1 //===-- X86AsmPrinter.cpp - Convert X86 LLVM code to AT&T assembly --------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file contains a printer that converts from our internal representation
10 // of machine-dependent LLVM code to X86 machine code.
12 //===----------------------------------------------------------------------===//
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 "llvm/BinaryFormat/COFF.h"
22 #include "llvm/BinaryFormat/ELF.h"
23 #include "llvm/CodeGen/MachineConstantPool.h"
24 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
25 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
26 #include "llvm/IR/DerivedTypes.h"
27 #include "llvm/IR/InlineAsm.h"
28 #include "llvm/IR/Mangler.h"
29 #include "llvm/IR/Module.h"
30 #include "llvm/IR/Type.h"
31 #include "llvm/MC/MCCodeEmitter.h"
32 #include "llvm/MC/MCContext.h"
33 #include "llvm/MC/MCExpr.h"
34 #include "llvm/MC/MCSectionCOFF.h"
35 #include "llvm/MC/MCSectionELF.h"
36 #include "llvm/MC/MCSectionMachO.h"
37 #include "llvm/MC/MCStreamer.h"
38 #include "llvm/MC/MCSymbol.h"
39 #include "llvm/Support/Debug.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/MachineValueType.h"
42 #include "llvm/Support/TargetRegistry.h"
45 X86AsmPrinter::X86AsmPrinter(TargetMachine &TM,
46 std::unique_ptr<MCStreamer> Streamer)
47 : AsmPrinter(TM, std::move(Streamer)), SM(*this), FM(*this) {}
49 //===----------------------------------------------------------------------===//
50 // Primitive Helper Functions.
51 //===----------------------------------------------------------------------===//
53 /// runOnMachineFunction - Emit the function body.
55 bool X86AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
56 Subtarget = &MF.getSubtarget<X86Subtarget>();
58 SMShadowTracker.startFunction(MF);
59 CodeEmitter.reset(TM.getTarget().createMCCodeEmitter(
60 *Subtarget->getInstrInfo(), *Subtarget->getRegisterInfo(),
64 Subtarget->isTargetWin32() && MF.getMMI().getModule()->getCodeViewFlag();
66 SetupMachineFunction(MF);
68 if (Subtarget->isTargetCOFF()) {
69 bool Local = MF.getFunction().hasLocalLinkage();
70 OutStreamer->BeginCOFFSymbolDef(CurrentFnSym);
71 OutStreamer->EmitCOFFSymbolStorageClass(
72 Local ? COFF::IMAGE_SYM_CLASS_STATIC : COFF::IMAGE_SYM_CLASS_EXTERNAL);
73 OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_FUNCTION
74 << COFF::SCT_COMPLEX_TYPE_SHIFT);
75 OutStreamer->EndCOFFSymbolDef();
78 // Emit the rest of the function body.
81 // Emit the XRay table for this function.
86 // We didn't modify anything.
90 void X86AsmPrinter::EmitFunctionBodyStart() {
93 static_cast<X86TargetStreamer *>(OutStreamer->getTargetStreamer()))
96 MF->getInfo<X86MachineFunctionInfo>()->getArgumentStackSize());
100 void X86AsmPrinter::EmitFunctionBodyEnd() {
103 static_cast<X86TargetStreamer *>(OutStreamer->getTargetStreamer()))
104 XTS->emitFPOEndProc();
108 /// PrintSymbolOperand - Print a raw symbol reference operand. This handles
109 /// jump tables, constant pools, global address and external symbols, all of
110 /// which print to a label with various suffixes for relocation types etc.
111 void X86AsmPrinter::PrintSymbolOperand(const MachineOperand &MO,
113 switch (MO.getType()) {
114 default: llvm_unreachable("unknown symbol type!");
115 case MachineOperand::MO_ConstantPoolIndex:
116 GetCPISymbol(MO.getIndex())->print(O, MAI);
117 printOffset(MO.getOffset(), O);
119 case MachineOperand::MO_GlobalAddress: {
120 const GlobalValue *GV = MO.getGlobal();
123 if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
124 MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE)
125 GVSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
127 GVSym = getSymbol(GV);
129 // Handle dllimport linkage.
130 if (MO.getTargetFlags() == X86II::MO_DLLIMPORT)
131 GVSym = OutContext.getOrCreateSymbol(Twine("__imp_") + GVSym->getName());
132 else if (MO.getTargetFlags() == X86II::MO_COFFSTUB)
134 OutContext.getOrCreateSymbol(Twine(".refptr.") + GVSym->getName());
136 if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
137 MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE) {
138 MCSymbol *Sym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
139 MachineModuleInfoImpl::StubValueTy &StubSym =
140 MMI->getObjFileInfo<MachineModuleInfoMachO>().getGVStubEntry(Sym);
141 if (!StubSym.getPointer())
142 StubSym = MachineModuleInfoImpl::StubValueTy(getSymbol(GV),
143 !GV->hasInternalLinkage());
146 // If the name begins with a dollar-sign, enclose it in parens. We do this
147 // to avoid having it look like an integer immediate to the assembler.
148 if (GVSym->getName()[0] != '$')
149 GVSym->print(O, MAI);
152 GVSym->print(O, MAI);
155 printOffset(MO.getOffset(), O);
160 switch (MO.getTargetFlags()) {
162 llvm_unreachable("Unknown target flag on GV operand");
163 case X86II::MO_NO_FLAG: // No flag.
165 case X86II::MO_DARWIN_NONLAZY:
166 case X86II::MO_DLLIMPORT:
167 case X86II::MO_COFFSTUB:
168 // These affect the name of the symbol, not any suffix.
170 case X86II::MO_GOT_ABSOLUTE_ADDRESS:
172 MF->getPICBaseSymbol()->print(O, MAI);
175 case X86II::MO_PIC_BASE_OFFSET:
176 case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
178 MF->getPICBaseSymbol()->print(O, MAI);
180 case X86II::MO_TLSGD: O << "@TLSGD"; break;
181 case X86II::MO_TLSLD: O << "@TLSLD"; break;
182 case X86II::MO_TLSLDM: O << "@TLSLDM"; break;
183 case X86II::MO_GOTTPOFF: O << "@GOTTPOFF"; break;
184 case X86II::MO_INDNTPOFF: O << "@INDNTPOFF"; break;
185 case X86II::MO_TPOFF: O << "@TPOFF"; break;
186 case X86II::MO_DTPOFF: O << "@DTPOFF"; break;
187 case X86II::MO_NTPOFF: O << "@NTPOFF"; break;
188 case X86II::MO_GOTNTPOFF: O << "@GOTNTPOFF"; break;
189 case X86II::MO_GOTPCREL: O << "@GOTPCREL"; break;
190 case X86II::MO_GOT: O << "@GOT"; break;
191 case X86II::MO_GOTOFF: O << "@GOTOFF"; break;
192 case X86II::MO_PLT: O << "@PLT"; break;
193 case X86II::MO_TLVP: O << "@TLVP"; break;
194 case X86II::MO_TLVP_PIC_BASE:
196 MF->getPICBaseSymbol()->print(O, MAI);
198 case X86II::MO_SECREL: O << "@SECREL32"; break;
202 void X86AsmPrinter::PrintOperand(const MachineInstr *MI, unsigned OpNo,
204 const MachineOperand &MO = MI->getOperand(OpNo);
205 const bool IsATT = MI->getInlineAsmDialect() == InlineAsm::AD_ATT;
206 switch (MO.getType()) {
207 default: llvm_unreachable("unknown operand type!");
208 case MachineOperand::MO_Register: {
211 O << X86ATTInstPrinter::getRegisterName(MO.getReg());
215 case MachineOperand::MO_Immediate:
221 case MachineOperand::MO_ConstantPoolIndex:
222 case MachineOperand::MO_GlobalAddress: {
223 switch (MI->getInlineAsmDialect()) {
224 case InlineAsm::AD_ATT:
227 case InlineAsm::AD_Intel:
231 PrintSymbolOperand(MO, O);
234 case MachineOperand::MO_BlockAddress: {
235 MCSymbol *Sym = GetBlockAddressSymbol(MO.getBlockAddress());
242 /// PrintModifiedOperand - Print subregisters based on supplied modifier,
243 /// deferring to PrintOperand() if no modifier was supplied or if operand is not
245 void X86AsmPrinter::PrintModifiedOperand(const MachineInstr *MI, unsigned OpNo,
246 raw_ostream &O, const char *Modifier) {
247 const MachineOperand &MO = MI->getOperand(OpNo);
248 if (!Modifier || MO.getType() != MachineOperand::MO_Register)
249 return PrintOperand(MI, OpNo, O);
250 if (MI->getInlineAsmDialect() == InlineAsm::AD_ATT)
252 Register Reg = MO.getReg();
253 if (strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
254 unsigned Size = (strcmp(Modifier+6,"64") == 0) ? 64 :
255 (strcmp(Modifier+6,"32") == 0) ? 32 :
256 (strcmp(Modifier+6,"16") == 0) ? 16 : 8;
257 Reg = getX86SubSuperRegister(Reg, Size);
259 O << X86ATTInstPrinter::getRegisterName(Reg);
262 /// PrintPCRelImm - This is used to print an immediate value that ends up
263 /// being encoded as a pc-relative value. These print slightly differently, for
264 /// example, a $ is not emitted.
265 void X86AsmPrinter::PrintPCRelImm(const MachineInstr *MI, unsigned OpNo,
267 const MachineOperand &MO = MI->getOperand(OpNo);
268 switch (MO.getType()) {
269 default: llvm_unreachable("Unknown pcrel immediate operand");
270 case MachineOperand::MO_Register:
271 // pc-relativeness was handled when computing the value in the reg.
272 PrintOperand(MI, OpNo, O);
274 case MachineOperand::MO_Immediate:
277 case MachineOperand::MO_GlobalAddress:
278 PrintSymbolOperand(MO, O);
283 void X86AsmPrinter::PrintLeaMemReference(const MachineInstr *MI, unsigned OpNo,
284 raw_ostream &O, const char *Modifier) {
285 const MachineOperand &BaseReg = MI->getOperand(OpNo + X86::AddrBaseReg);
286 const MachineOperand &IndexReg = MI->getOperand(OpNo + X86::AddrIndexReg);
287 const MachineOperand &DispSpec = MI->getOperand(OpNo + X86::AddrDisp);
289 // If we really don't want to print out (rip), don't.
290 bool HasBaseReg = BaseReg.getReg() != 0;
291 if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") &&
292 BaseReg.getReg() == X86::RIP)
295 // HasParenPart - True if we will print out the () part of the mem ref.
296 bool HasParenPart = IndexReg.getReg() || HasBaseReg;
298 switch (DispSpec.getType()) {
300 llvm_unreachable("unknown operand type!");
301 case MachineOperand::MO_Immediate: {
302 int DispVal = DispSpec.getImm();
303 if (DispVal || !HasParenPart)
307 case MachineOperand::MO_GlobalAddress:
308 case MachineOperand::MO_ConstantPoolIndex:
309 PrintSymbolOperand(DispSpec, O);
313 if (Modifier && strcmp(Modifier, "H") == 0)
317 assert(IndexReg.getReg() != X86::ESP &&
318 "X86 doesn't allow scaling by ESP");
322 PrintModifiedOperand(MI, OpNo + X86::AddrBaseReg, O, Modifier);
324 if (IndexReg.getReg()) {
326 PrintModifiedOperand(MI, OpNo + X86::AddrIndexReg, O, Modifier);
327 unsigned ScaleVal = MI->getOperand(OpNo + X86::AddrScaleAmt).getImm();
329 O << ',' << ScaleVal;
335 void X86AsmPrinter::PrintMemReference(const MachineInstr *MI, unsigned OpNo,
336 raw_ostream &O, const char *Modifier) {
337 assert(isMem(*MI, OpNo) && "Invalid memory reference!");
338 const MachineOperand &Segment = MI->getOperand(OpNo + X86::AddrSegmentReg);
339 if (Segment.getReg()) {
340 PrintModifiedOperand(MI, OpNo + X86::AddrSegmentReg, O, Modifier);
343 PrintLeaMemReference(MI, OpNo, O, Modifier);
347 void X86AsmPrinter::PrintIntelMemReference(const MachineInstr *MI,
348 unsigned OpNo, raw_ostream &O,
349 const char *Modifier) {
350 const MachineOperand &BaseReg = MI->getOperand(OpNo + X86::AddrBaseReg);
351 unsigned ScaleVal = MI->getOperand(OpNo + X86::AddrScaleAmt).getImm();
352 const MachineOperand &IndexReg = MI->getOperand(OpNo + X86::AddrIndexReg);
353 const MachineOperand &DispSpec = MI->getOperand(OpNo + X86::AddrDisp);
354 const MachineOperand &SegReg = MI->getOperand(OpNo + X86::AddrSegmentReg);
356 // If we really don't want to print out (rip), don't.
357 bool HasBaseReg = BaseReg.getReg() != 0;
358 if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") &&
359 BaseReg.getReg() == X86::RIP)
362 // If this has a segment register, print it.
363 if (SegReg.getReg()) {
364 PrintOperand(MI, OpNo + X86::AddrSegmentReg, O);
370 bool NeedPlus = false;
372 PrintOperand(MI, OpNo + X86::AddrBaseReg, O);
376 if (IndexReg.getReg()) {
377 if (NeedPlus) O << " + ";
379 O << ScaleVal << '*';
380 PrintOperand(MI, OpNo + X86::AddrIndexReg, O);
384 if (!DispSpec.isImm()) {
385 if (NeedPlus) O << " + ";
386 PrintOperand(MI, OpNo + X86::AddrDisp, O);
388 int64_t DispVal = DispSpec.getImm();
389 if (DispVal || (!IndexReg.getReg() && !HasBaseReg)) {
404 static bool printAsmMRegister(X86AsmPrinter &P, const MachineOperand &MO,
405 char Mode, raw_ostream &O) {
406 Register Reg = MO.getReg();
407 bool EmitPercent = true;
409 if (!X86::GR8RegClass.contains(Reg) &&
410 !X86::GR16RegClass.contains(Reg) &&
411 !X86::GR32RegClass.contains(Reg) &&
412 !X86::GR64RegClass.contains(Reg))
416 default: return true; // Unknown mode.
417 case 'b': // Print QImode register
418 Reg = getX86SubSuperRegister(Reg, 8);
420 case 'h': // Print QImode high register
421 Reg = getX86SubSuperRegister(Reg, 8, true);
423 case 'w': // Print HImode register
424 Reg = getX86SubSuperRegister(Reg, 16);
426 case 'k': // Print SImode register
427 Reg = getX86SubSuperRegister(Reg, 32);
433 // Print 64-bit register names if 64-bit integer registers are available.
434 // Otherwise, print 32-bit register names.
435 Reg = getX86SubSuperRegister(Reg, P.getSubtarget().is64Bit() ? 64 : 32);
442 O << X86ATTInstPrinter::getRegisterName(Reg);
446 /// PrintAsmOperand - Print out an operand for an inline asm expression.
448 bool X86AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
449 const char *ExtraCode, raw_ostream &O) {
450 // Does this asm operand have a single letter operand modifier?
451 if (ExtraCode && ExtraCode[0]) {
452 if (ExtraCode[1] != 0) return true; // Unknown modifier.
454 const MachineOperand &MO = MI->getOperand(OpNo);
456 switch (ExtraCode[0]) {
458 // See if this is a generic print operand
459 return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
460 case 'a': // This is an address. Currently only 'i' and 'r' are expected.
461 switch (MO.getType()) {
464 case MachineOperand::MO_Immediate:
467 case MachineOperand::MO_ConstantPoolIndex:
468 case MachineOperand::MO_JumpTableIndex:
469 case MachineOperand::MO_ExternalSymbol:
470 llvm_unreachable("unexpected operand type!");
471 case MachineOperand::MO_GlobalAddress:
472 PrintSymbolOperand(MO, O);
473 if (Subtarget->isPICStyleRIPRel())
476 case MachineOperand::MO_Register:
478 PrintOperand(MI, OpNo, O);
483 case 'c': // Don't print "$" before a global var name or constant.
484 switch (MO.getType()) {
486 PrintOperand(MI, OpNo, O);
488 case MachineOperand::MO_Immediate:
491 case MachineOperand::MO_ConstantPoolIndex:
492 case MachineOperand::MO_JumpTableIndex:
493 case MachineOperand::MO_ExternalSymbol:
494 llvm_unreachable("unexpected operand type!");
495 case MachineOperand::MO_GlobalAddress:
496 PrintSymbolOperand(MO, O);
501 case 'A': // Print '*' before a register (it must be a register)
504 PrintOperand(MI, OpNo, O);
509 case 'b': // Print QImode register
510 case 'h': // Print QImode high register
511 case 'w': // Print HImode register
512 case 'k': // Print SImode register
513 case 'q': // Print DImode register
514 case 'V': // Print native register without '%'
516 return printAsmMRegister(*this, MO, ExtraCode[0], O);
517 PrintOperand(MI, OpNo, O);
520 case 'P': // This is the operand of a call, treat specially.
521 PrintPCRelImm(MI, OpNo, O);
524 case 'n': // Negate the immediate or print a '-' before the operand.
525 // Note: this is a temporary solution. It should be handled target
526 // independently as part of the 'MC' work.
535 PrintOperand(MI, OpNo, O);
539 bool X86AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
540 const char *ExtraCode,
542 if (ExtraCode && ExtraCode[0]) {
543 if (ExtraCode[1] != 0) return true; // Unknown modifier.
545 switch (ExtraCode[0]) {
546 default: return true; // Unknown modifier.
547 case 'b': // Print QImode register
548 case 'h': // Print QImode high register
549 case 'w': // Print HImode register
550 case 'k': // Print SImode register
551 case 'q': // Print SImode register
552 // These only apply to registers, ignore on mem.
555 if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
556 return true; // Unsupported modifier in Intel inline assembly.
558 PrintMemReference(MI, OpNo, O, "H");
561 case 'P': // Don't print @PLT, but do print as memory.
562 if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
563 PrintIntelMemReference(MI, OpNo, O, "no-rip");
565 PrintMemReference(MI, OpNo, O, "no-rip");
570 if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
571 PrintIntelMemReference(MI, OpNo, O, nullptr);
573 PrintMemReference(MI, OpNo, O, nullptr);
578 void X86AsmPrinter::EmitStartOfAsmFile(Module &M) {
579 const Triple &TT = TM.getTargetTriple();
581 if (TT.isOSBinFormatELF()) {
582 // Assemble feature flags that may require creation of a note section.
583 unsigned FeatureFlagsAnd = 0;
584 if (M.getModuleFlag("cf-protection-branch"))
585 FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_IBT;
586 if (M.getModuleFlag("cf-protection-return"))
587 FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_SHSTK;
589 if (FeatureFlagsAnd) {
590 // Emit a .note.gnu.property section with the flags.
591 if (!TT.isArch32Bit() && !TT.isArch64Bit())
592 llvm_unreachable("CFProtection used on invalid architecture!");
593 MCSection *Cur = OutStreamer->getCurrentSectionOnly();
594 MCSection *Nt = MMI->getContext().getELFSection(
595 ".note.gnu.property", ELF::SHT_NOTE, ELF::SHF_ALLOC);
596 OutStreamer->SwitchSection(Nt);
598 // Emitting note header.
599 int WordSize = TT.isArch64Bit() ? 8 : 4;
600 EmitAlignment(WordSize == 4 ? Align(4) : Align(8));
601 OutStreamer->EmitIntValue(4, 4 /*size*/); // data size for "GNU\0"
602 OutStreamer->EmitIntValue(8 + WordSize, 4 /*size*/); // Elf_Prop size
603 OutStreamer->EmitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4 /*size*/);
604 OutStreamer->EmitBytes(StringRef("GNU", 4)); // note name
606 // Emitting an Elf_Prop for the CET properties.
607 OutStreamer->EmitIntValue(ELF::GNU_PROPERTY_X86_FEATURE_1_AND, 4);
608 OutStreamer->EmitIntValue(4, 4); // data size
609 OutStreamer->EmitIntValue(FeatureFlagsAnd, 4); // data
610 EmitAlignment(WordSize == 4 ? Align(4) : Align(8)); // padding
612 OutStreamer->endSection(Nt);
613 OutStreamer->SwitchSection(Cur);
617 if (TT.isOSBinFormatMachO())
618 OutStreamer->SwitchSection(getObjFileLowering().getTextSection());
620 if (TT.isOSBinFormatCOFF()) {
621 // Emit an absolute @feat.00 symbol. This appears to be some kind of
622 // compiler features bitfield read by link.exe.
623 MCSymbol *S = MMI->getContext().getOrCreateSymbol(StringRef("@feat.00"));
624 OutStreamer->BeginCOFFSymbolDef(S);
625 OutStreamer->EmitCOFFSymbolStorageClass(COFF::IMAGE_SYM_CLASS_STATIC);
626 OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_NULL);
627 OutStreamer->EndCOFFSymbolDef();
628 int64_t Feat00Flags = 0;
630 if (TT.getArch() == Triple::x86) {
631 // According to the PE-COFF spec, the LSB of this value marks the object
632 // for "registered SEH". This means that all SEH handler entry points
633 // must be registered in .sxdata. Use of any unregistered handlers will
634 // cause the process to terminate immediately. LLVM does not know how to
635 // register any SEH handlers, so its object files should be safe.
639 if (M.getModuleFlag("cfguard"))
640 Feat00Flags |= 0x800; // Object is CFG-aware.
642 OutStreamer->EmitSymbolAttribute(S, MCSA_Global);
643 OutStreamer->EmitAssignment(
644 S, MCConstantExpr::create(Feat00Flags, MMI->getContext()));
646 OutStreamer->EmitSyntaxDirective();
648 // If this is not inline asm and we're in 16-bit
649 // mode prefix assembly with .code16.
650 bool is16 = TT.getEnvironment() == Triple::CODE16;
651 if (M.getModuleInlineAsm().empty() && is16)
652 OutStreamer->EmitAssemblerFlag(MCAF_Code16);
656 emitNonLazySymbolPointer(MCStreamer &OutStreamer, MCSymbol *StubLabel,
657 MachineModuleInfoImpl::StubValueTy &MCSym) {
659 OutStreamer.EmitLabel(StubLabel);
660 // .indirect_symbol _foo
661 OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
664 // External to current translation unit.
665 OutStreamer.EmitIntValue(0, 4/*size*/);
667 // Internal to current translation unit.
669 // When we place the LSDA into the TEXT section, the type info
670 // pointers need to be indirect and pc-rel. We accomplish this by
671 // using NLPs; however, sometimes the types are local to the file.
672 // We need to fill in the value for the NLP in those cases.
673 OutStreamer.EmitValue(
674 MCSymbolRefExpr::create(MCSym.getPointer(), OutStreamer.getContext()),
678 static void emitNonLazyStubs(MachineModuleInfo *MMI, MCStreamer &OutStreamer) {
680 MachineModuleInfoMachO &MMIMacho =
681 MMI->getObjFileInfo<MachineModuleInfoMachO>();
683 // Output stubs for dynamically-linked functions.
684 MachineModuleInfoMachO::SymbolListTy Stubs;
686 // Output stubs for external and common global variables.
687 Stubs = MMIMacho.GetGVStubList();
688 if (!Stubs.empty()) {
689 OutStreamer.SwitchSection(MMI->getContext().getMachOSection(
690 "__IMPORT", "__pointers", MachO::S_NON_LAZY_SYMBOL_POINTERS,
691 SectionKind::getMetadata()));
693 for (auto &Stub : Stubs)
694 emitNonLazySymbolPointer(OutStreamer, Stub.first, Stub.second);
697 OutStreamer.AddBlankLine();
701 void X86AsmPrinter::EmitEndOfAsmFile(Module &M) {
702 const Triple &TT = TM.getTargetTriple();
704 if (TT.isOSBinFormatMachO()) {
705 // Mach-O uses non-lazy symbol stubs to encode per-TU information into
706 // global table for symbol lookup.
707 emitNonLazyStubs(MMI, *OutStreamer);
709 // Emit stack and fault map information.
711 FM.serializeToFaultMapSection();
713 // This flag tells the linker that no global symbols contain code that fall
714 // through to other global symbols (e.g. an implementation of multiple entry
715 // points). If this doesn't occur, the linker can safely perform dead code
716 // stripping. Since LLVM never generates code that does this, it is always
718 OutStreamer->EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
719 } else if (TT.isOSBinFormatCOFF()) {
720 if (MMI->usesMSVCFloatingPoint()) {
721 // In Windows' libcmt.lib, there is a file which is linked in only if the
722 // symbol _fltused is referenced. Linking this in causes some
725 // 1. For x86-32, it will set the x87 rounding mode to 53-bit instead of
726 // 64-bit mantissas at program start.
728 // 2. It links in support routines for floating-point in scanf and printf.
730 // MSVC emits an undefined reference to _fltused when there are any
731 // floating point operations in the program (including calls). A program
732 // that only has: `scanf("%f", &global_float);` may fail to trigger this,
733 // but oh well...that's a documented issue.
734 StringRef SymbolName =
735 (TT.getArch() == Triple::x86) ? "__fltused" : "_fltused";
736 MCSymbol *S = MMI->getContext().getOrCreateSymbol(SymbolName);
737 OutStreamer->EmitSymbolAttribute(S, MCSA_Global);
741 } else if (TT.isOSBinFormatELF()) {
743 FM.serializeToFaultMapSection();
747 //===----------------------------------------------------------------------===//
748 // Target Registry Stuff
749 //===----------------------------------------------------------------------===//
751 // Force static initialization.
752 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeX86AsmPrinter() {
753 RegisterAsmPrinter<X86AsmPrinter> X(getTheX86_32Target());
754 RegisterAsmPrinter<X86AsmPrinter> Y(getTheX86_64Target());