1 /* Definitions for expressions stored in reversed prefix form, for GDB.
3 Copyright (C) 1986, 1989, 1992, 1994, 2000, 2003, 2005, 2007, 2008, 2009,
4 2010, 2011 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #if !defined (EXPRESSION_H)
22 #define EXPRESSION_H 1
25 #include "symtab.h" /* Needed for "struct block" type. */
26 #include "doublest.h" /* Needed for DOUBLEST. */
29 /* Definitions for saved C expressions. */
31 /* An expression is represented as a vector of union exp_element's.
32 Each exp_element is an opcode, except that some opcodes cause
33 the following exp_element to be treated as a long or double constant
34 or as a variable. The opcodes are obeyed, using a stack for temporaries.
35 The value is left on the temporary stack at the end. */
37 /* When it is necessary to include a string,
38 it can occupy as many exp_elements as it needs.
39 We find the length of the string using strlen,
40 divide to find out how many exp_elements are used up,
41 and skip that many. Strings, like numbers, are indicated
42 by the preceding opcode. */
46 /* Used when it's necessary to pass an opcode which will be ignored,
47 or to catch uninitialized values. */
50 /* BINOP_... operate on two values computed by following subexpressions,
51 replacing them by one result value. They take no immediate arguments. */
58 BINOP_MOD
, /* mod (Knuth 1.2.4) */
61 BINOP_LOGICAL_AND
, /* && */
62 BINOP_LOGICAL_OR
, /* || */
63 BINOP_BITWISE_AND
, /* & */
64 BINOP_BITWISE_IOR
, /* | */
65 BINOP_BITWISE_XOR
, /* ^ */
67 BINOP_NOTEQUAL
, /* != */
75 BINOP_SUBSCRIPT
, /* x[y] */
76 BINOP_EXP
, /* Exponentiation */
83 /* STRUCTOP_MEMBER is used for pointer-to-member constructs.
84 X . * Y translates into X STRUCTOP_MEMBER Y. */
87 /* STRUCTOP_MPTR is used for pointer-to-member constructs
88 when X is a pointer instead of an aggregate. */
91 /* TYPE_INSTANCE is used when the user specifies a specific
92 type instantiation for overloaded methods/functions.
95 TYPE_INSTANCE num_types type0 ... typeN num_types TYPE_INSTANCE. */
100 /* For Modula-2 integer division DIV. */
103 BINOP_ASSIGN_MODIFY
, /* +=, -=, *=, and so on.
104 The following exp_element is another opcode,
105 a BINOP_, saying how to modify.
106 Then comes another BINOP_ASSIGN_MODIFY,
107 making three exp_elements in total. */
109 /* Modula-2 standard (binary) procedures. */
112 /* Concatenate two operands, such as character strings or bitstrings.
113 If the first operand is a integer expression, then it means concatenate
114 the second operand with itself that many times. */
117 /* For (the deleted) Chill and Pascal. */
118 BINOP_IN
, /* Returns 1 iff ARG1 IN ARG2. */
120 /* This is the "colon operator" used various places in (the
124 /* This must be the highest BINOP_ value, for expprint.c. */
127 /* Operates on three values computed by following subexpressions. */
128 TERNOP_COND
, /* ?: */
130 /* A sub-string/sub-array. (the deleted) Chill syntax:
131 OP1(OP2:OP3). Return elements OP2 through OP3 of OP1. */
134 /* A sub-string/sub-array. (The deleted) Chill syntax: OP1(OP2 UP
135 OP3). Return OP3 elements of OP1, starting with element
139 /* Multidimensional subscript operator, such as Modula-2 x[a,b,...].
140 The dimensionality is encoded in the operator, like the number of
141 function arguments in OP_FUNCALL, I.E. <OP><dimension><OP>.
142 The value of the first following subexpression is subscripted
143 by each of the next following subexpressions, one per dimension. */
146 /* The OP_... series take immediate following arguments.
147 After the arguments come another OP_... (the same one)
148 so that the grouping can be recognized from the end. */
150 /* OP_LONG is followed by a type pointer in the next exp_element
151 and the long constant value in the following exp_element.
152 Then comes another OP_LONG.
153 Thus, the operation occupies four exp_elements. */
156 /* OP_DOUBLE is similar but takes a DOUBLEST constant instead of a
160 /* OP_VAR_VALUE takes one struct block * in the following element,
161 and one struct symbol * in the following exp_element, followed
162 by another OP_VAR_VALUE, making four exp_elements. If the
163 block is non-NULL, evaluate the symbol relative to the
164 innermost frame executing in that block; if the block is NULL
165 use the selected frame. */
168 /* OP_LAST is followed by an integer in the next exp_element.
169 The integer is zero for the last value printed,
170 or it is the absolute number of a history element.
171 With another OP_LAST at the end, this makes three exp_elements. */
174 /* OP_REGISTER is followed by a string in the next exp_element.
175 This is the name of a register to fetch. */
178 /* OP_INTERNALVAR is followed by an internalvar ptr in the next
179 exp_element. With another OP_INTERNALVAR at the end, this
180 makes three exp_elements. */
183 /* OP_FUNCALL is followed by an integer in the next exp_element.
184 The integer is the number of args to the function call.
185 That many plus one values from following subexpressions
186 are used, the first one being the function.
187 The integer is followed by a repeat of OP_FUNCALL,
188 making three exp_elements. */
191 /* OP_OBJC_MSGCALL is followed by a string in the next exp_element
192 and then an integer. The string is the selector string. The
193 integer is the number of arguments to the message call. That
194 many plus one values are used, the first one being the object
195 pointer. This is an Objective C message. */
198 /* This is EXACTLY like OP_FUNCALL but is semantically different.
199 In F77, array subscript expressions, substring expressions and
200 function calls are all exactly the same syntactically. They
201 may only be disambiguated at runtime. Thus this operator,
202 which indicates that we have found something of the form
203 <name> ( <stuff> ). */
204 OP_F77_UNDETERMINED_ARGLIST
,
206 /* OP_COMPLEX takes a type in the following element, followed by another
207 OP_COMPLEX, making three exp_elements. It is followed by two double
208 args, and converts them into a complex number of the given type. */
211 /* OP_STRING represents a string constant.
212 Its format is the same as that of a STRUCTOP, but the string
213 data is just made into a string constant when the operation
217 /* OP_BITSTRING represents a packed bitstring constant.
218 Its format is the same as that of a STRUCTOP, but the bitstring
219 data is just made into a bitstring constant when the operation
223 /* OP_ARRAY creates an array constant out of the following subexpressions.
224 It is followed by two exp_elements, the first containing an integer
225 that is the lower bound of the array and the second containing another
226 integer that is the upper bound of the array. The second integer is
227 followed by a repeat of OP_ARRAY, making four exp_elements total.
228 The bounds are used to compute the number of following subexpressions
229 to consume, as well as setting the bounds in the created array constant.
230 The type of the elements is taken from the type of the first subexp,
231 and they must all match. */
234 /* UNOP_CAST is followed by a type pointer in the next exp_element.
235 With another UNOP_CAST at the end, this makes three exp_elements.
236 It casts the value of the following subexpression. */
239 /* The C++ dynamic_cast operator. */
242 /* The C++ reinterpret_cast operator. */
243 UNOP_REINTERPRET_CAST
,
245 /* UNOP_MEMVAL is followed by a type pointer in the next exp_element
246 With another UNOP_MEMVAL at the end, this makes three exp_elements.
247 It casts the contents of the word addressed by the value of the
248 following subexpression. */
251 /* UNOP_MEMVAL_TLS is followed by a `struct objfile' pointer in the next
252 exp_element and a type pointer in the following exp_element.
253 With another UNOP_MEMVAL_TLS at the end, this makes four exp_elements.
254 It casts the contents of the word offsetted by the value of the
255 following subexpression from the TLS specified by `struct objfile'. */
258 /* UNOP_... operate on one value from a following subexpression
259 and replace it with a result. They take no immediate arguments. */
261 UNOP_NEG
, /* Unary - */
262 UNOP_LOGICAL_NOT
, /* Unary ! */
263 UNOP_COMPLEMENT
, /* Unary ~ */
264 UNOP_IND
, /* Unary * */
265 UNOP_ADDR
, /* Unary & */
266 UNOP_PREINCREMENT
, /* ++ before an expression */
267 UNOP_POSTINCREMENT
, /* ++ after an expression */
268 UNOP_PREDECREMENT
, /* -- before an expression */
269 UNOP_POSTDECREMENT
, /* -- after an expression */
270 UNOP_SIZEOF
, /* Unary sizeof (followed by expression) */
272 UNOP_PLUS
, /* Unary plus */
274 UNOP_CAP
, /* Modula-2 standard (unary) procedures */
285 OP_BOOL
, /* Modula-2 builtin BOOLEAN type */
286 OP_M2_STRING
, /* Modula-2 string constants */
288 /* STRUCTOP_... operate on a value from a following subexpression
289 by extracting a structure component specified by a string
290 that appears in the following exp_elements (as many as needed).
291 STRUCTOP_STRUCT is used for "." and STRUCTOP_PTR for "->".
292 They differ only in the error message given in case the value is
293 not suitable or the structure component specified is not found.
295 The length of the string follows the opcode, followed by
296 BYTES_TO_EXP_ELEM(length) elements containing the data of the
297 string, followed by the length again and the opcode again. */
302 /* C++: OP_THIS is just a placeholder for the class instance variable.
303 It just comes in a tight (OP_THIS, OP_THIS) pair. */
306 /* Objective-C: OP_OBJC_SELF is just a placeholder for the class
307 instance variable. It just comes in a tight (OP_OBJC_SELF,
308 OP_OBJC_SELF) pair. */
311 /* Objective C: "@selector" pseudo-operator. */
314 /* OP_SCOPE surrounds a type name and a field name. The type
315 name is encoded as one element, but the field name stays as
316 a string, which, of course, is variable length. */
319 /* Used to represent named structure field values in brace
320 initializers (or tuples as they are called in (the deleted)
323 The gcc C syntax is NAME:VALUE or .NAME=VALUE, the (the
324 deleted) Chill syntax is .NAME:VALUE. Multiple labels (as in
325 the (the deleted) Chill syntax .NAME1,.NAME2:VALUE) is
326 represented as if it were .NAME1:(.NAME2:VALUE) (though that is
327 not valid (the deleted) Chill syntax).
329 The NAME is represented as for STRUCTOP_STRUCT; VALUE follows. */
332 /* OP_TYPE is for parsing types, and used with the "ptype" command
333 so we can look up types that are qualified by scope, either with
334 the GDB "::" operator, or the Modula-2 '.' operator. */
337 /* An un-looked-up identifier. */
340 /* An Objective C Foundation Class NSString constant. */
343 /* A F90 array range operator (for "exp:exp", "exp:", ":exp" and ":"). */
346 /* OP_DECFLOAT is followed by a type pointer in the next exp_element
347 and a dec long constant value in the following exp_element.
348 Then comes another OP_DECFLOAT. */
351 /* OP_ADL_FUNC specifies that the function is to be looked up in an
352 Argument Dependent manner (Koenig lookup). */
355 /* First extension operator. Individual language modules define
356 extra operators in *.inc include files below always starting with
357 numbering at OP_EXTENDED0:
358 BINOP_MOGRIFY = OP_EXTENDED0,
363 /* Last possible extension operator. Defined to provide an
364 explicit and finite number of extended operators. */
365 OP_EXTENDED_LAST
= 0xff,
366 /* NOTE: Eventually, we expect to convert to an object-oriented
367 formulation for expression operators that does away with the
368 need for these extension operators, and indeed for this
369 entire enumeration type. Therefore, consider the OP_EXTENDED
370 definitions to be a temporary measure. */
372 /* Each language specific set of operators starts at OP_EXTENDED0. */
373 #include "ada-operator.inc"
375 /* Existing only to swallow the last comma (',') from last .inc file. */
381 enum exp_opcode opcode
;
382 struct symbol
*symbol
;
384 DOUBLEST doubleconst
;
385 gdb_byte decfloatconst
[16];
386 /* Really sizeof (union exp_element) characters (or less for the last
387 element of a string). */
390 struct internalvar
*internalvar
;
392 struct objfile
*objfile
;
397 const struct language_defn
*language_defn
; /* language it was
399 struct gdbarch
*gdbarch
; /* architecture it was parsed in. */
401 union exp_element elts
[1];
404 /* Macros for converting between number of expression elements and bytes
405 to store that many expression elements. */
407 #define EXP_ELEM_TO_BYTES(elements) \
408 ((elements) * sizeof (union exp_element))
409 #define BYTES_TO_EXP_ELEM(bytes) \
410 (((bytes) + sizeof (union exp_element) - 1) / sizeof (union exp_element))
414 extern struct expression
*parse_expression (char *);
416 extern struct type
*parse_field_expression (char *, char **);
418 extern struct expression
*parse_exp_1 (char **, struct block
*, int);
420 /* For use by parsers; set if we want to parse an expression and
421 attempt to complete a field name. */
422 extern int in_parse_field
;
424 /* The innermost context required by the stack and register variables
425 we've encountered so far. To use this, set it to NULL, then call
426 parse_<whatever>, then look at it. */
427 extern struct block
*innermost_block
;
431 /* Values of NOSIDE argument to eval_subexp. */
436 EVAL_SKIP
, /* Only effect is to increment pos. */
437 EVAL_AVOID_SIDE_EFFECTS
/* Don't modify any variables or
438 call any functions. The value
439 returned will have the correct
440 type, and will have an
441 approximately correct lvalue
442 type (inaccuracy: anything that is
443 listed as being in a register in
444 the function in which it was
445 declared will be lval_register). */
448 extern struct value
*evaluate_subexp_standard
449 (struct type
*, struct expression
*, int *, enum noside
);
451 /* From expprint.c */
453 extern void print_expression (struct expression
*, struct ui_file
*);
455 extern char *op_string (enum exp_opcode
);
457 extern void dump_raw_expression (struct expression
*,
458 struct ui_file
*, char *);
459 extern void dump_prefix_expression (struct expression
*, struct ui_file
*);
461 #endif /* !defined (EXPRESSION_H) */