Remove unused right-to-left AST traversal support

src/compiler/translator/IntermNode.h

@@ -588,12 +588,10 @@ class TIntermTraverser : angle::NonCopyable
   public:
     POOL_ALLOCATOR_NEW_DELETE();
     // TODO(zmo): remove default values.
-    TIntermTraverser(bool preVisit = true, bool inVisit = false, bool postVisit = false,
-                     bool rightToLeft = false)
+    TIntermTraverser(bool preVisit = true, bool inVisit = false, bool postVisit = false)
         : preVisit(preVisit),
           inVisit(inVisit),
           postVisit(postVisit),
-          rightToLeft(rightToLeft),
           mDepth(0),
           mMaxDepth(0),
           mTemporaryIndex(nullptr)
@@ -649,7 +647,6 @@ class TIntermTraverser : angle::NonCopyable
     const bool preVisit;
     const bool inVisit;
     const bool postVisit;
-    const bool rightToLeft;
 
     // If traversers need to replace nodes, they can add the replacements in
     // mReplacements/mMultiReplacements during traversal and the user of the traverser should call
@@ -766,7 +763,7 @@ class TMaxDepthTraverser : public TIntermTraverser
   public:
     POOL_ALLOCATOR_NEW_DELETE();
     TMaxDepthTraverser(int depthLimit)
-        : TIntermTraverser(true, true, false, false),
+        : TIntermTraverser(true, true, false),
           mDepthLimit(depthLimit) { }
 
     virtual bool visitBinary(Visit, TIntermBinary *) { return depthCheck(); }

src/compiler/translator/IntermTraverse.cpp

@@ -9,17 +9,11 @@
 
 void TIntermTraverser::pushParentBlock(TIntermAggregate *node)
 {
-    if (rightToLeft)
-        mParentBlockStack.push_back(ParentBlock(node, node->getSequence()->size() - 1));
-    else
     mParentBlockStack.push_back(ParentBlock(node, 0));
 }
 
 void TIntermTraverser::incrementParentBlockPos()
 {
-    if (rightToLeft)
-        --mParentBlockStack.back().pos;
-    else
     ++mParentBlockStack.back().pos;
 }
 
@@ -102,9 +96,6 @@ void TIntermTraverser::nextTemporaryIndex()
 // if preVisit is turned on and the type specific function
 // returns false.
 //
-// preVisit, postVisit, and rightToLeft control what order
-// nodes are visited in.
-//
 
 //
 // Traversal functions for terminals are straighforward....
@@ -139,19 +130,6 @@ void TIntermBinary::traverse(TIntermTraverser *it)
     {
         it->incrementDepth(this);
 
-        if (it->rightToLeft)
-        {
-            if (mRight)
-                mRight->traverse(it);
-
-            if (it->inVisit)
-                visit = it->visitBinary(InVisit, this);
-
-            if (visit && mLeft)
-                mLeft->traverse(it);
-        }
-        else
-        {
         if (mLeft)
             mLeft->traverse(it);
 
@@ -160,7 +138,6 @@ void TIntermBinary::traverse(TIntermTraverser *it)
 
         if (visit && mRight)
             mRight->traverse(it);
-        }
 
         it->decrementDepth();
     }
@@ -210,26 +187,6 @@ void TIntermAggregate::traverse(TIntermTraverser *it)
 
         it->incrementDepth(this);
 
-        if (it->rightToLeft)
-        {
-            for (TIntermSequence::reverse_iterator sit = mSequence.rbegin();
-                 sit != mSequence.rend(); sit++)
-            {
-                (*sit)->traverse(it);
-
-                if (visit && it->inVisit)
-                {
-                    if (*sit != mSequence.front())
-                        visit = it->visitAggregate(InVisit, this);
-                }
-                if (mOp == EOpSequence)
-                {
-                    it->incrementParentBlockPos();
-                }
-            }
-        }
-        else
-        {
         for (TIntermSequence::iterator sit = mSequence.begin();
                 sit != mSequence.end(); sit++)
         {
@@ -245,7 +202,6 @@ void TIntermAggregate::traverse(TIntermTraverser *it)
                 it->incrementParentBlockPos();
             }
         }
-        }
 
         it->decrementDepth();
 
@@ -270,22 +226,11 @@ void TIntermSelection::traverse(TIntermTraverser *it)
     if (visit)
     {
         it->incrementDepth(this);
-        if (it->rightToLeft)
-        {
-            if (mFalseBlock)
-                mFalseBlock->traverse(it);
-            if (mTrueBlock)
-                mTrueBlock->traverse(it);
-            mCondition->traverse(it);
-        }
-        else
-        {
         mCondition->traverse(it);
         if (mTrueBlock)
             mTrueBlock->traverse(it);
         if (mFalseBlock)
             mFalseBlock->traverse(it);
-        }
         it->decrementDepth();
     }
 
@@ -306,23 +251,11 @@ void TIntermSwitch::traverse(TIntermTraverser *it)
     if (visit)
     {
         it->incrementDepth(this);
-        if (it->rightToLeft)
-        {
-            if (mStatementList)
-                mStatementList->traverse(it);
-            if (it->inVisit)
-                visit = it->visitSwitch(InVisit, this);
-            if (visit)
-                mInit->traverse(it);
-        }
-        else
-        {
         mInit->traverse(it);
         if (it->inVisit)
             visit = it->visitSwitch(InVisit, this);
         if (visit && mStatementList)
             mStatementList->traverse(it);
-        }
         it->decrementDepth();
     }
 
@@ -361,22 +294,6 @@ void TIntermLoop::traverse(TIntermTraverser *it)
     {
         it->incrementDepth(this);
 
-        if (it->rightToLeft)
-        {
-            if (mExpr)
-                mExpr->traverse(it);
-
-            if (mBody)
-                mBody->traverse(it);
-
-            if (mCond)
-                mCond->traverse(it);
-
-            if (mInit)
-                mInit->traverse(it);
-        }
-        else
-        {
         if (mInit)
             mInit->traverse(it);
 
@@ -388,7 +305,6 @@ void TIntermLoop::traverse(TIntermTraverser *it)
 
         if (mExpr)
             mExpr->traverse(it);
-        }
 
         it->decrementDepth();
     }

src/compiler/translator/RewriteElseBlocks.cpp

@@ -40,7 +40,7 @@ TIntermUnary *MakeNewUnary(TOperator op, TIntermTyped *operand)
 }
 
 ElseBlockRewriter::ElseBlockRewriter()
-    : TIntermTraverser(true, false, true, false),
+    : TIntermTraverser(true, false, true),
       mTemporaryIndex(0),
       mFunctionType(NULL)
 {}