ws.con commit doc: rewrite description for rev-parse --short (fb87327)
   1/*
   2 * Whitespace rules
   3 *
   4 * Copyright (c) 2007 Junio C Hamano
   5 */
   6
   7#include "cache.h"
   8#include "attr.h"
   9
  10static struct whitespace_rule {
  11        const char *rule_name;
  12        unsigned rule_bits;
  13        unsigned loosens_error:1,
  14                exclude_default:1;
  15} whitespace_rule_names[] = {
  16        { "trailing-space", WS_TRAILING_SPACE, 0 },
  17        { "space-before-tab", WS_SPACE_BEFORE_TAB, 0 },
  18        { "indent-with-non-tab", WS_INDENT_WITH_NON_TAB, 0 },
  19        { "cr-at-eol", WS_CR_AT_EOL, 1 },
  20        { "blank-at-eol", WS_BLANK_AT_EOL, 0 },
  21        { "blank-at-eof", WS_BLANK_AT_EOF, 0 },
  22        { "tab-in-indent", WS_TAB_IN_INDENT, 0, 1 },
  23};
  24
  25unsigned parse_whitespace_rule(const char *string)
  26{
  27        unsigned rule = WS_DEFAULT_RULE;
  28
  29        while (string) {
  30                int i;
  31                size_t len;
  32                const char *ep;
  33                int negated = 0;
  34
  35                string = string + strspn(string, ", \t\n\r");
  36                ep = strchrnul(string, ',');
  37                len = ep - string;
  38
  39                if (*string == '-') {
  40                        negated = 1;
  41                        string++;
  42                        len--;
  43                }
  44                if (!len)
  45                        break;
  46                for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
  47                        if (strncmp(whitespace_rule_names[i].rule_name,
  48                                    string, len))
  49                                continue;
  50                        if (negated)
  51                                rule &= ~whitespace_rule_names[i].rule_bits;
  52                        else
  53                                rule |= whitespace_rule_names[i].rule_bits;
  54                        break;
  55                }
  56                if (strncmp(string, "tabwidth=", 9) == 0) {
  57                        unsigned tabwidth = atoi(string + 9);
  58                        if (0 < tabwidth && tabwidth < 0100) {
  59                                rule &= ~WS_TAB_WIDTH_MASK;
  60                                rule |= tabwidth;
  61                        }
  62                        else
  63                                warning("tabwidth %.*s out of range",
  64                                        (int)(len - 9), string + 9);
  65                }
  66                string = ep;
  67        }
  68
  69        if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
  70                die("cannot enforce both tab-in-indent and indent-with-non-tab");
  71        return rule;
  72}
  73
  74unsigned whitespace_rule(const char *pathname)
  75{
  76        static struct attr_check *attr_whitespace_rule;
  77
  78        if (!attr_whitespace_rule)
  79                attr_whitespace_rule = attr_check_initl("whitespace", NULL);
  80
  81        if (!git_check_attr(pathname, attr_whitespace_rule)) {
  82                const char *value;
  83
  84                value = attr_whitespace_rule->items[0].value;
  85                if (ATTR_TRUE(value)) {
  86                        /* true (whitespace) */
  87                        unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
  88                        int i;
  89                        for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
  90                                if (!whitespace_rule_names[i].loosens_error &&
  91                                    !whitespace_rule_names[i].exclude_default)
  92                                        all_rule |= whitespace_rule_names[i].rule_bits;
  93                        return all_rule;
  94                } else if (ATTR_FALSE(value)) {
  95                        /* false (-whitespace) */
  96                        return ws_tab_width(whitespace_rule_cfg);
  97                } else if (ATTR_UNSET(value)) {
  98                        /* reset to default (!whitespace) */
  99                        return whitespace_rule_cfg;
 100                } else {
 101                        /* string */
 102                        return parse_whitespace_rule(value);
 103                }
 104        } else {
 105                return whitespace_rule_cfg;
 106        }
 107}
 108
 109/* The returned string should be freed by the caller. */
 110char *whitespace_error_string(unsigned ws)
 111{
 112        struct strbuf err = STRBUF_INIT;
 113        if ((ws & WS_TRAILING_SPACE) == WS_TRAILING_SPACE)
 114                strbuf_addstr(&err, "trailing whitespace");
 115        else {
 116                if (ws & WS_BLANK_AT_EOL)
 117                        strbuf_addstr(&err, "trailing whitespace");
 118                if (ws & WS_BLANK_AT_EOF) {
 119                        if (err.len)
 120                                strbuf_addstr(&err, ", ");
 121                        strbuf_addstr(&err, "new blank line at EOF");
 122                }
 123        }
 124        if (ws & WS_SPACE_BEFORE_TAB) {
 125                if (err.len)
 126                        strbuf_addstr(&err, ", ");
 127                strbuf_addstr(&err, "space before tab in indent");
 128        }
 129        if (ws & WS_INDENT_WITH_NON_TAB) {
 130                if (err.len)
 131                        strbuf_addstr(&err, ", ");
 132                strbuf_addstr(&err, "indent with spaces");
 133        }
 134        if (ws & WS_TAB_IN_INDENT) {
 135                if (err.len)
 136                        strbuf_addstr(&err, ", ");
 137                strbuf_addstr(&err, "tab in indent");
 138        }
 139        return strbuf_detach(&err, NULL);
 140}
 141
 142/* If stream is non-NULL, emits the line after checking. */
 143static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
 144                                FILE *stream, const char *set,
 145                                const char *reset, const char *ws)
 146{
 147        unsigned result = 0;
 148        int written = 0;
 149        int trailing_whitespace = -1;
 150        int trailing_newline = 0;
 151        int trailing_carriage_return = 0;
 152        int i;
 153
 154        /* Logic is simpler if we temporarily ignore the trailing newline. */
 155        if (len > 0 && line[len - 1] == '\n') {
 156                trailing_newline = 1;
 157                len--;
 158        }
 159        if ((ws_rule & WS_CR_AT_EOL) &&
 160            len > 0 && line[len - 1] == '\r') {
 161                trailing_carriage_return = 1;
 162                len--;
 163        }
 164
 165        /* Check for trailing whitespace. */
 166        if (ws_rule & WS_BLANK_AT_EOL) {
 167                for (i = len - 1; i >= 0; i--) {
 168                        if (isspace(line[i])) {
 169                                trailing_whitespace = i;
 170                                result |= WS_BLANK_AT_EOL;
 171                        }
 172                        else
 173                                break;
 174                }
 175        }
 176
 177        if (trailing_whitespace == -1)
 178                trailing_whitespace = len;
 179
 180        /* Check indentation */
 181        for (i = 0; i < trailing_whitespace; i++) {
 182                if (line[i] == ' ')
 183                        continue;
 184                if (line[i] != '\t')
 185                        break;
 186                if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
 187                        result |= WS_SPACE_BEFORE_TAB;
 188                        if (stream) {
 189                                fputs(ws, stream);
 190                                fwrite(line + written, i - written, 1, stream);
 191                                fputs(reset, stream);
 192                                fwrite(line + i, 1, 1, stream);
 193                        }
 194                } else if (ws_rule & WS_TAB_IN_INDENT) {
 195                        result |= WS_TAB_IN_INDENT;
 196                        if (stream) {
 197                                fwrite(line + written, i - written, 1, stream);
 198                                fputs(ws, stream);
 199                                fwrite(line + i, 1, 1, stream);
 200                                fputs(reset, stream);
 201                        }
 202                } else if (stream) {
 203                        fwrite(line + written, i - written + 1, 1, stream);
 204                }
 205                written = i + 1;
 206        }
 207
 208        /* Check for indent using non-tab. */
 209        if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= ws_tab_width(ws_rule)) {
 210                result |= WS_INDENT_WITH_NON_TAB;
 211                if (stream) {
 212                        fputs(ws, stream);
 213                        fwrite(line + written, i - written, 1, stream);
 214                        fputs(reset, stream);
 215                }
 216                written = i;
 217        }
 218
 219        if (stream) {
 220                /*
 221                 * Now the rest of the line starts at "written".
 222                 * The non-highlighted part ends at "trailing_whitespace".
 223                 */
 224
 225                /* Emit non-highlighted (middle) segment. */
 226                if (trailing_whitespace - written > 0) {
 227                        fputs(set, stream);
 228                        fwrite(line + written,
 229                            trailing_whitespace - written, 1, stream);
 230                        fputs(reset, stream);
 231                }
 232
 233                /* Highlight errors in trailing whitespace. */
 234                if (trailing_whitespace != len) {
 235                        fputs(ws, stream);
 236                        fwrite(line + trailing_whitespace,
 237                            len - trailing_whitespace, 1, stream);
 238                        fputs(reset, stream);
 239                }
 240                if (trailing_carriage_return)
 241                        fputc('\r', stream);
 242                if (trailing_newline)
 243                        fputc('\n', stream);
 244        }
 245        return result;
 246}
 247
 248void ws_check_emit(const char *line, int len, unsigned ws_rule,
 249                   FILE *stream, const char *set,
 250                   const char *reset, const char *ws)
 251{
 252        (void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
 253}
 254
 255unsigned ws_check(const char *line, int len, unsigned ws_rule)
 256{
 257        return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
 258}
 259
 260int ws_blank_line(const char *line, int len, unsigned ws_rule)
 261{
 262        /*
 263         * We _might_ want to treat CR differently from other
 264         * whitespace characters when ws_rule has WS_CR_AT_EOL, but
 265         * for now we just use this stupid definition.
 266         */
 267        while (len-- > 0) {
 268                if (!isspace(*line))
 269                        return 0;
 270                line++;
 271        }
 272        return 1;
 273}
 274
 275/* Copy the line onto the end of the strbuf while fixing whitespaces */
 276void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule, int *error_count)
 277{
 278        /*
 279         * len is number of bytes to be copied from src, starting
 280         * at src.  Typically src[len-1] is '\n', unless this is
 281         * the incomplete last line.
 282         */
 283        int i;
 284        int add_nl_to_tail = 0;
 285        int add_cr_to_tail = 0;
 286        int fixed = 0;
 287        int last_tab_in_indent = -1;
 288        int last_space_in_indent = -1;
 289        int need_fix_leading_space = 0;
 290
 291        /*
 292         * Strip trailing whitespace
 293         */
 294        if (ws_rule & WS_BLANK_AT_EOL) {
 295                if (0 < len && src[len - 1] == '\n') {
 296                        add_nl_to_tail = 1;
 297                        len--;
 298                        if (0 < len && src[len - 1] == '\r') {
 299                                add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
 300                                len--;
 301                        }
 302                }
 303                if (0 < len && isspace(src[len - 1])) {
 304                        while (0 < len && isspace(src[len-1]))
 305                                len--;
 306                        fixed = 1;
 307                }
 308        }
 309
 310        /*
 311         * Check leading whitespaces (indent)
 312         */
 313        for (i = 0; i < len; i++) {
 314                char ch = src[i];
 315                if (ch == '\t') {
 316                        last_tab_in_indent = i;
 317                        if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
 318                            0 <= last_space_in_indent)
 319                            need_fix_leading_space = 1;
 320                } else if (ch == ' ') {
 321                        last_space_in_indent = i;
 322                        if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
 323                            ws_tab_width(ws_rule) <= i - last_tab_in_indent)
 324                                need_fix_leading_space = 1;
 325                } else
 326                        break;
 327        }
 328
 329        if (need_fix_leading_space) {
 330                /* Process indent ourselves */
 331                int consecutive_spaces = 0;
 332                int last = last_tab_in_indent + 1;
 333
 334                if (ws_rule & WS_INDENT_WITH_NON_TAB) {
 335                        /* have "last" point at one past the indent */
 336                        if (last_tab_in_indent < last_space_in_indent)
 337                                last = last_space_in_indent + 1;
 338                        else
 339                                last = last_tab_in_indent + 1;
 340                }
 341
 342                /*
 343                 * between src[0..last-1], strip the funny spaces,
 344                 * updating them to tab as needed.
 345                 */
 346                for (i = 0; i < last; i++) {
 347                        char ch = src[i];
 348                        if (ch != ' ') {
 349                                consecutive_spaces = 0;
 350                                strbuf_addch(dst, ch);
 351                        } else {
 352                                consecutive_spaces++;
 353                                if (consecutive_spaces == ws_tab_width(ws_rule)) {
 354                                        strbuf_addch(dst, '\t');
 355                                        consecutive_spaces = 0;
 356                                }
 357                        }
 358                }
 359                while (0 < consecutive_spaces--)
 360                        strbuf_addch(dst, ' ');
 361                len -= last;
 362                src += last;
 363                fixed = 1;
 364        } else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
 365                /* Expand tabs into spaces */
 366                int start = dst->len;
 367                int last = last_tab_in_indent + 1;
 368                for (i = 0; i < last; i++) {
 369                        if (src[i] == '\t')
 370                                do {
 371                                        strbuf_addch(dst, ' ');
 372                                } while ((dst->len - start) % ws_tab_width(ws_rule));
 373                        else
 374                                strbuf_addch(dst, src[i]);
 375                }
 376                len -= last;
 377                src += last;
 378                fixed = 1;
 379        }
 380
 381        strbuf_add(dst, src, len);
 382        if (add_cr_to_tail)
 383                strbuf_addch(dst, '\r');
 384        if (add_nl_to_tail)
 385                strbuf_addch(dst, '\n');
 386        if (fixed && error_count)
 387                (*error_count)++;
 388}