MachineModuleInfo.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
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#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"
24using namespace llvm;
25using namespace llvm::dwarf;
26
27// Handle the Pass registration stuff necessary to use DataLayout's.
28INITIALIZE_PASS(MachineModuleInfo, "machinemoduleinfo",
29                "Machine Module Information", false, false)
30char MachineModuleInfo::ID = 0;
31
32// Out of line virtual method.
33MachineModuleInfoImpl::~MachineModuleInfoImpl() {}
34
35namespace llvm {
36class MMIAddrLabelMapCallbackPtr : CallbackVH {
37  MMIAddrLabelMap *Map;
38public:
39  MMIAddrLabelMapCallbackPtr() : Map(0) {}
40  MMIAddrLabelMapCallbackPtr(Value *V) : CallbackVH(V), Map(0) {}
41
42  void setPtr(BasicBlock *BB) {
43    ValueHandleBase::operator=(BB);
44  }
45
46  void setMap(MMIAddrLabelMap *map) { Map = map; }
47
48  void deleted() override;
49  void allUsesReplacedWith(Value *V2) override;
50};
51
52class MMIAddrLabelMap {
53  MCContext &Context;
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;
58
59    Function *Fn;   // The containing function of the BasicBlock.
60    unsigned Index; // The index in BBCallbacks for the BasicBlock.
61  };
62
63  DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry> AddrLabelSymbols;
64
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;
68
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
72  /// function body.
73  DenseMap<AssertingVH<Function>, std::vector<MCSymbol*> >
74    DeletedAddrLabelsNeedingEmission;
75public:
76
77  MMIAddrLabelMap(MCContext &context) : Context(context) {}
78  ~MMIAddrLabelMap() {
79    assert(DeletedAddrLabelsNeedingEmission.empty() &&
80           "Some labels for deleted blocks never got emitted");
81
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*>*>();
87  }
88
89  MCSymbol *getAddrLabelSymbol(BasicBlock *BB);
90  std::vector<MCSymbol*> getAddrLabelSymbolToEmit(BasicBlock *BB);
91
92  void takeDeletedSymbolsForFunction(Function *F,
93                                     std::vector<MCSymbol*> &Result);
94
95  void UpdateForDeletedBlock(BasicBlock *BB);
96  void UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New);
97};
98}
99
100MCSymbol *MMIAddrLabelMap::getAddrLabelSymbol(BasicBlock *BB) {
101  assert(BB->hasAddressTaken() &&
102         "Shouldn't get label for block without address taken");
103  AddrLabelSymEntry &Entry = AddrLabelSymbols[BB];
104
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];
111  }
112
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;
121  return Result;
122}
123
124std::vector<MCSymbol*>
125MMIAddrLabelMap::getAddrLabelSymbolToEmit(BasicBlock *BB) {
126  assert(BB->hasAddressTaken() &&
127         "Shouldn't get label for block without address taken");
128  AddrLabelSymEntry &Entry = AddrLabelSymbols[BB];
129
130  std::vector<MCSymbol*> Result;
131
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);
137  else
138    Result = *Entry.Symbols.get<std::vector<MCSymbol*>*>();
139  return Result;
140}
141
142
143/// takeDeletedSymbolsForFunction - If we have any deleted symbols for F, return
144/// them.
145void MMIAddrLabelMap::
146takeDeletedSymbolsForFunction(Function *F, std::vector<MCSymbol*> &Result) {
147  DenseMap<AssertingVH<Function>, std::vector<MCSymbol*> >::iterator I =
148    DeletedAddrLabelsNeedingEmission.find(F);
149
150  // If there are no entries for the function, just return.
151  if (I == DeletedAddrLabelsNeedingEmission.end()) return;
152
153  // Otherwise, take the list.
154  std::swap(Result, I->second);
155  DeletedAddrLabelsNeedingEmission.erase(I);
156}
157
158
159void 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] = 0;  // Clear the callback.
167
168  assert((BB->getParent() == 0 || BB->getParent() == Entry.Fn) &&
169         "Block/parent mismatch");
170
171  // Handle both the single and the multiple symbols cases.
172  if (MCSymbol *Sym = Entry.Symbols.dyn_cast<MCSymbol*>()) {
173    if (Sym->isDefined())
174      return;
175
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);
181  } else {
182    std::vector<MCSymbol*> *Syms = Entry.Symbols.get<std::vector<MCSymbol*>*>();
183
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.
187
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
192      // 'Entry'.
193      DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym);
194    }
195
196    // The entry is deleted, free the memory associated with the symbol list.
197    delete Syms;
198  }
199}
200
201void 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?");
206
207  AddrLabelSymEntry &NewEntry = AddrLabelSymbols[New];
208
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.
213    return;
214  }
215
216  BBCallbacks[OldEntry.Index] = 0;    // Update the callback.
217
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;
224  }
225
226  std::vector<MCSymbol*> *SymList =
227    NewEntry.Symbols.get<std::vector<MCSymbol*>*>();
228
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);
232    return;
233  }
234
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());
238  delete Syms;
239}
240
241
242void MMIAddrLabelMapCallbackPtr::deleted() {
243  Map->UpdateForDeletedBlock(cast<BasicBlock>(getValPtr()));
244}
245
246void MMIAddrLabelMapCallbackPtr::allUsesReplacedWith(Value *V2) {
247  Map->UpdateForRAUWBlock(cast<BasicBlock>(getValPtr()), cast<BasicBlock>(V2));
248}
249
250
251//===----------------------------------------------------------------------===//
252
253MachineModuleInfo::MachineModuleInfo(const MCAsmInfo &MAI,
254                                     const MCRegisterInfo &MRI,
255                                     const MCObjectFileInfo *MOFI)
256  : ImmutablePass(ID), Context(&MAI, &MRI, MOFI, 0, false) {
257  initializeMachineModuleInfoPass(*PassRegistry::getPassRegistry());
258}
259
260MachineModuleInfo::MachineModuleInfo()
261  : ImmutablePass(ID), Context(0, 0, 0) {
262  llvm_unreachable("This MachineModuleInfo constructor should never be called, "
263                   "MMI should always be explicitly constructed by "
264                   "LLVMTargetMachine");
265}
266
267MachineModuleInfo::~MachineModuleInfo() {
268}
269
270bool MachineModuleInfo::doInitialization(Module &M) {
271
272  ObjFileMMI = 0;
273  CompactUnwindEncoding = 0;
274  CurCallSite = 0;
275  CallsEHReturn = 0;
276  CallsUnwindInit = 0;
277  DbgInfoAvailable = UsesVAFloatArgument = false;
278  // Always emit some info, by default "no personality" info.
279  Personalities.push_back(NULL);
280  AddrLabelSymbols = 0;
281  TheModule = 0;
282
283  return false;
284}
285
286bool MachineModuleInfo::doFinalization(Module &M) {
287
288  Personalities.clear();
289
290  delete AddrLabelSymbols;
291  AddrLabelSymbols = 0;
292
293  Context.reset();
294
295  delete ObjFileMMI;
296  ObjFileMMI = 0;
297
298  return false;
299}
300
301/// EndFunction - Discard function meta information.
302///
303void MachineModuleInfo::EndFunction() {
304  // Clean up frame info.
305  FrameInstructions.clear();
306
307  // Clean up exception info.
308  LandingPads.clear();
309  CallSiteMap.clear();
310  TypeInfos.clear();
311  FilterIds.clear();
312  FilterEnds.clear();
313  CallsEHReturn = 0;
314  CallsUnwindInit = 0;
315  CompactUnwindEncoding = 0;
316  VariableDbgInfos.clear();
317}
318
319/// AnalyzeModule - Scan the module for global debug information.
320///
321void MachineModuleInfo::AnalyzeModule(const Module &M) {
322  // Insert functions in the llvm.used array (but not llvm.compiler.used) into
323  // UsedFunctions.
324  const GlobalVariable *GV = M.getGlobalVariable("llvm.used");
325  if (!GV || !GV->hasInitializer()) return;
326
327  // Should be an array of 'i8*'.
328  const ConstantArray *InitList = cast<ConstantArray>(GV->getInitializer());
329
330  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
331    if (const Function *F =
332          dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts()))
333      UsedFunctions.insert(F);
334}
335
336//===- Address of Block Management ----------------------------------------===//
337
338
339/// getAddrLabelSymbol - Return the symbol to be used for the specified basic
340/// block when its address is taken.  This cannot be its normal LBB label
341/// because the block may be accessed outside its containing function.
342MCSymbol *MachineModuleInfo::getAddrLabelSymbol(const BasicBlock *BB) {
343  // Lazily create AddrLabelSymbols.
344  if (AddrLabelSymbols == 0)
345    AddrLabelSymbols = new MMIAddrLabelMap(Context);
346  return AddrLabelSymbols->getAddrLabelSymbol(const_cast<BasicBlock*>(BB));
347}
348
349/// getAddrLabelSymbolToEmit - Return the symbol to be used for the specified
350/// basic block when its address is taken.  If other blocks were RAUW'd to
351/// this one, we may have to emit them as well, return the whole set.
352std::vector<MCSymbol*> MachineModuleInfo::
353getAddrLabelSymbolToEmit(const BasicBlock *BB) {
354  // Lazily create AddrLabelSymbols.
355  if (AddrLabelSymbols == 0)
356    AddrLabelSymbols = new MMIAddrLabelMap(Context);
357 return AddrLabelSymbols->getAddrLabelSymbolToEmit(const_cast<BasicBlock*>(BB));
358}
359
360
361/// takeDeletedSymbolsForFunction - If the specified function has had any
362/// references to address-taken blocks generated, but the block got deleted,
363/// return the symbol now so we can emit it.  This prevents emitting a
364/// reference to a symbol that has no definition.
365void MachineModuleInfo::
366takeDeletedSymbolsForFunction(const Function *F,
367                              std::vector<MCSymbol*> &Result) {
368  // If no blocks have had their addresses taken, we're done.
369  if (AddrLabelSymbols == 0) return;
370  return AddrLabelSymbols->
371     takeDeletedSymbolsForFunction(const_cast<Function*>(F), Result);
372}
373
374//===- EH -----------------------------------------------------------------===//
375
376/// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
377/// specified MachineBasicBlock.
378LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo
379    (MachineBasicBlock *LandingPad) {
380  unsigned N = LandingPads.size();
381  for (unsigned i = 0; i < N; ++i) {
382    LandingPadInfo &LP = LandingPads[i];
383    if (LP.LandingPadBlock == LandingPad)
384      return LP;
385  }
386
387  LandingPads.push_back(LandingPadInfo(LandingPad));
388  return LandingPads[N];
389}
390
391/// addInvoke - Provide the begin and end labels of an invoke style call and
392/// associate it with a try landing pad block.
393void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad,
394                                  MCSymbol *BeginLabel, MCSymbol *EndLabel) {
395  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
396  LP.BeginLabels.push_back(BeginLabel);
397  LP.EndLabels.push_back(EndLabel);
398}
399
400/// addLandingPad - Provide the label of a try LandingPad block.
401///
402MCSymbol *MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) {
403  MCSymbol *LandingPadLabel = Context.CreateTempSymbol();
404  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
405  LP.LandingPadLabel = LandingPadLabel;
406  return LandingPadLabel;
407}
408
409/// addPersonality - Provide the personality function for the exception
410/// information.
411void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad,
412                                       const Function *Personality) {
413  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
414  LP.Personality = Personality;
415
416  for (unsigned i = 0; i < Personalities.size(); ++i)
417    if (Personalities[i] == Personality)
418      return;
419
420  // If this is the first personality we're adding go
421  // ahead and add it at the beginning.
422  if (Personalities[0] == NULL)
423    Personalities[0] = Personality;
424  else
425    Personalities.push_back(Personality);
426}
427
428/// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
429///
430void MachineModuleInfo::
431addCatchTypeInfo(MachineBasicBlock *LandingPad,
432                 ArrayRef<const GlobalVariable *> TyInfo) {
433  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
434  for (unsigned N = TyInfo.size(); N; --N)
435    LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
436}
437
438/// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
439///
440void MachineModuleInfo::
441addFilterTypeInfo(MachineBasicBlock *LandingPad,
442                  ArrayRef<const GlobalVariable *> TyInfo) {
443  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
444  std::vector<unsigned> IdsInFilter(TyInfo.size());
445  for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
446    IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
447  LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
448}
449
450/// addCleanup - Add a cleanup action for a landing pad.
451///
452void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) {
453  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
454  LP.TypeIds.push_back(0);
455}
456
457/// TidyLandingPads - Remap landing pad labels and remove any deleted landing
458/// pads.
459void MachineModuleInfo::TidyLandingPads(DenseMap<MCSymbol*, uintptr_t> *LPMap) {
460  for (unsigned i = 0; i != LandingPads.size(); ) {
461    LandingPadInfo &LandingPad = LandingPads[i];
462    if (LandingPad.LandingPadLabel &&
463        !LandingPad.LandingPadLabel->isDefined() &&
464        (!LPMap || (*LPMap)[LandingPad.LandingPadLabel] == 0))
465      LandingPad.LandingPadLabel = 0;
466
467    // Special case: we *should* emit LPs with null LP MBB. This indicates
468    // "nounwind" case.
469    if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
470      LandingPads.erase(LandingPads.begin() + i);
471      continue;
472    }
473
474    for (unsigned j = 0, e = LandingPads[i].BeginLabels.size(); j != e; ++j) {
475      MCSymbol *BeginLabel = LandingPad.BeginLabels[j];
476      MCSymbol *EndLabel = LandingPad.EndLabels[j];
477      if ((BeginLabel->isDefined() ||
478           (LPMap && (*LPMap)[BeginLabel] != 0)) &&
479          (EndLabel->isDefined() ||
480           (LPMap && (*LPMap)[EndLabel] != 0))) continue;
481
482      LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
483      LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
484      --j, --e;
485    }
486
487    // Remove landing pads with no try-ranges.
488    if (LandingPads[i].BeginLabels.empty()) {
489      LandingPads.erase(LandingPads.begin() + i);
490      continue;
491    }
492
493    // If there is no landing pad, ensure that the list of typeids is empty.
494    // If the only typeid is a cleanup, this is the same as having no typeids.
495    if (!LandingPad.LandingPadBlock ||
496        (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
497      LandingPad.TypeIds.clear();
498    ++i;
499  }
500}
501
502/// setCallSiteLandingPad - Map the landing pad's EH symbol to the call site
503/// indexes.
504void MachineModuleInfo::setCallSiteLandingPad(MCSymbol *Sym,
505                                              ArrayRef<unsigned> Sites) {
506  LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end());
507}
508
509/// getTypeIDFor - Return the type id for the specified typeinfo.  This is
510/// function wide.
511unsigned MachineModuleInfo::getTypeIDFor(const GlobalVariable *TI) {
512  for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
513    if (TypeInfos[i] == TI) return i + 1;
514
515  TypeInfos.push_back(TI);
516  return TypeInfos.size();
517}
518
519/// getFilterIDFor - Return the filter id for the specified typeinfos.  This is
520/// function wide.
521int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) {
522  // If the new filter coincides with the tail of an existing filter, then
523  // re-use the existing filter.  Folding filters more than this requires
524  // re-ordering filters and/or their elements - probably not worth it.
525  for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
526       E = FilterEnds.end(); I != E; ++I) {
527    unsigned i = *I, j = TyIds.size();
528
529    while (i && j)
530      if (FilterIds[--i] != TyIds[--j])
531        goto try_next;
532
533    if (!j)
534      // The new filter coincides with range [i, end) of the existing filter.
535      return -(1 + i);
536
537try_next:;
538  }
539
540  // Add the new filter.
541  int FilterID = -(1 + FilterIds.size());
542  FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
543  FilterIds.insert(FilterIds.end(), TyIds.begin(), TyIds.end());
544  FilterEnds.push_back(FilterIds.size());
545  FilterIds.push_back(0); // terminator
546  return FilterID;
547}
548
549/// getPersonality - Return the personality function for the current function.
550const Function *MachineModuleInfo::getPersonality() const {
551  // FIXME: Until PR1414 will be fixed, we're using 1 personality function per
552  // function
553  return !LandingPads.empty() ? LandingPads[0].Personality : NULL;
554}
555
556/// getPersonalityIndex - Return unique index for current personality
557/// function. NULL/first personality function should always get zero index.
558unsigned MachineModuleInfo::getPersonalityIndex() const {
559  const Function* Personality = NULL;
560
561  // Scan landing pads. If there is at least one non-NULL personality - use it.
562  for (unsigned i = 0, e = LandingPads.size(); i != e; ++i)
563    if (LandingPads[i].Personality) {
564      Personality = LandingPads[i].Personality;
565      break;
566    }
567
568  for (unsigned i = 0, e = Personalities.size(); i < e; ++i) {
569    if (Personalities[i] == Personality)
570      return i;
571  }
572
573  // This will happen if the current personality function is
574  // in the zero index.
575  return 0;
576}
577