C++ SubstitutionList类代码示例

SubstitutionMap GenericEnvironment::
getSubstitutionMap(SubstitutionList subs) const {
  SubstitutionMap result;

  for (auto depTy : getGenericSignature()->getAllDependentTypes()) {

    // Map the interface type to a context type.
    auto contextTy = depTy.subst(QueryInterfaceTypeSubstitutions(this),
                                 MakeAbstractConformanceForGenericType());

    auto sub = subs.front();
    subs = subs.slice(1);

    // Record the replacement type and its conformances.
    if (auto *archetype = contextTy->getAs<ArchetypeType>()) {
      result.addSubstitution(CanArchetypeType(archetype), sub.getReplacement());
      for (auto conformance : sub.getConformances())
        result.addConformance(CanType(archetype), conformance);
      continue;
    }

    // FIXME: getAllDependentTypes() includes generic type parameters that
    // have been made concrete.
    assert(contextTy->hasError() || depTy->is<GenericTypeParamType>());
  }

  assert(subs.empty() && "did not use all substitutions?!");

  populateParentMap(result);
  return result;
}

static void emitTypeTraitBuiltin(IRGenFunction &IGF,
                                 Explosion &out,
                                 Explosion &args,
                                 SubstitutionList substitutions,
                                 TypeTraitResult (TypeBase::*trait)()) {
  assert(substitutions.size() == 1
         && "type trait should have gotten single type parameter");
  args.claimNext();
  
  // Lower away the trait to a tristate 0 = no, 1 = yes, 2 = maybe.
  unsigned result;
  switch ((substitutions[0].getReplacement().getPointer()->*trait)()) {
  case TypeTraitResult::IsNot:
    result = 0;
    break;
  case TypeTraitResult::Is:
    result = 1;
    break;
  case TypeTraitResult::CanBe:
    result = 2;
    break;
  }

  out.add(llvm::ConstantInt::get(IGF.IGM.Int8Ty, result));
}

/// Specialized emitter for Builtin.destroy.
static ManagedValue emitBuiltinDestroy(SILGenFunction &gen,
                                       SILLocation loc,
                                       SubstitutionList substitutions,
                                       ArrayRef<ManagedValue> args,
                                       CanFunctionType formalApplyType,
                                       SGFContext C) {
  assert(args.size() == 2 && "destroy should have two arguments");
  assert(substitutions.size() == 1 &&
         "destroy should have a single substitution");
  // The substitution determines the type of the thing we're destroying.
  auto &ti = gen.getTypeLowering(substitutions[0].getReplacement());
  
  // Destroy is a no-op for trivial types.
  if (ti.isTrivial())
    return ManagedValue::forUnmanaged(gen.emitEmptyTuple(loc));
  
  SILType destroyType = ti.getLoweredType();

  // Convert the pointer argument to a SIL address.
  SILValue addr =
    gen.B.createPointerToAddress(loc, args[1].getUnmanagedValue(),
                                 destroyType.getAddressType(),
                                 /*isStrict*/ true);
  
  // Destroy the value indirectly. Canonicalization will promote to loads
  // and releases if appropriate.
  gen.B.createDestroyAddr(loc, addr);
  
  return ManagedValue::forUnmanaged(gen.emitEmptyTuple(loc));
}

static ManagedValue emitBuiltinAssign(SILGenFunction &gen,
                                      SILLocation loc,
                                      SubstitutionList substitutions,
                                      ArrayRef<ManagedValue> args,
                                      CanFunctionType formalApplyType,
                                      SGFContext C) {
  assert(args.size() >= 2 && "assign should have two arguments");
  assert(substitutions.size() == 1 &&
         "assign should have a single substitution");

  // The substitution determines the type of the thing we're destroying.
  CanType assignFormalType = substitutions[0].getReplacement()->getCanonicalType();
  SILType assignType = gen.getLoweredType(assignFormalType);
  
  // Convert the destination pointer argument to a SIL address.
  SILValue addr = gen.B.createPointerToAddress(loc,
                                               args.back().getUnmanagedValue(),
                                               assignType.getAddressType(),
                                               /*isStrict*/ true);
  
  // Build the value to be assigned, reconstructing tuples if needed.
  auto src = RValue::withPreExplodedElements(args.slice(0, args.size() - 1),
                                             assignFormalType);
  
  std::move(src).assignInto(gen, loc, addr);

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

static ManagedValue emitCastFromReferenceType(SILGenFunction &gen,
                                         SILLocation loc,
                                         SubstitutionList substitutions,
                                         ArrayRef<ManagedValue> args,
                                         SGFContext C) {
  assert(args.size() == 1 && "cast should have a single argument");
  assert(substitutions.size() == 1 &&
         "cast should have a single substitution");

  // The substitution determines the destination type.
  SILType destType = gen.getLoweredType(substitutions[0].getReplacement());
  
  // Bail if the source type is not a class reference of some kind.
  if (!substitutions[0].getReplacement()->isBridgeableObjectType()
      || !destType.isObject()) {
    gen.SGM.diagnose(loc, diag::invalid_sil_builtin,
                     "castFromNativeObject dest must be an object type");
    // Recover by propagating an undef result.
    SILValue result = SILUndef::get(destType, gen.SGM.M);
    return ManagedValue::forUnmanaged(result);
  }
  
  // Save the cleanup on the argument so we can forward it onto the cast
  // result.
  auto cleanup = args[0].getCleanup();

  // Take the reference type argument and cast it.
  SILValue result = gen.B.createUncheckedRefCast(loc, args[0].getValue(),
                                                 destType);
  // Return the cast result with the original cleanup.
  return ManagedValue(result, cleanup);
}

/// Specialized emitter for Builtin.castReference.
static ManagedValue
emitBuiltinCastReference(SILGenFunction &SGF,
                         SILLocation loc,
                         SubstitutionList substitutions,
                         ArrayRef<ManagedValue> args,
                         SGFContext C) {
  assert(args.size() == 1 && "castReference should be given one argument");
  assert(substitutions.size() == 2 && "castReference should have two subs");

  auto fromTy = substitutions[0].getReplacement();
  auto toTy = substitutions[1].getReplacement();
  auto &fromTL = SGF.getTypeLowering(fromTy);
  auto &toTL = SGF.getTypeLowering(toTy);
  assert(!fromTL.isTrivial() && !toTL.isTrivial() && "expected ref type");

  if (!fromTL.isAddress() || !toTL.isAddress()) { 
    if (auto refCast = SGF.B.tryCreateUncheckedRefCast(loc, args[0].getValue(),
                                                       toTL.getLoweredType())) {
      // Create a reference cast, forwarding the cleanup.
      // The cast takes the source reference.
      return ManagedValue(refCast, args[0].getCleanup());
    }
  }
  // We are either casting between address-only types, or cannot promote to a
  // cast of reference values.
  //
  // If the from/to types are invalid, then use a cast that will fail at
  // runtime. We cannot catch these errors with SIL verification because they
  // may legitimately occur during code specialization on dynamically
  // unreachable paths.
  //
  // TODO: For now, we leave invalid casts in address form so that the runtime
  // will trap. We could emit a noreturn call here instead which would provide
  // more information to the optimizer.
  SILValue srcVal = args[0].forward(SGF);
  SILValue fromAddr;
  if (!fromTL.isAddress()) {
    // Move the loadable value into a "source temp".  Since the source and
    // dest are RC identical, store the reference into the source temp without
    // a retain. The cast will load the reference from the source temp and
    // store it into a dest temp effectively forwarding the cleanup.
    fromAddr = SGF.emitTemporaryAllocation(loc, srcVal->getType());
    fromTL.emitStore(SGF.B, loc, srcVal, fromAddr,
                     StoreOwnershipQualifier::Init);
  } else {
    // The cast loads directly from the source address.
    fromAddr = srcVal;
  }
  // Create a "dest temp" to hold the reference after casting it.
  SILValue toAddr = SGF.emitTemporaryAllocation(loc, toTL.getLoweredType());
  SGF.B.createUncheckedRefCastAddr(loc, fromAddr, fromTy->getCanonicalType(),
                                   toAddr, toTy->getCanonicalType());
  // Forward it along and register a cleanup.
  if (toTL.isAddress())
    return SGF.emitManagedBufferWithCleanup(toAddr);

  // Load the destination value.
  auto result = toTL.emitLoad(SGF.B, loc, toAddr, LoadOwnershipQualifier::Take);
  return SGF.emitManagedRValueWithCleanup(result);
}

/// Specialized emitter for Builtin.castReferenceFromBridgeObject.
static ManagedValue emitBuiltinCastReferenceFromBridgeObject(
                                                  SILGenFunction &gen,
                                                  SILLocation loc,
                                                  SubstitutionList subs,
                                                  ArrayRef<ManagedValue> args,
                                                  CanFunctionType formalApplyType,
                                                  SGFContext C) {
  assert(args.size() == 1 && "cast should have one argument");
  assert(subs.size() == 1 && "cast should have a type substitution");

  // The substitution determines the destination type.
  SILType destType = gen.getLoweredType(subs[0].getReplacement());
  
  // Bail if the source type is not a class reference of some kind.
  if (!subs[0].getReplacement()->isBridgeableObjectType()
      || !destType.isObject()) {
    gen.SGM.diagnose(loc, diag::invalid_sil_builtin,
                 "castReferenceFromBridgeObject dest must be an object type");
    // Recover by propagating an undef result.
    SILValue result = SILUndef::get(destType, gen.SGM.M);
    return ManagedValue::forUnmanaged(result);
  }
  
  SILValue result = gen.B.createBridgeObjectToRef(loc, args[0].forward(gen),
                                                  destType);
  return gen.emitManagedRValueWithCleanup(result);
}

static ManagedValue emitBuiltinAllocWithTailElems(SILGenFunction &gen,
                                              SILLocation loc,
                                              SubstitutionList subs,
                                              ArrayRef<ManagedValue> args,
                                              CanFunctionType formalApplyType,
                                              SGFContext C) {
  unsigned NumTailTypes = subs.size() - 1;
  assert(args.size() == NumTailTypes * 2 + 1 &&
         "wrong number of substitutions for allocWithTailElems");

  // The substitution determines the element type for bound memory.
  SILType RefType = gen.getLoweredType(subs[0].getReplacement()->
                                  getCanonicalType()).getObjectType();

  SmallVector<ManagedValue, 4> Counts;
  SmallVector<SILType, 4> ElemTypes;
  for (unsigned Idx = 0; Idx < NumTailTypes; ++Idx) {
    Counts.push_back(args[Idx * 2 + 1]);
    ElemTypes.push_back(gen.getLoweredType(subs[Idx+1].getReplacement()->
                                           getCanonicalType()).getObjectType());
  }
  ManagedValue Metatype = args[0];
  if (isa<MetatypeInst>(Metatype)) {
    assert(Metatype.getType().getMetatypeInstanceType(gen.SGM.M) == RefType &&
           "substituted type does not match operand metatype");
    return gen.B.createAllocRef(loc, RefType, false, false,
                                ElemTypes, Counts);
  } else {
    return gen.B.createAllocRefDynamic(loc, Metatype, RefType, false,
                                       ElemTypes, Counts);
  }
}

static ManagedValue emitCastToReferenceType(SILGenFunction &SGF,
                                            SILLocation loc,
                                            SubstitutionList substitutions,
                                            ArrayRef<ManagedValue> args,
                                            SGFContext C,
                                            SILType objPointerType) {
  assert(args.size() == 1 && "cast should have a single argument");
  assert(substitutions.size() == 1 && "cast should have a type substitution");
  
  // Bail if the source type is not a class reference of some kind.
  if (!substitutions[0].getReplacement()->mayHaveSuperclass() &&
      !substitutions[0].getReplacement()->isClassExistentialType()) {
    SGF.SGM.diagnose(loc, diag::invalid_sil_builtin,
                     "castToNativeObject source must be a class");
    SILValue undef = SILUndef::get(objPointerType, SGF.SGM.M);
    return ManagedValue::forUnmanaged(undef);
  }

  // Grab the argument.
  ManagedValue arg = args[0];

  // If the argument is existential, open it.
  if (substitutions[0].getReplacement()->isClassExistentialType()) {
    auto openedTy
      = ArchetypeType::getOpened(substitutions[0].getReplacement());
    SILType loweredOpenedTy = SGF.getLoweredLoadableType(openedTy);
    arg = SGF.B.createOpenExistentialRef(loc, arg, loweredOpenedTy);
  }

  // Return the cast result.
  return SGF.B.createUncheckedRefCast(loc, arg, objPointerType);
}

/// Specialized emitter for Builtin.reinterpretCast.
static ManagedValue emitBuiltinReinterpretCast(SILGenFunction &gen,
                                         SILLocation loc,
                                         SubstitutionList substitutions,
                                         ArrayRef<ManagedValue> args,
                                         CanFunctionType formalApplyType,
                                         SGFContext C) {
  assert(args.size() == 1 && "reinterpretCast should be given one argument");
  assert(substitutions.size() == 2 && "reinterpretCast should have two subs");
  
  auto &fromTL = gen.getTypeLowering(substitutions[0].getReplacement());
  auto &toTL = gen.getTypeLowering(substitutions[1].getReplacement());
  
  // If casting between address-only types, cast the address.
  if (!fromTL.isLoadable() || !toTL.isLoadable()) {
    SILValue fromAddr;

    // If the from value is loadable, move it to a buffer.
    if (fromTL.isLoadable()) {
      fromAddr = gen.emitTemporaryAllocation(loc, args[0].getValue()->getType());
      fromTL.emitStore(gen.B, loc, args[0].getValue(), fromAddr,
                       StoreOwnershipQualifier::Init);
    } else {
      fromAddr = args[0].getValue();
    }
    auto toAddr = gen.B.createUncheckedAddrCast(loc, fromAddr,
                                      toTL.getLoweredType().getAddressType());
    
    // Load and retain the destination value if it's loadable. Leave the cleanup
    // on the original value since we don't know anything about it's type.
    if (toTL.isLoadable()) {
      return gen.emitManagedLoadCopy(loc, toAddr, toTL);
    }
    // Leave the cleanup on the original value.
    if (toTL.isTrivial())
      return ManagedValue::forUnmanaged(toAddr);

    // Initialize the +1 result buffer without taking the incoming value. The
    // source and destination cleanups will be independent.
    return gen.B.bufferForExpr(
        loc, toTL.getLoweredType(), toTL, C,
        [&](SILValue bufferAddr) {
          gen.B.createCopyAddr(loc, toAddr, bufferAddr, IsNotTake,
                               IsInitialization);
        });
  }
  // Create the appropriate bitcast based on the source and dest types.
  auto &in = args[0];
  SILValue out = gen.B.createUncheckedBitCast(loc, in.getValue(),
                                              toTL.getLoweredType());

  // If the cast reduces to unchecked_ref_cast, then the source and dest
  // have identical cleanup, so just forward the cleanup as an optimization.
  if (isa<UncheckedRefCastInst>(out))
    return ManagedValue(out, in.getCleanup());

  // Otherwise leave the original cleanup and retain the cast value.
  return gen.emitManagedRetain(loc, out, toTL);
}

/// Compute substitutions for making a direct call to a SIL function with
/// @convention(witness_method) convention.
///
/// Such functions have a substituted generic signature where the
/// abstract `Self` parameter from the original type of the protocol
/// requirement is replaced by a concrete type.
///
/// Thus, the original substitutions of the apply instruction that
/// are written in terms of the requirement's generic signature need
/// to be remapped to substitutions suitable for the witness signature.
///
/// \param conformanceRef The (possibly-specialized) conformance
/// \param requirementSig The generic signature of the requirement
/// \param witnessThunkSig The generic signature of the witness method
/// \param origSubs The substitutions from the call instruction
/// \param newSubs New substitutions are stored here
static void getWitnessMethodSubstitutions(
    SILModule &M,
    ProtocolConformanceRef conformanceRef,
    GenericSignature *requirementSig,
    GenericSignature *witnessThunkSig,
    SubstitutionList origSubs,
    bool isDefaultWitness,
    SmallVectorImpl<Substitution> &newSubs) {

  if (witnessThunkSig == nullptr)
    return;

  if (isDefaultWitness) {
    newSubs.append(origSubs.begin(), origSubs.end());
    return;
  }

  assert(!conformanceRef.isAbstract());
  auto conformance = conformanceRef.getConcrete();

  // If `Self` maps to a bound generic type, this gives us the
  // substitutions for the concrete type's generic parameters.
  auto baseSubMap = getSubstitutionsForProtocolConformance(conformanceRef);

  unsigned baseDepth = 0;
  auto *rootConformance = conformance->getRootNormalConformance();
  if (auto *witnessSig = rootConformance->getGenericSignature())
    baseDepth = witnessSig->getGenericParams().back()->getDepth() + 1;

  auto origDepth = 1;
  auto origSubMap = requirementSig->getSubstitutionMap(origSubs);

  auto subMap =
    SubstitutionMap::combineSubstitutionMaps(baseSubMap,
                                             origSubMap, 
                                             CombineSubstitutionMaps::AtDepth,
                                             baseDepth,
                                             origDepth,
                                             witnessThunkSig);

  witnessThunkSig->getSubstitutions(subMap, newSubs);
}

static SubstitutionMap
getSubstitutionsForProtocolConformance(ProtocolConformanceRef CRef) {
  auto C = CRef.getConcrete();

  // Walk down to the base NormalProtocolConformance.
  SubstitutionList Subs;
  const ProtocolConformance *ParentC = C;
  while (!isa<NormalProtocolConformance>(ParentC)) {
    switch (ParentC->getKind()) {
    case ProtocolConformanceKind::Normal:
      llvm_unreachable("should have exited the loop?!");
    case ProtocolConformanceKind::Inherited:
      ParentC = cast<InheritedProtocolConformance>(ParentC)
        ->getInheritedConformance();
      break;
    case ProtocolConformanceKind::Specialized: {
      auto SC = cast<SpecializedProtocolConformance>(ParentC);
      ParentC = SC->getGenericConformance();
      assert(Subs.empty() && "multiple conformance specializations?!");
      Subs = SC->getGenericSubstitutions();
      break;
    }
    }
  }
  const NormalProtocolConformance *NormalC
    = cast<NormalProtocolConformance>(ParentC);

  // 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.
  if (!NormalC->getType()->isSpecialized())
    return SubstitutionMap();

  if (Subs.empty()) {
    auto *DC = NormalC->getDeclContext();
    return NormalC->getType()
      ->getContextSubstitutionMap(DC->getParentModule(), DC);
  }

  return NormalC->getGenericSignature()->getSubstitutionMap(Subs);
}

shared_ptr<Predicate> PredicateEntry::substitute(SubstitutionList & substitution_list) const {
	vector<shared_ptr<SymbolTableEntry>> symbols;
	for (auto i = _symbols.begin(); i != _symbols.end(); ++i) {
		symbols.push_back(substitution_list.find_value(*i));
	}
	PredicateEntry p(string(_name), symbols);
	ostringstream s;
	s << "(" << p.text() << ")";
	Parser parser(s.str());

	return parser.parse_predicate();
}

// @brief Returns true if the PredicateEnry matches with other PredicateEntry
// @return bool 		
bool PredicateEntry::matches(shared_ptr<SymbolTableEntry> other, SubstitutionList & substitution_list) const {
	if (!other->is_predicate()) {
		return false;
	}
	shared_ptr<PredicateEntry> otherp = dynamic_pointer_cast<PredicateEntry>(other);

	if (_name != otherp->_name || _symbols.size() != otherp->_symbols.size()) {
		return false;
	}

	for (unsigned int i = 0; i < _symbols.size(); ++i) {
		shared_ptr<SymbolTableEntry> ci_value = substitution_list.find_value(_symbols[i]);
		shared_ptr<SymbolTableEntry> oi_value = substitution_list.find_value(otherp->_symbols[i]);
		shared_ptr<SymbolTableEntry> ci = substitution_list.find_non_null(_symbols[i]);
		shared_ptr<SymbolTableEntry> oi = substitution_list.find_non_null(otherp->_symbols[i]);
		if (!ci_value || !oi_value) {
			//semantic error
			return false;
		}

		if (!(*ci_value == *oi_value)) {
			if (ci_value->is_constant() && oi_value->is_constant()) {
				return false;
			} 

			if (!ci_value->is_constant()) {
				substitution_list.add(ci, oi);
			} else { //!oi->is_constant()
				substitution_list.add(oi, ci);
			}
		} 
	}
	return true;
}

int Specialization::substituteVariablesWithConst(SgNode* node, ConstReporter* constReporter) {
   typedef pair<SgExpression*,int> SubstitutionPair;
   typedef list<SubstitutionPair > SubstitutionList;
   SubstitutionList substitutionList;
   RoseAst ast(node);
   for(RoseAst::iterator i=ast.begin();i!=ast.end();++i) {
     if(constReporter->isConst(*i)) {
       int varIntValue=constReporter->getConstInt();
       SgVarRefExp* varRefExp=constReporter->getVarRefExp();
       SubstitutionPair p=make_pair(varRefExp,varIntValue);
       substitutionList.push_back(p);
     }
   }
   for(SubstitutionList::iterator i=substitutionList.begin(); i!=substitutionList.end(); ++i) {
     // buildSignedIntType()
     // buildFloatType()
     // buildDoubleType()
     // SgIntVal* buildIntVal(int)
     SgNodeHelper::replaceExpression((*i).first,SageBuilder::buildIntVal((*i).second),false);
   }
   return (int)substitutionList.size();
 }