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1//===-- X86AsmPrinter.h - X86 implementation of AsmPrinter ------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLVM_LIB_TARGET_X86_X86ASMPRINTER_H10#define LLVM_LIB_TARGET_X86_X86ASMPRINTER_H11 12#include "llvm/CodeGen/AsmPrinter.h"13#include "llvm/CodeGen/FaultMaps.h"14#include "llvm/CodeGen/StackMaps.h"15 16// Implemented in X86MCInstLower.cpp17namespace {18 class X86MCInstLower;19}20 21namespace llvm {22class MCCodeEmitter;23class MCStreamer;24class X86Subtarget;25class TargetMachine;26 27class LLVM_LIBRARY_VISIBILITY X86AsmPrinter : public AsmPrinter {28public:29 static char ID;30 31private:32 const X86Subtarget *Subtarget = nullptr;33 FaultMaps FM;34 std::unique_ptr<MCCodeEmitter> CodeEmitter;35 bool EmitFPOData = false;36 bool ShouldEmitWeakSwiftAsyncExtendedFramePointerFlags = false;37 bool IndCSPrefix = false;38 bool EnableImportCallOptimization = false;39 40 enum ImportCallKind : unsigned {41 IMAGE_RETPOLINE_AMD64_IMPORT_BR = 0x02,42 IMAGE_RETPOLINE_AMD64_IMPORT_CALL = 0x03,43 IMAGE_RETPOLINE_AMD64_INDIR_BR = 0x04,44 IMAGE_RETPOLINE_AMD64_INDIR_CALL = 0x05,45 IMAGE_RETPOLINE_AMD64_INDIR_BR_REX = 0x06,46 IMAGE_RETPOLINE_AMD64_CFG_BR = 0x08,47 IMAGE_RETPOLINE_AMD64_CFG_CALL = 0x09,48 IMAGE_RETPOLINE_AMD64_CFG_BR_REX = 0x0A,49 IMAGE_RETPOLINE_AMD64_SWITCHTABLE_FIRST = 0x010,50 IMAGE_RETPOLINE_AMD64_SWITCHTABLE_LAST = 0x01F,51 };52 struct ImportCallInfo {53 MCSymbol *CalleeSymbol;54 ImportCallKind Kind;55 };56 DenseMap<MCSection *, std::vector<ImportCallInfo>>57 SectionToImportedFunctionCalls;58 59 // This utility class tracks the length of a stackmap instruction's 'shadow'.60 // It is used by the X86AsmPrinter to ensure that the stackmap shadow61 // invariants (i.e. no other stackmaps, patchpoints, or control flow within62 // the shadow) are met, while outputting a minimal number of NOPs for padding.63 //64 // To minimise the number of NOPs used, the shadow tracker counts the number65 // of instruction bytes output since the last stackmap. Only if there are too66 // few instruction bytes to cover the shadow are NOPs used for padding.67 class StackMapShadowTracker {68 public:69 void startFunction(MachineFunction &MF) {70 this->MF = &MF;71 }72 void count(const MCInst &Inst, const MCSubtargetInfo &STI,73 MCCodeEmitter *CodeEmitter);74 75 // Called to signal the start of a shadow of RequiredSize bytes.76 void reset(unsigned RequiredSize) {77 RequiredShadowSize = RequiredSize;78 CurrentShadowSize = 0;79 InShadow = true;80 }81 82 // Called before every stackmap/patchpoint, and at the end of basic blocks,83 // to emit any necessary padding-NOPs.84 void emitShadowPadding(MCStreamer &OutStreamer, const MCSubtargetInfo &STI);85 private:86 const MachineFunction *MF = nullptr;87 bool InShadow = false;88 89 // RequiredShadowSize holds the length of the shadow specified in the most90 // recently encountered STACKMAP instruction.91 // CurrentShadowSize counts the number of bytes encoded since the most92 // recently encountered STACKMAP, stopping when that number is greater than93 // or equal to RequiredShadowSize.94 unsigned RequiredShadowSize = 0, CurrentShadowSize = 0;95 };96 97 StackMapShadowTracker SMShadowTracker;98 99 // All instructions emitted by the X86AsmPrinter should use this helper100 // method.101 //102 // This helper function invokes the SMShadowTracker on each instruction before103 // outputting it to the OutStream. This allows the shadow tracker to minimise104 // the number of NOPs used for stackmap padding.105 void EmitAndCountInstruction(MCInst &Inst);106 void LowerSTACKMAP(const MachineInstr &MI);107 void LowerPATCHPOINT(const MachineInstr &MI, X86MCInstLower &MCIL);108 void LowerSTATEPOINT(const MachineInstr &MI, X86MCInstLower &MCIL);109 void LowerFAULTING_OP(const MachineInstr &MI, X86MCInstLower &MCIL);110 void LowerPATCHABLE_OP(const MachineInstr &MI, X86MCInstLower &MCIL);111 112 void LowerTlsAddr(X86MCInstLower &MCInstLowering, const MachineInstr &MI);113 114 // XRay-specific lowering for X86.115 void LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI,116 X86MCInstLower &MCIL);117 void LowerPATCHABLE_RET(const MachineInstr &MI, X86MCInstLower &MCIL);118 void LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI, X86MCInstLower &MCIL);119 void LowerPATCHABLE_EVENT_CALL(const MachineInstr &MI, X86MCInstLower &MCIL);120 void LowerPATCHABLE_TYPED_EVENT_CALL(const MachineInstr &MI,121 X86MCInstLower &MCIL);122 123 void LowerFENTRY_CALL(const MachineInstr &MI, X86MCInstLower &MCIL);124 125 // KCFI specific lowering for X86.126 uint32_t MaskKCFIType(uint32_t Value);127 void EmitKCFITypePadding(const MachineFunction &MF, bool HasType = true);128 void LowerKCFI_CHECK(const MachineInstr &MI);129 130 // Address sanitizer specific lowering for X86.131 void LowerASAN_CHECK_MEMACCESS(const MachineInstr &MI);132 133 // Choose between emitting .seh_ directives and .cv_fpo_ directives.134 void EmitSEHInstruction(const MachineInstr *MI);135 136 void PrintSymbolOperand(const MachineOperand &MO, raw_ostream &O) override;137 void PrintOperand(const MachineInstr *MI, unsigned OpNo, raw_ostream &O);138 void PrintModifiedOperand(const MachineInstr *MI, unsigned OpNo,139 raw_ostream &O, StringRef Modifier = {});140 void PrintPCRelImm(const MachineInstr *MI, unsigned OpNo, raw_ostream &O);141 void PrintLeaMemReference(const MachineInstr *MI, unsigned OpNo,142 raw_ostream &O, StringRef Modifier = {});143 void PrintMemReference(const MachineInstr *MI, unsigned OpNo, raw_ostream &O,144 StringRef Modifier = {});145 void PrintIntelMemReference(const MachineInstr *MI, unsigned OpNo,146 raw_ostream &O, StringRef Modifier = {});147 const MCSubtargetInfo *getIFuncMCSubtargetInfo() const override;148 void emitMachOIFuncStubBody(Module &M, const GlobalIFunc &GI,149 MCSymbol *LazyPointer) override;150 void emitMachOIFuncStubHelperBody(Module &M, const GlobalIFunc &GI,151 MCSymbol *LazyPointer) override;152 153 void emitCallInstruction(const llvm::MCInst &MCI);154 void maybeEmitNopAfterCallForWindowsEH(const MachineInstr *MI);155 156 // Emits a label to mark the next instruction as being relevant to Import Call157 // Optimization.158 void emitLabelAndRecordForImportCallOptimization(ImportCallKind Kind);159 160public:161 X86AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer);162 163 StringRef getPassName() const override {164 return "X86 Assembly Printer";165 }166 167 const X86Subtarget &getSubtarget() const { return *Subtarget; }168 169 void emitStartOfAsmFile(Module &M) override;170 171 void emitEndOfAsmFile(Module &M) override;172 173 void emitInstruction(const MachineInstr *MI) override;174 175 void emitBasicBlockEnd(const MachineBasicBlock &MBB) override;176 177 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,178 const char *ExtraCode, raw_ostream &O) override;179 bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,180 const char *ExtraCode, raw_ostream &O) override;181 182 bool doInitialization(Module &M) override {183 SMShadowTracker.reset(0);184 SM.reset();185 FM.reset();186 return AsmPrinter::doInitialization(M);187 }188 189 bool runOnMachineFunction(MachineFunction &MF) override;190 void emitFunctionBodyStart() override;191 void emitFunctionBodyEnd() override;192 void emitKCFITypeId(const MachineFunction &MF) override;193 194 bool shouldEmitWeakSwiftAsyncExtendedFramePointerFlags() const override {195 return ShouldEmitWeakSwiftAsyncExtendedFramePointerFlags;196 }197};198 199} // end namespace llvm200 201#endif202