133 lines · cpp
1//===-- CodeGen/AsmPrinter/ARMException.cpp - ARM EHABI Exception Impl ----===//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// This file contains support for writing DWARF exception info into asm files.10//11//===----------------------------------------------------------------------===//12 13#include "DwarfException.h"14#include "llvm/ADT/Twine.h"15#include "llvm/CodeGen/AsmPrinter.h"16#include "llvm/CodeGen/MachineFunction.h"17#include "llvm/IR/Function.h"18#include "llvm/MC/MCAsmInfo.h"19#include "llvm/MC/MCStreamer.h"20using namespace llvm;21 22ARMException::ARMException(AsmPrinter *A) : EHStreamer(A) {}23 24ARMException::~ARMException() = default;25 26ARMTargetStreamer &ARMException::getTargetStreamer() {27 MCTargetStreamer &TS = *Asm->OutStreamer->getTargetStreamer();28 return static_cast<ARMTargetStreamer &>(TS);29}30 31void ARMException::beginFunction(const MachineFunction *MF) {32 if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)33 getTargetStreamer().emitFnStart();34 // See if we need call frame info.35 AsmPrinter::CFISection CFISecType = Asm->getFunctionCFISectionType(*MF);36 assert(CFISecType != AsmPrinter::CFISection::EH &&37 "non-EH CFI not yet supported in prologue with EHABI lowering");38 39 if (CFISecType == AsmPrinter::CFISection::Debug) {40 if (!hasEmittedCFISections) {41 if (Asm->getModuleCFISectionType() == AsmPrinter::CFISection::Debug)42 Asm->OutStreamer->emitCFISections(false, true, false);43 hasEmittedCFISections = true;44 }45 46 shouldEmitCFI = true;47 Asm->OutStreamer->emitCFIStartProc(false);48 }49}50 51void ARMException::markFunctionEnd() {52 if (shouldEmitCFI)53 Asm->OutStreamer->emitCFIEndProc();54}55 56/// endFunction - Gather and emit post-function exception information.57///58void ARMException::endFunction(const MachineFunction *MF) {59 ARMTargetStreamer &ATS = getTargetStreamer();60 const Function &F = MF->getFunction();61 const Function *Per = nullptr;62 if (F.hasPersonalityFn())63 Per = dyn_cast<Function>(F.getPersonalityFn()->stripPointerCasts());64 bool forceEmitPersonality =65 F.hasPersonalityFn() && !isNoOpWithoutInvoke(classifyEHPersonality(Per)) &&66 F.needsUnwindTableEntry();67 bool shouldEmitPersonality = forceEmitPersonality ||68 !MF->getLandingPads().empty();69 if (!Asm->MF->getFunction().needsUnwindTableEntry() &&70 !shouldEmitPersonality)71 ATS.emitCantUnwind();72 else if (shouldEmitPersonality) {73 // Emit references to personality.74 if (Per) {75 MCSymbol *PerSym = Asm->getSymbol(Per);76 ATS.emitPersonality(PerSym);77 }78 79 // Emit .handlerdata directive.80 ATS.emitHandlerData();81 82 // Emit actual exception table83 emitExceptionTable();84 }85 86 if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)87 ATS.emitFnEnd();88}89 90void ARMException::emitTypeInfos(unsigned TTypeEncoding,91 MCSymbol *TTBaseLabel) {92 const MachineFunction *MF = Asm->MF;93 const std::vector<const GlobalValue *> &TypeInfos = MF->getTypeInfos();94 const std::vector<unsigned> &FilterIds = MF->getFilterIds();95 96 bool VerboseAsm = Asm->OutStreamer->isVerboseAsm();97 98 int Entry = 0;99 // Emit the Catch TypeInfos.100 if (VerboseAsm && !TypeInfos.empty()) {101 Asm->OutStreamer->AddComment(">> Catch TypeInfos <<");102 Asm->OutStreamer->addBlankLine();103 Entry = TypeInfos.size();104 }105 106 for (const GlobalValue *GV : reverse(TypeInfos)) {107 if (VerboseAsm)108 Asm->OutStreamer->AddComment("TypeInfo " + Twine(Entry--));109 Asm->emitTTypeReference(GV, TTypeEncoding);110 }111 112 Asm->OutStreamer->emitLabel(TTBaseLabel);113 114 // Emit the Exception Specifications.115 if (VerboseAsm && !FilterIds.empty()) {116 Asm->OutStreamer->AddComment(">> Filter TypeInfos <<");117 Asm->OutStreamer->addBlankLine();118 Entry = 0;119 }120 for (std::vector<unsigned>::const_iterator121 I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) {122 unsigned TypeID = *I;123 if (VerboseAsm) {124 --Entry;125 if (TypeID != 0)126 Asm->OutStreamer->AddComment("FilterInfo " + Twine(Entry));127 }128 129 Asm->emitTTypeReference((TypeID == 0 ? nullptr : TypeInfos[TypeID - 1]),130 TTypeEncoding);131 }132}133