whitespace: fix off-by-one error in non-space-in-indent checking
[git/git.git] / ws.c
CommitLineData
cf1b7869
JH
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};
18
19unsigned 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
58static 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
67unsigned 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}
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97
98/* The returned string should be freed by the caller. */
99char *whitespace_error_string(unsigned ws)
100{
101 struct strbuf err;
102 strbuf_init(&err, 0);
103 if (ws & WS_TRAILING_SPACE)
420f4f04 104 strbuf_addstr(&err, "trailing whitespace");
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105 if (ws & WS_SPACE_BEFORE_TAB) {
106 if (err.len)
107 strbuf_addstr(&err, ", ");
420f4f04 108 strbuf_addstr(&err, "space before tab in indent");
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109 }
110 if (ws & WS_INDENT_WITH_NON_TAB) {
111 if (err.len)
112 strbuf_addstr(&err, ", ");
420f4f04 113 strbuf_addstr(&err, "indent with spaces");
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114 }
115 return strbuf_detach(&err, NULL);
116}
117
118/* If stream is non-NULL, emits the line after checking. */
119unsigned 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. */
4d9697c7 162 if ((ws_rule & WS_INDENT_WITH_NON_TAB) && leading_space >= 7)
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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}