llvm/lib/IR/Module.cpp

   1 //===- Module.cpp - Implement the Module class ----------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the Module class for the IR library.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/IR/Module.h"
  14 #include "SymbolTableListTraitsImpl.h"
  15 #include "llvm/ADT/SmallString.h"
  16 #include "llvm/ADT/SmallVector.h"
  17 #include "llvm/ADT/StringMap.h"
  18 #include "llvm/ADT/StringRef.h"
  19 #include "llvm/ADT/Twine.h"
  20 #include "llvm/IR/Attributes.h"
  21 #include "llvm/IR/Comdat.h"
  22 #include "llvm/IR/Constants.h"
  23 #include "llvm/IR/DataLayout.h"
  24 #include "llvm/IR/DebugInfoMetadata.h"
  25 #include "llvm/IR/DerivedTypes.h"
  26 #include "llvm/IR/Function.h"
  27 #include "llvm/IR/GVMaterializer.h"
  28 #include "llvm/IR/GlobalAlias.h"
  29 #include "llvm/IR/GlobalIFunc.h"
  30 #include "llvm/IR/GlobalValue.h"
  31 #include "llvm/IR/GlobalVariable.h"
  32 #include "llvm/IR/LLVMContext.h"
  33 #include "llvm/IR/Metadata.h"
  34 #include "llvm/IR/ModuleSummaryIndex.h"
  35 #include "llvm/IR/SymbolTableListTraits.h"
  36 #include "llvm/IR/Type.h"
  37 #include "llvm/IR/TypeFinder.h"
  38 #include "llvm/IR/Value.h"
  39 #include "llvm/IR/ValueSymbolTable.h"
  40 #include "llvm/Support/Casting.h"
  41 #include "llvm/Support/CodeGen.h"
  42 #include "llvm/Support/Error.h"
  43 #include "llvm/Support/MemoryBuffer.h"
  44 #include "llvm/Support/Path.h"
  45 #include "llvm/Support/RandomNumberGenerator.h"
  46 #include "llvm/Support/VersionTuple.h"
  47 #include <algorithm>
  48 #include <cassert>
  49 #include <cstdint>
  50 #include <memory>
  51 #include <optional>
  52 #include <utility>
  53 #include <vector>
  54
  55 using namespace llvm;
  56
  57 //===----------------------------------------------------------------------===//
  58 // Methods to implement the globals and functions lists.
  59 //
  60
  61 // Explicit instantiations of SymbolTableListTraits since some of the methods
  62 // are not in the public header file.
  63 template class llvm::SymbolTableListTraits<Function>;
  64 template class llvm::SymbolTableListTraits<GlobalVariable>;
  65 template class llvm::SymbolTableListTraits<GlobalAlias>;
  66 template class llvm::SymbolTableListTraits<GlobalIFunc>;
  67
  68 //===----------------------------------------------------------------------===//
  69 // Primitive Module methods.
  70 //
  71
  72 Module::Module(StringRef MID, LLVMContext &C)
  73     : Context(C), ValSymTab(std::make_unique<ValueSymbolTable>(-1)),
  74       ModuleID(std::string(MID)), SourceFileName(std::string(MID)), DL(""),
  75       IsNewDbgInfoFormat(false) {
  76   Context.addModule(this);
  77 }
  78
  79 Module::~Module() {
  80   Context.removeModule(this);
  81   dropAllReferences();
  82   GlobalList.clear();
  83   FunctionList.clear();
  84   AliasList.clear();
  85   IFuncList.clear();
  86 }
  87
  88 std::unique_ptr<RandomNumberGenerator>
  89 Module::createRNG(const StringRef Name) const {
  90   SmallString<32> Salt(Name);
  91
  92   // This RNG is guaranteed to produce the same random stream only
  93   // when the Module ID and thus the input filename is the same. This
  94   // might be problematic if the input filename extension changes
  95   // (e.g. from .c to .bc or .ll).
  96   //
  97   // We could store this salt in NamedMetadata, but this would make
  98   // the parameter non-const. This would unfortunately make this
  99   // interface unusable by any Machine passes, since they only have a
 100   // const reference to their IR Module. Alternatively we can always
 101   // store salt metadata from the Module constructor.
 102   Salt += sys::path::filename(getModuleIdentifier());
 103
 104   return std::unique_ptr<RandomNumberGenerator>(
 105       new RandomNumberGenerator(Salt));
 106 }
 107
 108 /// getNamedValue - Return the first global value in the module with
 109 /// the specified name, of arbitrary type.  This method returns null
 110 /// if a global with the specified name is not found.
 111 GlobalValue *Module::getNamedValue(StringRef Name) const {
 112   return cast_or_null<GlobalValue>(getValueSymbolTable().lookup(Name));
 113 }
 114
 115 unsigned Module::getNumNamedValues() const {
 116   return getValueSymbolTable().size();
 117 }
 118
 119 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
 120 /// This ID is uniqued across modules in the current LLVMContext.
 121 unsigned Module::getMDKindID(StringRef Name) const {
 122   return Context.getMDKindID(Name);
 123 }
 124
 125 /// getMDKindNames - Populate client supplied SmallVector with the name for
 126 /// custom metadata IDs registered in this LLVMContext.   ID #0 is not used,
 127 /// so it is filled in as an empty string.
 128 void Module::getMDKindNames(SmallVectorImpl<StringRef> &Result) const {
 129   return Context.getMDKindNames(Result);
 130 }
 131
 132 void Module::getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const {
 133   return Context.getOperandBundleTags(Result);
 134 }
 135
 136 //===----------------------------------------------------------------------===//
 137 // Methods for easy access to the functions in the module.
 138 //
 139
 140 // getOrInsertFunction - Look up the specified function in the module symbol
 141 // table.  If it does not exist, add a prototype for the function and return
 142 // it.  This is nice because it allows most passes to get away with not handling
 143 // the symbol table directly for this common task.
 144 //
 145 FunctionCallee Module::getOrInsertFunction(StringRef Name, FunctionType *Ty,
 146                                            AttributeList AttributeList) {
 147   // See if we have a definition for the specified function already.
 148   GlobalValue *F = getNamedValue(Name);
 149   if (!F) {
 150     // Nope, add it
 151     Function *New = Function::Create(Ty, GlobalVariable::ExternalLinkage,
 152                                      DL.getProgramAddressSpace(), Name);
 153     if (!New->isIntrinsic())       // Intrinsics get attrs set on construction
 154       New->setAttributes(AttributeList);
 155     FunctionList.push_back(New);
 156     return {Ty, New}; // Return the new prototype.
 157   }
 158
 159   // Otherwise, we just found the existing function or a prototype.
 160   return {Ty, F};
 161 }
 162
 163 FunctionCallee Module::getOrInsertFunction(StringRef Name, FunctionType *Ty) {
 164   return getOrInsertFunction(Name, Ty, AttributeList());
 165 }
 166
 167 // getFunction - Look up the specified function in the module symbol table.
 168 // If it does not exist, return null.
 169 //
 170 Function *Module::getFunction(StringRef Name) const {
 171   return dyn_cast_or_null<Function>(getNamedValue(Name));
 172 }
 173
 174 //===----------------------------------------------------------------------===//
 175 // Methods for easy access to the global variables in the module.
 176 //
 177
 178 /// getGlobalVariable - Look up the specified global variable in the module
 179 /// symbol table.  If it does not exist, return null.  The type argument
 180 /// should be the underlying type of the global, i.e., it should not have
 181 /// the top-level PointerType, which represents the address of the global.
 182 /// If AllowLocal is set to true, this function will return types that
 183 /// have an local. By default, these types are not returned.
 184 ///
 185 GlobalVariable *Module::getGlobalVariable(StringRef Name,
 186                                           bool AllowLocal) const {
 187   if (GlobalVariable *Result =
 188       dyn_cast_or_null<GlobalVariable>(getNamedValue(Name)))
 189     if (AllowLocal || !Result->hasLocalLinkage())
 190       return Result;
 191   return nullptr;
 192 }
 193
 194 /// getOrInsertGlobal - Look up the specified global in the module symbol table.
 195 ///   1. If it does not exist, add a declaration of the global and return it.
 196 ///   2. Else, the global exists but has the wrong type: return the function
 197 ///      with a constantexpr cast to the right type.
 198 ///   3. Finally, if the existing global is the correct declaration, return the
 199 ///      existing global.
 200 Constant *Module::getOrInsertGlobal(
 201     StringRef Name, Type *Ty,
 202     function_ref<GlobalVariable *()> CreateGlobalCallback) {
 203   // See if we have a definition for the specified global already.
 204   GlobalVariable *GV = dyn_cast_or_null<GlobalVariable>(getNamedValue(Name));
 205   if (!GV)
 206     GV = CreateGlobalCallback();
 207   assert(GV && "The CreateGlobalCallback is expected to create a global");
 208
 209   // Otherwise, we just found the existing function or a prototype.
 210   return GV;
 211 }
 212
 213 // Overload to construct a global variable using its constructor's defaults.
 214 Constant *Module::getOrInsertGlobal(StringRef Name, Type *Ty) {
 215   return getOrInsertGlobal(Name, Ty, [&] {
 216     return new GlobalVariable(*this, Ty, false, GlobalVariable::ExternalLinkage,
 217                               nullptr, Name);
 218   });
 219 }
 220
 221 //===----------------------------------------------------------------------===//
 222 // Methods for easy access to the global variables in the module.
 223 //
 224
 225 // getNamedAlias - Look up the specified global in the module symbol table.
 226 // If it does not exist, return null.
 227 //
 228 GlobalAlias *Module::getNamedAlias(StringRef Name) const {
 229   return dyn_cast_or_null<GlobalAlias>(getNamedValue(Name));
 230 }
 231
 232 GlobalIFunc *Module::getNamedIFunc(StringRef Name) const {
 233   return dyn_cast_or_null<GlobalIFunc>(getNamedValue(Name));
 234 }
 235
 236 /// getNamedMetadata - Return the first NamedMDNode in the module with the
 237 /// specified name. This method returns null if a NamedMDNode with the
 238 /// specified name is not found.
 239 NamedMDNode *Module::getNamedMetadata(const Twine &Name) const {
 240   SmallString<256> NameData;
 241   StringRef NameRef = Name.toStringRef(NameData);
 242   return NamedMDSymTab.lookup(NameRef);
 243 }
 244
 245 /// getOrInsertNamedMetadata - Return the first named MDNode in the module
 246 /// with the specified name. This method returns a new NamedMDNode if a
 247 /// NamedMDNode with the specified name is not found.
 248 NamedMDNode *Module::getOrInsertNamedMetadata(StringRef Name) {
 249   NamedMDNode *&NMD = NamedMDSymTab[Name];
 250   if (!NMD) {
 251     NMD = new NamedMDNode(Name);
 252     NMD->setParent(this);
 253     insertNamedMDNode(NMD);
 254   }
 255   return NMD;
 256 }
 257
 258 /// eraseNamedMetadata - Remove the given NamedMDNode from this module and
 259 /// delete it.
 260 void Module::eraseNamedMetadata(NamedMDNode *NMD) {
 261   NamedMDSymTab.erase(NMD->getName());
 262   eraseNamedMDNode(NMD);
 263 }
 264
 265 bool Module::isValidModFlagBehavior(Metadata *MD, ModFlagBehavior &MFB) {
 266   if (ConstantInt *Behavior = mdconst::dyn_extract_or_null<ConstantInt>(MD)) {
 267     uint64_t Val = Behavior->getLimitedValue();
 268     if (Val >= ModFlagBehaviorFirstVal && Val <= ModFlagBehaviorLastVal) {
 269       MFB = static_cast<ModFlagBehavior>(Val);
 270       return true;
 271     }
 272   }
 273   return false;
 274 }
 275
 276 bool Module::isValidModuleFlag(const MDNode &ModFlag, ModFlagBehavior &MFB,
 277                                MDString *&Key, Metadata *&Val) {
 278   if (ModFlag.getNumOperands() < 3)
 279     return false;
 280   if (!isValidModFlagBehavior(ModFlag.getOperand(0), MFB))
 281     return false;
 282   MDString *K = dyn_cast_or_null<MDString>(ModFlag.getOperand(1));
 283   if (!K)
 284     return false;
 285   Key = K;
 286   Val = ModFlag.getOperand(2);
 287   return true;
 288 }
 289
 290 /// getModuleFlagsMetadata - Returns the module flags in the provided vector.
 291 void Module::
 292 getModuleFlagsMetadata(SmallVectorImpl<ModuleFlagEntry> &Flags) const {
 293   const NamedMDNode *ModFlags = getModuleFlagsMetadata();
 294   if (!ModFlags) return;
 295
 296   for (const MDNode *Flag : ModFlags->operands()) {
 297     ModFlagBehavior MFB;
 298     MDString *Key = nullptr;
 299     Metadata *Val = nullptr;
 300     if (isValidModuleFlag(*Flag, MFB, Key, Val)) {
 301       // Check the operands of the MDNode before accessing the operands.
 302       // The verifier will actually catch these failures.
 303       Flags.push_back(ModuleFlagEntry(MFB, Key, Val));
 304     }
 305   }
 306 }
 307
 308 /// Return the corresponding value if Key appears in module flags, otherwise
 309 /// return null.
 310 Metadata *Module::getModuleFlag(StringRef Key) const {
 311   SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
 312   getModuleFlagsMetadata(ModuleFlags);
 313   for (const ModuleFlagEntry &MFE : ModuleFlags) {
 314     if (Key == MFE.Key->getString())
 315       return MFE.Val;
 316   }
 317   return nullptr;
 318 }
 319
 320 /// getModuleFlagsMetadata - Returns the NamedMDNode in the module that
 321 /// represents module-level flags. This method returns null if there are no
 322 /// module-level flags.
 323 NamedMDNode *Module::getModuleFlagsMetadata() const {
 324   return getNamedMetadata("llvm.module.flags");
 325 }
 326
 327 /// getOrInsertModuleFlagsMetadata - Returns the NamedMDNode in the module that
 328 /// represents module-level flags. If module-level flags aren't found, it
 329 /// creates the named metadata that contains them.
 330 NamedMDNode *Module::getOrInsertModuleFlagsMetadata() {
 331   return getOrInsertNamedMetadata("llvm.module.flags");
 332 }
 333
 334 /// addModuleFlag - Add a module-level flag to the module-level flags
 335 /// metadata. It will create the module-level flags named metadata if it doesn't
 336 /// already exist.
 337 void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
 338                            Metadata *Val) {
 339   Type *Int32Ty = Type::getInt32Ty(Context);
 340   Metadata *Ops[3] = {
 341       ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Behavior)),
 342       MDString::get(Context, Key), Val};
 343   getOrInsertModuleFlagsMetadata()->addOperand(MDNode::get(Context, Ops));
 344 }
 345 void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
 346                            Constant *Val) {
 347   addModuleFlag(Behavior, Key, ConstantAsMetadata::get(Val));
 348 }
 349 void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
 350                            uint32_t Val) {
 351   Type *Int32Ty = Type::getInt32Ty(Context);
 352   addModuleFlag(Behavior, Key, ConstantInt::get(Int32Ty, Val));
 353 }
 354 void Module::addModuleFlag(MDNode *Node) {
 355   assert(Node->getNumOperands() == 3 &&
 356          "Invalid number of operands for module flag!");
 357   assert(mdconst::hasa<ConstantInt>(Node->getOperand(0)) &&
 358          isa<MDString>(Node->getOperand(1)) &&
 359          "Invalid operand types for module flag!");
 360   getOrInsertModuleFlagsMetadata()->addOperand(Node);
 361 }
 362
 363 void Module::setModuleFlag(ModFlagBehavior Behavior, StringRef Key,
 364                            Metadata *Val) {
 365   NamedMDNode *ModFlags = getOrInsertModuleFlagsMetadata();
 366   // Replace the flag if it already exists.
 367   for (unsigned I = 0, E = ModFlags->getNumOperands(); I != E; ++I) {
 368     MDNode *Flag = ModFlags->getOperand(I);
 369     ModFlagBehavior MFB;
 370     MDString *K = nullptr;
 371     Metadata *V = nullptr;
 372     if (isValidModuleFlag(*Flag, MFB, K, V) && K->getString() == Key) {
 373       Flag->replaceOperandWith(2, Val);
 374       return;
 375     }
 376   }
 377   addModuleFlag(Behavior, Key, Val);
 378 }
 379
 380 void Module::setDataLayout(StringRef Desc) {
 381   DL.reset(Desc);
 382 }
 383
 384 void Module::setDataLayout(const DataLayout &Other) { DL = Other; }
 385
 386 DICompileUnit *Module::debug_compile_units_iterator::operator*() const {
 387   return cast<DICompileUnit>(CUs->getOperand(Idx));
 388 }
 389 DICompileUnit *Module::debug_compile_units_iterator::operator->() const {
 390   return cast<DICompileUnit>(CUs->getOperand(Idx));
 391 }
 392
 393 void Module::debug_compile_units_iterator::SkipNoDebugCUs() {
 394   while (CUs && (Idx < CUs->getNumOperands()) &&
 395          ((*this)->getEmissionKind() == DICompileUnit::NoDebug))
 396     ++Idx;
 397 }
 398
 399 iterator_range<Module::global_object_iterator> Module::global_objects() {
 400   return concat<GlobalObject>(functions(), globals());
 401 }
 402 iterator_range<Module::const_global_object_iterator>
 403 Module::global_objects() const {
 404   return concat<const GlobalObject>(functions(), globals());
 405 }
 406
 407 iterator_range<Module::global_value_iterator> Module::global_values() {
 408   return concat<GlobalValue>(functions(), globals(), aliases(), ifuncs());
 409 }
 410 iterator_range<Module::const_global_value_iterator>
 411 Module::global_values() const {
 412   return concat<const GlobalValue>(functions(), globals(), aliases(), ifuncs());
 413 }
 414
 415 //===----------------------------------------------------------------------===//
 416 // Methods to control the materialization of GlobalValues in the Module.
 417 //
 418 void Module::setMaterializer(GVMaterializer *GVM) {
 419   assert(!Materializer &&
 420          "Module already has a GVMaterializer.  Call materializeAll"
 421          " to clear it out before setting another one.");
 422   Materializer.reset(GVM);
 423 }
 424
 425 Error Module::materialize(GlobalValue *GV) {
 426   if (!Materializer)
 427     return Error::success();
 428
 429   return Materializer->materialize(GV);
 430 }
 431
 432 Error Module::materializeAll() {
 433   if (!Materializer)
 434     return Error::success();
 435   std::unique_ptr<GVMaterializer> M = std::move(Materializer);
 436   return M->materializeModule();
 437 }
 438
 439 Error Module::materializeMetadata() {
 440   if (!Materializer)
 441     return Error::success();
 442   return Materializer->materializeMetadata();
 443 }
 444
 445 //===----------------------------------------------------------------------===//
 446 // Other module related stuff.
 447 //
 448
 449 std::vector<StructType *> Module::getIdentifiedStructTypes() const {
 450   // If we have a materializer, it is possible that some unread function
 451   // uses a type that is currently not visible to a TypeFinder, so ask
 452   // the materializer which types it created.
 453   if (Materializer)
 454     return Materializer->getIdentifiedStructTypes();
 455
 456   std::vector<StructType *> Ret;
 457   TypeFinder SrcStructTypes;
 458   SrcStructTypes.run(*this, true);
 459   Ret.assign(SrcStructTypes.begin(), SrcStructTypes.end());
 460   return Ret;
 461 }
 462
 463 std::string Module::getUniqueIntrinsicName(StringRef BaseName, Intrinsic::ID Id,
 464                                            const FunctionType *Proto) {
 465   auto Encode = [&BaseName](unsigned Suffix) {
 466     return (Twine(BaseName) + "." + Twine(Suffix)).str();
 467   };
 468
 469   {
 470     // fast path - the prototype is already known
 471     auto UinItInserted = UniquedIntrinsicNames.insert({{Id, Proto}, 0});
 472     if (!UinItInserted.second)
 473       return Encode(UinItInserted.first->second);
 474   }
 475
 476   // Not known yet. A new entry was created with index 0. Check if there already
 477   // exists a matching declaration, or select a new entry.
 478
 479   // Start looking for names with the current known maximum count (or 0).
 480   auto NiidItInserted = CurrentIntrinsicIds.insert({BaseName, 0});
 481   unsigned Count = NiidItInserted.first->second;
 482
 483   // This might be slow if a whole population of intrinsics already existed, but
 484   // we cache the values for later usage.
 485   std::string NewName;
 486   while (true) {
 487     NewName = Encode(Count);
 488     GlobalValue *F = getNamedValue(NewName);
 489     if (!F) {
 490       // Reserve this entry for the new proto
 491       UniquedIntrinsicNames[{Id, Proto}] = Count;
 492       break;
 493     }
 494
 495     // A declaration with this name already exists. Remember it.
 496     FunctionType *FT = dyn_cast<FunctionType>(F->getValueType());
 497     auto UinItInserted = UniquedIntrinsicNames.insert({{Id, FT}, Count});
 498     if (FT == Proto) {
 499       // It was a declaration for our prototype. This entry was allocated in the
 500       // beginning. Update the count to match the existing declaration.
 501       UinItInserted.first->second = Count;
 502       break;
 503     }
 504
 505     ++Count;
 506   }
 507
 508   NiidItInserted.first->second = Count + 1;
 509
 510   return NewName;
 511 }
 512
 513 // dropAllReferences() - This function causes all the subelements to "let go"
 514 // of all references that they are maintaining.  This allows one to 'delete' a
 515 // whole module at a time, even though there may be circular references... first
 516 // all references are dropped, and all use counts go to zero.  Then everything
 517 // is deleted for real.  Note that no operations are valid on an object that
 518 // has "dropped all references", except operator delete.
 519 //
 520 void Module::dropAllReferences() {
 521   for (Function &F : *this)
 522     F.dropAllReferences();
 523
 524   for (GlobalVariable &GV : globals())
 525     GV.dropAllReferences();
 526
 527   for (GlobalAlias &GA : aliases())
 528     GA.dropAllReferences();
 529
 530   for (GlobalIFunc &GIF : ifuncs())
 531     GIF.dropAllReferences();
 532 }
 533
 534 unsigned Module::getNumberRegisterParameters() const {
 535   auto *Val =
 536       cast_or_null<ConstantAsMetadata>(getModuleFlag("NumRegisterParameters"));
 537   if (!Val)
 538     return 0;
 539   return cast<ConstantInt>(Val->getValue())->getZExtValue();
 540 }
 541
 542 unsigned Module::getDwarfVersion() const {
 543   auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("Dwarf Version"));
 544   if (!Val)
 545     return 0;
 546   return cast<ConstantInt>(Val->getValue())->getZExtValue();
 547 }
 548
 549 bool Module::isDwarf64() const {
 550   auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("DWARF64"));
 551   return Val && cast<ConstantInt>(Val->getValue())->isOne();
 552 }
 553
 554 unsigned Module::getCodeViewFlag() const {
 555   auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("CodeView"));
 556   if (!Val)
 557     return 0;
 558   return cast<ConstantInt>(Val->getValue())->getZExtValue();
 559 }
 560
 561 unsigned Module::getInstructionCount() const {
 562   unsigned NumInstrs = 0;
 563   for (const Function &F : FunctionList)
 564     NumInstrs += F.getInstructionCount();
 565   return NumInstrs;
 566 }
 567
 568 Comdat *Module::getOrInsertComdat(StringRef Name) {
 569   auto &Entry = *ComdatSymTab.insert(std::make_pair(Name, Comdat())).first;
 570   Entry.second.Name = &Entry;
 571   return &Entry.second;
 572 }
 573
 574 PICLevel::Level Module::getPICLevel() const {
 575   auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("PIC Level"));
 576
 577   if (!Val)
 578     return PICLevel::NotPIC;
 579
 580   return static_cast<PICLevel::Level>(
 581       cast<ConstantInt>(Val->getValue())->getZExtValue());
 582 }
 583
 584 void Module::setPICLevel(PICLevel::Level PL) {
 585   // The merge result of a non-PIC object and a PIC object can only be reliably
 586   // used as a non-PIC object, so use the Min merge behavior.
 587   addModuleFlag(ModFlagBehavior::Min, "PIC Level", PL);
 588 }
 589
 590 PIELevel::Level Module::getPIELevel() const {
 591   auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("PIE Level"));
 592
 593   if (!Val)
 594     return PIELevel::Default;
 595
 596   return static_cast<PIELevel::Level>(
 597       cast<ConstantInt>(Val->getValue())->getZExtValue());
 598 }
 599
 600 void Module::setPIELevel(PIELevel::Level PL) {
 601   addModuleFlag(ModFlagBehavior::Max, "PIE Level", PL);
 602 }
 603
 604 std::optional<CodeModel::Model> Module::getCodeModel() const {
 605   auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("Code Model"));
 606
 607   if (!Val)
 608     return std::nullopt;
 609
 610   return static_cast<CodeModel::Model>(
 611       cast<ConstantInt>(Val->getValue())->getZExtValue());
 612 }
 613
 614 void Module::setCodeModel(CodeModel::Model CL) {
 615   // Linking object files with different code models is undefined behavior
 616   // because the compiler would have to generate additional code (to span
 617   // longer jumps) if a larger code model is used with a smaller one.
 618   // Therefore we will treat attempts to mix code models as an error.
 619   addModuleFlag(ModFlagBehavior::Error, "Code Model", CL);
 620 }
 621
 622 std::optional<uint64_t> Module::getLargeDataThreshold() const {
 623   auto *Val =
 624       cast_or_null<ConstantAsMetadata>(getModuleFlag("Large Data Threshold"));
 625
 626   if (!Val)
 627     return std::nullopt;
 628
 629   return cast<ConstantInt>(Val->getValue())->getZExtValue();
 630 }
 631
 632 void Module::setLargeDataThreshold(uint64_t Threshold) {
 633   // Since the large data threshold goes along with the code model, the merge
 634   // behavior is the same.
 635   addModuleFlag(ModFlagBehavior::Error, "Large Data Threshold",
 636                 ConstantInt::get(Type::getInt64Ty(Context), Threshold));
 637 }
 638
 639 void Module::setProfileSummary(Metadata *M, ProfileSummary::Kind Kind) {
 640   if (Kind == ProfileSummary::PSK_CSInstr)
 641     setModuleFlag(ModFlagBehavior::Error, "CSProfileSummary", M);
 642   else
 643     setModuleFlag(ModFlagBehavior::Error, "ProfileSummary", M);
 644 }
 645
 646 Metadata *Module::getProfileSummary(bool IsCS) const {
 647   return (IsCS ? getModuleFlag("CSProfileSummary")
 648                : getModuleFlag("ProfileSummary"));
 649 }
 650
 651 bool Module::getSemanticInterposition() const {
 652   Metadata *MF = getModuleFlag("SemanticInterposition");
 653
 654   auto *Val = cast_or_null<ConstantAsMetadata>(MF);
 655   if (!Val)
 656     return false;
 657
 658   return cast<ConstantInt>(Val->getValue())->getZExtValue();
 659 }
 660
 661 void Module::setSemanticInterposition(bool SI) {
 662   addModuleFlag(ModFlagBehavior::Error, "SemanticInterposition", SI);
 663 }
 664
 665 void Module::setOwnedMemoryBuffer(std::unique_ptr<MemoryBuffer> MB) {
 666   OwnedMemoryBuffer = std::move(MB);
 667 }
 668
 669 bool Module::getRtLibUseGOT() const {
 670   auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("RtLibUseGOT"));
 671   return Val && (cast<ConstantInt>(Val->getValue())->getZExtValue() > 0);
 672 }
 673
 674 void Module::setRtLibUseGOT() {
 675   addModuleFlag(ModFlagBehavior::Max, "RtLibUseGOT", 1);
 676 }
 677
 678 bool Module::getDirectAccessExternalData() const {
 679   auto *Val = cast_or_null<ConstantAsMetadata>(
 680       getModuleFlag("direct-access-external-data"));
 681   if (Val)
 682     return cast<ConstantInt>(Val->getValue())->getZExtValue() > 0;
 683   return getPICLevel() == PICLevel::NotPIC;
 684 }
 685
 686 void Module::setDirectAccessExternalData(bool Value) {
 687   addModuleFlag(ModFlagBehavior::Max, "direct-access-external-data", Value);
 688 }
 689
 690 UWTableKind Module::getUwtable() const {
 691   if (auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("uwtable")))
 692     return UWTableKind(cast<ConstantInt>(Val->getValue())->getZExtValue());
 693   return UWTableKind::None;
 694 }
 695
 696 void Module::setUwtable(UWTableKind Kind) {
 697   addModuleFlag(ModFlagBehavior::Max, "uwtable", uint32_t(Kind));
 698 }
 699
 700 FramePointerKind Module::getFramePointer() const {
 701   auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("frame-pointer"));
 702   return static_cast<FramePointerKind>(
 703       Val ? cast<ConstantInt>(Val->getValue())->getZExtValue() : 0);
 704 }
 705
 706 void Module::setFramePointer(FramePointerKind Kind) {
 707   addModuleFlag(ModFlagBehavior::Max, "frame-pointer", static_cast<int>(Kind));
 708 }
 709
 710 StringRef Module::getStackProtectorGuard() const {
 711   Metadata *MD = getModuleFlag("stack-protector-guard");
 712   if (auto *MDS = dyn_cast_or_null<MDString>(MD))
 713     return MDS->getString();
 714   return {};
 715 }
 716
 717 void Module::setStackProtectorGuard(StringRef Kind) {
 718   MDString *ID = MDString::get(getContext(), Kind);
 719   addModuleFlag(ModFlagBehavior::Error, "stack-protector-guard", ID);
 720 }
 721
 722 StringRef Module::getStackProtectorGuardReg() const {
 723   Metadata *MD = getModuleFlag("stack-protector-guard-reg");
 724   if (auto *MDS = dyn_cast_or_null<MDString>(MD))
 725     return MDS->getString();
 726   return {};
 727 }
 728
 729 void Module::setStackProtectorGuardReg(StringRef Reg) {
 730   MDString *ID = MDString::get(getContext(), Reg);
 731   addModuleFlag(ModFlagBehavior::Error, "stack-protector-guard-reg", ID);
 732 }
 733
 734 StringRef Module::getStackProtectorGuardSymbol() const {
 735   Metadata *MD = getModuleFlag("stack-protector-guard-symbol");
 736   if (auto *MDS = dyn_cast_or_null<MDString>(MD))
 737     return MDS->getString();
 738   return {};
 739 }
 740
 741 void Module::setStackProtectorGuardSymbol(StringRef Symbol) {
 742   MDString *ID = MDString::get(getContext(), Symbol);
 743   addModuleFlag(ModFlagBehavior::Error, "stack-protector-guard-symbol", ID);
 744 }
 745
 746 int Module::getStackProtectorGuardOffset() const {
 747   Metadata *MD = getModuleFlag("stack-protector-guard-offset");
 748   if (auto *CI = mdconst::dyn_extract_or_null<ConstantInt>(MD))
 749     return CI->getSExtValue();
 750   return INT_MAX;
 751 }
 752
 753 void Module::setStackProtectorGuardOffset(int Offset) {
 754   addModuleFlag(ModFlagBehavior::Error, "stack-protector-guard-offset", Offset);
 755 }
 756
 757 unsigned Module::getOverrideStackAlignment() const {
 758   Metadata *MD = getModuleFlag("override-stack-alignment");
 759   if (auto *CI = mdconst::dyn_extract_or_null<ConstantInt>(MD))
 760     return CI->getZExtValue();
 761   return 0;
 762 }
 763
 764 unsigned Module::getMaxTLSAlignment() const {
 765   Metadata *MD = getModuleFlag("MaxTLSAlign");
 766   if (auto *CI = mdconst::dyn_extract_or_null<ConstantInt>(MD))
 767     return CI->getZExtValue();
 768   return 0;
 769 }
 770
 771 void Module::setOverrideStackAlignment(unsigned Align) {
 772   addModuleFlag(ModFlagBehavior::Error, "override-stack-alignment", Align);
 773 }
 774
 775 static void addSDKVersionMD(const VersionTuple &V, Module &M, StringRef Name) {
 776   SmallVector<unsigned, 3> Entries;
 777   Entries.push_back(V.getMajor());
 778   if (auto Minor = V.getMinor()) {
 779     Entries.push_back(*Minor);
 780     if (auto Subminor = V.getSubminor())
 781       Entries.push_back(*Subminor);
 782     // Ignore the 'build' component as it can't be represented in the object
 783     // file.
 784   }
 785   M.addModuleFlag(Module::ModFlagBehavior::Warning, Name,
 786                   ConstantDataArray::get(M.getContext(), Entries));
 787 }
 788
 789 void Module::setSDKVersion(const VersionTuple &V) {
 790   addSDKVersionMD(V, *this, "SDK Version");
 791 }
 792
 793 static VersionTuple getSDKVersionMD(Metadata *MD) {
 794   auto *CM = dyn_cast_or_null<ConstantAsMetadata>(MD);
 795   if (!CM)
 796     return {};
 797   auto *Arr = dyn_cast_or_null<ConstantDataArray>(CM->getValue());
 798   if (!Arr)
 799     return {};
 800   auto getVersionComponent = [&](unsigned Index) -> std::optional<unsigned> {
 801     if (Index >= Arr->getNumElements())
 802       return std::nullopt;
 803     return (unsigned)Arr->getElementAsInteger(Index);
 804   };
 805   auto Major = getVersionComponent(0);
 806   if (!Major)
 807     return {};
 808   VersionTuple Result = VersionTuple(*Major);
 809   if (auto Minor = getVersionComponent(1)) {
 810     Result = VersionTuple(*Major, *Minor);
 811     if (auto Subminor = getVersionComponent(2)) {
 812       Result = VersionTuple(*Major, *Minor, *Subminor);
 813     }
 814   }
 815   return Result;
 816 }
 817
 818 VersionTuple Module::getSDKVersion() const {
 819   return getSDKVersionMD(getModuleFlag("SDK Version"));
 820 }
 821
 822 GlobalVariable *llvm::collectUsedGlobalVariables(
 823     const Module &M, SmallVectorImpl<GlobalValue *> &Vec, bool CompilerUsed) {
 824   const char *Name = CompilerUsed ? "llvm.compiler.used" : "llvm.used";
 825   GlobalVariable *GV = M.getGlobalVariable(Name);
 826   if (!GV || !GV->hasInitializer())
 827     return GV;
 828
 829   const ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
 830   for (Value *Op : Init->operands()) {
 831     GlobalValue *G = cast<GlobalValue>(Op->stripPointerCasts());
 832     Vec.push_back(G);
 833   }
 834   return GV;
 835 }
 836
 837 void Module::setPartialSampleProfileRatio(const ModuleSummaryIndex &Index) {
 838   if (auto *SummaryMD = getProfileSummary(/*IsCS*/ false)) {
 839     std::unique_ptr<ProfileSummary> ProfileSummary(
 840         ProfileSummary::getFromMD(SummaryMD));
 841     if (ProfileSummary) {
 842       if (ProfileSummary->getKind() != ProfileSummary::PSK_Sample ||
 843           !ProfileSummary->isPartialProfile())
 844         return;
 845       uint64_t BlockCount = Index.getBlockCount();
 846       uint32_t NumCounts = ProfileSummary->getNumCounts();
 847       if (!NumCounts)
 848         return;
 849       double Ratio = (double)BlockCount / NumCounts;
 850       ProfileSummary->setPartialProfileRatio(Ratio);
 851       setProfileSummary(ProfileSummary->getMD(getContext()),
 852                         ProfileSummary::PSK_Sample);
 853     }
 854   }
 855 }
 856
 857 StringRef Module::getDarwinTargetVariantTriple() const {
 858   if (const auto *MD = getModuleFlag("darwin.target_variant.triple"))
 859     return cast<MDString>(MD)->getString();
 860   return "";
 861 }
 862
 863 void Module::setDarwinTargetVariantTriple(StringRef T) {
 864   addModuleFlag(ModFlagBehavior::Override, "darwin.target_variant.triple",
 865                 MDString::get(getContext(), T));
 866 }
 867
 868 VersionTuple Module::getDarwinTargetVariantSDKVersion() const {
 869   return getSDKVersionMD(getModuleFlag("darwin.target_variant.SDK Version"));
 870 }
 871
 872 void Module::setDarwinTargetVariantSDKVersion(VersionTuple Version) {
 873   addSDKVersionMD(Version, *this, "darwin.target_variant.SDK Version");
 874 }