Index: head/contrib/llvm/include/llvm/MC/MCFragment.h
===================================================================
--- head/contrib/llvm/include/llvm/MC/MCFragment.h	(revision 328595)
+++ head/contrib/llvm/include/llvm/MC/MCFragment.h	(revision 328596)
@@ -1,659 +1,666 @@
 //===- MCFragment.h - Fragment type hierarchy -------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_MC_MCFRAGMENT_H
 #define LLVM_MC_MCFRAGMENT_H
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/ilist_node.h"
 #include "llvm/MC/MCFixup.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/SMLoc.h"
 #include <cstdint>
 #include <utility>
 
 namespace llvm {
 
 class MCSection;
 class MCSubtargetInfo;
 class MCSymbol;
 
 class MCFragment : public ilist_node_with_parent<MCFragment, MCSection> {
   friend class MCAsmLayout;
 
 public:
   enum FragmentType : uint8_t {
     FT_Align,
     FT_Data,
     FT_CompactEncodedInst,
     FT_Fill,
     FT_Relaxable,
     FT_Org,
     FT_Dwarf,
     FT_DwarfFrame,
     FT_LEB,
     FT_Padding,
     FT_SymbolId,
     FT_CVInlineLines,
     FT_CVDefRange,
     FT_Dummy
   };
 
 private:
   FragmentType Kind;
 
 protected:
   bool HasInstructions;
 
 private:
   /// \brief Should this fragment be aligned to the end of a bundle?
   bool AlignToBundleEnd;
 
   uint8_t BundlePadding;
 
   /// LayoutOrder - The layout order of this fragment.
   unsigned LayoutOrder;
 
   /// The data for the section this fragment is in.
   MCSection *Parent;
 
   /// Atom - The atom this fragment is in, as represented by it's defining
   /// symbol.
   const MCSymbol *Atom;
 
   /// \name Assembler Backend Data
   /// @{
   //
   // FIXME: This could all be kept private to the assembler implementation.
 
   /// Offset - The offset of this fragment in its section. This is ~0 until
   /// initialized.
   uint64_t Offset;
 
   /// @}
 
 protected:
   MCFragment(FragmentType Kind, bool HasInstructions,
              uint8_t BundlePadding, MCSection *Parent = nullptr);
 
   ~MCFragment();
 
 public:
   MCFragment() = delete;
   MCFragment(const MCFragment &) = delete;
   MCFragment &operator=(const MCFragment &) = delete;
 
   /// Destroys the current fragment.
   ///
   /// This must be used instead of delete as MCFragment is non-virtual.
   /// This method will dispatch to the appropriate subclass.
   void destroy();
 
   FragmentType getKind() const { return Kind; }
 
   MCSection *getParent() const { return Parent; }
   void setParent(MCSection *Value) { Parent = Value; }
 
   const MCSymbol *getAtom() const { return Atom; }
   void setAtom(const MCSymbol *Value) { Atom = Value; }
 
   unsigned getLayoutOrder() const { return LayoutOrder; }
   void setLayoutOrder(unsigned Value) { LayoutOrder = Value; }
 
   /// \brief Does this fragment have instructions emitted into it? By default
   /// this is false, but specific fragment types may set it to true.
   bool hasInstructions() const { return HasInstructions; }
 
   /// \brief Should this fragment be placed at the end of an aligned bundle?
   bool alignToBundleEnd() const { return AlignToBundleEnd; }
   void setAlignToBundleEnd(bool V) { AlignToBundleEnd = V; }
 
   /// \brief Get the padding size that must be inserted before this fragment.
   /// Used for bundling. By default, no padding is inserted.
   /// Note that padding size is restricted to 8 bits. This is an optimization
   /// to reduce the amount of space used for each fragment. In practice, larger
   /// padding should never be required.
   uint8_t getBundlePadding() const { return BundlePadding; }
 
   /// \brief Set the padding size for this fragment. By default it's a no-op,
   /// and only some fragments have a meaningful implementation.
   void setBundlePadding(uint8_t N) { BundlePadding = N; }
 
   /// \brief Return true if given frgment has FT_Dummy type.
   bool isDummy() const { return Kind == FT_Dummy; }
 
   void dump() const;
 };
 
 class MCDummyFragment : public MCFragment {
 public:
   explicit MCDummyFragment(MCSection *Sec)
       : MCFragment(FT_Dummy, false, 0, Sec) {}
 
   static bool classof(const MCFragment *F) { return F->getKind() == FT_Dummy; }
 };
 
 /// Interface implemented by fragments that contain encoded instructions and/or
 /// data.
 ///
 class MCEncodedFragment : public MCFragment {
 protected:
   MCEncodedFragment(MCFragment::FragmentType FType, bool HasInstructions,
                     MCSection *Sec)
       : MCFragment(FType, HasInstructions, 0, Sec) {}
 
 public:
   static bool classof(const MCFragment *F) {
     MCFragment::FragmentType Kind = F->getKind();
     switch (Kind) {
     default:
       return false;
     case MCFragment::FT_Relaxable:
     case MCFragment::FT_CompactEncodedInst:
     case MCFragment::FT_Data:
       return true;
     }
   }
 };
 
 /// Interface implemented by fragments that contain encoded instructions and/or
 /// data.
 ///
 template<unsigned ContentsSize>
 class MCEncodedFragmentWithContents : public MCEncodedFragment {
   SmallVector<char, ContentsSize> Contents;
 
 protected:
   MCEncodedFragmentWithContents(MCFragment::FragmentType FType,
                                 bool HasInstructions,
                                 MCSection *Sec)
       : MCEncodedFragment(FType, HasInstructions, Sec) {}
 
 public:
   SmallVectorImpl<char> &getContents() { return Contents; }
   const SmallVectorImpl<char> &getContents() const { return Contents; }
 };
 
 /// Interface implemented by fragments that contain encoded instructions and/or
 /// data and also have fixups registered.
 ///
 template<unsigned ContentsSize, unsigned FixupsSize>
 class MCEncodedFragmentWithFixups :
   public MCEncodedFragmentWithContents<ContentsSize> {
 
   /// Fixups - The list of fixups in this fragment.
   SmallVector<MCFixup, FixupsSize> Fixups;
 
 protected:
   MCEncodedFragmentWithFixups(MCFragment::FragmentType FType,
                               bool HasInstructions,
                               MCSection *Sec)
       : MCEncodedFragmentWithContents<ContentsSize>(FType, HasInstructions,
                                                     Sec) {}
 
 public:
   using const_fixup_iterator = SmallVectorImpl<MCFixup>::const_iterator;
   using fixup_iterator = SmallVectorImpl<MCFixup>::iterator;
 
   SmallVectorImpl<MCFixup> &getFixups() { return Fixups; }
   const SmallVectorImpl<MCFixup> &getFixups() const { return Fixups; }
 
   fixup_iterator fixup_begin() { return Fixups.begin(); }
   const_fixup_iterator fixup_begin() const { return Fixups.begin(); }
 
   fixup_iterator fixup_end() { return Fixups.end(); }
   const_fixup_iterator fixup_end() const { return Fixups.end(); }
 
   static bool classof(const MCFragment *F) {
     MCFragment::FragmentType Kind = F->getKind();
     return Kind == MCFragment::FT_Relaxable || Kind == MCFragment::FT_Data ||
            Kind == MCFragment::FT_CVDefRange;
   }
 };
 
 /// Fragment for data and encoded instructions.
 ///
 class MCDataFragment : public MCEncodedFragmentWithFixups<32, 4> {
 public:
   MCDataFragment(MCSection *Sec = nullptr)
       : MCEncodedFragmentWithFixups<32, 4>(FT_Data, false, Sec) {}
 
   void setHasInstructions(bool V) { HasInstructions = V; }
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_Data;
   }
 };
 
 /// This is a compact (memory-size-wise) fragment for holding an encoded
 /// instruction (non-relaxable) that has no fixups registered. When applicable,
 /// it can be used instead of MCDataFragment and lead to lower memory
 /// consumption.
 ///
 class MCCompactEncodedInstFragment : public MCEncodedFragmentWithContents<4> {
 public:
   MCCompactEncodedInstFragment(MCSection *Sec = nullptr)
       : MCEncodedFragmentWithContents(FT_CompactEncodedInst, true, Sec) {
   }
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_CompactEncodedInst;
   }
 };
 
 /// A relaxable fragment holds on to its MCInst, since it may need to be
 /// relaxed during the assembler layout and relaxation stage.
 ///
 class MCRelaxableFragment : public MCEncodedFragmentWithFixups<8, 1> {
 
   /// Inst - The instruction this is a fragment for.
   MCInst Inst;
 
   /// STI - The MCSubtargetInfo in effect when the instruction was encoded.
   const MCSubtargetInfo &STI;
 
 public:
   MCRelaxableFragment(const MCInst &Inst, const MCSubtargetInfo &STI,
                       MCSection *Sec = nullptr)
       : MCEncodedFragmentWithFixups(FT_Relaxable, true, Sec),
         Inst(Inst), STI(STI) {}
 
   const MCInst &getInst() const { return Inst; }
   void setInst(const MCInst &Value) { Inst = Value; }
 
   const MCSubtargetInfo &getSubtargetInfo() { return STI; }
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_Relaxable;
   }
 };
 
 class MCAlignFragment : public MCFragment {
   /// Alignment - The alignment to ensure, in bytes.
   unsigned Alignment;
 
   /// EmitNops - Flag to indicate that (optimal) NOPs should be emitted instead
   /// of using the provided value. The exact interpretation of this flag is
   /// target dependent.
   bool EmitNops : 1;
 
   /// Value - Value to use for filling padding bytes.
   int64_t Value;
 
   /// ValueSize - The size of the integer (in bytes) of \p Value.
   unsigned ValueSize;
 
   /// MaxBytesToEmit - The maximum number of bytes to emit; if the alignment
   /// cannot be satisfied in this width then this fragment is ignored.
   unsigned MaxBytesToEmit;
 
 public:
   MCAlignFragment(unsigned Alignment, int64_t Value, unsigned ValueSize,
                   unsigned MaxBytesToEmit, MCSection *Sec = nullptr)
       : MCFragment(FT_Align, false, 0, Sec), Alignment(Alignment),
         EmitNops(false), Value(Value),
         ValueSize(ValueSize), MaxBytesToEmit(MaxBytesToEmit) {}
 
   /// \name Accessors
   /// @{
 
   unsigned getAlignment() const { return Alignment; }
 
   int64_t getValue() const { return Value; }
 
   unsigned getValueSize() const { return ValueSize; }
 
   unsigned getMaxBytesToEmit() const { return MaxBytesToEmit; }
 
   bool hasEmitNops() const { return EmitNops; }
   void setEmitNops(bool Value) { EmitNops = Value; }
 
   /// @}
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_Align;
   }
 };
 
 /// Fragment for adding required padding.
 /// This fragment is always inserted before an instruction, and holds that
 /// instruction as context information (as well as a mask of kinds) for
 /// determining the padding size.
 ///
 class MCPaddingFragment : public MCFragment {
   /// A mask containing all the kinds relevant to this fragment. i.e. the i'th
   /// bit will be set iff kind i is relevant to this fragment.
   uint64_t PaddingPoliciesMask;
   /// A boolean indicating if this fragment will actually hold padding. If its
   /// value is false, then this fragment serves only as a placeholder,
   /// containing data to assist other insertion point in their decision making.
   bool IsInsertionPoint;
 
   uint64_t Size;
 
   struct MCInstInfo {
     bool IsInitialized;
     MCInst Inst;
     /// A boolean indicating whether the instruction pointed by this fragment is
     /// a fixed size instruction or a relaxable instruction held by a
     /// MCRelaxableFragment.
     bool IsImmutableSizedInst;
     union {
       /// If the instruction is a fixed size instruction, hold its size.
       size_t InstSize;
       /// Otherwise, hold a pointer to the MCRelaxableFragment holding it.
       MCRelaxableFragment *InstFragment;
     };
   };
   MCInstInfo InstInfo;
 
 public:
   static const uint64_t PFK_None = UINT64_C(0);
 
   enum MCPaddingFragmentKind {
     // values 0-7 are reserved for future target independet values.
 
     FirstTargetPerfNopFragmentKind = 8,
 
     /// Limit range of target MCPerfNopFragment kinds to fit in uint64_t
     MaxTargetPerfNopFragmentKind = 63
   };
 
   MCPaddingFragment(MCSection *Sec = nullptr)
       : MCFragment(FT_Padding, false, 0, Sec), PaddingPoliciesMask(PFK_None),
         IsInsertionPoint(false), Size(UINT64_C(0)),
         InstInfo({false, MCInst(), false, {0}}) {}
 
   bool isInsertionPoint() const { return IsInsertionPoint; }
   void setAsInsertionPoint() { IsInsertionPoint = true; }
   uint64_t getPaddingPoliciesMask() const { return PaddingPoliciesMask; }
   void setPaddingPoliciesMask(uint64_t Value) { PaddingPoliciesMask = Value; }
   bool hasPaddingPolicy(uint64_t PolicyMask) const {
     assert(isPowerOf2_64(PolicyMask) &&
            "Policy mask must contain exactly one policy");
     return (getPaddingPoliciesMask() & PolicyMask) != PFK_None;
   }
   const MCInst &getInst() const {
     assert(isInstructionInitialized() && "Fragment has no instruction!");
     return InstInfo.Inst;
   }
   size_t getInstSize() const {
     assert(isInstructionInitialized() && "Fragment has no instruction!");
     if (InstInfo.IsImmutableSizedInst)
       return InstInfo.InstSize;
     assert(InstInfo.InstFragment != nullptr &&
            "Must have a valid InstFragment to retrieve InstSize from");
     return InstInfo.InstFragment->getContents().size();
   }
   void setInstAndInstSize(const MCInst &Inst, size_t InstSize) {
 	InstInfo.IsInitialized = true;
     InstInfo.IsImmutableSizedInst = true;
     InstInfo.Inst = Inst;
     InstInfo.InstSize = InstSize;
   }
   void setInstAndInstFragment(const MCInst &Inst,
                               MCRelaxableFragment *InstFragment) {
     InstInfo.IsInitialized = true;
     InstInfo.IsImmutableSizedInst = false;
     InstInfo.Inst = Inst;
     InstInfo.InstFragment = InstFragment;
   }
   uint64_t getSize() const { return Size; }
   void setSize(uint64_t Value) { Size = Value; }
   bool isInstructionInitialized() const { return InstInfo.IsInitialized; }
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_Padding;
   }
 };
 
 class MCFillFragment : public MCFragment {
   /// Value to use for filling bytes.
   uint8_t Value;
 
   /// The number of bytes to insert.
-  uint64_t Size;
+  const MCExpr &Size;
 
+  /// Source location of the directive that this fragment was created for.
+  SMLoc Loc;
+
 public:
-  MCFillFragment(uint8_t Value, uint64_t Size, MCSection *Sec = nullptr)
-      : MCFragment(FT_Fill, false, 0, Sec), Value(Value), Size(Size) {}
+  MCFillFragment(uint8_t Value, const MCExpr &Size, SMLoc Loc,
+                 MCSection *Sec = nullptr)
+      : MCFragment(FT_Fill, false, 0, Sec), Value(Value), Size(Size), Loc(Loc) {
+  }
 
   uint8_t getValue() const { return Value; }
-  uint64_t getSize() const { return Size; }
+  const MCExpr &getSize() const { return Size; }
+
+  SMLoc getLoc() const { return Loc; }
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_Fill;
   }
 };
 
 class MCOrgFragment : public MCFragment {
   /// Offset - The offset this fragment should start at.
   const MCExpr *Offset;
 
   /// Value - Value to use for filling bytes.
   int8_t Value;
 
   /// Loc - Source location of the directive that this fragment was created for.
   SMLoc Loc;
 
 public:
   MCOrgFragment(const MCExpr &Offset, int8_t Value, SMLoc Loc,
                 MCSection *Sec = nullptr)
       : MCFragment(FT_Org, false, 0, Sec), Offset(&Offset), Value(Value), Loc(Loc) {}
 
   /// \name Accessors
   /// @{
 
   const MCExpr &getOffset() const { return *Offset; }
 
   uint8_t getValue() const { return Value; }
 
   SMLoc getLoc() const { return Loc; }
 
   /// @}
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_Org;
   }
 };
 
 class MCLEBFragment : public MCFragment {
   /// Value - The value this fragment should contain.
   const MCExpr *Value;
 
   /// IsSigned - True if this is a sleb128, false if uleb128.
   bool IsSigned;
 
   SmallString<8> Contents;
 
 public:
   MCLEBFragment(const MCExpr &Value_, bool IsSigned_, MCSection *Sec = nullptr)
       : MCFragment(FT_LEB, false, 0, Sec), Value(&Value_), IsSigned(IsSigned_) {
     Contents.push_back(0);
   }
 
   /// \name Accessors
   /// @{
 
   const MCExpr &getValue() const { return *Value; }
 
   bool isSigned() const { return IsSigned; }
 
   SmallString<8> &getContents() { return Contents; }
   const SmallString<8> &getContents() const { return Contents; }
 
   /// @}
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_LEB;
   }
 };
 
 class MCDwarfLineAddrFragment : public MCFragment {
   /// LineDelta - the value of the difference between the two line numbers
   /// between two .loc dwarf directives.
   int64_t LineDelta;
 
   /// AddrDelta - The expression for the difference of the two symbols that
   /// make up the address delta between two .loc dwarf directives.
   const MCExpr *AddrDelta;
 
   SmallString<8> Contents;
 
 public:
   MCDwarfLineAddrFragment(int64_t LineDelta, const MCExpr &AddrDelta,
                           MCSection *Sec = nullptr)
       : MCFragment(FT_Dwarf, false, 0, Sec), LineDelta(LineDelta),
         AddrDelta(&AddrDelta) {
     Contents.push_back(0);
   }
 
   /// \name Accessors
   /// @{
 
   int64_t getLineDelta() const { return LineDelta; }
 
   const MCExpr &getAddrDelta() const { return *AddrDelta; }
 
   SmallString<8> &getContents() { return Contents; }
   const SmallString<8> &getContents() const { return Contents; }
 
   /// @}
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_Dwarf;
   }
 };
 
 class MCDwarfCallFrameFragment : public MCFragment {
   /// AddrDelta - The expression for the difference of the two symbols that
   /// make up the address delta between two .cfi_* dwarf directives.
   const MCExpr *AddrDelta;
 
   SmallString<8> Contents;
 
 public:
   MCDwarfCallFrameFragment(const MCExpr &AddrDelta, MCSection *Sec = nullptr)
       : MCFragment(FT_DwarfFrame, false, 0, Sec), AddrDelta(&AddrDelta) {
     Contents.push_back(0);
   }
 
   /// \name Accessors
   /// @{
 
   const MCExpr &getAddrDelta() const { return *AddrDelta; }
 
   SmallString<8> &getContents() { return Contents; }
   const SmallString<8> &getContents() const { return Contents; }
 
   /// @}
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_DwarfFrame;
   }
 };
 
 /// Represents a symbol table index fragment.
 class MCSymbolIdFragment : public MCFragment {
   const MCSymbol *Sym;
 
 public:
   MCSymbolIdFragment(const MCSymbol *Sym, MCSection *Sec = nullptr)
       : MCFragment(FT_SymbolId, false, 0, Sec), Sym(Sym) {}
 
   /// \name Accessors
   /// @{
 
   const MCSymbol *getSymbol() { return Sym; }
   const MCSymbol *getSymbol() const { return Sym; }
 
   /// @}
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_SymbolId;
   }
 };
 
 /// Fragment representing the binary annotations produced by the
 /// .cv_inline_linetable directive.
 class MCCVInlineLineTableFragment : public MCFragment {
   unsigned SiteFuncId;
   unsigned StartFileId;
   unsigned StartLineNum;
   const MCSymbol *FnStartSym;
   const MCSymbol *FnEndSym;
   SmallString<8> Contents;
 
   /// CodeViewContext has the real knowledge about this format, so let it access
   /// our members.
   friend class CodeViewContext;
 
 public:
   MCCVInlineLineTableFragment(unsigned SiteFuncId, unsigned StartFileId,
                               unsigned StartLineNum, const MCSymbol *FnStartSym,
                               const MCSymbol *FnEndSym,
                               MCSection *Sec = nullptr)
       : MCFragment(FT_CVInlineLines, false, 0, Sec), SiteFuncId(SiteFuncId),
         StartFileId(StartFileId), StartLineNum(StartLineNum),
         FnStartSym(FnStartSym), FnEndSym(FnEndSym) {}
 
   /// \name Accessors
   /// @{
 
   const MCSymbol *getFnStartSym() const { return FnStartSym; }
   const MCSymbol *getFnEndSym() const { return FnEndSym; }
 
   SmallString<8> &getContents() { return Contents; }
   const SmallString<8> &getContents() const { return Contents; }
 
   /// @}
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_CVInlineLines;
   }
 };
 
 /// Fragment representing the .cv_def_range directive.
 class MCCVDefRangeFragment : public MCEncodedFragmentWithFixups<32, 4> {
   SmallVector<std::pair<const MCSymbol *, const MCSymbol *>, 2> Ranges;
   SmallString<32> FixedSizePortion;
 
   /// CodeViewContext has the real knowledge about this format, so let it access
   /// our members.
   friend class CodeViewContext;
 
 public:
   MCCVDefRangeFragment(
       ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
       StringRef FixedSizePortion, MCSection *Sec = nullptr)
       : MCEncodedFragmentWithFixups<32, 4>(FT_CVDefRange, false, Sec),
         Ranges(Ranges.begin(), Ranges.end()),
         FixedSizePortion(FixedSizePortion) {}
 
   /// \name Accessors
   /// @{
   ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> getRanges() const {
     return Ranges;
   }
 
   StringRef getFixedSizePortion() const { return FixedSizePortion; }
   /// @}
 
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_CVDefRange;
   }
 };
 
 } // end namespace llvm
 
 #endif // LLVM_MC_MCFRAGMENT_H
Index: head/contrib/llvm/lib/MC/MCAssembler.cpp
===================================================================
--- head/contrib/llvm/lib/MC/MCAssembler.cpp	(revision 328595)
+++ head/contrib/llvm/lib/MC/MCAssembler.cpp	(revision 328596)
@@ -1,988 +1,998 @@
 //===- lib/MC/MCAssembler.cpp - Assembler Backend Implementation ----------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCAsmLayout.h"
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCCodeView.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCFixup.h"
 #include "llvm/MC/MCFixupKindInfo.h"
 #include "llvm/MC/MCFragment.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCSection.h"
 #include "llvm/MC/MCSectionELF.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/LEB128.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <cstdint>
 #include <cstring>
 #include <tuple>
 #include <utility>
 
 using namespace llvm;
 
 #define DEBUG_TYPE "assembler"
 
 namespace {
 namespace stats {
 
 STATISTIC(EmittedFragments, "Number of emitted assembler fragments - total");
 STATISTIC(EmittedRelaxableFragments,
           "Number of emitted assembler fragments - relaxable");
 STATISTIC(EmittedDataFragments,
           "Number of emitted assembler fragments - data");
 STATISTIC(EmittedCompactEncodedInstFragments,
           "Number of emitted assembler fragments - compact encoded inst");
 STATISTIC(EmittedAlignFragments,
           "Number of emitted assembler fragments - align");
 STATISTIC(EmittedFillFragments,
           "Number of emitted assembler fragments - fill");
 STATISTIC(EmittedOrgFragments,
           "Number of emitted assembler fragments - org");
 STATISTIC(evaluateFixup, "Number of evaluated fixups");
 STATISTIC(FragmentLayouts, "Number of fragment layouts");
 STATISTIC(ObjectBytes, "Number of emitted object file bytes");
 STATISTIC(RelaxationSteps, "Number of assembler layout and relaxation steps");
 STATISTIC(RelaxedInstructions, "Number of relaxed instructions");
 STATISTIC(PaddingFragmentsRelaxations,
           "Number of Padding Fragments relaxations");
 STATISTIC(PaddingFragmentsBytes,
           "Total size of all padding from adding Fragments");
 
 } // end namespace stats
 } // end anonymous namespace
 
 // FIXME FIXME FIXME: There are number of places in this file where we convert
 // what is a 64-bit assembler value used for computation into a value in the
 // object file, which may truncate it. We should detect that truncation where
 // invalid and report errors back.
 
 /* *** */
 
 MCAssembler::MCAssembler(MCContext &Context, MCAsmBackend &Backend,
                          MCCodeEmitter &Emitter, MCObjectWriter &Writer)
     : Context(Context), Backend(Backend), Emitter(Emitter), Writer(Writer),
       BundleAlignSize(0), RelaxAll(false), SubsectionsViaSymbols(false),
       IncrementalLinkerCompatible(false), ELFHeaderEFlags(0) {
   VersionInfo.Major = 0; // Major version == 0 for "none specified"
 }
 
 MCAssembler::~MCAssembler() = default;
 
 void MCAssembler::reset() {
   Sections.clear();
   Symbols.clear();
   IndirectSymbols.clear();
   DataRegions.clear();
   LinkerOptions.clear();
   FileNames.clear();
   ThumbFuncs.clear();
   BundleAlignSize = 0;
   RelaxAll = false;
   SubsectionsViaSymbols = false;
   IncrementalLinkerCompatible = false;
   ELFHeaderEFlags = 0;
   LOHContainer.reset();
   VersionInfo.Major = 0;
 
   // reset objects owned by us
   getBackend().reset();
   getEmitter().reset();
   getWriter().reset();
   getLOHContainer().reset();
 }
 
 bool MCAssembler::registerSection(MCSection &Section) {
   if (Section.isRegistered())
     return false;
   Sections.push_back(&Section);
   Section.setIsRegistered(true);
   return true;
 }
 
 bool MCAssembler::isThumbFunc(const MCSymbol *Symbol) const {
   if (ThumbFuncs.count(Symbol))
     return true;
 
   if (!Symbol->isVariable())
     return false;
 
   const MCExpr *Expr = Symbol->getVariableValue();
 
   MCValue V;
   if (!Expr->evaluateAsRelocatable(V, nullptr, nullptr))
     return false;
 
   if (V.getSymB() || V.getRefKind() != MCSymbolRefExpr::VK_None)
     return false;
 
   const MCSymbolRefExpr *Ref = V.getSymA();
   if (!Ref)
     return false;
 
   if (Ref->getKind() != MCSymbolRefExpr::VK_None)
     return false;
 
   const MCSymbol &Sym = Ref->getSymbol();
   if (!isThumbFunc(&Sym))
     return false;
 
   ThumbFuncs.insert(Symbol); // Cache it.
   return true;
 }
 
 bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
   // Non-temporary labels should always be visible to the linker.
   if (!Symbol.isTemporary())
     return true;
 
   // Absolute temporary labels are never visible.
   if (!Symbol.isInSection())
     return false;
 
   if (Symbol.isUsedInReloc())
     return true;
 
   return false;
 }
 
 const MCSymbol *MCAssembler::getAtom(const MCSymbol &S) const {
   // Linker visible symbols define atoms.
   if (isSymbolLinkerVisible(S))
     return &S;
 
   // Absolute and undefined symbols have no defining atom.
   if (!S.isInSection())
     return nullptr;
 
   // Non-linker visible symbols in sections which can't be atomized have no
   // defining atom.
   if (!getContext().getAsmInfo()->isSectionAtomizableBySymbols(
           *S.getFragment()->getParent()))
     return nullptr;
 
   // Otherwise, return the atom for the containing fragment.
   return S.getFragment()->getAtom();
 }
 
 bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
                                 const MCFixup &Fixup, const MCFragment *DF,
                                 MCValue &Target, uint64_t &Value) const {
   ++stats::evaluateFixup;
 
   // FIXME: This code has some duplication with recordRelocation. We should
   // probably merge the two into a single callback that tries to evaluate a
   // fixup and records a relocation if one is needed.
 
   // On error claim to have completely evaluated the fixup, to prevent any
   // further processing from being done.
   const MCExpr *Expr = Fixup.getValue();
   MCContext &Ctx = getContext();
   Value = 0;
   if (!Expr->evaluateAsRelocatable(Target, &Layout, &Fixup)) {
     Ctx.reportError(Fixup.getLoc(), "expected relocatable expression");
     return true;
   }
   if (const MCSymbolRefExpr *RefB = Target.getSymB()) {
     if (RefB->getKind() != MCSymbolRefExpr::VK_None) {
       Ctx.reportError(Fixup.getLoc(),
                       "unsupported subtraction of qualified symbol");
       return true;
     }
   }
 
   bool IsPCRel = Backend.getFixupKindInfo(
     Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel;
 
   bool IsResolved;
   if (IsPCRel) {
     if (Target.getSymB()) {
       IsResolved = false;
     } else if (!Target.getSymA()) {
       IsResolved = false;
     } else {
       const MCSymbolRefExpr *A = Target.getSymA();
       const MCSymbol &SA = A->getSymbol();
       if (A->getKind() != MCSymbolRefExpr::VK_None || SA.isUndefined()) {
         IsResolved = false;
       } else {
         IsResolved = getWriter().isSymbolRefDifferenceFullyResolvedImpl(
             *this, SA, *DF, false, true);
       }
     }
   } else {
     IsResolved = Target.isAbsolute();
   }
 
   Value = Target.getConstant();
 
   if (const MCSymbolRefExpr *A = Target.getSymA()) {
     const MCSymbol &Sym = A->getSymbol();
     if (Sym.isDefined())
       Value += Layout.getSymbolOffset(Sym);
   }
   if (const MCSymbolRefExpr *B = Target.getSymB()) {
     const MCSymbol &Sym = B->getSymbol();
     if (Sym.isDefined())
       Value -= Layout.getSymbolOffset(Sym);
   }
 
   bool ShouldAlignPC = Backend.getFixupKindInfo(Fixup.getKind()).Flags &
                          MCFixupKindInfo::FKF_IsAlignedDownTo32Bits;
   assert((ShouldAlignPC ? IsPCRel : true) &&
     "FKF_IsAlignedDownTo32Bits is only allowed on PC-relative fixups!");
 
   if (IsPCRel) {
     uint32_t Offset = Layout.getFragmentOffset(DF) + Fixup.getOffset();
 
     // A number of ARM fixups in Thumb mode require that the effective PC
     // address be determined as the 32-bit aligned version of the actual offset.
     if (ShouldAlignPC) Offset &= ~0x3;
     Value -= Offset;
   }
 
   // Let the backend force a relocation if needed.
   if (IsResolved && Backend.shouldForceRelocation(*this, Fixup, Target))
     IsResolved = false;
 
   return IsResolved;
 }
 
 uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout,
                                           const MCFragment &F) const {
   switch (F.getKind()) {
   case MCFragment::FT_Data:
     return cast<MCDataFragment>(F).getContents().size();
   case MCFragment::FT_Relaxable:
     return cast<MCRelaxableFragment>(F).getContents().size();
   case MCFragment::FT_CompactEncodedInst:
     return cast<MCCompactEncodedInstFragment>(F).getContents().size();
-  case MCFragment::FT_Fill:
-    return cast<MCFillFragment>(F).getSize();
+  case MCFragment::FT_Fill: {
+    auto &FF = cast<MCFillFragment>(F);
+    int64_t Size = 0;
+    if (!FF.getSize().evaluateAsAbsolute(Size, Layout))
+      getContext().reportError(FF.getLoc(),
+                               "expected assembly-time absolute expression");
+    if (Size < 0) {
+      getContext().reportError(FF.getLoc(), "invalid number of bytes");
+      return 0;
+    }
+    return Size;
+  }
 
   case MCFragment::FT_LEB:
     return cast<MCLEBFragment>(F).getContents().size();
 
   case MCFragment::FT_Padding:
     return cast<MCPaddingFragment>(F).getSize();
 
   case MCFragment::FT_SymbolId:
     return 4;
 
   case MCFragment::FT_Align: {
     const MCAlignFragment &AF = cast<MCAlignFragment>(F);
     unsigned Offset = Layout.getFragmentOffset(&AF);
     unsigned Size = OffsetToAlignment(Offset, AF.getAlignment());
     // If we are padding with nops, force the padding to be larger than the
     // minimum nop size.
     if (Size > 0 && AF.hasEmitNops()) {
       while (Size % getBackend().getMinimumNopSize())
         Size += AF.getAlignment();
     }
     if (Size > AF.getMaxBytesToEmit())
       return 0;
     return Size;
   }
 
   case MCFragment::FT_Org: {
     const MCOrgFragment &OF = cast<MCOrgFragment>(F);
     MCValue Value;
     if (!OF.getOffset().evaluateAsValue(Value, Layout)) {
       getContext().reportError(OF.getLoc(),
                                "expected assembly-time absolute expression");
         return 0;
     }
 
     uint64_t FragmentOffset = Layout.getFragmentOffset(&OF);
     int64_t TargetLocation = Value.getConstant();
     if (const MCSymbolRefExpr *A = Value.getSymA()) {
       uint64_t Val;
       if (!Layout.getSymbolOffset(A->getSymbol(), Val)) {
         getContext().reportError(OF.getLoc(), "expected absolute expression");
         return 0;
       }
       TargetLocation += Val;
     }
     int64_t Size = TargetLocation - FragmentOffset;
     if (Size < 0 || Size >= 0x40000000) {
       getContext().reportError(
           OF.getLoc(), "invalid .org offset '" + Twine(TargetLocation) +
                            "' (at offset '" + Twine(FragmentOffset) + "')");
       return 0;
     }
     return Size;
   }
 
   case MCFragment::FT_Dwarf:
     return cast<MCDwarfLineAddrFragment>(F).getContents().size();
   case MCFragment::FT_DwarfFrame:
     return cast<MCDwarfCallFrameFragment>(F).getContents().size();
   case MCFragment::FT_CVInlineLines:
     return cast<MCCVInlineLineTableFragment>(F).getContents().size();
   case MCFragment::FT_CVDefRange:
     return cast<MCCVDefRangeFragment>(F).getContents().size();
   case MCFragment::FT_Dummy:
     llvm_unreachable("Should not have been added");
   }
 
   llvm_unreachable("invalid fragment kind");
 }
 
 void MCAsmLayout::layoutFragment(MCFragment *F) {
   MCFragment *Prev = F->getPrevNode();
 
   // We should never try to recompute something which is valid.
   assert(!isFragmentValid(F) && "Attempt to recompute a valid fragment!");
   // We should never try to compute the fragment layout if its predecessor
   // isn't valid.
   assert((!Prev || isFragmentValid(Prev)) &&
          "Attempt to compute fragment before its predecessor!");
 
   ++stats::FragmentLayouts;
 
   // Compute fragment offset and size.
   if (Prev)
     F->Offset = Prev->Offset + getAssembler().computeFragmentSize(*this, *Prev);
   else
     F->Offset = 0;
   LastValidFragment[F->getParent()] = F;
 
   // If bundling is enabled and this fragment has instructions in it, it has to
   // obey the bundling restrictions. With padding, we'll have:
   //
   //
   //        BundlePadding
   //             |||
   // -------------------------------------
   //   Prev  |##########|       F        |
   // -------------------------------------
   //                    ^
   //                    |
   //                    F->Offset
   //
   // The fragment's offset will point to after the padding, and its computed
   // size won't include the padding.
   //
   // When the -mc-relax-all flag is used, we optimize bundling by writting the
   // padding directly into fragments when the instructions are emitted inside
   // the streamer. When the fragment is larger than the bundle size, we need to
   // ensure that it's bundle aligned. This means that if we end up with
   // multiple fragments, we must emit bundle padding between fragments.
   //
   // ".align N" is an example of a directive that introduces multiple
   // fragments. We could add a special case to handle ".align N" by emitting
   // within-fragment padding (which would produce less padding when N is less
   // than the bundle size), but for now we don't.
   //
   if (Assembler.isBundlingEnabled() && F->hasInstructions()) {
     assert(isa<MCEncodedFragment>(F) &&
            "Only MCEncodedFragment implementations have instructions");
     uint64_t FSize = Assembler.computeFragmentSize(*this, *F);
 
     if (!Assembler.getRelaxAll() && FSize > Assembler.getBundleAlignSize())
       report_fatal_error("Fragment can't be larger than a bundle size");
 
     uint64_t RequiredBundlePadding = computeBundlePadding(Assembler, F,
                                                           F->Offset, FSize);
     if (RequiredBundlePadding > UINT8_MAX)
       report_fatal_error("Padding cannot exceed 255 bytes");
     F->setBundlePadding(static_cast<uint8_t>(RequiredBundlePadding));
     F->Offset += RequiredBundlePadding;
   }
 }
 
 void MCAssembler::registerSymbol(const MCSymbol &Symbol, bool *Created) {
   bool New = !Symbol.isRegistered();
   if (Created)
     *Created = New;
   if (New) {
     Symbol.setIsRegistered(true);
     Symbols.push_back(&Symbol);
   }
 }
 
 void MCAssembler::writeFragmentPadding(const MCFragment &F, uint64_t FSize,
                                        MCObjectWriter *OW) const {
   // Should NOP padding be written out before this fragment?
   unsigned BundlePadding = F.getBundlePadding();
   if (BundlePadding > 0) {
     assert(isBundlingEnabled() &&
            "Writing bundle padding with disabled bundling");
     assert(F.hasInstructions() &&
            "Writing bundle padding for a fragment without instructions");
 
     unsigned TotalLength = BundlePadding + static_cast<unsigned>(FSize);
     if (F.alignToBundleEnd() && TotalLength > getBundleAlignSize()) {
       // If the padding itself crosses a bundle boundary, it must be emitted
       // in 2 pieces, since even nop instructions must not cross boundaries.
       //             v--------------v   <- BundleAlignSize
       //        v---------v             <- BundlePadding
       // ----------------------------
       // | Prev |####|####|    F    |
       // ----------------------------
       //        ^-------------------^   <- TotalLength
       unsigned DistanceToBoundary = TotalLength - getBundleAlignSize();
       if (!getBackend().writeNopData(DistanceToBoundary, OW))
           report_fatal_error("unable to write NOP sequence of " +
                              Twine(DistanceToBoundary) + " bytes");
       BundlePadding -= DistanceToBoundary;
     }
     if (!getBackend().writeNopData(BundlePadding, OW))
       report_fatal_error("unable to write NOP sequence of " +
                          Twine(BundlePadding) + " bytes");
   }
 }
 
 /// \brief Write the fragment \p F to the output file.
 static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout,
                           const MCFragment &F) {
   MCObjectWriter *OW = &Asm.getWriter();
 
   // FIXME: Embed in fragments instead?
   uint64_t FragmentSize = Asm.computeFragmentSize(Layout, F);
 
   Asm.writeFragmentPadding(F, FragmentSize, OW);
 
   // This variable (and its dummy usage) is to participate in the assert at
   // the end of the function.
   uint64_t Start = OW->getStream().tell();
   (void) Start;
 
   ++stats::EmittedFragments;
 
   switch (F.getKind()) {
   case MCFragment::FT_Align: {
     ++stats::EmittedAlignFragments;
     const MCAlignFragment &AF = cast<MCAlignFragment>(F);
     assert(AF.getValueSize() && "Invalid virtual align in concrete fragment!");
 
     uint64_t Count = FragmentSize / AF.getValueSize();
 
     // FIXME: This error shouldn't actually occur (the front end should emit
     // multiple .align directives to enforce the semantics it wants), but is
     // severe enough that we want to report it. How to handle this?
     if (Count * AF.getValueSize() != FragmentSize)
       report_fatal_error("undefined .align directive, value size '" +
                         Twine(AF.getValueSize()) +
                         "' is not a divisor of padding size '" +
                         Twine(FragmentSize) + "'");
 
     // See if we are aligning with nops, and if so do that first to try to fill
     // the Count bytes.  Then if that did not fill any bytes or there are any
     // bytes left to fill use the Value and ValueSize to fill the rest.
     // If we are aligning with nops, ask that target to emit the right data.
     if (AF.hasEmitNops()) {
       if (!Asm.getBackend().writeNopData(Count, OW))
         report_fatal_error("unable to write nop sequence of " +
                           Twine(Count) + " bytes");
       break;
     }
 
     // Otherwise, write out in multiples of the value size.
     for (uint64_t i = 0; i != Count; ++i) {
       switch (AF.getValueSize()) {
       default: llvm_unreachable("Invalid size!");
       case 1: OW->write8 (uint8_t (AF.getValue())); break;
       case 2: OW->write16(uint16_t(AF.getValue())); break;
       case 4: OW->write32(uint32_t(AF.getValue())); break;
       case 8: OW->write64(uint64_t(AF.getValue())); break;
       }
     }
     break;
   }
 
   case MCFragment::FT_Data: 
     ++stats::EmittedDataFragments;
     OW->writeBytes(cast<MCDataFragment>(F).getContents());
     break;
 
   case MCFragment::FT_Relaxable:
     ++stats::EmittedRelaxableFragments;
     OW->writeBytes(cast<MCRelaxableFragment>(F).getContents());
     break;
 
   case MCFragment::FT_CompactEncodedInst:
     ++stats::EmittedCompactEncodedInstFragments;
     OW->writeBytes(cast<MCCompactEncodedInstFragment>(F).getContents());
     break;
 
   case MCFragment::FT_Fill: {
     ++stats::EmittedFillFragments;
     const MCFillFragment &FF = cast<MCFillFragment>(F);
     uint8_t V = FF.getValue();
     const unsigned MaxChunkSize = 16;
     char Data[MaxChunkSize];
     memcpy(Data, &V, 1);
     for (unsigned I = 1; I < MaxChunkSize; ++I)
       Data[I] = Data[0];
 
-    uint64_t Size = FF.getSize();
+    uint64_t Size = FragmentSize;
     for (unsigned ChunkSize = MaxChunkSize; ChunkSize; ChunkSize /= 2) {
       StringRef Ref(Data, ChunkSize);
       for (uint64_t I = 0, E = Size / ChunkSize; I != E; ++I)
         OW->writeBytes(Ref);
       Size = Size % ChunkSize;
     }
     break;
   }
 
   case MCFragment::FT_LEB: {
     const MCLEBFragment &LF = cast<MCLEBFragment>(F);
     OW->writeBytes(LF.getContents());
     break;
   }
 
   case MCFragment::FT_Padding: {
     if (!Asm.getBackend().writeNopData(FragmentSize, OW))
       report_fatal_error("unable to write nop sequence of " +
                          Twine(FragmentSize) + " bytes");
     break;
   }
 
   case MCFragment::FT_SymbolId: {
     const MCSymbolIdFragment &SF = cast<MCSymbolIdFragment>(F);
     OW->write32(SF.getSymbol()->getIndex());
     break;
   }
 
   case MCFragment::FT_Org: {
     ++stats::EmittedOrgFragments;
     const MCOrgFragment &OF = cast<MCOrgFragment>(F);
 
     for (uint64_t i = 0, e = FragmentSize; i != e; ++i)
       OW->write8(uint8_t(OF.getValue()));
 
     break;
   }
 
   case MCFragment::FT_Dwarf: {
     const MCDwarfLineAddrFragment &OF = cast<MCDwarfLineAddrFragment>(F);
     OW->writeBytes(OF.getContents());
     break;
   }
   case MCFragment::FT_DwarfFrame: {
     const MCDwarfCallFrameFragment &CF = cast<MCDwarfCallFrameFragment>(F);
     OW->writeBytes(CF.getContents());
     break;
   }
   case MCFragment::FT_CVInlineLines: {
     const auto &OF = cast<MCCVInlineLineTableFragment>(F);
     OW->writeBytes(OF.getContents());
     break;
   }
   case MCFragment::FT_CVDefRange: {
     const auto &DRF = cast<MCCVDefRangeFragment>(F);
     OW->writeBytes(DRF.getContents());
     break;
   }
   case MCFragment::FT_Dummy:
     llvm_unreachable("Should not have been added");
   }
 
   assert(OW->getStream().tell() - Start == FragmentSize &&
          "The stream should advance by fragment size");
 }
 
 void MCAssembler::writeSectionData(const MCSection *Sec,
                                    const MCAsmLayout &Layout) const {
   // Ignore virtual sections.
   if (Sec->isVirtualSection()) {
     assert(Layout.getSectionFileSize(Sec) == 0 && "Invalid size for section!");
 
     // Check that contents are only things legal inside a virtual section.
     for (const MCFragment &F : *Sec) {
       switch (F.getKind()) {
       default: llvm_unreachable("Invalid fragment in virtual section!");
       case MCFragment::FT_Data: {
         // Check that we aren't trying to write a non-zero contents (or fixups)
         // into a virtual section. This is to support clients which use standard
         // directives to fill the contents of virtual sections.
         const MCDataFragment &DF = cast<MCDataFragment>(F);
         if (DF.fixup_begin() != DF.fixup_end())
           report_fatal_error("cannot have fixups in virtual section!");
         for (unsigned i = 0, e = DF.getContents().size(); i != e; ++i)
           if (DF.getContents()[i]) {
             if (auto *ELFSec = dyn_cast<const MCSectionELF>(Sec))
               report_fatal_error("non-zero initializer found in section '" +
                   ELFSec->getSectionName() + "'");
             else
               report_fatal_error("non-zero initializer found in virtual section");
           }
         break;
       }
       case MCFragment::FT_Align:
         // Check that we aren't trying to write a non-zero value into a virtual
         // section.
         assert((cast<MCAlignFragment>(F).getValueSize() == 0 ||
                 cast<MCAlignFragment>(F).getValue() == 0) &&
                "Invalid align in virtual section!");
         break;
       case MCFragment::FT_Fill:
         assert((cast<MCFillFragment>(F).getValue() == 0) &&
                "Invalid fill in virtual section!");
         break;
       }
     }
 
     return;
   }
 
   uint64_t Start = getWriter().getStream().tell();
   (void)Start;
 
   for (const MCFragment &F : *Sec)
     writeFragment(*this, Layout, F);
 
   assert(getWriter().getStream().tell() - Start ==
          Layout.getSectionAddressSize(Sec));
 }
 
 std::tuple<MCValue, uint64_t, bool>
 MCAssembler::handleFixup(const MCAsmLayout &Layout, MCFragment &F,
                          const MCFixup &Fixup) {
   // Evaluate the fixup.
   MCValue Target;
   uint64_t FixedValue;
   bool IsResolved = evaluateFixup(Layout, Fixup, &F, Target, FixedValue);
   if (!IsResolved) {
     // The fixup was unresolved, we need a relocation. Inform the object
     // writer of the relocation, and give it an opportunity to adjust the
     // fixup value if need be.
     getWriter().recordRelocation(*this, Layout, &F, Fixup, Target, FixedValue);
   }
   return std::make_tuple(Target, FixedValue, IsResolved);
 }
 
 void MCAssembler::layout(MCAsmLayout &Layout) {
   DEBUG_WITH_TYPE("mc-dump", {
       errs() << "assembler backend - pre-layout\n--\n";
       dump(); });
 
   // Create dummy fragments and assign section ordinals.
   unsigned SectionIndex = 0;
   for (MCSection &Sec : *this) {
     // Create dummy fragments to eliminate any empty sections, this simplifies
     // layout.
     if (Sec.getFragmentList().empty())
       new MCDataFragment(&Sec);
 
     Sec.setOrdinal(SectionIndex++);
   }
 
   // Assign layout order indices to sections and fragments.
   for (unsigned i = 0, e = Layout.getSectionOrder().size(); i != e; ++i) {
     MCSection *Sec = Layout.getSectionOrder()[i];
     Sec->setLayoutOrder(i);
 
     unsigned FragmentIndex = 0;
     for (MCFragment &Frag : *Sec)
       Frag.setLayoutOrder(FragmentIndex++);
   }
 
   // Layout until everything fits.
   while (layoutOnce(Layout))
     if (getContext().hadError())
       return;
 
   DEBUG_WITH_TYPE("mc-dump", {
       errs() << "assembler backend - post-relaxation\n--\n";
       dump(); });
 
   // Finalize the layout, including fragment lowering.
   finishLayout(Layout);
 
   DEBUG_WITH_TYPE("mc-dump", {
       errs() << "assembler backend - final-layout\n--\n";
       dump(); });
 
   // Allow the object writer a chance to perform post-layout binding (for
   // example, to set the index fields in the symbol data).
   getWriter().executePostLayoutBinding(*this, Layout);
 
   // Evaluate and apply the fixups, generating relocation entries as necessary.
   for (MCSection &Sec : *this) {
     for (MCFragment &Frag : Sec) {
       // Data and relaxable fragments both have fixups.  So only process
       // those here.
       // FIXME: Is there a better way to do this?  MCEncodedFragmentWithFixups
       // being templated makes this tricky.
       if (isa<MCEncodedFragment>(&Frag) &&
           isa<MCCompactEncodedInstFragment>(&Frag))
         continue;
       if (!isa<MCEncodedFragment>(&Frag) && !isa<MCCVDefRangeFragment>(&Frag))
         continue;
       ArrayRef<MCFixup> Fixups;
       MutableArrayRef<char> Contents;
       if (auto *FragWithFixups = dyn_cast<MCDataFragment>(&Frag)) {
         Fixups = FragWithFixups->getFixups();
         Contents = FragWithFixups->getContents();
       } else if (auto *FragWithFixups = dyn_cast<MCRelaxableFragment>(&Frag)) {
         Fixups = FragWithFixups->getFixups();
         Contents = FragWithFixups->getContents();
       } else if (auto *FragWithFixups = dyn_cast<MCCVDefRangeFragment>(&Frag)) {
         Fixups = FragWithFixups->getFixups();
         Contents = FragWithFixups->getContents();
       } else
         llvm_unreachable("Unknown fragment with fixups!");
       for (const MCFixup &Fixup : Fixups) {
         uint64_t FixedValue;
         bool IsResolved;
         MCValue Target;
         std::tie(Target, FixedValue, IsResolved) =
             handleFixup(Layout, Frag, Fixup);
         getBackend().applyFixup(*this, Fixup, Target, Contents, FixedValue,
                                 IsResolved);
       }
     }
   }
 }
 
 void MCAssembler::Finish() {
   // Create the layout object.
   MCAsmLayout Layout(*this);
   layout(Layout);
 
   raw_ostream &OS = getWriter().getStream();
   uint64_t StartOffset = OS.tell();
 
   // Write the object file.
   getWriter().writeObject(*this, Layout);
 
   stats::ObjectBytes += OS.tell() - StartOffset;
 }
 
 bool MCAssembler::fixupNeedsRelaxation(const MCFixup &Fixup,
                                        const MCRelaxableFragment *DF,
                                        const MCAsmLayout &Layout) const {
   MCValue Target;
   uint64_t Value;
   bool Resolved = evaluateFixup(Layout, Fixup, DF, Target, Value);
   if (Target.getSymA() &&
       Target.getSymA()->getKind() == MCSymbolRefExpr::VK_X86_ABS8 &&
       Fixup.getKind() == FK_Data_1)
     return false;
   return getBackend().fixupNeedsRelaxationAdvanced(Fixup, Resolved, Value, DF,
                                                    Layout);
 }
 
 bool MCAssembler::fragmentNeedsRelaxation(const MCRelaxableFragment *F,
                                           const MCAsmLayout &Layout) const {
   // If this inst doesn't ever need relaxation, ignore it. This occurs when we
   // are intentionally pushing out inst fragments, or because we relaxed a
   // previous instruction to one that doesn't need relaxation.
   if (!getBackend().mayNeedRelaxation(F->getInst()))
     return false;
 
   for (const MCFixup &Fixup : F->getFixups())
     if (fixupNeedsRelaxation(Fixup, F, Layout))
       return true;
 
   return false;
 }
 
 bool MCAssembler::relaxInstruction(MCAsmLayout &Layout,
                                    MCRelaxableFragment &F) {
   if (!fragmentNeedsRelaxation(&F, Layout))
     return false;
 
   ++stats::RelaxedInstructions;
 
   // FIXME-PERF: We could immediately lower out instructions if we can tell
   // they are fully resolved, to avoid retesting on later passes.
 
   // Relax the fragment.
 
   MCInst Relaxed;
   getBackend().relaxInstruction(F.getInst(), F.getSubtargetInfo(), Relaxed);
 
   // Encode the new instruction.
   //
   // FIXME-PERF: If it matters, we could let the target do this. It can
   // probably do so more efficiently in many cases.
   SmallVector<MCFixup, 4> Fixups;
   SmallString<256> Code;
   raw_svector_ostream VecOS(Code);
   getEmitter().encodeInstruction(Relaxed, VecOS, Fixups, F.getSubtargetInfo());
 
   // Update the fragment.
   F.setInst(Relaxed);
   F.getContents() = Code;
   F.getFixups() = Fixups;
 
   return true;
 }
 
 bool MCAssembler::relaxPaddingFragment(MCAsmLayout &Layout,
                                        MCPaddingFragment &PF) {
   uint64_t OldSize = PF.getSize();
   if (!getBackend().relaxFragment(&PF, Layout))
     return false;
   uint64_t NewSize = PF.getSize();
 
   ++stats::PaddingFragmentsRelaxations;
   stats::PaddingFragmentsBytes += NewSize;
   stats::PaddingFragmentsBytes -= OldSize;
   return true;
 }
 
 bool MCAssembler::relaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) {
   uint64_t OldSize = LF.getContents().size();
   int64_t Value;
   bool Abs = LF.getValue().evaluateKnownAbsolute(Value, Layout);
   if (!Abs)
     report_fatal_error("sleb128 and uleb128 expressions must be absolute");
   SmallString<8> &Data = LF.getContents();
   Data.clear();
   raw_svector_ostream OSE(Data);
   if (LF.isSigned())
     encodeSLEB128(Value, OSE);
   else
     encodeULEB128(Value, OSE);
   return OldSize != LF.getContents().size();
 }
 
 bool MCAssembler::relaxDwarfLineAddr(MCAsmLayout &Layout,
                                      MCDwarfLineAddrFragment &DF) {
   MCContext &Context = Layout.getAssembler().getContext();
   uint64_t OldSize = DF.getContents().size();
   int64_t AddrDelta;
   bool Abs = DF.getAddrDelta().evaluateKnownAbsolute(AddrDelta, Layout);
   assert(Abs && "We created a line delta with an invalid expression");
   (void) Abs;
   int64_t LineDelta;
   LineDelta = DF.getLineDelta();
   SmallString<8> &Data = DF.getContents();
   Data.clear();
   raw_svector_ostream OSE(Data);
   MCDwarfLineAddr::Encode(Context, getDWARFLinetableParams(), LineDelta,
                           AddrDelta, OSE);
   return OldSize != Data.size();
 }
 
 bool MCAssembler::relaxDwarfCallFrameFragment(MCAsmLayout &Layout,
                                               MCDwarfCallFrameFragment &DF) {
   MCContext &Context = Layout.getAssembler().getContext();
   uint64_t OldSize = DF.getContents().size();
   int64_t AddrDelta;
   bool Abs = DF.getAddrDelta().evaluateKnownAbsolute(AddrDelta, Layout);
   assert(Abs && "We created call frame with an invalid expression");
   (void) Abs;
   SmallString<8> &Data = DF.getContents();
   Data.clear();
   raw_svector_ostream OSE(Data);
   MCDwarfFrameEmitter::EncodeAdvanceLoc(Context, AddrDelta, OSE);
   return OldSize != Data.size();
 }
 
 bool MCAssembler::relaxCVInlineLineTable(MCAsmLayout &Layout,
                                          MCCVInlineLineTableFragment &F) {
   unsigned OldSize = F.getContents().size();
   getContext().getCVContext().encodeInlineLineTable(Layout, F);
   return OldSize != F.getContents().size();
 }
 
 bool MCAssembler::relaxCVDefRange(MCAsmLayout &Layout,
                                   MCCVDefRangeFragment &F) {
   unsigned OldSize = F.getContents().size();
   getContext().getCVContext().encodeDefRange(Layout, F);
   return OldSize != F.getContents().size();
 }
 
 bool MCAssembler::layoutSectionOnce(MCAsmLayout &Layout, MCSection &Sec) {
   // Holds the first fragment which needed relaxing during this layout. It will
   // remain NULL if none were relaxed.
   // When a fragment is relaxed, all the fragments following it should get
   // invalidated because their offset is going to change.
   MCFragment *FirstRelaxedFragment = nullptr;
 
   // Attempt to relax all the fragments in the section.
   for (MCSection::iterator I = Sec.begin(), IE = Sec.end(); I != IE; ++I) {
     // Check if this is a fragment that needs relaxation.
     bool RelaxedFrag = false;
     switch(I->getKind()) {
     default:
       break;
     case MCFragment::FT_Relaxable:
       assert(!getRelaxAll() &&
              "Did not expect a MCRelaxableFragment in RelaxAll mode");
       RelaxedFrag = relaxInstruction(Layout, *cast<MCRelaxableFragment>(I));
       break;
     case MCFragment::FT_Dwarf:
       RelaxedFrag = relaxDwarfLineAddr(Layout,
                                        *cast<MCDwarfLineAddrFragment>(I));
       break;
     case MCFragment::FT_DwarfFrame:
       RelaxedFrag =
         relaxDwarfCallFrameFragment(Layout,
                                     *cast<MCDwarfCallFrameFragment>(I));
       break;
     case MCFragment::FT_LEB:
       RelaxedFrag = relaxLEB(Layout, *cast<MCLEBFragment>(I));
       break;
     case MCFragment::FT_Padding:
       RelaxedFrag = relaxPaddingFragment(Layout, *cast<MCPaddingFragment>(I));
       break;
     case MCFragment::FT_CVInlineLines:
       RelaxedFrag =
           relaxCVInlineLineTable(Layout, *cast<MCCVInlineLineTableFragment>(I));
       break;
     case MCFragment::FT_CVDefRange:
       RelaxedFrag = relaxCVDefRange(Layout, *cast<MCCVDefRangeFragment>(I));
       break;
     }
     if (RelaxedFrag && !FirstRelaxedFragment)
       FirstRelaxedFragment = &*I;
   }
   if (FirstRelaxedFragment) {
     Layout.invalidateFragmentsFrom(FirstRelaxedFragment);
     return true;
   }
   return false;
 }
 
 bool MCAssembler::layoutOnce(MCAsmLayout &Layout) {
   ++stats::RelaxationSteps;
 
   bool WasRelaxed = false;
   for (iterator it = begin(), ie = end(); it != ie; ++it) {
     MCSection &Sec = *it;
     while (layoutSectionOnce(Layout, Sec))
       WasRelaxed = true;
   }
 
   return WasRelaxed;
 }
 
 void MCAssembler::finishLayout(MCAsmLayout &Layout) {
   // The layout is done. Mark every fragment as valid.
   for (unsigned int i = 0, n = Layout.getSectionOrder().size(); i != n; ++i) {
     MCSection &Section = *Layout.getSectionOrder()[i];
     Layout.getFragmentOffset(&*Section.rbegin());
     computeFragmentSize(Layout, *Section.rbegin());
   }
   getBackend().finishLayout(*this, Layout);
 }
Index: head/contrib/llvm/lib/MC/MCObjectStreamer.cpp
===================================================================
--- head/contrib/llvm/lib/MC/MCObjectStreamer.cpp	(revision 328595)
+++ head/contrib/llvm/lib/MC/MCObjectStreamer.cpp	(revision 328596)
@@ -1,632 +1,621 @@
 //===- lib/MC/MCObjectStreamer.cpp - Object File MCStreamer Interface -----===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/MC/MCObjectStreamer.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCCodeView.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCSection.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/SourceMgr.h"
 using namespace llvm;
 
 MCObjectStreamer::MCObjectStreamer(MCContext &Context,
                                    std::unique_ptr<MCAsmBackend> TAB,
                                    raw_pwrite_stream &OS,
                                    std::unique_ptr<MCCodeEmitter> Emitter)
     : MCStreamer(Context), ObjectWriter(TAB->createObjectWriter(OS)),
       TAB(std::move(TAB)), Emitter(std::move(Emitter)),
       Assembler(llvm::make_unique<MCAssembler>(Context, *this->TAB,
                                                *this->Emitter, *ObjectWriter)),
       EmitEHFrame(true), EmitDebugFrame(false) {}
 
 MCObjectStreamer::~MCObjectStreamer() {}
 
 void MCObjectStreamer::flushPendingLabels(MCFragment *F, uint64_t FOffset) {
   if (PendingLabels.empty())
     return;
   if (!F) {
     F = new MCDataFragment();
     MCSection *CurSection = getCurrentSectionOnly();
     CurSection->getFragmentList().insert(CurInsertionPoint, F);
     F->setParent(CurSection);
   }
   for (MCSymbol *Sym : PendingLabels) {
     Sym->setFragment(F);
     Sym->setOffset(FOffset);
   }
   PendingLabels.clear();
 }
 
 void MCObjectStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi,
                                               const MCSymbol *Lo,
                                               unsigned Size) {
   // If not assigned to the same (valid) fragment, fallback.
   if (!Hi->getFragment() || Hi->getFragment() != Lo->getFragment() ||
       Hi->isVariable() || Lo->isVariable()) {
     MCStreamer::emitAbsoluteSymbolDiff(Hi, Lo, Size);
     return;
   }
 
   EmitIntValue(Hi->getOffset() - Lo->getOffset(), Size);
 }
 
 void MCObjectStreamer::reset() {
   if (Assembler)
     Assembler->reset();
   CurInsertionPoint = MCSection::iterator();
   EmitEHFrame = true;
   EmitDebugFrame = false;
   PendingLabels.clear();
   MCStreamer::reset();
 }
 
 void MCObjectStreamer::EmitFrames(MCAsmBackend *MAB) {
   if (!getNumFrameInfos())
     return;
 
   if (EmitEHFrame)
     MCDwarfFrameEmitter::Emit(*this, MAB, true);
 
   if (EmitDebugFrame)
     MCDwarfFrameEmitter::Emit(*this, MAB, false);
 }
 
 MCFragment *MCObjectStreamer::getCurrentFragment() const {
   assert(getCurrentSectionOnly() && "No current section!");
 
   if (CurInsertionPoint != getCurrentSectionOnly()->getFragmentList().begin())
     return &*std::prev(CurInsertionPoint);
 
   return nullptr;
 }
 
 MCDataFragment *MCObjectStreamer::getOrCreateDataFragment() {
   MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
   // When bundling is enabled, we don't want to add data to a fragment that
   // already has instructions (see MCELFStreamer::EmitInstToData for details)
   if (!F || (Assembler->isBundlingEnabled() && !Assembler->getRelaxAll() &&
              F->hasInstructions())) {
     F = new MCDataFragment();
     insert(F);
   }
   return F;
 }
 
 MCPaddingFragment *MCObjectStreamer::getOrCreatePaddingFragment() {
   MCPaddingFragment *F =
       dyn_cast_or_null<MCPaddingFragment>(getCurrentFragment());
   if (!F) {
     F = new MCPaddingFragment();
     insert(F);
   }
   return F;
 }
 
 void MCObjectStreamer::visitUsedSymbol(const MCSymbol &Sym) {
   Assembler->registerSymbol(Sym);
 }
 
 void MCObjectStreamer::EmitCFISections(bool EH, bool Debug) {
   MCStreamer::EmitCFISections(EH, Debug);
   EmitEHFrame = EH;
   EmitDebugFrame = Debug;
 }
 
 void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
                                      SMLoc Loc) {
   MCStreamer::EmitValueImpl(Value, Size, Loc);
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
 
   MCCVLineEntry::Make(this);
   MCDwarfLineEntry::Make(this, getCurrentSectionOnly());
 
   // Avoid fixups when possible.
   int64_t AbsValue;
   if (Value->evaluateAsAbsolute(AbsValue, getAssembler())) {
     if (!isUIntN(8 * Size, AbsValue) && !isIntN(8 * Size, AbsValue)) {
       getContext().reportError(
           Loc, "value evaluated as " + Twine(AbsValue) + " is out of range.");
       return;
     }
     EmitIntValue(AbsValue, Size);
     return;
   }
   DF->getFixups().push_back(
       MCFixup::create(DF->getContents().size(), Value,
                       MCFixup::getKindForSize(Size, false), Loc));
   DF->getContents().resize(DF->getContents().size() + Size, 0);
 }
 
 MCSymbol *MCObjectStreamer::EmitCFILabel() {
   MCSymbol *Label = getContext().createTempSymbol("cfi", true);
   EmitLabel(Label);
   return Label;
 }
 
 void MCObjectStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
   // We need to create a local symbol to avoid relocations.
   Frame.Begin = getContext().createTempSymbol();
   EmitLabel(Frame.Begin);
 }
 
 void MCObjectStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
   Frame.End = getContext().createTempSymbol();
   EmitLabel(Frame.End);
 }
 
 void MCObjectStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc) {
   MCStreamer::EmitLabel(Symbol, Loc);
 
   getAssembler().registerSymbol(*Symbol);
 
   // If there is a current fragment, mark the symbol as pointing into it.
   // Otherwise queue the label and set its fragment pointer when we emit the
   // next fragment.
   auto *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
   if (F && !(getAssembler().isBundlingEnabled() &&
              getAssembler().getRelaxAll())) {
     Symbol->setFragment(F);
     Symbol->setOffset(F->getContents().size());
   } else {
     PendingLabels.push_back(Symbol);
   }
 }
 
 void MCObjectStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc, MCFragment *F) {
   MCStreamer::EmitLabel(Symbol, Loc);
   getAssembler().registerSymbol(*Symbol);
   auto *DF = dyn_cast_or_null<MCDataFragment>(F);
   if (DF)
     Symbol->setFragment(F);
   else
     PendingLabels.push_back(Symbol);
 }
 
 void MCObjectStreamer::EmitULEB128Value(const MCExpr *Value) {
   int64_t IntValue;
   if (Value->evaluateAsAbsolute(IntValue, getAssembler())) {
     EmitULEB128IntValue(IntValue);
     return;
   }
   insert(new MCLEBFragment(*Value, false));
 }
 
 void MCObjectStreamer::EmitSLEB128Value(const MCExpr *Value) {
   int64_t IntValue;
   if (Value->evaluateAsAbsolute(IntValue, getAssembler())) {
     EmitSLEB128IntValue(IntValue);
     return;
   }
   insert(new MCLEBFragment(*Value, true));
 }
 
 void MCObjectStreamer::EmitWeakReference(MCSymbol *Alias,
                                          const MCSymbol *Symbol) {
   report_fatal_error("This file format doesn't support weak aliases.");
 }
 
 void MCObjectStreamer::ChangeSection(MCSection *Section,
                                      const MCExpr *Subsection) {
   changeSectionImpl(Section, Subsection);
 }
 
 bool MCObjectStreamer::changeSectionImpl(MCSection *Section,
                                          const MCExpr *Subsection) {
   assert(Section && "Cannot switch to a null section!");
   flushPendingLabels(nullptr);
   getContext().clearDwarfLocSeen();
 
   bool Created = getAssembler().registerSection(*Section);
 
   int64_t IntSubsection = 0;
   if (Subsection &&
       !Subsection->evaluateAsAbsolute(IntSubsection, getAssembler()))
     report_fatal_error("Cannot evaluate subsection number");
   if (IntSubsection < 0 || IntSubsection > 8192)
     report_fatal_error("Subsection number out of range");
   CurInsertionPoint =
       Section->getSubsectionInsertionPoint(unsigned(IntSubsection));
   return Created;
 }
 
 void MCObjectStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
   getAssembler().registerSymbol(*Symbol);
   MCStreamer::EmitAssignment(Symbol, Value);
 }
 
 bool MCObjectStreamer::mayHaveInstructions(MCSection &Sec) const {
   return Sec.hasInstructions();
 }
 
 void MCObjectStreamer::EmitInstruction(const MCInst &Inst,
                                        const MCSubtargetInfo &STI, bool) {
   getAssembler().getBackend().handleCodePaddingInstructionBegin(Inst);
   EmitInstructionImpl(Inst, STI);
   getAssembler().getBackend().handleCodePaddingInstructionEnd(Inst);
 }
 
 void MCObjectStreamer::EmitInstructionImpl(const MCInst &Inst,
                                            const MCSubtargetInfo &STI) {
   MCStreamer::EmitInstruction(Inst, STI);
 
   MCSection *Sec = getCurrentSectionOnly();
   Sec->setHasInstructions(true);
 
   // Now that a machine instruction has been assembled into this section, make
   // a line entry for any .loc directive that has been seen.
   MCCVLineEntry::Make(this);
   MCDwarfLineEntry::Make(this, getCurrentSectionOnly());
 
   // If this instruction doesn't need relaxation, just emit it as data.
   MCAssembler &Assembler = getAssembler();
   if (!Assembler.getBackend().mayNeedRelaxation(Inst)) {
     EmitInstToData(Inst, STI);
     return;
   }
 
   // Otherwise, relax and emit it as data if either:
   // - The RelaxAll flag was passed
   // - Bundling is enabled and this instruction is inside a bundle-locked
   //   group. We want to emit all such instructions into the same data
   //   fragment.
   if (Assembler.getRelaxAll() ||
       (Assembler.isBundlingEnabled() && Sec->isBundleLocked())) {
     MCInst Relaxed;
     getAssembler().getBackend().relaxInstruction(Inst, STI, Relaxed);
     while (getAssembler().getBackend().mayNeedRelaxation(Relaxed))
       getAssembler().getBackend().relaxInstruction(Relaxed, STI, Relaxed);
     EmitInstToData(Relaxed, STI);
     return;
   }
 
   // Otherwise emit to a separate fragment.
   EmitInstToFragment(Inst, STI);
 }
 
 void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst,
                                           const MCSubtargetInfo &STI) {
   if (getAssembler().getRelaxAll() && getAssembler().isBundlingEnabled())
     llvm_unreachable("All instructions should have already been relaxed");
 
   // Always create a new, separate fragment here, because its size can change
   // during relaxation.
   MCRelaxableFragment *IF = new MCRelaxableFragment(Inst, STI);
   insert(IF);
 
   SmallString<128> Code;
   raw_svector_ostream VecOS(Code);
   getAssembler().getEmitter().encodeInstruction(Inst, VecOS, IF->getFixups(),
                                                 STI);
   IF->getContents().append(Code.begin(), Code.end());
 }
 
 #ifndef NDEBUG
 static const char *const BundlingNotImplementedMsg =
   "Aligned bundling is not implemented for this object format";
 #endif
 
 void MCObjectStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
   llvm_unreachable(BundlingNotImplementedMsg);
 }
 
 void MCObjectStreamer::EmitBundleLock(bool AlignToEnd) {
   llvm_unreachable(BundlingNotImplementedMsg);
 }
 
 void MCObjectStreamer::EmitBundleUnlock() {
   llvm_unreachable(BundlingNotImplementedMsg);
 }
 
 void MCObjectStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
                                              unsigned Column, unsigned Flags,
                                              unsigned Isa,
                                              unsigned Discriminator,
                                              StringRef FileName) {
   // In case we see two .loc directives in a row, make sure the
   // first one gets a line entry.
   MCDwarfLineEntry::Make(this, getCurrentSectionOnly());
 
   this->MCStreamer::EmitDwarfLocDirective(FileNo, Line, Column, Flags,
                                           Isa, Discriminator, FileName);
 }
 
 static const MCExpr *buildSymbolDiff(MCObjectStreamer &OS, const MCSymbol *A,
                                      const MCSymbol *B) {
   MCContext &Context = OS.getContext();
   MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
   const MCExpr *ARef = MCSymbolRefExpr::create(A, Variant, Context);
   const MCExpr *BRef = MCSymbolRefExpr::create(B, Variant, Context);
   const MCExpr *AddrDelta =
       MCBinaryExpr::create(MCBinaryExpr::Sub, ARef, BRef, Context);
   return AddrDelta;
 }
 
 static void emitDwarfSetLineAddr(MCObjectStreamer &OS,
                                  MCDwarfLineTableParams Params,
                                  int64_t LineDelta, const MCSymbol *Label,
                                  int PointerSize) {
   // emit the sequence to set the address
   OS.EmitIntValue(dwarf::DW_LNS_extended_op, 1);
   OS.EmitULEB128IntValue(PointerSize + 1);
   OS.EmitIntValue(dwarf::DW_LNE_set_address, 1);
   OS.EmitSymbolValue(Label, PointerSize);
 
   // emit the sequence for the LineDelta (from 1) and a zero address delta.
   MCDwarfLineAddr::Emit(&OS, Params, LineDelta, 0);
 }
 
 void MCObjectStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta,
                                                 const MCSymbol *LastLabel,
                                                 const MCSymbol *Label,
                                                 unsigned PointerSize) {
   if (!LastLabel) {
     emitDwarfSetLineAddr(*this, Assembler->getDWARFLinetableParams(), LineDelta,
                          Label, PointerSize);
     return;
   }
   const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel);
   int64_t Res;
   if (AddrDelta->evaluateAsAbsolute(Res, getAssembler())) {
     MCDwarfLineAddr::Emit(this, Assembler->getDWARFLinetableParams(), LineDelta,
                           Res);
     return;
   }
   insert(new MCDwarfLineAddrFragment(LineDelta, *AddrDelta));
 }
 
 void MCObjectStreamer::EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
                                                  const MCSymbol *Label) {
   const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel);
   int64_t Res;
   if (AddrDelta->evaluateAsAbsolute(Res, getAssembler())) {
     MCDwarfFrameEmitter::EmitAdvanceLoc(*this, Res);
     return;
   }
   insert(new MCDwarfCallFrameFragment(*AddrDelta));
 }
 
 void MCObjectStreamer::EmitCVLocDirective(unsigned FunctionId, unsigned FileNo,
                                           unsigned Line, unsigned Column,
                                           bool PrologueEnd, bool IsStmt,
                                           StringRef FileName, SMLoc Loc) {
   // In case we see two .cv_loc directives in a row, make sure the
   // first one gets a line entry.
   MCCVLineEntry::Make(this);
 
   this->MCStreamer::EmitCVLocDirective(FunctionId, FileNo, Line, Column,
                                        PrologueEnd, IsStmt, FileName, Loc);
 }
 
 void MCObjectStreamer::EmitCVLinetableDirective(unsigned FunctionId,
                                                 const MCSymbol *Begin,
                                                 const MCSymbol *End) {
   getContext().getCVContext().emitLineTableForFunction(*this, FunctionId, Begin,
                                                        End);
   this->MCStreamer::EmitCVLinetableDirective(FunctionId, Begin, End);
 }
 
 void MCObjectStreamer::EmitCVInlineLinetableDirective(
     unsigned PrimaryFunctionId, unsigned SourceFileId, unsigned SourceLineNum,
     const MCSymbol *FnStartSym, const MCSymbol *FnEndSym) {
   getContext().getCVContext().emitInlineLineTableForFunction(
       *this, PrimaryFunctionId, SourceFileId, SourceLineNum, FnStartSym,
       FnEndSym);
   this->MCStreamer::EmitCVInlineLinetableDirective(
       PrimaryFunctionId, SourceFileId, SourceLineNum, FnStartSym, FnEndSym);
 }
 
 void MCObjectStreamer::EmitCVDefRangeDirective(
     ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
     StringRef FixedSizePortion) {
   getContext().getCVContext().emitDefRange(*this, Ranges, FixedSizePortion);
   this->MCStreamer::EmitCVDefRangeDirective(Ranges, FixedSizePortion);
 }
 
 void MCObjectStreamer::EmitCVStringTableDirective() {
   getContext().getCVContext().emitStringTable(*this);
 }
 void MCObjectStreamer::EmitCVFileChecksumsDirective() {
   getContext().getCVContext().emitFileChecksums(*this);
 }
 
 void MCObjectStreamer::EmitCVFileChecksumOffsetDirective(unsigned FileNo) {
   getContext().getCVContext().emitFileChecksumOffset(*this, FileNo);
 }
 
 void MCObjectStreamer::EmitBytes(StringRef Data) {
   MCCVLineEntry::Make(this);
   MCDwarfLineEntry::Make(this, getCurrentSectionOnly());
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
   DF->getContents().append(Data.begin(), Data.end());
 }
 
 void MCObjectStreamer::EmitValueToAlignment(unsigned ByteAlignment,
                                             int64_t Value,
                                             unsigned ValueSize,
                                             unsigned MaxBytesToEmit) {
   if (MaxBytesToEmit == 0)
     MaxBytesToEmit = ByteAlignment;
   insert(new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit));
 
   // Update the maximum alignment on the current section if necessary.
   MCSection *CurSec = getCurrentSectionOnly();
   if (ByteAlignment > CurSec->getAlignment())
     CurSec->setAlignment(ByteAlignment);
 }
 
 void MCObjectStreamer::EmitCodeAlignment(unsigned ByteAlignment,
                                          unsigned MaxBytesToEmit) {
   EmitValueToAlignment(ByteAlignment, 0, 1, MaxBytesToEmit);
   cast<MCAlignFragment>(getCurrentFragment())->setEmitNops(true);
 }
 
 void MCObjectStreamer::emitValueToOffset(const MCExpr *Offset,
                                          unsigned char Value,
                                          SMLoc Loc) {
   insert(new MCOrgFragment(*Offset, Value, Loc));
 }
 
 void MCObjectStreamer::EmitCodePaddingBasicBlockStart(
     const MCCodePaddingContext &Context) {
   getAssembler().getBackend().handleCodePaddingBasicBlockStart(this, Context);
 }
 
 void MCObjectStreamer::EmitCodePaddingBasicBlockEnd(
     const MCCodePaddingContext &Context) {
   getAssembler().getBackend().handleCodePaddingBasicBlockEnd(Context);
 }
 
 // Associate DTPRel32 fixup with data and resize data area
 void MCObjectStreamer::EmitDTPRel32Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
 
   DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
                                             Value, FK_DTPRel_4));
   DF->getContents().resize(DF->getContents().size() + 4, 0);
 }
 
 // Associate DTPRel64 fixup with data and resize data area
 void MCObjectStreamer::EmitDTPRel64Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
 
   DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
                                             Value, FK_DTPRel_8));
   DF->getContents().resize(DF->getContents().size() + 8, 0);
 }
 
 // Associate TPRel32 fixup with data and resize data area
 void MCObjectStreamer::EmitTPRel32Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
 
   DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
                                             Value, FK_TPRel_4));
   DF->getContents().resize(DF->getContents().size() + 4, 0);
 }
 
 // Associate TPRel64 fixup with data and resize data area
 void MCObjectStreamer::EmitTPRel64Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
 
   DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
                                             Value, FK_TPRel_8));
   DF->getContents().resize(DF->getContents().size() + 8, 0);
 }
 
 // Associate GPRel32 fixup with data and resize data area
 void MCObjectStreamer::EmitGPRel32Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
 
   DF->getFixups().push_back(
       MCFixup::create(DF->getContents().size(), Value, FK_GPRel_4));
   DF->getContents().resize(DF->getContents().size() + 4, 0);
 }
 
 // Associate GPRel64 fixup with data and resize data area
 void MCObjectStreamer::EmitGPRel64Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
 
   DF->getFixups().push_back(
       MCFixup::create(DF->getContents().size(), Value, FK_GPRel_4));
   DF->getContents().resize(DF->getContents().size() + 8, 0);
 }
 
 bool MCObjectStreamer::EmitRelocDirective(const MCExpr &Offset, StringRef Name,
                                           const MCExpr *Expr, SMLoc Loc) {
   int64_t OffsetValue;
   if (!Offset.evaluateAsAbsolute(OffsetValue))
     llvm_unreachable("Offset is not absolute");
 
   if (OffsetValue < 0)
     llvm_unreachable("Offset is negative");
 
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
 
   Optional<MCFixupKind> MaybeKind = Assembler->getBackend().getFixupKind(Name);
   if (!MaybeKind.hasValue())
     return true;
 
   MCFixupKind Kind = *MaybeKind;
 
   if (Expr == nullptr)
     Expr =
         MCSymbolRefExpr::create(getContext().createTempSymbol(), getContext());
   DF->getFixups().push_back(MCFixup::create(OffsetValue, Expr, Kind, Loc));
   return false;
 }
 
 void MCObjectStreamer::emitFill(const MCExpr &NumBytes, uint64_t FillValue,
                                 SMLoc Loc) {
   MCDataFragment *DF = getOrCreateDataFragment();
   flushPendingLabels(DF, DF->getContents().size());
 
-  int64_t IntNumBytes;
-  if (!NumBytes.evaluateAsAbsolute(IntNumBytes, getAssembler())) {
-    getContext().reportError(Loc, "expected absolute expression");
-    return;
-  }
-
-  if (IntNumBytes < 0) {
-    getContext().reportError(Loc, "invalid number of bytes");
-    return;
-  }
-
   assert(getCurrentSectionOnly() && "need a section");
-  insert(new MCFillFragment(FillValue, IntNumBytes));
+  insert(new MCFillFragment(FillValue, NumBytes, Loc));
 }
 
 void MCObjectStreamer::emitFill(const MCExpr &NumValues, int64_t Size,
                                 int64_t Expr, SMLoc Loc) {
   int64_t IntNumValues;
   if (!NumValues.evaluateAsAbsolute(IntNumValues, getAssembler())) {
     getContext().reportError(Loc, "expected absolute expression");
     return;
   }
 
   if (IntNumValues < 0) {
     getContext().getSourceManager()->PrintMessage(
         Loc, SourceMgr::DK_Warning,
         "'.fill' directive with negative repeat count has no effect");
     return;
   }
 
   MCStreamer::emitFill(IntNumValues, Size, Expr);
 }
 
 void MCObjectStreamer::EmitFileDirective(StringRef Filename) {
   getAssembler().addFileName(Filename);
 }
 
 void MCObjectStreamer::FinishImpl() {
   // If we are generating dwarf for assembly source files dump out the sections.
   if (getContext().getGenDwarfForAssembly())
     MCGenDwarfInfo::Emit(this);
 
   // Dump out the dwarf file & directory tables and line tables.
   MCDwarfLineTable::Emit(this, getAssembler().getDWARFLinetableParams());
 
   flushPendingLabels(nullptr);
   getAssembler().Finish();
 }
Index: head/contrib/llvm/lib/MC/WasmObjectWriter.cpp
===================================================================
--- head/contrib/llvm/lib/MC/WasmObjectWriter.cpp	(revision 328595)
+++ head/contrib/llvm/lib/MC/WasmObjectWriter.cpp	(revision 328596)
@@ -1,1385 +1,1388 @@
 //===- lib/MC/WasmObjectWriter.cpp - Wasm File Writer ---------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements Wasm object file writer information.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/BinaryFormat/Wasm.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCAsmLayout.h"
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCFixupKindInfo.h"
 #include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCSectionWasm.h"
 #include "llvm/MC/MCSymbolWasm.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/MC/MCWasmObjectWriter.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/LEB128.h"
 #include "llvm/Support/StringSaver.h"
 #include <vector>
 
 using namespace llvm;
 
 #define DEBUG_TYPE "mc"
 
 namespace {
 
 // For patching purposes, we need to remember where each section starts, both
 // for patching up the section size field, and for patching up references to
 // locations within the section.
 struct SectionBookkeeping {
   // Where the size of the section is written.
   uint64_t SizeOffset;
   // Where the contents of the section starts (after the header).
   uint64_t ContentsOffset;
 };
 
 // The signature of a wasm function, in a struct capable of being used as a
 // DenseMap key.
 struct WasmFunctionType {
   // Support empty and tombstone instances, needed by DenseMap.
   enum { Plain, Empty, Tombstone } State;
 
   // The return types of the function.
   SmallVector<wasm::ValType, 1> Returns;
 
   // The parameter types of the function.
   SmallVector<wasm::ValType, 4> Params;
 
   WasmFunctionType() : State(Plain) {}
 
   bool operator==(const WasmFunctionType &Other) const {
     return State == Other.State && Returns == Other.Returns &&
            Params == Other.Params;
   }
 };
 
 // Traits for using WasmFunctionType in a DenseMap.
 struct WasmFunctionTypeDenseMapInfo {
   static WasmFunctionType getEmptyKey() {
     WasmFunctionType FuncTy;
     FuncTy.State = WasmFunctionType::Empty;
     return FuncTy;
   }
   static WasmFunctionType getTombstoneKey() {
     WasmFunctionType FuncTy;
     FuncTy.State = WasmFunctionType::Tombstone;
     return FuncTy;
   }
   static unsigned getHashValue(const WasmFunctionType &FuncTy) {
     uintptr_t Value = FuncTy.State;
     for (wasm::ValType Ret : FuncTy.Returns)
       Value += DenseMapInfo<int32_t>::getHashValue(int32_t(Ret));
     for (wasm::ValType Param : FuncTy.Params)
       Value += DenseMapInfo<int32_t>::getHashValue(int32_t(Param));
     return Value;
   }
   static bool isEqual(const WasmFunctionType &LHS,
                       const WasmFunctionType &RHS) {
     return LHS == RHS;
   }
 };
 
 // A wasm data segment.  A wasm binary contains only a single data section
 // but that can contain many segments, each with their own virtual location
 // in memory.  Each MCSection data created by llvm is modeled as its own
 // wasm data segment.
 struct WasmDataSegment {
   MCSectionWasm *Section;
   StringRef Name;
   uint32_t Offset;
   uint32_t Alignment;
   uint32_t Flags;
   SmallVector<char, 4> Data;
 };
 
 // A wasm import to be written into the import section.
 struct WasmImport {
   StringRef ModuleName;
   StringRef FieldName;
   unsigned Kind;
   int32_t Type;
   bool IsMutable;
 };
 
 // A wasm function to be written into the function section.
 struct WasmFunction {
   int32_t Type;
   const MCSymbolWasm *Sym;
 };
 
 // A wasm export to be written into the export section.
 struct WasmExport {
   StringRef FieldName;
   unsigned Kind;
   uint32_t Index;
 };
 
 // A wasm global to be written into the global section.
 struct WasmGlobal {
   wasm::ValType Type;
   bool IsMutable;
   bool HasImport;
   uint64_t InitialValue;
   uint32_t ImportIndex;
 };
 
 // Information about a single relocation.
 struct WasmRelocationEntry {
   uint64_t Offset;                  // Where is the relocation.
   const MCSymbolWasm *Symbol;       // The symbol to relocate with.
   int64_t Addend;                   // A value to add to the symbol.
   unsigned Type;                    // The type of the relocation.
   const MCSectionWasm *FixupSection;// The section the relocation is targeting.
 
   WasmRelocationEntry(uint64_t Offset, const MCSymbolWasm *Symbol,
                       int64_t Addend, unsigned Type,
                       const MCSectionWasm *FixupSection)
       : Offset(Offset), Symbol(Symbol), Addend(Addend), Type(Type),
         FixupSection(FixupSection) {}
 
   bool hasAddend() const {
     switch (Type) {
     case wasm::R_WEBASSEMBLY_MEMORY_ADDR_LEB:
     case wasm::R_WEBASSEMBLY_MEMORY_ADDR_SLEB:
     case wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32:
       return true;
     default:
       return false;
     }
   }
 
   void print(raw_ostream &Out) const {
     Out << "Off=" << Offset << ", Sym=" << *Symbol << ", Addend=" << Addend
         << ", Type=" << Type
         << ", FixupSection=" << FixupSection->getSectionName();
   }
 
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
   LLVM_DUMP_METHOD void dump() const { print(dbgs()); }
 #endif
 };
 
 #if !defined(NDEBUG)
 raw_ostream &operator<<(raw_ostream &OS, const WasmRelocationEntry &Rel) {
   Rel.print(OS);
   return OS;
 }
 #endif
 
 class WasmObjectWriter : public MCObjectWriter {
   /// Helper struct for containing some precomputed information on symbols.
   struct WasmSymbolData {
     const MCSymbolWasm *Symbol;
     StringRef Name;
 
     // Support lexicographic sorting.
     bool operator<(const WasmSymbolData &RHS) const { return Name < RHS.Name; }
   };
 
   /// The target specific Wasm writer instance.
   std::unique_ptr<MCWasmObjectTargetWriter> TargetObjectWriter;
 
   // Relocations for fixing up references in the code section.
   std::vector<WasmRelocationEntry> CodeRelocations;
 
   // Relocations for fixing up references in the data section.
   std::vector<WasmRelocationEntry> DataRelocations;
 
   // Index values to use for fixing up call_indirect type indices.
   // Maps function symbols to the index of the type of the function
   DenseMap<const MCSymbolWasm *, uint32_t> TypeIndices;
   // Maps function symbols to the table element index space. Used
   // for TABLE_INDEX relocation types (i.e. address taken functions).
   DenseMap<const MCSymbolWasm *, uint32_t> IndirectSymbolIndices;
   // Maps function/global symbols to the function/global index space.
   DenseMap<const MCSymbolWasm *, uint32_t> SymbolIndices;
 
   DenseMap<WasmFunctionType, int32_t, WasmFunctionTypeDenseMapInfo>
       FunctionTypeIndices;
   SmallVector<WasmFunctionType, 4> FunctionTypes;
   SmallVector<WasmGlobal, 4> Globals;
   unsigned NumGlobalImports = 0;
 
   // TargetObjectWriter wrappers.
   bool is64Bit() const { return TargetObjectWriter->is64Bit(); }
   unsigned getRelocType(const MCValue &Target, const MCFixup &Fixup) const {
     return TargetObjectWriter->getRelocType(Target, Fixup);
   }
 
   void startSection(SectionBookkeeping &Section, unsigned SectionId,
                     const char *Name = nullptr);
   void endSection(SectionBookkeeping &Section);
 
 public:
   WasmObjectWriter(std::unique_ptr<MCWasmObjectTargetWriter> MOTW,
                    raw_pwrite_stream &OS)
       : MCObjectWriter(OS, /*IsLittleEndian=*/true),
         TargetObjectWriter(std::move(MOTW)) {}
 
 private:
   ~WasmObjectWriter() override;
 
   void reset() override {
     CodeRelocations.clear();
     DataRelocations.clear();
     TypeIndices.clear();
     SymbolIndices.clear();
     IndirectSymbolIndices.clear();
     FunctionTypeIndices.clear();
     FunctionTypes.clear();
     Globals.clear();
     MCObjectWriter::reset();
     NumGlobalImports = 0;
   }
 
   void writeHeader(const MCAssembler &Asm);
 
   void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
                         const MCFragment *Fragment, const MCFixup &Fixup,
                         MCValue Target, uint64_t &FixedValue) override;
 
   void executePostLayoutBinding(MCAssembler &Asm,
                                 const MCAsmLayout &Layout) override;
 
   void writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
 
   void writeString(const StringRef Str) {
     encodeULEB128(Str.size(), getStream());
     writeBytes(Str);
   }
 
   void writeValueType(wasm::ValType Ty) {
     encodeSLEB128(int32_t(Ty), getStream());
   }
 
   void writeTypeSection(ArrayRef<WasmFunctionType> FunctionTypes);
   void writeImportSection(ArrayRef<WasmImport> Imports, uint32_t DataSize,
                           uint32_t NumElements);
   void writeFunctionSection(ArrayRef<WasmFunction> Functions);
   void writeGlobalSection();
   void writeExportSection(ArrayRef<WasmExport> Exports);
   void writeElemSection(ArrayRef<uint32_t> TableElems);
   void writeCodeSection(const MCAssembler &Asm, const MCAsmLayout &Layout,
                         ArrayRef<WasmFunction> Functions);
   void writeDataSection(ArrayRef<WasmDataSegment> Segments);
   void writeNameSection(ArrayRef<WasmFunction> Functions,
                         ArrayRef<WasmImport> Imports,
                         uint32_t NumFuncImports);
   void writeCodeRelocSection();
   void writeDataRelocSection();
   void writeLinkingMetaDataSection(
       ArrayRef<WasmDataSegment> Segments, uint32_t DataSize,
       const SmallVector<std::pair<StringRef, uint32_t>, 4> &SymbolFlags,
       const SmallVector<std::pair<uint16_t, uint32_t>, 2> &InitFuncs);
 
   uint32_t getProvisionalValue(const WasmRelocationEntry &RelEntry);
   void applyRelocations(ArrayRef<WasmRelocationEntry> Relocations,
                         uint64_t ContentsOffset);
 
   void writeRelocations(ArrayRef<WasmRelocationEntry> Relocations);
   uint32_t getRelocationIndexValue(const WasmRelocationEntry &RelEntry);
   uint32_t getFunctionType(const MCSymbolWasm& Symbol);
   uint32_t registerFunctionType(const MCSymbolWasm& Symbol);
 };
 
 } // end anonymous namespace
 
 WasmObjectWriter::~WasmObjectWriter() {}
 
 // Write out a section header and a patchable section size field.
 void WasmObjectWriter::startSection(SectionBookkeeping &Section,
                                     unsigned SectionId,
                                     const char *Name) {
   assert((Name != nullptr) == (SectionId == wasm::WASM_SEC_CUSTOM) &&
          "Only custom sections can have names");
 
   DEBUG(dbgs() << "startSection " << SectionId << ": " << Name << "\n");
   encodeULEB128(SectionId, getStream());
 
   Section.SizeOffset = getStream().tell();
 
   // The section size. We don't know the size yet, so reserve enough space
   // for any 32-bit value; we'll patch it later.
   encodeULEB128(UINT32_MAX, getStream());
 
   // The position where the section starts, for measuring its size.
   Section.ContentsOffset = getStream().tell();
 
   // Custom sections in wasm also have a string identifier.
   if (SectionId == wasm::WASM_SEC_CUSTOM) {
     assert(Name);
     writeString(StringRef(Name));
   }
 }
 
 // Now that the section is complete and we know how big it is, patch up the
 // section size field at the start of the section.
 void WasmObjectWriter::endSection(SectionBookkeeping &Section) {
   uint64_t Size = getStream().tell() - Section.ContentsOffset;
   if (uint32_t(Size) != Size)
     report_fatal_error("section size does not fit in a uint32_t");
 
   DEBUG(dbgs() << "endSection size=" << Size << "\n");
 
   // Write the final section size to the payload_len field, which follows
   // the section id byte.
   uint8_t Buffer[16];
   unsigned SizeLen = encodeULEB128(Size, Buffer, 5);
   assert(SizeLen == 5);
   getStream().pwrite((char *)Buffer, SizeLen, Section.SizeOffset);
 }
 
 // Emit the Wasm header.
 void WasmObjectWriter::writeHeader(const MCAssembler &Asm) {
   writeBytes(StringRef(wasm::WasmMagic, sizeof(wasm::WasmMagic)));
   writeLE32(wasm::WasmVersion);
 }
 
 void WasmObjectWriter::executePostLayoutBinding(MCAssembler &Asm,
                                                 const MCAsmLayout &Layout) {
 }
 
 void WasmObjectWriter::recordRelocation(MCAssembler &Asm,
                                         const MCAsmLayout &Layout,
                                         const MCFragment *Fragment,
                                         const MCFixup &Fixup, MCValue Target,
                                         uint64_t &FixedValue) {
   MCAsmBackend &Backend = Asm.getBackend();
   bool IsPCRel = Backend.getFixupKindInfo(Fixup.getKind()).Flags &
                  MCFixupKindInfo::FKF_IsPCRel;
   const auto &FixupSection = cast<MCSectionWasm>(*Fragment->getParent());
   uint64_t C = Target.getConstant();
   uint64_t FixupOffset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
   MCContext &Ctx = Asm.getContext();
 
   // The .init_array isn't translated as data, so don't do relocations in it.
   if (FixupSection.getSectionName().startswith(".init_array"))
     return;
 
   if (const MCSymbolRefExpr *RefB = Target.getSymB()) {
     assert(RefB->getKind() == MCSymbolRefExpr::VK_None &&
            "Should not have constructed this");
 
     // Let A, B and C being the components of Target and R be the location of
     // the fixup. If the fixup is not pcrel, we want to compute (A - B + C).
     // If it is pcrel, we want to compute (A - B + C - R).
 
     // In general, Wasm has no relocations for -B. It can only represent (A + C)
     // or (A + C - R). If B = R + K and the relocation is not pcrel, we can
     // replace B to implement it: (A - R - K + C)
     if (IsPCRel) {
       Ctx.reportError(
           Fixup.getLoc(),
           "No relocation available to represent this relative expression");
       return;
     }
 
     const auto &SymB = cast<MCSymbolWasm>(RefB->getSymbol());
 
     if (SymB.isUndefined()) {
       Ctx.reportError(Fixup.getLoc(),
                       Twine("symbol '") + SymB.getName() +
                           "' can not be undefined in a subtraction expression");
       return;
     }
 
     assert(!SymB.isAbsolute() && "Should have been folded");
     const MCSection &SecB = SymB.getSection();
     if (&SecB != &FixupSection) {
       Ctx.reportError(Fixup.getLoc(),
                       "Cannot represent a difference across sections");
       return;
     }
 
     uint64_t SymBOffset = Layout.getSymbolOffset(SymB);
     uint64_t K = SymBOffset - FixupOffset;
     IsPCRel = true;
     C -= K;
   }
 
   // We either rejected the fixup or folded B into C at this point.
   const MCSymbolRefExpr *RefA = Target.getSymA();
   const auto *SymA = RefA ? cast<MCSymbolWasm>(&RefA->getSymbol()) : nullptr;
 
   if (SymA && SymA->isVariable()) {
     const MCExpr *Expr = SymA->getVariableValue();
     const auto *Inner = cast<MCSymbolRefExpr>(Expr);
     if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF)
       llvm_unreachable("weakref used in reloc not yet implemented");
   }
 
   // Put any constant offset in an addend. Offsets can be negative, and
   // LLVM expects wrapping, in contrast to wasm's immediates which can't
   // be negative and don't wrap.
   FixedValue = 0;
 
   if (SymA)
     SymA->setUsedInReloc();
 
   assert(!IsPCRel);
   assert(SymA);
 
   unsigned Type = getRelocType(Target, Fixup);
 
   WasmRelocationEntry Rec(FixupOffset, SymA, C, Type, &FixupSection);
   DEBUG(dbgs() << "WasmReloc: " << Rec << "\n");
 
   if (FixupSection.isWasmData())
     DataRelocations.push_back(Rec);
   else if (FixupSection.getKind().isText())
     CodeRelocations.push_back(Rec);
   else if (!FixupSection.getKind().isMetadata())
     // TODO(sbc): Add support for debug sections.
     llvm_unreachable("unexpected section type");
 }
 
 // Write X as an (unsigned) LEB value at offset Offset in Stream, padded
 // to allow patching.
 static void
 WritePatchableLEB(raw_pwrite_stream &Stream, uint32_t X, uint64_t Offset) {
   uint8_t Buffer[5];
   unsigned SizeLen = encodeULEB128(X, Buffer, 5);
   assert(SizeLen == 5);
   Stream.pwrite((char *)Buffer, SizeLen, Offset);
 }
 
 // Write X as an signed LEB value at offset Offset in Stream, padded
 // to allow patching.
 static void
 WritePatchableSLEB(raw_pwrite_stream &Stream, int32_t X, uint64_t Offset) {
   uint8_t Buffer[5];
   unsigned SizeLen = encodeSLEB128(X, Buffer, 5);
   assert(SizeLen == 5);
   Stream.pwrite((char *)Buffer, SizeLen, Offset);
 }
 
 // Write X as a plain integer value at offset Offset in Stream.
 static void WriteI32(raw_pwrite_stream &Stream, uint32_t X, uint64_t Offset) {
   uint8_t Buffer[4];
   support::endian::write32le(Buffer, X);
   Stream.pwrite((char *)Buffer, sizeof(Buffer), Offset);
 }
 
 static const MCSymbolWasm* ResolveSymbol(const MCSymbolWasm& Symbol) {
   if (Symbol.isVariable()) {
     const MCExpr *Expr = Symbol.getVariableValue();
     auto *Inner = cast<MCSymbolRefExpr>(Expr);
     return cast<MCSymbolWasm>(&Inner->getSymbol());
   }
   return &Symbol;
 }
 
 // Compute a value to write into the code at the location covered
 // by RelEntry. This value isn't used by the static linker, since
 // we have addends; it just serves to make the code more readable
 // and to make standalone wasm modules directly usable.
 uint32_t
 WasmObjectWriter::getProvisionalValue(const WasmRelocationEntry &RelEntry) {
   const MCSymbolWasm *Sym = ResolveSymbol(*RelEntry.Symbol);
 
   // For undefined symbols, use a hopefully invalid value.
   if (!Sym->isDefined(/*SetUsed=*/false))
     return UINT32_MAX;
 
   uint32_t GlobalIndex = SymbolIndices[Sym];
   const WasmGlobal& Global = Globals[GlobalIndex - NumGlobalImports];
   uint64_t Address = Global.InitialValue + RelEntry.Addend;
 
   // Ignore overflow. LLVM allows address arithmetic to silently wrap.
   uint32_t Value = Address;
 
   return Value;
 }
 
 static void addData(SmallVectorImpl<char> &DataBytes,
                     MCSectionWasm &DataSection) {
   DEBUG(errs() << "addData: " << DataSection.getSectionName() << "\n");
 
   DataBytes.resize(alignTo(DataBytes.size(), DataSection.getAlignment()));
 
   size_t LastFragmentSize = 0;
   for (const MCFragment &Frag : DataSection) {
     if (Frag.hasInstructions())
       report_fatal_error("only data supported in data sections");
 
     if (auto *Align = dyn_cast<MCAlignFragment>(&Frag)) {
       if (Align->getValueSize() != 1)
         report_fatal_error("only byte values supported for alignment");
       // If nops are requested, use zeros, as this is the data section.
       uint8_t Value = Align->hasEmitNops() ? 0 : Align->getValue();
       uint64_t Size = std::min<uint64_t>(alignTo(DataBytes.size(),
                                                  Align->getAlignment()),
                                          DataBytes.size() +
                                              Align->getMaxBytesToEmit());
       DataBytes.resize(Size, Value);
     } else if (auto *Fill = dyn_cast<MCFillFragment>(&Frag)) {
-      DataBytes.insert(DataBytes.end(), Fill->getSize(), Fill->getValue());
+      int64_t Size;
+      if (!Fill->getSize().evaluateAsAbsolute(Size))
+        llvm_unreachable("The fill should be an assembler constant");
+      DataBytes.insert(DataBytes.end(), Size, Fill->getValue());
     } else {
       const auto &DataFrag = cast<MCDataFragment>(Frag);
       const SmallVectorImpl<char> &Contents = DataFrag.getContents();
 
       DataBytes.insert(DataBytes.end(), Contents.begin(), Contents.end());
       LastFragmentSize = Contents.size();
     }
   }
 
   // Don't allow empty segments, or segments that end with zero-sized
   // fragment, otherwise the linker cannot map symbols to a unique
   // data segment.  This can be triggered by zero-sized structs
   // See: test/MC/WebAssembly/bss.ll
   if (LastFragmentSize == 0)
     DataBytes.resize(DataBytes.size() + 1);
   DEBUG(dbgs() << "addData -> " << DataBytes.size() << "\n");
 }
 
 uint32_t WasmObjectWriter::getRelocationIndexValue(
     const WasmRelocationEntry &RelEntry) {
   switch (RelEntry.Type) {
   case wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB:
   case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32:
     if (!IndirectSymbolIndices.count(RelEntry.Symbol))
       report_fatal_error("symbol not found in table index space: " +
                          RelEntry.Symbol->getName());
     return IndirectSymbolIndices[RelEntry.Symbol];
   case wasm::R_WEBASSEMBLY_FUNCTION_INDEX_LEB:
   case wasm::R_WEBASSEMBLY_GLOBAL_INDEX_LEB:
   case wasm::R_WEBASSEMBLY_MEMORY_ADDR_LEB:
   case wasm::R_WEBASSEMBLY_MEMORY_ADDR_SLEB:
   case wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32:
     if (!SymbolIndices.count(RelEntry.Symbol))
       report_fatal_error("symbol not found in function/global index space: " +
                          RelEntry.Symbol->getName());
     return SymbolIndices[RelEntry.Symbol];
   case wasm::R_WEBASSEMBLY_TYPE_INDEX_LEB:
     if (!TypeIndices.count(RelEntry.Symbol))
       report_fatal_error("symbol not found in type index space: " +
                          RelEntry.Symbol->getName());
     return TypeIndices[RelEntry.Symbol];
   default:
     llvm_unreachable("invalid relocation type");
   }
 }
 
 // Apply the portions of the relocation records that we can handle ourselves
 // directly.
 void WasmObjectWriter::applyRelocations(
     ArrayRef<WasmRelocationEntry> Relocations, uint64_t ContentsOffset) {
   raw_pwrite_stream &Stream = getStream();
   for (const WasmRelocationEntry &RelEntry : Relocations) {
     uint64_t Offset = ContentsOffset +
                       RelEntry.FixupSection->getSectionOffset() +
                       RelEntry.Offset;
 
     DEBUG(dbgs() << "applyRelocation: " << RelEntry << "\n");
     switch (RelEntry.Type) {
     case wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB:
     case wasm::R_WEBASSEMBLY_FUNCTION_INDEX_LEB:
     case wasm::R_WEBASSEMBLY_TYPE_INDEX_LEB:
     case wasm::R_WEBASSEMBLY_GLOBAL_INDEX_LEB: {
       uint32_t Index = getRelocationIndexValue(RelEntry);
       WritePatchableSLEB(Stream, Index, Offset);
       break;
     }
     case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32: {
       uint32_t Index = getRelocationIndexValue(RelEntry);
       WriteI32(Stream, Index, Offset);
       break;
     }
     case wasm::R_WEBASSEMBLY_MEMORY_ADDR_SLEB: {
       uint32_t Value = getProvisionalValue(RelEntry);
       WritePatchableSLEB(Stream, Value, Offset);
       break;
     }
     case wasm::R_WEBASSEMBLY_MEMORY_ADDR_LEB: {
       uint32_t Value = getProvisionalValue(RelEntry);
       WritePatchableLEB(Stream, Value, Offset);
       break;
     }
     case wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32: {
       uint32_t Value = getProvisionalValue(RelEntry);
       WriteI32(Stream, Value, Offset);
       break;
     }
     default:
       llvm_unreachable("invalid relocation type");
     }
   }
 }
 
 // Write out the portions of the relocation records that the linker will
 // need to handle.
 void WasmObjectWriter::writeRelocations(
     ArrayRef<WasmRelocationEntry> Relocations) {
   raw_pwrite_stream &Stream = getStream();
   for (const WasmRelocationEntry& RelEntry : Relocations) {
 
     uint64_t Offset = RelEntry.Offset +
                       RelEntry.FixupSection->getSectionOffset();
     uint32_t Index = getRelocationIndexValue(RelEntry);
 
     encodeULEB128(RelEntry.Type, Stream);
     encodeULEB128(Offset, Stream);
     encodeULEB128(Index, Stream);
     if (RelEntry.hasAddend())
       encodeSLEB128(RelEntry.Addend, Stream);
   }
 }
 
 void WasmObjectWriter::writeTypeSection(
     ArrayRef<WasmFunctionType> FunctionTypes) {
   if (FunctionTypes.empty())
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_TYPE);
 
   encodeULEB128(FunctionTypes.size(), getStream());
 
   for (const WasmFunctionType &FuncTy : FunctionTypes) {
     encodeSLEB128(wasm::WASM_TYPE_FUNC, getStream());
     encodeULEB128(FuncTy.Params.size(), getStream());
     for (wasm::ValType Ty : FuncTy.Params)
       writeValueType(Ty);
     encodeULEB128(FuncTy.Returns.size(), getStream());
     for (wasm::ValType Ty : FuncTy.Returns)
       writeValueType(Ty);
   }
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeImportSection(ArrayRef<WasmImport> Imports,
                                           uint32_t DataSize,
                                           uint32_t NumElements) {
   if (Imports.empty())
     return;
 
   uint32_t NumPages = (DataSize + wasm::WasmPageSize - 1) / wasm::WasmPageSize;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_IMPORT);
 
   encodeULEB128(Imports.size(), getStream());
   for (const WasmImport &Import : Imports) {
     writeString(Import.ModuleName);
     writeString(Import.FieldName);
 
     encodeULEB128(Import.Kind, getStream());
 
     switch (Import.Kind) {
     case wasm::WASM_EXTERNAL_FUNCTION:
       encodeULEB128(Import.Type, getStream());
       break;
     case wasm::WASM_EXTERNAL_GLOBAL:
       encodeSLEB128(int32_t(Import.Type), getStream());
       encodeULEB128(int32_t(Import.IsMutable), getStream());
       break;
     case wasm::WASM_EXTERNAL_MEMORY:
       encodeULEB128(0, getStream()); // flags
       encodeULEB128(NumPages, getStream()); // initial
       break;
     case wasm::WASM_EXTERNAL_TABLE:
       encodeSLEB128(int32_t(Import.Type), getStream());
       encodeULEB128(0, getStream()); // flags
       encodeULEB128(NumElements, getStream()); // initial
       break;
     default:
       llvm_unreachable("unsupported import kind");
     }
   }
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeFunctionSection(ArrayRef<WasmFunction> Functions) {
   if (Functions.empty())
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_FUNCTION);
 
   encodeULEB128(Functions.size(), getStream());
   for (const WasmFunction &Func : Functions)
     encodeULEB128(Func.Type, getStream());
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeGlobalSection() {
   if (Globals.empty())
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_GLOBAL);
 
   encodeULEB128(Globals.size(), getStream());
   for (const WasmGlobal &Global : Globals) {
     writeValueType(Global.Type);
     write8(Global.IsMutable);
 
     if (Global.HasImport) {
       assert(Global.InitialValue == 0);
       write8(wasm::WASM_OPCODE_GET_GLOBAL);
       encodeULEB128(Global.ImportIndex, getStream());
     } else {
       assert(Global.ImportIndex == 0);
       write8(wasm::WASM_OPCODE_I32_CONST);
       encodeSLEB128(Global.InitialValue, getStream()); // offset
     }
     write8(wasm::WASM_OPCODE_END);
   }
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeExportSection(ArrayRef<WasmExport> Exports) {
   if (Exports.empty())
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_EXPORT);
 
   encodeULEB128(Exports.size(), getStream());
   for (const WasmExport &Export : Exports) {
     writeString(Export.FieldName);
     encodeSLEB128(Export.Kind, getStream());
     encodeULEB128(Export.Index, getStream());
   }
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeElemSection(ArrayRef<uint32_t> TableElems) {
   if (TableElems.empty())
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_ELEM);
 
   encodeULEB128(1, getStream()); // number of "segments"
   encodeULEB128(0, getStream()); // the table index
 
   // init expr for starting offset
   write8(wasm::WASM_OPCODE_I32_CONST);
   encodeSLEB128(0, getStream());
   write8(wasm::WASM_OPCODE_END);
 
   encodeULEB128(TableElems.size(), getStream());
   for (uint32_t Elem : TableElems)
     encodeULEB128(Elem, getStream());
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeCodeSection(const MCAssembler &Asm,
                                         const MCAsmLayout &Layout,
                                         ArrayRef<WasmFunction> Functions) {
   if (Functions.empty())
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_CODE);
 
   encodeULEB128(Functions.size(), getStream());
 
   for (const WasmFunction &Func : Functions) {
     auto &FuncSection = static_cast<MCSectionWasm &>(Func.Sym->getSection());
 
     int64_t Size = 0;
     if (!Func.Sym->getSize()->evaluateAsAbsolute(Size, Layout))
       report_fatal_error(".size expression must be evaluatable");
 
     encodeULEB128(Size, getStream());
     FuncSection.setSectionOffset(getStream().tell() - Section.ContentsOffset);
     Asm.writeSectionData(&FuncSection, Layout);
   }
 
   // Apply fixups.
   applyRelocations(CodeRelocations, Section.ContentsOffset);
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeDataSection(ArrayRef<WasmDataSegment> Segments) {
   if (Segments.empty())
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_DATA);
 
   encodeULEB128(Segments.size(), getStream()); // count
 
   for (const WasmDataSegment & Segment : Segments) {
     encodeULEB128(0, getStream()); // memory index
     write8(wasm::WASM_OPCODE_I32_CONST);
     encodeSLEB128(Segment.Offset, getStream()); // offset
     write8(wasm::WASM_OPCODE_END);
     encodeULEB128(Segment.Data.size(), getStream()); // size
     Segment.Section->setSectionOffset(getStream().tell() - Section.ContentsOffset);
     writeBytes(Segment.Data); // data
   }
 
   // Apply fixups.
   applyRelocations(DataRelocations, Section.ContentsOffset);
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeNameSection(
     ArrayRef<WasmFunction> Functions,
     ArrayRef<WasmImport> Imports,
     unsigned NumFuncImports) {
   uint32_t TotalFunctions = NumFuncImports + Functions.size();
   if (TotalFunctions == 0)
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_CUSTOM, "name");
   SectionBookkeeping SubSection;
   startSection(SubSection, wasm::WASM_NAMES_FUNCTION);
 
   encodeULEB128(TotalFunctions, getStream());
   uint32_t Index = 0;
   for (const WasmImport &Import : Imports) {
     if (Import.Kind == wasm::WASM_EXTERNAL_FUNCTION) {
       encodeULEB128(Index, getStream());
       writeString(Import.FieldName);
       ++Index;
     }
   }
   for (const WasmFunction &Func : Functions) {
     encodeULEB128(Index, getStream());
     writeString(Func.Sym->getName());
     ++Index;
   }
 
   endSection(SubSection);
   endSection(Section);
 }
 
 void WasmObjectWriter::writeCodeRelocSection() {
   // See: https://github.com/WebAssembly/tool-conventions/blob/master/Linking.md
   // for descriptions of the reloc sections.
 
   if (CodeRelocations.empty())
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_CUSTOM, "reloc.CODE");
 
   encodeULEB128(wasm::WASM_SEC_CODE, getStream());
   encodeULEB128(CodeRelocations.size(), getStream());
 
   writeRelocations(CodeRelocations);
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeDataRelocSection() {
   // See: https://github.com/WebAssembly/tool-conventions/blob/master/Linking.md
   // for descriptions of the reloc sections.
 
   if (DataRelocations.empty())
     return;
 
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_CUSTOM, "reloc.DATA");
 
   encodeULEB128(wasm::WASM_SEC_DATA, getStream());
   encodeULEB128(DataRelocations.size(), getStream());
 
   writeRelocations(DataRelocations);
 
   endSection(Section);
 }
 
 void WasmObjectWriter::writeLinkingMetaDataSection(
     ArrayRef<WasmDataSegment> Segments, uint32_t DataSize,
     const SmallVector<std::pair<StringRef, uint32_t>, 4> &SymbolFlags,
     const SmallVector<std::pair<uint16_t, uint32_t>, 2> &InitFuncs) {
   SectionBookkeeping Section;
   startSection(Section, wasm::WASM_SEC_CUSTOM, "linking");
   SectionBookkeeping SubSection;
 
   if (SymbolFlags.size() != 0) {
     startSection(SubSection, wasm::WASM_SYMBOL_INFO);
     encodeULEB128(SymbolFlags.size(), getStream());
     for (auto Pair: SymbolFlags) {
       writeString(Pair.first);
       encodeULEB128(Pair.second, getStream());
     }
     endSection(SubSection);
   }
 
   if (DataSize > 0) {
     startSection(SubSection, wasm::WASM_DATA_SIZE);
     encodeULEB128(DataSize, getStream());
     endSection(SubSection);
   }
 
   if (Segments.size()) {
     startSection(SubSection, wasm::WASM_SEGMENT_INFO);
     encodeULEB128(Segments.size(), getStream());
     for (const WasmDataSegment &Segment : Segments) {
       writeString(Segment.Name);
       encodeULEB128(Segment.Alignment, getStream());
       encodeULEB128(Segment.Flags, getStream());
     }
     endSection(SubSection);
   }
 
   if (!InitFuncs.empty()) {
     startSection(SubSection, wasm::WASM_INIT_FUNCS);
     encodeULEB128(InitFuncs.size(), getStream());
     for (auto &StartFunc : InitFuncs) {
       encodeULEB128(StartFunc.first, getStream()); // priority
       encodeULEB128(StartFunc.second, getStream()); // function index
     }
     endSection(SubSection);
   }
 
   endSection(Section);
 }
 
 uint32_t WasmObjectWriter::getFunctionType(const MCSymbolWasm& Symbol) {
   assert(Symbol.isFunction());
   assert(TypeIndices.count(&Symbol));
   return TypeIndices[&Symbol];
 }
 
 uint32_t WasmObjectWriter::registerFunctionType(const MCSymbolWasm& Symbol) {
   assert(Symbol.isFunction());
 
   WasmFunctionType F;
   const MCSymbolWasm* ResolvedSym = ResolveSymbol(Symbol);
   F.Returns = ResolvedSym->getReturns();
   F.Params = ResolvedSym->getParams();
 
   auto Pair =
       FunctionTypeIndices.insert(std::make_pair(F, FunctionTypes.size()));
   if (Pair.second)
     FunctionTypes.push_back(F);
   TypeIndices[&Symbol] = Pair.first->second;
 
   DEBUG(dbgs() << "registerFunctionType: " << Symbol << " new:" << Pair.second << "\n");
   DEBUG(dbgs() << "  -> type index: " << Pair.first->second << "\n");
   return Pair.first->second;
 }
 
 void WasmObjectWriter::writeObject(MCAssembler &Asm,
                                    const MCAsmLayout &Layout) {
   DEBUG(dbgs() << "WasmObjectWriter::writeObject\n");
   MCContext &Ctx = Asm.getContext();
   wasm::ValType PtrType = is64Bit() ? wasm::ValType::I64 : wasm::ValType::I32;
 
   // Collect information from the available symbols.
   SmallVector<WasmFunction, 4> Functions;
   SmallVector<uint32_t, 4> TableElems;
   SmallVector<WasmImport, 4> Imports;
   SmallVector<WasmExport, 4> Exports;
   SmallVector<std::pair<StringRef, uint32_t>, 4> SymbolFlags;
   SmallVector<std::pair<uint16_t, uint32_t>, 2> InitFuncs;
   unsigned NumFuncImports = 0;
   SmallVector<WasmDataSegment, 4> DataSegments;
   uint32_t DataSize = 0;
 
   // In the special .global_variables section, we've encoded global
   // variables used by the function. Translate them into the Globals
   // list.
   MCSectionWasm *GlobalVars =
       Ctx.getWasmSection(".global_variables", SectionKind::getMetadata());
   if (!GlobalVars->getFragmentList().empty()) {
     if (GlobalVars->getFragmentList().size() != 1)
       report_fatal_error("only one .global_variables fragment supported");
     const MCFragment &Frag = *GlobalVars->begin();
     if (Frag.hasInstructions() || Frag.getKind() != MCFragment::FT_Data)
       report_fatal_error("only data supported in .global_variables");
     const auto &DataFrag = cast<MCDataFragment>(Frag);
     if (!DataFrag.getFixups().empty())
       report_fatal_error("fixups not supported in .global_variables");
     const SmallVectorImpl<char> &Contents = DataFrag.getContents();
     for (const uint8_t *p = (const uint8_t *)Contents.data(),
                      *end = (const uint8_t *)Contents.data() + Contents.size();
          p != end; ) {
       WasmGlobal G;
       if (end - p < 3)
         report_fatal_error("truncated global variable encoding");
       G.Type = wasm::ValType(int8_t(*p++));
       G.IsMutable = bool(*p++);
       G.HasImport = bool(*p++);
       if (G.HasImport) {
         G.InitialValue = 0;
 
         WasmImport Import;
         Import.ModuleName = (const char *)p;
         const uint8_t *nul = (const uint8_t *)memchr(p, '\0', end - p);
         if (!nul)
           report_fatal_error("global module name must be nul-terminated");
         p = nul + 1;
         nul = (const uint8_t *)memchr(p, '\0', end - p);
         if (!nul)
           report_fatal_error("global base name must be nul-terminated");
         Import.FieldName = (const char *)p;
         p = nul + 1;
 
         Import.Kind = wasm::WASM_EXTERNAL_GLOBAL;
         Import.Type = int32_t(G.Type);
 
         G.ImportIndex = NumGlobalImports;
         ++NumGlobalImports;
 
         Imports.push_back(Import);
       } else {
         unsigned n;
         G.InitialValue = decodeSLEB128(p, &n);
         G.ImportIndex = 0;
         if ((ptrdiff_t)n > end - p)
           report_fatal_error("global initial value must be valid SLEB128");
         p += n;
       }
       Globals.push_back(G);
     }
   }
 
   // For now, always emit the memory import, since loads and stores are not
   // valid without it. In the future, we could perhaps be more clever and omit
   // it if there are no loads or stores.
   MCSymbolWasm *MemorySym =
       cast<MCSymbolWasm>(Ctx.getOrCreateSymbol("__linear_memory"));
   WasmImport MemImport;
   MemImport.ModuleName = MemorySym->getModuleName();
   MemImport.FieldName = MemorySym->getName();
   MemImport.Kind = wasm::WASM_EXTERNAL_MEMORY;
   Imports.push_back(MemImport);
 
   // For now, always emit the table section, since indirect calls are not
   // valid without it. In the future, we could perhaps be more clever and omit
   // it if there are no indirect calls.
   MCSymbolWasm *TableSym =
       cast<MCSymbolWasm>(Ctx.getOrCreateSymbol("__indirect_function_table"));
   WasmImport TableImport;
   TableImport.ModuleName = TableSym->getModuleName();
   TableImport.FieldName = TableSym->getName();
   TableImport.Kind = wasm::WASM_EXTERNAL_TABLE;
   TableImport.Type = wasm::WASM_TYPE_ANYFUNC;
   Imports.push_back(TableImport);
 
   // Populate FunctionTypeIndices and Imports.
   for (const MCSymbol &S : Asm.symbols()) {
     const auto &WS = static_cast<const MCSymbolWasm &>(S);
 
     // Register types for all functions, including those with private linkage
     // (making them
     // because wasm always needs a type signature.
     if (WS.isFunction())
       registerFunctionType(WS);
 
     if (WS.isTemporary())
       continue;
 
     // If the symbol is not defined in this translation unit, import it.
     if (!WS.isDefined(/*SetUsed=*/false) || WS.isVariable()) {
       WasmImport Import;
       Import.ModuleName = WS.getModuleName();
       Import.FieldName = WS.getName();
 
       if (WS.isFunction()) {
         Import.Kind = wasm::WASM_EXTERNAL_FUNCTION;
         Import.Type = getFunctionType(WS);
         SymbolIndices[&WS] = NumFuncImports;
         ++NumFuncImports;
       } else {
         Import.Kind = wasm::WASM_EXTERNAL_GLOBAL;
         Import.Type = int32_t(PtrType);
         Import.IsMutable = false;
         SymbolIndices[&WS] = NumGlobalImports;
 
         // If this global is the stack pointer, make it mutable.
         if (WS.getName() == "__stack_pointer")
           Import.IsMutable = true;
 
         ++NumGlobalImports;
       }
 
       Imports.push_back(Import);
     }
   }
 
   for (MCSection &Sec : Asm) {
     auto &Section = static_cast<MCSectionWasm &>(Sec);
     if (!Section.isWasmData())
       continue;
 
     // .init_array sections are handled specially elsewhere.
     if (cast<MCSectionWasm>(Sec).getSectionName().startswith(".init_array"))
       continue;
 
     DataSize = alignTo(DataSize, Section.getAlignment());
     DataSegments.emplace_back();
     WasmDataSegment &Segment = DataSegments.back();
     Segment.Name = Section.getSectionName();
     Segment.Offset = DataSize;
     Segment.Section = &Section;
     addData(Segment.Data, Section);
     Segment.Alignment = Section.getAlignment();
     Segment.Flags = 0;
     DataSize += Segment.Data.size();
     Section.setMemoryOffset(Segment.Offset);
   }
 
   // Handle regular defined and undefined symbols.
   for (const MCSymbol &S : Asm.symbols()) {
     // Ignore unnamed temporary symbols, which aren't ever exported, imported,
     // or used in relocations.
     if (S.isTemporary() && S.getName().empty())
       continue;
 
     const auto &WS = static_cast<const MCSymbolWasm &>(S);
     DEBUG(dbgs() << "MCSymbol: '" << S << "'"
                  << " isDefined=" << S.isDefined() << " isExternal="
                  << S.isExternal() << " isTemporary=" << S.isTemporary()
                  << " isFunction=" << WS.isFunction()
                  << " isWeak=" << WS.isWeak()
                  << " isHidden=" << WS.isHidden()
                  << " isVariable=" << WS.isVariable() << "\n");
 
     if (WS.isWeak() || WS.isHidden()) {
       uint32_t Flags = (WS.isWeak() ? wasm::WASM_SYMBOL_BINDING_WEAK : 0) |
           (WS.isHidden() ? wasm::WASM_SYMBOL_VISIBILITY_HIDDEN : 0);
       SymbolFlags.emplace_back(WS.getName(), Flags);
     }
 
     if (WS.isVariable())
       continue;
 
     unsigned Index;
 
     if (WS.isFunction()) {
       if (WS.isDefined(/*SetUsed=*/false)) {
         if (WS.getOffset() != 0)
           report_fatal_error(
               "function sections must contain one function each");
 
         if (WS.getSize() == 0)
           report_fatal_error(
               "function symbols must have a size set with .size");
 
         // A definition. Take the next available index.
         Index = NumFuncImports + Functions.size();
 
         // Prepare the function.
         WasmFunction Func;
         Func.Type = getFunctionType(WS);
         Func.Sym = &WS;
         SymbolIndices[&WS] = Index;
         Functions.push_back(Func);
       } else {
         // An import; the index was assigned above.
         Index = SymbolIndices.find(&WS)->second;
       }
 
       DEBUG(dbgs() << "  -> function index: " << Index << "\n");
    } else {
       if (WS.isTemporary() && !WS.getSize())
         continue;
 
       if (!WS.isDefined(/*SetUsed=*/false))
         continue;
 
       if (!WS.getSize())
         report_fatal_error("data symbols must have a size set with .size: " +
                            WS.getName());
 
       int64_t Size = 0;
       if (!WS.getSize()->evaluateAsAbsolute(Size, Layout))
         report_fatal_error(".size expression must be evaluatable");
 
       // For each global, prepare a corresponding wasm global holding its
       // address.  For externals these will also be named exports.
       Index = NumGlobalImports + Globals.size();
       auto &DataSection = static_cast<MCSectionWasm &>(WS.getSection());
 
       WasmGlobal Global;
       Global.Type = PtrType;
       Global.IsMutable = false;
       Global.HasImport = false;
       Global.InitialValue = DataSection.getMemoryOffset() + Layout.getSymbolOffset(WS);
       Global.ImportIndex = 0;
       SymbolIndices[&WS] = Index;
       DEBUG(dbgs() << "  -> global index: " << Index << "\n");
       Globals.push_back(Global);
     }
 
     // If the symbol is visible outside this translation unit, export it.
     if (WS.isDefined(/*SetUsed=*/false)) {
       WasmExport Export;
       Export.FieldName = WS.getName();
       Export.Index = Index;
       if (WS.isFunction())
         Export.Kind = wasm::WASM_EXTERNAL_FUNCTION;
       else
         Export.Kind = wasm::WASM_EXTERNAL_GLOBAL;
       DEBUG(dbgs() << "  -> export " << Exports.size() << "\n");
       Exports.push_back(Export);
       if (!WS.isExternal())
         SymbolFlags.emplace_back(WS.getName(), wasm::WASM_SYMBOL_BINDING_LOCAL);
     }
   }
 
   // Handle weak aliases. We need to process these in a separate pass because
   // we need to have processed the target of the alias before the alias itself
   // and the symbols are not necessarily ordered in this way.
   for (const MCSymbol &S : Asm.symbols()) {
     if (!S.isVariable())
       continue;
 
     assert(S.isDefined(/*SetUsed=*/false));
 
     // Find the target symbol of this weak alias and export that index
     const auto &WS = static_cast<const MCSymbolWasm &>(S);
     const MCSymbolWasm *ResolvedSym = ResolveSymbol(WS);
     DEBUG(dbgs() << WS.getName() << ": weak alias of '" << *ResolvedSym << "'\n");
     assert(SymbolIndices.count(ResolvedSym) > 0);
     uint32_t Index = SymbolIndices.find(ResolvedSym)->second;
     DEBUG(dbgs() << "  -> index:" << Index << "\n");
 
     WasmExport Export;
     Export.FieldName = WS.getName();
     Export.Index = Index;
     if (WS.isFunction())
       Export.Kind = wasm::WASM_EXTERNAL_FUNCTION;
     else
       Export.Kind = wasm::WASM_EXTERNAL_GLOBAL;
     DEBUG(dbgs() << "  -> export " << Exports.size() << "\n");
     Exports.push_back(Export);
 
     if (!WS.isExternal())
       SymbolFlags.emplace_back(WS.getName(), wasm::WASM_SYMBOL_BINDING_LOCAL);
   }
 
   {
     auto HandleReloc = [&](const WasmRelocationEntry &Rel) {
       // Functions referenced by a relocation need to prepared to be called
       // indirectly.
       const MCSymbolWasm& WS = *Rel.Symbol;
       if (WS.isFunction() && IndirectSymbolIndices.count(&WS) == 0) {
         switch (Rel.Type) {
         case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32:
         case wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB:
         case wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32:
         case wasm::R_WEBASSEMBLY_MEMORY_ADDR_SLEB: {
           uint32_t Index = SymbolIndices.find(&WS)->second;
           IndirectSymbolIndices[&WS] = TableElems.size();
           DEBUG(dbgs() << "  -> adding to table: " << TableElems.size() << "\n");
           TableElems.push_back(Index);
           registerFunctionType(WS);
           break;
         }
         default:
           break;
         }
       }
     };
 
     for (const WasmRelocationEntry &RelEntry : CodeRelocations)
       HandleReloc(RelEntry);
     for (const WasmRelocationEntry &RelEntry : DataRelocations)
       HandleReloc(RelEntry);
   }
 
   // Translate .init_array section contents into start functions.
   for (const MCSection &S : Asm) {
     const auto &WS = static_cast<const MCSectionWasm &>(S);
     if (WS.getSectionName().startswith(".fini_array"))
       report_fatal_error(".fini_array sections are unsupported");
     if (!WS.getSectionName().startswith(".init_array"))
       continue;
     if (WS.getFragmentList().empty())
       continue;
     if (WS.getFragmentList().size() != 2)
       report_fatal_error("only one .init_array section fragment supported");
     const MCFragment &AlignFrag = *WS.begin();
     if (AlignFrag.getKind() != MCFragment::FT_Align)
       report_fatal_error(".init_array section should be aligned");
     if (cast<MCAlignFragment>(AlignFrag).getAlignment() != (is64Bit() ? 8 : 4))
       report_fatal_error(".init_array section should be aligned for pointers");
     const MCFragment &Frag = *std::next(WS.begin());
     if (Frag.hasInstructions() || Frag.getKind() != MCFragment::FT_Data)
       report_fatal_error("only data supported in .init_array section");
     uint16_t Priority = UINT16_MAX;
     if (WS.getSectionName().size() != 11) {
       if (WS.getSectionName()[11] != '.')
         report_fatal_error(".init_array section priority should start with '.'");
       if (WS.getSectionName().substr(12).getAsInteger(10, Priority))
         report_fatal_error("invalid .init_array section priority");
     }
     const auto &DataFrag = cast<MCDataFragment>(Frag);
     const SmallVectorImpl<char> &Contents = DataFrag.getContents();
     for (const uint8_t *p = (const uint8_t *)Contents.data(),
                      *end = (const uint8_t *)Contents.data() + Contents.size();
          p != end; ++p) {
       if (*p != 0)
         report_fatal_error("non-symbolic data in .init_array section");
     }
     for (const MCFixup &Fixup : DataFrag.getFixups()) {
       assert(Fixup.getKind() == MCFixup::getKindForSize(is64Bit() ? 8 : 4, false));
       const MCExpr *Expr = Fixup.getValue();
       auto *Sym = dyn_cast<MCSymbolRefExpr>(Expr);
       if (!Sym)
         report_fatal_error("fixups in .init_array should be symbol references");
       if (Sym->getKind() != MCSymbolRefExpr::VK_WebAssembly_FUNCTION)
         report_fatal_error("symbols in .init_array should be for functions");
       auto I = SymbolIndices.find(cast<MCSymbolWasm>(&Sym->getSymbol()));
       if (I == SymbolIndices.end())
         report_fatal_error("symbols in .init_array should be defined");
       uint32_t Index = I->second;
       InitFuncs.push_back(std::make_pair(Priority, Index));
     }
   }
 
   // Write out the Wasm header.
   writeHeader(Asm);
 
   writeTypeSection(FunctionTypes);
   writeImportSection(Imports, DataSize, TableElems.size());
   writeFunctionSection(Functions);
   // Skip the "table" section; we import the table instead.
   // Skip the "memory" section; we import the memory instead.
   writeGlobalSection();
   writeExportSection(Exports);
   writeElemSection(TableElems);
   writeCodeSection(Asm, Layout, Functions);
   writeDataSection(DataSegments);
   writeNameSection(Functions, Imports, NumFuncImports);
   writeCodeRelocSection();
   writeDataRelocSection();
   writeLinkingMetaDataSection(DataSegments, DataSize, SymbolFlags,
                               InitFuncs);
 
   // TODO: Translate the .comment section to the output.
   // TODO: Translate debug sections to the output.
 }
 
 std::unique_ptr<MCObjectWriter>
 llvm::createWasmObjectWriter(std::unique_ptr<MCWasmObjectTargetWriter> MOTW,
                              raw_pwrite_stream &OS) {
   // FIXME: Can't use make_unique<WasmObjectWriter>(...) as WasmObjectWriter's
   //        destructor is private. Is that necessary?
   return std::unique_ptr<MCObjectWriter>(
       new WasmObjectWriter(std::move(MOTW), OS));
 }