Reduce the number of components initialized by lldb-server to reduce static binary size.

[flackr]

Summary

Separate out the necessary component initialization for lldb-server such that the linker can greatly reduce the binary size. With this patch the size of lldb-server on my 64 bit linux release build drops from 46MB to 26MB. I've run tests and manually tested remote debugging but let me know if there's anything else I can do to verify I haven't left anything uninitialized which is used by lldb-server.

[tberghammer]

Please do the same separation for the Terminate methods also. In most of the case (probably all) it is ensured that calling Terminate without Initialize won't cause any problem but I think it is a very bad practice to rely on this behavior and I expect some further reduction in size from that change.

tools/lldb-server/lldb-gdbserver.cpp

510–511

Are you sure you don't have to initialize the debugger?

[flackr]

Separated termination to allow only calling Terminate on components initialized by InitializeForLLGS. No noticeable increased binary size reduction but this is definitely more correct behavior moving forward.

[flackr]

tools/lldb-server/lldb-gdbserver.cpp

510–511

It does not seem to be necessary, but I could update Debugger::initialize to take which lldb initialization we require if we want to initialize in case it's relied on to coordinate when to call lldb_private::Terminate if you think we should coordinate this through Debugger.

[flackr]

tools/lldb-server/lldb-gdbserver.cpp

510–511

Sorry, parameters wouldn't work because it's not known at link time what values the function will be called with, but Debugger could not implicitly call lldb_private::Initialize though then the reference counting it does should probably also be moved to the initialize method.

[flackr]

Add python back to the components initialized / terminated for LLGS - found that "lldb-server platform" needs python. No noticeable affect to binary size.

[tberghammer]

It looks good to me but please run the full test suit before and after this change and make sure there is no regression (both on Linux and Mac if possible).

Added Greg as a reviewer, please wait for a response from him.

[flackr]

In D7880#130280, @tberghammer wrote:

It looks good to me but please run the full test suit before and after this change and make sure there is no regression (both on Linux and Mac if possible).

Confirmed, no regressions on Linux or Mac full test suite.

[clayborg]

This would also be a good time to try and always initialize all plugins. There are many apple plug-ins which should be completely safe to compile into LLDB for cross debugging to MacOSX and iOS. See inlined comments above.

source/lldb.cpp

227

Note that these #defines are needed because ProcessLinux only runs natively on linux, unlike the #if defined (APPLE) ones that are removing code for no real reason since apple always runs through GDB remote and all other plug-ins are abstracted from the host system and should be able to be cross compiled.

240

Remove the #if defined (APPLE) and always compile these for cross debugging.

243

Remove the #if defined (APPLE) and always compile these for cross debugging.

292

Remove the #if defined (APPLE) and always compile these for cross debugging.

305

Remove the #if defined (APPLE) and always compile these for cross debugging.

333–336

Remove the #if defined (APPLE) and the #endif. These plug-ins should be always compiled into LLDB binaries so that cross debugging can be done. There should be no code that relies headers from a native system in any of these.

[flackr]

Add most apple plugins to all OS compilations and lldb initialization except those which require Mac specific includes.

[flackr]

Hey, I tried to move everything over and then moved plugins back to guarded by #if defined(APPLE) on a case by case basis as I found out why they would not compile and included the reasons in responses to your original comments. Please take a look, thanks.

source/lldb.cpp

240

ProcessMachCore and ProcessKDP depend on DynamicLoaderDarwinKernel which depends on PlatformDarwinKernel which includes Mac-specific sources (Host/macosx/cfcpp/CFCBundle.h)

292

ObjectFileMacho: includes RegisterContextDarwin_x86_64 and extends RegisterContextDarwin_x86_64 which includes <mach/*>

DynamicLoaderDarwinKernel, as mentioned earlier includes mac only resources.

SymbolVendorMacOSX requires libxml2, while I was able to update the Linux build to find this I had some trouble getting cmake to find it in Windows. If we want to add this I think (I may be mistaken) we need to include the path to GnuWin32 (which includes libxml2) as a cmake config parameter so that it can locate libxml2.

[tberghammer]

Please fix the configure+make based compilation as it needs the same changes you made in cmake (I am not sure if xcode needs this changes too or not).

/mnt/ssd/ll/git/build/configure/Release+Asserts/lib/liblldbInitAndLog.a(lldb.o): In function `lldb_private::InitializeForLLGS()':
/mnt/ssd/ll/git/llvm/tools/lldb/source/lldb.cpp:(.text._ZN12lldb_private17InitializeForLLGSEv+0x11a): undefined reference to `ObjectContainerUniversalMachO::Initialize()'
/mnt/ssd/ll/git/llvm/tools/lldb/source/lldb.cpp:(.text._ZN12lldb_private17InitializeForLLGSEv+0x12e): undefined reference to `SystemRuntimeMacOSX::Initialize()'
/mnt/ssd/ll/git/build/configure/Release+Asserts/lib/liblldbInitAndLog.a(lldb.o): In function `lldb_private::TerminateLLGS()':
/mnt/ssd/ll/git/llvm/tools/lldb/source/lldb.cpp:(.text._ZN12lldb_private13TerminateLLGSEv+0x88): undefined reference to `ObjectContainerUniversalMachO::Terminate()'
/mnt/ssd/ll/git/llvm/tools/lldb/source/lldb.cpp:(.text._ZN12lldb_private13TerminateLLGSEv+0x9c): undefined reference to `SystemRuntimeMacOSX::Terminate()'

[flackr]

Fix configure + Makefile build. xcode should not need any changes given it's just enabling things which were previously mac only, but I will double check a build using xcode.

[flackr]

In D7880#131093, @tberghammer wrote:

Please fix the configure+make based compilation as it needs the same changes you made in cmake (I am not sure if xcode needs this changes too or not).

/mnt/ssd/ll/git/build/configure/Release+Asserts/lib/liblldbInitAndLog.a(lldb.o): In function `lldb_private::InitializeForLLGS()':
/mnt/ssd/ll/git/llvm/tools/lldb/source/lldb.cpp:(.text._ZN12lldb_private17InitializeForLLGSEv+0x11a): undefined reference to `ObjectContainerUniversalMachO::Initialize()'
/mnt/ssd/ll/git/llvm/tools/lldb/source/lldb.cpp:(.text._ZN12lldb_private17InitializeForLLGSEv+0x12e): undefined reference to `SystemRuntimeMacOSX::Initialize()'
/mnt/ssd/ll/git/build/configure/Release+Asserts/lib/liblldbInitAndLog.a(lldb.o): In function `lldb_private::TerminateLLGS()':
/mnt/ssd/ll/git/llvm/tools/lldb/source/lldb.cpp:(.text._ZN12lldb_private13TerminateLLGSEv+0x88): undefined reference to `ObjectContainerUniversalMachO::Terminate()'
/mnt/ssd/ll/git/llvm/tools/lldb/source/lldb.cpp:(.text._ZN12lldb_private13TerminateLLGSEv+0x9c): undefined reference to `SystemRuntimeMacOSX::Terminate()'

Done, thanks for catching that and reminding me.

[clayborg]

Ok, thanks for trying. We shouldn't require the inclusion of MacOSX plug-ins for this patch.

[flackr]

In D7880#131248, @clayborg wrote:

Ok, thanks for trying. We shouldn't require the inclusion of MacOSX plug-ins for this patch.

Thanks. Just to confirm, should I commit the patch including what I could (diff 5)? Or defer on including them and commit diff 3?

[zturner]

CMakeLists.txt

360 ↗

(On Diff #20855)

Can you revert all changes to this file?

[flackr]

Removed no-op changes to CMakeLists.txt

[flackr]

CMakeLists.txt

360 ↗

(On Diff #20855)

Of course, done. I missed that after testing whether cmake would just find xml2 from GnuWin32 on Windows.

[emaste]

This broke the FreeBSD configure+make build

[emaste]

Hopefully fixed with r231180

[vharron]

Sorry Ed! Thanks for the fix.

[emaste]

In D7880#134115, @vharron wrote:

Sorry Ed! Thanks for the fix.

No worries, it's good to get these cleanups in.

BTW there are a set of straightforward instructions for getting a FreeBSD VM set up for testing on our wiki: https://wiki.freebsd.org/lldb

include/lldb/lldb-private.h

 ///
 /// This function should be called prior to using any lldb
 /// classes to ensure they have a chance to do any static
 /// initialization that they need to do.
 //------------------------------------------------------------------
 void
 Initialize();
 
+//------------------------------------------------------------------
+/// Initializes subset of lldb for LLGS.
+///
+/// This function only initializes the set of components and plugins
+/// necessary for lldb-platform and lldb-gdbserver, reducing the
+/// impact on the statically linked binary size.
+//------------------------------------------------------------------
+void
+InitializeForLLGS();
 
 //------------------------------------------------------------------
 /// Notifies any classes that lldb will be terminating soon.
 ///
 /// This function will be called when the Debugger shared instance
 /// is being destructed and will give classes the ability to clean
 /// up any threads or other resources they have that they might not
 /// be able to clean up in their own destructors.

 /// that have been allocated during initialization or during
 /// function calls. No lldb functions should be called after
 /// calling this function without again calling DCInitialize()
 /// again.
 //------------------------------------------------------------------
 void
 Terminate();
 
+//------------------------------------------------------------------
+/// Terminates subset of lldb initialized by InitializeForLLGS
+///
+/// This function optionally can be called when clients are done
+/// using lldb functionality to free up any static resources
+/// that have been allocated during initialization or during
+/// function calls. No lldb functions should be called after
+/// calling this function without again calling DCInitialize()
+/// again.
+//------------------------------------------------------------------
+void
+TerminateLLGS();
 
 const char *
 GetVersion ();
 
 const char *
 GetVoteAsCString (Vote vote);
 
 const char *

source/lldb.cpp

 
 static void fatal_error_handler(void *user_data, const std::string& reason,
                                 bool gen_crash_diag) {
     Host::SetCrashDescription(reason.c_str());
     ::abort();
 }
 
 void
-lldb_private::Initialize ()
+lldb_private::InitializeForLLGS ()
 {
-    // Make sure we inialize only once
+    // Make sure we initialize only once
     static Mutex g_inited_mutex(Mutex::eMutexTypeRecursive);
     static bool g_inited = false;
 
     Mutex::Locker locker(g_inited_mutex);
     if (!g_inited)
     {
         g_inited = true;
 
#if defined(_MSC_VER)
             _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
             _CrtSetReportFile(_CRT_WARN, _CRTDBG_FILE_STDERR);
             _CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDERR);
         }
 #endif
 
         Log::Initialize();
         HostInfo::Initialize();
-        Timer::Initialize ();
-        Timer scoped_timer (__PRETTY_FUNCTION__, __PRETTY_FUNCTION__);
+        Timer::Initialize();
+        Timer scoped_timer(__PRETTY_FUNCTION__, __PRETTY_FUNCTION__);
 
-        // Initialize LLVM and Clang
-        llvm::InitializeAllTargets();
-        llvm::InitializeAllAsmPrinters();
-        llvm::InitializeAllTargetMCs();
-        llvm::InitializeAllDisassemblers();
         llvm::install_fatal_error_handler(fatal_error_handler, 0);
 
         // Initialize plug-ins
-        ABIMacOSX_i386::Initialize();
-        ABIMacOSX_arm::Initialize();
-        ABIMacOSX_arm64::Initialize();
-        ABISysV_x86_64::Initialize();
-        ABISysV_ppc::Initialize();
-        ABISysV_ppc64::Initialize();
-        DisassemblerLLVMC::Initialize();
+
         ObjectContainerBSDArchive::Initialize();
         ObjectFileELF::Initialize();
         SymbolVendorELF::Initialize();
         SymbolFileDWARF::Initialize();
         SymbolFileSymtab::Initialize();
         UnwindAssemblyInstEmulation::Initialize();
         UnwindAssembly_x86::Initialize();
-        EmulateInstructionARM::Initialize ();
-        EmulateInstructionARM64::Initialize ();
-        ObjectFilePECOFF::Initialize ();
-        DynamicLoaderPOSIXDYLD::Initialize ();
+        EmulateInstructionARM::Initialize();
+        EmulateInstructionARM64::Initialize();
+        ObjectFilePECOFF::Initialize();
+        DynamicLoaderPOSIXDYLD::Initialize();
         PlatformFreeBSD::Initialize();
         PlatformLinux::Initialize();
         PlatformWindows::Initialize();
         PlatformKalimba::Initialize();
         PlatformAndroid::Initialize();
         SymbolFileDWARFDebugMap::Initialize();
         ItaniumABILanguageRuntime::Initialize();
-#ifndef LLDB_DISABLE_PYTHON
-        ScriptInterpreterPython::InitializePrivate();
-        OperatingSystemPython::Initialize();
-#endif
-        JITLoaderGDB::Initialize();
-        ProcessElfCore::Initialize();
-        MemoryHistoryASan::Initialize();
-        AddressSanitizerRuntime::Initialize();
-        
 #if defined (__APPLE__)
         //----------------------------------------------------------------------
         // Apple/Darwin hosted plugins
         //----------------------------------------------------------------------
         DynamicLoaderMacOSXDYLD::Initialize();
         DynamicLoaderDarwinKernel::Initialize();
         AppleObjCRuntimeV2::Initialize();
         AppleObjCRuntimeV1::Initialize();
         ObjectContainerUniversalMachO::Initialize();
         ObjectFileMachO::Initialize();
-        ProcessKDP::Initialize();
-        ProcessMachCore::Initialize();
+
         SymbolVendorMacOSX::Initialize();
         PlatformDarwinKernel::Initialize();
         PlatformRemoteiOS::Initialize();
         PlatformMacOSX::Initialize();
         PlatformiOSSimulator::Initialize();
         SystemRuntimeMacOSX::Initialize();
 #endif
+
+#ifndef LLDB_DISABLE_PYTHON
+        ScriptInterpreterPython::InitializePrivate();
+        OperatingSystemPython::Initialize();
+#endif
+    }
+}
+
+void
+lldb_private::Initialize ()
+{
+    // Make sure we initialize only once
+    static Mutex g_inited_mutex(Mutex::eMutexTypeRecursive);
+    static bool g_inited = false;
+
+    InitializeForLLGS();
+    Mutex::Locker locker(g_inited_mutex);
+    if (!g_inited)
+    {
+        g_inited = true;
+        // Initialize LLVM and Clang
+        llvm::InitializeAllTargets();
+        llvm::InitializeAllAsmPrinters();
+        llvm::InitializeAllTargetMCs();
+        llvm::InitializeAllDisassemblers();
+
+        ABIMacOSX_i386::Initialize();
+        ABIMacOSX_arm::Initialize();
+        ABIMacOSX_arm64::Initialize();
+        ABISysV_x86_64::Initialize();
+        ABISysV_ppc::Initialize();
+        ABISysV_ppc64::Initialize();
+        DisassemblerLLVMC::Initialize();
+
+        JITLoaderGDB::Initialize();
+        ProcessElfCore::Initialize();
+        MemoryHistoryASan::Initialize();
+        AddressSanitizerRuntime::Initialize();
+
 #if defined (__linux__)
         //----------------------------------------------------------------------
         // Linux hosted plugins
         //----------------------------------------------------------------------
         ProcessLinux::Initialize();
 #endif
 #if defined(_MSC_VER)
         DynamicLoaderWindows::Initialize();
         ProcessWindows::Initialize();
 #endif
 #if defined (__FreeBSD__)
         ProcessFreeBSD::Initialize();
 #endif
-
+#if defined (__APPLE__)
+        ProcessKDP::Initialize();
+        ProcessMachCore::Initialize();
+#endif
         //----------------------------------------------------------------------
         // Platform agnostic plugins
         //----------------------------------------------------------------------
-        PlatformRemoteGDBServer::Initialize ();
+        PlatformRemoteGDBServer::Initialize();
+
         ProcessGDBRemote::Initialize();
         DynamicLoaderStatic::Initialize();
 
         // Scan for any system or user LLDB plug-ins
         PluginManager::Initialize();
 
         // The process settings need to know about installed plug-ins, so the Settings must be initialized
         // AFTER PluginManager::Initialize is called.
-        
         Debugger::SettingsInitialize();
+
     }
 }
 
 void
 lldb_private::WillTerminate()
 {
     Host::WillTerminate();
 }
 
 void
-lldb_private::Terminate ()
+lldb_private::TerminateLLGS ()
 {
     Timer scoped_timer (__PRETTY_FUNCTION__, __PRETTY_FUNCTION__);
-    
-    // Terminate and unload and loaded system or user LLDB plug-ins
-    PluginManager::Terminate();
-    ABIMacOSX_i386::Terminate();
-    ABIMacOSX_arm::Terminate();
-    ABIMacOSX_arm64::Terminate();
-    ABISysV_x86_64::Terminate();
-    ABISysV_ppc::Terminate();
-    ABISysV_ppc64::Terminate();
-    DisassemblerLLVMC::Terminate();
     ObjectContainerBSDArchive::Terminate();
     ObjectFileELF::Terminate();
     SymbolVendorELF::Terminate();
     SymbolFileDWARF::Terminate();
     SymbolFileSymtab::Terminate();
     UnwindAssembly_x86::Terminate();
     UnwindAssemblyInstEmulation::Terminate();
     EmulateInstructionARM::Terminate ();
     EmulateInstructionARM64::Terminate ();
     ObjectFilePECOFF::Terminate ();
     DynamicLoaderPOSIXDYLD::Terminate ();
     PlatformFreeBSD::Terminate();
     PlatformLinux::Terminate();
     PlatformWindows::Terminate();
     PlatformKalimba::Terminate();
     PlatformAndroid::Terminate();
     SymbolFileDWARFDebugMap::Terminate();
     ItaniumABILanguageRuntime::Terminate();
-#ifndef LLDB_DISABLE_PYTHON
-    OperatingSystemPython::Terminate();
-#endif
-    JITLoaderGDB::Terminate();
-    ProcessElfCore::Terminate();
-    MemoryHistoryASan::Terminate();
-    AddressSanitizerRuntime::Terminate();
-    
 #if defined (__APPLE__)
     DynamicLoaderMacOSXDYLD::Terminate();
     DynamicLoaderDarwinKernel::Terminate();
     AppleObjCRuntimeV2::Terminate();
     AppleObjCRuntimeV1::Terminate();
     ObjectContainerUniversalMachO::Terminate();
     ObjectFileMachO::Terminate();
-    ProcessMachCore::Terminate();
-    ProcessKDP::Terminate();
     SymbolVendorMacOSX::Terminate();
     PlatformMacOSX::Terminate();
     PlatformDarwinKernel::Terminate();
     PlatformRemoteiOS::Terminate();
     PlatformiOSSimulator::Terminate();
     SystemRuntimeMacOSX::Terminate();
 #endif
 
-    Debugger::SettingsTerminate ();
+#ifndef LLDB_DISABLE_PYTHON
+    OperatingSystemPython::Terminate();
+#endif
+
+    Log::Terminate();
+}
+
+void
+lldb_private::Terminate ()
+{
+    Timer scoped_timer (__PRETTY_FUNCTION__, __PRETTY_FUNCTION__);
+    // Terminate and unload and loaded system or user LLDB plug-ins
+    PluginManager::Terminate();
+    ABIMacOSX_i386::Terminate();
+    ABIMacOSX_arm::Terminate();
+    ABIMacOSX_arm64::Terminate();
+    ABISysV_x86_64::Terminate();
+    ABISysV_ppc::Terminate();
+    ABISysV_ppc64::Terminate();
+    DisassemblerLLVMC::Terminate();
+
+    JITLoaderGDB::Terminate();
+    ProcessElfCore::Terminate();
+    MemoryHistoryASan::Terminate();
+    AddressSanitizerRuntime::Terminate();
 
+#if defined (__APPLE__)
+    ProcessMachCore::Terminate();
+    ProcessKDP::Terminate();
+#endif
 #if defined(_MSC_VER)
     DynamicLoaderWindows::Terminate();
 #endif
 
 #if defined (__linux__)
     ProcessLinux::Terminate();
 #endif
 
 #if defined (__FreeBSD__)
     ProcessFreeBSD::Terminate();
 #endif
+    Debugger::SettingsTerminate ();
 
     PlatformRemoteGDBServer::Terminate();
     ProcessGDBRemote::Terminate();
     DynamicLoaderStatic::Terminate();
-
-    Log::Terminate();
+    TerminateLLGS();
 }
 
 #if defined (__APPLE__)
 extern "C" const unsigned char liblldb_coreVersionString[];
 #else
 
 #include "clang/Basic/Version.h"
 

tools/lldb-server/lldb-gdbserver.cpp

#endif
     Args log_args;
     Error error;
     int ch;
     std::string platform_name;
     std::string attach_target;
     std::string named_pipe_path;
     bool reverse_connect = false;
 
-    Debugger::Initialize (NULL);
-
     lldb::DebuggerSP debugger_sp = Debugger::CreateInstance ();
 
     debugger_sp->SetInputFileHandle(stdin, false);
     debugger_sp->SetOutputFileHandle(stdout, false);
     debugger_sp->SetErrorFileHandle(stderr, false);
 
     // ProcessLaunchInfo launch_info;
     ProcessAttachInfo attach_info;
#endif
     else if (argc > 0)
         handle_launch (gdb_server, argc, argv);
 
     // Print version info.
     printf("%s-%s", LLGS_PROGRAM_NAME, LLGS_VERSION_STR);
 
     ConnectToRemote (gdb_server, reverse_connect, host_and_port, progname, subcommand, named_pipe_path.c_str ());
 
-    Debugger::Terminate ();
-
     fprintf(stderr, "lldb-gdbserver exiting...\n");
 
     return 0;
 }

tools/lldb-server/lldb-platform.cpp

main_platform (int argc, char *argv[])
     argc--;
     argv++;
     signal (SIGPIPE, SIG_IGN);
     signal (SIGHUP, signal_handler);
     int long_option_index = 0;
     Error error;
     std::string listen_host_port;
     int ch;
-    Debugger::Initialize(NULL);
 
     lldb::DebuggerSP debugger_sp = Debugger::CreateInstance ();
 
     debugger_sp->SetInputFileHandle(stdin, false);
     debugger_sp->SetOutputFileHandle(stdout, false);
     debugger_sp->SetErrorFileHandle(stderr, false);
     
     GDBRemoteCommunicationServerPlatform::PortMap gdbserver_portmap;
do {
                 else
                 {
                     fprintf(stderr, "error: handshake with client failed\n");
                 }
             }
         }
     } while (g_stay_alive);
 
-    Debugger::Terminate();
-
     fprintf(stderr, "lldb-platform exiting...\n");
 
     return 0;
 }

tools/lldb-server/lldb-server.cpp

 //===-- lldb-server.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/lldb-private.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 
 static void
 display_usage (const char *progname)
 {
     fprintf(stderr, "Usage:\n"
             "  %s g[dbserver] [options]\n"
             "  %s p[latform] [options]\n"
             "Invoke subcommand for additional help\n", progname, progname);
     exit(0);
 }
 
 // Forward declarations of subcommand main methods.
 int main_gdbserver (int argc, char *argv[]);
 int main_platform (int argc, char *argv[]);
 
+static void
+initialize ()
+{
+    lldb_private::InitializeForLLGS();
+}
+
+static void
+terminate ()
+{
+    lldb_private::WillTerminate();
+    lldb_private::TerminateLLGS();
+}
+
 //----------------------------------------------------------------------
 // main
 //----------------------------------------------------------------------
 int
 main (int argc, char *argv[])
 {
     int option_error = 0;
     const char *progname = argv[0];
     if (argc < 2)
     {
         display_usage(progname);
         exit(option_error);
     }
     else if (argv[1][0] == 'g')
     {
+        initialize();
         main_gdbserver(argc, argv);
+        terminate();
     }
     else if (argv[1][0] == 'p')
     {
+        initialize();
         main_platform(argc, argv);
+        terminate();
     }
     else {
         display_usage(progname);
         exit(option_error);
     }
 }