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