1/* Declarations and definitions dealing with attribute handling.
2 Copyright (C) 2013-2017 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING3. If not see
18<http://www.gnu.org/licenses/>. */
19
20#ifndef GCC_ATTRIBS_H
21#define GCC_ATTRIBS_H
22
23extern const struct attribute_spec *lookup_attribute_spec (const_tree);
24extern void init_attributes (void);
25
26/* Process the attributes listed in ATTRIBUTES and install them in *NODE,
27 which is either a DECL (including a TYPE_DECL) or a TYPE. If a DECL,
28 it should be modified in place; if a TYPE, a copy should be created
29 unless ATTR_FLAG_TYPE_IN_PLACE is set in FLAGS. FLAGS gives further
30 information, in the form of a bitwise OR of flags in enum attribute_flags
31 from tree.h. Depending on these flags, some attributes may be
32 returned to be applied at a later stage (for example, to apply
33 a decl attribute to the declaration rather than to its type). */
34extern tree decl_attributes (tree *, tree, int, tree = NULL_TREE);
35
36extern bool cxx11_attribute_p (const_tree);
37extern tree get_attribute_name (const_tree);
38extern void apply_tm_attr (tree, tree);
39extern tree make_attribute (const char *, const char *, tree);
40
41extern struct scoped_attributes* register_scoped_attributes (const struct attribute_spec *,
42 const char *);
43
44extern char *sorted_attr_string (tree);
45extern bool common_function_versions (tree, tree);
46extern char *make_unique_name (tree, const char *, bool);
47extern tree make_dispatcher_decl (const tree);
48extern bool is_function_default_version (const tree);
49
50/* Return a type like TTYPE except that its TYPE_ATTRIBUTES
51 is ATTRIBUTE.
52
53 Such modified types already made are recorded so that duplicates
54 are not made. */
55
56extern tree build_type_attribute_variant (tree, tree);
57extern tree build_decl_attribute_variant (tree, tree);
58extern tree build_type_attribute_qual_variant (tree, tree, int);
59
60extern bool attribute_value_equal (const_tree, const_tree);
61
62/* Return 0 if the attributes for two types are incompatible, 1 if they
63 are compatible, and 2 if they are nearly compatible (which causes a
64 warning to be generated). */
65extern int comp_type_attributes (const_tree, const_tree);
66
67/* Default versions of target-overridable functions. */
68extern tree merge_decl_attributes (tree, tree);
69extern tree merge_type_attributes (tree, tree);
70
71/* Remove any instances of attribute ATTR_NAME in LIST and return the
72 modified list. */
73
74extern tree remove_attribute (const char *, tree);
75
76/* Given two attributes lists, return a list of their union. */
77
78extern tree merge_attributes (tree, tree);
79
80/* Duplicate all attributes with name NAME in ATTR list to *ATTRS if
81 they are missing there. */
82
83extern void duplicate_one_attribute (tree *, tree, const char *);
84
85/* Duplicate all attributes from user DECL to the corresponding
86 builtin that should be propagated. */
87
88extern void copy_attributes_to_builtin (tree);
89
90/* Given two Windows decl attributes lists, possibly including
91 dllimport, return a list of their union . */
92extern tree merge_dllimport_decl_attributes (tree, tree);
93
94/* Handle a "dllimport" or "dllexport" attribute. */
95extern tree handle_dll_attribute (tree *, tree, tree, int, bool *);
96
97extern int attribute_list_equal (const_tree, const_tree);
98extern int attribute_list_contained (const_tree, const_tree);
99
100/* The backbone of lookup_attribute(). ATTR_LEN is the string length
101 of ATTR_NAME, and LIST is not NULL_TREE.
102
103 The function is called from lookup_attribute in order to optimize
104 for size. */
105extern tree private_lookup_attribute (const char *attr_name, size_t attr_len,
106 tree list);
107
108/* For a given IDENTIFIER_NODE, strip leading and trailing '_' characters
109 so that we have a canonical form of attribute names. */
110
111static inline tree
112canonicalize_attr_name (tree attr_name)
113{
114 const size_t l = IDENTIFIER_LENGTH (attr_name);
115 const char *s = IDENTIFIER_POINTER (attr_name);
116
117 if (l > 4 && s[0] == '_' && s[1] == '_' && s[l - 1] == '_' && s[l - 2] == '_')
118 return get_identifier_with_length (s + 2, l - 4);
119
120 return attr_name;
121}
122
123/* Compare attribute identifiers ATTR1 and ATTR2 with length ATTR1_LEN and
124 ATTR2_LEN. */
125
126static inline bool
127cmp_attribs (const char *attr1, size_t attr1_len,
128 const char *attr2, size_t attr2_len)
129{
130 return attr1_len == attr2_len && strncmp (attr1, attr2, attr1_len) == 0;
131}
132
133/* Compare attribute identifiers ATTR1 and ATTR2. */
134
135static inline bool
136cmp_attribs (const char *attr1, const char *attr2)
137{
138 return cmp_attribs (attr1, strlen (attr1), attr2, strlen (attr2));
139}
140
141/* Given an identifier node IDENT and a string ATTR_NAME, return true
142 if the identifier node is a valid attribute name for the string. */
143
144static inline bool
145is_attribute_p (const char *attr_name, const_tree ident)
146{
147 return cmp_attribs (attr_name, strlen (attr_name),
148 IDENTIFIER_POINTER (ident), IDENTIFIER_LENGTH (ident));
149}
150
151/* Given an attribute name ATTR_NAME and a list of attributes LIST,
152 return a pointer to the attribute's list element if the attribute
153 is part of the list, or NULL_TREE if not found. If the attribute
154 appears more than once, this only returns the first occurrence; the
155 TREE_CHAIN of the return value should be passed back in if further
156 occurrences are wanted. ATTR_NAME must be in the form 'text' (not
157 '__text__'). */
158
159static inline tree
160lookup_attribute (const char *attr_name, tree list)
161{
162 gcc_checking_assert (attr_name[0] != '_');
163 /* In most cases, list is NULL_TREE. */
164 if (list == NULL_TREE)
165 return NULL_TREE;
166 else
167 {
168 size_t attr_len = strlen (attr_name);
169 /* Do the strlen() before calling the out-of-line implementation.
170 In most cases attr_name is a string constant, and the compiler
171 will optimize the strlen() away. */
172 return private_lookup_attribute (attr_name, attr_len, list);
173 }
174}
175
176/* Given an attribute name ATTR_NAME and a list of attributes LIST,
177 return a pointer to the attribute's list first element if the attribute
178 starts with ATTR_NAME. ATTR_NAME must be in the form 'text' (not
179 '__text__'). */
180
181static inline tree
182lookup_attribute_by_prefix (const char *attr_name, tree list)
183{
184 gcc_checking_assert (attr_name[0] != '_');
185 /* In most cases, list is NULL_TREE. */
186 if (list == NULL_TREE)
187 return NULL_TREE;
188 else
189 {
190 size_t attr_len = strlen (attr_name);
191 while (list)
192 {
193 size_t ident_len = IDENTIFIER_LENGTH (get_attribute_name (list));
194
195 if (attr_len > ident_len)
196 {
197 list = TREE_CHAIN (list);
198 continue;
199 }
200
201 const char *p = IDENTIFIER_POINTER (get_attribute_name (list));
202 gcc_checking_assert (attr_len == 0 || p[0] != '_');
203
204 if (strncmp (attr_name, p, attr_len) == 0)
205 break;
206
207 list = TREE_CHAIN (list);
208 }
209
210 return list;
211 }
212}
213
214#endif // GCC_ATTRIBS_H
215