in patch output. */
 254         int context;
 255
 256         int interhunkcontext;
 257
 258         /* Affects the way detection logic for complete rewrites, renames and
 259          * copies.
 260          */
 261         int break_opt;
 262         int detect_rename;
 263
 264         int irreversible_delete;
 265         int skip_stat_unmatch;
 266         int line_termination;
 267
 268         /* The output format used when `diff_flush()` is run. */
 269         int output_format;
 270
 271         unsigned pickaxe_opts;
 272
 273         /* Affects the way detection logic for complete rewrites, renames and
 274          * copies.
 275          */
 276         int rename_score;
 277         int rename_limit;
 278
 279         int needed_rename_limit;
 280         int degraded_cc_to_c;
 281         int show_rename_progress;
 282         int dirstat_permille;
 283         int setup;
 284
 285         /* Number of hexdigits to abbreviate raw format output to. */
 286         int abbrev;
 287
 288         /* If non-zero, then stop computing after this many changes. */
 289         int max_changes;
 290         /* For internal use only. */
 291         int num_changes;
 292
 293         int ita_invisible_in_index;
 294 /* white-space error highlighting */
 295 #define WSEH_NEW (1<<12)
 296 #define WSEH_CONTEXT (1<<13)
 297 #define WSEH_OLD (1<<14)
 298         unsigned ws_error_highlight;
 299         const char *prefix;
 300         int prefix_length;
 301         const char *stat_sep;
 302         int xdl_opts;
 303
 304         /* see Documentation/diff-options.txt */
 305         char **anchors;
 306         size_t anchors_nr, anchors_alloc;
 307
 308         int stat_width;
 309         int stat_name_width;
 310         int stat_graph_width;
 311         int stat_count;
 312         const char *word_regex;
 313         enum diff_words_type word_diff;
 314         enum diff_submodule_format submodule_format;
 315
 316         struct oidset *objfind;
 317
 318         /* this is set by diffcore for DIFF_FORMAT_PATCH */
 319         int found_changes;
 320
 321         /* to support internal diff recursion by --follow hack*/
 322         int found_follow;
 323
 324         /* Callback which allows tweaking the options in diff_setup_done(). */
 325         void (*set_default)(struct diff_options *);
 326
 327         FILE *file;
 328         int close_file;
 329
 330 #define OUTPUT_INDICATOR_NEW 0
 331 #define OUTPUT_INDICATOR_OLD 1
 332 #define OUTPUT_INDICATOR_CONTEXT 2
 333         char output_indicators[3];
 334
 335         struct pathspec pathspec;
 336         pathchange_fn_t pathchange;
 337         change_fn_t change;
 338         add_remove_fn_t add_remove;
 339         void *change_fn_data;
 340         diff_format_fn_t format_callback;
 341         void *format_callback_data;
 342         diff_prefix_fn_t output_prefix;
 343         void *output_prefix_data;
 344
 345         int diff_path_counter;
 346
 347         struct emitted_diff_symbols *emitted_symbols;
 348         enum {
 349                 COLOR_MOVED_NO = 0,
 350                 COLOR_MOVED_PLAIN = 1,
 351                 COLOR_MOVED_BLOCKS = 2,
 352                 COLOR_MOVED_ZEBRA = 3,
 353                 COLOR_MOVED_ZEBRA_DIM = 4,
 354         } color_moved;
 355         #define COLOR_MOVED_DEFAULT COLOR_MOVED_ZEBRA
 356         #define COLOR_MOVED_MIN_ALNUM_COUNT 20
 357
 358         /* XDF_WHITESPACE_FLAGS regarding block detection are set at 2, 3, 4 */
 359         #define COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE (1<<5)
 360         #define COLOR_MOVED_WS_ERROR (1<<0)
 361         unsigned color_moved_ws_handling;
 362
 363         struct repository *repo;
 364         struct option *parseopts;
 365 };
 366
 367 unsigned diff_filter_bit(char status);
 368
 369 void diff_emit_submodule_del(struct diff_options *o, const char *line);
 370 void diff_emit_submodule_add(struct diff_options *o, const char *line);
 371 void diff_emit_submodule_untracked(struct diff_options *o, const char *path);
 372 void diff_emit_submodule_modified(struct diff_options *o, const char *path);
 373 void diff_emit_submodule_header(struct diff_options *o, const char *header);
 374 void diff_emit_submodule_error(struct diff_options *o, const char *err);
 375 void diff_emit_submodule_pipethrough(struct diff_options *o,
 376                                      const char *line, int len);
 377
 378 struct diffstat_t {
 379         int nr;
 380         int alloc;
 381         struct diffstat_file {
 382                 char *from_name;
 383                 char *name;
 384                 char *print_name;
 385                 const char *comments;
 386                 unsigned is_unmerged:1;
 387                 unsigned is_binary:1;
 388                 unsigned is_renamed:1;
 389                 unsigned is_interesting:1;
 390                 uintmax_t added, deleted;
 391         } **files;
 392 };
 393
 394 enum color_diff {
 395         DIFF_RESET = 0,
 396         DIFF_CONTEXT = 1,
 397         DIFF_METAINFO = 2,
 398         DIFF_FRAGINFO = 3,
 399         DIFF_FILE_OLD = 4,
 400         DIFF_FILE_NEW = 5,
 401         DIFF_COMMIT = 6,
 402         DIFF_WHITESPACE = 7,
 403         DIFF_FUNCINFO = 8,
 404         DIFF_FILE_OLD_MOVED = 9,
 405         DIFF_FILE_OLD_MOVED_ALT = 10,
 406         DIFF_FILE_OLD_MOVED_DIM = 11,
 407         DIFF_FILE_OLD_MOVED_ALT_DIM = 12,
 408         DIFF_FILE_NEW_MOVED = 13,
 409         DIFF_FILE_NEW_MOVED_ALT = 14,
 410         DIFF_FILE_NEW_MOVED_DIM = 15,
 411         DIFF_FILE_NEW_MOVED_ALT_DIM = 16,
 412         DIFF_CONTEXT_DIM = 17,
 413         DIFF_FILE_OLD_DIM = 18,
 414         DIFF_FILE_NEW_DIM = 19,
 415         DIFF_CONTEXT_BOLD = 20,
 416         DIFF_FILE_OLD_BOLD = 21,
 417         DIFF_FILE_NEW_BOLD = 22,
 418 };
 419
 420 const char *diff_get_color(int diff_use_color, enum color_diff ix);
 421 #define diff_get_color_opt(o, ix) \
 422         diff_get_color((o)->use_color, ix)
 423
 424
 425 const char *diff_line_prefix(struct diff_options *);
 426
 427
 428 extern const char mime_boundary_leader[];
 429
 430 struct combine_diff_path *diff_tree_paths(
 431         struct combine_diff_path *p, const struct object_id *oid,
 432         const struct object_id **parents_oid, int nparent,
 433         struct strbuf *base, struct diff_options *opt);
 434 void diff_tree_oid(const struct object_id *old_oid,
 435                    const struct object_id *new_oid,
 436                    const char *base, struct diff_options *opt);
 437 void diff_root_tree_oid(const struct object_id *new_oid, const char *base,
 438                         struct diff_options *opt);
 439
 440 struct combine_diff_path {
 441         struct combine_diff_path *next;
 442         char *path;
 443         unsigned int mode;
 444         struct object_id oid;
 445         struct combine_diff_parent {
 446                 char status;
 447                 unsigned int mode;
 448                 struct object_id oid;
 449                 struct strbuf path;
 450         } parent[FLEX_ARRAY];
 451 };
 452 #define combine_diff_path_size(n, l) \
 453         st_add4(sizeof(struct combine_diff_path), (l), 1, \
 454                 st_mult(sizeof(struct combine_diff_parent), (n)))
 455
 456 void show_combined_diff(struct combine_diff_path *elem, int num_parent,
 457                         int dense, struct rev_info *);
 458
 459 void diff_tree_combined(const struct object_id *oid, const struct oid_array *parents, int dense, struct rev_info *rev);
 460
 461 void diff_tree_combined_merge(const struct commit *commit, int dense, struct rev_info *rev);
 462
 463 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b);
 464
 465 int diff_can_quit_early(struct diff_options *);
 466
 467 void diff_addremove(struct diff_options *,
 468                     int addremove,
 469                     unsigned mode,
 470                     const struct object_id *oid,
 471                     int oid_valid,
 472                     const char *fullpath, unsigned dirty_submodule);
 473
 474 void diff_change(struct diff_options *,
 475                  unsigned mode1, unsigned mode2,
 476                  const struct object_id *old_oid,
 477                  const struct object_id *new_oid,
 478                  int old_oid_valid, int new_oid_valid,
 479                  const char *fullpath,
 480                  unsigned dirty_submodule1, unsigned dirty_submodule2);
 481
 482 struct diff_filepair *diff_unmerge(struct diff_options *, const char *path);
 483
 484 void compute_diffstat(struct diff_options *options, struct diffstat_t *diffstat,
 485                       struct diff_queue_struct *q);
 486 void free_diffstat_info(struct diffstat_t *diffstat);
 487
 488 #define DIFF_SETUP_REVERSE              1
 489 #define DIFF_SETUP_USE_SIZE_CACHE       4
 490
 491 /*
 492  * Poor man's alternative to parse-option, to allow both stuck form
 493  * (--option=value) and separate form (--option value).
 494  */
 495 int parse_long_opt(const char *opt, const char **argv,
 496                    const char **optarg);
 497
 498 int git_diff_basic_config(const char *var, const char *value, void *cb);
 499 int git_diff_heuristic_config(const char *var, const char *value, void *cb);
 500 void init_diff_ui_defaults(void);
 501 int git_diff_ui_config(const char *var, const char *value, void *cb);
 502 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
 503 #define diff_setup(diffopts) repo_diff_setup(the_repository, diffopts)
 504 #endif
 505 void repo_diff_setup(struct repository *, struct diff_options *);
 506 int diff_opt_parse(struct diff_options *, const char **, int, const char *);
 507 void diff_setup_done(struct diff_options *);
 508 int git_config_rename(const char *var, const char *value);
 509
 510 #define DIFF_DETECT_RENAME      1
 511 #define DIFF_DETECT_COPY        2
 512
 513 #define DIFF_PICKAXE_ALL        1
 514 #define DIFF_PICKAXE_REGEX      2
 515
 516 #define DIFF_PICKAXE_KIND_S     4 /* traditional plumbing counter */
 517 #define DIFF_PICKAXE_KIND_G     8 /* grep in the patch */
 518 #define DIFF_PICKAXE_KIND_OBJFIND       16 /* specific object IDs */
 519
 520 #define DIFF_PICKAXE_KINDS_MASK (DIFF_PICKAXE_KIND_S | \
 521                                  DIFF_PICKAXE_KIND_G | \
 522                                  DIFF_PICKAXE_KIND_OBJFIND)
 523
 524 #define DIFF_PICKAXE_IGNORE_CASE        32
 525
 526 void diffcore_std(struct diff_options *);
 527 void diffcore_fix_diff_index(void);
 528
 529 #define COMMON_DIFF_OPTIONS_HELP \
 530 "\ncommon diff options:\n" \
 531 "  -z            output diff-raw with lines terminated with NUL.\n" \
 532 "  -p            output patch format.\n" \
 533 "  -u            synonym for -p.\n" \
 534 "  --patch-with-raw\n" \
 535 "                output both a patch and the diff-raw format.\n" \
 536 "  --stat        show diffstat instead of patch.\n" \
 537 "  --numstat     show numeric diffstat instead of patch.\n" \
 538 "  --patch-with-stat\n" \
 539 "                output a patch and prepend its diffstat.\n" \
 540 "  --name-only   show only names of changed files.\n" \
 541 "  --name-status show names and status of changed files.\n" \
 542 "  --full-index  show full object name on index lines.\n" \
 543 "  --abbrev=<n>  abbreviate object names in diff-tree header and diff-raw.\n" \
 544 "  -R            swap input file pairs.\n" \
 545 "  -B            detect complete rewrites.\n" \
 546 "  -M            detect renames.\n" \
 547 "  -C            detect copies.\n" \
 548 "  --find-copies-harder\n" \
 549 "                try unchanged files as candidate for copy detection.\n" \
 550 "  -l<n>         limit rename attempts up to <n> paths.\n" \
 551 "  -O<file>      reorder diffs according to the <file>.\n" \
 552 "  -S<string>    find filepair whose only one side contains the string.\n" \
 553 "  --pickaxe-all\n" \
 554 "                show all files diff when -S is used and hit is found.\n" \
 555 "  -a  --text    treat all files as text.\n"
 556
 557 int diff_queue_is_empty(void);
 558 void diff_flush(struct diff_options*);
 559 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc);
 560
 561 /* diff-raw status letters */
 562 #define DIFF_STATUS_ADDED               'A'
 563 #define DIFF_STATUS_COPIED              'C'
 564 #define DIFF_STATUS_DELETED             'D'
 565 #define DIFF_STATUS_MODIFIED            'M'
 566 #define DIFF_STATUS_RENAMED             'R'
 567 #define DIFF_STATUS_TYPE_CHANGED        'T'
 568 #define DIFF_STATUS_UNKNOWN             'X'
 569 #define DIFF_STATUS_UNMERGED            'U'
 570
 571 /* these are not diff-raw status letters proper, but used by
 572  * diffcore-filter insn to specify additional restrictions.
 573  */
 574 #define DIFF_STATUS_FILTER_AON          '*'
 575 #define DIFF_STATUS_FILTER_BROKEN       'B'
 576
 577 /*
 578  * This is different from find_unique_abbrev() in that
 579  * it stuffs the result with dots for alignment.
 580  */
 581 const char *diff_aligned_abbrev(const struct object_id *sha1, int);
 582
 583 /* do not report anything on removed paths */
 584 #define DIFF_SILENT_ON_REMOVED 01
 585 /* report racily-clean paths as modified */
 586 #define DIFF_RACY_IS_MODIFIED 02
 587 int run_diff_files(struct rev_info *revs, unsigned int option);
 588 int run_diff_index(struct rev_info *revs, int cached);
 589
 590 int do_diff_cache(const struct object_id *, struct diff_options *);
 591 int diff_flush_patch_id(struct diff_options *, struct object_id *, int, int);
 592 void flush_one_hunk(struct object_id *result, git_hash_ctx *ctx);
 593
 594 int diff_result_code(struct diff_options *, int);
 595
 596 int diff_no_index(struct rev_info *,
 597                   int implicit_no_index, int, const char **);
 598
 599 int index_differs_from(struct repository *r, const char *def,
 600                        const struct diff_flags *flags,
 601                        int ita_invisible_in_index);
 602
 603 /*
 604  * Emit an interdiff of two object ID's to 'diff_options.file' optionally
 605  * indented by 'indent' spaces.
 606  */
 607 void show_interdiff(const struct object_id *, const struct object_id *,
 608                     int indent, struct diff_options *);
 609
 610 /*
 611  * Fill the contents of the filespec "df", respecting any textconv defined by
 612  * its userdiff driver.  The "driver" parameter must come from a
 613  * previous call to get_textconv(), and therefore should either be NULL or have
 614  * textconv enabled.
 615  *
 616  * Note that the memory ownership of the resulting buffer depends on whether
 617  * the driver field is NULL. If it is, then the memory belongs to the filespec
 618  * struct. If it is non-NULL, then "outbuf" points to a newly allocated buffer
 619  * that should be freed by the caller.
 620  */
 621 size_t fill_textconv(struct repository *r,
 622                      struct userdiff_driver *driver,
 623                      struct diff_filespec *df,
 624                      char **outbuf);
 625
 626 /*
 627  * Look up the userdiff driver for the given filespec, and return it if
 628  * and only if it has textconv enabled (otherwise return NULL). The result
 629  * can be passed to fill_textconv().
 630  */
 631 struct userdiff_driver *get_textconv(struct repository *r,
 632                                      struct diff_filespec *one);
 633
 634 /*
 635  * Prepare diff_filespec and convert it using diff textconv API
 636  * if the textconv driver exists.
 637  * Return 1 if the conversion succeeds, 0 otherwise.
 638  */
 639 int textconv_object(struct repository *repo,
 640                     const char *path,
 641                     unsigned mode,
 642                     const struct object_id *oid, int oid_valid,
 643                     char **buf, unsigned long *buf_size);
 644
 645 int parse_rename_score(const char **cp_p);
 646
 647 long parse_algorithm_value(const char *value);
 648
 649 void print_stat_summary(FILE *fp, int files,
 650                         int insertions, int deletions);
 651 void setup_diff_pager(struct diff_options *);
 652
 653 #endif /* DIFF_H */