code review 88950043: compiler: Use backend interface for constant expressions.

compiler: Use backend interface for constant expressions.

[cmang, 2014-04-17 17:41:35]

Hello iant@golang.org (cc: gofrontend-dev@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/gofrontend

[cmang, 2014-04-17 17:41:55]

On 2014/04/17 17:41:35, cmang wrote:
> Hello mailto:iant@golang.org (cc: mailto:gofrontend-dev@googlegroups.com),
> 
> I'd like you to review this change to
> https://code.google.com/p/gofrontend

Diff of gcc/go/go-gcc.cc:

Index: gcc/go/go-gcc.cc
======================================================================
--- a/gcc/go/go-gcc.cc
+++ b/gcc/go/go-gcc.cc
@@ -227,6 +227,10 @@ class Gcc_backend : public Backend
   indirect_expression(Bexpression* expr, bool known_valid, Location);
 
   Bexpression*
+  named_constant_expression(Btype* btype, const std::string& name,
+			    Bexpression* val, Location);
+
+  Bexpression*
   integer_constant_expression(Btype* btype, mpz_t val);
 
   Bexpression*
@@ -962,6 +966,29 @@ Gcc_backend::indirect_expression(Bexpression* expr, bool
known_valid,
   return tree_to_expr(ret);
 }
 
+// Return an expression that declares a constant named NAME with the
+// constant value VAL in BTYPE.
+
+Bexpression*
+Gcc_backend::named_constant_expression(Btype* btype, const std::string& name,
+				       Bexpression* val, Location location)
+{
+  tree type_tree = btype->get_tree();
+  tree const_val = val->get_tree();
+  if (type_tree == error_mark_node || const_val == error_mark_node)
+    return this->error_expression();
+
+  tree name_tree = get_identifier_from_string(name);
+  tree decl = build_decl(location.gcc_location(), CONST_DECL, name_tree,
+			 type_tree);
+  DECL_INITIAL(decl) = const_val;
+  TREE_CONSTANT(decl) = 1;
+  TREE_READONLY(decl) = 1;
+
+  go_preserve_from_gc(decl);
+  return this->make_expression(decl);
+}
+
 // Return a typed value as a constant integer.
 
 Bexpression*

[iant, 2014-04-17 20:39:58]

LGTM

[iant, 2014-04-17 20:40:43]

*** Submitted as
https://code.google.com/p/gofrontend/source/detail?r=65e8167d03ec ***

compiler: Use backend interface for constant expressions.

R=iant
CC=gofrontend-dev
https://codereview.appspot.com/88950043

Committer: Ian Lance Taylor <iant@golang.org>