commit dd0d3426ac7ca0320978258c72d34eb4e4cec1a2
author Jamie Madill <jmadill@chromium.org> Wed Mar 26 14:01:56 2014 -0400
committer Jamie Madill <jmadill@chromium.org> Mon Mar 31 16:02:53 2014 +0000
tree 7629162c66e87ac59e4e5d1f032c672b878ecb0e
parent d19fae55ead928d372bfe6d0e6321046b6d01b18

Use a heap-memory traversal to free compiler resources.

The stack-memory traversal is prone to stack overflow. See the
WebGL conformance test long-expressions-should-not-crash.

BUG=angle:584

Change-Id: I02d72bc2e4101b7141d609c50303403ea8298e60
Reviewed-on: https://chromium-review.googlesource.com/191930
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Nicolas Capens <nicolascapens@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>

src/compiler/translator/intermediate.h

diff --git a/src/compiler/translator/intermediate.h b/src/compiler/translator/intermediate.h
index db3481c..b09fc9e 100644
--- a/src/compiler/translator/intermediate.h
+++ b/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 @@
     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 @@
     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 @@
     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 @@
     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 @@
 
     TIntermTyped* fold(TOperator, TIntermTyped*, TInfoSink&);
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const {}
+
 protected:
     ConstantUnion *unionArrayPointer;
 };
@@ -451,6 +464,8 @@
     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 @@
     void setUseEmulatedFunction() { useEmulatedFunction = true; }
     bool getUseEmulatedFunction() { return useEmulatedFunction; }
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const;
+
 protected:
     TIntermTyped* operand;
 
@@ -525,6 +542,8 @@
     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 @@
     TIntermNode* getFalseBlock() const { return falseBlock; }
     TIntermSelection* getAsSelectionNode() { return this; }
 
+    virtual void enqueueChildren(std::queue<TIntermNode*> *nodeQueue) const;
+
 protected:
     TIntermTyped* condition;
     TIntermNode* trueBlock;