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-rw-r--r--third_party/git/attr.h212
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diff --git a/third_party/git/attr.h b/third_party/git/attr.h
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+#ifndef ATTR_H
+#define ATTR_H
+
+/**
+ * gitattributes mechanism gives a uniform way to associate various attributes
+ * to set of paths.
+ *
+ *
+ * Querying Specific Attributes
+ * ----------------------------
+ *
+ * - Prepare `struct attr_check` using attr_check_initl() function, enumerating
+ *   the names of attributes whose values you are interested in, terminated with
+ *   a NULL pointer.  Alternatively, an empty `struct attr_check` can be
+ *   prepared by calling `attr_check_alloc()` function and then attributes you
+ *   want to ask about can be added to it with `attr_check_append()` function.
+ *
+ * - Call `git_check_attr()` to check the attributes for the path.
+ *
+ * - Inspect `attr_check` structure to see how each of the attribute in the
+ *   array is defined for the path.
+ *
+ *
+ * Example
+ * -------
+ *
+ * To see how attributes "crlf" and "ident" are set for different paths.
+ *
+ * - Prepare a `struct attr_check` with two elements (because we are checking
+ *   two attributes):
+ *
+ * ------------
+ * static struct attr_check *check;
+ * static void setup_check(void)
+ * {
+ * 	if (check)
+ * 		return; // already done
+ * check = attr_check_initl("crlf", "ident", NULL);
+ * }
+ * ------------
+ *
+ * - Call `git_check_attr()` with the prepared `struct attr_check`:
+ *
+ * ------------
+ * const char *path;
+ *
+ * setup_check();
+ * git_check_attr(path, check);
+ * ------------
+ *
+ * - Act on `.value` member of the result, left in `check->items[]`:
+ *
+ * ------------
+ * const char *value = check->items[0].value;
+ *
+ * if (ATTR_TRUE(value)) {
+ * The attribute is Set, by listing only the name of the
+ * attribute in the gitattributes file for the path.
+ * } else if (ATTR_FALSE(value)) {
+ * The attribute is Unset, by listing the name of the
+ *         attribute prefixed with a dash - for the path.
+ * } else if (ATTR_UNSET(value)) {
+ * The attribute is neither set nor unset for the path.
+ * } else if (!strcmp(value, "input")) {
+ * If none of ATTR_TRUE(), ATTR_FALSE(), or ATTR_UNSET() is
+ *         true, the value is a string set in the gitattributes
+ * file for the path by saying "attr=value".
+ * } else if (... other check using value as string ...) {
+ * ...
+ * }
+ * ------------
+ *
+ * To see how attributes in argv[] are set for different paths, only
+ * the first step in the above would be different.
+ *
+ * ------------
+ * static struct attr_check *check;
+ * static void setup_check(const char **argv)
+ * {
+ *     check = attr_check_alloc();
+ *     while (*argv) {
+ *         struct git_attr *attr = git_attr(*argv);
+ *         attr_check_append(check, attr);
+ *         argv++;
+ *     }
+ * }
+ * ------------
+ *
+ *
+ * Querying All Attributes
+ * -----------------------
+ *
+ * To get the values of all attributes associated with a file:
+ *
+ * - Prepare an empty `attr_check` structure by calling `attr_check_alloc()`.
+ *
+ * - Call `git_all_attrs()`, which populates the `attr_check` with the
+ * attributes attached to the path.
+ *
+ * - Iterate over the `attr_check.items[]` array to examine the attribute
+ * names and values. The name of the attribute described by an
+ * `attr_check.items[]` object can be retrieved via
+ * `git_attr_name(check->items[i].attr)`. (Please note that no items will be
+ * returned for unset attributes, so `ATTR_UNSET()` will return false for all
+ * returned `attr_check.items[]` objects.)
+ *
+ * - Free the `attr_check` struct by calling `attr_check_free()`.
+ */
+
+struct index_state;
+
+/**
+ * An attribute is an opaque object that is identified by its name. Pass the
+ * name to `git_attr()` function to obtain the object of this type.
+ * The internal representation of this structure is of no interest to the
+ * calling programs. The name of the attribute can be retrieved by calling
+ * `git_attr_name()`.
+ */
+struct git_attr;
+
+/* opaque structures used internally for attribute collection */
+struct all_attrs_item;
+struct attr_stack;
+struct index_state;
+
+/*
+ * Given a string, return the gitattribute object that
+ * corresponds to it.
+ */
+const struct git_attr *git_attr(const char *);
+
+/* Internal use */
+extern const char git_attr__true[];
+extern const char git_attr__false[];
+
+/**
+ * Attribute Values
+ * ----------------
+ *
+ * An attribute for a path can be in one of four states: Set, Unset, Unspecified
+ * or set to a string, and `.value` member of `struct attr_check_item` records
+ * it. The three macros check these, if none of them returns true, `.value`
+ * member points at a string value of the attribute for the path.
+ */
+
+/* Returns true if the attribute is Set for the path. */
+#define ATTR_TRUE(v) ((v) == git_attr__true)
+
+/* Returns true if the attribute is Unset for the path. */
+#define ATTR_FALSE(v) ((v) == git_attr__false)
+
+/* Returns true if the attribute is Unspecified for the path. */
+#define ATTR_UNSET(v) ((v) == NULL)
+
+/* This structure represents one attribute and its value. */
+struct attr_check_item {
+	const struct git_attr *attr;
+	const char *value;
+};
+
+/**
+ * This structure represents a collection of `attr_check_item`. It is passed to
+ * `git_check_attr()` function, specifying the attributes to check, and
+ * receives their values.
+ */
+struct attr_check {
+	int nr;
+	int alloc;
+	struct attr_check_item *items;
+	int all_attrs_nr;
+	struct all_attrs_item *all_attrs;
+	struct attr_stack *stack;
+};
+
+struct attr_check *attr_check_alloc(void);
+struct attr_check *attr_check_initl(const char *, ...);
+struct attr_check *attr_check_dup(const struct attr_check *check);
+
+struct attr_check_item *attr_check_append(struct attr_check *check,
+					  const struct git_attr *attr);
+
+void attr_check_reset(struct attr_check *check);
+void attr_check_clear(struct attr_check *check);
+void attr_check_free(struct attr_check *check);
+
+/*
+ * Return the name of the attribute represented by the argument.  The
+ * return value is a pointer to a null-delimited string that is part
+ * of the internal data structure; it should not be modified or freed.
+ */
+const char *git_attr_name(const struct git_attr *);
+
+void git_check_attr(const struct index_state *istate,
+		    const char *path, struct attr_check *check);
+
+/*
+ * Retrieve all attributes that apply to the specified path.
+ * check holds the attributes and their values.
+ */
+void git_all_attrs(const struct index_state *istate,
+		   const char *path, struct attr_check *check);
+
+enum git_attr_direction {
+	GIT_ATTR_CHECKIN,
+	GIT_ATTR_CHECKOUT,
+	GIT_ATTR_INDEX
+};
+void git_attr_set_direction(enum git_attr_direction new_direction);
+
+void attr_start(void);
+
+#endif /* ATTR_H */