LowerTypeTests: Thread summary and action from the API and command line into the pass.

[pcc]

Summary

Also move command line handling out of the pass constructor and into
a separate function.

[mehdi_amini]

LGTM.

llvm/include/llvm/Transforms/IPO.h

227

Document the arguments, especially mention that Index can be null when Action is None.

llvm/include/llvm/Transforms/IPO.h

 //
 ModulePass *createMetaRenamerPass();
 
 //===----------------------------------------------------------------------===//
 /// createBarrierNoopPass - This pass is purely a module pass barrier in a pass
 /// manager.
 ModulePass *createBarrierNoopPass();
 
+/// What to do with the summary when running the LowerTypeTests pass.
+enum class LowerTypeTestsSummaryAction {
+  None,   ///< Do nothing.
+  Import, ///< Import typeid resolutions from summary and globals.
+  Export, ///< Export typeid resolutions to summary and globals.
+};
+
 /// \brief This pass lowers type metadata and the llvm.type.test intrinsic to
 /// bitsets.
-ModulePass *createLowerTypeTestsPass();
+ModulePass *createLowerTypeTestsPass(LowerTypeTestsSummaryAction Action,
+                                     ModuleSummaryIndex *Index);
 
 /// \brief This pass export CFI checks for use by external modules.
 ModulePass *createCrossDSOCFIPass();
 
 /// \brief This pass implements whole-program devirtualization using type
 /// metadata.
 ModulePass *createWholeProgramDevirtPass();
 

llvm/lib/Transforms/IPO/LowerTypeTests.cpp

 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/ModuleUtils.h"
 
 using namespace llvm;
 using namespace lowertypetests;
 
+using SummaryAction = LowerTypeTestsSummaryAction;
+
 #define DEBUG_TYPE "lowertypetests"
 
 STATISTIC(ByteArraySizeBits, "Byte array size in bits");
 STATISTIC(ByteArraySizeBytes, "Byte array size in bytes");
 STATISTIC(NumByteArraysCreated, "Number of byte arrays created");
 STATISTIC(NumTypeTestCallsLowered, "Number of type test calls lowered");
 STATISTIC(NumTypeIdDisjointSets, "Number of disjoint sets of type identifiers");
 
 static cl::opt<bool> AvoidReuse(
     "lowertypetests-avoid-reuse",
     cl::desc("Try to avoid reuse of byte array addresses using aliases"),
     cl::Hidden, cl::init(true));
 
-static cl::opt<std::string> ClSummaryAction(
+static cl::opt<SummaryAction> ClSummaryAction(
     "lowertypetests-summary-action",
-    cl::desc("What to do with the summary when running this pass"), cl::Hidden);
+    cl::desc("What to do with the summary when running this pass"),
+    cl::values(clEnumValN(SummaryAction::None, "none", "Do nothing"),
+               clEnumValN(SummaryAction::Import, "import",
+                          "Import typeid resolutions from summary and globals"),
+               clEnumValN(SummaryAction::Export, "export",
+                          "Export typeid resolutions to summary and globals")),
+    cl::Hidden);
 
 static cl::opt<std::string> ClReadSummary(
     "lowertypetests-read-summary",
     cl::desc("Read summary from given YAML file before running pass"),
     cl::Hidden);
 
 static cl::opt<std::string> ClWriteSummary(
     "lowertypetests-write-summary",
public:
   ArrayRef<MDNode *> types() const {
     return makeArrayRef(getTrailingObjects<MDNode *>(), NTypes);
   }
 };
 
 class LowerTypeTestsModule {
   Module &M;
 
-  // This is for testing purposes only.
-  std::unique_ptr<ModuleSummaryIndex> OwnedSummary;
+  SummaryAction Action;
+  ModuleSummaryIndex *Summary;
 
   bool LinkerSubsectionsViaSymbols;
   Triple::ArchType Arch;
   Triple::OSType OS;
   Triple::ObjectFormatType ObjectFormat;
 
   IntegerType *Int1Ty = Type::getInt1Ty(M.getContext());
   IntegerType *Int8Ty = Type::getInt8Ty(M.getContext());
class LowerTypeTestsModule {
   void replaceWeakDeclarationWithJumpTablePtr(Function *F, Constant *JT);
   void moveInitializerToModuleConstructor(GlobalVariable *GV);
   void findGlobalVariableUsersOf(Constant *C,
                                  SmallSetVector<GlobalVariable *, 8> &Out);
 
   void createJumpTable(Function *F, ArrayRef<GlobalTypeMember *> Functions);
 
 public:
-  LowerTypeTestsModule(Module &M);
-  ~LowerTypeTestsModule();
+  LowerTypeTestsModule(Module &M, SummaryAction Action,
+                       ModuleSummaryIndex *Summary);
   bool lower();
+
+  // Lower the module using the action and summary passed as command line
+  // arguments. For testing purposes only.
+  static bool runForTesting(Module &M);
 };
 
 struct LowerTypeTests : public ModulePass {
   static char ID;
-  LowerTypeTests() : ModulePass(ID) {
+
+  bool UseCommandLine = false;
+
+  SummaryAction Action;
+  ModuleSummaryIndex *Summary;
+
+  LowerTypeTests() : ModulePass(ID), UseCommandLine(true) {
+    initializeLowerTypeTestsPass(*PassRegistry::getPassRegistry());
+  }
+
+  LowerTypeTests(SummaryAction Action, ModuleSummaryIndex *Summary)
+      : ModulePass(ID), Action(Action), Summary(Summary) {
     initializeLowerTypeTestsPass(*PassRegistry::getPassRegistry());
   }
 
   bool runOnModule(Module &M) override {
     if (skipModule(M))
       return false;
-    return LowerTypeTestsModule(M).lower();
+    if (UseCommandLine)
+      return LowerTypeTestsModule::runForTesting(M);
+    return LowerTypeTestsModule(M, Action, Summary).lower();
   }
 };
 
 } // anonymous namespace
 
 INITIALIZE_PASS(LowerTypeTests, "lowertypetests", "Lower type metadata", false,
                 false)
 char LowerTypeTests::ID = 0;
 
-ModulePass *llvm::createLowerTypeTestsPass() { return new LowerTypeTests; }
+ModulePass *llvm::createLowerTypeTestsPass(SummaryAction Action,
+                                           ModuleSummaryIndex *Summary) {
+  return new LowerTypeTests(Action, Summary);
+}
 
 /// Build a bit set for TypeId using the object layouts in
 /// GlobalLayout.
 BitSetInfo LowerTypeTestsModule::buildBitSet(
     Metadata *TypeId,
     const DenseMap<GlobalTypeMember *, uint64_t> &GlobalLayout) {
   BitSetBuilder BSB;
 
for (auto &&F : GLB.Fragments) {
       }
     }
 
     buildBitSetsFromFunctions(TypeIds, OrderedFns);
   }
 }
 
 /// Lower all type tests in this module.
-LowerTypeTestsModule::LowerTypeTestsModule(Module &M) : M(M) {
+LowerTypeTestsModule::LowerTypeTestsModule(Module &M, SummaryAction Action,
+                                           ModuleSummaryIndex *Summary)
+    : M(M), Action(Action), Summary(Summary) {
+  // FIXME: Use these fields.
+  (void)this->Action;
+  (void)this->Summary;
+
+  Triple TargetTriple(M.getTargetTriple());
+  LinkerSubsectionsViaSymbols = TargetTriple.isMacOSX();
+  Arch = TargetTriple.getArch();
+  OS = TargetTriple.getOS();
+  ObjectFormat = TargetTriple.getObjectFormat();
+}
+
+bool LowerTypeTestsModule::runForTesting(Module &M) {
+  ModuleSummaryIndex Summary;
+
   // Handle the command-line summary arguments. This code is for testing
   // purposes only, so we handle errors directly.
-  if (!ClSummaryAction.empty()) {
-    OwnedSummary = make_unique<ModuleSummaryIndex>();
-    if (!ClReadSummary.empty()) {
-      ExitOnError ExitOnErr("-lowertypetests-read-summary: " + ClReadSummary +
-                            ": ");
-      auto ReadSummaryFile =
-          ExitOnErr(errorOrToExpected(MemoryBuffer::getFile(ClReadSummary)));
 
-      yaml::Input In(ReadSummaryFile->getBuffer());
-      In >> *OwnedSummary;
-      ExitOnErr(errorCodeToError(In.error()));
-    }
-  }
+    In >> Summary;
 
-  Triple TargetTriple(M.getTargetTriple());
-  LinkerSubsectionsViaSymbols = TargetTriple.isMacOSX();
-  Arch = TargetTriple.getArch();
-  OS = TargetTriple.getOS();
-  ObjectFormat = TargetTriple.getObjectFormat();
-}
-
-LowerTypeTestsModule::~LowerTypeTestsModule() {
-  if (ClSummaryAction.empty() || ClWriteSummary.empty())
-    return;
+  bool Changed = LowerTypeTestsModule(M, ClSummaryAction, &Summary).lower();
 
+  if (!ClWriteSummary.empty()) {
     ExitOnError ExitOnErr("-lowertypetests-write-summary: " + ClWriteSummary +
                           ": ");
     std::error_code EC;
     raw_fd_ostream OS(ClWriteSummary, EC, sys::fs::F_Text);
     ExitOnErr(errorCodeToError(EC));
 
     yaml::Output Out(OS);
-  Out << *OwnedSummary;
+    Out << Summary;
+  }
+
+  return Changed;
 }
 
 bool LowerTypeTestsModule::lower() {
   Function *TypeTestFunc =
       M.getFunction(Intrinsic::getName(Intrinsic::type_test));
   if (!TypeTestFunc || TypeTestFunc->use_empty())
     return false;
 
bool LowerTypeTestsModule::lower() {
 
   allocateByteArrays();
 
   return true;
 }
 
 PreservedAnalyses LowerTypeTestsPass::run(Module &M,
                                           ModuleAnalysisManager &AM) {
-  bool Changed = LowerTypeTestsModule(M).lower();
+  bool Changed =
+      LowerTypeTestsModule(M, SummaryAction::None, /*Summary=*/nullptr).lower();
   if (!Changed)
     return PreservedAnalyses::all();
   return PreservedAnalyses::none();
 }

llvm/lib/Transforms/IPO/PassManagerBuilder.cpp

void PassManagerBuilder::populateLTOPassManager(legacy::PassManagerBase &PM) {
 
   // Create a function that performs CFI checks for cross-DSO calls with targets
   // in the current module.
   PM.add(createCrossDSOCFIPass());
 
   // Lower type metadata and the type.test intrinsic. This pass supports Clang's
   // control flow integrity mechanisms (-fsanitize=cfi*) and needs to run at
   // link time if CFI is enabled. The pass does nothing if CFI is disabled.
-  PM.add(createLowerTypeTestsPass());
+  PM.add(createLowerTypeTestsPass(LowerTypeTestsSummaryAction::None,
+                                  /*Summary=*/nullptr));
 
   if (OptLevel != 0)
     addLateLTOOptimizationPasses(PM);
 
   if (VerifyOutput)
     PM.add(createVerifierPass());
 }