//===-- llvm/CodeGen/MachineModuleInfo.cpp ----------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/MachineModuleInfo.h" #include "llvm/ADT/PointerUnion.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineFunctionPass.h" #include "llvm/CodeGen/Passes.h" #include "llvm/IR/Constants.h" #include "llvm/IR/DerivedTypes.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/Module.h" #include "llvm/MC/MCObjectFileInfo.h" #include "llvm/MC/MCSymbol.h" #include "llvm/Support/Dwarf.h" #include "llvm/Support/ErrorHandling.h" using namespace llvm; using namespace llvm::dwarf; // Handle the Pass registration stuff necessary to use DataLayout's. INITIALIZE_PASS(MachineModuleInfo, "machinemoduleinfo", "Machine Module Information", false, false) char MachineModuleInfo::ID = 0; // Out of line virtual method. MachineModuleInfoImpl::~MachineModuleInfoImpl() {} namespace llvm { class MMIAddrLabelMapCallbackPtr : CallbackVH { MMIAddrLabelMap *Map; public: MMIAddrLabelMapCallbackPtr() : Map(nullptr) {} MMIAddrLabelMapCallbackPtr(Value *V) : CallbackVH(V), Map(nullptr) {} void setPtr(BasicBlock *BB) { ValueHandleBase::operator=(BB); } void setMap(MMIAddrLabelMap *map) { Map = map; } void deleted() override; void allUsesReplacedWith(Value *V2) override; }; class MMIAddrLabelMap { MCContext &Context; struct AddrLabelSymEntry { /// Symbols - The symbols for the label. This is a pointer union that is /// either one symbol (the common case) or a list of symbols. PointerUnion<MCSymbol *, std::vector<MCSymbol*>*> Symbols; Function *Fn; // The containing function of the BasicBlock. unsigned Index; // The index in BBCallbacks for the BasicBlock. }; DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry> AddrLabelSymbols; /// BBCallbacks - Callbacks for the BasicBlock's that we have entries for. We /// use this so we get notified if a block is deleted or RAUWd. std::vector<MMIAddrLabelMapCallbackPtr> BBCallbacks; /// DeletedAddrLabelsNeedingEmission - This is a per-function list of symbols /// whose corresponding BasicBlock got deleted. These symbols need to be /// emitted at some point in the file, so AsmPrinter emits them after the /// function body. DenseMap<AssertingVH<Function>, std::vector<MCSymbol*> > DeletedAddrLabelsNeedingEmission; public: MMIAddrLabelMap(MCContext &context) : Context(context) {} ~MMIAddrLabelMap() { assert(DeletedAddrLabelsNeedingEmission.empty() && "Some labels for deleted blocks never got emitted"); // Deallocate any of the 'list of symbols' case. for (DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry>::iterator I = AddrLabelSymbols.begin(), E = AddrLabelSymbols.end(); I != E; ++I) if (I->second.Symbols.is<std::vector<MCSymbol*>*>()) delete I->second.Symbols.get<std::vector<MCSymbol*>*>(); } MCSymbol *getAddrLabelSymbol(BasicBlock *BB); std::vector<MCSymbol*> getAddrLabelSymbolToEmit(BasicBlock *BB); void takeDeletedSymbolsForFunction(Function *F, std::vector<MCSymbol*> &Result); void UpdateForDeletedBlock(BasicBlock *BB); void UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New); }; } MCSymbol *MMIAddrLabelMap::getAddrLabelSymbol(BasicBlock *BB) { assert(BB->hasAddressTaken() && "Shouldn't get label for block without address taken"); AddrLabelSymEntry &Entry = AddrLabelSymbols[BB]; // If we already had an entry for this block, just return it. if (!Entry.Symbols.isNull()) { assert(BB->getParent() == Entry.Fn && "Parent changed"); if (Entry.Symbols.is<MCSymbol*>()) return Entry.Symbols.get<MCSymbol*>(); return (*Entry.Symbols.get<std::vector<MCSymbol*>*>())[0]; } // Otherwise, this is a new entry, create a new symbol for it and add an // entry to BBCallbacks so we can be notified if the BB is deleted or RAUWd. BBCallbacks.push_back(BB); BBCallbacks.back().setMap(this); Entry.Index = BBCallbacks.size()-1; Entry.Fn = BB->getParent(); MCSymbol *Result = Context.CreateTempSymbol(); Entry.Symbols = Result; return Result; } std::vector<MCSymbol*> MMIAddrLabelMap::getAddrLabelSymbolToEmit(BasicBlock *BB) { assert(BB->hasAddressTaken() && "Shouldn't get label for block without address taken"); AddrLabelSymEntry &Entry = AddrLabelSymbols[BB]; std::vector<MCSymbol*> Result; // If we already had an entry for this block, just return it. if (Entry.Symbols.isNull()) Result.push_back(getAddrLabelSymbol(BB)); else if (MCSymbol *Sym = Entry.Symbols.dyn_cast<MCSymbol*>()) Result.push_back(Sym); else Result = *Entry.Symbols.get<std::vector<MCSymbol*>*>(); return Result; } /// takeDeletedSymbolsForFunction - If we have any deleted symbols for F, return /// them. void MMIAddrLabelMap:: takeDeletedSymbolsForFunction(Function *F, std::vector<MCSymbol*> &Result) { DenseMap<AssertingVH<Function>, std::vector<MCSymbol*> >::iterator I = DeletedAddrLabelsNeedingEmission.find(F); // If there are no entries for the function, just return. if (I == DeletedAddrLabelsNeedingEmission.end()) return; // Otherwise, take the list. std::swap(Result, I->second); DeletedAddrLabelsNeedingEmission.erase(I); } void MMIAddrLabelMap::UpdateForDeletedBlock(BasicBlock *BB) { // If the block got deleted, there is no need for the symbol. If the symbol // was already emitted, we can just forget about it, otherwise we need to // queue it up for later emission when the function is output. AddrLabelSymEntry Entry = AddrLabelSymbols[BB]; AddrLabelSymbols.erase(BB); assert(!Entry.Symbols.isNull() && "Didn't have a symbol, why a callback?"); BBCallbacks[Entry.Index] = nullptr; // Clear the callback. assert((BB->getParent() == nullptr || BB->getParent() == Entry.Fn) && "Block/parent mismatch"); // Handle both the single and the multiple symbols cases. if (MCSymbol *Sym = Entry.Symbols.dyn_cast<MCSymbol*>()) { if (Sym->isDefined()) return; // If the block is not yet defined, we need to emit it at the end of the // function. Add the symbol to the DeletedAddrLabelsNeedingEmission list // for the containing Function. Since the block is being deleted, its // parent may already be removed, we have to get the function from 'Entry'. DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym); } else { std::vector<MCSymbol*> *Syms = Entry.Symbols.get<std::vector<MCSymbol*>*>(); for (unsigned i = 0, e = Syms->size(); i != e; ++i) { MCSymbol *Sym = (*Syms)[i]; if (Sym->isDefined()) continue; // Ignore already emitted labels. // If the block is not yet defined, we need to emit it at the end of the // function. Add the symbol to the DeletedAddrLabelsNeedingEmission list // for the containing Function. Since the block is being deleted, its // parent may already be removed, we have to get the function from // 'Entry'. DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym); } // The entry is deleted, free the memory associated with the symbol list. delete Syms; } } void MMIAddrLabelMap::UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New) { // Get the entry for the RAUW'd block and remove it from our map. AddrLabelSymEntry OldEntry = AddrLabelSymbols[Old]; AddrLabelSymbols.erase(Old); assert(!OldEntry.Symbols.isNull() && "Didn't have a symbol, why a callback?"); AddrLabelSymEntry &NewEntry = AddrLabelSymbols[New]; // If New is not address taken, just move our symbol over to it. if (NewEntry.Symbols.isNull()) { BBCallbacks[OldEntry.Index].setPtr(New); // Update the callback. NewEntry = OldEntry; // Set New's entry. return; } BBCallbacks[OldEntry.Index] = nullptr; // Update the callback. // Otherwise, we need to add the old symbol to the new block's set. If it is // just a single entry, upgrade it to a symbol list. if (MCSymbol *PrevSym = NewEntry.Symbols.dyn_cast<MCSymbol*>()) { std::vector<MCSymbol*> *SymList = new std::vector<MCSymbol*>(); SymList->push_back(PrevSym); NewEntry.Symbols = SymList; } std::vector<MCSymbol*> *SymList = NewEntry.Symbols.get<std::vector<MCSymbol*>*>(); // If the old entry was a single symbol, add it. if (MCSymbol *Sym = OldEntry.Symbols.dyn_cast<MCSymbol*>()) { SymList->push_back(Sym); return; } // Otherwise, concatenate the list. std::vector<MCSymbol*> *Syms =OldEntry.Symbols.get<std::vector<MCSymbol*>*>(); SymList->insert(SymList->end(), Syms->begin(), Syms->end()); delete Syms; } void MMIAddrLabelMapCallbackPtr::deleted() { Map->UpdateForDeletedBlock(cast<BasicBlock>(getValPtr())); } void MMIAddrLabelMapCallbackPtr::allUsesReplacedWith(Value *V2) { Map->UpdateForRAUWBlock(cast<BasicBlock>(getValPtr()), cast<BasicBlock>(V2)); } //===----------------------------------------------------------------------===// MachineModuleInfo::MachineModuleInfo(const MCAsmInfo &MAI, const MCRegisterInfo &MRI, const MCObjectFileInfo *MOFI) : ImmutablePass(ID), Context(&MAI, &MRI, MOFI, nullptr, false) { initializeMachineModuleInfoPass(*PassRegistry::getPassRegistry()); } MachineModuleInfo::MachineModuleInfo() : ImmutablePass(ID), Context(nullptr, nullptr, nullptr) { llvm_unreachable("This MachineModuleInfo constructor should never be called, " "MMI should always be explicitly constructed by " "LLVMTargetMachine"); } MachineModuleInfo::~MachineModuleInfo() { } bool MachineModuleInfo::doInitialization(Module &M) { ObjFileMMI = nullptr; CompactUnwindEncoding = 0; CurCallSite = 0; CallsEHReturn = 0; CallsUnwindInit = 0; DbgInfoAvailable = UsesVAFloatArgument = false; // Always emit some info, by default "no personality" info. Personalities.push_back(nullptr); AddrLabelSymbols = nullptr; TheModule = nullptr; return false; } bool MachineModuleInfo::doFinalization(Module &M) { Personalities.clear(); delete AddrLabelSymbols; AddrLabelSymbols = nullptr; Context.reset(); delete ObjFileMMI; ObjFileMMI = nullptr; return false; } /// EndFunction - Discard function meta information. /// void MachineModuleInfo::EndFunction() { // Clean up frame info. FrameInstructions.clear(); // Clean up exception info. LandingPads.clear(); CallSiteMap.clear(); TypeInfos.clear(); FilterIds.clear(); FilterEnds.clear(); CallsEHReturn = 0; CallsUnwindInit = 0; CompactUnwindEncoding = 0; VariableDbgInfos.clear(); } /// AnalyzeModule - Scan the module for global debug information. /// void MachineModuleInfo::AnalyzeModule(const Module &M) { // Insert functions in the llvm.used array (but not llvm.compiler.used) into // UsedFunctions. const GlobalVariable *GV = M.getGlobalVariable("llvm.used"); if (!GV || !GV->hasInitializer()) return; // Should be an array of 'i8*'. const ConstantArray *InitList = cast<ConstantArray>(GV->getInitializer()); for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) if (const Function *F = dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts())) UsedFunctions.insert(F); } //===- Address of Block Management ----------------------------------------===// /// getAddrLabelSymbol - Return the symbol to be used for the specified basic /// block when its address is taken. This cannot be its normal LBB label /// because the block may be accessed outside its containing function. MCSymbol *MachineModuleInfo::getAddrLabelSymbol(const BasicBlock *BB) { // Lazily create AddrLabelSymbols. if (!AddrLabelSymbols) AddrLabelSymbols = new MMIAddrLabelMap(Context); return AddrLabelSymbols->getAddrLabelSymbol(const_cast<BasicBlock*>(BB)); } /// getAddrLabelSymbolToEmit - Return the symbol to be used for the specified /// basic block when its address is taken. If other blocks were RAUW'd to /// this one, we may have to emit them as well, return the whole set. std::vector<MCSymbol*> MachineModuleInfo:: getAddrLabelSymbolToEmit(const BasicBlock *BB) { // Lazily create AddrLabelSymbols. if (!AddrLabelSymbols) AddrLabelSymbols = new MMIAddrLabelMap(Context); return AddrLabelSymbols->getAddrLabelSymbolToEmit(const_cast<BasicBlock*>(BB)); } /// takeDeletedSymbolsForFunction - If the specified function has had any /// references to address-taken blocks generated, but the block got deleted, /// return the symbol now so we can emit it. This prevents emitting a /// reference to a symbol that has no definition. void MachineModuleInfo:: takeDeletedSymbolsForFunction(const Function *F, std::vector<MCSymbol*> &Result) { // If no blocks have had their addresses taken, we're done. if (!AddrLabelSymbols) return; return AddrLabelSymbols-> takeDeletedSymbolsForFunction(const_cast<Function*>(F), Result); } //===- EH -----------------------------------------------------------------===// /// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the /// specified MachineBasicBlock. LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo (MachineBasicBlock *LandingPad) { unsigned N = LandingPads.size(); for (unsigned i = 0; i < N; ++i) { LandingPadInfo &LP = LandingPads[i]; if (LP.LandingPadBlock == LandingPad) return LP; } LandingPads.push_back(LandingPadInfo(LandingPad)); return LandingPads[N]; } /// addInvoke - Provide the begin and end labels of an invoke style call and /// associate it with a try landing pad block. void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad, MCSymbol *BeginLabel, MCSymbol *EndLabel) { LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); LP.BeginLabels.push_back(BeginLabel); LP.EndLabels.push_back(EndLabel); } /// addLandingPad - Provide the label of a try LandingPad block. /// MCSymbol *MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) { MCSymbol *LandingPadLabel = Context.CreateTempSymbol(); LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); LP.LandingPadLabel = LandingPadLabel; return LandingPadLabel; } /// addPersonality - Provide the personality function for the exception /// information. void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad, const Function *Personality) { LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); LP.Personality = Personality; for (unsigned i = 0; i < Personalities.size(); ++i) if (Personalities[i] == Personality) return; // If this is the first personality we're adding go // ahead and add it at the beginning. if (!Personalities[0]) Personalities[0] = Personality; else Personalities.push_back(Personality); } /// addCatchTypeInfo - Provide the catch typeinfo for a landing pad. /// void MachineModuleInfo:: addCatchTypeInfo(MachineBasicBlock *LandingPad, ArrayRef<const GlobalVariable *> TyInfo) { LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); for (unsigned N = TyInfo.size(); N; --N) LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1])); } /// addFilterTypeInfo - Provide the filter typeinfo for a landing pad. /// void MachineModuleInfo:: addFilterTypeInfo(MachineBasicBlock *LandingPad, ArrayRef<const GlobalVariable *> TyInfo) { LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); std::vector<unsigned> IdsInFilter(TyInfo.size()); for (unsigned I = 0, E = TyInfo.size(); I != E; ++I) IdsInFilter[I] = getTypeIDFor(TyInfo[I]); LP.TypeIds.push_back(getFilterIDFor(IdsInFilter)); } /// addCleanup - Add a cleanup action for a landing pad. /// void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) { LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); LP.TypeIds.push_back(0); } /// TidyLandingPads - Remap landing pad labels and remove any deleted landing /// pads. void MachineModuleInfo::TidyLandingPads(DenseMap<MCSymbol*, uintptr_t> *LPMap) { for (unsigned i = 0; i != LandingPads.size(); ) { LandingPadInfo &LandingPad = LandingPads[i]; if (LandingPad.LandingPadLabel && !LandingPad.LandingPadLabel->isDefined() && (!LPMap || (*LPMap)[LandingPad.LandingPadLabel] == 0)) LandingPad.LandingPadLabel = nullptr; // Special case: we *should* emit LPs with null LP MBB. This indicates // "nounwind" case. if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) { LandingPads.erase(LandingPads.begin() + i); continue; } for (unsigned j = 0, e = LandingPads[i].BeginLabels.size(); j != e; ++j) { MCSymbol *BeginLabel = LandingPad.BeginLabels[j]; MCSymbol *EndLabel = LandingPad.EndLabels[j]; if ((BeginLabel->isDefined() || (LPMap && (*LPMap)[BeginLabel] != 0)) && (EndLabel->isDefined() || (LPMap && (*LPMap)[EndLabel] != 0))) continue; LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j); LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j); --j, --e; } // Remove landing pads with no try-ranges. if (LandingPads[i].BeginLabels.empty()) { LandingPads.erase(LandingPads.begin() + i); continue; } // If there is no landing pad, ensure that the list of typeids is empty. // If the only typeid is a cleanup, this is the same as having no typeids. if (!LandingPad.LandingPadBlock || (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0])) LandingPad.TypeIds.clear(); ++i; } } /// setCallSiteLandingPad - Map the landing pad's EH symbol to the call site /// indexes. void MachineModuleInfo::setCallSiteLandingPad(MCSymbol *Sym, ArrayRef<unsigned> Sites) { LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end()); } /// getTypeIDFor - Return the type id for the specified typeinfo. This is /// function wide. unsigned MachineModuleInfo::getTypeIDFor(const GlobalVariable *TI) { for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i) if (TypeInfos[i] == TI) return i + 1; TypeInfos.push_back(TI); return TypeInfos.size(); } /// getFilterIDFor - Return the filter id for the specified typeinfos. This is /// function wide. int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) { // If the new filter coincides with the tail of an existing filter, then // re-use the existing filter. Folding filters more than this requires // re-ordering filters and/or their elements - probably not worth it. for (std::vector<unsigned>::iterator I = FilterEnds.begin(), E = FilterEnds.end(); I != E; ++I) { unsigned i = *I, j = TyIds.size(); while (i && j) if (FilterIds[--i] != TyIds[--j]) goto try_next; if (!j) // The new filter coincides with range [i, end) of the existing filter. return -(1 + i); try_next:; } // Add the new filter. int FilterID = -(1 + FilterIds.size()); FilterIds.reserve(FilterIds.size() + TyIds.size() + 1); FilterIds.insert(FilterIds.end(), TyIds.begin(), TyIds.end()); FilterEnds.push_back(FilterIds.size()); FilterIds.push_back(0); // terminator return FilterID; } /// getPersonality - Return the personality function for the current function. const Function *MachineModuleInfo::getPersonality() const { // FIXME: Until PR1414 will be fixed, we're using 1 personality function per // function return !LandingPads.empty() ? LandingPads[0].Personality : nullptr; } /// getPersonalityIndex - Return unique index for current personality /// function. NULL/first personality function should always get zero index. unsigned MachineModuleInfo::getPersonalityIndex() const { const Function* Personality = nullptr; // Scan landing pads. If there is at least one non-NULL personality - use it. for (unsigned i = 0, e = LandingPads.size(); i != e; ++i) if (LandingPads[i].Personality) { Personality = LandingPads[i].Personality; break; } for (unsigned i = 0, e = Personalities.size(); i < e; ++i) { if (Personalities[i] == Personality) return i; } // This will happen if the current personality function is // in the zero index. return 0; }