1 files changed, 132 insertions, 0 deletions
diff --git a/src/3rdparty/angle/src/compiler/translator/WrapSwitchStatementsInBlocks.cpp b/src/3rdparty/angle/src/compiler/translator/WrapSwitchStatementsInBlocks.cpp
new file mode 100644
index 0000000000..85a11c998d
--- /dev/null
+++ b/src/3rdparty/angle/src/compiler/translator/WrapSwitchStatementsInBlocks.cpp
@@ -0,0 +1,132 @@
+//
+// 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.
+//
+// WrapSwitchStatementsInBlocks.cpp: Wrap switch statements in blocks and declare all switch-scoped
+// variables there to make the AST compatible with HLSL output.
+//
+// switch (init)
+// {
+//     case 0:
+//         float f;
+//     default:
+//         f = 1.0;
+// }
+//
+// becomes
+//
+// {
+//     float f;
+//     switch (init)
+//     {
+//         case 0:
+//         default:
+//             f = 1.0;
+//     }
+// }
+
+#include "compiler/translator/WrapSwitchStatementsInBlocks.h"
+
+#include "compiler/translator/IntermNode.h"
+#include "compiler/translator/IntermTraverse.h"
+
+namespace sh
+{
+
+namespace
+{
+
+class WrapSwitchStatementsInBlocksTraverser : public TIntermTraverser
+{
+  public:
+    WrapSwitchStatementsInBlocksTraverser() : TIntermTraverser(true, false, false), mDidWrap(false)
+    {
+    }
+
+    bool visitSwitch(Visit visit, TIntermSwitch *node) override;
+
+    bool didWrap() const { return mDidWrap; }
+
+  private:
+    bool mDidWrap;
+};
+
+bool WrapSwitchStatementsInBlocksTraverser::visitSwitch(Visit, TIntermSwitch *node)
+{
+    std::vector<TIntermDeclaration *> declarations;
+    TIntermSequence *statementList = node->getStatementList()->getSequence();
+    for (TIntermNode *statement : *statementList)
+    {
+        TIntermDeclaration *asDeclaration = statement->getAsDeclarationNode();
+        if (asDeclaration)
+        {
+            declarations.push_back(asDeclaration);
+        }
+    }
+    if (declarations.empty())
+    {
+        // We don't need to wrap the switch if it doesn't contain declarations as its direct
+        // descendants.
+        return true;
+    }
+
+    TIntermBlock *wrapperBlock = new TIntermBlock();
+    for (TIntermDeclaration *declaration : declarations)
+    {
+        // SeparateDeclarations should have already been run.
+        ASSERT(declaration->getSequence()->size() == 1);
+
+        TIntermDeclaration *declarationInBlock = new TIntermDeclaration();
+        TIntermSymbol *declaratorAsSymbol = declaration->getSequence()->at(0)->getAsSymbolNode();
+        if (declaratorAsSymbol)
+        {
+            // This is a simple declaration like: "float f;"
+            // Remove the declaration from inside the switch and put it in the wrapping block.
+            TIntermSequence emptyReplacement;
+            mMultiReplacements.push_back(NodeReplaceWithMultipleEntry(
+                node->getStatementList(), declaration, emptyReplacement));
+
+            declarationInBlock->appendDeclarator(declaratorAsSymbol->deepCopy());
+        }
+        else
+        {
+            // This is an init declaration like: "float f = 0.0;"
+            // Change the init declaration inside the switch into an assignment and put a plain
+            // declaration in the wrapping block.
+            TIntermBinary *declaratorAsBinary =
+                declaration->getSequence()->at(0)->getAsBinaryNode();
+            ASSERT(declaratorAsBinary);
+
+            TIntermBinary *initAssignment = new TIntermBinary(
+                EOpAssign, declaratorAsBinary->getLeft(), declaratorAsBinary->getRight());
+
+            queueReplacementWithParent(node->getStatementList(), declaration, initAssignment,
+                                       OriginalNode::IS_DROPPED);
+
+            declarationInBlock->appendDeclarator(declaratorAsBinary->getLeft()->deepCopy());
+        }
+        wrapperBlock->appendStatement(declarationInBlock);
+    }
+
+    wrapperBlock->appendStatement(node);
+    queueReplacement(wrapperBlock, OriginalNode::BECOMES_CHILD);
+    mDidWrap = true;
+
+    // Should be fine to process multiple switch statements, even nesting ones in the same
+    // traversal.
+    return true;
+}
+
+}  // anonymous namespace
+
+// Wrap switch statements in the AST into blocks when needed.
+bool WrapSwitchStatementsInBlocks(TIntermBlock *root)
+{
+    WrapSwitchStatementsInBlocksTraverser traverser;
+    root->traverse(&traverser);
+    traverser.updateTree();
+    return traverser.didWrap();
+}
+
+}  // namespace sh