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1#ifndef ATTR_H
2#define ATTR_H
3
4/**
5 * gitattributes mechanism gives a uniform way to associate various attributes
6 * to set of paths.
7 *
8 *
9 * Querying Specific Attributes
10 * ----------------------------
11 *
12 * - Prepare `struct attr_check` using attr_check_initl() function, enumerating
13 * the names of attributes whose values you are interested in, terminated with
14 * a NULL pointer. Alternatively, an empty `struct attr_check` can be
15 * prepared by calling `attr_check_alloc()` function and then attributes you
16 * want to ask about can be added to it with `attr_check_append()` function.
17 *
18 * - Call `git_check_attr()` to check the attributes for the path.
19 *
20 * - Inspect `attr_check` structure to see how each of the attribute in the
21 * array is defined for the path.
22 *
23 *
24 * Example
25 * -------
26 *
27 * To see how attributes "crlf" and "ident" are set for different paths.
28 *
29 * - Prepare a `struct attr_check` with two elements (because we are checking
30 * two attributes):
31 *
32 * ------------
33 * static struct attr_check *check;
34 * static void setup_check(void)
35 * {
36 * if (check)
37 * return; // already done
38 * check = attr_check_initl("crlf", "ident", NULL);
39 * }
40 * ------------
41 *
42 * - Call `git_check_attr()` with the prepared `struct attr_check`:
43 *
44 * ------------
45 * const char *path;
46 *
47 * setup_check();
48 * git_check_attr(&the_index, path, check);
49 * ------------
50 *
51 * - Act on `.value` member of the result, left in `check->items[]`:
52 *
53 * ------------
54 * const char *value = check->items[0].value;
55 *
56 * if (ATTR_TRUE(value)) {
57 * The attribute is Set, by listing only the name of the
58 * attribute in the gitattributes file for the path.
59 * } else if (ATTR_FALSE(value)) {
60 * The attribute is Unset, by listing the name of the
61 * attribute prefixed with a dash - for the path.
62 * } else if (ATTR_UNSET(value)) {
63 * The attribute is neither set nor unset for the path.
64 * } else if (!strcmp(value, "input")) {
65 * If none of ATTR_TRUE(), ATTR_FALSE(), or ATTR_UNSET() is
66 * true, the value is a string set in the gitattributes
67 * file for the path by saying "attr=value".
68 * } else if (... other check using value as string ...) {
69 * ...
70 * }
71 * ------------
72 *
73 * To see how attributes in argv[] are set for different paths, only
74 * the first step in the above would be different.
75 *
76 * ------------
77 * static struct attr_check *check;
78 * static void setup_check(const char **argv)
79 * {
80 * check = attr_check_alloc();
81 * while (*argv) {
82 * struct git_attr *attr = git_attr(*argv);
83 * attr_check_append(check, attr);
84 * argv++;
85 * }
86 * }
87 * ------------
88 *
89 *
90 * Querying All Attributes
91 * -----------------------
92 *
93 * To get the values of all attributes associated with a file:
94 *
95 * - Prepare an empty `attr_check` structure by calling `attr_check_alloc()`.
96 *
97 * - Call `git_all_attrs()`, which populates the `attr_check` with the
98 * attributes attached to the path.
99 *
100 * - Iterate over the `attr_check.items[]` array to examine the attribute
101 * names and values. The name of the attribute described by an
102 * `attr_check.items[]` object can be retrieved via
103 * `git_attr_name(check->items[i].attr)`. (Please note that no items will be
104 * returned for unset attributes, so `ATTR_UNSET()` will return false for all
105 * returned `attr_check.items[]` objects.)
106 *
107 * - Free the `attr_check` struct by calling `attr_check_free()`.
108 */
109
110/**
111 * The maximum line length for a gitattributes file. If the line exceeds this
112 * length we will ignore it.
113 */
114#define ATTR_MAX_LINE_LENGTH 2048
115
116 /**
117 * The maximum size of the giattributes file. If the file exceeds this size we
118 * will ignore it.
119 */
120#define ATTR_MAX_FILE_SIZE (100 * 1024 * 1024)
121
122struct index_state;
123
124/**
125 * An attribute is an opaque object that is identified by its name. Pass the
126 * name to `git_attr()` function to obtain the object of this type.
127 * The internal representation of this structure is of no interest to the
128 * calling programs. The name of the attribute can be retrieved by calling
129 * `git_attr_name()`.
130 */
131struct git_attr;
132
133/* opaque structures used internally for attribute collection */
134struct all_attrs_item;
135struct attr_stack;
136
137/*
138 * The textual object name for the tree-ish used by git_check_attr()
139 * to read attributes from (instead of from the working tree).
140 */
141void set_git_attr_source(const char *);
142
143/*
144 * Given a string, return the gitattribute object that
145 * corresponds to it.
146 */
147const struct git_attr *git_attr(const char *);
148
149/* Internal use */
150extern const char git_attr__true[];
151extern const char git_attr__false[];
152
153/**
154 * Attribute Values
155 * ----------------
156 *
157 * An attribute for a path can be in one of four states: Set, Unset, Unspecified
158 * or set to a string, and `.value` member of `struct attr_check_item` records
159 * it. The three macros check these, if none of them returns true, `.value`
160 * member points at a string value of the attribute for the path.
161 */
162
163/* Returns true if the attribute is Set for the path. */
164#define ATTR_TRUE(v) ((v) == git_attr__true)
165
166/* Returns true if the attribute is Unset for the path. */
167#define ATTR_FALSE(v) ((v) == git_attr__false)
168
169/* Returns true if the attribute is Unspecified for the path. */
170#define ATTR_UNSET(v) ((v) == NULL)
171
172/* This structure represents one attribute and its value. */
173struct attr_check_item {
174 const struct git_attr *attr;
175 const char *value;
176};
177
178/**
179 * This structure represents a collection of `attr_check_item`. It is passed to
180 * `git_check_attr()` function, specifying the attributes to check, and
181 * receives their values.
182 */
183struct attr_check {
184 int nr;
185 int alloc;
186 struct attr_check_item *items;
187 int all_attrs_nr;
188 struct all_attrs_item *all_attrs;
189 struct attr_stack *stack;
190};
191
192struct attr_check *attr_check_alloc(void);
193
194LAST_ARG_MUST_BE_NULL
195struct attr_check *attr_check_initl(const char *, ...);
196struct attr_check *attr_check_dup(const struct attr_check *check);
197
198struct attr_check_item *attr_check_append(struct attr_check *check,
199 const struct git_attr *attr);
200
201void attr_check_reset(struct attr_check *check);
202void attr_check_clear(struct attr_check *check);
203void attr_check_free(struct attr_check *check);
204
205/*
206 * Return the name of the attribute represented by the argument. The
207 * return value is a pointer to a null-delimited string that is part
208 * of the internal data structure; it should not be modified or freed.
209 */
210const char *git_attr_name(const struct git_attr *);
211
212void git_check_attr(struct index_state *istate,
213 const char *path,
214 struct attr_check *check);
215
216/*
217 * Retrieve all attributes that apply to the specified path.
218 * check holds the attributes and their values.
219 */
220void git_all_attrs(struct index_state *istate,
221 const char *path, struct attr_check *check);
222
223enum git_attr_direction {
224 GIT_ATTR_CHECKIN,
225 GIT_ATTR_CHECKOUT,
226 GIT_ATTR_INDEX
227};
228void git_attr_set_direction(enum git_attr_direction new_direction);
229
230void attr_start(void);
231
232/* Return the system gitattributes file. */
233const char *git_attr_system_file(void);
234
235/* Return the global gitattributes file, if any. */
236const char *git_attr_global_file(void);
237
238/* Return whether the system gitattributes file is enabled and should be used. */
239int git_attr_system_is_enabled(void);
240
241extern char *git_attr_tree;
242
243/*
244 * Exposed for fuzz-testing only.
245 */
246
247/* What does a matched pattern decide? */
248struct attr_state {
249 const struct git_attr *attr;
250 const char *setto;
251};
252
253struct pattern {
254 const char *pattern;
255 int patternlen;
256 int nowildcardlen;
257 unsigned flags; /* PATTERN_FLAG_* */
258};
259
260/*
261 * One rule, as from a .gitattributes file.
262 *
263 * If is_macro is true, then u.attr is a pointer to the git_attr being
264 * defined.
265 *
266 * If is_macro is false, then u.pat is the filename pattern to which the
267 * rule applies.
268 *
269 * In either case, num_attr is the number of attributes affected by
270 * this rule, and state is an array listing them. The attributes are
271 * listed as they appear in the file (macros unexpanded).
272 */
273struct match_attr {
274 union {
275 struct pattern pat;
276 const struct git_attr *attr;
277 } u;
278 char is_macro;
279 size_t num_attr;
280 struct attr_state state[FLEX_ARRAY];
281};
282
283struct match_attr *parse_attr_line(const char *line, const char *src,
284 int lineno, unsigned flags);
285
286#endif /* ATTR_H */