path: root/gdb/value.h

/* Definitions for values of C expressions, for GDB.
   Copyright 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996
   Free Software Foundation, Inc.

This file is part of GDB.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#if !defined (VALUE_H)
#define VALUE_H 1

/*
 * The structure which defines the type of a value.  It should never
 * be possible for a program lval value to survive over a call to the inferior
 * (ie to be put into the history list or an internal variable).
 */
enum lval_type {
  /* Not an lval.  */
  not_lval,
  /* In memory.  Could be a saved register.  */
  lval_memory,
  /* In a register.  */
  lval_register,
  /* In a gdb internal variable.  */
  lval_internalvar,
  /* Part of a gdb internal variable (structure field).  */
  lval_internalvar_component,
  /* In a register series in a frame not the current one, which may have been
     partially saved or saved in different places (otherwise would be
     lval_register or lval_memory).  */
  lval_reg_frame_relative
};

struct value
  {
    /* Type of value; either not an lval, or one of the various
       different possible kinds of lval.  */
    enum lval_type lval;
    /* Is it modifiable?  Only relevant if lval != not_lval.  */
    int modifiable;
    /* Location of value (if lval).  */
    union
      {
	/* Address in inferior or byte of registers structure.  */
	CORE_ADDR address;
	/* Pointer to internal variable.  */
	struct internalvar *internalvar;
	/* Number of register.  Only used with
	   lval_reg_frame_relative.  */
	int regnum;
      } location;
    /* Describes offset of a value within lval of a structure in bytes.
       This is used in retrieving contents from target memory. [Note also
       the member embedded_offset below.] */
    int offset;	
    /* Only used for bitfields; number of bits contained in them.  */
    int bitsize;
    /* Only used for bitfields; position of start of field.
       For BITS_BIG_ENDIAN=0 targets, it is the position of the LSB.
       For BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
    int bitpos;
    /* Frame value is relative to.  In practice, this address is only
       used if the value is stored in several registers in other than
       the current frame, and these registers have not all been saved
       at the same place in memory.  This will be described in the
       lval enum above as "lval_reg_frame_relative".  */
    CORE_ADDR frame_addr;
    /* Type of the value.  */
    struct type *type;
    /* Type of the enclosing object if this is an embedded subobject.
       The member embedded_offset gives the real position of the subobject
       if type is not the same as enclosing_type.

       If the type field is a pointer type, then enclosing_type is 
       a pointer type pointing to the real (enclosing) type of the target
       object. */
    struct type *enclosing_type;
    /* Values are stored in a chain, so that they can be deleted
       easily over calls to the inferior.  Values assigned to internal
       variables or put into the value history are taken off this
       list.  */
    struct value *next;

    /* ??? When is this used?  */
    union {
      CORE_ADDR memaddr;
      char *myaddr;
    } substring_addr;

    /* Register number if the value is from a register.  Is not kept
       if you take a field of a structure that is stored in a
       register.  Shouldn't it be?  */
    short regno;
    /* If zero, contents of this value are in the contents field.
       If nonzero, contents are in inferior memory at address
       in the location.address field plus the offset field
       (and the lval field should be lval_memory).  */
    char lazy;
    /* If nonzero, this is the value of a variable which does not
       actually exist in the program.  */
    char optimized_out;
    /* If this value represents an object that is embedded inside a
       larger object (e.g., a base subobject in C++), this gives the
       offset (in bytes) from the start of the contents buffer where
       the embedded object begins. This is required because some C++
       runtime implementations lay out objects (especially virtual bases
       with possibly negative offsets to ancestors).
       Note: This may be positive or negative! Also note that this offset
       is not used when retrieving contents from target memory; the entire
       enclosing object has to be retrieved always, and the offset for
       that is given by the member offset above. */
    int embedded_offset;
    /* If this value represents a pointer to an object that is embedded
       in another object, this gives the embedded_offset of the object
       that is pointed to. */
    int pointed_to_offset;
    /* The BFD section associated with this value.  */
    asection *bfd_section;
    /* Actual contents of the value.  For use of this value; setting
       it uses the stuff above.  Not valid if lazy is nonzero.
       Target byte-order.  We force it to be aligned properly for any
       possible value.  Note that a value therefore extends beyond
       what is declared here.  */
    union {
      long contents[1];
      double force_double_align;
      LONGEST force_longlong_align;
      char *literal_data;
    } aligner;
    /* Do not add any new members here -- contents above will trash them */
  };

typedef struct value *value_ptr;

#define VALUE_TYPE(val) (val)->type
#define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type
#define VALUE_LAZY(val) (val)->lazy
/* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
   the gdb buffer used to hold a copy of the contents of the lval.  
   VALUE_CONTENTS is used when the contents of the buffer are needed --
   it uses value_fetch_lazy() to load the buffer from the process being 
   debugged if it hasn't already been loaded.  VALUE_CONTENTS_RAW is 
   used when data is being stored into the buffer, or when it is 
   certain that the contents of the buffer are valid.
   Note: The contents pointer is adjusted by the offset required to
   get to the real subobject, if the value happens to represent
   something embedded in a larger run-time object. */

#define VALUE_CONTENTS_RAW(val) ((char *) (val)->aligner.contents + (val)->embedded_offset)
#define VALUE_CONTENTS(val) ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)),\
			     VALUE_CONTENTS_RAW(val))

/* The ALL variants of the above two macros do not adjust the returned
   pointer by the embedded_offset value. */
  
#define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents)
#define VALUE_CONTENTS_ALL(val) ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)),\
                                 VALUE_CONTENTS_ALL_RAW(val))
  
  
extern int value_fetch_lazy PARAMS ((value_ptr val));

#define VALUE_LVAL(val) (val)->lval
#define VALUE_ADDRESS(val) (val)->location.address
#define VALUE_INTERNALVAR(val) (val)->location.internalvar
#define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
#define VALUE_FRAME(val) ((val)->frame_addr)
#define VALUE_OFFSET(val) (val)->offset
#define VALUE_BITSIZE(val) (val)->bitsize
#define VALUE_BITPOS(val) (val)->bitpos
#define VALUE_NEXT(val) (val)->next
#define VALUE_REGNO(val) (val)->regno
#define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
#define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset)
#define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset)
#define VALUE_BFD_SECTION(val) ((val)->bfd_section)

/* Convert a REF to the object referenced. */

#define COERCE_REF(arg)    \
do { struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg));\
     if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF)		\
	 arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp),	\
			      unpack_long (VALUE_TYPE (arg),		\
					   VALUE_CONTENTS (arg)),       \
			      VALUE_BFD_SECTION (arg));			\
    } while (0)

/* If ARG is an array, convert it to a pointer.
   If ARG is an enum, convert it to an integer.
   If ARG is a function, convert it to a function pointer.

   References are dereferenced.  */

#define COERCE_ARRAY(arg)    \
do { COERCE_REF(arg);							\
  if (current_language->c_style_arrays					\
      && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY)		\
    arg = value_coerce_array (arg);					\
  if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC)                   \
    arg = value_coerce_function (arg);                                  \
} while (0)

#define COERCE_NUMBER(arg)  \
  do { COERCE_ARRAY(arg);  COERCE_ENUM(arg); } while (0)

#define COERCE_VARYING_ARRAY(arg, real_arg_type)	\
{ if (chill_varying_type (real_arg_type))  \
    arg = varying_to_slice (arg), real_arg_type = VALUE_TYPE (arg); }

/* If ARG is an enum, convert it to an integer.  */

#define COERCE_ENUM(arg)   { \
  if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM)	\
    arg = value_cast (builtin_type_unsigned_int, arg);			\
}

/* Internal variables (variables for convenience of use of debugger)
   are recorded as a chain of these structures.  */

struct internalvar
{
  struct internalvar *next;
  char *name;
  value_ptr value;
};

/* Pointer to member function.  Depends on compiler implementation. */

#define METHOD_PTR_IS_VIRTUAL(ADDR)  ((ADDR) & 0x80000000)
#define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
#define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))


#include "symtab.h"
#include "gdbtypes.h"
#include "expression.h"

#ifdef __STDC__
struct frame_info;
struct fn_field;
#endif

extern void
print_address_demangle PARAMS ((CORE_ADDR, GDB_FILE *, int));

extern LONGEST value_as_long PARAMS ((value_ptr val));

extern DOUBLEST value_as_double PARAMS ((value_ptr val));

extern CORE_ADDR value_as_pointer PARAMS ((value_ptr val));

extern LONGEST unpack_long PARAMS ((struct type *type, char *valaddr));

extern DOUBLEST unpack_double PARAMS ((struct type *type, char *valaddr,
				       int *invp));

extern CORE_ADDR unpack_pointer PARAMS ((struct type *type, char *valaddr));

extern LONGEST unpack_field_as_long PARAMS ((struct type *type, char *valaddr,
					     int fieldno));

extern value_ptr value_from_longest PARAMS ((struct type *type, LONGEST num));

extern value_ptr value_from_double PARAMS ((struct type *type, DOUBLEST num));

extern value_ptr value_at PARAMS ((struct type *type, CORE_ADDR addr, asection *sect));

extern value_ptr value_at_lazy PARAMS ((struct type *type, CORE_ADDR addr, asection *sect));

extern value_ptr value_from_register PARAMS ((struct type *type, int regnum,
					  struct frame_info * frame));

extern value_ptr value_of_variable PARAMS ((struct symbol *var,
					    struct block *b));

extern value_ptr value_of_register PARAMS ((int regnum));

extern int symbol_read_needs_frame PARAMS ((struct symbol *));

extern value_ptr read_var_value PARAMS ((struct symbol *var,
					 struct frame_info *frame));

extern value_ptr locate_var_value PARAMS ((struct symbol *var,
				       struct frame_info *frame));

extern value_ptr allocate_value PARAMS ((struct type *type));

extern value_ptr allocate_repeat_value PARAMS ((struct type *type, int count));

extern value_ptr value_mark PARAMS ((void));

extern void value_free_to_mark PARAMS ((value_ptr mark));

extern value_ptr value_string PARAMS ((char *ptr, int len));
extern value_ptr value_bitstring PARAMS ((char *ptr, int len));

extern value_ptr value_array PARAMS ((int lowbound, int highbound,
				      value_ptr *elemvec));

extern value_ptr value_concat PARAMS ((value_ptr arg1, value_ptr arg2));

extern value_ptr value_binop PARAMS ((value_ptr arg1, value_ptr arg2,
				      enum exp_opcode op));

extern value_ptr value_add PARAMS ((value_ptr arg1, value_ptr arg2));

extern value_ptr value_sub PARAMS ((value_ptr arg1, value_ptr arg2));

extern value_ptr value_coerce_array PARAMS ((value_ptr arg1));

extern value_ptr value_coerce_function PARAMS ((value_ptr arg1));

extern value_ptr value_ind PARAMS ((value_ptr arg1));

extern value_ptr value_addr PARAMS ((value_ptr arg1));

extern value_ptr value_assign PARAMS ((value_ptr toval, value_ptr fromval));

extern value_ptr value_neg PARAMS ((value_ptr arg1));

extern value_ptr value_complement PARAMS ((value_ptr arg1));

extern value_ptr value_struct_elt PARAMS ((value_ptr *argp, value_ptr *args,
					   char *name,
					   int *static_memfuncp, char *err));

extern value_ptr value_struct_elt_for_reference PARAMS ((struct type *domain,
							 int offset,
							 struct type *curtype,
							 char *name,
							 struct type *intype));

extern value_ptr value_static_field PARAMS ((struct type *type, int fieldno));

extern struct fn_field *value_find_oload_method_list PARAMS ((value_ptr *, char *, int, int *, int *, struct type **, int *));

extern int find_overload_match PARAMS ((struct type ** arg_types, int nargs, char * name, int method, int lax, value_ptr obj, struct symbol *fsym, value_ptr *valp, struct symbol **symp, int *staticp));

extern value_ptr value_field PARAMS ((value_ptr arg1, int fieldno));

extern value_ptr value_primitive_field PARAMS ((value_ptr arg1, int offset,
						int fieldno,
						struct type *arg_type));

extern struct type *
value_rtti_type PARAMS ((value_ptr, int *, int *, int *));

extern struct type *
value_rtti_target_type PARAMS ((value_ptr, int *, int *, int *));

extern value_ptr
value_full_object PARAMS ((value_ptr, struct type *, int, int, int));

extern value_ptr value_cast PARAMS ((struct type *type, value_ptr arg2));

extern value_ptr value_zero PARAMS ((struct type *type, enum lval_type lv));

extern value_ptr value_repeat PARAMS ((value_ptr arg1, int count));

extern value_ptr value_subscript PARAMS ((value_ptr array, value_ptr idx));

extern value_ptr value_from_vtable_info PARAMS ((value_ptr arg,
						 struct type *type));

extern value_ptr value_being_returned PARAMS ((struct type *valtype, 
					       char *retbuf,
					       int struct_return));

extern value_ptr value_in PARAMS ((value_ptr element, value_ptr set));

extern int value_bit_index PARAMS ((struct type *type, char *addr, int index));

extern int using_struct_return PARAMS ((value_ptr function, CORE_ADDR funcaddr,
					struct type *value_type, int gcc_p));

extern void set_return_value PARAMS ((value_ptr val));

extern value_ptr evaluate_expression PARAMS ((struct expression *exp));

extern value_ptr evaluate_type PARAMS ((struct expression *exp));

extern value_ptr evaluate_subexp_with_coercion PARAMS ((struct expression *,
							int *, enum noside));

extern value_ptr parse_and_eval PARAMS ((char *exp));

extern value_ptr parse_to_comma_and_eval PARAMS ((char **expp));

extern struct type *parse_and_eval_type PARAMS ((char *p, int length));

extern CORE_ADDR parse_and_eval_address PARAMS ((char *exp));

extern CORE_ADDR parse_and_eval_address_1 PARAMS ((char **expptr));

extern value_ptr access_value_history PARAMS ((int num));

extern value_ptr value_of_internalvar PARAMS ((struct internalvar *var));

extern void set_internalvar PARAMS ((struct internalvar *var, value_ptr val));

extern void set_internalvar_component PARAMS ((struct internalvar *var,
					       int offset,
					       int bitpos, int bitsize,
					       value_ptr newvalue));

extern struct internalvar *lookup_internalvar PARAMS ((char *name));

extern int value_equal PARAMS ((value_ptr arg1, value_ptr arg2));

extern int value_less PARAMS ((value_ptr arg1, value_ptr arg2));

extern int value_logical_not PARAMS ((value_ptr arg1));

/* C++ */

extern value_ptr value_of_this PARAMS ((int complain));

extern value_ptr value_x_binop PARAMS ((value_ptr arg1, value_ptr arg2,
					enum exp_opcode op,
					enum exp_opcode otherop,
					enum noside noside));

extern value_ptr value_x_unop PARAMS ((value_ptr arg1, enum exp_opcode op,
				       enum noside noside));

extern value_ptr value_fn_field PARAMS ((value_ptr *arg1p, struct fn_field *f,
					 int j,
					 struct type* type, int offset));

extern value_ptr value_virtual_fn_field PARAMS ((value_ptr *arg1p,
						 struct fn_field *f, int j,
						 struct type *type,
						 int offset));

extern int binop_user_defined_p PARAMS ((enum exp_opcode op,
					 value_ptr arg1, value_ptr arg2));

extern int unop_user_defined_p PARAMS ((enum exp_opcode op, value_ptr arg1));

extern int destructor_name_p PARAMS ((const char *name,
				      const struct type *type));

#define value_free(val) free ((PTR)val)

extern void free_all_values PARAMS ((void));

extern void release_value PARAMS ((value_ptr val));

extern int record_latest_value PARAMS ((value_ptr val));

extern void registers_changed PARAMS ((void));

extern void read_register_bytes PARAMS ((int regbyte, char *myaddr, int len));

extern void write_register_bytes PARAMS ((int regbyte, char *myaddr, int len));

extern void
read_register_gen PARAMS ((int regno, char *myaddr));

extern CORE_ADDR
read_register PARAMS ((int regno));

extern CORE_ADDR
read_register_pid PARAMS ((int regno, int pid));

extern void
write_register PARAMS ((int regno, LONGEST val));

extern void
write_register_pid PARAMS ((int regno, CORE_ADDR val, int pid));

extern void
supply_register PARAMS ((int regno, char *val));

extern void get_saved_register PARAMS ((char *raw_buffer, int *optimized,
					CORE_ADDR *addrp,
					struct frame_info *frame,
					int regnum, enum lval_type *lval));

extern void
modify_field PARAMS ((char *addr, LONGEST fieldval, int bitpos, int bitsize));

extern void
type_print PARAMS ((struct type *type, char *varstring, GDB_FILE *stream,
		    int show));

extern char *baseclass_addr PARAMS ((struct type *type, int index,
				     char *valaddr,
				     value_ptr *valuep, int *errp));

extern void
print_longest PARAMS ((GDB_FILE *stream, int format, int use_local,
		       LONGEST val));

extern void
print_floating PARAMS ((char *valaddr, struct type *type, GDB_FILE *stream));

extern int value_print PARAMS ((value_ptr val, GDB_FILE *stream, int format,
				enum val_prettyprint pretty));

extern void
value_print_array_elements PARAMS ((value_ptr val, GDB_FILE* stream,
				    int format, enum val_prettyprint pretty));

extern value_ptr
value_release_to_mark PARAMS ((value_ptr mark));

extern int
val_print PARAMS ((struct type *type, char *valaddr, int embedded_offset, CORE_ADDR address,
		   GDB_FILE *stream, int format, int deref_ref,
		   int recurse, enum val_prettyprint pretty));

extern int
val_print_string PARAMS ((CORE_ADDR addr, int len, int width, GDB_FILE *stream));

extern void
print_variable_value PARAMS ((struct symbol *var, struct frame_info *frame,
			      GDB_FILE *stream));

extern int check_field PARAMS ((value_ptr, const char *));

extern void
c_typedef_print PARAMS ((struct type *type, struct symbol *news, GDB_FILE *stream));

extern char *
internalvar_name PARAMS ((struct internalvar *var));

extern void
clear_value_history PARAMS ((void));

extern void
clear_internalvars PARAMS ((void));

/* From values.c */

extern value_ptr value_copy PARAMS ((value_ptr));

extern int baseclass_offset PARAMS ((struct type *, int, char *, CORE_ADDR));

/* From valops.c */

extern value_ptr varying_to_slice PARAMS ((value_ptr));

extern value_ptr value_slice PARAMS ((value_ptr, int, int));

extern value_ptr call_function_by_hand PARAMS ((value_ptr, int, value_ptr *));

extern value_ptr value_literal_complex PARAMS ((value_ptr, value_ptr, struct type*));

extern void find_rt_vbase_offset PARAMS ((struct type *, struct type *, char *, int, int *, int *));

extern value_ptr find_function_in_inferior PARAMS ((char *));

extern value_ptr value_allocate_space_in_inferior PARAMS ((int));

extern CORE_ADDR default_push_arguments PARAMS ((int nargs, value_ptr *args,
						 CORE_ADDR sp,
						 int struct_return,
						 CORE_ADDR struct_addr));

#endif	/* !defined (VALUE_H) */