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diff --git a/lib/CodeGen/AsmPrinter/EHStreamer.h b/lib/CodeGen/AsmPrinter/EHStreamer.h
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+++ b/lib/CodeGen/AsmPrinter/EHStreamer.h
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+//===-- EHStreamer.h - Exception Handling Directive Streamer ---*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for writing exception info into assembly files.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_ASMPRINTER_EHSTREAMER_H
+#define LLVM_CODEGEN_ASMPRINTER_EHSTREAMER_H
+
+#include "AsmPrinterHandler.h"
+#include "llvm/ADT/DenseMap.h"
+
+namespace llvm {
+struct LandingPadInfo;
+class MachineModuleInfo;
+class MachineInstr;
+class MachineFunction;
+class AsmPrinter;
+
+template <typename T>
+class SmallVectorImpl;
+
+/// Emits exception handling directives.
+class EHStreamer : public AsmPrinterHandler {
+protected:
+  /// Target of directive emission.
+  AsmPrinter *Asm;
+
+  /// Collected machine module information.
+  MachineModuleInfo *MMI;
+
+  /// How many leading type ids two landing pads have in common.
+  static unsigned sharedTypeIDs(const LandingPadInfo *L,
+                                const LandingPadInfo *R);
+
+  /// Structure holding a try-range and the associated landing pad.
+  struct PadRange {
+    // The index of the landing pad.
+    unsigned PadIndex;
+    // The index of the begin and end labels in the landing pad's label lists.
+    unsigned RangeIndex;
+  };
+
+  typedef DenseMap<MCSymbol *, PadRange> RangeMapType;
+
+  /// Structure describing an entry in the actions table.
+  struct ActionEntry {
+    int ValueForTypeID; // The value to write - may not be equal to the type id.
+    int NextAction;
+    unsigned Previous;
+  };
+
+  /// Structure describing an entry in the call-site table.
+  struct CallSiteEntry {
+    // The 'try-range' is BeginLabel .. EndLabel.
+    MCSymbol *BeginLabel; // zero indicates the start of the function.
+    MCSymbol *EndLabel;   // zero indicates the end of the function.
+
+    // The landing pad starts at PadLabel.
+    MCSymbol *PadLabel;   // zero indicates that there is no landing pad.
+    unsigned Action;
+  };
+
+  /// Compute the actions table and gather the first action index for each
+  /// landing pad site.
+  unsigned computeActionsTable(const SmallVectorImpl<const LandingPadInfo*>&LPs,
+                               SmallVectorImpl<ActionEntry> &Actions,
+                               SmallVectorImpl<unsigned> &FirstActions);
+
+  /// Return `true' if this is a call to a function marked `nounwind'. Return
+  /// `false' otherwise.
+  bool callToNoUnwindFunction(const MachineInstr *MI);
+
+  /// Compute the call-site table.  The entry for an invoke has a try-range
+  /// containing the call, a non-zero landing pad and an appropriate action.
+  /// The entry for an ordinary call has a try-range containing the call and
+  /// zero for the landing pad and the action.  Calls marked 'nounwind' have
+  /// no entry and must not be contained in the try-range of any entry - they
+  /// form gaps in the table.  Entries must be ordered by try-range address.
+
+  void computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
+                            const RangeMapType &PadMap,
+                            const SmallVectorImpl<const LandingPadInfo *> &LPs,
+                            const SmallVectorImpl<unsigned> &FirstActions);
+
+  /// Emit landing pads and actions.
+  ///
+  /// The general organization of the table is complex, but the basic concepts
+  /// are easy.  First there is a header which describes the location and
+  /// organization of the three components that follow.
+  ///  1. The landing pad site information describes the range of code covered
+  ///     by the try.  In our case it's an accumulation of the ranges covered
+  ///     by the invokes in the try.  There is also a reference to the landing
+  ///     pad that handles the exception once processed.  Finally an index into
+  ///     the actions table.
+  ///  2. The action table, in our case, is composed of pairs of type ids
+  ///     and next action offset.  Starting with the action index from the
+  ///     landing pad site, each type Id is checked for a match to the current
+  ///     exception.  If it matches then the exception and type id are passed
+  ///     on to the landing pad.  Otherwise the next action is looked up.  This
+  ///     chain is terminated with a next action of zero.  If no type id is
+  ///     found the frame is unwound and handling continues.
+  ///  3. Type id table contains references to all the C++ typeinfo for all
+  ///     catches in the function.  This tables is reversed indexed base 1.
+  void emitExceptionTable();
+
+  virtual void emitTypeInfos(unsigned TTypeEncoding);
+
+public:
+  EHStreamer(AsmPrinter *A);
+  virtual ~EHStreamer();
+
+  /// Emit all exception information that should come after the content.
+  void endModule() override;
+
+  /// Gather pre-function exception information.  Assumes being emitted
+  /// immediately after the function entry point.
+  void beginFunction(const MachineFunction *MF) override;
+
+  /// Gather and emit post-function exception information.
+  void endFunction(const MachineFunction *) override;
+
+  // Unused.
+  void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override {}
+  void beginInstruction(const MachineInstr *MI) override {}
+  void endInstruction() override {}
+};
+}
+
+#endif
+