Use backend interface for expression statements.

	* go-gcc.cc (Gcc_backend::expression_statement): New function.

From-SVN: r172051

gcc/go/ChangeLog

+2011-04-06  Ian Lance Taylor  <iant@google.com>
+
+	* go-gcc.cc (Gcc_backend::expression_statement): New function.
+
 2011-04-04  Ian Lance Taylor  <iant@google.com>
 
 	* go-gcc.c (class Blabel): Define.

gcc/go/go-gcc.cc

@@ -167,6 +167,9 @@ class Gcc_backend : public Backend
   // Statements.
 
   Bstatement*
+  expression_statement(Bexpression*);
+
+  Bstatement*
   assignment_statement(Bexpression* lhs, Bexpression* rhs, source_location);
 
   Bstatement*
@@ -206,6 +209,15 @@ get_identifier_from_string(const std::string& str)
 {
   return get_identifier_with_length(str.data(), str.length());
 }
+
+// An expression as a statement.
+
+Bstatement*
+Gcc_backend::expression_statement(Bexpression* expr)
+{
+  return this->make_statement(expr->get_tree());
+}
+
 // Assignment.
 
 Bstatement*

gcc/go/gofrontend/backend.h

@@ -107,6 +107,10 @@ class Backend
 
   // Statements.
 
+  // Create an expression statement.
+  virtual Bstatement*
+  expression_statement(Bexpression*) = 0;
+
   // Create an assignment statement.
   virtual Bstatement*
   assignment_statement(Bexpression* lhs, Bexpression* rhs,

gcc/go/gofrontend/statements.cc

@@ -1551,8 +1551,7 @@ class Expression_statement : public Statement
   do_may_fall_through() const;
 
   tree
-  do_get_tree(Translate_context* context)
-  { return this->expr_->get_tree(context); }
+  do_get_tree(Translate_context* context);
 
  private:
   Expression* expr_;
@@ -1589,6 +1588,17 @@ Expression_statement::do_may_fall_through() const
   return true;
 }
 
+// Convert to backend representation.
+
+tree
+Expression_statement::do_get_tree(Translate_context* context)
+{
+  tree expr_tree = this->expr_->get_tree(context);
+  Bexpression* bexpr = tree_to_expr(expr_tree);
+  Bstatement* ret = context->backend()->expression_statement(bexpr);
+  return statement_to_tree(ret);
+}
+
 // Make an expression statement from an Expression.
 
 Statement*