llvm.org GIT mirror llvm / release_38 lib / CodeGen / MachineModuleInfo.cpp
release_38

Tree @release_38 (Download .tar.gz)

MachineModuleInfo.cpp @release_38raw · history · blame

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
//===-- 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/ADT/TinyPtrVector.h"
#include "llvm/Analysis/EHPersonalities.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 final : 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.
    TinyPtrVector<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");
  }

  ArrayRef<MCSymbol *> getAddrLabelSymbolToEmit(BasicBlock *BB);

  void takeDeletedSymbolsForFunction(Function *F,
                                     std::vector<MCSymbol*> &Result);

  void UpdateForDeletedBlock(BasicBlock *BB);
  void UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New);
};
}

ArrayRef<MCSymbol *> MMIAddrLabelMap::getAddrLabelSymbolToEmit(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.empty()) {
    assert(BB->getParent() == Entry.Fn && "Parent changed");
    return Entry.Symbols;
  }

  // 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.emplace_back(BB);
  BBCallbacks.back().setMap(this);
  Entry.Index = BBCallbacks.size() - 1;
  Entry.Fn = BB->getParent();
  Entry.Symbols.push_back(Context.createTempSymbol());
  return Entry.Symbols;
}

/// 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 = std::move(AddrLabelSymbols[BB]);
  AddrLabelSymbols.erase(BB);
  assert(!Entry.Symbols.empty() && "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");

  for (MCSymbol *Sym : Entry.Symbols) {
    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);
  }
}

void MMIAddrLabelMap::UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New) {
  // Get the entry for the RAUW'd block and remove it from our map.
  AddrLabelSymEntry OldEntry = std::move(AddrLabelSymbols[Old]);
  AddrLabelSymbols.erase(Old);
  assert(!OldEntry.Symbols.empty() && "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.empty()) {
    BBCallbacks[OldEntry.Index].setPtr(New);    // Update the callback.
    NewEntry = std::move(OldEntry);             // Set New's entry.
    return;
  }

  BBCallbacks[OldEntry.Index] = nullptr;    // Update the callback.

  // Otherwise, we need to add the old symbols to the new block's set.
  NewEntry.Symbols.insert(NewEntry.Symbols.end(), OldEntry.Symbols.begin(),
                          OldEntry.Symbols.end());
}


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;
  CurCallSite = 0;
  CallsEHReturn = false;
  CallsUnwindInit = false;
  HasEHFunclets = false;
  DbgInfoAvailable = UsesVAFloatArgument = UsesMorestackAddr = false;
  PersonalityTypeCache = EHPersonality::Unknown;
  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();
  PersonalityTypeCache = EHPersonality::Unknown;
  CallSiteMap.clear();
  TypeInfos.clear();
  FilterIds.clear();
  FilterEnds.clear();
  CallsEHReturn = false;
  CallsUnwindInit = false;
  HasEHFunclets = false;
  VariableDbgInfos.clear();
}

//===- Address of Block Management ----------------------------------------===//

/// 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.
ArrayRef<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;
}

void MachineModuleInfo::addPersonality(const Function *Personality) {
  for (unsigned i = 0; i < Personalities.size(); ++i)
    if (Personalities[i] == Personality)
      return;
  Personalities.push_back(Personality);
}

/// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
///
void MachineModuleInfo::
addCatchTypeInfo(MachineBasicBlock *LandingPad,
                 ArrayRef<const GlobalValue *> 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 GlobalValue *> 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);
}

void MachineModuleInfo::addSEHCatchHandler(MachineBasicBlock *LandingPad,
                                           const Function *Filter,
                                           const BlockAddress *RecoverBA) {
  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
  SEHHandler Handler;
  Handler.FilterOrFinally = Filter;
  Handler.RecoverBA = RecoverBA;
  LP.SEHHandlers.push_back(Handler);
}

void MachineModuleInfo::addSEHCleanupHandler(MachineBasicBlock *LandingPad,
                                             const Function *Cleanup) {
  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
  SEHHandler Handler;
  Handler.FilterOrFinally = Cleanup;
  Handler.RecoverBA = nullptr;
  LP.SEHHandlers.push_back(Handler);
}

/// 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 GlobalValue *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;
}