//===------ DarwinToolChains.cpp - Job invocations (Darwin-specific) ------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 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
//
//===----------------------------------------------------------------------===//

#include "ToolChains.h"

#include "swift/Basic/Dwarf.h"
#include "swift/Basic/LLVM.h"
#include "swift/Basic/Platform.h"
#include "swift/Basic/Range.h"
#include "swift/Basic/TaskQueue.h"
#include "swift/Config.h"
#include "swift/Driver/Compilation.h"
#include "swift/Driver/Driver.h"
#include "swift/Driver/Job.h"
#include "swift/Frontend/Frontend.h"
#include "swift/Option/Options.h"
#include "clang/Basic/Version.h"
#include "clang/Driver/Util.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Option/Arg.h"
#include "llvm/Option/ArgList.h"
#include "llvm/ProfileData/InstrProf.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/Program.h"

using namespace swift;
using namespace swift::driver;
using namespace llvm::opt;

std::string
toolchains::Darwin::findProgramRelativeToSwiftImpl(StringRef name) const {
  StringRef swiftPath = getDriver().getSwiftProgramPath();
  StringRef swiftBinDir = llvm::sys::path::parent_path(swiftPath);

  // See if we're in an Xcode toolchain.
  bool hasToolchain = false;
  llvm::SmallString<128> path{swiftBinDir};
  llvm::sys::path::remove_filename(path); // bin
  llvm::sys::path::remove_filename(path); // usr
  if (llvm::sys::path::extension(path) == ".xctoolchain") {
    hasToolchain = true;
    llvm::sys::path::remove_filename(path); // *.xctoolchain
    llvm::sys::path::remove_filename(path); // Toolchains
    llvm::sys::path::append(path, "usr", "bin");
  }

  StringRef paths[] = {swiftBinDir, path};
  auto pathsRef = llvm::makeArrayRef(paths);
  if (!hasToolchain)
    pathsRef = pathsRef.drop_back();

  auto result = llvm::sys::findProgramByName(name, pathsRef);
  if (result)
    return result.get();
  return {};
}

ToolChain::InvocationInfo
toolchains::Darwin::constructInvocation(const InterpretJobAction &job,
                                        const JobContext &context) const {
  InvocationInfo II = ToolChain::constructInvocation(job, context);

  SmallString<128> runtimeLibraryPath;
  getRuntimeLibraryPath(runtimeLibraryPath, context.Args, /*Shared=*/true);

  addPathEnvironmentVariableIfNeeded(II.ExtraEnvironment, "DYLD_LIBRARY_PATH",
                                     ":", options::OPT_L, context.Args,
                                     runtimeLibraryPath);
  addPathEnvironmentVariableIfNeeded(II.ExtraEnvironment, "DYLD_FRAMEWORK_PATH",
                                     ":", options::OPT_F, context.Args);
  // FIXME: Add options::OPT_Fsystem paths to DYLD_FRAMEWORK_PATH as well.
  return II;
}

static StringRef
getDarwinLibraryNameSuffixForTriple(const llvm::Triple &triple,
                                    bool distinguishSimulator = true) {
  const DarwinPlatformKind kind = getDarwinPlatformKind(triple);
  const DarwinPlatformKind effectiveKind =
      distinguishSimulator ? kind : getNonSimulatorPlatform(kind);
  switch (effectiveKind) {
  case DarwinPlatformKind::MacOS:
    return "osx";
  case DarwinPlatformKind::IPhoneOS:
    return "ios";
  case DarwinPlatformKind::IPhoneOSSimulator:
    return "iossim";
  case DarwinPlatformKind::TvOS:
    return "tvos";
  case DarwinPlatformKind::TvOSSimulator:
    return "tvossim";
  case DarwinPlatformKind::WatchOS:
    return "watchos";
  case DarwinPlatformKind::WatchOSSimulator:
    return "watchossim";
  }
  llvm_unreachable("Unsupported Darwin platform");
}

std::string toolchains::Darwin::sanitizerRuntimeLibName(StringRef Sanitizer,
                                                        bool shared) const {
  return (Twine("libclang_rt.") + Sanitizer + "_" +
          getDarwinLibraryNameSuffixForTriple(this->getTriple()) +
          (shared ? "_dynamic.dylib" : ".a"))
      .str();
}

static void addLinkRuntimeLibRPath(const ArgList &Args,
                                   ArgStringList &Arguments,
                                   StringRef DarwinLibName,
                                   const ToolChain &TC) {
  // Adding the rpaths might negatively interact when other rpaths are involved,
  // so we should make sure we add the rpaths last, after all user-specified
  // rpaths. This is currently true from this place, but we need to be
  // careful if this function is ever called before user's rpaths are emitted.
  assert(DarwinLibName.endswith(".dylib") && "must be a dynamic library");

  // Add @executable_path to rpath to support having the dylib copied with
  // the executable.
  Arguments.push_back("-rpath");
  Arguments.push_back("@executable_path");

  // Add the path to the resource dir to rpath to support using the dylib
  // from the default location without copying.

  SmallString<128> ClangLibraryPath;
  TC.getClangLibraryPath(Args, ClangLibraryPath);

  Arguments.push_back("-rpath");
  Arguments.push_back(Args.MakeArgString(ClangLibraryPath));
}

static void addLinkSanitizerLibArgsForDarwin(const ArgList &Args,
                                             ArgStringList &Arguments,
                                             StringRef Sanitizer,
                                             const ToolChain &TC,
                                             bool shared = true) {
  // Sanitizer runtime libraries requires C++.
  Arguments.push_back("-lc++");
  // Add explicit dependency on -lc++abi, as -lc++ doesn't re-export
  // all RTTI-related symbols that are used.
  Arguments.push_back("-lc++abi");

  auto LibName = TC.sanitizerRuntimeLibName(Sanitizer, shared);
  TC.addLinkRuntimeLib(Args, Arguments, LibName);

  if (shared)
    addLinkRuntimeLibRPath(Args, Arguments, LibName, TC);
}

/// Runs <code>xcrun -f clang</code> in order to find the location of Clang for
/// the currently active Xcode.
///
/// We get the "currently active" part by passing through the DEVELOPER_DIR
/// environment variable (along with the rest of the environment).
static bool findXcodeClangPath(llvm::SmallVectorImpl<char> &path) {
  assert(path.empty());

  auto xcrunPath = llvm::sys::findProgramByName("xcrun");
  if (!xcrunPath.getError()) {
    const char *args[] = {"-f", "clang", nullptr};
    sys::TaskQueue queue;
    queue.addTask(xcrunPath->c_str(), args, /*Env=*/llvm::None,
                  /*Context=*/nullptr,
                  /*SeparateErrors=*/true);
    queue.execute(nullptr,
                  [&path](sys::ProcessId PID, int returnCode, StringRef output,
                          StringRef errors,
                          sys::TaskProcessInformation ProcInfo,
                          void *unused) -> sys::TaskFinishedResponse {
                    if (returnCode == 0) {
                      output = output.rtrim();
                      path.append(output.begin(), output.end());
                    }
                    return sys::TaskFinishedResponse::ContinueExecution;
                  });
  }

  return !path.empty();
}

static void addVersionString(const ArgList &inputArgs, ArgStringList &arguments,
                             unsigned major, unsigned minor, unsigned micro) {
  llvm::SmallString<8> buf;
  llvm::raw_svector_ostream os{buf};
  os << major << '.' << minor << '.' << micro;
  arguments.push_back(inputArgs.MakeArgString(os.str()));
}

/// Returns true if the compiler depends on features provided by the ObjC
/// runtime that are not present on the deployment target indicated by
/// \p triple.
static bool wantsObjCRuntime(const llvm::Triple &triple) {
  assert((!triple.isTvOS() || triple.isiOS()) &&
         "tvOS is considered a kind of iOS");

  // When updating the versions listed here, please record the most recent
  // feature being depended on and when it was introduced:
  //
  // - The hook to override class_getImageName (macOS 10.14 and equivalent)
  if (triple.isiOS())
    return triple.isOSVersionLT(12);
  if (triple.isMacOSX())
    return triple.isMacOSXVersionLT(10, 14);
  if (triple.isWatchOS())
    return triple.isOSVersionLT(5);
  llvm_unreachable("unknown Darwin OS");
}

ToolChain::InvocationInfo
toolchains::Darwin::constructInvocation(const LinkJobAction &job,
                                        const JobContext &context) const {
  assert(context.Output.getPrimaryOutputType() == file_types::TY_Image &&
         "Invalid linker output type.");

  if (context.Args.hasFlag(options::OPT_static_executable,
                           options::OPT_no_static_executable, false)) {
    llvm::report_fatal_error("-static-executable is not supported on Darwin");
  }

  const Driver &D = getDriver();
  const llvm::Triple &Triple = getTriple();

  // Configure the toolchain.
  // By default, use the system `ld` to link.
  const char *LD = "ld";
  if (const Arg *A = context.Args.getLastArg(options::OPT_tools_directory)) {
    StringRef toolchainPath(A->getValue());

    // If there is a 'ld' in the toolchain folder, use that instead.
    if (auto toolchainLD =
            llvm::sys::findProgramByName("ld", {toolchainPath})) {
      LD = context.Args.MakeArgString(toolchainLD.get());
    }
  }

  InvocationInfo II = {LD};
  ArgStringList &Arguments = II.Arguments;

  if (context.shouldUseInputFileList()) {
    Arguments.push_back("-filelist");
    Arguments.push_back(context.getTemporaryFilePath("inputs", "LinkFileList"));
    II.FilelistInfos.push_back({Arguments.back(), file_types::TY_Object,
                                FilelistInfo::WhichFiles::Input});
  } else {
    addPrimaryInputsOfType(Arguments, context.Inputs, context.Args,
                           file_types::TY_Object);
  }

  addInputsOfType(Arguments, context.InputActions, file_types::TY_Object);

  if (context.OI.CompilerMode == OutputInfo::Mode::SingleCompile)
    addInputsOfType(Arguments, context.Inputs, context.Args,
                    file_types::TY_SwiftModuleFile, "-add_ast_path");
  else
    addPrimaryInputsOfType(Arguments, context.Inputs, context.Args,
                           file_types::TY_SwiftModuleFile, "-add_ast_path");

  // Add all .swiftmodule file inputs as arguments, preceded by the
  // "-add_ast_path" linker option.
  addInputsOfType(Arguments, context.InputActions,
                  file_types::TY_SwiftModuleFile, "-add_ast_path");

  switch (job.getKind()) {
  case LinkKind::None:
    llvm_unreachable("invalid link kind");
  case LinkKind::Executable:
    // The default for ld; no extra flags necessary.
    break;
  case LinkKind::DynamicLibrary:
    Arguments.push_back("-dylib");
    break;
  }

  assert(Triple.isOSDarwin());

  // FIXME: If we used Clang as a linker instead of going straight to ld,
  // we wouldn't have to replicate a bunch of Clang's logic here.

  // Always link the regular compiler_rt if it's present.
  //
  // Note: Normally we'd just add this unconditionally, but it's valid to build
  // Swift and use it as a linker without building compiler_rt.
  SmallString<128> CompilerRTPath;
  getClangLibraryPath(context.Args, CompilerRTPath);
  llvm::sys::path::append(
      CompilerRTPath,
      Twine("libclang_rt.") +
        getDarwinLibraryNameSuffixForTriple(Triple, /*simulator*/false) +
        ".a");
  if (llvm::sys::fs::exists(CompilerRTPath))
    Arguments.push_back(context.Args.MakeArgString(CompilerRTPath));

  if (context.Args.hasFlag(options::OPT_link_objc_runtime,
                           options::OPT_no_link_objc_runtime,
                           /*Default=*/wantsObjCRuntime(Triple))) {
    llvm::SmallString<128> ARCLiteLib(D.getSwiftProgramPath());
    llvm::sys::path::remove_filename(ARCLiteLib); // 'swift'
    llvm::sys::path::remove_filename(ARCLiteLib); // 'bin'
    llvm::sys::path::append(ARCLiteLib, "lib", "arc");

    if (!llvm::sys::fs::is_directory(ARCLiteLib)) {
      // If we don't have a 'lib/arc/' directory, find the "arclite" library
      // relative to the Clang in the active Xcode.
      ARCLiteLib.clear();
      if (findXcodeClangPath(ARCLiteLib)) {
        llvm::sys::path::remove_filename(ARCLiteLib); // 'clang'
        llvm::sys::path::remove_filename(ARCLiteLib); // 'bin'
        llvm::sys::path::append(ARCLiteLib, "lib", "arc");
      }
    }

    if (!ARCLiteLib.empty()) {
      llvm::sys::path::append(ARCLiteLib, "libarclite_");
      ARCLiteLib += getPlatformNameForTriple(Triple);
      ARCLiteLib += ".a";

      Arguments.push_back("-force_load");
      Arguments.push_back(context.Args.MakeArgString(ARCLiteLib));

      // Arclite depends on CoreFoundation.
      Arguments.push_back("-framework");
      Arguments.push_back("CoreFoundation");
    } else {
      // FIXME: We should probably diagnose this, but this is not a place where
      // we can emit diagnostics. Silently ignore it for now.
    }
  }

  context.Args.AddAllArgValues(Arguments, options::OPT_Xlinker);
  context.Args.AddAllArgs(Arguments, options::OPT_linker_option_Group);
  for (const Arg *arg :
       context.Args.filtered(options::OPT_F, options::OPT_Fsystem)) {
    Arguments.push_back("-F");
    Arguments.push_back(arg->getValue());
  }

  if (context.Args.hasArg(options::OPT_enable_app_extension)) {
    // Keep this string fixed in case the option used by the
    // compiler itself changes.
    Arguments.push_back("-application_extension");
  }

  // Linking sanitizers will add rpaths, which might negatively interact when
  // other rpaths are involved, so we should make sure we add the rpaths after
  // all user-specified rpaths.
  if (context.OI.SelectedSanitizers & SanitizerKind::Address)
    addLinkSanitizerLibArgsForDarwin(context.Args, Arguments, "asan", *this);

  if (context.OI.SelectedSanitizers & SanitizerKind::Thread)
    addLinkSanitizerLibArgsForDarwin(context.Args, Arguments, "tsan", *this);

  // Only link in libFuzzer for executables.
  if (job.getKind() == LinkKind::Executable &&
      (context.OI.SelectedSanitizers & SanitizerKind::Fuzzer))
    addLinkSanitizerLibArgsForDarwin(context.Args, Arguments, "fuzzer", *this,
                                     /*shared=*/false);

  if (context.Args.hasArg(options::OPT_embed_bitcode,
                          options::OPT_embed_bitcode_marker)) {
    Arguments.push_back("-bitcode_bundle");
  }

  if (!context.OI.SDKPath.empty()) {
    Arguments.push_back("-syslibroot");
    Arguments.push_back(context.Args.MakeArgString(context.OI.SDKPath));
  }

  Arguments.push_back("-lobjc");
  Arguments.push_back("-lSystem");

  Arguments.push_back("-arch");
  Arguments.push_back(context.Args.MakeArgString(getTriple().getArchName()));

  // Add the runtime library link path, which is platform-specific and found
  // relative to the compiler.
  SmallString<128> RuntimeLibPath;
  getRuntimeLibraryPath(RuntimeLibPath, context.Args, /*Shared=*/true);

  // Link the standard library.
  Arguments.push_back("-L");
  if (context.Args.hasFlag(options::OPT_static_stdlib,
                           options::OPT_no_static_stdlib, false)) {
    SmallString<128> StaticRuntimeLibPath;
    getRuntimeLibraryPath(StaticRuntimeLibPath, context.Args, /*Shared=*/false);
    Arguments.push_back(context.Args.MakeArgString(StaticRuntimeLibPath));
    Arguments.push_back("-lc++");
    Arguments.push_back("-framework");
    Arguments.push_back("Foundation");
    Arguments.push_back("-force_load_swift_libs");
  } else {
    Arguments.push_back(context.Args.MakeArgString(RuntimeLibPath));
    // FIXME: We probably shouldn't be adding an rpath here unless we know ahead
    // of time the standard library won't be copied. SR-1967
    Arguments.push_back("-rpath");
    Arguments.push_back(context.Args.MakeArgString(RuntimeLibPath));
  }

  if (context.Args.hasArg(options::OPT_profile_generate)) {
    SmallString<128> LibProfile;
    getClangLibraryPath(context.Args, LibProfile);

    StringRef RT;
    if (Triple.isiOS()) {
      if (Triple.isTvOS())
        RT = "tvos";
      else
        RT = "ios";
    } else if (Triple.isWatchOS()) {
      RT = "watchos";
    } else {
      assert(Triple.isMacOSX());
      RT = "osx";
    }

    StringRef Sim;
    if (tripleIsAnySimulator(Triple)) {
      Sim = "sim";
    }

    llvm::sys::path::append(LibProfile,
                            "libclang_rt.profile_" + RT + Sim + ".a");

    // FIXME: Continue accepting the old path for simulator libraries for now.
    if (!Sim.empty() && !llvm::sys::fs::exists(LibProfile)) {
      llvm::sys::path::remove_filename(LibProfile);
      llvm::sys::path::append(LibProfile, "libclang_rt.profile_" + RT + ".a");
    }

    Arguments.push_back(context.Args.MakeArgString(LibProfile));
  }

  // FIXME: Properly handle deployment targets.
  assert(Triple.isiOS() || Triple.isWatchOS() || Triple.isMacOSX());
  if (Triple.isiOS()) {
    bool isiOSSimulator = tripleIsiOSSimulator(Triple);
    if (Triple.isTvOS()) {
      if (isiOSSimulator)
        Arguments.push_back("-tvos_simulator_version_min");
      else
        Arguments.push_back("-tvos_version_min");
    } else {
      if (isiOSSimulator)
        Arguments.push_back("-ios_simulator_version_min");
      else
        Arguments.push_back("-iphoneos_version_min");
    }
    unsigned major, minor, micro;
    Triple.getiOSVersion(major, minor, micro);
    addVersionString(context.Args, Arguments, major, minor, micro);
  } else if (Triple.isWatchOS()) {
    if (tripleIsWatchSimulator(Triple))
      Arguments.push_back("-watchos_simulator_version_min");
    else
      Arguments.push_back("-watchos_version_min");
    unsigned major, minor, micro;
    Triple.getOSVersion(major, minor, micro);
    addVersionString(context.Args, Arguments, major, minor, micro);
  } else {
    Arguments.push_back("-macosx_version_min");
    unsigned major, minor, micro;
    Triple.getMacOSXVersion(major, minor, micro);
    addVersionString(context.Args, Arguments, major, minor, micro);
  }

  Arguments.push_back("-no_objc_category_merging");

  // This should be the last option, for convenience in checking output.
  Arguments.push_back("-o");
  Arguments.push_back(
      context.Args.MakeArgString(context.Output.getPrimaryOutputFilename()));

  return II;
}

bool toolchains::Darwin::shouldStoreInvocationInDebugInfo() const {
  // This matches the behavior in Clang (see
  // clang/lib/driver/ToolChains/Darwin.cpp).
  if (const char *S = ::getenv("RC_DEBUG_OPTIONS"))
    return S[0] != '\0';
  return false;
}