Merge 'wip/next' into dev

Change-Id: Iff9ee5e23bb326c4371ec8ed81d56f2f05d680e9

1 files changed, 52 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/dfg/DFGLiveCatchVariablePreservationPhase.h b/Source/JavaScriptCore/dfg/DFGLiveCatchVariablePreservationPhase.h
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+++ b/Source/JavaScriptCore/dfg/DFGLiveCatchVariablePreservationPhase.h
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+/*
+ * Copyright (C) 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef DFGLiveCatchVariablePreservationPhase_h
+#define DFGLiveCatchVariablePreservationPhase_h
+
+#if ENABLE(DFG_JIT)
+
+namespace JSC { namespace DFG {
+
+class Graph;
+
+// This phase ensures that we maintain liveness for locals
+// that are live in the "catch" block. Because a "catch"
+// block will not be in the control flow graph, we need to ensure
+// anything live inside the "catch" block in bytecode will maintain 
+// liveness inside the "try" block for an OSR exit from the "try" 
+// block into the "catch" block in the case of an exception being thrown.
+//
+// The mechanism currently used to demonstrate liveness to OSR exit
+// is ensuring all variables live in a "catch" are flushed to the
+// stack inside the "try" block.
+
+bool performLiveCatchVariablePreservationPhase(Graph&);
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)
+
+#endif // DFGLiveCatchVariablePreservationPhase_h