Split out the DwarfException class into its own file. No functionality change,
though the classes have been marked with "VISIBILITY_HIDDEN".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71827 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfException.cpp b/lib/CodeGen/AsmPrinter/DwarfException.cpp
new file mode 100644
index 0000000..b68f521
--- /dev/null
+++ b/lib/CodeGen/AsmPrinter/DwarfException.cpp
@@ -0,0 +1,709 @@
+//===-- CodeGen/AsmPrinter/DwarfException.cpp - Dwarf Exception Impl ------===//
+//
+//                     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 dwarf exception info into asm files.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DwarfException.h"
+#include "llvm/Module.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineLocation.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/ADT/StringExtras.h"
+using namespace llvm;
+
+static TimerGroup &getDwarfTimerGroup() {
+  static TimerGroup DwarfTimerGroup("Dwarf Exception");
+  return DwarfTimerGroup;
+}
+
+void DwarfException::EmitCommonEHFrame(const Function *Personality,
+                                       unsigned Index) {
+  // Size and sign of stack growth.
+  int stackGrowth =
+    Asm->TM.getFrameInfo()->getStackGrowthDirection() ==
+    TargetFrameInfo::StackGrowsUp ?
+    TD->getPointerSize() : -TD->getPointerSize();
+
+  // Begin eh frame section.
+  Asm->SwitchToTextSection(TAI->getDwarfEHFrameSection());
+
+  if (!TAI->doesRequireNonLocalEHFrameLabel())
+    O << TAI->getEHGlobalPrefix();
+
+  O << "EH_frame" << Index << ":\n";
+  EmitLabel("section_eh_frame", Index);
+
+  // Define base labels.
+  EmitLabel("eh_frame_common", Index);
+
+  // Define the eh frame length.
+  EmitDifference("eh_frame_common_end", Index,
+                 "eh_frame_common_begin", Index, true);
+  Asm->EOL("Length of Common Information Entry");
+
+  // EH frame header.
+  EmitLabel("eh_frame_common_begin", Index);
+  Asm->EmitInt32((int)0);
+  Asm->EOL("CIE Identifier Tag");
+  Asm->EmitInt8(dwarf::DW_CIE_VERSION);
+  Asm->EOL("CIE Version");
+
+  // The personality presence indicates that language specific information will
+  // show up in the eh frame.
+  Asm->EmitString(Personality ? "zPLR" : "zR");
+  Asm->EOL("CIE Augmentation");
+
+  // Round out reader.
+  Asm->EmitULEB128Bytes(1);
+  Asm->EOL("CIE Code Alignment Factor");
+  Asm->EmitSLEB128Bytes(stackGrowth);
+  Asm->EOL("CIE Data Alignment Factor");
+  Asm->EmitInt8(RI->getDwarfRegNum(RI->getRARegister(), true));
+  Asm->EOL("CIE Return Address Column");
+
+  // If there is a personality, we need to indicate the functions location.
+  if (Personality) {
+    Asm->EmitULEB128Bytes(7);
+    Asm->EOL("Augmentation Size");
+
+    if (TAI->getNeedsIndirectEncoding()) {
+      Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 |
+                    dwarf::DW_EH_PE_indirect);
+      Asm->EOL("Personality (pcrel sdata4 indirect)");
+    } else {
+      Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
+      Asm->EOL("Personality (pcrel sdata4)");
+    }
+
+    PrintRelDirective(true);
+    O << TAI->getPersonalityPrefix();
+    Asm->EmitExternalGlobal((const GlobalVariable *)(Personality));
+    O << TAI->getPersonalitySuffix();
+    if (strcmp(TAI->getPersonalitySuffix(), "+4@GOTPCREL"))
+      O << "-" << TAI->getPCSymbol();
+    Asm->EOL("Personality");
+
+    Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
+    Asm->EOL("LSDA Encoding (pcrel sdata4)");
+
+    Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
+    Asm->EOL("FDE Encoding (pcrel sdata4)");
+  } else {
+    Asm->EmitULEB128Bytes(1);
+    Asm->EOL("Augmentation Size");
+
+    Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
+    Asm->EOL("FDE Encoding (pcrel sdata4)");
+  }
+
+  // Indicate locations of general callee saved registers in frame.
+  std::vector<MachineMove> Moves;
+  RI->getInitialFrameState(Moves);
+  EmitFrameMoves(NULL, 0, Moves, true);
+
+  // On Darwin the linker honors the alignment of eh_frame, which means it must
+  // be 8-byte on 64-bit targets to match what gcc does.  Otherwise you get
+  // holes which confuse readers of eh_frame.
+  Asm->EmitAlignment(TD->getPointerSize() == sizeof(int32_t) ? 2 : 3,
+                     0, 0, false);
+  EmitLabel("eh_frame_common_end", Index);
+
+  Asm->EOL();
+}
+
+/// EmitEHFrame - Emit function exception frame information.
+///
+void DwarfException::EmitEHFrame(const FunctionEHFrameInfo &EHFrameInfo) {
+  assert(!EHFrameInfo.function->hasAvailableExternallyLinkage() && 
+         "Should not emit 'available externally' functions at all");
+
+  Function::LinkageTypes linkage = EHFrameInfo.function->getLinkage();
+  Asm->SwitchToTextSection(TAI->getDwarfEHFrameSection());
+
+  // Externally visible entry into the functions eh frame info. If the
+  // corresponding function is static, this should not be externally visible.
+  if (linkage != Function::InternalLinkage &&
+      linkage != Function::PrivateLinkage) {
+    if (const char *GlobalEHDirective = TAI->getGlobalEHDirective())
+      O << GlobalEHDirective << EHFrameInfo.FnName << "\n";
+  }
+
+  // If corresponding function is weak definition, this should be too.
+  if ((linkage == Function::WeakAnyLinkage ||
+       linkage == Function::WeakODRLinkage ||
+       linkage == Function::LinkOnceAnyLinkage ||
+       linkage == Function::LinkOnceODRLinkage) &&
+      TAI->getWeakDefDirective())
+    O << TAI->getWeakDefDirective() << EHFrameInfo.FnName << "\n";
+
+  // If there are no calls then you can't unwind.  This may mean we can omit the
+  // EH Frame, but some environments do not handle weak absolute symbols. If
+  // UnwindTablesMandatory is set we cannot do this optimization; the unwind
+  // info is to be available for non-EH uses.
+  if (!EHFrameInfo.hasCalls &&
+      !UnwindTablesMandatory &&
+      ((linkage != Function::WeakAnyLinkage &&
+        linkage != Function::WeakODRLinkage &&
+        linkage != Function::LinkOnceAnyLinkage &&
+        linkage != Function::LinkOnceODRLinkage) ||
+       !TAI->getWeakDefDirective() ||
+       TAI->getSupportsWeakOmittedEHFrame())) {
+    O << EHFrameInfo.FnName << " = 0\n";
+    // This name has no connection to the function, so it might get
+    // dead-stripped when the function is not, erroneously.  Prohibit
+    // dead-stripping unconditionally.
+    if (const char *UsedDirective = TAI->getUsedDirective())
+      O << UsedDirective << EHFrameInfo.FnName << "\n\n";
+  } else {
+    O << EHFrameInfo.FnName << ":\n";
+
+    // EH frame header.
+    EmitDifference("eh_frame_end", EHFrameInfo.Number,
+                   "eh_frame_begin", EHFrameInfo.Number, true);
+    Asm->EOL("Length of Frame Information Entry");
+
+    EmitLabel("eh_frame_begin", EHFrameInfo.Number);
+
+    if (TAI->doesRequireNonLocalEHFrameLabel()) {
+      PrintRelDirective(true, true);
+      PrintLabelName("eh_frame_begin", EHFrameInfo.Number);
+
+      if (!TAI->isAbsoluteEHSectionOffsets())
+        O << "-EH_frame" << EHFrameInfo.PersonalityIndex;
+    } else {
+      EmitSectionOffset("eh_frame_begin", "eh_frame_common",
+                        EHFrameInfo.Number, EHFrameInfo.PersonalityIndex,
+                        true, true, false);
+    }
+
+    Asm->EOL("FDE CIE offset");
+
+    EmitReference("eh_func_begin", EHFrameInfo.Number, true, true);
+    Asm->EOL("FDE initial location");
+    EmitDifference("eh_func_end", EHFrameInfo.Number,
+                   "eh_func_begin", EHFrameInfo.Number, true);
+    Asm->EOL("FDE address range");
+
+    // If there is a personality and landing pads then point to the language
+    // specific data area in the exception table.
+    if (EHFrameInfo.PersonalityIndex) {
+      Asm->EmitULEB128Bytes(4);
+      Asm->EOL("Augmentation size");
+
+      if (EHFrameInfo.hasLandingPads)
+        EmitReference("exception", EHFrameInfo.Number, true, true);
+      else
+        Asm->EmitInt32((int)0);
+      Asm->EOL("Language Specific Data Area");
+    } else {
+      Asm->EmitULEB128Bytes(0);
+      Asm->EOL("Augmentation size");
+    }
+
+    // Indicate locations of function specific callee saved registers in frame.
+    EmitFrameMoves("eh_func_begin", EHFrameInfo.Number, EHFrameInfo.Moves, 
+                   true);
+
+    // On Darwin the linker honors the alignment of eh_frame, which means it
+    // must be 8-byte on 64-bit targets to match what gcc does.  Otherwise you
+    // get holes which confuse readers of eh_frame.
+    Asm->EmitAlignment(TD->getPointerSize() == sizeof(int32_t) ? 2 : 3,
+                       0, 0, false);
+    EmitLabel("eh_frame_end", EHFrameInfo.Number);
+
+    // If the function is marked used, this table should be also.  We cannot
+    // make the mark unconditional in this case, since retaining the table also
+    // retains the function in this case, and there is code around that depends
+    // on unused functions (calling undefined externals) being dead-stripped to
+    // link correctly.  Yes, there really is.
+    if (MMI->getUsedFunctions().count(EHFrameInfo.function))
+      if (const char *UsedDirective = TAI->getUsedDirective())
+        O << UsedDirective << EHFrameInfo.FnName << "\n\n";
+  }
+}
+
+/// EmitExceptionTable - 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 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.
+
+/// SharedTypeIds - How many leading type ids two landing pads have in common.
+unsigned DwarfException::SharedTypeIds(const LandingPadInfo *L,
+                                       const LandingPadInfo *R) {
+  const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
+  unsigned LSize = LIds.size(), RSize = RIds.size();
+  unsigned MinSize = LSize < RSize ? LSize : RSize;
+  unsigned Count = 0;
+
+  for (; Count != MinSize; ++Count)
+    if (LIds[Count] != RIds[Count])
+      return Count;
+
+  return Count;
+}
+
+/// PadLT - Order landing pads lexicographically by type id.
+bool DwarfException::PadLT(const LandingPadInfo *L, const LandingPadInfo *R) {
+  const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
+  unsigned LSize = LIds.size(), RSize = RIds.size();
+  unsigned MinSize = LSize < RSize ? LSize : RSize;
+
+  for (unsigned i = 0; i != MinSize; ++i)
+    if (LIds[i] != RIds[i])
+      return LIds[i] < RIds[i];
+
+  return LSize < RSize;
+}
+
+void DwarfException::EmitExceptionTable() {
+  const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
+  const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
+  const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
+  if (PadInfos.empty()) return;
+
+  // Sort the landing pads in order of their type ids.  This is used to fold
+  // duplicate actions.
+  SmallVector<const LandingPadInfo *, 64> LandingPads;
+  LandingPads.reserve(PadInfos.size());
+  for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
+    LandingPads.push_back(&PadInfos[i]);
+  std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
+
+  // Negative type ids index into FilterIds, positive type ids index into
+  // TypeInfos.  The value written for a positive type id is just the type id
+  // itself.  For a negative type id, however, the value written is the
+  // (negative) byte offset of the corresponding FilterIds entry.  The byte
+  // offset is usually equal to the type id, because the FilterIds entries are
+  // written using a variable width encoding which outputs one byte per entry as
+  // long as the value written is not too large, but can differ.  This kind of
+  // complication does not occur for positive type ids because type infos are
+  // output using a fixed width encoding.  FilterOffsets[i] holds the byte
+  // offset corresponding to FilterIds[i].
+  SmallVector<int, 16> FilterOffsets;
+  FilterOffsets.reserve(FilterIds.size());
+  int Offset = -1;
+  for(std::vector<unsigned>::const_iterator I = FilterIds.begin(),
+        E = FilterIds.end(); I != E; ++I) {
+    FilterOffsets.push_back(Offset);
+    Offset -= TargetAsmInfo::getULEB128Size(*I);
+  }
+
+  // Compute the actions table and gather the first action index for each
+  // landing pad site.
+  SmallVector<ActionEntry, 32> Actions;
+  SmallVector<unsigned, 64> FirstActions;
+  FirstActions.reserve(LandingPads.size());
+
+  int FirstAction = 0;
+  unsigned SizeActions = 0;
+  for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
+    const LandingPadInfo *LP = LandingPads[i];
+    const std::vector<int> &TypeIds = LP->TypeIds;
+    const unsigned NumShared = i ? SharedTypeIds(LP, LandingPads[i-1]) : 0;
+    unsigned SizeSiteActions = 0;
+
+    if (NumShared < TypeIds.size()) {
+      unsigned SizeAction = 0;
+      ActionEntry *PrevAction = 0;
+
+      if (NumShared) {
+        const unsigned SizePrevIds = LandingPads[i-1]->TypeIds.size();
+        assert(Actions.size());
+        PrevAction = &Actions.back();
+        SizeAction = TargetAsmInfo::getSLEB128Size(PrevAction->NextAction) +
+          TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
+
+        for (unsigned j = NumShared; j != SizePrevIds; ++j) {
+          SizeAction -=
+            TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
+          SizeAction += -PrevAction->NextAction;
+          PrevAction = PrevAction->Previous;
+        }
+      }
+
+      // Compute the actions.
+      for (unsigned I = NumShared, M = TypeIds.size(); I != M; ++I) {
+        int TypeID = TypeIds[I];
+        assert(-1-TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
+        int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
+        unsigned SizeTypeID = TargetAsmInfo::getSLEB128Size(ValueForTypeID);
+
+        int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
+        SizeAction = SizeTypeID + TargetAsmInfo::getSLEB128Size(NextAction);
+        SizeSiteActions += SizeAction;
+
+        ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
+        Actions.push_back(Action);
+
+        PrevAction = &Actions.back();
+      }
+
+      // Record the first action of the landing pad site.
+      FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
+    } // else identical - re-use previous FirstAction
+
+    FirstActions.push_back(FirstAction);
+
+    // Compute this sites contribution to size.
+    SizeActions += SizeSiteActions;
+  }
+
+  // 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.
+  SmallVector<CallSiteEntry, 64> CallSites;
+
+  RangeMapType PadMap;
+
+  // Invokes and nounwind calls have entries in PadMap (due to being bracketed
+  // by try-range labels when lowered).  Ordinary calls do not, so appropriate
+  // try-ranges for them need be deduced.
+  for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
+    const LandingPadInfo *LandingPad = LandingPads[i];
+    for (unsigned j = 0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
+      unsigned BeginLabel = LandingPad->BeginLabels[j];
+      assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
+      PadRange P = { i, j };
+      PadMap[BeginLabel] = P;
+    }
+  }
+
+  // The end label of the previous invoke or nounwind try-range.
+  unsigned LastLabel = 0;
+
+  // Whether there is a potentially throwing instruction (currently this means
+  // an ordinary call) between the end of the previous try-range and now.
+  bool SawPotentiallyThrowing = false;
+
+  // Whether the last callsite entry was for an invoke.
+  bool PreviousIsInvoke = false;
+
+  // Visit all instructions in order of address.
+  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
+       I != E; ++I) {
+    for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
+         MI != E; ++MI) {
+      if (!MI->isLabel()) {
+        SawPotentiallyThrowing |= MI->getDesc().isCall();
+        continue;
+      }
+
+      unsigned BeginLabel = MI->getOperand(0).getImm();
+      assert(BeginLabel && "Invalid label!");
+
+      // End of the previous try-range?
+      if (BeginLabel == LastLabel)
+        SawPotentiallyThrowing = false;
+
+      // Beginning of a new try-range?
+      RangeMapType::iterator L = PadMap.find(BeginLabel);
+      if (L == PadMap.end())
+        // Nope, it was just some random label.
+        continue;
+
+      PadRange P = L->second;
+      const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
+
+      assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
+             "Inconsistent landing pad map!");
+
+      // If some instruction between the previous try-range and this one may
+      // throw, create a call-site entry with no landing pad for the region
+      // between the try-ranges.
+      if (SawPotentiallyThrowing) {
+        CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
+        CallSites.push_back(Site);
+        PreviousIsInvoke = false;
+      }
+
+      LastLabel = LandingPad->EndLabels[P.RangeIndex];
+      assert(BeginLabel && LastLabel && "Invalid landing pad!");
+
+      if (LandingPad->LandingPadLabel) {
+        // This try-range is for an invoke.
+        CallSiteEntry Site = {BeginLabel, LastLabel,
+                              LandingPad->LandingPadLabel,
+                              FirstActions[P.PadIndex]};
+
+        // Try to merge with the previous call-site.
+        if (PreviousIsInvoke) {
+          CallSiteEntry &Prev = CallSites.back();
+          if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
+            // Extend the range of the previous entry.
+            Prev.EndLabel = Site.EndLabel;
+            continue;
+          }
+        }
+
+        // Otherwise, create a new call-site.
+        CallSites.push_back(Site);
+        PreviousIsInvoke = true;
+      } else {
+        // Create a gap.
+        PreviousIsInvoke = false;
+      }
+    }
+  }
+
+  // If some instruction between the previous try-range and the end of the
+  // function may throw, create a call-site entry with no landing pad for the
+  // region following the try-range.
+  if (SawPotentiallyThrowing) {
+    CallSiteEntry Site = {LastLabel, 0, 0, 0};
+    CallSites.push_back(Site);
+  }
+
+  // Final tallies.
+
+  // Call sites.
+  const unsigned SiteStartSize  = sizeof(int32_t); // DW_EH_PE_udata4
+  const unsigned SiteLengthSize = sizeof(int32_t); // DW_EH_PE_udata4
+  const unsigned LandingPadSize = sizeof(int32_t); // DW_EH_PE_udata4
+  unsigned SizeSites = CallSites.size() * (SiteStartSize +
+                                           SiteLengthSize +
+                                           LandingPadSize);
+  for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
+    SizeSites += TargetAsmInfo::getULEB128Size(CallSites[i].Action);
+
+  // Type infos.
+  const unsigned TypeInfoSize = TD->getPointerSize(); // DW_EH_PE_absptr
+  unsigned SizeTypes = TypeInfos.size() * TypeInfoSize;
+
+  unsigned TypeOffset = sizeof(int8_t) + // Call site format
+    TargetAsmInfo::getULEB128Size(SizeSites) + // Call-site table length
+    SizeSites + SizeActions + SizeTypes;
+
+  unsigned TotalSize = sizeof(int8_t) + // LPStart format
+                       sizeof(int8_t) + // TType format
+           TargetAsmInfo::getULEB128Size(TypeOffset) + // TType base offset
+                       TypeOffset;
+
+  unsigned SizeAlign = (4 - TotalSize) & 3;
+
+  // Begin the exception table.
+  Asm->SwitchToDataSection(TAI->getDwarfExceptionSection());
+  Asm->EmitAlignment(2, 0, 0, false);
+  O << "GCC_except_table" << SubprogramCount << ":\n";
+
+  for (unsigned i = 0; i != SizeAlign; ++i) {
+    Asm->EmitInt8(0);
+    Asm->EOL("Padding");
+    }
+
+  EmitLabel("exception", SubprogramCount);
+
+  // Emit the header.
+  Asm->EmitInt8(dwarf::DW_EH_PE_omit);
+  Asm->EOL("LPStart format (DW_EH_PE_omit)");
+  Asm->EmitInt8(dwarf::DW_EH_PE_absptr);
+  Asm->EOL("TType format (DW_EH_PE_absptr)");
+  Asm->EmitULEB128Bytes(TypeOffset);
+  Asm->EOL("TType base offset");
+  Asm->EmitInt8(dwarf::DW_EH_PE_udata4);
+  Asm->EOL("Call site format (DW_EH_PE_udata4)");
+  Asm->EmitULEB128Bytes(SizeSites);
+  Asm->EOL("Call-site table length");
+
+  // Emit the landing pad site information.
+  for (unsigned i = 0; i < CallSites.size(); ++i) {
+    CallSiteEntry &S = CallSites[i];
+    const char *BeginTag;
+    unsigned BeginNumber;
+
+    if (!S.BeginLabel) {
+      BeginTag = "eh_func_begin";
+      BeginNumber = SubprogramCount;
+    } else {
+      BeginTag = "label";
+      BeginNumber = S.BeginLabel;
+    }
+
+    EmitSectionOffset(BeginTag, "eh_func_begin", BeginNumber, SubprogramCount,
+                      true, true);
+    Asm->EOL("Region start");
+
+    if (!S.EndLabel)
+      EmitDifference("eh_func_end", SubprogramCount, BeginTag, BeginNumber,
+                     true);
+    else
+      EmitDifference("label", S.EndLabel, BeginTag, BeginNumber, true);
+
+    Asm->EOL("Region length");
+
+    if (!S.PadLabel)
+      Asm->EmitInt32(0);
+    else
+      EmitSectionOffset("label", "eh_func_begin", S.PadLabel, SubprogramCount,
+                        true, true);
+
+    Asm->EOL("Landing pad");
+
+    Asm->EmitULEB128Bytes(S.Action);
+    Asm->EOL("Action");
+  }
+
+  // Emit the actions.
+  for (unsigned I = 0, N = Actions.size(); I != N; ++I) {
+    ActionEntry &Action = Actions[I];
+
+    Asm->EmitSLEB128Bytes(Action.ValueForTypeID);
+    Asm->EOL("TypeInfo index");
+    Asm->EmitSLEB128Bytes(Action.NextAction);
+    Asm->EOL("Next action");
+  }
+
+  // Emit the type ids.
+  for (unsigned M = TypeInfos.size(); M; --M) {
+    GlobalVariable *GV = TypeInfos[M - 1];
+    PrintRelDirective();
+
+    if (GV) {
+      std::string GLN;
+      O << Asm->getGlobalLinkName(GV, GLN);
+    } else {
+      O << "0";
+    }
+
+    Asm->EOL("TypeInfo");
+  }
+
+  // Emit the filter typeids.
+  for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) {
+    unsigned TypeID = FilterIds[j];
+    Asm->EmitULEB128Bytes(TypeID);
+    Asm->EOL("Filter TypeInfo index");
+  }
+
+  Asm->EmitAlignment(2, 0, 0, false);
+}
+
+  //===--------------------------------------------------------------------===//
+  // Main entry points.
+  //
+DwarfException::DwarfException(raw_ostream &OS, AsmPrinter *A,
+                               const TargetAsmInfo *T)
+  : Dwarf(OS, A, T, "eh"), shouldEmitTable(false), shouldEmitMoves(false),
+    shouldEmitTableModule(false), shouldEmitMovesModule(false),
+    ExceptionTimer(0) {
+  if (TimePassesIsEnabled) 
+    ExceptionTimer = new Timer("Dwarf Exception Writer",
+                               getDwarfTimerGroup());
+}
+
+DwarfException::~DwarfException() {
+  delete ExceptionTimer;
+}
+
+/// EndModule - Emit all exception information that should come after the
+/// content.
+void DwarfException::EndModule() {
+  if (TimePassesIsEnabled)
+    ExceptionTimer->startTimer();
+
+  if (shouldEmitMovesModule || shouldEmitTableModule) {
+    const std::vector<Function *> Personalities = MMI->getPersonalities();
+    for (unsigned i = 0; i < Personalities.size(); ++i)
+      EmitCommonEHFrame(Personalities[i], i);
+
+    for (std::vector<FunctionEHFrameInfo>::iterator I = EHFrames.begin(),
+           E = EHFrames.end(); I != E; ++I)
+      EmitEHFrame(*I);
+  }
+
+  if (TimePassesIsEnabled)
+    ExceptionTimer->stopTimer();
+}
+
+/// BeginFunction - Gather pre-function exception information.  Assumes being
+/// emitted immediately after the function entry point.
+void DwarfException::BeginFunction(MachineFunction *MF) {
+  if (TimePassesIsEnabled)
+    ExceptionTimer->startTimer();
+
+  this->MF = MF;
+  shouldEmitTable = shouldEmitMoves = false;
+
+  if (MMI && TAI->doesSupportExceptionHandling()) {
+    // Map all labels and get rid of any dead landing pads.
+    MMI->TidyLandingPads();
+
+    // If any landing pads survive, we need an EH table.
+    if (MMI->getLandingPads().size())
+      shouldEmitTable = true;
+
+    // See if we need frame move info.
+    if (!MF->getFunction()->doesNotThrow() || UnwindTablesMandatory)
+      shouldEmitMoves = true;
+
+    if (shouldEmitMoves || shouldEmitTable)
+      // Assumes in correct section after the entry point.
+      EmitLabel("eh_func_begin", ++SubprogramCount);
+  }
+
+  shouldEmitTableModule |= shouldEmitTable;
+  shouldEmitMovesModule |= shouldEmitMoves;
+
+  if (TimePassesIsEnabled)
+    ExceptionTimer->stopTimer();
+}
+
+/// EndFunction - Gather and emit post-function exception information.
+///
+void DwarfException::EndFunction() {
+  if (TimePassesIsEnabled) 
+    ExceptionTimer->startTimer();
+
+  if (shouldEmitMoves || shouldEmitTable) {
+    EmitLabel("eh_func_end", SubprogramCount);
+    EmitExceptionTable();
+
+    // Save EH frame information
+    std::string Name;
+    EHFrames.push_back(
+        FunctionEHFrameInfo(getAsm()->getCurrentFunctionEHName(MF, Name),
+                            SubprogramCount,
+                            MMI->getPersonalityIndex(),
+                            MF->getFrameInfo()->hasCalls(),
+                            !MMI->getLandingPads().empty(),
+                            MMI->getFrameMoves(),
+                            MF->getFunction()));
+  }
+
+  if (TimePassesIsEnabled) 
+    ExceptionTimer->stopTimer();
+}