source/Host/common/HostInfoBase.cpp - llvm-project/lldb - Git at Google

 //===-- HostInfoBase.cpp --------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #include "lldb/Host/Config.h"

 #include "lldb/Host/FileSystem.h"
 #include "lldb/Host/Host.h"
 #include "lldb/Host/HostInfo.h"
 #include "lldb/Host/HostInfoBase.h"
 #include "lldb/Utility/ArchSpec.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 (FileSystem::Instance().Exists(m_lldb_process_tmp_dir)) {
       // 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());
     }
   }

   llvm::once_flag m_host_triple_once;
   llvm::Triple m_host_triple;

   llvm::once_flag m_host_arch_once;
   ArchSpec m_host_arch_32;
   ArchSpec m_host_arch_64;

   llvm::once_flag m_lldb_so_dir_once;
   FileSpec m_lldb_so_dir;
   llvm::once_flag m_lldb_support_exe_dir_once;
   FileSpec m_lldb_support_exe_dir;
   llvm::once_flag m_lldb_headers_dir_once;
   FileSpec m_lldb_headers_dir;
   llvm::once_flag m_lldb_clang_resource_dir_once;
   FileSpec m_lldb_clang_resource_dir;
   llvm::once_flag m_lldb_system_plugin_dir_once;
   FileSpec m_lldb_system_plugin_dir;
   llvm::once_flag m_lldb_user_plugin_dir_once;
   FileSpec m_lldb_user_plugin_dir;
   llvm::once_flag m_lldb_process_tmp_dir_once;
   FileSpec m_lldb_process_tmp_dir;
   llvm::once_flag m_lldb_global_tmp_dir_once;
   FileSpec m_lldb_global_tmp_dir;
 };
 } // namespace

 static HostInfoBaseFields *g_fields = nullptr;
 static HostInfoBase::SharedLibraryDirectoryHelper *g_shlib_dir_helper = nullptr;

 void HostInfoBase::Initialize(SharedLibraryDirectoryHelper *helper) {
   g_shlib_dir_helper = helper;
   g_fields = new HostInfoBaseFields();
 }

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

 llvm::Triple HostInfoBase::GetTargetTriple() {
   llvm::call_once(g_fields->m_host_triple_once, []() {
     g_fields->m_host_triple =
         HostInfo::GetArchitecture().GetTriple();
   });
   return g_fields->m_host_triple;
 }

 const ArchSpec &HostInfoBase::GetArchitecture(ArchitectureKind arch_kind) {
   llvm::call_once(g_fields->m_host_arch_once, []() {
     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;
 }

 llvm::Optional<HostInfoBase::ArchitectureKind> HostInfoBase::ParseArchitectureKind(llvm::StringRef kind) {
   return llvm::StringSwitch<llvm::Optional<ArchitectureKind>>(kind)
       .Case(LLDB_ARCH_DEFAULT, eArchKindDefault)
       .Case(LLDB_ARCH_DEFAULT_32BIT, eArchKind32)
       .Case(LLDB_ARCH_DEFAULT_64BIT, eArchKind64)
       .Default(llvm::None);
 }

 FileSpec HostInfoBase::GetShlibDir() {
   llvm::call_once(g_fields->m_lldb_so_dir_once, []() {
     if (!HostInfo::ComputeSharedLibraryDirectory(g_fields->m_lldb_so_dir))
       g_fields->m_lldb_so_dir = FileSpec();
     Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
     LLDB_LOG(log, "shlib dir -> `{0}`", g_fields->m_lldb_so_dir);
   });
   return g_fields->m_lldb_so_dir;
 }

 FileSpec HostInfoBase::GetSupportExeDir() {
   llvm::call_once(g_fields->m_lldb_support_exe_dir_once, []() {
     if (!HostInfo::ComputeSupportExeDirectory(g_fields->m_lldb_support_exe_dir))
       g_fields->m_lldb_support_exe_dir = FileSpec();
     Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
     LLDB_LOG(log, "support exe dir -> `{0}`", g_fields->m_lldb_support_exe_dir);
   });
   return g_fields->m_lldb_support_exe_dir;
 }

 FileSpec HostInfoBase::GetHeaderDir() {
   llvm::call_once(g_fields->m_lldb_headers_dir_once, []() {
     if (!HostInfo::ComputeHeaderDirectory(g_fields->m_lldb_headers_dir))
       g_fields->m_lldb_headers_dir = FileSpec();
     Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
     LLDB_LOG(log, "header dir -> `{0}`", g_fields->m_lldb_headers_dir);
   });
   return g_fields->m_lldb_headers_dir;
 }

 FileSpec HostInfoBase::GetSystemPluginDir() {
   llvm::call_once(g_fields->m_lldb_system_plugin_dir_once, []() {
     if (!HostInfo::ComputeSystemPluginsDirectory(g_fields->m_lldb_system_plugin_dir))
       g_fields->m_lldb_system_plugin_dir = FileSpec();
     Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
     LLDB_LOG(log, "system plugin dir -> `{0}`",
              g_fields->m_lldb_system_plugin_dir);
   });
   return g_fields->m_lldb_system_plugin_dir;
 }

 FileSpec HostInfoBase::GetUserPluginDir() {
   llvm::call_once(g_fields->m_lldb_user_plugin_dir_once, []() {
     if (!HostInfo::ComputeUserPluginsDirectory(g_fields->m_lldb_user_plugin_dir))
       g_fields->m_lldb_user_plugin_dir = FileSpec();
     Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
     LLDB_LOG(log, "user plugin dir -> `{0}`", g_fields->m_lldb_user_plugin_dir);
   });
   return g_fields->m_lldb_user_plugin_dir;
 }

 FileSpec HostInfoBase::GetProcessTempDir() {
   llvm::call_once(g_fields->m_lldb_process_tmp_dir_once, []() {
     if (!HostInfo::ComputeProcessTempFileDirectory( g_fields->m_lldb_process_tmp_dir))
       g_fields->m_lldb_process_tmp_dir = FileSpec();
     Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
     LLDB_LOG(log, "process temp dir -> `{0}`",
              g_fields->m_lldb_process_tmp_dir);
   });
   return g_fields->m_lldb_process_tmp_dir;
 }

 FileSpec HostInfoBase::GetGlobalTempDir() {
   llvm::call_once(g_fields->m_lldb_global_tmp_dir_once, []() {
     if (!HostInfo::ComputeGlobalTempFileDirectory( g_fields->m_lldb_global_tmp_dir))
       g_fields->m_lldb_global_tmp_dir = FileSpec();

     Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
     LLDB_LOG(log, "global temp dir -> `{0}`", g_fields->m_lldb_global_tmp_dir);
   });
   return g_fields->m_lldb_global_tmp_dir;
 }

 ArchSpec HostInfoBase::GetAugmentedArchSpec(llvm::StringRef triple) {
   if (triple.empty())
     return ArchSpec();
   llvm::Triple normalized_triple(llvm::Triple::normalize(triple));
   if (!ArchSpec::ContainsOnlyArch(normalized_triple))
     return ArchSpec(triple);

   if (auto kind = HostInfo::ParseArchitectureKind(triple))
     return HostInfo::GetArchitecture(*kind);

   llvm::Triple host_triple(llvm::sys::getDefaultTargetTriple());

   if (normalized_triple.getVendorName().empty())
     normalized_triple.setVendor(host_triple.getVendor());
   if (normalized_triple.getOSName().empty())
     normalized_triple.setOS(host_triple.getOS());
   if (normalized_triple.getEnvironmentName().empty())
     normalized_triple.setEnvironment(host_triple.getEnvironment());
   return ArchSpec(normalized_triple);
 }

 bool HostInfoBase::ComputePathRelativeToLibrary(FileSpec &file_spec,
                                                 llvm::StringRef dir) {
   Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);

   FileSpec lldb_file_spec = GetShlibDir();
   if (!lldb_file_spec)
     return false;

   std::string raw_path = lldb_file_spec.GetPath();
   LLDB_LOGF(log,
             "HostInfo::%s() attempting to "
             "derive the path %s relative to liblldb install path: %s",
             __FUNCTION__, dir.data(), raw_path.c_str());

   // Drop bin (windows) or lib
   llvm::StringRef parent_path = llvm::sys::path::parent_path(raw_path);
   if (parent_path.empty()) {
     LLDB_LOGF(log,
               "HostInfo::%s() failed to find liblldb within the shared "
               "lib path",
               __FUNCTION__);
     return false;
   }

   raw_path = (parent_path + dir).str();
   LLDB_LOGF(log, "HostInfo::%s() derived the path as: %s", __FUNCTION__,
             raw_path.c_str());
   file_spec.GetDirectory().SetString(raw_path);
   return (bool)file_spec.GetDirectory();
 }

 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 other posix systems, we will get .../lib(64|32)?/liblldb.so.

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

   if (g_shlib_dir_helper)
     g_shlib_dir_helper(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) {
   file_spec = GetShlibDir();
   return bool(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()));
   FileSystem::Instance().Resolve(file_spec);
   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::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::ppc64le:
   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;
   }
 }
	//===-- HostInfoBase.cpp --------------------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#include "lldb/Host/Config.h"

	#include "lldb/Host/FileSystem.h"
	#include "lldb/Host/Host.h"
	#include "lldb/Host/HostInfo.h"
	#include "lldb/Host/HostInfoBase.h"
	#include "lldb/Utility/ArchSpec.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 (FileSystem::Instance().Exists(m_lldb_process_tmp_dir)) {
	// 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());
	}
	}

	llvm::once_flag m_host_triple_once;
	llvm::Triple m_host_triple;

	llvm::once_flag m_host_arch_once;
	ArchSpec m_host_arch_32;
	ArchSpec m_host_arch_64;

	llvm::once_flag m_lldb_so_dir_once;
	FileSpec m_lldb_so_dir;
	llvm::once_flag m_lldb_support_exe_dir_once;
	FileSpec m_lldb_support_exe_dir;
	llvm::once_flag m_lldb_headers_dir_once;
	FileSpec m_lldb_headers_dir;
	llvm::once_flag m_lldb_clang_resource_dir_once;
	FileSpec m_lldb_clang_resource_dir;
	llvm::once_flag m_lldb_system_plugin_dir_once;
	FileSpec m_lldb_system_plugin_dir;
	llvm::once_flag m_lldb_user_plugin_dir_once;
	FileSpec m_lldb_user_plugin_dir;
	llvm::once_flag m_lldb_process_tmp_dir_once;
	FileSpec m_lldb_process_tmp_dir;
	llvm::once_flag m_lldb_global_tmp_dir_once;
	FileSpec m_lldb_global_tmp_dir;
	};
	} // namespace

	static HostInfoBaseFields *g_fields = nullptr;
	static HostInfoBase::SharedLibraryDirectoryHelper *g_shlib_dir_helper = nullptr;

	void HostInfoBase::Initialize(SharedLibraryDirectoryHelper *helper) {
	g_shlib_dir_helper = helper;
	g_fields = new HostInfoBaseFields();
	}

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

	llvm::Triple HostInfoBase::GetTargetTriple() {
	llvm::call_once(g_fields->m_host_triple_once, []() {
	g_fields->m_host_triple =
	HostInfo::GetArchitecture().GetTriple();
	});
	return g_fields->m_host_triple;
	}

	const ArchSpec &HostInfoBase::GetArchitecture(ArchitectureKind arch_kind) {
	llvm::call_once(g_fields->m_host_arch_once, []() {
	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;
	}

	llvm::Optional<HostInfoBase::ArchitectureKind> HostInfoBase::ParseArchitectureKind(llvm::StringRef kind) {
	return llvm::StringSwitch<llvm::Optional<ArchitectureKind>>(kind)
	.Case(LLDB_ARCH_DEFAULT, eArchKindDefault)
	.Case(LLDB_ARCH_DEFAULT_32BIT, eArchKind32)
	.Case(LLDB_ARCH_DEFAULT_64BIT, eArchKind64)
	.Default(llvm::None);
	}

	FileSpec HostInfoBase::GetShlibDir() {
	llvm::call_once(g_fields->m_lldb_so_dir_once, []() {
	if (!HostInfo::ComputeSharedLibraryDirectory(g_fields->m_lldb_so_dir))
	g_fields->m_lldb_so_dir = FileSpec();
	Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
	LLDB_LOG(log, "shlib dir -> `{0}`", g_fields->m_lldb_so_dir);
	});
	return g_fields->m_lldb_so_dir;
	}

	FileSpec HostInfoBase::GetSupportExeDir() {
	llvm::call_once(g_fields->m_lldb_support_exe_dir_once, []() {
	if (!HostInfo::ComputeSupportExeDirectory(g_fields->m_lldb_support_exe_dir))
	g_fields->m_lldb_support_exe_dir = FileSpec();
	Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
	LLDB_LOG(log, "support exe dir -> `{0}`", g_fields->m_lldb_support_exe_dir);
	});
	return g_fields->m_lldb_support_exe_dir;
	}

	FileSpec HostInfoBase::GetHeaderDir() {
	llvm::call_once(g_fields->m_lldb_headers_dir_once, []() {
	if (!HostInfo::ComputeHeaderDirectory(g_fields->m_lldb_headers_dir))
	g_fields->m_lldb_headers_dir = FileSpec();
	Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
	LLDB_LOG(log, "header dir -> `{0}`", g_fields->m_lldb_headers_dir);
	});
	return g_fields->m_lldb_headers_dir;
	}

	FileSpec HostInfoBase::GetSystemPluginDir() {
	llvm::call_once(g_fields->m_lldb_system_plugin_dir_once, []() {
	if (!HostInfo::ComputeSystemPluginsDirectory(g_fields->m_lldb_system_plugin_dir))
	g_fields->m_lldb_system_plugin_dir = FileSpec();
	Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
	LLDB_LOG(log, "system plugin dir -> `{0}`",
	g_fields->m_lldb_system_plugin_dir);
	});
	return g_fields->m_lldb_system_plugin_dir;
	}

	FileSpec HostInfoBase::GetUserPluginDir() {
	llvm::call_once(g_fields->m_lldb_user_plugin_dir_once, []() {
	if (!HostInfo::ComputeUserPluginsDirectory(g_fields->m_lldb_user_plugin_dir))
	g_fields->m_lldb_user_plugin_dir = FileSpec();
	Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
	LLDB_LOG(log, "user plugin dir -> `{0}`", g_fields->m_lldb_user_plugin_dir);
	});
	return g_fields->m_lldb_user_plugin_dir;
	}

	FileSpec HostInfoBase::GetProcessTempDir() {
	llvm::call_once(g_fields->m_lldb_process_tmp_dir_once, []() {
	if (!HostInfo::ComputeProcessTempFileDirectory( g_fields->m_lldb_process_tmp_dir))
	g_fields->m_lldb_process_tmp_dir = FileSpec();
	Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
	LLDB_LOG(log, "process temp dir -> `{0}`",
	g_fields->m_lldb_process_tmp_dir);
	});
	return g_fields->m_lldb_process_tmp_dir;
	}

	FileSpec HostInfoBase::GetGlobalTempDir() {
	llvm::call_once(g_fields->m_lldb_global_tmp_dir_once, []() {
	if (!HostInfo::ComputeGlobalTempFileDirectory( g_fields->m_lldb_global_tmp_dir))
	g_fields->m_lldb_global_tmp_dir = FileSpec();

	Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
	LLDB_LOG(log, "global temp dir -> `{0}`", g_fields->m_lldb_global_tmp_dir);
	});
	return g_fields->m_lldb_global_tmp_dir;
	}

	ArchSpec HostInfoBase::GetAugmentedArchSpec(llvm::StringRef triple) {
	if (triple.empty())
	return ArchSpec();
	llvm::Triple normalized_triple(llvm::Triple::normalize(triple));
	if (!ArchSpec::ContainsOnlyArch(normalized_triple))
	return ArchSpec(triple);

	if (auto kind = HostInfo::ParseArchitectureKind(triple))
	return HostInfo::GetArchitecture(*kind);

	llvm::Triple host_triple(llvm::sys::getDefaultTargetTriple());

	if (normalized_triple.getVendorName().empty())
	normalized_triple.setVendor(host_triple.getVendor());
	if (normalized_triple.getOSName().empty())
	normalized_triple.setOS(host_triple.getOS());
	if (normalized_triple.getEnvironmentName().empty())
	normalized_triple.setEnvironment(host_triple.getEnvironment());
	return ArchSpec(normalized_triple);
	}

	bool HostInfoBase::ComputePathRelativeToLibrary(FileSpec &file_spec,
	llvm::StringRef dir) {
	Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);

	FileSpec lldb_file_spec = GetShlibDir();
	if (!lldb_file_spec)
	return false;

	std::string raw_path = lldb_file_spec.GetPath();
	LLDB_LOGF(log,
	"HostInfo::%s() attempting to "
	"derive the path %s relative to liblldb install path: %s",
	__FUNCTION__, dir.data(), raw_path.c_str());

	// Drop bin (windows) or lib
	llvm::StringRef parent_path = llvm::sys::path::parent_path(raw_path);
	if (parent_path.empty()) {
	LLDB_LOGF(log,
	"HostInfo::%s() failed to find liblldb within the shared "
	"lib path",
	__FUNCTION__);
	return false;
	}

	raw_path = (parent_path + dir).str();
	LLDB_LOGF(log, "HostInfo::%s() derived the path as: %s", __FUNCTION__,
	raw_path.c_str());
	file_spec.GetDirectory().SetString(raw_path);
	return (bool)file_spec.GetDirectory();
	}

	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 other posix systems, we will get .../lib(64\|32)?/liblldb.so.

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

	if (g_shlib_dir_helper)
	g_shlib_dir_helper(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) {
	file_spec = GetShlibDir();
	return bool(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()));
	FileSystem::Instance().Resolve(file_spec);
	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::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::ppc64le:
	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;
	}
	}