1 //===-- CodeGen/AsmPrinter/ARMException.cpp - ARM EHABI Exception Impl ----===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file contains support for writing DWARF exception info into asm files. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "DwarfException.h" 15 #include "llvm/ADT/SmallString.h" 16 #include "llvm/ADT/StringExtras.h" 17 #include "llvm/ADT/Twine.h" 18 #include "llvm/CodeGen/AsmPrinter.h" 19 #include "llvm/CodeGen/MachineFrameInfo.h" 20 #include "llvm/CodeGen/MachineFunction.h" 21 #include "llvm/CodeGen/MachineModuleInfo.h" 22 #include "llvm/IR/DataLayout.h" 23 #include "llvm/IR/Mangler.h" 24 #include "llvm/IR/Module.h" 25 #include "llvm/MC/MCAsmInfo.h" 26 #include "llvm/MC/MCContext.h" 27 #include "llvm/MC/MCExpr.h" 28 #include "llvm/MC/MCSection.h" 29 #include "llvm/MC/MCStreamer.h" 30 #include "llvm/MC/MCSymbol.h" 31 #include "llvm/Support/CommandLine.h" 32 #include "llvm/Support/Dwarf.h" 33 #include "llvm/Support/FormattedStream.h" 34 #include "llvm/Target/TargetFrameLowering.h" 35 #include "llvm/Target/TargetOptions.h" 36 #include "llvm/Target/TargetRegisterInfo.h" 37 using namespace llvm; 38 ARMException(AsmPrinter * A)39ARMException::ARMException(AsmPrinter *A) : DwarfCFIExceptionBase(A) {} 40 ~ARMException()41ARMException::~ARMException() {} 42 getTargetStreamer()43ARMTargetStreamer &ARMException::getTargetStreamer() { 44 MCTargetStreamer &TS = *Asm->OutStreamer->getTargetStreamer(); 45 return static_cast<ARMTargetStreamer &>(TS); 46 } 47 48 /// endModule - Emit all exception information that should come after the 49 /// content. endModule()50void ARMException::endModule() { 51 if (shouldEmitCFI) 52 Asm->OutStreamer->EmitCFISections(false, true); 53 } 54 beginFunction(const MachineFunction * MF)55void ARMException::beginFunction(const MachineFunction *MF) { 56 if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM) 57 getTargetStreamer().emitFnStart(); 58 // See if we need call frame info. 59 AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves(); 60 assert(MoveType != AsmPrinter::CFI_M_EH && 61 "non-EH CFI not yet supported in prologue with EHABI lowering"); 62 if (MoveType == AsmPrinter::CFI_M_Debug) { 63 shouldEmitCFI = true; 64 Asm->OutStreamer->EmitCFIStartProc(false); 65 } 66 } 67 68 /// endFunction - Gather and emit post-function exception information. 69 /// endFunction(const MachineFunction * MF)70void ARMException::endFunction(const MachineFunction *MF) { 71 ARMTargetStreamer &ATS = getTargetStreamer(); 72 const Function *F = MF->getFunction(); 73 const Function *Per = nullptr; 74 if (F->hasPersonalityFn()) 75 Per = dyn_cast<Function>(F->getPersonalityFn()->stripPointerCasts()); 76 bool forceEmitPersonality = 77 F->hasPersonalityFn() && !isNoOpWithoutInvoke(classifyEHPersonality(Per)) && 78 F->needsUnwindTableEntry(); 79 bool shouldEmitPersonality = forceEmitPersonality || 80 !MMI->getLandingPads().empty(); 81 if (!Asm->MF->getFunction()->needsUnwindTableEntry() && 82 !shouldEmitPersonality) 83 ATS.emitCantUnwind(); 84 else if (shouldEmitPersonality) { 85 // Emit references to personality. 86 if (Per) { 87 MCSymbol *PerSym = Asm->getSymbol(Per); 88 Asm->OutStreamer->EmitSymbolAttribute(PerSym, MCSA_Global); 89 ATS.emitPersonality(PerSym); 90 } 91 92 // Emit .handlerdata directive. 93 ATS.emitHandlerData(); 94 95 // Emit actual exception table 96 emitExceptionTable(); 97 } 98 99 if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM) 100 ATS.emitFnEnd(); 101 } 102 emitTypeInfos(unsigned TTypeEncoding)103void ARMException::emitTypeInfos(unsigned TTypeEncoding) { 104 const std::vector<const GlobalValue *> &TypeInfos = MMI->getTypeInfos(); 105 const std::vector<unsigned> &FilterIds = MMI->getFilterIds(); 106 107 bool VerboseAsm = Asm->OutStreamer->isVerboseAsm(); 108 109 int Entry = 0; 110 // Emit the Catch TypeInfos. 111 if (VerboseAsm && !TypeInfos.empty()) { 112 Asm->OutStreamer->AddComment(">> Catch TypeInfos <<"); 113 Asm->OutStreamer->AddBlankLine(); 114 Entry = TypeInfos.size(); 115 } 116 117 for (const GlobalValue *GV : reverse(TypeInfos)) { 118 if (VerboseAsm) 119 Asm->OutStreamer->AddComment("TypeInfo " + Twine(Entry--)); 120 Asm->EmitTTypeReference(GV, TTypeEncoding); 121 } 122 123 // Emit the Exception Specifications. 124 if (VerboseAsm && !FilterIds.empty()) { 125 Asm->OutStreamer->AddComment(">> Filter TypeInfos <<"); 126 Asm->OutStreamer->AddBlankLine(); 127 Entry = 0; 128 } 129 for (std::vector<unsigned>::const_iterator 130 I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) { 131 unsigned TypeID = *I; 132 if (VerboseAsm) { 133 --Entry; 134 if (TypeID != 0) 135 Asm->OutStreamer->AddComment("FilterInfo " + Twine(Entry)); 136 } 137 138 Asm->EmitTTypeReference((TypeID == 0 ? nullptr : TypeInfos[TypeID - 1]), 139 TTypeEncoding); 140 } 141 } 142