class.c

GCC编译器源代码

		      tree value = VF_BASETYPE_VALUE (vfields);
		      b->vfields = tree_cons (base_binfo, value, b->vfields);
		      if (DECL_NAME (CLASSTYPE_VFIELD (value))
			  == DECL_NAME (CLASSTYPE_VFIELD (basetype)))
			VF_NORMAL_VALUE (b->vfields) = basetype;
		      else
			VF_NORMAL_VALUE (b->vfields) = VF_NORMAL_VALUE (vfields);
		    }
		  vfields = TREE_CHAIN (vfields);
		}

	      if (b->has_virtual == 0)
		{
		  first_vfn_base_index = i;

		  /* Update these two, now that we know what vtable we are
		     going to extend.  This is so that we can add virtual
		     functions, and override them properly.  */
		  BINFO_VTABLE (t_binfo) = TYPE_BINFO_VTABLE (basetype);
		  BINFO_VIRTUALS (t_binfo) = TYPE_BINFO_VIRTUALS (basetype);
		  b->has_virtual = CLASSTYPE_VSIZE (basetype);
		  b->vfield = CLASSTYPE_VFIELD (basetype);
		  CLASSTYPE_VFIELD (t) = b->vfield;
		  /* When we install the first one, set the VF_NORMAL_VALUE
		     to be the current class, as this it is the most derived
		     class.  Hopefully, this is not set to something else
		     later.  (mrs) */
		  vfields = b->vfields;
		  while (vfields)
		    {
		      if (DECL_NAME (CLASSTYPE_VFIELD (t))
			  == DECL_NAME (CLASSTYPE_VFIELD (basetype)))
			{
			  VF_NORMAL_VALUE (vfields) = t;
			  /* There should only be one of them!  And it should
			     always be found, if we get into here.  (mrs)  */
			  break;
			}
		      vfields = TREE_CHAIN (vfields);
		    }
		}
	    }
	}
    }

  /* Must come after offsets are fixed for all bases.  */
  for (i = 0; i < n_baseclasses; i++)
    {
      tree base_binfo = TREE_VEC_ELT (binfos, i);
      tree basetype = BINFO_TYPE (base_binfo);

      if (get_base_distance (basetype, t_binfo, 0, (tree*)0) == -2)
	{
	  cp_warning ("direct base `%T' inaccessible in `%T' due to ambiguity",
		      basetype, t);
	}
    }
  {
    tree v = get_vbase_types (t_binfo);

    for (; v; v = TREE_CHAIN (v))
      {
	tree basetype = BINFO_TYPE (v);
	if (get_base_distance (basetype, t_binfo, 0, (tree*)0) == -2)
	  {
	    if (extra_warnings)
	      cp_warning ("virtual base `%T' inaccessible in `%T' due to ambiguity",
			  basetype, t);
	  }
      }
  }    

  {
    tree vfields;
    /* Find the base class with the largest number of virtual functions.  */
    for (vfields = b->vfields; vfields; vfields = TREE_CHAIN (vfields))
      {
	if (CLASSTYPE_VSIZE (VF_BASETYPE_VALUE (vfields)) > b->max_has_virtual)
	  b->max_has_virtual = CLASSTYPE_VSIZE (VF_BASETYPE_VALUE (vfields));
	if (VF_DERIVED_VALUE (vfields)
	    && CLASSTYPE_VSIZE (VF_DERIVED_VALUE (vfields)) > b->max_has_virtual)
	  b->max_has_virtual = CLASSTYPE_VSIZE (VF_DERIVED_VALUE (vfields));
      }
  }

  if (b->vfield == 0)
    /* If all virtual functions come only from virtual baseclasses.  */
    return -1;

  /* Update the rtti base if we have a non-virtual base class version
     of it.  */
  b->rtti = CLASSTYPE_RTTI (BINFO_TYPE (TREE_VEC_ELT (binfos, first_vfn_base_index)));

  return first_vfn_base_index;
}

static int
typecode_p (type, code)
     tree type;
     enum tree_code code;
{
  return (TREE_CODE (type) == code
	  || (TREE_CODE (type) == REFERENCE_TYPE
	      && TREE_CODE (TREE_TYPE (type)) == code));
}

/* Set memoizing fields and bits of T (and its variants) for later use.
   MAX_HAS_VIRTUAL is the largest size of any T's virtual function tables.  */

static void
finish_struct_bits (t, max_has_virtual)
     tree t;
     int max_has_virtual;
{
  int i, n_baseclasses = CLASSTYPE_N_BASECLASSES (t);

  /* Fix up variants (if any).  */
  tree variants = TYPE_NEXT_VARIANT (t);
  while (variants)
    {
      /* These fields are in the _TYPE part of the node, not in
	 the TYPE_LANG_SPECIFIC component, so they are not shared.  */
      TYPE_HAS_CONSTRUCTOR (variants) = TYPE_HAS_CONSTRUCTOR (t);
      TYPE_HAS_DESTRUCTOR (variants) = TYPE_HAS_DESTRUCTOR (t);
      TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
      TYPE_NEEDS_DESTRUCTOR (variants) = TYPE_NEEDS_DESTRUCTOR (t);

      TYPE_USES_COMPLEX_INHERITANCE (variants) = TYPE_USES_COMPLEX_INHERITANCE (t);
      TYPE_VIRTUAL_P (variants) = TYPE_VIRTUAL_P (t);
      TYPE_USES_VIRTUAL_BASECLASSES (variants) = TYPE_USES_VIRTUAL_BASECLASSES (t);
      /* Copy whatever these are holding today.  */
      TYPE_MIN_VALUE (variants) = TYPE_MIN_VALUE (t);
      TYPE_MAX_VALUE (variants) = TYPE_MAX_VALUE (t);
      TYPE_FIELDS (variants) = TYPE_FIELDS (t);
      TYPE_SIZE (variants) = TYPE_SIZE (t);
      variants = TYPE_NEXT_VARIANT (variants);
    }

  if (n_baseclasses && max_has_virtual)
    {
      /* Done by `finish_struct' for classes without baseclasses.  */
      int might_have_abstract_virtuals = CLASSTYPE_ABSTRACT_VIRTUALS (t) != 0;
      tree binfos = TYPE_BINFO_BASETYPES (t);
      for (i = n_baseclasses-1; i >= 0; i--)
	{
	  might_have_abstract_virtuals
	    |= (CLASSTYPE_ABSTRACT_VIRTUALS (BINFO_TYPE (TREE_VEC_ELT (binfos, i))) != 0);
	  if (might_have_abstract_virtuals)
	    break;
	}
      if (might_have_abstract_virtuals)
	{
	  /* We use error_mark_node from override_one_vtable to signal
	     an artificial abstract.  */
	  if (CLASSTYPE_ABSTRACT_VIRTUALS (t) == error_mark_node)
	    CLASSTYPE_ABSTRACT_VIRTUALS (t) = NULL_TREE;
	  CLASSTYPE_ABSTRACT_VIRTUALS (t) = get_abstract_virtuals (t);
	}
    }

  if (n_baseclasses)
    {
      /* Notice whether this class has type conversion functions defined.  */
      tree binfo = TYPE_BINFO (t);
      tree binfos = BINFO_BASETYPES (binfo);
      tree basetype;

      for (i = n_baseclasses-1; i >= 0; i--)
	{
	  basetype = BINFO_TYPE (TREE_VEC_ELT (binfos, i));

	  if (TYPE_HAS_CONVERSION (basetype))
	    {
	      TYPE_HAS_CONVERSION (t) = 1;
	      TYPE_HAS_INT_CONVERSION (t) |= TYPE_HAS_INT_CONVERSION (basetype);
	      TYPE_HAS_REAL_CONVERSION (t) |= TYPE_HAS_REAL_CONVERSION (basetype);
	    }
	  if (CLASSTYPE_MAX_DEPTH (basetype) >= CLASSTYPE_MAX_DEPTH (t))
	    CLASSTYPE_MAX_DEPTH (t) = CLASSTYPE_MAX_DEPTH (basetype) + 1;
	}
    }

  /* If this type has a copy constructor, force its mode to be BLKmode, and
     force its TREE_ADDRESSABLE bit to be nonzero.  This will cause it to
     be passed by invisible reference and prevent it from being returned in
     a register.

     Also do this if the class has BLKmode but can still be returned in
     registers, since function_cannot_inline_p won't let us inline
     functions returning such a type.  This affects the HP-PA.  */
  if (! TYPE_HAS_TRIVIAL_INIT_REF (t)
      || (TYPE_MODE (t) == BLKmode && ! aggregate_value_p (t)
	  && CLASSTYPE_NON_AGGREGATE (t)))
    {
      tree variants;
      DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
      for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
	{
	  TYPE_MODE (variants) = BLKmode;
	  TREE_ADDRESSABLE (variants) = 1;
	}
    }
}

/* Add FNDECL to the method_vec growing on the class_obstack.  Used by
   finish_struct_methods.  Note, FNDECL cannot be a constructor or
   destructor, those cases are handled by the caller.  */

static void
grow_method (fndecl, method_vec_ptr)
     tree fndecl;
     tree *method_vec_ptr;
{
  tree method_vec = (tree)obstack_base (&class_obstack);

  /* Start off past the constructors and destructor.  */
  tree *testp = &TREE_VEC_ELT (method_vec, 2);

  while (testp < (tree *) obstack_next_free (&class_obstack)
	 && (*testp == NULL_TREE || DECL_NAME (*testp) != DECL_NAME (fndecl)))
    testp++;

  if (testp < (tree *) obstack_next_free (&class_obstack))
    {
      tree *p;
      for (p = testp; *p; )
	p = &DECL_CHAIN (*p);
      *p = fndecl;
    }
  else
    {
      obstack_ptr_grow (&class_obstack, fndecl);
      *method_vec_ptr = (tree)obstack_base (&class_obstack);
    }
}

/* Warn about duplicate methods in fn_fields.  Also compact method
   lists so that lookup can be made faster.

   Algorithm: Outer loop builds lists by method name.  Inner loop
   checks for redundant method names within a list.

   Data Structure: List of method lists.  The outer list is a
   TREE_LIST, whose TREE_PURPOSE field is the field name and the
   TREE_VALUE is the DECL_CHAIN of the FUNCTION_DECLs.  TREE_CHAIN
   links the entire list of methods for TYPE_METHODS.  Friends are
   chained in the same way as member functions (? TREE_CHAIN or
   DECL_CHAIN), but they live in the TREE_TYPE field of the outer
   list.  That allows them to be quickly deleted, and requires no
   extra storage.

   If there are any constructors/destructors, they are moved to the
   front of the list.  This makes pushclass more efficient.

   We also link each field which has shares a name with its baseclass
   to the head of the list of fields for that base class.  This allows
   us to reduce search time in places like `build_method_call' to
   consider only reasonably likely functions.  */

tree
finish_struct_methods (t, fn_fields, nonprivate_method)
     tree t;
     tree fn_fields;
     int nonprivate_method;
{
  tree method_vec;
  tree save_fn_fields = fn_fields;
  tree ctor_name = constructor_name (t);
  int i, n_baseclasses = CLASSTYPE_N_BASECLASSES (t);

  /* Now prepare to gather fn_fields into vector.  */
  struct obstack *ambient_obstack = current_obstack;
  current_obstack = &class_obstack;
  method_vec = make_tree_vec (2);
  current_obstack = ambient_obstack;

  /* Now make this a live vector.  */
  obstack_free (&class_obstack, method_vec);

  /* Save room for constructors and destructors.  */
  obstack_blank (&class_obstack, sizeof (struct tree_vec) + sizeof (struct tree *));

  /* First fill in entry 0 with the constructors, entry 1 with destructors,
     and the next few with type conversion operators (if any).  */

  for (; fn_fields; fn_fields = TREE_CHAIN (fn_fields))
    {
      tree fn_name = DECL_NAME (fn_fields);

      /* Clear out this flag.

	 @@ Doug may figure out how to break
	 @@ this with nested classes and friends.  */
      DECL_IN_AGGR_P (fn_fields) = 0;

      /* Note here that a copy ctor is private, so we don't dare generate
 	 a default copy constructor for a class that has a member
 	 of this type without making sure they have access to it.  */
      if (fn_name == ctor_name)
 	{
 	  tree parmtypes = FUNCTION_ARG_CHAIN (fn_fields);
 	  tree parmtype = parmtypes ? TREE_VALUE (parmtypes) : void_type_node;
	  
 	  if (TREE_CODE (parmtype) == REFERENCE_TYPE
 	      && TYPE_MAIN_VARIANT (TREE_TYPE (parmtype)) == t)
 	    {
 	      if (TREE_CHAIN (parmtypes) == NULL_TREE
 		  || TREE_CHAIN (parmtypes) == void_list_node
 		  || TREE_PURPOSE (TREE_CHAIN (parmtypes)))
 		{
 		  if (TREE_PROTECTED (fn_fields))
 		    TYPE_HAS_NONPUBLIC_CTOR (t) = 1;
 		  else if (TREE_PRIVATE (fn_fields))
 		    TYPE_HAS_NONPUBLIC_CTOR (t) = 2;
 		}
 	    }
	  if (DESTRUCTOR_NAME_P (DECL_ASSEMBLER_NAME (fn_fields)))
	    {	    
	      /* Destructors go in slot 1.  */
	      DECL_CHAIN (fn_fields) = TREE_VEC_ELT (method_vec, 1);
	      TREE_VEC_ELT (method_vec, 1) = fn_fields;
	    }
	  else
	    {
	      /* Constructors go in slot 0.  */
	      DECL_CHAIN (fn_fields) = TREE_VEC_ELT (method_vec, 0);
	      TREE_VEC_ELT (method_vec, 0) = fn_fields;
	    }
 	}
      else if (IDENTIFIER_TYPENAME_P (fn_name))
	{
	  tree return_type = TREE_TYPE (TREE_TYPE (fn_fields));

	  if (typecode_p (return_type, INTEGER_TYPE)
	      || typecode_p (return_type, BOOLEAN_TYPE)
	      || typecode_p (return_type, ENUMERAL_TYPE))
	    TYPE_HAS_INT_CONVERSION (t) = 1;
	  else if (typecode_p (return_type, REAL_TYPE))
	    TYPE_HAS_REAL_CONVERSION (t) = 1;

	  grow_method (fn_fields, &method_vec);
	}
    }

  fn_fields = save_fn_fields;
  for (; fn_fields; fn_fields = TREE_CHAIN (fn_fields))
    {
      tree fn_name = DECL_NAME (fn_fields);

      if (fn_name == ctor_name || IDENTIFIER_TYPENAME_P (fn_name))
	continue;

      if (fn_name == ansi_opname[(int) MODIFY_EXPR])
	{
	  tree parmtype = TREE_VALUE (FUNCTION_ARG_CHAIN (fn_fields));

	  if (copy_assignment_arg_p (parmtype, DECL_VIRTUAL_P (fn_fields)))
	    {
	      if (TREE_PROTECTED (fn_fields))
		TYPE_HAS_NONPUBLIC_ASSIGN_REF (t) = 1;
	      else if (TREE_PRIVATE (fn_fields))
		TYPE_HAS_NONPUBLIC_ASSIGN_REF (t) = 2;
	    }
	}

      grow_method (fn_fields, &method_vec);
    }

  TREE_VEC_LENGTH (method_vec) = (tree *)obstack_next_free (&class_obstack)
    - (&TREE_VEC_ELT (method_vec, 0));
  obstack_finish (&class_obstack);
  CLASSTYPE_METHOD_VEC (t) = method_vec;

  if (nonprivate_method == 0
      && CLASSTYPE_FRIEND_CLASSES (t) == NULL_TREE
      && DECL_FRIENDLIST (TYPE_MAIN_DECL (t)) == NULL_TREE)
    {
      tree binfos = BINFO_BASETYPES (TYPE_BINFO (t));
      for (i = 0; i < n_baseclasses; i++)
	if (TREE_VIA_PUBLIC (TREE_VEC_ELT (binfos, i))
	    || TREE_VIA_PROTECTED (TREE_VEC_ELT (binfos, i)))
	  {
	    nonprivate_method = 1;
	    break;
	  }
      if (nonprivate_method == 0 
	  && warn_ctor_dtor_privacy)
	cp_warning ("all member functions in class `%T' are private", t);
    }

  /* Warn if all destructors are private (in which case this class is
     effectively unusable.  */
  if (TYPE_HAS_DESTRUCTOR (t))
    {
      tree dtor = TREE_VEC_ELT (method_vec, 1);

      /* Wild parse errors can cause this to happen.  */
      if (dtor == NULL_TREE)
	TYPE_HAS_DESTRUCTOR (t) = 0;
      else if (TREE_PRIVATE (dtor)
	       && CLASSTYPE_FRIEND_CLASSES (t) == NULL_TREE
	       && DECL_FRIENDLIST (TYPE_MAIN_DECL (t)) == NULL_TREE
	       && warn_ctor_dtor_privacy)
	cp_warning ("`%#T' only defines a private destructor and has no friends",
		    t);
    }

  /* Now for each member function (except for constructors and
     destructors), compute where member functions of the same
     name reside in base classes.  */
  if (n_baseclasses != 0
      && TREE_VEC_LENGTH (method_ve