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Remove dead code.

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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
This commit is contained in:
Rafael Espindola 2013-10-07 13:54:50 +00:00
parent ef8c4ca252
commit d0acc84b2b
3 changed files with 1 additions and 214 deletions
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45
include/llvm/ExecutionEngine/ExecutionEngine.h
View File

@ -16,7 +16,6 @@
#define LLVM_EXECUTIONENGINE_EXECUTIONENGINE_H
#include "llvm-c/ExecutionEngine.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/ValueMap.h"
@ -153,15 +152,6 @@ protected:
/// abort.
void *(*LazyFunctionCreator)(const std::string &);
/// ExceptionTableRegister - If Exception Handling is set, the JIT will
/// register dwarf tables with this function.
typedef void (*EERegisterFn)(void*);
EERegisterFn ExceptionTableRegister;
EERegisterFn ExceptionTableDeregister;
/// This maps functions to their exception tables frames.
DenseMap<const Function*, void*> AllExceptionTables;
public:
/// lock - This lock protects the ExecutionEngine, JIT, JITResolver and
/// JITEmitter classes. It must be held while changing the internal state of
@ -489,41 +479,6 @@ public:
LazyFunctionCreator = P;
}
/// InstallExceptionTableRegister - The JIT will use the given function
/// to register the exception tables it generates.
void InstallExceptionTableRegister(EERegisterFn F) {
ExceptionTableRegister = F;
}
void InstallExceptionTableDeregister(EERegisterFn F) {
ExceptionTableDeregister = F;
}
/// RegisterTable - Registers the given pointer as an exception table. It
/// uses the ExceptionTableRegister function.
void RegisterTable(const Function *fn, void* res) {
if (ExceptionTableRegister) {
ExceptionTableRegister(res);
AllExceptionTables[fn] = res;
}
}
/// DeregisterTable - Deregisters the exception frame previously registered
/// for the given function.
void DeregisterTable(const Function *Fn) {
if (ExceptionTableDeregister) {
DenseMap<const Function*, void*>::iterator frame =
AllExceptionTables.find(Fn);
if(frame != AllExceptionTables.end()) {
ExceptionTableDeregister(frame->second);
AllExceptionTables.erase(frame);
}
}
}
/// DeregisterAllTables - Deregisters all previously registered pointers to an
/// exception tables. It uses the ExceptionTableoDeregister function.
void DeregisterAllTables();
protected:
explicit ExecutionEngine(Module *M);

14
lib/ExecutionEngine/ExecutionEngine.cpp
View File

@ -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.

156
lib/ExecutionEngine/JIT/JIT.cpp
View File

@ -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;