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        { "blank-at-eof", WS_BLANK_AT_EOF },
  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                                all_rule |= whitespace_rule_names[i].rule_bits;
  84                        return all_rule;
  85                } else if (ATTR_FALSE(value)) {
  86                        /* false (-whitespace) */
  87                        return 0;
  88                } else if (ATTR_UNSET(value)) {
  89                        /* reset to default (!whitespace) */
  90                        return whitespace_rule_cfg;
  91                } else {
  92                        /* string */
  93                        return parse_whitespace_rule(value);
  94                }
  95        } else {
  96                return whitespace_rule_cfg;
  97        }
  98}
  99
 100/* The returned string should be freed by the caller. */
 101char *whitespace_error_string(unsigned ws)
 102{
 103        struct strbuf err;
 104        strbuf_init(&err, 0);
 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        if (ws & WS_BLANK_AT_EOF) {
 118                if (err.len)
 119                        strbuf_addstr(&err, ", ");
 120                strbuf_addstr(&err, "new blank line at EOF");
 121        }
 122        return strbuf_detach(&err, NULL);
 123}
 124
 125/* If stream is non-NULL, emits the line after checking. */
 126static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
 127                                FILE *stream, const char *set,
 128                                const char *reset, const char *ws)
 129{
 130        unsigned result = 0;
 131        int written = 0;
 132        int trailing_whitespace = -1;
 133        int trailing_newline = 0;
 134        int trailing_carriage_return = 0;
 135        int i;
 136
 137        /* Logic is simpler if we temporarily ignore the trailing newline. */
 138        if (len > 0 && line[len - 1] == '\n') {
 139                trailing_newline = 1;
 140                len--;
 141        }
 142        if ((ws_rule & WS_CR_AT_EOL) &&
 143            len > 0 && line[len - 1] == '\r') {
 144                trailing_carriage_return = 1;
 145                len--;
 146        }
 147
 148        /* Check for trailing whitespace. */
 149        if (ws_rule & WS_TRAILING_SPACE) {
 150                for (i = len - 1; i >= 0; i--) {
 151                        if (isspace(line[i])) {
 152                                trailing_whitespace = i;
 153                                result |= WS_TRAILING_SPACE;
 154                        }
 155                        else
 156                                break;
 157                }
 158        }
 159
 160        /* Check for space before tab in initial indent. */
 161        for (i = 0; i < len; i++) {
 162                if (line[i] == ' ')
 163                        continue;
 164                if (line[i] != '\t')
 165                        break;
 166                if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
 167                        result |= WS_SPACE_BEFORE_TAB;
 168                        if (stream) {
 169                                fputs(ws, stream);
 170                                fwrite(line + written, i - written, 1, stream);
 171                                fputs(reset, stream);
 172                        }
 173                } else if (stream)
 174                        fwrite(line + written, i - written, 1, stream);
 175                if (stream)
 176                        fwrite(line + i, 1, 1, stream);
 177                written = i + 1;
 178        }
 179
 180        /* Check for indent using non-tab. */
 181        if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= 8) {
 182                result |= WS_INDENT_WITH_NON_TAB;
 183                if (stream) {
 184                        fputs(ws, stream);
 185                        fwrite(line + written, i - written, 1, stream);
 186                        fputs(reset, stream);
 187                }
 188                written = i;
 189        }
 190
 191        if (stream) {
 192                /*
 193                 * Now the rest of the line starts at "written".
 194                 * The non-highlighted part ends at "trailing_whitespace".
 195                 */
 196                if (trailing_whitespace == -1)
 197                        trailing_whitespace = len;
 198
 199                /* Emit non-highlighted (middle) segment. */
 200                if (trailing_whitespace - written > 0) {
 201                        fputs(set, stream);
 202                        fwrite(line + written,
 203                            trailing_whitespace - written, 1, stream);
 204                        fputs(reset, stream);
 205                }
 206
 207                /* Highlight errors in trailing whitespace. */
 208                if (trailing_whitespace != len) {
 209                        fputs(ws, stream);
 210                        fwrite(line + trailing_whitespace,
 211                            len - trailing_whitespace, 1, stream);
 212                        fputs(reset, stream);
 213                }
 214                if (trailing_carriage_return)
 215                        fputc('\r', stream);
 216                if (trailing_newline)
 217                        fputc('\n', stream);
 218        }
 219        return result;
 220}
 221
 222void ws_check_emit(const char *line, int len, unsigned ws_rule,
 223                   FILE *stream, const char *set,
 224                   const char *reset, const char *ws)
 225{
 226        (void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
 227}
 228
 229unsigned ws_check(const char *line, int len, unsigned ws_rule)
 230{
 231        return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
 232}
 233
 234int ws_blank_line(const char *line, int len, unsigned ws_rule)
 235{
 236        /*
 237         * We _might_ want to treat CR differently from other
 238         * whitespace characters when ws_rule has WS_CR_AT_EOL, but
 239         * for now we just use this stupid definition.
 240         */
 241        while (len-- > 0) {
 242                if (!isspace(*line))
 243                        return 0;
 244                line++;
 245        }
 246        return 1;
 247}
 248
 249/* Copy the line to the buffer while fixing whitespaces */
 250int ws_fix_copy(char *dst, const char *src, int len, unsigned ws_rule, int *error_count)
 251{
 252        /*
 253         * len is number of bytes to be copied from src, starting
 254         * at src.  Typically src[len-1] is '\n', unless this is
 255         * the incomplete last line.
 256         */
 257        int i;
 258        int add_nl_to_tail = 0;
 259        int add_cr_to_tail = 0;
 260        int fixed = 0;
 261        int last_tab_in_indent = -1;
 262        int last_space_in_indent = -1;
 263        int need_fix_leading_space = 0;
 264        char *buf;
 265
 266        /*
 267         * Strip trailing whitespace
 268         */
 269        if ((ws_rule & WS_TRAILING_SPACE) &&
 270            (2 <= len && isspace(src[len-2]))) {
 271                if (src[len - 1] == '\n') {
 272                        add_nl_to_tail = 1;
 273                        len--;
 274                        if (1 < len && src[len - 1] == '\r') {
 275                                add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
 276                                len--;
 277                        }
 278                }
 279                if (0 < len && isspace(src[len - 1])) {
 280                        while (0 < len && isspace(src[len-1]))
 281                                len--;
 282                        fixed = 1;
 283                }
 284        }
 285
 286        /*
 287         * Check leading whitespaces (indent)
 288         */
 289        for (i = 0; i < len; i++) {
 290                char ch = src[i];
 291                if (ch == '\t') {
 292                        last_tab_in_indent = i;
 293                        if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
 294                            0 <= last_space_in_indent)
 295                            need_fix_leading_space = 1;
 296                } else if (ch == ' ') {
 297                        last_space_in_indent = i;
 298                        if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
 299                            8 <= i - last_tab_in_indent)
 300                                need_fix_leading_space = 1;
 301                } else
 302                        break;
 303        }
 304
 305        buf = dst;
 306        if (need_fix_leading_space) {
 307                /* Process indent ourselves */
 308                int consecutive_spaces = 0;
 309                int last = last_tab_in_indent + 1;
 310
 311                if (ws_rule & WS_INDENT_WITH_NON_TAB) {
 312                        /* have "last" point at one past the indent */
 313                        if (last_tab_in_indent < last_space_in_indent)
 314                                last = last_space_in_indent + 1;
 315                        else
 316                                last = last_tab_in_indent + 1;
 317                }
 318
 319                /*
 320                 * between src[0..last-1], strip the funny spaces,
 321                 * updating them to tab as needed.
 322                 */
 323                for (i = 0; i < last; i++) {
 324                        char ch = src[i];
 325                        if (ch != ' ') {
 326                                consecutive_spaces = 0;
 327                                *dst++ = ch;
 328                        } else {
 329                                consecutive_spaces++;
 330                                if (consecutive_spaces == 8) {
 331                                        *dst++ = '\t';
 332                                        consecutive_spaces = 0;
 333                                }
 334                        }
 335                }
 336                while (0 < consecutive_spaces--)
 337                        *dst++ = ' ';
 338                len -= last;
 339                src += last;
 340                fixed = 1;
 341        }
 342
 343        memcpy(dst, src, len);
 344        if (add_cr_to_tail)
 345                dst[len++] = '\r';
 346        if (add_nl_to_tail)
 347                dst[len++] = '\n';
 348        if (fixed && error_count)
 349                (*error_count)++;
 350        return dst + len - buf;
 351}