Reduce the number of components initialized for LLGS further.

[flackr]

Summary

In http://reviews.llvm.org/D7880 the initialization for LLGS was separated out so that LLGS could initialize only the components it needs to. This further reduces the set of components initialized for LLGS.

[tberghammer]

It looks good to me, but I think you can remove the following modules also (haven't tested it):

ObjectContainerBSDArchive
ObjectContainerUniversalMachO
ObjectFileELF
ObjectFileMachO
ObjectFilePECOFF
DynamicLoaderPOSIXDYLD
DynamicLoaderMacOSXDYLD
DynamicLoaderDarwinKernel

[vharron]

ObjectFileELF

LLGS needs this.

[tberghammer]

In D8112#136299, @vharron wrote:

ObjectFileELF

LLGS needs this.

What is it used for?

AFAIK it is only used by ProcessElfCore what is currently not initialized by LLGS. Is it mean we have to put back the initialization of ProcessElfCore into LLGS?

[vharron]

LLGS uses it to confirm that the target file has the correct architecture
(e.g. x86_64) before launch. If it doesn't have ObjectFileELF plugin
loaded, nothing can parse the ELF file.

[tberghammer]

Thanks for your explanation. It makes sense, but I think LLGS not necessarily have to parse any ELF file because it can be done on LLDB side (it already can send down the architecture of an executable). I suggest to leave it in LLGS for now, and if later we want to reduce the size of LLGS further, then we can remove it (possibly after some re-factoring).

[vharron]

Agreed completely.

[flackr]

In D8112#136393, @vharron wrote:

LLGS uses it to confirm that the target file has the correct architecture
(e.g. x86_64) before launch. If it doesn't have ObjectFileELF plugin
loaded, nothing can parse the ELF file.

Yes, just to confirm this is exactly what I was seeing when I tried to remove this. The long term removal plan sounds good to me too.

[tberghammer]

I don't see any removed component needed in LLGS and we can address the removal of the additional components later.

source/lldb.cpp

#endif
         Timer scoped_timer(__PRETTY_FUNCTION__, __PRETTY_FUNCTION__);
 
         llvm::install_fatal_error_handler(fatal_error_handler, 0);
 
         // Initialize plug-ins
 
         ObjectContainerBSDArchive::Initialize();
         ObjectFileELF::Initialize();
-        SymbolVendorELF::Initialize();
-        SymbolFileDWARF::Initialize();
-        SymbolFileSymtab::Initialize();
-        UnwindAssemblyInstEmulation::Initialize();
-        UnwindAssembly_x86::Initialize();
-        EmulateInstructionARM::Initialize();
-        EmulateInstructionARM64::Initialize();
         ObjectFilePECOFF::Initialize();
         DynamicLoaderPOSIXDYLD::Initialize();
         PlatformFreeBSD::Initialize();
         PlatformLinux::Initialize();
         PlatformWindows::Initialize();
         PlatformKalimba::Initialize();
         PlatformAndroid::Initialize();
-        SymbolFileDWARFDebugMap::Initialize();
-        ItaniumABILanguageRuntime::Initialize();
 
         //----------------------------------------------------------------------
         // Apple/Darwin hosted plugins
         //----------------------------------------------------------------------
         DynamicLoaderMacOSXDYLD::Initialize();
-        AppleObjCRuntimeV2::Initialize();
-        AppleObjCRuntimeV1::Initialize();
         ObjectContainerUniversalMachO::Initialize();
 
         PlatformRemoteiOS::Initialize();
         PlatformMacOSX::Initialize();
         PlatformiOSSimulator::Initialize();
-        SystemRuntimeMacOSX::Initialize();
 
 #if defined (__APPLE__)
-        SymbolVendorMacOSX::Initialize();
         DynamicLoaderDarwinKernel::Initialize();
         PlatformDarwinKernel::Initialize();
         ObjectFileMachO::Initialize();
 #endif
 
 #ifndef LLDB_DISABLE_PYTHON
         ScriptInterpreterPython::InitializePrivate();
         OperatingSystemPython::Initialize();
if (!g_inited)
         ABISysV_ppc64::Initialize();
         DisassemblerLLVMC::Initialize();
 
         JITLoaderGDB::Initialize();
         ProcessElfCore::Initialize();
         MemoryHistoryASan::Initialize();
         AddressSanitizerRuntime::Initialize();
 
+        SymbolVendorELF::Initialize();
+        SymbolFileDWARF::Initialize();
+        SymbolFileSymtab::Initialize();
+        UnwindAssemblyInstEmulation::Initialize();
+        UnwindAssembly_x86::Initialize();
+        EmulateInstructionARM::Initialize();
+        EmulateInstructionARM64::Initialize();
+        SymbolFileDWARFDebugMap::Initialize();
+        ItaniumABILanguageRuntime::Initialize();
+        AppleObjCRuntimeV2::Initialize();
+        AppleObjCRuntimeV1::Initialize();
+        SystemRuntimeMacOSX::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__)
+        SymbolVendorMacOSX::Initialize();
         ProcessKDP::Initialize();
         ProcessMachCore::Initialize();
 #endif
         //----------------------------------------------------------------------
         // Platform agnostic plugins
         //----------------------------------------------------------------------
         PlatformRemoteGDBServer::Initialize();
 

 }
 
 void
 lldb_private::TerminateLLGS ()
 {
     Timer scoped_timer (__PRETTY_FUNCTION__, __PRETTY_FUNCTION__);
     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();
     DynamicLoaderMacOSXDYLD::Terminate();
-    AppleObjCRuntimeV2::Terminate();
-    AppleObjCRuntimeV1::Terminate();
     ObjectContainerUniversalMachO::Terminate();
     PlatformMacOSX::Terminate();
     PlatformRemoteiOS::Terminate();
     PlatformiOSSimulator::Terminate();
-    SystemRuntimeMacOSX::Terminate();
 
 #if defined (__APPLE__)
     DynamicLoaderDarwinKernel::Terminate();
     ObjectFileMachO::Terminate();
     PlatformDarwinKernel::Terminate();
-    SymbolVendorMacOSX::Terminate();
 #endif
 #ifndef LLDB_DISABLE_PYTHON
     OperatingSystemPython::Terminate();
 #endif
 
     Log::Terminate();
 }
 
lldb_private::Terminate ()
     ABISysV_ppc::Terminate();
     ABISysV_ppc64::Terminate();
     DisassemblerLLVMC::Terminate();
 
     JITLoaderGDB::Terminate();
     ProcessElfCore::Terminate();
     MemoryHistoryASan::Terminate();
     AddressSanitizerRuntime::Terminate();
+    SymbolVendorELF::Terminate();
+    SymbolFileDWARF::Terminate();
+    SymbolFileSymtab::Terminate();
+    UnwindAssembly_x86::Terminate();
+    UnwindAssemblyInstEmulation::Terminate();
+    EmulateInstructionARM::Terminate();
+    EmulateInstructionARM64::Terminate();
+    SymbolFileDWARFDebugMap::Terminate();
+    ItaniumABILanguageRuntime::Terminate();
+    AppleObjCRuntimeV2::Terminate();
+    AppleObjCRuntimeV1::Terminate();
+    SystemRuntimeMacOSX::Terminate();
 
 #if defined (__APPLE__)
     ProcessMachCore::Terminate();
     ProcessKDP::Terminate();
+    SymbolVendorMacOSX::Terminate();
 #endif
 #if defined(_MSC_VER)
     DynamicLoaderWindows::Terminate();
 #endif
 
 #if defined (__linux__)
     ProcessLinux::Terminate();
 #endif