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 32enum 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}; 40DEF_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 58enum 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 79union 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 95struct 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 104typedef 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 116class innermost_block_tracker; 117extern expression_up parse_expression (const char *, 118 innermost_block_tracker * = nullptr); 119 120extern expression_up parse_expression_with_language (const char *string, 121 enum language lang); 122 123extern struct type *parse_expression_for_completion 124 (const char *, gdb::unique_xmalloc_ptr<char> *, enum type_code *); 125 126class innermost_block_tracker; 127extern 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 135enum 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 155extern struct value *evaluate_subexp_standard 156 (struct type *, struct expression *, int *, enum noside); 157 158/* From expprint.c */ 159 160extern void print_expression (struct expression *, struct ui_file *); 161 162extern const char *op_name (struct expression *exp, enum exp_opcode opcode); 163 164extern const char *op_string (enum exp_opcode); 165 166extern void dump_raw_expression (struct expression *, 167 struct ui_file *, const char *); 168extern 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 176enum 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) */ 195