ws.con commit Merge branch 'maint' (5b5275f)
   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 = strchr(string, ',');
  37                if (!ep)
  38                        len = strlen(string);
  39                else
  40                        len = ep - string;
  41
  42                if (*string == '-') {
  43                        negated = 1;
  44                        string++;
  45                        len--;
  46                }
  47                if (!len)
  48                        break;
  49                for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
  50                        if (strncmp(whitespace_rule_names[i].rule_name,
  51                                    string, len))
  52                                continue;
  53                        if (negated)
  54                                rule &= ~whitespace_rule_names[i].rule_bits;
  55                        else
  56                                rule |= whitespace_rule_names[i].rule_bits;
  57                        break;
  58                }
  59                string = ep;
  60        }
  61
  62        if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
  63                die("cannot enforce both tab-in-indent and indent-with-non-tab");
  64        return rule;
  65}
  66
  67static void setup_whitespace_attr_check(struct git_attr_check *check)
  68{
  69        static struct git_attr *attr_whitespace;
  70
  71        if (!attr_whitespace)
  72                attr_whitespace = git_attr("whitespace");
  73        check[0].attr = attr_whitespace;
  74}
  75
  76unsigned whitespace_rule(const char *pathname)
  77{
  78        struct git_attr_check attr_whitespace_rule;
  79
  80        setup_whitespace_attr_check(&attr_whitespace_rule);
  81        if (!git_checkattr(pathname, 1, &attr_whitespace_rule)) {
  82                const char *value;
  83
  84                value = attr_whitespace_rule.value;
  85                if (ATTR_TRUE(value)) {
  86                        /* true (whitespace) */
  87                        unsigned all_rule = 0;
  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 0;
  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        /* Check indentation */
 178        for (i = 0; i < len; i++) {
 179                if (line[i] == ' ')
 180                        continue;
 181                if (line[i] != '\t')
 182                        break;
 183                if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
 184                        result |= WS_SPACE_BEFORE_TAB;
 185                        if (stream) {
 186                                fputs(ws, stream);
 187                                fwrite(line + written, i - written, 1, stream);
 188                                fputs(reset, stream);
 189                                fwrite(line + i, 1, 1, stream);
 190                        }
 191                } else if (ws_rule & WS_TAB_IN_INDENT) {
 192                        result |= WS_TAB_IN_INDENT;
 193                        if (stream) {
 194                                fwrite(line + written, i - written, 1, stream);
 195                                fputs(ws, stream);
 196                                fwrite(line + i, 1, 1, stream);
 197                                fputs(reset, stream);
 198                        }
 199                } else if (stream) {
 200                        fwrite(line + written, i - written + 1, 1, stream);
 201                }
 202                written = i + 1;
 203        }
 204
 205        /* Check for indent using non-tab. */
 206        if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= 8) {
 207                result |= WS_INDENT_WITH_NON_TAB;
 208                if (stream) {
 209                        fputs(ws, stream);
 210                        fwrite(line + written, i - written, 1, stream);
 211                        fputs(reset, stream);
 212                }
 213                written = i;
 214        }
 215
 216        if (stream) {
 217                /*
 218                 * Now the rest of the line starts at "written".
 219                 * The non-highlighted part ends at "trailing_whitespace".
 220                 */
 221                if (trailing_whitespace == -1)
 222                        trailing_whitespace = len;
 223
 224                /* Emit non-highlighted (middle) segment. */
 225                if (trailing_whitespace - written > 0) {
 226                        fputs(set, stream);
 227                        fwrite(line + written,
 228                            trailing_whitespace - written, 1, stream);
 229                        fputs(reset, stream);
 230                }
 231
 232                /* Highlight errors in trailing whitespace. */
 233                if (trailing_whitespace != len) {
 234                        fputs(ws, stream);
 235                        fwrite(line + trailing_whitespace,
 236                            len - trailing_whitespace, 1, stream);
 237                        fputs(reset, stream);
 238                }
 239                if (trailing_carriage_return)
 240                        fputc('\r', stream);
 241                if (trailing_newline)
 242                        fputc('\n', stream);
 243        }
 244        return result;
 245}
 246
 247void ws_check_emit(const char *line, int len, unsigned ws_rule,
 248                   FILE *stream, const char *set,
 249                   const char *reset, const char *ws)
 250{
 251        (void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
 252}
 253
 254unsigned ws_check(const char *line, int len, unsigned ws_rule)
 255{
 256        return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
 257}
 258
 259int ws_blank_line(const char *line, int len, unsigned ws_rule)
 260{
 261        /*
 262         * We _might_ want to treat CR differently from other
 263         * whitespace characters when ws_rule has WS_CR_AT_EOL, but
 264         * for now we just use this stupid definition.
 265         */
 266        while (len-- > 0) {
 267                if (!isspace(*line))
 268                        return 0;
 269                line++;
 270        }
 271        return 1;
 272}
 273
 274/* Copy the line onto the end of the strbuf while fixing whitespaces */
 275void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule, int *error_count)
 276{
 277        /*
 278         * len is number of bytes to be copied from src, starting
 279         * at src.  Typically src[len-1] is '\n', unless this is
 280         * the incomplete last line.
 281         */
 282        int i;
 283        int add_nl_to_tail = 0;
 284        int add_cr_to_tail = 0;
 285        int fixed = 0;
 286        int last_tab_in_indent = -1;
 287        int last_space_in_indent = -1;
 288        int need_fix_leading_space = 0;
 289
 290        /*
 291         * Strip trailing whitespace
 292         */
 293        if (ws_rule & WS_BLANK_AT_EOL) {
 294                if (0 < len && src[len - 1] == '\n') {
 295                        add_nl_to_tail = 1;
 296                        len--;
 297                        if (0 < len && src[len - 1] == '\r') {
 298                                add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
 299                                len--;
 300                        }
 301                }
 302                if (0 < len && isspace(src[len - 1])) {
 303                        while (0 < len && isspace(src[len-1]))
 304                                len--;
 305                        fixed = 1;
 306                }
 307        }
 308
 309        /*
 310         * Check leading whitespaces (indent)
 311         */
 312        for (i = 0; i < len; i++) {
 313                char ch = src[i];
 314                if (ch == '\t') {
 315                        last_tab_in_indent = i;
 316                        if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
 317                            0 <= last_space_in_indent)
 318                            need_fix_leading_space = 1;
 319                } else if (ch == ' ') {
 320                        last_space_in_indent = i;
 321                        if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
 322                            8 <= i - last_tab_in_indent)
 323                                need_fix_leading_space = 1;
 324                } else
 325                        break;
 326        }
 327
 328        if (need_fix_leading_space) {
 329                /* Process indent ourselves */
 330                int consecutive_spaces = 0;
 331                int last = last_tab_in_indent + 1;
 332
 333                if (ws_rule & WS_INDENT_WITH_NON_TAB) {
 334                        /* have "last" point at one past the indent */
 335                        if (last_tab_in_indent < last_space_in_indent)
 336                                last = last_space_in_indent + 1;
 337                        else
 338                                last = last_tab_in_indent + 1;
 339                }
 340
 341                /*
 342                 * between src[0..last-1], strip the funny spaces,
 343                 * updating them to tab as needed.
 344                 */
 345                for (i = 0; i < last; i++) {
 346                        char ch = src[i];
 347                        if (ch != ' ') {
 348                                consecutive_spaces = 0;
 349                                strbuf_addch(dst, ch);
 350                        } else {
 351                                consecutive_spaces++;
 352                                if (consecutive_spaces == 8) {
 353                                        strbuf_addch(dst, '\t');
 354                                        consecutive_spaces = 0;
 355                                }
 356                        }
 357                }
 358                while (0 < consecutive_spaces--)
 359                        strbuf_addch(dst, ' ');
 360                len -= last;
 361                src += last;
 362                fixed = 1;
 363        } else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
 364                /* Expand tabs into spaces */
 365                int last = last_tab_in_indent + 1;
 366                for (i = 0; i < last; i++) {
 367                        if (src[i] == '\t')
 368                                do {
 369                                        strbuf_addch(dst, ' ');
 370                                } while (dst->len % 8);
 371                        else
 372                                strbuf_addch(dst, src[i]);
 373                }
 374                len -= last;
 375                src += last;
 376                fixed = 1;
 377        }
 378
 379        strbuf_add(dst, src, len);
 380        if (add_cr_to_tail)
 381                strbuf_addch(dst, '\r');
 382        if (add_nl_to_tail)
 383                strbuf_addch(dst, '\n');
 384        if (fixed && error_count)
 385                (*error_count)++;
 386}