C++ SubstitutionMap::empty方法代码示例

Witness::Witness(ValueDecl *decl, SubstitutionMap substitutions,
                 GenericEnvironment *syntheticEnv,
                 SubstitutionMap reqToSynthesizedEnvSubs) {
  if (!syntheticEnv && substitutions.empty() &&
      reqToSynthesizedEnvSubs.empty()) {
    storage = decl;
    return;
  }

  auto &ctx = decl->getASTContext();
  auto declRef = ConcreteDeclRef(decl, substitutions);
  auto storedMem = ctx.Allocate(sizeof(StoredWitness), alignof(StoredWitness));
  auto stored = new (storedMem) StoredWitness{declRef, syntheticEnv,
                                              reqToSynthesizedEnvSubs};

  storage = stored;
}

static ManagedValue emitBuiltinClassifyBridgeObject(SILGenFunction &SGF,
                                                    SILLocation loc,
                                                    SubstitutionMap subs,
                                                    ArrayRef<ManagedValue> args,
                                                    SGFContext C) {
  assert(args.size() == 1 && "classify should have one argument");
  assert(subs.empty() && "classify should not have subs");

  SILValue result = SGF.B.createClassifyBridgeObject(loc, args[0].getValue());
  return ManagedValue::forUnmanaged(result);
}

SubstitutionMap ProtocolConformance::getSubstitutions(ModuleDecl *M) const {
  // Walk down to the base NormalProtocolConformance.
  SubstitutionMap subMap;
  const ProtocolConformance *parent = this;
  while (!isa<NormalProtocolConformance>(parent)) {
    switch (parent->getKind()) {
    case ProtocolConformanceKind::Normal:
      llvm_unreachable("should have exited the loop?!");
    case ProtocolConformanceKind::Inherited:
      parent =
          cast<InheritedProtocolConformance>(parent)->getInheritedConformance();
      break;
    case ProtocolConformanceKind::Specialized: {
      auto SC = cast<SpecializedProtocolConformance>(parent);
      parent = SC->getGenericConformance();
      assert(subMap.empty() && "multiple conformance specializations?!");
      subMap = SC->getSubstitutionMap();
      break;
    }
    }
  }

  // Found something; we're done!
  if (!subMap.empty())
    return subMap;

  // If the normal conformance is for a generic type, and we didn't hit a
  // specialized conformance, collect the substitutions from the generic type.
  // FIXME: The AST should do this for us.
  const NormalProtocolConformance *normalC =
      cast<NormalProtocolConformance>(parent);

  if (!normalC->getType()->isSpecialized())
    return SubstitutionMap();

  auto *DC = normalC->getDeclContext();
  return normalC->getType()->getContextSubstitutionMap(M, DC);
}

static ManagedValue emitBuiltinCastBitPatternFromBridgeObject(
                                                  SILGenFunction &SGF,
                                                  SILLocation loc,
                                                  SubstitutionMap subs,
                                                  ArrayRef<ManagedValue> args,
                                                  SGFContext C) {
  assert(args.size() == 1 && "cast should have one argument");
  assert(subs.empty() && "cast should not have subs");

  SILType wordType = SILType::getBuiltinWordType(SGF.getASTContext());
  SILValue result = SGF.B.createBridgeObjectToWord(loc, args[0].getValue(),
                                                   wordType);
  return ManagedValue::forUnmanaged(result);
}

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);
}

/// Specialized emitter for Builtin.endUnpairedAccessModifyAccess.
static ManagedValue emitBuiltinEndUnpairedAccess(SILGenFunction &SGF,
                                                    SILLocation loc,
                                           SubstitutionMap substitutions,
                                           ArrayRef<ManagedValue> args,
                                           SGFContext C) {
  assert(substitutions.empty() &&
        "Builtin.endUnpairedAccess should have no substitutions");
  assert(args.size() == 1 &&
         "endUnpairedAccess should be given one argument");

  SILType valueBufferTy =
      SGF.getLoweredType(SGF.getASTContext().TheUnsafeValueBufferType);

  SILValue buffer = SGF.B.createPointerToAddress(loc,
                                                 args[0].getUnmanagedValue(),
                                                valueBufferTy.getAddressType(),
                                                 /*strict*/ true,
                                                 /*invariant*/ false);
  SGF.B.createEndUnpairedAccess(loc, buffer, SILAccessEnforcement::Dynamic,
                                /*aborted*/ false,
                                /*fromBuiltin*/ true);

  return ManagedValue::forUnmanaged(SGF.emitEmptyTuple(loc));
}

ManagedValue
SILGenFunction::emitClosureValue(SILLocation loc, SILDeclRef constant,
                                 CanType expectedType,
                                 SubstitutionMap subs) {
  auto closure = *constant.getAnyFunctionRef();
  auto captureInfo = closure.getCaptureInfo();
  auto loweredCaptureInfo = SGM.Types.getLoweredLocalCaptures(closure);
  auto hasCaptures = SGM.Types.hasLoweredLocalCaptures(closure);

  auto constantInfo = getConstantInfo(constant);
  SILValue functionRef = emitGlobalFunctionRef(loc, constant, constantInfo);
  SILType functionTy = functionRef->getType();

  // Apply substitutions.
  auto pft = constantInfo.SILFnType;

  auto *dc = closure.getAsDeclContext()->getParent();
  if (dc->isLocalContext() && !loweredCaptureInfo.hasGenericParamCaptures()) {
    // If the lowered function type is not polymorphic but we were given
    // substitutions, we have a closure in a generic context which does not
    // capture generic parameters. Just drop the substitutions.
    subs = { };
  } else if (closure.getAbstractClosureExpr()) {
    // If we have a closure expression in generic context, Sema won't give
    // us substitutions, so we just use the forwarding substitutions from
    // context.
    subs = getForwardingSubstitutionMap();
  }

  bool wasSpecialized = false;
  if (!subs.empty()) {
    auto specialized = pft->substGenericArgs(F.getModule(), subs);
    functionTy = SILType::getPrimitiveObjectType(specialized);
    wasSpecialized = true;
  }

  // If we're in top-level code, we don't need to physically capture script
  // globals, but we still need to mark them as escaping so that DI can flag
  // uninitialized uses.
  if (this == SGM.TopLevelSGF) {
    SGM.emitMarkFunctionEscapeForTopLevelCodeGlobals(
        loc, captureInfo);
  }

  if (!hasCaptures && !wasSpecialized) {
    auto result = ManagedValue::forUnmanaged(functionRef);
    return emitOrigToSubstValue(loc, result,
                                AbstractionPattern(expectedType),
                                expectedType);
  }

  SmallVector<ManagedValue, 4> capturedArgs;
  emitCaptures(loc, closure, CaptureEmission::PartialApplication,
               capturedArgs);

  // The partial application takes ownership of the context parameters.
  SmallVector<SILValue, 4> forwardedArgs;
  for (auto capture : capturedArgs)
    forwardedArgs.push_back(capture.forward(*this));

  auto calleeConvention = ParameterConvention::Direct_Guaranteed;

  SILType closureTy = SILGenBuilder::getPartialApplyResultType(
      functionRef->getType(), capturedArgs.size(), SGM.M, subs,
      calleeConvention);

  auto toClosure =
    B.createPartialApply(loc, functionRef, functionTy,
                         subs, forwardedArgs, closureTy);
  auto result = emitManagedRValueWithCleanup(toClosure);

  // Get the lowered AST types:
  //  - the original type
  auto origFormalType = AbstractionPattern(constantInfo.LoweredType);

  // - the substituted type
  auto substFormalType = expectedType;

  // Generalize if necessary.
  result = emitOrigToSubstValue(loc, result, origFormalType,
                                substFormalType);

  return result;
}