userdiff.c

   1 #define USE_THE_REPOSITORY_VARIABLE
   2 #define DISABLE_SIGN_COMPARE_WARNINGS
   3
   4 #include "git-compat-util.h"
   5 #include "config.h"
   6 #include "userdiff.h"
   7 #include "attr.h"
   8 #include "strbuf.h"
   9 #include "environment.h"
  10
  11 static struct userdiff_driver *drivers;
  12 static int ndrivers;
  13 static int drivers_alloc;
  14
  15 #define PATTERNS(lang, rx, wrx) { \
  16         .name = lang, \
  17         .binary = -1, \
  18         .funcname = { \
  19                 .pattern = rx, \
  20                 .cflags = REG_EXTENDED, \
  21         }, \
  22         .word_regex = wrx "|[^[:space:]]|[\xc0-\xff][\x80-\xbf]+", \
  23         .word_regex_multi_byte = wrx "|[^[:space:]]", \
  24 }
  25 #define IPATTERN(lang, rx, wrx) { \
  26         .name = lang, \
  27         .binary = -1, \
  28         .funcname = { \
  29                 .pattern = rx, \
  30                 .cflags = REG_EXTENDED | REG_ICASE, \
  31         }, \
  32         .word_regex = wrx "|[^[:space:]]|[\xc0-\xff][\x80-\xbf]+", \
  33         .word_regex_multi_byte = wrx "|[^[:space:]]", \
  34 }
  35
  36 /*
  37  * Built-in drivers for various languages, sorted by their names
  38  * (except that the "default" is left at the end).
  39  *
  40  * When writing or updating patterns, assume that the contents these
  41  * patterns are applied to are syntactically correct.  The patterns
  42  * can be simple without implementing all syntactical corner cases, as
  43  * long as they are sufficiently permissive.
  44  */
  45 static struct userdiff_driver builtin_drivers[] = {
  46 IPATTERN("ada",
  47          "!^(.*[ \t])?(is[ \t]+new|renames|is[ \t]+separate)([ \t].*)?$\n"
  48          "!^[ \t]*with[ \t].*$\n"
  49          "^[ \t]*((procedure|function)[ \t]+.*)$\n"
  50          "^[ \t]*((package|protected|task)[ \t]+.*)$",
  51          /* -- */
  52          "[a-zA-Z][a-zA-Z0-9_]*"
  53          "|[-+]?[0-9][0-9#_.aAbBcCdDeEfF]*([eE][+-]?[0-9_]+)?"
  54          "|=>|\\.\\.|\\*\\*|:=|/=|>=|<=|<<|>>|<>"),
  55 PATTERNS("bash",
  56          /* Optional leading indentation */
  57          "^[ \t]*"
  58          /* Start of captured text */
  59          "("
  60          "("
  61              /* POSIX identifier with mandatory parentheses */
  62              "([a-zA-Z_][a-zA-Z0-9_]*[ \t]*\\([ \t]*\\))"
  63          "|"
  64              /* Bashism identifier with optional parentheses */
  65              "(function[ \t]+[a-zA-Z_][a-zA-Z0-9_]*(([ \t]*\\([ \t]*\\))|([ \t]+)))"
  66          ")"
  67          /* Everything after the function header is captured  */
  68          ".*$"
  69          /* End of captured text */
  70          ")",
  71          /* -- */
  72          /* Identifiers: variable and function names */
  73           "[a-zA-Z_][a-zA-Z0-9_]*"
  74          /* Shell variables: $VAR, ${VAR} */
  75           "|\\$[a-zA-Z0-9_]+|\\$\\{"
  76           /*Command list separators and redirection operators  */
  77          "|\\|\\||&&|<<|>>"
  78          /* Operators ending in '=' (comparison + compound assignment) */
  79          "|==|!=|<=|>=|[-+*/%&|^]="
  80          /* Additional parameter expansion operators */
  81          "|:=|:-|:\\+|:\\?|##|%%|\\^\\^|,,"
  82          /* Command-line options (to avoid splitting -option) */
  83          "|[-a-zA-Z0-9_]+"
  84          /* Brackets and grouping symbols */
  85          "|\\(|\\)|\\{|\\}|\\[|\\]"),
  86 PATTERNS("bibtex",
  87          "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
  88          /* -- */
  89          "[={}\"]|[^={}\" \t]+"),
  90 PATTERNS("cpp",
  91          /* Jump targets or access declarations */
  92          "!^[ \t]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*])\n"
  93          /* functions/methods, variables, and compounds at top level */
  94          "^((::[[:space:]]*)?[A-Za-z_].*)$",
  95          /* -- */
  96          /* identifiers and keywords */
  97          "[a-zA-Z_][a-zA-Z0-9_]*"
  98          /* decimal and octal integers as well as floatingpoint numbers */
  99          "|[0-9][0-9.]*([Ee][-+]?[0-9]+)?[fFlLuU]*"
 100          /* hexadecimal and binary integers */
 101          "|0[xXbB][0-9a-fA-F]+[lLuU]*"
 102          /* floatingpoint numbers that begin with a decimal point */
 103          "|\\.[0-9][0-9]*([Ee][-+]?[0-9]+)?[fFlL]?"
 104          "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->\\*?|\\.\\*|<=>"),
 105 PATTERNS("csharp",
 106          /*
 107           * Jump over reserved keywords which are illegal method names, but which
 108           * can be followed by parentheses without special characters in between,
 109           * making them look like methods.
 110           */
 111          "!(^|[ \t]+)" /* Start of line or whitespace. */
 112                 "(do|while|for|foreach|if|else|new|default|return|switch|case|throw"
 113                 "|catch|using|lock|fixed)"
 114                 "([ \t(]+|$)\n" /* Whitespace, "(", or end of line. */
 115          /*
 116           * Methods/constructors:
 117           * The strategy is to identify a minimum of two groups (any combination
 118           * of keywords/type/name) before the opening parenthesis, and without
 119           * final unexpected characters, normally only used in ordinary statements.
 120           */
 121          "^[ \t]*" /* Remove leading whitespace. */
 122                 "(" /* Start chunk header capture. */
 123                 "(" /* First group. */
 124                         "[][[:alnum:]@_.]" /* Name. */
 125                         "(<[][[:alnum:]@_, \t<>]+>)?" /* Optional generic parameters. */
 126                 ")+"
 127                 "([ \t]+" /* Subsequent groups, prepended with space. */
 128                         "([][[:alnum:]@_.](<[][[:alnum:]@_, \t<>]+>)?)+"
 129                 ")+"
 130                 "[ \t]*" /* Optional space before parameters start. */
 131                 "\\(" /* Start of method parameters. */
 132                 "[^;]*" /* Allow complex parameters, but exclude statements (;). */
 133                 ")$\n" /* Close chunk header capture. */
 134          /*
 135           * Properties:
 136           * As with methods, expect a minimum of two groups. But, more trivial than
 137           * methods, the vast majority of properties long enough to be worth
 138           * showing a chunk header for don't include "=:;,()" on the line they are
 139           * defined, since they don't have a parameter list.
 140           */
 141          "^[ \t]*("
 142                 "([][[:alnum:]@_.](<[][[:alnum:]@_, \t<>]+>)?)+"
 143                 "([ \t]+"
 144                         "([][[:alnum:]@_.](<[][[:alnum:]@_, \t<>]+>)?)+"
 145                 ")+" /* Up to here, same as methods regex. */
 146                 "[^;=:,()]*" /* Compared to methods, no parameter list allowed. */
 147                 ")$\n"
 148          /* Type definitions */
 149          "^[ \t]*(((static|public|internal|private|protected|new|unsafe|sealed|abstract|partial)[ \t]+)*(class|enum|interface|struct|record)[ \t]+.*)$\n"
 150          /* Namespace */
 151          "^[ \t]*(namespace[ \t]+.*)$",
 152          /* -- */
 153          "[a-zA-Z_][a-zA-Z0-9_]*"
 154          "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
 155          "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
 156 IPATTERN("css",
 157          "![:;][[:space:]]*$\n"
 158          "^[:[@.#]?[_a-z0-9].*$",
 159          /* -- */
 160          /*
 161           * This regex comes from W3C CSS specs. Should theoretically also
 162           * allow ISO 10646 characters U+00A0 and higher,
 163           * but they are not handled in this regex.
 164           */
 165          "-?[_a-zA-Z][-_a-zA-Z0-9]*" /* identifiers */
 166          "|-?[0-9]+|\\#[0-9a-fA-F]+" /* numbers */
 167 ),
 168 PATTERNS("dts",
 169          "!;\n"
 170          "!=\n"
 171          /* lines beginning with a word optionally preceded by '&' or the root */
 172          "^[ \t]*((/[ \t]*\\{|&?[a-zA-Z_]).*)",
 173          /* -- */
 174          /* Property names and math operators */
 175          "[a-zA-Z0-9,._+?#-]+"
 176          "|[-+*/%&^|!~]|>>|<<|&&|\\|\\|"),
 177 PATTERNS("elixir",
 178          "^[ \t]*((def(macro|module|impl|protocol|p)?|test)[ \t].*)$",
 179          /* -- */
 180          /* Atoms, names, and module attributes */
 181          "[@:]?[a-zA-Z0-9@_?!]+"
 182          /* Numbers with specific base */
 183          "|[-+]?0[xob][0-9a-fA-F]+"
 184          /* Numbers */
 185          "|[-+]?[0-9][0-9_.]*([eE][-+]?[0-9_]+)?"
 186          /* Operators and atoms that represent them */
 187          "|:?(\\+\\+|--|\\.\\.|~~~|<>|\\^\\^\\^|<?\\|>|<<<?|>?>>|<<?~|~>?>|<~>|<=|>=|===?|!==?|=~|&&&?|\\|\\|\\|?|=>|<-|\\\\\\\\|->)"
 188          /* Not real operators, but should be grouped */
 189          "|:?%[A-Za-z0-9_.]\\{\\}?"),
 190 IPATTERN("fortran",
 191          /* Don't match comment lines */
 192          "!^([C*]|[ \t]*!)\n"
 193          /* Don't match 'module procedure' lines */
 194          "!^[ \t]*MODULE[ \t]+PROCEDURE[ \t]\n"
 195          /* Program, module, block data */
 196          "^[ \t]*((END[ \t]+)?(PROGRAM|MODULE|BLOCK[ \t]+DATA"
 197                 /* Subroutines and functions */
 198                 "|([^!'\" \t]+[ \t]+)*(SUBROUTINE|FUNCTION))[ \t]+[A-Z].*)$",
 199          /* -- */
 200          "[a-zA-Z][a-zA-Z0-9_]*"
 201          "|\\.([Ee][Qq]|[Nn][Ee]|[Gg][TtEe]|[Ll][TtEe]|[Tt][Rr][Uu][Ee]|[Ff][Aa][Ll][Ss][Ee]|[Aa][Nn][Dd]|[Oo][Rr]|[Nn]?[Ee][Qq][Vv]|[Nn][Oo][Tt])\\."
 202          /* numbers and format statements like 2E14.4, or ES12.6, 9X.
 203           * Don't worry about format statements without leading digits since
 204           * they would have been matched above as a variable anyway. */
 205          "|[-+]?[0-9.]+([AaIiDdEeFfLlTtXx][Ss]?[-+]?[0-9.]*)?(_[a-zA-Z0-9][a-zA-Z0-9_]*)?"
 206          "|//|\\*\\*|::|[/<>=]="),
 207 IPATTERN("fountain",
 208          "^((\\.[^.]|(int|ext|est|int\\.?/ext|i/e)[. ]).*)$",
 209          /* -- */
 210          "[^ \t-]+"),
 211 PATTERNS("golang",
 212          /* Functions */
 213          "^[ \t]*(func[ \t]*.*(\\{[ \t]*)?)\n"
 214          /* Structs and interfaces */
 215          "^[ \t]*(type[ \t].*(struct|interface)[ \t]*(\\{[ \t]*)?)",
 216          /* -- */
 217          "[a-zA-Z_][a-zA-Z0-9_]*"
 218          "|[-+0-9.eE]+i?|0[xX]?[0-9a-fA-F]+i?"
 219          "|[-+*/<>%&^|=!:]=|--|\\+\\+|<<=?|>>=?|&\\^=?|&&|\\|\\||<-|\\.{3}"),
 220 PATTERNS("html",
 221          "^[ \t]*(<[Hh][1-6]([ \t].*)?>.*)$",
 222          /* -- */
 223          "[^<>= \t]+"),
 224 PATTERNS("ini",
 225          "^[ \t]*\\[[^]]+\\]",
 226          /* -- */
 227          "[^ \t]+"),
 228 PATTERNS("java",
 229          "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
 230          /* Class, enum, interface, and record declarations */
 231          "^[ \t]*(([a-z-]+[ \t]+)*(class|enum|interface|record)[ \t]+.*)$\n"
 232          /* Method definitions; note that constructor signatures are not */
 233          /* matched because they are indistinguishable from method calls. */
 234          "^[ \t]*(([A-Za-z_<>&][][?&<>.,A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$",
 235          /* -- */
 236          "[a-zA-Z_][a-zA-Z0-9_]*"
 237          "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
 238          "|[-+*/<>%&^|=!]="
 239          "|--|\\+\\+|<<=?|>>>?=?|&&|\\|\\|"),
 240 PATTERNS("kotlin",
 241          "^[ \t]*(([a-z]+[ \t]+)*(fun|class|interface)[ \t]+.*)$",
 242          /* -- */
 243          "[a-zA-Z_][a-zA-Z0-9_]*"
 244          /* hexadecimal and binary numbers */
 245          "|0[xXbB][0-9a-fA-F_]+[lLuU]*"
 246          /* integers and floats */
 247          "|[0-9][0-9_]*([.][0-9_]*)?([Ee][-+]?[0-9]+)?[fFlLuU]*"
 248          /* floating point numbers beginning with decimal point */
 249          "|[.][0-9][0-9_]*([Ee][-+]?[0-9]+)?[fFlLuU]?"
 250          /* unary and binary operators */
 251          "|[-+*/<>%&^|=!]==?|--|\\+\\+|<<=|>>=|&&|\\|\\||->|\\.\\*|!!|[?:.][.:]"),
 252 PATTERNS("markdown",
 253          "^ {0,3}#{1,6}[ \t].*",
 254          /* -- */
 255          "[^<>= \t]+"),
 256 PATTERNS("matlab",
 257          /*
 258           * Octave pattern is mostly the same as matlab, except that '%%%' and
 259           * '##' can also be used to begin code sections, in addition to '%%'
 260           * that is understood by both.
 261           */
 262          "^[[:space:]]*((classdef|function)[[:space:]].*)$|^(%%%?|##)[[:space:]].*$",
 263          /* -- */
 264          "[a-zA-Z_][a-zA-Z0-9_]*|[-+0-9.e]+|[=~<>]=|\\.[*/\\^']|\\|\\||&&"),
 265 PATTERNS("objc",
 266          /* Negate C statements that can look like functions */
 267          "!^[ \t]*(do|for|if|else|return|switch|while)\n"
 268          /* Objective-C methods */
 269          "^[ \t]*([-+][ \t]*\\([ \t]*[A-Za-z_][A-Za-z_0-9* \t]*\\)[ \t]*[A-Za-z_].*)$\n"
 270          /* C functions */
 271          "^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$\n"
 272          /* Objective-C class/protocol definitions */
 273          "^(@(implementation|interface|protocol)[ \t].*)$",
 274          /* -- */
 275          "[a-zA-Z_][a-zA-Z0-9_]*"
 276          "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
 277          "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
 278 PATTERNS("pascal",
 279          "^(((class[ \t]+)?(procedure|function)|constructor|destructor|interface"
 280          "|implementation|initialization|finalization)[ \t]*.*)$\n"
 281          "^(.*=[ \t]*(class|record).*)$",
 282          /* -- */
 283          "[a-zA-Z_][a-zA-Z0-9_]*"
 284          "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
 285          "|<>|<=|>=|:=|\\.\\."),
 286 PATTERNS("perl",
 287          "^package .*\n"
 288          "^sub [[:alnum:]_':]+[ \t]*"
 289                 "(\\([^)]*\\)[ \t]*)?" /* prototype */
 290                 /*
 291                  * Attributes.  A regex can't count nested parentheses,
 292                  * so just slurp up whatever we see, taking care not
 293                  * to accept lines like "sub foo; # defined elsewhere".
 294                  *
 295                  * An attribute could contain a semicolon, but at that
 296                  * point it seems reasonable enough to give up.
 297                  */
 298                 "(:[^;#]*)?"
 299                 "(\\{[ \t]*)?" /* brace can come here or on the next line */
 300                 "(#.*)?$\n" /* comment */
 301          "^(BEGIN|END|INIT|CHECK|UNITCHECK|AUTOLOAD|DESTROY)[ \t]*"
 302                 "(\\{[ \t]*)?" /* brace can come here or on the next line */
 303                 "(#.*)?$\n"
 304          "^=head[0-9] .*",      /* POD */
 305          /* -- */
 306          "[[:alpha:]_'][[:alnum:]_']*"
 307          "|0[xb]?[0-9a-fA-F_]*"
 308          /* taking care not to interpret 3..5 as (3.)(.5) */
 309          "|[0-9a-fA-F_]+(\\.[0-9a-fA-F_]+)?([eE][-+]?[0-9_]+)?"
 310          "|=>|-[rwxoRWXOezsfdlpSugkbctTBMAC>]|~~|::"
 311          "|&&=|\\|\\|=|//=|\\*\\*="
 312          "|&&|\\|\\||//|\\+\\+|--|\\*\\*|\\.\\.\\.?"
 313          "|[-+*/%.^&<>=!|]="
 314          "|=~|!~"
 315          "|<<|<>|<=>|>>"),
 316 PATTERNS("php",
 317          "^[\t ]*(((public|protected|private|static|abstract|final)[\t ]+)*function.*)$\n"
 318          "^[\t ]*((((final|abstract)[\t ]+)?class|enum|interface|trait).*)$",
 319          /* -- */
 320          "[a-zA-Z_][a-zA-Z0-9_]*"
 321          "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
 322          "|[-+*/<>%&^|=!.]=|--|\\+\\+|<<=?|>>=?|===|&&|\\|\\||::|->"),
 323 PATTERNS("python",
 324          "^[ \t]*((class|(async[ \t]+)?def)[ \t].*)$",
 325          /* -- */
 326          "[a-zA-Z_][a-zA-Z0-9_]*"
 327          "|[-+0-9.e]+[jJlL]?|0[xX]?[0-9a-fA-F]+[lL]?"
 328          "|[-+*/<>%&^|=!]=|//=?|<<=?|>>=?|\\*\\*=?"),
 329          /* -- */
 330 PATTERNS("r",
 331         "^[ \t]*([a-zA-z][a-zA-Z0-9_.]*[ \t]*(<-|=)[ \t]*function.*)$",
 332         /* -- */
 333         "[^ \t]+"),
 334 PATTERNS("ruby",
 335          "^[ \t]*((class|module|def)[ \t].*)$",
 336          /* -- */
 337          "(@|@@|\\$)?[a-zA-Z_][a-zA-Z0-9_]*"
 338          "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+|\\?(\\\\C-)?(\\\\M-)?."
 339          "|//=?|[-+*/<>%&^|=!]=|<<=?|>>=?|===|\\.{1,3}|::|[!=]~"),
 340 PATTERNS("rust",
 341          "^[\t ]*((pub(\\([^\\)]+\\))?[\t ]+)?((async|const|unsafe|extern([\t ]+\"[^\"]+\"))[\t ]+)?(struct|enum|union|mod|trait|fn|impl|macro_rules!)[< \t]+[^;]*)$",
 342          /* -- */
 343          "[a-zA-Z_][a-zA-Z0-9_]*"
 344          "|[0-9][0-9_a-fA-Fiosuxz]*(\\.([0-9]*[eE][+-]?)?[0-9_fF]*)?"
 345          "|[-+*\\/<>%&^|=!:]=|<<=?|>>=?|&&|\\|\\||->|=>|\\.{2}=|\\.{3}|::"),
 346 PATTERNS("scheme",
 347          "^[\t ]*(\\(((define|def(struct|syntax|class|method|rules|record|proto|alias)?)[-*/ \t]|(library|module|struct|class)[*+ \t]).*)$",
 348          /*
 349           * R7RS valid identifiers include any sequence enclosed
 350           * within vertical lines having no backslashes
 351           */
 352          "\\|([^\\\\]*)\\|"
 353          /* All other words should be delimited by spaces or parentheses */
 354          "|([^][)(}{[ \t])+"),
 355 PATTERNS("tex", "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$",
 356          "\\\\[a-zA-Z@]+|\\\\.|([a-zA-Z0-9]|[^\x01-\x7f])+"),
 357 { .name = "default", .binary = -1 },
 358 };
 359 #undef PATTERNS
 360 #undef IPATTERN
 361
 362 static struct userdiff_driver driver_true = {
 363         .name = "diff=true",
 364         .binary = 0,
 365 };
 366
 367 static struct userdiff_driver driver_false = {
 368         .name = "!diff",
 369         .binary = 1,
 370 };
 371
 372 struct find_by_namelen_data {
 373         const char *name;
 374         size_t len;
 375         struct userdiff_driver *driver;
 376 };
 377
 378 static int userdiff_find_by_namelen_cb(struct userdiff_driver *driver,
 379                                        enum userdiff_driver_type type UNUSED,
 380                                        void *priv)
 381 {
 382         struct find_by_namelen_data *cb_data = priv;
 383
 384         if (!xstrncmpz(driver->name, cb_data->name, cb_data->len)) {
 385                 cb_data->driver = driver;
 386                 return 1; /* tell the caller to stop iterating */
 387         }
 388         return 0;
 389 }
 390
 391 static int regexec_supports_multi_byte_chars(void)
 392 {
 393         static const char not_space[] = "[^[:space:]]";
 394         static const char utf8_multi_byte_char[] = "\xc2\xa3";
 395         regex_t re;
 396         regmatch_t match;
 397         static int result = -1;
 398
 399         if (result != -1)
 400                 return result;
 401         if (regcomp(&re, not_space, REG_EXTENDED))
 402                 BUG("invalid regular expression: %s", not_space);
 403         result = !regexec(&re, utf8_multi_byte_char, 1, &match, 0) &&
 404                 match.rm_so == 0 &&
 405                 match.rm_eo == strlen(utf8_multi_byte_char);
 406         regfree(&re);
 407         return result;
 408 }
 409
 410 static struct userdiff_driver *userdiff_find_by_namelen(const char *name, size_t len)
 411 {
 412         struct find_by_namelen_data udcbdata = {
 413                 .name = name,
 414                 .len = len,
 415         };
 416         for_each_userdiff_driver(userdiff_find_by_namelen_cb, &udcbdata);
 417         return udcbdata.driver;
 418 }
 419
 420 static int parse_funcname(struct userdiff_funcname *f, const char *k,
 421                 const char *v, int cflags)
 422 {
 423         f->pattern = NULL;
 424         FREE_AND_NULL(f->pattern_owned);
 425         if (git_config_string(&f->pattern_owned, k, v) < 0)
 426                 return -1;
 427         f->pattern = f->pattern_owned;
 428         f->cflags = cflags;
 429         return 0;
 430 }
 431
 432 static int parse_tristate(int *b, const char *k, const char *v)
 433 {
 434         if (v && !strcasecmp(v, "auto"))
 435                 *b = -1;
 436         else
 437                 *b = git_config_bool(k, v);
 438         return 0;
 439 }
 440
 441 static int parse_bool(int *b, const char *k, const char *v)
 442 {
 443         *b = git_config_bool(k, v);
 444         return 0;
 445 }
 446
 447 int userdiff_config(const char *k, const char *v)
 448 {
 449         struct userdiff_driver *drv;
 450         const char *name, *type;
 451         size_t namelen;
 452
 453         if (parse_config_key(k, "diff", &name, &namelen, &type) || !name)
 454                 return 0;
 455
 456         drv = userdiff_find_by_namelen(name, namelen);
 457         if (!drv) {
 458                 ALLOC_GROW(drivers, ndrivers+1, drivers_alloc);
 459                 drv = &drivers[ndrivers++];
 460                 memset(drv, 0, sizeof(*drv));
 461                 drv->name = xmemdupz(name, namelen);
 462                 drv->binary = -1;
 463         }
 464
 465         if (!strcmp(type, "funcname"))
 466                 return parse_funcname(&drv->funcname, k, v, 0);
 467         if (!strcmp(type, "xfuncname"))
 468                 return parse_funcname(&drv->funcname, k, v, REG_EXTENDED);
 469         if (!strcmp(type, "binary"))
 470                 return parse_tristate(&drv->binary, k, v);
 471         if (!strcmp(type, "command")) {
 472                 FREE_AND_NULL(drv->external.cmd);
 473                 return git_config_string(&drv->external.cmd, k, v);
 474         }
 475         if (!strcmp(type, "trustexitcode")) {
 476                 drv->external.trust_exit_code = git_config_bool(k, v);
 477                 return 0;
 478         }
 479         if (!strcmp(type, "textconv")) {
 480                 int ret;
 481                 FREE_AND_NULL(drv->textconv_owned);
 482                 ret = git_config_string(&drv->textconv_owned, k, v);
 483                 drv->textconv = drv->textconv_owned;
 484                 return ret;
 485         }
 486         if (!strcmp(type, "cachetextconv"))
 487                 return parse_bool(&drv->textconv_want_cache, k, v);
 488         if (!strcmp(type, "wordregex")) {
 489                 int ret;
 490                 FREE_AND_NULL(drv->word_regex_owned);
 491                 ret = git_config_string(&drv->word_regex_owned, k, v);
 492                 drv->word_regex = drv->word_regex_owned;
 493                 return ret;
 494         }
 495         if (!strcmp(type, "algorithm")) {
 496                 int ret;
 497                 FREE_AND_NULL(drv->algorithm_owned);
 498                 ret = git_config_string(&drv->algorithm_owned, k, v);
 499                 drv->algorithm = drv->algorithm_owned;
 500                 return ret;
 501         }
 502
 503         return 0;
 504 }
 505
 506 struct userdiff_driver *userdiff_find_by_name(const char *name)
 507 {
 508         int len = strlen(name);
 509         struct userdiff_driver *driver = userdiff_find_by_namelen(name, len);
 510         if (driver && driver->word_regex_multi_byte) {
 511                 if (regexec_supports_multi_byte_chars())
 512                         driver->word_regex = driver->word_regex_multi_byte;
 513                 driver->word_regex_multi_byte = NULL;
 514         }
 515         return driver;
 516 }
 517
 518 struct userdiff_driver *userdiff_find_by_path(struct index_state *istate,
 519                                               const char *path)
 520 {
 521         static struct attr_check *check;
 522
 523         if (!check)
 524                 check = attr_check_initl("diff", NULL);
 525         if (!path)
 526                 return NULL;
 527         git_check_attr(istate, path, check);
 528
 529         if (ATTR_TRUE(check->items[0].value))
 530                 return &driver_true;
 531         if (ATTR_FALSE(check->items[0].value))
 532                 return &driver_false;
 533         if (ATTR_UNSET(check->items[0].value))
 534                 return NULL;
 535         return userdiff_find_by_name(check->items[0].value);
 536 }
 537
 538 struct userdiff_driver *userdiff_get_textconv(struct repository *r,
 539                                               struct userdiff_driver *driver)
 540 {
 541         if (!driver->textconv)
 542                 return NULL;
 543
 544         if (driver->textconv_want_cache && !driver->textconv_cache &&
 545             have_git_dir()) {
 546                 struct notes_cache *c = xmalloc(sizeof(*c));
 547                 struct strbuf name = STRBUF_INIT;
 548
 549                 strbuf_addf(&name, "textconv/%s", driver->name);
 550                 notes_cache_init(r, c, name.buf, driver->textconv);
 551                 driver->textconv_cache = c;
 552                 strbuf_release(&name);
 553         }
 554
 555         return driver;
 556 }
 557
 558 static int for_each_userdiff_driver_list(each_userdiff_driver_fn fn,
 559                                          enum userdiff_driver_type type, void *cb_data,
 560                                          struct userdiff_driver *drv,
 561                                          int drv_size)
 562 {
 563         int i;
 564         int ret;
 565         for (i = 0; i < drv_size; i++) {
 566                 struct userdiff_driver *item = drv + i;
 567                 if ((ret = fn(item, type, cb_data)))
 568                         return ret;
 569         }
 570         return 0;
 571 }
 572
 573 int for_each_userdiff_driver(each_userdiff_driver_fn fn, void *cb_data)
 574 {
 575         int ret;
 576
 577         ret = for_each_userdiff_driver_list(fn, USERDIFF_DRIVER_TYPE_CUSTOM,
 578                                             cb_data, drivers, ndrivers);
 579         if (ret)
 580                 return ret;
 581
 582         ret = for_each_userdiff_driver_list(fn, USERDIFF_DRIVER_TYPE_BUILTIN,
 583                                             cb_data, builtin_drivers,
 584                                             ARRAY_SIZE(builtin_drivers));
 585         if (ret)
 586                 return ret;
 587
 588         return 0;
 589 }