Merge pull request #28407 from DokFaust/df/GDBlistener

Hooked GDB to JITEventListener, cleaned jitlayers GDB interface
JuliaLang · Aug 16, 2018 · d936625 · d936625
2 parents e23515d + ff2b0ce
commit d936625
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Showing 3 changed files with 9 additions and 93 deletions.
diff --git a/src/codegen.cpp b/src/codegen.cpp
@@ -7471,6 +7471,11 @@ extern "C" void *jl_init_llvm(void)
     jl_data_layout.reset(DL);
 #endif
 
+// Register GDB event listener
+#ifdef JL_DEBUG_BUILD
+    jl_ExecutionEngine->RegisterJITEventListener(JITEventListener::createGDBRegistrationListener());
+#endif
+
 #ifdef JL_USE_INTEL_JITEVENTS
     if (jl_using_intel_jitevents)
         jl_ExecutionEngine->RegisterJITEventListener(JITEventListener::createIntelJITEventListener());

diff --git a/src/jitlayers.cpp b/src/jitlayers.cpp
@@ -54,7 +54,6 @@ namespace llvm {
 #include <llvm/IR/DataLayout.h>
 #include <llvm/Support/DynamicLibrary.h>
 
-
 #include <llvm/Support/raw_ostream.h>
 #include <llvm/Support/FormattedStream.h>
 #include <llvm/ADT/StringMap.h>
@@ -284,72 +283,6 @@ void jl_add_optimization_passes(LLVMPassManagerRef PM, int opt_level) {
     addOptimizationPasses(unwrap(PM), opt_level);
 }
 
-// ------------------------ TEMPORARILY COPIED FROM LLVM -----------------
-// 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.
-  extern struct jit_descriptor __jit_debug_descriptor;
-
-  LLVM_ATTRIBUTE_NOINLINE extern void __jit_debug_register_code();
-}
-
-namespace {
-
-// Use a local variable to hold the addresses to avoid generating a PLT
-// on the function call.
-// It messes up the GDB lookup logic with dynamically linked LLVM.
-// (Ref https://sourceware.org/bugzilla/show_bug.cgi?id=20633)
-// Use `volatile` to make sure the call always loads this slot.
-void (*volatile jit_debug_register_code)() = __jit_debug_register_code;
-
-using namespace llvm;
-using namespace llvm::object;
-using namespace llvm::orc;
-
-/// 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();
-}
-}
-// ------------------------ END OF TEMPORARY COPY FROM LLVM -----------------
-
 #if defined(_OS_LINUX_) || defined(_OS_WINDOWS_) || defined(_OS_FREEBSD_)
 // Resolve non-lock free atomic functions in the libatomic1 library.
 // This is the library that provides support for c11/c++11 atomic operations.
@@ -387,7 +320,7 @@ template <typename ObjT, typename LoadResult>
 void JuliaOJIT::DebugObjectRegistrar::registerObject(RTDyldObjHandleT H, const ObjT &Object,
                                                      const LoadResult &LO)
 {
-    OwningBinary<object::ObjectFile> SavedObject = LO->getObjectForDebug(*Object);
+    object::OwningBinary<object::ObjectFile> SavedObject = LO->getObjectForDebug(*Object);
 
     // If the debug object is unavailable, save (a copy of) the original object
     // for our backtraces
@@ -396,16 +329,15 @@ void JuliaOJIT::DebugObjectRegistrar::registerObject(RTDyldObjHandleT H, const O
         // ownership of the original buffer
         auto NewBuffer = MemoryBuffer::getMemBufferCopy(Object->getData(),
                                                         Object->getFileName());
-        auto NewObj = ObjectFile::createObjectFile(NewBuffer->getMemBufferRef());
+        auto NewObj = object::ObjectFile::createObjectFile(NewBuffer->getMemBufferRef());
         assert(NewObj);
-        SavedObject = OwningBinary<object::ObjectFile>(std::move(*NewObj),
+        SavedObject = object::OwningBinary<object::ObjectFile>(std::move(*NewObj),
                                                        std::move(NewBuffer));
     }
     else {
-        NotifyGDB(SavedObject);
+        JIT.NotifyFinalizer(*(SavedObject.getBinary()), *LO);
     }
 
-    JIT.NotifyFinalizer(*Object, *LO);
     SavedObjects.push_back(std::move(SavedObject));
 
     ORCNotifyObjectEmitted(JuliaListener.get(), *Object,
@@ -436,7 +368,6 @@ void JuliaOJIT::DebugObjectRegistrar::registerObject(RTDyldObjHandleT H, const O
     }
 }
 
-// TODO: hook up RegisterJITEventListener, instead of hard-coding the GDB and JuliaListener targets
 template <typename ObjSetT, typename LoadResult>
 void JuliaOJIT::DebugObjectRegistrar::operator()(RTDyldObjHandleT H,
                 const ObjSetT &Objects, const LoadResult &LOS)
@@ -456,24 +387,6 @@ void JuliaOJIT::DebugObjectRegistrar::operator()(RTDyldObjHandleT H,
 #endif
 }
 
-void JuliaOJIT::DebugObjectRegistrar::NotifyGDB(OwningBinary<object::ObjectFile> &DebugObj)
-{
-    const char *Buffer = DebugObj.getBinary()->getMemoryBufferRef().getBufferStart();
-    size_t      Size = DebugObj.getBinary()->getMemoryBufferRef().getBufferSize();
-
-    assert(Buffer && "Attempt to register a null object with a debugger.");
-    jit_code_entry *JITCodeEntry = new jit_code_entry();
-
-    if (!JITCodeEntry) {
-        jl_printf(JL_STDERR, "WARNING: Allocation failed when registering a JIT entry!\n");
-    }
-    else {
-        JITCodeEntry->symfile_addr = Buffer;
-        JITCodeEntry->symfile_size = Size;
-
-        NotifyDebugger(JITCodeEntry);
-    }
-}
 
 object::OwningBinary<object::ObjectFile> JuliaOJIT::CompilerT::operator()(Module &M)
 {

diff --git a/src/jitlayers.h b/src/jitlayers.h
@@ -103,7 +103,6 @@ using RTDyldObjHandleT = orc::ObjectLinkingLayerBase::ObjSetHandleT;
 
 class JuliaOJIT {
     // Custom object emission notification handler for the JuliaOJIT
-    // TODO: hook up RegisterJITEventListener, instead of hard-coding the GDB and JuliaListener targets
     class DebugObjectRegistrar {
     public:
         DebugObjectRegistrar(JuliaOJIT &JIT);
@@ -112,7 +111,6 @@ class JuliaOJIT {
     private:
         template <typename ObjT, typename LoadResult>
         void registerObject(RTDyldObjHandleT H, const ObjT &Object, const LoadResult &LO);
-        void NotifyGDB(object::OwningBinary<object::ObjectFile> &DebugObj);
         std::vector<object::OwningBinary<object::ObjectFile>> SavedObjects;
         std::unique_ptr<JITEventListener> JuliaListener;
         JuliaOJIT &JIT;