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      1 //===- lib/MC/MCStreamer.cpp - Streaming Machine Code Output --------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 #include "llvm/MC/MCAsmInfo.h"
     11 #include "llvm/MC/MCContext.h"
     12 #include "llvm/MC/MCStreamer.h"
     13 #include "llvm/MC/MCExpr.h"
     14 #include "llvm/MC/MCObjectWriter.h"
     15 #include "llvm/MC/MCSymbol.h"
     16 #include "llvm/Support/ErrorHandling.h"
     17 #include "llvm/Support/raw_ostream.h"
     18 #include "llvm/ADT/SmallString.h"
     19 #include "llvm/ADT/Twine.h"
     20 #include <cstdlib>
     21 using namespace llvm;
     22 
     23 MCStreamer::MCStreamer(MCContext &Ctx) : Context(Ctx), EmitEHFrame(true),
     24                                          EmitDebugFrame(false),
     25                                          CurrentW64UnwindInfo(0),
     26                                          LastSymbol(0),
     27                                          UniqueCodeBeginSuffix(0),
     28                                          UniqueDataBeginSuffix(0) {
     29   const MCSection *section = NULL;
     30   SectionStack.push_back(std::make_pair(section, section));
     31 }
     32 
     33 MCStreamer::~MCStreamer() {
     34   for (unsigned i = 0; i < getNumW64UnwindInfos(); ++i)
     35     delete W64UnwindInfos[i];
     36 }
     37 
     38 const MCExpr *MCStreamer::BuildSymbolDiff(MCContext &Context,
     39                                           const MCSymbol *A,
     40                                           const MCSymbol *B) {
     41   MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
     42   const MCExpr *ARef =
     43     MCSymbolRefExpr::Create(A, Variant, Context);
     44   const MCExpr *BRef =
     45     MCSymbolRefExpr::Create(B, Variant, Context);
     46   const MCExpr *AddrDelta =
     47     MCBinaryExpr::Create(MCBinaryExpr::Sub, ARef, BRef, Context);
     48   return AddrDelta;
     49 }
     50 
     51 const MCExpr *MCStreamer::ForceExpAbs(const MCExpr* Expr) {
     52   if (Context.getAsmInfo().hasAggressiveSymbolFolding() ||
     53       isa<MCSymbolRefExpr>(Expr))
     54     return Expr;
     55 
     56   MCSymbol *ABS = Context.CreateTempSymbol();
     57   EmitAssignment(ABS, Expr);
     58   return MCSymbolRefExpr::Create(ABS, Context);
     59 }
     60 
     61 raw_ostream &MCStreamer::GetCommentOS() {
     62   // By default, discard comments.
     63   return nulls();
     64 }
     65 
     66 void MCStreamer::EmitDwarfSetLineAddr(int64_t LineDelta,
     67                                       const MCSymbol *Label, int PointerSize) {
     68   // emit the sequence to set the address
     69   EmitIntValue(dwarf::DW_LNS_extended_op, 1);
     70   EmitULEB128IntValue(PointerSize + 1);
     71   EmitIntValue(dwarf::DW_LNE_set_address, 1);
     72   EmitSymbolValue(Label, PointerSize);
     73 
     74   // emit the sequence for the LineDelta (from 1) and a zero address delta.
     75   MCDwarfLineAddr::Emit(this, LineDelta, 0);
     76 }
     77 
     78 /// EmitIntValue - Special case of EmitValue that avoids the client having to
     79 /// pass in a MCExpr for constant integers.
     80 void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size,
     81                               unsigned AddrSpace) {
     82   assert(Size <= 8 && "Invalid size");
     83   assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
     84          "Invalid size");
     85   char buf[8];
     86   const bool isLittleEndian = Context.getAsmInfo().isLittleEndian();
     87   for (unsigned i = 0; i != Size; ++i) {
     88     unsigned index = isLittleEndian ? i : (Size - i - 1);
     89     buf[i] = uint8_t(Value >> (index * 8));
     90   }
     91   EmitBytes(StringRef(buf, Size), AddrSpace);
     92 }
     93 
     94 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
     95 /// client having to pass in a MCExpr for constant integers.
     96 void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace,
     97                                      unsigned Padding) {
     98   SmallString<128> Tmp;
     99   raw_svector_ostream OSE(Tmp);
    100   MCObjectWriter::EncodeULEB128(Value, OSE, Padding);
    101   EmitBytes(OSE.str(), AddrSpace);
    102 }
    103 
    104 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
    105 /// client having to pass in a MCExpr for constant integers.
    106 void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) {
    107   SmallString<128> Tmp;
    108   raw_svector_ostream OSE(Tmp);
    109   MCObjectWriter::EncodeSLEB128(Value, OSE);
    110   EmitBytes(OSE.str(), AddrSpace);
    111 }
    112 
    113 void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size,
    114                               unsigned AddrSpace) {
    115   const MCExpr *ABS = ForceExpAbs(Value);
    116   EmitValue(ABS, Size, AddrSpace);
    117 }
    118 
    119 
    120 void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
    121                            unsigned AddrSpace) {
    122   EmitValueImpl(Value, Size, AddrSpace);
    123 }
    124 
    125 void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
    126                                   unsigned AddrSpace) {
    127   EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size,
    128                 AddrSpace);
    129 }
    130 
    131 void MCStreamer::EmitGPRel64Value(const MCExpr *Value) {
    132   report_fatal_error("unsupported directive in streamer");
    133 }
    134 
    135 void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
    136   report_fatal_error("unsupported directive in streamer");
    137 }
    138 
    139 /// EmitFill - Emit NumBytes bytes worth of the value specified by
    140 /// FillValue.  This implements directives such as '.space'.
    141 void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
    142                           unsigned AddrSpace) {
    143   const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
    144   for (uint64_t i = 0, e = NumBytes; i != e; ++i)
    145     EmitValue(E, 1, AddrSpace);
    146 }
    147 
    148 bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
    149                                         StringRef Directory,
    150                                         StringRef Filename) {
    151   return getContext().GetDwarfFile(Directory, Filename, FileNo) == 0;
    152 }
    153 
    154 void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
    155                                        unsigned Column, unsigned Flags,
    156                                        unsigned Isa,
    157                                        unsigned Discriminator,
    158                                        StringRef FileName) {
    159   getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
    160                                   Discriminator);
    161 }
    162 
    163 MCDwarfFrameInfo *MCStreamer::getCurrentFrameInfo() {
    164   if (FrameInfos.empty())
    165     return NULL;
    166   return &FrameInfos.back();
    167 }
    168 
    169 void MCStreamer::EnsureValidFrame() {
    170   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    171   if (!CurFrame || CurFrame->End)
    172     report_fatal_error("No open frame");
    173 }
    174 
    175 void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
    176                                      MCSymbol *EHSymbol) {
    177 }
    178 
    179 void MCStreamer::EmitLabel(MCSymbol *Symbol) {
    180   assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
    181   assert(getCurrentSection() && "Cannot emit before setting section!");
    182   Symbol->setSection(*getCurrentSection());
    183   LastSymbol = Symbol;
    184 }
    185 
    186 void MCStreamer::EmitDataRegion() {
    187   if (RegionIndicator == Data) return;
    188 
    189   MCContext &Context = getContext();
    190   const MCAsmInfo &MAI = Context.getAsmInfo();
    191   if (!MAI.getSupportsDataRegions()) return;
    192 
    193   // Generate a unique symbol name.
    194   MCSymbol *NewSym = Context.GetOrCreateSymbol(MAI.getDataBeginLabelName() +
    195                                                Twine(UniqueDataBeginSuffix++));
    196   EmitLabel(NewSym);
    197 
    198   RegionIndicator = Data;
    199 }
    200 
    201 void MCStreamer::EmitCodeRegion() {
    202   if (RegionIndicator == Code) return;
    203 
    204   MCContext &Context = getContext();
    205   const MCAsmInfo &MAI = Context.getAsmInfo();
    206   if (!MAI.getSupportsDataRegions()) return;
    207 
    208   // Generate a unique symbol name.
    209   MCSymbol *NewSym = Context.GetOrCreateSymbol(MAI.getCodeBeginLabelName() +
    210                                                Twine(UniqueCodeBeginSuffix++));
    211   EmitLabel(NewSym);
    212 
    213   RegionIndicator = Code;
    214 }
    215 
    216 void MCStreamer::EmitJumpTable8Region() {
    217   if (RegionIndicator == JumpTable8) return;
    218 
    219   MCContext &Context = getContext();
    220   const MCAsmInfo &MAI = Context.getAsmInfo();
    221   if (!MAI.getSupportsDataRegions()) return;
    222 
    223   // Generate a unique symbol name.
    224   MCSymbol *NewSym =
    225     Context.GetOrCreateSymbol(MAI.getJumpTable8BeginLabelName() +
    226                               Twine(UniqueDataBeginSuffix++));
    227   EmitLabel(NewSym);
    228 
    229   RegionIndicator = JumpTable8;
    230 }
    231 
    232 void MCStreamer::EmitJumpTable16Region() {
    233   if (RegionIndicator == JumpTable16) return;
    234 
    235   MCContext &Context = getContext();
    236   const MCAsmInfo &MAI = Context.getAsmInfo();
    237   if (!MAI.getSupportsDataRegions()) return;
    238 
    239   // Generate a unique symbol name.
    240   MCSymbol *NewSym =
    241     Context.GetOrCreateSymbol(MAI.getJumpTable16BeginLabelName() +
    242                               Twine(UniqueDataBeginSuffix++));
    243   EmitLabel(NewSym);
    244 
    245   RegionIndicator = JumpTable16;
    246 }
    247 
    248 
    249 void MCStreamer::EmitJumpTable32Region() {
    250   if (RegionIndicator == JumpTable32) return;
    251 
    252   MCContext &Context = getContext();
    253   const MCAsmInfo &MAI = Context.getAsmInfo();
    254   if (!MAI.getSupportsDataRegions()) return;
    255 
    256   // Generate a unique symbol name.
    257   MCSymbol *NewSym =
    258     Context.GetOrCreateSymbol(MAI.getJumpTable32BeginLabelName() +
    259                               Twine(UniqueDataBeginSuffix++));
    260   EmitLabel(NewSym);
    261 
    262   RegionIndicator = JumpTable32;
    263 }
    264 
    265 void MCStreamer::EmitCompactUnwindEncoding(uint32_t CompactUnwindEncoding) {
    266   EnsureValidFrame();
    267   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    268   CurFrame->CompactUnwindEncoding = CompactUnwindEncoding;
    269 }
    270 
    271 void MCStreamer::EmitCFISections(bool EH, bool Debug) {
    272   assert(EH || Debug);
    273   EmitEHFrame = EH;
    274   EmitDebugFrame = Debug;
    275 }
    276 
    277 void MCStreamer::EmitCFIStartProc() {
    278   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    279   if (CurFrame && !CurFrame->End)
    280     report_fatal_error("Starting a frame before finishing the previous one!");
    281 
    282   MCDwarfFrameInfo Frame;
    283   EmitCFIStartProcImpl(Frame);
    284 
    285   FrameInfos.push_back(Frame);
    286   RegionIndicator = Code;
    287 }
    288 
    289 void MCStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
    290 }
    291 
    292 void MCStreamer::RecordProcStart(MCDwarfFrameInfo &Frame) {
    293   Frame.Function = LastSymbol;
    294   // If the function is externally visible, we need to create a local
    295   // symbol to avoid relocations.
    296   StringRef Prefix = getContext().getAsmInfo().getPrivateGlobalPrefix();
    297   if (LastSymbol && LastSymbol->getName().startswith(Prefix)) {
    298     Frame.Begin = LastSymbol;
    299   } else {
    300     Frame.Begin = getContext().CreateTempSymbol();
    301     EmitLabel(Frame.Begin);
    302   }
    303 }
    304 
    305 void MCStreamer::EmitCFIEndProc() {
    306   EnsureValidFrame();
    307   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    308   EmitCFIEndProcImpl(*CurFrame);
    309 }
    310 
    311 void MCStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
    312 }
    313 
    314 void MCStreamer::RecordProcEnd(MCDwarfFrameInfo &Frame) {
    315   Frame.End = getContext().CreateTempSymbol();
    316   EmitLabel(Frame.End);
    317 }
    318 
    319 void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
    320   EnsureValidFrame();
    321   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    322   MCSymbol *Label = getContext().CreateTempSymbol();
    323   EmitLabel(Label);
    324   MachineLocation Dest(MachineLocation::VirtualFP);
    325   MachineLocation Source(Register, -Offset);
    326   MCCFIInstruction Instruction(Label, Dest, Source);
    327   CurFrame->Instructions.push_back(Instruction);
    328 }
    329 
    330 void MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
    331   EnsureValidFrame();
    332   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    333   MCSymbol *Label = getContext().CreateTempSymbol();
    334   EmitLabel(Label);
    335   MachineLocation Dest(MachineLocation::VirtualFP);
    336   MachineLocation Source(MachineLocation::VirtualFP, -Offset);
    337   MCCFIInstruction Instruction(Label, Dest, Source);
    338   CurFrame->Instructions.push_back(Instruction);
    339 }
    340 
    341 void MCStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
    342   EnsureValidFrame();
    343   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    344   MCSymbol *Label = getContext().CreateTempSymbol();
    345   EmitLabel(Label);
    346   MachineLocation Dest(MachineLocation::VirtualFP);
    347   MachineLocation Source(MachineLocation::VirtualFP, Adjustment);
    348   MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
    349   CurFrame->Instructions.push_back(Instruction);
    350 }
    351 
    352 void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
    353   EnsureValidFrame();
    354   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    355   MCSymbol *Label = getContext().CreateTempSymbol();
    356   EmitLabel(Label);
    357   MachineLocation Dest(Register);
    358   MachineLocation Source(MachineLocation::VirtualFP);
    359   MCCFIInstruction Instruction(Label, Dest, Source);
    360   CurFrame->Instructions.push_back(Instruction);
    361 }
    362 
    363 void MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
    364   EnsureValidFrame();
    365   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    366   MCSymbol *Label = getContext().CreateTempSymbol();
    367   EmitLabel(Label);
    368   MachineLocation Dest(Register, Offset);
    369   MachineLocation Source(Register, Offset);
    370   MCCFIInstruction Instruction(Label, Dest, Source);
    371   CurFrame->Instructions.push_back(Instruction);
    372 }
    373 
    374 void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
    375   EnsureValidFrame();
    376   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    377   MCSymbol *Label = getContext().CreateTempSymbol();
    378   EmitLabel(Label);
    379   MachineLocation Dest(Register, Offset);
    380   MachineLocation Source(Register, Offset);
    381   MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
    382   CurFrame->Instructions.push_back(Instruction);
    383 }
    384 
    385 void MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
    386                                     unsigned Encoding) {
    387   EnsureValidFrame();
    388   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    389   CurFrame->Personality = Sym;
    390   CurFrame->PersonalityEncoding = Encoding;
    391 }
    392 
    393 void MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
    394   EnsureValidFrame();
    395   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    396   CurFrame->Lsda = Sym;
    397   CurFrame->LsdaEncoding = Encoding;
    398 }
    399 
    400 void MCStreamer::EmitCFIRememberState() {
    401   EnsureValidFrame();
    402   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    403   MCSymbol *Label = getContext().CreateTempSymbol();
    404   EmitLabel(Label);
    405   MCCFIInstruction Instruction(MCCFIInstruction::RememberState, Label);
    406   CurFrame->Instructions.push_back(Instruction);
    407 }
    408 
    409 void MCStreamer::EmitCFIRestoreState() {
    410   // FIXME: Error if there is no matching cfi_remember_state.
    411   EnsureValidFrame();
    412   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    413   MCSymbol *Label = getContext().CreateTempSymbol();
    414   EmitLabel(Label);
    415   MCCFIInstruction Instruction(MCCFIInstruction::RestoreState, Label);
    416   CurFrame->Instructions.push_back(Instruction);
    417 }
    418 
    419 void MCStreamer::EmitCFISameValue(int64_t Register) {
    420   EnsureValidFrame();
    421   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    422   MCSymbol *Label = getContext().CreateTempSymbol();
    423   EmitLabel(Label);
    424   MCCFIInstruction Instruction(MCCFIInstruction::SameValue, Label, Register);
    425   CurFrame->Instructions.push_back(Instruction);
    426 }
    427 
    428 void MCStreamer::EmitCFIRestore(int64_t Register) {
    429   EnsureValidFrame();
    430   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    431   MCSymbol *Label = getContext().CreateTempSymbol();
    432   EmitLabel(Label);
    433   MCCFIInstruction Instruction(MCCFIInstruction::Restore, Label, Register);
    434   CurFrame->Instructions.push_back(Instruction);
    435 }
    436 
    437 void MCStreamer::EmitCFIEscape(StringRef Values) {
    438   EnsureValidFrame();
    439   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    440   MCSymbol *Label = getContext().CreateTempSymbol();
    441   EmitLabel(Label);
    442   MCCFIInstruction Instruction(MCCFIInstruction::Escape, Label, Values);
    443   CurFrame->Instructions.push_back(Instruction);
    444 }
    445 
    446 void MCStreamer::EmitCFISignalFrame() {
    447   EnsureValidFrame();
    448   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
    449   CurFrame->IsSignalFrame = true;
    450 }
    451 
    452 void MCStreamer::setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame) {
    453   W64UnwindInfos.push_back(Frame);
    454   CurrentW64UnwindInfo = W64UnwindInfos.back();
    455 }
    456 
    457 void MCStreamer::EnsureValidW64UnwindInfo() {
    458   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    459   if (!CurFrame || CurFrame->End)
    460     report_fatal_error("No open Win64 EH frame function!");
    461 }
    462 
    463 void MCStreamer::EmitWin64EHStartProc(const MCSymbol *Symbol) {
    464   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    465   if (CurFrame && !CurFrame->End)
    466     report_fatal_error("Starting a function before ending the previous one!");
    467   MCWin64EHUnwindInfo *Frame = new MCWin64EHUnwindInfo;
    468   Frame->Begin = getContext().CreateTempSymbol();
    469   Frame->Function = Symbol;
    470   EmitLabel(Frame->Begin);
    471   setCurrentW64UnwindInfo(Frame);
    472 }
    473 
    474 void MCStreamer::EmitWin64EHEndProc() {
    475   EnsureValidW64UnwindInfo();
    476   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    477   if (CurFrame->ChainedParent)
    478     report_fatal_error("Not all chained regions terminated!");
    479   CurFrame->End = getContext().CreateTempSymbol();
    480   EmitLabel(CurFrame->End);
    481 }
    482 
    483 void MCStreamer::EmitWin64EHStartChained() {
    484   EnsureValidW64UnwindInfo();
    485   MCWin64EHUnwindInfo *Frame = new MCWin64EHUnwindInfo;
    486   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    487   Frame->Begin = getContext().CreateTempSymbol();
    488   Frame->Function = CurFrame->Function;
    489   Frame->ChainedParent = CurFrame;
    490   EmitLabel(Frame->Begin);
    491   setCurrentW64UnwindInfo(Frame);
    492 }
    493 
    494 void MCStreamer::EmitWin64EHEndChained() {
    495   EnsureValidW64UnwindInfo();
    496   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    497   if (!CurFrame->ChainedParent)
    498     report_fatal_error("End of a chained region outside a chained region!");
    499   CurFrame->End = getContext().CreateTempSymbol();
    500   EmitLabel(CurFrame->End);
    501   CurrentW64UnwindInfo = CurFrame->ChainedParent;
    502 }
    503 
    504 void MCStreamer::EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
    505                                     bool Except) {
    506   EnsureValidW64UnwindInfo();
    507   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    508   if (CurFrame->ChainedParent)
    509     report_fatal_error("Chained unwind areas can't have handlers!");
    510   CurFrame->ExceptionHandler = Sym;
    511   if (!Except && !Unwind)
    512     report_fatal_error("Don't know what kind of handler this is!");
    513   if (Unwind)
    514     CurFrame->HandlesUnwind = true;
    515   if (Except)
    516     CurFrame->HandlesExceptions = true;
    517 }
    518 
    519 void MCStreamer::EmitWin64EHHandlerData() {
    520   EnsureValidW64UnwindInfo();
    521   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    522   if (CurFrame->ChainedParent)
    523     report_fatal_error("Chained unwind areas can't have handlers!");
    524 }
    525 
    526 void MCStreamer::EmitWin64EHPushReg(unsigned Register) {
    527   EnsureValidW64UnwindInfo();
    528   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    529   MCSymbol *Label = getContext().CreateTempSymbol();
    530   MCWin64EHInstruction Inst(Win64EH::UOP_PushNonVol, Label, Register);
    531   EmitLabel(Label);
    532   CurFrame->Instructions.push_back(Inst);
    533 }
    534 
    535 void MCStreamer::EmitWin64EHSetFrame(unsigned Register, unsigned Offset) {
    536   EnsureValidW64UnwindInfo();
    537   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    538   if (CurFrame->LastFrameInst >= 0)
    539     report_fatal_error("Frame register and offset already specified!");
    540   if (Offset & 0x0F)
    541     report_fatal_error("Misaligned frame pointer offset!");
    542   MCWin64EHInstruction Inst(Win64EH::UOP_SetFPReg, NULL, Register, Offset);
    543   CurFrame->LastFrameInst = CurFrame->Instructions.size();
    544   CurFrame->Instructions.push_back(Inst);
    545 }
    546 
    547 void MCStreamer::EmitWin64EHAllocStack(unsigned Size) {
    548   EnsureValidW64UnwindInfo();
    549   if (Size & 7)
    550     report_fatal_error("Misaligned stack allocation!");
    551   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    552   MCSymbol *Label = getContext().CreateTempSymbol();
    553   MCWin64EHInstruction Inst(Label, Size);
    554   EmitLabel(Label);
    555   CurFrame->Instructions.push_back(Inst);
    556 }
    557 
    558 void MCStreamer::EmitWin64EHSaveReg(unsigned Register, unsigned Offset) {
    559   EnsureValidW64UnwindInfo();
    560   if (Offset & 7)
    561     report_fatal_error("Misaligned saved register offset!");
    562   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    563   MCSymbol *Label = getContext().CreateTempSymbol();
    564   MCWin64EHInstruction Inst(
    565      Offset > 512*1024-8 ? Win64EH::UOP_SaveNonVolBig : Win64EH::UOP_SaveNonVol,
    566                             Label, Register, Offset);
    567   EmitLabel(Label);
    568   CurFrame->Instructions.push_back(Inst);
    569 }
    570 
    571 void MCStreamer::EmitWin64EHSaveXMM(unsigned Register, unsigned Offset) {
    572   EnsureValidW64UnwindInfo();
    573   if (Offset & 0x0F)
    574     report_fatal_error("Misaligned saved vector register offset!");
    575   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    576   MCSymbol *Label = getContext().CreateTempSymbol();
    577   MCWin64EHInstruction Inst(
    578     Offset > 512*1024-16 ? Win64EH::UOP_SaveXMM128Big : Win64EH::UOP_SaveXMM128,
    579                             Label, Register, Offset);
    580   EmitLabel(Label);
    581   CurFrame->Instructions.push_back(Inst);
    582 }
    583 
    584 void MCStreamer::EmitWin64EHPushFrame(bool Code) {
    585   EnsureValidW64UnwindInfo();
    586   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    587   if (CurFrame->Instructions.size() > 0)
    588     report_fatal_error("If present, PushMachFrame must be the first UOP");
    589   MCSymbol *Label = getContext().CreateTempSymbol();
    590   MCWin64EHInstruction Inst(Win64EH::UOP_PushMachFrame, Label, Code);
    591   EmitLabel(Label);
    592   CurFrame->Instructions.push_back(Inst);
    593 }
    594 
    595 void MCStreamer::EmitWin64EHEndProlog() {
    596   EnsureValidW64UnwindInfo();
    597   MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
    598   CurFrame->PrologEnd = getContext().CreateTempSymbol();
    599   EmitLabel(CurFrame->PrologEnd);
    600 }
    601 
    602 void MCStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol) {
    603   llvm_unreachable("This file format doesn't support this directive");
    604 }
    605 
    606 void MCStreamer::EmitFnStart() {
    607   errs() << "Not implemented yet\n";
    608   abort();
    609 }
    610 
    611 void MCStreamer::EmitFnEnd() {
    612   errs() << "Not implemented yet\n";
    613   abort();
    614 }
    615 
    616 void MCStreamer::EmitCantUnwind() {
    617   errs() << "Not implemented yet\n";
    618   abort();
    619 }
    620 
    621 void MCStreamer::EmitHandlerData() {
    622   errs() << "Not implemented yet\n";
    623   abort();
    624 }
    625 
    626 void MCStreamer::EmitPersonality(const MCSymbol *Personality) {
    627   errs() << "Not implemented yet\n";
    628   abort();
    629 }
    630 
    631 void MCStreamer::EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset) {
    632   errs() << "Not implemented yet\n";
    633   abort();
    634 }
    635 
    636 void MCStreamer::EmitPad(int64_t Offset) {
    637   errs() << "Not implemented yet\n";
    638   abort();
    639 }
    640 
    641 void MCStreamer::EmitRegSave(const SmallVectorImpl<unsigned> &RegList, bool) {
    642   errs() << "Not implemented yet\n";
    643   abort();
    644 }
    645 
    646 /// EmitRawText - If this file is backed by an assembly streamer, this dumps
    647 /// the specified string in the output .s file.  This capability is
    648 /// indicated by the hasRawTextSupport() predicate.
    649 void MCStreamer::EmitRawText(StringRef String) {
    650   errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
    651   " something must not be fully mc'ized\n";
    652   abort();
    653 }
    654 
    655 void MCStreamer::EmitRawText(const Twine &T) {
    656   SmallString<128> Str;
    657   T.toVector(Str);
    658   EmitRawText(Str.str());
    659 }
    660 
    661 void MCStreamer::EmitFrames(bool usingCFI) {
    662   if (!getNumFrameInfos())
    663     return;
    664 
    665   if (EmitEHFrame)
    666     MCDwarfFrameEmitter::Emit(*this, usingCFI, true);
    667 
    668   if (EmitDebugFrame)
    669     MCDwarfFrameEmitter::Emit(*this, usingCFI, false);
    670 }
    671 
    672 void MCStreamer::EmitW64Tables() {
    673   if (!getNumW64UnwindInfos())
    674     return;
    675 
    676   MCWin64EHUnwindEmitter::Emit(*this);
    677 }
    678 
    679 void MCStreamer::Finish() {
    680   if (!FrameInfos.empty() && !FrameInfos.back().End)
    681     report_fatal_error("Unfinished frame!");
    682 
    683   FinishImpl();
    684 }
    685