//===-- HostInfoBase.cpp ----------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/Host/Config.h"

#include "lldb/Core/ArchSpec.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/Host.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Host/HostInfoBase.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/StreamString.h"

#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/Support/Threading.h"
#include "llvm/Support/raw_ostream.h"

#include <mutex>
#include <thread>

using namespace lldb;
using namespace lldb_private;

namespace {
//----------------------------------------------------------------------
// The HostInfoBaseFields is a work around for windows not supporting
// static variables correctly in a thread safe way. Really each of the
// variables in HostInfoBaseFields should live in the functions in which
// they are used and each one should be static, but the work around is
// in place to avoid this restriction. Ick.
//----------------------------------------------------------------------

struct HostInfoBaseFields {
  ~HostInfoBaseFields() {
    if (m_lldb_process_tmp_dir.Exists()) {
      // Remove the LLDB temporary directory if we have one. Set "recurse" to
      // true to all files that were created for the LLDB process can be cleaned
      // up.
      llvm::sys::fs::remove_directories(m_lldb_process_tmp_dir.GetPath());
    }
  }

  std::string m_host_triple;

  ArchSpec m_host_arch_32;
  ArchSpec m_host_arch_64;

  FileSpec m_lldb_so_dir;
  FileSpec m_lldb_support_exe_dir;
  FileSpec m_lldb_headers_dir;
  FileSpec m_lldb_python_dir;
  FileSpec m_lldb_clang_resource_dir;
  FileSpec m_lldb_system_plugin_dir;
  FileSpec m_lldb_user_plugin_dir;
  FileSpec m_lldb_process_tmp_dir;
  FileSpec m_lldb_global_tmp_dir;
};

HostInfoBaseFields *g_fields = nullptr;
}

void HostInfoBase::Initialize() { g_fields = new HostInfoBaseFields(); }

void HostInfoBase::Terminate() {
  delete g_fields;
  g_fields = nullptr;
}

llvm::StringRef HostInfoBase::GetTargetTriple() {
  static llvm::once_flag g_once_flag;
  llvm::call_once(g_once_flag, []() {
    g_fields->m_host_triple =
        HostInfo::GetArchitecture().GetTriple().getTriple();
  });
  return g_fields->m_host_triple;
}

const ArchSpec &HostInfoBase::GetArchitecture(ArchitectureKind arch_kind) {
  static llvm::once_flag g_once_flag;
  llvm::call_once(g_once_flag, []() {
    HostInfo::ComputeHostArchitectureSupport(g_fields->m_host_arch_32,
                                             g_fields->m_host_arch_64);
  });

  // If an explicit 32 or 64-bit architecture was requested, return that.
  if (arch_kind == eArchKind32)
    return g_fields->m_host_arch_32;
  if (arch_kind == eArchKind64)
    return g_fields->m_host_arch_64;

  // Otherwise prefer the 64-bit architecture if it is valid.
  return (g_fields->m_host_arch_64.IsValid()) ? g_fields->m_host_arch_64
                                              : g_fields->m_host_arch_32;
}

bool HostInfoBase::GetLLDBPath(lldb::PathType type, FileSpec &file_spec) {
  file_spec.Clear();

#if defined(LLDB_DISABLE_PYTHON)
  if (type == lldb::ePathTypePythonDir)
    return false;
#endif

  FileSpec *result = nullptr;
  switch (type) {
  case lldb::ePathTypeLLDBShlibDir: {
    static llvm::once_flag g_once_flag;
    static bool success = false;
    llvm::call_once(g_once_flag, []() {
      success =
          HostInfo::ComputeSharedLibraryDirectory(g_fields->m_lldb_so_dir);
      Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
      if (log)
        log->Printf("HostInfoBase::GetLLDBPath(ePathTypeLLDBShlibDir) => '%s'",
                    g_fields->m_lldb_so_dir.GetPath().c_str());
    });
    if (success)
      result = &g_fields->m_lldb_so_dir;
  } break;
  case lldb::ePathTypeSupportExecutableDir: {
    static llvm::once_flag g_once_flag;
    static bool success = false;
    llvm::call_once(g_once_flag, []() {
      success = HostInfo::ComputeSupportExeDirectory(
          g_fields->m_lldb_support_exe_dir);
      Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
      if (log)
        log->Printf(
            "HostInfoBase::GetLLDBPath(ePathTypeSupportExecutableDir) => '%s'",
            g_fields->m_lldb_support_exe_dir.GetPath().c_str());
    });
    if (success)
      result = &g_fields->m_lldb_support_exe_dir;
  } break;
  case lldb::ePathTypeHeaderDir: {
    static llvm::once_flag g_once_flag;
    static bool success = false;
    llvm::call_once(g_once_flag, []() {
      success = HostInfo::ComputeHeaderDirectory(g_fields->m_lldb_headers_dir);
      Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
      if (log)
        log->Printf("HostInfoBase::GetLLDBPath(ePathTypeHeaderDir) => '%s'",
                    g_fields->m_lldb_headers_dir.GetPath().c_str());
    });
    if (success)
      result = &g_fields->m_lldb_headers_dir;
  } break;
  case lldb::ePathTypePythonDir: {
    static llvm::once_flag g_once_flag;
    static bool success = false;
    llvm::call_once(g_once_flag, []() {
      success = HostInfo::ComputePythonDirectory(g_fields->m_lldb_python_dir);
      Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
      if (log)
        log->Printf("HostInfoBase::GetLLDBPath(ePathTypePythonDir) => '%s'",
                    g_fields->m_lldb_python_dir.GetPath().c_str());
    });
    if (success)
      result = &g_fields->m_lldb_python_dir;
  } break;
  case lldb::ePathTypeClangDir: {
    static llvm::once_flag g_once_flag;
    static bool success = false;
    llvm::call_once(g_once_flag, []() {
      success =
          HostInfo::ComputeClangDirectory(g_fields->m_lldb_clang_resource_dir);
      Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
      if (log)
        log->Printf(
            "HostInfoBase::GetLLDBPath(ePathTypeClangResourceDir) => '%s'",
            g_fields->m_lldb_clang_resource_dir.GetPath().c_str());
    });
    if (success)
      result = &g_fields->m_lldb_clang_resource_dir;
  } break;
  case lldb::ePathTypeLLDBSystemPlugins: {
    static llvm::once_flag g_once_flag;
    static bool success = false;
    llvm::call_once(g_once_flag, []() {
      success = HostInfo::ComputeSystemPluginsDirectory(
          g_fields->m_lldb_system_plugin_dir);
      Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
      if (log)
        log->Printf(
            "HostInfoBase::GetLLDBPath(ePathTypeLLDBSystemPlugins) => '%s'",
            g_fields->m_lldb_system_plugin_dir.GetPath().c_str());
    });
    if (success)
      result = &g_fields->m_lldb_system_plugin_dir;
  } break;
  case lldb::ePathTypeLLDBUserPlugins: {
    static llvm::once_flag g_once_flag;
    static bool success = false;
    llvm::call_once(g_once_flag, []() {
      success = HostInfo::ComputeUserPluginsDirectory(
          g_fields->m_lldb_user_plugin_dir);
      Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
      if (log)
        log->Printf(
            "HostInfoBase::GetLLDBPath(ePathTypeLLDBUserPlugins) => '%s'",
            g_fields->m_lldb_user_plugin_dir.GetPath().c_str());
    });
    if (success)
      result = &g_fields->m_lldb_user_plugin_dir;
  } break;
  case lldb::ePathTypeLLDBTempSystemDir: {
    static llvm::once_flag g_once_flag;
    static bool success = false;
    llvm::call_once(g_once_flag, []() {
      success = HostInfo::ComputeProcessTempFileDirectory(
          g_fields->m_lldb_process_tmp_dir);
      Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
      if (log)
        log->Printf(
            "HostInfoBase::GetLLDBPath(ePathTypeLLDBTempSystemDir) => '%s'",
            g_fields->m_lldb_process_tmp_dir.GetPath().c_str());
    });
    if (success)
      result = &g_fields->m_lldb_process_tmp_dir;
  } break;
  case lldb::ePathTypeGlobalLLDBTempSystemDir: {
    static llvm::once_flag g_once_flag;
    static bool success = false;
    llvm::call_once(g_once_flag, []() {
      success = HostInfo::ComputeGlobalTempFileDirectory(
          g_fields->m_lldb_global_tmp_dir);
      Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
      if (log)
        log->Printf("HostInfoBase::GetLLDBPath("
                    "ePathTypeGlobalLLDBTempSystemDir) => '%s'",
                    g_fields->m_lldb_global_tmp_dir.GetPath().c_str());
    });
    if (success)
      result = &g_fields->m_lldb_global_tmp_dir;
  } break;
  }

  if (!result)
    return false;
  file_spec = *result;
  return true;
}

bool HostInfoBase::ComputeSharedLibraryDirectory(FileSpec &file_spec) {
  // To get paths related to LLDB we get the path to the executable that
  // contains this function. On MacOSX this will be "LLDB.framework/.../LLDB",
  // on linux this is assumed to be the "lldb" main executable. If LLDB on
  // linux is actually in a shared library (liblldb.so) then this function will
  // need to be modified to "do the right thing".

  FileSpec lldb_file_spec(
      Host::GetModuleFileSpecForHostAddress(reinterpret_cast<void *>(
          reinterpret_cast<intptr_t>(HostInfoBase::GetLLDBPath))));

  // This is necessary because when running the testsuite the shlib might be a
  // symbolic link inside the Python resource dir.
  FileSystem::ResolveSymbolicLink(lldb_file_spec, lldb_file_spec);

  // Remove the filename so that this FileSpec only represents the directory.
  file_spec.GetDirectory() = lldb_file_spec.GetDirectory();

  return (bool)file_spec.GetDirectory();
}

bool HostInfoBase::ComputeSupportExeDirectory(FileSpec &file_spec) {
  return GetLLDBPath(lldb::ePathTypeLLDBShlibDir, file_spec);
}

bool HostInfoBase::ComputeProcessTempFileDirectory(FileSpec &file_spec) {
  FileSpec temp_file_spec;
  if (!HostInfo::ComputeGlobalTempFileDirectory(temp_file_spec))
    return false;

  std::string pid_str{llvm::to_string(Host::GetCurrentProcessID())};
  temp_file_spec.AppendPathComponent(pid_str);
  if (llvm::sys::fs::create_directory(temp_file_spec.GetPath()))
    return false;

  file_spec.GetDirectory().SetCString(temp_file_spec.GetCString());
  return true;
}

bool HostInfoBase::ComputeTempFileBaseDirectory(FileSpec &file_spec) {
  llvm::SmallVector<char, 16> tmpdir;
  llvm::sys::path::system_temp_directory(/*ErasedOnReboot*/ true, tmpdir);
  file_spec = FileSpec(std::string(tmpdir.data(), tmpdir.size()), true);
  return true;
}

bool HostInfoBase::ComputeGlobalTempFileDirectory(FileSpec &file_spec) {
  file_spec.Clear();

  FileSpec temp_file_spec;
  if (!HostInfo::ComputeTempFileBaseDirectory(temp_file_spec))
    return false;

  temp_file_spec.AppendPathComponent("lldb");
  if (llvm::sys::fs::create_directory(temp_file_spec.GetPath()))
    return false;

  file_spec.GetDirectory().SetCString(temp_file_spec.GetCString());
  return true;
}

bool HostInfoBase::ComputeHeaderDirectory(FileSpec &file_spec) {
  // TODO(zturner): Figure out how to compute the header directory for all
  // platforms.
  return false;
}

bool HostInfoBase::ComputeSystemPluginsDirectory(FileSpec &file_spec) {
  // TODO(zturner): Figure out how to compute the system plugins directory for
  // all platforms.
  return false;
}

bool HostInfoBase::ComputeClangDirectory(FileSpec &file_spec) { return false; }

bool HostInfoBase::ComputeUserPluginsDirectory(FileSpec &file_spec) {
  // TODO(zturner): Figure out how to compute the user plugins directory for all
  // platforms.
  return false;
}

void HostInfoBase::ComputeHostArchitectureSupport(ArchSpec &arch_32,
                                                  ArchSpec &arch_64) {
  llvm::Triple triple(llvm::sys::getProcessTriple());

  arch_32.Clear();
  arch_64.Clear();

  switch (triple.getArch()) {
  default:
    arch_32.SetTriple(triple);
    break;

  case llvm::Triple::aarch64:
  case llvm::Triple::ppc64:
  case llvm::Triple::x86_64:
    arch_64.SetTriple(triple);
    arch_32.SetTriple(triple.get32BitArchVariant());
    break;

  case llvm::Triple::mips64:
  case llvm::Triple::mips64el:
  case llvm::Triple::sparcv9:
  case llvm::Triple::systemz:
    arch_64.SetTriple(triple);
    break;
  }
}
