expr.c

gcc-2.95.3 Linux下最常用的C编译器

     enum tree_code condition;
     tree type;
     int target_pc;
{
  tree value1, value2;
  flush_quick_stack ();
  /* note: pop values in opposite order */
  value2 = pop_value (type);
  value1 = pop_value (type);
  /* Maybe should check value1 and value2 for type compatibility ??? */
  expand_compare (condition, value1, value2, target_pc);
}

static void
expand_java_goto (target_pc)
     int target_pc;
{
  tree target_label = lookup_label (target_pc);
  flush_quick_stack ();
  expand_goto (target_label);
}

#if 0
static void
expand_java_call (target_pc, return_address)
     int target_pc, return_address;
{
  tree target_label = lookup_label (target_pc);
  tree value = build_int_2 (return_address, return_address < 0 ? -1 : 0);
  push_value (value);
  flush_quick_stack ();
  expand_goto (target_label);
}

static void
expand_java_ret (return_address)
     tree return_address ATTRIBUTE_UNUSED;
{
  warning ("ret instruction not implemented");
#if 0
  tree target_label = lookup_label (target_pc);
  flush_quick_stack ();
  expand_goto (target_label);
#endif
}
#endif

/* Recursive helper function to pop argument types during verifiation. */

void
pop_argument_types (arg_types)
     tree arg_types;
{
  if (arg_types == end_params_node)
    return;
  if (TREE_CODE (arg_types) == TREE_LIST)
    {
      pop_argument_types (TREE_CHAIN (arg_types));
      pop_type (TREE_VALUE (arg_types));
      return;
    }
  abort ();
}

static tree
pop_arguments (arg_types)
     tree arg_types;
{
  if (arg_types == end_params_node)
    return NULL_TREE;
  if (TREE_CODE (arg_types) == TREE_LIST)
    {
      tree tail = pop_arguments (TREE_CHAIN (arg_types));
      tree type = TREE_VALUE (arg_types);
      tree arg = pop_value (type);
#ifdef PROMOTE_PROTOTYPES
      if (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)
	  && INTEGRAL_TYPE_P (type))
	arg = convert (integer_type_node, arg);
#endif
      return tree_cons (NULL_TREE, arg, tail);
    }
  abort ();
}

/* Build an expression to initialize the class CLAS.
   if EXPR is non-NULL, returns an expression to first call the initializer
   (if it is needed) and then calls EXPR. */

tree
build_class_init (clas, expr)
     tree clas, expr;
{
  tree init;
  if (inherits_from_p (current_class, clas))
    return expr;
  init = build (CALL_EXPR, void_type_node,
		build_address_of (soft_initclass_node),
		build_tree_list (NULL_TREE, build_class_ref (clas)),
		NULL_TREE);
  TREE_SIDE_EFFECTS (init) = 1;
  if (expr != NULL_TREE)
    {
      expr = build (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
      TREE_SIDE_EFFECTS (expr) = 1;
      return expr;
    }
  return init;
}

static tree methods_ident = NULL_TREE;
static tree ncode_ident = NULL_TREE;
tree dtable_ident = NULL_TREE;

tree
build_known_method_ref (method, method_type, self_type, method_signature, arg_list)
     tree method, method_type ATTRIBUTE_UNUSED, self_type,
          method_signature ATTRIBUTE_UNUSED, arg_list ATTRIBUTE_UNUSED;
{
  tree func;
  if (is_compiled_class (self_type))
    {
      make_decl_rtl (method, NULL, 1);
      func = build1 (ADDR_EXPR, method_ptr_type_node, method);
    }
  else
    {
      /* We don't know whether the method has been (statically) compiled.
	 Compile this code to get a reference to the method's code:
	 
	 SELF_TYPE->methods[METHOD_INDEX].ncode
	 
	 This is guaranteed to work (assuming SELF_TYPE has
	 been initialized), since if the method is not compiled yet,
	 its ncode points to a trampoline that forces compilation. */
      
      int method_index = 0;
      tree meth;
      tree ref = build_class_ref (self_type);
      ref = build1 (INDIRECT_REF, class_type_node, ref);
      if (ncode_ident == NULL_TREE)
	ncode_ident = get_identifier ("ncode");
      if (methods_ident == NULL_TREE)
	methods_ident = get_identifier ("methods");
      ref = build (COMPONENT_REF, method_ptr_type_node, ref,
		   lookup_field (&class_type_node, methods_ident));
      for (meth = TYPE_METHODS (CLASS_TO_HANDLE_TYPE (self_type));
	   ; meth = TREE_CHAIN (meth))
	{
	  if (method == meth)
	    break;
	  if (meth == NULL_TREE)
	    fatal ("method '%s' not found in class",
		   IDENTIFIER_POINTER (DECL_NAME (method)));
	  method_index++;
	}
      method_index *= int_size_in_bytes (method_type_node);
      ref = fold (build (PLUS_EXPR, method_ptr_type_node,
			 ref, build_int_2 (method_index, 0)));
      ref = build1 (INDIRECT_REF, method_type_node, ref);
      func = build (COMPONENT_REF, nativecode_ptr_type_node,
		    ref,
		    lookup_field (&method_type_node, ncode_ident));
    }
  return func;
}

tree
invoke_build_dtable (is_invoke_interface, arg_list)
     int is_invoke_interface;
     tree arg_list;
{
  tree dtable, objectref;

  TREE_VALUE (arg_list) = save_expr (TREE_VALUE (arg_list));

  /* If we're dealing with interfaces and if the objectref
     argument is an array then get the dispatch table of the class
     Object rather than the one from the objectref.  */
  objectref = (is_invoke_interface 
	       && is_array_type_p (TREE_TYPE (TREE_VALUE (arg_list))) ?
	       object_type_node : TREE_VALUE (arg_list));
  
  if (dtable_ident == NULL_TREE)
    dtable_ident = get_identifier ("vtable");
  dtable = build1 (INDIRECT_REF, object_type_node, objectref );
  dtable = build (COMPONENT_REF, dtable_ptr_type, dtable,
		  lookup_field (&object_type_node, dtable_ident));

  return dtable;
}

tree 
build_invokevirtual (dtable, method)
     tree dtable, method;
{
  tree func;
  tree nativecode_ptr_ptr_type_node
    = build_pointer_type (nativecode_ptr_type_node);
  int method_index = TREE_INT_CST_LOW (DECL_VINDEX (method));
  /* Add one to skip "class" field of dtable, and one to skip unused
     vtable entry (for C++ compatibility). */
  method_index += 2;
  method_index
    *= int_size_in_bytes (nativecode_ptr_ptr_type_node);
  func = fold (build (PLUS_EXPR, nativecode_ptr_ptr_type_node,
		      dtable, build_int_2 (method_index, 0)));
  func = build1 (INDIRECT_REF, nativecode_ptr_type_node, func);

  return func;
}

tree
build_invokeinterface (dtable, method_name, method_signature)
     tree dtable, method_name, method_signature;
{
  static tree class_ident = NULL_TREE;
  tree lookup_arg;

  /* We expand invokeinterface here.  _Jv_LookupInterfaceMethod() will
     ensure that the selected method exists, is public and not
     abstract nor static.  */
	    
  if (class_ident == NULL_TREE)
    class_ident = get_identifier ("class");
  
  dtable = build1 (INDIRECT_REF, dtable_type, dtable);
  dtable = build (COMPONENT_REF, class_ptr_type, dtable,
		  lookup_field (&dtable_type, class_ident));
  lookup_arg = build_tree_list (NULL_TREE, 
				(build_utf8_ref 
				 (unmangle_classname
				  (IDENTIFIER_POINTER(method_signature),
				   IDENTIFIER_LENGTH(method_signature)))));
  lookup_arg = tree_cons (NULL_TREE, dtable,
			  tree_cons (NULL_TREE, build_utf8_ref (method_name),
				     lookup_arg));
  return build (CALL_EXPR, ptr_type_node, 
		build_address_of (soft_lookupinterfacemethod_node),
		lookup_arg, NULL_TREE);
}
  
/* Expand one of the invoke_* opcodes.
   OCPODE is the specific opcode.
   METHOD_REF_INDEX is an index into the constant pool.
   NARGS is the number of arguments, or -1 if not specified. */

static void
expand_invoke (opcode, method_ref_index, nargs)
     int opcode;
     int method_ref_index;
     int nargs ATTRIBUTE_UNUSED;
{
  tree method_signature = COMPONENT_REF_SIGNATURE(&current_jcf->cpool, method_ref_index);
  tree method_name = COMPONENT_REF_NAME (&current_jcf->cpool, method_ref_index);
  tree self_type = get_class_constant
    (current_jcf, COMPONENT_REF_CLASS_INDEX(&current_jcf->cpool, method_ref_index));
  char *self_name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (self_type)));
  tree call, func, method, arg_list, method_type;

  if (! CLASS_LOADED_P (self_type))
    {
      load_class (self_type, 1);
      if (TREE_CODE (TYPE_SIZE (self_type)) == ERROR_MARK)
	fatal ("failed to find class '%s'", self_name);
    }
  layout_class_methods (self_type);

  if (method_name == init_identifier_node)
    method = lookup_java_constructor (CLASS_TO_HANDLE_TYPE (self_type),
				      method_signature);
  else
    method = lookup_java_method (CLASS_TO_HANDLE_TYPE (self_type),
				 method_name, method_signature);
  if (method == NULL_TREE)
    {
      error ("Class '%s' has no method named '%s' matching signature '%s'",
	     self_name,
	     IDENTIFIER_POINTER (method_name),
	     IDENTIFIER_POINTER (method_signature));
    }
  /* Invoke static can't invoke static/abstract method */
  else if (opcode == OPCODE_invokestatic)
    {
      if (!METHOD_STATIC (method))
	{
	  error ("invokestatic on non static method");
	  method = NULL_TREE;
	}
      else if (METHOD_ABSTRACT (method))
	{
	  error ("invokestatic on abstract method");
	  method = NULL_TREE;
	}
    }
  else
    {
      if (METHOD_STATIC (method))
	{
	  error ("invoke[non-static] on static method");
	  method = NULL_TREE;
	}
    }

  if (method == NULL_TREE)
    {
      method_type = get_type_from_signature (method_signature);
      pop_arguments (TYPE_ARG_TYPES (method_type));
      if (opcode != OPCODE_invokestatic) 
	pop_type (self_type);
      method_type = promote_type (TREE_TYPE (method_type));
      push_value (convert (method_type, integer_zero_node));
      return;
    }

  method_type = TREE_TYPE (method);
  arg_list = pop_arguments (TYPE_ARG_TYPES (method_type));
  flush_quick_stack ();

  func = NULL_TREE;
  if (opcode == OPCODE_invokestatic || opcode == OPCODE_invokespecial
      || (opcode == OPCODE_invokevirtual
	  && (METHOD_PRIVATE (method)
	      || METHOD_FINAL (method) 
	      || CLASS_FINAL (TYPE_NAME (self_type)))))
    func = build_known_method_ref (method, method_type, self_type,
				   method_signature, arg_list);
  else
    {
      tree dtable = invoke_build_dtable (opcode == OPCODE_invokeinterface, 
					 arg_list);
      if (opcode == OPCODE_invokevirtual)
	func = build_invokevirtual (dtable, method);
      else
	func = build_invokeinterface (dtable, method_name, method_signature);
    }
  func = build1 (NOP_EXPR, build_pointer_type (method_type), func);
  call = build (CALL_EXPR, TREE_TYPE (method_type), func, arg_list, NULL_TREE);
  TREE_SIDE_EFFECTS (call) = 1;

  if (TREE_CODE (TREE_TYPE (method_type)) == VOID_TYPE)
    expand_expr_stmt (call);
  else
    {
      push_value (call);
      flush_quick_stack ();
    }
}


/* Expand an operation to extract from or store into a field.
   IS_STATIC is 1 iff the field is static.
   IS_PUTTING is 1 for putting into a field;  0 for getting from the field.
   FIELD_REF_INDEX is an index into the constant pool.  */

static void
expand_java_field_op (is_static, is_putting, field_ref_index)
     int is_static;
     int is_putting;
     int field_ref_index;
{
  tree self_type = 
      get_class_constant (current_jcf, 
			  COMPONENT_REF_CLASS_INDEX (&current_jcf->cpool, 
						     field_ref_index));
  char *self_name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (self_type)));
  tree field_name = COMPONENT_REF_NAME (&current_jcf->cpool, field_ref_index);
  tree field_signature = COMPONENT_REF_SIGNATURE (&current_jcf->cpool, 
						  field_ref_index);
  tree field_type = get_type_from_signature (field_signature);
  tree new_value = is_putting ? pop_value (field_type) : NULL_TREE;
  tree field_ref;
  int is_error = 0;
  tree field_decl = lookup_field (&self_type, field_name);
  if (field_decl == error_mark_node)
    {
      is_error = 1;
    }
  else if (field_decl == NULL_TREE)
    {
      error ("Missing field '%s' in '%s'",
	     IDENTIFIER_POINTER (field_name), self_name);
      is_error = 1;
    }
  else if (build_java_signature (TREE_TYPE (field_decl)) != field_signature)
    {
      error ("Mismatching signature for field '%s' in '%s'",
	     IDENTIFIER_POINTER (field_name), self_name);
      is_error = 1;
    }
  field_ref = is_static ? NULL_TREE : pop_value (self_type);
  if (is_error)
    {
      if (! is_putting)
	push_value (convert (field_type, integer_zero_node));
      flush_quick_stack ();
      return;
    }

  /* Inline references to java.lang.PRIMTYPE.TYPE.
     In addition to being a useful (minor) optimization,
     this is also needed to avoid circularities in the implementation
     of these fields in libjava. */
  if (field_name == TYPE_identifier_node && ! is_putting
      && ! flag_emit_class_files && field_type == class_ptr_type
      && strncmp (self_name, "java.lang.", 10) == 0)
    {
      tree typ = build_primtype_type_ref (self_name);
      if (typ)
	{
	  push_value (typ);
	  return;
	}
    }

  field_ref = build_field_ref (field_ref, self_type, field_name);
  if (is_static)
    field_ref = build_class_init (self_type, field_ref);
  if (is_putting)
    {
      flush_quick_stack ();
      if (FIELD_FINAL (field_decl))
	{
	  if (DECL_CONTEXT (field_decl) != current_class)
	    error_with_decl (field_decl,
		     "assignment to final field `%s' not in field's class");
	  else if (FIELD_STATIC (field_decl))
	    {
	      if (!IS_CLINIT (current_function_decl))
		error_with_decl (field_decl, 
             "assignment to final static field `%s' not in class initializer");
	    }
	  else
	    {
	      if (! DECL_CONSTRUCTOR_P (current_function_decl))
		error_with_decl (field_decl, "assignment to final field `%s' "
				 "not in constructor");
	    }
	}