Use a heap-memory traversal to free compiler resources.

src/compiler/translator/Intermediate.cpp

@@ -786,6 +786,26 @@ bool TIntermLoop::replaceChildNode(
     return false;
 }
 
+void TIntermLoop::enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const
+{
+    if (init)
+    {
+        nodeQueue->push(init);
+    }
+    if (cond)
+    {
+        nodeQueue->push(cond);
+    }
+    if (expr)
+    {
+        nodeQueue->push(expr);
+    }
+    if (body)
+    {
+        nodeQueue->push(body);
+    }
+}
+
 bool TIntermBranch::replaceChildNode(
     TIntermNode *original, TIntermNode *replacement)
 {
@@ -793,6 +813,14 @@ bool TIntermBranch::replaceChildNode(
     return false;
 }
 
+void TIntermBranch::enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const
+{
+    if (expression)
+    {
+        nodeQueue->push(expression);
+    }
+}
+
 bool TIntermBinary::replaceChildNode(
     TIntermNode *original, TIntermNode *replacement)
 {
@@ -801,6 +829,18 @@ bool TIntermBinary::replaceChildNode(
     return false;
 }
 
+void TIntermBinary::enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const
+{
+    if (left)
+    {
+        nodeQueue->push(left);
+    }
+    if (right)
+    {
+        nodeQueue->push(right);
+    }
+}
+
 bool TIntermUnary::replaceChildNode(
     TIntermNode *original, TIntermNode *replacement)
 {
@@ -808,6 +848,14 @@ bool TIntermUnary::replaceChildNode(
     return false;
 }
 
+void TIntermUnary::enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const
+{
+    if (operand)
+    {
+        nodeQueue->push(operand);
+    }
+}
+
 bool TIntermAggregate::replaceChildNode(
     TIntermNode *original, TIntermNode *replacement)
 {
@@ -818,6 +866,14 @@ bool TIntermAggregate::replaceChildNode(
     return false;
 }
 
+void TIntermAggregate::enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const
+{
+    for (size_t childIndex = 0; childIndex < sequence.size(); childIndex++)
+    {
+        nodeQueue->push(sequence[childIndex]);
+    }
+}
+
 bool TIntermSelection::replaceChildNode(
     TIntermNode *original, TIntermNode *replacement)
 {
@@ -827,6 +883,22 @@ bool TIntermSelection::replaceChildNode(
     return false;
 }
 
+void TIntermSelection::enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const
+{
+    if (condition)
+    {
+        nodeQueue->push(condition);
+    }
+    if (trueBlock)
+    {
+        nodeQueue->push(trueBlock);
+    }
+    if (falseBlock)
+    {
+        nodeQueue->push(falseBlock);
+    }
+}
+
 //
 // Say whether or not an operation node changes the value of a variable.
 //

src/compiler/translator/RemoveTree.cpp

@@ -8,70 +8,22 @@
 #include "compiler/translator/RemoveTree.h"
 
 //
-// Code to recursively delete the intermediate tree.
+// Code to delete the intermediate tree.
 //
-
-class RemoveTree : public TIntermTraverser
-{
-public:
-	RemoveTree() : TIntermTraverser(false, false, true)
-	{
-	}
-
-protected:
-	void visitSymbol(TIntermSymbol*);
-	void visitConstantUnion(TIntermConstantUnion*);
-	bool visitBinary(Visit visit, TIntermBinary*);
-	bool visitUnary(Visit visit, TIntermUnary*);
-	bool visitSelection(Visit visit, TIntermSelection*);
-	bool visitAggregate(Visit visit, TIntermAggregate*);
-};
-
-void RemoveTree::visitSymbol(TIntermSymbol* node)
-{
-	delete node;
-}
-
-bool RemoveTree::visitBinary(Visit visit, TIntermBinary* node)
-{
-	delete node;
-
-	return true;
-}
-
-bool RemoveTree::visitUnary(Visit visit, TIntermUnary* node)
-{
-    delete node;
-
-	return true;
-}
-
-bool RemoveTree::visitAggregate(Visit visit, TIntermAggregate* node)
+void RemoveAllTreeNodes(TIntermNode* root)
 {
-	delete node;
+    std::queue<TIntermNode*> nodeQueue;
 
-	return true;
-}
+    nodeQueue.push(root);
 
-bool RemoveTree::visitSelection(Visit visit, TIntermSelection* node)
-{
-	delete node;
+    while (!nodeQueue.empty())
+    {
+        TIntermNode *node = nodeQueue.front();
+        nodeQueue.pop();
 
-	return true;
-}
-
-void RemoveTree::visitConstantUnion(TIntermConstantUnion* node)
-{
-	delete node;
-}
-
-//
-// Entry point.
-//
-void RemoveAllTreeNodes(TIntermNode* root)
-{
-    RemoveTree it;
+        node->enqueueChildren(&nodeQueue);
 
-    root->traverse(&it);
+        delete node;
+    }
 }
 

src/compiler/translator/intermediate.h

@@ -19,6 +19,7 @@
 #include "GLSLANG/ShaderLang.h"
 
 #include <algorithm>
+#include <queue>
 #include "compiler/translator/Common.h"
 #include "compiler/translator/Types.h"
 #include "compiler/translator/ConstantUnion.h"
@@ -243,6 +244,10 @@ public:
     virtual bool replaceChildNode(
         TIntermNode *original, TIntermNode *replacement) = 0;
 
+    // For traversing a tree in no particular order, but using
+    // heap memory.
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const = 0;
+
 protected:
     TSourceLoc line;
 };
@@ -328,6 +333,8 @@ public:
     void setUnrollFlag(bool flag) { unrollFlag = flag; }
     bool getUnrollFlag() { return unrollFlag; }
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const;
+
 protected:
     TLoopType type;
     TIntermNode* init;  // for-loop initialization
@@ -354,6 +361,8 @@ public:
     TOperator getFlowOp() { return flowOp; }
     TIntermTyped* getExpression() { return expression; }
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const;
+
 protected:
     TOperator flowOp;
     TIntermTyped* expression;  // non-zero except for "return exp;" statements
@@ -381,6 +390,8 @@ public:
     virtual TIntermSymbol* getAsSymbolNode() { return this; }
     virtual bool replaceChildNode(TIntermNode *, TIntermNode *) { return false; }
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const {}
+
 protected:
     int id;
     TString symbol;
@@ -405,6 +416,8 @@ public:
 
     TIntermTyped* fold(TOperator, TIntermTyped*, TInfoSink&);
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const {}
+
 protected:
     ConstantUnion *unionArrayPointer;
 };
@@ -451,6 +464,8 @@ public:
     void setAddIndexClamp() { addIndexClamp = true; }
     bool getAddIndexClamp() { return addIndexClamp; }
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const;
+
 protected:
     TIntermTyped* left;
     TIntermTyped* right;
@@ -481,6 +496,8 @@ public:
     void setUseEmulatedFunction() { useEmulatedFunction = true; }
     bool getUseEmulatedFunction() { return useEmulatedFunction; }
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const;
+
 protected:
     TIntermTyped* operand;
 
@@ -525,6 +542,8 @@ public:
     void setUseEmulatedFunction() { useEmulatedFunction = true; }
     bool getUseEmulatedFunction() { return useEmulatedFunction; }
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const;
+
 protected:
     TIntermAggregate(const TIntermAggregate&); // disallow copy constructor
     TIntermAggregate& operator=(const TIntermAggregate&); // disallow assignment operator
@@ -563,6 +582,8 @@ public:
     TIntermNode* getFalseBlock() const { return falseBlock; }
     TIntermSelection* getAsSelectionNode() { return this; }
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const;
+
 protected:
     TIntermTyped* condition;
     TIntermNode* trueBlock;