binutils-gdb/gdb/c-valprint.c

/* Support for printing C values for GDB, the GNU debugger.
   Copyright 1986, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997
             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.  */

#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "expression.h"
#include "value.h"
#include "demangle.h"
#include "valprint.h"
#include "language.h"
#include "c-lang.h"


/* Print data of type TYPE located at VALADDR (within GDB), which came from
   the inferior at address ADDRESS, onto stdio stream STREAM according to
   FORMAT (a letter or 0 for natural format).  The data at VALADDR is in
   target byte order.

   If the data are a string pointer, returns the number of string characters
   printed.

   If DEREF_REF is nonzero, then dereference references, otherwise just print
   them like pointers.

   The PRETTY parameter controls prettyprinting.  */

int
c_val_print (type, valaddr, address, stream, format, deref_ref, recurse,
	     pretty)
     struct type *type;
     char *valaddr;
     CORE_ADDR address;
     GDB_FILE *stream;
     int format;
     int deref_ref;
     int recurse;
     enum val_prettyprint pretty;
{
  register unsigned int i = 0;		/* Number of characters printed */
  unsigned len;
  struct type *elttype;
  unsigned eltlen;
  LONGEST val;
  CORE_ADDR addr;

  CHECK_TYPEDEF (type);
  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_ARRAY:
      if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
	{
	  elttype = check_typedef (TYPE_TARGET_TYPE (type));
	  eltlen = TYPE_LENGTH (elttype);
	  len = TYPE_LENGTH (type) / eltlen;
	  if (prettyprint_arrays)
	    {
	      print_spaces_filtered (2 + 2 * recurse, stream);
	    }
	  /* For an array of chars, print with string syntax.  */
	  if (eltlen == 1 &&
	      ((TYPE_CODE (elttype) == TYPE_CODE_INT)
	       || ((current_language->la_language == language_m2)
		   && (TYPE_CODE (elttype) == TYPE_CODE_CHAR)))
	      && (format == 0 || format == 's'))
	    {
	      /* If requested, look for the first null char and only print
		 elements up to it.  */
	      if (stop_print_at_null)
		{
		  int temp_len;
		  
		  /* Look for a NULL char. */
		  for (temp_len = 0;
		       valaddr[temp_len]
		       && temp_len < len && temp_len < print_max;
		       temp_len++);
		  len = temp_len;
		}
	      
	      LA_PRINT_STRING (stream, valaddr, len, 0);
	      i = len;
	    }
	  else
	    {
	      fprintf_filtered (stream, "{");
	      /* If this is a virtual function table, print the 0th
		 entry specially, and the rest of the members normally.  */
	      if (cp_is_vtbl_ptr_type (elttype))
		{
		  i = 1;
		  fprintf_filtered (stream, "%d vtable entries", len - 1);
		}
	      else
		{
		  i = 0;
		}
	      val_print_array_elements (type, valaddr, address, stream,
					format, deref_ref, recurse, pretty, i);
	      fprintf_filtered (stream, "}");
	    }
	  break;
	}
      /* Array of unspecified length: treat like pointer to first elt.  */
      addr = address;
      goto print_unpacked_pointer;

    case TYPE_CODE_PTR:
      if (format && format != 's')
	{
	  print_scalar_formatted (valaddr, type, format, 0, stream);
	  break;
	}
      if (vtblprint && cp_is_vtbl_ptr_type(type))
	{
          /* Print the unmangled name if desired.  */
	  /* Print vtable entry - we only get here if we ARE using
	     -fvtable_thunks.  (Otherwise, look under TYPE_CODE_STRUCT.) */
	  print_address_demangle(extract_address (valaddr, TYPE_LENGTH (type)),
				 stream, demangle);
	  break;
	}
      elttype = check_typedef (TYPE_TARGET_TYPE (type));
      if (TYPE_CODE (elttype) == TYPE_CODE_METHOD)
	{
	  cp_print_class_method (valaddr, type, stream);
	}
      else if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
	{
	  cp_print_class_member (valaddr,
				 TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
				 stream, "&");
	}
      else
	{
	  addr = unpack_pointer (type, valaddr);
	print_unpacked_pointer:
          elttype = check_typedef (TYPE_TARGET_TYPE (type));

	  if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
	    {
	      /* Try to print what function it points to.  */
	      print_address_demangle (addr, stream, demangle);
	      /* Return value is irrelevant except for string pointers.  */
	      return (0);
	    }

	  if (addressprint && format != 's')
	    {
	      print_address_numeric (addr, 1, stream);
	    }

	  /* For a pointer to char or unsigned char, also print the string
	     pointed to, unless pointer is null.  */
	  if (TYPE_LENGTH (elttype) == 1
	      && TYPE_CODE (elttype) == TYPE_CODE_INT
	      && (format == 0 || format == 's')
	      && addr != 0)
	    {
	      i = val_print_string (addr, 0, stream);
	    }
	  else if (cp_is_vtbl_member(type))
  	    {
	      /* print vtbl's nicely */
	      CORE_ADDR vt_address = unpack_pointer (type, valaddr);

	      struct minimal_symbol *msymbol =
		lookup_minimal_symbol_by_pc (vt_address);
	      if ((msymbol != NULL) &&
		  (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
		{
		  fputs_filtered (" <", stream);
		  fputs_filtered (SYMBOL_SOURCE_NAME (msymbol), stream);
		  fputs_filtered (">", stream);
		}
	      if (vt_address && vtblprint)
	        {
		  value_ptr vt_val;
	          struct symbol *wsym = (struct symbol *)NULL;
	          struct type *wtype;
		  struct symtab *s;
		  struct block *block = (struct block *)NULL;
		  int is_this_fld;

		  if (msymbol != NULL)
              	    wsym = lookup_symbol (SYMBOL_NAME(msymbol), block, 
				VAR_NAMESPACE, &is_this_fld, &s);
 
		  if (wsym)
		    {
	              wtype = SYMBOL_TYPE(wsym);
		    }
		  else
		    {
		      wtype = TYPE_TARGET_TYPE(type);
		    }
		  vt_val = value_at (wtype, vt_address, NULL);
		  val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val),
			     VALUE_ADDRESS (vt_val), stream, format,
			     deref_ref, recurse + 1, pretty);
		  if (pretty)
		    {
		      fprintf_filtered (stream, "\n");
		      print_spaces_filtered (2 + 2 * recurse, stream);
		    }
	        }
	      }

	  /* Return number of characters printed, including the terminating
	     '\0' if we reached the end.  val_print_string takes care including
	     the terminating '\0' if necessary.  */
	  return i;
	}
      break;

    case TYPE_CODE_MEMBER:
      error ("not implemented: member type in c_val_print");
      break;

    case TYPE_CODE_REF:
      elttype = check_typedef (TYPE_TARGET_TYPE (type));
      if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
        {
	  cp_print_class_member (valaddr,
				 TYPE_DOMAIN_TYPE (elttype),
				 stream, "");
	  break;
	}
      if (addressprint)
        {
	  fprintf_filtered (stream, "@");
	  print_address_numeric
	    (extract_address (valaddr,
			      TARGET_PTR_BIT / HOST_CHAR_BIT), 1, stream);
	  if (deref_ref)
	    fputs_filtered (": ", stream);
        }
      /* De-reference the reference.  */
      if (deref_ref)
	{
	  if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
	    {
	      value_ptr deref_val =
		value_at
		  (TYPE_TARGET_TYPE (type),
		   unpack_pointer (lookup_pointer_type (builtin_type_void),
				   valaddr),
		   NULL);
	      val_print (VALUE_TYPE (deref_val),
			 VALUE_CONTENTS (deref_val),
			 VALUE_ADDRESS (deref_val), stream, format,
			 deref_ref, recurse + 1, pretty);
	    }
	  else
	    fputs_filtered ("???", stream);
	}
      break;

    case TYPE_CODE_UNION:
      if (recurse && !unionprint)
	{
	  fprintf_filtered (stream, "{...}");
	  break;
	}
      /* Fall through.  */
    case TYPE_CODE_STRUCT:
      if (vtblprint && cp_is_vtbl_ptr_type(type))
	{
          /* Print the unmangled name if desired.  */
	  /* Print vtable entry - we only get here if NOT using
	     -fvtable_thunks.  (Otherwise, look under TYPE_CODE_PTR.) */
          print_address_demangle (extract_address (
	        valaddr + TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8,
	        TYPE_LENGTH (TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET))),
              stream, demangle);
	}
      else
	cp_print_value_fields (type, valaddr, address, stream, format,
			       recurse, pretty, NULL, 0);
      break;

    case TYPE_CODE_ENUM:
      if (format)
	{
	  print_scalar_formatted (valaddr, type, format, 0, stream);
	  break;
	}
      len = TYPE_NFIELDS (type);
      val = unpack_long (type, valaddr);
      for (i = 0; i < len; i++)
	{
	  QUIT;
	  if (val == TYPE_FIELD_BITPOS (type, i))
	    {
	      break;
	    }
	}
      if (i < len)
	{
	  fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
	}
      else
	{
	  print_longest (stream, 'd', 0, val);
	}
      break;

    case TYPE_CODE_FUNC:
      if (format)
	{
	  print_scalar_formatted (valaddr, type, format, 0, stream);
	  break;
	}
      /* FIXME, we should consider, at least for ANSI C language, eliminating
	 the distinction made between FUNCs and POINTERs to FUNCs.  */
      fprintf_filtered (stream, "{");
      type_print (type, "", stream, -1);
      fprintf_filtered (stream, "} ");
      /* Try to print what function it points to, and its address.  */
      print_address_demangle (address, stream, demangle);
      break;

    case TYPE_CODE_BOOL:
      format = format ? format : output_format;
      if (format)
	print_scalar_formatted (valaddr, type, format, 0, stream);
      else
	{
	  val = unpack_long (type, valaddr);
	  if (val == 0)
	    fputs_filtered ("false", stream);
	  else if (val == 1)
	    fputs_filtered ("true", stream);
	  else
	    print_longest (stream, 'd', 0, val);
	}
      break;

    case TYPE_CODE_RANGE:
      /* FIXME: create_range_type does not set the unsigned bit in a
	 range type (I think it probably should copy it from the target
	 type), so we won't print values which are too large to
	 fit in a signed integer correctly.  */
      /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
	 print with the target type, though, because the size of our type
	 and the target type might differ).  */
      /* FALLTHROUGH */

    case TYPE_CODE_INT:
      format = format ? format : output_format;
      if (format)
	{
	  print_scalar_formatted (valaddr, type, format, 0, stream);
	}
      else
	{
	  val_print_type_code_int (type, valaddr, stream);
	  /* C and C++ has no single byte int type, char is used instead.
	     Since we don't know whether the value is really intended to
	     be used as an integer or a character, print the character
	     equivalent as well. */
	  if (TYPE_LENGTH (type) == 1)
	    {
	      fputs_filtered (" ", stream);
	      LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr),
			     stream);
	    }
	}
      break;

    case TYPE_CODE_CHAR:
      format = format ? format : output_format;
      if (format)
	{
	  print_scalar_formatted (valaddr, type, format, 0, stream);
	}
      else
	{
	  fprintf_filtered (stream, TYPE_UNSIGNED (type) ? "%u" : "%d",
			    unpack_long (type, valaddr));
	  fputs_filtered (" ", stream);
	  LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr), stream);
	}
      break;

    case TYPE_CODE_FLT:
      if (format)
	{
	  print_scalar_formatted (valaddr, type, format, 0, stream);
	}
      else
	{
	  print_floating (valaddr, type, stream);
	}
      break;

    case TYPE_CODE_VOID:
      fprintf_filtered (stream, "void");
      break;

    case TYPE_CODE_ERROR:
      fprintf_filtered (stream, "<error type>");
      break;

    case TYPE_CODE_UNDEF:
      /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
	 dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
	 and no complete type for struct foo in that file.  */
      fprintf_filtered (stream, "<incomplete type>");
      break;

    default:
      error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
    }
  gdb_flush (stream);
  return (0);
}

int
c_value_print (val, stream, format, pretty)
     value_ptr val;
     GDB_FILE *stream;
     int format;
     enum val_prettyprint pretty;
{
  struct type *type = VALUE_TYPE (val);

  /* If it is a pointer, indicate what it points to.

     Print type also if it is a reference.

     C++: if it is a member pointer, we will take care
     of that when we print it.  */
  if (TYPE_CODE (type) == TYPE_CODE_PTR ||
      TYPE_CODE (type) == TYPE_CODE_REF)
    {
      /* Hack:  remove (char *) for char strings.  Their
	 type is indicated by the quoted string anyway. */
      if (TYPE_CODE (type) == TYPE_CODE_PTR &&
	  TYPE_NAME (type) == NULL &&
	  TYPE_NAME (TYPE_TARGET_TYPE (type)) != NULL &&
	  STREQ (TYPE_NAME (TYPE_TARGET_TYPE (type)), "char"))
	{
	  /* Print nothing */
	}
      else
	{
	  fprintf_filtered (stream, "(");
	  type_print (type, "", stream, -1);
	  fprintf_filtered (stream, ") ");
	}
    }
  return val_print (type, VALUE_CONTENTS (val),
		    VALUE_ADDRESS (val) + VALUE_OFFSET (val),
		    stream, format, 1, 0, pretty);
}