1 files changed, 33 insertions, 71 deletions

diff --git a/source/Host/posix/HostInfoPosix.cpp b/source/Host/posix/HostInfoPosix.cpp
index 4763ebc9b9d4..f300e22e9e5c 100644
--- a/source/Host/posix/HostInfoPosix.cpp
+++ b/source/Host/posix/HostInfoPosix.cpp
@@ -1,13 +1,13 @@
 //===-- HostInfoPosix.cpp ---------------------------------------*- C++ -*-===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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/posix/HostInfoPosix.h"
+#include "lldb/Utility/UserIDResolver.h"
 #include "lldb/Utility/Log.h"
 
 #include "llvm/ADT/SmallString.h"
@@ -49,40 +49,38 @@ bool HostInfoPosix::GetHostname(std::string &s) {
 #define USE_GETPWUID
 #endif
 
-#ifdef USE_GETPWUID
-static std::mutex s_getpwuid_lock;
-#endif
+namespace {
+class PosixUserIDResolver : public UserIDResolver {
+protected:
+  llvm::Optional<std::string> DoGetUserName(id_t uid) override;
+  llvm::Optional<std::string> DoGetGroupName(id_t gid) override;
+};
+} // namespace
 
-const char *HostInfoPosix::LookupUserName(uint32_t uid,
-                                          std::string &user_name) {
+llvm::Optional<std::string> PosixUserIDResolver::DoGetUserName(id_t uid) {
 #ifdef USE_GETPWUID
   // getpwuid_r is missing from android-9
-  // make getpwuid thread safe with a mutex
-  std::lock_guard<std::mutex> lock(s_getpwuid_lock);
+  // UserIDResolver provides some thread safety by making sure noone calls this
+  // function concurrently, but using getpwuid is ultimately not thread-safe as
+  // we don't know who else might be calling it.
   struct passwd *user_info_ptr = ::getpwuid(uid);
-  if (user_info_ptr) {
-    user_name.assign(user_info_ptr->pw_name);
-    return user_name.c_str();
-  }
+  if (user_info_ptr)
+    return std::string(user_info_ptr->pw_name);
 #else
   struct passwd user_info;
   struct passwd *user_info_ptr = &user_info;
   char user_buffer[PATH_MAX];
   size_t user_buffer_size = sizeof(user_buffer);
   if (::getpwuid_r(uid, &user_info, user_buffer, user_buffer_size,
-                   &user_info_ptr) == 0) {
-    if (user_info_ptr) {
-      user_name.assign(user_info_ptr->pw_name);
-      return user_name.c_str();
-    }
+                   &user_info_ptr) == 0 &&
+      user_info_ptr) {
+    return std::string(user_info_ptr->pw_name);
   }
 #endif
-  user_name.clear();
-  return nullptr;
+  return llvm::None;
 }
 
-const char *HostInfoPosix::LookupGroupName(uint32_t gid,
-                                           std::string &group_name) {
+llvm::Optional<std::string> PosixUserIDResolver::DoGetGroupName(id_t gid) {
 #ifndef __ANDROID__
   char group_buffer[PATH_MAX];
   size_t group_buffer_size = sizeof(group_buffer);
@@ -91,24 +89,25 @@ const char *HostInfoPosix::LookupGroupName(uint32_t gid,
   // Try the threadsafe version first
   if (::getgrgid_r(gid, &group_info, group_buffer, group_buffer_size,
                    &group_info_ptr) == 0) {
-    if (group_info_ptr) {
-      group_name.assign(group_info_ptr->gr_name);
-      return group_name.c_str();
-    }
+    if (group_info_ptr)
+      return std::string(group_info_ptr->gr_name);
   } else {
     // The threadsafe version isn't currently working for me on darwin, but the
     // non-threadsafe version is, so I am calling it below.
     group_info_ptr = ::getgrgid(gid);
-    if (group_info_ptr) {
-      group_name.assign(group_info_ptr->gr_name);
-      return group_name.c_str();
-    }
+    if (group_info_ptr)
+      return std::string(group_info_ptr->gr_name);
   }
-  group_name.clear();
 #else
   assert(false && "getgrgid_r() not supported on Android");
 #endif
-  return NULL;
+  return llvm::None;
+}
+
+static llvm::ManagedStatic<PosixUserIDResolver> g_user_id_resolver;
+
+UserIDResolver &HostInfoPosix::GetUserIDResolver() {
+  return *g_user_id_resolver;
 }
 
 uint32_t HostInfoPosix::GetUserID() { return getuid(); }
@@ -121,43 +120,6 @@ uint32_t HostInfoPosix::GetEffectiveGroupID() { return getegid(); }
 
 FileSpec HostInfoPosix::GetDefaultShell() { return FileSpec("/bin/sh"); }
 
-bool HostInfoPosix::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();
-  // drop library directory
-  llvm::StringRef parent_path = llvm::sys::path::parent_path(raw_path);
-
-  // Most Posix systems (e.g. Linux/*BSD) will attempt to replace a */lib with
-  // */bin as the base directory for helper exe programs.  This will fail if
-  // the /lib and /bin directories are rooted in entirely different trees.
-  if (log)
-    log->Printf("HostInfoPosix::ComputePathRelativeToLibrary() attempting to "
-                "derive the %s path from this path: %s",
-                dir.data(), raw_path.c_str());
-
-  if (!parent_path.empty()) {
-    // Now write in bin in place of lib.
-    raw_path = (parent_path + dir).str();
-
-    if (log)
-      log->Printf("Host::%s() derived the bin path as: %s", __FUNCTION__,
-                  raw_path.c_str());
-  } else {
-    if (log)
-      log->Printf("Host::%s() failed to find /lib/liblldb within the shared "
-                  "lib path, bailing on bin path construction",
-                  __FUNCTION__);
-  }
-  file_spec.GetDirectory().SetString(raw_path);
-  return (bool)file_spec.GetDirectory();
-}
-
 bool HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec) {
   return ComputePathRelativeToLibrary(file_spec, "/bin");
 }