1 /* Parser definitions for GDB.
3 Copyright (C) 1986-2021 Free Software Foundation, Inc.
5 Modified from expread.y by the Department of Computer Science at the
6 State University of New York at Buffalo.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #if !defined (PARSER_DEFS_H)
24 #define PARSER_DEFS_H 1
26 #include "expression.h"
32 class innermost_block_tracker
;
34 extern bool parser_debug
;
36 /* A class that can be used to build a "struct expression". */
40 /* Constructor. LANG is the language used to parse the expression.
41 And GDBARCH is the gdbarch to use during parsing. */
43 expr_builder (const struct language_defn
*lang
,
44 struct gdbarch
*gdbarch
);
46 DISABLE_COPY_AND_ASSIGN (expr_builder
);
48 /* Resize the allocated expression to the correct size, and return
49 it as an expression_up -- passing ownership to the caller. */
50 ATTRIBUTE_UNUSED_RESULT expression_up
release ();
52 /* Return the gdbarch that was passed to the constructor. */
54 struct gdbarch
*gdbarch ()
56 return expout
->gdbarch
;
59 /* Return the language that was passed to the constructor. */
61 const struct language_defn
*language ()
63 return expout
->language_defn
;
66 /* The size of the expression above. */
70 /* The expression related to this parser state. */
74 /* The number of elements already in the expression. This is used
75 to know where to put new elements. */
80 /* This is used for expression completion. */
82 struct expr_completion_state
84 /* The index of the last struct expression directly before a '.' or
85 '->'. This is set when parsing and is only used when completing a
86 field name. It is -1 if no dereference operation was found. */
87 int expout_last_struct
= -1;
89 /* If we are completing a tagged type name, this will be nonzero. */
90 enum type_code expout_tag_completion_type
= TYPE_CODE_UNDEF
;
92 /* The token for tagged type name completion. */
93 gdb::unique_xmalloc_ptr
<char> expout_completion_name
;
96 /* An instance of this type is instantiated during expression parsing,
97 and passed to the appropriate parser. It holds both inputs to the
98 parser, and result. */
100 struct parser_state
: public expr_builder
102 /* Constructor. LANG is the language used to parse the expression.
103 And GDBARCH is the gdbarch to use during parsing. */
105 parser_state (const struct language_defn
*lang
,
106 struct gdbarch
*gdbarch
,
107 const struct block
*context_block
,
108 CORE_ADDR context_pc
,
112 innermost_block_tracker
*tracker
,
114 : expr_builder (lang
, gdbarch
),
115 expression_context_block (context_block
),
116 expression_context_pc (context_pc
),
117 comma_terminates (comma
),
119 parse_completion (completion
),
120 block_tracker (tracker
),
121 void_context_p (void_p
)
125 DISABLE_COPY_AND_ASSIGN (parser_state
);
127 /* Begin counting arguments for a function call,
128 saving the data about any containing call. */
130 void start_arglist ()
132 m_funcall_chain
.push_back (arglist_len
);
136 /* Return the number of arguments in a function call just terminated,
137 and restore the data for the containing function call. */
141 int val
= arglist_len
;
142 arglist_len
= m_funcall_chain
.back ();
143 m_funcall_chain
.pop_back ();
147 /* Mark the current index as the starting location of a structure
148 expression. This is used when completing on field names. */
150 void mark_struct_expression ();
152 /* Indicate that the current parser invocation is completing a tag.
153 TAG is the type code of the tag, and PTR and LENGTH represent the
154 start of the tag name. */
156 void mark_completion_tag (enum type_code tag
, const char *ptr
, int length
);
159 /* If this is nonzero, this block is used as the lexical context for
162 const struct block
* const expression_context_block
;
164 /* If expression_context_block is non-zero, then this is the PC
165 within the block that we want to evaluate expressions at. When
166 debugging C or C++ code, we use this to find the exact line we're
167 at, and then look up the macro definitions active at that
169 const CORE_ADDR expression_context_pc
;
171 /* Nonzero means stop parsing on first comma (if not within parentheses). */
173 int comma_terminates
;
175 /* During parsing of a C expression, the pointer to the next character
176 is in this variable. */
180 /* After a token has been recognized, this variable points to it.
181 Currently used only for error reporting. */
182 const char *prev_lexptr
= nullptr;
184 /* Number of arguments seen so far in innermost function call. */
188 /* True if parsing an expression to attempt completion. */
189 int parse_completion
;
191 /* Completion state is updated here. */
192 expr_completion_state m_completion_state
;
194 /* The innermost block tracker. */
195 innermost_block_tracker
*block_tracker
;
197 /* True if no value is expected from the expression. */
202 /* Data structure for saving values of arglist_len for function calls whose
203 arguments contain other function calls. */
205 std::vector
<int> m_funcall_chain
;
208 /* When parsing expressions we track the innermost block that was
211 class innermost_block_tracker
214 innermost_block_tracker (innermost_block_tracker_types types
215 = INNERMOST_BLOCK_FOR_SYMBOLS
)
217 m_innermost_block (NULL
)
220 /* Update the stored innermost block if the new block B is more inner
221 than the currently stored block, or if no block is stored yet. The
222 type T tells us whether the block B was for a symbol or for a
223 register. The stored innermost block is only updated if the type T is
224 a type we are interested in, the types we are interested in are held
225 in M_TYPES and set during RESET. */
226 void update (const struct block
*b
, innermost_block_tracker_types t
);
228 /* Overload of main UPDATE method which extracts the block from BS. */
229 void update (const struct block_symbol
&bs
)
231 update (bs
.block
, INNERMOST_BLOCK_FOR_SYMBOLS
);
234 /* Return the stored innermost block. Can be nullptr if no symbols or
235 registers were found during an expression parse, and so no innermost
236 block was defined. */
237 const struct block
*block () const
239 return m_innermost_block
;
243 /* The type of innermost block being looked for. */
244 innermost_block_tracker_types m_types
;
246 /* The currently stored innermost block found while parsing an
248 const struct block
*m_innermost_block
;
251 /* A string token, either a char-string or bit-string. Char-strings are
252 used, for example, for the names of symbols. */
256 /* Pointer to first byte of char-string or first bit of bit-string. */
258 /* Length of string in bytes for char-string or bits for bit-string. */
264 /* A language-specific type field. */
266 /* Pointer to first byte of char-string or first bit of bit-string. */
268 /* Length of string in bytes for char-string or bits for bit-string. */
275 struct typed_stoken
*tokens
;
280 struct stoken stoken
;
286 struct stoken stoken
;
287 struct block_symbol sym
;
288 int is_a_field_of_this
;
291 struct objc_class_str
293 struct stoken stoken
;
298 /* Reverse an expression from suffix form (in which it is constructed)
299 to prefix form (in which we can conveniently print or execute it).
300 Ordinarily this always returns -1. However, if LAST_STRUCT
301 is not -1 (i.e., we are trying to complete a field name), it will
302 return the index of the subexpression which is the left-hand-side
303 of the struct operation at LAST_STRUCT. */
305 extern int prefixify_expression (struct expression
*expr
,
306 int last_struct
= -1);
308 extern void write_exp_elt_opcode (struct expr_builder
*, enum exp_opcode
);
310 extern void write_exp_elt_sym (struct expr_builder
*, struct symbol
*);
312 extern void write_exp_elt_longcst (struct expr_builder
*, LONGEST
);
314 extern void write_exp_elt_floatcst (struct expr_builder
*, const gdb_byte
*);
316 extern void write_exp_elt_type (struct expr_builder
*, struct type
*);
318 extern void write_exp_elt_intern (struct expr_builder
*, struct internalvar
*);
320 extern void write_exp_string (struct expr_builder
*, struct stoken
);
322 void write_exp_string_vector (struct expr_builder
*, int type
,
323 struct stoken_vector
*vec
);
325 extern void write_exp_bitstring (struct expr_builder
*, struct stoken
);
327 extern void write_exp_elt_block (struct expr_builder
*, const struct block
*);
329 extern void write_exp_elt_objfile (struct expr_builder
*,
330 struct objfile
*objfile
);
332 extern void write_exp_msymbol (struct expr_builder
*,
333 struct bound_minimal_symbol
);
335 extern void write_dollar_variable (struct parser_state
*, struct stoken str
);
337 /* Write a reference to a symbol to the expression being built in PS.
338 NAME is the name of the symbol to write; SYM is the symbol. If SYM
339 is nullptr (meaning the 'symbol' member), a minimal symbol will be
340 searched for and used if available. Throws an exception if SYM is
341 nullptr and no minimal symbol can be found. */
343 extern void write_exp_symbol_reference (struct parser_state
*ps
,
345 struct block_symbol sym
);
347 extern const char *find_template_name_end (const char *);
349 extern std::string
copy_name (struct stoken
);
351 extern int dump_subexp (struct expression
*, struct ui_file
*, int);
353 extern int dump_subexp_body_standard (struct expression
*,
354 struct ui_file
*, int);
356 /* Dump (to STREAM) a function call like expression at position ELT in the
357 expression array EXP. Return a new value for ELT just after the
358 function call expression. */
360 extern int dump_subexp_body_funcall (struct expression
*exp
,
361 struct ui_file
*stream
, int elt
);
363 extern void operator_length (const struct expression
*, int, int *, int *);
365 extern void operator_length_standard (const struct expression
*, int, int *,
368 extern int operator_check_standard (struct expression
*exp
, int pos
,
370 (struct objfile
*objfile
, void *data
),
373 extern bool parse_float (const char *p
, int len
,
374 const struct type
*type
, gdb_byte
*data
);
376 /* These codes indicate operator precedences for expression printing,
377 least tightly binding first. */
378 /* Adding 1 to a precedence value is done for binary operators,
379 on the operand which is more tightly bound, so that operators
380 of equal precedence within that operand will get parentheses. */
381 /* PREC_HYPER and PREC_ABOVE_COMMA are not the precedence of any operator;
382 they are used as the "surrounding precedence" to force
383 various kinds of things to be parenthesized. */
386 PREC_NULL
, PREC_COMMA
, PREC_ABOVE_COMMA
, PREC_ASSIGN
, PREC_LOGICAL_OR
,
387 PREC_LOGICAL_AND
, PREC_BITWISE_IOR
, PREC_BITWISE_AND
, PREC_BITWISE_XOR
,
388 PREC_EQUAL
, PREC_ORDER
, PREC_SHIFT
, PREC_ADD
, PREC_MUL
, PREC_REPEAT
,
389 PREC_HYPER
, PREC_PREFIX
, PREC_SUFFIX
, PREC_BUILTIN_FUNCTION
392 /* Table mapping opcodes into strings for printing operators
393 and precedences of the operators. */
398 enum exp_opcode opcode
;
399 /* Precedence of operator. These values are used only by comparisons. */
400 enum precedence precedence
;
402 /* For a binary operator: 1 iff right associate.
403 For a unary operator: 1 iff postfix. */
407 /* Information needed to print, prefixify, and evaluate expressions for
410 struct exp_descriptor
412 /* Print subexpression. */
413 void (*print_subexp
) (struct expression
*, int *, struct ui_file
*,
416 /* Returns number of exp_elements needed to represent an operator and
417 the number of subexpressions it takes. */
418 void (*operator_length
) (const struct expression
*, int, int*, int *);
420 /* Call OBJFILE_FUNC for any objfile found being referenced by the
421 single operator of EXP at position POS. Operator parameters are
422 located at positive (POS + number) offsets in EXP. OBJFILE_FUNC
423 should never be called with NULL OBJFILE. OBJFILE_FUNC should
424 get passed an arbitrary caller supplied DATA pointer. If it
425 returns non-zero value then (any other) non-zero value should be
426 immediately returned to the caller. Otherwise zero should be
428 int (*operator_check
) (struct expression
*exp
, int pos
,
429 int (*objfile_func
) (struct objfile
*objfile
,
433 /* Dump the rest of this (prefix) expression after the operator
434 itself has been printed. See dump_subexp_body_standard in
436 int (*dump_subexp_body
) (struct expression
*, struct ui_file
*, int);
438 /* Evaluate an expression. */
439 struct value
*(*evaluate_exp
) (struct type
*, struct expression
*,
444 /* Default descriptor containing standard definitions of all
446 extern const struct exp_descriptor exp_descriptor_standard
;
448 /* Functions used by language-specific extended operators to (recursively)
449 print/dump subexpressions. */
451 extern void print_subexp (struct expression
*, int *, struct ui_file
*,
454 extern void print_subexp_standard (struct expression
*, int *,
455 struct ui_file
*, enum precedence
);
457 /* Print a function call like expression to STREAM. This is called as a
458 helper function by which point the expression node identifying this as a
459 function call has already been stripped off and POS should point to the
460 number of function call arguments. EXP is the object containing the
461 list of expression elements. */
463 extern void print_subexp_funcall (struct expression
*exp
, int *pos
,
464 struct ui_file
*stream
);
466 /* Function used to avoid direct calls to fprintf
467 in the code generated by the bison parser. */
469 extern void parser_fprintf (FILE *, const char *, ...) ATTRIBUTE_PRINTF (2, 3);
471 extern int exp_uses_objfile (struct expression
*exp
, struct objfile
*objfile
);
473 #endif /* PARSER_DEFS_H */