--- /dev/null
+//===- UseListOrder.cpp - Implement Use List Order functions --------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Implement use list order functions to modify use-list order and verify it
+// doesn't change after serialization.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/UseListOrder.h"
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FileUtilities.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/SourceMgr.h"
+
+#include <random>
+#include <vector>
+
+#define DEBUG_TYPE "use-list-order"
+
+using namespace llvm;
+
+static cl::opt<bool> PreserveBitcodeUseListOrder(
+ "preserve-bc-use-list-order",
+ cl::desc("Experimental support to preserve bitcode use-list order."),
+ cl::init(false), cl::Hidden);
+
+bool llvm::shouldPreserveBitcodeUseListOrder() {
+ return PreserveBitcodeUseListOrder;
+}
+
+static void shuffleValueUseLists(Value *V, std::minstd_rand0 &Gen,
+ DenseSet<Value *> &Seen) {
+ if (!Seen.insert(V).second)
+ return;
+
+ if (auto *C = dyn_cast<Constant>(V))
+ if (!isa<GlobalValue>(C))
+ for (Value *Op : C->operands())
+ shuffleValueUseLists(Op, Gen, Seen);
+
+ if (V->use_empty() || std::next(V->use_begin()) == V->use_end())
+ // Nothing to shuffle for 0 or 1 users.
+ return;
+
+ // Generate random numbers between 10 and 99, which will line up nicely in
+ // debug output. We're not worried about collisons here.
+ DEBUG(dbgs() << "V = "; V->dump());
+ std::uniform_int_distribution<short> Dist(10, 99);
+ SmallDenseMap<const Use *, short, 16> Order;
+ for (const Use &U : V->uses()) {
+ auto I = Dist(Gen);
+ Order[&U] = I;
+ DEBUG(dbgs() << " - order: " << I << ", U = "; U.getUser()->dump());
+ }
+
+ DEBUG(dbgs() << " => shuffle\n");
+ V->sortUseList(
+ [&Order](const Use &L, const Use &R) { return Order[&L] < Order[&R]; });
+
+ DEBUG({
+ for (const Use &U : V->uses())
+ DEBUG(dbgs() << " - order: " << Order.lookup(&U) << ", U = ";
+ U.getUser()->dump());
+ });
+}
+
+void llvm::shuffleUseLists(Module &M, unsigned SeedOffset) {
+ DEBUG(dbgs() << "*** shuffle-use-lists ***\n");
+ std::minstd_rand0 Gen(std::minstd_rand0::default_seed + SeedOffset);
+ DenseSet<Value *> Seen;
+
+ // Shuffle the use-list of each value that would be serialized to an IR file
+ // (bitcode or assembly).
+ auto shuffle = [&](Value *V) { shuffleValueUseLists(V, Gen, Seen); };
+
+ // Globals.
+ for (GlobalVariable &G : M.globals())
+ shuffle(&G);
+ for (GlobalAlias &A : M.aliases())
+ shuffle(&A);
+ for (Function &F : M)
+ shuffle(&F);
+
+ // Constants used by globals.
+ for (GlobalVariable &G : M.globals())
+ if (G.hasInitializer())
+ shuffle(G.getInitializer());
+ for (GlobalAlias &A : M.aliases())
+ shuffle(A.getAliasee());
+ for (Function &F : M)
+ if (F.hasPrefixData())
+ shuffle(F.getPrefixData());
+
+ // Function bodies.
+ for (Function &F : M) {
+ for (Argument &A : F.args())
+ shuffle(&A);
+ for (BasicBlock &BB : F)
+ shuffle(&BB);
+ for (BasicBlock &BB : F)
+ for (Instruction &I : BB)
+ shuffle(&I);
+
+ // Constants used by instructions.
+ for (BasicBlock &BB : F)
+ for (Instruction &I : BB)
+ for (Value *Op : I.operands())
+ if ((isa<Constant>(Op) && !isa<GlobalValue>(*Op)) ||
+ isa<InlineAsm>(Op))
+ shuffle(Op);
+ }
+
+ DEBUG(dbgs() << "\n");
+}
+
+namespace {
+
+struct TempFile {
+ std::string Filename;
+ FileRemover Remover;
+ bool init(const std::string &Ext);
+ bool writeBitcode(const Module &M) const;
+ bool writeAssembly(const Module &M) const;
+ std::unique_ptr<Module> readBitcode(LLVMContext &Context) const;
+ std::unique_ptr<Module> readAssembly(LLVMContext &Context) const;
+};
+
+struct ValueMapping {
+ DenseMap<const Value *, unsigned> IDs;
+ std::vector<const Value *> Values;
+
+ /// \brief Construct a value mapping for module.
+ ///
+ /// Creates mapping from every value in \c M to an ID. This mapping includes
+ /// un-referencable values.
+ ///
+ /// Every \a Value that gets serialized in some way should be represented
+ /// here. The order needs to be deterministic, but it's unnecessary to match
+ /// the value-ids in the bitcode writer.
+ ///
+ /// All constants that are referenced by other values are included in the
+ /// mapping, but others -- which wouldn't be serialized -- are not.
+ ValueMapping(const Module &M);
+
+ /// \brief Map a value.
+ ///
+ /// Maps a value. If it's a constant, maps all of its operands first.
+ void map(const Value *V);
+ unsigned lookup(const Value *V) const { return IDs.lookup(V); }
+};
+
+} // end namespace
+
+bool TempFile::init(const std::string &Ext) {
+ SmallVector<char, 64> Vector;
+ DEBUG(dbgs() << " - create-temp-file\n");
+ if (auto EC = sys::fs::createTemporaryFile("use-list-order", Ext, Vector)) {
+ DEBUG(dbgs() << "error: " << EC.message() << "\n");
+ return true;
+ }
+ assert(!Vector.empty());
+
+ Filename.assign(Vector.data(), Vector.data() + Vector.size());
+ Remover.setFile(Filename);
+ DEBUG(dbgs() << " - filename = " << Filename << "\n");
+ return false;
+}
+
+bool TempFile::writeBitcode(const Module &M) const {
+ DEBUG(dbgs() << " - write bitcode\n");
+ std::string ErrorInfo;
+ raw_fd_ostream OS(Filename.c_str(), ErrorInfo, sys::fs::F_None);
+ if (!ErrorInfo.empty()) {
+ DEBUG(dbgs() << "error: " << ErrorInfo << "\n");
+ return true;
+ }
+
+ WriteBitcodeToFile(&M, OS);
+ return false;
+}
+
+bool TempFile::writeAssembly(const Module &M) const {
+ DEBUG(dbgs() << " - write assembly\n");
+ std::string ErrorInfo;
+ raw_fd_ostream OS(Filename.c_str(), ErrorInfo, sys::fs::F_Text);
+ if (!ErrorInfo.empty()) {
+ DEBUG(dbgs() << "error: " << ErrorInfo << "\n");
+ return true;
+ }
+
+ OS << M;
+ return false;
+}
+
+std::unique_ptr<Module> TempFile::readBitcode(LLVMContext &Context) const {
+ DEBUG(dbgs() << " - read bitcode\n");
+ ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOr =
+ MemoryBuffer::getFile(Filename);
+ if (!BufferOr) {
+ DEBUG(dbgs() << "error: " << BufferOr.getError().message() << "\n");
+ return nullptr;
+ }
+
+ std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOr.get());
+ ErrorOr<Module *> ModuleOr = parseBitcodeFile(Buffer.release(), Context);
+ if (!ModuleOr) {
+ DEBUG(dbgs() << "error: " << ModuleOr.getError().message() << "\n");
+ return nullptr;
+ }
+ return std::unique_ptr<Module>(ModuleOr.get());
+}
+
+std::unique_ptr<Module> TempFile::readAssembly(LLVMContext &Context) const {
+ DEBUG(dbgs() << " - read assembly\n");
+ SMDiagnostic Err;
+ std::unique_ptr<Module> M(ParseAssemblyFile(Filename, Err, Context));
+ if (!M.get())
+ DEBUG(dbgs() << "error: "; Err.print("verify-use-list-order", dbgs()));
+ return M;
+}
+
+ValueMapping::ValueMapping(const Module &M) {
+ // Every value should be mapped, including things like void instructions and
+ // basic blocks that are kept out of the ValueEnumerator.
+ //
+ // The current mapping order makes it easier to debug the tables. It happens
+ // to be similar to the ID mapping when writing ValueEnumerator, but they
+ // aren't (and needn't be) in sync.
+
+ // Globals.
+ for (const GlobalVariable &G : M.globals())
+ map(&G);
+ for (const GlobalAlias &A : M.aliases())
+ map(&A);
+ for (const Function &F : M)
+ map(&F);
+
+ // Constants used by globals.
+ for (const GlobalVariable &G : M.globals())
+ if (G.hasInitializer())
+ map(G.getInitializer());
+ for (const GlobalAlias &A : M.aliases())
+ map(A.getAliasee());
+ for (const Function &F : M)
+ if (F.hasPrefixData())
+ map(F.getPrefixData());
+
+ // Function bodies.
+ for (const Function &F : M) {
+ for (const Argument &A : F.args())
+ map(&A);
+ for (const BasicBlock &BB : F)
+ map(&BB);
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ map(&I);
+
+ // Constants used by instructions.
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ for (const Value *Op : I.operands())
+ if ((isa<Constant>(Op) && !isa<GlobalValue>(*Op)) ||
+ isa<InlineAsm>(Op))
+ map(Op);
+ }
+}
+
+void ValueMapping::map(const Value *V) {
+ if (IDs.lookup(V))
+ return;
+
+ if (auto *C = dyn_cast<Constant>(V))
+ if (!isa<GlobalValue>(C))
+ for (const Value *Op : C->operands())
+ map(Op);
+
+ Values.push_back(V);
+ IDs[V] = Values.size();
+}
+
+#ifndef NDEBUG
+static void dumpMapping(const ValueMapping &VM) {
+ dbgs() << "value-mapping (size = " << VM.Values.size() << "):\n";
+ for (unsigned I = 0, E = VM.Values.size(); I != E; ++I) {
+ dbgs() << " - id = " << I << ", value = ";
+ VM.Values[I]->dump();
+ }
+}
+
+static void debugValue(const ValueMapping &M, unsigned I, StringRef Desc) {
+ const Value *V = M.Values[I];
+ dbgs() << " - " << Desc << " value = ";
+ V->dump();
+ for (const Use &U : V->uses()) {
+ dbgs() << " => use: op = " << U.getOperandNo()
+ << ", user-id = " << M.IDs.lookup(U.getUser()) << ", user = ";
+ U.getUser()->dump();
+ }
+}
+
+static void debugUserMismatch(const ValueMapping &L, const ValueMapping &R,
+ unsigned I) {
+ dbgs() << " - fail: user mismatch: ID = " << I << "\n";
+ debugValue(L, I, "LHS");
+ debugValue(R, I, "RHS");
+
+ dbgs() << "\nlhs-";
+ dumpMapping(L);
+ dbgs() << "\nrhs-";
+ dumpMapping(R);
+}
+
+static void debugSizeMismatch(const ValueMapping &L, const ValueMapping &R) {
+ dbgs() << " - fail: map size: " << L.Values.size()
+ << " != " << R.Values.size() << "\n";
+ dbgs() << "\nlhs-";
+ dumpMapping(L);
+ dbgs() << "\nrhs-";
+ dumpMapping(R);
+}
+#endif
+
+static bool matches(const ValueMapping &LM, const ValueMapping &RM) {
+ DEBUG(dbgs() << "compare value maps\n");
+ if (LM.Values.size() != RM.Values.size()) {
+ DEBUG(debugSizeMismatch(LM, RM));
+ return false;
+ }
+
+ // This mapping doesn't include dangling constant users, since those don't
+ // get serialized. However, checking if users are constant and calling
+ // isConstantUsed() on every one is very expensive. Instead, just check if
+ // the user is mapped.
+ auto skipUnmappedUsers =
+ [&](Value::const_use_iterator &U, Value::const_use_iterator E,
+ const ValueMapping &M) {
+ while (U != E && !M.lookup(U->getUser()))
+ ++U;
+ };
+
+ // Iterate through all values, and check that both mappings have the same
+ // users.
+ for (unsigned I = 0, E = LM.Values.size(); I != E; ++I) {
+ const Value *L = LM.Values[I];
+ const Value *R = RM.Values[I];
+ auto LU = L->use_begin(), LE = L->use_end();
+ auto RU = R->use_begin(), RE = R->use_end();
+ skipUnmappedUsers(LU, LE, LM);
+ skipUnmappedUsers(RU, RE, RM);
+
+ while (LU != LE) {
+ if (RU == RE) {
+ DEBUG(debugUserMismatch(LM, RM, I));
+ return false;
+ }
+ if (LM.lookup(LU->getUser()) != RM.lookup(RU->getUser())) {
+ DEBUG(debugUserMismatch(LM, RM, I));
+ return false;
+ }
+ if (LU->getOperandNo() != RU->getOperandNo()) {
+ DEBUG(debugUserMismatch(LM, RM, I));
+ return false;
+ }
+ skipUnmappedUsers(++LU, LE, LM);
+ skipUnmappedUsers(++RU, RE, RM);
+ }
+ if (RU != RE) {
+ DEBUG(debugUserMismatch(LM, RM, I));
+ return false;
+ }
+ }
+
+ return true;
+}
+
+bool llvm::verifyBitcodeUseListOrder(const Module &M) {
+ DEBUG(dbgs() << "*** verify-use-list-order: bitcode ***\n");
+ TempFile F;
+ if (F.init("bc"))
+ return false;
+
+ if (F.writeBitcode(M))
+ return false;
+
+ LLVMContext Context;
+ std::unique_ptr<Module> OtherM = F.readBitcode(Context);
+ if (!OtherM)
+ return false;
+
+ return matches(ValueMapping(M), ValueMapping(*OtherM));
+}
+
+bool llvm::verifyAssemblyUseListOrder(const Module &M) {
+ DEBUG(dbgs() << "*** verify-use-list-order: assembly ***\n");
+ TempFile F;
+ if (F.init("ll"))
+ return false;
+
+ if (F.writeAssembly(M))
+ return false;
+
+ LLVMContext Context;
+ std::unique_ptr<Module> OtherM = F.readAssembly(Context);
+ if (!OtherM)
+ return false;
+
+ return matches(ValueMapping(M), ValueMapping(*OtherM));
+}