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Nothing but polishing comments. 

llvm-svn: 149515
This commit is contained in:
Howard Hinnant 2012-02-01 16:56:40 +00:00
parent 97981bdeb0
commit 62efe0b062
1 changed files with 27 additions and 8 deletions
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35
libcxxabi/src/cxa_personality.cpp
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@ -296,10 +296,9 @@ get_shim_type_info(int64_t ttypeIndex, const uint8_t* classInfo,
uint8_t ttypeEncoding, bool native_exception,
_Unwind_Exception* unwind_exception)
{
// TODO: Move this check sooner
if (classInfo == 0)
{
// this should not happen
// this should not happen. Indicates corrupted eh_table.
call_terminate(native_exception, unwind_exception);
}
switch (ttypeEncoding & 0x0F)
@ -320,8 +319,7 @@ get_shim_type_info(int64_t ttypeIndex, const uint8_t* classInfo,
ttypeIndex *= 8;
break;
default:
// TODO: Move this check sooner
// this should not happen
// this should not happen. Indicates corrupted eh_table.
call_terminate(native_exception, unwind_exception);
}
classInfo -= ttypeIndex;
@ -343,10 +341,9 @@ exception_spec_can_catch(int64_t specIndex, const uint8_t* classInfo,
uint8_t ttypeEncoding, const __shim_type_info* excpType,
void* adjustedPtr, _Unwind_Exception* unwind_exception)
{
// TODO: Move this check sooner
if (classInfo == 0)
{
// this should not happen
// this should not happen. Indicates corrupted eh_table.
call_terminate(false, unwind_exception);
}
// specIndex is negative of 1-based byte offset into classInfo;
@ -411,7 +408,7 @@ namespace
struct scan_results
{
int64_t ttypeIndex; // > 0 catch handler, < 0 exception spec handler, == 0 a cleanup
const uint8_t* actionRecord; // Currently unused. TODO: Remove?
const uint8_t* actionRecord; // Currently unused. Retained to ease future maintenance.
const uint8_t* languageSpecificData; // Needed only for __cxa_call_unexpected
uintptr_t landingPad; // null -> nothing found, else something found
void* adjustedPtr; // Used in cxa_exception.cpp
@ -792,9 +789,12 @@ __gxx_personality_v0(int version, _Unwind_Action actions, uint64_t exceptionClas
scan_results results;
if (actions & _UA_SEARCH_PHASE)
{
// Phase 1 search: All we're looking for in phase 1 is a handler that
// halts unwinding
scan_eh_tab(results, actions, native_exception, unwind_exception, context);
if (results.reason == _URC_HANDLER_FOUND)
{
// Found one. Can we cache the results somewhere to optimize phase 2?
if (native_exception)
{
__cxa_exception* exception_header = (__cxa_exception*)(unwind_exception+1) - 1;
@ -806,14 +806,22 @@ __gxx_personality_v0(int version, _Unwind_Action actions, uint64_t exceptionClas
}
return _URC_HANDLER_FOUND;
}
// Did not find a catching-handler. Return the results of the scan
// (normally _URC_CONTINUE_UNWIND, but could have been _URC_FATAL_PHASE1_ERROR
// if we were called improperly).
return results.reason;
}
if (actions & _UA_CLEANUP_PHASE)
{
// Phase 2 search:
// Did we find a catching handler in phase 1?
if (actions & _UA_HANDLER_FRAME)
{
// Yes, phase 1 said we have a catching handler here.
// Did we cache the results of the scan?
if (native_exception)
{
// Yes, reload the results from the cache.
__cxa_exception* exception_header = (__cxa_exception*)(unwind_exception+1) - 1;
results.ttypeIndex = exception_header->handlerSwitchValue;
results.actionRecord = exception_header->actionRecord;
@ -823,26 +831,37 @@ __gxx_personality_v0(int version, _Unwind_Action actions, uint64_t exceptionClas
}
else
{
// No, do the scan again to reload the results.
scan_eh_tab(results, actions, native_exception, unwind_exception, context);
// Phase 1 told us we would find a handler. Now in Phase 2 we
// didn't find a handler. The eh table should not be changing!
if (results.reason != _URC_HANDLER_FOUND)
call_terminate(native_exception, unwind_exception);
}
// Jump to the handler
_Unwind_SetGR(context, __builtin_eh_return_data_regno(0), (uintptr_t)unwind_exception);
_Unwind_SetGR(context, __builtin_eh_return_data_regno(1), results.ttypeIndex);
_Unwind_SetIP(context, results.landingPad);
return _URC_INSTALL_CONTEXT;
}
// Either we didn't do a phase 1 search (due to forced unwinding), or
// phase 1 reported no catching-handlers.
// Search for a (non-catching) cleanup
scan_eh_tab(results, actions, native_exception, unwind_exception, context);
if (results.reason == _URC_HANDLER_FOUND)
{
// Found a non-catching handler. Jump to it:
_Unwind_SetGR(context, __builtin_eh_return_data_regno(0), (uintptr_t)unwind_exception);
_Unwind_SetGR(context, __builtin_eh_return_data_regno(1), results.ttypeIndex);
_Unwind_SetIP(context, results.landingPad);
return _URC_INSTALL_CONTEXT;
}
// Did not find a cleanup. Return the results of the scan
// (normally _URC_CONTINUE_UNWIND, but could have been _URC_FATAL_PHASE2_ERROR
// if we were called improperly).
return results.reason;
}
// Neither _UA_SEARCH_PHASE nor _UA_CLEANUP_PHASE
// We were called improperly: neither a phase 1 or phase 2 search
return _URC_FATAL_PHASE1_ERROR;
}