Initial import from TransGaming
git-svn-id: https://angleproject.googlecode.com/svn/trunk@2 736b8ea6-26fd-11df-bfd4-992fa37f6226
diff --git a/Compiler/QualifierAlive.cpp b/Compiler/QualifierAlive.cpp
new file mode 100644
index 0000000..e47fd6f
--- /dev/null
+++ b/Compiler/QualifierAlive.cpp
@@ -0,0 +1,58 @@
+//
+// Copyright (c) 2002-2010 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+#include "intermediate.h"
+
+class TAliveTraverser : public TIntermTraverser {
+public:
+ TAliveTraverser(TQualifier q) : TIntermTraverser(true, false, false, true), found(false), qualifier(q)
+ {
+ }
+
+ bool wasFound() { return found; }
+
+protected:
+ bool found;
+ TQualifier qualifier;
+
+ void visitSymbol(TIntermSymbol*);
+ bool visitSelection(Visit, TIntermSelection*);
+};
+
+//
+// Report whether or not a variable of the given qualifier type
+// is guaranteed written. Not always possible to determine if
+// it is written conditionally.
+//
+// ?? It does not do this well yet, this is just a place holder
+// that simply determines if it was reference at all, anywhere.
+//
+bool QualifierWritten(TIntermNode* node, TQualifier qualifier)
+{
+ TAliveTraverser it(qualifier);
+
+ if (node)
+ node->traverse(&it);
+
+ return it.wasFound();
+}
+
+void TAliveTraverser::visitSymbol(TIntermSymbol* node)
+{
+ //
+ // If it's what we're looking for, record it.
+ //
+ if (node->getQualifier() == qualifier)
+ found = true;
+}
+
+bool TAliveTraverser::visitSelection(Visit preVisit, TIntermSelection* node)
+{
+ if (wasFound())
+ return false;
+
+ return true;
+}