//===--- SILModule.cpp - SILModule implementation -------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

#include "swift/SIL/SILModule.h"
#include "swift/SIL/SILExternalSource.h"
#include "swift/SIL/SILValue.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/StringSwitch.h"
using namespace swift;

namespace swift {
  /// SILTypeList - The uniqued backing store for the SILValue type list.  This
  /// is only exposed out of SILValue as an ArrayRef of types, so it should
  /// never be used outside of libSIL.
  class SILTypeList : public llvm::FoldingSetNode {
  public:
    unsigned NumTypes;
    SILType Types[1];  // Actually variable sized.
    
    void Profile(llvm::FoldingSetNodeID &ID) const {
      for (unsigned i = 0, e = NumTypes; i != e; ++i) {
        ID.AddPointer(Types[i].getOpaqueValue());
      }
    }
  };
} // end namespace swift.

void SILExternalSource::anchor() {
}

/// SILTypeListUniquingType - This is the type of the folding set maintained by
/// SILModule that these things are uniqued into.
typedef llvm::FoldingSet<SILTypeList> SILTypeListUniquingType;

SILModule::SILModule(Module *SwiftModule)
  : TheSwiftModule(SwiftModule), Stage(SILStage::Raw), Types(*this) {
  TypeListUniquing = new SILTypeListUniquingType();
}

SILModule::~SILModule() {
  delete (SILTypeListUniquingType*)TypeListUniquing;
}

std::pair<SILWitnessTable *, ArrayRef<Substitution>>
SILModule::lookUpWitnessTable(const ProtocolConformance *C) {
  // Walk down to the base NormalProtocolConformance.
  const ProtocolConformance *ParentC = C;
  ArrayRef<Substitution> Subs;
  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);
  
  // Did we already find this?
  auto found = WitnessTableLookupCache.find(NormalC);
  if (found != WitnessTableLookupCache.end())
    return {found->second, Subs};
  
  // If not, search through the witness table list, caching the entries we
  // visit.
  for (SILWitnessTable &WT : witnessTables) {
    WitnessTableLookupCache[WT.getConformance()] = &WT;
    
    if (WT.getConformance() == NormalC)
      return {&WT, Subs};
  }
  return {nullptr, Subs};
}

SILFunction *SILModule::getOrCreateSharedFunction(SILLocation loc,
                                                  StringRef name,
                                                  CanSILFunctionType type,
                                                  IsBare_t isBareSILFunction,
                                                IsTransparent_t isTransparent) {
  auto linkage = SILLinkage::Shared;

  if (auto fn = lookUpFunction(name)) {
    assert(fn->getLoweredFunctionType() == type);
    assert(fn->getLinkage() == linkage);
    return fn;
  }

  return SILFunction::create(*this, linkage, name, type,
                             loc, isBareSILFunction, isTransparent);
}

ArrayRef<SILType> ValueBase::getTypes() const {
  // No results.
  if (TypeOrTypeList.isNull())
    return ArrayRef<SILType>();
  // Arbitrary list of results.
  if (auto *TypeList = TypeOrTypeList.dyn_cast<SILTypeList*>())
    return ArrayRef<SILType>(TypeList->Types, TypeList->NumTypes);
  // Single result.
  return TypeOrTypeList.get<SILType>();
}



/// getSILTypeList - Get a uniqued pointer to a SIL type list.  This can only
/// be used by SILValue.
SILTypeList *SILModule::getSILTypeList(ArrayRef<SILType> Types) const {
  assert(Types.size() > 1 && "Shouldn't use type list for 0 or 1 types");
  auto UniqueMap = (SILTypeListUniquingType*)TypeListUniquing;
  
  llvm::FoldingSetNodeID ID;
  for (auto T : Types) {
    ID.AddPointer(T.getOpaqueValue());
  }
  
  // If we already have this type list, just return it.
  void *InsertPoint = 0;
  if (SILTypeList *TypeList = UniqueMap->FindNodeOrInsertPos(ID, InsertPoint))
    return TypeList;
  
  // Otherwise, allocate a new one.
  void *NewListP = BPA.Allocate(sizeof(SILTypeList)+
                                sizeof(SILType)*(Types.size()-1),
                                alignof(SILTypeList));
  SILTypeList *NewList = new (NewListP) SILTypeList();
  NewList->NumTypes = Types.size();
  std::copy(Types.begin(), Types.end(), NewList->Types);
  
  UniqueMap->InsertNode(NewList, InsertPoint);
  return NewList;
}

const IntrinsicInfo &SILModule::getIntrinsicInfo(Identifier ID) {
  unsigned OldSize = IntrinsicIDCache.size();
  IntrinsicInfo &Info = IntrinsicIDCache[ID];

  // If the element was is in the cache, return it.
  if (OldSize == IntrinsicIDCache.size())
    return Info;

  // Otherwise, lookup the ID and Type and store them in the map.
  StringRef NameRef = getBuiltinBaseName(getASTContext(), ID.str(), Info.Types);
  Info.ID =
    (llvm::Intrinsic::ID)getLLVMIntrinsicID(NameRef, !Info.Types.empty());

  return Info;
}

const BuiltinInfo &SILModule::getBuiltinInfo(Identifier ID) {
  unsigned OldSize = BuiltinIDCache.size();
  BuiltinInfo &Info = BuiltinIDCache[ID];

  // If the element was is in the cache, return it.
  if (OldSize == BuiltinIDCache.size())
    return Info;

  // Otherwise, lookup the ID and Type and store them in the map.
  // Find the matching ID.
  StringRef OperationName =
    getBuiltinBaseName(getASTContext(), ID.str(), Info.Types);

  // Several operation names have suffixes and don't match the name from
  // Builtins.def, so handle those first.
  if (OperationName.startswith("fence_"))
    Info.ID = BuiltinValueKind::Fence;
  else if (OperationName.startswith("cmpxchg_"))
    Info.ID = BuiltinValueKind::CmpXChg;
  else if (OperationName.startswith("atomicrmw_"))
    Info.ID = BuiltinValueKind::AtomicRMW;
  else {
    // Switch through the rest of builtins.
    Info.ID = llvm::StringSwitch<BuiltinValueKind>(OperationName)
#define BUILTIN(ID, Name, Attrs) \
      .Case(Name, BuiltinValueKind::ID)
#include "swift/AST/Builtins.def"
      .Default(BuiltinValueKind::None);
  }

  return Info;
}