| 1 | /* Definitions for expressions stored in reversed prefix form, for GDB. |
| 2 | |
| 3 | Copyright (C) 1986-2020 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #if !defined (EXPRESSION_H) |
| 21 | #define EXPRESSION_H 1 |
| 22 | |
| 23 | #include "gdbtypes.h" |
| 24 | |
| 25 | /* While parsing expressions we need to track the innermost lexical block |
| 26 | that we encounter. In some situations we need to track the innermost |
| 27 | block just for symbols, and in other situations we want to track the |
| 28 | innermost block for symbols and registers. These flags are used by the |
| 29 | innermost block tracker to control which blocks we consider for the |
| 30 | innermost block. These flags can be combined together as needed. */ |
| 31 | |
| 32 | enum innermost_block_tracker_type |
| 33 | { |
| 34 | /* Track the innermost block for symbols within an expression. */ |
| 35 | INNERMOST_BLOCK_FOR_SYMBOLS = (1 << 0), |
| 36 | |
| 37 | /* Track the innermost block for registers within an expression. */ |
| 38 | INNERMOST_BLOCK_FOR_REGISTERS = (1 << 1) |
| 39 | }; |
| 40 | DEF_ENUM_FLAGS_TYPE (enum innermost_block_tracker_type, |
| 41 | innermost_block_tracker_types); |
| 42 | |
| 43 | /* Definitions for saved C expressions. */ |
| 44 | |
| 45 | /* An expression is represented as a vector of union exp_element's. |
| 46 | Each exp_element is an opcode, except that some opcodes cause |
| 47 | the following exp_element to be treated as a long or double constant |
| 48 | or as a variable. The opcodes are obeyed, using a stack for temporaries. |
| 49 | The value is left on the temporary stack at the end. */ |
| 50 | |
| 51 | /* When it is necessary to include a string, |
| 52 | it can occupy as many exp_elements as it needs. |
| 53 | We find the length of the string using strlen, |
| 54 | divide to find out how many exp_elements are used up, |
| 55 | and skip that many. Strings, like numbers, are indicated |
| 56 | by the preceding opcode. */ |
| 57 | |
| 58 | enum exp_opcode : uint8_t |
| 59 | { |
| 60 | #define OP(name) name , |
| 61 | |
| 62 | #include "std-operator.def" |
| 63 | |
| 64 | /* First extension operator. Individual language modules define extra |
| 65 | operators in *.def include files below with numbers higher than |
| 66 | OP_EXTENDED0. */ |
| 67 | OP (OP_EXTENDED0) |
| 68 | |
| 69 | /* Language specific operators. */ |
| 70 | #include "ada-operator.def" |
| 71 | #include "fortran-operator.def" |
| 72 | |
| 73 | #undef OP |
| 74 | |
| 75 | /* Existing only to swallow the last comma (',') from last .inc file. */ |
| 76 | OP_UNUSED_LAST |
| 77 | }; |
| 78 | |
| 79 | union exp_element |
| 80 | { |
| 81 | enum exp_opcode opcode; |
| 82 | struct symbol *symbol; |
| 83 | struct minimal_symbol *msymbol; |
| 84 | LONGEST longconst; |
| 85 | gdb_byte floatconst[16]; |
| 86 | /* Really sizeof (union exp_element) characters (or less for the last |
| 87 | element of a string). */ |
| 88 | char string; |
| 89 | struct type *type; |
| 90 | struct internalvar *internalvar; |
| 91 | const struct block *block; |
| 92 | struct objfile *objfile; |
| 93 | }; |
| 94 | |
| 95 | struct expression |
| 96 | { |
| 97 | const struct language_defn *language_defn; /* language it was |
| 98 | entered in. */ |
| 99 | struct gdbarch *gdbarch; /* architecture it was parsed in. */ |
| 100 | int nelts; |
| 101 | union exp_element elts[1]; |
| 102 | }; |
| 103 | |
| 104 | typedef gdb::unique_xmalloc_ptr<expression> expression_up; |
| 105 | |
| 106 | /* Macros for converting between number of expression elements and bytes |
| 107 | to store that many expression elements. */ |
| 108 | |
| 109 | #define EXP_ELEM_TO_BYTES(elements) \ |
| 110 | ((elements) * sizeof (union exp_element)) |
| 111 | #define BYTES_TO_EXP_ELEM(bytes) \ |
| 112 | (((bytes) + sizeof (union exp_element) - 1) / sizeof (union exp_element)) |
| 113 | |
| 114 | /* From parse.c */ |
| 115 | |
| 116 | class innermost_block_tracker; |
| 117 | extern expression_up parse_expression (const char *, |
| 118 | innermost_block_tracker * = nullptr); |
| 119 | |
| 120 | extern expression_up parse_expression_with_language (const char *string, |
| 121 | enum language lang); |
| 122 | |
| 123 | extern struct type *parse_expression_for_completion |
| 124 | (const char *, gdb::unique_xmalloc_ptr<char> *, enum type_code *); |
| 125 | |
| 126 | class innermost_block_tracker; |
| 127 | extern expression_up parse_exp_1 (const char **, CORE_ADDR pc, |
| 128 | const struct block *, int, |
| 129 | innermost_block_tracker * = nullptr); |
| 130 | |
| 131 | /* From eval.c */ |
| 132 | |
| 133 | /* Values of NOSIDE argument to eval_subexp. */ |
| 134 | |
| 135 | enum noside |
| 136 | { |
| 137 | EVAL_NORMAL, |
| 138 | EVAL_SKIP, /* Only effect is to increment pos. |
| 139 | Return type information where |
| 140 | possible. */ |
| 141 | EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or |
| 142 | call any functions. The value |
| 143 | returned will have the correct |
| 144 | type, and will have an |
| 145 | approximately correct lvalue |
| 146 | type (inaccuracy: anything that is |
| 147 | listed as being in a register in |
| 148 | the function in which it was |
| 149 | declared will be lval_register). |
| 150 | Ideally this would not even read |
| 151 | target memory, but currently it |
| 152 | does in many situations. */ |
| 153 | }; |
| 154 | |
| 155 | extern struct value *evaluate_subexp_standard |
| 156 | (struct type *, struct expression *, int *, enum noside); |
| 157 | |
| 158 | /* From expprint.c */ |
| 159 | |
| 160 | extern void print_expression (struct expression *, struct ui_file *); |
| 161 | |
| 162 | extern const char *op_name (struct expression *exp, enum exp_opcode opcode); |
| 163 | |
| 164 | extern const char *op_string (enum exp_opcode); |
| 165 | |
| 166 | extern void dump_raw_expression (struct expression *, |
| 167 | struct ui_file *, const char *); |
| 168 | extern void dump_prefix_expression (struct expression *, struct ui_file *); |
| 169 | |
| 170 | /* In an OP_RANGE expression, either bound could be empty, indicating |
| 171 | that its value is by default that of the corresponding bound of the |
| 172 | array or string. Also, the upper end of the range can be exclusive |
| 173 | or inclusive. So we have six sorts of subrange. This enumeration |
| 174 | type is to identify this. */ |
| 175 | |
| 176 | enum range_type |
| 177 | { |
| 178 | /* Neither the low nor the high bound was given -- so this refers to |
| 179 | the entire available range. */ |
| 180 | BOTH_BOUND_DEFAULT, |
| 181 | /* The low bound was not given and the high bound is inclusive. */ |
| 182 | LOW_BOUND_DEFAULT, |
| 183 | /* The high bound was not given and the low bound in inclusive. */ |
| 184 | HIGH_BOUND_DEFAULT, |
| 185 | /* Both bounds were given and both are inclusive. */ |
| 186 | NONE_BOUND_DEFAULT, |
| 187 | /* The low bound was not given and the high bound is exclusive. */ |
| 188 | NONE_BOUND_DEFAULT_EXCLUSIVE, |
| 189 | /* Both bounds were given. The low bound is inclusive and the high |
| 190 | bound is exclusive. */ |
| 191 | LOW_BOUND_DEFAULT_EXCLUSIVE, |
| 192 | }; |
| 193 | |
| 194 | #endif /* !defined (EXPRESSION_H) */ |