1 | /* Declarations and definitions dealing with attribute handling. |
2 | Copyright (C) 2013-2023 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along 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 | |
23 | extern const struct attribute_spec *lookup_attribute_spec (const_tree); |
24 | extern void free_attr_data (); |
25 | extern void init_attributes (void); |
26 | |
27 | /* Process the attributes listed in ATTRIBUTES and install them in *NODE, |
28 | which is either a DECL (including a TYPE_DECL) or a TYPE. If a DECL, |
29 | it should be modified in place; if a TYPE, a copy should be created |
30 | unless ATTR_FLAG_TYPE_IN_PLACE is set in FLAGS. FLAGS gives further |
31 | information, in the form of a bitwise OR of flags in enum attribute_flags |
32 | from tree.h. Depending on these flags, some attributes may be |
33 | returned to be applied at a later stage (for example, to apply |
34 | a decl attribute to the declaration rather than to its type). */ |
35 | extern tree decl_attributes (tree *, tree, int, tree = NULL_TREE); |
36 | |
37 | extern bool cxx11_attribute_p (const_tree); |
38 | extern tree get_attribute_name (const_tree); |
39 | extern tree get_attribute_namespace (const_tree); |
40 | extern void apply_tm_attr (tree, tree); |
41 | extern tree make_attribute (const char *, const char *, tree); |
42 | extern bool attribute_ignored_p (tree); |
43 | extern bool attribute_ignored_p (const attribute_spec *const); |
44 | |
45 | extern struct scoped_attributes* register_scoped_attributes (const struct attribute_spec *, |
46 | const char *, |
47 | bool = false); |
48 | |
49 | extern char *sorted_attr_string (tree); |
50 | extern bool common_function_versions (tree, tree); |
51 | extern tree make_dispatcher_decl (const tree); |
52 | extern bool is_function_default_version (const tree); |
53 | extern void handle_ignored_attributes_option (vec<char *> *); |
54 | |
55 | /* Return a type like TTYPE except that its TYPE_ATTRIBUTES |
56 | is ATTRIBUTE. |
57 | |
58 | Such modified types already made are recorded so that duplicates |
59 | are not made. */ |
60 | |
61 | extern tree build_type_attribute_variant (tree, tree); |
62 | extern tree build_decl_attribute_variant (tree, tree); |
63 | extern tree build_type_attribute_qual_variant (tree, tree, int); |
64 | |
65 | extern bool simple_cst_list_equal (const_tree, const_tree); |
66 | extern bool attribute_value_equal (const_tree, const_tree); |
67 | |
68 | /* Return 0 if the attributes for two types are incompatible, 1 if they |
69 | are compatible, and 2 if they are nearly compatible (which causes a |
70 | warning to be generated). */ |
71 | extern int comp_type_attributes (const_tree, const_tree); |
72 | |
73 | extern tree affects_type_identity_attributes (tree, bool = true); |
74 | extern tree restrict_type_identity_attributes_to (tree, tree); |
75 | |
76 | /* Default versions of target-overridable functions. */ |
77 | extern tree merge_decl_attributes (tree, tree); |
78 | extern tree merge_type_attributes (tree, tree); |
79 | |
80 | /* Remove any instances of attribute ATTR_NAME in LIST and return the |
81 | modified list. */ |
82 | |
83 | extern tree remove_attribute (const char *, tree); |
84 | |
85 | /* Similarly but also with specific attribute namespace. */ |
86 | |
87 | extern tree remove_attribute (const char *, const char *, tree); |
88 | |
89 | /* Given two attributes lists, return a list of their union. */ |
90 | |
91 | extern tree merge_attributes (tree, tree); |
92 | |
93 | /* Duplicate all attributes with name NAME in ATTR list to *ATTRS if |
94 | they are missing there. */ |
95 | |
96 | extern void duplicate_one_attribute (tree *, tree, const char *); |
97 | |
98 | /* Duplicate all attributes from user DECL to the corresponding |
99 | builtin that should be propagated. */ |
100 | |
101 | extern void copy_attributes_to_builtin (tree); |
102 | |
103 | /* Given two Windows decl attributes lists, possibly including |
104 | dllimport, return a list of their union . */ |
105 | extern tree merge_dllimport_decl_attributes (tree, tree); |
106 | |
107 | /* Handle a "dllimport" or "dllexport" attribute. */ |
108 | extern tree handle_dll_attribute (tree *, tree, tree, int, bool *); |
109 | |
110 | extern int attribute_list_equal (const_tree, const_tree); |
111 | extern int attribute_list_contained (const_tree, const_tree); |
112 | |
113 | /* The backbone of lookup_attribute(). ATTR_LEN is the string length |
114 | of ATTR_NAME, and LIST is not NULL_TREE. |
115 | |
116 | The function is called from lookup_attribute in order to optimize |
117 | for size. */ |
118 | extern tree private_lookup_attribute (const char *attr_name, size_t attr_len, |
119 | tree list); |
120 | extern tree private_lookup_attribute (const char *attr_ns, |
121 | const char *attr_name, |
122 | size_t attr_ns_len, size_t attr_len, |
123 | tree list); |
124 | |
125 | extern unsigned decls_mismatched_attributes (tree, tree, tree, |
126 | const char* const[], |
127 | pretty_printer*); |
128 | |
129 | extern void maybe_diag_alias_attributes (tree, tree); |
130 | |
131 | /* For a given string S of length L, strip leading and trailing '_' characters |
132 | so that we have a canonical form of attribute names. NB: This function may |
133 | change S and L. */ |
134 | |
135 | template <typename T> |
136 | inline bool |
137 | canonicalize_attr_name (const char *&s, T &l) |
138 | { |
139 | if (l > 4 && s[0] == '_' && s[1] == '_' && s[l - 1] == '_' && s[l - 2] == '_') |
140 | { |
141 | s += 2; |
142 | l -= 4; |
143 | return true; |
144 | } |
145 | return false; |
146 | } |
147 | |
148 | /* For a given IDENTIFIER_NODE, strip leading and trailing '_' characters |
149 | so that we have a canonical form of attribute names. */ |
150 | |
151 | inline tree |
152 | canonicalize_attr_name (tree attr_name) |
153 | { |
154 | size_t l = IDENTIFIER_LENGTH (attr_name); |
155 | const char *s = IDENTIFIER_POINTER (attr_name); |
156 | |
157 | if (canonicalize_attr_name (s, l)) |
158 | return get_identifier_with_length (s, l); |
159 | |
160 | return attr_name; |
161 | } |
162 | |
163 | /* Compare attribute identifiers ATTR1 and ATTR2 with length ATTR1_LEN and |
164 | ATTR2_LEN. */ |
165 | |
166 | inline bool |
167 | cmp_attribs (const char *attr1, size_t attr1_len, |
168 | const char *attr2, size_t attr2_len) |
169 | { |
170 | return attr1_len == attr2_len && strncmp (s1: attr1, s2: attr2, n: attr1_len) == 0; |
171 | } |
172 | |
173 | /* Compare attribute identifiers ATTR1 and ATTR2. */ |
174 | |
175 | inline bool |
176 | cmp_attribs (const char *attr1, const char *attr2) |
177 | { |
178 | return cmp_attribs (attr1, attr1_len: strlen (s: attr1), attr2, attr2_len: strlen (s: attr2)); |
179 | } |
180 | |
181 | /* Given an identifier node IDENT and a string ATTR_NAME, return true |
182 | if the identifier node is a valid attribute name for the string. */ |
183 | |
184 | inline bool |
185 | is_attribute_p (const char *attr_name, const_tree ident) |
186 | { |
187 | return cmp_attribs (attr1: attr_name, attr1_len: strlen (s: attr_name), |
188 | IDENTIFIER_POINTER (ident), IDENTIFIER_LENGTH (ident)); |
189 | } |
190 | |
191 | /* Given an attribute ATTR and a string ATTR_NS, return true |
192 | if the attribute namespace is valid for the string. ATTR_NS "" stands |
193 | for standard attribute (NULL get_attribute_namespace) or "gnu" |
194 | namespace. */ |
195 | |
196 | inline bool |
197 | is_attribute_namespace_p (const char *attr_ns, const_tree attr) |
198 | { |
199 | tree ident = get_attribute_namespace (attr); |
200 | if (attr_ns == NULL) |
201 | return ident == NULL_TREE; |
202 | if (attr_ns[0]) |
203 | return ident && is_attribute_p (attr_name: attr_ns, ident); |
204 | return ident == NULL_TREE || is_attribute_p (attr_name: "gnu" , ident); |
205 | } |
206 | |
207 | /* Given an attribute name ATTR_NAME and a list of attributes LIST, |
208 | return a pointer to the attribute's list element if the attribute |
209 | is part of the list, or NULL_TREE if not found. If the attribute |
210 | appears more than once, this only returns the first occurrence; the |
211 | TREE_CHAIN of the return value should be passed back in if further |
212 | occurrences are wanted. ATTR_NAME must be in the form 'text' (not |
213 | '__text__'). */ |
214 | |
215 | inline tree |
216 | lookup_attribute (const char *attr_name, tree list) |
217 | { |
218 | if (CHECKING_P && attr_name[0] != '_') |
219 | { |
220 | size_t attr_len = strlen (s: attr_name); |
221 | gcc_checking_assert (!canonicalize_attr_name (attr_name, attr_len)); |
222 | } |
223 | /* In most cases, list is NULL_TREE. */ |
224 | if (list == NULL_TREE) |
225 | return NULL_TREE; |
226 | else |
227 | { |
228 | size_t attr_len = strlen (s: attr_name); |
229 | /* Do the strlen() before calling the out-of-line implementation. |
230 | In most cases attr_name is a string constant, and the compiler |
231 | will optimize the strlen() away. */ |
232 | return private_lookup_attribute (attr_name, attr_len, list); |
233 | } |
234 | } |
235 | |
236 | /* Similar to lookup_attribute, but also match the attribute namespace. |
237 | ATTR_NS "" stands for either standard attribute or "gnu" namespace. */ |
238 | |
239 | inline tree |
240 | lookup_attribute (const char *attr_ns, const char *attr_name, tree list) |
241 | { |
242 | if (CHECKING_P && attr_name[0] != '_') |
243 | { |
244 | size_t attr_len = strlen (s: attr_name); |
245 | gcc_checking_assert (!canonicalize_attr_name (attr_name, attr_len)); |
246 | } |
247 | if (CHECKING_P && attr_ns && attr_ns[0] != '_') |
248 | { |
249 | size_t attr_ns_len = strlen (s: attr_ns); |
250 | gcc_checking_assert (!canonicalize_attr_name (attr_ns, attr_ns_len)); |
251 | } |
252 | /* In most cases, list is NULL_TREE. */ |
253 | if (list == NULL_TREE) |
254 | return NULL_TREE; |
255 | else |
256 | { |
257 | size_t attr_ns_len = attr_ns ? strlen (s: attr_ns) : 0; |
258 | size_t attr_len = strlen (s: attr_name); |
259 | /* Do the strlen() before calling the out-of-line implementation. |
260 | In most cases attr_name is a string constant, and the compiler |
261 | will optimize the strlen() away. */ |
262 | return private_lookup_attribute (attr_ns, attr_name, |
263 | attr_ns_len, attr_len, list); |
264 | } |
265 | } |
266 | |
267 | /* Given an attribute name ATTR_NAME and a list of attributes LIST, |
268 | return a pointer to the attribute's list first element if the attribute |
269 | starts with ATTR_NAME. ATTR_NAME must be in the form 'text' (not |
270 | '__text__'). */ |
271 | |
272 | inline tree |
273 | lookup_attribute_by_prefix (const char *attr_name, tree list) |
274 | { |
275 | gcc_checking_assert (attr_name[0] != '_'); |
276 | /* In most cases, list is NULL_TREE. */ |
277 | if (list == NULL_TREE) |
278 | return NULL_TREE; |
279 | else |
280 | { |
281 | size_t attr_len = strlen (s: attr_name); |
282 | while (list) |
283 | { |
284 | tree name = get_attribute_name (list); |
285 | size_t ident_len = IDENTIFIER_LENGTH (name); |
286 | |
287 | if (attr_len > ident_len) |
288 | { |
289 | list = TREE_CHAIN (list); |
290 | continue; |
291 | } |
292 | |
293 | const char *p = IDENTIFIER_POINTER (name); |
294 | gcc_checking_assert (attr_len == 0 || p[0] != '_' |
295 | || (ident_len > 1 && p[1] != '_')); |
296 | if (strncmp (s1: attr_name, s2: p, n: attr_len) == 0) |
297 | break; |
298 | |
299 | list = TREE_CHAIN (list); |
300 | } |
301 | |
302 | return list; |
303 | } |
304 | } |
305 | |
306 | /* Description of a function argument declared with attribute access. |
307 | Used as an "iterator" over all such arguments in a function declaration |
308 | or call. */ |
309 | |
310 | struct attr_access |
311 | { |
312 | /* The beginning and end of the internal string representation. */ |
313 | const char *str, *end; |
314 | /* The attribute pointer argument. */ |
315 | tree ptr; |
316 | /* For a declaration, a TREE_CHAIN of VLA bound expressions stored |
317 | in TREE_VALUE and their positions in the argument list (stored |
318 | in TREE_PURPOSE). Each expression may be a PARM_DECL or some |
319 | other DECL (for ordinary variables), or an EXPR for other |
320 | expressions (e.g., funcion calls). */ |
321 | tree size; |
322 | |
323 | /* The zero-based position of each of the formal function arguments. |
324 | For the optional SIZARG, UINT_MAX when not specified. For VLAs |
325 | with multiple variable bounds, SIZARG is the position corresponding |
326 | to the most significant bound in the argument list. Positions of |
327 | subsequent bounds are in the TREE_PURPOSE field of the SIZE chain. */ |
328 | unsigned ptrarg; |
329 | unsigned sizarg; |
330 | /* For internal specifications only, the constant minimum size of |
331 | the array, zero if not specified, and HWI_M1U for the unspecified |
332 | VLA [*] notation. Meaningless for external (explicit) access |
333 | specifications. */ |
334 | unsigned HOST_WIDE_INT minsize; |
335 | |
336 | /* The access mode. */ |
337 | access_mode mode; |
338 | |
339 | /* Set for an attribute added internally rather than by an explicit |
340 | declaration. */ |
341 | bool internal_p; |
342 | /* Set for the T[static MINSIZE] array notation for nonzero MINSIZE |
343 | less than HWI_M1U. */ |
344 | bool static_p; |
345 | |
346 | /* Return the number of specified VLA bounds. */ |
347 | unsigned vla_bounds (unsigned *) const; |
348 | |
349 | /* Return internal representation as STRING_CST. */ |
350 | tree to_internal_string () const; |
351 | |
352 | /* Return the human-readable representation of the external attribute |
353 | specification (as it might appear in the source code) as STRING_CST. */ |
354 | tree to_external_string () const; |
355 | |
356 | /* Return argument of array type formatted as a readable string. */ |
357 | std::string array_as_string (tree) const; |
358 | |
359 | /* Return the access mode corresponding to the character code. */ |
360 | static access_mode from_mode_char (char); |
361 | |
362 | /* Reset front end-specific attribute access data from attributes. */ |
363 | static void free_lang_data (tree); |
364 | |
365 | /* The character codes corresponding to all the access modes. */ |
366 | static constexpr char mode_chars[5] = { '-', 'r', 'w', 'x', '^' }; |
367 | |
368 | /* The strings corresponding to just the external access modes. */ |
369 | static constexpr char mode_names[4][11] = |
370 | { |
371 | "none" , "read_only" , "write_only" , "read_write" |
372 | }; |
373 | }; |
374 | |
375 | inline access_mode |
376 | attr_access::from_mode_char (char c) |
377 | { |
378 | switch (c) |
379 | { |
380 | case mode_chars[access_none]: return access_none; |
381 | case mode_chars[access_read_only]: return access_read_only; |
382 | case mode_chars[access_write_only]: return access_write_only; |
383 | case mode_chars[access_read_write]: return access_read_write; |
384 | case mode_chars[access_deferred]: return access_deferred; |
385 | } |
386 | gcc_unreachable (); |
387 | } |
388 | |
389 | /* Used to define rdwr_map below. */ |
390 | struct rdwr_access_hash: int_hash<int, -1> { }; |
391 | |
392 | /* A mapping between argument number corresponding to attribute access |
393 | mode (read_only, write_only, or read_write) and operands. */ |
394 | struct attr_access; |
395 | typedef hash_map<rdwr_access_hash, attr_access> rdwr_map; |
396 | |
397 | extern void init_attr_rdwr_indices (rdwr_map *, tree); |
398 | extern attr_access *get_parm_access (rdwr_map &, tree, |
399 | tree = current_function_decl); |
400 | |
401 | #endif // GCC_ATTRIBS_H |
402 | |