forked from OSchip/llvm-project
2851 lines
104 KiB
C++
2851 lines
104 KiB
C++
//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the AsmPrinter class.
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//
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//===----------------------------------------------------------------------===//
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#include "AsmPrinterHandler.h"
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#include "CodeViewDebug.h"
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#include "DwarfDebug.h"
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#include "DwarfException.h"
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#include "WinException.h"
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#include "llvm/ADT/APFloat.h"
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#include "llvm/ADT/APInt.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/ADT/Triple.h"
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#include "llvm/ADT/Twine.h"
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#include "llvm/Analysis/ConstantFolding.h"
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#include "llvm/Analysis/ObjectUtils.h"
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#include "llvm/CodeGen/Analysis.h"
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#include "llvm/CodeGen/AsmPrinter.h"
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#include "llvm/CodeGen/GCMetadata.h"
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#include "llvm/CodeGen/GCMetadataPrinter.h"
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#include "llvm/CodeGen/GCStrategy.h"
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#include "llvm/CodeGen/MachineBasicBlock.h"
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#include "llvm/CodeGen/MachineConstantPool.h"
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#include "llvm/CodeGen/MachineFrameInfo.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineFunctionPass.h"
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#include "llvm/CodeGen/MachineInstr.h"
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#include "llvm/CodeGen/MachineInstrBundle.h"
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#include "llvm/CodeGen/MachineJumpTableInfo.h"
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#include "llvm/CodeGen/MachineLoopInfo.h"
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#include "llvm/CodeGen/MachineMemOperand.h"
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#include "llvm/CodeGen/MachineModuleInfoImpls.h"
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#include "llvm/CodeGen/MachineOperand.h"
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#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
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#include "llvm/IR/BasicBlock.h"
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#include "llvm/IR/Constant.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/DebugInfoMetadata.h"
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#include "llvm/IR/DerivedTypes.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/GlobalAlias.h"
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#include "llvm/IR/GlobalIFunc.h"
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#include "llvm/IR/GlobalIndirectSymbol.h"
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#include "llvm/IR/GlobalObject.h"
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#include "llvm/IR/GlobalValue.h"
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#include "llvm/IR/GlobalVariable.h"
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#include "llvm/IR/Mangler.h"
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#include "llvm/IR/Metadata.h"
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#include "llvm/IR/Module.h"
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#include "llvm/IR/Operator.h"
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#include "llvm/IR/Value.h"
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#include "llvm/MC/MCAsmInfo.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCDirectives.h"
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#include "llvm/MC/MCExpr.h"
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#include "llvm/MC/MCInst.h"
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#include "llvm/MC/MCSection.h"
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#include "llvm/MC/MCSectionELF.h"
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#include "llvm/MC/MCSectionMachO.h"
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#include "llvm/MC/MCStreamer.h"
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#include "llvm/MC/MCSubtargetInfo.h"
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#include "llvm/MC/MCSymbol.h"
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#include "llvm/MC/MCTargetOptions.h"
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#include "llvm/MC/MCValue.h"
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#include "llvm/MC/SectionKind.h"
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#include "llvm/Pass.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/Compiler.h"
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#include "llvm/Support/Dwarf.h"
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#include "llvm/Support/ELF.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/Format.h"
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#include "llvm/Support/MathExtras.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Support/TargetRegistry.h"
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#include "llvm/Support/Timer.h"
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#include "llvm/Target/TargetFrameLowering.h"
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#include "llvm/Target/TargetInstrInfo.h"
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#include "llvm/Target/TargetLowering.h"
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#include "llvm/Target/TargetLoweringObjectFile.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Target/TargetRegisterInfo.h"
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#include "llvm/Target/TargetSubtargetInfo.h"
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#include <algorithm>
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#include <cassert>
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#include <cinttypes>
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#include <cstdint>
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#include <limits>
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#include <memory>
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#include <string>
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#include <utility>
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#include <vector>
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using namespace llvm;
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#define DEBUG_TYPE "asm-printer"
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static const char *const DWARFGroupName = "dwarf";
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static const char *const DWARFGroupDescription = "DWARF Emission";
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static const char *const DbgTimerName = "emit";
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static const char *const DbgTimerDescription = "Debug Info Emission";
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static const char *const EHTimerName = "write_exception";
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static const char *const EHTimerDescription = "DWARF Exception Writer";
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static const char *const CodeViewLineTablesGroupName = "linetables";
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static const char *const CodeViewLineTablesGroupDescription =
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"CodeView Line Tables";
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STATISTIC(EmittedInsts, "Number of machine instrs printed");
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static cl::opt<bool>
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PrintSchedule("print-schedule", cl::Hidden, cl::init(false),
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cl::desc("Print 'sched: [latency:throughput]' in .s output"));
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char AsmPrinter::ID = 0;
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typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
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static gcp_map_type &getGCMap(void *&P) {
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if (!P)
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P = new gcp_map_type();
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return *(gcp_map_type*)P;
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}
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/// getGVAlignmentLog2 - Return the alignment to use for the specified global
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/// value in log2 form. This rounds up to the preferred alignment if possible
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/// and legal.
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static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &DL,
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unsigned InBits = 0) {
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unsigned NumBits = 0;
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if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
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NumBits = DL.getPreferredAlignmentLog(GVar);
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// If InBits is specified, round it to it.
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if (InBits > NumBits)
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NumBits = InBits;
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// If the GV has a specified alignment, take it into account.
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if (GV->getAlignment() == 0)
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return NumBits;
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unsigned GVAlign = Log2_32(GV->getAlignment());
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// If the GVAlign is larger than NumBits, or if we are required to obey
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// NumBits because the GV has an assigned section, obey it.
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if (GVAlign > NumBits || GV->hasSection())
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NumBits = GVAlign;
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return NumBits;
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}
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AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
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: MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
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OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)) {
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VerboseAsm = OutStreamer->isVerboseAsm();
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}
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AsmPrinter::~AsmPrinter() {
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assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
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if (GCMetadataPrinters) {
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gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
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delete &GCMap;
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GCMetadataPrinters = nullptr;
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}
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}
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bool AsmPrinter::isPositionIndependent() const {
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return TM.isPositionIndependent();
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}
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/// getFunctionNumber - Return a unique ID for the current function.
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///
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unsigned AsmPrinter::getFunctionNumber() const {
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return MF->getFunctionNumber();
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}
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const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
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return *TM.getObjFileLowering();
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}
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const DataLayout &AsmPrinter::getDataLayout() const {
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return MMI->getModule()->getDataLayout();
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}
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// Do not use the cached DataLayout because some client use it without a Module
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// (llvm-dsymutil, llvm-dwarfdump).
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unsigned AsmPrinter::getPointerSize() const { return TM.getPointerSize(); }
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const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
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assert(MF && "getSubtargetInfo requires a valid MachineFunction!");
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return MF->getSubtarget<MCSubtargetInfo>();
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}
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void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
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S.EmitInstruction(Inst, getSubtargetInfo());
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}
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/// getCurrentSection() - Return the current section we are emitting to.
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const MCSection *AsmPrinter::getCurrentSection() const {
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return OutStreamer->getCurrentSectionOnly();
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}
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void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
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AU.setPreservesAll();
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MachineFunctionPass::getAnalysisUsage(AU);
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AU.addRequired<MachineModuleInfo>();
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AU.addRequired<MachineOptimizationRemarkEmitterPass>();
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AU.addRequired<GCModuleInfo>();
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if (isVerbose())
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AU.addRequired<MachineLoopInfo>();
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}
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bool AsmPrinter::doInitialization(Module &M) {
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MMI = getAnalysisIfAvailable<MachineModuleInfo>();
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// Initialize TargetLoweringObjectFile.
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const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
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.Initialize(OutContext, TM);
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OutStreamer->InitSections(false);
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// Emit the version-min deplyment target directive if needed.
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//
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// FIXME: If we end up with a collection of these sorts of Darwin-specific
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// or ELF-specific things, it may make sense to have a platform helper class
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// that will work with the target helper class. For now keep it here, as the
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// alternative is duplicated code in each of the target asm printers that
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// use the directive, where it would need the same conditionalization
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// anyway.
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const Triple &TT = TM.getTargetTriple();
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// If there is a version specified, Major will be non-zero.
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if (TT.isOSDarwin() && TT.getOSMajorVersion() != 0) {
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unsigned Major, Minor, Update;
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MCVersionMinType VersionType;
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if (TT.isWatchOS()) {
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VersionType = MCVM_WatchOSVersionMin;
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TT.getWatchOSVersion(Major, Minor, Update);
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} else if (TT.isTvOS()) {
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VersionType = MCVM_TvOSVersionMin;
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TT.getiOSVersion(Major, Minor, Update);
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} else if (TT.isMacOSX()) {
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VersionType = MCVM_OSXVersionMin;
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if (!TT.getMacOSXVersion(Major, Minor, Update))
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Major = 0;
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} else {
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VersionType = MCVM_IOSVersionMin;
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TT.getiOSVersion(Major, Minor, Update);
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}
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if (Major != 0)
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OutStreamer->EmitVersionMin(VersionType, Major, Minor, Update);
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}
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// Allow the target to emit any magic that it wants at the start of the file.
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EmitStartOfAsmFile(M);
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// Very minimal debug info. It is ignored if we emit actual debug info. If we
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// don't, this at least helps the user find where a global came from.
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if (MAI->hasSingleParameterDotFile()) {
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// .file "foo.c"
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OutStreamer->EmitFileDirective(M.getSourceFileName());
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}
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GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
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assert(MI && "AsmPrinter didn't require GCModuleInfo?");
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for (auto &I : *MI)
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if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
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MP->beginAssembly(M, *MI, *this);
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// Emit module-level inline asm if it exists.
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if (!M.getModuleInlineAsm().empty()) {
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// We're at the module level. Construct MCSubtarget from the default CPU
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// and target triple.
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std::unique_ptr<MCSubtargetInfo> STI(TM.getTarget().createMCSubtargetInfo(
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TM.getTargetTriple().str(), TM.getTargetCPU(),
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TM.getTargetFeatureString()));
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OutStreamer->AddComment("Start of file scope inline assembly");
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OutStreamer->AddBlankLine();
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EmitInlineAsm(M.getModuleInlineAsm()+"\n",
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OutContext.getSubtargetCopy(*STI), TM.Options.MCOptions);
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OutStreamer->AddComment("End of file scope inline assembly");
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OutStreamer->AddBlankLine();
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}
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if (MAI->doesSupportDebugInformation()) {
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bool EmitCodeView = MMI->getModule()->getCodeViewFlag();
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if (EmitCodeView && (TM.getTargetTriple().isKnownWindowsMSVCEnvironment() ||
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TM.getTargetTriple().isWindowsItaniumEnvironment())) {
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Handlers.push_back(HandlerInfo(new CodeViewDebug(this),
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DbgTimerName, DbgTimerDescription,
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CodeViewLineTablesGroupName,
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CodeViewLineTablesGroupDescription));
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}
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if (!EmitCodeView || MMI->getModule()->getDwarfVersion()) {
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DD = new DwarfDebug(this, &M);
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DD->beginModule();
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Handlers.push_back(HandlerInfo(DD, DbgTimerName, DbgTimerDescription,
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DWARFGroupName, DWARFGroupDescription));
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}
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}
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switch (MAI->getExceptionHandlingType()) {
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case ExceptionHandling::SjLj:
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case ExceptionHandling::DwarfCFI:
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case ExceptionHandling::ARM:
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isCFIMoveForDebugging = true;
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if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
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break;
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for (auto &F: M.getFunctionList()) {
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// If the module contains any function with unwind data,
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// .eh_frame has to be emitted.
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// Ignore functions that won't get emitted.
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if (!F.isDeclarationForLinker() && F.needsUnwindTableEntry()) {
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isCFIMoveForDebugging = false;
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break;
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}
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}
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break;
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default:
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isCFIMoveForDebugging = false;
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break;
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}
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EHStreamer *ES = nullptr;
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switch (MAI->getExceptionHandlingType()) {
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case ExceptionHandling::None:
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break;
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case ExceptionHandling::SjLj:
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case ExceptionHandling::DwarfCFI:
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ES = new DwarfCFIException(this);
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break;
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case ExceptionHandling::ARM:
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ES = new ARMException(this);
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break;
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case ExceptionHandling::WinEH:
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switch (MAI->getWinEHEncodingType()) {
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default: llvm_unreachable("unsupported unwinding information encoding");
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case WinEH::EncodingType::Invalid:
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break;
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case WinEH::EncodingType::X86:
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case WinEH::EncodingType::Itanium:
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ES = new WinException(this);
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break;
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}
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break;
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}
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if (ES)
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Handlers.push_back(HandlerInfo(ES, EHTimerName, EHTimerDescription,
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DWARFGroupName, DWARFGroupDescription));
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return false;
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}
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static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
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if (!MAI.hasWeakDefCanBeHiddenDirective())
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return false;
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return canBeOmittedFromSymbolTable(GV);
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}
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void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
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GlobalValue::LinkageTypes Linkage = GV->getLinkage();
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switch (Linkage) {
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case GlobalValue::CommonLinkage:
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case GlobalValue::LinkOnceAnyLinkage:
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case GlobalValue::LinkOnceODRLinkage:
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case GlobalValue::WeakAnyLinkage:
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case GlobalValue::WeakODRLinkage:
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if (MAI->hasWeakDefDirective()) {
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// .globl _foo
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OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
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if (!canBeHidden(GV, *MAI))
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// .weak_definition _foo
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OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
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else
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OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
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} else if (MAI->hasLinkOnceDirective()) {
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// .globl _foo
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OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
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//NOTE: linkonce is handled by the section the symbol was assigned to.
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} else {
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// .weak _foo
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OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Weak);
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}
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return;
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case GlobalValue::ExternalLinkage:
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// If external, declare as a global symbol: .globl _foo
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OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
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return;
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case GlobalValue::PrivateLinkage:
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case GlobalValue::InternalLinkage:
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return;
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case GlobalValue::AppendingLinkage:
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case GlobalValue::AvailableExternallyLinkage:
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case GlobalValue::ExternalWeakLinkage:
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llvm_unreachable("Should never emit this");
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}
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llvm_unreachable("Unknown linkage type!");
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}
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void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
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const GlobalValue *GV) const {
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TM.getNameWithPrefix(Name, GV, getObjFileLowering().getMangler());
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}
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MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
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return TM.getSymbol(GV);
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}
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/// EmitGlobalVariable - Emit the specified global variable to the .s file.
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void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
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bool IsEmuTLSVar = TM.Options.EmulatedTLS && GV->isThreadLocal();
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assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&
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"No emulated TLS variables in the common section");
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// Never emit TLS variable xyz in emulated TLS model.
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// The initialization value is in __emutls_t.xyz instead of xyz.
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if (IsEmuTLSVar)
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return;
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if (GV->hasInitializer()) {
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// Check to see if this is a special global used by LLVM, if so, emit it.
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if (EmitSpecialLLVMGlobal(GV))
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return;
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// Skip the emission of global equivalents. The symbol can be emitted later
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// on by emitGlobalGOTEquivs in case it turns out to be needed.
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if (GlobalGOTEquivs.count(getSymbol(GV)))
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return;
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if (isVerbose()) {
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// When printing the control variable __emutls_v.*,
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// we don't need to print the original TLS variable name.
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GV->printAsOperand(OutStreamer->GetCommentOS(),
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/*PrintType=*/false, GV->getParent());
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OutStreamer->GetCommentOS() << '\n';
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}
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}
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MCSymbol *GVSym = getSymbol(GV);
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MCSymbol *EmittedSym = GVSym;
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// getOrCreateEmuTLSControlSym only creates the symbol with name and default
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// attributes.
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// GV's or GVSym's attributes will be used for the EmittedSym.
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EmitVisibility(EmittedSym, GV->getVisibility(), !GV->isDeclaration());
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if (!GV->hasInitializer()) // External globals require no extra code.
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return;
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GVSym->redefineIfPossible();
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if (GVSym->isDefined() || GVSym->isVariable())
|
|
report_fatal_error("symbol '" + Twine(GVSym->getName()) +
|
|
"' is already defined");
|
|
|
|
if (MAI->hasDotTypeDotSizeDirective())
|
|
OutStreamer->EmitSymbolAttribute(EmittedSym, MCSA_ELF_TypeObject);
|
|
|
|
SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
|
|
|
|
const DataLayout &DL = GV->getParent()->getDataLayout();
|
|
uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
|
|
|
|
// If the alignment is specified, we *must* obey it. Overaligning a global
|
|
// with a specified alignment is a prompt way to break globals emitted to
|
|
// sections and expected to be contiguous (e.g. ObjC metadata).
|
|
unsigned AlignLog = getGVAlignmentLog2(GV, DL);
|
|
|
|
for (const HandlerInfo &HI : Handlers) {
|
|
NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
|
|
HI.TimerGroupName, HI.TimerGroupDescription,
|
|
TimePassesIsEnabled);
|
|
HI.Handler->setSymbolSize(GVSym, Size);
|
|
}
|
|
|
|
// Handle common symbols
|
|
if (GVKind.isCommon()) {
|
|
if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
|
|
unsigned Align = 1 << AlignLog;
|
|
if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
|
|
Align = 0;
|
|
|
|
// .comm _foo, 42, 4
|
|
OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
|
|
return;
|
|
}
|
|
|
|
// Determine to which section this global should be emitted.
|
|
MCSection *TheSection = getObjFileLowering().SectionForGlobal(GV, GVKind, TM);
|
|
|
|
// If we have a bss global going to a section that supports the
|
|
// zerofill directive, do so here.
|
|
if (GVKind.isBSS() && MAI->hasMachoZeroFillDirective() &&
|
|
TheSection->isVirtualSection()) {
|
|
if (Size == 0)
|
|
Size = 1; // zerofill of 0 bytes is undefined.
|
|
unsigned Align = 1 << AlignLog;
|
|
EmitLinkage(GV, GVSym);
|
|
// .zerofill __DATA, __bss, _foo, 400, 5
|
|
OutStreamer->EmitZerofill(TheSection, GVSym, Size, Align);
|
|
return;
|
|
}
|
|
|
|
// If this is a BSS local symbol and we are emitting in the BSS
|
|
// section use .lcomm/.comm directive.
|
|
if (GVKind.isBSSLocal() &&
|
|
getObjFileLowering().getBSSSection() == TheSection) {
|
|
if (Size == 0)
|
|
Size = 1; // .comm Foo, 0 is undefined, avoid it.
|
|
unsigned Align = 1 << AlignLog;
|
|
|
|
// Use .lcomm only if it supports user-specified alignment.
|
|
// Otherwise, while it would still be correct to use .lcomm in some
|
|
// cases (e.g. when Align == 1), the external assembler might enfore
|
|
// some -unknown- default alignment behavior, which could cause
|
|
// spurious differences between external and integrated assembler.
|
|
// Prefer to simply fall back to .local / .comm in this case.
|
|
if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
|
|
// .lcomm _foo, 42
|
|
OutStreamer->EmitLocalCommonSymbol(GVSym, Size, Align);
|
|
return;
|
|
}
|
|
|
|
if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
|
|
Align = 0;
|
|
|
|
// .local _foo
|
|
OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Local);
|
|
// .comm _foo, 42, 4
|
|
OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
|
|
return;
|
|
}
|
|
|
|
// Handle thread local data for mach-o which requires us to output an
|
|
// additional structure of data and mangle the original symbol so that we
|
|
// can reference it later.
|
|
//
|
|
// TODO: This should become an "emit thread local global" method on TLOF.
|
|
// All of this macho specific stuff should be sunk down into TLOFMachO and
|
|
// stuff like "TLSExtraDataSection" should no longer be part of the parent
|
|
// TLOF class. This will also make it more obvious that stuff like
|
|
// MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
|
|
// specific code.
|
|
if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
|
|
// Emit the .tbss symbol
|
|
MCSymbol *MangSym =
|
|
OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
|
|
|
|
if (GVKind.isThreadBSS()) {
|
|
TheSection = getObjFileLowering().getTLSBSSSection();
|
|
OutStreamer->EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
|
|
} else if (GVKind.isThreadData()) {
|
|
OutStreamer->SwitchSection(TheSection);
|
|
|
|
EmitAlignment(AlignLog, GV);
|
|
OutStreamer->EmitLabel(MangSym);
|
|
|
|
EmitGlobalConstant(GV->getParent()->getDataLayout(),
|
|
GV->getInitializer());
|
|
}
|
|
|
|
OutStreamer->AddBlankLine();
|
|
|
|
// Emit the variable struct for the runtime.
|
|
MCSection *TLVSect = getObjFileLowering().getTLSExtraDataSection();
|
|
|
|
OutStreamer->SwitchSection(TLVSect);
|
|
// Emit the linkage here.
|
|
EmitLinkage(GV, GVSym);
|
|
OutStreamer->EmitLabel(GVSym);
|
|
|
|
// Three pointers in size:
|
|
// - __tlv_bootstrap - used to make sure support exists
|
|
// - spare pointer, used when mapped by the runtime
|
|
// - pointer to mangled symbol above with initializer
|
|
unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
|
|
OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
|
|
PtrSize);
|
|
OutStreamer->EmitIntValue(0, PtrSize);
|
|
OutStreamer->EmitSymbolValue(MangSym, PtrSize);
|
|
|
|
OutStreamer->AddBlankLine();
|
|
return;
|
|
}
|
|
|
|
MCSymbol *EmittedInitSym = GVSym;
|
|
|
|
OutStreamer->SwitchSection(TheSection);
|
|
|
|
EmitLinkage(GV, EmittedInitSym);
|
|
EmitAlignment(AlignLog, GV);
|
|
|
|
OutStreamer->EmitLabel(EmittedInitSym);
|
|
|
|
EmitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());
|
|
|
|
if (MAI->hasDotTypeDotSizeDirective())
|
|
// .size foo, 42
|
|
OutStreamer->emitELFSize(EmittedInitSym,
|
|
MCConstantExpr::create(Size, OutContext));
|
|
|
|
OutStreamer->AddBlankLine();
|
|
}
|
|
|
|
/// Emit the directive and value for debug thread local expression
|
|
///
|
|
/// \p Value - The value to emit.
|
|
/// \p Size - The size of the integer (in bytes) to emit.
|
|
void AsmPrinter::EmitDebugThreadLocal(const MCExpr *Value,
|
|
unsigned Size) const {
|
|
OutStreamer->EmitValue(Value, Size);
|
|
}
|
|
|
|
/// EmitFunctionHeader - This method emits the header for the current
|
|
/// function.
|
|
void AsmPrinter::EmitFunctionHeader() {
|
|
const Function *F = MF->getFunction();
|
|
|
|
if (isVerbose())
|
|
OutStreamer->GetCommentOS() << "-- Begin function " << F->getName() << '\n';
|
|
|
|
// Print out constants referenced by the function
|
|
EmitConstantPool();
|
|
|
|
// Print the 'header' of function.
|
|
OutStreamer->SwitchSection(getObjFileLowering().SectionForGlobal(F, TM));
|
|
EmitVisibility(CurrentFnSym, F->getVisibility());
|
|
|
|
EmitLinkage(F, CurrentFnSym);
|
|
if (MAI->hasFunctionAlignment())
|
|
EmitAlignment(MF->getAlignment(), F);
|
|
|
|
if (MAI->hasDotTypeDotSizeDirective())
|
|
OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
|
|
|
|
if (isVerbose()) {
|
|
F->printAsOperand(OutStreamer->GetCommentOS(),
|
|
/*PrintType=*/false, F->getParent());
|
|
OutStreamer->GetCommentOS() << '\n';
|
|
}
|
|
|
|
// Emit the prefix data.
|
|
if (F->hasPrefixData()) {
|
|
if (MAI->hasSubsectionsViaSymbols()) {
|
|
// Preserving prefix data on platforms which use subsections-via-symbols
|
|
// is a bit tricky. Here we introduce a symbol for the prefix data
|
|
// and use the .alt_entry attribute to mark the function's real entry point
|
|
// as an alternative entry point to the prefix-data symbol.
|
|
MCSymbol *PrefixSym = OutContext.createLinkerPrivateTempSymbol();
|
|
OutStreamer->EmitLabel(PrefixSym);
|
|
|
|
EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrefixData());
|
|
|
|
// Emit an .alt_entry directive for the actual function symbol.
|
|
OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_AltEntry);
|
|
} else {
|
|
EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrefixData());
|
|
}
|
|
}
|
|
|
|
// Emit the CurrentFnSym. This is a virtual function to allow targets to
|
|
// do their wild and crazy things as required.
|
|
EmitFunctionEntryLabel();
|
|
|
|
// If the function had address-taken blocks that got deleted, then we have
|
|
// references to the dangling symbols. Emit them at the start of the function
|
|
// so that we don't get references to undefined symbols.
|
|
std::vector<MCSymbol*> DeadBlockSyms;
|
|
MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
|
|
for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
|
|
OutStreamer->AddComment("Address taken block that was later removed");
|
|
OutStreamer->EmitLabel(DeadBlockSyms[i]);
|
|
}
|
|
|
|
if (CurrentFnBegin) {
|
|
if (MAI->useAssignmentForEHBegin()) {
|
|
MCSymbol *CurPos = OutContext.createTempSymbol();
|
|
OutStreamer->EmitLabel(CurPos);
|
|
OutStreamer->EmitAssignment(CurrentFnBegin,
|
|
MCSymbolRefExpr::create(CurPos, OutContext));
|
|
} else {
|
|
OutStreamer->EmitLabel(CurrentFnBegin);
|
|
}
|
|
}
|
|
|
|
// Emit pre-function debug and/or EH information.
|
|
for (const HandlerInfo &HI : Handlers) {
|
|
NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
|
|
HI.TimerGroupDescription, TimePassesIsEnabled);
|
|
HI.Handler->beginFunction(MF);
|
|
}
|
|
|
|
// Emit the prologue data.
|
|
if (F->hasPrologueData())
|
|
EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrologueData());
|
|
}
|
|
|
|
/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
|
|
/// function. This can be overridden by targets as required to do custom stuff.
|
|
void AsmPrinter::EmitFunctionEntryLabel() {
|
|
CurrentFnSym->redefineIfPossible();
|
|
|
|
// The function label could have already been emitted if two symbols end up
|
|
// conflicting due to asm renaming. Detect this and emit an error.
|
|
if (CurrentFnSym->isVariable())
|
|
report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
|
|
"' is a protected alias");
|
|
if (CurrentFnSym->isDefined())
|
|
report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
|
|
"' label emitted multiple times to assembly file");
|
|
|
|
return OutStreamer->EmitLabel(CurrentFnSym);
|
|
}
|
|
|
|
/// emitComments - Pretty-print comments for instructions.
|
|
static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS,
|
|
AsmPrinter *AP) {
|
|
const MachineFunction *MF = MI.getParent()->getParent();
|
|
const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
|
|
|
|
// Check for spills and reloads
|
|
int FI;
|
|
|
|
const MachineFrameInfo &MFI = MF->getFrameInfo();
|
|
bool Commented = false;
|
|
|
|
// We assume a single instruction only has a spill or reload, not
|
|
// both.
|
|
const MachineMemOperand *MMO;
|
|
if (TII->isLoadFromStackSlotPostFE(MI, FI)) {
|
|
if (MFI.isSpillSlotObjectIndex(FI)) {
|
|
MMO = *MI.memoperands_begin();
|
|
CommentOS << MMO->getSize() << "-byte Reload";
|
|
Commented = true;
|
|
}
|
|
} else if (TII->hasLoadFromStackSlot(MI, MMO, FI)) {
|
|
if (MFI.isSpillSlotObjectIndex(FI)) {
|
|
CommentOS << MMO->getSize() << "-byte Folded Reload";
|
|
Commented = true;
|
|
}
|
|
} else if (TII->isStoreToStackSlotPostFE(MI, FI)) {
|
|
if (MFI.isSpillSlotObjectIndex(FI)) {
|
|
MMO = *MI.memoperands_begin();
|
|
CommentOS << MMO->getSize() << "-byte Spill";
|
|
Commented = true;
|
|
}
|
|
} else if (TII->hasStoreToStackSlot(MI, MMO, FI)) {
|
|
if (MFI.isSpillSlotObjectIndex(FI)) {
|
|
CommentOS << MMO->getSize() << "-byte Folded Spill";
|
|
Commented = true;
|
|
}
|
|
}
|
|
|
|
// Check for spill-induced copies
|
|
if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) {
|
|
Commented = true;
|
|
CommentOS << " Reload Reuse";
|
|
}
|
|
|
|
if (Commented && AP->EnablePrintSchedInfo)
|
|
// If any comment was added above and we need sched info comment then
|
|
// add this new comment just after the above comment w/o "\n" between them.
|
|
CommentOS << " " << MF->getSubtarget().getSchedInfoStr(MI) << "\n";
|
|
else if (Commented)
|
|
CommentOS << "\n";
|
|
}
|
|
|
|
/// emitImplicitDef - This method emits the specified machine instruction
|
|
/// that is an implicit def.
|
|
void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
|
|
unsigned RegNo = MI->getOperand(0).getReg();
|
|
|
|
SmallString<128> Str;
|
|
raw_svector_ostream OS(Str);
|
|
OS << "implicit-def: "
|
|
<< PrintReg(RegNo, MF->getSubtarget().getRegisterInfo());
|
|
|
|
OutStreamer->AddComment(OS.str());
|
|
OutStreamer->AddBlankLine();
|
|
}
|
|
|
|
static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
|
|
std::string Str;
|
|
raw_string_ostream OS(Str);
|
|
OS << "kill:";
|
|
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
|
|
const MachineOperand &Op = MI->getOperand(i);
|
|
assert(Op.isReg() && "KILL instruction must have only register operands");
|
|
OS << ' '
|
|
<< PrintReg(Op.getReg(),
|
|
AP.MF->getSubtarget().getRegisterInfo())
|
|
<< (Op.isDef() ? "<def>" : "<kill>");
|
|
}
|
|
AP.OutStreamer->AddComment(OS.str());
|
|
AP.OutStreamer->AddBlankLine();
|
|
}
|
|
|
|
/// emitDebugValueComment - This method handles the target-independent form
|
|
/// of DBG_VALUE, returning true if it was able to do so. A false return
|
|
/// means the target will need to handle MI in EmitInstruction.
|
|
static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
|
|
// This code handles only the 4-operand target-independent form.
|
|
if (MI->getNumOperands() != 4)
|
|
return false;
|
|
|
|
SmallString<128> Str;
|
|
raw_svector_ostream OS(Str);
|
|
OS << "DEBUG_VALUE: ";
|
|
|
|
const DILocalVariable *V = MI->getDebugVariable();
|
|
if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
|
|
StringRef Name = SP->getName();
|
|
if (!Name.empty())
|
|
OS << Name << ":";
|
|
}
|
|
OS << V->getName();
|
|
OS << " <- ";
|
|
|
|
// The second operand is only an offset if it's an immediate.
|
|
bool MemLoc = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
|
|
int64_t Offset = MemLoc ? MI->getOperand(1).getImm() : 0;
|
|
const DIExpression *Expr = MI->getDebugExpression();
|
|
if (Expr->getNumElements()) {
|
|
OS << '[';
|
|
bool NeedSep = false;
|
|
for (auto Op : Expr->expr_ops()) {
|
|
if (NeedSep)
|
|
OS << ", ";
|
|
else
|
|
NeedSep = true;
|
|
OS << dwarf::OperationEncodingString(Op.getOp());
|
|
for (unsigned I = 0; I < Op.getNumArgs(); ++I)
|
|
OS << ' ' << Op.getArg(I);
|
|
}
|
|
OS << "] ";
|
|
}
|
|
|
|
// Register or immediate value. Register 0 means undef.
|
|
if (MI->getOperand(0).isFPImm()) {
|
|
APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
|
|
if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
|
|
OS << (double)APF.convertToFloat();
|
|
} else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
|
|
OS << APF.convertToDouble();
|
|
} else {
|
|
// There is no good way to print long double. Convert a copy to
|
|
// double. Ah well, it's only a comment.
|
|
bool ignored;
|
|
APF.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven,
|
|
&ignored);
|
|
OS << "(long double) " << APF.convertToDouble();
|
|
}
|
|
} else if (MI->getOperand(0).isImm()) {
|
|
OS << MI->getOperand(0).getImm();
|
|
} else if (MI->getOperand(0).isCImm()) {
|
|
MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
|
|
} else {
|
|
unsigned Reg;
|
|
if (MI->getOperand(0).isReg()) {
|
|
Reg = MI->getOperand(0).getReg();
|
|
} else {
|
|
assert(MI->getOperand(0).isFI() && "Unknown operand type");
|
|
const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
|
|
Offset += TFI->getFrameIndexReference(*AP.MF,
|
|
MI->getOperand(0).getIndex(), Reg);
|
|
MemLoc = true;
|
|
}
|
|
if (Reg == 0) {
|
|
// Suppress offset, it is not meaningful here.
|
|
OS << "undef";
|
|
// NOTE: Want this comment at start of line, don't emit with AddComment.
|
|
AP.OutStreamer->emitRawComment(OS.str());
|
|
return true;
|
|
}
|
|
if (MemLoc)
|
|
OS << '[';
|
|
OS << PrintReg(Reg, AP.MF->getSubtarget().getRegisterInfo());
|
|
}
|
|
|
|
if (MemLoc)
|
|
OS << '+' << Offset << ']';
|
|
|
|
// NOTE: Want this comment at start of line, don't emit with AddComment.
|
|
AP.OutStreamer->emitRawComment(OS.str());
|
|
return true;
|
|
}
|
|
|
|
AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
|
|
if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
|
|
MF->getFunction()->needsUnwindTableEntry())
|
|
return CFI_M_EH;
|
|
|
|
if (MMI->hasDebugInfo())
|
|
return CFI_M_Debug;
|
|
|
|
return CFI_M_None;
|
|
}
|
|
|
|
bool AsmPrinter::needsSEHMoves() {
|
|
return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
|
|
}
|
|
|
|
void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
|
|
ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
|
|
if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
|
|
ExceptionHandlingType != ExceptionHandling::ARM)
|
|
return;
|
|
|
|
if (needsCFIMoves() == CFI_M_None)
|
|
return;
|
|
|
|
// If there is no "real" instruction following this CFI instruction, skip
|
|
// emitting it; it would be beyond the end of the function's FDE range.
|
|
auto *MBB = MI.getParent();
|
|
auto I = std::next(MI.getIterator());
|
|
while (I != MBB->end() && I->isTransient())
|
|
++I;
|
|
if (I == MBB->instr_end() &&
|
|
MBB->getReverseIterator() == MBB->getParent()->rbegin())
|
|
return;
|
|
|
|
const std::vector<MCCFIInstruction> &Instrs = MF->getFrameInstructions();
|
|
unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
|
|
const MCCFIInstruction &CFI = Instrs[CFIIndex];
|
|
emitCFIInstruction(CFI);
|
|
}
|
|
|
|
void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
|
|
// The operands are the MCSymbol and the frame offset of the allocation.
|
|
MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
|
|
int FrameOffset = MI.getOperand(1).getImm();
|
|
|
|
// Emit a symbol assignment.
|
|
OutStreamer->EmitAssignment(FrameAllocSym,
|
|
MCConstantExpr::create(FrameOffset, OutContext));
|
|
}
|
|
|
|
/// EmitFunctionBody - This method emits the body and trailer for a
|
|
/// function.
|
|
void AsmPrinter::EmitFunctionBody() {
|
|
EmitFunctionHeader();
|
|
|
|
// Emit target-specific gunk before the function body.
|
|
EmitFunctionBodyStart();
|
|
|
|
bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
|
|
|
|
// Print out code for the function.
|
|
bool HasAnyRealCode = false;
|
|
int NumInstsInFunction = 0;
|
|
for (auto &MBB : *MF) {
|
|
// Print a label for the basic block.
|
|
EmitBasicBlockStart(MBB);
|
|
for (auto &MI : MBB) {
|
|
|
|
// Print the assembly for the instruction.
|
|
if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
|
|
!MI.isDebugValue()) {
|
|
HasAnyRealCode = true;
|
|
++NumInstsInFunction;
|
|
}
|
|
|
|
if (ShouldPrintDebugScopes) {
|
|
for (const HandlerInfo &HI : Handlers) {
|
|
NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
|
|
HI.TimerGroupName, HI.TimerGroupDescription,
|
|
TimePassesIsEnabled);
|
|
HI.Handler->beginInstruction(&MI);
|
|
}
|
|
}
|
|
|
|
if (isVerbose())
|
|
emitComments(MI, OutStreamer->GetCommentOS(), this);
|
|
|
|
switch (MI.getOpcode()) {
|
|
case TargetOpcode::CFI_INSTRUCTION:
|
|
emitCFIInstruction(MI);
|
|
break;
|
|
|
|
case TargetOpcode::LOCAL_ESCAPE:
|
|
emitFrameAlloc(MI);
|
|
break;
|
|
|
|
case TargetOpcode::EH_LABEL:
|
|
case TargetOpcode::GC_LABEL:
|
|
OutStreamer->EmitLabel(MI.getOperand(0).getMCSymbol());
|
|
break;
|
|
case TargetOpcode::INLINEASM:
|
|
EmitInlineAsm(&MI);
|
|
break;
|
|
case TargetOpcode::DBG_VALUE:
|
|
if (isVerbose()) {
|
|
if (!emitDebugValueComment(&MI, *this))
|
|
EmitInstruction(&MI);
|
|
}
|
|
break;
|
|
case TargetOpcode::IMPLICIT_DEF:
|
|
if (isVerbose()) emitImplicitDef(&MI);
|
|
break;
|
|
case TargetOpcode::KILL:
|
|
if (isVerbose()) emitKill(&MI, *this);
|
|
break;
|
|
default:
|
|
EmitInstruction(&MI);
|
|
break;
|
|
}
|
|
|
|
if (ShouldPrintDebugScopes) {
|
|
for (const HandlerInfo &HI : Handlers) {
|
|
NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
|
|
HI.TimerGroupName, HI.TimerGroupDescription,
|
|
TimePassesIsEnabled);
|
|
HI.Handler->endInstruction();
|
|
}
|
|
}
|
|
}
|
|
|
|
EmitBasicBlockEnd(MBB);
|
|
}
|
|
|
|
EmittedInsts += NumInstsInFunction;
|
|
MachineOptimizationRemarkAnalysis R(DEBUG_TYPE, "InstructionCount",
|
|
MF->getFunction()->getSubprogram(),
|
|
&MF->front());
|
|
R << ore::NV("NumInstructions", NumInstsInFunction)
|
|
<< " instructions in function";
|
|
ORE->emit(R);
|
|
|
|
// If the function is empty and the object file uses .subsections_via_symbols,
|
|
// then we need to emit *something* to the function body to prevent the
|
|
// labels from collapsing together. Just emit a noop.
|
|
// Similarly, don't emit empty functions on Windows either. It can lead to
|
|
// duplicate entries (two functions with the same RVA) in the Guard CF Table
|
|
// after linking, causing the kernel not to load the binary:
|
|
// https://developercommunity.visualstudio.com/content/problem/45366/vc-linker-creates-invalid-dll-with-clang-cl.html
|
|
// FIXME: Hide this behind some API in e.g. MCAsmInfo or MCTargetStreamer.
|
|
const Triple &TT = TM.getTargetTriple();
|
|
if (!HasAnyRealCode && (MAI->hasSubsectionsViaSymbols() ||
|
|
(TT.isOSWindows() && TT.isOSBinFormatCOFF()))) {
|
|
MCInst Noop;
|
|
MF->getSubtarget().getInstrInfo()->getNoop(Noop);
|
|
|
|
// Targets can opt-out of emitting the noop here by leaving the opcode
|
|
// unspecified.
|
|
if (Noop.getOpcode()) {
|
|
OutStreamer->AddComment("avoids zero-length function");
|
|
OutStreamer->EmitInstruction(Noop, getSubtargetInfo());
|
|
}
|
|
}
|
|
|
|
const Function *F = MF->getFunction();
|
|
for (const auto &BB : *F) {
|
|
if (!BB.hasAddressTaken())
|
|
continue;
|
|
MCSymbol *Sym = GetBlockAddressSymbol(&BB);
|
|
if (Sym->isDefined())
|
|
continue;
|
|
OutStreamer->AddComment("Address of block that was removed by CodeGen");
|
|
OutStreamer->EmitLabel(Sym);
|
|
}
|
|
|
|
// Emit target-specific gunk after the function body.
|
|
EmitFunctionBodyEnd();
|
|
|
|
if (!MF->getLandingPads().empty() || MMI->hasDebugInfo() ||
|
|
MF->hasEHFunclets() || MAI->hasDotTypeDotSizeDirective()) {
|
|
// Create a symbol for the end of function.
|
|
CurrentFnEnd = createTempSymbol("func_end");
|
|
OutStreamer->EmitLabel(CurrentFnEnd);
|
|
}
|
|
|
|
// If the target wants a .size directive for the size of the function, emit
|
|
// it.
|
|
if (MAI->hasDotTypeDotSizeDirective()) {
|
|
// We can get the size as difference between the function label and the
|
|
// temp label.
|
|
const MCExpr *SizeExp = MCBinaryExpr::createSub(
|
|
MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
|
|
MCSymbolRefExpr::create(CurrentFnSymForSize, OutContext), OutContext);
|
|
OutStreamer->emitELFSize(CurrentFnSym, SizeExp);
|
|
}
|
|
|
|
for (const HandlerInfo &HI : Handlers) {
|
|
NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
|
|
HI.TimerGroupDescription, TimePassesIsEnabled);
|
|
HI.Handler->markFunctionEnd();
|
|
}
|
|
|
|
// Print out jump tables referenced by the function.
|
|
EmitJumpTableInfo();
|
|
|
|
// Emit post-function debug and/or EH information.
|
|
for (const HandlerInfo &HI : Handlers) {
|
|
NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
|
|
HI.TimerGroupDescription, TimePassesIsEnabled);
|
|
HI.Handler->endFunction(MF);
|
|
}
|
|
|
|
if (isVerbose())
|
|
OutStreamer->GetCommentOS() << "-- End function\n";
|
|
|
|
OutStreamer->AddBlankLine();
|
|
}
|
|
|
|
/// \brief Compute the number of Global Variables that uses a Constant.
|
|
static unsigned getNumGlobalVariableUses(const Constant *C) {
|
|
if (!C)
|
|
return 0;
|
|
|
|
if (isa<GlobalVariable>(C))
|
|
return 1;
|
|
|
|
unsigned NumUses = 0;
|
|
for (auto *CU : C->users())
|
|
NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
|
|
|
|
return NumUses;
|
|
}
|
|
|
|
/// \brief Only consider global GOT equivalents if at least one user is a
|
|
/// cstexpr inside an initializer of another global variables. Also, don't
|
|
/// handle cstexpr inside instructions. During global variable emission,
|
|
/// candidates are skipped and are emitted later in case at least one cstexpr
|
|
/// isn't replaced by a PC relative GOT entry access.
|
|
static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
|
|
unsigned &NumGOTEquivUsers) {
|
|
// Global GOT equivalents are unnamed private globals with a constant
|
|
// pointer initializer to another global symbol. They must point to a
|
|
// GlobalVariable or Function, i.e., as GlobalValue.
|
|
if (!GV->hasGlobalUnnamedAddr() || !GV->hasInitializer() ||
|
|
!GV->isConstant() || !GV->isDiscardableIfUnused() ||
|
|
!dyn_cast<GlobalValue>(GV->getOperand(0)))
|
|
return false;
|
|
|
|
// To be a got equivalent, at least one of its users need to be a constant
|
|
// expression used by another global variable.
|
|
for (auto *U : GV->users())
|
|
NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
|
|
|
|
return NumGOTEquivUsers > 0;
|
|
}
|
|
|
|
/// \brief Unnamed constant global variables solely contaning a pointer to
|
|
/// another globals variable is equivalent to a GOT table entry; it contains the
|
|
/// the address of another symbol. Optimize it and replace accesses to these
|
|
/// "GOT equivalents" by using the GOT entry for the final global instead.
|
|
/// Compute GOT equivalent candidates among all global variables to avoid
|
|
/// emitting them if possible later on, after it use is replaced by a GOT entry
|
|
/// access.
|
|
void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
|
|
if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
|
|
return;
|
|
|
|
for (const auto &G : M.globals()) {
|
|
unsigned NumGOTEquivUsers = 0;
|
|
if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
|
|
continue;
|
|
|
|
const MCSymbol *GOTEquivSym = getSymbol(&G);
|
|
GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
|
|
}
|
|
}
|
|
|
|
/// \brief Constant expressions using GOT equivalent globals may not be eligible
|
|
/// for PC relative GOT entry conversion, in such cases we need to emit such
|
|
/// globals we previously omitted in EmitGlobalVariable.
|
|
void AsmPrinter::emitGlobalGOTEquivs() {
|
|
if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
|
|
return;
|
|
|
|
SmallVector<const GlobalVariable *, 8> FailedCandidates;
|
|
for (auto &I : GlobalGOTEquivs) {
|
|
const GlobalVariable *GV = I.second.first;
|
|
unsigned Cnt = I.second.second;
|
|
if (Cnt)
|
|
FailedCandidates.push_back(GV);
|
|
}
|
|
GlobalGOTEquivs.clear();
|
|
|
|
for (auto *GV : FailedCandidates)
|
|
EmitGlobalVariable(GV);
|
|
}
|
|
|
|
void AsmPrinter::emitGlobalIndirectSymbol(Module &M,
|
|
const GlobalIndirectSymbol& GIS) {
|
|
MCSymbol *Name = getSymbol(&GIS);
|
|
|
|
if (GIS.hasExternalLinkage() || !MAI->getWeakRefDirective())
|
|
OutStreamer->EmitSymbolAttribute(Name, MCSA_Global);
|
|
else if (GIS.hasWeakLinkage() || GIS.hasLinkOnceLinkage())
|
|
OutStreamer->EmitSymbolAttribute(Name, MCSA_WeakReference);
|
|
else
|
|
assert(GIS.hasLocalLinkage() && "Invalid alias or ifunc linkage");
|
|
|
|
// Set the symbol type to function if the alias has a function type.
|
|
// This affects codegen when the aliasee is not a function.
|
|
if (GIS.getType()->getPointerElementType()->isFunctionTy()) {
|
|
OutStreamer->EmitSymbolAttribute(Name, MCSA_ELF_TypeFunction);
|
|
if (isa<GlobalIFunc>(GIS))
|
|
OutStreamer->EmitSymbolAttribute(Name, MCSA_ELF_TypeIndFunction);
|
|
}
|
|
|
|
EmitVisibility(Name, GIS.getVisibility());
|
|
|
|
const MCExpr *Expr = lowerConstant(GIS.getIndirectSymbol());
|
|
|
|
if (isa<GlobalAlias>(&GIS) && MAI->hasAltEntry() && isa<MCBinaryExpr>(Expr))
|
|
OutStreamer->EmitSymbolAttribute(Name, MCSA_AltEntry);
|
|
|
|
// Emit the directives as assignments aka .set:
|
|
OutStreamer->EmitAssignment(Name, Expr);
|
|
|
|
if (auto *GA = dyn_cast<GlobalAlias>(&GIS)) {
|
|
// If the aliasee does not correspond to a symbol in the output, i.e. the
|
|
// alias is not of an object or the aliased object is private, then set the
|
|
// size of the alias symbol from the type of the alias. We don't do this in
|
|
// other situations as the alias and aliasee having differing types but same
|
|
// size may be intentional.
|
|
const GlobalObject *BaseObject = GA->getBaseObject();
|
|
if (MAI->hasDotTypeDotSizeDirective() && GA->getValueType()->isSized() &&
|
|
(!BaseObject || BaseObject->hasPrivateLinkage())) {
|
|
const DataLayout &DL = M.getDataLayout();
|
|
uint64_t Size = DL.getTypeAllocSize(GA->getValueType());
|
|
OutStreamer->emitELFSize(Name, MCConstantExpr::create(Size, OutContext));
|
|
}
|
|
}
|
|
}
|
|
|
|
bool AsmPrinter::doFinalization(Module &M) {
|
|
// Set the MachineFunction to nullptr so that we can catch attempted
|
|
// accesses to MF specific features at the module level and so that
|
|
// we can conditionalize accesses based on whether or not it is nullptr.
|
|
MF = nullptr;
|
|
|
|
// Gather all GOT equivalent globals in the module. We really need two
|
|
// passes over the globals: one to compute and another to avoid its emission
|
|
// in EmitGlobalVariable, otherwise we would not be able to handle cases
|
|
// where the got equivalent shows up before its use.
|
|
computeGlobalGOTEquivs(M);
|
|
|
|
// Emit global variables.
|
|
for (const auto &G : M.globals())
|
|
EmitGlobalVariable(&G);
|
|
|
|
// Emit remaining GOT equivalent globals.
|
|
emitGlobalGOTEquivs();
|
|
|
|
// Emit visibility info for declarations
|
|
for (const Function &F : M) {
|
|
if (!F.isDeclarationForLinker())
|
|
continue;
|
|
GlobalValue::VisibilityTypes V = F.getVisibility();
|
|
if (V == GlobalValue::DefaultVisibility)
|
|
continue;
|
|
|
|
MCSymbol *Name = getSymbol(&F);
|
|
EmitVisibility(Name, V, false);
|
|
}
|
|
|
|
const TargetLoweringObjectFile &TLOF = getObjFileLowering();
|
|
|
|
// Emit module flags.
|
|
SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
|
|
M.getModuleFlagsMetadata(ModuleFlags);
|
|
if (!ModuleFlags.empty())
|
|
TLOF.emitModuleFlags(*OutStreamer, ModuleFlags, TM);
|
|
|
|
if (TM.getTargetTriple().isOSBinFormatELF()) {
|
|
MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
|
|
|
|
// Output stubs for external and common global variables.
|
|
MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
|
|
if (!Stubs.empty()) {
|
|
OutStreamer->SwitchSection(TLOF.getDataSection());
|
|
const DataLayout &DL = M.getDataLayout();
|
|
|
|
for (const auto &Stub : Stubs) {
|
|
OutStreamer->EmitLabel(Stub.first);
|
|
OutStreamer->EmitSymbolValue(Stub.second.getPointer(),
|
|
DL.getPointerSize());
|
|
}
|
|
}
|
|
}
|
|
|
|
// Finalize debug and EH information.
|
|
for (const HandlerInfo &HI : Handlers) {
|
|
NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
|
|
HI.TimerGroupDescription, TimePassesIsEnabled);
|
|
HI.Handler->endModule();
|
|
delete HI.Handler;
|
|
}
|
|
Handlers.clear();
|
|
DD = nullptr;
|
|
|
|
// If the target wants to know about weak references, print them all.
|
|
if (MAI->getWeakRefDirective()) {
|
|
// FIXME: This is not lazy, it would be nice to only print weak references
|
|
// to stuff that is actually used. Note that doing so would require targets
|
|
// to notice uses in operands (due to constant exprs etc). This should
|
|
// happen with the MC stuff eventually.
|
|
|
|
// Print out module-level global objects here.
|
|
for (const auto &GO : M.global_objects()) {
|
|
if (!GO.hasExternalWeakLinkage())
|
|
continue;
|
|
OutStreamer->EmitSymbolAttribute(getSymbol(&GO), MCSA_WeakReference);
|
|
}
|
|
}
|
|
|
|
OutStreamer->AddBlankLine();
|
|
|
|
// Print aliases in topological order, that is, for each alias a = b,
|
|
// b must be printed before a.
|
|
// This is because on some targets (e.g. PowerPC) linker expects aliases in
|
|
// such an order to generate correct TOC information.
|
|
SmallVector<const GlobalAlias *, 16> AliasStack;
|
|
SmallPtrSet<const GlobalAlias *, 16> AliasVisited;
|
|
for (const auto &Alias : M.aliases()) {
|
|
for (const GlobalAlias *Cur = &Alias; Cur;
|
|
Cur = dyn_cast<GlobalAlias>(Cur->getAliasee())) {
|
|
if (!AliasVisited.insert(Cur).second)
|
|
break;
|
|
AliasStack.push_back(Cur);
|
|
}
|
|
for (const GlobalAlias *AncestorAlias : llvm::reverse(AliasStack))
|
|
emitGlobalIndirectSymbol(M, *AncestorAlias);
|
|
AliasStack.clear();
|
|
}
|
|
for (const auto &IFunc : M.ifuncs())
|
|
emitGlobalIndirectSymbol(M, IFunc);
|
|
|
|
GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
|
|
assert(MI && "AsmPrinter didn't require GCModuleInfo?");
|
|
for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
|
|
if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
|
|
MP->finishAssembly(M, *MI, *this);
|
|
|
|
// Emit llvm.ident metadata in an '.ident' directive.
|
|
EmitModuleIdents(M);
|
|
|
|
// Emit __morestack address if needed for indirect calls.
|
|
if (MMI->usesMorestackAddr()) {
|
|
unsigned Align = 1;
|
|
MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
|
|
getDataLayout(), SectionKind::getReadOnly(),
|
|
/*C=*/nullptr, Align);
|
|
OutStreamer->SwitchSection(ReadOnlySection);
|
|
|
|
MCSymbol *AddrSymbol =
|
|
OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
|
|
OutStreamer->EmitLabel(AddrSymbol);
|
|
|
|
unsigned PtrSize = MAI->getCodePointerSize();
|
|
OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
|
|
PtrSize);
|
|
}
|
|
|
|
// If we don't have any trampolines, then we don't require stack memory
|
|
// to be executable. Some targets have a directive to declare this.
|
|
Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
|
|
if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
|
|
if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
|
|
OutStreamer->SwitchSection(S);
|
|
|
|
// Allow the target to emit any magic that it wants at the end of the file,
|
|
// after everything else has gone out.
|
|
EmitEndOfAsmFile(M);
|
|
|
|
MMI = nullptr;
|
|
|
|
OutStreamer->Finish();
|
|
OutStreamer->reset();
|
|
|
|
return false;
|
|
}
|
|
|
|
MCSymbol *AsmPrinter::getCurExceptionSym() {
|
|
if (!CurExceptionSym)
|
|
CurExceptionSym = createTempSymbol("exception");
|
|
return CurExceptionSym;
|
|
}
|
|
|
|
void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
|
|
this->MF = &MF;
|
|
// Get the function symbol.
|
|
CurrentFnSym = getSymbol(MF.getFunction());
|
|
CurrentFnSymForSize = CurrentFnSym;
|
|
CurrentFnBegin = nullptr;
|
|
CurExceptionSym = nullptr;
|
|
bool NeedsLocalForSize = MAI->needsLocalForSize();
|
|
if (!MF.getLandingPads().empty() || MMI->hasDebugInfo() ||
|
|
MF.hasEHFunclets() || NeedsLocalForSize) {
|
|
CurrentFnBegin = createTempSymbol("func_begin");
|
|
if (NeedsLocalForSize)
|
|
CurrentFnSymForSize = CurrentFnBegin;
|
|
}
|
|
|
|
ORE = &getAnalysis<MachineOptimizationRemarkEmitterPass>().getORE();
|
|
if (isVerbose())
|
|
LI = &getAnalysis<MachineLoopInfo>();
|
|
|
|
const TargetSubtargetInfo &STI = MF.getSubtarget();
|
|
EnablePrintSchedInfo = PrintSchedule.getNumOccurrences()
|
|
? PrintSchedule
|
|
: STI.supportPrintSchedInfo();
|
|
}
|
|
|
|
namespace {
|
|
|
|
// Keep track the alignment, constpool entries per Section.
|
|
struct SectionCPs {
|
|
MCSection *S;
|
|
unsigned Alignment;
|
|
SmallVector<unsigned, 4> CPEs;
|
|
|
|
SectionCPs(MCSection *s, unsigned a) : S(s), Alignment(a) {}
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
/// EmitConstantPool - Print to the current output stream assembly
|
|
/// representations of the constants in the constant pool MCP. This is
|
|
/// used to print out constants which have been "spilled to memory" by
|
|
/// the code generator.
|
|
///
|
|
void AsmPrinter::EmitConstantPool() {
|
|
const MachineConstantPool *MCP = MF->getConstantPool();
|
|
const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
|
|
if (CP.empty()) return;
|
|
|
|
// Calculate sections for constant pool entries. We collect entries to go into
|
|
// the same section together to reduce amount of section switch statements.
|
|
SmallVector<SectionCPs, 4> CPSections;
|
|
for (unsigned i = 0, e = CP.size(); i != e; ++i) {
|
|
const MachineConstantPoolEntry &CPE = CP[i];
|
|
unsigned Align = CPE.getAlignment();
|
|
|
|
SectionKind Kind = CPE.getSectionKind(&getDataLayout());
|
|
|
|
const Constant *C = nullptr;
|
|
if (!CPE.isMachineConstantPoolEntry())
|
|
C = CPE.Val.ConstVal;
|
|
|
|
MCSection *S = getObjFileLowering().getSectionForConstant(getDataLayout(),
|
|
Kind, C, Align);
|
|
|
|
// The number of sections are small, just do a linear search from the
|
|
// last section to the first.
|
|
bool Found = false;
|
|
unsigned SecIdx = CPSections.size();
|
|
while (SecIdx != 0) {
|
|
if (CPSections[--SecIdx].S == S) {
|
|
Found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!Found) {
|
|
SecIdx = CPSections.size();
|
|
CPSections.push_back(SectionCPs(S, Align));
|
|
}
|
|
|
|
if (Align > CPSections[SecIdx].Alignment)
|
|
CPSections[SecIdx].Alignment = Align;
|
|
CPSections[SecIdx].CPEs.push_back(i);
|
|
}
|
|
|
|
// Now print stuff into the calculated sections.
|
|
const MCSection *CurSection = nullptr;
|
|
unsigned Offset = 0;
|
|
for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
|
|
for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
|
|
unsigned CPI = CPSections[i].CPEs[j];
|
|
MCSymbol *Sym = GetCPISymbol(CPI);
|
|
if (!Sym->isUndefined())
|
|
continue;
|
|
|
|
if (CurSection != CPSections[i].S) {
|
|
OutStreamer->SwitchSection(CPSections[i].S);
|
|
EmitAlignment(Log2_32(CPSections[i].Alignment));
|
|
CurSection = CPSections[i].S;
|
|
Offset = 0;
|
|
}
|
|
|
|
MachineConstantPoolEntry CPE = CP[CPI];
|
|
|
|
// Emit inter-object padding for alignment.
|
|
unsigned AlignMask = CPE.getAlignment() - 1;
|
|
unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
|
|
OutStreamer->EmitZeros(NewOffset - Offset);
|
|
|
|
Type *Ty = CPE.getType();
|
|
Offset = NewOffset + getDataLayout().getTypeAllocSize(Ty);
|
|
|
|
OutStreamer->EmitLabel(Sym);
|
|
if (CPE.isMachineConstantPoolEntry())
|
|
EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
|
|
else
|
|
EmitGlobalConstant(getDataLayout(), CPE.Val.ConstVal);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// EmitJumpTableInfo - Print assembly representations of the jump tables used
|
|
/// by the current function to the current output stream.
|
|
///
|
|
void AsmPrinter::EmitJumpTableInfo() {
|
|
const DataLayout &DL = MF->getDataLayout();
|
|
const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
|
|
if (!MJTI) return;
|
|
if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
|
|
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
|
|
if (JT.empty()) return;
|
|
|
|
// Pick the directive to use to print the jump table entries, and switch to
|
|
// the appropriate section.
|
|
const Function *F = MF->getFunction();
|
|
const TargetLoweringObjectFile &TLOF = getObjFileLowering();
|
|
bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
|
|
MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
|
|
*F);
|
|
if (JTInDiffSection) {
|
|
// Drop it in the readonly section.
|
|
MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(*F, TM);
|
|
OutStreamer->SwitchSection(ReadOnlySection);
|
|
}
|
|
|
|
EmitAlignment(Log2_32(MJTI->getEntryAlignment(DL)));
|
|
|
|
// Jump tables in code sections are marked with a data_region directive
|
|
// where that's supported.
|
|
if (!JTInDiffSection)
|
|
OutStreamer->EmitDataRegion(MCDR_DataRegionJT32);
|
|
|
|
for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
|
|
const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
|
|
|
|
// If this jump table was deleted, ignore it.
|
|
if (JTBBs.empty()) continue;
|
|
|
|
// For the EK_LabelDifference32 entry, if using .set avoids a relocation,
|
|
/// emit a .set directive for each unique entry.
|
|
if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
|
|
MAI->doesSetDirectiveSuppressReloc()) {
|
|
SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
|
|
const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
|
|
const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
|
|
for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
|
|
const MachineBasicBlock *MBB = JTBBs[ii];
|
|
if (!EmittedSets.insert(MBB).second)
|
|
continue;
|
|
|
|
// .set LJTSet, LBB32-base
|
|
const MCExpr *LHS =
|
|
MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
|
|
OutStreamer->EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
|
|
MCBinaryExpr::createSub(LHS, Base,
|
|
OutContext));
|
|
}
|
|
}
|
|
|
|
// On some targets (e.g. Darwin) we want to emit two consecutive labels
|
|
// before each jump table. The first label is never referenced, but tells
|
|
// the assembler and linker the extents of the jump table object. The
|
|
// second label is actually referenced by the code.
|
|
if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
|
|
// FIXME: This doesn't have to have any specific name, just any randomly
|
|
// named and numbered 'l' label would work. Simplify GetJTISymbol.
|
|
OutStreamer->EmitLabel(GetJTISymbol(JTI, true));
|
|
|
|
OutStreamer->EmitLabel(GetJTISymbol(JTI));
|
|
|
|
for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
|
|
EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
|
|
}
|
|
if (!JTInDiffSection)
|
|
OutStreamer->EmitDataRegion(MCDR_DataRegionEnd);
|
|
}
|
|
|
|
/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
|
|
/// current stream.
|
|
void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
|
|
const MachineBasicBlock *MBB,
|
|
unsigned UID) const {
|
|
assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
|
|
const MCExpr *Value = nullptr;
|
|
switch (MJTI->getEntryKind()) {
|
|
case MachineJumpTableInfo::EK_Inline:
|
|
llvm_unreachable("Cannot emit EK_Inline jump table entry");
|
|
case MachineJumpTableInfo::EK_Custom32:
|
|
Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
|
|
MJTI, MBB, UID, OutContext);
|
|
break;
|
|
case MachineJumpTableInfo::EK_BlockAddress:
|
|
// EK_BlockAddress - Each entry is a plain address of block, e.g.:
|
|
// .word LBB123
|
|
Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
|
|
break;
|
|
case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
|
|
// EK_GPRel32BlockAddress - Each entry is an address of block, encoded
|
|
// with a relocation as gp-relative, e.g.:
|
|
// .gprel32 LBB123
|
|
MCSymbol *MBBSym = MBB->getSymbol();
|
|
OutStreamer->EmitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
|
|
return;
|
|
}
|
|
|
|
case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
|
|
// EK_GPRel64BlockAddress - Each entry is an address of block, encoded
|
|
// with a relocation as gp-relative, e.g.:
|
|
// .gpdword LBB123
|
|
MCSymbol *MBBSym = MBB->getSymbol();
|
|
OutStreamer->EmitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
|
|
return;
|
|
}
|
|
|
|
case MachineJumpTableInfo::EK_LabelDifference32: {
|
|
// Each entry is the address of the block minus the address of the jump
|
|
// table. This is used for PIC jump tables where gprel32 is not supported.
|
|
// e.g.:
|
|
// .word LBB123 - LJTI1_2
|
|
// If the .set directive avoids relocations, this is emitted as:
|
|
// .set L4_5_set_123, LBB123 - LJTI1_2
|
|
// .word L4_5_set_123
|
|
if (MAI->doesSetDirectiveSuppressReloc()) {
|
|
Value = MCSymbolRefExpr::create(GetJTSetSymbol(UID, MBB->getNumber()),
|
|
OutContext);
|
|
break;
|
|
}
|
|
Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
|
|
const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
|
|
const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
|
|
Value = MCBinaryExpr::createSub(Value, Base, OutContext);
|
|
break;
|
|
}
|
|
}
|
|
|
|
assert(Value && "Unknown entry kind!");
|
|
|
|
unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
|
|
OutStreamer->EmitValue(Value, EntrySize);
|
|
}
|
|
|
|
/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
|
|
/// special global used by LLVM. If so, emit it and return true, otherwise
|
|
/// do nothing and return false.
|
|
bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
|
|
if (GV->getName() == "llvm.used") {
|
|
if (MAI->hasNoDeadStrip()) // No need to emit this at all.
|
|
EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
|
|
return true;
|
|
}
|
|
|
|
// Ignore debug and non-emitted data. This handles llvm.compiler.used.
|
|
if (GV->getSection() == "llvm.metadata" ||
|
|
GV->hasAvailableExternallyLinkage())
|
|
return true;
|
|
|
|
if (!GV->hasAppendingLinkage()) return false;
|
|
|
|
assert(GV->hasInitializer() && "Not a special LLVM global!");
|
|
|
|
if (GV->getName() == "llvm.global_ctors") {
|
|
EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
|
|
/* isCtor */ true);
|
|
|
|
return true;
|
|
}
|
|
|
|
if (GV->getName() == "llvm.global_dtors") {
|
|
EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
|
|
/* isCtor */ false);
|
|
|
|
return true;
|
|
}
|
|
|
|
report_fatal_error("unknown special variable");
|
|
}
|
|
|
|
/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
|
|
/// global in the specified llvm.used list for which emitUsedDirectiveFor
|
|
/// is true, as being used with this directive.
|
|
void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
|
|
// Should be an array of 'i8*'.
|
|
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
|
|
const GlobalValue *GV =
|
|
dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
|
|
if (GV)
|
|
OutStreamer->EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
|
|
}
|
|
}
|
|
|
|
namespace {
|
|
|
|
struct Structor {
|
|
int Priority = 0;
|
|
Constant *Func = nullptr;
|
|
GlobalValue *ComdatKey = nullptr;
|
|
|
|
Structor() = default;
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
|
|
/// priority.
|
|
void AsmPrinter::EmitXXStructorList(const DataLayout &DL, const Constant *List,
|
|
bool isCtor) {
|
|
// Should be an array of '{ int, void ()* }' structs. The first value is the
|
|
// init priority.
|
|
if (!isa<ConstantArray>(List)) return;
|
|
|
|
// Sanity check the structors list.
|
|
const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
|
|
if (!InitList) return; // Not an array!
|
|
StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
|
|
// FIXME: Only allow the 3-field form in LLVM 4.0.
|
|
if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
|
|
return; // Not an array of two or three elements!
|
|
if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
|
|
!isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
|
|
if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
|
|
return; // Not (int, ptr, ptr).
|
|
|
|
// Gather the structors in a form that's convenient for sorting by priority.
|
|
SmallVector<Structor, 8> Structors;
|
|
for (Value *O : InitList->operands()) {
|
|
ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
|
|
if (!CS) continue; // Malformed.
|
|
if (CS->getOperand(1)->isNullValue())
|
|
break; // Found a null terminator, skip the rest.
|
|
ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
|
|
if (!Priority) continue; // Malformed.
|
|
Structors.push_back(Structor());
|
|
Structor &S = Structors.back();
|
|
S.Priority = Priority->getLimitedValue(65535);
|
|
S.Func = CS->getOperand(1);
|
|
if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
|
|
S.ComdatKey =
|
|
dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
|
|
}
|
|
|
|
// Emit the function pointers in the target-specific order
|
|
unsigned Align = Log2_32(DL.getPointerPrefAlignment());
|
|
std::stable_sort(Structors.begin(), Structors.end(),
|
|
[](const Structor &L,
|
|
const Structor &R) { return L.Priority < R.Priority; });
|
|
for (Structor &S : Structors) {
|
|
const TargetLoweringObjectFile &Obj = getObjFileLowering();
|
|
const MCSymbol *KeySym = nullptr;
|
|
if (GlobalValue *GV = S.ComdatKey) {
|
|
if (GV->isDeclarationForLinker())
|
|
// If the associated variable is not defined in this module
|
|
// (it might be available_externally, or have been an
|
|
// available_externally definition that was dropped by the
|
|
// EliminateAvailableExternally pass), some other TU
|
|
// will provide its dynamic initializer.
|
|
continue;
|
|
|
|
KeySym = getSymbol(GV);
|
|
}
|
|
MCSection *OutputSection =
|
|
(isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
|
|
: Obj.getStaticDtorSection(S.Priority, KeySym));
|
|
OutStreamer->SwitchSection(OutputSection);
|
|
if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
|
|
EmitAlignment(Align);
|
|
EmitXXStructor(DL, S.Func);
|
|
}
|
|
}
|
|
|
|
void AsmPrinter::EmitModuleIdents(Module &M) {
|
|
if (!MAI->hasIdentDirective())
|
|
return;
|
|
|
|
if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
|
|
for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
|
|
const MDNode *N = NMD->getOperand(i);
|
|
assert(N->getNumOperands() == 1 &&
|
|
"llvm.ident metadata entry can have only one operand");
|
|
const MDString *S = cast<MDString>(N->getOperand(0));
|
|
OutStreamer->EmitIdent(S->getString());
|
|
}
|
|
}
|
|
}
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
// Emission and print routines
|
|
//
|
|
|
|
/// EmitInt8 - Emit a byte directive and value.
|
|
///
|
|
void AsmPrinter::EmitInt8(int Value) const {
|
|
OutStreamer->EmitIntValue(Value, 1);
|
|
}
|
|
|
|
/// EmitInt16 - Emit a short directive and value.
|
|
///
|
|
void AsmPrinter::EmitInt16(int Value) const {
|
|
OutStreamer->EmitIntValue(Value, 2);
|
|
}
|
|
|
|
/// EmitInt32 - Emit a long directive and value.
|
|
///
|
|
void AsmPrinter::EmitInt32(int Value) const {
|
|
OutStreamer->EmitIntValue(Value, 4);
|
|
}
|
|
|
|
/// Emit something like ".long Hi-Lo" where the size in bytes of the directive
|
|
/// is specified by Size and Hi/Lo specify the labels. This implicitly uses
|
|
/// .set if it avoids relocations.
|
|
void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
|
|
unsigned Size) const {
|
|
OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
|
|
}
|
|
|
|
/// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
|
|
/// where the size in bytes of the directive is specified by Size and Label
|
|
/// specifies the label. This implicitly uses .set if it is available.
|
|
void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
|
|
unsigned Size,
|
|
bool IsSectionRelative) const {
|
|
if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
|
|
OutStreamer->EmitCOFFSecRel32(Label, Offset);
|
|
if (Size > 4)
|
|
OutStreamer->EmitZeros(Size - 4);
|
|
return;
|
|
}
|
|
|
|
// Emit Label+Offset (or just Label if Offset is zero)
|
|
const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
|
|
if (Offset)
|
|
Expr = MCBinaryExpr::createAdd(
|
|
Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
|
|
|
|
OutStreamer->EmitValue(Expr, Size);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// EmitAlignment - Emit an alignment directive to the specified power of
|
|
// two boundary. For example, if you pass in 3 here, you will get an 8
|
|
// byte alignment. If a global value is specified, and if that global has
|
|
// an explicit alignment requested, it will override the alignment request
|
|
// if required for correctness.
|
|
//
|
|
void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
|
|
if (GV)
|
|
NumBits = getGVAlignmentLog2(GV, GV->getParent()->getDataLayout(), NumBits);
|
|
|
|
if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
|
|
|
|
assert(NumBits <
|
|
static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
|
|
"undefined behavior");
|
|
if (getCurrentSection()->getKind().isText())
|
|
OutStreamer->EmitCodeAlignment(1u << NumBits);
|
|
else
|
|
OutStreamer->EmitValueToAlignment(1u << NumBits);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Constant emission.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
|
|
MCContext &Ctx = OutContext;
|
|
|
|
if (CV->isNullValue() || isa<UndefValue>(CV))
|
|
return MCConstantExpr::create(0, Ctx);
|
|
|
|
if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
|
|
return MCConstantExpr::create(CI->getZExtValue(), Ctx);
|
|
|
|
if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
|
|
return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
|
|
|
|
if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
|
|
return MCSymbolRefExpr::create(GetBlockAddressSymbol(BA), Ctx);
|
|
|
|
const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
|
|
if (!CE) {
|
|
llvm_unreachable("Unknown constant value to lower!");
|
|
}
|
|
|
|
switch (CE->getOpcode()) {
|
|
default:
|
|
// If the code isn't optimized, there may be outstanding folding
|
|
// opportunities. Attempt to fold the expression using DataLayout as a
|
|
// last resort before giving up.
|
|
if (Constant *C = ConstantFoldConstant(CE, getDataLayout()))
|
|
if (C != CE)
|
|
return lowerConstant(C);
|
|
|
|
// Otherwise report the problem to the user.
|
|
{
|
|
std::string S;
|
|
raw_string_ostream OS(S);
|
|
OS << "Unsupported expression in static initializer: ";
|
|
CE->printAsOperand(OS, /*PrintType=*/false,
|
|
!MF ? nullptr : MF->getFunction()->getParent());
|
|
report_fatal_error(OS.str());
|
|
}
|
|
case Instruction::GetElementPtr: {
|
|
// Generate a symbolic expression for the byte address
|
|
APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
|
|
cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
|
|
|
|
const MCExpr *Base = lowerConstant(CE->getOperand(0));
|
|
if (!OffsetAI)
|
|
return Base;
|
|
|
|
int64_t Offset = OffsetAI.getSExtValue();
|
|
return MCBinaryExpr::createAdd(Base, MCConstantExpr::create(Offset, Ctx),
|
|
Ctx);
|
|
}
|
|
|
|
case Instruction::Trunc:
|
|
// We emit the value and depend on the assembler to truncate the generated
|
|
// expression properly. This is important for differences between
|
|
// blockaddress labels. Since the two labels are in the same function, it
|
|
// is reasonable to treat their delta as a 32-bit value.
|
|
LLVM_FALLTHROUGH;
|
|
case Instruction::BitCast:
|
|
return lowerConstant(CE->getOperand(0));
|
|
|
|
case Instruction::IntToPtr: {
|
|
const DataLayout &DL = getDataLayout();
|
|
|
|
// Handle casts to pointers by changing them into casts to the appropriate
|
|
// integer type. This promotes constant folding and simplifies this code.
|
|
Constant *Op = CE->getOperand(0);
|
|
Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
|
|
false/*ZExt*/);
|
|
return lowerConstant(Op);
|
|
}
|
|
|
|
case Instruction::PtrToInt: {
|
|
const DataLayout &DL = getDataLayout();
|
|
|
|
// Support only foldable casts to/from pointers that can be eliminated by
|
|
// changing the pointer to the appropriately sized integer type.
|
|
Constant *Op = CE->getOperand(0);
|
|
Type *Ty = CE->getType();
|
|
|
|
const MCExpr *OpExpr = lowerConstant(Op);
|
|
|
|
// We can emit the pointer value into this slot if the slot is an
|
|
// integer slot equal to the size of the pointer.
|
|
if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
|
|
return OpExpr;
|
|
|
|
// Otherwise the pointer is smaller than the resultant integer, mask off
|
|
// the high bits so we are sure to get a proper truncation if the input is
|
|
// a constant expr.
|
|
unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
|
|
const MCExpr *MaskExpr = MCConstantExpr::create(~0ULL >> (64-InBits), Ctx);
|
|
return MCBinaryExpr::createAnd(OpExpr, MaskExpr, Ctx);
|
|
}
|
|
|
|
case Instruction::Sub: {
|
|
GlobalValue *LHSGV;
|
|
APInt LHSOffset;
|
|
if (IsConstantOffsetFromGlobal(CE->getOperand(0), LHSGV, LHSOffset,
|
|
getDataLayout())) {
|
|
GlobalValue *RHSGV;
|
|
APInt RHSOffset;
|
|
if (IsConstantOffsetFromGlobal(CE->getOperand(1), RHSGV, RHSOffset,
|
|
getDataLayout())) {
|
|
const MCExpr *RelocExpr =
|
|
getObjFileLowering().lowerRelativeReference(LHSGV, RHSGV, TM);
|
|
if (!RelocExpr)
|
|
RelocExpr = MCBinaryExpr::createSub(
|
|
MCSymbolRefExpr::create(getSymbol(LHSGV), Ctx),
|
|
MCSymbolRefExpr::create(getSymbol(RHSGV), Ctx), Ctx);
|
|
int64_t Addend = (LHSOffset - RHSOffset).getSExtValue();
|
|
if (Addend != 0)
|
|
RelocExpr = MCBinaryExpr::createAdd(
|
|
RelocExpr, MCConstantExpr::create(Addend, Ctx), Ctx);
|
|
return RelocExpr;
|
|
}
|
|
}
|
|
}
|
|
// else fallthrough
|
|
|
|
// The MC library also has a right-shift operator, but it isn't consistently
|
|
// signed or unsigned between different targets.
|
|
case Instruction::Add:
|
|
case Instruction::Mul:
|
|
case Instruction::SDiv:
|
|
case Instruction::SRem:
|
|
case Instruction::Shl:
|
|
case Instruction::And:
|
|
case Instruction::Or:
|
|
case Instruction::Xor: {
|
|
const MCExpr *LHS = lowerConstant(CE->getOperand(0));
|
|
const MCExpr *RHS = lowerConstant(CE->getOperand(1));
|
|
switch (CE->getOpcode()) {
|
|
default: llvm_unreachable("Unknown binary operator constant cast expr");
|
|
case Instruction::Add: return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
|
|
case Instruction::Sub: return MCBinaryExpr::createSub(LHS, RHS, Ctx);
|
|
case Instruction::Mul: return MCBinaryExpr::createMul(LHS, RHS, Ctx);
|
|
case Instruction::SDiv: return MCBinaryExpr::createDiv(LHS, RHS, Ctx);
|
|
case Instruction::SRem: return MCBinaryExpr::createMod(LHS, RHS, Ctx);
|
|
case Instruction::Shl: return MCBinaryExpr::createShl(LHS, RHS, Ctx);
|
|
case Instruction::And: return MCBinaryExpr::createAnd(LHS, RHS, Ctx);
|
|
case Instruction::Or: return MCBinaryExpr::createOr (LHS, RHS, Ctx);
|
|
case Instruction::Xor: return MCBinaryExpr::createXor(LHS, RHS, Ctx);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
|
|
AsmPrinter &AP,
|
|
const Constant *BaseCV = nullptr,
|
|
uint64_t Offset = 0);
|
|
|
|
static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
|
|
|
|
/// isRepeatedByteSequence - Determine whether the given value is
|
|
/// composed of a repeated sequence of identical bytes and return the
|
|
/// byte value. If it is not a repeated sequence, return -1.
|
|
static int isRepeatedByteSequence(const ConstantDataSequential *V) {
|
|
StringRef Data = V->getRawDataValues();
|
|
assert(!Data.empty() && "Empty aggregates should be CAZ node");
|
|
char C = Data[0];
|
|
for (unsigned i = 1, e = Data.size(); i != e; ++i)
|
|
if (Data[i] != C) return -1;
|
|
return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
|
|
}
|
|
|
|
/// isRepeatedByteSequence - Determine whether the given value is
|
|
/// composed of a repeated sequence of identical bytes and return the
|
|
/// byte value. If it is not a repeated sequence, return -1.
|
|
static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
|
|
if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
|
|
uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
|
|
assert(Size % 8 == 0);
|
|
|
|
// Extend the element to take zero padding into account.
|
|
APInt Value = CI->getValue().zextOrSelf(Size);
|
|
if (!Value.isSplat(8))
|
|
return -1;
|
|
|
|
return Value.zextOrTrunc(8).getZExtValue();
|
|
}
|
|
if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
|
|
// Make sure all array elements are sequences of the same repeated
|
|
// byte.
|
|
assert(CA->getNumOperands() != 0 && "Should be a CAZ");
|
|
Constant *Op0 = CA->getOperand(0);
|
|
int Byte = isRepeatedByteSequence(Op0, DL);
|
|
if (Byte == -1)
|
|
return -1;
|
|
|
|
// All array elements must be equal.
|
|
for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
|
|
if (CA->getOperand(i) != Op0)
|
|
return -1;
|
|
return Byte;
|
|
}
|
|
|
|
if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
|
|
return isRepeatedByteSequence(CDS);
|
|
|
|
return -1;
|
|
}
|
|
|
|
static void emitGlobalConstantDataSequential(const DataLayout &DL,
|
|
const ConstantDataSequential *CDS,
|
|
AsmPrinter &AP) {
|
|
// See if we can aggregate this into a .fill, if so, emit it as such.
|
|
int Value = isRepeatedByteSequence(CDS, DL);
|
|
if (Value != -1) {
|
|
uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
|
|
// Don't emit a 1-byte object as a .fill.
|
|
if (Bytes > 1)
|
|
return AP.OutStreamer->emitFill(Bytes, Value);
|
|
}
|
|
|
|
// If this can be emitted with .ascii/.asciz, emit it as such.
|
|
if (CDS->isString())
|
|
return AP.OutStreamer->EmitBytes(CDS->getAsString());
|
|
|
|
// Otherwise, emit the values in successive locations.
|
|
unsigned ElementByteSize = CDS->getElementByteSize();
|
|
if (isa<IntegerType>(CDS->getElementType())) {
|
|
for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
|
|
if (AP.isVerbose())
|
|
AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
|
|
CDS->getElementAsInteger(i));
|
|
AP.OutStreamer->EmitIntValue(CDS->getElementAsInteger(i),
|
|
ElementByteSize);
|
|
}
|
|
} else {
|
|
for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I)
|
|
emitGlobalConstantFP(cast<ConstantFP>(CDS->getElementAsConstant(I)), AP);
|
|
}
|
|
|
|
unsigned Size = DL.getTypeAllocSize(CDS->getType());
|
|
unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
|
|
CDS->getNumElements();
|
|
if (unsigned Padding = Size - EmittedSize)
|
|
AP.OutStreamer->EmitZeros(Padding);
|
|
}
|
|
|
|
static void emitGlobalConstantArray(const DataLayout &DL,
|
|
const ConstantArray *CA, AsmPrinter &AP,
|
|
const Constant *BaseCV, uint64_t Offset) {
|
|
// See if we can aggregate some values. Make sure it can be
|
|
// represented as a series of bytes of the constant value.
|
|
int Value = isRepeatedByteSequence(CA, DL);
|
|
|
|
if (Value != -1) {
|
|
uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
|
|
AP.OutStreamer->emitFill(Bytes, Value);
|
|
}
|
|
else {
|
|
for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
|
|
emitGlobalConstantImpl(DL, CA->getOperand(i), AP, BaseCV, Offset);
|
|
Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
|
|
}
|
|
}
|
|
}
|
|
|
|
static void emitGlobalConstantVector(const DataLayout &DL,
|
|
const ConstantVector *CV, AsmPrinter &AP) {
|
|
for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
|
|
emitGlobalConstantImpl(DL, CV->getOperand(i), AP);
|
|
|
|
unsigned Size = DL.getTypeAllocSize(CV->getType());
|
|
unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
|
|
CV->getType()->getNumElements();
|
|
if (unsigned Padding = Size - EmittedSize)
|
|
AP.OutStreamer->EmitZeros(Padding);
|
|
}
|
|
|
|
static void emitGlobalConstantStruct(const DataLayout &DL,
|
|
const ConstantStruct *CS, AsmPrinter &AP,
|
|
const Constant *BaseCV, uint64_t Offset) {
|
|
// Print the fields in successive locations. Pad to align if needed!
|
|
unsigned Size = DL.getTypeAllocSize(CS->getType());
|
|
const StructLayout *Layout = DL.getStructLayout(CS->getType());
|
|
uint64_t SizeSoFar = 0;
|
|
for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
|
|
const Constant *Field = CS->getOperand(i);
|
|
|
|
// Print the actual field value.
|
|
emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar);
|
|
|
|
// Check if padding is needed and insert one or more 0s.
|
|
uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
|
|
uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
|
|
- Layout->getElementOffset(i)) - FieldSize;
|
|
SizeSoFar += FieldSize + PadSize;
|
|
|
|
// Insert padding - this may include padding to increase the size of the
|
|
// current field up to the ABI size (if the struct is not packed) as well
|
|
// as padding to ensure that the next field starts at the right offset.
|
|
AP.OutStreamer->EmitZeros(PadSize);
|
|
}
|
|
assert(SizeSoFar == Layout->getSizeInBytes() &&
|
|
"Layout of constant struct may be incorrect!");
|
|
}
|
|
|
|
static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
|
|
APInt API = CFP->getValueAPF().bitcastToAPInt();
|
|
|
|
// First print a comment with what we think the original floating-point value
|
|
// should have been.
|
|
if (AP.isVerbose()) {
|
|
SmallString<8> StrVal;
|
|
CFP->getValueAPF().toString(StrVal);
|
|
|
|
if (CFP->getType())
|
|
CFP->getType()->print(AP.OutStreamer->GetCommentOS());
|
|
else
|
|
AP.OutStreamer->GetCommentOS() << "Printing <null> Type";
|
|
AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
|
|
}
|
|
|
|
// Now iterate through the APInt chunks, emitting them in endian-correct
|
|
// order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
|
|
// floats).
|
|
unsigned NumBytes = API.getBitWidth() / 8;
|
|
unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
|
|
const uint64_t *p = API.getRawData();
|
|
|
|
// PPC's long double has odd notions of endianness compared to how LLVM
|
|
// handles it: p[0] goes first for *big* endian on PPC.
|
|
if (AP.getDataLayout().isBigEndian() && !CFP->getType()->isPPC_FP128Ty()) {
|
|
int Chunk = API.getNumWords() - 1;
|
|
|
|
if (TrailingBytes)
|
|
AP.OutStreamer->EmitIntValue(p[Chunk--], TrailingBytes);
|
|
|
|
for (; Chunk >= 0; --Chunk)
|
|
AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
|
|
} else {
|
|
unsigned Chunk;
|
|
for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
|
|
AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
|
|
|
|
if (TrailingBytes)
|
|
AP.OutStreamer->EmitIntValue(p[Chunk], TrailingBytes);
|
|
}
|
|
|
|
// Emit the tail padding for the long double.
|
|
const DataLayout &DL = AP.getDataLayout();
|
|
AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
|
|
DL.getTypeStoreSize(CFP->getType()));
|
|
}
|
|
|
|
static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
|
|
const DataLayout &DL = AP.getDataLayout();
|
|
unsigned BitWidth = CI->getBitWidth();
|
|
|
|
// Copy the value as we may massage the layout for constants whose bit width
|
|
// is not a multiple of 64-bits.
|
|
APInt Realigned(CI->getValue());
|
|
uint64_t ExtraBits = 0;
|
|
unsigned ExtraBitsSize = BitWidth & 63;
|
|
|
|
if (ExtraBitsSize) {
|
|
// The bit width of the data is not a multiple of 64-bits.
|
|
// The extra bits are expected to be at the end of the chunk of the memory.
|
|
// Little endian:
|
|
// * Nothing to be done, just record the extra bits to emit.
|
|
// Big endian:
|
|
// * Record the extra bits to emit.
|
|
// * Realign the raw data to emit the chunks of 64-bits.
|
|
if (DL.isBigEndian()) {
|
|
// Basically the structure of the raw data is a chunk of 64-bits cells:
|
|
// 0 1 BitWidth / 64
|
|
// [chunk1][chunk2] ... [chunkN].
|
|
// The most significant chunk is chunkN and it should be emitted first.
|
|
// However, due to the alignment issue chunkN contains useless bits.
|
|
// Realign the chunks so that they contain only useless information:
|
|
// ExtraBits 0 1 (BitWidth / 64) - 1
|
|
// chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
|
|
ExtraBits = Realigned.getRawData()[0] &
|
|
(((uint64_t)-1) >> (64 - ExtraBitsSize));
|
|
Realigned.lshrInPlace(ExtraBitsSize);
|
|
} else
|
|
ExtraBits = Realigned.getRawData()[BitWidth / 64];
|
|
}
|
|
|
|
// We don't expect assemblers to support integer data directives
|
|
// for more than 64 bits, so we emit the data in at most 64-bit
|
|
// quantities at a time.
|
|
const uint64_t *RawData = Realigned.getRawData();
|
|
for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
|
|
uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
|
|
AP.OutStreamer->EmitIntValue(Val, 8);
|
|
}
|
|
|
|
if (ExtraBitsSize) {
|
|
// Emit the extra bits after the 64-bits chunks.
|
|
|
|
// Emit a directive that fills the expected size.
|
|
uint64_t Size = AP.getDataLayout().getTypeAllocSize(CI->getType());
|
|
Size -= (BitWidth / 64) * 8;
|
|
assert(Size && Size * 8 >= ExtraBitsSize &&
|
|
(ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
|
|
== ExtraBits && "Directive too small for extra bits.");
|
|
AP.OutStreamer->EmitIntValue(ExtraBits, Size);
|
|
}
|
|
}
|
|
|
|
/// \brief Transform a not absolute MCExpr containing a reference to a GOT
|
|
/// equivalent global, by a target specific GOT pc relative access to the
|
|
/// final symbol.
|
|
static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
|
|
const Constant *BaseCst,
|
|
uint64_t Offset) {
|
|
// The global @foo below illustrates a global that uses a got equivalent.
|
|
//
|
|
// @bar = global i32 42
|
|
// @gotequiv = private unnamed_addr constant i32* @bar
|
|
// @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
|
|
// i64 ptrtoint (i32* @foo to i64))
|
|
// to i32)
|
|
//
|
|
// The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
|
|
// check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
|
|
// form:
|
|
//
|
|
// foo = cstexpr, where
|
|
// cstexpr := <gotequiv> - "." + <cst>
|
|
// cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
|
|
//
|
|
// After canonicalization by evaluateAsRelocatable `ME` turns into:
|
|
//
|
|
// cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
|
|
// gotpcrelcst := <offset from @foo base> + <cst>
|
|
//
|
|
MCValue MV;
|
|
if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
|
|
return;
|
|
const MCSymbolRefExpr *SymA = MV.getSymA();
|
|
if (!SymA)
|
|
return;
|
|
|
|
// Check that GOT equivalent symbol is cached.
|
|
const MCSymbol *GOTEquivSym = &SymA->getSymbol();
|
|
if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
|
|
return;
|
|
|
|
const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
|
|
if (!BaseGV)
|
|
return;
|
|
|
|
// Check for a valid base symbol
|
|
const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
|
|
const MCSymbolRefExpr *SymB = MV.getSymB();
|
|
|
|
if (!SymB || BaseSym != &SymB->getSymbol())
|
|
return;
|
|
|
|
// Make sure to match:
|
|
//
|
|
// gotpcrelcst := <offset from @foo base> + <cst>
|
|
//
|
|
// If gotpcrelcst is positive it means that we can safely fold the pc rel
|
|
// displacement into the GOTPCREL. We can also can have an extra offset <cst>
|
|
// if the target knows how to encode it.
|
|
//
|
|
int64_t GOTPCRelCst = Offset + MV.getConstant();
|
|
if (GOTPCRelCst < 0)
|
|
return;
|
|
if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
|
|
return;
|
|
|
|
// Emit the GOT PC relative to replace the got equivalent global, i.e.:
|
|
//
|
|
// bar:
|
|
// .long 42
|
|
// gotequiv:
|
|
// .quad bar
|
|
// foo:
|
|
// .long gotequiv - "." + <cst>
|
|
//
|
|
// is replaced by the target specific equivalent to:
|
|
//
|
|
// bar:
|
|
// .long 42
|
|
// foo:
|
|
// .long bar@GOTPCREL+<gotpcrelcst>
|
|
//
|
|
AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
|
|
const GlobalVariable *GV = Result.first;
|
|
int NumUses = (int)Result.second;
|
|
const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
|
|
const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
|
|
*ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
|
|
FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
|
|
|
|
// Update GOT equivalent usage information
|
|
--NumUses;
|
|
if (NumUses >= 0)
|
|
AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
|
|
}
|
|
|
|
static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
|
|
AsmPrinter &AP, const Constant *BaseCV,
|
|
uint64_t Offset) {
|
|
uint64_t Size = DL.getTypeAllocSize(CV->getType());
|
|
|
|
// Globals with sub-elements such as combinations of arrays and structs
|
|
// are handled recursively by emitGlobalConstantImpl. Keep track of the
|
|
// constant symbol base and the current position with BaseCV and Offset.
|
|
if (!BaseCV && CV->hasOneUse())
|
|
BaseCV = dyn_cast<Constant>(CV->user_back());
|
|
|
|
if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
|
|
return AP.OutStreamer->EmitZeros(Size);
|
|
|
|
if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
|
|
switch (Size) {
|
|
case 1:
|
|
case 2:
|
|
case 4:
|
|
case 8:
|
|
if (AP.isVerbose())
|
|
AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
|
|
CI->getZExtValue());
|
|
AP.OutStreamer->EmitIntValue(CI->getZExtValue(), Size);
|
|
return;
|
|
default:
|
|
emitGlobalConstantLargeInt(CI, AP);
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
|
|
return emitGlobalConstantFP(CFP, AP);
|
|
|
|
if (isa<ConstantPointerNull>(CV)) {
|
|
AP.OutStreamer->EmitIntValue(0, Size);
|
|
return;
|
|
}
|
|
|
|
if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
|
|
return emitGlobalConstantDataSequential(DL, CDS, AP);
|
|
|
|
if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
|
|
return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset);
|
|
|
|
if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
|
|
return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset);
|
|
|
|
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
|
|
// Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
|
|
// vectors).
|
|
if (CE->getOpcode() == Instruction::BitCast)
|
|
return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
|
|
|
|
if (Size > 8) {
|
|
// If the constant expression's size is greater than 64-bits, then we have
|
|
// to emit the value in chunks. Try to constant fold the value and emit it
|
|
// that way.
|
|
Constant *New = ConstantFoldConstant(CE, DL);
|
|
if (New && New != CE)
|
|
return emitGlobalConstantImpl(DL, New, AP);
|
|
}
|
|
}
|
|
|
|
if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
|
|
return emitGlobalConstantVector(DL, V, AP);
|
|
|
|
// Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
|
|
// thread the streamer with EmitValue.
|
|
const MCExpr *ME = AP.lowerConstant(CV);
|
|
|
|
// Since lowerConstant already folded and got rid of all IR pointer and
|
|
// integer casts, detect GOT equivalent accesses by looking into the MCExpr
|
|
// directly.
|
|
if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
|
|
handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
|
|
|
|
AP.OutStreamer->EmitValue(ME, Size);
|
|
}
|
|
|
|
/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
|
|
void AsmPrinter::EmitGlobalConstant(const DataLayout &DL, const Constant *CV) {
|
|
uint64_t Size = DL.getTypeAllocSize(CV->getType());
|
|
if (Size)
|
|
emitGlobalConstantImpl(DL, CV, *this);
|
|
else if (MAI->hasSubsectionsViaSymbols()) {
|
|
// If the global has zero size, emit a single byte so that two labels don't
|
|
// look like they are at the same location.
|
|
OutStreamer->EmitIntValue(0, 1);
|
|
}
|
|
}
|
|
|
|
void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
|
|
// Target doesn't support this yet!
|
|
llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
|
|
}
|
|
|
|
void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
|
|
if (Offset > 0)
|
|
OS << '+' << Offset;
|
|
else if (Offset < 0)
|
|
OS << Offset;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Symbol Lowering Routines.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
|
|
return OutContext.createTempSymbol(Name, true);
|
|
}
|
|
|
|
MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
|
|
return MMI->getAddrLabelSymbol(BA->getBasicBlock());
|
|
}
|
|
|
|
MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
|
|
return MMI->getAddrLabelSymbol(BB);
|
|
}
|
|
|
|
/// GetCPISymbol - Return the symbol for the specified constant pool entry.
|
|
MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
|
|
const DataLayout &DL = getDataLayout();
|
|
return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
|
|
"CPI" + Twine(getFunctionNumber()) + "_" +
|
|
Twine(CPID));
|
|
}
|
|
|
|
/// GetJTISymbol - Return the symbol for the specified jump table entry.
|
|
MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
|
|
return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
|
|
}
|
|
|
|
/// GetJTSetSymbol - Return the symbol for the specified jump table .set
|
|
/// FIXME: privatize to AsmPrinter.
|
|
MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
|
|
const DataLayout &DL = getDataLayout();
|
|
return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
|
|
Twine(getFunctionNumber()) + "_" +
|
|
Twine(UID) + "_set_" + Twine(MBBID));
|
|
}
|
|
|
|
MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
|
|
StringRef Suffix) const {
|
|
return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, TM);
|
|
}
|
|
|
|
/// Return the MCSymbol for the specified ExternalSymbol.
|
|
MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
|
|
SmallString<60> NameStr;
|
|
Mangler::getNameWithPrefix(NameStr, Sym, getDataLayout());
|
|
return OutContext.getOrCreateSymbol(NameStr);
|
|
}
|
|
|
|
/// PrintParentLoopComment - Print comments about parent loops of this one.
|
|
static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
|
|
unsigned FunctionNumber) {
|
|
if (!Loop) return;
|
|
PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
|
|
OS.indent(Loop->getLoopDepth()*2)
|
|
<< "Parent Loop BB" << FunctionNumber << "_"
|
|
<< Loop->getHeader()->getNumber()
|
|
<< " Depth=" << Loop->getLoopDepth() << '\n';
|
|
}
|
|
|
|
|
|
/// PrintChildLoopComment - Print comments about child loops within
|
|
/// the loop for this basic block, with nesting.
|
|
static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
|
|
unsigned FunctionNumber) {
|
|
// Add child loop information
|
|
for (const MachineLoop *CL : *Loop) {
|
|
OS.indent(CL->getLoopDepth()*2)
|
|
<< "Child Loop BB" << FunctionNumber << "_"
|
|
<< CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
|
|
<< '\n';
|
|
PrintChildLoopComment(OS, CL, FunctionNumber);
|
|
}
|
|
}
|
|
|
|
/// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
|
|
static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
|
|
const MachineLoopInfo *LI,
|
|
const AsmPrinter &AP) {
|
|
// Add loop depth information
|
|
const MachineLoop *Loop = LI->getLoopFor(&MBB);
|
|
if (!Loop) return;
|
|
|
|
MachineBasicBlock *Header = Loop->getHeader();
|
|
assert(Header && "No header for loop");
|
|
|
|
// If this block is not a loop header, just print out what is the loop header
|
|
// and return.
|
|
if (Header != &MBB) {
|
|
AP.OutStreamer->AddComment(" in Loop: Header=BB" +
|
|
Twine(AP.getFunctionNumber())+"_" +
|
|
Twine(Loop->getHeader()->getNumber())+
|
|
" Depth="+Twine(Loop->getLoopDepth()));
|
|
return;
|
|
}
|
|
|
|
// Otherwise, it is a loop header. Print out information about child and
|
|
// parent loops.
|
|
raw_ostream &OS = AP.OutStreamer->GetCommentOS();
|
|
|
|
PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
|
|
|
|
OS << "=>";
|
|
OS.indent(Loop->getLoopDepth()*2-2);
|
|
|
|
OS << "This ";
|
|
if (Loop->empty())
|
|
OS << "Inner ";
|
|
OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
|
|
|
|
PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
|
|
}
|
|
|
|
/// EmitBasicBlockStart - This method prints the label for the specified
|
|
/// MachineBasicBlock, an alignment (if present) and a comment describing
|
|
/// it if appropriate.
|
|
void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
|
|
// End the previous funclet and start a new one.
|
|
if (MBB.isEHFuncletEntry()) {
|
|
for (const HandlerInfo &HI : Handlers) {
|
|
HI.Handler->endFunclet();
|
|
HI.Handler->beginFunclet(MBB);
|
|
}
|
|
}
|
|
|
|
// Emit an alignment directive for this block, if needed.
|
|
if (unsigned Align = MBB.getAlignment())
|
|
EmitAlignment(Align);
|
|
|
|
// If the block has its address taken, emit any labels that were used to
|
|
// reference the block. It is possible that there is more than one label
|
|
// here, because multiple LLVM BB's may have been RAUW'd to this block after
|
|
// the references were generated.
|
|
if (MBB.hasAddressTaken()) {
|
|
const BasicBlock *BB = MBB.getBasicBlock();
|
|
if (isVerbose())
|
|
OutStreamer->AddComment("Block address taken");
|
|
|
|
// MBBs can have their address taken as part of CodeGen without having
|
|
// their corresponding BB's address taken in IR
|
|
if (BB->hasAddressTaken())
|
|
for (MCSymbol *Sym : MMI->getAddrLabelSymbolToEmit(BB))
|
|
OutStreamer->EmitLabel(Sym);
|
|
}
|
|
|
|
// Print some verbose block comments.
|
|
if (isVerbose()) {
|
|
if (const BasicBlock *BB = MBB.getBasicBlock()) {
|
|
if (BB->hasName()) {
|
|
BB->printAsOperand(OutStreamer->GetCommentOS(),
|
|
/*PrintType=*/false, BB->getModule());
|
|
OutStreamer->GetCommentOS() << '\n';
|
|
}
|
|
}
|
|
emitBasicBlockLoopComments(MBB, LI, *this);
|
|
}
|
|
|
|
// Print the main label for the block.
|
|
if (MBB.pred_empty() ||
|
|
(isBlockOnlyReachableByFallthrough(&MBB) && !MBB.isEHFuncletEntry())) {
|
|
if (isVerbose()) {
|
|
// NOTE: Want this comment at start of line, don't emit with AddComment.
|
|
OutStreamer->emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
|
|
}
|
|
} else {
|
|
OutStreamer->EmitLabel(MBB.getSymbol());
|
|
}
|
|
}
|
|
|
|
void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
|
|
bool IsDefinition) const {
|
|
MCSymbolAttr Attr = MCSA_Invalid;
|
|
|
|
switch (Visibility) {
|
|
default: break;
|
|
case GlobalValue::HiddenVisibility:
|
|
if (IsDefinition)
|
|
Attr = MAI->getHiddenVisibilityAttr();
|
|
else
|
|
Attr = MAI->getHiddenDeclarationVisibilityAttr();
|
|
break;
|
|
case GlobalValue::ProtectedVisibility:
|
|
Attr = MAI->getProtectedVisibilityAttr();
|
|
break;
|
|
}
|
|
|
|
if (Attr != MCSA_Invalid)
|
|
OutStreamer->EmitSymbolAttribute(Sym, Attr);
|
|
}
|
|
|
|
/// isBlockOnlyReachableByFallthough - Return true if the basic block has
|
|
/// exactly one predecessor and the control transfer mechanism between
|
|
/// the predecessor and this block is a fall-through.
|
|
bool AsmPrinter::
|
|
isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
|
|
// If this is a landing pad, it isn't a fall through. If it has no preds,
|
|
// then nothing falls through to it.
|
|
if (MBB->isEHPad() || MBB->pred_empty())
|
|
return false;
|
|
|
|
// If there isn't exactly one predecessor, it can't be a fall through.
|
|
if (MBB->pred_size() > 1)
|
|
return false;
|
|
|
|
// The predecessor has to be immediately before this block.
|
|
MachineBasicBlock *Pred = *MBB->pred_begin();
|
|
if (!Pred->isLayoutSuccessor(MBB))
|
|
return false;
|
|
|
|
// If the block is completely empty, then it definitely does fall through.
|
|
if (Pred->empty())
|
|
return true;
|
|
|
|
// Check the terminators in the previous blocks
|
|
for (const auto &MI : Pred->terminators()) {
|
|
// If it is not a simple branch, we are in a table somewhere.
|
|
if (!MI.isBranch() || MI.isIndirectBranch())
|
|
return false;
|
|
|
|
// If we are the operands of one of the branches, this is not a fall
|
|
// through. Note that targets with delay slots will usually bundle
|
|
// terminators with the delay slot instruction.
|
|
for (ConstMIBundleOperands OP(MI); OP.isValid(); ++OP) {
|
|
if (OP->isJTI())
|
|
return false;
|
|
if (OP->isMBB() && OP->getMBB() == MBB)
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
|
|
if (!S.usesMetadata())
|
|
return nullptr;
|
|
|
|
assert(!S.useStatepoints() && "statepoints do not currently support custom"
|
|
" stackmap formats, please see the documentation for a description of"
|
|
" the default format. If you really need a custom serialized format,"
|
|
" please file a bug");
|
|
|
|
gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
|
|
gcp_map_type::iterator GCPI = GCMap.find(&S);
|
|
if (GCPI != GCMap.end())
|
|
return GCPI->second.get();
|
|
|
|
auto Name = S.getName();
|
|
|
|
for (GCMetadataPrinterRegistry::iterator
|
|
I = GCMetadataPrinterRegistry::begin(),
|
|
E = GCMetadataPrinterRegistry::end(); I != E; ++I)
|
|
if (Name == I->getName()) {
|
|
std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
|
|
GMP->S = &S;
|
|
auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
|
|
return IterBool.first->second.get();
|
|
}
|
|
|
|
report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
|
|
}
|
|
|
|
/// Pin vtable to this file.
|
|
AsmPrinterHandler::~AsmPrinterHandler() = default;
|
|
|
|
void AsmPrinterHandler::markFunctionEnd() {}
|
|
|
|
// In the binary's "xray_instr_map" section, an array of these function entries
|
|
// describes each instrumentation point. When XRay patches your code, the index
|
|
// into this table will be given to your handler as a patch point identifier.
|
|
void AsmPrinter::XRayFunctionEntry::emit(int Bytes, MCStreamer *Out,
|
|
const MCSymbol *CurrentFnSym) const {
|
|
Out->EmitSymbolValue(Sled, Bytes);
|
|
Out->EmitSymbolValue(CurrentFnSym, Bytes);
|
|
auto Kind8 = static_cast<uint8_t>(Kind);
|
|
Out->EmitBytes(StringRef(reinterpret_cast<const char *>(&Kind8), 1));
|
|
Out->EmitBytes(
|
|
StringRef(reinterpret_cast<const char *>(&AlwaysInstrument), 1));
|
|
Out->EmitZeros(2 * Bytes - 2); // Pad the previous two entries
|
|
}
|
|
|
|
void AsmPrinter::emitXRayTable() {
|
|
if (Sleds.empty())
|
|
return;
|
|
|
|
auto PrevSection = OutStreamer->getCurrentSectionOnly();
|
|
auto Fn = MF->getFunction();
|
|
MCSection *InstMap = nullptr;
|
|
MCSection *FnSledIndex = nullptr;
|
|
if (MF->getSubtarget().getTargetTriple().isOSBinFormatELF()) {
|
|
if (Fn->hasComdat()) {
|
|
InstMap = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
|
|
ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
|
|
Fn->getComdat()->getName());
|
|
FnSledIndex = OutContext.getELFSection("xray_fn_idx", ELF::SHT_PROGBITS,
|
|
ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
|
|
Fn->getComdat()->getName());
|
|
} else {
|
|
InstMap = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
|
|
ELF::SHF_ALLOC);
|
|
FnSledIndex = OutContext.getELFSection("xray_fn_idx", ELF::SHT_PROGBITS,
|
|
ELF::SHF_ALLOC);
|
|
}
|
|
} else if (MF->getSubtarget().getTargetTriple().isOSBinFormatMachO()) {
|
|
InstMap = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
|
|
SectionKind::getReadOnlyWithRel());
|
|
FnSledIndex = OutContext.getMachOSection("__DATA", "xray_fn_idx", 0,
|
|
SectionKind::getReadOnlyWithRel());
|
|
} else {
|
|
llvm_unreachable("Unsupported target");
|
|
}
|
|
|
|
// Before we switch over, we force a reference to a label inside the
|
|
// xray_instr_map and xray_fn_idx sections. Since this function is always
|
|
// called just before the function's end, we assume that this is happening
|
|
// after the last return instruction. We also use the synthetic label in the
|
|
// xray_inster_map as a delimeter for the range of sleds for this function in
|
|
// the index.
|
|
auto WordSizeBytes = MAI->getCodePointerSize();
|
|
MCSymbol *SledsStart = OutContext.createTempSymbol("xray_synthetic_", true);
|
|
MCSymbol *IdxRef = OutContext.createTempSymbol("xray_fn_idx_synth_", true);
|
|
OutStreamer->EmitCodeAlignment(16);
|
|
OutStreamer->EmitSymbolValue(SledsStart, WordSizeBytes, false);
|
|
OutStreamer->EmitSymbolValue(IdxRef, WordSizeBytes, false);
|
|
|
|
// Now we switch to the instrumentation map section. Because this is done
|
|
// per-function, we are able to create an index entry that will represent the
|
|
// range of sleds associated with a function.
|
|
OutStreamer->SwitchSection(InstMap);
|
|
OutStreamer->EmitLabel(SledsStart);
|
|
for (const auto &Sled : Sleds)
|
|
Sled.emit(WordSizeBytes, OutStreamer.get(), CurrentFnSym);
|
|
MCSymbol *SledsEnd = OutContext.createTempSymbol("xray_synthetic_end", true);
|
|
OutStreamer->EmitLabel(SledsEnd);
|
|
|
|
// We then emit a single entry in the index per function. We use the symbols
|
|
// that bound the instrumentation map as the range for a specific function.
|
|
// Each entry here will be 2 * word size aligned, as we're writing down two
|
|
// pointers. This should work for both 32-bit and 64-bit platforms.
|
|
OutStreamer->SwitchSection(FnSledIndex);
|
|
OutStreamer->EmitCodeAlignment(2 * WordSizeBytes);
|
|
OutStreamer->EmitLabel(IdxRef);
|
|
OutStreamer->EmitSymbolValue(SledsStart, WordSizeBytes);
|
|
OutStreamer->EmitSymbolValue(SledsEnd, WordSizeBytes);
|
|
OutStreamer->SwitchSection(PrevSection);
|
|
Sleds.clear();
|
|
}
|
|
|
|
void AsmPrinter::recordSled(MCSymbol *Sled, const MachineInstr &MI,
|
|
SledKind Kind) {
|
|
auto Fn = MI.getParent()->getParent()->getFunction();
|
|
auto Attr = Fn->getFnAttribute("function-instrument");
|
|
bool LogArgs = Fn->hasFnAttribute("xray-log-args");
|
|
bool AlwaysInstrument =
|
|
Attr.isStringAttribute() && Attr.getValueAsString() == "xray-always";
|
|
if (Kind == SledKind::FUNCTION_ENTER && LogArgs)
|
|
Kind = SledKind::LOG_ARGS_ENTER;
|
|
Sleds.emplace_back(
|
|
XRayFunctionEntry{ Sled, CurrentFnSym, Kind, AlwaysInstrument, Fn });
|
|
}
|
|
|
|
uint16_t AsmPrinter::getDwarfVersion() const {
|
|
return OutStreamer->getContext().getDwarfVersion();
|
|
}
|
|
|
|
void AsmPrinter::setDwarfVersion(uint16_t Version) {
|
|
OutStreamer->getContext().setDwarfVersion(Version);
|
|
}
|