f4afcddd4f3d41a920ee269c1750e5c5c6c0dfc7
   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};
  23
  24unsigned parse_whitespace_rule(const char *string)
  25{
  26        unsigned rule = WS_DEFAULT_RULE;
  27
  28        while (string) {
  29                int i;
  30                size_t len;
  31                const char *ep;
  32                int negated = 0;
  33
  34                string = string + strspn(string, ", \t\n\r");
  35                ep = strchr(string, ',');
  36                if (!ep)
  37                        len = strlen(string);
  38                else
  39                        len = ep - string;
  40
  41                if (*string == '-') {
  42                        negated = 1;
  43                        string++;
  44                        len--;
  45                }
  46                if (!len)
  47                        break;
  48                for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
  49                        if (strncmp(whitespace_rule_names[i].rule_name,
  50                                    string, len))
  51                                continue;
  52                        if (negated)
  53                                rule &= ~whitespace_rule_names[i].rule_bits;
  54                        else
  55                                rule |= whitespace_rule_names[i].rule_bits;
  56                        break;
  57                }
  58                string = ep;
  59        }
  60        return rule;
  61}
  62
  63static void setup_whitespace_attr_check(struct git_attr_check *check)
  64{
  65        static struct git_attr *attr_whitespace;
  66
  67        if (!attr_whitespace)
  68                attr_whitespace = git_attr("whitespace");
  69        check[0].attr = attr_whitespace;
  70}
  71
  72unsigned whitespace_rule(const char *pathname)
  73{
  74        struct git_attr_check attr_whitespace_rule;
  75
  76        setup_whitespace_attr_check(&attr_whitespace_rule);
  77        if (!git_checkattr(pathname, 1, &attr_whitespace_rule)) {
  78                const char *value;
  79
  80                value = attr_whitespace_rule.value;
  81                if (ATTR_TRUE(value)) {
  82                        /* true (whitespace) */
  83                        unsigned all_rule = 0;
  84                        int i;
  85                        for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
  86                                if (!whitespace_rule_names[i].loosens_error &&
  87                                    !whitespace_rule_names[i].exclude_default)
  88                                        all_rule |= whitespace_rule_names[i].rule_bits;
  89                        return all_rule;
  90                } else if (ATTR_FALSE(value)) {
  91                        /* false (-whitespace) */
  92                        return 0;
  93                } else if (ATTR_UNSET(value)) {
  94                        /* reset to default (!whitespace) */
  95                        return whitespace_rule_cfg;
  96                } else {
  97                        /* string */
  98                        return parse_whitespace_rule(value);
  99                }
 100        } else {
 101                return whitespace_rule_cfg;
 102        }
 103}
 104
 105/* The returned string should be freed by the caller. */
 106char *whitespace_error_string(unsigned ws)
 107{
 108        struct strbuf err = STRBUF_INIT;
 109        if ((ws & WS_TRAILING_SPACE) == WS_TRAILING_SPACE)
 110                strbuf_addstr(&err, "trailing whitespace");
 111        else {
 112                if (ws & WS_BLANK_AT_EOL)
 113                        strbuf_addstr(&err, "trailing whitespace");
 114                if (ws & WS_BLANK_AT_EOF) {
 115                        if (err.len)
 116                                strbuf_addstr(&err, ", ");
 117                        strbuf_addstr(&err, "new blank line at EOF");
 118                }
 119        }
 120        if (ws & WS_SPACE_BEFORE_TAB) {
 121                if (err.len)
 122                        strbuf_addstr(&err, ", ");
 123                strbuf_addstr(&err, "space before tab in indent");
 124        }
 125        if (ws & WS_INDENT_WITH_NON_TAB) {
 126                if (err.len)
 127                        strbuf_addstr(&err, ", ");
 128                strbuf_addstr(&err, "indent with spaces");
 129        }
 130        return strbuf_detach(&err, NULL);
 131}
 132
 133/* If stream is non-NULL, emits the line after checking. */
 134static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
 135                                FILE *stream, const char *set,
 136                                const char *reset, const char *ws)
 137{
 138        unsigned result = 0;
 139        int written = 0;
 140        int trailing_whitespace = -1;
 141        int trailing_newline = 0;
 142        int trailing_carriage_return = 0;
 143        int i;
 144
 145        /* Logic is simpler if we temporarily ignore the trailing newline. */
 146        if (len > 0 && line[len - 1] == '\n') {
 147                trailing_newline = 1;
 148                len--;
 149        }
 150        if ((ws_rule & WS_CR_AT_EOL) &&
 151            len > 0 && line[len - 1] == '\r') {
 152                trailing_carriage_return = 1;
 153                len--;
 154        }
 155
 156        /* Check for trailing whitespace. */
 157        if (ws_rule & WS_BLANK_AT_EOL) {
 158                for (i = len - 1; i >= 0; i--) {
 159                        if (isspace(line[i])) {
 160                                trailing_whitespace = i;
 161                                result |= WS_BLANK_AT_EOL;
 162                        }
 163                        else
 164                                break;
 165                }
 166        }
 167
 168        /* Check for space before tab in initial indent. */
 169        for (i = 0; i < len; i++) {
 170                if (line[i] == ' ')
 171                        continue;
 172                if (line[i] != '\t')
 173                        break;
 174                if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
 175                        result |= WS_SPACE_BEFORE_TAB;
 176                        if (stream) {
 177                                fputs(ws, stream);
 178                                fwrite(line + written, i - written, 1, stream);
 179                                fputs(reset, stream);
 180                        }
 181                } else if (stream)
 182                        fwrite(line + written, i - written, 1, stream);
 183                if (stream)
 184                        fwrite(line + i, 1, 1, stream);
 185                written = i + 1;
 186        }
 187
 188        /* Check for indent using non-tab. */
 189        if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= 8) {
 190                result |= WS_INDENT_WITH_NON_TAB;
 191                if (stream) {
 192                        fputs(ws, stream);
 193                        fwrite(line + written, i - written, 1, stream);
 194                        fputs(reset, stream);
 195                }
 196                written = i;
 197        }
 198
 199        if (stream) {
 200                /*
 201                 * Now the rest of the line starts at "written".
 202                 * The non-highlighted part ends at "trailing_whitespace".
 203                 */
 204                if (trailing_whitespace == -1)
 205                        trailing_whitespace = len;
 206
 207                /* Emit non-highlighted (middle) segment. */
 208                if (trailing_whitespace - written > 0) {
 209                        fputs(set, stream);
 210                        fwrite(line + written,
 211                            trailing_whitespace - written, 1, stream);
 212                        fputs(reset, stream);
 213                }
 214
 215                /* Highlight errors in trailing whitespace. */
 216                if (trailing_whitespace != len) {
 217                        fputs(ws, stream);
 218                        fwrite(line + trailing_whitespace,
 219                            len - trailing_whitespace, 1, stream);
 220                        fputs(reset, stream);
 221                }
 222                if (trailing_carriage_return)
 223                        fputc('\r', stream);
 224                if (trailing_newline)
 225                        fputc('\n', stream);
 226        }
 227        return result;
 228}
 229
 230void ws_check_emit(const char *line, int len, unsigned ws_rule,
 231                   FILE *stream, const char *set,
 232                   const char *reset, const char *ws)
 233{
 234        (void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
 235}
 236
 237unsigned ws_check(const char *line, int len, unsigned ws_rule)
 238{
 239        return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
 240}
 241
 242int ws_blank_line(const char *line, int len, unsigned ws_rule)
 243{
 244        /*
 245         * We _might_ want to treat CR differently from other
 246         * whitespace characters when ws_rule has WS_CR_AT_EOL, but
 247         * for now we just use this stupid definition.
 248         */
 249        while (len-- > 0) {
 250                if (!isspace(*line))
 251                        return 0;
 252                line++;
 253        }
 254        return 1;
 255}
 256
 257/* Copy the line to the buffer while fixing whitespaces */
 258int ws_fix_copy(char *dst, const char *src, int len, unsigned ws_rule, int *error_count)
 259{
 260        /*
 261         * len is number of bytes to be copied from src, starting
 262         * at src.  Typically src[len-1] is '\n', unless this is
 263         * the incomplete last line.
 264         */
 265        int i;
 266        int add_nl_to_tail = 0;
 267        int add_cr_to_tail = 0;
 268        int fixed = 0;
 269        int last_tab_in_indent = -1;
 270        int last_space_in_indent = -1;
 271        int need_fix_leading_space = 0;
 272        char *buf;
 273
 274        /*
 275         * Strip trailing whitespace
 276         */
 277        if (ws_rule & WS_BLANK_AT_EOL) {
 278                if (0 < len && src[len - 1] == '\n') {
 279                        add_nl_to_tail = 1;
 280                        len--;
 281                        if (0 < len && src[len - 1] == '\r') {
 282                                add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
 283                                len--;
 284                        }
 285                }
 286                if (0 < len && isspace(src[len - 1])) {
 287                        while (0 < len && isspace(src[len-1]))
 288                                len--;
 289                        fixed = 1;
 290                }
 291        }
 292
 293        /*
 294         * Check leading whitespaces (indent)
 295         */
 296        for (i = 0; i < len; i++) {
 297                char ch = src[i];
 298                if (ch == '\t') {
 299                        last_tab_in_indent = i;
 300                        if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
 301                            0 <= last_space_in_indent)
 302                            need_fix_leading_space = 1;
 303                } else if (ch == ' ') {
 304                        last_space_in_indent = i;
 305                        if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
 306                            8 <= i - last_tab_in_indent)
 307                                need_fix_leading_space = 1;
 308                } else
 309                        break;
 310        }
 311
 312        buf = dst;
 313        if (need_fix_leading_space) {
 314                /* Process indent ourselves */
 315                int consecutive_spaces = 0;
 316                int last = last_tab_in_indent + 1;
 317
 318                if (ws_rule & WS_INDENT_WITH_NON_TAB) {
 319                        /* have "last" point at one past the indent */
 320                        if (last_tab_in_indent < last_space_in_indent)
 321                                last = last_space_in_indent + 1;
 322                        else
 323                                last = last_tab_in_indent + 1;
 324                }
 325
 326                /*
 327                 * between src[0..last-1], strip the funny spaces,
 328                 * updating them to tab as needed.
 329                 */
 330                for (i = 0; i < last; i++) {
 331                        char ch = src[i];
 332                        if (ch != ' ') {
 333                                consecutive_spaces = 0;
 334                                *dst++ = ch;
 335                        } else {
 336                                consecutive_spaces++;
 337                                if (consecutive_spaces == 8) {
 338                                        *dst++ = '\t';
 339                                        consecutive_spaces = 0;
 340                                }
 341                        }
 342                }
 343                while (0 < consecutive_spaces--)
 344                        *dst++ = ' ';
 345                len -= last;
 346                src += last;
 347                fixed = 1;
 348        }
 349
 350        memcpy(dst, src, len);
 351        if (add_cr_to_tail)
 352                dst[len++] = '\r';
 353        if (add_nl_to_tail)
 354                dst[len++] = '\n';
 355        if (fixed && error_count)
 356                (*error_count)++;
 357        return dst + len - buf;
 358}