| //===- verify-uselistorder.cpp - The LLVM Modular Optimizer ---------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Verify that use-list order can be serialized correctly. After reading the |
| // provided IR, this tool shuffles the use-lists and then writes and reads to a |
| // separate Module whose use-list orders are compared to the original. |
| // |
| // The shuffles are deterministic, but guarantee that use-lists will change. |
| // The algorithm per iteration is as follows: |
| // |
| // 1. Seed the random number generator. The seed is different for each |
| // shuffle. Shuffle 0 uses default+0, shuffle 1 uses default+1, and so on. |
| // |
| // 2. Visit every Value in a deterministic order. |
| // |
| // 3. Assign a random number to each Use in the Value's use-list in order. |
| // |
| // 4. If the numbers are already in order, reassign numbers until they aren't. |
| // |
| // 5. Sort the use-list using Value::sortUseList(), which is a stable sort. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/DenseSet.h" |
| #include "llvm/AsmParser/Parser.h" |
| #include "llvm/Bitcode/BitcodeReader.h" |
| #include "llvm/Bitcode/BitcodeWriter.h" |
| #include "llvm/IR/LLVMContext.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/IR/UseListOrder.h" |
| #include "llvm/IR/Verifier.h" |
| #include "llvm/IRReader/IRReader.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/FileUtilities.h" |
| #include "llvm/Support/InitLLVM.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/SourceMgr.h" |
| #include "llvm/Support/SystemUtils.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <random> |
| #include <vector> |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "uselistorder" |
| |
| static cl::OptionCategory Cat("verify-uselistorder Options"); |
| |
| static cl::opt<std::string> InputFilename(cl::Positional, |
| cl::desc("<input bitcode file>"), |
| cl::init("-"), |
| cl::value_desc("filename")); |
| |
| static cl::opt<bool> SaveTemps("save-temps", cl::desc("Save temp files"), |
| cl::cat(Cat)); |
| |
| static cl::opt<unsigned> |
| NumShuffles("num-shuffles", |
| cl::desc("Number of times to shuffle and verify use-lists"), |
| cl::init(1), cl::cat(Cat)); |
| |
| extern cl::opt<cl::boolOrDefault> PreserveInputDbgFormat; |
| |
| 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; |
| |
| /// 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); |
| |
| /// 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; |
| LLVM_DEBUG(dbgs() << " - create-temp-file\n"); |
| if (auto EC = sys::fs::createTemporaryFile("uselistorder", Ext, Vector)) { |
| errs() << "verify-uselistorder: error: " << EC.message() << "\n"; |
| return true; |
| } |
| assert(!Vector.empty()); |
| |
| Filename.assign(Vector.data(), Vector.data() + Vector.size()); |
| Remover.setFile(Filename, !SaveTemps); |
| if (SaveTemps) |
| outs() << " - filename = " << Filename << "\n"; |
| return false; |
| } |
| |
| bool TempFile::writeBitcode(const Module &M) const { |
| LLVM_DEBUG(dbgs() << " - write bitcode\n"); |
| std::error_code EC; |
| raw_fd_ostream OS(Filename, EC, sys::fs::OF_None); |
| if (EC) { |
| errs() << "verify-uselistorder: error: " << EC.message() << "\n"; |
| return true; |
| } |
| |
| WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true); |
| return false; |
| } |
| |
| bool TempFile::writeAssembly(const Module &M) const { |
| LLVM_DEBUG(dbgs() << " - write assembly\n"); |
| std::error_code EC; |
| raw_fd_ostream OS(Filename, EC, sys::fs::OF_TextWithCRLF); |
| if (EC) { |
| errs() << "verify-uselistorder: error: " << EC.message() << "\n"; |
| return true; |
| } |
| |
| M.print(OS, nullptr, /* ShouldPreserveUseListOrder */ true); |
| return false; |
| } |
| |
| std::unique_ptr<Module> TempFile::readBitcode(LLVMContext &Context) const { |
| LLVM_DEBUG(dbgs() << " - read bitcode\n"); |
| ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOr = |
| MemoryBuffer::getFile(Filename); |
| if (!BufferOr) { |
| errs() << "verify-uselistorder: error: " << BufferOr.getError().message() |
| << "\n"; |
| return nullptr; |
| } |
| |
| MemoryBuffer *Buffer = BufferOr.get().get(); |
| Expected<std::unique_ptr<Module>> ModuleOr = |
| parseBitcodeFile(Buffer->getMemBufferRef(), Context); |
| if (!ModuleOr) { |
| logAllUnhandledErrors(ModuleOr.takeError(), errs(), |
| "verify-uselistorder: error: "); |
| return nullptr; |
| } |
| |
| return std::move(ModuleOr.get()); |
| } |
| |
| std::unique_ptr<Module> TempFile::readAssembly(LLVMContext &Context) const { |
| LLVM_DEBUG(dbgs() << " - read assembly\n"); |
| SMDiagnostic Err; |
| std::unique_ptr<Module> M = parseAssemblyFile(Filename, Err, Context); |
| if (!M) |
| Err.print("verify-uselistorder", errs()); |
| 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 GlobalIFunc &IF : M.ifuncs()) |
| map(&IF); |
| 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 GlobalIFunc &IF : M.ifuncs()) |
| map(IF.getResolver()); |
| for (const Function &F : M) |
| for (Value *Op : F.operands()) |
| map(Op); |
| |
| // 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 DbgVariableRecord &DVR : |
| filterDbgVars(I.getDbgRecordRange())) { |
| for (Value *Op : DVR.location_ops()) |
| map(Op); |
| if (DVR.isDbgAssign()) |
| map(DVR.getAddress()); |
| } |
| for (const Value *Op : I.operands()) { |
| // Look through a metadata wrapper. |
| if (const auto *MAV = dyn_cast<MetadataAsValue>(Op)) |
| if (const auto *VAM = dyn_cast<ValueAsMetadata>(MAV->getMetadata())) |
| Op = VAM->getValue(); |
| |
| 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) { |
| LLVM_DEBUG(dbgs() << "compare value maps\n"); |
| if (LM.Values.size() != RM.Values.size()) { |
| LLVM_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) { |
| LLVM_DEBUG(debugUserMismatch(LM, RM, I)); |
| return false; |
| } |
| if (LM.lookup(LU->getUser()) != RM.lookup(RU->getUser())) { |
| LLVM_DEBUG(debugUserMismatch(LM, RM, I)); |
| return false; |
| } |
| if (LU->getOperandNo() != RU->getOperandNo()) { |
| LLVM_DEBUG(debugUserMismatch(LM, RM, I)); |
| return false; |
| } |
| skipUnmappedUsers(++LU, LE, LM); |
| skipUnmappedUsers(++RU, RE, RM); |
| } |
| if (RU != RE) { |
| LLVM_DEBUG(debugUserMismatch(LM, RM, I)); |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| static void verifyAfterRoundTrip(const Module &M, |
| std::unique_ptr<Module> OtherM) { |
| if (!OtherM) |
| report_fatal_error("parsing failed"); |
| if (verifyModule(*OtherM, &errs())) |
| report_fatal_error("verification failed"); |
| if (!matches(ValueMapping(M), ValueMapping(*OtherM))) |
| report_fatal_error("use-list order changed"); |
| } |
| |
| static void verifyBitcodeUseListOrder(const Module &M) { |
| TempFile F; |
| if (F.init("bc")) |
| report_fatal_error("failed to initialize bitcode file"); |
| |
| if (F.writeBitcode(M)) |
| report_fatal_error("failed to write bitcode"); |
| |
| LLVMContext Context; |
| verifyAfterRoundTrip(M, F.readBitcode(Context)); |
| } |
| |
| static void verifyAssemblyUseListOrder(const Module &M) { |
| TempFile F; |
| if (F.init("ll")) |
| report_fatal_error("failed to initialize assembly file"); |
| |
| if (F.writeAssembly(M)) |
| report_fatal_error("failed to write assembly"); |
| |
| LLVMContext Context; |
| verifyAfterRoundTrip(M, F.readAssembly(Context)); |
| } |
| |
| static void verifyUseListOrder(const Module &M) { |
| outs() << "verify bitcode\n"; |
| verifyBitcodeUseListOrder(M); |
| outs() << "verify assembly\n"; |
| verifyAssemblyUseListOrder(M); |
| } |
| |
| 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 collisions here. |
| LLVM_DEBUG(dbgs() << "V = "; V->dump()); |
| std::uniform_int_distribution<short> Dist(10, 99); |
| SmallDenseMap<const Use *, short, 16> Order; |
| auto compareUses = |
| [&Order](const Use &L, const Use &R) { return Order[&L] < Order[&R]; }; |
| do { |
| for (const Use &U : V->uses()) { |
| auto I = Dist(Gen); |
| Order[&U] = I; |
| LLVM_DEBUG(dbgs() << " - order: " << I << ", op = " << U.getOperandNo() |
| << ", U = "; |
| U.getUser()->dump()); |
| } |
| } while (std::is_sorted(V->use_begin(), V->use_end(), compareUses)); |
| |
| LLVM_DEBUG(dbgs() << " => shuffle\n"); |
| V->sortUseList(compareUses); |
| |
| LLVM_DEBUG({ |
| for (const Use &U : V->uses()) { |
| dbgs() << " - order: " << Order.lookup(&U) |
| << ", op = " << U.getOperandNo() << ", U = "; |
| U.getUser()->dump(); |
| } |
| }); |
| } |
| |
| static void reverseValueUseLists(Value *V, 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()) |
| reverseValueUseLists(Op, Seen); |
| |
| if (V->use_empty() || std::next(V->use_begin()) == V->use_end()) |
| // Nothing to shuffle for 0 or 1 users. |
| return; |
| |
| LLVM_DEBUG({ |
| dbgs() << "V = "; |
| V->dump(); |
| for (const Use &U : V->uses()) { |
| dbgs() << " - order: op = " << U.getOperandNo() << ", U = "; |
| U.getUser()->dump(); |
| } |
| dbgs() << " => reverse\n"; |
| }); |
| |
| V->reverseUseList(); |
| |
| LLVM_DEBUG({ |
| for (const Use &U : V->uses()) { |
| dbgs() << " - order: op = " << U.getOperandNo() << ", U = "; |
| U.getUser()->dump(); |
| } |
| }); |
| } |
| |
| template <class Changer> |
| static void changeUseLists(Module &M, Changer changeValueUseList) { |
| // Visit every value that would be serialized to an IR file. |
| // |
| // Globals. |
| for (GlobalVariable &G : M.globals()) |
| changeValueUseList(&G); |
| for (GlobalAlias &A : M.aliases()) |
| changeValueUseList(&A); |
| for (GlobalIFunc &IF : M.ifuncs()) |
| changeValueUseList(&IF); |
| for (Function &F : M) |
| changeValueUseList(&F); |
| |
| // Constants used by globals. |
| for (GlobalVariable &G : M.globals()) |
| if (G.hasInitializer()) |
| changeValueUseList(G.getInitializer()); |
| for (GlobalAlias &A : M.aliases()) |
| changeValueUseList(A.getAliasee()); |
| for (GlobalIFunc &IF : M.ifuncs()) |
| changeValueUseList(IF.getResolver()); |
| for (Function &F : M) |
| for (Value *Op : F.operands()) |
| changeValueUseList(Op); |
| |
| // Function bodies. |
| for (Function &F : M) { |
| for (Argument &A : F.args()) |
| changeValueUseList(&A); |
| for (BasicBlock &BB : F) |
| changeValueUseList(&BB); |
| for (BasicBlock &BB : F) |
| for (Instruction &I : BB) |
| changeValueUseList(&I); |
| |
| // Constants used by instructions. |
| for (BasicBlock &BB : F) |
| for (Instruction &I : BB) |
| for (Value *Op : I.operands()) { |
| // Look through a metadata wrapper. |
| if (auto *MAV = dyn_cast<MetadataAsValue>(Op)) |
| if (auto *VAM = dyn_cast<ValueAsMetadata>(MAV->getMetadata())) |
| Op = VAM->getValue(); |
| if ((isa<Constant>(Op) && !isa<GlobalValue>(*Op)) || |
| isa<InlineAsm>(Op)) |
| changeValueUseList(Op); |
| } |
| } |
| |
| if (verifyModule(M, &errs())) |
| report_fatal_error("verification failed"); |
| } |
| |
| static void shuffleUseLists(Module &M, unsigned SeedOffset) { |
| std::minstd_rand0 Gen(std::minstd_rand0::default_seed + SeedOffset); |
| DenseSet<Value *> Seen; |
| changeUseLists(M, [&](Value *V) { shuffleValueUseLists(V, Gen, Seen); }); |
| LLVM_DEBUG(dbgs() << "\n"); |
| } |
| |
| static void reverseUseLists(Module &M) { |
| DenseSet<Value *> Seen; |
| changeUseLists(M, [&](Value *V) { reverseValueUseLists(V, Seen); }); |
| LLVM_DEBUG(dbgs() << "\n"); |
| } |
| |
| int main(int argc, char **argv) { |
| PreserveInputDbgFormat = cl::boolOrDefault::BOU_TRUE; |
| InitLLVM X(argc, argv); |
| |
| // Enable debug stream buffering. |
| EnableDebugBuffering = true; |
| |
| cl::HideUnrelatedOptions(Cat); |
| cl::ParseCommandLineOptions(argc, argv, |
| "llvm tool to verify use-list order\n"); |
| |
| LLVMContext Context; |
| SMDiagnostic Err; |
| |
| // Load the input module... |
| std::unique_ptr<Module> M = parseIRFile(InputFilename, Err, Context); |
| |
| if (!M) { |
| Err.print(argv[0], errs()); |
| return 1; |
| } |
| if (verifyModule(*M, &errs())) { |
| errs() << argv[0] << ": " << InputFilename |
| << ": error: input module is broken!\n"; |
| return 1; |
| } |
| |
| // Verify the use lists now and after reversing them. |
| outs() << "*** verify-uselistorder ***\n"; |
| verifyUseListOrder(*M); |
| outs() << "reverse\n"; |
| reverseUseLists(*M); |
| verifyUseListOrder(*M); |
| |
| for (unsigned I = 0, E = NumShuffles; I != E; ++I) { |
| outs() << "\n"; |
| |
| // Shuffle with a different (deterministic) seed each time. |
| outs() << "shuffle (" << I + 1 << " of " << E << ")\n"; |
| shuffleUseLists(*M, I); |
| |
| // Verify again before and after reversing. |
| verifyUseListOrder(*M); |
| outs() << "reverse\n"; |
| reverseUseLists(*M); |
| verifyUseListOrder(*M); |
| } |
| |
| return 0; |
| } |