1 files changed, 51 insertions, 0 deletions
diff --git a/src/3rdparty/angle/src/compiler/translator/IsASTDepthBelowLimit.cpp b/src/3rdparty/angle/src/compiler/translator/IsASTDepthBelowLimit.cpp
new file mode 100644
index 0000000000..aaad4f3c68
--- /dev/null
+++ b/src/3rdparty/angle/src/compiler/translator/IsASTDepthBelowLimit.cpp
@@ -0,0 +1,51 @@
+//
+// Copyright (c) 2017 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/translator/IsASTDepthBelowLimit.h"
+
+#include "compiler/translator/IntermTraverse.h"
+
+namespace sh
+{
+
+namespace
+{
+
+// Traverse the tree and compute max depth. Takes a maximum depth limit to prevent stack overflow.
+class MaxDepthTraverser : public TIntermTraverser
+{
+  public:
+    MaxDepthTraverser(int depthLimit) : TIntermTraverser(true, true, false), mDepthLimit(depthLimit)
+    {
+    }
+
+    bool visitBinary(Visit, TIntermBinary *) override { return depthCheck(); }
+    bool visitUnary(Visit, TIntermUnary *) override { return depthCheck(); }
+    bool visitTernary(Visit, TIntermTernary *) override { return depthCheck(); }
+    bool visitSwizzle(Visit, TIntermSwizzle *) override { return depthCheck(); }
+    bool visitIfElse(Visit, TIntermIfElse *) override { return depthCheck(); }
+    bool visitAggregate(Visit, TIntermAggregate *) override { return depthCheck(); }
+    bool visitBlock(Visit, TIntermBlock *) override { return depthCheck(); }
+    bool visitLoop(Visit, TIntermLoop *) override { return depthCheck(); }
+    bool visitBranch(Visit, TIntermBranch *) override { return depthCheck(); }
+
+  protected:
+    bool depthCheck() const { return mMaxDepth < mDepthLimit; }
+
+    int mDepthLimit;
+};
+
+}  // anonymous namespace
+
+bool IsASTDepthBelowLimit(TIntermNode *root, int maxDepth)
+{
+    MaxDepthTraverser traverser(maxDepth + 1);
+    root->traverse(&traverser);
+
+    return traverser.getMaxDepth() <= maxDepth;
+}
+
+}  // namespace sh