1 /* Declarations and definitions dealing with attribute handling. 2 Copyright (C) 2013-2020 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 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). */ 34 extern tree decl_attributes (tree *, tree, int, tree = NULL_TREE); 35 36 extern bool cxx11_attribute_p (const_tree); 37 extern tree get_attribute_name (const_tree); 38 extern tree get_attribute_namespace (const_tree); 39 extern void apply_tm_attr (tree, tree); 40 extern tree make_attribute (const char *, const char *, tree); 41 42 extern struct scoped_attributes* register_scoped_attributes (const struct attribute_spec *, 43 const char *); 44 45 extern char *sorted_attr_string (tree); 46 extern bool common_function_versions (tree, tree); 47 extern char *make_unique_name (tree, const char *, bool); 48 extern tree make_dispatcher_decl (const tree); 49 extern bool is_function_default_version (const tree); 50 51 /* Return a type like TTYPE except that its TYPE_ATTRIBUTES 52 is ATTRIBUTE. 53 54 Such modified types already made are recorded so that duplicates 55 are not made. */ 56 57 extern tree build_type_attribute_variant (tree, tree); 58 extern tree build_decl_attribute_variant (tree, tree); 59 extern tree build_type_attribute_qual_variant (tree, tree, int); 60 61 extern bool attribute_value_equal (const_tree, const_tree); 62 63 /* Return 0 if the attributes for two types are incompatible, 1 if they 64 are compatible, and 2 if they are nearly compatible (which causes a 65 warning to be generated). */ 66 extern int comp_type_attributes (const_tree, const_tree); 67 68 /* Default versions of target-overridable functions. */ 69 extern tree merge_decl_attributes (tree, tree); 70 extern tree merge_type_attributes (tree, tree); 71 72 /* Remove any instances of attribute ATTR_NAME in LIST and return the 73 modified list. */ 74 75 extern tree remove_attribute (const char *, tree); 76 77 /* Given two attributes lists, return a list of their union. */ 78 79 extern tree merge_attributes (tree, tree); 80 81 /* Duplicate all attributes with name NAME in ATTR list to *ATTRS if 82 they are missing there. */ 83 84 extern void duplicate_one_attribute (tree *, tree, const char *); 85 86 /* Duplicate all attributes from user DECL to the corresponding 87 builtin that should be propagated. */ 88 89 extern void copy_attributes_to_builtin (tree); 90 91 /* Given two Windows decl attributes lists, possibly including 92 dllimport, return a list of their union . */ 93 extern tree merge_dllimport_decl_attributes (tree, tree); 94 95 /* Handle a "dllimport" or "dllexport" attribute. */ 96 extern tree handle_dll_attribute (tree *, tree, tree, int, bool *); 97 98 extern int attribute_list_equal (const_tree, const_tree); 99 extern int attribute_list_contained (const_tree, const_tree); 100 101 /* The backbone of lookup_attribute(). ATTR_LEN is the string length 102 of ATTR_NAME, and LIST is not NULL_TREE. 103 104 The function is called from lookup_attribute in order to optimize 105 for size. */ 106 extern tree private_lookup_attribute (const char *attr_name, size_t attr_len, 107 tree list); 108 109 extern unsigned decls_mismatched_attributes (tree, tree, tree, 110 const char* const[], 111 pretty_printer*); 112 113 extern void maybe_diag_alias_attributes (tree, tree); 114 115 /* For a given IDENTIFIER_NODE, strip leading and trailing '_' characters 116 so that we have a canonical form of attribute names. */ 117 118 static inline tree 119 canonicalize_attr_name (tree attr_name) 120 { 121 const size_t l = IDENTIFIER_LENGTH (attr_name); 122 const char *s = IDENTIFIER_POINTER (attr_name); 123 124 if (l > 4 && s[0] == '_' && s[1] == '_' && s[l - 1] == '_' && s[l - 2] == '_') 125 return get_identifier_with_length (s + 2, l - 4); 126 127 return attr_name; 128 } 129 130 /* Compare attribute identifiers ATTR1 and ATTR2 with length ATTR1_LEN and 131 ATTR2_LEN. */ 132 133 static inline bool 134 cmp_attribs (const char *attr1, size_t attr1_len, 135 const char *attr2, size_t attr2_len) 136 { 137 return attr1_len == attr2_len && strncmp (attr1, attr2, attr1_len) == 0; 138 } 139 140 /* Compare attribute identifiers ATTR1 and ATTR2. */ 141 142 static inline bool 143 cmp_attribs (const char *attr1, const char *attr2) 144 { 145 return cmp_attribs (attr1, strlen (attr1), attr2, strlen (attr2)); 146 } 147 148 /* Given an identifier node IDENT and a string ATTR_NAME, return true 149 if the identifier node is a valid attribute name for the string. */ 150 151 static inline bool 152 is_attribute_p (const char *attr_name, const_tree ident) 153 { 154 return cmp_attribs (attr_name, strlen (attr_name), 155 IDENTIFIER_POINTER (ident), IDENTIFIER_LENGTH (ident)); 156 } 157 158 /* Given an attribute name ATTR_NAME and a list of attributes LIST, 159 return a pointer to the attribute's list element if the attribute 160 is part of the list, or NULL_TREE if not found. If the attribute 161 appears more than once, this only returns the first occurrence; the 162 TREE_CHAIN of the return value should be passed back in if further 163 occurrences are wanted. ATTR_NAME must be in the form 'text' (not 164 '__text__'). */ 165 166 static inline tree 167 lookup_attribute (const char *attr_name, tree list) 168 { 169 gcc_checking_assert (attr_name[0] != '_'); 170 /* In most cases, list is NULL_TREE. */ 171 if (list == NULL_TREE) 172 return NULL_TREE; 173 else 174 { 175 size_t attr_len = strlen (attr_name); 176 /* Do the strlen() before calling the out-of-line implementation. 177 In most cases attr_name is a string constant, and the compiler 178 will optimize the strlen() away. */ 179 return private_lookup_attribute (attr_name, attr_len, list); 180 } 181 } 182 183 /* Given an attribute name ATTR_NAME and a list of attributes LIST, 184 return a pointer to the attribute's list first element if the attribute 185 starts with ATTR_NAME. ATTR_NAME must be in the form 'text' (not 186 '__text__'). */ 187 188 static inline tree 189 lookup_attribute_by_prefix (const char *attr_name, tree list) 190 { 191 gcc_checking_assert (attr_name[0] != '_'); 192 /* In most cases, list is NULL_TREE. */ 193 if (list == NULL_TREE) 194 return NULL_TREE; 195 else 196 { 197 size_t attr_len = strlen (attr_name); 198 while (list) 199 { 200 size_t ident_len = IDENTIFIER_LENGTH (get_attribute_name (list)); 201 202 if (attr_len > ident_len) 203 { 204 list = TREE_CHAIN (list); 205 continue; 206 } 207 208 const char *p = IDENTIFIER_POINTER (get_attribute_name (list)); 209 gcc_checking_assert (attr_len == 0 || p[0] != '_'); 210 211 if (strncmp (attr_name, p, attr_len) == 0) 212 break; 213 214 list = TREE_CHAIN (list); 215 } 216 217 return list; 218 } 219 } 220 221 /* Description of a function argument declared with attribute access. 222 Used as an "iterator" over all such arguments in a function declaration 223 or call. */ 224 225 struct attr_access 226 { 227 /* The attribute pointer argument. */ 228 tree ptr; 229 /* The size of the pointed-to object or NULL when not specified. */ 230 tree size; 231 232 /* The zero-based number of each of the formal function arguments. */ 233 unsigned ptrarg; 234 unsigned sizarg; 235 236 /* The access mode. */ 237 enum access_mode { read_only, write_only, read_write }; 238 access_mode mode; 239 }; 240 241 #endif // GCC_ATTRIBS_H 242