cp-typeck.c

早期freebsd实现

	    return p2 == void_type_node && TREE_PURPOSE (t1);
	  return TREE_PURPOSE (t1) || TREE_PURPOSE (t2);
#endif
	}
      /* Target types are compatible--just make sure that if
	 we use parameter lists, that they are ok as well.  */
      if (TREE_CODE (p1) == FUNCTION_TYPE || TREE_CODE (p1) == METHOD_TYPE)
	switch (comp_target_parms (TYPE_ARG_TYPES (p1),
				   TYPE_ARG_TYPES (p2),
				   strict))
	  {
	  case 0:
	    return 0;
	  case 1:
	    break;
	  case 2:
	    warn_contravariance = 1;
	  }

      if (TREE_PURPOSE (t1) && TREE_PURPOSE (t2))
	{
	  int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
	  if (cmp < 0)
	    my_friendly_abort (114);
	  if (cmp == 0)
	    return 0;
	}
    }
  return 1 + warn_contravariance;
}

/* Return 1 if PARMS specifies a fixed number of parameters
   and none of their types is affected by default promotions.  */

static int
self_promoting_args_p (parms)
     tree parms;
{
  register tree t;
  for (t = parms; t; t = TREE_CHAIN (t))
    {
      register tree type = TREE_VALUE (t);

      if (TREE_CHAIN (t) == 0 && type != void_type_node)
	return 0;

      if (TYPE_MAIN_VARIANT (type) == float_type_node)
	return 0;

      if (type == 0)
	return 0;

      if (C_PROMOTING_INTEGER_TYPE_P (type))
	return 0;
    }
  return 1;
}

/* Return an unsigned type the same as TYPE in other respects.

   C++: must make these work for type variants as well.  */

tree
unsigned_type (type)
     tree type;
{
  tree type1 = TYPE_MAIN_VARIANT (type);
  if (type1 == signed_char_type_node || type1 == char_type_node)
    return unsigned_char_type_node;
  if (type1 == integer_type_node)
    return unsigned_type_node;
  if (type1 == short_integer_type_node)
    return short_unsigned_type_node;
  if (type1 == long_integer_type_node)
    return long_unsigned_type_node;
  if (type1 == long_long_integer_type_node)
    return long_long_unsigned_type_node;
  return type;
}

/* Return a signed type the same as TYPE in other respects.  */

tree
signed_type (type)
     tree type;
{
  tree type1 = TYPE_MAIN_VARIANT (type);
  if (type1 == unsigned_char_type_node || type1 == char_type_node)
    return signed_char_type_node;
  if (type1 == unsigned_type_node)
    return integer_type_node;
  if (type1 == short_unsigned_type_node)
    return short_integer_type_node;
  if (type1 == long_unsigned_type_node)
    return long_integer_type_node;
  if (type1 == long_long_unsigned_type_node)
    return long_long_integer_type_node;
  return type;
}

/* Return a type the same as TYPE except unsigned or
   signed according to UNSIGNEDP.  */

tree
signed_or_unsigned_type (unsignedp, type)
     int unsignedp;
     tree type;
{
  if (TREE_CODE (type) != INTEGER_TYPE)
    return type;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (signed_char_type_node))
    return unsignedp ? unsigned_char_type_node : signed_char_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) 
    return unsignedp ? unsigned_type_node : integer_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (short_integer_type_node)) 
    return unsignedp ? short_unsigned_type_node : short_integer_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (long_integer_type_node)) 
    return unsignedp ? long_unsigned_type_node : long_integer_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (long_long_integer_type_node)) 
    return (unsignedp ? long_long_unsigned_type_node
	    : long_long_integer_type_node);
  return type;
}

tree
c_sizeof (type)
     tree type;
{
  enum tree_code code = TREE_CODE (type);

  if (code == FUNCTION_TYPE)
    {
      if (pedantic || warn_pointer_arith)
	pedwarn ("ANSI C++ forbids taking the sizeof a function type");
      return size_int (1);
    }
  if (code == METHOD_TYPE)
    {
      if (pedantic || warn_pointer_arith)
	pedwarn ("ANSI C++ forbids taking the sizeof a method type");
      return size_int (1);
    }
  if (code == VOID_TYPE)
    {
      if (pedantic || warn_pointer_arith)
	pedwarn ("ANSI C++ forbids taking the sizeof a void type");
      return size_int (1);
    }
  if (code == ERROR_MARK)
    return size_int (1);
  /* C++: this is really correct!  */
  if (code == REFERENCE_TYPE)
    type = TREE_TYPE (type);

  if (TYPE_SIZE (type) == 0)
    {
      error ("sizeof applied to an incomplete type");
      return size_int (0);
    }

  /* Convert in case a char is more than one unit.  */
  return size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type), 
		     size_int (TYPE_PRECISION (char_type_node)));
}

tree
c_sizeof_nowarn (type)
     tree type;
{
  enum tree_code code = TREE_CODE (type);

  if (code == FUNCTION_TYPE
      || code == METHOD_TYPE
      || code == VOID_TYPE
      || code == ERROR_MARK)
    return size_int (1);
  if (code == REFERENCE_TYPE)
    type = TREE_TYPE (type);

  if (TYPE_SIZE (type) == 0)
    {
      /* ??? Tiemann, why have any diagnostic here?
	 There is none in the corresponding function for C.  */
      warning ("sizeof applied to an incomplete type");
      return size_int (0);
    }

  /* Convert in case a char is more than one unit.  */
  return size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type), 
		     size_int (TYPE_PRECISION (char_type_node)));
}

/* Implement the __alignof keyword: Return the minimum required
   alignment of TYPE, measured in bytes.  */

tree
c_alignof (type)
     tree type;
{
  enum tree_code code = TREE_CODE (type);

  if (code == FUNCTION_TYPE || code == METHOD_TYPE)
    return size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);

  if (code == VOID_TYPE || code == ERROR_MARK)
    return size_int (1);

  /* C++: this is really correct!  */
  if (code == REFERENCE_TYPE)
    type = TREE_TYPE (type);

  return size_int (TYPE_ALIGN (type) / BITS_PER_UNIT);
}

/* Perform default promotions for C data used in expressions.
   Arrays and functions are converted to pointers;
   enumeral types or short or char, to int.
   In addition, manifest constants symbols are replaced by their values.

   C++: this will automatically bash references to their target type.  */

tree
default_conversion (exp)
     tree exp;
{
  register tree type = TREE_TYPE (exp);
  register enum tree_code code = TREE_CODE (type);

  if (code == OFFSET_TYPE)
    {
      if (TREE_CODE (exp) == OFFSET_REF)
	return default_conversion (resolve_offset_ref (exp));

      type = TREE_TYPE (type);
      code = TREE_CODE (type);
    }

  if (code == REFERENCE_TYPE)
    {
      exp = convert_from_reference (exp);
      type = TREE_TYPE (exp);
      code = TREE_CODE (type);
    }

  /* Constants can be used directly unless they're not loadable.  */
  if (TREE_CODE (exp) == CONST_DECL)
    exp = DECL_INITIAL (exp);
  /* Replace a nonvolatile const static variable with its value.  */
  else if (TREE_READONLY_DECL_P (exp) && DECL_MODE (exp) != BLKmode)
    {
      exp = decl_constant_value (exp);
      type = TREE_TYPE (exp);
    }

  /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
     Strip such NOP_EXPRs, since EXP is being used in non-lvalue context.  */
  if (TREE_CODE (exp) == NOP_EXPR
      && TREE_TYPE (exp) == TREE_TYPE (TREE_OPERAND (exp, 0)))
    exp = TREE_OPERAND (exp, 0);

  /* Normally convert enums to int,
     but convert wide enums to something wider.  */
  if (code == ENUMERAL_TYPE)
    {
      type = type_for_size (MAX (TYPE_PRECISION (type),
				 TYPE_PRECISION (integer_type_node)),
			    (flag_traditional && TREE_UNSIGNED (type)));
      return convert (type, exp);
    }

  if (C_PROMOTING_INTEGER_TYPE_P (type))
    {
      /* Traditionally, unsignedness is preserved in default promotions.
         Otherwise, retain unsignedness if really not getting bigger.  */
      if (TREE_UNSIGNED (type)
	  && (flag_traditional
	      || TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
	return convert (unsigned_type_node, exp);
      return convert (integer_type_node, exp);
    }
  if (flag_traditional
      && TYPE_MAIN_VARIANT (type) == float_type_node)
    return convert (double_type_node, exp);
  if (code == VOID_TYPE)
    {
      error ("void value not ignored as it ought to be");
      return error_mark_node;
    }
  if (code == FUNCTION_TYPE)
    {
      return build_unary_op (ADDR_EXPR, exp, 0);
    }
  if (code == METHOD_TYPE)
    {
      if (TREE_CODE (exp) == OFFSET_REF)
	{
	  my_friendly_assert (TREE_CODE (TREE_OPERAND (exp, 1)) == FUNCTION_DECL,
			      308);
	  return build_unary_op (ADDR_EXPR, TREE_OPERAND (exp, 1), 0);
	}
      return build_unary_op (ADDR_EXPR, exp, 0);
    }
  if (code == ARRAY_TYPE)
    {
      register tree adr;
      tree restype = TREE_TYPE (type);
      tree ptrtype;

      if (TREE_CODE (exp) == INDIRECT_REF)
	{
	  /* Stripping away the INDIRECT_REF is not the right
	     thing to do for references...  */
	  tree inner = TREE_OPERAND (exp, 0);
	  if (TREE_CODE (TREE_TYPE (inner)) == REFERENCE_TYPE)
	    {
	      inner = build1 (CONVERT_EXPR,
			      build_pointer_type (TREE_TYPE (TREE_TYPE (inner))),
			      inner);
	      TREE_REFERENCE_EXPR (inner) = 1;
	    }
	  return convert (TYPE_POINTER_TO (TREE_TYPE (type)), inner);
	}

      if (TREE_CODE (exp) == COMPOUND_EXPR)
	{
	  tree op1 = default_conversion (TREE_OPERAND (exp, 1));
	  return build (COMPOUND_EXPR, TREE_TYPE (op1),
			TREE_OPERAND (exp, 0), op1);
	}

      if (!lvalue_p (exp)
	  && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
	{
	  error ("invalid use of non-lvalue array");
	  return error_mark_node;
	}

      if (TYPE_READONLY (type) || TYPE_VOLATILE (type))
	restype = build_type_variant (restype, TYPE_READONLY (type),
				      TYPE_VOLATILE (type));

      ptrtype = build_pointer_type (restype);

      if (TREE_CODE (exp) == VAR_DECL)
	{
	  /* ??? This is not really quite correct
	     in that the type of the operand of ADDR_EXPR
	     is not the target type of the type of the ADDR_EXPR itself.
	     Question is, can this lossage be avoided?  */
	  adr = build1 (ADDR_EXPR, ptrtype, exp);
	  if (mark_addressable (exp) == 0)
	    return error_mark_node;
	  TREE_CONSTANT (adr) = staticp (exp);
	  TREE_SIDE_EFFECTS (adr) = 0;   /* Default would be, same as EXP.  */
	  return adr;
	}
      /* This way is better for a COMPONENT_REF since it can
	 simplify the offset for a component.  */
      adr = build_unary_op (ADDR_EXPR, exp, 1);
      return convert (ptrtype, adr);
    }
  return exp;
}

/* Like `build_component_ref, but uses an already found field.
   Must compute visibility for C_C_D.  Otherwise, ok.  */
tree
build_component_ref_1 (datum, field, protect)
     tree datum, field;
     int protect;
{
  register tree basetype = TREE_TYPE (datum);
  register enum tree_code code = TREE_CODE (basetype);
  register tree ref;

  if (code == REFERENCE_TYPE)
    {
      datum = convert_from_reference (datum);
      basetype = TREE_TYPE (datum);
      code = TREE_CODE (basetype);
    }

  if (! IS_AGGR_TYPE_CODE (code))
    {
      if (code != ERROR_MARK)
	error_with_decl (field, "request for member `%s' in something not a class, structure or union");
      return error_mark_node;
    }

  if (TYPE_SIZE (basetype) == 0)
    {
      incomplete_type_error (0, basetype);
      return error_mark_node;
    }

  /* Look up component name in the structure type definition.  */

  if (field == error_mark_node)
    my_friendly_abort (115);

  if (TREE_STATIC (field))
    return field;

  if (datum == C_C_D && ! DECL_PUBLIC (field))
    {
      enum visibility_type visibility
	= compute_visibility (TYPE_BINFO (current_class_type), field);

    if (visibility == visibility_private)
      {
	error_with_decl (field, "field `%s' is private");
	return error_mark_node;
      }
    else if (visibility == visibility_protected)
      {
	error_with_decl (field, "field `%s' is protected");
	return error_mark_node;
      }
    }

  ref = build (COMPONENT_REF, TREE_TYPE (field), datum, field);

  if (TREE_READONLY (datum) || TREE_READONLY (field))
    TREE_READONLY (ref) = 1;
  if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (field))
    TREE_THIS_VOLATILE (ref) = 1;

  return ref;
}

tree
build_component_ref (datum, component, basetype_path, protect)
     tree datum, component, basetype_path;
     int protect;
{
  register tree basetype = TREE_TYPE (datum);
  register enum tree_code code = TREE_CODE (basetype);
  register tree field = NULL;
  register tree ref;