1 /* Definitions for expressions stored in reversed prefix form, for GDB.
3 Copyright (C) 1986-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
20 #if !defined (EXPRESSION_H)
21 #define EXPRESSION_H 1
24 #include "symtab.h" /* Needed for "struct block" type. */
26 /* While parsing expressions we need to track the innermost lexical block
27 that we encounter. In some situations we need to track the innermost
28 block just for symbols, and in other situations we want to track the
29 innermost block for symbols and registers. These flags are used by the
30 innermost block tracker to control which blocks we consider for the
31 innermost block. These flags can be combined together as needed. */
33 enum innermost_block_tracker_type
35 /* Track the innermost block for symbols within an expression. */
36 INNERMOST_BLOCK_FOR_SYMBOLS = (1 << 0),
38 /* Track the innermost block for registers within an expression. */
39 INNERMOST_BLOCK_FOR_REGISTERS = (1 << 1)
41 DEF_ENUM_FLAGS_TYPE (enum innermost_block_tracker_type,
42 innermost_block_tracker_types);
44 /* Definitions for saved C expressions. */
46 /* An expression is represented as a vector of union exp_element's.
47 Each exp_element is an opcode, except that some opcodes cause
48 the following exp_element to be treated as a long or double constant
49 or as a variable. The opcodes are obeyed, using a stack for temporaries.
50 The value is left on the temporary stack at the end. */
52 /* When it is necessary to include a string,
53 it can occupy as many exp_elements as it needs.
54 We find the length of the string using strlen,
55 divide to find out how many exp_elements are used up,
56 and skip that many. Strings, like numbers, are indicated
57 by the preceding opcode. */
59 enum exp_opcode : uint8_t
61 #define OP(name) name ,
63 #include "std-operator.def"
65 /* First extension operator. Individual language modules define extra
66 operators in *.def include files below with numbers higher than
70 /* Language specific operators. */
71 #include "ada-operator.def"
75 /* Existing only to swallow the last comma (',') from last .inc file. */
81 enum exp_opcode opcode;
82 struct symbol *symbol;
83 struct minimal_symbol *msymbol;
85 gdb_byte floatconst[16];
86 /* Really sizeof (union exp_element) characters (or less for the last
87 element of a string). */
90 struct internalvar *internalvar;
91 const struct block *block;
92 struct objfile *objfile;
97 const struct language_defn *language_defn; /* language it was
99 struct gdbarch *gdbarch; /* architecture it was parsed in. */
101 union exp_element elts[1];
104 typedef gdb::unique_xmalloc_ptr<expression> expression_up;
106 /* Macros for converting between number of expression elements and bytes
107 to store that many expression elements. */
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))
116 extern expression_up parse_expression (const char *);
118 extern expression_up parse_expression_with_language (const char *string,
121 extern struct type *parse_expression_for_completion
122 (const char *, gdb::unique_xmalloc_ptr<char> *, enum type_code *);
124 extern expression_up parse_exp_1 (const char **, CORE_ADDR pc,
125 const struct block *, int,
126 innermost_block_tracker_types
127 = INNERMOST_BLOCK_FOR_SYMBOLS);
129 /* For use by parsers; set if we want to parse an expression and
130 attempt completion. */
131 extern int parse_completion;
135 /* Values of NOSIDE argument to eval_subexp. */
140 EVAL_SKIP, /* Only effect is to increment pos.
141 Return type information where
143 EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or
144 call any functions. The value
145 returned will have the correct
146 type, and will have an
147 approximately correct lvalue
148 type (inaccuracy: anything that is
149 listed as being in a register in
150 the function in which it was
151 declared will be lval_register).
152 Ideally this would not even read
153 target memory, but currently it
154 does in many situations. */
157 extern struct value *evaluate_subexp_standard
158 (struct type *, struct expression *, int *, enum noside);
160 /* From expprint.c */
162 extern void print_expression (struct expression *, struct ui_file *);
164 extern const char *op_name (struct expression *exp, enum exp_opcode opcode);
166 extern const char *op_string (enum exp_opcode);
168 extern void dump_raw_expression (struct expression *,
169 struct ui_file *, const char *);
170 extern void dump_prefix_expression (struct expression *, struct ui_file *);
172 /* In an OP_RANGE expression, either bound could be empty, indicating
173 that its value is by default that of the corresponding bound of the
174 array or string. Also, the upper end of the range can be exclusive
175 or inclusive. So we have six sorts of subrange. This enumeration
176 type is to identify this. */
180 /* Neither the low nor the high bound was given -- so this refers to
181 the entire available range. */
183 /* The low bound was not given and the high bound is inclusive. */
185 /* The high bound was not given and the low bound in inclusive. */
187 /* Both bounds were given and both are inclusive. */
189 /* The low bound was not given and the high bound is exclusive. */
190 NONE_BOUND_DEFAULT_EXCLUSIVE,
191 /* Both bounds were given. The low bound is inclusive and the high
192 bound is exclusive. */
193 LOW_BOUND_DEFAULT_EXCLUSIVE,
196 #endif /* !defined (EXPRESSION_H) */