1//===-- X86AsmPrinter.cpp - Convert X86 LLVM code to AT&T assembly --------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file contains a printer that converts from our internal representation
10// of machine-dependent LLVM code to X86 machine code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "X86AsmPrinter.h"
15#include "MCTargetDesc/X86ATTInstPrinter.h"
16#include "MCTargetDesc/X86BaseInfo.h"
17#include "MCTargetDesc/X86TargetStreamer.h"
18#include "TargetInfo/X86TargetInfo.h"
19#include "X86InstrInfo.h"
20#include "X86MachineFunctionInfo.h"
21#include "X86Subtarget.h"
22#include "llvm/BinaryFormat/COFF.h"
23#include "llvm/BinaryFormat/ELF.h"
24#include "llvm/CodeGen/MachineConstantPool.h"
25#include "llvm/CodeGen/MachineModuleInfoImpls.h"
26#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
27#include "llvm/IR/DerivedTypes.h"
28#include "llvm/IR/InlineAsm.h"
29#include "llvm/IR/Mangler.h"
30#include "llvm/IR/Module.h"
31#include "llvm/IR/Type.h"
32#include "llvm/MC/MCCodeEmitter.h"
33#include "llvm/MC/MCContext.h"
34#include "llvm/MC/MCExpr.h"
35#include "llvm/MC/MCSectionCOFF.h"
36#include "llvm/MC/MCSectionELF.h"
37#include "llvm/MC/MCSectionMachO.h"
38#include "llvm/MC/MCStreamer.h"
39#include "llvm/MC/MCSymbol.h"
40#include "llvm/Support/Debug.h"
41#include "llvm/Support/ErrorHandling.h"
42#include "llvm/Support/MachineValueType.h"
43#include "llvm/Support/TargetRegistry.h"
44#include "llvm/Target/TargetMachine.h"
45
46using namespace llvm;
47
48X86AsmPrinter::X86AsmPrinter(TargetMachine &TM,
49                             std::unique_ptr<MCStreamer> Streamer)
50    : AsmPrinter(TM, std::move(Streamer)), SM(*this), FM(*this) {}
51
52//===----------------------------------------------------------------------===//
53// Primitive Helper Functions.
54//===----------------------------------------------------------------------===//
55
56/// runOnMachineFunction - Emit the function body.
57///
58bool X86AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
59  Subtarget = &MF.getSubtarget<X86Subtarget>();
60
61  SMShadowTracker.startFunction(MF);
62  CodeEmitter.reset(TM.getTarget().createMCCodeEmitter(
63      *Subtarget->getInstrInfo(), *Subtarget->getRegisterInfo(),
64      MF.getContext()));
65
66  EmitFPOData =
67      Subtarget->isTargetWin32() && MF.getMMI().getModule()->getCodeViewFlag();
68
69  SetupMachineFunction(MF);
70
71  if (Subtarget->isTargetCOFF()) {
72    bool Local = MF.getFunction().hasLocalLinkage();
73    OutStreamer->BeginCOFFSymbolDef(CurrentFnSym);
74    OutStreamer->EmitCOFFSymbolStorageClass(
75        Local ? COFF::IMAGE_SYM_CLASS_STATIC : COFF::IMAGE_SYM_CLASS_EXTERNAL);
76    OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_FUNCTION
77                                               << COFF::SCT_COMPLEX_TYPE_SHIFT);
78    OutStreamer->EndCOFFSymbolDef();
79  }
80
81  // Emit the rest of the function body.
82  emitFunctionBody();
83
84  // Emit the XRay table for this function.
85  emitXRayTable();
86
87  EmitFPOData = false;
88
89  // We didn't modify anything.
90  return false;
91}
92
93void X86AsmPrinter::emitFunctionBodyStart() {
94  if (EmitFPOData) {
95    if (auto *XTS =
96        static_cast<X86TargetStreamer *>(OutStreamer->getTargetStreamer()))
97      XTS->emitFPOProc(
98          CurrentFnSym,
99          MF->getInfo<X86MachineFunctionInfo>()->getArgumentStackSize());
100  }
101}
102
103void X86AsmPrinter::emitFunctionBodyEnd() {
104  if (EmitFPOData) {
105    if (auto *XTS =
106            static_cast<X86TargetStreamer *>(OutStreamer->getTargetStreamer()))
107      XTS->emitFPOEndProc();
108  }
109}
110
111/// PrintSymbolOperand - Print a raw symbol reference operand.  This handles
112/// jump tables, constant pools, global address and external symbols, all of
113/// which print to a label with various suffixes for relocation types etc.
114void X86AsmPrinter::PrintSymbolOperand(const MachineOperand &MO,
115                                       raw_ostream &O) {
116  switch (MO.getType()) {
117  default: llvm_unreachable("unknown symbol type!");
118  case MachineOperand::MO_ConstantPoolIndex:
119    GetCPISymbol(MO.getIndex())->print(O, MAI);
120    printOffset(MO.getOffset(), O);
121    break;
122  case MachineOperand::MO_GlobalAddress: {
123    const GlobalValue *GV = MO.getGlobal();
124
125    MCSymbol *GVSym;
126    if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
127        MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE)
128      GVSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
129    else
130      GVSym = getSymbolPreferLocal(*GV);
131
132    // Handle dllimport linkage.
133    if (MO.getTargetFlags() == X86II::MO_DLLIMPORT)
134      GVSym = OutContext.getOrCreateSymbol(Twine("__imp_") + GVSym->getName());
135    else if (MO.getTargetFlags() == X86II::MO_COFFSTUB)
136      GVSym =
137          OutContext.getOrCreateSymbol(Twine(".refptr.") + GVSym->getName());
138
139    if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
140        MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE) {
141      MCSymbol *Sym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
142      MachineModuleInfoImpl::StubValueTy &StubSym =
143          MMI->getObjFileInfo<MachineModuleInfoMachO>().getGVStubEntry(Sym);
144      if (!StubSym.getPointer())
145        StubSym = MachineModuleInfoImpl::StubValueTy(getSymbol(GV),
146                                                     !GV->hasInternalLinkage());
147    }
148
149    // If the name begins with a dollar-sign, enclose it in parens.  We do this
150    // to avoid having it look like an integer immediate to the assembler.
151    if (GVSym->getName()[0] != '$')
152      GVSym->print(O, MAI);
153    else {
154      O << '(';
155      GVSym->print(O, MAI);
156      O << ')';
157    }
158    printOffset(MO.getOffset(), O);
159    break;
160  }
161  }
162
163  switch (MO.getTargetFlags()) {
164  default:
165    llvm_unreachable("Unknown target flag on GV operand");
166  case X86II::MO_NO_FLAG:    // No flag.
167    break;
168  case X86II::MO_DARWIN_NONLAZY:
169  case X86II::MO_DLLIMPORT:
170  case X86II::MO_COFFSTUB:
171    // These affect the name of the symbol, not any suffix.
172    break;
173  case X86II::MO_GOT_ABSOLUTE_ADDRESS:
174    O << " + [.-";
175    MF->getPICBaseSymbol()->print(O, MAI);
176    O << ']';
177    break;
178  case X86II::MO_PIC_BASE_OFFSET:
179  case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
180    O << '-';
181    MF->getPICBaseSymbol()->print(O, MAI);
182    break;
183  case X86II::MO_TLSGD:     O << "@TLSGD";     break;
184  case X86II::MO_TLSLD:     O << "@TLSLD";     break;
185  case X86II::MO_TLSLDM:    O << "@TLSLDM";    break;
186  case X86II::MO_GOTTPOFF:  O << "@GOTTPOFF";  break;
187  case X86II::MO_INDNTPOFF: O << "@INDNTPOFF"; break;
188  case X86II::MO_TPOFF:     O << "@TPOFF";     break;
189  case X86II::MO_DTPOFF:    O << "@DTPOFF";    break;
190  case X86II::MO_NTPOFF:    O << "@NTPOFF";    break;
191  case X86II::MO_GOTNTPOFF: O << "@GOTNTPOFF"; break;
192  case X86II::MO_GOTPCREL:  O << "@GOTPCREL";  break;
193  case X86II::MO_GOT:       O << "@GOT";       break;
194  case X86II::MO_GOTOFF:    O << "@GOTOFF";    break;
195  case X86II::MO_PLT:       O << "@PLT";       break;
196  case X86II::MO_TLVP:      O << "@TLVP";      break;
197  case X86II::MO_TLVP_PIC_BASE:
198    O << "@TLVP" << '-';
199    MF->getPICBaseSymbol()->print(O, MAI);
200    break;
201  case X86II::MO_SECREL:    O << "@SECREL32";  break;
202  }
203}
204
205void X86AsmPrinter::PrintOperand(const MachineInstr *MI, unsigned OpNo,
206                                 raw_ostream &O) {
207  const MachineOperand &MO = MI->getOperand(OpNo);
208  const bool IsATT = MI->getInlineAsmDialect() == InlineAsm::AD_ATT;
209  switch (MO.getType()) {
210  default: llvm_unreachable("unknown operand type!");
211  case MachineOperand::MO_Register: {
212    if (IsATT)
213      O << '%';
214    O << X86ATTInstPrinter::getRegisterName(MO.getReg());
215    return;
216  }
217
218  case MachineOperand::MO_Immediate:
219    if (IsATT)
220      O << '$';
221    O << MO.getImm();
222    return;
223
224  case MachineOperand::MO_ConstantPoolIndex:
225  case MachineOperand::MO_GlobalAddress: {
226    switch (MI->getInlineAsmDialect()) {
227    case InlineAsm::AD_ATT:
228      O << '$';
229      break;
230    case InlineAsm::AD_Intel:
231      O << "offset ";
232      break;
233    }
234    PrintSymbolOperand(MO, O);
235    break;
236  }
237  case MachineOperand::MO_BlockAddress: {
238    MCSymbol *Sym = GetBlockAddressSymbol(MO.getBlockAddress());
239    Sym->print(O, MAI);
240    break;
241  }
242  }
243}
244
245/// PrintModifiedOperand - Print subregisters based on supplied modifier,
246/// deferring to PrintOperand() if no modifier was supplied or if operand is not
247/// a register.
248void X86AsmPrinter::PrintModifiedOperand(const MachineInstr *MI, unsigned OpNo,
249                                         raw_ostream &O, const char *Modifier) {
250  const MachineOperand &MO = MI->getOperand(OpNo);
251  if (!Modifier || MO.getType() != MachineOperand::MO_Register)
252    return PrintOperand(MI, OpNo, O);
253  if (MI->getInlineAsmDialect() == InlineAsm::AD_ATT)
254    O << '%';
255  Register Reg = MO.getReg();
256  if (strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
257    unsigned Size = (strcmp(Modifier+6,"64") == 0) ? 64 :
258        (strcmp(Modifier+6,"32") == 0) ? 32 :
259        (strcmp(Modifier+6,"16") == 0) ? 16 : 8;
260    Reg = getX86SubSuperRegister(Reg, Size);
261  }
262  O << X86ATTInstPrinter::getRegisterName(Reg);
263}
264
265/// PrintPCRelImm - This is used to print an immediate value that ends up
266/// being encoded as a pc-relative value.  These print slightly differently, for
267/// example, a $ is not emitted.
268void X86AsmPrinter::PrintPCRelImm(const MachineInstr *MI, unsigned OpNo,
269                                  raw_ostream &O) {
270  const MachineOperand &MO = MI->getOperand(OpNo);
271  switch (MO.getType()) {
272  default: llvm_unreachable("Unknown pcrel immediate operand");
273  case MachineOperand::MO_Register:
274    // pc-relativeness was handled when computing the value in the reg.
275    PrintOperand(MI, OpNo, O);
276    return;
277  case MachineOperand::MO_Immediate:
278    O << MO.getImm();
279    return;
280  case MachineOperand::MO_GlobalAddress:
281    PrintSymbolOperand(MO, O);
282    return;
283  }
284}
285
286void X86AsmPrinter::PrintLeaMemReference(const MachineInstr *MI, unsigned OpNo,
287                                         raw_ostream &O, const char *Modifier) {
288  const MachineOperand &BaseReg = MI->getOperand(OpNo + X86::AddrBaseReg);
289  const MachineOperand &IndexReg = MI->getOperand(OpNo + X86::AddrIndexReg);
290  const MachineOperand &DispSpec = MI->getOperand(OpNo + X86::AddrDisp);
291
292  // If we really don't want to print out (rip), don't.
293  bool HasBaseReg = BaseReg.getReg() != 0;
294  if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") &&
295      BaseReg.getReg() == X86::RIP)
296    HasBaseReg = false;
297
298  // HasParenPart - True if we will print out the () part of the mem ref.
299  bool HasParenPart = IndexReg.getReg() || HasBaseReg;
300
301  switch (DispSpec.getType()) {
302  default:
303    llvm_unreachable("unknown operand type!");
304  case MachineOperand::MO_Immediate: {
305    int DispVal = DispSpec.getImm();
306    if (DispVal || !HasParenPart)
307      O << DispVal;
308    break;
309  }
310  case MachineOperand::MO_GlobalAddress:
311  case MachineOperand::MO_ConstantPoolIndex:
312    PrintSymbolOperand(DispSpec, O);
313    break;
314  }
315
316  if (Modifier && strcmp(Modifier, "H") == 0)
317    O << "+8";
318
319  if (HasParenPart) {
320    assert(IndexReg.getReg() != X86::ESP &&
321           "X86 doesn't allow scaling by ESP");
322
323    O << '(';
324    if (HasBaseReg)
325      PrintModifiedOperand(MI, OpNo + X86::AddrBaseReg, O, Modifier);
326
327    if (IndexReg.getReg()) {
328      O << ',';
329      PrintModifiedOperand(MI, OpNo + X86::AddrIndexReg, O, Modifier);
330      unsigned ScaleVal = MI->getOperand(OpNo + X86::AddrScaleAmt).getImm();
331      if (ScaleVal != 1)
332        O << ',' << ScaleVal;
333    }
334    O << ')';
335  }
336}
337
338void X86AsmPrinter::PrintMemReference(const MachineInstr *MI, unsigned OpNo,
339                                      raw_ostream &O, const char *Modifier) {
340  assert(isMem(*MI, OpNo) && "Invalid memory reference!");
341  const MachineOperand &Segment = MI->getOperand(OpNo + X86::AddrSegmentReg);
342  if (Segment.getReg()) {
343    PrintModifiedOperand(MI, OpNo + X86::AddrSegmentReg, O, Modifier);
344    O << ':';
345  }
346  PrintLeaMemReference(MI, OpNo, O, Modifier);
347}
348
349
350void X86AsmPrinter::PrintIntelMemReference(const MachineInstr *MI,
351                                           unsigned OpNo, raw_ostream &O,
352                                           const char *Modifier) {
353  const MachineOperand &BaseReg = MI->getOperand(OpNo + X86::AddrBaseReg);
354  unsigned ScaleVal = MI->getOperand(OpNo + X86::AddrScaleAmt).getImm();
355  const MachineOperand &IndexReg = MI->getOperand(OpNo + X86::AddrIndexReg);
356  const MachineOperand &DispSpec = MI->getOperand(OpNo + X86::AddrDisp);
357  const MachineOperand &SegReg = MI->getOperand(OpNo + X86::AddrSegmentReg);
358
359  // If we really don't want to print out (rip), don't.
360  bool HasBaseReg = BaseReg.getReg() != 0;
361  if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") &&
362      BaseReg.getReg() == X86::RIP)
363    HasBaseReg = false;
364
365  // If this has a segment register, print it.
366  if (SegReg.getReg()) {
367    PrintOperand(MI, OpNo + X86::AddrSegmentReg, O);
368    O << ':';
369  }
370
371  O << '[';
372
373  bool NeedPlus = false;
374  if (HasBaseReg) {
375    PrintOperand(MI, OpNo + X86::AddrBaseReg, O);
376    NeedPlus = true;
377  }
378
379  if (IndexReg.getReg()) {
380    if (NeedPlus) O << " + ";
381    if (ScaleVal != 1)
382      O << ScaleVal << '*';
383    PrintOperand(MI, OpNo + X86::AddrIndexReg, O);
384    NeedPlus = true;
385  }
386
387  if (!DispSpec.isImm()) {
388    if (NeedPlus) O << " + ";
389    PrintOperand(MI, OpNo + X86::AddrDisp, O);
390  } else {
391    int64_t DispVal = DispSpec.getImm();
392    if (DispVal || (!IndexReg.getReg() && !HasBaseReg)) {
393      if (NeedPlus) {
394        if (DispVal > 0)
395          O << " + ";
396        else {
397          O << " - ";
398          DispVal = -DispVal;
399        }
400      }
401      O << DispVal;
402    }
403  }
404  O << ']';
405}
406
407static bool printAsmMRegister(X86AsmPrinter &P, const MachineOperand &MO,
408                              char Mode, raw_ostream &O) {
409  Register Reg = MO.getReg();
410  bool EmitPercent = MO.getParent()->getInlineAsmDialect() == InlineAsm::AD_ATT;
411
412  if (!X86::GR8RegClass.contains(Reg) &&
413      !X86::GR16RegClass.contains(Reg) &&
414      !X86::GR32RegClass.contains(Reg) &&
415      !X86::GR64RegClass.contains(Reg))
416    return true;
417
418  switch (Mode) {
419  default: return true;  // Unknown mode.
420  case 'b': // Print QImode register
421    Reg = getX86SubSuperRegister(Reg, 8);
422    break;
423  case 'h': // Print QImode high register
424    Reg = getX86SubSuperRegister(Reg, 8, true);
425    break;
426  case 'w': // Print HImode register
427    Reg = getX86SubSuperRegister(Reg, 16);
428    break;
429  case 'k': // Print SImode register
430    Reg = getX86SubSuperRegister(Reg, 32);
431    break;
432  case 'V':
433    EmitPercent = false;
434    LLVM_FALLTHROUGH;
435  case 'q':
436    // Print 64-bit register names if 64-bit integer registers are available.
437    // Otherwise, print 32-bit register names.
438    Reg = getX86SubSuperRegister(Reg, P.getSubtarget().is64Bit() ? 64 : 32);
439    break;
440  }
441
442  if (EmitPercent)
443    O << '%';
444
445  O << X86ATTInstPrinter::getRegisterName(Reg);
446  return false;
447}
448
449static bool printAsmVRegister(X86AsmPrinter &P, const MachineOperand &MO,
450                              char Mode, raw_ostream &O) {
451  unsigned Reg = MO.getReg();
452  bool EmitPercent = MO.getParent()->getInlineAsmDialect() == InlineAsm::AD_ATT;
453
454  unsigned Index;
455  if (X86::VR128XRegClass.contains(Reg))
456    Index = Reg - X86::XMM0;
457  else if (X86::VR256XRegClass.contains(Reg))
458    Index = Reg - X86::YMM0;
459  else if (X86::VR512RegClass.contains(Reg))
460    Index = Reg - X86::ZMM0;
461  else
462    return true;
463
464  switch (Mode) {
465  default: // Unknown mode.
466    return true;
467  case 'x': // Print V4SFmode register
468    Reg = X86::XMM0 + Index;
469    break;
470  case 't': // Print V8SFmode register
471    Reg = X86::YMM0 + Index;
472    break;
473  case 'g': // Print V16SFmode register
474    Reg = X86::ZMM0 + Index;
475    break;
476  }
477
478  if (EmitPercent)
479    O << '%';
480
481  O << X86ATTInstPrinter::getRegisterName(Reg);
482  return false;
483}
484
485/// PrintAsmOperand - Print out an operand for an inline asm expression.
486///
487bool X86AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
488                                    const char *ExtraCode, raw_ostream &O) {
489  // Does this asm operand have a single letter operand modifier?
490  if (ExtraCode && ExtraCode[0]) {
491    if (ExtraCode[1] != 0) return true; // Unknown modifier.
492
493    const MachineOperand &MO = MI->getOperand(OpNo);
494
495    switch (ExtraCode[0]) {
496    default:
497      // See if this is a generic print operand
498      return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
499    case 'a': // This is an address.  Currently only 'i' and 'r' are expected.
500      switch (MO.getType()) {
501      default:
502        return true;
503      case MachineOperand::MO_Immediate:
504        O << MO.getImm();
505        return false;
506      case MachineOperand::MO_ConstantPoolIndex:
507      case MachineOperand::MO_JumpTableIndex:
508      case MachineOperand::MO_ExternalSymbol:
509        llvm_unreachable("unexpected operand type!");
510      case MachineOperand::MO_GlobalAddress:
511        PrintSymbolOperand(MO, O);
512        if (Subtarget->isPICStyleRIPRel())
513          O << "(%rip)";
514        return false;
515      case MachineOperand::MO_Register:
516        O << '(';
517        PrintOperand(MI, OpNo, O);
518        O << ')';
519        return false;
520      }
521
522    case 'c': // Don't print "$" before a global var name or constant.
523      switch (MO.getType()) {
524      default:
525        PrintOperand(MI, OpNo, O);
526        break;
527      case MachineOperand::MO_Immediate:
528        O << MO.getImm();
529        break;
530      case MachineOperand::MO_ConstantPoolIndex:
531      case MachineOperand::MO_JumpTableIndex:
532      case MachineOperand::MO_ExternalSymbol:
533        llvm_unreachable("unexpected operand type!");
534      case MachineOperand::MO_GlobalAddress:
535        PrintSymbolOperand(MO, O);
536        break;
537      }
538      return false;
539
540    case 'A': // Print '*' before a register (it must be a register)
541      if (MO.isReg()) {
542        O << '*';
543        PrintOperand(MI, OpNo, O);
544        return false;
545      }
546      return true;
547
548    case 'b': // Print QImode register
549    case 'h': // Print QImode high register
550    case 'w': // Print HImode register
551    case 'k': // Print SImode register
552    case 'q': // Print DImode register
553    case 'V': // Print native register without '%'
554      if (MO.isReg())
555        return printAsmMRegister(*this, MO, ExtraCode[0], O);
556      PrintOperand(MI, OpNo, O);
557      return false;
558
559    case 'x': // Print V4SFmode register
560    case 't': // Print V8SFmode register
561    case 'g': // Print V16SFmode register
562      if (MO.isReg())
563        return printAsmVRegister(*this, MO, ExtraCode[0], O);
564      PrintOperand(MI, OpNo, O);
565      return false;
566
567    case 'P': // This is the operand of a call, treat specially.
568      PrintPCRelImm(MI, OpNo, O);
569      return false;
570
571    case 'n': // Negate the immediate or print a '-' before the operand.
572      // Note: this is a temporary solution. It should be handled target
573      // independently as part of the 'MC' work.
574      if (MO.isImm()) {
575        O << -MO.getImm();
576        return false;
577      }
578      O << '-';
579    }
580  }
581
582  PrintOperand(MI, OpNo, O);
583  return false;
584}
585
586bool X86AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
587                                          const char *ExtraCode,
588                                          raw_ostream &O) {
589  if (ExtraCode && ExtraCode[0]) {
590    if (ExtraCode[1] != 0) return true; // Unknown modifier.
591
592    switch (ExtraCode[0]) {
593    default: return true;  // Unknown modifier.
594    case 'b': // Print QImode register
595    case 'h': // Print QImode high register
596    case 'w': // Print HImode register
597    case 'k': // Print SImode register
598    case 'q': // Print SImode register
599      // These only apply to registers, ignore on mem.
600      break;
601    case 'H':
602      if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
603        return true;  // Unsupported modifier in Intel inline assembly.
604      } else {
605        PrintMemReference(MI, OpNo, O, "H");
606      }
607      return false;
608    case 'P': // Don't print @PLT, but do print as memory.
609      if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
610        PrintIntelMemReference(MI, OpNo, O, "no-rip");
611      } else {
612        PrintMemReference(MI, OpNo, O, "no-rip");
613      }
614      return false;
615    }
616  }
617  if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
618    PrintIntelMemReference(MI, OpNo, O, nullptr);
619  } else {
620    PrintMemReference(MI, OpNo, O, nullptr);
621  }
622  return false;
623}
624
625void X86AsmPrinter::emitStartOfAsmFile(Module &M) {
626  const Triple &TT = TM.getTargetTriple();
627
628  if (TT.isOSBinFormatELF()) {
629    // Assemble feature flags that may require creation of a note section.
630    unsigned FeatureFlagsAnd = 0;
631    if (M.getModuleFlag("cf-protection-branch"))
632      FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_IBT;
633    if (M.getModuleFlag("cf-protection-return"))
634      FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_SHSTK;
635
636    if (FeatureFlagsAnd) {
637      // Emit a .note.gnu.property section with the flags.
638      if (!TT.isArch32Bit() && !TT.isArch64Bit())
639        llvm_unreachable("CFProtection used on invalid architecture!");
640      MCSection *Cur = OutStreamer->getCurrentSectionOnly();
641      MCSection *Nt = MMI->getContext().getELFSection(
642          ".note.gnu.property", ELF::SHT_NOTE, ELF::SHF_ALLOC);
643      OutStreamer->SwitchSection(Nt);
644
645      // Emitting note header.
646      int WordSize = TT.isArch64Bit() ? 8 : 4;
647      emitAlignment(WordSize == 4 ? Align(4) : Align(8));
648      OutStreamer->emitIntValue(4, 4 /*size*/); // data size for "GNU\0"
649      OutStreamer->emitIntValue(8 + WordSize, 4 /*size*/); // Elf_Prop size
650      OutStreamer->emitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4 /*size*/);
651      OutStreamer->emitBytes(StringRef("GNU", 4)); // note name
652
653      // Emitting an Elf_Prop for the CET properties.
654      OutStreamer->emitInt32(ELF::GNU_PROPERTY_X86_FEATURE_1_AND);
655      OutStreamer->emitInt32(4);                          // data size
656      OutStreamer->emitInt32(FeatureFlagsAnd);            // data
657      emitAlignment(WordSize == 4 ? Align(4) : Align(8)); // padding
658
659      OutStreamer->endSection(Nt);
660      OutStreamer->SwitchSection(Cur);
661    }
662  }
663
664  if (TT.isOSBinFormatMachO())
665    OutStreamer->SwitchSection(getObjFileLowering().getTextSection());
666
667  if (TT.isOSBinFormatCOFF()) {
668    // Emit an absolute @feat.00 symbol.  This appears to be some kind of
669    // compiler features bitfield read by link.exe.
670    MCSymbol *S = MMI->getContext().getOrCreateSymbol(StringRef("@feat.00"));
671    OutStreamer->BeginCOFFSymbolDef(S);
672    OutStreamer->EmitCOFFSymbolStorageClass(COFF::IMAGE_SYM_CLASS_STATIC);
673    OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_NULL);
674    OutStreamer->EndCOFFSymbolDef();
675    int64_t Feat00Flags = 0;
676
677    if (TT.getArch() == Triple::x86) {
678      // According to the PE-COFF spec, the LSB of this value marks the object
679      // for "registered SEH".  This means that all SEH handler entry points
680      // must be registered in .sxdata.  Use of any unregistered handlers will
681      // cause the process to terminate immediately.  LLVM does not know how to
682      // register any SEH handlers, so its object files should be safe.
683      Feat00Flags |= 1;
684    }
685
686    if (M.getModuleFlag("cfguard"))
687      Feat00Flags |= 0x800; // Object is CFG-aware.
688
689    OutStreamer->emitSymbolAttribute(S, MCSA_Global);
690    OutStreamer->emitAssignment(
691        S, MCConstantExpr::create(Feat00Flags, MMI->getContext()));
692  }
693  OutStreamer->emitSyntaxDirective();
694
695  // If this is not inline asm and we're in 16-bit
696  // mode prefix assembly with .code16.
697  bool is16 = TT.getEnvironment() == Triple::CODE16;
698  if (M.getModuleInlineAsm().empty() && is16)
699    OutStreamer->emitAssemblerFlag(MCAF_Code16);
700}
701
702static void
703emitNonLazySymbolPointer(MCStreamer &OutStreamer, MCSymbol *StubLabel,
704                         MachineModuleInfoImpl::StubValueTy &MCSym) {
705  // L_foo$stub:
706  OutStreamer.emitLabel(StubLabel);
707  //   .indirect_symbol _foo
708  OutStreamer.emitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
709
710  if (MCSym.getInt())
711    // External to current translation unit.
712    OutStreamer.emitIntValue(0, 4/*size*/);
713  else
714    // Internal to current translation unit.
715    //
716    // When we place the LSDA into the TEXT section, the type info
717    // pointers need to be indirect and pc-rel. We accomplish this by
718    // using NLPs; however, sometimes the types are local to the file.
719    // We need to fill in the value for the NLP in those cases.
720    OutStreamer.emitValue(
721        MCSymbolRefExpr::create(MCSym.getPointer(), OutStreamer.getContext()),
722        4 /*size*/);
723}
724
725static void emitNonLazyStubs(MachineModuleInfo *MMI, MCStreamer &OutStreamer) {
726
727  MachineModuleInfoMachO &MMIMacho =
728      MMI->getObjFileInfo<MachineModuleInfoMachO>();
729
730  // Output stubs for dynamically-linked functions.
731  MachineModuleInfoMachO::SymbolListTy Stubs;
732
733  // Output stubs for external and common global variables.
734  Stubs = MMIMacho.GetGVStubList();
735  if (!Stubs.empty()) {
736    OutStreamer.SwitchSection(MMI->getContext().getMachOSection(
737        "__IMPORT", "__pointers", MachO::S_NON_LAZY_SYMBOL_POINTERS,
738        SectionKind::getMetadata()));
739
740    for (auto &Stub : Stubs)
741      emitNonLazySymbolPointer(OutStreamer, Stub.first, Stub.second);
742
743    Stubs.clear();
744    OutStreamer.AddBlankLine();
745  }
746}
747
748void X86AsmPrinter::emitEndOfAsmFile(Module &M) {
749  const Triple &TT = TM.getTargetTriple();
750
751  if (TT.isOSBinFormatMachO()) {
752    // Mach-O uses non-lazy symbol stubs to encode per-TU information into
753    // global table for symbol lookup.
754    emitNonLazyStubs(MMI, *OutStreamer);
755
756    // Emit stack and fault map information.
757    emitStackMaps(SM);
758    FM.serializeToFaultMapSection();
759
760    // This flag tells the linker that no global symbols contain code that fall
761    // through to other global symbols (e.g. an implementation of multiple entry
762    // points). If this doesn't occur, the linker can safely perform dead code
763    // stripping. Since LLVM never generates code that does this, it is always
764    // safe to set.
765    OutStreamer->emitAssemblerFlag(MCAF_SubsectionsViaSymbols);
766  } else if (TT.isOSBinFormatCOFF()) {
767    if (MMI->usesMSVCFloatingPoint()) {
768      // In Windows' libcmt.lib, there is a file which is linked in only if the
769      // symbol _fltused is referenced. Linking this in causes some
770      // side-effects:
771      //
772      // 1. For x86-32, it will set the x87 rounding mode to 53-bit instead of
773      // 64-bit mantissas at program start.
774      //
775      // 2. It links in support routines for floating-point in scanf and printf.
776      //
777      // MSVC emits an undefined reference to _fltused when there are any
778      // floating point operations in the program (including calls). A program
779      // that only has: `scanf("%f", &global_float);` may fail to trigger this,
780      // but oh well...that's a documented issue.
781      StringRef SymbolName =
782          (TT.getArch() == Triple::x86) ? "__fltused" : "_fltused";
783      MCSymbol *S = MMI->getContext().getOrCreateSymbol(SymbolName);
784      OutStreamer->emitSymbolAttribute(S, MCSA_Global);
785      return;
786    }
787    emitStackMaps(SM);
788  } else if (TT.isOSBinFormatELF()) {
789    emitStackMaps(SM);
790    FM.serializeToFaultMapSection();
791  }
792}
793
794//===----------------------------------------------------------------------===//
795// Target Registry Stuff
796//===----------------------------------------------------------------------===//
797
798// Force static initialization.
799extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeX86AsmPrinter() {
800  RegisterAsmPrinter<X86AsmPrinter> X(getTheX86_32Target());
801  RegisterAsmPrinter<X86AsmPrinter> Y(getTheX86_64Target());
802}
803