aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/llvm12/lib/IR/Module.cpp
blob: b4f10e2e2d23974f78998fd0e652a756108ed6ca (plain) (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
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
//===- Module.cpp - Implement the Module class ----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the Module class for the IR library.
//
//===----------------------------------------------------------------------===//

#include "llvm/IR/Module.h"
#include "SymbolTableListTraitsImpl.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/Comdat.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GVMaterializer.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalIFunc.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/ModuleSummaryIndex.h"
#include "llvm/IR/SymbolTableListTraits.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/TypeFinder.h"
#include "llvm/IR/Value.h"
#include "llvm/IR/ValueSymbolTable.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/RandomNumberGenerator.h"
#include "llvm/Support/VersionTuple.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <memory>
#include <utility>
#include <vector>

using namespace llvm;

//===----------------------------------------------------------------------===//
// Methods to implement the globals and functions lists.
//

// Explicit instantiations of SymbolTableListTraits since some of the methods
// are not in the public header file.
template class llvm::SymbolTableListTraits<Function>;
template class llvm::SymbolTableListTraits<GlobalVariable>;
template class llvm::SymbolTableListTraits<GlobalAlias>;
template class llvm::SymbolTableListTraits<GlobalIFunc>;

//===----------------------------------------------------------------------===//
// Primitive Module methods.
//

Module::Module(StringRef MID, LLVMContext &C)
    : Context(C), ValSymTab(std::make_unique<ValueSymbolTable>()),
      Materializer(), ModuleID(std::string(MID)),
      SourceFileName(std::string(MID)), DL("") {
  Context.addModule(this);
}

Module::~Module() {
  Context.removeModule(this);
  dropAllReferences();
  GlobalList.clear();
  FunctionList.clear();
  AliasList.clear();
  IFuncList.clear();
}

std::unique_ptr<RandomNumberGenerator>
Module::createRNG(const StringRef Name) const {
  SmallString<32> Salt(Name);

  // This RNG is guaranteed to produce the same random stream only
  // when the Module ID and thus the input filename is the same. This
  // might be problematic if the input filename extension changes
  // (e.g. from .c to .bc or .ll).
  //
  // We could store this salt in NamedMetadata, but this would make
  // the parameter non-const. This would unfortunately make this
  // interface unusable by any Machine passes, since they only have a
  // const reference to their IR Module. Alternatively we can always
  // store salt metadata from the Module constructor.
  Salt += sys::path::filename(getModuleIdentifier());

  return std::unique_ptr<RandomNumberGenerator>(
      new RandomNumberGenerator(Salt));
}

/// getNamedValue - Return the first global value in the module with
/// the specified name, of arbitrary type.  This method returns null
/// if a global with the specified name is not found.
GlobalValue *Module::getNamedValue(StringRef Name) const {
  return cast_or_null<GlobalValue>(getValueSymbolTable().lookup(Name));
}

/// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
/// This ID is uniqued across modules in the current LLVMContext.
unsigned Module::getMDKindID(StringRef Name) const {
  return Context.getMDKindID(Name);
}

/// getMDKindNames - Populate client supplied SmallVector with the name for
/// custom metadata IDs registered in this LLVMContext.   ID #0 is not used,
/// so it is filled in as an empty string.
void Module::getMDKindNames(SmallVectorImpl<StringRef> &Result) const {
  return Context.getMDKindNames(Result);
}

void Module::getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const {
  return Context.getOperandBundleTags(Result);
}

//===----------------------------------------------------------------------===//
// Methods for easy access to the functions in the module.
//

// getOrInsertFunction - Look up the specified function in the module symbol
// table.  If it does not exist, add a prototype for the function and return
// it.  This is nice because it allows most passes to get away with not handling
// the symbol table directly for this common task.
//
FunctionCallee Module::getOrInsertFunction(StringRef Name, FunctionType *Ty,
                                           AttributeList AttributeList) {
  // See if we have a definition for the specified function already.
  GlobalValue *F = getNamedValue(Name);
  if (!F) {
    // Nope, add it
    Function *New = Function::Create(Ty, GlobalVariable::ExternalLinkage,
                                     DL.getProgramAddressSpace(), Name);
    if (!New->isIntrinsic())       // Intrinsics get attrs set on construction
      New->setAttributes(AttributeList);
    FunctionList.push_back(New);
    return {Ty, New}; // Return the new prototype.
  }

  // If the function exists but has the wrong type, return a bitcast to the
  // right type.
  auto *PTy = PointerType::get(Ty, F->getAddressSpace());
  if (F->getType() != PTy)
    return {Ty, ConstantExpr::getBitCast(F, PTy)};

  // Otherwise, we just found the existing function or a prototype.
  return {Ty, F};
}

FunctionCallee Module::getOrInsertFunction(StringRef Name, FunctionType *Ty) {
  return getOrInsertFunction(Name, Ty, AttributeList());
}

// getFunction - Look up the specified function in the module symbol table.
// If it does not exist, return null.
//
Function *Module::getFunction(StringRef Name) const {
  return dyn_cast_or_null<Function>(getNamedValue(Name));
}

//===----------------------------------------------------------------------===//
// Methods for easy access to the global variables in the module.
//

/// getGlobalVariable - Look up the specified global variable in the module
/// symbol table.  If it does not exist, return null.  The type argument
/// should be the underlying type of the global, i.e., it should not have
/// the top-level PointerType, which represents the address of the global.
/// If AllowLocal is set to true, this function will return types that
/// have an local. By default, these types are not returned.
///
GlobalVariable *Module::getGlobalVariable(StringRef Name,
                                          bool AllowLocal) const {
  if (GlobalVariable *Result =
      dyn_cast_or_null<GlobalVariable>(getNamedValue(Name)))
    if (AllowLocal || !Result->hasLocalLinkage())
      return Result;
  return nullptr;
}

/// getOrInsertGlobal - Look up the specified global in the module symbol table.
///   1. If it does not exist, add a declaration of the global and return it.
///   2. Else, the global exists but has the wrong type: return the function
///      with a constantexpr cast to the right type.
///   3. Finally, if the existing global is the correct declaration, return the
///      existing global.
Constant *Module::getOrInsertGlobal(
    StringRef Name, Type *Ty,
    function_ref<GlobalVariable *()> CreateGlobalCallback) {
  // See if we have a definition for the specified global already.
  GlobalVariable *GV = dyn_cast_or_null<GlobalVariable>(getNamedValue(Name));
  if (!GV)
    GV = CreateGlobalCallback();
  assert(GV && "The CreateGlobalCallback is expected to create a global");

  // If the variable exists but has the wrong type, return a bitcast to the
  // right type.
  Type *GVTy = GV->getType();
  PointerType *PTy = PointerType::get(Ty, GVTy->getPointerAddressSpace());
  if (GVTy != PTy)
    return ConstantExpr::getBitCast(GV, PTy);

  // Otherwise, we just found the existing function or a prototype.
  return GV;
}

// Overload to construct a global variable using its constructor's defaults.
Constant *Module::getOrInsertGlobal(StringRef Name, Type *Ty) {
  return getOrInsertGlobal(Name, Ty, [&] {
    return new GlobalVariable(*this, Ty, false, GlobalVariable::ExternalLinkage,
                              nullptr, Name);
  });
}

//===----------------------------------------------------------------------===//
// Methods for easy access to the global variables in the module.
//

// getNamedAlias - Look up the specified global in the module symbol table.
// If it does not exist, return null.
//
GlobalAlias *Module::getNamedAlias(StringRef Name) const {
  return dyn_cast_or_null<GlobalAlias>(getNamedValue(Name));
}

GlobalIFunc *Module::getNamedIFunc(StringRef Name) const {
  return dyn_cast_or_null<GlobalIFunc>(getNamedValue(Name));
}

/// getNamedMetadata - Return the first NamedMDNode in the module with the
/// specified name. This method returns null if a NamedMDNode with the
/// specified name is not found.
NamedMDNode *Module::getNamedMetadata(const Twine &Name) const {
  SmallString<256> NameData;
  StringRef NameRef = Name.toStringRef(NameData);
  return NamedMDSymTab.lookup(NameRef);
}

/// getOrInsertNamedMetadata - Return the first named MDNode in the module
/// with the specified name. This method returns a new NamedMDNode if a
/// NamedMDNode with the specified name is not found.
NamedMDNode *Module::getOrInsertNamedMetadata(StringRef Name) {
  NamedMDNode *&NMD = NamedMDSymTab[Name];
  if (!NMD) {
    NMD = new NamedMDNode(Name);
    NMD->setParent(this);
    NamedMDList.push_back(NMD);
  }
  return NMD;
}

/// eraseNamedMetadata - Remove the given NamedMDNode from this module and
/// delete it.
void Module::eraseNamedMetadata(NamedMDNode *NMD) {
  NamedMDSymTab.erase(NMD->getName());
  NamedMDList.erase(NMD->getIterator());
}

bool Module::isValidModFlagBehavior(Metadata *MD, ModFlagBehavior &MFB) {
  if (ConstantInt *Behavior = mdconst::dyn_extract_or_null<ConstantInt>(MD)) {
    uint64_t Val = Behavior->getLimitedValue();
    if (Val >= ModFlagBehaviorFirstVal && Val <= ModFlagBehaviorLastVal) {
      MFB = static_cast<ModFlagBehavior>(Val);
      return true;
    }
  }
  return false;
}

bool Module::isValidModuleFlag(const MDNode &ModFlag, ModFlagBehavior &MFB,
                               MDString *&Key, Metadata *&Val) {
  if (ModFlag.getNumOperands() < 3)
    return false;
  if (!isValidModFlagBehavior(ModFlag.getOperand(0), MFB))
    return false;
  MDString *K = dyn_cast_or_null<MDString>(ModFlag.getOperand(1));
  if (!K)
    return false;
  Key = K;
  Val = ModFlag.getOperand(2);
  return true;
}

/// getModuleFlagsMetadata - Returns the module flags in the provided vector.
void Module::
getModuleFlagsMetadata(SmallVectorImpl<ModuleFlagEntry> &Flags) const {
  const NamedMDNode *ModFlags = getModuleFlagsMetadata();
  if (!ModFlags) return;

  for (const MDNode *Flag : ModFlags->operands()) {
    ModFlagBehavior MFB;
    MDString *Key = nullptr;
    Metadata *Val = nullptr;
    if (isValidModuleFlag(*Flag, MFB, Key, Val)) {
      // Check the operands of the MDNode before accessing the operands.
      // The verifier will actually catch these failures.
      Flags.push_back(ModuleFlagEntry(MFB, Key, Val));
    }
  }
}

/// Return the corresponding value if Key appears in module flags, otherwise
/// return null.
Metadata *Module::getModuleFlag(StringRef Key) const {
  SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
  getModuleFlagsMetadata(ModuleFlags);
  for (const ModuleFlagEntry &MFE : ModuleFlags) {
    if (Key == MFE.Key->getString())
      return MFE.Val;
  }
  return nullptr;
}

/// getModuleFlagsMetadata - Returns the NamedMDNode in the module that
/// represents module-level flags. This method returns null if there are no
/// module-level flags.
NamedMDNode *Module::getModuleFlagsMetadata() const {
  return getNamedMetadata("llvm.module.flags");
}

/// getOrInsertModuleFlagsMetadata - Returns the NamedMDNode in the module that
/// represents module-level flags. If module-level flags aren't found, it
/// creates the named metadata that contains them.
NamedMDNode *Module::getOrInsertModuleFlagsMetadata() {
  return getOrInsertNamedMetadata("llvm.module.flags");
}

/// addModuleFlag - Add a module-level flag to the module-level flags
/// metadata. It will create the module-level flags named metadata if it doesn't
/// already exist.
void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
                           Metadata *Val) {
  Type *Int32Ty = Type::getInt32Ty(Context);
  Metadata *Ops[3] = {
      ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Behavior)),
      MDString::get(Context, Key), Val};
  getOrInsertModuleFlagsMetadata()->addOperand(MDNode::get(Context, Ops));
}
void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
                           Constant *Val) {
  addModuleFlag(Behavior, Key, ConstantAsMetadata::get(Val));
}
void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
                           uint32_t Val) {
  Type *Int32Ty = Type::getInt32Ty(Context);
  addModuleFlag(Behavior, Key, ConstantInt::get(Int32Ty, Val));
}
void Module::addModuleFlag(MDNode *Node) {
  assert(Node->getNumOperands() == 3 &&
         "Invalid number of operands for module flag!");
  assert(mdconst::hasa<ConstantInt>(Node->getOperand(0)) &&
         isa<MDString>(Node->getOperand(1)) &&
         "Invalid operand types for module flag!");
  getOrInsertModuleFlagsMetadata()->addOperand(Node);
}

void Module::setModuleFlag(ModFlagBehavior Behavior, StringRef Key,
                           Metadata *Val) {
  NamedMDNode *ModFlags = getOrInsertModuleFlagsMetadata();
  // Replace the flag if it already exists.
  for (unsigned I = 0, E = ModFlags->getNumOperands(); I != E; ++I) {
    MDNode *Flag = ModFlags->getOperand(I);
    ModFlagBehavior MFB;
    MDString *K = nullptr;
    Metadata *V = nullptr;
    if (isValidModuleFlag(*Flag, MFB, K, V) && K->getString() == Key) {
      Flag->replaceOperandWith(2, Val);
      return;
    }
  }
  addModuleFlag(Behavior, Key, Val);
}

void Module::setDataLayout(StringRef Desc) {
  DL.reset(Desc);
}

void Module::setDataLayout(const DataLayout &Other) { DL = Other; }

const DataLayout &Module::getDataLayout() const { return DL; }

DICompileUnit *Module::debug_compile_units_iterator::operator*() const {
  return cast<DICompileUnit>(CUs->getOperand(Idx));
}
DICompileUnit *Module::debug_compile_units_iterator::operator->() const {
  return cast<DICompileUnit>(CUs->getOperand(Idx));
}

void Module::debug_compile_units_iterator::SkipNoDebugCUs() {
  while (CUs && (Idx < CUs->getNumOperands()) &&
         ((*this)->getEmissionKind() == DICompileUnit::NoDebug))
    ++Idx;
}

iterator_range<Module::global_object_iterator> Module::global_objects() {
  return concat<GlobalObject>(functions(), globals());
}
iterator_range<Module::const_global_object_iterator>
Module::global_objects() const {
  return concat<const GlobalObject>(functions(), globals());
}

iterator_range<Module::global_value_iterator> Module::global_values() {
  return concat<GlobalValue>(functions(), globals(), aliases(), ifuncs());
}
iterator_range<Module::const_global_value_iterator>
Module::global_values() const {
  return concat<const GlobalValue>(functions(), globals(), aliases(), ifuncs());
}

//===----------------------------------------------------------------------===//
// Methods to control the materialization of GlobalValues in the Module.
//
void Module::setMaterializer(GVMaterializer *GVM) {
  assert(!Materializer &&
         "Module already has a GVMaterializer.  Call materializeAll"
         " to clear it out before setting another one.");
  Materializer.reset(GVM);
}

Error Module::materialize(GlobalValue *GV) {
  if (!Materializer)
    return Error::success();

  return Materializer->materialize(GV);
}

Error Module::materializeAll() {
  if (!Materializer)
    return Error::success();
  std::unique_ptr<GVMaterializer> M = std::move(Materializer);
  return M->materializeModule();
}

Error Module::materializeMetadata() {
  if (!Materializer)
    return Error::success();
  return Materializer->materializeMetadata();
}

//===----------------------------------------------------------------------===//
// Other module related stuff.
//

std::vector<StructType *> Module::getIdentifiedStructTypes() const {
  // If we have a materializer, it is possible that some unread function
  // uses a type that is currently not visible to a TypeFinder, so ask
  // the materializer which types it created.
  if (Materializer)
    return Materializer->getIdentifiedStructTypes();

  std::vector<StructType *> Ret;
  TypeFinder SrcStructTypes;
  SrcStructTypes.run(*this, true);
  Ret.assign(SrcStructTypes.begin(), SrcStructTypes.end());
  return Ret;
}

// dropAllReferences() - This function causes all the subelements to "let go"
// of all references that they are maintaining.  This allows one to 'delete' a
// whole module at a time, even though there may be circular references... first
// all references are dropped, and all use counts go to zero.  Then everything
// is deleted for real.  Note that no operations are valid on an object that
// has "dropped all references", except operator delete.
//
void Module::dropAllReferences() {
  for (Function &F : *this)
    F.dropAllReferences();

  for (GlobalVariable &GV : globals())
    GV.dropAllReferences();

  for (GlobalAlias &GA : aliases())
    GA.dropAllReferences();

  for (GlobalIFunc &GIF : ifuncs())
    GIF.dropAllReferences();
}

unsigned Module::getNumberRegisterParameters() const {
  auto *Val =
      cast_or_null<ConstantAsMetadata>(getModuleFlag("NumRegisterParameters"));
  if (!Val)
    return 0;
  return cast<ConstantInt>(Val->getValue())->getZExtValue();
}

unsigned Module::getDwarfVersion() const {
  auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("Dwarf Version"));
  if (!Val)
    return 0;
  return cast<ConstantInt>(Val->getValue())->getZExtValue();
}

unsigned Module::getCodeViewFlag() const {
  auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("CodeView"));
  if (!Val)
    return 0;
  return cast<ConstantInt>(Val->getValue())->getZExtValue();
}

unsigned Module::getInstructionCount() {
  unsigned NumInstrs = 0;
  for (Function &F : FunctionList)
    NumInstrs += F.getInstructionCount();
  return NumInstrs;
}

Comdat *Module::getOrInsertComdat(StringRef Name) {
  auto &Entry = *ComdatSymTab.insert(std::make_pair(Name, Comdat())).first;
  Entry.second.Name = &Entry;
  return &Entry.second;
}

PICLevel::Level Module::getPICLevel() const {
  auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("PIC Level"));

  if (!Val)
    return PICLevel::NotPIC;

  return static_cast<PICLevel::Level>(
      cast<ConstantInt>(Val->getValue())->getZExtValue());
}

void Module::setPICLevel(PICLevel::Level PL) {
  addModuleFlag(ModFlagBehavior::Max, "PIC Level", PL);
}

PIELevel::Level Module::getPIELevel() const {
  auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("PIE Level"));

  if (!Val)
    return PIELevel::Default;

  return static_cast<PIELevel::Level>(
      cast<ConstantInt>(Val->getValue())->getZExtValue());
}

void Module::setPIELevel(PIELevel::Level PL) {
  addModuleFlag(ModFlagBehavior::Max, "PIE Level", PL);
}

Optional<CodeModel::Model> Module::getCodeModel() const {
  auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("Code Model"));

  if (!Val)
    return None;

  return static_cast<CodeModel::Model>(
      cast<ConstantInt>(Val->getValue())->getZExtValue());
}

void Module::setCodeModel(CodeModel::Model CL) {
  // Linking object files with different code models is undefined behavior
  // because the compiler would have to generate additional code (to span
  // longer jumps) if a larger code model is used with a smaller one.
  // Therefore we will treat attempts to mix code models as an error.
  addModuleFlag(ModFlagBehavior::Error, "Code Model", CL);
}

void Module::setProfileSummary(Metadata *M, ProfileSummary::Kind Kind) {
  if (Kind == ProfileSummary::PSK_CSInstr)
    setModuleFlag(ModFlagBehavior::Error, "CSProfileSummary", M);
  else
    setModuleFlag(ModFlagBehavior::Error, "ProfileSummary", M);
}

Metadata *Module::getProfileSummary(bool IsCS) const {
  return (IsCS ? getModuleFlag("CSProfileSummary")
               : getModuleFlag("ProfileSummary"));
}

bool Module::getSemanticInterposition() const {
  Metadata *MF = getModuleFlag("SemanticInterposition");

  auto *Val = cast_or_null<ConstantAsMetadata>(MF);
  if (!Val)
    return false;

  return cast<ConstantInt>(Val->getValue())->getZExtValue();
}

void Module::setSemanticInterposition(bool SI) {
  addModuleFlag(ModFlagBehavior::Error, "SemanticInterposition", SI);
}

void Module::setOwnedMemoryBuffer(std::unique_ptr<MemoryBuffer> MB) {
  OwnedMemoryBuffer = std::move(MB);
}

bool Module::getRtLibUseGOT() const {
  auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("RtLibUseGOT"));
  return Val && (cast<ConstantInt>(Val->getValue())->getZExtValue() > 0);
}

void Module::setRtLibUseGOT() {
  addModuleFlag(ModFlagBehavior::Max, "RtLibUseGOT", 1);
}

void Module::setSDKVersion(const VersionTuple &V) {
  SmallVector<unsigned, 3> Entries;
  Entries.push_back(V.getMajor());
  if (auto Minor = V.getMinor()) {
    Entries.push_back(*Minor);
    if (auto Subminor = V.getSubminor())
      Entries.push_back(*Subminor);
    // Ignore the 'build' component as it can't be represented in the object
    // file.
  }
  addModuleFlag(ModFlagBehavior::Warning, "SDK Version",
                ConstantDataArray::get(Context, Entries));
}

VersionTuple Module::getSDKVersion() const {
  auto *CM = dyn_cast_or_null<ConstantAsMetadata>(getModuleFlag("SDK Version"));
  if (!CM)
    return {};
  auto *Arr = dyn_cast_or_null<ConstantDataArray>(CM->getValue());
  if (!Arr)
    return {};
  auto getVersionComponent = [&](unsigned Index) -> Optional<unsigned> {
    if (Index >= Arr->getNumElements())
      return None;
    return (unsigned)Arr->getElementAsInteger(Index);
  };
  auto Major = getVersionComponent(0);
  if (!Major)
    return {};
  VersionTuple Result = VersionTuple(*Major);
  if (auto Minor = getVersionComponent(1)) {
    Result = VersionTuple(*Major, *Minor);
    if (auto Subminor = getVersionComponent(2)) {
      Result = VersionTuple(*Major, *Minor, *Subminor);
    }
  }
  return Result;
}

GlobalVariable *llvm::collectUsedGlobalVariables(
    const Module &M, SmallPtrSetImpl<GlobalValue *> &Set, bool CompilerUsed) {
  const char *Name = CompilerUsed ? "llvm.compiler.used" : "llvm.used";
  GlobalVariable *GV = M.getGlobalVariable(Name);
  if (!GV || !GV->hasInitializer())
    return GV;

  const ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
  for (Value *Op : Init->operands()) {
    GlobalValue *G = cast<GlobalValue>(Op->stripPointerCasts());
    Set.insert(G);
  }
  return GV;
}

void Module::setPartialSampleProfileRatio(const ModuleSummaryIndex &Index) {
  if (auto *SummaryMD = getProfileSummary(/*IsCS*/ false)) {
    std::unique_ptr<ProfileSummary> ProfileSummary(
        ProfileSummary::getFromMD(SummaryMD));
    if (ProfileSummary) {
      if (ProfileSummary->getKind() != ProfileSummary::PSK_Sample ||
          !ProfileSummary->isPartialProfile())
        return;
      uint64_t BlockCount = Index.getBlockCount();
      uint32_t NumCounts = ProfileSummary->getNumCounts();
      if (!NumCounts)
        return;
      double Ratio = (double)BlockCount / NumCounts;
      ProfileSummary->setPartialProfileRatio(Ratio);
      setProfileSummary(ProfileSummary->getMD(getContext()),
                        ProfileSummary::PSK_Sample);
    }
  }
}