expr.c

gcc-2.95.3 Linux下最常用的C编译器

      TREE_SIDE_EFFECTS (check) = 1;
      expand_expr_stmt (check);
    }
  
  expand_assignment (build_java_arrayaccess (array,
					     rhs_type_node,
					     index),
		     rhs_node, 0, 0);
}

/* Expand the evaluation of ARRAY[INDEX]. build_java_check_indexed_type makes 
   sure that LHS is an array type. May expand some bound checking and NULL
   pointer checking.  
   LHS_TYPE_NODE is the type of ARRAY[INDEX]. But in the case of CHAR/BYTE/
   BOOLEAN/SHORT, we push a promoted type back to the stack.
*/

static void
expand_java_arrayload (lhs_type_node )
    tree lhs_type_node;
{
  tree load_node;
  tree index_node = pop_value (int_type_node);
  tree array_node = pop_value (ptr_type_node);

  index_node = save_expr (index_node);
  array_node = save_expr (array_node);
  lhs_type_node   = build_java_check_indexed_type (array_node, lhs_type_node);

  load_node = build_java_arrayaccess (array_node,
				      lhs_type_node,
				      index_node);

  if (INTEGRAL_TYPE_P (lhs_type_node) && TYPE_PRECISION (lhs_type_node) <= 32)
    load_node = fold (build1 (NOP_EXPR, int_type_node, load_node));
  push_value (load_node);
}

/* Expands .length. Makes sure that we deal with and array and may expand
   a NULL check on the array object.  */

static void
expand_java_array_length ()
{
  tree array  = pop_value (ptr_type_node);
  tree length = build_java_array_length_access (array);

  push_value (build_java_arraynull_check (array, length, int_type_node));
}

/* Emit code for the call to _Jv_Monitor{Enter,Exit}. CALL can be
   either soft_monitorenter_node or soft_monitorexit_node.  */

static tree
build_java_monitor (call, object)
    tree call;
    tree object;
{
  return (build (CALL_EXPR,
		 void_type_node,
		 build_address_of (call),
		 build_tree_list (NULL_TREE, object),
		 NULL_TREE));
}

/* Emit code for one of the PUSHC instructions. */

static void
expand_java_pushc (ival, type)
     int ival;
     tree type;
{
  tree value;
  if (type == ptr_type_node && ival == 0)
    value = null_pointer_node;
  else if (type == int_type_node || type == long_type_node)
    {
      value = build_int_2 (ival, ival < 0 ? -1 : 0);
      TREE_TYPE (value) = type;
    }
  else if (type == float_type_node || type == double_type_node)
    {
      REAL_VALUE_TYPE x;
#ifdef REAL_ARITHMETIC
      REAL_VALUE_FROM_INT (x, ival, 0, TYPE_MODE (type));
#else
      x = ival;
#endif
      value = build_real (type, x);
    }
  else
    fatal ("internal error in expand_java_pushc");
  push_value (value);
}

static void
expand_java_return (type)
     tree type;
{
  if (type == void_type_node)
    expand_null_return ();
  else
    {
      tree retval = pop_value (type);
      tree res = DECL_RESULT (current_function_decl);
      retval = build (MODIFY_EXPR, TREE_TYPE (res), res, retval);
      TREE_SIDE_EFFECTS (retval) = 1;
      expand_return (retval);
    }
}

tree
build_address_of (value)
     tree value;
{
  return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (value)), value);
}

static void
expand_java_NEW (type)
     tree type;
{
  if (! CLASS_LOADED_P (type))
    load_class (type, 1);
  layout_class_methods (type);
  push_value (build (CALL_EXPR, promote_type (type),
		     build_address_of (alloc_object_node),
		     tree_cons (NULL_TREE, build_class_ref (type),
				build_tree_list (NULL_TREE,
						 size_in_bytes (type))),
		     NULL_TREE));
}

static void
expand_java_INSTANCEOF (type)
     tree type;
{
  tree value = pop_value (object_ptr_type_node);
  value = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (soft_instanceof_node)),
		 build_address_of (soft_instanceof_node),
		 tree_cons (NULL_TREE, value,
			    build_tree_list (NULL_TREE,
					     build_class_ref (type))),
		 NULL_TREE);
  push_value (value);
}

static void
expand_java_CHECKCAST (type)
     tree type;
{
  tree value = pop_value (ptr_type_node);
  value = build (CALL_EXPR, promote_type (type),
		 build_address_of (soft_checkcast_node),
		 tree_cons (NULL_TREE, build_class_ref (type),
			    build_tree_list (NULL_TREE, value)),
		 NULL_TREE);
  push_value (value);
}

static void
expand_iinc (local_var_index, ival, pc)
     unsigned int local_var_index;
     int ival;
     int pc;
{
    tree local_var, res;
    tree constant_value;

    flush_quick_stack ();
    local_var = find_local_variable (local_var_index, int_type_node, pc);
    constant_value = build_int_2 (ival, ival < 0 ? -1 : 0);
    res = fold (build (PLUS_EXPR, int_type_node, local_var, constant_value));
    expand_assignment (local_var, res, 0, 0);
}

tree
build_java_binop (op, type, arg1, arg2)
     enum tree_code op;
     tree type, arg1, arg2;
{
  tree mask;
  switch (op)
    {
    case URSHIFT_EXPR:
      {
	tree u_type = unsigned_type (type);
	arg1 = convert (u_type, arg1);
	arg1 = build_java_binop (RSHIFT_EXPR, u_type, arg1, arg2);
	return convert (type, arg1);
      }
    case LSHIFT_EXPR:
    case RSHIFT_EXPR:
      mask = build_int_2 (TYPE_PRECISION (TREE_TYPE (arg1)) - 1, 0);
      arg2 = fold (build (BIT_AND_EXPR, int_type_node, arg2, mask));
      break;

    case COMPARE_L_EXPR:  /* arg1 > arg2 ?  1 : arg1 == arg2 ? 0 : -1 */
    case COMPARE_G_EXPR:  /* arg1 < arg2 ? -1 : arg1 == arg2 ? 0 :  1 */
      arg1 = save_expr (arg1);  arg2 = save_expr (arg2);
      {
	tree ifexp1 = fold ( build (op == COMPARE_L_EXPR ? GT_EXPR : LT_EXPR,
				    boolean_type_node, arg1, arg2));
	tree ifexp2 = fold ( build (EQ_EXPR, boolean_type_node, arg1, arg2));
	tree second_compare = fold (build (COND_EXPR, int_type_node,
					   ifexp2, integer_zero_node,
					   op == COMPARE_L_EXPR
					   ? integer_negative_one_node
					   : integer_one_node));
	return fold (build (COND_EXPR, int_type_node, ifexp1,
			    op == COMPARE_L_EXPR ? integer_one_node
			    : integer_negative_one_node,
			    second_compare));
      }
    case COMPARE_EXPR:
      arg1 = save_expr (arg1);  arg2 = save_expr (arg2);
      {
	tree ifexp1 = fold ( build (LT_EXPR, boolean_type_node, arg1, arg2));
	tree ifexp2 = fold ( build (GT_EXPR, boolean_type_node, arg1, arg2));
	tree second_compare = fold ( build (COND_EXPR, int_type_node,
					    ifexp2, integer_one_node,
					    integer_zero_node));
	return fold (build (COND_EXPR, int_type_node,
			    ifexp1, integer_negative_one_node, second_compare));
      }

    case TRUNC_MOD_EXPR:
      if (TREE_CODE (type) == REAL_TYPE)
	{
	  tree call;
	  if (type != double_type_node)
	    {
	      arg1 = convert (double_type_node, arg1);
	      arg2 = convert (double_type_node, arg2);
	    }
	  call = build (CALL_EXPR, double_type_node,
			build_address_of (soft_fmod_node),
			tree_cons (NULL_TREE, arg1,
				   build_tree_list (NULL_TREE, arg2)),
			NULL_TREE);
	  if (type != double_type_node)
	    call = convert (type, call);
	  return call;
	}
      break;
    default:  ;
    }
  return fold (build (op, type, arg1, arg2));
}

static void
expand_java_binop (type, op)
     tree type;  enum tree_code op;
{
  tree larg, rarg;
  tree ltype = type;
  tree rtype = type;
  switch (op)
    {
    case LSHIFT_EXPR:
    case RSHIFT_EXPR:
    case URSHIFT_EXPR:
      rtype = int_type_node;
      rarg = pop_value (rtype);
      break;
    default:
      rarg = pop_value (rtype);
    }
  larg = pop_value (ltype);
  push_value (build_java_binop (op, type, larg, rarg));
}

/* Lookup the field named NAME in *TYPEP or its super classes.
   If not found, return NULL_TREE.
   (If the *TYPEP is not found, return error_mark_node.)
   If found, return the FIELD_DECL, and set *TYPEP to the
   class containing the field. */

tree
lookup_field (typep, name)
     tree *typep;
     tree name;
{
  if (CLASS_P (*typep) && !CLASS_LOADED_P (*typep))
    {
      load_class (*typep, 1);
      if (!TYPE_SIZE (*typep) || TREE_CODE (TYPE_SIZE (*typep)) == ERROR_MARK)
	return error_mark_node;
    }
  do
    {
      tree field, basetype_vec;
      int n, i;

      for (field = TYPE_FIELDS (*typep); field; field = TREE_CHAIN (field))
	if (DECL_NAME (field) == name)
	  return field;

      /* Process implemented interfaces. */
      basetype_vec = TYPE_BINFO_BASETYPES (*typep);
      n = TREE_VEC_LENGTH (basetype_vec);
      for (i = 0; i < n; i++)
	{
	  tree t = BINFO_TYPE (TREE_VEC_ELT (basetype_vec, i));
	  if ((field = lookup_field (&t, name)))
	    return field;
	}
      *typep = CLASSTYPE_SUPER (*typep);
    } while (*typep);
  return NULL_TREE;
}

/* Look up the field named NAME in object SELF_VALUE,
   which has class SELF_CLASS (a non-handle RECORD_TYPE).
   SELF_VALUE is NULL_TREE if looking for a static field. */

tree
build_field_ref (self_value, self_class, name)
     tree self_value, self_class, name;
{
  tree base_class = self_class;
  tree field_decl = lookup_field (&base_class, name);
  if (field_decl == NULL_TREE)
    {
      error ("field `%s' not found", IDENTIFIER_POINTER (name));
      return error_mark_node;
    }
  if (self_value == NULL_TREE)
    {
      return build_static_field_ref (field_decl);
    }
  else
    {
      tree base_handle_type = promote_type (base_class);
      if (base_handle_type != TREE_TYPE (self_value))
	self_value = fold (build1 (NOP_EXPR, base_handle_type, self_value));
#ifdef JAVA_USE_HANDLES
      self_value = unhand_expr (self_value);
#endif
      self_value = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (self_value)),
			   self_value);
      return fold (build (COMPONENT_REF, TREE_TYPE (field_decl),
			  self_value, field_decl));
    }
}

tree
lookup_label (pc)
     int pc;
{
  tree name;
  char buf[32];
  ASM_GENERATE_INTERNAL_LABEL(buf, "LJpc=", pc);
  name = get_identifier (buf);
  if (IDENTIFIER_LOCAL_VALUE (name))
    return IDENTIFIER_LOCAL_VALUE (name);
  else
    {
      /* The type of the address of a label is return_address_type_node. */
      tree decl = create_label_decl (name);
      LABEL_PC (decl) = pc;
      label_rtx (decl);
      return pushdecl (decl);
    }
}

/* Generate a unique name for the purpose of loops and switches
   labels, and try-catch-finally blocks label or temporary variables.  */

tree
generate_name ()
{
  static int l_number = 0;
  char buff [32];
  ASM_GENERATE_INTERNAL_LABEL(buff, "LJv", l_number);
  l_number++;
  return get_identifier (buff);
}

tree
create_label_decl (name)
     tree name;
{
  tree decl;
  push_obstacks (&permanent_obstack, &permanent_obstack);
  decl = build_decl (LABEL_DECL, name, 
		     TREE_TYPE (return_address_type_node));
  pop_obstacks ();
  DECL_CONTEXT (decl) = current_function_decl;
  DECL_IGNORED_P (decl) = 1;
  return decl;
}

/* This maps a bytecode offset (PC) to various flags. */
char *instruction_bits;

static void
note_label (current_pc, target_pc)
     int current_pc ATTRIBUTE_UNUSED, target_pc;
{
  lookup_label (target_pc);
  instruction_bits [target_pc] |= BCODE_JUMP_TARGET;
}

/* Emit code to jump to TARGET_PC if VALUE1 CONDITION VALUE2,
   where CONDITION is one of one the compare operators. */

static void
expand_compare (condition, value1, value2, target_pc)
     enum tree_code condition;
     tree value1, value2;
     int target_pc;
{
  tree target = lookup_label (target_pc);
  tree cond = fold (build (condition, boolean_type_node, value1, value2));
  expand_start_cond (truthvalue_conversion (cond), 0);
  expand_goto (target);
  expand_end_cond ();
}

/* Emit code for a TEST-type opcode. */

static void
expand_test (condition, type, target_pc)
     enum tree_code condition;
     tree type;
     int target_pc;
{
  tree value1, value2;
  flush_quick_stack ();
  value1 = pop_value (type);
  value2 = (type == ptr_type_node) ? null_pointer_node : integer_zero_node;
  expand_compare (condition, value1, value2, target_pc);
}

/* Emit code for a COND-type opcode. */

static void
expand_cond (condition, type, target_pc)