[lldb] Fix leak in test

[vitalybuka]

Summary

Test leaks if we run
tools/lldb/unittests/Host/HostTests without --gtest_filter

[teemperor]

I think we should instead implement the Terminate function that the plugin system provides to tear down our state. I made a patch in D104093 that
moves the once_flags to the internal state struct, so with a proper Terminate implementation + my patch this should all work properly.

HostInfoLinux::Terminate() {
  assert(g_fields && "Missing call to Initialize?");
  delete g_fields;
  g_fields = nullptr;
  HostInfoBase::Terminate();
}

lldb/source/Host/linux/HostInfoLinux.cpp

41

Please instead add a HostInfoLinux::Terminate() function that deletes and zeroes g_fields (see HostInfoBase::Terminate). Initialize -> Terminate should set up and tear down the data structures if possible (not saying that LLDB is doing this consistently at the moment, but that's the idea at least).

[teemperor]

lldb/unittests/Host/HostInfoTest.cpp

64

HostInfoTestInitialization maybe?

[vitalybuka]

::Terminate

[teemperor]

LGTM, big thanks for the patch & quick turnaround!

lldb/include/lldb/Host/linux/HostInfoLinux.h

 //===-- HostInfoLinux.h -----------------------------------------*- C++ -*-===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef lldb_Host_linux_HostInfoLinux_h_
 #define lldb_Host_linux_HostInfoLinux_h_
 
 #include "lldb/Host/posix/HostInfoPosix.h"
 #include "lldb/Utility/FileSpec.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/VersionTuple.h"
 
 #include <string>
 
 namespace lldb_private {
 
 class HostInfoLinux : public HostInfoPosix {
   friend class HostInfoBase;
 
 private:
   // Static class, unconstructable.
   HostInfoLinux();
   ~HostInfoLinux();
 
 public:
   static void Initialize(SharedLibraryDirectoryHelper *helper = nullptr);
+  static void Terminate();
 
   static llvm::VersionTuple GetOSVersion();
   static bool GetOSBuildString(std::string &s);
   static bool GetOSKernelDescription(std::string &s);
   static llvm::StringRef GetDistributionId();
   static FileSpec GetProgramFileSpec();
 
 protected:

lldb/source/Host/linux/HostInfoLinux.cpp

 //===-- HostInfoLinux.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/linux/HostInfoLinux.h"
 #include "lldb/Host/Config.h"
 #include "lldb/Host/FileSystem.h"
 #include "lldb/Utility/Log.h"
 
 #include "llvm/Support/Threading.h"
 
 #include <climits>
 #include <cstdio>

 };
 
 HostInfoLinuxFields *g_fields = nullptr;
 }
 
 void HostInfoLinux::Initialize(SharedLibraryDirectoryHelper *helper) {
   HostInfoPosix::Initialize(helper);
 
   g_fields = new HostInfoLinuxFields();
 }
 
+void HostInfoLinux::Terminate() {
+  assert(g_fields && "Missing call to Initialize?");
+  delete g_fields;
+  g_fields = nullptr;
+  HostInfoBase::Terminate();
+}
+
 llvm::VersionTuple HostInfoLinux::GetOSVersion() {
   assert(g_fields && "Missing call to Initialize?");
   llvm::call_once(g_fields->m_os_version_once_flag, []() {
     struct utsname un;
     if (uname(&un) != 0)
       return;
 
     llvm::StringRef release = un.release;

lldb/unittests/Host/HostInfoTest.cpp

 //===-- HostInfoTest.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/HostInfo.h"
 #include "TestingSupport/SubsystemRAII.h"
 #include "TestingSupport/TestUtilities.h"
 #include "lldb/Host/FileSystem.h"
 #include "lldb/lldb-defines.h"
 #include "llvm/Support/Host.h"
 #include "gtest/gtest.h"
 
 using namespace lldb_private;

 TEST_F(HostInfoTest, GetXcodeSDK) {
   EXPECT_FALSE(HostInfo::GetXcodeSDKPath(XcodeSDK("MacOSX.sdk")).empty());
   // These are expected to fall back to an available version.
   EXPECT_FALSE(HostInfo::GetXcodeSDKPath(XcodeSDK("MacOSX9999.sdk")).empty());
   // This is expected to fail.
   EXPECT_TRUE(HostInfo::GetXcodeSDKPath(XcodeSDK("CeciNestPasUnOS.sdk")).empty());
 }
 #endif
+
+TEST(HostInfoTestInitialization, InitTwice) {
+  llvm::VersionTuple Version;
+  {
+    SubsystemRAII<FileSystem, HostInfo> subsystems;
+    Version = HostInfo::GetOSVersion();
+  }
+
+  {
+    SubsystemRAII<FileSystem, HostInfo> subsystems;
+    EXPECT_EQ(Version, HostInfo::GetOSVersion());
+  }
+}