NetBSD/sys/lib/libunwind/libunwind.cxx

388 lines
12 KiB
C++

//===--------------------------- libuwind.cpp -----------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//
// Implements C++ ABI Exception Handling Level 1 as documented at:
// http://mentorembedded.github.io/cxx-abi/abi-eh.html
//
//===----------------------------------------------------------------------===//
#define _UNWIND_GCC_EXTENSIONS
#include <unwind.h>
#include "UnwindCursor.hpp"
using namespace _Unwind;
typedef CFI_Parser<LocalAddressSpace, NativeUnwindRegisters> MyCFIParser;
// Internal object representing the address space of this process.
static LocalAddressSpace sThisAddressSpace(MyCFIParser::findPCRange);
typedef UnwindCursor<LocalAddressSpace, NativeUnwindRegisters> ThisUnwindCursor;
static _Unwind_Reason_Code unwind_phase1(ThisUnwindCursor &cursor,
struct _Unwind_Exception *exc) {
cursor.setInfoBasedOnIPRegister();
// Walk frames looking for a place to stop.
for (;;) {
// Get next frame.
// First frame is _Unwind_RaiseException and skipped.
switch (cursor.step()) {
case UNW_STEP_END:
return _URC_END_OF_STACK;
case UNW_STEP_FAILED:
return _URC_FATAL_PHASE1_ERROR;
case UNW_STEP_SUCCESS:
break;
}
// Check if there is a personality routine for this frame.
unw_proc_info_t frameInfo;
cursor.getInfo(&frameInfo);
if (frameInfo.end_ip == 0)
return _URC_FATAL_PHASE1_ERROR;
if (frameInfo.handler == 0)
continue; // No personality routine, so try next frame.
__personality_routine p = (__personality_routine)(frameInfo.handler);
_Unwind_Reason_Code result = (*p)(1, _UA_SEARCH_PHASE, exc->exception_class,
exc, (struct _Unwind_Context *)(&cursor));
switch (result) {
case _URC_HANDLER_FOUND:
// This is either a catch clause or a local variable
// with destructor.
// Stop search and remember the frame for phase 2.
exc->private_2 = cursor.getSP();
return _URC_NO_REASON;
case _URC_CONTINUE_UNWIND:
// Continue unwinding
break;
default:
// Bad personality routine.
return _URC_FATAL_PHASE1_ERROR;
}
}
}
static _Unwind_Reason_Code unwind_phase2(ThisUnwindCursor &cursor,
struct _Unwind_Exception *exc) {
cursor.setInfoBasedOnIPRegister();
// Walk frames until the frame selected in phase 1 is reached.
for (;;) {
// Get next frame.
// First frame is _Unwind_RaiseException and skipped.
switch (cursor.step()) {
case UNW_STEP_END:
return _URC_END_OF_STACK;
case UNW_STEP_FAILED:
return _URC_FATAL_PHASE2_ERROR;
case UNW_STEP_SUCCESS:
break;
}
unw_proc_info_t frameInfo;
cursor.getInfo(&frameInfo);
if (frameInfo.end_ip == 0)
return _URC_FATAL_PHASE2_ERROR;
if (frameInfo.handler == 0)
continue; // No personality routine, continue.
uintptr_t sp = cursor.getSP();
_Unwind_Action action = _UA_CLEANUP_PHASE;
// If this frame was selected in phase 1,
// inform the personality routine.
if (sp == exc->private_2)
action = (_Unwind_Action)(action | _UA_HANDLER_FRAME);
__personality_routine p = (__personality_routine)(frameInfo.handler);
_Unwind_Reason_Code result = (*p)(1, action, exc->exception_class, exc,
(struct _Unwind_Context *)(&cursor));
switch (result) {
case _URC_CONTINUE_UNWIND:
// Continue unwinding unless the selected frame passed.
if (sp == exc->private_2)
return _URC_FATAL_PHASE2_ERROR;
break;
case _URC_INSTALL_CONTEXT:
// Transfer control to landing pad.
cursor.jumpto();
default:
// Bad personality routine.
return _URC_FATAL_PHASE2_ERROR;
}
}
}
static _Unwind_Reason_Code unwind_phase2_forced(ThisUnwindCursor &cursor,
struct _Unwind_Exception *exc,
_Unwind_Stop_Fn stop,
void *stop_arg) {
_Unwind_Action action;
cursor.setInfoBasedOnIPRegister();
// Walk frames until the frame selected in phase 1 is reached.
for (;;) {
// Get next frame.
// First frame is _Unwind_RaiseException and skipped.
switch (cursor.step()) {
case UNW_STEP_END:
case UNW_STEP_FAILED:
// End of stack or error condition.
// Call the stop function one last time.
action = (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE |
_UA_END_OF_STACK);
(*stop)(1, action, exc->exception_class, exc,
(struct _Unwind_Context *)(&cursor), stop_arg);
// Didn't stop at the expected frame, so return error.
return _URC_FATAL_PHASE2_ERROR;
case UNW_STEP_SUCCESS:
break;
}
unw_proc_info_t frameInfo;
cursor.getInfo(&frameInfo);
if (frameInfo.end_ip == 0)
return _URC_FATAL_PHASE2_ERROR;
// Call stop function for each frame
action = (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
_Unwind_Reason_Code result =
(*stop)(1, action, exc->exception_class, exc,
(struct _Unwind_Context *)(&cursor), stop_arg);
if (result != _URC_NO_REASON)
return _URC_FATAL_PHASE2_ERROR;
if (frameInfo.handler == 0)
continue; // No personality routine, continue.
__personality_routine p = (__personality_routine)(frameInfo.handler);
result = (*p)(1, action, exc->exception_class, exc,
(struct _Unwind_Context *)(&cursor));
switch (result) {
case _URC_CONTINUE_UNWIND:
// Destructors called, continue.
break;
case _URC_INSTALL_CONTEXT:
// Transfer control to landing pad.
cursor.jumpto();
default:
// Bad personality routine.
return _URC_FATAL_PHASE2_ERROR;
}
}
}
_Unwind_Reason_Code _Unwind_RaiseException(struct _Unwind_Exception *exc) {
NativeUnwindRegisters registers;
ThisUnwindCursor cursor1(registers, sThisAddressSpace);
ThisUnwindCursor cursor2(registers, sThisAddressSpace);
// Mark this as a non-forced unwind for _Unwind_Resume().
exc->private_1 = 0;
exc->private_2 = 0;
// Phase 1: searching.
_Unwind_Reason_Code phase1 = unwind_phase1(cursor1, exc);
if (phase1 != _URC_NO_REASON)
return phase1;
// Phase 2: cleaning up.
return unwind_phase2(cursor2, exc);
}
_Unwind_Reason_Code _Unwind_ForcedUnwind(struct _Unwind_Exception *exc,
_Unwind_Stop_Fn stop, void *stop_arg) {
NativeUnwindRegisters registers;
ThisUnwindCursor cursor(registers, sThisAddressSpace);
// Mark this as forced unwind for _Unwind_Resume().
exc->private_1 = (uintptr_t)stop;
exc->private_2 = (uintptr_t)stop_arg;
return unwind_phase2_forced(cursor, exc, stop, stop_arg);
}
void _Unwind_Resume(struct _Unwind_Exception *exc) {
NativeUnwindRegisters registers;
ThisUnwindCursor cursor(registers, sThisAddressSpace);
if (exc->private_1 != 0)
unwind_phase2_forced(cursor, exc, (_Unwind_Stop_Fn)exc->private_1,
(void *)exc->private_2);
else
unwind_phase2(cursor, exc);
abort();
}
_Unwind_Reason_Code _Unwind_Resume_or_Rethrow(struct _Unwind_Exception *exc) {
// This is a re-throw, if this is a non-forced unwind
// and the stopping place was found.
// In that case, call _Unwind_RaiseException() as if
// it was a new exception.
if (exc->private_1 != 0)
_Unwind_Resume(exc);
// This can return if there is no catch clause.
// In that case, __cxa_rethrow is expected to call std::terminate().
return _Unwind_RaiseException(exc);
}
void _Unwind_DeleteException(struct _Unwind_Exception *exc) {
if (exc->exception_cleanup != NULL)
(*exc->exception_cleanup)(_URC_FOREIGN_EXCEPTION_CAUGHT, exc);
}
uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {
ThisUnwindCursor *cursor = (ThisUnwindCursor *)context;
return cursor->getReg(index);
}
void _Unwind_SetGR(struct _Unwind_Context *context, int index,
uintptr_t new_value) {
ThisUnwindCursor *cursor = (ThisUnwindCursor *)context;
cursor->setReg(index, new_value);
}
uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
ThisUnwindCursor *cursor = (ThisUnwindCursor *)context;
return cursor->getIP();
}
uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context, int *isSignalFrame) {
ThisUnwindCursor *cursor = (ThisUnwindCursor *)context;
*isSignalFrame = cursor->isSignalFrame() ? 1 : 0;
return cursor->getIP();
}
void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t new_value) {
ThisUnwindCursor *cursor = (ThisUnwindCursor *)context;
cursor->setIP(new_value);
unw_proc_info_t info;
cursor->getInfo(&info);
cursor->setInfoBasedOnIPRegister(false);
}
uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context) {
ThisUnwindCursor *cursor = (ThisUnwindCursor *)context;
unw_proc_info_t frameInfo;
cursor->getInfo(&frameInfo);
return frameInfo.end_ip ? frameInfo.start_ip : 0;
}
uintptr_t _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
ThisUnwindCursor *cursor = (ThisUnwindCursor *)context;
unw_proc_info_t frameInfo;
cursor->getInfo(&frameInfo);
return frameInfo.end_ip ? frameInfo.lsda : 0;
}
_Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn callback, void *ref) {
NativeUnwindRegisters registers;
ThisUnwindCursor cursor(registers, sThisAddressSpace);
cursor.setInfoBasedOnIPRegister();
// Walk each frame.
while (true) {
// Ask libuwind to get next frame (skip over first frame which is
// _Unwind_Backtrace()).
if (cursor.step() != UNW_STEP_SUCCESS)
return _URC_END_OF_STACK;
// Call trace function with this frame.
_Unwind_Reason_Code result =
(*callback)((struct _Unwind_Context *)(&cursor), ref);
if (result != _URC_NO_REASON)
return result;
}
}
uintptr_t _Unwind_GetCFA(struct _Unwind_Context *context) {
ThisUnwindCursor *cursor = (ThisUnwindCursor *)context;
return cursor->getSP();
}
void *_Unwind_FindEnclosingFunction(void *pc) {
NativeUnwindRegisters registers;
ThisUnwindCursor cursor(registers, sThisAddressSpace);
unw_proc_info_t info;
cursor.setIP((uintptr_t)pc);
cursor.setInfoBasedOnIPRegister();
cursor.getInfo(&info);
return info.end_ip ? (void *)info.start_ip : NULL;
}
void *_Unwind_Find_FDE(void *pc, struct dwarf_eh_bases *bases) {
NativeUnwindRegisters registers;
ThisUnwindCursor cursor(registers, sThisAddressSpace);
unw_proc_info_t info;
cursor.setIP((uintptr_t)pc);
cursor.setInfoBasedOnIPRegister();
cursor.getInfo(&info);
if (info.end_ip == 0)
return NULL;
bases->tbase = 0; /* Not supported */
bases->dbase = (void *)info.data_base;
bases->func = (void *)info.start_ip;
return (void *)info.unwind_info;
}
uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context *context) {
ThisUnwindCursor *cursor = (ThisUnwindCursor *)context;
unw_proc_info_t frameInfo;
cursor->getInfo(&frameInfo);
return frameInfo.data_base;
}
uintptr_t _Unwind_GetTextRelBase(struct _Unwind_Context *context) { return 0; }
void __register_frame(const void *fde) {
MyCFIParser::pint_t pcStart, pcEnd;
MyCFIParser::findPCRange(sThisAddressSpace, (uintptr_t)fde, pcStart, pcEnd);
if (pcEnd == 0)
return; // Bad FDE.
sThisAddressSpace.addFDE(pcStart, pcEnd, (uintptr_t)fde);
}
void __register_frame_info(const void *ehframe, void *storage) {
sThisAddressSpace.setLazyReload();
}
void __deregister_frame(const void *fde) {
MyCFIParser::pint_t pcStart, pcEnd;
MyCFIParser::findPCRange(sThisAddressSpace, (uintptr_t)fde, pcStart, pcEnd);
if (pcEnd == 0)
return; // Bad FDE.
sThisAddressSpace.removeFDE(pcStart, pcEnd, (uintptr_t)fde);
}
void *__deregister_frame_info(const void *ehFrameStart) {
sThisAddressSpace.removeDSO((LocalAddressSpace::pint_t)ehFrameStart);
return NULL;
}