1 //===-- llvm/CodeGen/MachineModuleInfo.cpp ----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/CodeGen/MachineModuleInfo.h"
11 #include "llvm/ADT/PointerUnion.h"
12 #include "llvm/Analysis/ValueTracking.h"
13 #include "llvm/CodeGen/MachineFunction.h"
14 #include "llvm/CodeGen/MachineFunctionPass.h"
15 #include "llvm/CodeGen/Passes.h"
16 #include "llvm/IR/Constants.h"
17 #include "llvm/IR/DerivedTypes.h"
18 #include "llvm/IR/GlobalVariable.h"
19 #include "llvm/IR/Module.h"
20 #include "llvm/MC/MCObjectFileInfo.h"
21 #include "llvm/MC/MCSymbol.h"
22 #include "llvm/Support/Dwarf.h"
23 #include "llvm/Support/ErrorHandling.h"
25 using namespace llvm::dwarf;
27 // Handle the Pass registration stuff necessary to use DataLayout's.
28 INITIALIZE_PASS(MachineModuleInfo, "machinemoduleinfo",
29 "Machine Module Information", false, false)
30 char MachineModuleInfo::ID = 0;
32 // Out of line virtual method.
33 MachineModuleInfoImpl::~MachineModuleInfoImpl() {}
36 class MMIAddrLabelMapCallbackPtr : CallbackVH {
39 MMIAddrLabelMapCallbackPtr() : Map(nullptr) {}
40 MMIAddrLabelMapCallbackPtr(Value *V) : CallbackVH(V), Map(nullptr) {}
42 void setPtr(BasicBlock *BB) {
43 ValueHandleBase::operator=(BB);
46 void setMap(MMIAddrLabelMap *map) { Map = map; }
48 void deleted() override;
49 void allUsesReplacedWith(Value *V2) override;
52 class MMIAddrLabelMap {
54 struct AddrLabelSymEntry {
55 /// Symbols - The symbols for the label. This is a pointer union that is
56 /// either one symbol (the common case) or a list of symbols.
57 PointerUnion<MCSymbol *, std::vector<MCSymbol*>*> Symbols;
59 Function *Fn; // The containing function of the BasicBlock.
60 unsigned Index; // The index in BBCallbacks for the BasicBlock.
63 DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry> AddrLabelSymbols;
65 /// BBCallbacks - Callbacks for the BasicBlock's that we have entries for. We
66 /// use this so we get notified if a block is deleted or RAUWd.
67 std::vector<MMIAddrLabelMapCallbackPtr> BBCallbacks;
69 /// DeletedAddrLabelsNeedingEmission - This is a per-function list of symbols
70 /// whose corresponding BasicBlock got deleted. These symbols need to be
71 /// emitted at some point in the file, so AsmPrinter emits them after the
73 DenseMap<AssertingVH<Function>, std::vector<MCSymbol*> >
74 DeletedAddrLabelsNeedingEmission;
77 MMIAddrLabelMap(MCContext &context) : Context(context) {}
79 assert(DeletedAddrLabelsNeedingEmission.empty() &&
80 "Some labels for deleted blocks never got emitted");
82 // Deallocate any of the 'list of symbols' case.
83 for (DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry>::iterator
84 I = AddrLabelSymbols.begin(), E = AddrLabelSymbols.end(); I != E; ++I)
85 if (I->second.Symbols.is<std::vector<MCSymbol*>*>())
86 delete I->second.Symbols.get<std::vector<MCSymbol*>*>();
89 MCSymbol *getAddrLabelSymbol(BasicBlock *BB);
90 std::vector<MCSymbol*> getAddrLabelSymbolToEmit(BasicBlock *BB);
92 void takeDeletedSymbolsForFunction(Function *F,
93 std::vector<MCSymbol*> &Result);
95 void UpdateForDeletedBlock(BasicBlock *BB);
96 void UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New);
100 MCSymbol *MMIAddrLabelMap::getAddrLabelSymbol(BasicBlock *BB) {
101 assert(BB->hasAddressTaken() &&
102 "Shouldn't get label for block without address taken");
103 AddrLabelSymEntry &Entry = AddrLabelSymbols[BB];
105 // If we already had an entry for this block, just return it.
106 if (!Entry.Symbols.isNull()) {
107 assert(BB->getParent() == Entry.Fn && "Parent changed");
108 if (Entry.Symbols.is<MCSymbol*>())
109 return Entry.Symbols.get<MCSymbol*>();
110 return (*Entry.Symbols.get<std::vector<MCSymbol*>*>())[0];
113 // Otherwise, this is a new entry, create a new symbol for it and add an
114 // entry to BBCallbacks so we can be notified if the BB is deleted or RAUWd.
115 BBCallbacks.push_back(BB);
116 BBCallbacks.back().setMap(this);
117 Entry.Index = BBCallbacks.size()-1;
118 Entry.Fn = BB->getParent();
119 MCSymbol *Result = Context.CreateTempSymbol();
120 Entry.Symbols = Result;
124 std::vector<MCSymbol*>
125 MMIAddrLabelMap::getAddrLabelSymbolToEmit(BasicBlock *BB) {
126 assert(BB->hasAddressTaken() &&
127 "Shouldn't get label for block without address taken");
128 AddrLabelSymEntry &Entry = AddrLabelSymbols[BB];
130 std::vector<MCSymbol*> Result;
132 // If we already had an entry for this block, just return it.
133 if (Entry.Symbols.isNull())
134 Result.push_back(getAddrLabelSymbol(BB));
135 else if (MCSymbol *Sym = Entry.Symbols.dyn_cast<MCSymbol*>())
136 Result.push_back(Sym);
138 Result = *Entry.Symbols.get<std::vector<MCSymbol*>*>();
143 /// takeDeletedSymbolsForFunction - If we have any deleted symbols for F, return
145 void MMIAddrLabelMap::
146 takeDeletedSymbolsForFunction(Function *F, std::vector<MCSymbol*> &Result) {
147 DenseMap<AssertingVH<Function>, std::vector<MCSymbol*> >::iterator I =
148 DeletedAddrLabelsNeedingEmission.find(F);
150 // If there are no entries for the function, just return.
151 if (I == DeletedAddrLabelsNeedingEmission.end()) return;
153 // Otherwise, take the list.
154 std::swap(Result, I->second);
155 DeletedAddrLabelsNeedingEmission.erase(I);
159 void MMIAddrLabelMap::UpdateForDeletedBlock(BasicBlock *BB) {
160 // If the block got deleted, there is no need for the symbol. If the symbol
161 // was already emitted, we can just forget about it, otherwise we need to
162 // queue it up for later emission when the function is output.
163 AddrLabelSymEntry Entry = AddrLabelSymbols[BB];
164 AddrLabelSymbols.erase(BB);
165 assert(!Entry.Symbols.isNull() && "Didn't have a symbol, why a callback?");
166 BBCallbacks[Entry.Index] = nullptr; // Clear the callback.
168 assert((BB->getParent() == nullptr || BB->getParent() == Entry.Fn) &&
169 "Block/parent mismatch");
171 // Handle both the single and the multiple symbols cases.
172 if (MCSymbol *Sym = Entry.Symbols.dyn_cast<MCSymbol*>()) {
173 if (Sym->isDefined())
176 // If the block is not yet defined, we need to emit it at the end of the
177 // function. Add the symbol to the DeletedAddrLabelsNeedingEmission list
178 // for the containing Function. Since the block is being deleted, its
179 // parent may already be removed, we have to get the function from 'Entry'.
180 DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym);
182 std::vector<MCSymbol*> *Syms = Entry.Symbols.get<std::vector<MCSymbol*>*>();
184 for (unsigned i = 0, e = Syms->size(); i != e; ++i) {
185 MCSymbol *Sym = (*Syms)[i];
186 if (Sym->isDefined()) continue; // Ignore already emitted labels.
188 // If the block is not yet defined, we need to emit it at the end of the
189 // function. Add the symbol to the DeletedAddrLabelsNeedingEmission list
190 // for the containing Function. Since the block is being deleted, its
191 // parent may already be removed, we have to get the function from
193 DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym);
196 // The entry is deleted, free the memory associated with the symbol list.
201 void MMIAddrLabelMap::UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New) {
202 // Get the entry for the RAUW'd block and remove it from our map.
203 AddrLabelSymEntry OldEntry = AddrLabelSymbols[Old];
204 AddrLabelSymbols.erase(Old);
205 assert(!OldEntry.Symbols.isNull() && "Didn't have a symbol, why a callback?");
207 AddrLabelSymEntry &NewEntry = AddrLabelSymbols[New];
209 // If New is not address taken, just move our symbol over to it.
210 if (NewEntry.Symbols.isNull()) {
211 BBCallbacks[OldEntry.Index].setPtr(New); // Update the callback.
212 NewEntry = OldEntry; // Set New's entry.
216 BBCallbacks[OldEntry.Index] = nullptr; // Update the callback.
218 // Otherwise, we need to add the old symbol to the new block's set. If it is
219 // just a single entry, upgrade it to a symbol list.
220 if (MCSymbol *PrevSym = NewEntry.Symbols.dyn_cast<MCSymbol*>()) {
221 std::vector<MCSymbol*> *SymList = new std::vector<MCSymbol*>();
222 SymList->push_back(PrevSym);
223 NewEntry.Symbols = SymList;
226 std::vector<MCSymbol*> *SymList =
227 NewEntry.Symbols.get<std::vector<MCSymbol*>*>();
229 // If the old entry was a single symbol, add it.
230 if (MCSymbol *Sym = OldEntry.Symbols.dyn_cast<MCSymbol*>()) {
231 SymList->push_back(Sym);
235 // Otherwise, concatenate the list.
236 std::vector<MCSymbol*> *Syms =OldEntry.Symbols.get<std::vector<MCSymbol*>*>();
237 SymList->insert(SymList->end(), Syms->begin(), Syms->end());
242 void MMIAddrLabelMapCallbackPtr::deleted() {
243 Map->UpdateForDeletedBlock(cast<BasicBlock>(getValPtr()));
246 void MMIAddrLabelMapCallbackPtr::allUsesReplacedWith(Value *V2) {
247 Map->UpdateForRAUWBlock(cast<BasicBlock>(getValPtr()), cast<BasicBlock>(V2));
251 //===----------------------------------------------------------------------===//
253 MachineModuleInfo::MachineModuleInfo(const MCAsmInfo &MAI,
254 const MCRegisterInfo &MRI,
255 const MCObjectFileInfo *MOFI)
256 : ImmutablePass(ID), Context(&MAI, &MRI, MOFI, nullptr, false) {
257 initializeMachineModuleInfoPass(*PassRegistry::getPassRegistry());
260 MachineModuleInfo::MachineModuleInfo()
261 : ImmutablePass(ID), Context(nullptr, nullptr, nullptr) {
262 llvm_unreachable("This MachineModuleInfo constructor should never be called, "
263 "MMI should always be explicitly constructed by "
264 "LLVMTargetMachine");
267 MachineModuleInfo::~MachineModuleInfo() {
270 bool MachineModuleInfo::doInitialization(Module &M) {
272 ObjFileMMI = nullptr;
276 DbgInfoAvailable = UsesVAFloatArgument = UsesMorestackAddr = false;
277 // Always emit some info, by default "no personality" info.
278 Personalities.push_back(nullptr);
279 PersonalityTypeCache = EHPersonality::None;
280 AddrLabelSymbols = nullptr;
286 bool MachineModuleInfo::doFinalization(Module &M) {
288 Personalities.clear();
290 delete AddrLabelSymbols;
291 AddrLabelSymbols = nullptr;
296 ObjFileMMI = nullptr;
301 /// EndFunction - Discard function meta information.
303 void MachineModuleInfo::EndFunction() {
304 // Clean up frame info.
305 FrameInstructions.clear();
307 // Clean up exception info.
315 VariableDbgInfos.clear();
318 /// AnalyzeModule - Scan the module for global debug information.
320 void MachineModuleInfo::AnalyzeModule(const Module &M) {
321 // Insert functions in the llvm.used array (but not llvm.compiler.used) into
323 const GlobalVariable *GV = M.getGlobalVariable("llvm.used");
324 if (!GV || !GV->hasInitializer()) return;
326 // Should be an array of 'i8*'.
327 const ConstantArray *InitList = cast<ConstantArray>(GV->getInitializer());
329 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
330 if (const Function *F =
331 dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts()))
332 UsedFunctions.insert(F);
335 //===- Address of Block Management ----------------------------------------===//
338 /// getAddrLabelSymbol - Return the symbol to be used for the specified basic
339 /// block when its address is taken. This cannot be its normal LBB label
340 /// because the block may be accessed outside its containing function.
341 MCSymbol *MachineModuleInfo::getAddrLabelSymbol(const BasicBlock *BB) {
342 // Lazily create AddrLabelSymbols.
343 if (!AddrLabelSymbols)
344 AddrLabelSymbols = new MMIAddrLabelMap(Context);
345 return AddrLabelSymbols->getAddrLabelSymbol(const_cast<BasicBlock*>(BB));
348 /// getAddrLabelSymbolToEmit - Return the symbol to be used for the specified
349 /// basic block when its address is taken. If other blocks were RAUW'd to
350 /// this one, we may have to emit them as well, return the whole set.
351 std::vector<MCSymbol*> MachineModuleInfo::
352 getAddrLabelSymbolToEmit(const BasicBlock *BB) {
353 // Lazily create AddrLabelSymbols.
354 if (!AddrLabelSymbols)
355 AddrLabelSymbols = new MMIAddrLabelMap(Context);
356 return AddrLabelSymbols->getAddrLabelSymbolToEmit(const_cast<BasicBlock*>(BB));
360 /// takeDeletedSymbolsForFunction - If the specified function has had any
361 /// references to address-taken blocks generated, but the block got deleted,
362 /// return the symbol now so we can emit it. This prevents emitting a
363 /// reference to a symbol that has no definition.
364 void MachineModuleInfo::
365 takeDeletedSymbolsForFunction(const Function *F,
366 std::vector<MCSymbol*> &Result) {
367 // If no blocks have had their addresses taken, we're done.
368 if (!AddrLabelSymbols) return;
369 return AddrLabelSymbols->
370 takeDeletedSymbolsForFunction(const_cast<Function*>(F), Result);
373 //===- EH -----------------------------------------------------------------===//
375 /// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
376 /// specified MachineBasicBlock.
377 LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo
378 (MachineBasicBlock *LandingPad) {
379 unsigned N = LandingPads.size();
380 for (unsigned i = 0; i < N; ++i) {
381 LandingPadInfo &LP = LandingPads[i];
382 if (LP.LandingPadBlock == LandingPad)
386 LandingPads.push_back(LandingPadInfo(LandingPad));
387 return LandingPads[N];
390 /// addInvoke - Provide the begin and end labels of an invoke style call and
391 /// associate it with a try landing pad block.
392 void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad,
393 MCSymbol *BeginLabel, MCSymbol *EndLabel) {
394 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
395 LP.BeginLabels.push_back(BeginLabel);
396 LP.EndLabels.push_back(EndLabel);
399 /// addLandingPad - Provide the label of a try LandingPad block.
401 MCSymbol *MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) {
402 MCSymbol *LandingPadLabel = Context.CreateTempSymbol();
403 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
404 LP.LandingPadLabel = LandingPadLabel;
405 return LandingPadLabel;
408 /// addPersonality - Provide the personality function for the exception
410 void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad,
411 const Function *Personality) {
412 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
413 LP.Personality = Personality;
415 for (unsigned i = 0; i < Personalities.size(); ++i)
416 if (Personalities[i] == Personality)
419 // If this is the first personality we're adding go
420 // ahead and add it at the beginning.
421 if (!Personalities[0])
422 Personalities[0] = Personality;
424 Personalities.push_back(Personality);
427 /// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
429 void MachineModuleInfo::
430 addCatchTypeInfo(MachineBasicBlock *LandingPad,
431 ArrayRef<const GlobalValue *> TyInfo) {
432 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
433 for (unsigned N = TyInfo.size(); N; --N)
434 LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
437 /// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
439 void MachineModuleInfo::
440 addFilterTypeInfo(MachineBasicBlock *LandingPad,
441 ArrayRef<const GlobalValue *> TyInfo) {
442 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
443 std::vector<unsigned> IdsInFilter(TyInfo.size());
444 for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
445 IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
446 LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
449 /// addCleanup - Add a cleanup action for a landing pad.
451 void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) {
452 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
453 LP.TypeIds.push_back(0);
457 MachineModuleInfo::addClauseForLandingPad(MachineBasicBlock *LandingPad) {
458 MCSymbol *ClauseLabel = Context.CreateTempSymbol();
459 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
460 LP.ClauseLabels.push_back(ClauseLabel);
464 /// TidyLandingPads - Remap landing pad labels and remove any deleted landing
466 void MachineModuleInfo::TidyLandingPads(DenseMap<MCSymbol*, uintptr_t> *LPMap) {
467 for (unsigned i = 0; i != LandingPads.size(); ) {
468 LandingPadInfo &LandingPad = LandingPads[i];
469 if (LandingPad.LandingPadLabel &&
470 !LandingPad.LandingPadLabel->isDefined() &&
471 (!LPMap || (*LPMap)[LandingPad.LandingPadLabel] == 0))
472 LandingPad.LandingPadLabel = nullptr;
474 // Special case: we *should* emit LPs with null LP MBB. This indicates
476 if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
477 LandingPads.erase(LandingPads.begin() + i);
481 for (unsigned j = 0, e = LandingPads[i].BeginLabels.size(); j != e; ++j) {
482 MCSymbol *BeginLabel = LandingPad.BeginLabels[j];
483 MCSymbol *EndLabel = LandingPad.EndLabels[j];
484 if ((BeginLabel->isDefined() ||
485 (LPMap && (*LPMap)[BeginLabel] != 0)) &&
486 (EndLabel->isDefined() ||
487 (LPMap && (*LPMap)[EndLabel] != 0))) continue;
489 LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
490 LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
494 // Remove landing pads with no try-ranges.
495 if (LandingPads[i].BeginLabels.empty()) {
496 LandingPads.erase(LandingPads.begin() + i);
500 // If there is no landing pad, ensure that the list of typeids is empty.
501 // If the only typeid is a cleanup, this is the same as having no typeids.
502 if (!LandingPad.LandingPadBlock ||
503 (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
504 LandingPad.TypeIds.clear();
509 /// setCallSiteLandingPad - Map the landing pad's EH symbol to the call site
511 void MachineModuleInfo::setCallSiteLandingPad(MCSymbol *Sym,
512 ArrayRef<unsigned> Sites) {
513 LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end());
516 /// getTypeIDFor - Return the type id for the specified typeinfo. This is
518 unsigned MachineModuleInfo::getTypeIDFor(const GlobalValue *TI) {
519 for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
520 if (TypeInfos[i] == TI) return i + 1;
522 TypeInfos.push_back(TI);
523 return TypeInfos.size();
526 /// getFilterIDFor - Return the filter id for the specified typeinfos. This is
528 int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) {
529 // If the new filter coincides with the tail of an existing filter, then
530 // re-use the existing filter. Folding filters more than this requires
531 // re-ordering filters and/or their elements - probably not worth it.
532 for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
533 E = FilterEnds.end(); I != E; ++I) {
534 unsigned i = *I, j = TyIds.size();
537 if (FilterIds[--i] != TyIds[--j])
541 // The new filter coincides with range [i, end) of the existing filter.
547 // Add the new filter.
548 int FilterID = -(1 + FilterIds.size());
549 FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
550 FilterIds.insert(FilterIds.end(), TyIds.begin(), TyIds.end());
551 FilterEnds.push_back(FilterIds.size());
552 FilterIds.push_back(0); // terminator
556 /// getPersonality - Return the personality function for the current function.
557 const Function *MachineModuleInfo::getPersonality() const {
558 for (const LandingPadInfo &LPI : LandingPads)
560 return LPI.Personality;
564 EHPersonality MachineModuleInfo::getPersonalityTypeSlow() {
565 const Function *Per = getPersonality();
567 PersonalityTypeCache = EHPersonality::None;
568 else if (Per->getName() == "__C_specific_handler")
569 PersonalityTypeCache = EHPersonality::Win64SEH;
570 else // Assume everything else is Itanium.
571 PersonalityTypeCache = EHPersonality::Itanium;
572 return PersonalityTypeCache;
575 /// getPersonalityIndex - Return unique index for current personality
576 /// function. NULL/first personality function should always get zero index.
577 unsigned MachineModuleInfo::getPersonalityIndex() const {
578 const Function* Personality = nullptr;
580 // Scan landing pads. If there is at least one non-NULL personality - use it.
581 for (unsigned i = 0, e = LandingPads.size(); i != e; ++i)
582 if (LandingPads[i].Personality) {
583 Personality = LandingPads[i].Personality;
587 for (unsigned i = 0, e = Personalities.size(); i < e; ++i) {
588 if (Personalities[i] == Personality)
592 // This will happen if the current personality function is
593 // in the zero index.