1 files changed, 96 insertions, 10 deletions

diff --git a/gcc/go/gofrontend/expressions.h b/gcc/go/gofrontend/expressions.h
index e3747cc..9f8f4e9 100644
--- a/gcc/go/gofrontend/expressions.h
+++ b/gcc/go/gofrontend/expressions.h
@@ -62,6 +62,7 @@ class Type_guard_expression;
 class Heap_expression;
 class Receive_expression;
 class Slice_value_expression;
+class Slice_info_expression;
 class Conditional_expression;
 class Compound_expression;
 class Numeric_constant;
@@ -731,6 +732,10 @@ class Expression
   call_expression()
   { return this->convert<Call_expression, EXPRESSION_CALL>(); }
 
+  const Call_expression*
+  call_expression() const
+  { return this->convert<const Call_expression, EXPRESSION_CALL>(); }
+
   // If this is a call_result expression, return the Call_result_expression
   // structure.  Otherwise, return NULL.  This is a controlled dynamic
   // cast.
@@ -900,6 +905,14 @@ class Expression
   compound_expression()
   { return this->convert<Compound_expression, EXPRESSION_COMPOUND>(); }
 
+  // If this is a slice info expression, return the
+  // Slice_info_expression structure.  Otherwise, return NULL.
+  Slice_info_expression*
+  slice_info_expression()
+  {
+    return this->convert<Slice_info_expression, EXPRESSION_SLICE_INFO>();
+  }
+
   // Return true if this is a composite literal.
   bool
   is_composite_literal() const;
@@ -2451,13 +2464,16 @@ class Call_expression : public Expression
 
   // Whether this is a call to builtin function.
   virtual bool
-  is_builtin()
+  is_builtin() const
   { return false; }
 
   // Convert to a Builtin_call_expression, or return NULL.
   inline Builtin_call_expression*
   builtin_call_expression();
 
+  inline const Builtin_call_expression*
+  builtin_call_expression() const;
+
  protected:
   int
   do_traverse(Traverse*);
@@ -2608,18 +2624,20 @@ class Builtin_call_expression : public Call_expression
       BUILTIN_RECOVER,
 
       // Builtin functions from the unsafe package.
+      BUILTIN_ADD,
       BUILTIN_ALIGNOF,
       BUILTIN_OFFSETOF,
-      BUILTIN_SIZEOF
+      BUILTIN_SIZEOF,
+      BUILTIN_SLICE
     };
 
   Builtin_function_code
-  code()
+  code() const
   { return this->code_; }
 
   // This overrides Call_expression::is_builtin.
   bool
-  is_builtin()
+  is_builtin() const
   { return true; }
 
   // Return whether EXPR, of array type, is a constant if passed to
@@ -2715,6 +2733,14 @@ Call_expression::builtin_call_expression()
           : NULL);
 }
 
+inline const Builtin_call_expression*
+Call_expression::builtin_call_expression() const
+{
+  return (this->is_builtin()
+          ? static_cast<const Builtin_call_expression*>(this)
+          : NULL);
+}
+
 // A single result from a call which returns multiple results.
 
 class Call_result_expression : public Expression
@@ -3806,9 +3832,6 @@ class Struct_construction_expression : public Expression,
   Expression*
   do_copy();
 
-  Expression*
-  do_flatten(Gogo*, Named_object*, Statement_inserter*);
-
   Bexpression*
   do_get_backend(Translate_context*);
 
@@ -3881,9 +3904,6 @@ protected:
   indexes()
   { return this->indexes_; }
 
-  Expression*
-  do_flatten(Gogo*, Named_object*, Statement_inserter*);
-
   // Get the backend constructor for the array values.
   Bexpression*
   get_constructor(Translate_context* context, Btype* btype);
@@ -4266,6 +4286,60 @@ class Slice_value_expression : public Expression
   Expression* cap_;
 };
 
+// An expression that evaluates to some characteristic of a slice.
+// This is used when indexing, bound-checking, or nil checking a slice.
+
+class Slice_info_expression : public Expression
+{
+ public:
+  Slice_info_expression(Expression* slice, Slice_info slice_info,
+                        Location location)
+    : Expression(EXPRESSION_SLICE_INFO, location),
+      slice_(slice), slice_info_(slice_info)
+  { }
+
+  // The slice operand of this slice info expression.
+  Expression*
+  slice() const
+  { return this->slice_; }
+
+  // The info this expression is about.
+  Slice_info
+  info() const
+  { return this->slice_info_; }
+
+ protected:
+  Type*
+  do_type();
+
+  void
+  do_determine_type(const Type_context*)
+  { }
+
+  Expression*
+  do_copy()
+  {
+    return new Slice_info_expression(this->slice_->copy(), this->slice_info_,
+                                     this->location());
+  }
+
+  Bexpression*
+  do_get_backend(Translate_context* context);
+
+  void
+  do_dump_expression(Ast_dump_context*) const;
+
+  void
+  do_issue_nil_check()
+  { this->slice_->issue_nil_check(); }
+
+ private:
+  // The slice for which we are getting information.
+  Expression* slice_;
+  // What information we want.
+  Slice_info slice_info_;
+};
+
 // Conditional expressions.
 
 class Conditional_expression : public Expression
@@ -4281,6 +4355,14 @@ class Conditional_expression : public Expression
   condition() const
   { return this->cond_; }
 
+  Expression*
+  then_expr() const
+  { return this->then_; }
+
+  Expression*
+  else_expr() const
+  { return this->else_; }
+
  protected:
   int
   do_traverse(Traverse*);
@@ -4326,6 +4408,10 @@ class Compound_expression : public Expression
   init() const
   { return this->init_; }
 
+  Expression*
+  expr() const
+  { return this->expr_; }
+
  protected:
   int
   do_traverse(Traverse*);