//===--- Linking.cpp - Name mangling for IRGen entities -------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
//  This file implements name mangling for IRGen entities with linkage.
//
//===----------------------------------------------------------------------===//

#include "swift/IRGen/Linking.h"
#include "IRGenMangler.h"
#include "IRGenModule.h"
#include "swift/AST/ASTMangler.h"
#include "swift/SIL/SILGlobalVariable.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/raw_ostream.h"

using namespace swift;
using namespace irgen;
using namespace Mangle;

bool swift::irgen::useDllStorage(const llvm::Triple &triple) {
  return triple.isOSBinFormatCOFF() && !triple.isOSCygMing();
}

UniversalLinkageInfo::UniversalLinkageInfo(IRGenModule &IGM)
    : UniversalLinkageInfo(IGM.Triple, IGM.IRGen.hasMultipleIGMs(),
                           IGM.getSILModule().isWholeModule()) {}

UniversalLinkageInfo::UniversalLinkageInfo(const llvm::Triple &triple,
                                           bool hasMultipleIGMs,
                                           bool isWholeModule)
    : IsELFObject(triple.isOSBinFormatELF()),
      UseDLLStorage(useDllStorage(triple)), HasMultipleIGMs(hasMultipleIGMs),
      IsWholeModule(isWholeModule) {}

/// Mangle this entity into the given buffer.
void LinkEntity::mangle(SmallVectorImpl<char> &buffer) const {
  llvm::raw_svector_ostream stream(buffer);
  mangle(stream);
}

/// Mangle this entity into the given stream.
void LinkEntity::mangle(raw_ostream &buffer) const {
  std::string Result = mangleAsString();
  buffer.write(Result.data(), Result.size());
}

/// Mangle this entity as a std::string.
std::string LinkEntity::mangleAsString() const {
  IRGenMangler mangler;
  switch (getKind()) {
    case Kind::DispatchThunk:
      return mangler.mangleEntity(getDecl(), /*isCurried=*/false,
                                  ASTMangler::SymbolKind::SwiftDispatchThunk);

    case Kind::DispatchThunkInitializer:
      return mangler.mangleConstructorEntity(
          cast<ConstructorDecl>(getDecl()),
          /*isAllocating=*/false,
          /*isCurried=*/false,
          ASTMangler::SymbolKind::SwiftDispatchThunk);

    case Kind::DispatchThunkAllocator:
      return mangler.mangleConstructorEntity(
          cast<ConstructorDecl>(getDecl()),
          /*isAllocating=*/true,
          /*isCurried=*/false,
          ASTMangler::SymbolKind::SwiftDispatchThunk);

    case Kind::ValueWitness:
      return mangler.mangleValueWitness(getType(), getValueWitness());

    case Kind::ValueWitnessTable:
      return mangler.mangleValueWitnessTable(getType());

    case Kind::TypeMetadataAccessFunction:
      return mangler.mangleTypeMetadataAccessFunction(getType());

    case Kind::TypeMetadataLazyCacheVariable:
      return mangler.mangleTypeMetadataLazyCacheVariable(getType());

    case Kind::TypeMetadataInstantiationCache:
      return mangler.mangleTypeMetadataInstantiationCache(
                                              cast<NominalTypeDecl>(getDecl()));

    case Kind::TypeMetadataInstantiationFunction:
      return mangler.mangleTypeMetadataInstantiationFunction(
                                              cast<NominalTypeDecl>(getDecl()));

    case Kind::TypeMetadataCompletionFunction:
      return mangler.mangleTypeMetadataCompletionFunction(
                                              cast<NominalTypeDecl>(getDecl()));

    case Kind::TypeMetadata:
      switch (getMetadataAddress()) {
        case TypeMetadataAddress::FullMetadata:
          return mangler.mangleTypeFullMetadataFull(getType());
        case TypeMetadataAddress::AddressPoint:
          return mangler.mangleTypeMetadataFull(getType());
      }
      llvm_unreachable("invalid metadata address");

    case Kind::TypeMetadataPattern:
      return mangler.mangleTypeMetadataPattern(
                                          cast<NominalTypeDecl>(getDecl()));

    case Kind::ForeignTypeMetadataCandidate:
      return mangler.mangleTypeMetadataFull(getType());

    case Kind::SwiftMetaclassStub:
      return mangler.mangleClassMetaClass(cast<ClassDecl>(getDecl()));

    case Kind::ClassMetadataBaseOffset:               // class metadata base offset
      return mangler.mangleClassMetadataBaseOffset(cast<ClassDecl>(getDecl()));

    case Kind::NominalTypeDescriptor:
      return mangler.mangleNominalTypeDescriptor(
                                          cast<NominalTypeDecl>(getDecl()));

    case Kind::PropertyDescriptor:
      return mangler.manglePropertyDescriptor(
                                          cast<AbstractStorageDecl>(getDecl()));

    case Kind::ModuleDescriptor:
      return mangler.mangleModuleDescriptor(cast<ModuleDecl>(getDecl()));
  
    case Kind::ExtensionDescriptor:
      return mangler.mangleExtensionDescriptor(getExtension());
    
    case Kind::AnonymousDescriptor:
      return mangler.mangleAnonymousDescriptor(getDeclContext());

    case Kind::ProtocolDescriptor:
      return mangler.mangleProtocolDescriptor(cast<ProtocolDecl>(getDecl()));

    case Kind::ProtocolConformanceDescriptor:
      return mangler.mangleProtocolConformanceDescriptor(
                     cast<NormalProtocolConformance>(getProtocolConformance()));

    case Kind::FieldOffset:
      return mangler.mangleFieldOffset(getDecl());

    case Kind::DirectProtocolWitnessTable:
      return mangler.mangleDirectProtocolWitnessTable(getProtocolConformance());

    case Kind::GenericProtocolWitnessTableCache:
      return mangler.mangleGenericProtocolWitnessTableCache(
                                                      getProtocolConformance());

    case Kind::GenericProtocolWitnessTableInstantiationFunction:
      return mangler.mangleGenericProtocolWitnessTableInstantiationFunction(
                                                      getProtocolConformance());

    case Kind::ProtocolWitnessTableAccessFunction:
      return mangler.mangleProtocolWitnessTableAccessFunction(
                                                      getProtocolConformance());

    case Kind::ProtocolWitnessTableLazyAccessFunction:
      return mangler.mangleProtocolWitnessTableLazyAccessFunction(getType(),
                                                      getProtocolConformance());

    case Kind::ProtocolWitnessTableLazyCacheVariable:
      return mangler.mangleProtocolWitnessTableLazyCacheVariable(getType(),
                                                      getProtocolConformance());

    case Kind::AssociatedTypeMetadataAccessFunction:
      return mangler.mangleAssociatedTypeMetadataAccessFunction(
                  getProtocolConformance(), getAssociatedType()->getNameStr());

    case Kind::AssociatedTypeWitnessTableAccessFunction: {
      auto assocConf = getAssociatedConformance();
      return mangler.mangleAssociatedTypeWitnessTableAccessFunction(
                  getProtocolConformance(), assocConf.first, assocConf.second);
    }

    case Kind::CoroutineContinuationPrototype:
      return mangler.mangleCoroutineContinuationPrototype(
                                              cast<SILFunctionType>(getType()));

      // An Objective-C class reference reference. The symbol is private, so
      // the mangling is unimportant; it should just be readable in LLVM IR.
    case Kind::ObjCClassRef: {
      llvm::SmallString<64> tempBuffer;
      StringRef name = cast<ClassDecl>(getDecl())->getObjCRuntimeName(tempBuffer);
      std::string Result("\01l_OBJC_CLASS_REF_$_");
      Result.append(name.data(), name.size());
      return Result;
    }

      // An Objective-C class reference;  not a swift mangling.
    case Kind::ObjCClass: {
      llvm::SmallString<64> TempBuffer;
      StringRef Name = cast<ClassDecl>(getDecl())->getObjCRuntimeName(TempBuffer);
      std::string Result("OBJC_CLASS_$_");
      Result.append(Name.data(), Name.size());
      return Result;
    }

      // An Objective-C metaclass reference;  not a swift mangling.
    case Kind::ObjCMetaclass: {
      llvm::SmallString<64> TempBuffer;
      StringRef Name = cast<ClassDecl>(getDecl())->getObjCRuntimeName(TempBuffer);
      std::string Result("OBJC_METACLASS_$_");
      Result.append(Name.data(), Name.size());
      return Result;
    }

    case Kind::SILFunction:
      return getSILFunction()->getName();
    case Kind::SILGlobalVariable:
      return getSILGlobalVariable()->getName();

    case Kind::ReflectionBuiltinDescriptor:
      return mangler.mangleReflectionBuiltinDescriptor(getType());
    case Kind::ReflectionFieldDescriptor:
      return mangler.mangleReflectionFieldDescriptor(getType());
    case Kind::ReflectionAssociatedTypeDescriptor:
      return mangler.mangleReflectionAssociatedTypeDescriptor(
                                                      getProtocolConformance());
  }
  llvm_unreachable("bad entity kind!");
}