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