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