ws.c

   1 /*
   2  * Whitespace rules
   3  *
   4  * Copyright (c) 2007 Junio C Hamano
   5  */
   6
   7 #include "cache.h"
   8 #include "attr.h"
   9
  10 static 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 };
  18
  19 unsigned parse_whitespace_rule(const char *string)
  20 {
  21         unsigned rule = WS_DEFAULT_RULE;
  22
  23         while (string) {
  24                 int i;
  25                 size_t len;
  26                 const char *ep;
  27                 int negated = 0;
  28
  29                 string = string + strspn(string, ", \t\n\r");
  30                 ep = strchr(string, ',');
  31                 if (!ep)
  32                         len = strlen(string);
  33                 else
  34                         len = ep - string;
  35
  36                 if (*string == '-') {
  37                         negated = 1;
  38                         string++;
  39                         len--;
  40                 }
  41                 if (!len)
  42                         break;
  43                 for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
  44                         if (strncmp(whitespace_rule_names[i].rule_name,
  45                                     string, len))
  46                                 continue;
  47                         if (negated)
  48                                 rule &= ~whitespace_rule_names[i].rule_bits;
  49                         else
  50                                 rule |= whitespace_rule_names[i].rule_bits;
  51                         break;
  52                 }
  53                 string = ep;
  54         }
  55         return rule;
  56 }
  57
  58 static void setup_whitespace_attr_check(struct git_attr_check *check)
  59 {
  60         static struct git_attr *attr_whitespace;
  61
  62         if (!attr_whitespace)
  63                 attr_whitespace = git_attr("whitespace", 10);
  64         check[0].attr = attr_whitespace;
  65 }
  66
  67 unsigned whitespace_rule(const char *pathname)
  68 {
  69         struct git_attr_check attr_whitespace_rule;
  70
  71         setup_whitespace_attr_check(&attr_whitespace_rule);
  72         if (!git_checkattr(pathname, 1, &attr_whitespace_rule)) {
  73                 const char *value;
  74
  75                 value = attr_whitespace_rule.value;
  76                 if (ATTR_TRUE(value)) {
  77                         /* true (whitespace) */
  78                         unsigned all_rule = 0;
  79                         int i;
  80                         for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
  81                                 all_rule |= whitespace_rule_names[i].rule_bits;
  82                         return all_rule;
  83                 } else if (ATTR_FALSE(value)) {
  84                         /* false (-whitespace) */
  85                         return 0;
  86                 } else if (ATTR_UNSET(value)) {
  87                         /* reset to default (!whitespace) */
  88                         return whitespace_rule_cfg;
  89                 } else {
  90                         /* string */
  91                         return parse_whitespace_rule(value);
  92                 }
  93         } else {
  94                 return whitespace_rule_cfg;
  95         }
  96 }
  97
  98 /* The returned string should be freed by the caller. */
  99 char *whitespace_error_string(unsigned ws)
 100 {
 101         struct strbuf err;
 102         strbuf_init(&err, 0);
 103         if (ws & WS_TRAILING_SPACE)
 104                 strbuf_addstr(&err, "Adds trailing whitespace");
 105         if (ws & WS_SPACE_BEFORE_TAB) {
 106                 if (err.len)
 107                         strbuf_addstr(&err, ", ");
 108                 strbuf_addstr(&err, "Space in indent is followed by a tab");
 109         }
 110         if (ws & WS_INDENT_WITH_NON_TAB) {
 111                 if (err.len)
 112                         strbuf_addstr(&err, ", ");
 113                 strbuf_addstr(&err, "Indent more than 8 places with spaces");
 114         }
 115         return strbuf_detach(&err, NULL);
 116 }
 117
 118 /* If stream is non-NULL, emits the line after checking. */
 119 unsigned check_and_emit_line(const char *line, int len, unsigned ws_rule,
 120                              FILE *stream, const char *set,
 121                              const char *reset, const char *ws)
 122 {
 123         unsigned result = 0;
 124         int leading_space = -1;
 125         int trailing_whitespace = -1;
 126         int trailing_newline = 0;
 127         int i;
 128
 129         /* Logic is simpler if we temporarily ignore the trailing newline. */
 130         if (len > 0 && line[len - 1] == '\n') {
 131                 trailing_newline = 1;
 132                 len--;
 133         }
 134
 135         /* Check for trailing whitespace. */
 136         if (ws_rule & WS_TRAILING_SPACE) {
 137                 for (i = len - 1; i >= 0; i--) {
 138                         if (isspace(line[i])) {
 139                                 trailing_whitespace = i;
 140                                 result |= WS_TRAILING_SPACE;
 141                         }
 142                         else
 143                                 break;
 144                 }
 145         }
 146
 147         /* Check for space before tab in initial indent. */
 148         for (i = 0; i < len; i++) {
 149                 if (line[i] == '\t') {
 150                         if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
 151                             (leading_space != -1))
 152                                 result |= WS_SPACE_BEFORE_TAB;
 153                         break;
 154                 }
 155                 else if (line[i] == ' ')
 156                         leading_space = i;
 157                 else
 158                         break;
 159         }
 160
 161         /* Check for indent using non-tab. */
 162         if ((ws_rule & WS_INDENT_WITH_NON_TAB) && leading_space >= 8)
 163                 result |= WS_INDENT_WITH_NON_TAB;
 164
 165         if (stream) {
 166                 /* Highlight errors in leading whitespace. */
 167                 if ((result & WS_SPACE_BEFORE_TAB) ||
 168                     (result & WS_INDENT_WITH_NON_TAB)) {
 169                         fputs(ws, stream);
 170                         fwrite(line, leading_space + 1, 1, stream);
 171                         fputs(reset, stream);
 172                         leading_space++;
 173                 }
 174                 else
 175                         leading_space = 0;
 176
 177                 /* Now the rest of the line starts at leading_space.
 178                  * The non-highlighted part ends at trailing_whitespace. */
 179                 if (trailing_whitespace == -1)
 180                         trailing_whitespace = len;
 181
 182                 /* Emit non-highlighted (middle) segment. */
 183                 if (trailing_whitespace - leading_space > 0) {
 184                         fputs(set, stream);
 185                         fwrite(line + leading_space,
 186                             trailing_whitespace - leading_space, 1, stream);
 187                         fputs(reset, stream);
 188                 }
 189
 190                 /* Highlight errors in trailing whitespace. */
 191                 if (trailing_whitespace != len) {
 192                         fputs(ws, stream);
 193                         fwrite(line + trailing_whitespace,
 194                             len - trailing_whitespace, 1, stream);
 195                         fputs(reset, stream);
 196                 }
 197                 if (trailing_newline)
 198                         fputc('\n', stream);
 199         }
 200         return result;
 201 }