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llvm/lib/Target/X86/X86AsmPrinter.cpp
Philip Reames ec9de4677a Add support for StackMap section for ELF/Linux systems 
This patch adds code to emits the StackMap section on ELF systems. This section is required to support llvm.experimental.stackmap and llvm.experimental.patchpoint intrinsics.

Reviewers: ributzka, echristo

Differential Revision: http://reviews.llvm.org/D4574



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214538 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-01 18:47:09 +00:00

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//===-- 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/ADT/SmallString.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/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) {
SMShadowTracker.startFunction(MF);
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();
}
// Have common code print out the function header with linkage info etc.
EmitFunctionHeader();
// Emit the rest of the function body.
EmitFunctionBody();
// 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:
O << *P.GetCPISymbol(MO.getIndex());
P.printOffset(MO.getOffset(), O);
break;
case MachineOperand::MO_GlobalAddress: {
const GlobalValue *GV = MO.getGlobal();
MCSymbol *GVSym;
if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB)
GVSym = P.getSymbolWithGlobalValueBase(GV, "$stub");
else if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE ||
MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE)
GVSym = P.getSymbolWithGlobalValueBase(GV, "$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, "$non_lazy_ptr");
MachineModuleInfoImpl::StubValueTy &StubSym =
P.MMI->getObjFileInfo<MachineModuleInfoMachO>().getGVStubEntry(Sym);
if (!StubSym.getPointer())
StubSym = MachineModuleInfoImpl::
StubValueTy(P.getSymbol(GV), !GV->hasInternalLinkage());
} else if (MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE){
MCSymbol *Sym = P.getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
MachineModuleInfoImpl::StubValueTy &StubSym =
P.MMI->getObjFileInfo<MachineModuleInfoMachO>().getHiddenGVStubEntry(
Sym);
if (!StubSym.getPointer())
StubSym = MachineModuleInfoImpl::
StubValueTy(P.getSymbol(GV), !GV->hasInternalLinkage());
} else if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB) {
MCSymbol *Sym = P.getSymbolWithGlobalValueBase(GV, "$stub");
MachineModuleInfoImpl::StubValueTy &StubSym =
P.MMI->getObjFileInfo<MachineModuleInfoMachO>().getFnStubEntry(Sym);
if (!StubSym.getPointer())
StubSym = MachineModuleInfoImpl::
StubValueTy(P.getSymbol(GV), !GV->hasInternalLinkage());
}
// If the name begins with a dollar-sign, enclose it in parens. We do this
// to avoid having it look like an integer immediate to the assembler.
if (GVSym->getName()[0] != '$')
O << *GVSym;
else
O << '(' << *GVSym << ')';
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:
case X86II::MO_DARWIN_STUB:
// These affect the name of the symbol, not any suffix.
break;
case X86II::MO_GOT_ABSOLUTE_ADDRESS:
O << " + [.-" << *P.MF->getPICBaseSymbol() << ']';
break;
case X86II::MO_PIC_BASE_OFFSET:
case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE:
O << '-' << *P.MF->getPICBaseSymbol();
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();
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) {
MVT::SimpleValueType VT = (strcmp(Modifier+6,"64") == 0) ?
MVT::i64 : ((strcmp(Modifier+6, "32") == 0) ? MVT::i32 :
((strcmp(Modifier+6,"16") == 0) ? MVT::i16 : MVT::i8));
Reg = getX86SubSuperRegister(Reg, VT);
}
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, MVT::i8);
break;
case 'h': // Print QImode high register
Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
break;
case 'w': // Print HImode register
Reg = getX86SubSuperRegister(Reg, MVT::i16);
break;
case 'k': // Print SImode register
Reg = getX86SubSuperRegister(Reg, MVT::i32);
break;
case 'q':
// Print 64-bit register names if 64-bit integer registers are available.
// Otherwise, print 32-bit register names.
MVT::SimpleValueType Ty = P.getSubtarget().is64Bit() ? MVT::i64 : MVT::i32;
Reg = getX86SubSuperRegister(Reg, Ty);
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) {
if (Subtarget->isTargetMacho())
OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
if (Subtarget->isTargetCOFF()) {
// Emit an absolute @feat.00 symbol. This appears to be some kind of
// compiler features bitfield read by link.exe.
if (!Subtarget->is64Bit()) {
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.
S->setAbsolute();
OutStreamer.EmitSymbolAttribute(S, MCSA_Global);
OutStreamer.EmitAssignment(
S, MCConstantExpr::Create(int64_t(1), MMI->getContext()));
}
}
}
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()) {
SectionKind Kind = CPE.getSectionKind(TM.getDataLayout());
const Constant *C = CPE.Val.ConstVal;
const MCSectionCOFF *S = cast<MCSectionCOFF>(
getObjFileLowering().getSectionForConstant(Kind, C));
if (MCSymbol *Sym = S->getCOMDATSymbol()) {
if (Sym->isUndefined())
OutStreamer.EmitSymbolAttribute(Sym, MCSA_Global);
return Sym;
}
}
}
return AsmPrinter::GetCPISymbol(CPID);
}
void X86AsmPrinter::GenerateExportDirective(const MCSymbol *Sym, bool IsData) {
SmallString<128> Directive;
raw_svector_ostream OS(Directive);
StringRef Name = Sym->getName();
if (Subtarget->isTargetKnownWindowsMSVC())
OS << " /EXPORT:";
else
OS << " -export:";
if ((Subtarget->isTargetWindowsGNU() || Subtarget->isTargetWindowsCygwin()) &&
(Name[0] == getDataLayout().getGlobalPrefix()))
Name = Name.drop_front();
OS << Name;
if (IsData) {
if (Subtarget->isTargetKnownWindowsMSVC())
OS << ",DATA";
else
OS << ",data";
}
OS.flush();
OutStreamer.EmitBytes(Directive);
}
void X86AsmPrinter::EmitEndOfAsmFile(Module &M) {
if (Subtarget->isTargetMacho()) {
// All darwin targets use mach-o.
MachineModuleInfoMachO &MMIMacho =
MMI->getObjFileInfo<MachineModuleInfoMachO>();
// Output stubs for dynamically-linked functions.
MachineModuleInfoMachO::SymbolListTy Stubs;
Stubs = MMIMacho.GetFnStubList();
if (!Stubs.empty()) {
const MCSection *TheSection =
OutContext.getMachOSection("__IMPORT", "__jump_table",
MachO::S_SYMBOL_STUBS |
MachO::S_ATTR_SELF_MODIFYING_CODE |
MachO::S_ATTR_PURE_INSTRUCTIONS,
5, SectionKind::getMetadata());
OutStreamer.SwitchSection(TheSection);
for (const auto &Stub : Stubs) {
// L_foo$stub:
OutStreamer.EmitLabel(Stub.first);
// .indirect_symbol _foo
OutStreamer.EmitSymbolAttribute(Stub.second.getPointer(),
MCSA_IndirectSymbol);
// hlt; hlt; hlt; hlt; hlt hlt = 0xf4.
const char HltInsts[] = "\xf4\xf4\xf4\xf4\xf4";
OutStreamer.EmitBytes(StringRef(HltInsts, 5));
}
Stubs.clear();
OutStreamer.AddBlankLine();
}
// Output stubs for external and common global variables.
Stubs = MMIMacho.GetGVStubList();
if (!Stubs.empty()) {
const 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();
}
Stubs = MMIMacho.GetHiddenGVStubList();
if (!Stubs.empty()) {
const 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();
// 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 (Subtarget->isTargetKnownWindowsMSVC() && MMI->usesVAFloatArgument()) {
StringRef SymbolName = Subtarget->is64Bit() ? "_fltused" : "__fltused";
MCSymbol *S = MMI->getContext().GetOrCreateSymbol(SymbolName);
OutStreamer.EmitSymbolAttribute(S, MCSA_Global);
}
if (Subtarget->isTargetCOFF()) {
// Necessary for dllexport support
std::vector<const MCSymbol*> DLLExportedFns, DLLExportedGlobals;
for (const auto &Function : M)
if (Function.hasDLLExportStorageClass())
DLLExportedFns.push_back(getSymbol(&Function));
for (const auto &Global : M.globals())
if (Global.hasDLLExportStorageClass())
DLLExportedGlobals.push_back(getSymbol(&Global));
for (const auto &Alias : M.aliases()) {
if (!Alias.hasDLLExportStorageClass())
continue;
if (Alias.getType()->getElementType()->isFunctionTy())
DLLExportedFns.push_back(getSymbol(&Alias));
else
DLLExportedGlobals.push_back(getSymbol(&Alias));
}
// Output linker support code for dllexported globals on windows.
if (!DLLExportedGlobals.empty() || !DLLExportedFns.empty()) {
const TargetLoweringObjectFileCOFF &TLOFCOFF =
static_cast<const TargetLoweringObjectFileCOFF&>(getObjFileLowering());
OutStreamer.SwitchSection(TLOFCOFF.getDrectveSection());
for (auto & Symbol : DLLExportedGlobals)
GenerateExportDirective(Symbol, /*IsData=*/true);
for (auto & Symbol : DLLExportedFns)
GenerateExportDirective(Symbol, /*IsData=*/false);
}
}
if (Subtarget->isTargetELF()) {
const TargetLoweringObjectFileELF &TLOFELF =
static_cast<const TargetLoweringObjectFileELF &>(getObjFileLowering());
MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
// Output stubs for external and common global variables.
MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
if (!Stubs.empty()) {
OutStreamer.SwitchSection(TLOFELF.getDataRelSection());
const DataLayout *TD = TM.getDataLayout();
for (const auto &Stub : Stubs) {
OutStreamer.EmitLabel(Stub.first);
OutStreamer.EmitSymbolValue(Stub.second.getPointer(),
TD->getPointerSize());
}
Stubs.clear();
}
SM.serializeToStackMapSection();
}
}
//===----------------------------------------------------------------------===//
// Target Registry Stuff
//===----------------------------------------------------------------------===//
// Force static initialization.
extern "C" void LLVMInitializeX86AsmPrinter() {
RegisterAsmPrinter<X86AsmPrinter> X(TheX86_32Target);
RegisterAsmPrinter<X86AsmPrinter> Y(TheX86_64Target);
}
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