| 1 | /* Abstraction of various C++ ABI's we support, and the info we need |
| 2 | to get from them. |
| 3 | |
| 4 | Contributed by Daniel Berlin <dberlin@redhat.com> |
| 5 | |
| 6 | Copyright (C) 2001-2020 Free Software Foundation, Inc. |
| 7 | |
| 8 | This file is part of GDB. |
| 9 | |
| 10 | This program is free software; you can redistribute it and/or modify |
| 11 | it under the terms of the GNU General Public License as published by |
| 12 | the Free Software Foundation; either version 3 of the License, or |
| 13 | (at your option) any later version. |
| 14 | |
| 15 | This program is distributed in the hope that it will be useful, |
| 16 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | GNU General Public License for more details. |
| 19 | |
| 20 | You should have received a copy of the GNU General Public License |
| 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 22 | |
| 23 | #ifndef CP_ABI_H |
| 24 | #define CP_ABI_H |
| 25 | |
| 26 | struct fn_field; |
| 27 | struct type; |
| 28 | struct value; |
| 29 | struct ui_file; |
| 30 | struct frame_info; |
| 31 | |
| 32 | /* The functions here that attempt to determine what sort of thing a |
| 33 | mangled name refers to may well be revised in the future. It would |
| 34 | certainly be cleaner to carry this information explicitly in GDB's |
| 35 | data structures than to derive it from the mangled name. */ |
| 36 | |
| 37 | |
| 38 | /* Kinds of constructors. All these values are guaranteed to be |
| 39 | non-zero. */ |
| 40 | enum ctor_kinds { |
| 41 | |
| 42 | /* Initialize a complete object, including virtual bases, using |
| 43 | memory provided by caller. */ |
| 44 | complete_object_ctor = 1, |
| 45 | |
| 46 | /* Initialize a base object of some larger object. */ |
| 47 | base_object_ctor, |
| 48 | |
| 49 | /* An allocating complete-object constructor. */ |
| 50 | complete_object_allocating_ctor |
| 51 | }; |
| 52 | |
| 53 | /* Return non-zero iff NAME is the mangled name of a constructor. |
| 54 | Actually, return an `enum ctor_kind' value describing what *kind* |
| 55 | of constructor it is. */ |
| 56 | extern enum ctor_kinds is_constructor_name (const char *name); |
| 57 | |
| 58 | |
| 59 | /* Kinds of destructors. All these values are guaranteed to be |
| 60 | non-zero. */ |
| 61 | enum dtor_kinds { |
| 62 | |
| 63 | /* A destructor which finalizes the entire object, and then calls |
| 64 | `delete' on its storage. */ |
| 65 | deleting_dtor = 1, |
| 66 | |
| 67 | /* A destructor which finalizes the entire object, but does not call |
| 68 | `delete'. */ |
| 69 | complete_object_dtor, |
| 70 | |
| 71 | /* A destructor which finalizes a subobject of some larger |
| 72 | object. */ |
| 73 | base_object_dtor |
| 74 | }; |
| 75 | |
| 76 | /* Return non-zero iff NAME is the mangled name of a destructor. |
| 77 | Actually, return an `enum dtor_kind' value describing what *kind* |
| 78 | of destructor it is. */ |
| 79 | extern enum dtor_kinds is_destructor_name (const char *name); |
| 80 | |
| 81 | |
| 82 | /* Return non-zero iff NAME is the mangled name of a vtable. */ |
| 83 | extern int is_vtable_name (const char *name); |
| 84 | |
| 85 | |
| 86 | /* Return non-zero iff NAME is the un-mangled name of an operator, |
| 87 | perhaps scoped within some class. */ |
| 88 | extern int is_operator_name (const char *name); |
| 89 | |
| 90 | |
| 91 | /* Return an object's virtual function as a value. |
| 92 | |
| 93 | VALUEP is a pointer to a pointer to a value, holding the object |
| 94 | whose virtual function we want to invoke. If the ABI requires a |
| 95 | virtual function's caller to adjust the `this' pointer by an amount |
| 96 | retrieved from the vtable before invoking the function (i.e., we're |
| 97 | not using "vtable thunks" to do the adjustment automatically), then |
| 98 | this function may set *VALUEP to point to a new object with an |
| 99 | appropriately tweaked address. |
| 100 | |
| 101 | The J'th element of the overload set F is the virtual function of |
| 102 | *VALUEP we want to invoke. |
| 103 | |
| 104 | TYPE is the base type of *VALUEP whose method we're invoking --- |
| 105 | this is the type containing F. OFFSET is the offset of that base |
| 106 | type within *VALUEP. */ |
| 107 | extern struct value *value_virtual_fn_field (struct value **valuep, |
| 108 | struct fn_field *f, |
| 109 | int j, |
| 110 | struct type *type, |
| 111 | int offset); |
| 112 | |
| 113 | |
| 114 | /* Try to find the run-time type of VALUE, using C++ run-time type |
| 115 | information. Return the run-time type, or zero if we can't figure |
| 116 | it out. |
| 117 | |
| 118 | If we do find the run-time type: |
| 119 | - Set *FULL to non-zero if VALUE already contains the complete |
| 120 | run-time object, not just some embedded base class of the object. |
| 121 | - Set *TOP and *USING_ENC to indicate where the enclosing object |
| 122 | starts relative to VALUE: |
| 123 | - If *USING_ENC is zero, then *TOP is the offset from the start |
| 124 | of the complete object to the start of the embedded subobject |
| 125 | VALUE represents. In other words, the enclosing object starts |
| 126 | at VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) + |
| 127 | value_embedded_offset (VALUE) + *TOP |
| 128 | - If *USING_ENC is non-zero, then *TOP is the offset from the |
| 129 | address of the complete object to the enclosing object stored |
| 130 | in VALUE. In other words, the enclosing object starts at |
| 131 | VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) + *TOP. |
| 132 | If VALUE's type and enclosing type are the same, then these two |
| 133 | cases are equivalent. |
| 134 | |
| 135 | FULL, TOP, and USING_ENC can each be zero, in which case we don't |
| 136 | provide the corresponding piece of information. */ |
| 137 | extern struct type *value_rtti_type (struct value *value, |
| 138 | int *full, LONGEST *top, |
| 139 | int *using_enc); |
| 140 | |
| 141 | /* Compute the offset of the baseclass which is the INDEXth baseclass |
| 142 | of class TYPE, for value at VALADDR (in host) at ADDRESS (in |
| 143 | target), offset by EMBEDDED_OFFSET. VALADDR points to the raw |
| 144 | contents of VAL. The result is the offset of the baseclass value |
| 145 | relative to (the address of)(ARG) + OFFSET. */ |
| 146 | |
| 147 | extern int baseclass_offset (struct type *type, |
| 148 | int index, const gdb_byte *valaddr, |
| 149 | LONGEST embedded_offset, |
| 150 | CORE_ADDR address, |
| 151 | const struct value *val); |
| 152 | |
| 153 | /* Describe the target of a pointer to method. CONTENTS is the byte |
| 154 | pattern representing the pointer to method. TYPE is the pointer to |
| 155 | method type. STREAM is the stream to print it to. */ |
| 156 | void cplus_print_method_ptr (const gdb_byte *contents, |
| 157 | struct type *type, |
| 158 | struct ui_file *stream); |
| 159 | |
| 160 | /* Return the size of a pointer to member function of type |
| 161 | TO_TYPE. */ |
| 162 | int cplus_method_ptr_size (struct type *to_type); |
| 163 | |
| 164 | /* Return the method which should be called by applying METHOD_PTR to |
| 165 | *THIS_P, and adjust *THIS_P if necessary. */ |
| 166 | struct value *cplus_method_ptr_to_value (struct value **this_p, |
| 167 | struct value *method_ptr); |
| 168 | |
| 169 | /* Create the byte pattern in CONTENTS representing a pointer of type |
| 170 | TYPE to member function at ADDRESS (if IS_VIRTUAL is 0) or with |
| 171 | virtual table offset ADDRESS (if IS_VIRTUAL is 1). This is the |
| 172 | opposite of cplus_method_ptr_to_value. */ |
| 173 | void cplus_make_method_ptr (struct type *type, gdb_byte *CONTENTS, |
| 174 | CORE_ADDR address, int is_virtual); |
| 175 | |
| 176 | /* Print the vtable for VALUE, if there is one. If there is no |
| 177 | vtable, print a message, but do not throw. */ |
| 178 | |
| 179 | void cplus_print_vtable (struct value *value); |
| 180 | |
| 181 | /* Implement 'typeid': find the type info for VALUE, if possible. If |
| 182 | the type info cannot be found, throw an exception. */ |
| 183 | |
| 184 | extern struct value *cplus_typeid (struct value *value); |
| 185 | |
| 186 | /* Return the type of 'typeid' for the current C++ ABI on the given |
| 187 | architecture. */ |
| 188 | |
| 189 | extern struct type *cplus_typeid_type (struct gdbarch *gdbarch); |
| 190 | |
| 191 | /* Given a value which holds a pointer to a std::type_info, return the |
| 192 | type which that type_info represents. Throw an exception if the |
| 193 | type cannot be found. */ |
| 194 | |
| 195 | extern struct type *cplus_type_from_type_info (struct value *value); |
| 196 | |
| 197 | /* Given a value which holds a pointer to a std::type_info, return the |
| 198 | name of the type which that type_info represents. Throw an |
| 199 | exception if the type name cannot be found. */ |
| 200 | |
| 201 | extern std::string cplus_typename_from_type_info (struct value *value); |
| 202 | |
| 203 | /* Determine if we are currently in a C++ thunk. If so, get the |
| 204 | address of the routine we are thunking to and continue to there |
| 205 | instead. */ |
| 206 | |
| 207 | CORE_ADDR cplus_skip_trampoline (struct frame_info *frame, |
| 208 | CORE_ADDR stop_pc); |
| 209 | |
| 210 | /* Return a struct that provides pass-by-reference information |
| 211 | about the given TYPE. */ |
| 212 | |
| 213 | extern struct language_pass_by_ref_info cp_pass_by_reference |
| 214 | (struct type *type); |
| 215 | |
| 216 | struct cp_abi_ops |
| 217 | { |
| 218 | const char *shortname; |
| 219 | const char *longname; |
| 220 | const char *doc; |
| 221 | |
| 222 | /* ABI-specific implementations for the functions declared |
| 223 | above. */ |
| 224 | enum ctor_kinds (*is_constructor_name) (const char *name); |
| 225 | enum dtor_kinds (*is_destructor_name) (const char *name); |
| 226 | int (*is_vtable_name) (const char *name); |
| 227 | int (*is_operator_name) (const char *name); |
| 228 | struct value *(*virtual_fn_field) (struct value **arg1p, |
| 229 | struct fn_field * f, |
| 230 | int j, struct type * type, |
| 231 | int offset); |
| 232 | struct type *(*rtti_type) (struct value *v, int *full, |
| 233 | LONGEST *top, int *using_enc); |
| 234 | int (*baseclass_offset) (struct type *type, int index, |
| 235 | const bfd_byte *valaddr, LONGEST embedded_offset, |
| 236 | CORE_ADDR address, const struct value *val); |
| 237 | void (*print_method_ptr) (const gdb_byte *contents, |
| 238 | struct type *type, |
| 239 | struct ui_file *stream); |
| 240 | int (*method_ptr_size) (struct type *); |
| 241 | void (*make_method_ptr) (struct type *, gdb_byte *, |
| 242 | CORE_ADDR, int); |
| 243 | struct value * (*method_ptr_to_value) (struct value **, |
| 244 | struct value *); |
| 245 | void (*print_vtable) (struct value *); |
| 246 | struct value *(*get_typeid) (struct value *value); |
| 247 | struct type *(*get_typeid_type) (struct gdbarch *gdbarch); |
| 248 | struct type *(*get_type_from_type_info) (struct value *value); |
| 249 | std::string (*get_typename_from_type_info) (struct value *value); |
| 250 | CORE_ADDR (*skip_trampoline) (struct frame_info *, CORE_ADDR); |
| 251 | struct language_pass_by_ref_info (*pass_by_reference) (struct type *type); |
| 252 | }; |
| 253 | |
| 254 | |
| 255 | extern int register_cp_abi (struct cp_abi_ops *abi); |
| 256 | extern void set_cp_abi_as_auto_default (const char *short_name); |
| 257 | |
| 258 | #endif /* CP_ABI_H */ |