1 //===-- llvm/CodeGen/MachineModuleInfo.cpp ----------------------*- C++ -*-===// 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 #include "llvm/CodeGen/MachineModuleInfo.h" 11 12 #include "llvm/Constants.h" 13 #include "llvm/DerivedTypes.h" 14 #include "llvm/GlobalVariable.h" 15 #include "llvm/Intrinsics.h" 16 #include "llvm/Instructions.h" 17 #include "llvm/Module.h" 18 #include "llvm/Analysis/ValueTracking.h" 19 #include "llvm/CodeGen/MachineFunctionPass.h" 20 #include "llvm/CodeGen/MachineFunction.h" 21 #include "llvm/CodeGen/Passes.h" 22 #include "llvm/Target/TargetInstrInfo.h" 23 #include "llvm/Target/TargetMachine.h" 24 #include "llvm/Target/TargetOptions.h" 25 #include "llvm/MC/MCAsmInfo.h" 26 #include "llvm/MC/MCSymbol.h" 27 #include "llvm/Support/Dwarf.h" 28 #include "llvm/Support/ErrorHandling.h" 29 using namespace llvm; 30 using namespace llvm::dwarf; 31 32 // Handle the Pass registration stuff necessary to use TargetData's. 33 static RegisterPass<MachineModuleInfo> 34 X("machinemoduleinfo", "Machine Module Information"); 35 char MachineModuleInfo::ID = 0; 36 37 // Out of line virtual method. 38 MachineModuleInfoImpl::~MachineModuleInfoImpl() {} 39 40 //===----------------------------------------------------------------------===// 41 42 MachineModuleInfo::MachineModuleInfo(const MCAsmInfo &MAI) 43 : ImmutablePass(&ID), Context(MAI), 44 ObjFileMMI(0), NextLabelIDToReturn(1), 45 CurCallSite(0), CallsEHReturn(0), CallsUnwindInit(0), DbgInfoAvailable(false){ 46 // Always emit some info, by default "no personality" info. 47 Personalities.push_back(NULL); 48 } 49 50 MachineModuleInfo::MachineModuleInfo() 51 : ImmutablePass(&ID), Context(*(MCAsmInfo*)0) { 52 assert(0 && "This MachineModuleInfo constructor should never be called, MMI " 53 "should always be explicitly constructed by LLVMTargetMachine"); 54 abort(); 55 } 56 57 MachineModuleInfo::~MachineModuleInfo() { 58 delete ObjFileMMI; 59 } 60 61 /// doInitialization - Initialize the state for a new module. 62 /// 63 bool MachineModuleInfo::doInitialization() { 64 return false; 65 } 66 67 /// doFinalization - Tear down the state after completion of a module. 68 /// 69 bool MachineModuleInfo::doFinalization() { 70 return false; 71 } 72 73 /// getLabelSym - Turn a label ID into a symbol. 74 MCSymbol *MachineModuleInfo::getLabelSym(unsigned ID) { 75 return Context.GetOrCreateTemporarySymbol 76 (Twine(Context.getAsmInfo().getPrivateGlobalPrefix()) + "Label" +Twine(ID)); 77 } 78 79 /// EndFunction - Discard function meta information. 80 /// 81 void MachineModuleInfo::EndFunction() { 82 // Clean up frame info. 83 FrameMoves.clear(); 84 85 // Clean up exception info. 86 LandingPads.clear(); 87 CallSiteMap.clear(); 88 TypeInfos.clear(); 89 FilterIds.clear(); 90 FilterEnds.clear(); 91 CallsEHReturn = 0; 92 CallsUnwindInit = 0; 93 VariableDbgInfo.clear(); 94 } 95 96 /// AnalyzeModule - Scan the module for global debug information. 97 /// 98 void MachineModuleInfo::AnalyzeModule(Module &M) { 99 // Insert functions in the llvm.used array (but not llvm.compiler.used) into 100 // UsedFunctions. 101 GlobalVariable *GV = M.getGlobalVariable("llvm.used"); 102 if (!GV || !GV->hasInitializer()) return; 103 104 // Should be an array of 'i8*'. 105 ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer()); 106 if (InitList == 0) return; 107 108 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 109 if (Function *F = 110 dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts())) 111 UsedFunctions.insert(F); 112 } 113 114 //===-EH-------------------------------------------------------------------===// 115 116 /// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the 117 /// specified MachineBasicBlock. 118 LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo 119 (MachineBasicBlock *LandingPad) { 120 unsigned N = LandingPads.size(); 121 for (unsigned i = 0; i < N; ++i) { 122 LandingPadInfo &LP = LandingPads[i]; 123 if (LP.LandingPadBlock == LandingPad) 124 return LP; 125 } 126 127 LandingPads.push_back(LandingPadInfo(LandingPad)); 128 return LandingPads[N]; 129 } 130 131 /// addInvoke - Provide the begin and end labels of an invoke style call and 132 /// associate it with a try landing pad block. 133 void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad, 134 MCSymbol *BeginLabel, MCSymbol *EndLabel) { 135 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 136 LP.BeginLabels.push_back(BeginLabel); 137 LP.EndLabels.push_back(EndLabel); 138 } 139 140 /// addLandingPad - Provide the label of a try LandingPad block. 141 /// 142 unsigned MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) { 143 unsigned LandingPadID = NextLabelID(); 144 MCSymbol *LandingPadLabel = getLabelSym(LandingPadID); 145 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 146 LP.LandingPadLabel = LandingPadLabel; 147 return LandingPadID; 148 } 149 150 /// addPersonality - Provide the personality function for the exception 151 /// information. 152 void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad, 153 Function *Personality) { 154 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 155 LP.Personality = Personality; 156 157 for (unsigned i = 0; i < Personalities.size(); ++i) 158 if (Personalities[i] == Personality) 159 return; 160 161 // If this is the first personality we're adding go 162 // ahead and add it at the beginning. 163 if (Personalities[0] == NULL) 164 Personalities[0] = Personality; 165 else 166 Personalities.push_back(Personality); 167 } 168 169 /// addCatchTypeInfo - Provide the catch typeinfo for a landing pad. 170 /// 171 void MachineModuleInfo::addCatchTypeInfo(MachineBasicBlock *LandingPad, 172 std::vector<GlobalVariable *> &TyInfo) { 173 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 174 for (unsigned N = TyInfo.size(); N; --N) 175 LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1])); 176 } 177 178 /// addFilterTypeInfo - Provide the filter typeinfo for a landing pad. 179 /// 180 void MachineModuleInfo::addFilterTypeInfo(MachineBasicBlock *LandingPad, 181 std::vector<GlobalVariable *> &TyInfo) { 182 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 183 std::vector<unsigned> IdsInFilter(TyInfo.size()); 184 for (unsigned I = 0, E = TyInfo.size(); I != E; ++I) 185 IdsInFilter[I] = getTypeIDFor(TyInfo[I]); 186 LP.TypeIds.push_back(getFilterIDFor(IdsInFilter)); 187 } 188 189 /// addCleanup - Add a cleanup action for a landing pad. 190 /// 191 void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) { 192 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 193 LP.TypeIds.push_back(0); 194 } 195 196 /// TidyLandingPads - Remap landing pad labels and remove any deleted landing 197 /// pads. 198 void MachineModuleInfo::TidyLandingPads() { 199 for (unsigned i = 0; i != LandingPads.size(); ) { 200 LandingPadInfo &LandingPad = LandingPads[i]; 201 if (LandingPad.LandingPadLabel && !LandingPad.LandingPadLabel->isDefined()) 202 LandingPad.LandingPadLabel = 0; 203 204 // Special case: we *should* emit LPs with null LP MBB. This indicates 205 // "nounwind" case. 206 if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) { 207 LandingPads.erase(LandingPads.begin() + i); 208 continue; 209 } 210 211 for (unsigned j = 0, e = LandingPads[i].BeginLabels.size(); j != e; ++j) { 212 MCSymbol *BeginLabel = LandingPad.BeginLabels[j]; 213 MCSymbol *EndLabel = LandingPad.EndLabels[j]; 214 if (BeginLabel->isDefined() && EndLabel->isDefined()) continue; 215 216 LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j); 217 LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j); 218 --j, --e; 219 } 220 221 // Remove landing pads with no try-ranges. 222 if (LandingPads[i].BeginLabels.empty()) { 223 LandingPads.erase(LandingPads.begin() + i); 224 continue; 225 } 226 227 // If there is no landing pad, ensure that the list of typeids is empty. 228 // If the only typeid is a cleanup, this is the same as having no typeids. 229 if (!LandingPad.LandingPadBlock || 230 (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0])) 231 LandingPad.TypeIds.clear(); 232 ++i; 233 } 234 } 235 236 /// getTypeIDFor - Return the type id for the specified typeinfo. This is 237 /// function wide. 238 unsigned MachineModuleInfo::getTypeIDFor(GlobalVariable *TI) { 239 for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i) 240 if (TypeInfos[i] == TI) return i + 1; 241 242 TypeInfos.push_back(TI); 243 return TypeInfos.size(); 244 } 245 246 /// getFilterIDFor - Return the filter id for the specified typeinfos. This is 247 /// function wide. 248 int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) { 249 // If the new filter coincides with the tail of an existing filter, then 250 // re-use the existing filter. Folding filters more than this requires 251 // re-ordering filters and/or their elements - probably not worth it. 252 for (std::vector<unsigned>::iterator I = FilterEnds.begin(), 253 E = FilterEnds.end(); I != E; ++I) { 254 unsigned i = *I, j = TyIds.size(); 255 256 while (i && j) 257 if (FilterIds[--i] != TyIds[--j]) 258 goto try_next; 259 260 if (!j) 261 // The new filter coincides with range [i, end) of the existing filter. 262 return -(1 + i); 263 264 try_next:; 265 } 266 267 // Add the new filter. 268 int FilterID = -(1 + FilterIds.size()); 269 FilterIds.reserve(FilterIds.size() + TyIds.size() + 1); 270 for (unsigned I = 0, N = TyIds.size(); I != N; ++I) 271 FilterIds.push_back(TyIds[I]); 272 FilterEnds.push_back(FilterIds.size()); 273 FilterIds.push_back(0); // terminator 274 return FilterID; 275 } 276 277 /// getPersonality - Return the personality function for the current function. 278 Function *MachineModuleInfo::getPersonality() const { 279 // FIXME: Until PR1414 will be fixed, we're using 1 personality function per 280 // function 281 return !LandingPads.empty() ? LandingPads[0].Personality : NULL; 282 } 283 284 /// getPersonalityIndex - Return unique index for current personality 285 /// function. NULL/first personality function should always get zero index. 286 unsigned MachineModuleInfo::getPersonalityIndex() const { 287 const Function* Personality = NULL; 288 289 // Scan landing pads. If there is at least one non-NULL personality - use it. 290 for (unsigned i = 0; i != LandingPads.size(); ++i) 291 if (LandingPads[i].Personality) { 292 Personality = LandingPads[i].Personality; 293 break; 294 } 295 296 for (unsigned i = 0; i < Personalities.size(); ++i) { 297 if (Personalities[i] == Personality) 298 return i; 299 } 300 301 // This will happen if the current personality function is 302 // in the zero index. 303 return 0; 304 } 305 306