MFC 261991:

Upgrade our copy of llvm/clang to 3.4 release.  This version supports
all of the features in the current working draft of the upcoming C++
standard, provisionally named C++1y.

The code generator's performance is greatly increased, and the loop
auto-vectorizer is now enabled at -Os and -O2 in addition to -O3.  The
PowerPC backend has made several major improvements to code generation
quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
backends have all seen major feature work.

Release notes for llvm and clang can be found here:
<http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>

MFC 262121 (by emaste):

Update lldb for clang/llvm 3.4 import

This commit largely restores the lldb source to the upstream r196259
snapshot with the addition of threaded inferior support and a few bug
fixes.

Specific upstream lldb revisions restored include:
   SVN      git
  181387  779e6ac
  181703  7bef4e2
  182099  b31044e
  182650  f2dcf35
  182683  0d91b80
  183862  15c1774
  183929  99447a6
  184177  0b2934b
  184948  4dc3761
  184954  007e7bc
  186990  eebd175

Sponsored by:	DARPA, AFRL

MFC 262186 (by emaste):

Fix mismerge in r262121

A break statement was lost in the merge.  The error had no functional
impact, but restore it to reduce the diff against upstream.

MFC 262303:

Pull in r197521 from upstream clang trunk (by rdivacky):

  Use the integrated assembler by default on FreeBSD/ppc and ppc64.

Requested by:	jhibbits

MFC 262611:

Pull in r196874 from upstream llvm trunk:

  Fix a crash that occurs when PWD is invalid.

  MCJIT needs to be able to run in hostile environments, even when PWD
  is invalid. There's no need to crash MCJIT in this case.

  The obvious fix is to simply leave MCContext's CompilationDir empty
  when PWD can't be determined. This way, MCJIT clients,
  and other clients that link with LLVM don't need a valid working directory.

  If we do want to guarantee valid CompilationDir, that should be done
  only for clients of getCompilationDir(). This is as simple as checking
  for an empty string.

  The only current use of getCompilationDir is EmitGenDwarfInfo, which
  won't conceivably run with an invalid working dir. However, in the
  purely hypothetically and untestable case that this happens, the
  AT_comp_dir will be omitted from the compilation_unit DIE.

This should help fix assertions occurring with ports-mgmt/tinderbox,
when it is using jails, and sometimes invalidates clang's current
working directory.

Reported by:	decke

MFC 262809:

Pull in r203007 from upstream clang trunk:

  Don't produce an alias between destructors with different calling conventions.

  Fixes pr19007.

(Please note that is an LLVM PR identifier, not a FreeBSD one.)

This should fix Firefox and/or libxul crashes (due to problems with
regparm/stdcall calling conventions) on i386.

Reported by:	multiple users on freebsd-current
PR:		bin/187103

MFC 263048:

Repair recognition of "CC" as an alias for the C++ compiler, since it
was silently broken by upstream for a Windows-specific use-case.

Apparently some versions of CMake still rely on this archaic feature...

Reported by:	rakuco

MFC 263049:

Garbage collect the old way of adding the libstdc++ include directories
in clang's InitHeaderSearch.cpp.  This has been superseded by David
Chisnall's commit in r255321.

Moreover, if libc++ is used, the libstdc++ include directories should
not be in the search path at all.  These directories are now only used
if you pass -stdlib=libstdc++.

1 files changed, 605 insertions, 130 deletions

diff --git a/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index 6c3d247..471897d 100644
--- a/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -13,6 +13,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "ARMBuildAttrs.h"
+#include "ARMFPUName.h"
 #include "ARMRegisterInfo.h"
 #include "ARMUnwindOp.h"
 #include "ARMUnwindOpAsm.h"
@@ -27,6 +29,7 @@
 #include "llvm/MC/MCELFSymbolFlags.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstPrinter.h"
 #include "llvm/MC/MCObjectStreamer.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSection.h"
@@ -36,7 +39,9 @@
 #include "llvm/MC/MCValue.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ELF.h"
+#include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/raw_ostream.h"
+#include <algorithm>
 
 using namespace llvm;
 
@@ -45,8 +50,218 @@ static std::string GetAEABIUnwindPersonalityName(unsigned Index) {
   return (Twine("__aeabi_unwind_cpp_pr") + Twine(Index)).str();
 }
 
+static const char *GetFPUName(unsigned ID) {
+  switch (ID) {
+  default:
+    llvm_unreachable("Unknown FPU kind");
+    break;
+#define ARM_FPU_NAME(NAME, ID) case ARM::ID: return NAME;
+#include "ARMFPUName.def"
+  }
+  return NULL;
+}
+
 namespace {
 
+class ARMELFStreamer;
+
+class ARMTargetAsmStreamer : public ARMTargetStreamer {
+  formatted_raw_ostream &OS;
+  MCInstPrinter &InstPrinter;
+
+  virtual void emitFnStart();
+  virtual void emitFnEnd();
+  virtual void emitCantUnwind();
+  virtual void emitPersonality(const MCSymbol *Personality);
+  virtual void emitHandlerData();
+  virtual void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0);
+  virtual void emitPad(int64_t Offset);
+  virtual void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
+                           bool isVector);
+
+  virtual void switchVendor(StringRef Vendor);
+  virtual void emitAttribute(unsigned Attribute, unsigned Value);
+  virtual void emitTextAttribute(unsigned Attribute, StringRef String);
+  virtual void emitFPU(unsigned FPU);
+  virtual void finishAttributeSection();
+
+public:
+  ARMTargetAsmStreamer(formatted_raw_ostream &OS, MCInstPrinter &InstPrinter);
+};
+
+ARMTargetAsmStreamer::ARMTargetAsmStreamer(formatted_raw_ostream &OS,
+                                           MCInstPrinter &InstPrinter)
+    : OS(OS), InstPrinter(InstPrinter) {}
+void ARMTargetAsmStreamer::emitFnStart() { OS << "\t.fnstart\n"; }
+void ARMTargetAsmStreamer::emitFnEnd() { OS << "\t.fnend\n"; }
+void ARMTargetAsmStreamer::emitCantUnwind() { OS << "\t.cantunwind\n"; }
+void ARMTargetAsmStreamer::emitPersonality(const MCSymbol *Personality) {
+  OS << "\t.personality " << Personality->getName() << '\n';
+}
+void ARMTargetAsmStreamer::emitHandlerData() { OS << "\t.handlerdata\n"; }
+void ARMTargetAsmStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
+                                     int64_t Offset) {
+  OS << "\t.setfp\t";
+  InstPrinter.printRegName(OS, FpReg);
+  OS << ", ";
+  InstPrinter.printRegName(OS, SpReg);
+  if (Offset)
+    OS << ", #" << Offset;
+  OS << '\n';
+}
+void ARMTargetAsmStreamer::emitPad(int64_t Offset) {
+  OS << "\t.pad\t#" << Offset << '\n';
+}
+void ARMTargetAsmStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
+                                       bool isVector) {
+  assert(RegList.size() && "RegList should not be empty");
+  if (isVector)
+    OS << "\t.vsave\t{";
+  else
+    OS << "\t.save\t{";
+
+  InstPrinter.printRegName(OS, RegList[0]);
+
+  for (unsigned i = 1, e = RegList.size(); i != e; ++i) {
+    OS << ", ";
+    InstPrinter.printRegName(OS, RegList[i]);
+  }
+
+  OS << "}\n";
+}
+void ARMTargetAsmStreamer::switchVendor(StringRef Vendor) {
+}
+void ARMTargetAsmStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
+  OS << "\t.eabi_attribute\t" << Attribute << ", " << Twine(Value) << "\n";
+}
+void ARMTargetAsmStreamer::emitTextAttribute(unsigned Attribute,
+                                             StringRef String) {
+  switch (Attribute) {
+  default: llvm_unreachable("Unsupported Text attribute in ASM Mode");
+  case ARMBuildAttrs::CPU_name:
+    OS << "\t.cpu\t" << String.lower() << "\n";
+    break;
+  }
+}
+void ARMTargetAsmStreamer::emitFPU(unsigned FPU) {
+  OS << "\t.fpu\t" << GetFPUName(FPU) << "\n";
+}
+void ARMTargetAsmStreamer::finishAttributeSection() {
+}
+
+class ARMTargetELFStreamer : public ARMTargetStreamer {
+private:
+  // This structure holds all attributes, accounting for
+  // their string/numeric value, so we can later emmit them
+  // in declaration order, keeping all in the same vector
+  struct AttributeItem {
+    enum {
+      HiddenAttribute = 0,
+      NumericAttribute,
+      TextAttribute
+    } Type;
+    unsigned Tag;
+    unsigned IntValue;
+    StringRef StringValue;
+
+    static bool LessTag(const AttributeItem &LHS, const AttributeItem &RHS) {
+      return (LHS.Tag < RHS.Tag);
+    }
+  };
+
+  StringRef CurrentVendor;
+  unsigned FPU;
+  SmallVector<AttributeItem, 64> Contents;
+
+  const MCSection *AttributeSection;
+
+  // FIXME: this should be in a more generic place, but
+  // getULEBSize() is in MCAsmInfo and will be moved to MCDwarf
+  static size_t getULEBSize(int Value) {
+    size_t Size = 0;
+    do {
+      Value >>= 7;
+      Size += sizeof(int8_t); // Is this really necessary?
+    } while (Value);
+    return Size;
+  }
+
+  AttributeItem *getAttributeItem(unsigned Attribute) {
+    for (size_t i = 0; i < Contents.size(); ++i)
+      if (Contents[i].Tag == Attribute)
+        return &Contents[i];
+    return 0;
+  }
+
+  void setAttributeItem(unsigned Attribute, unsigned Value,
+                        bool OverwriteExisting) {
+    // Look for existing attribute item
+    if (AttributeItem *Item = getAttributeItem(Attribute)) {
+      if (!OverwriteExisting)
+        return;
+      Item->IntValue = Value;
+      return;
+    }
+
+    // Create new attribute item
+    AttributeItem Item = {
+      AttributeItem::NumericAttribute,
+      Attribute,
+      Value,
+      StringRef("")
+    };
+    Contents.push_back(Item);
+  }
+
+  void setAttributeItem(unsigned Attribute, StringRef Value,
+                        bool OverwriteExisting) {
+    // Look for existing attribute item
+    if (AttributeItem *Item = getAttributeItem(Attribute)) {
+      if (!OverwriteExisting)
+        return;
+      Item->StringValue = Value;
+      return;
+    }
+
+    // Create new attribute item
+    AttributeItem Item = {
+      AttributeItem::TextAttribute,
+      Attribute,
+      0,
+      Value
+    };
+    Contents.push_back(Item);
+  }
+
+  void emitFPUDefaultAttributes();
+
+  ARMELFStreamer &getStreamer();
+
+  virtual void emitFnStart();
+  virtual void emitFnEnd();
+  virtual void emitCantUnwind();
+  virtual void emitPersonality(const MCSymbol *Personality);
+  virtual void emitHandlerData();
+  virtual void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0);
+  virtual void emitPad(int64_t Offset);
+  virtual void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
+                           bool isVector);
+
+  virtual void switchVendor(StringRef Vendor);
+  virtual void emitAttribute(unsigned Attribute, unsigned Value);
+  virtual void emitTextAttribute(unsigned Attribute, StringRef String);
+  virtual void emitFPU(unsigned FPU);
+  virtual void finishAttributeSection();
+
+  size_t calculateContentSize() const;
+
+public:
+  ARMTargetELFStreamer()
+    : ARMTargetStreamer(), CurrentVendor("aeabi"), FPU(ARM::INVALID_FPU),
+      AttributeSection(0) {
+  }
+};
+
 /// Extend the generic ELFStreamer class so that it can emit mapping symbols at
 /// the appropriate points in the object files. These symbols are defined in the
 /// ARM ELF ABI: infocenter.arm.com/help/topic/com.arm.../IHI0044D_aaelf.pdf.
@@ -61,27 +276,29 @@ namespace {
 /// by MachO. Beware!
 class ARMELFStreamer : public MCELFStreamer {
 public:
-  ARMELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &OS,
-                 MCCodeEmitter *Emitter, bool IsThumb)
-      : MCELFStreamer(SK_ARMELFStreamer, Context, TAB, OS, Emitter),
+  friend class ARMTargetELFStreamer;
+
+  ARMELFStreamer(MCContext &Context, MCTargetStreamer *TargetStreamer,
+                 MCAsmBackend &TAB, raw_ostream &OS, MCCodeEmitter *Emitter,
+                 bool IsThumb)
+      : MCELFStreamer(Context, TargetStreamer, TAB, OS, Emitter),
         IsThumb(IsThumb), MappingSymbolCounter(0), LastEMS(EMS_None) {
     Reset();
   }
 
   ~ARMELFStreamer() {}
 
+  virtual void FinishImpl();
+
   // ARM exception handling directives
-  virtual void EmitFnStart();
-  virtual void EmitFnEnd();
-  virtual void EmitCantUnwind();
-  virtual void EmitPersonality(const MCSymbol *Per);
-  virtual void EmitHandlerData();
-  virtual void EmitSetFP(unsigned NewFpReg,
-                         unsigned NewSpReg,
-                         int64_t Offset = 0);
-  virtual void EmitPad(int64_t Offset);
-  virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
-                           bool isVector);
+  void emitFnStart();
+  void emitFnEnd();
+  void emitCantUnwind();
+  void emitPersonality(const MCSymbol *Per);
+  void emitHandlerData();
+  void emitSetFP(unsigned NewFpReg, unsigned NewSpReg, int64_t Offset = 0);
+  void emitPad(int64_t Offset);
+  void emitRegSave(const SmallVectorImpl<unsigned> &RegList, bool isVector);
 
   virtual void ChangeSection(const MCSection *Section,
                              const MCExpr *Subsection) {
@@ -109,18 +326,17 @@ public:
   /// This is one of the functions used to emit data into an ELF section, so the
   /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
   /// necessary.
-  virtual void EmitBytes(StringRef Data, unsigned AddrSpace) {
+  virtual void EmitBytes(StringRef Data) {
     EmitDataMappingSymbol();
-    MCELFStreamer::EmitBytes(Data, AddrSpace);
+    MCELFStreamer::EmitBytes(Data);
   }
 
   /// This is one of the functions used to emit data into an ELF section, so the
   /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
   /// necessary.
-  virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
-                             unsigned AddrSpace) {
+  virtual void EmitValueImpl(const MCExpr *Value, unsigned Size) {
     EmitDataMappingSymbol();
-    MCELFStreamer::EmitValueImpl(Value, Size, AddrSpace);
+    MCELFStreamer::EmitValueImpl(Value, Size);
   }
 
   virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {
@@ -142,10 +358,6 @@ public:
     }
   }
 
-  static bool classof(const MCStreamer *S) {
-    return S->getKind() == SK_ARMELFStreamer;
-  }
-
 private:
   enum ElfMappingSymbol {
     EMS_None,
@@ -184,7 +396,7 @@ private:
     MCELF::SetType(SD, ELF::STT_NOTYPE);
     MCELF::SetBinding(SD, ELF::STB_LOCAL);
     SD.setExternal(false);
-    Symbol->setSection(*getCurrentSection().first);
+    AssignSection(Symbol, getCurrentSection().first);
 
     const MCExpr *Value = MCSymbolRefExpr::Create(Start, getContext());
     Symbol->setVariableValue(Value);
@@ -203,7 +415,8 @@ private:
   void Reset();
 
   void EmitPersonalityFixup(StringRef Name);
-  void CollectUnwindOpcodes();
+  void FlushPendingOffset();
+  void FlushUnwindOpcodes(bool NoHandlerData);
 
   void SwitchToEHSection(const char *Prefix, unsigned Type, unsigned Flags,
                          SectionKind Kind, const MCSymbol &Fn);
@@ -220,17 +433,236 @@ private:
   MCSymbol *ExTab;
   MCSymbol *FnStart;
   const MCSymbol *Personality;
-  uint32_t VFPRegSave; // Register mask for {d31-d0}
-  uint32_t RegSave; // Register mask for {r15-r0}
-  int64_t SPOffset;
-  uint16_t FPReg;
-  int64_t FPOffset;
+  unsigned PersonalityIndex;
+  unsigned FPReg; // Frame pointer register
+  int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
+  int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
+  int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
   bool UsedFP;
   bool CantUnwind;
+  SmallVector<uint8_t, 64> Opcodes;
   UnwindOpcodeAssembler UnwindOpAsm;
 };
 } // end anonymous namespace
 
+ARMELFStreamer &ARMTargetELFStreamer::getStreamer() {
+  ARMELFStreamer *S = static_cast<ARMELFStreamer *>(Streamer);
+  return *S;
+}
+
+void ARMTargetELFStreamer::emitFnStart() { getStreamer().emitFnStart(); }
+void ARMTargetELFStreamer::emitFnEnd() { getStreamer().emitFnEnd(); }
+void ARMTargetELFStreamer::emitCantUnwind() { getStreamer().emitCantUnwind(); }
+void ARMTargetELFStreamer::emitPersonality(const MCSymbol *Personality) {
+  getStreamer().emitPersonality(Personality);
+}
+void ARMTargetELFStreamer::emitHandlerData() {
+  getStreamer().emitHandlerData();
+}
+void ARMTargetELFStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
+                                     int64_t Offset) {
+  getStreamer().emitSetFP(FpReg, SpReg, Offset);
+}
+void ARMTargetELFStreamer::emitPad(int64_t Offset) {
+  getStreamer().emitPad(Offset);
+}
+void ARMTargetELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
+                                       bool isVector) {
+  getStreamer().emitRegSave(RegList, isVector);
+}
+void ARMTargetELFStreamer::switchVendor(StringRef Vendor) {
+  assert(!Vendor.empty() && "Vendor cannot be empty.");
+
+  if (CurrentVendor == Vendor)
+    return;
+
+  if (!CurrentVendor.empty())
+    finishAttributeSection();
+
+  assert(Contents.empty() &&
+         ".ARM.attributes should be flushed before changing vendor");
+  CurrentVendor = Vendor;
+
+}
+void ARMTargetELFStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
+  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
+}
+void ARMTargetELFStreamer::emitTextAttribute(unsigned Attribute,
+                                             StringRef Value) {
+  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
+}
+void ARMTargetELFStreamer::emitFPU(unsigned Value) {
+  FPU = Value;
+}
+void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
+  switch (FPU) {
+  case ARM::VFP:
+  case ARM::VFPV2:
+    setAttributeItem(ARMBuildAttrs::VFP_arch,
+                     ARMBuildAttrs::AllowFPv2,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  case ARM::VFPV3:
+    setAttributeItem(ARMBuildAttrs::VFP_arch,
+                     ARMBuildAttrs::AllowFPv3A,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  case ARM::VFPV3_D16:
+    setAttributeItem(ARMBuildAttrs::VFP_arch,
+                     ARMBuildAttrs::AllowFPv3B,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  case ARM::VFPV4:
+    setAttributeItem(ARMBuildAttrs::VFP_arch,
+                     ARMBuildAttrs::AllowFPv4A,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  case ARM::VFPV4_D16:
+    setAttributeItem(ARMBuildAttrs::VFP_arch,
+                     ARMBuildAttrs::AllowFPv4B,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  case ARM::FP_ARMV8:
+    setAttributeItem(ARMBuildAttrs::VFP_arch,
+                     ARMBuildAttrs::AllowFPARMv8A,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  case ARM::NEON:
+    setAttributeItem(ARMBuildAttrs::VFP_arch,
+                     ARMBuildAttrs::AllowFPv3A,
+                     /* OverwriteExisting= */ false);
+    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
+                     ARMBuildAttrs::AllowNeon,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  case ARM::NEON_VFPV4:
+    setAttributeItem(ARMBuildAttrs::VFP_arch,
+                     ARMBuildAttrs::AllowFPv4A,
+                     /* OverwriteExisting= */ false);
+    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
+                     ARMBuildAttrs::AllowNeon2,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  case ARM::NEON_FP_ARMV8:
+  case ARM::CRYPTO_NEON_FP_ARMV8:
+    setAttributeItem(ARMBuildAttrs::VFP_arch,
+                     ARMBuildAttrs::AllowFPARMv8A,
+                     /* OverwriteExisting= */ false);
+    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
+                     ARMBuildAttrs::AllowNeonARMv8,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  default:
+    report_fatal_error("Unknown FPU: " + Twine(FPU));
+    break;
+  }
+}
+size_t ARMTargetELFStreamer::calculateContentSize() const {
+  size_t Result = 0;
+  for (size_t i = 0; i < Contents.size(); ++i) {
+    AttributeItem item = Contents[i];
+    switch (item.Type) {
+    case AttributeItem::HiddenAttribute:
+      break;
+    case AttributeItem::NumericAttribute:
+      Result += getULEBSize(item.Tag);
+      Result += getULEBSize(item.IntValue);
+      break;
+    case AttributeItem::TextAttribute:
+      Result += getULEBSize(item.Tag);
+      Result += item.StringValue.size() + 1; // string + '\0'
+      break;
+    }
+  }
+  return Result;
+}
+void ARMTargetELFStreamer::finishAttributeSection() {
+  // <format-version>
+  // [ <section-length> "vendor-name"
+  // [ <file-tag> <size> <attribute>*
+  //   | <section-tag> <size> <section-number>* 0 <attribute>*
+  //   | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
+  //   ]+
+  // ]*
+
+  if (FPU != ARM::INVALID_FPU)
+    emitFPUDefaultAttributes();
+
+  if (Contents.empty())
+    return;
+
+  std::sort(Contents.begin(), Contents.end(), AttributeItem::LessTag);
+
+  ARMELFStreamer &Streamer = getStreamer();
+
+  // Switch to .ARM.attributes section
+  if (AttributeSection) {
+    Streamer.SwitchSection(AttributeSection);
+  } else {
+    AttributeSection =
+      Streamer.getContext().getELFSection(".ARM.attributes",
+                                          ELF::SHT_ARM_ATTRIBUTES,
+                                          0,
+                                          SectionKind::getMetadata());
+    Streamer.SwitchSection(AttributeSection);
+
+    // Format version
+    Streamer.EmitIntValue(0x41, 1);
+  }
+
+  // Vendor size + Vendor name + '\0'
+  const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
+
+  // Tag + Tag Size
+  const size_t TagHeaderSize = 1 + 4;
+
+  const size_t ContentsSize = calculateContentSize();
+
+  Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
+  Streamer.EmitBytes(CurrentVendor);
+  Streamer.EmitIntValue(0, 1); // '\0'
+
+  Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
+  Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
+
+  // Size should have been accounted for already, now
+  // emit each field as its type (ULEB or String)
+  for (size_t i = 0; i < Contents.size(); ++i) {
+    AttributeItem item = Contents[i];
+    Streamer.EmitULEB128IntValue(item.Tag);
+    switch (item.Type) {
+    default: llvm_unreachable("Invalid attribute type");
+    case AttributeItem::NumericAttribute:
+      Streamer.EmitULEB128IntValue(item.IntValue);
+      break;
+    case AttributeItem::TextAttribute:
+      Streamer.EmitBytes(item.StringValue.upper());
+      Streamer.EmitIntValue(0, 1); // '\0'
+      break;
+    }
+  }
+
+  Contents.clear();
+  FPU = ARM::INVALID_FPU;
+}
+
+void ARMELFStreamer::FinishImpl() {
+  MCTargetStreamer &TS = getTargetStreamer();
+  ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
+  ATS.finishAttributeSection();
+
+  MCELFStreamer::FinishImpl();
+}
+
 inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
                                               unsigned Type,
                                               unsigned Flags,
@@ -279,81 +711,37 @@ inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
 }
 
 void ARMELFStreamer::Reset() {
-  const MCRegisterInfo &MRI = getContext().getRegisterInfo();
-
   ExTab = NULL;
   FnStart = NULL;
   Personality = NULL;
-  VFPRegSave = 0;
-  RegSave = 0;
-  FPReg = MRI.getEncodingValue(ARM::SP);
+  PersonalityIndex = NUM_PERSONALITY_INDEX;
+  FPReg = ARM::SP;
   FPOffset = 0;
   SPOffset = 0;
+  PendingOffset = 0;
   UsedFP = false;
   CantUnwind = false;
 
+  Opcodes.clear();
   UnwindOpAsm.Reset();
 }
 
-// Add the R_ARM_NONE fixup at the same position
-void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
-  const MCSymbol *PersonalitySym = getContext().GetOrCreateSymbol(Name);
-
-  const MCSymbolRefExpr *PersonalityRef =
-    MCSymbolRefExpr::Create(PersonalitySym,
-                            MCSymbolRefExpr::VK_ARM_NONE,
-                            getContext());
-
-  AddValueSymbols(PersonalityRef);
-  MCDataFragment *DF = getOrCreateDataFragment();
-  DF->getFixups().push_back(
-    MCFixup::Create(DF->getContents().size(), PersonalityRef,
-                    MCFixup::getKindForSize(4, false)));
-}
-
-void ARMELFStreamer::CollectUnwindOpcodes() {
-  if (UsedFP) {
-    UnwindOpAsm.EmitSetFP(FPReg);
-    UnwindOpAsm.EmitSPOffset(-FPOffset);
-  } else {
-    UnwindOpAsm.EmitSPOffset(SPOffset);
-  }
-  UnwindOpAsm.EmitVFPRegSave(VFPRegSave);
-  UnwindOpAsm.EmitRegSave(RegSave);
-  UnwindOpAsm.Finalize();
-}
-
-void ARMELFStreamer::EmitFnStart() {
+void ARMELFStreamer::emitFnStart() {
   assert(FnStart == 0);
   FnStart = getContext().CreateTempSymbol();
   EmitLabel(FnStart);
 }
 
-void ARMELFStreamer::EmitFnEnd() {
+void ARMELFStreamer::emitFnEnd() {
   assert(FnStart && ".fnstart must preceeds .fnend");
 
   // Emit unwind opcodes if there is no .handlerdata directive
-  if (!ExTab && !CantUnwind) {
-    CollectUnwindOpcodes();
-
-    unsigned PersonalityIndex = UnwindOpAsm.getPersonalityIndex();
-    if (PersonalityIndex == AEABI_UNWIND_CPP_PR1 ||
-        PersonalityIndex == AEABI_UNWIND_CPP_PR2) {
-      // For the __aeabi_unwind_cpp_pr1 and __aeabi_unwind_cpp_pr2, we have to
-      // emit the unwind opcodes in the corresponding ".ARM.extab" section, and
-      // then emit a reference to these unwind opcodes in the second word of
-      // the exception index table entry.
-      SwitchToExTabSection(*FnStart);
-      ExTab = getContext().CreateTempSymbol();
-      EmitLabel(ExTab);
-      EmitBytes(UnwindOpAsm.data(), 0);
-    }
-  }
+  if (!ExTab && !CantUnwind)
+    FlushUnwindOpcodes(true);
 
   // Emit the exception index table entry
   SwitchToExIdxSection(*FnStart);
 
-  unsigned PersonalityIndex = UnwindOpAsm.getPersonalityIndex();
   if (PersonalityIndex < NUM_PERSONALITY_INDEX)
     EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
 
@@ -362,37 +750,80 @@ void ARMELFStreamer::EmitFnEnd() {
                             MCSymbolRefExpr::VK_ARM_PREL31,
                             getContext());
 
-  EmitValue(FnStartRef, 4, 0);
+  EmitValue(FnStartRef, 4);
 
   if (CantUnwind) {
-    EmitIntValue(EXIDX_CANTUNWIND, 4, 0);
+    EmitIntValue(EXIDX_CANTUNWIND, 4);
   } else if (ExTab) {
     // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
     const MCSymbolRefExpr *ExTabEntryRef =
       MCSymbolRefExpr::Create(ExTab,
                               MCSymbolRefExpr::VK_ARM_PREL31,
                               getContext());
-    EmitValue(ExTabEntryRef, 4, 0);
+    EmitValue(ExTabEntryRef, 4);
   } else {
     // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
     // the second word of exception index table entry.  The size of the unwind
     // opcodes should always be 4 bytes.
     assert(PersonalityIndex == AEABI_UNWIND_CPP_PR0 &&
            "Compact model must use __aeabi_cpp_unwind_pr0 as personality");
-    assert(UnwindOpAsm.size() == 4u &&
+    assert(Opcodes.size() == 4u &&
            "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be equal to 4");
-    EmitBytes(UnwindOpAsm.data(), 0);
+    EmitBytes(StringRef(reinterpret_cast<const char*>(Opcodes.data()),
+                        Opcodes.size()));
   }
 
+  // Switch to the section containing FnStart
+  SwitchSection(&FnStart->getSection());
+
   // Clean exception handling frame information
   Reset();
 }
 
-void ARMELFStreamer::EmitCantUnwind() {
-  CantUnwind = true;
+void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
+
+// Add the R_ARM_NONE fixup at the same position
+void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
+  const MCSymbol *PersonalitySym = getContext().GetOrCreateSymbol(Name);
+
+  const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::Create(
+      PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
+
+  AddValueSymbols(PersonalityRef);
+  MCDataFragment *DF = getOrCreateDataFragment();
+  DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(),
+                                            PersonalityRef,
+                                            MCFixup::getKindForSize(4, false)));
+}
+
+void ARMELFStreamer::FlushPendingOffset() {
+  if (PendingOffset != 0) {
+    UnwindOpAsm.EmitSPOffset(-PendingOffset);
+    PendingOffset = 0;
+  }
 }
 
-void ARMELFStreamer::EmitHandlerData() {
+void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
+  // Emit the unwind opcode to restore $sp.
+  if (UsedFP) {
+    const MCRegisterInfo *MRI = getContext().getRegisterInfo();
+    int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
+    UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
+    UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
+  } else {
+    FlushPendingOffset();
+  }
+
+  // Finalize the unwind opcode sequence
+  UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
+
+  // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
+  // section.  Thus, we don't have to create an entry in the .ARM.extab
+  // section.
+  if (NoHandlerData && PersonalityIndex == AEABI_UNWIND_CPP_PR0)
+    return;
+
+  // Switch to .ARM.extab section.
   SwitchToExTabSection(*FnStart);
 
   // Create .ARM.extab label for offset in .ARM.exidx
@@ -400,73 +831,117 @@ void ARMELFStreamer::EmitHandlerData() {
   ExTab = getContext().CreateTempSymbol();
   EmitLabel(ExTab);
 
-  // Emit Personality
-  assert(Personality && ".personality directive must preceed .handlerdata");
-
-  const MCSymbolRefExpr *PersonalityRef =
-    MCSymbolRefExpr::Create(Personality,
-                            MCSymbolRefExpr::VK_ARM_PREL31,
-                            getContext());
+  // Emit personality
+  if (Personality) {
+    const MCSymbolRefExpr *PersonalityRef =
+      MCSymbolRefExpr::Create(Personality,
+                              MCSymbolRefExpr::VK_ARM_PREL31,
+                              getContext());
 
-  EmitValue(PersonalityRef, 4, 0);
+    EmitValue(PersonalityRef, 4);
+  }
 
   // Emit unwind opcodes
-  CollectUnwindOpcodes();
-  EmitBytes(UnwindOpAsm.data(), 0);
+  EmitBytes(StringRef(reinterpret_cast<const char *>(Opcodes.data()),
+                      Opcodes.size()));
+
+  // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
+  // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
+  // after the unwind opcodes.  The handler data consists of several 32-bit
+  // words, and should be terminated by zero.
+  //
+  // In case that the .handlerdata directive is not specified by the
+  // programmer, we should emit zero to terminate the handler data.
+  if (NoHandlerData && !Personality)
+    EmitIntValue(0, 4);
 }
 
-void ARMELFStreamer::EmitPersonality(const MCSymbol *Per) {
+void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
+
+void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
   Personality = Per;
   UnwindOpAsm.setPersonality(Per);
 }
 
-void ARMELFStreamer::EmitSetFP(unsigned NewFPReg,
-                               unsigned NewSPReg,
+void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
                                int64_t Offset) {
-  assert(SPOffset == 0 &&
-         "Current implementation assumes .setfp precedes .pad");
-
-  const MCRegisterInfo &MRI = getContext().getRegisterInfo();
-
-  uint16_t NewFPRegEncVal = MRI.getEncodingValue(NewFPReg);
-#ifndef NDEBUG
-  uint16_t NewSPRegEncVal = MRI.getEncodingValue(NewSPReg);
-#endif
-
-  assert((NewSPReg == ARM::SP || NewSPRegEncVal == FPReg) &&
+  assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
          "the operand of .setfp directive should be either $sp or $fp");
 
   UsedFP = true;
-  FPReg = NewFPRegEncVal;
-  FPOffset = Offset;
-}
+  FPReg = NewFPReg;
 
-void ARMELFStreamer::EmitPad(int64_t Offset) {
-  SPOffset += Offset;
+  if (NewSPReg == ARM::SP)
+    FPOffset = SPOffset + Offset;
+  else
+    FPOffset += Offset;
 }
 
-void ARMELFStreamer::EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
-                                 bool IsVector) {
-  const MCRegisterInfo &MRI = getContext().getRegisterInfo();
+void ARMELFStreamer::emitPad(int64_t Offset) {
+  // Track the change of the $sp offset
+  SPOffset -= Offset;
 
-#ifndef NDEBUG
-  unsigned Max = IsVector ? 32 : 16;
-#endif
-  uint32_t &RegMask = IsVector ? VFPRegSave : RegSave;
+  // To squash multiple .pad directives, we should delay the unwind opcode
+  // until the .save, .vsave, .handlerdata, or .fnend directives.
+  PendingOffset -= Offset;
+}
 
+void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
+                                 bool IsVector) {
+  // Collect the registers in the register list
+  unsigned Count = 0;
+  uint32_t Mask = 0;
+  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
   for (size_t i = 0; i < RegList.size(); ++i) {
-    unsigned Reg = MRI.getEncodingValue(RegList[i]);
-    assert(Reg < Max && "Register encoded value out of range");
-    RegMask |= 1u << Reg;
+    unsigned Reg = MRI->getEncodingValue(RegList[i]);
+    assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
+    unsigned Bit = (1u << Reg);
+    if ((Mask & Bit) == 0) {
+      Mask |= Bit;
+      ++Count;
+    }
   }
+
+  // Track the change the $sp offset: For the .save directive, the
+  // corresponding push instruction will decrease the $sp by (4 * Count).
+  // For the .vsave directive, the corresponding vpush instruction will
+  // decrease $sp by (8 * Count).
+  SPOffset -= Count * (IsVector ? 8 : 4);
+
+  // Emit the opcode
+  FlushPendingOffset();
+  if (IsVector)
+    UnwindOpAsm.EmitVFPRegSave(Mask);
+  else
+    UnwindOpAsm.EmitRegSave(Mask);
 }
 
 namespace llvm {
+
+MCStreamer *createMCAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
+                                bool isVerboseAsm, bool useLoc, bool useCFI,
+                                bool useDwarfDirectory,
+                                MCInstPrinter *InstPrint, MCCodeEmitter *CE,
+                                MCAsmBackend *TAB, bool ShowInst) {
+  ARMTargetAsmStreamer *S = new ARMTargetAsmStreamer(OS, *InstPrint);
+
+  return llvm::createAsmStreamer(Ctx, S, OS, isVerboseAsm, useLoc, useCFI,
+                                 useDwarfDirectory, InstPrint, CE, TAB,
+                                 ShowInst);
+}
+
   MCELFStreamer* createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
                                       raw_ostream &OS, MCCodeEmitter *Emitter,
                                       bool RelaxAll, bool NoExecStack,
                                       bool IsThumb) {
-    ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
+    ARMTargetELFStreamer *TS = new ARMTargetELFStreamer();
+    ARMELFStreamer *S =
+        new ARMELFStreamer(Context, TS, TAB, OS, Emitter, IsThumb);
+    // FIXME: This should eventually end up somewhere else where more
+    // intelligent flag decisions can be made. For now we are just maintaining
+    // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
+    S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
+
     if (RelaxAll)
       S->getAssembler().setRelaxAll(true);
     if (NoExecStack)