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authorDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
committerDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
commit0b57cec536236d46e3dba9bd041533462f33dbb7 (patch)
tree56229dbdbbf76d18580f72f789003db17246c8d9 /contrib/llvm-project/llvm/lib/IR/Module.cpp
parent718ef55ec7785aae63f98f8ca05dc07ed399c16d (diff)
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-rw-r--r--contrib/llvm-project/llvm/lib/IR/Module.cpp611
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+//===- 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/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), Materializer(), ModuleID(MID), SourceFileName(MID), DL("") {
+ ValSymTab = new ValueSymbolTable();
+ NamedMDSymTab = new StringMap<NamedMDNode *>();
+ Context.addModule(this);
+}
+
+Module::~Module() {
+ Context.removeModule(this);
+ dropAllReferences();
+ GlobalList.clear();
+ FunctionList.clear();
+ AliasList.clear();
+ IFuncList.clear();
+ NamedMDList.clear();
+ delete ValSymTab;
+ delete static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab);
+}
+
+std::unique_ptr<RandomNumberGenerator> Module::createRNG(const Pass* P) const {
+ SmallString<32> Salt(P->getPassName());
+
+ // 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 static_cast<StringMap<NamedMDNode*> *>(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 =
+ (*static_cast<StringMap<NamedMDNode *> *>(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) {
+ static_cast<StringMap<NamedMDNode *> *>(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;
+}
+
+/// 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;
+ if (Flag->getNumOperands() >= 3 &&
+ isValidModFlagBehavior(Flag->getOperand(0), MFB) &&
+ dyn_cast_or_null<MDString>(Flag->getOperand(1))) {
+ // Check the operands of the MDNode before accessing the operands.
+ // The verifier will actually catch these failures.
+ MDString *Key = cast<MDString>(Flag->getOperand(1));
+ Metadata *Val = Flag->getOperand(2);
+ 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::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;
+}
+
+//===----------------------------------------------------------------------===//
+// 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)
+ addModuleFlag(ModFlagBehavior::Error, "CSProfileSummary", M);
+ else
+ addModuleFlag(ModFlagBehavior::Error, "ProfileSummary", M);
+}
+
+Metadata *Module::getProfileSummary(bool IsCS) {
+ return (IsCS ? getModuleFlag("CSProfileSummary")
+ : getModuleFlag("ProfileSummary"));
+}
+
+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->stripPointerCastsNoFollowAliases());
+ Set.insert(G);
+ }
+ return GV;
+}