Use backend interface for named types and array types.

	* go-gcc.cc (Gcc_backend::struct_type): Call fill_in_struct.
	(Gcc_backend::fill_in_struct): New function.
	(Gcc_backend::array_type): Implement.
	(Gcc_backend::fill_in_array): New function.
	(Gcc_backend::placeholder_pointer_type): New function.
	(Gcc_backend::set_placeholder_pointer_type): New function.
	(Gcc_backend::set_placeholder_function_type): New function.
	(Gcc_backend::placeholder_struct_type): New function.
	(Gcc_backend::set_placeholder_struct_type): New function.
	(Gcc_backend::placeholder_array_type): New function.
	(Gcc_backend::set_placeholder_array_type): New function.
	(Gcc_backend::named_type): New function.
	(Gcc_backend::circular_pointer_type): New function.
	(Gcc_backend::is_circular_pointer_type): New function.

From-SVN: r173380

gcc/go/ChangeLog

+2011-05-04  Ian Lance Taylor  <iant@google.com>
+
+	* go-gcc.cc (Gcc_backend::struct_type): Call fill_in_struct.
+	(Gcc_backend::fill_in_struct): New function.
+	(Gcc_backend::array_type): Implement.
+	(Gcc_backend::fill_in_array): New function.
+	(Gcc_backend::placeholder_pointer_type): New function.
+	(Gcc_backend::set_placeholder_pointer_type): New function.
+	(Gcc_backend::set_placeholder_function_type): New function.
+	(Gcc_backend::placeholder_struct_type): New function.
+	(Gcc_backend::set_placeholder_struct_type): New function.
+	(Gcc_backend::placeholder_array_type): New function.
+	(Gcc_backend::set_placeholder_array_type): New function.
+	(Gcc_backend::named_type): New function.
+	(Gcc_backend::circular_pointer_type): New function.
+	(Gcc_backend::is_circular_pointer_type): New function.
+
 2011-04-26  Ian Lance Taylor  <iant@google.com>
 
 	* go-gcc.cc (Gcc_backend::struct_type): Implement.

gcc/go/go-gcc.cc

@@ -161,8 +161,38 @@ class Gcc_backend : public Backend
   struct_type(const std::vector<Btyped_identifier>&);
 
   Btype*
-  array_type(const Btype* /* element_type */, const Bexpression* /* length */)
-  { gcc_unreachable(); }
+  array_type(Btype*, Bexpression*);
+
+  Btype*
+  placeholder_pointer_type(const std::string&, source_location, bool);
+
+  bool
+  set_placeholder_pointer_type(Btype*, Btype*);
+
+  bool
+  set_placeholder_function_type(Btype*, Btype*);
+
+  Btype*
+  placeholder_struct_type(const std::string&, source_location);
+
+  bool
+  set_placeholder_struct_type(Btype* placeholder,
+			      const std::vector<Btyped_identifier>&);
+
+  Btype*
+  placeholder_array_type(const std::string&, source_location);
+
+  bool
+  set_placeholder_array_type(Btype*, Btype*, Bexpression*);
+
+  Btype*
+  named_type(const std::string&, Btype*, source_location);
+
+  Btype*
+  circular_pointer_type(Btype*, bool);
+
+  bool
+  is_circular_pointer_type(Btype*);
 
   // Statements.
 
@@ -270,6 +300,12 @@ class Gcc_backend : public Backend
   Btype*
   make_type(tree t)
   { return new Btype(t); }
+
+  Btype*
+  fill_in_struct(Btype*, const std::vector<Btyped_identifier>&);
+
+  Btype*
+  fill_in_array(Btype*, Btype*, Bexpression*);
 };
 
 // A helper function.
@@ -453,7 +489,16 @@ Gcc_backend::function_type(const Btyped_identifier& receiver,
 Btype*
 Gcc_backend::struct_type(const std::vector<Btyped_identifier>& fields)
 {
-  tree ret = make_node(RECORD_TYPE);
+  return this->fill_in_struct(this->make_type(make_node(RECORD_TYPE)), fields);
+}
+
+// Fill in the fields of a struct type.
+
+Btype*
+Gcc_backend::fill_in_struct(Btype* fill,
+			    const std::vector<Btyped_identifier>& fields)
+{
+  tree fill_tree = fill->get_tree();
   tree field_trees = NULL_TREE;
   tree* pp = &field_trees;
   for (std::vector<Btyped_identifier>::const_iterator p = fields.begin();
@@ -465,15 +510,192 @@ Gcc_backend::struct_type(const std::vector<Btyped_identifier>& fields)
       if (type_tree == error_mark_node)
 	return this->error_type();
       tree field = build_decl(p->location, FIELD_DECL, name_tree, type_tree);
-      DECL_CONTEXT(field) = ret;
+      DECL_CONTEXT(field) = fill_tree;
       *pp = field;
       pp = &DECL_CHAIN(field);
     }
-  TYPE_FIELDS(ret) = field_trees;
-  layout_type(ret);
+  TYPE_FIELDS(fill_tree) = field_trees;
+  layout_type(fill_tree);
+  return fill;
+}
+
+// Make an array type.
+
+Btype*
+Gcc_backend::array_type(Btype* element_btype, Bexpression* length)
+{
+  return this->fill_in_array(this->make_type(make_node(ARRAY_TYPE)),
+			     element_btype, length);
+}
+
+// Fill in an array type.
+
+Btype*
+Gcc_backend::fill_in_array(Btype* fill, Btype* element_type,
+			   Bexpression* length)
+{
+  tree element_type_tree = element_type->get_tree();
+  tree length_tree = length->get_tree();
+  if (element_type_tree == error_mark_node || length_tree == error_mark_node)
+    return this->error_type();
+
+  gcc_assert(TYPE_SIZE(element_type_tree) != NULL_TREE);
+
+  length_tree = fold_convert(sizetype, length_tree);
+
+  // build_index_type takes the maximum index, which is one less than
+  // the length.
+  tree index_type_tree = build_index_type(fold_build2(MINUS_EXPR, sizetype,
+						      length_tree,
+						      size_one_node));
+
+  tree fill_tree = fill->get_tree();
+  TREE_TYPE(fill_tree) = element_type_tree;
+  TYPE_DOMAIN(fill_tree) = index_type_tree;
+  TYPE_ADDR_SPACE(fill_tree) = TYPE_ADDR_SPACE(element_type_tree);
+  layout_type(fill_tree);
+
+  if (TYPE_STRUCTURAL_EQUALITY_P(element_type_tree))
+    SET_TYPE_STRUCTURAL_EQUALITY(fill_tree);
+  else if (TYPE_CANONICAL(element_type_tree) != element_type_tree
+	   || TYPE_CANONICAL(index_type_tree) != index_type_tree)
+    TYPE_CANONICAL(fill_tree) =
+      build_array_type(TYPE_CANONICAL(element_type_tree),
+		       TYPE_CANONICAL(index_type_tree));
+
+  return fill;
+}
+
+// Create a placeholder for a pointer type.
+
+Btype*
+Gcc_backend::placeholder_pointer_type(const std::string& name,
+				      source_location location, bool)
+{
+  tree ret = build_variant_type_copy(ptr_type_node);
+  tree decl = build_decl(location, TYPE_DECL,
+			 get_identifier_from_string(name),
+			 ret);
+  TYPE_NAME(ret) = decl;
+  return this->make_type(ret);
+}
+
+// Set the real target type for a placeholder pointer type.
+
+bool
+Gcc_backend::set_placeholder_pointer_type(Btype* placeholder,
+					  Btype* to_type)
+{
+  tree pt = placeholder->get_tree();
+  if (pt == error_mark_node)
+    return false;
+  gcc_assert(TREE_CODE(pt) == POINTER_TYPE);
+  tree tt = to_type->get_tree();
+  if (tt == error_mark_node)
+    {
+      TREE_TYPE(pt) = tt;
+      return false;
+    }
+  gcc_assert(TREE_CODE(tt) == POINTER_TYPE);
+  TREE_TYPE(pt) = TREE_TYPE(tt);
+  return true;
+}
+
+// Set the real values for a placeholder function type.
+
+bool
+Gcc_backend::set_placeholder_function_type(Btype* placeholder, Btype* ft)
+{
+  return this->set_placeholder_pointer_type(placeholder, ft);
+}
+
+// Create a placeholder for a struct type.
+
+Btype*
+Gcc_backend::placeholder_struct_type(const std::string& name,
+				     source_location location)
+{
+  tree ret = make_node(RECORD_TYPE);
+  tree decl = build_decl(location, TYPE_DECL,
+			 get_identifier_from_string(name),
+			 ret);
+  TYPE_NAME(ret) = decl;
   return this->make_type(ret);
 }
 
+// Fill in the fields of a placeholder struct type.
+
+bool
+Gcc_backend::set_placeholder_struct_type(
+    Btype* placeholder,
+    const std::vector<Btyped_identifier>& fields)
+{
+  tree t = placeholder->get_tree();
+  gcc_assert(TREE_CODE(t) == RECORD_TYPE && TYPE_FIELDS(t) == NULL_TREE);
+  Btype* r = this->fill_in_struct(placeholder, fields);
+  return r->get_tree() != error_mark_node;
+}
+
+// Create a placeholder for an array type.
+
+Btype*
+Gcc_backend::placeholder_array_type(const std::string& name,
+				    source_location location)
+{
+  tree ret = make_node(ARRAY_TYPE);
+  tree decl = build_decl(location, TYPE_DECL,
+			 get_identifier_from_string(name),
+			 ret);
+  TYPE_NAME(ret) = decl;
+  return this->make_type(ret);
+}
+
+// Fill in the fields of a placeholder array type.
+
+bool
+Gcc_backend::set_placeholder_array_type(Btype* placeholder,
+					Btype* element_btype,
+					Bexpression* length)
+{
+  tree t = placeholder->get_tree();
+  gcc_assert(TREE_CODE(t) == ARRAY_TYPE && TREE_TYPE(t) == NULL_TREE);
+  Btype* r = this->fill_in_array(placeholder, element_btype, length);
+  return r->get_tree() != error_mark_node;
+}
+
+// Return a named version of a type.
+
+Btype*
+Gcc_backend::named_type(const std::string& name, Btype* btype,
+			source_location location)
+{
+  tree type = btype->get_tree();
+  if (type == error_mark_node)
+    return this->error_type();
+  type = build_variant_type_copy(type);
+  tree decl = build_decl(location, TYPE_DECL,
+			 get_identifier_from_string(name),
+			 type);
+  TYPE_NAME(type) = decl;
+  return this->make_type(type);
+}
+
+// Return a pointer type used as a marker for a circular type.
+
+Btype*
+Gcc_backend::circular_pointer_type(Btype*, bool)
+{
+  return this->make_type(ptr_type_node);
+}
+
+// Return whether we might be looking at a circular type.
+
+bool
+Gcc_backend::is_circular_pointer_type(Btype* btype)
+{
+  return btype->get_tree() == ptr_type_node;
+}
+
 // An expression as a statement.
 
 Bstatement*

gcc/go/gofrontend/backend.h

@@ -108,7 +108,93 @@ class Backend
 
   // Get an array type.
   virtual Btype*
-  array_type(const Btype* element_type, const Bexpression* length) = 0;
+  array_type(Btype* element_type, Bexpression* length) = 0;
+
+  // Create a placeholder pointer type.  This is used for a named
+  // pointer type, since in Go a pointer type may refer to itself.
+  // NAME is the name of the type, and the location is where the named
+  // type is defined.  FOR_FUNCTION is true if this is for a Go
+  // function type, which corresponds to a C/C++ pointer to function
+  // type.  The return value will later be passed as the first
+  // parameter to set_placeholder_pointer_type or
+  // set_placeholder_function_type.
+  virtual Btype*
+  placeholder_pointer_type(const std::string& name, source_location,
+			   bool for_function) = 0;
+
+  // Fill in a placeholder pointer type as a pointer.  This takes a
+  // type returned by placeholder_pointer_type and arranges for it to
+  // point to to_type.  Returns true on success, false on failure.
+  virtual bool
+  set_placeholder_pointer_type(Btype* placeholder, Btype* to_type) = 0;
+
+  // Fill in a placeholder pointer type as a function.  This takes a
+  // type returned by placeholder_pointer_type and arranges for it to
+  // become a real Go function type (which corresponds to a C/C++
+  // pointer to function type).  FT will be something returned by the
+  // function_type method.  Returns true on success, false on failure.
+  virtual bool
+  set_placeholder_function_type(Btype* placeholder, Btype* ft) = 0;
+
+  // Create a placeholder struct type.  This is used for a named
+  // struct type, as with placeholder_pointer_type.
+  virtual Btype*
+  placeholder_struct_type(const std::string& name, source_location) = 0;
+
+  // Fill in a placeholder struct type.  This takes a type returned by
+  // placeholder_struct_type and arranges for it to become a real
+  // struct type.  The parameter is as for struct_type.  Returns true
+  // on success, false on failure.
+  virtual bool
+  set_placeholder_struct_type(Btype* placeholder,
+			      const std::vector<Btyped_identifier>& fields)
+  			= 0;
+
+  // Create a placeholder array type.  This is used for a named array
+  // type, as with placeholder_pointer_type, to handle cases like
+  // type A []*A.
+  virtual Btype*
+  placeholder_array_type(const std::string& name, source_location) = 0;
+
+  // Fill in a placeholder array type.  This takes a type returned by
+  // placeholder_array_type and arranges for it to become a real array
+  // type.  The parameters are as for array_type.  Returns true on
+  // success, false on failure.
+  virtual bool
+  set_placeholder_array_type(Btype* placeholder, Btype* element_type,
+			     Bexpression* length) = 0;
+
+  // Return a named version of a type.  The location is the location
+  // of the type definition.  This will not be called for a type
+  // created via placeholder_pointer_type, placeholder_struct_type, or
+  // placeholder_array_type..  (It may be called for a pointer,
+  // struct, or array type in a case like "type P *byte; type Q P".)
+  virtual Btype*
+  named_type(const std::string& name, Btype*, source_location) = 0;
+
+  // Create a marker for a circular pointer type.  Go pointer and
+  // function types can refer to themselves in ways that are not
+  // permitted in C/C++.  When a circular type is found, this function
+  // is called for the circular reference.  This permits the backend
+  // to decide how to handle such a type.  PLACEHOLDER is the
+  // placeholder type which has already been created; if the backend
+  // is prepared to handle a circular pointer type, it may simply
+  // return PLACEHOLDER.  FOR_FUNCTION is true if this is for a
+  // function type.
+  //
+  // For "type P *P" the sequence of calls will be
+  //   bt1 = placeholder_pointer_type();
+  //   bt2 = circular_pointer_type(bt1, false);
+  //   set_placeholder_pointer_type(bt1, bt2);
+  virtual Btype*
+  circular_pointer_type(Btype* placeholder, bool for_function) = 0;
+
+  // Return whether the argument could be a special type created by
+  // circular_pointer_type.  This is used to introduce explicit type
+  // conversions where needed.  If circular_pointer_type returns its
+  // PLACEHOLDER parameter, this may safely always return false.
+  virtual bool
+  is_circular_pointer_type(Btype*) = 0;
 
   // Statements.
 

gcc/go/gofrontend/types.h

@@ -42,6 +42,8 @@ class Function;
 class Translate_context;
 class Export;
 class Import;
+class Btype;
+class Bexpression;
 
 // Type codes used in type descriptors.  These must match the values
 // in libgo/runtime/go-type.h.  They also match the values in the gc
@@ -973,10 +975,11 @@ class Type
   static unsigned int
   hash_string(const std::string&, unsigned int);
 
-  // Return a tree for the underlying type of a named type.
-  static tree
-  get_named_type_tree(Gogo* gogo, Type* base_type)
-  { return base_type->get_tree_without_hash(gogo); }
+  // Return the backend representation for the underlying type of a
+  // named type.
+  static Btype*
+  get_named_base_btype(Gogo* gogo, Type* base_type)
+  { return base_type->get_btype_without_hash(gogo); }
 
  private:
   // Convert to the desired type classification, or return NULL.  This
@@ -1100,6 +1103,11 @@ class Type
   tree
   get_tree_without_hash(Gogo*);
 
+  // Get the backend representation for a type without looking in the
+  // hash table for identical types.
+  Btype*
+  get_btype_without_hash(Gogo*);
+
   // A mapping from Type to tree, used to ensure that the GIMPLE
   // representation of identical types is identical.
   typedef Unordered_map_hash(const Type*, tree, Type_hash_identical,
@@ -1952,10 +1960,6 @@ class Struct_type : public Type
   static Struct_type*
   do_import(Import*);
 
-  // Fill in the fields for a named struct type.
-  tree
-  fill_in_tree(Gogo*, tree);
-
   static Type*
   make_struct_type_descriptor_type();
 
@@ -2056,9 +2060,13 @@ class Array_type : public Type
   static Array_type*
   do_import(Import*);
 
-  // Fill in the fields for a named array type.
-  tree
-  fill_in_array_tree(Gogo*, tree);
+  // Return the backend representation of the element type.
+  Btype*
+  get_backend_element(Gogo*);
+
+  // Return the backend representation of the length.
+  Bexpression*
+  get_backend_length(Gogo*);
 
   // Fill in the fields for a named slice type.
   tree
@@ -2430,7 +2438,7 @@ class Named_type : public Type
       named_object_(named_object), in_function_(NULL), type_(type),
       local_methods_(NULL), all_methods_(NULL),
       interface_method_tables_(NULL), pointer_interface_method_tables_(NULL),
-      location_(location), named_tree_(NULL), dependencies_(),
+      location_(location), named_btype_(NULL), dependencies_(),
       is_visible_(true), is_error_(false), is_converted_(false),
       is_circular_(false), seen_(0)
   { }
@@ -2676,9 +2684,10 @@ class Named_type : public Type
   Interface_method_tables* pointer_interface_method_tables_;
   // The location where this type was defined.
   source_location location_;
-  // The tree for this type while converting to GENERIC.  This is used
-  // to avoid endless recursion when a named type refers to itself.
-  tree named_tree_;
+  // The backend representation of this type during backend
+  // conversion.  This is used to avoid endless recursion when a named
+  // type refers to itself.
+  Btype* named_btype_;
   // A list of types which must be converted to the backend
   // representation before this type can be converted.  This is for
   // cases like