From c9f0684580f85592b305d5bc74cabe56c0e3dc51 Mon Sep 17 00:00:00 2001 From: Nekotekina Date: Wed, 23 Oct 2019 12:58:18 +0300 Subject: [PATCH] Disable GDBRegistrationListener It makes emitting object extremely slow. GDB doesn't work properly with it anyway. GDB also often crashes because it cannot read the format. --- .../GDBRegistrationListener.cpp | 165 +----------------- 1 file changed, 1 insertion(+), 164 deletions(-) diff --git a/lib/ExecutionEngine/GDBRegistrationListener.cpp b/lib/ExecutionEngine/GDBRegistrationListener.cpp index 7ed025fbb48..4c45bf76e34 100644 --- a/lib/ExecutionEngine/GDBRegistrationListener.cpp +++ b/lib/ExecutionEngine/GDBRegistrationListener.cpp @@ -19,77 +19,16 @@ using namespace llvm; using namespace llvm::object; -// This must be kept in sync with gdb/gdb/jit.h . -extern "C" { - - typedef enum { - JIT_NOACTION = 0, - JIT_REGISTER_FN, - JIT_UNREGISTER_FN - } jit_actions_t; - - struct jit_code_entry { - struct jit_code_entry *next_entry; - struct jit_code_entry *prev_entry; - const char *symfile_addr; - uint64_t symfile_size; - }; - - struct jit_descriptor { - uint32_t version; - // This should be jit_actions_t, but we want to be specific about the - // bit-width. - uint32_t action_flag; - struct jit_code_entry *relevant_entry; - struct jit_code_entry *first_entry; - }; - - // We put information about the JITed function in this global, which the - // debugger reads. Make sure to specify the version statically, because the - // debugger checks the version before we can set it during runtime. - struct jit_descriptor __jit_debug_descriptor = { 1, 0, nullptr, nullptr }; - - // Debuggers puts a breakpoint in this function. - LLVM_ATTRIBUTE_NOINLINE void __jit_debug_register_code() { - // The noinline and the asm prevent calls to this function from being - // optimized out. -#if !defined(_MSC_VER) - asm volatile("":::"memory"); -#endif - } - -} - namespace { -struct RegisteredObjectInfo { - RegisteredObjectInfo() {} - - RegisteredObjectInfo(std::size_t Size, jit_code_entry *Entry, - OwningBinary Obj) - : Size(Size), Entry(Entry), Obj(std::move(Obj)) {} - - std::size_t Size; - jit_code_entry *Entry; - OwningBinary Obj; -}; - -// Buffer for an in-memory object file in executable memory -typedef llvm::DenseMap - RegisteredObjectBufferMap; - /// Global access point for the JIT debugging interface designed for use with a /// singleton toolbox. Handles thread-safe registration and deregistration of /// object files that are in executable memory managed by the client of this /// class. class GDBJITRegistrationListener : public JITEventListener { - /// A map of in-memory object files that have been registered with the - /// JIT interface. - RegisteredObjectBufferMap ObjectBufferMap; - public: /// Instantiates the JIT service. - GDBJITRegistrationListener() : ObjectBufferMap() {} + GDBJITRegistrationListener() {} /// Unregisters each object that was previously registered and releases all /// internal resources. @@ -105,119 +44,17 @@ public: /// frees associated resources. /// Returns true if @p Object was found in ObjectBufferMap. void notifyFreeingObject(ObjectKey K) override; - -private: - /// Deregister the debug info for the given object file from the debugger - /// and delete any temporary copies. This private method does not remove - /// the function from Map so that it can be called while iterating over Map. - void deregisterObjectInternal(RegisteredObjectBufferMap::iterator I); }; -/// Lock used to serialize all jit registration events, since they -/// modify global variables. -ManagedStatic JITDebugLock; - -/// Do the registration. -void NotifyDebugger(jit_code_entry* JITCodeEntry) { - __jit_debug_descriptor.action_flag = JIT_REGISTER_FN; - - // Insert this entry at the head of the list. - JITCodeEntry->prev_entry = nullptr; - jit_code_entry* NextEntry = __jit_debug_descriptor.first_entry; - JITCodeEntry->next_entry = NextEntry; - if (NextEntry) { - NextEntry->prev_entry = JITCodeEntry; - } - __jit_debug_descriptor.first_entry = JITCodeEntry; - __jit_debug_descriptor.relevant_entry = JITCodeEntry; - __jit_debug_register_code(); -} - GDBJITRegistrationListener::~GDBJITRegistrationListener() { - // Free all registered object files. - std::lock_guard locked(*JITDebugLock); - for (RegisteredObjectBufferMap::iterator I = ObjectBufferMap.begin(), - E = ObjectBufferMap.end(); - I != E; ++I) { - // Call the private method that doesn't update the map so our iterator - // doesn't break. - deregisterObjectInternal(I); - } - ObjectBufferMap.clear(); } void GDBJITRegistrationListener::notifyObjectLoaded( ObjectKey K, const ObjectFile &Obj, const RuntimeDyld::LoadedObjectInfo &L) { - - OwningBinary DebugObj = L.getObjectForDebug(Obj); - - // Bail out if debug objects aren't supported. - if (!DebugObj.getBinary()) - return; - - const char *Buffer = DebugObj.getBinary()->getMemoryBufferRef().getBufferStart(); - size_t Size = DebugObj.getBinary()->getMemoryBufferRef().getBufferSize(); - - std::lock_guard locked(*JITDebugLock); - assert(ObjectBufferMap.find(K) == ObjectBufferMap.end() && - "Second attempt to perform debug registration."); - jit_code_entry* JITCodeEntry = new jit_code_entry(); - - if (!JITCodeEntry) { - llvm::report_fatal_error( - "Allocation failed when registering a JIT entry!\n"); - } else { - JITCodeEntry->symfile_addr = Buffer; - JITCodeEntry->symfile_size = Size; - - ObjectBufferMap[K] = - RegisteredObjectInfo(Size, JITCodeEntry, std::move(DebugObj)); - NotifyDebugger(JITCodeEntry); - } } void GDBJITRegistrationListener::notifyFreeingObject(ObjectKey K) { - std::lock_guard locked(*JITDebugLock); - RegisteredObjectBufferMap::iterator I = ObjectBufferMap.find(K); - - if (I != ObjectBufferMap.end()) { - deregisterObjectInternal(I); - ObjectBufferMap.erase(I); - } -} - -void GDBJITRegistrationListener::deregisterObjectInternal( - RegisteredObjectBufferMap::iterator I) { - - jit_code_entry*& JITCodeEntry = I->second.Entry; - - // Do the unregistration. - { - __jit_debug_descriptor.action_flag = JIT_UNREGISTER_FN; - - // Remove the jit_code_entry from the linked list. - jit_code_entry* PrevEntry = JITCodeEntry->prev_entry; - jit_code_entry* NextEntry = JITCodeEntry->next_entry; - - if (NextEntry) { - NextEntry->prev_entry = PrevEntry; - } - if (PrevEntry) { - PrevEntry->next_entry = NextEntry; - } - else { - assert(__jit_debug_descriptor.first_entry == JITCodeEntry); - __jit_debug_descriptor.first_entry = NextEntry; - } - - // Tell the debugger which entry we removed, and unregister the code. - __jit_debug_descriptor.relevant_entry = JITCodeEntry; - __jit_debug_register_code(); - } - - delete JITCodeEntry; - JITCodeEntry = nullptr; } llvm::ManagedStatic GDBRegListener;