diff mbox

[C++] Lazier rtti

Message ID 8a527f72-b94e-6f72-e709-188438006df7@acm.org
State New
Headers show

Commit Message

Nathan Sidwell June 16, 2017, 2:23 p.m. UTC
The rtti descriptor classes and associated variables are constructed as 
needed during compilation.  On the modules branch I found it best to 
write them by special reference and reconstruct them on read back.  That 
meant some changes to how rtti currently handles them.  This patch 
implements most of those changes, which are useful in their own right.

Internally we use an enumeration to identify the different 
__FOO_type_info classes, and create pseudo versions that don't escape 
the compilation.  These match definitions in the cxxabi.h header file. 
However, we were tangling up 'tell me the index for the typeinfo 
container for type X', with 'construct the typeinfo container for type 
X'.  This patch cleanly separates those questions (between which I can 
insert module streaming).

The typeinfo construction now lazily constructs all these descriptor 
types.  It removes a hole in the enumeration (there are no VMI 
descriptors with zero bases).  Also, when looking to see if we're 
building the runtime (needed to enable a piece of internal magic), we no 
longer use xref_tag, which will construct an incomplete type.  Instead 
use regular qualified lookup in the ABI namespace.

Applied to trunk.

nathan
diff mbox

Patch

2017-06-16  Nathan Sidwell  <nathan@acm.org>

	Make rtti lazier
	* rtti.c (enum tinfo_kind): Add TK_DERIVED_TYPES,
	TK_VMI_CLASS_TYPES, TK_MAX.  Delete TK_FIXED.
	(tinfo_names): New.
	(typeid_ok_p): Add quotes to error messages.  Use get_tinfo_desc.
	(get_tinfo_decl): Use get_tinfo_desc.
	(get_pseudo_ti_init): Likewise. Adjust VMI construction.
	(create_pseudo_type_info): Delete.
	(get_pseudo_ti_index): Just determine the index.
	(get_tinfo_desc): New.  Create all types lazily.
	(create_tinfo_types): Just allocate the descriptor array.
	(emit_support_tinfos): Use non-inserting type lookup.  Set builtin
	location.

Index: rtti.c
===================================================================
--- rtti.c	(revision 249255)
+++ rtti.c	(working copy)
@@ -75,7 +75,8 @@  enum tinfo_kind
 {
   TK_TYPE_INFO_TYPE,    /* abi::__type_info_pseudo */
   TK_BASE_TYPE,		/* abi::__base_class_type_info */
-  TK_BUILTIN_TYPE,	/* abi::__fundamental_type_info */
+  TK_DERIVED_TYPES,	/* Start of types derived from abi::__type_info  */
+  TK_BUILTIN_TYPE = TK_DERIVED_TYPES,	/* abi::__fundamental_type_info */
   TK_ARRAY_TYPE,	/* abi::__array_type_info */
   TK_FUNCTION_TYPE,	/* abi::__function_type_info */
   TK_ENUMERAL_TYPE,	/* abi::__enum_type_info */
@@ -83,8 +84,26 @@  enum tinfo_kind
   TK_POINTER_MEMBER_TYPE, /* abi::__pointer_to_member_type_info */
   TK_CLASS_TYPE,	/* abi::__class_type_info */
   TK_SI_CLASS_TYPE,	/* abi::__si_class_type_info */
-  TK_FIXED		/* end of fixed descriptors. */
-  /* ...		   abi::__vmi_type_info<I> */
+  TK_VMI_CLASS_TYPES,	/* abi::__vmi_class_type_info<int> */
+  TK_MAX
+};
+
+/* Names of the tinfo types.  Must be same order as TK enumeration
+   above.  */
+
+static const char *const tinfo_names[TK_MAX] =
+{
+  "__type_info",
+  "__base_class_type_info",
+  "__fundamental_type_info",
+  "__array_type_info",
+  "__function_type_info",
+  "__enum_type_info",
+  "__pointer_type_info",
+  "__pointer_to_member_type_info",
+  "__class_type_info",
+  "__si_class_type_info",
+  "__vmi_class_type_info"
 };
 
 /* Helper macro to get maximum scalar-width of pointer or of the 'long'-type.
@@ -115,9 +134,9 @@  static tree generic_initializer (tinfo_s
 static tree ptr_initializer (tinfo_s *, tree);
 static tree ptm_initializer (tinfo_s *, tree);
 static tree class_initializer (tinfo_s *, tree, unsigned, ...);
-static void create_pseudo_type_info (int, const char *, ...);
 static tree get_pseudo_ti_init (tree, unsigned);
 static unsigned get_pseudo_ti_index (tree);
+static tinfo_s *get_tinfo_desc (unsigned);
 static void create_tinfo_types (void);
 static bool typeinfo_in_lib_p (tree);
 
@@ -289,30 +308,27 @@  get_tinfo_decl_dynamic (tree exp, tsubst
 static bool
 typeid_ok_p (void)
 {
-  tree pseudo_type_info, type_info_type;
-
   if (! flag_rtti)
     {
-      error ("cannot use typeid with -fno-rtti");
+      error ("cannot use %<typeid%> with -fno-rtti");
       return false;
     }
 
   if (!COMPLETE_TYPE_P (const_type_info_type_node))
     {
-      error ("must #include <typeinfo> before using typeid");
+      error ("must %<#include <typeinfo>%> before using %<typeid%>");
       return false;
     }
 
-  pseudo_type_info = (*tinfo_descs)[TK_TYPE_INFO_TYPE].type;
-  type_info_type = TYPE_MAIN_VARIANT (const_type_info_type_node);
+  tree pseudo = TYPE_MAIN_VARIANT (get_tinfo_desc (TK_TYPE_INFO_TYPE)->type);
+  tree real = TYPE_MAIN_VARIANT (const_type_info_type_node);
 
   /* Make sure abi::__type_info_pseudo has the same alias set
      as std::type_info.  */
-  if (! TYPE_ALIAS_SET_KNOWN_P (pseudo_type_info))
-    TYPE_ALIAS_SET (pseudo_type_info) = get_alias_set (type_info_type);
+  if (! TYPE_ALIAS_SET_KNOWN_P (pseudo))
+    TYPE_ALIAS_SET (pseudo) = get_alias_set (real);
   else
-    gcc_assert (TYPE_ALIAS_SET (pseudo_type_info)
-		== get_alias_set (type_info_type));
+    gcc_assert (TYPE_ALIAS_SET (pseudo) == get_alias_set (real));
 
   return true;
 }
@@ -428,8 +444,8 @@  get_tinfo_decl (tree type)
   if (!d)
     {
       int ix = get_pseudo_ti_index (type);
-      tinfo_s *ti = &(*tinfo_descs)[ix];
-
+      const tinfo_s *ti = get_tinfo_desc (ix);
+      
       d = build_lang_decl (VAR_DECL, name, ti->type);
       SET_DECL_ASSEMBLER_NAME (d, name);
       /* Remember the type it is for.  */
@@ -1105,7 +1121,7 @@  typeinfo_in_lib_p (tree type)
 static tree
 get_pseudo_ti_init (tree type, unsigned tk_index)
 {
-  tinfo_s *ti = &(*tinfo_descs)[tk_index];
+  tinfo_s *ti = get_tinfo_desc (tk_index);
 
   gcc_assert (at_eof);
   switch (tk_index)
@@ -1140,22 +1156,18 @@  get_pseudo_ti_init (tree type, unsigned
 	int hint = ((CLASSTYPE_REPEATED_BASE_P (type) << 0)
 		    | (CLASSTYPE_DIAMOND_SHAPED_P (type) << 1));
 	tree binfo = TYPE_BINFO (type);
-	int nbases = BINFO_N_BASE_BINFOS (binfo);
+	unsigned nbases = BINFO_N_BASE_BINFOS (binfo);
 	vec<tree, va_gc> *base_accesses = BINFO_BASE_ACCESSES (binfo);
 	tree offset_type = LONGPTR_T;
-	tree base_inits = NULL_TREE;
-	int ix;
 	vec<constructor_elt, va_gc> *init_vec = NULL;
-	constructor_elt *e;
 
-	gcc_assert (tk_index >= TK_FIXED);
+	gcc_assert (tk_index - TK_VMI_CLASS_TYPES + 1 == nbases);
 
 	vec_safe_grow (init_vec, nbases);
 	/* Generate the base information initializer.  */
-	for (ix = nbases; ix--;)
+	for (unsigned ix = nbases; ix--;)
 	  {
 	    tree base_binfo = BINFO_BASE_BINFO (binfo, ix);
-	    tree base_init;
 	    int flags = 0;
 	    tree tinfo;
 	    tree offset;
@@ -1185,12 +1197,12 @@  get_pseudo_ti_init (tree type, unsigned
 	    vec_alloc (v, 2);
 	    CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, tinfo);
 	    CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, offset);
-	    base_init = build_constructor (init_list_type_node, v);
-	    e = &(*init_vec)[ix];
+	    tree base_init = build_constructor (init_list_type_node, v);
+	    constructor_elt *e = &(*init_vec)[ix];
 	    e->index = NULL_TREE;
 	    e->value = base_init;
 	  }
-	base_inits = build_constructor (init_list_type_node, init_vec);
+	tree base_inits = build_constructor (init_list_type_node, init_vec);
 
 	/* get_tinfo_ptr might have reallocated the tinfo_descs vector.  */
 	ti = &(*tinfo_descs)[tk_index];
@@ -1202,69 +1214,6 @@  get_pseudo_ti_init (tree type, unsigned
     }
 }
 
-/* Generate the RECORD_TYPE containing the data layout of a type_info
-   derivative as used by the runtime. This layout must be consistent with
-   that defined in the runtime support. Also generate the VAR_DECL for the
-   type's vtable. We explicitly manage the vtable member, and name it for
-   real type as used in the runtime. The RECORD type has a different name,
-   to avoid collisions.  Return a TREE_LIST who's TINFO_PSEUDO_TYPE
-   is the generated type and TINFO_VTABLE_NAME is the name of the
-   vtable.  We have to delay generating the VAR_DECL of the vtable
-   until the end of the translation, when we'll have seen the library
-   definition, if there was one.
-
-   REAL_NAME is the runtime's name of the type. Trailing arguments are
-   additional FIELD_DECL's for the structure. The final argument must be
-   NULL.  */
-
-static void
-create_pseudo_type_info (int tk, const char *real_name, ...)
-{
-  tinfo_s *ti;
-  tree pseudo_type;
-  char *pseudo_name;
-  tree fields;
-  tree field_decl;
-  va_list ap;
-
-  va_start (ap, real_name);
-
-  /* Generate the pseudo type name.  */
-  pseudo_name = (char *) alloca (strlen (real_name) + 30);
-  strcpy (pseudo_name, real_name);
-  strcat (pseudo_name, "_pseudo");
-  if (tk >= TK_FIXED)
-    sprintf (pseudo_name + strlen (pseudo_name), "%d", tk - TK_FIXED);
-
-  /* First field is the pseudo type_info base class.  */
-  fields = build_decl (input_location,
-		       FIELD_DECL, NULL_TREE,
-		       (*tinfo_descs)[TK_TYPE_INFO_TYPE].type);
-
-  /* Now add the derived fields.  */
-  while ((field_decl = va_arg (ap, tree)))
-    {
-      DECL_CHAIN (field_decl) = fields;
-      fields = field_decl;
-    }
-
-  /* Create the pseudo type.  */
-  pseudo_type = make_class_type (RECORD_TYPE);
-  finish_builtin_struct (pseudo_type, pseudo_name, fields, NULL_TREE);
-  CLASSTYPE_AS_BASE (pseudo_type) = pseudo_type;
-
-  ti = &(*tinfo_descs)[tk];
-  ti->type = cp_build_qualified_type (pseudo_type, TYPE_QUAL_CONST);
-  ti->name = get_identifier (real_name);
-  ti->vtable = NULL_TREE;
-
-  /* Pretend this is public so determine_visibility doesn't give vtables
-     internal linkage.  */
-  TREE_PUBLIC (TYPE_MAIN_DECL (ti->type)) = 1;
-
-  va_end (ap);
-}
-
 /* Return the index of a pseudo type info type node used to describe
    TYPE.  TYPE must be a complete type (or cv void), except at the end
    of the translation unit.  */
@@ -1299,23 +1248,16 @@  get_pseudo_ti_index (tree type)
     case UNION_TYPE:
     case RECORD_TYPE:
       if (TYPE_PTRMEMFUNC_P (type))
-	{
-	  ix = TK_POINTER_MEMBER_TYPE;
-	  break;
-	}
+	ix = TK_POINTER_MEMBER_TYPE;
       else if (!COMPLETE_TYPE_P (type))
 	{
 	  if (!at_eof)
 	    cxx_incomplete_type_error (NULL_TREE, type);
 	  ix = TK_CLASS_TYPE;
-	  break;
 	}
       else if (!TYPE_BINFO (type)
 	       || !BINFO_N_BASE_BINFOS (TYPE_BINFO (type)))
-	{
-	  ix = TK_CLASS_TYPE;
-	  break;
-	}
+	ix = TK_CLASS_TYPE;
       else
 	{
 	  tree binfo = TYPE_BINFO (type);
@@ -1327,49 +1269,13 @@  get_pseudo_ti_index (tree type)
 	      && (*base_accesses)[0] == access_public_node
 	      && !BINFO_VIRTUAL_P (base_binfo)
 	      && integer_zerop (BINFO_OFFSET (base_binfo)))
-	    {
-	      /* single non-virtual public.  */
-	      ix = TK_SI_CLASS_TYPE;
-	      break;
-	    }
+	    /* single non-virtual public.  */
+	    ix = TK_SI_CLASS_TYPE;
 	  else
-	    {
-	      tinfo_s *ti;
-	      tree array_domain, base_array;
-
-	      ix = TK_FIXED + num_bases;
-	      if (vec_safe_length (tinfo_descs) <= ix)
-		{
-		  /* too short, extend.  */
-		  unsigned len = vec_safe_length (tinfo_descs);
-
-		  vec_safe_grow (tinfo_descs, ix + 1);
-		  while (tinfo_descs->iterate (len++, &ti))
-		    ti->type = ti->vtable = ti->name = NULL_TREE;
-		}
-	      else if ((*tinfo_descs)[ix].type)
-		/* already created.  */
-		break;
-
-	      /* Create the array of __base_class_type_info entries.  */
-	      array_domain = build_index_type (size_int (num_bases - 1));
-	      base_array = build_array_type ((*tinfo_descs)[TK_BASE_TYPE].type,
-					     array_domain);
-
-	      push_abi_namespace ();
-	      create_pseudo_type_info
-		(ix, "__vmi_class_type_info",
-		 build_decl (input_location,
-			     FIELD_DECL, NULL_TREE, integer_type_node),
-		 build_decl (input_location,
-			     FIELD_DECL, NULL_TREE, integer_type_node),
-		 build_decl (input_location,
-			     FIELD_DECL, NULL_TREE, base_array),
-		 NULL);
-	      pop_abi_namespace ();
-	      break;
-	    }
+	    ix = TK_VMI_CLASS_TYPES + num_bases - 1;
 	}
+      break;
+
     default:
       ix = TK_BUILTIN_TYPE;
       break;
@@ -1377,107 +1283,202 @@  get_pseudo_ti_index (tree type)
   return ix;
 }
 
-/* Make sure the required builtin types exist for generating the type_info
-   variable definitions.  */
+/* Return pointer to tinfo descriptor.  Possibly creating the tinfo
+   descriptor in the first place.  */
 
-static void
-create_tinfo_types (void)
+static tinfo_s *
+get_tinfo_desc (unsigned ix)
 {
-  tinfo_s *ti;
+  unsigned len = tinfo_descs->length ();
 
-  gcc_assert (!tinfo_descs);
+  if (len <= ix)
+    {
+      /* too short, extend.  */
+      len = ix + 1 - len;
+      vec_safe_reserve (tinfo_descs, len);
+      tinfo_s elt;
+      elt.type = elt.vtable = elt.name = NULL_TREE;
+      while (len--)
+	tinfo_descs->quick_push (elt);
+    }
 
-  vec_safe_grow (tinfo_descs, TK_FIXED);
+  tinfo_s *res = &(*tinfo_descs)[ix];
 
-  push_abi_namespace ();
+  if (res->type)
+    return res;
 
-  /* Create the internal type_info structure. This is used as a base for
-     the other structures.  */
-  {
-    tree field, fields;
+  /* Ok, we have to create it.  This layout must be consistent with
+     that defined in the runtime support.  We explicitly manage the
+     vtable member, and name it for real type as used in the runtime.
+     The RECORD type has a different name, to avoid collisions.  We
+     have to delay generating the VAR_DECL of the vtable until the end
+     of the translation, when we'll have seen the library definition,
+     if there was one.  */
 
-    field = build_decl (BUILTINS_LOCATION,
-			FIELD_DECL, NULL_TREE, const_ptr_type_node);
-    fields = field;
-
-    field = build_decl (BUILTINS_LOCATION,
-			FIELD_DECL, NULL_TREE, const_string_type_node);
-    DECL_CHAIN (field) = fields;
-    fields = field;
-
-    ti = &(*tinfo_descs)[TK_TYPE_INFO_TYPE];
-    ti->type = make_class_type (RECORD_TYPE);
-    ti->vtable = NULL_TREE;
-    ti->name = NULL_TREE;
-    finish_builtin_struct (ti->type, "__type_info_pseudo",
-			   fields, NULL_TREE);
-  }
+  /* Fields to add, chained in reverse order.  */
+  tree fields = NULL_TREE;
 
-  /* Fundamental type_info */
-  create_pseudo_type_info (TK_BUILTIN_TYPE, "__fundamental_type_info", NULL);
+  if (ix >= TK_DERIVED_TYPES)
+    {
+      /* First field is the pseudo type_info base class.  */
+      tree fld_base = build_decl (BUILTINS_LOCATION, FIELD_DECL, NULL_TREE,
+				  get_tinfo_desc (TK_TYPE_INFO_TYPE)->type);
 
-  /* Array, function and enum type_info. No additional fields.  */
-  create_pseudo_type_info (TK_ARRAY_TYPE, "__array_type_info", NULL);
-  create_pseudo_type_info (TK_FUNCTION_TYPE, "__function_type_info", NULL);
-  create_pseudo_type_info (TK_ENUMERAL_TYPE, "__enum_type_info", NULL);
-
-  /* Class type_info.  No additional fields.  */
-  create_pseudo_type_info (TK_CLASS_TYPE, "__class_type_info", NULL);
-
-  /* Single public non-virtual base class. Add pointer to base class.
-     This is really a descendant of __class_type_info.  */
-  create_pseudo_type_info (TK_SI_CLASS_TYPE, "__si_class_type_info",
-	    build_decl (BUILTINS_LOCATION,
-			FIELD_DECL, NULL_TREE, type_info_ptr_type),
-	    NULL);
+      DECL_CHAIN (fld_base) = fields;
+      fields = fld_base;
+    }
 
-  /* Base class internal helper. Pointer to base type, offset to base,
-     flags.  */
-  {
-    tree field, fields;
+  switch (ix)
+    {
+    case TK_TYPE_INFO_TYPE:
+      {
+	tree fld_ptr = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				   NULL_TREE, const_ptr_type_node);
+	fields = fld_ptr;
+
+	tree fld_str = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				   NULL_TREE, const_string_type_node);
+	DECL_CHAIN (fld_str) = fields;
+	fields = fld_str;
+	break;
+      }
 
-    field = build_decl (BUILTINS_LOCATION,
-			FIELD_DECL, NULL_TREE, type_info_ptr_type);
-    fields = field;
-
-    field = build_decl (BUILTINS_LOCATION,
-			FIELD_DECL, NULL_TREE, LONGPTR_T);
-    DECL_CHAIN (field) = fields;
-    fields = field;
-
-    ti = &(*tinfo_descs)[TK_BASE_TYPE];
-
-    ti->type = make_class_type (RECORD_TYPE);
-    ti->vtable = NULL_TREE;
-    ti->name = NULL_TREE;
-    finish_builtin_struct (ti->type, "__base_class_type_info_pseudo",
-			   fields, NULL_TREE);
-  }
+    case TK_BASE_TYPE:
+      {
+	/* Base class internal helper. Pointer to base type, offset to
+	   base, flags.  */
+	tree fld_ptr = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				   NULL_TREE, type_info_ptr_type);
+	DECL_CHAIN (fld_ptr) = fields;
+	fields = fld_ptr;
+
+	tree fld_flag = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				    NULL_TREE, LONGPTR_T);
+	DECL_CHAIN (fld_flag) = fields;
+	fields = fld_flag;
+	break;
+      }
+
+    case TK_BUILTIN_TYPE:
+      /* Fundamental type_info */
+      break;
+
+    case TK_ARRAY_TYPE:
+      break;
+
+    case TK_FUNCTION_TYPE:
+      break;
+
+    case TK_ENUMERAL_TYPE:
+      break;
 
-  /* Pointer type_info. Adds two fields, qualification mask
-     and pointer to the pointed to type.  This is really a descendant of
-     __pbase_type_info.  */
-  create_pseudo_type_info (TK_POINTER_TYPE, "__pointer_type_info",
-       build_decl (BUILTINS_LOCATION, 
-		   FIELD_DECL, NULL_TREE, integer_type_node),
-       build_decl (BUILTINS_LOCATION,
-		   FIELD_DECL, NULL_TREE, type_info_ptr_type),
-       NULL);
-
-  /* Pointer to member data type_info.  Add qualifications flags,
-     pointer to the member's type info and pointer to the class.
-     This is really a descendant of __pbase_type_info.  */
-  create_pseudo_type_info (TK_POINTER_MEMBER_TYPE,
-       "__pointer_to_member_type_info",
-	build_decl (BUILTINS_LOCATION,
-		    FIELD_DECL, NULL_TREE, integer_type_node),
-	build_decl (BUILTINS_LOCATION,
-		    FIELD_DECL, NULL_TREE, type_info_ptr_type),
-	build_decl (BUILTINS_LOCATION,
-		    FIELD_DECL, NULL_TREE, type_info_ptr_type),
-	NULL);
+    case TK_POINTER_TYPE:
+    case TK_POINTER_MEMBER_TYPE:
+      {
+	/* Pointer type_info. Adds two fields, qualification mask and
+	   pointer to the pointed to type.  This is really a
+	   descendant of __pbase_type_info.  */
+	tree fld_mask = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				    NULL_TREE, integer_type_node);
+	DECL_CHAIN (fld_mask) = fields;
+	fields = fld_mask;
+
+	tree fld_ptr = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				   NULL_TREE, type_info_ptr_type);
+	DECL_CHAIN (fld_ptr) = fields;
+	fields = fld_ptr;
+
+	if (ix == TK_POINTER_MEMBER_TYPE)
+	  {
+	    /* Add a pointer to the class too.  */
+	    tree fld_cls = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				   NULL_TREE, type_info_ptr_type);
+	    DECL_CHAIN (fld_cls) = fields;
+	    fields = fld_cls;
+	  }
+	break;
+      }
+
+    case TK_CLASS_TYPE:
+      /* Class type_info.  No additional fields.  */
+      break;
+
+    case TK_SI_CLASS_TYPE:
+      {
+	/* Single public non-virtual base class. Add pointer to base
+	   class.  This is really a descendant of
+	   __class_type_info.  */
+	tree fld_ptr = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				   NULL_TREE, type_info_ptr_type);
+	DECL_CHAIN (fld_ptr) = fields;
+	fields = fld_ptr;
+	break;
+      }
+
+    default: /* Multiple inheritance.  */
+      {
+	unsigned num_bases = ix - TK_VMI_CLASS_TYPES + 1;
+
+	tree fld_flg = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				   NULL_TREE, integer_type_node);
+	DECL_CHAIN (fld_flg) = fields;
+	fields = fld_flg;
+	
+	tree fld_cnt = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				   NULL_TREE, integer_type_node);
+	DECL_CHAIN (fld_cnt) = fields;
+	fields = fld_cnt;
+
+	/* Create the array of __base_class_type_info entries.  */
+	tree domain = build_index_type (size_int (num_bases - 1));
+	tree array = build_array_type (get_tinfo_desc (TK_BASE_TYPE)->type,
+				       domain);
+	tree fld_ary = build_decl (BUILTINS_LOCATION, FIELD_DECL,
+				   NULL_TREE, array);
+	DECL_CHAIN (fld_ary) = fields;
+	fields = fld_ary;
+	break;
+      }
+    }
+
+  push_abi_namespace ();
+
+  /* Generate the pseudo type name.  */
+  const char *real_name = tinfo_names[ix < TK_VMI_CLASS_TYPES
+				      ? ix : unsigned (TK_VMI_CLASS_TYPES)];
+  size_t name_len = strlen (real_name);
+  char *pseudo_name = (char *) alloca (name_len + 30);
+  memcpy (pseudo_name, real_name, name_len);
+  /* Those >= TK_VMI_CLASS_TYPES need a discriminator, may as well
+     apply it to all.  See get_peudo_tinfo_index where we make use of
+     this.  */
+  sprintf (pseudo_name + name_len, "_pseudo_%d", ix);
+
+  /* Create the pseudo type.  */
+  tree pseudo_type = make_class_type (RECORD_TYPE);
+  /* Pass the fields chained in reverse.  */
+  finish_builtin_struct (pseudo_type, pseudo_name, fields, NULL_TREE);
+  CLASSTYPE_AS_BASE (pseudo_type) = pseudo_type;
+
+  res->type = cp_build_qualified_type (pseudo_type, TYPE_QUAL_CONST);
+  res->name = get_identifier (real_name);
+
+  /* Pretend this is public so determine_visibility doesn't give vtables
+     internal linkage.  */
+  TREE_PUBLIC (TYPE_MAIN_DECL (res->type)) = 1;
 
   pop_abi_namespace ();
+  return res;
+}
+
+/* We lazily create the type info types.  */
+
+static void
+create_tinfo_types (void)
+{
+  gcc_assert (!tinfo_descs);
+
+  vec_alloc (tinfo_descs, TK_MAX + 20);
 }
 
 /* Helper for emit_support_tinfos. Emits the type_info descriptor of
@@ -1545,18 +1546,23 @@  emit_support_tinfos (void)
     0
   };
   int ix;
-  tree bltn_type, dtor;
 
-  push_abi_namespace ();
-  bltn_type = xref_tag (class_type,
-			get_identifier ("__fundamental_type_info"),
-			/*tag_scope=*/ts_current, false);
-  pop_abi_namespace ();
+  /* Look for a defined class.  */
+  tree bltn_type = lookup_qualified_name
+    (abi_node, get_identifier ("__fundamental_type_info"), true, false, false);
+  if (TREE_CODE (bltn_type) != TYPE_DECL)
+    return;
+
+  bltn_type = TREE_TYPE (bltn_type);
   if (!COMPLETE_TYPE_P (bltn_type))
     return;
-  dtor = CLASSTYPE_DESTRUCTORS (bltn_type);
+  tree dtor = CLASSTYPE_DESTRUCTORS (bltn_type);
   if (!dtor || DECL_EXTERNAL (dtor))
     return;
+
+  /* All these are really builtins.  So set the location.  */
+  location_t saved_loc = input_location;
+  input_location = BUILTINS_LOCATION;
   doing_runtime = 1;
   for (ix = 0; fundamentals[ix]; ix++)
     emit_support_tinfo_1 (*fundamentals[ix]);
@@ -1568,6 +1574,7 @@  emit_support_tinfos (void)
       }
   for (tree t = registered_builtin_types; t; t = TREE_CHAIN (t))
     emit_support_tinfo_1 (TREE_VALUE (t));
+  input_location = saved_loc;
 }
 
 /* Finish a type info decl. DECL_PTR is a pointer to an unemitted
@@ -1606,7 +1613,7 @@  emit_tinfo_decl (tree decl)
       TREE_PUBLIC (decl) = 0;
       DECL_EXTERNAL (decl) = 0;
       DECL_INTERFACE_KNOWN (decl) = 1;
-    }
+    }u
 
   import_export_decl (decl);
   if (DECL_NOT_REALLY_EXTERN (decl) && decl_needed_p (decl))