blob: 92a6874eb7be7cb0e7ffccd59eadbc0b547848c3 [file] [log] [blame]
//
// 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 "compiler/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;
}