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Diffstat (limited to 'tools/verify-uselistorder/verify-uselistorder.cpp')
| -rw-r--r-- | tools/verify-uselistorder/verify-uselistorder.cpp | 562 |
1 files changed, 562 insertions, 0 deletions
diff --git a/tools/verify-uselistorder/verify-uselistorder.cpp b/tools/verify-uselistorder/verify-uselistorder.cpp new file mode 100644 index 0000000..992a5b0 --- /dev/null +++ b/tools/verify-uselistorder/verify-uselistorder.cpp @@ -0,0 +1,562 @@ +//===- verify-uselistorder.cpp - The LLVM Modular Optimizer ---------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// 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/ReaderWriter.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/ManagedStatic.h" +#include "llvm/Support/MemoryBuffer.h" +#include "llvm/Support/PrettyStackTrace.h" +#include "llvm/Support/Signals.h" +#include "llvm/Support/SourceMgr.h" +#include "llvm/Support/SystemUtils.h" +#include <random> +#include <vector> + +using namespace llvm; + +#define DEBUG_TYPE "use-list-order" + +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::init(false)); + +static cl::opt<unsigned> + NumShuffles("num-shuffles", + cl::desc("Number of times to shuffle and verify use-lists"), + cl::init(1)); + +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)) { + (void)EC; + DEBUG(dbgs() << "error: " << EC.message() << "\n"); + return true; + } + assert(!Vector.empty()); + + Filename.assign(Vector.data(), Vector.data() + Vector.size()); + Remover.setFile(Filename, !SaveTemps); + DEBUG(dbgs() << " - filename = " << Filename << "\n"); + return false; +} + +bool TempFile::writeBitcode(const Module &M) const { + DEBUG(dbgs() << " - write bitcode\n"); + std::error_code EC; + raw_fd_ostream OS(Filename, EC, sys::fs::F_None); + if (EC) { + DEBUG(dbgs() << "error: " << EC.message() << "\n"); + return true; + } + + WriteBitcodeToFile(&M, OS); + return false; +} + +bool TempFile::writeAssembly(const Module &M) const { + DEBUG(dbgs() << " - write assembly\n"); + std::error_code EC; + raw_fd_ostream OS(Filename, EC, sys::fs::F_Text); + if (EC) { + DEBUG(dbgs() << "error: " << EC.message() << "\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; + } + + MemoryBuffer *Buffer = BufferOr.get().get(); + ErrorOr<Module *> ModuleOr = + parseBitcodeFile(Buffer->getMemBufferRef(), 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; +} + +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) { + errs() << "*** verify-use-list-order: bitcode ***\n"; + 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) { + errs() << "*** verify-use-list-order: assembly ***\n"; + 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) { + verifyBitcodeUseListOrder(M); + 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 collisons here. + 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; + DEBUG(dbgs() << " - order: " << I << ", op = " << U.getOperandNo() + << ", U = "; + U.getUser()->dump()); + } + } while (std::is_sorted(V->use_begin(), V->use_end(), compareUses)); + + DEBUG(dbgs() << " => shuffle\n"); + V->sortUseList(compareUses); + + 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; + + 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(); + + 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 (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 (Function &F : M) + if (F.hasPrefixData()) + changeValueUseList(F.getPrefixData()); + + // 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()) + 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) { + errs() << "*** shuffle-use-lists ***\n"; + std::minstd_rand0 Gen(std::minstd_rand0::default_seed + SeedOffset); + DenseSet<Value *> Seen; + changeUseLists(M, [&](Value *V) { shuffleValueUseLists(V, Gen, Seen); }); + DEBUG(dbgs() << "\n"); +} + +static void reverseUseLists(Module &M) { + errs() << "*** reverse-use-lists ***\n"; + DenseSet<Value *> Seen; + changeUseLists(M, [&](Value *V) { reverseValueUseLists(V, Seen); }); + DEBUG(dbgs() << "\n"); +} + +int main(int argc, char **argv) { + sys::PrintStackTraceOnErrorSignal(); + llvm::PrettyStackTraceProgram X(argc, argv); + + // Enable debug stream buffering. + EnableDebugBuffering = true; + + llvm_shutdown_obj Y; // Call llvm_shutdown() on exit. + LLVMContext &Context = getGlobalContext(); + + cl::ParseCommandLineOptions(argc, argv, + "llvm tool to verify use-list order\n"); + + SMDiagnostic Err; + + // Load the input module... + std::unique_ptr<Module> M = parseIRFile(InputFilename, Err, Context); + + if (!M.get()) { + Err.print(argv[0], errs()); + return 1; + } + if (verifyModule(*M, &errs())) + report_fatal_error("verification failed"); + + errs() << "*** verify-use-list-order ***\n"; + // Can't verify if order isn't preserved. + if (!shouldPreserveBitcodeUseListOrder()) { + errs() << "warning: forcing -preserve-bc-use-list-order\n"; + setPreserveBitcodeUseListOrder(true); + } + if (!shouldPreserveAssemblyUseListOrder()) { + errs() << "warning: forcing -preserve-ll-use-list-order\n"; + setPreserveAssemblyUseListOrder(true); + } + + // Verify the use lists now and after reversing them. + verifyUseListOrder(*M); + reverseUseLists(*M); + verifyUseListOrder(*M); + + for (unsigned I = 0, E = NumShuffles; I != E; ++I) { + errs() << "*** shuffle iteration: " << I + 1 << " of " << E << " ***\n"; + + // Shuffle with a different (deterministic) seed each time. + shuffleUseLists(*M, I); + + // Verify again before and after reversing. + verifyUseListOrder(*M); + reverseUseLists(*M); + verifyUseListOrder(*M); + } + + return 0; +} |