compiler: Use backend interface for function declarations.

	* go-gcc.cc (Backend::error_function): New function.
	(Backend::function): New function.
	(Backend::make_function): New function.
	(function_to_tree): New function.

From-SVN: r203403

9 files changed, 368 insertions, 309 deletions

diff --git a/gcc/go/ChangeLog b/gcc/go/ChangeLog
index eddf393..6d6217b 100644
--- a/gcc/go/ChangeLog
+++ b/gcc/go/ChangeLog
@@ -1,3 +1,10 @@
+2013-10-10  Chris Manghane  <cmang@google.com>
+
+	* go-gcc.cc (Backend::error_function): New function.
+	(Backend::function): New function.
+	(Backend::make_function): New function.
+	(function_to_tree): New function.
+
 2013-10-04  Chris Manghane  <cmang@google.com>
 
 	* go-gcc.cc (Backend::convert_expression): New function.
diff --git a/gcc/go/go-gcc.cc b/gcc/go/go-gcc.cc
index fcfd41b..6b77d94 100644
--- a/gcc/go/go-gcc.cc
+++ b/gcc/go/go-gcc.cc
@@ -334,6 +334,17 @@ class Gcc_backend : public Backend
   Bexpression*
   label_address(Blabel*, Location);
 
+  // Functions.
+
+  Bfunction*
+  error_function()
+  { return this->make_function(error_mark_node); }
+
+  Bfunction*
+  function(Btype* fntype, const std::string& name, const std::string& asm_name,
+           bool is_visible, bool is_declaration, bool is_inlinable,
+           bool disable_split_stack, bool in_unique_section, Location);
+
  private:
   // Make a Bexpression from a tree.
   Bexpression*
@@ -350,6 +361,10 @@ class Gcc_backend : public Backend
   make_type(tree t)
   { return new Btype(t); }
 
+  Bfunction*
+  make_function(tree t)
+  { return new Bfunction(t); }
+
   Btype*
   fill_in_struct(Btype*, const std::vector<Btyped_identifier>&);
 
@@ -1724,6 +1739,56 @@ Gcc_backend::label_address(Blabel* label, Location location)
   return this->make_expression(ret);
 }
 
+// Declare or define a new function.
+
+Bfunction*
+Gcc_backend::function(Btype* fntype, const std::string& name,
+                      const std::string& asm_name, bool is_visible,
+                      bool is_declaration, bool is_inlinable,
+                      bool disable_split_stack, bool in_unique_section,
+                      Location location)
+{
+  tree functype = fntype->get_tree();
+  if (functype != error_mark_node)
+    {
+      gcc_assert(FUNCTION_POINTER_TYPE_P(functype));
+      functype = TREE_TYPE(functype);
+    }
+  tree id = get_identifier_from_string(name);
+  if (functype == error_mark_node || id == error_mark_node)
+    return this->error_function();
+
+  tree decl = build_decl(location.gcc_location(), FUNCTION_DECL, id, functype);
+  if (!asm_name.empty())
+    SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(asm_name));
+  if (is_visible)
+    TREE_PUBLIC(decl) = 1;
+  if (is_declaration)
+    DECL_EXTERNAL(decl) = 1;
+  else
+    {
+      tree restype = TREE_TYPE(functype);
+      tree resdecl =
+          build_decl(location.gcc_location(), RESULT_DECL, NULL_TREE, restype);
+      DECL_ARTIFICIAL(resdecl) = 1;
+      DECL_IGNORED_P(resdecl) = 1;
+      DECL_CONTEXT(resdecl) = decl;
+      DECL_RESULT(decl) = resdecl;
+    }
+  if (!is_inlinable)
+    DECL_UNINLINABLE(decl) = 1;
+  if (disable_split_stack)
+    {
+      tree attr = get_identifier("__no_split_stack__");
+      DECL_ATTRIBUTES(decl) = tree_cons(attr, NULL_TREE, NULL_TREE);
+    }
+  if (in_unique_section)
+    resolve_unique_section(decl, 0, 1);
+
+  go_preserve_from_gc(decl);
+  return new Bfunction(decl);
+}
+
 // The single backend.
 
 static Gcc_backend gcc_backend;
@@ -1799,3 +1864,9 @@ var_to_tree(Bvariable* bv)
 {
   return bv->get_tree();
 }
+
+tree
+function_to_tree(Bfunction* bf)
+{
+  return bf->get_tree();
+}
diff --git a/gcc/go/gofrontend/backend.h b/gcc/go/gofrontend/backend.h
index fa3e3cc..e73c98c 100644
--- a/gcc/go/gofrontend/backend.h
+++ b/gcc/go/gofrontend/backend.h
@@ -23,7 +23,7 @@ class Bexpression;
 // The backend representation of a statement.
 class Bstatement;
 
-// The backend representation of a function definition.
+// The backend representation of a function definition or declaration.
 class Bfunction;
 
 // The backend representation of a block.
@@ -498,6 +498,32 @@ class Backend
   // recover.
   virtual Bexpression*
   label_address(Blabel*, Location) = 0;
+
+  // Functions.
+
+  // Create an error function.  This is used for cases which should
+  // not occur in a correct program, in order to keep the compilation
+  // going without crashing.
+  virtual Bfunction*
+  error_function() = 0;
+
+  // Declare or define a function of FNTYPE.
+  // NAME is the Go name of the function. ASM_NAME, if not the empty string, is
+  // the name that should be used in the symbol table; this will be non-empty if
+  // a magic extern comment is used.
+  // IS_VISIBLE is true if this function should be visible outside of the
+  // current compilation unit. IS_DECLARATION is true if this is a function
+  // declaration rather than a definition; the function definition will be in
+  // another compilation unit.
+  // IS_INLINABLE is true if the function can be inlined.
+  // DISABLE_SPLIT_STACK is true if this function may not split the stack; this
+  // is used for the implementation of recover.
+  // IN_UNIQUE_SECTION is true if this function should be put into a unique
+  // location if possible; this is used for field tracking.
+  virtual Bfunction*
+  function(Btype* fntype, const std::string& name, const std::string& asm_name,
+           bool is_visible, bool is_declaration, bool is_inlinable,
+           bool disable_split_stack, bool in_unique_section, Location) = 0;
 };
 
 // The backend interface has to define this function.
@@ -517,5 +543,6 @@ extern tree expr_to_tree(Bexpression*);
 extern tree stat_to_tree(Bstatement*);
 extern tree block_to_tree(Bblock*);
 extern tree var_to_tree(Bvariable*);
+extern tree function_to_tree(Bfunction*);
 
 #endif // !defined(GO_BACKEND_H)
diff --git a/gcc/go/gofrontend/expressions.cc b/gcc/go/gofrontend/expressions.cc
index 0647a50..37f8822 100644
--- a/gcc/go/gofrontend/expressions.cc
+++ b/gcc/go/gofrontend/expressions.cc
@@ -1240,15 +1240,11 @@ Func_expression::get_code_pointer(Gogo* gogo, Named_object* no, Location loc)
       return error_mark_node;
     }
 
-  tree id = no->get_id(gogo);
-  if (id == error_mark_node)
-    return error_mark_node;
-
   tree fndecl;
   if (no->is_function())
-    fndecl = no->func_value()->get_or_make_decl(gogo, no, id);
+    fndecl = no->func_value()->get_or_make_decl(gogo, no);
   else if (no->is_function_declaration())
-    fndecl = no->func_declaration_value()->get_or_make_decl(gogo, no, id);
+    fndecl = no->func_declaration_value()->get_or_make_decl(gogo, no);
   else
     go_unreachable();
 
@@ -9825,14 +9821,8 @@ Call_expression::do_get_tree(Translate_context* context)
     }
 
   tree fntype_tree = type_to_tree(fntype->get_backend(gogo));
-  if (fntype_tree == error_mark_node)
-    return error_mark_node;
-  go_assert(POINTER_TYPE_P(fntype_tree));
-  if (TREE_TYPE(fntype_tree) == error_mark_node)
-    return error_mark_node;
-  go_assert(TREE_CODE(TREE_TYPE(fntype_tree)) == RECORD_TYPE);
-  tree fnfield_type = TREE_TYPE(TYPE_FIELDS(TREE_TYPE(fntype_tree)));
-  if (fnfield_type == error_mark_node)
+  tree fnfield_type = type_to_tree(fntype->get_backend_fntype(gogo));
+  if (fntype_tree == error_mark_node || fnfield_type == error_mark_node)
     return error_mark_node;
   go_assert(FUNCTION_POINTER_TYPE_P(fnfield_type));
   tree rettype = TREE_TYPE(TREE_TYPE(fnfield_type));
diff --git a/gcc/go/gofrontend/gogo-tree.cc b/gcc/go/gofrontend/gogo-tree.cc
index a95f290..78a8c6a 100644
--- a/gcc/go/gofrontend/gogo-tree.cc
+++ b/gcc/go/gofrontend/gogo-tree.cc
@@ -985,74 +985,6 @@ Gogo::write_globals()
   delete[] vec;
 }
 
-// Get a tree for the identifier for a named object.
-
-tree
-Named_object::get_id(Gogo* gogo)
-{
-  go_assert(!this->is_variable() && !this->is_result_variable());
-  std::string decl_name;
-  if (this->is_function_declaration()
-      && !this->func_declaration_value()->asm_name().empty())
-    decl_name = this->func_declaration_value()->asm_name();
-  else if (this->is_type()
-	   && Linemap::is_predeclared_location(this->type_value()->location()))
-    {
-      // We don't need the package name for builtin types.
-      decl_name = Gogo::unpack_hidden_name(this->name_);
-    }
-  else
-    {
-      std::string package_name;
-      if (this->package_ == NULL)
-	package_name = gogo->package_name();
-      else
-	package_name = this->package_->package_name();
-
-      // Note that this will be misleading if this is an unexported
-      // method generated for an embedded imported type.  In that case
-      // the unexported method should have the package name of the
-      // package from which it is imported, but we are going to give
-      // it our package name.  Fixing this would require knowing the
-      // package name, but we only know the package path.  It might be
-      // better to use package paths here anyhow.  This doesn't affect
-      // the assembler code, because we always set that name in
-      // Function::get_or_make_decl anyhow.  FIXME.
-
-      decl_name = package_name + '.' + Gogo::unpack_hidden_name(this->name_);
-
-      Function_type* fntype;
-      if (this->is_function())
-	fntype = this->func_value()->type();
-      else if (this->is_function_declaration())
-	fntype = this->func_declaration_value()->type();
-      else
-	fntype = NULL;
-      if (fntype != NULL && fntype->is_method())
-	{
-	  decl_name.push_back('.');
-	  decl_name.append(fntype->receiver()->type()->mangled_name(gogo));
-	}
-    }
-  if (this->is_type())
-    {
-      unsigned int index;
-      const Named_object* in_function = this->type_value()->in_function(&index);
-      if (in_function != NULL)
-	{
-	  decl_name += '$' + Gogo::unpack_hidden_name(in_function->name());
-	  if (index > 0)
-	    {
-	      char buf[30];
-	      snprintf(buf, sizeof buf, "%u", index);
-	      decl_name += '$';
-	      decl_name += buf;
-	    }
-	}
-    }
-  return get_identifier_from_string(decl_name);
-}
-
 // Get a tree for a named object.
 
 tree
@@ -1067,11 +999,6 @@ Named_object::get_tree(Gogo* gogo, Named_object* function)
       return error_mark_node;
     }
 
-  tree name;
-  if (this->classification_ == NAMED_OBJECT_TYPE)
-    name = NULL_TREE;
-  else
-    name = this->get_id(gogo);
   tree decl;
   switch (this->classification_)
     {
@@ -1099,6 +1026,7 @@ Named_object::get_tree(Gogo* gogo, Named_object* function)
 	      decl = error_mark_node;
 	    else if (INTEGRAL_TYPE_P(TREE_TYPE(expr_tree)))
 	      {
+                tree name = get_identifier_from_string(this->get_id(gogo));
 		decl = build_decl(named_constant->location().gcc_location(),
                                   CONST_DECL, name, TREE_TYPE(expr_tree));
 		DECL_INITIAL(decl) = expr_tree;
@@ -1161,7 +1089,7 @@ Named_object::get_tree(Gogo* gogo, Named_object* function)
     case NAMED_OBJECT_FUNC:
       {
 	Function* func = this->u_.func_value;
-	decl = func->get_or_make_decl(gogo, this, name);
+	decl = func->get_or_make_decl(gogo, this);
 	if (decl != error_mark_node)
 	  {
 	    if (func->block() != NULL)
@@ -1289,120 +1217,83 @@ Variable::get_init_block(Gogo* gogo, Named_object* function, tree var_decl)
 // Get a tree for a function decl.
 
 tree
-Function::get_or_make_decl(Gogo* gogo, Named_object* no, tree id)
+Function::get_or_make_decl(Gogo* gogo, Named_object* no)
 {
-  if (this->fndecl_ == NULL_TREE)
+  if (this->fndecl_ == NULL)
     {
-      tree functype = type_to_tree(this->type_->get_backend(gogo));
-
-      if (functype != error_mark_node)
-	{
-	  // The type of a function comes back as a pointer to a
-	  // struct whose first field is the function, but we want the
-	  // real function type for a function declaration.
-	  go_assert(POINTER_TYPE_P(functype)
-		    && TREE_CODE(TREE_TYPE(functype)) == RECORD_TYPE);
-	  functype = TREE_TYPE(TYPE_FIELDS(TREE_TYPE(functype)));
-	  go_assert(FUNCTION_POINTER_TYPE_P(functype));
-	  functype = TREE_TYPE(functype);
-	}
-
-      if (functype == error_mark_node)
-	this->fndecl_ = error_mark_node;
-      else
-	{
-	  tree decl = build_decl(this->location().gcc_location(), FUNCTION_DECL,
-                                 id, functype);
-
-	  this->fndecl_ = decl;
-
-	  if (no->package() != NULL)
-	    ;
-	  else if (this->enclosing_ != NULL || Gogo::is_thunk(no))
-	    ;
-	  else if (Gogo::unpack_hidden_name(no->name()) == "init"
-		   && !this->type_->is_method())
-	    ;
-	  else if (Gogo::unpack_hidden_name(no->name()) == "main"
-		   && gogo->is_main_package())
-	    TREE_PUBLIC(decl) = 1;
-	  // Methods have to be public even if they are hidden because
-	  // they can be pulled into type descriptors when using
-	  // anonymous fields.
-	  else if (!Gogo::is_hidden_name(no->name())
-		   || this->type_->is_method())
-	    {
-	      TREE_PUBLIC(decl) = 1;
-	      std::string pkgpath = gogo->pkgpath_symbol();
-	      if (this->type_->is_method()
-		  && Gogo::is_hidden_name(no->name())
-		  && Gogo::hidden_name_pkgpath(no->name()) != gogo->pkgpath())
-		{
-		  // This is a method we created for an unexported
-		  // method of an imported embedded type.  We need to
-		  // use the pkgpath of the imported package to avoid
-		  // a possible name collision.  See bug478 for a test
-		  // case.
-		  pkgpath = Gogo::hidden_name_pkgpath(no->name());
-		  pkgpath = Gogo::pkgpath_for_symbol(pkgpath);
-		}
-
-	      std::string asm_name = pkgpath;
-	      asm_name.append(1, '.');
-	      asm_name.append(Gogo::unpack_hidden_name(no->name()));
-	      if (this->type_->is_method())
-		{
-		  asm_name.append(1, '.');
-		  Type* rtype = this->type_->receiver()->type();
-		  asm_name.append(rtype->mangled_name(gogo));
-		}
-	      SET_DECL_ASSEMBLER_NAME(decl,
-				      get_identifier_from_string(asm_name));
-	    }
-
-	  // Why do we have to do this in the frontend?
-	  tree restype = TREE_TYPE(functype);
-	  tree resdecl =
-            build_decl(this->location().gcc_location(), RESULT_DECL, NULL_TREE,
-                       restype);
-	  DECL_ARTIFICIAL(resdecl) = 1;
-	  DECL_IGNORED_P(resdecl) = 1;
-	  DECL_CONTEXT(resdecl) = decl;
-	  DECL_RESULT(decl) = resdecl;
-
-	  // If a function calls the predeclared recover function, we
-	  // can't inline it, because recover behaves differently in a
-	  // function passed directly to defer.  If this is a recover
-	  // thunk that we built to test whether a function can be
-	  // recovered, we can't inline it, because that will mess up
-	  // our return address comparison.
-	  if (this->calls_recover_ || this->is_recover_thunk_)
-	    DECL_UNINLINABLE(decl) = 1;
-
-	  // If this is a thunk created to call a function which calls
-	  // the predeclared recover function, we need to disable
-	  // stack splitting for the thunk.
-	  if (this->is_recover_thunk_)
-	    {
-	      tree attr = get_identifier("__no_split_stack__");
-	      DECL_ATTRIBUTES(decl) = tree_cons(attr, NULL_TREE, NULL_TREE);
-	    }
-
-	  if (this->in_unique_section_)
-	    resolve_unique_section (decl, 0, 1);
+      std::string asm_name;
+      bool is_visible = false;
+      if (no->package() != NULL)
+        ;
+      else if (this->enclosing_ != NULL || Gogo::is_thunk(no))
+        ;
+      else if (Gogo::unpack_hidden_name(no->name()) == "init"
+               && !this->type_->is_method())
+        ;
+      else if (Gogo::unpack_hidden_name(no->name()) == "main"
+               && gogo->is_main_package())
+        is_visible = true;
+      // Methods have to be public even if they are hidden because
+      // they can be pulled into type descriptors when using
+      // anonymous fields.
+      else if (!Gogo::is_hidden_name(no->name())
+               || this->type_->is_method())
+        {
+          is_visible = true;
+          std::string pkgpath = gogo->pkgpath_symbol();
+          if (this->type_->is_method()
+              && Gogo::is_hidden_name(no->name())
+              && Gogo::hidden_name_pkgpath(no->name()) != gogo->pkgpath())
+            {
+              // This is a method we created for an unexported
+              // method of an imported embedded type.  We need to
+              // use the pkgpath of the imported package to avoid
+              // a possible name collision.  See bug478 for a test
+              // case.
+              pkgpath = Gogo::hidden_name_pkgpath(no->name());
+              pkgpath = Gogo::pkgpath_for_symbol(pkgpath);
+            }
+
+          asm_name = pkgpath;
+          asm_name.append(1, '.');
+          asm_name.append(Gogo::unpack_hidden_name(no->name()));
+          if (this->type_->is_method())
+            {
+              asm_name.append(1, '.');
+              Type* rtype = this->type_->receiver()->type();
+              asm_name.append(rtype->mangled_name(gogo));
+            }
+        }
 
-	  go_preserve_from_gc(decl);
-	}
+      // If a function calls the predeclared recover function, we
+      // can't inline it, because recover behaves differently in a
+      // function passed directly to defer.  If this is a recover
+      // thunk that we built to test whether a function can be
+      // recovered, we can't inline it, because that will mess up
+      // our return address comparison.
+      bool is_inlinable = !(this->calls_recover_ || this->is_recover_thunk_);
+
+      // If this is a thunk created to call a function which calls
+      // the predeclared recover function, we need to disable
+      // stack splitting for the thunk.
+      bool disable_split_stack = this->is_recover_thunk_;
+
+      Btype* functype = this->type_->get_backend_fntype(gogo);
+      this->fndecl_ =
+          gogo->backend()->function(functype, no->get_id(gogo), asm_name,
+                                    is_visible, false, is_inlinable,
+                                    disable_split_stack,
+                                    this->in_unique_section_, this->location());
     }
-  return this->fndecl_;
+  return function_to_tree(this->fndecl_);
 }
 
 // Get a tree for a function declaration.
 
 tree
-Function_declaration::get_or_make_decl(Gogo* gogo, Named_object* no, tree id)
+Function_declaration::get_or_make_decl(Gogo* gogo, Named_object* no)
 {
-  if (this->fndecl_ == NULL_TREE)
+  if (this->fndecl_ == NULL)
     {
       // Let Go code use an asm declaration to pick up a builtin
       // function.
@@ -1412,56 +1303,44 @@ Function_declaration::get_or_make_decl(Gogo* gogo, Named_object* no, tree id)
 	    builtin_functions.find(this->asm_name_);
 	  if (p != builtin_functions.end())
 	    {
-	      this->fndecl_ = p->second;
-	      return this->fndecl_;
+	      this->fndecl_ = tree_to_function(p->second);
+	      return p->second;
 	    }
 	}
 
-      tree functype = type_to_tree(this->fntype_->get_backend(gogo));
+      std::string asm_name;
+      if (this->asm_name_.empty())
+        {
+          asm_name = (no->package() == NULL
+                                  ? gogo->pkgpath_symbol()
+                                  : no->package()->pkgpath_symbol());
+          asm_name.append(1, '.');
+          asm_name.append(Gogo::unpack_hidden_name(no->name()));
+          if (this->fntype_->is_method())
+            {
+              asm_name.append(1, '.');
+              Type* rtype = this->fntype_->receiver()->type();
+              asm_name.append(rtype->mangled_name(gogo));
+            }
+        }
 
-      if (functype != error_mark_node)
-	{
-	  // The type of a function comes back as a pointer to a
-	  // struct whose first field is the function, but we want the
-	  // real function type for a function declaration.
-	  go_assert(POINTER_TYPE_P(functype)
-		    && TREE_CODE(TREE_TYPE(functype)) == RECORD_TYPE);
-	  functype = TREE_TYPE(TYPE_FIELDS(TREE_TYPE(functype)));
-	  go_assert(FUNCTION_POINTER_TYPE_P(functype));
-	  functype = TREE_TYPE(functype);
-	}
+      Btype* functype = this->fntype_->get_backend_fntype(gogo);
+      this->fndecl_ =
+          gogo->backend()->function(functype, no->get_id(gogo), asm_name,
+                                    true, true, true, false, false,
+                                    this->location());
+    }
 
-      tree decl;
-      if (functype == error_mark_node)
-	decl = error_mark_node;
-      else
-	{
-	  decl = build_decl(this->location().gcc_location(), FUNCTION_DECL, id,
-                            functype);
-	  TREE_PUBLIC(decl) = 1;
-	  DECL_EXTERNAL(decl) = 1;
+  return function_to_tree(this->fndecl_);
+}
 
-	  if (this->asm_name_.empty())
-	    {
-	      std::string asm_name = (no->package() == NULL
-				      ? gogo->pkgpath_symbol()
-				      : no->package()->pkgpath_symbol());
-	      asm_name.append(1, '.');
-	      asm_name.append(Gogo::unpack_hidden_name(no->name()));
-	      if (this->fntype_->is_method())
-		{
-		  asm_name.append(1, '.');
-		  Type* rtype = this->fntype_->receiver()->type();
-		  asm_name.append(rtype->mangled_name(gogo));
-		}
-	      SET_DECL_ASSEMBLER_NAME(decl,
-				      get_identifier_from_string(asm_name));
-	    }
-	}
-      this->fndecl_ = decl;
-      go_preserve_from_gc(decl);
-    }
-  return this->fndecl_;
+// Return the function's decl after it has been built.
+
+tree
+Function::get_decl() const
+{
+  go_assert(this->fndecl_ != NULL);
+  return function_to_tree(this->fndecl_);
 }
 
 // We always pass the receiver to a method as a pointer.  If the
@@ -1558,7 +1437,7 @@ Function::copy_parm_to_heap(Gogo* gogo, Named_object* no, tree var_decl)
 void
 Function::build_tree(Gogo* gogo, Named_object* named_function)
 {
-  tree fndecl = this->fndecl_;
+  tree fndecl = this->get_decl();
   go_assert(fndecl != NULL_TREE);
 
   tree params = NULL_TREE;
@@ -1796,7 +1675,7 @@ Function::build_defer_wrapper(Gogo* gogo, Named_object* named_function,
     set = NULL_TREE;
   else
     set = fold_build2_loc(end_loc.gcc_location(), MODIFY_EXPR, void_type_node,
-			  DECL_RESULT(this->fndecl_), retval);
+			  DECL_RESULT(this->get_decl()), retval);
   tree ret_stmt = fold_build1_loc(end_loc.gcc_location(), RETURN_EXPR,
                                   void_type_node, set);
   append_to_statement_list(ret_stmt, &stmt_list);
@@ -1851,7 +1730,7 @@ Function::build_defer_wrapper(Gogo* gogo, Named_object* named_function,
       retval = this->return_value(gogo, named_function, end_loc,
 				  &stmt_list);
       set = fold_build2_loc(end_loc.gcc_location(), MODIFY_EXPR, void_type_node,
-			    DECL_RESULT(this->fndecl_), retval);
+			    DECL_RESULT(this->get_decl()), retval);
       ret_stmt = fold_build1_loc(end_loc.gcc_location(), RETURN_EXPR,
                                  void_type_node, set);
 
@@ -1869,7 +1748,7 @@ Function::build_defer_wrapper(Gogo* gogo, Named_object* named_function,
   *fini = stmt_list;
 }
 
-// Return the value to assign to DECL_RESULT(this->fndecl_).  This may
+// Return the value to assign to DECL_RESULT(this->get_decl()).  This may
 // also add statements to STMT_LIST, which need to be executed before
 // the assignment.  This is used for a return statement with no
 // explicit values.
@@ -1902,7 +1781,7 @@ Function::return_value(Gogo* gogo, Named_object* named_function,
     }
   else
     {
-      tree rettype = TREE_TYPE(DECL_RESULT(this->fndecl_));
+      tree rettype = TREE_TYPE(DECL_RESULT(this->get_decl()));
       retval = create_tmp_var(rettype, "RESULT");
       tree field = TYPE_FIELDS(rettype);
       int index = 0;
@@ -2323,15 +2202,11 @@ Gogo::interface_method_table_for_type(const Interface_type* interface,
       go_assert(m != NULL);
 
       Named_object* no = m->named_object();
-
-      tree fnid = no->get_id(this);
-
       tree fndecl;
       if (no->is_function())
-	fndecl = no->func_value()->get_or_make_decl(this, no, fnid);
+	fndecl = no->func_value()->get_or_make_decl(this, no);
       else if (no->is_function_declaration())
-	fndecl = no->func_declaration_value()->get_or_make_decl(this, no,
-								fnid);
+	fndecl = no->func_declaration_value()->get_or_make_decl(this, no);
       else
 	go_unreachable();
       fndecl = build_fold_addr_expr(fndecl);
diff --git a/gcc/go/gofrontend/gogo.cc b/gcc/go/gofrontend/gogo.cc
index 9f918cb..a8f7754 100644
--- a/gcc/go/gofrontend/gogo.cc
+++ b/gcc/go/gofrontend/gogo.cc
@@ -5110,6 +5110,75 @@ Named_object::get_backend_variable(Gogo* gogo, Named_object* function)
     go_unreachable();
 }
 
+
+// Return the external identifier for this object.
+
+std::string
+Named_object::get_id(Gogo* gogo)
+{
+  go_assert(!this->is_variable() && !this->is_result_variable());
+  std::string decl_name;
+  if (this->is_function_declaration()
+      && !this->func_declaration_value()->asm_name().empty())
+    decl_name = this->func_declaration_value()->asm_name();
+  else if (this->is_type()
+	   && Linemap::is_predeclared_location(this->type_value()->location()))
+    {
+      // We don't need the package name for builtin types.
+      decl_name = Gogo::unpack_hidden_name(this->name_);
+    }
+  else
+    {
+      std::string package_name;
+      if (this->package_ == NULL)
+	package_name = gogo->package_name();
+      else
+	package_name = this->package_->package_name();
+
+      // Note that this will be misleading if this is an unexported
+      // method generated for an embedded imported type.  In that case
+      // the unexported method should have the package name of the
+      // package from which it is imported, but we are going to give
+      // it our package name.  Fixing this would require knowing the
+      // package name, but we only know the package path.  It might be
+      // better to use package paths here anyhow.  This doesn't affect
+      // the assembler code, because we always set that name in
+      // Function::get_or_make_decl anyhow.  FIXME.
+
+      decl_name = package_name + '.' + Gogo::unpack_hidden_name(this->name_);
+
+      Function_type* fntype;
+      if (this->is_function())
+	fntype = this->func_value()->type();
+      else if (this->is_function_declaration())
+	fntype = this->func_declaration_value()->type();
+      else
+	fntype = NULL;
+      if (fntype != NULL && fntype->is_method())
+	{
+	  decl_name.push_back('.');
+	  decl_name.append(fntype->receiver()->type()->mangled_name(gogo));
+	}
+    }
+  if (this->is_type())
+    {
+      unsigned int index;
+      const Named_object* in_function = this->type_value()->in_function(&index);
+      if (in_function != NULL)
+	{
+	  decl_name += '$' + Gogo::unpack_hidden_name(in_function->name());
+	  if (index > 0)
+	    {
+	      char buf[30];
+	      snprintf(buf, sizeof buf, "%u", index);
+	      decl_name += '$';
+	      decl_name += buf;
+	    }
+	}
+    }
+  return decl_name;
+}
+
 // Class Bindings.
 
 Bindings::Bindings(Bindings* enclosing)
diff --git a/gcc/go/gofrontend/gogo.h b/gcc/go/gofrontend/gogo.h
index 23968d4a..5b416b0 100644
--- a/gcc/go/gofrontend/gogo.h
+++ b/gcc/go/gofrontend/gogo.h
@@ -48,6 +48,7 @@ class Bstatement;
 class Bblock;
 class Bvariable;
 class Blabel;
+class Bfunction;
 
 // This file declares the basic classes used to hold the internal
 // representation of Go which is built by the parser.
@@ -1091,15 +1092,11 @@ class Function
 
   // Return the function's decl given an identifier.
   tree
-  get_or_make_decl(Gogo*, Named_object*, tree id);
+  get_or_make_decl(Gogo*, Named_object*);
 
   // Return the function's decl after it has been built.
   tree
-  get_decl() const
-  {
-    go_assert(this->fndecl_ != NULL);
-    return this->fndecl_;
-  }
+  get_decl() const;
 
   // Set the function decl to hold a tree of the function code.
   void
@@ -1170,7 +1167,7 @@ class Function
   // The function descriptor, if any.
   Expression* descriptor_;
   // The function decl.
-  tree fndecl_;
+  Bfunction* fndecl_;
   // The defer stack variable.  A pointer to this variable is used to
   // distinguish the defer stack for one function from another.  This
   // is NULL unless we actually need a defer stack.
@@ -1267,7 +1264,7 @@ class Function_declaration
 
   // Return a decl for the function given an identifier.
   tree
-  get_or_make_decl(Gogo*, Named_object*, tree id);
+  get_or_make_decl(Gogo*, Named_object*);
 
   // If there is a descriptor, build it into the backend
   // representation.
@@ -1290,7 +1287,7 @@ class Function_declaration
   // The function descriptor, if any.
   Expression* descriptor_;
   // The function decl if needed.
-  tree fndecl_;
+  Bfunction* fndecl_;
 };
 
 // A variable.
@@ -2181,8 +2178,8 @@ class Named_object
   Bvariable*
   get_backend_variable(Gogo*, Named_object* function);
 
-  // Return a tree for the external identifier for this object.
-  tree
+  // Return the external identifier for this object.
+  std::string
   get_id(Gogo*);
 
   // Return a tree representing this object.
diff --git a/gcc/go/gofrontend/types.cc b/gcc/go/gofrontend/types.cc
index 7fa84c5..f73ca7a 100644
--- a/gcc/go/gofrontend/types.cc
+++ b/gcc/go/gofrontend/types.cc
@@ -3383,6 +3383,68 @@ Function_type::do_hash_for_method(Gogo* gogo) const
 // Get the backend representation for a function type.
 
 Btype*
+Function_type::get_backend_fntype(Gogo* gogo)
+{
+  if (this->fnbtype_ == NULL)
+    {
+      Backend::Btyped_identifier breceiver;
+      if (this->receiver_ != NULL)
+        {
+          breceiver.name = Gogo::unpack_hidden_name(this->receiver_->name());
+
+          // We always pass the address of the receiver parameter, in
+          // order to make interface calls work with unknown types.
+          Type* rtype = this->receiver_->type();
+          if (rtype->points_to() == NULL)
+            rtype = Type::make_pointer_type(rtype);
+          breceiver.btype = rtype->get_backend(gogo);
+          breceiver.location = this->receiver_->location();
+        }
+
+      std::vector<Backend::Btyped_identifier> bparameters;
+      if (this->parameters_ != NULL)
+        {
+          bparameters.resize(this->parameters_->size());
+          size_t i = 0;
+          for (Typed_identifier_list::const_iterator p =
+                   this->parameters_->begin(); p != this->parameters_->end();
+               ++p, ++i)
+	    {
+              bparameters[i].name = Gogo::unpack_hidden_name(p->name());
+              bparameters[i].btype = p->type()->get_backend(gogo);
+              bparameters[i].location = p->location();
+            }
+          go_assert(i == bparameters.size());
+        }
+
+      std::vector<Backend::Btyped_identifier> bresults;
+      if (this->results_ != NULL)
+        {
+          bresults.resize(this->results_->size());
+          size_t i = 0;
+          for (Typed_identifier_list::const_iterator p =
+                   this->results_->begin(); p != this->results_->end();
+               ++p, ++i)
+	    {
+              bresults[i].name = Gogo::unpack_hidden_name(p->name());
+              bresults[i].btype = p->type()->get_backend(gogo);
+              bresults[i].location = p->location();
+            }
+          go_assert(i == bresults.size());
+        }
+
+      this->fnbtype_ = gogo->backend()->function_type(breceiver, bparameters,
+                                                      bresults,
+                                                      this->location());
+
+    }
+
+  return this->fnbtype_;
+}
+
+// Get the backend representation for a Go function type.
+
+Btype*
 Function_type::do_get_backend(Gogo* gogo)
 {
   // When we do anything with a function value other than call it, it
@@ -3395,57 +3457,9 @@ Function_type::do_get_backend(Gogo* gogo)
     gogo->backend()->placeholder_struct_type("__go_descriptor", loc);
   Btype* ptr_struct_type = gogo->backend()->pointer_type(struct_type);
 
-  Backend::Btyped_identifier breceiver;
-  if (this->receiver_ != NULL)
-    {
-      breceiver.name = Gogo::unpack_hidden_name(this->receiver_->name());
-
-      // We always pass the address of the receiver parameter, in
-      // order to make interface calls work with unknown types.
-      Type* rtype = this->receiver_->type();
-      if (rtype->points_to() == NULL)
-	rtype = Type::make_pointer_type(rtype);
-      breceiver.btype = rtype->get_backend(gogo);
-      breceiver.location = this->receiver_->location();
-    }
-
-  std::vector<Backend::Btyped_identifier> bparameters;
-  if (this->parameters_ != NULL)
-    {
-      bparameters.resize(this->parameters_->size());
-      size_t i = 0;
-      for (Typed_identifier_list::const_iterator p = this->parameters_->begin();
-	   p != this->parameters_->end();
-	   ++p, ++i)
-	{
-	  bparameters[i].name = Gogo::unpack_hidden_name(p->name());
-	  bparameters[i].btype = p->type()->get_backend(gogo);
-	  bparameters[i].location = p->location();
-	}
-      go_assert(i == bparameters.size());
-    }
-
-  std::vector<Backend::Btyped_identifier> bresults;
-  if (this->results_ != NULL)
-    {
-      bresults.resize(this->results_->size());
-      size_t i = 0;
-      for (Typed_identifier_list::const_iterator p = this->results_->begin();
-	   p != this->results_->end();
-	   ++p, ++i)
-	{
-	  bresults[i].name = Gogo::unpack_hidden_name(p->name());
-	  bresults[i].btype = p->type()->get_backend(gogo);
-	  bresults[i].location = p->location();
-	}
-      go_assert(i == bresults.size());
-    }
-
-  Btype* fntype = gogo->backend()->function_type(breceiver, bparameters,
-						 bresults, loc);
   std::vector<Backend::Btyped_identifier> fields(1);
   fields[0].name = "code";
-  fields[0].btype = fntype;
+  fields[0].btype = this->get_backend_fntype(gogo);
   fields[0].location = loc;
   if (!gogo->backend()->set_placeholder_struct_type(struct_type, fields))
     return gogo->backend()->error_type();
diff --git a/gcc/go/gofrontend/types.h b/gcc/go/gofrontend/types.h
index d8a3080..928c593 100644
--- a/gcc/go/gofrontend/types.h
+++ b/gcc/go/gofrontend/types.h
@@ -1717,7 +1717,8 @@ class Function_type : public Type
 		Typed_identifier_list* results, Location location)
     : Type(TYPE_FUNCTION),
       receiver_(receiver), parameters_(parameters), results_(results),
-      location_(location), is_varargs_(false), is_builtin_(false)
+      location_(location), is_varargs_(false), is_builtin_(false),
+      fnbtype_(NULL)
   { }
 
   // Get the receiver.
@@ -1798,6 +1799,11 @@ class Function_type : public Type
   static Type*
   make_function_type_descriptor_type();
 
+  // Return the backend representation of this function type. This is used
+  // as the real type of a backend function declaration or defintion.
+  Btype*
+  get_backend_fntype(Gogo*);
+
  protected:
   int
   do_traverse(Traverse*);
@@ -1851,6 +1857,9 @@ class Function_type : public Type
   // Whether this is a special builtin function which can not simply
   // be called.  This is used for len, cap, etc.
   bool is_builtin_;
+  // The backend representation of this type for backend function
+  // declarations and definitions.
+  Btype* fnbtype_;
 };
 
 // The type of a pointer.