//===--- ToolChain.cpp - Collections of tools for one platform ------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
/// \file This file defines the base implementation of the ToolChain class.
/// The platform-specific subclasses are implemented in ToolChains.cpp.
/// For organizational purposes, the platform-independent logic for
/// constructing job invocations is also located in ToolChains.cpp.
//
//===----------------------------------------------------------------------===//

#include "swift/Driver/ToolChain.h"

#include "swift/Driver/Driver.h"
#include "swift/Driver/Job.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Program.h"
#include "llvm/ADT/STLExtras.h"

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

const char * const ToolChain::SWIFT_EXECUTABLE_NAME;

std::unique_ptr<Job>
ToolChain::constructJob(const JobAction &JA,
                        SmallVectorImpl<const Job *> &&inputs,
                        std::unique_ptr<CommandOutput> output,
                        const ActionList &inputActions,
                        const llvm::opt::ArgList &args,
                        const OutputInfo &OI) const {
  JobContext context{inputs, *output, inputActions, args, OI};

  const char *executableName;
  llvm::opt::ArgStringList arguments;
  switch (JA.getKind()) {
#define CASE(K) case Action::K: \
    std::tie(executableName, arguments) = \
        constructInvocation(cast<K##Action>(JA), context); \
    break;
  CASE(CompileJob)
  CASE(BackendJob)
  CASE(MergeModuleJob)
  CASE(LinkJob)
  CASE(GenerateDSYMJob)
  CASE(AutolinkExtractJob)
  CASE(REPLJob)
#undef CASE
  case Action::Input:
    llvm_unreachable("not a JobAction");
  }

  // Special-case the Swift frontend.
  const char *executablePath = nullptr;
  if (StringRef(SWIFT_EXECUTABLE_NAME) == executableName) {
    executablePath = getDriver().getSwiftProgramPath().c_str();
  } else {
    std::string relativePath = findProgramRelativeToSwift(executableName);
    if (!relativePath.empty()) {
      executablePath = args.MakeArgString(relativePath);
    } else {
      auto systemPath = llvm::sys::findProgramByName(executableName);
      if (systemPath) {
        executablePath = args.MakeArgString(systemPath.get());
      } else {
        // For debugging purposes.
        executablePath = executableName;
      }
    }
  }

  return llvm::make_unique<Job>(JA, std::move(inputs), std::move(output),
                                executablePath, std::move(arguments));
}

std::string
ToolChain::findProgramRelativeToSwift(StringRef executableName) const {
  auto insertionResult =
      ProgramLookupCache.insert(std::make_pair(executableName, ""));
  if (insertionResult.second) {
    std::string path = findProgramRelativeToSwiftImpl(executableName);
    insertionResult.first->setValue(std::move(path));
  }
  return insertionResult.first->getValue();
}

std::string
ToolChain::findProgramRelativeToSwiftImpl(StringRef executableName) const {
  llvm::SmallString<128> path{getDriver().getSwiftProgramPath()};
  llvm::sys::path::remove_filename(path);
  auto result = llvm::sys::findProgramByName(executableName, {path});
  if (result)
    return result.get();
  return {};
}

types::ID ToolChain::lookupTypeForExtension(StringRef Ext) const {
  return types::lookupTypeForExtension(Ext);
}