+++ /dev/null
-//===----- GDBRegistrationListener.cpp - Registers objects with GDB -------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ExecutionEngine/JITEventListener.h"
-#include "llvm/Object/ObjectFile.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/Mutex.h"
-#include "llvm/Support/MutexGuard.h"
-#include "llvm/Support/ManagedStatic.h"
-
-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<ObjectFile> Obj)
- : Size(Size), Entry(Entry), Obj(std::move(Obj)) {}
-
- std::size_t Size;
- jit_code_entry *Entry;
- OwningBinary<ObjectFile> Obj;
-};
-
-// Buffer for an in-memory object file in executable memory
-typedef llvm::DenseMap< const char*, RegisteredObjectInfo>
- 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() {}
-
- /// Unregisters each object that was previously registered and releases all
- /// internal resources.
- virtual ~GDBJITRegistrationListener();
-
- /// Creates an entry in the JIT registry for the buffer @p Object,
- /// which must contain an object file in executable memory with any
- /// debug information for the debugger.
- void NotifyObjectEmitted(const ObjectFile &Object,
- const RuntimeDyld::LoadedObjectInfo &L) override;
-
- /// Removes the internal registration of @p Object, and
- /// frees associated resources.
- /// Returns true if @p Object was found in ObjectBufferMap.
- void NotifyFreeingObject(const ObjectFile &Object) 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<sys::Mutex> 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.
- llvm::MutexGuard 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::NotifyObjectEmitted(
- const ObjectFile &Object,
- const RuntimeDyld::LoadedObjectInfo &L) {
-
- OwningBinary<ObjectFile> DebugObj = L.getObjectForDebug(Object);
-
- // 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();
-
- const char *Key = Object.getMemoryBufferRef().getBufferStart();
-
- assert(Key && "Attempt to register a null object with a debugger.");
- llvm::MutexGuard locked(*JITDebugLock);
- assert(ObjectBufferMap.find(Key) == 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[Key] = RegisteredObjectInfo(Size, JITCodeEntry,
- std::move(DebugObj));
- NotifyDebugger(JITCodeEntry);
- }
-}
-
-void GDBJITRegistrationListener::NotifyFreeingObject(const ObjectFile& Object) {
- const char *Key = Object.getMemoryBufferRef().getBufferStart();
- llvm::MutexGuard locked(*JITDebugLock);
- RegisteredObjectBufferMap::iterator I = ObjectBufferMap.find(Key);
-
- 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<GDBJITRegistrationListener> GDBRegListener;
-
-} // end namespace
-
-namespace llvm {
-
-JITEventListener* JITEventListener::createGDBRegistrationListener() {
- return &*GDBRegListener;
-}
-
-} // namespace llvm
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