1 /* Definitions for expressions stored in reversed prefix form, for GDB.
3 Copyright (C) 1986-2020 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
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. */
32 enum innermost_block_tracker_type
34 /* Track the innermost block for symbols within an expression. */
35 INNERMOST_BLOCK_FOR_SYMBOLS
= (1 << 0),
37 /* Track the innermost block for registers within an expression. */
38 INNERMOST_BLOCK_FOR_REGISTERS
= (1 << 1)
40 DEF_ENUM_FLAGS_TYPE (enum innermost_block_tracker_type
,
41 innermost_block_tracker_types
);
43 /* Definitions for saved C expressions. */
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. */
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. */
58 enum exp_opcode
: uint8_t
60 #define OP(name) name ,
62 #include "std-operator.def"
66 /* Existing only to swallow the last comma (',') from last .inc file. */
70 /* Values of NOSIDE argument to eval_subexp. */
75 EVAL_SKIP
, /* Only effect is to increment pos.
76 Return type information where
78 EVAL_AVOID_SIDE_EFFECTS
/* Don't modify any variables or
79 call any functions. The value
80 returned will have the correct
81 type, and will have an
82 approximately correct lvalue
83 type (inaccuracy: anything that is
84 listed as being in a register in
85 the function in which it was
86 declared will be lval_register).
87 Ideally this would not even read
88 target memory, but currently it
89 does in many situations. */
94 enum exp_opcode opcode
;
95 struct symbol
*symbol
;
96 struct minimal_symbol
*msymbol
;
98 gdb_byte floatconst
[16];
99 /* Really sizeof (union exp_element) characters (or less for the last
100 element of a string). */
103 struct internalvar
*internalvar
;
104 const struct block
*block
;
105 struct objfile
*objfile
;
110 expression (const struct language_defn
*, struct gdbarch
*, size_t);
112 DISABLE_COPY_AND_ASSIGN (expression
);
114 void resize (size_t);
116 /* Return the opcode for the outermost sub-expression of this
118 enum exp_opcode
first_opcode () const
120 return elts
[0].opcode
;
123 /* Language it was entered in. */
124 const struct language_defn
*language_defn
;
125 /* Architecture it was parsed in. */
126 struct gdbarch
*gdbarch
;
128 union exp_element
*elts
;
131 typedef std::unique_ptr
<expression
> expression_up
;
133 /* Macros for converting between number of expression elements and bytes
134 to store that many expression elements. */
136 #define EXP_ELEM_TO_BYTES(elements) \
137 ((elements) * sizeof (union exp_element))
138 #define BYTES_TO_EXP_ELEM(bytes) \
139 (((bytes) + sizeof (union exp_element) - 1) / sizeof (union exp_element))
143 class innermost_block_tracker
;
144 extern expression_up
parse_expression (const char *,
145 innermost_block_tracker
* = nullptr);
147 extern expression_up
parse_expression_with_language (const char *string
,
150 extern struct type
*parse_expression_for_completion
151 (const char *, gdb::unique_xmalloc_ptr
<char> *, enum type_code
*);
153 class innermost_block_tracker
;
154 extern expression_up
parse_exp_1 (const char **, CORE_ADDR pc
,
155 const struct block
*, int,
156 innermost_block_tracker
* = nullptr);
160 extern struct value
*evaluate_subexp_standard
161 (struct type
*, struct expression
*, int *, enum noside
);
163 /* Evaluate a function call. The function to be called is in CALLEE and
164 the arguments passed to the function are in ARGVEC.
165 FUNCTION_NAME is the name of the function, if known.
166 DEFAULT_RETURN_TYPE is used as the function's return type if the return
169 extern struct value
*evaluate_subexp_do_call (expression
*exp
,
172 gdb::array_view
<value
*> argvec
,
173 const char *function_name
,
174 type
*default_return_type
);
176 /* From expprint.c */
178 extern void print_expression (struct expression
*, struct ui_file
*);
180 extern const char *op_name (enum exp_opcode opcode
);
182 extern const char *op_string (enum exp_opcode
);
184 extern void dump_raw_expression (struct expression
*,
185 struct ui_file
*, const char *);
186 extern void dump_prefix_expression (struct expression
*, struct ui_file
*);
188 /* In an OP_RANGE expression, either bound could be empty, indicating
189 that its value is by default that of the corresponding bound of the
190 array or string. Also, the upper end of the range can be exclusive
191 or inclusive. So we have six sorts of subrange. This enumeration
192 type is to identify this. */
194 enum range_flag
: unsigned
196 /* This is a standard range. Both the lower and upper bounds are
197 defined, and the bounds are inclusive. */
200 /* The low bound was not given. */
201 RANGE_LOW_BOUND_DEFAULT
= 1 << 0,
203 /* The high bound was not given. */
204 RANGE_HIGH_BOUND_DEFAULT
= 1 << 1,
206 /* The high bound of this range is exclusive. */
207 RANGE_HIGH_BOUND_EXCLUSIVE
= 1 << 2,
209 /* The range has a stride. */
210 RANGE_HAS_STRIDE
= 1 << 3,
213 DEF_ENUM_FLAGS_TYPE (enum range_flag
, range_flags
);
215 #endif /* !defined (EXPRESSION_H) */