* ch-exp.y (value_string_element, string_primitive_value,

[deliverable/binutils-gdb.git] / gdb / valops.c

/* Perform non-arithmetic operations on values, for GDB.
   Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994
   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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "value.h"
#include "frame.h"
#include "inferior.h"
#include "gdbcore.h"
#include "target.h"
#include "demangle.h"
#include "language.h"

#include <errno.h>
#include <string.h>

/* Local functions.  */

static int typecmp PARAMS ((int staticp, struct type *t1[], value_ptr t2[]));

static CORE_ADDR find_function_addr PARAMS ((value_ptr, struct type **));

static CORE_ADDR value_push PARAMS ((CORE_ADDR, value_ptr));

static CORE_ADDR value_arg_push PARAMS ((CORE_ADDR, value_ptr));

static value_ptr search_struct_field PARAMS ((char *, value_ptr, int,
                                              struct type *, int));

static value_ptr search_struct_method PARAMS ((char *, value_ptr *,
                                               value_ptr *,
                                               int, int *, struct type *));

static int check_field_in PARAMS ((struct type *, const char *));

static CORE_ADDR allocate_space_in_inferior PARAMS ((int));

static value_ptr f77_cast_into_complex PARAMS ((struct type *, value_ptr));

static value_ptr f77_assign_from_literal_string PARAMS ((value_ptr,
                                                         value_ptr));

static value_ptr f77_assign_from_literal_complex PARAMS ((value_ptr,
                                                          value_ptr));

#define VALUE_SUBSTRING_START(VAL) VALUE_FRAME(VAL)

\f
/* Allocate NBYTES of space in the inferior using the inferior's malloc
   and return a value that is a pointer to the allocated space. */

static CORE_ADDR
allocate_space_in_inferior (len)
     int len;
{
  register value_ptr val;
  register struct symbol *sym;
  struct minimal_symbol *msymbol;
  struct type *type;
  value_ptr blocklen;
  LONGEST maddr;

  /* Find the address of malloc in the inferior.  */

  sym = lookup_symbol ("malloc", 0, VAR_NAMESPACE, 0, NULL);
  if (sym != NULL)
    {
      if (SYMBOL_CLASS (sym) != LOC_BLOCK)
        {
          error ("\"malloc\" exists in this program but is not a function.");
        }
      val = value_of_variable (sym, NULL);
    }
  else
    {
      msymbol = lookup_minimal_symbol ("malloc", (struct objfile *) NULL);
      if (msymbol != NULL)
        {
          type = lookup_pointer_type (builtin_type_char);
          type = lookup_function_type (type);
          type = lookup_pointer_type (type);
          maddr = (LONGEST) SYMBOL_VALUE_ADDRESS (msymbol);
          val = value_from_longest (type, maddr);
        }
      else
        {
          error ("evaluation of this expression requires the program to have a function \"malloc\".");
        }
    }

  blocklen = value_from_longest (builtin_type_int, (LONGEST) len);
  val = call_function_by_hand (val, 1, &blocklen);
  if (value_logical_not (val))
    {
      error ("No memory available to program.");
    }
  return (value_as_long (val));
}

/* Cast value ARG2 to type TYPE and return as a value.
   More general than a C cast: accepts any two types of the same length,
   and if ARG2 is an lvalue it can be cast into anything at all.  */
/* In C++, casts may change pointer or object representations.  */

value_ptr
value_cast (type, arg2)
     struct type *type;
     register value_ptr arg2;
{
  register enum type_code code1;
  register enum type_code code2;
  register int scalar;

  if (VALUE_TYPE (arg2) == type)
    return arg2;

  COERCE_VARYING_ARRAY (arg2);

  /* Coerce arrays but not enums.  Enums will work as-is
     and coercing them would cause an infinite recursion.  */
  if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_ENUM)
    COERCE_ARRAY (arg2);

  code1 = TYPE_CODE (type);
  code2 = TYPE_CODE (VALUE_TYPE (arg2));

  if (code1 == TYPE_CODE_COMPLEX) 
    return f77_cast_into_complex (type, arg2); 
  if (code1 == TYPE_CODE_BOOL) 
    code1 = TYPE_CODE_INT; 
  if (code2 == TYPE_CODE_BOOL) 
    code2 = TYPE_CODE_INT; 

  scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
            || code2 == TYPE_CODE_ENUM || code2 == TYPE_CODE_RANGE);

  if (   code1 == TYPE_CODE_STRUCT
      && code2 == TYPE_CODE_STRUCT
      && TYPE_NAME (type) != 0)
    {
      /* Look in the type of the source to see if it contains the
         type of the target as a superclass.  If so, we'll need to
         offset the object in addition to changing its type.  */
      value_ptr v = search_struct_field (type_name_no_tag (type),
                                         arg2, 0, VALUE_TYPE (arg2), 1);
      if (v)
        {
          VALUE_TYPE (v) = type;
          return v;
        }
    }
  if (code1 == TYPE_CODE_FLT && scalar)
    return value_from_double (type, value_as_double (arg2));
  else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
            || code1 == TYPE_CODE_RANGE)
           && (scalar || code2 == TYPE_CODE_PTR))
    return value_from_longest (type, value_as_long (arg2));
  else if (TYPE_LENGTH (type) == TYPE_LENGTH (VALUE_TYPE (arg2)))
    {
      if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
        {
          /* Look in the type of the source to see if it contains the
             type of the target as a superclass.  If so, we'll need to
             offset the pointer rather than just change its type.  */
          struct type *t1 = TYPE_TARGET_TYPE (type);
          struct type *t2 = TYPE_TARGET_TYPE (VALUE_TYPE (arg2));
          if (   TYPE_CODE (t1) == TYPE_CODE_STRUCT
              && TYPE_CODE (t2) == TYPE_CODE_STRUCT
              && TYPE_NAME (t1) != 0) /* if name unknown, can't have supercl */
            {
              value_ptr v = search_struct_field (type_name_no_tag (t1),
                                                 value_ind (arg2), 0, t2, 1);
              if (v)
                {
                  v = value_addr (v);
                  VALUE_TYPE (v) = type;
                  return v;
                }
            }
          /* No superclass found, just fall through to change ptr type.  */
        }
      VALUE_TYPE (arg2) = type;
      return arg2;
    }
  else if (chill_varying_type (type))
    {
      struct type *range1, *range2, *eltype1, *eltype2;
      value_ptr val;
      int count1, count2;
      char *valaddr, *valaddr_data;
      if (code2 == TYPE_CODE_BITSTRING)
        error ("not implemented: converting bitstring to varying type");
      if ((code2 != TYPE_CODE_ARRAY && code2 != TYPE_CODE_STRING)
          || (eltype1 = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 1)),
              eltype2 = TYPE_TARGET_TYPE (VALUE_TYPE (arg2)),
              (TYPE_LENGTH (eltype1) != TYPE_LENGTH (eltype2)
               /* || TYPE_CODE (eltype1) != TYPE_CODE (eltype2) */ )))
        error ("Invalid conversion to varying type");
      range1 = TYPE_FIELD_TYPE (TYPE_FIELD_TYPE (type, 1), 0);
      range2 = TYPE_FIELD_TYPE (VALUE_TYPE (arg2), 0);
      count1 = TYPE_HIGH_BOUND (range1) - TYPE_LOW_BOUND (range1) + 1;
      count2 = TYPE_HIGH_BOUND (range2) - TYPE_LOW_BOUND (range2) + 1;
      if (count2 > count1)
        error ("target varying type is too small");
      val = allocate_value (type);
      valaddr = VALUE_CONTENTS_RAW (val);
      valaddr_data = valaddr + TYPE_FIELD_BITPOS (type, 1) / 8;
      /* Set val's __var_length field to count2. */
      store_signed_integer (valaddr, TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0)),
                            count2);
      /* Set the __var_data field to count2 elements copied from arg2. */
      memcpy (valaddr_data, VALUE_CONTENTS (arg2),
              count2 * TYPE_LENGTH (eltype2));
      /* Zero the rest of the __var_data field of val. */
      memset (valaddr_data + count2 * TYPE_LENGTH (eltype2), '\0',
              (count1 - count2) * TYPE_LENGTH (eltype2));
      return val;
    }
  else if (VALUE_LVAL (arg2) == lval_memory)
    {
      return value_at_lazy (type, VALUE_ADDRESS (arg2) + VALUE_OFFSET (arg2));
    }
  else if (code1 == TYPE_CODE_VOID)
    {
      return value_zero (builtin_type_void, not_lval);
    }
  else
    {
      error ("Invalid cast.");
      return 0;
    }
}

/* Create a value of type TYPE that is zero, and return it.  */

value_ptr
value_zero (type, lv)
     struct type *type;
     enum lval_type lv;
{
  register value_ptr val = allocate_value (type);

  memset (VALUE_CONTENTS (val), 0, TYPE_LENGTH (type));
  VALUE_LVAL (val) = lv;

  return val;
}

/* Return a value with type TYPE located at ADDR.  

   Call value_at only if the data needs to be fetched immediately;
   if we can be 'lazy' and defer the fetch, perhaps indefinately, call
   value_at_lazy instead.  value_at_lazy simply records the address of
   the data and sets the lazy-evaluation-required flag.  The lazy flag 
   is tested in the VALUE_CONTENTS macro, which is used if and when 
   the contents are actually required.  */

value_ptr
value_at (type, addr)
     struct type *type;
     CORE_ADDR addr;
{
  register value_ptr val;

  if (TYPE_CODE (type) == TYPE_CODE_VOID)
    error ("Attempt to dereference a generic pointer.");

  val = allocate_value (type);

  read_memory (addr, VALUE_CONTENTS_RAW (val), TYPE_LENGTH (type));

  VALUE_LVAL (val) = lval_memory;
  VALUE_ADDRESS (val) = addr;

  return val;
}

/* Return a lazy value with type TYPE located at ADDR (cf. value_at).  */

value_ptr
value_at_lazy (type, addr)
     struct type *type;
     CORE_ADDR addr;
{
  register value_ptr val;

  if (TYPE_CODE (type) == TYPE_CODE_VOID)
    error ("Attempt to dereference a generic pointer.");

  val = allocate_value (type);

  VALUE_LVAL (val) = lval_memory;
  VALUE_ADDRESS (val) = addr;
  VALUE_LAZY (val) = 1;

  return val;
}

/* Called only from the VALUE_CONTENTS macro, if the current data for
   a variable needs to be loaded into VALUE_CONTENTS(VAL).  Fetches the
   data from the user's process, and clears the lazy flag to indicate
   that the data in the buffer is valid.

   If the value is zero-length, we avoid calling read_memory, which would
   abort.  We mark the value as fetched anyway -- all 0 bytes of it.

   This function returns a value because it is used in the VALUE_CONTENTS
   macro as part of an expression, where a void would not work.  The
   value is ignored.  */

int
value_fetch_lazy (val)
     register value_ptr val;
{
  CORE_ADDR addr = VALUE_ADDRESS (val) + VALUE_OFFSET (val);

  if (TYPE_LENGTH (VALUE_TYPE (val)))
    read_memory (addr, VALUE_CONTENTS_RAW (val), 
                 TYPE_LENGTH (VALUE_TYPE (val)));
  VALUE_LAZY (val) = 0;
  return 0;
}


/* Store the contents of FROMVAL into the location of TOVAL.
   Return a new value with the location of TOVAL and contents of FROMVAL.  */

value_ptr
value_assign (toval, fromval)
     register value_ptr toval, fromval;
{
  register struct type *type;
  register value_ptr val;
  char raw_buffer[MAX_REGISTER_RAW_SIZE];
  int use_buffer = 0;

  if (current_language->la_language == language_fortran)
    {
      /* Deal with literal assignment in F77.  All composite (i.e. string
         and complex number types) types are allocated in the superior
         NOT the inferior.  Therefore assigment is somewhat tricky.  */

      if (TYPE_CODE (VALUE_TYPE (fromval)) == TYPE_CODE_LITERAL_STRING)
        return f77_assign_from_literal_string (toval, fromval);

      if (TYPE_CODE (VALUE_TYPE (fromval)) == TYPE_CODE_LITERAL_COMPLEX)
        return f77_assign_from_literal_complex (toval, fromval);
    }

  if (!toval->modifiable)
    error ("Left operand of assignment is not a modifiable lvalue.");

  COERCE_ARRAY (fromval);
  COERCE_REF (toval);

  type = VALUE_TYPE (toval);
  if (VALUE_LVAL (toval) != lval_internalvar)
    fromval = value_cast (type, fromval);

  /* If TOVAL is a special machine register requiring conversion
     of program values to a special raw format,
     convert FROMVAL's contents now, with result in `raw_buffer',
     and set USE_BUFFER to the number of bytes to write.  */

#ifdef REGISTER_CONVERTIBLE
  if (VALUE_REGNO (toval) >= 0
      && REGISTER_CONVERTIBLE (VALUE_REGNO (toval)))
    {
      int regno = VALUE_REGNO (toval);
      if (REGISTER_CONVERTIBLE (regno))
        {
          REGISTER_CONVERT_TO_RAW (VALUE_TYPE (fromval), regno,
                                   VALUE_CONTENTS (fromval), raw_buffer);
          use_buffer = REGISTER_RAW_SIZE (regno);
        }
    }
#endif

  switch (VALUE_LVAL (toval))
    {
    case lval_internalvar:
      set_internalvar (VALUE_INTERNALVAR (toval), fromval);
      break;

    case lval_internalvar_component:
      set_internalvar_component (VALUE_INTERNALVAR (toval),
                                 VALUE_OFFSET (toval),
                                 VALUE_BITPOS (toval),
                                 VALUE_BITSIZE (toval),
                                 fromval);
      break;

    case lval_memory:
      if (VALUE_BITSIZE (toval))
        {
          char buffer[sizeof (LONGEST)];
          /* We assume that the argument to read_memory is in units of
             host chars.  FIXME:  Is that correct?  */
          int len = (VALUE_BITPOS (toval)
                     + VALUE_BITSIZE (toval)
                     + HOST_CHAR_BIT - 1)
                    / HOST_CHAR_BIT;

          if (len > sizeof (LONGEST))
            error ("Can't handle bitfields which don't fit in a %d bit word.",
                   sizeof (LONGEST) * HOST_CHAR_BIT);

          read_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
                       buffer, len);
          modify_field (buffer, value_as_long (fromval),
                        VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
          write_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
                        buffer, len);
        }
      else if (use_buffer)
        write_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
                      raw_buffer, use_buffer);
      else
        write_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
                      VALUE_CONTENTS (fromval), TYPE_LENGTH (type));
      break;

    case lval_register:
      if (VALUE_BITSIZE (toval))
        {
          char buffer[sizeof (LONGEST)];
          int len = REGISTER_RAW_SIZE (VALUE_REGNO (toval));

          if (len > sizeof (LONGEST))
            error ("Can't handle bitfields in registers larger than %d bits.",
                   sizeof (LONGEST) * HOST_CHAR_BIT);

          if (VALUE_BITPOS (toval) + VALUE_BITSIZE (toval)
              > len * HOST_CHAR_BIT)
            /* Getting this right would involve being very careful about
               byte order.  */
            error ("\
Can't handle bitfield which doesn't fit in a single register.");

          read_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
                               buffer, len);
          modify_field (buffer, value_as_long (fromval),
                        VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
          write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
                                buffer, len);
        }
      else if (use_buffer)
        write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
                              raw_buffer, use_buffer);
      else
        {
          /* Do any conversion necessary when storing this type to more
             than one register.  */
#ifdef REGISTER_CONVERT_FROM_TYPE
          memcpy (raw_buffer, VALUE_CONTENTS (fromval), TYPE_LENGTH (type));
          REGISTER_CONVERT_FROM_TYPE(VALUE_REGNO (toval), type, raw_buffer);
          write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
                                raw_buffer, TYPE_LENGTH (type));
#else
          write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
                                VALUE_CONTENTS (fromval), TYPE_LENGTH (type));
#endif
        }
      /* Assigning to the stack pointer, frame pointer, and other
         (architecture and calling convention specific) registers may
         cause the frame cache to be out of date.  We just do this
         on all assignments to registers for simplicity; I doubt the slowdown
         matters.  */
      reinit_frame_cache ();
      break;

    case lval_reg_frame_relative:
      {
        /* value is stored in a series of registers in the frame
           specified by the structure.  Copy that value out, modify
           it, and copy it back in.  */
        int amount_to_copy = (VALUE_BITSIZE (toval) ? 1 : TYPE_LENGTH (type));
        int reg_size = REGISTER_RAW_SIZE (VALUE_FRAME_REGNUM (toval));
        int byte_offset = VALUE_OFFSET (toval) % reg_size;
        int reg_offset = VALUE_OFFSET (toval) / reg_size;
        int amount_copied;

        /* Make the buffer large enough in all cases.  */
        char *buffer = (char *) alloca (amount_to_copy
                                        + sizeof (LONGEST)
                                        + MAX_REGISTER_RAW_SIZE);

        int regno;
        struct frame_info *frame;

        /* Figure out which frame this is in currently.  */
        for (frame = get_current_frame ();
             frame && FRAME_FP (frame) != VALUE_FRAME (toval);
             frame = get_prev_frame (frame))
          ;

        if (!frame)
          error ("Value being assigned to is no longer active.");

        amount_to_copy += (reg_size - amount_to_copy % reg_size);

        /* Copy it out.  */
        for ((regno = VALUE_FRAME_REGNUM (toval) + reg_offset,
              amount_copied = 0);
             amount_copied < amount_to_copy;
             amount_copied += reg_size, regno++)
          {
            get_saved_register (buffer + amount_copied,
                                (int *)NULL, (CORE_ADDR *)NULL,
                                frame, regno, (enum lval_type *)NULL);
          }

        /* Modify what needs to be modified.  */
        if (VALUE_BITSIZE (toval))
          modify_field (buffer + byte_offset,
                        value_as_long (fromval),
                        VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
        else if (use_buffer)
          memcpy (buffer + byte_offset, raw_buffer, use_buffer);
        else
          memcpy (buffer + byte_offset, VALUE_CONTENTS (fromval),
                  TYPE_LENGTH (type));

        /* Copy it back.  */
        for ((regno = VALUE_FRAME_REGNUM (toval) + reg_offset,
              amount_copied = 0);
             amount_copied < amount_to_copy;
             amount_copied += reg_size, regno++)
          {
            enum lval_type lval;
            CORE_ADDR addr;
            int optim;

            /* Just find out where to put it.  */
            get_saved_register ((char *)NULL,
                                &optim, &addr, frame, regno, &lval);
            
            if (optim)
              error ("Attempt to assign to a value that was optimized out.");
            if (lval == lval_memory)
              write_memory (addr, buffer + amount_copied, reg_size);
            else if (lval == lval_register)
              write_register_bytes (addr, buffer + amount_copied, reg_size);
            else
              error ("Attempt to assign to an unmodifiable value.");
          }
      }
      break;
        

    default:
      error ("Left operand of assignment is not an lvalue.");
    }

  /* Return a value just like TOVAL except with the contents of FROMVAL
     (except in the case of the type if TOVAL is an internalvar).  */

  if (VALUE_LVAL (toval) == lval_internalvar
      || VALUE_LVAL (toval) == lval_internalvar_component)
    {
      type = VALUE_TYPE (fromval);
    }

  val = allocate_value (type);
  memcpy (val, toval, VALUE_CONTENTS_RAW (val) - (char *) val);
  memcpy (VALUE_CONTENTS_RAW (val), VALUE_CONTENTS (fromval),
          TYPE_LENGTH (type));
  VALUE_TYPE (val) = type;
  
  return val;
}

/* Extend a value VAL to COUNT repetitions of its type.  */

value_ptr
value_repeat (arg1, count)
     value_ptr arg1;
     int count;
{
  register value_ptr val;

  if (VALUE_LVAL (arg1) != lval_memory)
    error ("Only values in memory can be extended with '@'.");
  if (count < 1)
    error ("Invalid number %d of repetitions.", count);

  val = allocate_repeat_value (VALUE_TYPE (arg1), count);

  read_memory (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1),
               VALUE_CONTENTS_RAW (val),
               TYPE_LENGTH (VALUE_TYPE (val)) * count);
  VALUE_LVAL (val) = lval_memory;
  VALUE_ADDRESS (val) = VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1);

  return val;
}

value_ptr
value_of_variable (var, b)
     struct symbol *var;
     struct block *b;
{
  value_ptr val;
  struct frame_info *frame;

  if (b == NULL)
    /* Use selected frame.  */
    frame = NULL;
  else
    {
      frame = block_innermost_frame (b);
      if (frame == NULL && symbol_read_needs_frame (var))
        {
          if (BLOCK_FUNCTION (b) != NULL
              && SYMBOL_NAME (BLOCK_FUNCTION (b)) != NULL)
            error ("No frame is currently executing in block %s.",
                   SYMBOL_NAME (BLOCK_FUNCTION (b)));
          else
            error ("No frame is currently executing in specified block");
        }
    }
  val = read_var_value (var, frame);
  if (val == 0)
    error ("Address of symbol \"%s\" is unknown.", SYMBOL_SOURCE_NAME (var));
  return val;
}

/* Given a value which is an array, return a value which is a pointer to its
   first element, regardless of whether or not the array has a nonzero lower
   bound.

   FIXME:  A previous comment here indicated that this routine should be
   substracting the array's lower bound.  It's not clear to me that this
   is correct.  Given an array subscripting operation, it would certainly
   work to do the adjustment here, essentially computing:

   (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])

   However I believe a more appropriate and logical place to account for
   the lower bound is to do so in value_subscript, essentially computing:

   (&array[0] + ((index - lowerbound) * sizeof array[0]))

   As further evidence consider what would happen with operations other
   than array subscripting, where the caller would get back a value that
   had an address somewhere before the actual first element of the array,
   and the information about the lower bound would be lost because of
   the coercion to pointer type.
   */

value_ptr
value_coerce_array (arg1)
     value_ptr arg1;
{
  register struct type *type;

  if (VALUE_LVAL (arg1) != lval_memory)
    error ("Attempt to take address of value not located in memory.");

  /* Get type of elements.  */
  if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_ARRAY
      || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_STRING)
    type = TYPE_TARGET_TYPE (VALUE_TYPE (arg1));
  else
    /* A phony array made by value_repeat.
       Its type is the type of the elements, not an array type.  */
    type = VALUE_TYPE (arg1);

  return value_from_longest (lookup_pointer_type (type),
                       (LONGEST) (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
}

/* Given a value which is a function, return a value which is a pointer
   to it.  */

value_ptr
value_coerce_function (arg1)
     value_ptr arg1;
{

  if (VALUE_LVAL (arg1) != lval_memory)
    error ("Attempt to take address of value not located in memory.");

  return value_from_longest (lookup_pointer_type (VALUE_TYPE (arg1)),
                (LONGEST) (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
}  

/* Return a pointer value for the object for which ARG1 is the contents.  */

value_ptr
value_addr (arg1)
     value_ptr arg1;
{
  struct type *type = VALUE_TYPE (arg1);
  if (TYPE_CODE (type) == TYPE_CODE_REF)
    {
      /* Copy the value, but change the type from (T&) to (T*).
         We keep the same location information, which is efficient,
         and allows &(&X) to get the location containing the reference. */
      value_ptr arg2 = value_copy (arg1);
      VALUE_TYPE (arg2) = lookup_pointer_type (TYPE_TARGET_TYPE (type));
      return arg2;
    }
  if (current_language->c_style_arrays
      && (VALUE_REPEATED (arg1)
          || TYPE_CODE (type) == TYPE_CODE_ARRAY))
    return value_coerce_array (arg1);
  if (TYPE_CODE (type) == TYPE_CODE_FUNC)
    return value_coerce_function (arg1);

  if (VALUE_LVAL (arg1) != lval_memory)
    error ("Attempt to take address of value not located in memory.");

  return value_from_longest (lookup_pointer_type (type),
                (LONGEST) (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
}

/* Given a value of a pointer type, apply the C unary * operator to it.  */

value_ptr
value_ind (arg1)
     value_ptr arg1;
{
  COERCE_ARRAY (arg1);

  if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_MEMBER)
    error ("not implemented: member types in value_ind");

  /* Allow * on an integer so we can cast it to whatever we want.
     This returns an int, which seems like the most C-like thing
     to do.  "long long" variables are rare enough that
     BUILTIN_TYPE_LONGEST would seem to be a mistake.  */
  if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_INT)
    return value_at (builtin_type_int,
                     (CORE_ADDR) value_as_long (arg1));
  else if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_PTR)
    return value_at_lazy (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)),
                          value_as_pointer (arg1));
  error ("Attempt to take contents of a non-pointer value.");
  return 0;  /* For lint -- never reached */
}
\f
/* Pushing small parts of stack frames.  */

/* Push one word (the size of object that a register holds).  */

CORE_ADDR
push_word (sp, word)
     CORE_ADDR sp;
     unsigned LONGEST word;
{
  register int len = REGISTER_SIZE;
  char buffer[MAX_REGISTER_RAW_SIZE];

  store_unsigned_integer (buffer, len, word);
#if 1 INNER_THAN 2
  sp -= len;
  write_memory (sp, buffer, len);
#else /* stack grows upward */
  write_memory (sp, buffer, len);
  sp += len;
#endif /* stack grows upward */

  return sp;
}

/* Push LEN bytes with data at BUFFER.  */

CORE_ADDR
push_bytes (sp, buffer, len)
     CORE_ADDR sp;
     char *buffer;
     int len;
{
#if 1 INNER_THAN 2
  sp -= len;
  write_memory (sp, buffer, len);
#else /* stack grows upward */
  write_memory (sp, buffer, len);
  sp += len;
#endif /* stack grows upward */

  return sp;
}

/* Push onto the stack the specified value VALUE.  */

static CORE_ADDR
value_push (sp, arg)
     register CORE_ADDR sp;
     value_ptr arg;
{
  register int len = TYPE_LENGTH (VALUE_TYPE (arg));

#if 1 INNER_THAN 2
  sp -= len;
  write_memory (sp, VALUE_CONTENTS (arg), len);
#else /* stack grows upward */
  write_memory (sp, VALUE_CONTENTS (arg), len);
  sp += len;
#endif /* stack grows upward */

  return sp;
}

/* Perform the standard coercions that are specified
   for arguments to be passed to C functions.  */

value_ptr
value_arg_coerce (arg)
     value_ptr arg;
{
  register struct type *type;

  /* FIXME: We should coerce this according to the prototype (if we have
     one).  Right now we do a little bit of this in typecmp(), but that
     doesn't always get called.  For example, if passing a ref to a function
     without a prototype, we probably should de-reference it.  Currently
     we don't.  */

  if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ENUM)
    arg = value_cast (builtin_type_unsigned_int, arg);

#if 1   /* FIXME:  This is only a temporary patch.  -fnf */
  if (current_language->c_style_arrays
      && (VALUE_REPEATED (arg)
          || 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);
#endif

  type = VALUE_TYPE (arg);

  if (TYPE_CODE (type) == TYPE_CODE_INT
      && TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
    return value_cast (builtin_type_int, arg);

  if (TYPE_CODE (type) == TYPE_CODE_FLT
      && TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double))
    return value_cast (builtin_type_double, arg);

  return arg;
}

/* Push the value ARG, first coercing it as an argument
   to a C function.  */

static CORE_ADDR
value_arg_push (sp, arg)
     register CORE_ADDR sp;
     value_ptr arg;
{
  return value_push (sp, value_arg_coerce (arg));
}

/* Determine a function's address and its return type from its value. 
   Calls error() if the function is not valid for calling.  */

static CORE_ADDR
find_function_addr (function, retval_type)
     value_ptr function;
     struct type **retval_type;
{
  register struct type *ftype = VALUE_TYPE (function);
  register enum type_code code = TYPE_CODE (ftype);
  struct type *value_type;
  CORE_ADDR funaddr;

  /* If it's a member function, just look at the function
     part of it.  */

  /* Determine address to call.  */
  if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
    {
      funaddr = VALUE_ADDRESS (function);
      value_type = TYPE_TARGET_TYPE (ftype);
    }
  else if (code == TYPE_CODE_PTR)
    {
      funaddr = value_as_pointer (function);
      if (TYPE_CODE (TYPE_TARGET_TYPE (ftype)) == TYPE_CODE_FUNC
          || TYPE_CODE (TYPE_TARGET_TYPE (ftype)) == TYPE_CODE_METHOD)
        {
#ifdef CONVERT_FROM_FUNC_PTR_ADDR
          /* FIXME: This is a workaround for the unusual function
             pointer representation on the RS/6000, see comment
             in config/rs6000/tm-rs6000.h  */
          funaddr = CONVERT_FROM_FUNC_PTR_ADDR (funaddr);
#endif
          value_type = TYPE_TARGET_TYPE (TYPE_TARGET_TYPE (ftype));
        }
      else
        value_type = builtin_type_int;
    }
  else if (code == TYPE_CODE_INT)
    {
      /* Handle the case of functions lacking debugging info.
         Their values are characters since their addresses are char */
      if (TYPE_LENGTH (ftype) == 1)
        funaddr = value_as_pointer (value_addr (function));
      else
        /* Handle integer used as address of a function.  */
        funaddr = (CORE_ADDR) value_as_long (function);

      value_type = builtin_type_int;
    }
  else
    error ("Invalid data type for function to be called.");

  *retval_type = value_type;
  return funaddr;
}

#if defined (CALL_DUMMY)
/* All this stuff with a dummy frame may seem unnecessarily complicated
   (why not just save registers in GDB?).  The purpose of pushing a dummy
   frame which looks just like a real frame is so that if you call a
   function and then hit a breakpoint (get a signal, etc), "backtrace"
   will look right.  Whether the backtrace needs to actually show the
   stack at the time the inferior function was called is debatable, but
   it certainly needs to not display garbage.  So if you are contemplating
   making dummy frames be different from normal frames, consider that.  */

/* Perform a function call in the inferior.
   ARGS is a vector of values of arguments (NARGS of them).
   FUNCTION is a value, the function to be called.
   Returns a value representing what the function returned.
   May fail to return, if a breakpoint or signal is hit
   during the execution of the function.  */

value_ptr
call_function_by_hand (function, nargs, args)
     value_ptr function;
     int nargs;
     value_ptr *args;
{
  register CORE_ADDR sp;
  register int i;
  CORE_ADDR start_sp;
  /* CALL_DUMMY is an array of words (REGISTER_SIZE), but each word
     is in host byte order.  Before calling FIX_CALL_DUMMY, we byteswap it
     and remove any extra bytes which might exist because unsigned LONGEST is
     bigger than REGISTER_SIZE.  */
  static unsigned LONGEST dummy[] = CALL_DUMMY;
  char dummy1[REGISTER_SIZE * sizeof dummy / sizeof (unsigned LONGEST)];
  CORE_ADDR old_sp;
  struct type *value_type;
  unsigned char struct_return;
  CORE_ADDR struct_addr;
  struct inferior_status inf_status;
  struct cleanup *old_chain;
  CORE_ADDR funaddr;
  int using_gcc;
  CORE_ADDR real_pc;

  if (!target_has_execution)
    noprocess();

  save_inferior_status (&inf_status, 1);
  old_chain = make_cleanup (restore_inferior_status, &inf_status);

  /* PUSH_DUMMY_FRAME is responsible for saving the inferior registers
     (and POP_FRAME for restoring them).  (At least on most machines)
     they are saved on the stack in the inferior.  */
  PUSH_DUMMY_FRAME;

  old_sp = sp = read_sp ();

#if 1 INNER_THAN 2              /* Stack grows down */
  sp -= sizeof dummy1;
  start_sp = sp;
#else                           /* Stack grows up */
  start_sp = sp;
  sp += sizeof dummy1;
#endif

  funaddr = find_function_addr (function, &value_type);

  {
    struct block *b = block_for_pc (funaddr);
    /* If compiled without -g, assume GCC.  */
    using_gcc = b == NULL || BLOCK_GCC_COMPILED (b);
  }

  /* Are we returning a value using a structure return or a normal
     value return? */

  struct_return = using_struct_return (function, funaddr, value_type,
                                       using_gcc);

  /* Create a call sequence customized for this function
     and the number of arguments for it.  */
  for (i = 0; i < sizeof dummy / sizeof (dummy[0]); i++)
    store_unsigned_integer (&dummy1[i * REGISTER_SIZE],
                            REGISTER_SIZE,
                            (unsigned LONGEST)dummy[i]);

#ifdef GDB_TARGET_IS_HPPA
  real_pc = FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
                            value_type, using_gcc);
#else
  FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
                  value_type, using_gcc);
  real_pc = start_sp;
#endif

#if CALL_DUMMY_LOCATION == ON_STACK
  write_memory (start_sp, (char *)dummy1, sizeof dummy1);
#endif /* On stack.  */

#if CALL_DUMMY_LOCATION == BEFORE_TEXT_END
  /* Convex Unix prohibits executing in the stack segment. */
  /* Hope there is empty room at the top of the text segment. */
  {
    extern CORE_ADDR text_end;
    static checked = 0;
    if (!checked)
      for (start_sp = text_end - sizeof dummy1; start_sp < text_end; ++start_sp)
        if (read_memory_integer (start_sp, 1) != 0)
          error ("text segment full -- no place to put call");
    checked = 1;
    sp = old_sp;
    real_pc = text_end - sizeof dummy1;
    write_memory (real_pc, (char *)dummy1, sizeof dummy1);
  }
#endif /* Before text_end.  */

#if CALL_DUMMY_LOCATION == AFTER_TEXT_END
  {
    extern CORE_ADDR text_end;
    int errcode;
    sp = old_sp;
    real_pc = text_end;
    errcode = target_write_memory (real_pc, (char *)dummy1, sizeof dummy1);
    if (errcode != 0)
      error ("Cannot write text segment -- call_function failed");
  }
#endif /* After text_end.  */

#if CALL_DUMMY_LOCATION == AT_ENTRY_POINT
  real_pc = funaddr;
#endif /* At entry point.  */

#ifdef lint
  sp = old_sp;          /* It really is used, for some ifdef's... */
#endif

#ifdef STACK_ALIGN
  /* If stack grows down, we must leave a hole at the top. */
  {
    int len = 0;

    /* Reserve space for the return structure to be written on the
       stack, if necessary */

    if (struct_return)
      len += TYPE_LENGTH (value_type);
    
    for (i = nargs - 1; i >= 0; i--)
      len += TYPE_LENGTH (VALUE_TYPE (value_arg_coerce (args[i])));
#ifdef CALL_DUMMY_STACK_ADJUST
    len += CALL_DUMMY_STACK_ADJUST;
#endif
#if 1 INNER_THAN 2
    sp -= STACK_ALIGN (len) - len;
#else
    sp += STACK_ALIGN (len) - len;
#endif
  }
#endif /* STACK_ALIGN */

    /* Reserve space for the return structure to be written on the
       stack, if necessary */

    if (struct_return)
      {
#if 1 INNER_THAN 2
        sp -= TYPE_LENGTH (value_type);
        struct_addr = sp;
#else
        struct_addr = sp;
        sp += TYPE_LENGTH (value_type);
#endif
      }

#if defined (REG_STRUCT_HAS_ADDR)
  {
    /* This is a machine like the sparc, where we may need to pass a pointer
       to the structure, not the structure itself.  */
    for (i = nargs - 1; i >= 0; i--)
      if (TYPE_CODE (VALUE_TYPE (args[i])) == TYPE_CODE_STRUCT
          && REG_STRUCT_HAS_ADDR (using_gcc, VALUE_TYPE (args[i])))
        {
          CORE_ADDR addr;
#if !(1 INNER_THAN 2)
          /* The stack grows up, so the address of the thing we push
             is the stack pointer before we push it.  */
          addr = sp;
#endif
          /* Push the structure.  */
          sp = value_push (sp, args[i]);
#if 1 INNER_THAN 2
          /* The stack grows down, so the address of the thing we push
             is the stack pointer after we push it.  */
          addr = sp;
#endif
          /* The value we're going to pass is the address of the thing
             we just pushed.  */
          args[i] = value_from_longest (lookup_pointer_type (value_type),
                                        (LONGEST) addr);
        }
  }
#endif /* REG_STRUCT_HAS_ADDR.  */

#ifdef PUSH_ARGUMENTS
  PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr);
#else /* !PUSH_ARGUMENTS */
  for (i = nargs - 1; i >= 0; i--)
    sp = value_arg_push (sp, args[i]);
#endif /* !PUSH_ARGUMENTS */

#ifdef CALL_DUMMY_STACK_ADJUST
#if 1 INNER_THAN 2
  sp -= CALL_DUMMY_STACK_ADJUST;
#else
  sp += CALL_DUMMY_STACK_ADJUST;
#endif
#endif /* CALL_DUMMY_STACK_ADJUST */

  /* Store the address at which the structure is supposed to be
     written.  Note that this (and the code which reserved the space
     above) assumes that gcc was used to compile this function.  Since
     it doesn't cost us anything but space and if the function is pcc
     it will ignore this value, we will make that assumption.

     Also note that on some machines (like the sparc) pcc uses a 
     convention like gcc's.  */

  if (struct_return)
    STORE_STRUCT_RETURN (struct_addr, sp);

  /* Write the stack pointer.  This is here because the statements above
     might fool with it.  On SPARC, this write also stores the register
     window into the right place in the new stack frame, which otherwise
     wouldn't happen.  (See store_inferior_registers in sparc-nat.c.)  */
  write_sp (sp);

  {
    char retbuf[REGISTER_BYTES];
    char *name;
    struct symbol *symbol;

    name = NULL;
    symbol = find_pc_function (funaddr);
    if (symbol)
      {
        name = SYMBOL_SOURCE_NAME (symbol);
      }
    else
      {
        /* Try the minimal symbols.  */
        struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);

        if (msymbol)
          {
            name = SYMBOL_SOURCE_NAME (msymbol);
          }
      }
    if (name == NULL)
      {
        char format[80];
        sprintf (format, "at %s", local_hex_format ());
        name = alloca (80);
        /* FIXME-32x64: assumes funaddr fits in a long.  */
        sprintf (name, format, (unsigned long) funaddr);
      }

    /* Execute the stack dummy routine, calling FUNCTION.
       When it is done, discard the empty frame
       after storing the contents of all regs into retbuf.  */
    if (run_stack_dummy (real_pc + CALL_DUMMY_START_OFFSET, retbuf))
      {
        /* We stopped somewhere besides the call dummy.  */

        /* If we did the cleanups, we would print a spurious error message
           (Unable to restore previously selected frame), would write the
           registers from the inf_status (which is wrong), and would do other
           wrong things (like set stop_bpstat to the wrong thing).  */
        discard_cleanups (old_chain);
        /* Prevent memory leak.  */
        bpstat_clear (&inf_status.stop_bpstat);

        /* The following error message used to say "The expression
           which contained the function call has been discarded."  It
           is a hard concept to explain in a few words.  Ideally, GDB
           would be able to resume evaluation of the expression when
           the function finally is done executing.  Perhaps someday
           this will be implemented (it would not be easy).  */

        /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
           a C++ name with arguments and stuff.  */
        error ("\
The program being debugged stopped while in a function called from GDB.\n\
When the function (%s) is done executing, GDB will silently\n\
stop (instead of continuing to evaluate the expression containing\n\
the function call).", name);
      }

    do_cleanups (old_chain);

    /* Figure out the value returned by the function.  */
    return value_being_returned (value_type, retbuf, struct_return);
  }
}
#else /* no CALL_DUMMY.  */
value_ptr
call_function_by_hand (function, nargs, args)
     value_ptr function;
     int nargs;
     value_ptr *args;
{
  error ("Cannot invoke functions on this machine.");
}
#endif /* no CALL_DUMMY.  */

\f
/* Create a value for an array by allocating space in the inferior, copying
   the data into that space, and then setting up an array value.

   The array bounds are set from LOWBOUND and HIGHBOUND, and the array is
   populated from the values passed in ELEMVEC.

   The element type of the array is inherited from the type of the
   first element, and all elements must have the same size (though we
   don't currently enforce any restriction on their types). */

value_ptr
value_array (lowbound, highbound, elemvec)
     int lowbound;
     int highbound;
     value_ptr *elemvec;
{
  int nelem;
  int idx;
  int typelength;
  value_ptr val;
  struct type *rangetype;
  struct type *arraytype;
  CORE_ADDR addr;

  /* Validate that the bounds are reasonable and that each of the elements
     have the same size. */

  nelem = highbound - lowbound + 1;
  if (nelem <= 0)
    {
      error ("bad array bounds (%d, %d)", lowbound, highbound);
    }
  typelength = TYPE_LENGTH (VALUE_TYPE (elemvec[0]));
  for (idx = 0; idx < nelem; idx++)
    {
      if (TYPE_LENGTH (VALUE_TYPE (elemvec[idx])) != typelength)
        {
          error ("array elements must all be the same size");
        }
    }

  /* Allocate space to store the array in the inferior, and then initialize
     it by copying in each element.  FIXME:  Is it worth it to create a
     local buffer in which to collect each value and then write all the
     bytes in one operation? */

  addr = allocate_space_in_inferior (nelem * typelength);
  for (idx = 0; idx < nelem; idx++)
    {
      write_memory (addr + (idx * typelength), VALUE_CONTENTS (elemvec[idx]),
                    typelength);
    }

  /* Create the array type and set up an array value to be evaluated lazily. */

  rangetype = create_range_type ((struct type *) NULL, builtin_type_int,
                                 lowbound, highbound);
  arraytype = create_array_type ((struct type *) NULL, 
                                 VALUE_TYPE (elemvec[0]), rangetype);
  val = value_at_lazy (arraytype, addr);
  return (val);
}

/* Create a value for a string constant by allocating space in the inferior,
   copying the data into that space, and returning the address with type
   TYPE_CODE_STRING.  PTR points to the string constant data; LEN is number
   of characters.
   Note that string types are like array of char types with a lower bound of
   zero and an upper bound of LEN - 1.  Also note that the string may contain
   embedded null bytes. */

value_ptr
value_string (ptr, len)
     char *ptr;
     int len;
{
  value_ptr val;
  struct type *rangetype = create_range_type ((struct type *) NULL,
                                              builtin_type_int, 0, len - 1);
  struct type *stringtype
    = create_string_type ((struct type *) NULL, rangetype);
  CORE_ADDR addr;

  if (current_language->c_style_arrays == 0)
    {
      val = allocate_value (stringtype);
      memcpy (VALUE_CONTENTS_RAW (val), ptr, len);
      return val;
    }


  /* Allocate space to store the string in the inferior, and then
     copy LEN bytes from PTR in gdb to that address in the inferior. */

  addr = allocate_space_in_inferior (len);
  write_memory (addr, ptr, len);

  val = value_at_lazy (stringtype, addr);
  return (val);
}

value_ptr
value_bitstring (ptr, len)
     char *ptr;
     int len;
{
  value_ptr val;
  struct type *domain_type = create_range_type (NULL, builtin_type_int,
                                                0, len - 1);
  struct type *type = create_set_type ((struct type*) NULL, domain_type);
  TYPE_CODE (type) = TYPE_CODE_BITSTRING;
  val = allocate_value (type);
  memcpy (VALUE_CONTENTS_RAW (val), ptr, TYPE_LENGTH (type) / TARGET_CHAR_BIT);
  return val;
}
\f
/* See if we can pass arguments in T2 to a function which takes arguments
   of types T1.  Both t1 and t2 are NULL-terminated vectors.  If some
   arguments need coercion of some sort, then the coerced values are written
   into T2.  Return value is 0 if the arguments could be matched, or the
   position at which they differ if not.

   STATICP is nonzero if the T1 argument list came from a
   static member function.

   For non-static member functions, we ignore the first argument,
   which is the type of the instance variable.  This is because we want
   to handle calls with objects from derived classes.  This is not
   entirely correct: we should actually check to make sure that a
   requested operation is type secure, shouldn't we?  FIXME.  */

static int
typecmp (staticp, t1, t2)
     int staticp;
     struct type *t1[];
     value_ptr t2[];
{
  int i;

  if (t2 == 0)
    return 1;
  if (staticp && t1 == 0)
    return t2[1] != 0;
  if (t1 == 0)
    return 1;
  if (TYPE_CODE (t1[0]) == TYPE_CODE_VOID) return 0;
  if (t1[!staticp] == 0) return 0;
  for (i = !staticp; t1[i] && TYPE_CODE (t1[i]) != TYPE_CODE_VOID; i++)
    {
    struct type *tt1, *tt2;
      if (! t2[i])
        return i+1;
      tt1 = t1[i];
      tt2 = VALUE_TYPE(t2[i]);
      if (TYPE_CODE (tt1) == TYPE_CODE_REF
          /* We should be doing hairy argument matching, as below.  */
          && (TYPE_CODE (TYPE_TARGET_TYPE (tt1)) == TYPE_CODE (tt2)))
        {
          t2[i] = value_addr (t2[i]);
          continue;
        }

      while (TYPE_CODE (tt1) == TYPE_CODE_PTR
          && (TYPE_CODE(tt2)==TYPE_CODE_ARRAY || TYPE_CODE(tt2)==TYPE_CODE_PTR))
        {
           tt1 = TYPE_TARGET_TYPE(tt1); 
           tt2 = TYPE_TARGET_TYPE(tt2);
        }
      if (TYPE_CODE(tt1) == TYPE_CODE(tt2)) continue;
      /* Array to pointer is a `trivial conversion' according to the ARM.  */

      /* We should be doing much hairier argument matching (see section 13.2
         of the ARM), but as a quick kludge, just check for the same type
         code.  */
      if (TYPE_CODE (t1[i]) != TYPE_CODE (VALUE_TYPE (t2[i])))
        return i+1;
    }
  if (!t1[i]) return 0;
  return t2[i] ? i+1 : 0;
}

/* Helper function used by value_struct_elt to recurse through baseclasses.
   Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
   and search in it assuming it has (class) type TYPE.
   If found, return value, else return NULL.

   If LOOKING_FOR_BASECLASS, then instead of looking for struct fields,
   look for a baseclass named NAME.  */

static value_ptr
search_struct_field (name, arg1, offset, type, looking_for_baseclass)
     char *name;
     register value_ptr arg1;
     int offset;
     register struct type *type;
     int looking_for_baseclass;
{
  int i;

  check_stub_type (type);

  if (! looking_for_baseclass)
    for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
      {
        char *t_field_name = TYPE_FIELD_NAME (type, i);

        if (t_field_name && STREQ (t_field_name, name))
          {
            value_ptr v;
            if (TYPE_FIELD_STATIC (type, i))
              {
                char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, i);
                struct symbol *sym =
                    lookup_symbol (phys_name, 0, VAR_NAMESPACE, 0, NULL);
                if (sym == NULL)
                    error ("Internal error: could not find physical static variable named %s",
                           phys_name);
                v = value_at (TYPE_FIELD_TYPE (type, i),
                              (CORE_ADDR)SYMBOL_BLOCK_VALUE (sym));
              }
            else
              v = value_primitive_field (arg1, offset, i, type);
            if (v == 0)
              error("there is no field named %s", name);
            return v;
          }
        if (t_field_name && t_field_name[0] == '\0'
            && TYPE_CODE (TYPE_FIELD_TYPE (type, i)) == TYPE_CODE_UNION)
          {
            /* Look for a match through the fields of an anonymous union.  */
            value_ptr v;
            v = search_struct_field (name, arg1, offset,
                                     TYPE_FIELD_TYPE (type, i),
                                     looking_for_baseclass);
            if (v)
              return v;
          }
      }

  for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
    {
      value_ptr v;
      /* If we are looking for baseclasses, this is what we get when we
         hit them.  But it could happen that the base part's member name
         is not yet filled in.  */
      int found_baseclass = (looking_for_baseclass
                             && TYPE_BASECLASS_NAME (type, i) != NULL
                             && STREQ (name, TYPE_BASECLASS_NAME (type, i)));

      if (BASETYPE_VIA_VIRTUAL (type, i))
        {
          value_ptr v2;
          /* Fix to use baseclass_offset instead. FIXME */
          baseclass_addr (type, i, VALUE_CONTENTS (arg1) + offset,
                          &v2, (int *)NULL);
          if (v2 == 0)
            error ("virtual baseclass botch");
          if (found_baseclass)
            return v2;
          v = search_struct_field (name, v2, 0, TYPE_BASECLASS (type, i),
                                   looking_for_baseclass);
        }
      else if (found_baseclass)
        v = value_primitive_field (arg1, offset, i, type);
      else
        v = search_struct_field (name, arg1,
                                 offset + TYPE_BASECLASS_BITPOS (type, i) / 8,
                                 TYPE_BASECLASS (type, i),
                                 looking_for_baseclass);
      if (v) return v;
    }
  return NULL;
}

/* Helper function used by value_struct_elt to recurse through baseclasses.
   Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
   and search in it assuming it has (class) type TYPE.
   If found, return value, else if name matched and args not return (value)-1,
   else return NULL. */

static value_ptr
search_struct_method (name, arg1p, args, offset, static_memfuncp, type)
     char *name;
     register value_ptr *arg1p, *args;
     int offset, *static_memfuncp;
     register struct type *type;
{
  int i;
  value_ptr v;
  int name_matched = 0;
  char dem_opname[64];

  check_stub_type (type);
  for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
    {
      char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
      if (strncmp(t_field_name, "__", 2)==0 ||
        strncmp(t_field_name, "op", 2)==0 ||
        strncmp(t_field_name, "type", 4)==0 )
        {
          if (cplus_demangle_opname(t_field_name, dem_opname, DMGL_ANSI))
            t_field_name = dem_opname;
          else if (cplus_demangle_opname(t_field_name, dem_opname, 0))
            t_field_name = dem_opname; 
        }
      if (t_field_name && STREQ (t_field_name, name))
        {
          int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
          struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
          name_matched = 1; 

          if (j > 0 && args == 0)
            error ("cannot resolve overloaded method `%s'", name);
          while (j >= 0)
            {
              if (TYPE_FN_FIELD_STUB (f, j))
                check_stub_method (type, i, j);
              if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
                            TYPE_FN_FIELD_ARGS (f, j), args))
                {
                  if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
                    return value_virtual_fn_field (arg1p, f, j, type, offset);
                  if (TYPE_FN_FIELD_STATIC_P (f, j) && static_memfuncp)
                    *static_memfuncp = 1;
                  v = value_fn_field (arg1p, f, j, type, offset);
                  if (v != NULL) return v;
                }
              j--;
            }
        }
    }

  for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
    {
      int base_offset;

      if (BASETYPE_VIA_VIRTUAL (type, i))
        {
          base_offset = baseclass_offset (type, i, *arg1p, offset);
          if (base_offset == -1)
            error ("virtual baseclass botch");
        }
      else
        {
          base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
        }
      v = search_struct_method (name, arg1p, args, base_offset + offset,
                                static_memfuncp, TYPE_BASECLASS (type, i));
      if (v == (value_ptr) -1)
        {
          name_matched = 1;
        }
      else if (v)
        {
/* FIXME-bothner:  Why is this commented out?  Why is it here?  */
/*        *arg1p = arg1_tmp;*/
          return v;
        }
    }
  if (name_matched) return (value_ptr) -1;
  else return NULL;
}

/* Given *ARGP, a value of type (pointer to a)* structure/union,
   extract the component named NAME from the ultimate target structure/union
   and return it as a value with its appropriate type.
   ERR is used in the error message if *ARGP's type is wrong.

   C++: ARGS is a list of argument types to aid in the selection of
   an appropriate method. Also, handle derived types.

   STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
   where the truthvalue of whether the function that was resolved was
   a static member function or not is stored.

   ERR is an error message to be printed in case the field is not found.  */

value_ptr
value_struct_elt (argp, args, name, static_memfuncp, err)
     register value_ptr *argp, *args;
     char *name;
     int *static_memfuncp;
     char *err;
{
  register struct type *t;
  value_ptr v;

  COERCE_ARRAY (*argp);

  t = VALUE_TYPE (*argp);

  /* Follow pointers until we get to a non-pointer.  */

  while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
    {
      *argp = value_ind (*argp);
      /* Don't coerce fn pointer to fn and then back again!  */
      if (TYPE_CODE (VALUE_TYPE (*argp)) != TYPE_CODE_FUNC)
        COERCE_ARRAY (*argp);
      t = VALUE_TYPE (*argp);
    }

  if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
    error ("not implemented: member type in value_struct_elt");

  if (   TYPE_CODE (t) != TYPE_CODE_STRUCT
      && TYPE_CODE (t) != TYPE_CODE_UNION)
    error ("Attempt to extract a component of a value that is not a %s.", err);

  /* Assume it's not, unless we see that it is.  */
  if (static_memfuncp)
    *static_memfuncp =0;

  if (!args)
    {
      /* if there are no arguments ...do this...  */

      /* Try as a field first, because if we succeed, there
         is less work to be done.  */
      v = search_struct_field (name, *argp, 0, t, 0);
      if (v)
        return v;

      /* C++: If it was not found as a data field, then try to
         return it as a pointer to a method.  */

      if (destructor_name_p (name, t))
        error ("Cannot get value of destructor");

      v = search_struct_method (name, argp, args, 0, static_memfuncp, t);

      if (v == (value_ptr) -1)
        error ("Cannot take address of a method");
      else if (v == 0)
        {
          if (TYPE_NFN_FIELDS (t))
            error ("There is no member or method named %s.", name);
          else
            error ("There is no member named %s.", name);
        }
      return v;
    }

  if (destructor_name_p (name, t))
    {
      if (!args[1])
        {
          /* destructors are a special case.  */
          v = value_fn_field (NULL, TYPE_FN_FIELDLIST1 (t, 0),
                              TYPE_FN_FIELDLIST_LENGTH (t, 0), 0, 0);
          if (!v) error("could not find destructor function named %s.", name);
          else return v;
        }
      else
        {
          error ("destructor should not have any argument");
        }
    }
  else
    v = search_struct_method (name, argp, args, 0, static_memfuncp, t);

  if (v == (value_ptr) -1)
    {
        error("Argument list of %s mismatch with component in the structure.", name);
    }
  else if (v == 0)
    {
      /* See if user tried to invoke data as function.  If so,
         hand it back.  If it's not callable (i.e., a pointer to function),
         gdb should give an error.  */
      v = search_struct_field (name, *argp, 0, t, 0);
    }

  if (!v)
    error ("Structure has no component named %s.", name);
  return v;
}

/* C++: return 1 is NAME is a legitimate name for the destructor
   of type TYPE.  If TYPE does not have a destructor, or
   if NAME is inappropriate for TYPE, an error is signaled.  */
int
destructor_name_p (name, type)
     const char *name;
     const struct type *type;
{
  /* destructors are a special case.  */

  if (name[0] == '~')
    {
      char *dname = type_name_no_tag (type);
      char *cp = strchr (dname, '<');
      int len;

      /* Do not compare the template part for template classes.  */
      if (cp == NULL)
        len = strlen (dname);
      else
        len = cp - dname;
      if (strlen (name + 1) != len || !STREQN (dname, name + 1, len))
        error ("name of destructor must equal name of class");
      else
        return 1;
    }
  return 0;
}

/* Helper function for check_field: Given TYPE, a structure/union,
   return 1 if the component named NAME from the ultimate
   target structure/union is defined, otherwise, return 0. */

static int
check_field_in (type, name)
     register struct type *type;
     const char *name;
{
  register int i;

  for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
    {
      char *t_field_name = TYPE_FIELD_NAME (type, i);
      if (t_field_name && STREQ (t_field_name, name))
        return 1;
    }

  /* C++: If it was not found as a data field, then try to
     return it as a pointer to a method.  */

  /* Destructors are a special case.  */
  if (destructor_name_p (name, type))
    return 1;

  for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
    {
      if (STREQ (TYPE_FN_FIELDLIST_NAME (type, i), name))
        return 1;
    }

  for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
    if (check_field_in (TYPE_BASECLASS (type, i), name))
      return 1;
      
  return 0;
}


/* C++: Given ARG1, a value of type (pointer to a)* structure/union,
   return 1 if the component named NAME from the ultimate
   target structure/union is defined, otherwise, return 0.  */

int
check_field (arg1, name)
     register value_ptr arg1;
     const char *name;
{
  register struct type *t;

  COERCE_ARRAY (arg1);

  t = VALUE_TYPE (arg1);

  /* Follow pointers until we get to a non-pointer.  */

  while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
    t = TYPE_TARGET_TYPE (t);

  if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
    error ("not implemented: member type in check_field");

  if (   TYPE_CODE (t) != TYPE_CODE_STRUCT
      && TYPE_CODE (t) != TYPE_CODE_UNION)
    error ("Internal error: `this' is not an aggregate");

  return check_field_in (t, name);
}

/* C++: Given an aggregate type CURTYPE, and a member name NAME,
   return the address of this member as a "pointer to member"
   type.  If INTYPE is non-null, then it will be the type
   of the member we are looking for.  This will help us resolve
   "pointers to member functions".  This function is used
   to resolve user expressions of the form "DOMAIN::NAME".  */

value_ptr
value_struct_elt_for_reference (domain, offset, curtype, name, intype)
     struct type *domain, *curtype, *intype;
     int offset;
     char *name;
{
  register struct type *t = curtype;
  register int i;
  value_ptr v;

  if (   TYPE_CODE (t) != TYPE_CODE_STRUCT
      && TYPE_CODE (t) != TYPE_CODE_UNION)
    error ("Internal error: non-aggregate type to value_struct_elt_for_reference");

  for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
    {
      char *t_field_name = TYPE_FIELD_NAME (t, i);
      
      if (t_field_name && STREQ (t_field_name, name))
        {
          if (TYPE_FIELD_STATIC (t, i))
            {
              char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (t, i);
              struct symbol *sym =
                lookup_symbol (phys_name, 0, VAR_NAMESPACE, 0, NULL);
              if (sym == NULL)
                error ("Internal error: could not find physical static variable named %s",
                       phys_name);
              return value_at (SYMBOL_TYPE (sym),
                               (CORE_ADDR)SYMBOL_BLOCK_VALUE (sym));
            }
          if (TYPE_FIELD_PACKED (t, i))
            error ("pointers to bitfield members not allowed");
          
          return value_from_longest
            (lookup_reference_type (lookup_member_type (TYPE_FIELD_TYPE (t, i),
                                                        domain)),
             offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
        }
    }

  /* C++: If it was not found as a data field, then try to
     return it as a pointer to a method.  */

  /* Destructors are a special case.  */
  if (destructor_name_p (name, t))
    {
      error ("member pointers to destructors not implemented yet");
    }

  /* Perform all necessary dereferencing.  */
  while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
    intype = TYPE_TARGET_TYPE (intype);

  for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
    {
      char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
      char dem_opname[64];

      if (strncmp(t_field_name, "__", 2)==0 ||
        strncmp(t_field_name, "op", 2)==0 ||
        strncmp(t_field_name, "type", 4)==0 )
        {
          if (cplus_demangle_opname(t_field_name, dem_opname, DMGL_ANSI))
            t_field_name = dem_opname;
          else if (cplus_demangle_opname(t_field_name, dem_opname, 0))
            t_field_name = dem_opname; 
        }
      if (t_field_name && STREQ (t_field_name, name))
        {
          int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
          struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
          
          if (intype == 0 && j > 1)
            error ("non-unique member `%s' requires type instantiation", name);
          if (intype)
            {
              while (j--)
                if (TYPE_FN_FIELD_TYPE (f, j) == intype)
                  break;
              if (j < 0)
                error ("no member function matches that type instantiation");
            }
          else
            j = 0;
          
          if (TYPE_FN_FIELD_STUB (f, j))
            check_stub_method (t, i, j);
          if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
            {
              return value_from_longest
                (lookup_reference_type
                 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
                                      domain)),
                 (LONGEST) METHOD_PTR_FROM_VOFFSET
                  (TYPE_FN_FIELD_VOFFSET (f, j)));
            }
          else
            {
              struct symbol *s = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
                                                0, VAR_NAMESPACE, 0, NULL);
              if (s == NULL)
                {
                  v = 0;
                }
              else
                {
                  v = read_var_value (s, 0);
#if 0
                  VALUE_TYPE (v) = lookup_reference_type
                    (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
                                         domain));
#endif
                }
              return v;
            }
        }
    }
  for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
    {
      value_ptr v;
      int base_offset;

      if (BASETYPE_VIA_VIRTUAL (t, i))
        base_offset = 0;
      else
        base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
      v = value_struct_elt_for_reference (domain,
                                          offset + base_offset,
                                          TYPE_BASECLASS (t, i),
                                          name,
                                          intype);
      if (v)
        return v;
    }
  return 0;
}

/* C++: return the value of the class instance variable, if one exists.
   Flag COMPLAIN signals an error if the request is made in an
   inappropriate context.  */

value_ptr
value_of_this (complain)
     int complain;
{
  struct symbol *func, *sym;
  struct block *b;
  int i;
  static const char funny_this[] = "this";
  value_ptr this;

  if (selected_frame == 0)
    if (complain)
      error ("no frame selected");
    else return 0;

  func = get_frame_function (selected_frame);
  if (!func)
    {
      if (complain)
        error ("no `this' in nameless context");
      else return 0;
    }

  b = SYMBOL_BLOCK_VALUE (func);
  i = BLOCK_NSYMS (b);
  if (i <= 0)
    if (complain)
      error ("no args, no `this'");
    else return 0;

  /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
     symbol instead of the LOC_ARG one (if both exist).  */
  sym = lookup_block_symbol (b, funny_this, VAR_NAMESPACE);
  if (sym == NULL)
    {
      if (complain)
        error ("current stack frame not in method");
      else
        return NULL;
    }

  this = read_var_value (sym, selected_frame);
  if (this == 0 && complain)
    error ("`this' argument at unknown address");
  return this;
}

/* Create a value for a literal string.  We copy data into a local 
   (NOT inferior's memory) buffer, and then set up an array value.

   The array bounds are set from LOWBOUND and HIGHBOUND, and the array is
   populated from the values passed in ELEMVEC.

   The element type of the array is inherited from the type of the
   first element, and all elements must have the same size (though we
   don't currently enforce any restriction on their types). */

value_ptr
f77_value_literal_string (lowbound, highbound, elemvec)
     int lowbound;
     int highbound;
     value_ptr *elemvec;
{
  int nelem;
  int idx;
  int typelength;
  register value_ptr val;
  struct type *rangetype;
  struct type *arraytype;
  char *addr;

  /* Validate that the bounds are reasonable and that each of the elements
     have the same size. */

  nelem = highbound - lowbound + 1;
  if (nelem <= 0)
    error ("bad array bounds (%d, %d)", lowbound, highbound);
  typelength = TYPE_LENGTH (VALUE_TYPE (elemvec[0]));
  for (idx = 0; idx < nelem; idx++)
    {
      if (TYPE_LENGTH (VALUE_TYPE (elemvec[idx])) != typelength)
        error ("array elements must all be the same size");
    }

  /* Make sure we are dealing with characters */ 

  if (typelength != 1)
    error ("Found a non character type in a literal string "); 

  /* Allocate space to store the array */ 

  addr = xmalloc (nelem); 
  for (idx = 0; idx < nelem; idx++)
    {
      memcpy (addr + (idx), VALUE_CONTENTS (elemvec[idx]), 1);
    }

  rangetype = create_range_type ((struct type *) NULL, builtin_type_int,
                                 lowbound, highbound);

  arraytype = f77_create_literal_string_type ((struct type *) NULL, 
                                              rangetype); 

  val = allocate_value (arraytype); 

  /* Make sure that this the rest of the world knows that this is 
     a standard literal string, not one that is a substring of  
     some base */ 

  VALUE_SUBSTRING_MEMADDR (val) = (CORE_ADDR)0;

  VALUE_LAZY (val) = 0; 
  VALUE_LITERAL_DATA (val) = addr;

  /* Since this is a standard literal string with no real lval, 
     make sure that value_lval indicates this fact */ 

  VALUE_LVAL (val) = not_lval; 
  return val;
}

/* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH elements
   long, starting at LOWBOUND.  The result has the same lower bound as
   the original ARRAY.  */

value_ptr
value_slice (array, lowbound, length)
     value_ptr array;
     int lowbound, length;
{
  if (TYPE_CODE (VALUE_TYPE (array)) == TYPE_CODE_BITSTRING)
    error ("not implemented - bitstring slice");
  if (TYPE_CODE (VALUE_TYPE (array)) != TYPE_CODE_ARRAY
      && TYPE_CODE (VALUE_TYPE (array)) != TYPE_CODE_STRING)
    error ("cannot take slice of non-array");
  else
    {
      struct type *slice_range_type, *slice_type;
      value_ptr slice;
      struct type *range_type = TYPE_FIELD_TYPE (VALUE_TYPE (array), 0);
      struct type *element_type = TYPE_TARGET_TYPE (VALUE_TYPE (array));
      int lowerbound = TYPE_LOW_BOUND (range_type);
      int upperbound = TYPE_HIGH_BOUND (range_type);
      int offset = (lowbound - lowerbound) * TYPE_LENGTH (element_type);
      if (lowbound < lowerbound || length < 0
          || lowbound + length - 1 > upperbound)
        error ("slice out of range");
      slice_range_type = create_range_type ((struct type*) NULL,
                                            TYPE_TARGET_TYPE (range_type),
                                            lowerbound,
                                            lowerbound + length - 1);
      slice_type = create_array_type ((struct type*) NULL, element_type,
                                      slice_range_type);
      TYPE_CODE (slice_type) = TYPE_CODE (VALUE_TYPE (array));
      slice = allocate_value (slice_type);
      if (VALUE_LAZY (array))
        VALUE_LAZY (slice) = 1;
      else
        memcpy (VALUE_CONTENTS (slice), VALUE_CONTENTS (array) + offset,
                TYPE_LENGTH (slice_type));
      if (VALUE_LVAL (array) == lval_internalvar)
        VALUE_LVAL (slice) = lval_internalvar_component;
      else
        VALUE_LVAL (slice) = VALUE_LVAL (array);
      VALUE_ADDRESS (slice) = VALUE_ADDRESS (array);
      VALUE_OFFSET (slice) = VALUE_OFFSET (array) + offset;
      return slice;
    }
}

/* Assuming chill_varying_type (VARRAY) is true, return an equivalent
   value as a fixed-length array. */

value_ptr
varying_to_slice (varray)
     value_ptr varray;
{
  struct type *vtype = VALUE_TYPE (varray);
  LONGEST length = unpack_long (TYPE_FIELD_TYPE (vtype, 0),
                                VALUE_CONTENTS (varray)
                                + TYPE_FIELD_BITPOS (vtype, 0) / 8);
  return value_slice (value_primitive_field (varray, 0, 1, vtype), 0, length);
}

/* Create a value for a substring.  We copy data into a local 
   (NOT inferior's memory) buffer, and then set up an array value.

   The array bounds for the string are (1:(to-from +1))
   The elements of the string are all characters.  */

value_ptr
f77_value_substring (str, from, to)
     value_ptr str; 
     int from;
     int to; 
{
  int nelem;
  register value_ptr val;
  struct type *rangetype;
  struct type *arraytype;
  struct internalvar *var; 
  char *addr;

  /* Validate that the bounds are reasonable. */ 

  nelem = to - from + 1;
  if (nelem <= 0)
    error ("bad substring bounds (%d, %d)", from, to);

  rangetype = create_range_type ((struct type *) NULL, builtin_type_int,
                                 1, nelem);

  arraytype = f77_create_literal_string_type ((struct type *) NULL, 
                                              rangetype); 

  val = allocate_value (arraytype); 

  /* Allocate space to store the substring array */ 

  addr = xmalloc (nelem); 

  /* Copy over the data */

  /* In case we ever try to use this substring on the LHS of an assignment 
     remember where the SOURCE substring begins, for lval_memory 
     types this ptr is to a location in legal inferior memory, 
     for lval_internalvars it is a ptr. to superior memory. This 
     helps us out later when we do assigments like:

     set var ARR(2:3) = 'ab'
 
     */ 


  if (VALUE_LVAL (str) == lval_memory) 
    {
      if (VALUE_SUBSTRING_MEMADDR (str) == (CORE_ADDR)0)
        {
          /* This is a regular lval_memory string located in the
             inferior */ 

          VALUE_SUBSTRING_MEMADDR (val) = VALUE_ADDRESS (str) + (from - 1); 
          target_read_memory (VALUE_SUBSTRING_MEMADDR (val), addr, nelem);
        }
      else
        {

#if 0 
          /* str is a substring allocated in the superior. Just 
             do a memcpy */ 

          VALUE_SUBSTRING_MYADDR (val) = VALUE_LITERAL_DATA(str)+(from - 1); 
          memcpy(addr, VALUE_SUBSTRING_MYADDR (val), nelem); 
#else
          error ("Cannot get substrings of substrings"); 
#endif
        }
    }
  else
    if (VALUE_LVAL(str) == lval_internalvar)
      {
        /* Internal variables of type TYPE_CODE_LITERAL_STRING 
           have their data located in the superior 
           process not the inferior */ 
 
        var = VALUE_INTERNALVAR (str);
        
        if (VALUE_SUBSTRING_MEMADDR (str) == (CORE_ADDR)0) 
           VALUE_SUBSTRING_MYADDR (val) =
             ((char *) VALUE_LITERAL_DATA (var->value)) + (from - 1);
        else 
#if 0 
          VALUE_SUBSTRING_MYADDR (val) = VALUE_LITERAL_DATA(str)+(from -1);
#else
        error ("Cannot get substrings of substrings"); 
#endif
        memcpy (addr, VALUE_SUBSTRING_MYADDR (val), nelem);
      }
    else
      error ("Substrings can not be applied to this data item"); 

  VALUE_LAZY (val) = 0; 
  VALUE_LITERAL_DATA (val) = addr; 

  /* This literal string's *data* is located in the superior BUT 
     we do need to know where it came from (i.e. was the source
     string an internalvar or a regular lval_memory variable), so 
     we set the lval field to indicate this.  This will be useful 
     when we use this value on the LHS of an expr. */ 
     
  VALUE_LVAL (val) = VALUE_LVAL (str); 
  return val;
}

/* Create a value for a FORTRAN complex number.  Currently most of 
   the time values are coerced to COMPLEX*16 (i.e. a complex number 
   composed of 2 doubles.  This really should be a smarter routine 
   that figures out precision inteligently as opposed to assuming 
   doubles. FIXME: fmb */ 

value_ptr
f77_value_literal_complex (arg1, arg2, size)
     value_ptr arg1;
     value_ptr arg2;
     int size;
{
  struct type *complex_type; 
  register value_ptr val;
  char *addr; 

  if (size != 8 && size != 16 && size != 32)
    error ("Cannot create number of type 'complex*%d'", size);
  
  /* If either value comprising a complex number is a non-floating 
     type, cast to double. */

  if (TYPE_CODE (VALUE_TYPE (arg1)) != TYPE_CODE_FLT)
    arg1 = value_cast (builtin_type_f_real_s8, arg1);

  if (TYPE_CODE (VALUE_TYPE (arg1)) != TYPE_CODE_FLT)
    arg2 = value_cast (builtin_type_f_real_s8, arg2);
     
  complex_type = f77_create_literal_complex_type (VALUE_TYPE (arg1),
                                                  VALUE_TYPE (arg2)
#if 0
/* FIXME: does f77_create_literal_complex_type need to do something with
   this?  */
                                                  ,
                                                  size
#endif
                                                  );

  val = allocate_value (complex_type); 

  /* Now create a pointer to enough memory to hold the the two args */
  
  addr = xmalloc (TYPE_LENGTH (complex_type)); 

  /* Copy over the two components */

  memcpy (addr, VALUE_CONTENTS_RAW (arg1), TYPE_LENGTH (VALUE_TYPE (arg1)));
  
  memcpy (addr + TYPE_LENGTH (VALUE_TYPE (arg1)), VALUE_CONTENTS_RAW (arg2),
          TYPE_LENGTH (VALUE_TYPE (arg2)));

  VALUE_ADDRESS (val) = 0; /* Not located in the inferior */ 
  VALUE_LAZY (val) = 0; 
  VALUE_LITERAL_DATA (val) = addr; 

  /* Since this is a literal value, make sure that value_lval indicates 
     this fact */ 

  VALUE_LVAL (val) = not_lval; 
  return val;
}

/* Cast a value into the appropriate complex data type. Only works 
   if both values are complex.  */

static value_ptr
f77_cast_into_complex (type, val)
     struct type *type;
     register value_ptr val;
{
  register enum type_code valcode;
  float tmp_f;
  double tmp_d;
  register value_ptr piece1, piece2; 
   
  int lenfrom, lento;

  valcode = TYPE_CODE (VALUE_TYPE (val));

  /* This casting will only work if the right hand side is 
     either a regular complex type or a literal complex type. 
     I.e: this casting is only for size adjustment of 
     complex numbers not anything else. */ 

  if ((valcode != TYPE_CODE_COMPLEX) && 
      (valcode != TYPE_CODE_LITERAL_COMPLEX))
    error ("Cannot cast from a non complex type!"); 

  lenfrom = TYPE_LENGTH (VALUE_TYPE (val));
  lento =   TYPE_LENGTH (type); 

  if (lento == lenfrom)
    error ("Value to be cast is already of type %s", TYPE_NAME (type));

  if (lento == 32 || lenfrom == 32) 
    error ("Casting into/out of complex*32 unsupported"); 

  switch (lento)
    {
    case 16:
      {
        /* Since we have excluded lenfrom == 32 and 
           lenfrom == 16, it MUST be 8 */ 

        if (valcode == TYPE_CODE_LITERAL_COMPLEX) 
          {
            /* Located in superior's memory. Routine should 
               deal with both real literal complex numbers
               as well as internal vars */ 

            /* Grab the two 4 byte reals that make up the complex*8 */ 
                     
            tmp_f = *((float *) VALUE_LITERAL_DATA (val));
                     
            piece1 = value_from_double(builtin_type_f_real_s8,tmp_f);
            
            tmp_f = *((float *) (((char *) VALUE_LITERAL_DATA (val))
                                 + sizeof(float))); 
                     
            piece2 = value_from_double (builtin_type_f_real_s8, tmp_f);
          }
        else
          {
            /* Located in inferior memory, so first we need 
               to read the 2 floats that make up the 8 byte
               complex we are are casting from */ 

            read_memory ((CORE_ADDR) VALUE_CONTENTS (val),
                         (char *) &tmp_f, sizeof(float));
            
            piece1 = value_from_double (builtin_type_f_real_s8, tmp_f);
            
            read_memory ((CORE_ADDR) VALUE_CONTENTS (val) + sizeof(float),
                         (char *) &tmp_f, sizeof(float));
                     
            piece2 = value_from_double (builtin_type_f_real_s8, tmp_f);
          }
        return f77_value_literal_complex (piece1, piece2, 16);
      }

    case 8:
      {
        /* Since we have excluded lenfrom == 32 and 
           lenfrom == 8, it MUST be 16. NOTE: in this 
           case data may be since we are dropping precison */ 

        if (valcode == TYPE_CODE_LITERAL_COMPLEX) 
          {
            /* Located in superior's memory. Routine should 
               deal with both real literal complex numbers
               as well as internal vars */ 
            
            /* Grab the two 8 byte reals that make up the complex*16 */ 
                     
            tmp_d = *((double *) VALUE_LITERAL_DATA (val));
                     
            piece1 = value_from_double (builtin_type_f_real, tmp_d);

            tmp_d = *((double *) (((char *) VALUE_LITERAL_DATA (val))
                                  + sizeof(double)));
                     
            piece2 = value_from_double (builtin_type_f_real, tmp_d);
          }
        else
          {
            /* Located in inferior memory, so first we need to read the
               2 floats that make up the 8 byte complex we are are
               casting from.  */ 

            read_memory ((CORE_ADDR) VALUE_CONTENTS (val),
                         (char *) &tmp_d, sizeof(double));
                     
            piece1 = value_from_double (builtin_type_f_real, tmp_d);

            read_memory ((CORE_ADDR) VALUE_CONTENTS (val) + sizeof(double),
                         (char *) &tmp_f, sizeof(double));
                     
            piece2 = value_from_double (builtin_type_f_real, tmp_d);
          }
        return f77_value_literal_complex (piece1, piece2, 8);
      }
                     
    default:
      error ("Invalid F77 complex number cast");
    }
}

/* The following function is called in order to assign 
   a literal F77 array to either an internal GDB variable 
   or to a real array variable in the inferior. 
   This function is necessary because in F77, literal 
   arrays are allocated in the superior's memory space 
   NOT the inferior's.  This function provides a way to 
   get the F77 stuff to work without messing with the 
   way C deals with this issue. NOTE: we are assuming 
   that all F77 array literals are STRING array literals.  F77 
   users have no good way of expressing non-string 
   literal strings. 

   This routine now also handles assignment TO literal strings 
   in the peculiar case of substring assignments of the 
   form:

   STR(2:3) = 'foo' 

   */ 

static value_ptr
f77_assign_from_literal_string (toval, fromval)
     register value_ptr toval, fromval;
{
  register struct type *type = VALUE_TYPE (toval);
  register value_ptr val;
  struct internalvar *var; 
  int lenfrom, lento; 
  CORE_ADDR tmp_addr; 
  char *c; 

  lenfrom = TYPE_LENGTH (VALUE_TYPE (fromval));
  lento = TYPE_LENGTH (VALUE_TYPE (toval)); 
   
  if ((VALUE_LVAL (toval) == lval_internalvar
       || VALUE_LVAL (toval) == lval_memory)
      && VALUE_SUBSTRING_START (toval) != 0) 
    {
      /* We are assigning TO a substring type. This is of the form:
            
         set A(2:5) = 'foov'

         The result of this will be a modified toval not a brand new 
         value. This is high F77 weirdness.  */ 

      /* Simply overwrite the relevant memory, wherever it 
         exists. Use standard F77 character assignment rules 
         (if len(toval) > len(fromval) pad with blanks,
         if len(toval) < len(fromval) truncate else just copy. */ 

      if (VALUE_LVAL (toval) == lval_internalvar)
        {
          /* Memory in superior.  */ 
          var = VALUE_INTERNALVAR (toval); 
          memcpy ((char *) VALUE_SUBSTRING_START (toval),
                  (char *) VALUE_LITERAL_DATA (fromval),
                  (lento > lenfrom) ? lenfrom : lento); 
          
          /* Check to see if we have to pad. */

          if (lento > lenfrom) 
            {
              memset((char *) VALUE_SUBSTRING_START(toval) + lenfrom,
                     ' ', lento - lenfrom); 
            }
        }
      else
        {
          /* Memory in inferior.  */ 
          write_memory ((CORE_ADDR) VALUE_SUBSTRING_START (toval),
                        (char *) VALUE_LITERAL_DATA (fromval),
                        (lento > lenfrom) ? lenfrom : lento); 

          /* Check to see if we have to pad.  */

          if (lento > lenfrom) 
            {
              c = alloca (lento-lenfrom); 
              memset (c, ' ', lento - lenfrom);

              tmp_addr = VALUE_SUBSTRING_START (toval) + lenfrom; 
              write_memory (tmp_addr, c, lento - lenfrom);
            } 
        }
      return fromval;
    }
  else 
    { 
      if (VALUE_LVAL (toval) == lval_internalvar)
        type = VALUE_TYPE (fromval); 

      val = allocate_value (type);

      switch (VALUE_LVAL (toval))
        {
        case lval_internalvar:

          /* Internal variables are funny.  Their value information 
             is stored in the location.internalvar sub structure.  */ 

          var = VALUE_INTERNALVAR (toval); 

          /* The item in toval is a regular internal variable
             and this assignment is of the form:

             set var $foo = 'hello' */

          /* First free up any old stuff in this internalvar.  */

          free (VALUE_LITERAL_DATA (var->value));
          VALUE_LITERAL_DATA (var->value) = 0; 
          VALUE_LAZY (var->value) = 0; /* Disable lazy fetches since this 
                                          is not located in inferior. */ 

          /* Copy over the relevant value data from 'fromval' */

          set_internalvar (VALUE_INTERNALVAR (toval), fromval);

          /* Now replicate the VALUE_LITERAL_DATA field so that 
             we may later safely de-allocate fromval. */

          VALUE_LITERAL_DATA (var->value) = 
            malloc (TYPE_LENGTH (VALUE_TYPE (fromval)));
         
          memcpy((char *) VALUE_LITERAL_DATA (var->value), 
                 (char *) VALUE_LITERAL_DATA (fromval), 
                 lenfrom); 
         
          /* Copy over all relevant value data from 'toval'.  into 
             the structure to returned */ 

          memcpy (val, toval, sizeof(struct value));
         
          /* Lastly copy the pointer to the area where the 
             internalvar data is stored to the VALUE_CONTENTS field.
             This will be a helpful shortcut for printout 
             routines later */ 

          VALUE_LITERAL_DATA (val) = VALUE_LITERAL_DATA (var->value); 
          break;

        case lval_memory:

          /* We are copying memory from the local (superior) 
             literal string to a legitimate address in the 
             inferior. VALUE_ADDRESS is the address in 
             the inferior. VALUE_OFFSET is not used because
             structs do not exist in F77. */ 

          /* Copy over all relevant value data from 'toval'.  */ 

          memcpy (val, toval, sizeof(struct value));

          write_memory ((CORE_ADDR) VALUE_ADDRESS (val),
                        (char *) VALUE_LITERAL_DATA (fromval),
                        (lento > lenfrom) ? lenfrom : lento); 
               
          /* Check to see if we have to pad */
               
          if (lento > lenfrom) 
            {
              c = alloca (lento - lenfrom); 
              memset (c, ' ', lento - lenfrom);
              tmp_addr = VALUE_ADDRESS (val) + lenfrom; 
              write_memory (tmp_addr, c, lento - lenfrom);
            }
          break;

        default:
          error ("Unknown lval type in f77_assign_from_literal_string"); 
        }

      /* Now free up the transient literal string's storage. */

      free (VALUE_LITERAL_DATA (fromval)); 

      VALUE_TYPE (val) = type;
  
      return val; 
    }
}


/* The following function is called in order to assign a literal F77
   complex to either an internal GDB variable or to a real complex
   variable in the inferior.  This function is necessary because in F77,
   composite literals are allocated in the superior's memory space 
   NOT the inferior's.  This function provides a way to get the F77 stuff
   to work without messing with the way C deals with this issue. */ 

static value_ptr
f77_assign_from_literal_complex (toval, fromval)
     register value_ptr toval, fromval;
{
  register struct type *type = VALUE_TYPE (toval);
  register value_ptr val;
  struct internalvar *var; 
  float tmp_float=0;
  double tmp_double = 0;

  if (VALUE_LVAL (toval) == lval_internalvar)
    type = VALUE_TYPE (fromval); 

  /* Allocate a value node for the result.  */

  val = allocate_value (type);

  if (VALUE_LVAL (toval) == lval_internalvar)
    {
      /* Internal variables are funny.  Their value information 
         is stored in the location.internalvar sub structure.  */ 

      var = VALUE_INTERNALVAR (toval);

      /* First free up any old stuff in this internalvar. */

      free (VALUE_LITERAL_DATA (var->value));
      VALUE_LITERAL_DATA (var->value) = 0; 
      VALUE_LAZY (var->value) = 0; /* Disable lazy fetches since 
                                      this is not located in inferior. */ 
              
      /* Copy over the relevant value data from 'fromval'.  */

      set_internalvar (VALUE_INTERNALVAR (toval), fromval);

      /* Now replicate the VALUE_LITERAL_DATA field so that 
         we may later safely de-allocate  fromval.  */

      VALUE_LITERAL_DATA (var->value) = 
        malloc (TYPE_LENGTH (VALUE_TYPE (fromval)));
         
      memcpy ((char *) VALUE_LITERAL_DATA (var->value), 
              (char *) VALUE_LITERAL_DATA (fromval), 
              TYPE_LENGTH (VALUE_TYPE (fromval))); 

      /* Copy over all relevant value data from 'toval' into the
         structure to be returned.  */ 

      memcpy (val, toval, sizeof(struct value));
    }
  else
    { 
      /* We are copying memory from the local (superior) process to a
         legitimate address in the inferior. VALUE_ADDRESS is the
         address in the inferior. */ 

      /* Copy over all relevant value data from 'toval'.  */ 

      memcpy (val, toval, sizeof(struct value));
         
      if (TYPE_LENGTH (VALUE_TYPE (fromval))
          > TYPE_LENGTH (VALUE_TYPE (toval)))
        {
          /* Since all literals are actually complex*16 types, deal with
             the case when one tries to assign a literal to a complex*8.  */

          if ((TYPE_LENGTH(VALUE_TYPE(fromval)) == 16) && 
              (TYPE_LENGTH(VALUE_TYPE(toval)) == 8))
            {
              tmp_double = *((double *) VALUE_LITERAL_DATA (fromval));
              
              tmp_float = (float) tmp_double;

              write_memory (VALUE_ADDRESS(val),
                            (char *) &tmp_float, sizeof(float));

              tmp_double = *((double *) 
                             (((char *) VALUE_LITERAL_DATA (fromval))
                              + sizeof(double))); 
              
              tmp_float = (float) tmp_double;

              write_memory(VALUE_ADDRESS(val) + sizeof(float),
                           (char *) &tmp_float, sizeof(float));
            }
          else
            error ("Cannot assign literal complex to variable!");
        }
      else 
        {
          write_memory (VALUE_ADDRESS (val),
                        (char *) VALUE_LITERAL_DATA (fromval),
                        TYPE_LENGTH (VALUE_TYPE (fromval)));
        }
    }

  /* Now free up the transient literal string's storage */
   
  free (VALUE_LITERAL_DATA (fromval)); 

  VALUE_TYPE (val) = type;
  
  return val;
}