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