C++ SILModule::getASTContext方法代码示例

/// Can the given cast be performed by the scalar checked-cast
/// instructions?
bool swift::canUseScalarCheckedCastInstructions(SILModule &M,
                                                CanType sourceType,
                                                CanType targetType) {
  // Look through one level of optionality on the source.
  auto objectType = sourceType;
  if (auto type = objectType.getOptionalObjectType())
    objectType = type;

  // Casting to NSError needs to go through the indirect-cast case,
  // since it may conform to Error and require Error-to-NSError
  // bridging, unless we can statically see that the source type inherits
  // NSError.
  
  // A class-constrained archetype may be bound to NSError, unless it has a
  // non-NSError superclass constraint. Casts to archetypes thus must always be
  // indirect.
  if (auto archetype = targetType->getAs<ArchetypeType>()) {
    // Only ever permit this if the source type is a reference type.
    if (!objectType.isAnyClassReferenceType())
      return false;
    
      auto super = archetype->getSuperclass();
      if (super.isNull())
        return false;

    // A base class constraint that isn't NSError rules out the archetype being
    // bound to NSError.
    if (M.getASTContext().LangOpts.EnableObjCInterop) {
      if (auto nserror = M.Types.getNSErrorType())
         return !super->isEqual(nserror);
    }
    
    // If NSError wasn't loaded, any base class constraint must not be NSError.
    return true;
  }
  
  if (M.getASTContext().LangOpts.EnableObjCInterop
      && targetType == M.Types.getNSErrorType()) {
    // If we statically know the source is an NSError subclass, then the cast
    // can go through the scalar path (and it's trivially true so can be
    // killed).
    return targetType->isExactSuperclassOf(objectType);
  }
  
  // Three supported cases:
  // - metatype to metatype
  // - metatype to object
  // - object to object
  if ((objectType.isAnyClassReferenceType() || isa<AnyMetatypeType>(objectType))
      && targetType.isAnyClassReferenceType())
    return true;

  if (isa<AnyMetatypeType>(objectType) && isa<AnyMetatypeType>(targetType))
    return true;
  
  // Otherwise, we need to use the general indirect-cast functions.
  return false;
}

Emitter::Emitter(StringRef PassName, SILModule &M)
    : Module(M), PassName(PassName),
      PassedEnabled(
          M.getASTContext().LangOpts.OptimizationRemarkPassedPattern &&
          M.getASTContext().LangOpts.OptimizationRemarkPassedPattern->match(
              PassName)),
      MissedEnabled(
          M.getASTContext().LangOpts.OptimizationRemarkMissedPattern &&
          M.getASTContext().LangOpts.OptimizationRemarkMissedPattern->match(
              PassName)) {}

/// Returns the outlined function type.
///
/// This depends on the first instruction we matched. Either we matched a load
/// or we started the match at the class method instruction.
///
/// load %30 : *UITextField:
///   (@in_guaranteed InstanceType) -> (@owned Optional<BridgedInstanceType>)
/// objc_method %31 : UITextField
///   (@unowned InstanceType) -> (@owned Optional<BridgedInstanceType>)
///
CanSILFunctionType BridgedProperty::getOutlinedFunctionType(SILModule &M) {
  SmallVector<SILParameterInfo, 4> Parameters;
  if (auto *Load = dyn_cast<LoadInst>(FirstInst))
    Parameters.push_back(
      SILParameterInfo(Load->getType().getASTType(),
                       ParameterConvention::Indirect_In_Guaranteed));
  else
    Parameters.push_back(SILParameterInfo(cast<ObjCMethodInst>(FirstInst)
                                              ->getOperand()
                                              ->getType()
                                              .getASTType(),
                                          ParameterConvention::Direct_Unowned));
  SmallVector<SILResultInfo, 4> Results;

  Results.push_back(SILResultInfo(
                      switchInfo.Br->getArg(0)->getType().getASTType(),
                      ResultConvention::Owned));
  auto ExtInfo =
      SILFunctionType::ExtInfo(SILFunctionType::Representation::Thin,
                               /*pseudogeneric*/ false, /*noescape*/ false);
  auto FunctionType = SILFunctionType::get(
      nullptr, ExtInfo, SILCoroutineKind::None,
      ParameterConvention::Direct_Unowned, Parameters, /*yields*/ {},
      Results, None, M.getASTContext());
  return FunctionType;
}

static void emitRemark(SILModule &Module, const Remark<RemarkT> &R,
                       Diag<ArgTypes...> ID, bool DiagEnabled) {
  if (R.getLocation().isInvalid())
    return;
  if (auto *Out = Module.getOptRecordStream())
    // YAMLTraits takes a non-const reference even when outputting.
    *Out << const_cast<Remark<RemarkT> &>(R);
  if (DiagEnabled)
    Module.getASTContext().Diags.diagnose(R.getLocation(), ID, R.getMsg());
}

/// Emit a diagnostic for `poundAssert` builtins whose condition is
/// false or whose condition cannot be evaluated.
static void diagnosePoundAssert(const SILInstruction *I,
                                SILModule &M,
                                ConstExprEvaluator &constantEvaluator) {
  auto *builtinInst = dyn_cast<BuiltinInst>(I);
  if (!builtinInst ||
      builtinInst->getBuiltinKind() != BuiltinValueKind::PoundAssert)
    return;

  SmallVector<SymbolicValue, 1> values;
  constantEvaluator.computeConstantValues({builtinInst->getArguments()[0]},
                                          values);
  SymbolicValue value = values[0];
  if (!value.isConstant()) {
    diagnose(M.getASTContext(), I->getLoc().getSourceLoc(),
             diag::pound_assert_condition_not_constant);

    // If we have more specific information about what went wrong, emit
    // notes.
    if (value.getKind() == SymbolicValue::Unknown)
      value.emitUnknownDiagnosticNotes(builtinInst->getLoc());
    return;
  }
  assert(value.getKind() == SymbolicValue::Integer &&
         "sema prevents non-integer #assert condition");

  APInt intValue = value.getIntegerValue();
  assert(intValue.getBitWidth() == 1 &&
         "sema prevents non-int1 #assert condition");
  if (intValue.isNullValue()) {
    auto *message = cast<StringLiteralInst>(builtinInst->getArguments()[1]);
    StringRef messageValue = message->getValue();
    if (messageValue.empty())
      messageValue = "assertion failed";
    diagnose(M.getASTContext(), I->getLoc().getSourceLoc(),
             diag::pound_assert_failure, messageValue);
    return;
  }
}

// Convert the substituted function type into a specialized function type based
// on the ReabstractionInfo.
CanSILFunctionType ReabstractionInfo::
createSpecializedType(CanSILFunctionType SubstFTy, SILModule &M) const {
  llvm::SmallVector<SILResultInfo, 8> SpecializedResults;
  llvm::SmallVector<SILParameterInfo, 8> SpecializedParams;

  unsigned ResultIdx = 0;
  for (SILResultInfo RI : SubstFTy->getAllResults()) {
    if (RI.isDirect()) {
      SpecializedResults.push_back(RI);
    } else {
      if (isResultConverted(ResultIdx++)) {
        // Convert the indirect result to a direct result.
        SILType SILResTy = SILType::getPrimitiveObjectType(RI.getType());
        // Indirect results are passed as owned, so we also need to pass the
        // direct result as owned (except it's a trivial type).
        auto C = (SILResTy.isTrivial(M) ? ResultConvention::Unowned :
                  ResultConvention::Owned);
        SpecializedResults.push_back(SILResultInfo(RI.getType(), C));
      } else {
        // No conversion: re-use the original result info.
        SpecializedResults.push_back(RI);
      }
    }
  }
  unsigned ParamIdx = 0;
  for (SILParameterInfo PI : SubstFTy->getParameters()) {
    if (isParamConverted(ParamIdx++)) {
      // Convert the indirect parameter to a direct parameter.
      SILType SILParamTy = SILType::getPrimitiveObjectType(PI.getType());
      // Indirect parameters are passed as owned, so we also need to pass the
      // direct parameter as owned (except it's a trivial type).
      auto C = (SILParamTy.isTrivial(M) ? ParameterConvention::Direct_Unowned :
                ParameterConvention::Direct_Owned);
      SpecializedParams.push_back(SILParameterInfo(PI.getType(), C));
    } else {
      // No conversion: re-use the original parameter info.
      SpecializedParams.push_back(PI);
    }
  }
  return
    SILFunctionType::get(SubstFTy->getGenericSignature(),
                         SubstFTy->getExtInfo(),
                         SubstFTy->getCalleeConvention(), SpecializedParams,
                         SpecializedResults, SubstFTy->getOptionalErrorResult(),
                         M.getASTContext());
}

SILType SILBuilder::getPartialApplyResultType(SILType origTy, unsigned argCount,
                                        SILModule &M,
                                        SubstitutionMap subs,
                                        ParameterConvention calleeConvention,
                                        PartialApplyInst::OnStackKind onStack) {
  CanSILFunctionType FTI = origTy.castTo<SILFunctionType>();
  if (!subs.empty())
    FTI = FTI->substGenericArgs(M, subs);
  
  assert(!FTI->isPolymorphic()
         && "must provide substitutions for generic partial_apply");
  auto params = FTI->getParameters();
  auto newParams = params.slice(0, params.size() - argCount);

  auto extInfo = FTI->getExtInfo()
    .withRepresentation(SILFunctionType::Representation::Thick)
    .withIsPseudogeneric(false);
  if (onStack)
    extInfo = extInfo.withNoEscape();

  // If the original method has an @unowned_inner_pointer return, the partial
  // application thunk will lifetime-extend 'self' for us, converting the
  // return value to @unowned.
  //
  // If the original method has an @autoreleased return, the partial application
  // thunk will retain it for us, converting the return value to @owned.
  SmallVector<SILResultInfo, 4> results;
  results.append(FTI->getResults().begin(), FTI->getResults().end());
  for (auto &result : results) {
    if (result.getConvention() == ResultConvention::UnownedInnerPointer)
      result = SILResultInfo(result.getType(), ResultConvention::Unowned);
    else if (result.getConvention() == ResultConvention::Autoreleased)
      result = SILResultInfo(result.getType(), ResultConvention::Owned);
  }

  auto appliedFnType = SILFunctionType::get(nullptr, extInfo,
                                            FTI->getCoroutineKind(),
                                            calleeConvention,
                                            newParams,
                                            FTI->getYields(),
                                            results,
                                            FTI->getOptionalErrorResult(),
                                            M.getASTContext());

  return SILType::getPrimitiveObjectType(appliedFnType);
}

/// \brief Issue diagnostics whenever we see Builtin.static_report(1, ...).
static void diagnoseStaticReports(const SILInstruction *I,
                                  SILModule &M) {

  // Find out if we are dealing with Builtin.staticReport().
  if (auto *BI = dyn_cast<BuiltinInst>(I)) {
    const BuiltinInfo &B = BI->getBuiltinInfo();
    if (B.ID == BuiltinValueKind::StaticReport) {

      // Report diagnostic if the first argument has been folded to '1'.
      OperandValueArrayRef Args = BI->getArguments();
      IntegerLiteralInst *V = dyn_cast<IntegerLiteralInst>(Args[0]);
      if (!V || V->getValue() != 1)
        return;

      diagnose(M.getASTContext(), I->getLoc().getSourceLoc(),
               diag::static_report_error);
    }
  }
}

/// True if the given type value is nonnull, and the represented type is NSError
/// or CFError, the error classes for which we support "toll-free" bridging to
/// Error existentials.
static bool isBridgedErrorClass(SILModule &M,
                                Type t) {
  // There's no bridging if ObjC interop is disabled.
  if (!M.getASTContext().LangOpts.EnableObjCInterop)
    return false;

  if (!t)
    return false;

  if (auto archetypeType = t->getAs<ArchetypeType>())
    t = archetypeType->getSuperclass();

  // NSError (TODO: and CFError) can be bridged.
  auto nsErrorType = M.Types.getNSErrorType();
  if (t && nsErrorType && nsErrorType->isExactSuperclassOf(t)) {
    return true;
  }
  
  return false;
}

SILType SILType::getEnumElementType(EnumElementDecl *elt, SILModule &M) const {
  assert(elt->getDeclContext() == getEnumOrBoundGenericEnum());
  assert(elt->hasAssociatedValues());

  if (auto objectType = getSwiftRValueType().getAnyOptionalObjectType()) {
    assert(elt == M.getASTContext().getOptionalSomeDecl());
    return SILType(objectType, getCategory());
  }

  auto substEltTy =
    getSwiftRValueType()->getTypeOfMember(M.getSwiftModule(), elt,
                                          elt->getArgumentInterfaceType());
  auto loweredTy =
    M.Types.getLoweredType(M.Types.getAbstractionPattern(elt), substEltTy);

  // If the case is indirect, then the payload is boxed.
  if (elt->isIndirect() || elt->getParentEnum()->isIndirect())
    loweredTy = SILType::getPrimitiveObjectType(
      SILBoxType::get(loweredTy.getSwiftRValueType()));

  return SILType(loweredTy.getSwiftRValueType(), getCategory());
}

//.........这里部分代码省略.........
  // override the Member.
  //
  // As a result, substitutions provided by AI are for Member, whereas
  // substitutions in ClassInstanceType are for D2. And substitutions for D1
  // are not available directly in a general case. Therefore, they have to
  // be computed.
  //
  // What we know for sure:
  //   B is a superclass of D1
  //   D1 is a superclass of D2.
  // D1 can be the same as D2. D1 can be the same as B.
  //
  // So, substitutions from AI are for class B.
  // Substitutions for class D1 by means of bindSuperclass(), which starts
  // with a bound type ClassInstanceType and checks its superclasses until it
  // finds a bound superclass matching D1 and returns its substitutions.

  // Class F belongs to.
  CanType FSelfClass = GenCalleeType->getSelfParameter().getType();

  SILType FSelfSubstType;
  Module *Module = M.getSwiftModule();

  ArrayRef<Substitution> ClassSubs;

  if (GenCalleeType->isPolymorphic()) {
    // Declaration of the class F belongs to.
    if (auto *FSelfTypeDecl = FSelfClass.getNominalOrBoundGenericNominal()) {
      // Get the unbound generic type F belongs to.
      CanType FSelfGenericType =
        FSelfTypeDecl->getDeclaredType()->getCanonicalType();

      assert((isa<BoundGenericType>(ClassInstanceType.getSwiftRValueType()) ||
              isa<NominalType>(ClassInstanceType.getSwiftRValueType())) &&
             "Self type should be either a bound generic type"
             "or a non-generic type");

      assert((isa<UnboundGenericType>(FSelfGenericType) ||
              isa<NominalType>(FSelfGenericType)) &&
             "Method implementation self type should be generic");

      if (isa<BoundGenericType>(ClassInstanceType.getSwiftRValueType())) {
        auto BoundBaseType = bindSuperclass(FSelfGenericType,
                                            ClassInstanceType);
        if (auto BoundTy = BoundBaseType->getAs<BoundGenericType>()) {
          ClassSubs = BoundTy->getSubstitutions(Module, nullptr);
        }
      }
    }
  } else {
    // If the callee is not polymorphic, no substitutions are required.
    return {};
  }

  if (ClassSubs.empty())
    return AI.getSubstitutions();

  auto AISubs = AI.getSubstitutions();

  CanSILFunctionType AIGenCalleeType =
      AI.getCallee().getType().castTo<SILFunctionType>();

  CanType AISelfClass = AIGenCalleeType->getSelfParameter().getType();

  unsigned NextMethodParamIdx = 0;
  unsigned NumMethodParams = 0;
  if (AIGenCalleeType->isPolymorphic()) {
    NextMethodParamIdx = 0;
    // Generic parameters of the method start after generic parameters
    // of the instance class.
    if (auto AISelfClassSig =
            AISelfClass.getClassBound()->getGenericSignature()) {
      NextMethodParamIdx = AISelfClassSig->getGenericParams().size();
    }
    NumMethodParams = AISubs.size() - NextMethodParamIdx;
  }

  unsigned NumSubs = ClassSubs.size() + NumMethodParams;

  if (ClassSubs.size() == NumSubs)
    return ClassSubs;

  // Mix class subs with method specific subs from the AI substitutions.

  // Assumptions: AI substitutions contain first the substitutions for
  // a class of the method being invoked and then the substitutions
  // for a method being invoked.
  auto Subs = M.getASTContext().Allocate<Substitution>(NumSubs);

  unsigned i = 0;
  for (auto &S : ClassSubs) {
    Subs[i++] = S;
  }

  for (; i < NumSubs; ++i, ++NextMethodParamIdx) {
    Subs[i] = AISubs[NextMethodParamIdx];
  }

  return Subs;
}

SILModuleConventions::SILModuleConventions(const SILModule &M)
    : loweredAddresses(!M.getASTContext().LangOpts.EnableSILOpaqueValues) {}

bool swift::runSILDiagnosticPasses(SILModule &Module) {
  // Verify the module, if required.
  if (Module.getOptions().VerifyAll)
    Module.verify();

  // If we parsed a .sil file that is already in canonical form, don't rerun
  // the diagnostic passes.
  if (Module.getStage() == SILStage::Canonical)
    return false;

  auto &Ctx = Module.getASTContext();

  SILPassManager PM(&Module);

  if (SILViewSILGenCFG) {
    PM.resetAndRemoveTransformations();
    PM.addCFGPrinter();
    PM.runOneIteration();
  }

  // If we are asked do debug serialization, instead of running all diagnostic
  // passes, just run mandatory inlining with dead transparent function cleanup
  // disabled.
  if (Module.getOptions().DebugSerialization) {
    PM.addMandatoryInlining();
    PM.run();
    return Ctx.hadError();
  }

  // Otherwise run the rest of diagnostics.
  PM.addCapturePromotion();
  PM.addAllocBoxToStack();
  PM.addInOutDeshadowing();
  PM.addNoReturnFolding();
  PM.addDefiniteInitialization();

  PM.addMandatoryInlining();
  PM.addPredictableMemoryOptimizations();
  PM.addDiagnosticConstantPropagation();
  PM.addDiagnoseUnreachable();
  PM.addEmitDFDiagnostics();
  // Canonical swift requires all non cond_br critical edges to be split.
  PM.addSplitNonCondBrCriticalEdges();
  PM.run();

  // Generate diagnostics.
  Module.setStage(SILStage::Canonical);

  if (SILViewGuaranteedCFG) {
    PM.resetAndRemoveTransformations();
    PM.addCFGPrinter();
    PM.runOneIteration();
  }

  // Verify the module, if required.
  if (Module.getOptions().VerifyAll)
    Module.verify();
  else {
    DEBUG(Module.verify());
  }

  // If errors were produced during SIL analysis, return true.
  return Ctx.hadError();
}

/// \brief Issue an "unreachable code" diagnostic if the blocks contains or
/// leads to another block that contains user code.
///
/// Note, we rely on SILLocation information to determine if SILInstructions
/// correspond to user code.
static bool diagnoseUnreachableBlock(const SILBasicBlock &B,
                                     SILModule &M,
                                     const SILBasicBlockSet &Reachable,
                                     UnreachableUserCodeReportingState *State,
                                     const SILBasicBlock *TopLevelB,
                         llvm::SmallPtrSetImpl<const SILBasicBlock*> &Visited){
  if (Visited.count(&B))
    return false;
  Visited.insert(&B);
  
  assert(State);
  for (auto I = B.begin(), E = B.end(); I != E; ++I) {
    SILLocation Loc = I->getLoc();
    // If we've reached an implicit return, we have not found any user code and
    // can stop searching for it.
    if (Loc.is<ImplicitReturnLocation>() || Loc.isAutoGenerated())
      return false;

    // Check if the instruction corresponds to user-written code, also make
    // sure we don't report an error twice for the same instruction.
    if (isUserCode(&*I) && !State->BlocksWithErrors.count(&B)) {

      // Emit the diagnostic.
      auto BrInfoIter = State->MetaMap.find(TopLevelB);
      assert(BrInfoIter != State->MetaMap.end());
      auto BrInfo = BrInfoIter->second;

      switch (BrInfo.Kind) {
      case (UnreachableKind::FoldedBranch):
        // Emit the diagnostic on the unreachable block and emit the
        // note on the branch responsible for the unreachable code.
        diagnose(M.getASTContext(), Loc.getSourceLoc(), diag::unreachable_code);
        diagnose(M.getASTContext(), BrInfo.Loc.getSourceLoc(),
                 diag::unreachable_code_branch, BrInfo.CondIsAlwaysTrue);
        break;

      case (UnreachableKind::FoldedSwitchEnum): {
        // If we are warning about a switch condition being a constant, the main
        // emphasis should be on the condition (to ensure we have a single
        // message per switch).
        const SwitchStmt *SS = BrInfo.Loc.getAsASTNode<SwitchStmt>();
        if (!SS)
          break;
        assert(SS);
        const Expr *SE = SS->getSubjectExpr();
        diagnose(M.getASTContext(), SE->getLoc(), diag::switch_on_a_constant);
        diagnose(M.getASTContext(), Loc.getSourceLoc(),
                 diag::unreachable_code_note);
        break;
      }

      case (UnreachableKind::NoreturnCall): {
        // Specialcase when we are warning about unreachable code after a call
        // to a noreturn function.
        if (!BrInfo.Loc.isASTNode<ExplicitCastExpr>()) {
          assert(BrInfo.Loc.isASTNode<ApplyExpr>());
          diagnose(M.getASTContext(), Loc.getSourceLoc(),
                   diag::unreachable_code);
          diagnose(M.getASTContext(), BrInfo.Loc.getSourceLoc(),
                   diag::call_to_noreturn_note);
        }
        break;
      }
      }

      // Record that we've reported this unreachable block to avoid duplicates
      // in the future.
      State->BlocksWithErrors.insert(&B);
      return true;
    }
  }

  // This block could be empty if it's terminator has been folded.
  if (B.empty())
    return false;

  // If we have not found user code in this block, inspect it's successors.
  // Check if at least one of the successors contains user code.
  for (auto I = B.succ_begin(), E = B.succ_end(); I != E; ++I) {
    SILBasicBlock *SB = *I;
    bool HasReachablePred = false;
    for (auto PI = SB->pred_begin(), PE = SB->pred_end(); PI != PE; ++PI) {
      if (Reachable.count(*PI))
        HasReachablePred = true;
    }

    // If all of the predecessors of this successor are unreachable, check if
    // it contains user code.
    if (!HasReachablePred && diagnoseUnreachableBlock(*SB, M, Reachable,
                                                    State, TopLevelB, Visited))
      return true;
  }
  
  return false;
}

SILModuleConventions::SILModuleConventions(const SILModule &M)
    : loweredAddresses(!M.getASTContext().LangOpts.EnableSILOpaqueValues
                       || M.getStage() == SILStage::Lowered) {}