gdb/parser-defs.h

   1 /* Parser definitions for GDB.
   2
   3    Copyright (C) 1986-2017 Free Software Foundation, Inc.
   4
   5    Modified from expread.y by the Department of Computer Science at the
   6    State University of New York at Buffalo.
   7
   8    This file is part of GDB.
   9
  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.
  14
  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.
  19
  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/>.  */
  22
  23 #if !defined (PARSER_DEFS_H)
  24 #define PARSER_DEFS_H 1
  25
  26 #include "doublest.h"
  27 #include "vec.h"
  28 #include "expression.h"
  29
  30 struct block;
  31 struct language_defn;
  32 struct internalvar;
  33
  34 extern int parser_debug;
  35
  36 #define parse_gdbarch(ps) ((ps)->expout->gdbarch)
  37 #define parse_language(ps) ((ps)->expout->language_defn)
  38
  39 struct parser_state
  40 {
  41   /* The expression related to this parser state.  */
  42
  43   struct expression *expout;
  44
  45   /* The size of the expression above.  */
  46
  47   size_t expout_size;
  48
  49   /* The number of elements already in the expression.  This is used
  50      to know where to put new elements.  */
  51
  52   size_t expout_ptr;
  53 };
  54
  55 /* If this is nonzero, this block is used as the lexical context
  56    for symbol names.  */
  57
  58 extern const struct block *expression_context_block;
  59
  60 /* If expression_context_block is non-zero, then this is the PC within
  61    the block that we want to evaluate expressions at.  When debugging
  62    C or C++ code, we use this to find the exact line we're at, and
  63    then look up the macro definitions active at that point.  */
  64 extern CORE_ADDR expression_context_pc;
  65
  66 /* The innermost context required by the stack and register variables
  67    we've encountered so far.  */
  68 extern const struct block *innermost_block;
  69
  70 /* Number of arguments seen so far in innermost function call.  */
  71 extern int arglist_len;
  72
  73 /* A string token, either a char-string or bit-string.  Char-strings are
  74    used, for example, for the names of symbols.  */
  75
  76 struct stoken
  77   {
  78     /* Pointer to first byte of char-string or first bit of bit-string.  */
  79     const char *ptr;
  80     /* Length of string in bytes for char-string or bits for bit-string.  */
  81     int length;
  82   };
  83
  84 struct typed_stoken
  85   {
  86     /* A language-specific type field.  */
  87     int type;
  88     /* Pointer to first byte of char-string or first bit of bit-string.  */
  89     char *ptr;
  90     /* Length of string in bytes for char-string or bits for bit-string.  */
  91     int length;
  92   };
  93
  94 struct stoken_vector
  95   {
  96     int len;
  97     struct typed_stoken *tokens;
  98   };
  99
 100 struct ttype
 101   {
 102     struct stoken stoken;
 103     struct type *type;
 104   };
 105
 106 struct symtoken
 107   {
 108     struct stoken stoken;
 109     struct block_symbol sym;
 110     int is_a_field_of_this;
 111   };
 112
 113 struct objc_class_str
 114   {
 115     struct stoken stoken;
 116     struct type *type;
 117     int theclass;
 118   };
 119
 120 typedef struct type *type_ptr;
 121 DEF_VEC_P (type_ptr);
 122
 123 /* For parsing of complicated types.
 124    An array should be preceded in the list by the size of the array.  */
 125 enum type_pieces
 126   {
 127     tp_end = -1,
 128     tp_pointer,
 129     tp_reference,
 130     tp_rvalue_reference,
 131     tp_array,
 132     tp_function,
 133     tp_function_with_arguments,
 134     tp_const,
 135     tp_volatile,
 136     tp_space_identifier,
 137     tp_type_stack
 138   };
 139 /* The stack can contain either an enum type_pieces or an int.  */
 140 union type_stack_elt
 141   {
 142     enum type_pieces piece;
 143     int int_val;
 144     struct type_stack *stack_val;
 145     VEC (type_ptr) *typelist_val;
 146   };
 147
 148 /* The type stack is an instance of this structure.  */
 149
 150 struct type_stack
 151 {
 152   /* Elements on the stack.  */
 153   union type_stack_elt *elements;
 154   /* Current stack depth.  */
 155   int depth;
 156   /* Allocated size of stack.  */
 157   int size;
 158 };
 159
 160 /* Helper function to initialize the expout, expout_size, expout_ptr
 161    trio inside PS before it is used to store expression elements created
 162    during the parsing of an expression.  INITIAL_SIZE is the initial size of
 163    the expout array.  LANG is the language used to parse the expression.
 164    And GDBARCH is the gdbarch to use during parsing.  */
 165
 166 extern void initialize_expout (struct parser_state *ps,
 167                                size_t initial_size,
 168                                const struct language_defn *lang,
 169                                struct gdbarch *gdbarch);
 170
 171 /* Helper function that reallocates the EXPOUT inside PS in order to
 172    eliminate any unused space.  It is generally used when the expression
 173    has just been parsed and created.  */
 174
 175 extern void reallocate_expout (struct parser_state *ps);
 176
 177 /* Reverse an expression from suffix form (in which it is constructed)
 178    to prefix form (in which we can conveniently print or execute it).
 179    Ordinarily this always returns -1.  However, if EXPOUT_LAST_STRUCT
 180    is not -1 (i.e., we are trying to complete a field name), it will
 181    return the index of the subexpression which is the left-hand-side
 182    of the struct operation at EXPOUT_LAST_STRUCT.  */
 183
 184 extern int prefixify_expression (struct expression *expr);
 185
 186 extern void write_exp_elt_opcode (struct parser_state *, enum exp_opcode);
 187
 188 extern void write_exp_elt_sym (struct parser_state *, struct symbol *);
 189
 190 extern void write_exp_elt_longcst (struct parser_state *, LONGEST);
 191
 192 extern void write_exp_elt_dblcst (struct parser_state *, DOUBLEST);
 193
 194 extern void write_exp_elt_decfloatcst (struct parser_state *, gdb_byte *);
 195
 196 extern void write_exp_elt_type (struct parser_state *, struct type *);
 197
 198 extern void write_exp_elt_intern (struct parser_state *, struct internalvar *);
 199
 200 extern void write_exp_string (struct parser_state *, struct stoken);
 201
 202 void write_exp_string_vector (struct parser_state *, int type,
 203                               struct stoken_vector *vec);
 204
 205 extern void write_exp_bitstring (struct parser_state *, struct stoken);
 206
 207 extern void write_exp_elt_block (struct parser_state *, const struct block *);
 208
 209 extern void write_exp_elt_objfile (struct parser_state *,
 210                                    struct objfile *objfile);
 211
 212 extern void write_exp_msymbol (struct parser_state *,
 213                                struct bound_minimal_symbol);
 214
 215 extern void write_dollar_variable (struct parser_state *, struct stoken str);
 216
 217 extern void mark_struct_expression (struct parser_state *);
 218
 219 extern const char *find_template_name_end (const char *);
 220
 221 extern void start_arglist (void);
 222
 223 extern int end_arglist (void);
 224
 225 extern char *copy_name (struct stoken);
 226
 227 extern void insert_type (enum type_pieces);
 228
 229 extern void push_type (enum type_pieces);
 230
 231 extern void push_type_int (int);
 232
 233 extern void insert_type_address_space (struct parser_state *, char *);
 234
 235 extern enum type_pieces pop_type (void);
 236
 237 extern int pop_type_int (void);
 238
 239 extern struct type_stack *get_type_stack (void);
 240
 241 extern struct type_stack *append_type_stack (struct type_stack *to,
 242                                              struct type_stack *from);
 243
 244 extern void push_type_stack (struct type_stack *stack);
 245
 246 extern void type_stack_cleanup (void *arg);
 247
 248 extern void push_typelist (VEC (type_ptr) *typelist);
 249
 250 extern int dump_subexp (struct expression *, struct ui_file *, int);
 251
 252 extern int dump_subexp_body_standard (struct expression *,
 253                                       struct ui_file *, int);
 254
 255 extern void operator_length (const struct expression *, int, int *, int *);
 256
 257 extern void operator_length_standard (const struct expression *, int, int *,
 258                                       int *);
 259
 260 extern int operator_check_standard (struct expression *exp, int pos,
 261                                     int (*objfile_func)
 262                                       (struct objfile *objfile, void *data),
 263                                     void *data);
 264
 265 extern const char *op_name_standard (enum exp_opcode);
 266
 267 extern struct type *follow_types (struct type *);
 268
 269 extern type_instance_flags follow_type_instance_flags ();
 270
 271 extern void null_post_parser (struct expression **, int);
 272
 273 extern int parse_float (const char *p, int len, DOUBLEST *d,
 274                         const char **suffix);
 275
 276 extern int parse_c_float (struct gdbarch *gdbarch, const char *p, int len,
 277                           DOUBLEST *d, struct type **t);
 278
 279 /* During parsing of a C expression, the pointer to the next character
 280    is in this variable.  */
 281
 282 extern const char *lexptr;
 283
 284 /* After a token has been recognized, this variable points to it.
 285    Currently used only for error reporting.  */
 286 extern const char *prev_lexptr;
 287
 288 /* Current depth in parentheses within the expression.  */
 289
 290 extern int paren_depth;
 291
 292 /* Nonzero means stop parsing on first comma (if not within parentheses).  */
 293
 294 extern int comma_terminates;
 295 \f
 296 /* These codes indicate operator precedences for expression printing,
 297    least tightly binding first.  */
 298 /* Adding 1 to a precedence value is done for binary operators,
 299    on the operand which is more tightly bound, so that operators
 300    of equal precedence within that operand will get parentheses.  */
 301 /* PREC_HYPER and PREC_ABOVE_COMMA are not the precedence of any operator;
 302    they are used as the "surrounding precedence" to force
 303    various kinds of things to be parenthesized.  */
 304 enum precedence
 305   {
 306     PREC_NULL, PREC_COMMA, PREC_ABOVE_COMMA, PREC_ASSIGN, PREC_LOGICAL_OR,
 307     PREC_LOGICAL_AND, PREC_BITWISE_IOR, PREC_BITWISE_AND, PREC_BITWISE_XOR,
 308     PREC_EQUAL, PREC_ORDER, PREC_SHIFT, PREC_ADD, PREC_MUL, PREC_REPEAT,
 309     PREC_HYPER, PREC_PREFIX, PREC_SUFFIX, PREC_BUILTIN_FUNCTION
 310   };
 311
 312 /* Table mapping opcodes into strings for printing operators
 313    and precedences of the operators.  */
 314
 315 struct op_print
 316   {
 317     const char *string;
 318     enum exp_opcode opcode;
 319     /* Precedence of operator.  These values are used only by comparisons.  */
 320     enum precedence precedence;
 321
 322     /* For a binary operator:  1 iff right associate.
 323        For a unary operator:  1 iff postfix.  */
 324     int right_assoc;
 325   };
 326
 327 /* Information needed to print, prefixify, and evaluate expressions for
 328    a given language.  */
 329
 330 struct exp_descriptor
 331   {
 332     /* Print subexpression.  */
 333     void (*print_subexp) (struct expression *, int *, struct ui_file *,
 334                           enum precedence);
 335
 336     /* Returns number of exp_elements needed to represent an operator and
 337        the number of subexpressions it takes.  */
 338     void (*operator_length) (const struct expression*, int, int*, int *);
 339
 340     /* Call OBJFILE_FUNC for any objfile found being referenced by the
 341        single operator of EXP at position POS.  Operator parameters are
 342        located at positive (POS + number) offsets in EXP.  OBJFILE_FUNC
 343        should never be called with NULL OBJFILE.  OBJFILE_FUNC should
 344        get passed an arbitrary caller supplied DATA pointer.  If it
 345        returns non-zero value then (any other) non-zero value should be
 346        immediately returned to the caller.  Otherwise zero should be
 347        returned.  */
 348     int (*operator_check) (struct expression *exp, int pos,
 349                            int (*objfile_func) (struct objfile *objfile,
 350                                                 void *data),
 351                            void *data);
 352
 353     /* Name of this operator for dumping purposes.
 354        The returned value should never be NULL, even if EXP_OPCODE is
 355        an unknown opcode (a string containing an image of the numeric
 356        value of the opcode can be returned, for instance).  */
 357     const char *(*op_name) (enum exp_opcode);
 358
 359     /* Dump the rest of this (prefix) expression after the operator
 360        itself has been printed.  See dump_subexp_body_standard in
 361        (expprint.c).  */
 362     int (*dump_subexp_body) (struct expression *, struct ui_file *, int);
 363
 364     /* Evaluate an expression.  */
 365     struct value *(*evaluate_exp) (struct type *, struct expression *,
 366                                    int *, enum noside);
 367   };
 368
 369
 370 /* Default descriptor containing standard definitions of all
 371    elements.  */
 372 extern const struct exp_descriptor exp_descriptor_standard;
 373
 374 /* Functions used by language-specific extended operators to (recursively)
 375    print/dump subexpressions.  */
 376
 377 extern void print_subexp (struct expression *, int *, struct ui_file *,
 378                           enum precedence);
 379
 380 extern void print_subexp_standard (struct expression *, int *,
 381                                    struct ui_file *, enum precedence);
 382
 383 /* Function used to avoid direct calls to fprintf
 384    in the code generated by the bison parser.  */
 385
 386 extern void parser_fprintf (FILE *, const char *, ...) ATTRIBUTE_PRINTF (2, 3);
 387
 388 extern int exp_uses_objfile (struct expression *exp, struct objfile *objfile);
 389
 390 extern void mark_completion_tag (enum type_code, const char *ptr,
 391                                  int length);
 392
 393 /* Reallocate the `expout' pointer inside PS so that it can accommodate
 394    at least LENELT expression elements.  This function does nothing if
 395    there is enough room for the elements.  */
 396
 397 extern void increase_expout_size (struct parser_state *ps, size_t lenelt);
 398
 399 #endif /* PARSER_DEFS_H */
 400