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, it will call
  53  *   `diff_free()` to free any resources, e.g. those allocated in
  54  *   `diff_opt_parse()`.
  55  *
  56  * - Set `.no_free = 1` before calling `diff_flush()` to defer the
  57  *   freeing of allocated memory in diff_options. This is useful when
  58  *   `diff_flush()` is being called in a loop, rather than as a
  59  *   one-off. When setting `.no_free = 1` you must ensure that
  60  *   `diff_free()` is called at the end, either by flipping the flag
  61  *   before the last `diff_flush()` call, or by flipping it before
  62  *   calling `diff_free()` yourself.
  63  */
  64
  65 struct combine_diff_path;
  66 struct commit;
  67 struct diff_filespec;
  68 struct diff_options;
  69 struct diff_queue_struct;
  70 struct oid_array;
  71 struct option;
  72 struct repository;
  73 struct rev_info;
  74 struct strbuf;
  75 struct userdiff_driver;
  76
  77 typedef int (*pathchange_fn_t)(struct diff_options *options,
  78                  struct combine_diff_path *path);
  79
  80 typedef void (*change_fn_t)(struct diff_options *options,
  81                  unsigned old_mode, unsigned new_mode,
  82                  const struct object_id *old_oid,
  83                  const struct object_id *new_oid,
  84                  int old_oid_valid, int new_oid_valid,
  85                  const char *fullpath,
  86                  unsigned old_dirty_submodule, unsigned new_dirty_submodule);
  87
  88 typedef void (*add_remove_fn_t)(struct diff_options *options,
  89                     int addremove, unsigned mode,
  90                     const struct object_id *oid,
  91                     int oid_valid,
  92                     const char *fullpath, unsigned dirty_submodule);
  93
  94 typedef void (*diff_format_fn_t)(struct diff_queue_struct *q,
  95                 struct diff_options *options, void *data);
  96
  97 typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data);
  98
  99 #define DIFF_FORMAT_RAW         0x0001
 100 #define DIFF_FORMAT_DIFFSTAT    0x0002
 101 #define DIFF_FORMAT_NUMSTAT     0x0004
 102 #define DIFF_FORMAT_SUMMARY     0x0008
 103 #define DIFF_FORMAT_PATCH       0x0010
 104 #define DIFF_FORMAT_SHORTSTAT   0x0020
 105 #define DIFF_FORMAT_DIRSTAT     0x0040
 106
 107 /* These override all above */
 108 #define DIFF_FORMAT_NAME        0x0100
 109 #define DIFF_FORMAT_NAME_STATUS 0x0200
 110 #define DIFF_FORMAT_CHECKDIFF   0x0400
 111
 112 /* Same as output_format = 0 but we know that -s flag was given
 113  * and we should not give default value to output_format.
 114  */
 115 #define DIFF_FORMAT_NO_OUTPUT   0x0800
 116
 117 #define DIFF_FORMAT_CALLBACK    0x1000
 118
 119 #define DIFF_FLAGS_INIT { 0 }
 120 struct diff_flags {
 121
 122         /**
 123          * Tells if tree traversal done by tree-diff should recursively descend
 124          * into a tree object pair that are different in preimage and postimage set.
 125          */
 126         unsigned recursive;
 127         unsigned tree_in_recursive;
 128
 129         /* Affects the way how a file that is seemingly binary is treated. */
 130         unsigned binary;
 131         unsigned text;
 132
 133         /**
 134          * Tells the patch output format not to use abbreviated object names on the
 135          * "index" lines.
 136          */
 137         unsigned full_index;
 138
 139         /* Affects if diff-files shows removed files. */
 140         unsigned silent_on_remove;
 141
 142         /**
 143          * Tells the diffcore library that the caller is feeding unchanged
 144          * filepairs to allow copies from unmodified files be detected.
 145          */
 146         unsigned find_copies_harder;
 147
 148         unsigned follow_renames;
 149         unsigned rename_empty;
 150
 151         /* Internal; used for optimization to see if there is any change. */
 152         unsigned has_changes;
 153
 154         unsigned quick;
 155
 156         /**
 157          * Tells diff-files that the input is not tracked files but files in random
 158          * locations on the filesystem.
 159          */
 160         unsigned no_index;
 161
 162         /**
 163          * Tells output routine that it is Ok to call user specified patch output
 164          * routine.  Plumbing disables this to ensure stable output.
 165          */
 166         unsigned allow_external;
 167
 168         /**
 169          * For communication between the calling program and the options parser;
 170          * tell the calling program to signal the presence of difference using
 171          * program exit code.
 172          */
 173         unsigned exit_with_status;
 174
 175         /**
 176          * Tells the library that the calling program is feeding the filepairs
 177          * reversed; `one` is two, and `two` is one.
 178          */
 179         unsigned reverse_diff;
 180
 181         unsigned check_failed;
 182         unsigned relative_name;
 183         unsigned ignore_submodules;
 184         unsigned dirstat_cumulative;
 185         unsigned dirstat_by_file;
 186         unsigned allow_textconv;
 187         unsigned textconv_set_via_cmdline;
 188         unsigned diff_from_contents;
 189         unsigned dirty_submodules;
 190         unsigned ignore_untracked_in_submodules;
 191         unsigned ignore_submodule_set;
 192         unsigned ignore_dirty_submodules;
 193         unsigned override_submodule_config;
 194         unsigned dirstat_by_line;
 195         unsigned funccontext;
 196         unsigned default_follow_renames;
 197         unsigned stat_with_summary;
 198         unsigned suppress_diff_headers;
 199         unsigned dual_color_diffed_diffs;
 200         unsigned suppress_hunk_header_line_count;
 201 };
 202
 203 static inline void diff_flags_or(struct diff_flags *a,
 204                                  const struct diff_flags *b)
 205 {
 206         char *tmp_a = (char *)a;
 207         const char *tmp_b = (const char *)b;
 208         int i;
 209
 210         for (i = 0; i < sizeof(struct diff_flags); i++)
 211                 tmp_a[i] |= tmp_b[i];
 212 }
 213
 214 #define DIFF_XDL_TST(opts, flag)    ((opts)->xdl_opts & XDF_##flag)
 215 #define DIFF_XDL_SET(opts, flag)    ((opts)->xdl_opts |= XDF_##flag)
 216 #define DIFF_XDL_CLR(opts, flag)    ((opts)->xdl_opts &= ~XDF_##flag)
 217
 218 #define DIFF_WITH_ALG(opts, flag)   (((opts)->xdl_opts & ~XDF_DIFF_ALGORITHM_MASK) | XDF_##flag)
 219
 220 enum diff_words_type {
 221         DIFF_WORDS_NONE = 0,
 222         DIFF_WORDS_PORCELAIN,
 223         DIFF_WORDS_PLAIN,
 224         DIFF_WORDS_COLOR
 225 };
 226
 227 enum diff_submodule_format {
 228         DIFF_SUBMODULE_SHORT = 0,
 229         DIFF_SUBMODULE_LOG,
 230         DIFF_SUBMODULE_INLINE_DIFF
 231 };
 232
 233 /**
 234  * the set of options the calling program wants to affect the operation of
 235  * diffcore library with.
 236  */
 237 struct diff_options {
 238         const char *orderfile;
 239
 240         /*
 241          * "--rotate-to=<file>" would start showing at <file> and when
 242          * the output reaches the end, wrap around by default.
 243          * Setting skip_instead_of_rotate to true stops the output at the
 244          * end, effectively discarding the earlier part of the output
 245          * before <file>'s diff (this is used to implement the
 246          * "--skip-to=<file>" option).
 247          *
 248          * When rotate_to_strict is set, it is an error if there is no
 249          * <file> in the diff.  Otherwise, the output starts at the
 250          * path that is the same as, or first path that sorts after,
 251          * <file>.  Because it is unreasonable to require the exact
 252          * match for "git log -p --rotate-to=<file>" (i.e. not all
 253          * commit would touch that single <file>), "git log" sets it
 254          * to false.  "git diff" sets it to true to detect an error
 255          * in the command line option.
 256          */
 257         const char *rotate_to;
 258         int skip_instead_of_rotate;
 259         int rotate_to_strict;
 260
 261         /**
 262          * A constant string (can and typically does contain newlines to look for
 263          * a block of text, not just a single line) to filter out the filepairs
 264          * that do not change the number of strings contained in its preimage and
 265          * postimage of the diff_queue.
 266          */
 267         const char *pickaxe;
 268
 269         /* -I<regex> */
 270         regex_t **ignore_regex;
 271         size_t ignore_regex_nr, ignore_regex_alloc;
 272
 273         const char *single_follow;
 274         const char *a_prefix, *b_prefix;
 275         const char *line_prefix;
 276         size_t line_prefix_length;
 277
 278         /**
 279          * collection of boolean options that affects the operation, but some do
 280          * not have anything to do with the diffcore library.
 281          */
 282         struct diff_flags flags;
 283
 284         /* diff-filter bits */
 285         unsigned int filter;
 286
 287         int use_color;
 288
 289         /* Number of context lines to generate in patch output. */
 290         int context;
 291
 292         int interhunkcontext;
 293
 294         /* Affects the way detection logic for complete rewrites, renames and
 295          * copies.
 296          */
 297         int break_opt;
 298         int detect_rename;
 299
 300         int irreversible_delete;
 301         int skip_stat_unmatch;
 302         int line_termination;
 303
 304         /* The output format used when `diff_flush()` is run. */
 305         int output_format;
 306
 307         unsigned pickaxe_opts;
 308
 309         /* Affects the way detection logic for complete rewrites, renames and
 310          * copies.
 311          */
 312         int rename_score;
 313         int rename_limit;
 314
 315         int needed_rename_limit;
 316         int degraded_cc_to_c;
 317         int show_rename_progress;
 318         int dirstat_permille;
 319         int setup;
 320
 321         /* Number of hexdigits to abbreviate raw format output to. */
 322         int abbrev;
 323
 324         /* If non-zero, then stop computing after this many changes. */
 325         int max_changes;
 326
 327         int ita_invisible_in_index;
 328 /* white-space error highlighting */
 329 #define WSEH_NEW (1<<12)
 330 #define WSEH_CONTEXT (1<<13)
 331 #define WSEH_OLD (1<<14)
 332         unsigned ws_error_highlight;
 333         const char *prefix;
 334         int prefix_length;
 335         const char *stat_sep;
 336         int xdl_opts;
 337
 338         /* see Documentation/diff-options.txt */
 339         char **anchors;
 340         size_t anchors_nr, anchors_alloc;
 341
 342         int stat_width;
 343         int stat_name_width;
 344         int stat_graph_width;
 345         int stat_count;
 346         const char *word_regex;
 347         enum diff_words_type word_diff;
 348         enum diff_submodule_format submodule_format;
 349
 350         struct oidset *objfind;
 351
 352         /* this is set by diffcore for DIFF_FORMAT_PATCH */
 353         int found_changes;
 354
 355         /* to support internal diff recursion by --follow hack*/
 356         int found_follow;
 357
 358         /* Callback which allows tweaking the options in diff_setup_done(). */
 359         void (*set_default)(struct diff_options *);
 360
 361         FILE *file;
 362         int close_file;
 363
 364 #define OUTPUT_INDICATOR_NEW 0
 365 #define OUTPUT_INDICATOR_OLD 1
 366 #define OUTPUT_INDICATOR_CONTEXT 2
 367         char output_indicators[3];
 368
 369         struct pathspec pathspec;
 370         pathchange_fn_t pathchange;
 371         change_fn_t change;
 372         add_remove_fn_t add_remove;
 373         void *change_fn_data;
 374         diff_format_fn_t format_callback;
 375         void *format_callback_data;
 376         diff_prefix_fn_t output_prefix;
 377         void *output_prefix_data;
 378
 379         int diff_path_counter;
 380
 381         struct emitted_diff_symbols *emitted_symbols;
 382         enum {
 383                 COLOR_MOVED_NO = 0,
 384                 COLOR_MOVED_PLAIN = 1,
 385                 COLOR_MOVED_BLOCKS = 2,
 386                 COLOR_MOVED_ZEBRA = 3,
 387                 COLOR_MOVED_ZEBRA_DIM = 4,
 388         } color_moved;
 389         #define COLOR_MOVED_DEFAULT COLOR_MOVED_ZEBRA
 390         #define COLOR_MOVED_MIN_ALNUM_COUNT 20
 391
 392         /* XDF_WHITESPACE_FLAGS regarding block detection are set at 2, 3, 4 */
 393         #define COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE (1<<5)
 394         #define COLOR_MOVED_WS_ERROR (1<<0)
 395         unsigned color_moved_ws_handling;
 396
 397         struct repository *repo;
 398         struct option *parseopts;
 399
 400         int no_free;
 401 };
 402
 403 unsigned diff_filter_bit(char status);
 404
 405 void diff_emit_submodule_del(struct diff_options *o, const char *line);
 406 void diff_emit_submodule_add(struct diff_options *o, const char *line);
 407 void diff_emit_submodule_untracked(struct diff_options *o, const char *path);
 408 void diff_emit_submodule_modified(struct diff_options *o, const char *path);
 409 void diff_emit_submodule_header(struct diff_options *o, const char *header);
 410 void diff_emit_submodule_error(struct diff_options *o, const char *err);
 411 void diff_emit_submodule_pipethrough(struct diff_options *o,
 412                                      const char *line, int len);
 413
 414 struct diffstat_t {
 415         int nr;
 416         int alloc;
 417         struct diffstat_file {
 418                 char *from_name;
 419                 char *name;
 420                 char *print_name;
 421                 const char *comments;
 422                 unsigned is_unmerged:1;
 423                 unsigned is_binary:1;
 424                 unsigned is_renamed:1;
 425                 unsigned is_interesting:1;
 426                 uintmax_t added, deleted;
 427         } **files;
 428 };
 429
 430 enum color_diff {
 431         DIFF_RESET = 0,
 432         DIFF_CONTEXT = 1,
 433         DIFF_METAINFO = 2,
 434         DIFF_FRAGINFO = 3,
 435         DIFF_FILE_OLD = 4,
 436         DIFF_FILE_NEW = 5,
 437         DIFF_COMMIT = 6,
 438         DIFF_WHITESPACE = 7,
 439         DIFF_FUNCINFO = 8,
 440         DIFF_FILE_OLD_MOVED = 9,
 441         DIFF_FILE_OLD_MOVED_ALT = 10,
 442         DIFF_FILE_OLD_MOVED_DIM = 11,
 443         DIFF_FILE_OLD_MOVED_ALT_DIM = 12,
 444         DIFF_FILE_NEW_MOVED = 13,
 445         DIFF_FILE_NEW_MOVED_ALT = 14,
 446         DIFF_FILE_NEW_MOVED_DIM = 15,
 447         DIFF_FILE_NEW_MOVED_ALT_DIM = 16,
 448         DIFF_CONTEXT_DIM = 17,
 449         DIFF_FILE_OLD_DIM = 18,
 450         DIFF_FILE_NEW_DIM = 19,
 451         DIFF_CONTEXT_BOLD = 20,
 452         DIFF_FILE_OLD_BOLD = 21,
 453         DIFF_FILE_NEW_BOLD = 22,
 454 };
 455
 456 const char *diff_get_color(int diff_use_color, enum color_diff ix);
 457 #define diff_get_color_opt(o, ix) \
 458         diff_get_color((o)->use_color, ix)
 459
 460
 461 const char *diff_line_prefix(struct diff_options *);
 462
 463
 464 extern const char mime_boundary_leader[];
 465
 466 struct combine_diff_path *diff_tree_paths(
 467         struct combine_diff_path *p, const struct object_id *oid,
 468         const struct object_id **parents_oid, int nparent,
 469         struct strbuf *base, struct diff_options *opt);
 470 void diff_tree_oid(const struct object_id *old_oid,
 471                    const struct object_id *new_oid,
 472                    const char *base, struct diff_options *opt);
 473 void diff_root_tree_oid(const struct object_id *new_oid, const char *base,
 474                         struct diff_options *opt);
 475
 476 struct combine_diff_path {
 477         struct combine_diff_path *next;
 478         char *path;
 479         unsigned int mode;
 480         struct object_id oid;
 481         struct combine_diff_parent {
 482                 char status;
 483                 unsigned int mode;
 484                 struct object_id oid;
 485                 struct strbuf path;
 486         } parent[FLEX_ARRAY];
 487 };
 488 #define combine_diff_path_size(n, l) \
 489         st_add4(sizeof(struct combine_diff_path), (l), 1, \
 490                 st_mult(sizeof(struct combine_diff_parent), (n)))
 491
 492 void show_combined_diff(struct combine_diff_path *elem, int num_parent,
 493                         struct rev_info *);
 494
 495 void diff_tree_combined(const struct object_id *oid, const struct oid_array *parents, struct rev_info *rev);
 496
 497 void diff_tree_combined_merge(const struct commit *commit, struct rev_info *rev);
 498
 499 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b);
 500
 501 int diff_can_quit_early(struct diff_options *);
 502
 503 void diff_addremove(struct diff_options *,
 504                     int addremove,
 505                     unsigned mode,
 506                     const struct object_id *oid,
 507                     int oid_valid,
 508                     const char *fullpath, unsigned dirty_submodule);
 509
 510 void diff_change(struct diff_options *,
 511                  unsigned mode1, unsigned mode2,
 512                  const struct object_id *old_oid,
 513                  const struct object_id *new_oid,
 514                  int old_oid_valid, int new_oid_valid,
 515                  const char *fullpath,
 516                  unsigned dirty_submodule1, unsigned dirty_submodule2);
 517
 518 struct diff_filepair *diff_unmerge(struct diff_options *, const char *path);
 519
 520 void compute_diffstat(struct diff_options *options, struct diffstat_t *diffstat,
 521                       struct diff_queue_struct *q);
 522 void free_diffstat_info(struct diffstat_t *diffstat);
 523
 524 #define DIFF_SETUP_REVERSE              1
 525 #define DIFF_SETUP_USE_SIZE_CACHE       4
 526
 527 /*
 528  * Poor man's alternative to parse-option, to allow both stuck form
 529  * (--option=value) and separate form (--option value).
 530  */
 531 int parse_long_opt(const char *opt, const char **argv,
 532                    const char **optarg);
 533
 534 int git_diff_basic_config(const char *var, const char *value, void *cb);
 535 int git_diff_heuristic_config(const char *var, const char *value, void *cb);
 536 void init_diff_ui_defaults(void);
 537 int git_diff_ui_config(const char *var, const char *value, void *cb);
 538 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
 539 #define diff_setup(diffopts) repo_diff_setup(the_repository, diffopts)
 540 #endif
 541 void repo_diff_setup(struct repository *, struct diff_options *);
 542 int diff_opt_parse(struct diff_options *, const char **, int, const char *);
 543 void diff_setup_done(struct diff_options *);
 544 int git_config_rename(const char *var, const char *value);
 545
 546 #define DIFF_DETECT_RENAME      1
 547 #define DIFF_DETECT_COPY        2
 548
 549 #define DIFF_PICKAXE_ALL        1
 550 #define DIFF_PICKAXE_REGEX      2
 551
 552 #define DIFF_PICKAXE_KIND_S     4 /* traditional plumbing counter */
 553 #define DIFF_PICKAXE_KIND_G     8 /* grep in the patch */
 554 #define DIFF_PICKAXE_KIND_OBJFIND       16 /* specific object IDs */
 555
 556 #define DIFF_PICKAXE_KINDS_MASK (DIFF_PICKAXE_KIND_S | \
 557                                  DIFF_PICKAXE_KIND_G | \
 558                                  DIFF_PICKAXE_KIND_OBJFIND)
 559
 560 #define DIFF_PICKAXE_IGNORE_CASE        32
 561
 562 void diffcore_std(struct diff_options *);
 563 void diffcore_fix_diff_index(void);
 564
 565 #define COMMON_DIFF_OPTIONS_HELP \
 566 "\ncommon diff options:\n" \
 567 "  -z            output diff-raw with lines terminated with NUL.\n" \
 568 "  -p            output patch format.\n" \
 569 "  -u            synonym for -p.\n" \
 570 "  --patch-with-raw\n" \
 571 "                output both a patch and the diff-raw format.\n" \
 572 "  --stat        show diffstat instead of patch.\n" \
 573 "  --numstat     show numeric diffstat instead of patch.\n" \
 574 "  --patch-with-stat\n" \
 575 "                output a patch and prepend its diffstat.\n" \
 576 "  --name-only   show only names of changed files.\n" \
 577 "  --name-status show names and status of changed files.\n" \
 578 "  --full-index  show full object name on index lines.\n" \
 579 "  --abbrev=<n>  abbreviate object names in diff-tree header and diff-raw.\n" \
 580 "  -R            swap input file pairs.\n" \
 581 "  -B            detect complete rewrites.\n" \
 582 "  -M            detect renames.\n" \
 583 "  -C            detect copies.\n" \
 584 "  --find-copies-harder\n" \
 585 "                try unchanged files as candidate for copy detection.\n" \
 586 "  -l<n>         limit rename attempts up to <n> paths.\n" \
 587 "  -O<file>      reorder diffs according to the <file>.\n" \
 588 "  -S<string>    find filepair whose only one side contains the string.\n" \
 589 "  --pickaxe-all\n" \
 590 "                show all files diff when -S is used and hit is found.\n" \
 591 "  -a  --text    treat all files as text.\n"
 592
 593 int diff_queue_is_empty(void);
 594 void diff_flush(struct diff_options*);
 595 void diff_free(struct diff_options*);
 596 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc);
 597
 598 /* diff-raw status letters */
 599 #define DIFF_STATUS_ADDED               'A'
 600 #define DIFF_STATUS_COPIED              'C'
 601 #define DIFF_STATUS_DELETED             'D'
 602 #define DIFF_STATUS_MODIFIED            'M'
 603 #define DIFF_STATUS_RENAMED             'R'
 604 #define DIFF_STATUS_TYPE_CHANGED        'T'
 605 #define DIFF_STATUS_UNKNOWN             'X'
 606 #define DIFF_STATUS_UNMERGED            'U'
 607
 608 /* these are not diff-raw status letters proper, but used by
 609  * diffcore-filter insn to specify additional restrictions.
 610  */
 611 #define DIFF_STATUS_FILTER_AON          '*'
 612 #define DIFF_STATUS_FILTER_BROKEN       'B'
 613
 614 /*
 615  * This is different from find_unique_abbrev() in that
 616  * it stuffs the result with dots for alignment.
 617  */
 618 const char *diff_aligned_abbrev(const struct object_id *sha1, int);
 619
 620 void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb);
 621
 622 /* do not report anything on removed paths */
 623 #define DIFF_SILENT_ON_REMOVED 01
 624 /* report racily-clean paths as modified */
 625 #define DIFF_RACY_IS_MODIFIED 02
 626 int run_diff_files(struct rev_info *revs, unsigned int option);
 627
 628 #define DIFF_INDEX_CACHED 01
 629 #define DIFF_INDEX_MERGE_BASE 02
 630 int run_diff_index(struct rev_info *revs, unsigned int option);
 631
 632 int do_diff_cache(const struct object_id *, struct diff_options *);
 633 int diff_flush_patch_id(struct diff_options *, struct object_id *, int, int);
 634 void flush_one_hunk(struct object_id *result, git_hash_ctx *ctx);
 635
 636 int diff_result_code(struct diff_options *, int);
 637
 638 int diff_no_index(struct rev_info *,
 639                   int implicit_no_index, int, const char **);
 640
 641 int index_differs_from(struct repository *r, const char *def,
 642                        const struct diff_flags *flags,
 643                        int ita_invisible_in_index);
 644
 645 /*
 646  * Emit an interdiff of two object ID's to 'diff_options.file' optionally
 647  * indented by 'indent' spaces.
 648  */
 649 void show_interdiff(const struct object_id *, const struct object_id *,
 650                     int indent, struct diff_options *);
 651
 652 /*
 653  * Fill the contents of the filespec "df", respecting any textconv defined by
 654  * its userdiff driver.  The "driver" parameter must come from a
 655  * previous call to get_textconv(), and therefore should either be NULL or have
 656  * textconv enabled.
 657  *
 658  * Note that the memory ownership of the resulting buffer depends on whether
 659  * the driver field is NULL. If it is, then the memory belongs to the filespec
 660  * struct. If it is non-NULL, then "outbuf" points to a newly allocated buffer
 661  * that should be freed by the caller.
 662  */
 663 size_t fill_textconv(struct repository *r,
 664                      struct userdiff_driver *driver,
 665                      struct diff_filespec *df,
 666                      char **outbuf);
 667
 668 /*
 669  * Look up the userdiff driver for the given filespec, and return it if
 670  * and only if it has textconv enabled (otherwise return NULL). The result
 671  * can be passed to fill_textconv().
 672  */
 673 struct userdiff_driver *get_textconv(struct repository *r,
 674                                      struct diff_filespec *one);
 675
 676 /*
 677  * Prepare diff_filespec and convert it using diff textconv API
 678  * if the textconv driver exists.
 679  * Return 1 if the conversion succeeds, 0 otherwise.
 680  */
 681 int textconv_object(struct repository *repo,
 682                     const char *path,
 683                     unsigned mode,
 684                     const struct object_id *oid, int oid_valid,
 685                     char **buf, unsigned long *buf_size);
 686
 687 int parse_rename_score(const char **cp_p);
 688
 689 long parse_algorithm_value(const char *value);
 690
 691 void print_stat_summary(FILE *fp, int files,
 692                         int insertions, int deletions);
 693 void setup_diff_pager(struct diff_options *);
 694
 695 #endif /* DIFF_H */