Andrew's git - gitweb.git/blob

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