//===-- X86AsmPrinter.cpp - Convert X86 LLVM code to AT&T assembly --------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file contains a printer that converts from our internal representation // of machine-dependent LLVM code to X86 machine code. // //===----------------------------------------------------------------------===// #include "X86AsmPrinter.h" #include "InstPrinter/X86ATTInstPrinter.h" #include "MCTargetDesc/X86BaseInfo.h" #include "X86InstrInfo.h" #include "X86MachineFunctionInfo.h" #include "llvm/CodeGen/MachineConstantPool.h" #include "llvm/CodeGen/MachineModuleInfoImpls.h" #include "llvm/CodeGen/MachineValueType.h" #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h" #include "llvm/IR/DebugInfo.h" #include "llvm/IR/DerivedTypes.h" #include "llvm/IR/Mangler.h" #include "llvm/IR/Module.h" #include "llvm/IR/Type.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCCodeEmitter.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCSectionCOFF.h" #include "llvm/MC/MCSectionMachO.h" #include "llvm/MC/MCStreamer.h" #include "llvm/MC/MCSymbol.h" #include "llvm/Support/COFF.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/TargetRegistry.h" using namespace llvm; //===----------------------------------------------------------------------===// // Primitive Helper Functions. //===----------------------------------------------------------------------===// /// runOnMachineFunction - Emit the function body. /// bool X86AsmPrinter::runOnMachineFunction(MachineFunction &MF) { Subtarget = &MF.getSubtarget<X86Subtarget>(); SMShadowTracker.startFunction(MF); CodeEmitter.reset(TM.getTarget().createMCCodeEmitter( *MF.getSubtarget().getInstrInfo(), *MF.getSubtarget().getRegisterInfo(), MF.getContext())); SetupMachineFunction(MF); if (Subtarget->isTargetCOFF()) { bool Intrn = MF.getFunction()->hasInternalLinkage(); OutStreamer->BeginCOFFSymbolDef(CurrentFnSym); OutStreamer->EmitCOFFSymbolStorageClass(Intrn ? COFF::IMAGE_SYM_CLASS_STATIC : COFF::IMAGE_SYM_CLASS_EXTERNAL); OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_FUNCTION << COFF::SCT_COMPLEX_TYPE_SHIFT); OutStreamer->EndCOFFSymbolDef(); } // Emit the rest of the function body. EmitFunctionBody(); // Emit the XRay table for this function. EmitXRayTable(); // We didn't modify anything. return false; } /// printSymbolOperand - Print a raw symbol reference operand. This handles /// jump tables, constant pools, global address and external symbols, all of /// which print to a label with various suffixes for relocation types etc. static void printSymbolOperand(X86AsmPrinter &P, const MachineOperand &MO, raw_ostream &O) { switch (MO.getType()) { default: llvm_unreachable("unknown symbol type!"); case MachineOperand::MO_ConstantPoolIndex: P.GetCPISymbol(MO.getIndex())->print(O, P.MAI); P.printOffset(MO.getOffset(), O); break; case MachineOperand::MO_GlobalAddress: { const GlobalValue *GV = MO.getGlobal(); MCSymbol *GVSym; if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY || MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE) GVSym = P.getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr"); else GVSym = P.getSymbol(GV); // Handle dllimport linkage. if (MO.getTargetFlags() == X86II::MO_DLLIMPORT) GVSym = P.OutContext.getOrCreateSymbol(Twine("__imp_") + GVSym->getName()); if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY || MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE) { MCSymbol *Sym = P.getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr"); MachineModuleInfoImpl::StubValueTy &StubSym = P.MMI->getObjFileInfo<MachineModuleInfoMachO>().getGVStubEntry(Sym); if (!StubSym.getPointer()) StubSym = MachineModuleInfoImpl:: StubValueTy(P.getSymbol(GV), !GV->hasInternalLinkage()); } // If the name begins with a dollar-sign, enclose it in parens. We do this // to avoid having it look like an integer immediate to the assembler. if (GVSym->getName()[0] != '$') GVSym->print(O, P.MAI); else { O << '('; GVSym->print(O, P.MAI); O << ')'; } P.printOffset(MO.getOffset(), O); break; } } switch (MO.getTargetFlags()) { default: llvm_unreachable("Unknown target flag on GV operand"); case X86II::MO_NO_FLAG: // No flag. break; case X86II::MO_DARWIN_NONLAZY: case X86II::MO_DLLIMPORT: // These affect the name of the symbol, not any suffix. break; case X86II::MO_GOT_ABSOLUTE_ADDRESS: O << " + [.-"; P.MF->getPICBaseSymbol()->print(O, P.MAI); O << ']'; break; case X86II::MO_PIC_BASE_OFFSET: case X86II::MO_DARWIN_NONLAZY_PIC_BASE: O << '-'; P.MF->getPICBaseSymbol()->print(O, P.MAI); break; case X86II::MO_TLSGD: O << "@TLSGD"; break; case X86II::MO_TLSLD: O << "@TLSLD"; break; case X86II::MO_TLSLDM: O << "@TLSLDM"; break; case X86II::MO_GOTTPOFF: O << "@GOTTPOFF"; break; case X86II::MO_INDNTPOFF: O << "@INDNTPOFF"; break; case X86II::MO_TPOFF: O << "@TPOFF"; break; case X86II::MO_DTPOFF: O << "@DTPOFF"; break; case X86II::MO_NTPOFF: O << "@NTPOFF"; break; case X86II::MO_GOTNTPOFF: O << "@GOTNTPOFF"; break; case X86II::MO_GOTPCREL: O << "@GOTPCREL"; break; case X86II::MO_GOT: O << "@GOT"; break; case X86II::MO_GOTOFF: O << "@GOTOFF"; break; case X86II::MO_PLT: O << "@PLT"; break; case X86II::MO_TLVP: O << "@TLVP"; break; case X86II::MO_TLVP_PIC_BASE: O << "@TLVP" << '-'; P.MF->getPICBaseSymbol()->print(O, P.MAI); break; case X86II::MO_SECREL: O << "@SECREL32"; break; } } static void printOperand(X86AsmPrinter &P, const MachineInstr *MI, unsigned OpNo, raw_ostream &O, const char *Modifier = nullptr, unsigned AsmVariant = 0); /// printPCRelImm - This is used to print an immediate value that ends up /// being encoded as a pc-relative value. These print slightly differently, for /// example, a $ is not emitted. static void printPCRelImm(X86AsmPrinter &P, const MachineInstr *MI, unsigned OpNo, raw_ostream &O) { const MachineOperand &MO = MI->getOperand(OpNo); switch (MO.getType()) { default: llvm_unreachable("Unknown pcrel immediate operand"); case MachineOperand::MO_Register: // pc-relativeness was handled when computing the value in the reg. printOperand(P, MI, OpNo, O); return; case MachineOperand::MO_Immediate: O << MO.getImm(); return; case MachineOperand::MO_GlobalAddress: printSymbolOperand(P, MO, O); return; } } static void printOperand(X86AsmPrinter &P, const MachineInstr *MI, unsigned OpNo, raw_ostream &O, const char *Modifier, unsigned AsmVariant) { const MachineOperand &MO = MI->getOperand(OpNo); switch (MO.getType()) { default: llvm_unreachable("unknown operand type!"); case MachineOperand::MO_Register: { // FIXME: Enumerating AsmVariant, so we can remove magic number. if (AsmVariant == 0) O << '%'; unsigned Reg = MO.getReg(); if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) { unsigned Size = (strcmp(Modifier+6,"64") == 0) ? 64 : (strcmp(Modifier+6,"32") == 0) ? 32 : (strcmp(Modifier+6,"16") == 0) ? 16 : 8; Reg = getX86SubSuperRegister(Reg, Size); } O << X86ATTInstPrinter::getRegisterName(Reg); return; } case MachineOperand::MO_Immediate: if (AsmVariant == 0) O << '$'; O << MO.getImm(); return; case MachineOperand::MO_GlobalAddress: { if (AsmVariant == 0) O << '$'; printSymbolOperand(P, MO, O); break; } } } static void printLeaMemReference(X86AsmPrinter &P, const MachineInstr *MI, unsigned Op, raw_ostream &O, const char *Modifier = nullptr) { const MachineOperand &BaseReg = MI->getOperand(Op+X86::AddrBaseReg); const MachineOperand &IndexReg = MI->getOperand(Op+X86::AddrIndexReg); const MachineOperand &DispSpec = MI->getOperand(Op+X86::AddrDisp); // If we really don't want to print out (rip), don't. bool HasBaseReg = BaseReg.getReg() != 0; if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") && BaseReg.getReg() == X86::RIP) HasBaseReg = false; // HasParenPart - True if we will print out the () part of the mem ref. bool HasParenPart = IndexReg.getReg() || HasBaseReg; switch (DispSpec.getType()) { default: llvm_unreachable("unknown operand type!"); case MachineOperand::MO_Immediate: { int DispVal = DispSpec.getImm(); if (DispVal || !HasParenPart) O << DispVal; break; } case MachineOperand::MO_GlobalAddress: case MachineOperand::MO_ConstantPoolIndex: printSymbolOperand(P, DispSpec, O); } if (Modifier && strcmp(Modifier, "H") == 0) O << "+8"; if (HasParenPart) { assert(IndexReg.getReg() != X86::ESP && "X86 doesn't allow scaling by ESP"); O << '('; if (HasBaseReg) printOperand(P, MI, Op+X86::AddrBaseReg, O, Modifier); if (IndexReg.getReg()) { O << ','; printOperand(P, MI, Op+X86::AddrIndexReg, O, Modifier); unsigned ScaleVal = MI->getOperand(Op+X86::AddrScaleAmt).getImm(); if (ScaleVal != 1) O << ',' << ScaleVal; } O << ')'; } } static void printMemReference(X86AsmPrinter &P, const MachineInstr *MI, unsigned Op, raw_ostream &O, const char *Modifier = nullptr) { assert(isMem(*MI, Op) && "Invalid memory reference!"); const MachineOperand &Segment = MI->getOperand(Op+X86::AddrSegmentReg); if (Segment.getReg()) { printOperand(P, MI, Op+X86::AddrSegmentReg, O, Modifier); O << ':'; } printLeaMemReference(P, MI, Op, O, Modifier); } static void printIntelMemReference(X86AsmPrinter &P, const MachineInstr *MI, unsigned Op, raw_ostream &O, const char *Modifier = nullptr, unsigned AsmVariant = 1) { const MachineOperand &BaseReg = MI->getOperand(Op+X86::AddrBaseReg); unsigned ScaleVal = MI->getOperand(Op+X86::AddrScaleAmt).getImm(); const MachineOperand &IndexReg = MI->getOperand(Op+X86::AddrIndexReg); const MachineOperand &DispSpec = MI->getOperand(Op+X86::AddrDisp); const MachineOperand &SegReg = MI->getOperand(Op+X86::AddrSegmentReg); // If this has a segment register, print it. if (SegReg.getReg()) { printOperand(P, MI, Op+X86::AddrSegmentReg, O, Modifier, AsmVariant); O << ':'; } O << '['; bool NeedPlus = false; if (BaseReg.getReg()) { printOperand(P, MI, Op+X86::AddrBaseReg, O, Modifier, AsmVariant); NeedPlus = true; } if (IndexReg.getReg()) { if (NeedPlus) O << " + "; if (ScaleVal != 1) O << ScaleVal << '*'; printOperand(P, MI, Op+X86::AddrIndexReg, O, Modifier, AsmVariant); NeedPlus = true; } if (!DispSpec.isImm()) { if (NeedPlus) O << " + "; printOperand(P, MI, Op+X86::AddrDisp, O, Modifier, AsmVariant); } else { int64_t DispVal = DispSpec.getImm(); if (DispVal || (!IndexReg.getReg() && !BaseReg.getReg())) { if (NeedPlus) { if (DispVal > 0) O << " + "; else { O << " - "; DispVal = -DispVal; } } O << DispVal; } } O << ']'; } static bool printAsmMRegister(X86AsmPrinter &P, const MachineOperand &MO, char Mode, raw_ostream &O) { unsigned Reg = MO.getReg(); switch (Mode) { default: return true; // Unknown mode. case 'b': // Print QImode register Reg = getX86SubSuperRegister(Reg, 8); break; case 'h': // Print QImode high register Reg = getX86SubSuperRegister(Reg, 8, true); break; case 'w': // Print HImode register Reg = getX86SubSuperRegister(Reg, 16); break; case 'k': // Print SImode register Reg = getX86SubSuperRegister(Reg, 32); break; case 'q': // Print 64-bit register names if 64-bit integer registers are available. // Otherwise, print 32-bit register names. Reg = getX86SubSuperRegister(Reg, P.getSubtarget().is64Bit() ? 64 : 32); break; } O << '%' << X86ATTInstPrinter::getRegisterName(Reg); return false; } /// PrintAsmOperand - Print out an operand for an inline asm expression. /// bool X86AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, unsigned AsmVariant, const char *ExtraCode, raw_ostream &O) { // Does this asm operand have a single letter operand modifier? if (ExtraCode && ExtraCode[0]) { if (ExtraCode[1] != 0) return true; // Unknown modifier. const MachineOperand &MO = MI->getOperand(OpNo); switch (ExtraCode[0]) { default: // See if this is a generic print operand return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, O); case 'a': // This is an address. Currently only 'i' and 'r' are expected. switch (MO.getType()) { default: return true; case MachineOperand::MO_Immediate: O << MO.getImm(); return false; case MachineOperand::MO_ConstantPoolIndex: case MachineOperand::MO_JumpTableIndex: case MachineOperand::MO_ExternalSymbol: llvm_unreachable("unexpected operand type!"); case MachineOperand::MO_GlobalAddress: printSymbolOperand(*this, MO, O); if (Subtarget->isPICStyleRIPRel()) O << "(%rip)"; return false; case MachineOperand::MO_Register: O << '('; printOperand(*this, MI, OpNo, O); O << ')'; return false; } case 'c': // Don't print "$" before a global var name or constant. switch (MO.getType()) { default: printOperand(*this, MI, OpNo, O); break; case MachineOperand::MO_Immediate: O << MO.getImm(); break; case MachineOperand::MO_ConstantPoolIndex: case MachineOperand::MO_JumpTableIndex: case MachineOperand::MO_ExternalSymbol: llvm_unreachable("unexpected operand type!"); case MachineOperand::MO_GlobalAddress: printSymbolOperand(*this, MO, O); break; } return false; case 'A': // Print '*' before a register (it must be a register) if (MO.isReg()) { O << '*'; printOperand(*this, MI, OpNo, O); return false; } return true; case 'b': // Print QImode register case 'h': // Print QImode high register case 'w': // Print HImode register case 'k': // Print SImode register case 'q': // Print DImode register if (MO.isReg()) return printAsmMRegister(*this, MO, ExtraCode[0], O); printOperand(*this, MI, OpNo, O); return false; case 'P': // This is the operand of a call, treat specially. printPCRelImm(*this, MI, OpNo, O); return false; case 'n': // Negate the immediate or print a '-' before the operand. // Note: this is a temporary solution. It should be handled target // independently as part of the 'MC' work. if (MO.isImm()) { O << -MO.getImm(); return false; } O << '-'; } } printOperand(*this, MI, OpNo, O, /*Modifier*/ nullptr, AsmVariant); return false; } bool X86AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo, unsigned AsmVariant, const char *ExtraCode, raw_ostream &O) { if (AsmVariant) { printIntelMemReference(*this, MI, OpNo, O); return false; } if (ExtraCode && ExtraCode[0]) { if (ExtraCode[1] != 0) return true; // Unknown modifier. switch (ExtraCode[0]) { default: return true; // Unknown modifier. case 'b': // Print QImode register case 'h': // Print QImode high register case 'w': // Print HImode register case 'k': // Print SImode register case 'q': // Print SImode register // These only apply to registers, ignore on mem. break; case 'H': printMemReference(*this, MI, OpNo, O, "H"); return false; case 'P': // Don't print @PLT, but do print as memory. printMemReference(*this, MI, OpNo, O, "no-rip"); return false; } } printMemReference(*this, MI, OpNo, O); return false; } void X86AsmPrinter::EmitStartOfAsmFile(Module &M) { const Triple &TT = TM.getTargetTriple(); if (TT.isOSBinFormatMachO()) OutStreamer->SwitchSection(getObjFileLowering().getTextSection()); if (TT.isOSBinFormatCOFF()) { // Emit an absolute @feat.00 symbol. This appears to be some kind of // compiler features bitfield read by link.exe. if (TT.getArch() == Triple::x86) { MCSymbol *S = MMI->getContext().getOrCreateSymbol(StringRef("@feat.00")); OutStreamer->BeginCOFFSymbolDef(S); OutStreamer->EmitCOFFSymbolStorageClass(COFF::IMAGE_SYM_CLASS_STATIC); OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_NULL); OutStreamer->EndCOFFSymbolDef(); // According to the PE-COFF spec, the LSB of this value marks the object // for "registered SEH". This means that all SEH handler entry points // must be registered in .sxdata. Use of any unregistered handlers will // cause the process to terminate immediately. LLVM does not know how to // register any SEH handlers, so its object files should be safe. OutStreamer->EmitSymbolAttribute(S, MCSA_Global); OutStreamer->EmitAssignment( S, MCConstantExpr::create(int64_t(1), MMI->getContext())); } } OutStreamer->EmitSyntaxDirective(); // If this is not inline asm and we're in 16-bit // mode prefix assembly with .code16. bool is16 = TT.getEnvironment() == Triple::CODE16; if (M.getModuleInlineAsm().empty() && is16) OutStreamer->EmitAssemblerFlag(MCAF_Code16); } static void emitNonLazySymbolPointer(MCStreamer &OutStreamer, MCSymbol *StubLabel, MachineModuleInfoImpl::StubValueTy &MCSym) { // L_foo$stub: OutStreamer.EmitLabel(StubLabel); // .indirect_symbol _foo OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol); if (MCSym.getInt()) // External to current translation unit. OutStreamer.EmitIntValue(0, 4/*size*/); else // Internal to current translation unit. // // When we place the LSDA into the TEXT section, the type info // pointers need to be indirect and pc-rel. We accomplish this by // using NLPs; however, sometimes the types are local to the file. // We need to fill in the value for the NLP in those cases. OutStreamer.EmitValue( MCSymbolRefExpr::create(MCSym.getPointer(), OutStreamer.getContext()), 4 /*size*/); } MCSymbol *X86AsmPrinter::GetCPISymbol(unsigned CPID) const { if (Subtarget->isTargetKnownWindowsMSVC()) { const MachineConstantPoolEntry &CPE = MF->getConstantPool()->getConstants()[CPID]; if (!CPE.isMachineConstantPoolEntry()) { const DataLayout &DL = MF->getDataLayout(); SectionKind Kind = CPE.getSectionKind(&DL); const Constant *C = CPE.Val.ConstVal; unsigned Align = CPE.Alignment; if (const MCSectionCOFF *S = dyn_cast<MCSectionCOFF>( getObjFileLowering().getSectionForConstant(DL, Kind, C, Align))) { if (MCSymbol *Sym = S->getCOMDATSymbol()) { if (Sym->isUndefined()) OutStreamer->EmitSymbolAttribute(Sym, MCSA_Global); return Sym; } } } } return AsmPrinter::GetCPISymbol(CPID); } void X86AsmPrinter::EmitEndOfAsmFile(Module &M) { const Triple &TT = TM.getTargetTriple(); if (TT.isOSBinFormatMachO()) { // All darwin targets use mach-o. MachineModuleInfoMachO &MMIMacho = MMI->getObjFileInfo<MachineModuleInfoMachO>(); // Output stubs for dynamically-linked functions. MachineModuleInfoMachO::SymbolListTy Stubs; // Output stubs for external and common global variables. Stubs = MMIMacho.GetGVStubList(); if (!Stubs.empty()) { MCSection *TheSection = OutContext.getMachOSection( "__IMPORT", "__pointers", MachO::S_NON_LAZY_SYMBOL_POINTERS, SectionKind::getMetadata()); OutStreamer->SwitchSection(TheSection); for (auto &Stub : Stubs) emitNonLazySymbolPointer(*OutStreamer, Stub.first, Stub.second); Stubs.clear(); OutStreamer->AddBlankLine(); } SM.serializeToStackMapSection(); FM.serializeToFaultMapSection(); // Funny Darwin hack: This flag tells the linker that no global symbols // contain code that falls through to other global symbols (e.g. the obvious // implementation of multiple entry points). If this doesn't occur, the // linker can safely perform dead code stripping. Since LLVM never // generates code that does this, it is always safe to set. OutStreamer->EmitAssemblerFlag(MCAF_SubsectionsViaSymbols); } if (TT.isKnownWindowsMSVCEnvironment() && MMI->usesVAFloatArgument()) { StringRef SymbolName = (TT.getArch() == Triple::x86_64) ? "_fltused" : "__fltused"; MCSymbol *S = MMI->getContext().getOrCreateSymbol(SymbolName); OutStreamer->EmitSymbolAttribute(S, MCSA_Global); } if (TT.isOSBinFormatCOFF()) { const TargetLoweringObjectFileCOFF &TLOFCOFF = static_cast<const TargetLoweringObjectFileCOFF&>(getObjFileLowering()); std::string Flags; raw_string_ostream FlagsOS(Flags); for (const auto &Function : M) TLOFCOFF.emitLinkerFlagsForGlobal(FlagsOS, &Function, *Mang); for (const auto &Global : M.globals()) TLOFCOFF.emitLinkerFlagsForGlobal(FlagsOS, &Global, *Mang); for (const auto &Alias : M.aliases()) TLOFCOFF.emitLinkerFlagsForGlobal(FlagsOS, &Alias, *Mang); FlagsOS.flush(); // Output collected flags. if (!Flags.empty()) { OutStreamer->SwitchSection(TLOFCOFF.getDrectveSection()); OutStreamer->EmitBytes(Flags); } SM.serializeToStackMapSection(); } if (TT.isOSBinFormatELF()) { SM.serializeToStackMapSection(); FM.serializeToFaultMapSection(); } } //===----------------------------------------------------------------------===// // Target Registry Stuff //===----------------------------------------------------------------------===// // Force static initialization. extern "C" void LLVMInitializeX86AsmPrinter() { RegisterAsmPrinter<X86AsmPrinter> X(TheX86_32Target); RegisterAsmPrinter<X86AsmPrinter> Y(TheX86_64Target); }