| 1 | /* Definitions for expressions stored in reversed prefix form, for GDB. |
| 2 | |
| 3 | Copyright (C) 1986-2017 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 | |
| 24 | #include "symtab.h" /* Needed for "struct block" type. */ |
| 25 | #include "doublest.h" /* Needed for DOUBLEST. */ |
| 26 | |
| 27 | |
| 28 | /* Definitions for saved C expressions. */ |
| 29 | |
| 30 | /* An expression is represented as a vector of union exp_element's. |
| 31 | Each exp_element is an opcode, except that some opcodes cause |
| 32 | the following exp_element to be treated as a long or double constant |
| 33 | or as a variable. The opcodes are obeyed, using a stack for temporaries. |
| 34 | The value is left on the temporary stack at the end. */ |
| 35 | |
| 36 | /* When it is necessary to include a string, |
| 37 | it can occupy as many exp_elements as it needs. |
| 38 | We find the length of the string using strlen, |
| 39 | divide to find out how many exp_elements are used up, |
| 40 | and skip that many. Strings, like numbers, are indicated |
| 41 | by the preceding opcode. */ |
| 42 | |
| 43 | enum exp_opcode |
| 44 | { |
| 45 | #define OP(name) name , |
| 46 | |
| 47 | #include "std-operator.def" |
| 48 | |
| 49 | /* First extension operator. Individual language modules define extra |
| 50 | operators in *.def include files below with numbers higher than |
| 51 | OP_EXTENDED0. */ |
| 52 | OP (OP_EXTENDED0) |
| 53 | |
| 54 | /* Language specific operators. */ |
| 55 | #include "ada-operator.def" |
| 56 | |
| 57 | #undef OP |
| 58 | |
| 59 | /* Existing only to swallow the last comma (',') from last .inc file. */ |
| 60 | OP_UNUSED_LAST |
| 61 | }; |
| 62 | |
| 63 | union exp_element |
| 64 | { |
| 65 | enum exp_opcode opcode; |
| 66 | struct symbol *symbol; |
| 67 | LONGEST longconst; |
| 68 | DOUBLEST doubleconst; |
| 69 | gdb_byte decfloatconst[16]; |
| 70 | /* Really sizeof (union exp_element) characters (or less for the last |
| 71 | element of a string). */ |
| 72 | char string; |
| 73 | struct type *type; |
| 74 | struct internalvar *internalvar; |
| 75 | const struct block *block; |
| 76 | struct objfile *objfile; |
| 77 | }; |
| 78 | |
| 79 | struct expression |
| 80 | { |
| 81 | const struct language_defn *language_defn; /* language it was |
| 82 | entered in. */ |
| 83 | struct gdbarch *gdbarch; /* architecture it was parsed in. */ |
| 84 | int nelts; |
| 85 | union exp_element elts[1]; |
| 86 | }; |
| 87 | |
| 88 | typedef gdb::unique_xmalloc_ptr<expression> expression_up; |
| 89 | |
| 90 | /* Macros for converting between number of expression elements and bytes |
| 91 | to store that many expression elements. */ |
| 92 | |
| 93 | #define EXP_ELEM_TO_BYTES(elements) \ |
| 94 | ((elements) * sizeof (union exp_element)) |
| 95 | #define BYTES_TO_EXP_ELEM(bytes) \ |
| 96 | (((bytes) + sizeof (union exp_element) - 1) / sizeof (union exp_element)) |
| 97 | |
| 98 | /* From parse.c */ |
| 99 | |
| 100 | extern expression_up parse_expression (const char *); |
| 101 | |
| 102 | extern expression_up parse_expression_with_language (const char *string, |
| 103 | enum language lang); |
| 104 | |
| 105 | extern struct type *parse_expression_for_completion (const char *, char **, |
| 106 | enum type_code *); |
| 107 | |
| 108 | extern expression_up parse_exp_1 (const char **, CORE_ADDR pc, |
| 109 | const struct block *, int); |
| 110 | |
| 111 | /* For use by parsers; set if we want to parse an expression and |
| 112 | attempt completion. */ |
| 113 | extern int parse_completion; |
| 114 | |
| 115 | /* The innermost context required by the stack and register variables |
| 116 | we've encountered so far. To use this, set it to NULL, then call |
| 117 | parse_<whatever>, then look at it. */ |
| 118 | extern const struct block *innermost_block; |
| 119 | |
| 120 | /* From eval.c */ |
| 121 | |
| 122 | /* Values of NOSIDE argument to eval_subexp. */ |
| 123 | |
| 124 | enum noside |
| 125 | { |
| 126 | EVAL_NORMAL, |
| 127 | EVAL_SKIP, /* Only effect is to increment pos. */ |
| 128 | EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or |
| 129 | call any functions. The value |
| 130 | returned will have the correct |
| 131 | type, and will have an |
| 132 | approximately correct lvalue |
| 133 | type (inaccuracy: anything that is |
| 134 | listed as being in a register in |
| 135 | the function in which it was |
| 136 | declared will be lval_register). |
| 137 | Ideally this would not even read |
| 138 | target memory, but currently it |
| 139 | does in many situations. */ |
| 140 | }; |
| 141 | |
| 142 | extern struct value *evaluate_subexp_standard |
| 143 | (struct type *, struct expression *, int *, enum noside); |
| 144 | |
| 145 | /* From expprint.c */ |
| 146 | |
| 147 | extern void print_expression (struct expression *, struct ui_file *); |
| 148 | |
| 149 | extern char *op_name (struct expression *exp, enum exp_opcode opcode); |
| 150 | |
| 151 | extern char *op_string (enum exp_opcode); |
| 152 | |
| 153 | extern void dump_raw_expression (struct expression *, |
| 154 | struct ui_file *, char *); |
| 155 | extern void dump_prefix_expression (struct expression *, struct ui_file *); |
| 156 | |
| 157 | /* In an OP_RANGE expression, either bound could be empty, indicating |
| 158 | that its value is by default that of the corresponding bound of the |
| 159 | array or string. So we have four sorts of subrange. This |
| 160 | enumeration type is to identify this. */ |
| 161 | |
| 162 | enum range_type |
| 163 | { |
| 164 | BOTH_BOUND_DEFAULT, /* "(:)" */ |
| 165 | LOW_BOUND_DEFAULT, /* "(:high)" */ |
| 166 | HIGH_BOUND_DEFAULT, /* "(low:)" */ |
| 167 | NONE_BOUND_DEFAULT /* "(low:high)" */ |
| 168 | }; |
| 169 | |
| 170 | #endif /* !defined (EXPRESSION_H) */ |