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/Module.h" 24#include "llvm/MC/MCAsmInfo.h" 25#include "llvm/MC/MCContext.h" 26#include "llvm/MC/MCExpr.h" 27#include "llvm/MC/MCSection.h" 28#include "llvm/MC/MCStreamer.h" 29#include "llvm/MC/MCSymbol.h" 30#include "llvm/Support/CommandLine.h" 31#include "llvm/Support/Dwarf.h" 32#include "llvm/Support/FormattedStream.h" 33#include "llvm/Target/Mangler.h" 34#include "llvm/Target/TargetFrameLowering.h" 35#include "llvm/Target/TargetOptions.h" 36#include "llvm/Target/TargetRegisterInfo.h" 37using namespace llvm; 38 39static cl::opt<bool> 40EnableARMEHABIDescriptors("arm-enable-ehabi-descriptors", cl::Hidden, 41 cl::desc("Generate ARM EHABI tables with unwinding descriptors"), 42 cl::init(false)); 43 44 45ARMException::ARMException(AsmPrinter *A) 46 : DwarfException(A) {} 47 48ARMException::~ARMException() {} 49 50void ARMException::EndModule() { 51} 52 53/// BeginFunction - Gather pre-function exception information. Assumes it's 54/// being emitted immediately after the function entry point. 55void ARMException::BeginFunction(const MachineFunction *MF) { 56 Asm->OutStreamer.EmitFnStart(); 57 if (Asm->MF->getFunction()->needsUnwindTableEntry()) 58 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin", 59 Asm->getFunctionNumber())); 60} 61 62/// EndFunction - Gather and emit post-function exception information. 63/// 64void ARMException::EndFunction() { 65 if (!Asm->MF->getFunction()->needsUnwindTableEntry()) 66 Asm->OutStreamer.EmitCantUnwind(); 67 else { 68 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end", 69 Asm->getFunctionNumber())); 70 71 if (EnableARMEHABIDescriptors) { 72 // Map all labels and get rid of any dead landing pads. 73 MMI->TidyLandingPads(); 74 75 if (!MMI->getLandingPads().empty()) { 76 // Emit references to personality. 77 if (const Function * Personality = 78 MMI->getPersonalities()[MMI->getPersonalityIndex()]) { 79 MCSymbol *PerSym = Asm->Mang->getSymbol(Personality); 80 Asm->OutStreamer.EmitSymbolAttribute(PerSym, MCSA_Global); 81 Asm->OutStreamer.EmitPersonality(PerSym); 82 } 83 84 // Emit .handlerdata directive. 85 Asm->OutStreamer.EmitHandlerData(); 86 87 // Emit actual exception table 88 EmitExceptionTable(); 89 } 90 } 91 } 92 93 Asm->OutStreamer.EmitFnEnd(); 94} 95 96void ARMException::EmitTypeInfos(unsigned TTypeEncoding) { 97 const std::vector<const GlobalVariable *> &TypeInfos = MMI->getTypeInfos(); 98 const std::vector<unsigned> &FilterIds = MMI->getFilterIds(); 99 100 bool VerboseAsm = Asm->OutStreamer.isVerboseAsm(); 101 102 int Entry = 0; 103 // Emit the Catch TypeInfos. 104 if (VerboseAsm && !TypeInfos.empty()) { 105 Asm->OutStreamer.AddComment(">> Catch TypeInfos <<"); 106 Asm->OutStreamer.AddBlankLine(); 107 Entry = TypeInfos.size(); 108 } 109 110 for (std::vector<const GlobalVariable *>::const_reverse_iterator 111 I = TypeInfos.rbegin(), E = TypeInfos.rend(); I != E; ++I) { 112 const GlobalVariable *GV = *I; 113 if (VerboseAsm) 114 Asm->OutStreamer.AddComment("TypeInfo " + Twine(Entry--)); 115 Asm->EmitTTypeReference(GV, TTypeEncoding); 116 } 117 118 // Emit the Exception Specifications. 119 if (VerboseAsm && !FilterIds.empty()) { 120 Asm->OutStreamer.AddComment(">> Filter TypeInfos <<"); 121 Asm->OutStreamer.AddBlankLine(); 122 Entry = 0; 123 } 124 for (std::vector<unsigned>::const_iterator 125 I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) { 126 unsigned TypeID = *I; 127 if (VerboseAsm) { 128 --Entry; 129 if (TypeID != 0) 130 Asm->OutStreamer.AddComment("FilterInfo " + Twine(Entry)); 131 } 132 133 Asm->EmitTTypeReference((TypeID == 0 ? 0 : TypeInfos[TypeID - 1]), 134 TTypeEncoding); 135 } 136} 137