[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

38

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/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>
struct HostInfoLinuxFields {
   llvm::VersionTuple m_os_version;
 };
 
 HostInfoLinuxFields *g_fields = nullptr;
 }
 
 void HostInfoLinux::Initialize(SharedLibraryDirectoryHelper *helper) {
   HostInfoPosix::Initialize(helper);
-
+  if (!g_fields)
     g_fields = new HostInfoLinuxFields();
 }
 
 llvm::VersionTuple HostInfoLinux::GetOSVersion() {
   static llvm::once_flag g_once_flag;
   llvm::call_once(g_once_flag, []() {
     struct utsname un;
     if (uname(&un) != 0)
       return;

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(HostInfoTest2, InitTwice) {
+  llvm::VersionTuple Version;
+  {
+    SubsystemRAII<FileSystem, HostInfo> subsystems;
+    Version = HostInfo::GetOSVersion();
+  }
+
+  {
+    SubsystemRAII<FileSystem, HostInfo> subsystems;
+    EXPECT_EQ(Version, HostInfo::GetOSVersion());
+  }
+}