1 files changed, 174 insertions, 0 deletions
diff --git a/gfx/angle/src/compiler/translator/RemoveSwitchFallThrough.cpp b/gfx/angle/src/compiler/translator/RemoveSwitchFallThrough.cpp
new file mode 100755
index 000000000..dd995af47
--- /dev/null
+++ b/gfx/angle/src/compiler/translator/RemoveSwitchFallThrough.cpp
@@ -0,0 +1,174 @@
+//
+// Copyright (c) 2002-2015 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/RemoveSwitchFallThrough.h"
+
+namespace sh
+{
+
+TIntermBlock *RemoveSwitchFallThrough::removeFallThrough(TIntermBlock *statementList)
+{
+    RemoveSwitchFallThrough rm(statementList);
+    ASSERT(statementList);
+    statementList->traverse(&rm);
+    bool lastStatementWasBreak = rm.mLastStatementWasBreak;
+    rm.mLastStatementWasBreak = true;
+    rm.handlePreviousCase();
+    if (!lastStatementWasBreak)
+    {
+        TIntermBranch *finalBreak = new TIntermBranch(EOpBreak, nullptr);
+        rm.mStatementListOut->getSequence()->push_back(finalBreak);
+    }
+    return rm.mStatementListOut;
+}
+
+RemoveSwitchFallThrough::RemoveSwitchFallThrough(TIntermBlock *statementList)
+    : TIntermTraverser(true, false, false),
+      mStatementList(statementList),
+      mLastStatementWasBreak(false),
+      mPreviousCase(nullptr)
+{
+    mStatementListOut = new TIntermBlock();
+}
+
+void RemoveSwitchFallThrough::visitSymbol(TIntermSymbol *node)
+{
+    // Note that this assumes that switch statements which don't begin by a case statement
+    // have already been weeded out in validation.
+    mPreviousCase->getSequence()->push_back(node);
+    mLastStatementWasBreak = false;
+}
+
+void RemoveSwitchFallThrough::visitConstantUnion(TIntermConstantUnion *node)
+{
+    // Conditions of case labels are not traversed, so this is some other constant
+    // Could be just a statement like "0;"
+    mPreviousCase->getSequence()->push_back(node);
+    mLastStatementWasBreak = false;
+}
+
+bool RemoveSwitchFallThrough::visitBinary(Visit, TIntermBinary *node)
+{
+    mPreviousCase->getSequence()->push_back(node);
+    mLastStatementWasBreak = false;
+    return false;
+}
+
+bool RemoveSwitchFallThrough::visitUnary(Visit, TIntermUnary *node)
+{
+    mPreviousCase->getSequence()->push_back(node);
+    mLastStatementWasBreak = false;
+    return false;
+}
+
+bool RemoveSwitchFallThrough::visitTernary(Visit, TIntermTernary *node)
+{
+    mPreviousCase->getSequence()->push_back(node);
+    mLastStatementWasBreak = false;
+    return false;
+}
+
+bool RemoveSwitchFallThrough::visitIfElse(Visit, TIntermIfElse *node)
+{
+    mPreviousCase->getSequence()->push_back(node);
+    mLastStatementWasBreak = false;
+    return false;
+}
+
+bool RemoveSwitchFallThrough::visitSwitch(Visit, TIntermSwitch *node)
+{
+    mPreviousCase->getSequence()->push_back(node);
+    mLastStatementWasBreak = false;
+    // Don't go into nested switch statements
+    return false;
+}
+
+void RemoveSwitchFallThrough::outputSequence(TIntermSequence *sequence, size_t startIndex)
+{
+    for (size_t i = startIndex; i < sequence->size(); ++i)
+    {
+        mStatementListOut->getSequence()->push_back(sequence->at(i));
+    }
+}
+
+void RemoveSwitchFallThrough::handlePreviousCase()
+{
+    if (mPreviousCase)
+        mCasesSharingBreak.push_back(mPreviousCase);
+    if (mLastStatementWasBreak)
+    {
+        bool labelsWithNoStatements = true;
+        for (size_t i = 0; i < mCasesSharingBreak.size(); ++i)
+        {
+            if (mCasesSharingBreak.at(i)->getSequence()->size() > 1)
+            {
+                labelsWithNoStatements = false;
+            }
+            if (labelsWithNoStatements)
+            {
+                // Fall-through is allowed in case the label has no statements.
+                outputSequence(mCasesSharingBreak.at(i)->getSequence(), 0);
+            }
+            else
+            {
+                // Include all the statements that this case can fall through under the same label.
+                for (size_t j = i; j < mCasesSharingBreak.size(); ++j)
+                {
+                    size_t startIndex = j > i ? 1 : 0; // Add the label only from the first sequence.
+                    outputSequence(mCasesSharingBreak.at(j)->getSequence(), startIndex);
+
+                }
+            }
+        }
+        mCasesSharingBreak.clear();
+    }
+    mLastStatementWasBreak = false;
+    mPreviousCase = nullptr;
+}
+
+bool RemoveSwitchFallThrough::visitCase(Visit, TIntermCase *node)
+{
+    handlePreviousCase();
+    mPreviousCase = new TIntermBlock();
+    mPreviousCase->getSequence()->push_back(node);
+    // Don't traverse the condition of the case statement
+    return false;
+}
+
+bool RemoveSwitchFallThrough::visitAggregate(Visit, TIntermAggregate *node)
+{
+    mPreviousCase->getSequence()->push_back(node);
+    mLastStatementWasBreak = false;
+    return false;
+}
+
+bool RemoveSwitchFallThrough::visitBlock(Visit, TIntermBlock *node)
+{
+    if (node != mStatementList)
+    {
+        mPreviousCase->getSequence()->push_back(node);
+        mLastStatementWasBreak = false;
+        return false;
+    }
+    return true;
+}
+
+bool RemoveSwitchFallThrough::visitLoop(Visit, TIntermLoop *node)
+{
+    mPreviousCase->getSequence()->push_back(node);
+    mLastStatementWasBreak = false;
+    return false;
+}
+
+bool RemoveSwitchFallThrough::visitBranch(Visit, TIntermBranch *node)
+{
+    mPreviousCase->getSequence()->push_back(node);
+    // TODO: Verify that accepting return or continue statements here doesn't cause problems.
+    mLastStatementWasBreak = true;
+    return false;
+}
+
+}  // namespace sh