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) 40 : EHStreamer(A), shouldEmitCFI(false) {} 41 ~ARMException()42ARMException::~ARMException() {} 43 getTargetStreamer()44ARMTargetStreamer &ARMException::getTargetStreamer() { 45 MCTargetStreamer &TS = *Asm->OutStreamer.getTargetStreamer(); 46 return static_cast<ARMTargetStreamer &>(TS); 47 } 48 49 /// endModule - Emit all exception information that should come after the 50 /// content. endModule()51void ARMException::endModule() { 52 if (shouldEmitCFI) 53 Asm->OutStreamer.EmitCFISections(false, true); 54 } 55 56 /// beginFunction - Gather pre-function exception information. Assumes it's 57 /// being emitted immediately after the function entry point. beginFunction(const MachineFunction * MF)58void ARMException::beginFunction(const MachineFunction *MF) { 59 if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM) 60 getTargetStreamer().emitFnStart(); 61 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin", 62 Asm->getFunctionNumber())); 63 // See if we need call frame info. 64 AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves(); 65 assert(MoveType != AsmPrinter::CFI_M_EH && 66 "non-EH CFI not yet supported in prologue with EHABI lowering"); 67 if (MoveType == AsmPrinter::CFI_M_Debug) { 68 shouldEmitCFI = true; 69 Asm->OutStreamer.EmitCFIStartProc(false); 70 } 71 } 72 73 /// endFunction - Gather and emit post-function exception information. 74 /// endFunction(const MachineFunction *)75void ARMException::endFunction(const MachineFunction *) { 76 if (shouldEmitCFI) 77 Asm->OutStreamer.EmitCFIEndProc(); 78 79 // Map all labels and get rid of any dead landing pads. 80 MMI->TidyLandingPads(); 81 82 ARMTargetStreamer &ATS = getTargetStreamer(); 83 if (!Asm->MF->getFunction()->needsUnwindTableEntry() && 84 MMI->getLandingPads().empty()) 85 ATS.emitCantUnwind(); 86 else { 87 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end", 88 Asm->getFunctionNumber())); 89 if (!MMI->getLandingPads().empty()) { 90 // Emit references to personality. 91 if (const Function * Personality = 92 MMI->getPersonalities()[MMI->getPersonalityIndex()]) { 93 MCSymbol *PerSym = Asm->getSymbol(Personality); 94 Asm->OutStreamer.EmitSymbolAttribute(PerSym, MCSA_Global); 95 ATS.emitPersonality(PerSym); 96 } 97 98 // Emit .handlerdata directive. 99 ATS.emitHandlerData(); 100 101 // Emit actual exception table 102 emitExceptionTable(); 103 } 104 } 105 106 if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM) 107 ATS.emitFnEnd(); 108 } 109 emitTypeInfos(unsigned TTypeEncoding)110void ARMException::emitTypeInfos(unsigned TTypeEncoding) { 111 const std::vector<const GlobalVariable *> &TypeInfos = MMI->getTypeInfos(); 112 const std::vector<unsigned> &FilterIds = MMI->getFilterIds(); 113 114 bool VerboseAsm = Asm->OutStreamer.isVerboseAsm(); 115 116 int Entry = 0; 117 // Emit the Catch TypeInfos. 118 if (VerboseAsm && !TypeInfos.empty()) { 119 Asm->OutStreamer.AddComment(">> Catch TypeInfos <<"); 120 Asm->OutStreamer.AddBlankLine(); 121 Entry = TypeInfos.size(); 122 } 123 124 for (std::vector<const GlobalVariable *>::const_reverse_iterator 125 I = TypeInfos.rbegin(), E = TypeInfos.rend(); I != E; ++I) { 126 const GlobalVariable *GV = *I; 127 if (VerboseAsm) 128 Asm->OutStreamer.AddComment("TypeInfo " + Twine(Entry--)); 129 Asm->EmitTTypeReference(GV, TTypeEncoding); 130 } 131 132 // Emit the Exception Specifications. 133 if (VerboseAsm && !FilterIds.empty()) { 134 Asm->OutStreamer.AddComment(">> Filter TypeInfos <<"); 135 Asm->OutStreamer.AddBlankLine(); 136 Entry = 0; 137 } 138 for (std::vector<unsigned>::const_iterator 139 I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) { 140 unsigned TypeID = *I; 141 if (VerboseAsm) { 142 --Entry; 143 if (TypeID != 0) 144 Asm->OutStreamer.AddComment("FilterInfo " + Twine(Entry)); 145 } 146 147 Asm->EmitTTypeReference((TypeID == 0 ? nullptr : TypeInfos[TypeID - 1]), 148 TTypeEncoding); 149 } 150 } 151