Remove dead code.

Support for exception handling in the legacy JIT was removed in r181354 and
this code was dead since then.

Thanks to Yaron Keren for noticing it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192101 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 1 insertions, 169 deletions

diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index 95d5fcb..a8de420 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -56,9 +56,7 @@ ExecutionEngine *(*ExecutionEngine::InterpCtor)(Module *M,
 
 ExecutionEngine::ExecutionEngine(Module *M)
   : EEState(*this),
-    LazyFunctionCreator(0),
-    ExceptionTableRegister(0),
-    ExceptionTableDeregister(0) {
+    LazyFunctionCreator(0) {
   CompilingLazily         = false;
   GVCompilationDisabled   = false;
   SymbolSearchingDisabled = false;
@@ -72,16 +70,6 @@ ExecutionEngine::~ExecutionEngine() {
     delete Modules[i];
 }
 
-void ExecutionEngine::DeregisterAllTables() {
-  if (ExceptionTableDeregister) {
-    DenseMap<const Function*, void*>::iterator it = AllExceptionTables.begin();
-    DenseMap<const Function*, void*>::iterator ite = AllExceptionTables.end();
-    for (; it != ite; ++it)
-      ExceptionTableDeregister(it->second);
-    AllExceptionTables.clear();
-  }
-}
-
 namespace {
 /// \brief Helper class which uses a value handler to automatically deletes the
 /// memory block when the GlobalVariable is destroyed.
diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
index e0504d1c..246a675 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -67,140 +67,6 @@ static struct RegisterJIT {
 extern "C" void LLVMLinkInJIT() {
 }
 
-// Determine whether we can register EH tables.
-#if (defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__ia64__) && \
-     !defined(__USING_SJLJ_EXCEPTIONS__))
-#define HAVE_EHTABLE_SUPPORT 1
-#else
-#define HAVE_EHTABLE_SUPPORT 0
-#endif
-
-#if HAVE_EHTABLE_SUPPORT
-
-// libgcc defines the __register_frame function to dynamically register new
-// dwarf frames for exception handling. This functionality is not portable
-// across compilers and is only provided by GCC. We use the __register_frame
-// function here so that code generated by the JIT cooperates with the unwinding
-// runtime of libgcc. When JITting with exception handling enable, LLVM
-// generates dwarf frames and registers it to libgcc with __register_frame.
-//
-// The __register_frame function works with Linux.
-//
-// Unfortunately, this functionality seems to be in libgcc after the unwinding
-// library of libgcc for darwin was written. The code for darwin overwrites the
-// value updated by __register_frame with a value fetched with "keymgr".
-// "keymgr" is an obsolete functionality, which should be rewritten some day.
-// In the meantime, since "keymgr" is on all libgccs shipped with apple-gcc, we
-// need a workaround in LLVM which uses the "keymgr" to dynamically modify the
-// values of an opaque key, used by libgcc to find dwarf tables.
-
-extern "C" void __register_frame(void*);
-extern "C" void __deregister_frame(void*);
-
-#if defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED <= 1050
-# define USE_KEYMGR 1
-#else
-# define USE_KEYMGR 0
-#endif
-
-#if USE_KEYMGR
-
-namespace {
-
-// LibgccObject - This is the structure defined in libgcc. There is no #include
-// provided for this structure, so we also define it here. libgcc calls it
-// "struct object". The structure is undocumented in libgcc.
-struct LibgccObject {
-  void *unused1;
-  void *unused2;
-  void *unused3;
-
-  /// frame - Pointer to the exception table.
-  void *frame;
-
-  /// encoding -  The encoding of the object?
-  union {
-    struct {
-      unsigned long sorted : 1;
-      unsigned long from_array : 1;
-      unsigned long mixed_encoding : 1;
-      unsigned long encoding : 8;
-      unsigned long count : 21;
-    } b;
-    size_t i;
-  } encoding;
-
-  /// fde_end - libgcc defines this field only if some macro is defined. We
-  /// include this field even if it may not there, to make libgcc happy.
-  char *fde_end;
-
-  /// next - At least we know it's a chained list!
-  struct LibgccObject *next;
-};
-
-// "kemgr" stuff. Apparently, all frame tables are stored there.
-extern "C" void _keymgr_set_and_unlock_processwide_ptr(int, void *);
-extern "C" void *_keymgr_get_and_lock_processwide_ptr(int);
-#define KEYMGR_GCC3_DW2_OBJ_LIST        302     /* Dwarf2 object list  */
-
-/// LibgccObjectInfo - libgcc defines this struct as km_object_info. It
-/// probably contains all dwarf tables that are loaded.
-struct LibgccObjectInfo {
-
-  /// seenObjects - LibgccObjects already parsed by the unwinding runtime.
-  ///
-  struct LibgccObject* seenObjects;
-
-  /// unseenObjects - LibgccObjects not parsed yet by the unwinding runtime.
-  ///
-  struct LibgccObject* unseenObjects;
-
-  unsigned unused[2];
-};
-
-/// darwin_register_frame - Since __register_frame does not work with darwin's
-/// libgcc,we provide our own function, which "tricks" libgcc by modifying the
-/// "Dwarf2 object list" key.
-void DarwinRegisterFrame(void* FrameBegin) {
-  // Get the key.
-  LibgccObjectInfo* LOI = (struct LibgccObjectInfo*)
-    _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
-  assert(LOI && "This should be preallocated by the runtime");
-
-  // Allocate a new LibgccObject to represent this frame. Deallocation of this
-  // object may be impossible: since darwin code in libgcc was written after
-  // the ability to dynamically register frames, things may crash if we
-  // deallocate it.
-  struct LibgccObject* ob = (struct LibgccObject*)
-    malloc(sizeof(struct LibgccObject));
-
-  // Do like libgcc for the values of the field.
-  ob->unused1 = (void *)-1;
-  ob->unused2 = 0;
-  ob->unused3 = 0;
-  ob->frame = FrameBegin;
-  ob->encoding.i = 0;
-  ob->encoding.b.encoding = llvm::dwarf::DW_EH_PE_omit;
-
-  // Put the info on both places, as libgcc uses the first or the second
-  // field. Note that we rely on having two pointers here. If fde_end was a
-  // char, things would get complicated.
-  ob->fde_end = (char*)LOI->unseenObjects;
-  ob->next = LOI->unseenObjects;
-
-  // Update the key's unseenObjects list.
-  LOI->unseenObjects = ob;
-
-  // Finally update the "key". Apparently, libgcc requires it.
-  _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST,
-                                         LOI);
-
-}
-
-}
-#endif // __APPLE__
-#endif // HAVE_EHTABLE_SUPPORT
-
 /// createJIT - This is the factory method for creating a JIT for the current
 /// machine, it does not fall back to the interpreter.  This takes ownership
 /// of the module.
@@ -293,33 +159,11 @@ JIT::JIT(Module *M, TargetMachine &tm, TargetJITInfo &tji,
     report_fatal_error("Target does not support machine code emission!");
   }
 
-  // Register routine for informing unwinding runtime about new EH frames
-#if HAVE_EHTABLE_SUPPORT
-#if USE_KEYMGR
-  struct LibgccObjectInfo* LOI = (struct LibgccObjectInfo*)
-    _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
-
-  // The key is created on demand, and libgcc creates it the first time an
-  // exception occurs. Since we need the key to register frames, we create
-  // it now.
-  if (!LOI)
-    LOI = (LibgccObjectInfo*)calloc(sizeof(struct LibgccObjectInfo), 1);
-  _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, LOI);
-  InstallExceptionTableRegister(DarwinRegisterFrame);
-  // Not sure about how to deregister on Darwin.
-#else
-  InstallExceptionTableRegister(__register_frame);
-  InstallExceptionTableDeregister(__deregister_frame);
-#endif // __APPLE__
-#endif // HAVE_EHTABLE_SUPPORT
-
   // Initialize passes.
   PM.doInitialization();
 }
 
 JIT::~JIT() {
-  // Unregister all exception tables registered by this JIT.
-  DeregisterAllTables();
   // Cleanup.
   AllJits->Remove(this);
   delete jitstate;