| Index: third_party/libc++abi/src/cxa_personality.cpp
|
| ===================================================================
|
| --- third_party/libc++abi/src/cxa_personality.cpp (revision 0)
|
| +++ third_party/libc++abi/src/cxa_personality.cpp (revision 0)
|
| @@ -0,0 +1,1055 @@
|
| +//===------------------------- cxa_exception.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.
|
| +//
|
| +//
|
| +// This file implements the "Exception Handling APIs"
|
| +// http://www.codesourcery.com/public/cxx-abi/abi-eh.html
|
| +// http://www.intel.com/design/itanium/downloads/245358.htm
|
| +//
|
| +//===----------------------------------------------------------------------===//
|
| +
|
| +#include "unwind.h"
|
| +#include "cxa_exception.hpp"
|
| +#include "cxa_handlers.hpp"
|
| +#include "private_typeinfo.h"
|
| +#include <typeinfo>
|
| +#include <stdlib.h>
|
| +#include <assert.h>
|
| +
|
| +/*
|
| + Exception Header Layout:
|
| +
|
| ++---------------------------+-----------------------------+---------------+
|
| +| __cxa_exception | _Unwind_Exception CLNGC++\0 | thrown object |
|
| ++---------------------------+-----------------------------+---------------+
|
| + ^
|
| + |
|
| + +-------------------------------------------------------+
|
| + |
|
| ++---------------------------+-----------------------------+
|
| +| __cxa_dependent_exception | _Unwind_Exception CLNGC++\1 |
|
| ++---------------------------+-----------------------------+
|
| +
|
| + Exception Handling Table Layout:
|
| +
|
| ++-----------------+--------+
|
| +| lpStartEncoding | (char) |
|
| ++---------+-------+--------+---------------+-----------------------+
|
| +| lpStart | (encoded with lpStartEncoding) | defaults to funcStart |
|
| ++---------+-----+--------+-----------------+---------------+-------+
|
| +| ttypeEncoding | (char) | Encoding of the type_info table |
|
| ++---------------+-+------+----+----------------------------+----------------+
|
| +| classInfoOffset | (ULEB128) | Offset to type_info table, defaults to null |
|
| ++-----------------++--------+-+----------------------------+----------------+
|
| +| callSiteEncoding | (char) | Encoding for Call Site Table |
|
| ++------------------+--+-----+-----+------------------------+--------------------------+
|
| +| callSiteTableLength | (ULEB128) | Call Site Table length, used to find Action table |
|
| ++---------------------+-----------+---------------------------------------------------+
|
| +#if !__arm__
|
| ++---------------------+-----------+------------------------------------------------+
|
| +| Beginning of Call Site Table The current ip lies within the |
|
| +| ... (start, length) range of one of these |
|
| +| call sites. There may be action needed. |
|
| +| +-------------+---------------------------------+------------------------------+ |
|
| +| | start | (encoded with callSiteEncoding) | offset relative to funcStart | |
|
| +| | length | (encoded with callSiteEncoding) | length of code fragment | |
|
| +| | landingPad | (encoded with callSiteEncoding) | offset relative to lpStart | |
|
| +| | actionEntry | (ULEB128) | Action Table Index 1-based | |
|
| +| | | | actionEntry == 0 -> cleanup | |
|
| +| +-------------+---------------------------------+------------------------------+ |
|
| +| ... |
|
| ++----------------------------------------------------------------------------------+
|
| +#else // __arm_
|
| ++---------------------+-----------+------------------------------------------------+
|
| +| Beginning of Call Site Table The current ip is a 1-based index into |
|
| +| ... this table. Or it is -1 meaning no |
|
| +| action is needed. Or it is 0 meaning |
|
| +| terminate. |
|
| +| +-------------+---------------------------------+------------------------------+ |
|
| +| | landingPad | (ULEB128) | offset relative to lpStart | |
|
| +| | actionEntry | (ULEB128) | Action Table Index 1-based | |
|
| +| | | | actionEntry == 0 -> cleanup | |
|
| +| +-------------+---------------------------------+------------------------------+ |
|
| +| ... |
|
| ++----------------------------------------------------------------------------------+
|
| +#endif // __arm_
|
| ++---------------------------------------------------------------------+
|
| +| Beginning of Action Table ttypeIndex == 0 : cleanup |
|
| +| ... ttypeIndex > 0 : catch |
|
| +| ttypeIndex < 0 : exception spec |
|
| +| +--------------+-----------+--------------------------------------+ |
|
| +| | ttypeIndex | (SLEB128) | Index into type_info Table (1-based) | |
|
| +| | actionOffset | (SLEB128) | Offset into next Action Table entry | |
|
| +| +--------------+-----------+--------------------------------------+ |
|
| +| ... |
|
| ++---------------------------------------------------------------------+-----------------+
|
| +| type_info Table, but classInfoOffset does *not* point here! |
|
| +| +----------------+------------------------------------------------+-----------------+ |
|
| +| | Nth type_info* | Encoded with ttypeEncoding, 0 means catch(...) | ttypeIndex == N | |
|
| +| +----------------+------------------------------------------------+-----------------+ |
|
| +| ... |
|
| +| +----------------+------------------------------------------------+-----------------+ |
|
| +| | 1st type_info* | Encoded with ttypeEncoding, 0 means catch(...) | ttypeIndex == 1 | |
|
| +| +----------------+------------------------------------------------+-----------------+ |
|
| +| +---------------------------------------+-----------+------------------------------+ |
|
| +| | 1st ttypeIndex for 1st exception spec | (ULEB128) | classInfoOffset points here! | |
|
| +| | ... | (ULEB128) | | |
|
| +| | Mth ttypeIndex for 1st exception spec | (ULEB128) | | |
|
| +| | 0 | (ULEB128) | | |
|
| +| +---------------------------------------+------------------------------------------+ |
|
| +| ... |
|
| +| +---------------------------------------+------------------------------------------+ |
|
| +| | 0 | (ULEB128) | throw() | |
|
| +| +---------------------------------------+------------------------------------------+ |
|
| +| ... |
|
| +| +---------------------------------------+------------------------------------------+ |
|
| +| | 1st ttypeIndex for Nth exception spec | (ULEB128) | | |
|
| +| | ... | (ULEB128) | | |
|
| +| | Mth ttypeIndex for Nth exception spec | (ULEB128) | | |
|
| +| | 0 | (ULEB128) | | |
|
| +| +---------------------------------------+------------------------------------------+ |
|
| ++---------------------------------------------------------------------------------------+
|
| +
|
| +Notes:
|
| +
|
| +* ttypeIndex in the Action Table, and in the exception spec table, is an index,
|
| + not a byte count, if positive. It is a negative index offset of
|
| + classInfoOffset and the sizeof entry depends on ttypeEncoding.
|
| + But if ttypeIndex is negative, it is a positive 1-based byte offset into the
|
| + type_info Table.
|
| + And if ttypeIndex is zero, it refers to a catch (...).
|
| +
|
| +* landingPad can be 0, this implies there is nothing to be done.
|
| +
|
| +* landingPad != 0 and actionEntry == 0 implies a cleanup needs to be done
|
| + @landingPad.
|
| +
|
| +* A cleanup can also be found under landingPad != 0 and actionEntry != 0 in
|
| + the Action Table with ttypeIndex == 0.
|
| +*/
|
| +
|
| +namespace __cxxabiv1
|
| +{
|
| +
|
| +extern "C"
|
| +{
|
| +
|
| +// private API
|
| +
|
| +// Heavily borrowed from llvm/examples/ExceptionDemo/ExceptionDemo.cpp
|
| +
|
| +// DWARF Constants
|
| +enum
|
| +{
|
| + DW_EH_PE_absptr = 0x00,
|
| + DW_EH_PE_uleb128 = 0x01,
|
| + DW_EH_PE_udata2 = 0x02,
|
| + DW_EH_PE_udata4 = 0x03,
|
| + DW_EH_PE_udata8 = 0x04,
|
| + DW_EH_PE_sleb128 = 0x09,
|
| + DW_EH_PE_sdata2 = 0x0A,
|
| + DW_EH_PE_sdata4 = 0x0B,
|
| + DW_EH_PE_sdata8 = 0x0C,
|
| + DW_EH_PE_pcrel = 0x10,
|
| + DW_EH_PE_textrel = 0x20,
|
| + DW_EH_PE_datarel = 0x30,
|
| + DW_EH_PE_funcrel = 0x40,
|
| + DW_EH_PE_aligned = 0x50,
|
| + DW_EH_PE_indirect = 0x80,
|
| + DW_EH_PE_omit = 0xFF
|
| +};
|
| +
|
| +/// Read a uleb128 encoded value and advance pointer
|
| +/// See Variable Length Data Appendix C in:
|
| +/// @link http://dwarfstd.org/Dwarf4.pdf @unlink
|
| +/// @param data reference variable holding memory pointer to decode from
|
| +/// @returns decoded value
|
| +static
|
| +uintptr_t
|
| +readULEB128(const uint8_t** data)
|
| +{
|
| + uintptr_t result = 0;
|
| + uintptr_t shift = 0;
|
| + unsigned char byte;
|
| + const uint8_t *p = *data;
|
| + do
|
| + {
|
| + byte = *p++;
|
| + result |= static_cast<uintptr_t>(byte & 0x7F) << shift;
|
| + shift += 7;
|
| + } while (byte & 0x80);
|
| + *data = p;
|
| + return result;
|
| +}
|
| +
|
| +/// Read a sleb128 encoded value and advance pointer
|
| +/// See Variable Length Data Appendix C in:
|
| +/// @link http://dwarfstd.org/Dwarf4.pdf @unlink
|
| +/// @param data reference variable holding memory pointer to decode from
|
| +/// @returns decoded value
|
| +static
|
| +intptr_t
|
| +readSLEB128(const uint8_t** data)
|
| +{
|
| + uintptr_t result = 0;
|
| + uintptr_t shift = 0;
|
| + unsigned char byte;
|
| + const uint8_t *p = *data;
|
| + do
|
| + {
|
| + byte = *p++;
|
| + result |= static_cast<uintptr_t>(byte & 0x7F) << shift;
|
| + shift += 7;
|
| + } while (byte & 0x80);
|
| + *data = p;
|
| + if ((byte & 0x40) && (shift < (sizeof(result) << 3)))
|
| + result |= static_cast<uintptr_t>(~0) << shift;
|
| + return static_cast<intptr_t>(result);
|
| +}
|
| +
|
| +/// Read a pointer encoded value and advance pointer
|
| +/// See Variable Length Data in:
|
| +/// @link http://dwarfstd.org/Dwarf3.pdf @unlink
|
| +/// @param data reference variable holding memory pointer to decode from
|
| +/// @param encoding dwarf encoding type
|
| +/// @returns decoded value
|
| +static
|
| +uintptr_t
|
| +readEncodedPointer(const uint8_t** data, uint8_t encoding)
|
| +{
|
| + uintptr_t result = 0;
|
| + if (encoding == DW_EH_PE_omit)
|
| + return result;
|
| + const uint8_t* p = *data;
|
| + // first get value
|
| + switch (encoding & 0x0F)
|
| + {
|
| + case DW_EH_PE_absptr:
|
| + result = *((uintptr_t*)p);
|
| + p += sizeof(uintptr_t);
|
| + break;
|
| + case DW_EH_PE_uleb128:
|
| + result = readULEB128(&p);
|
| + break;
|
| + case DW_EH_PE_sleb128:
|
| + result = static_cast<uintptr_t>(readSLEB128(&p));
|
| + break;
|
| + case DW_EH_PE_udata2:
|
| + result = *((uint16_t*)p);
|
| + p += sizeof(uint16_t);
|
| + break;
|
| + case DW_EH_PE_udata4:
|
| + result = *((uint32_t*)p);
|
| + p += sizeof(uint32_t);
|
| + break;
|
| + case DW_EH_PE_udata8:
|
| + result = static_cast<uintptr_t>(*((uint64_t*)p));
|
| + p += sizeof(uint64_t);
|
| + break;
|
| + case DW_EH_PE_sdata2:
|
| + result = static_cast<uintptr_t>(*((int16_t*)p));
|
| + p += sizeof(int16_t);
|
| + break;
|
| + case DW_EH_PE_sdata4:
|
| + result = static_cast<uintptr_t>(*((int32_t*)p));
|
| + p += sizeof(int32_t);
|
| + break;
|
| + case DW_EH_PE_sdata8:
|
| + result = static_cast<uintptr_t>(*((int64_t*)p));
|
| + p += sizeof(int64_t);
|
| + break;
|
| + default:
|
| + // not supported
|
| + abort();
|
| + break;
|
| + }
|
| + // then add relative offset
|
| + switch (encoding & 0x70)
|
| + {
|
| + case DW_EH_PE_absptr:
|
| + // do nothing
|
| + break;
|
| + case DW_EH_PE_pcrel:
|
| + if (result)
|
| + result += (uintptr_t)(*data);
|
| + break;
|
| + case DW_EH_PE_textrel:
|
| + case DW_EH_PE_datarel:
|
| + case DW_EH_PE_funcrel:
|
| + case DW_EH_PE_aligned:
|
| + default:
|
| + // not supported
|
| + abort();
|
| + break;
|
| + }
|
| + // then apply indirection
|
| + if (result && (encoding & DW_EH_PE_indirect))
|
| + result = *((uintptr_t*)result);
|
| + *data = p;
|
| + return result;
|
| +}
|
| +
|
| +static
|
| +void
|
| +call_terminate(bool native_exception, _Unwind_Exception* unwind_exception)
|
| +{
|
| + __cxa_begin_catch(unwind_exception);
|
| + if (native_exception)
|
| + {
|
| + // Use the stored terminate_handler if possible
|
| + __cxa_exception* exception_header = (__cxa_exception*)(unwind_exception+1) - 1;
|
| + std::__terminate(exception_header->terminateHandler);
|
| + }
|
| + std::terminate();
|
| +}
|
| +
|
| +static
|
| +const __shim_type_info*
|
| +get_shim_type_info(uint64_t ttypeIndex, const uint8_t* classInfo,
|
| + uint8_t ttypeEncoding, bool native_exception,
|
| + _Unwind_Exception* unwind_exception)
|
| +{
|
| + if (classInfo == 0)
|
| + {
|
| + // this should not happen. Indicates corrupted eh_table.
|
| + call_terminate(native_exception, unwind_exception);
|
| + }
|
| + switch (ttypeEncoding & 0x0F)
|
| + {
|
| + case DW_EH_PE_absptr:
|
| + ttypeIndex *= sizeof(void*);
|
| + break;
|
| + case DW_EH_PE_udata2:
|
| + case DW_EH_PE_sdata2:
|
| + ttypeIndex *= 2;
|
| + break;
|
| + case DW_EH_PE_udata4:
|
| + case DW_EH_PE_sdata4:
|
| + ttypeIndex *= 4;
|
| + break;
|
| + case DW_EH_PE_udata8:
|
| + case DW_EH_PE_sdata8:
|
| + ttypeIndex *= 8;
|
| + break;
|
| + default:
|
| + // this should not happen. Indicates corrupted eh_table.
|
| + call_terminate(native_exception, unwind_exception);
|
| + }
|
| + classInfo -= ttypeIndex;
|
| + return (const __shim_type_info*)readEncodedPointer(&classInfo, ttypeEncoding);
|
| +}
|
| +
|
| +/*
|
| + This is checking a thrown exception type, excpType, against a possibly empty
|
| + list of catchType's which make up an exception spec.
|
| +
|
| + An exception spec acts like a catch handler, but in reverse. This "catch
|
| + handler" will catch an excpType if and only if none of the catchType's in
|
| + the list will catch a excpType. If any catchType in the list can catch an
|
| + excpType, then this exception spec does not catch the excpType.
|
| +*/
|
| +static
|
| +bool
|
| +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)
|
| +{
|
| + if (classInfo == 0)
|
| + {
|
| + // this should not happen. Indicates corrupted eh_table.
|
| + call_terminate(false, unwind_exception);
|
| + }
|
| + // specIndex is negative of 1-based byte offset into classInfo;
|
| + specIndex = -specIndex;
|
| + --specIndex;
|
| + const uint8_t* temp = classInfo + specIndex;
|
| + // If any type in the spec list can catch excpType, return false, else return true
|
| + // adjustments to adjustedPtr are ignored.
|
| + while (true)
|
| + {
|
| + uint64_t ttypeIndex = readULEB128(&temp);
|
| + if (ttypeIndex == 0)
|
| + break;
|
| + const __shim_type_info* catchType = get_shim_type_info(ttypeIndex,
|
| + classInfo,
|
| + ttypeEncoding,
|
| + true,
|
| + unwind_exception);
|
| + void* tempPtr = adjustedPtr;
|
| + if (catchType->can_catch(excpType, tempPtr))
|
| + return false;
|
| + }
|
| + return true;
|
| +}
|
| +
|
| +static
|
| +void*
|
| +get_thrown_object_ptr(_Unwind_Exception* unwind_exception)
|
| +{
|
| + // Even for foreign exceptions, the exception object is *probably* at unwind_exception + 1
|
| + // Regardless, this library is prohibited from touching a foreign exception
|
| + void* adjustedPtr = unwind_exception + 1;
|
| + if (unwind_exception->exception_class == kOurDependentExceptionClass)
|
| + adjustedPtr = ((__cxa_dependent_exception*)adjustedPtr - 1)->primaryException;
|
| + return adjustedPtr;
|
| +}
|
| +
|
| +namespace
|
| +{
|
| +
|
| +struct scan_results
|
| +{
|
| + int64_t ttypeIndex; // > 0 catch handler, < 0 exception spec handler, == 0 a cleanup
|
| + 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
|
| + _Unwind_Reason_Code reason; // One of _URC_FATAL_PHASE1_ERROR,
|
| + // _URC_FATAL_PHASE2_ERROR,
|
| + // _URC_CONTINUE_UNWIND,
|
| + // _URC_HANDLER_FOUND
|
| +};
|
| +
|
| +} // unnamed namespace
|
| +
|
| +static
|
| +void
|
| +set_registers(_Unwind_Exception* unwind_exception, _Unwind_Context* context,
|
| + const scan_results& results)
|
| +{
|
| +#if __arm__
|
| + _Unwind_SetGR(context, 0, reinterpret_cast<uintptr_t>(unwind_exception));
|
| + _Unwind_SetGR(context, 1, static_cast<uintptr_t>(results.ttypeIndex));
|
| +#else
|
| + _Unwind_SetGR(context, __builtin_eh_return_data_regno(0),
|
| + reinterpret_cast<uintptr_t>(unwind_exception));
|
| + _Unwind_SetGR(context, __builtin_eh_return_data_regno(1),
|
| + static_cast<uintptr_t>(results.ttypeIndex));
|
| +#endif
|
| + _Unwind_SetIP(context, results.landingPad);
|
| +}
|
| +
|
| +/*
|
| + There are 3 types of scans needed:
|
| +
|
| + 1. Scan for handler with native or foreign exception. If handler found,
|
| + save state and return _URC_HANDLER_FOUND, else return _URC_CONTINUE_UNWIND.
|
| + May also report an error on invalid input.
|
| + May terminate for invalid exception table.
|
| + _UA_SEARCH_PHASE
|
| +
|
| + 2. Scan for handler with foreign exception. Must return _URC_HANDLER_FOUND,
|
| + or call terminate.
|
| + _UA_CLEANUP_PHASE && _UA_HANDLER_FRAME && !native_exception
|
| +
|
| + 3. Scan for cleanups. If a handler is found and this isn't forced unwind,
|
| + then terminate, otherwise ignore the handler and keep looking for cleanup.
|
| + If a cleanup is found, return _URC_HANDLER_FOUND, else return _URC_CONTINUE_UNWIND.
|
| + May also report an error on invalid input.
|
| + May terminate for invalid exception table.
|
| + _UA_CLEANUP_PHASE && !_UA_HANDLER_FRAME
|
| +*/
|
| +
|
| +static
|
| +void
|
| +scan_eh_tab(scan_results& results, _Unwind_Action actions, bool native_exception,
|
| + _Unwind_Exception* unwind_exception, _Unwind_Context* context)
|
| +{
|
| + // Initialize results to found nothing but an error
|
| + results.ttypeIndex = 0;
|
| + results.actionRecord = 0;
|
| + results.languageSpecificData = 0;
|
| + results.landingPad = 0;
|
| + results.adjustedPtr = 0;
|
| + results.reason = _URC_FATAL_PHASE1_ERROR;
|
| + // Check for consistent actions
|
| + if (actions & _UA_SEARCH_PHASE)
|
| + {
|
| + // Do Phase 1
|
| + if (actions & (_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME | _UA_FORCE_UNWIND))
|
| + {
|
| + // None of these flags should be set during Phase 1
|
| + // Client error
|
| + results.reason = _URC_FATAL_PHASE1_ERROR;
|
| + return;
|
| + }
|
| + }
|
| + else if (actions & _UA_CLEANUP_PHASE)
|
| + {
|
| + if ((actions & _UA_HANDLER_FRAME) && (actions & _UA_FORCE_UNWIND))
|
| + {
|
| + // _UA_HANDLER_FRAME should only be set if phase 1 found a handler.
|
| + // If _UA_FORCE_UNWIND is set, phase 1 shouldn't have happened.
|
| + // Client error
|
| + results.reason = _URC_FATAL_PHASE2_ERROR;
|
| + return;
|
| + }
|
| + }
|
| + else // Neither _UA_SEARCH_PHASE nor _UA_CLEANUP_PHASE is set
|
| + {
|
| + // One of these should be set.
|
| + // Client error
|
| + results.reason = _URC_FATAL_PHASE1_ERROR;
|
| + return;
|
| + }
|
| + // Start scan by getting exception table address
|
| + const uint8_t* lsda = (const uint8_t*)_Unwind_GetLanguageSpecificData(context);
|
| + if (lsda == 0)
|
| + {
|
| + // There is no exception table
|
| + results.reason = _URC_CONTINUE_UNWIND;
|
| + return;
|
| + }
|
| + results.languageSpecificData = lsda;
|
| + // Get the current instruction pointer and offset it before next
|
| + // instruction in the current frame which threw the exception.
|
| + uintptr_t ip = _Unwind_GetIP(context) - 1;
|
| + // Get beginning current frame's code (as defined by the
|
| + // emitted dwarf code)
|
| + uintptr_t funcStart = _Unwind_GetRegionStart(context);
|
| +#if __arm__
|
| + if (ip == uintptr_t(-1))
|
| + {
|
| + // no action
|
| + results.reason = _URC_CONTINUE_UNWIND;
|
| + return;
|
| + }
|
| + else if (ip == 0)
|
| + call_terminate(native_exception, unwind_exception);
|
| + // ip is 1-based index into call site table
|
| +#else // __arm__
|
| + uintptr_t ipOffset = ip - funcStart;
|
| +#endif // __arm__
|
| + const uint8_t* classInfo = NULL;
|
| + // Note: See JITDwarfEmitter::EmitExceptionTable(...) for corresponding
|
| + // dwarf emission
|
| + // Parse LSDA header.
|
| + uint8_t lpStartEncoding = *lsda++;
|
| + const uint8_t* lpStart = (const uint8_t*)readEncodedPointer(&lsda, lpStartEncoding);
|
| + if (lpStart == 0)
|
| + lpStart = (const uint8_t*)funcStart;
|
| + uint8_t ttypeEncoding = *lsda++;
|
| + if (ttypeEncoding != DW_EH_PE_omit)
|
| + {
|
| + // Calculate type info locations in emitted dwarf code which
|
| + // were flagged by type info arguments to llvm.eh.selector
|
| + // intrinsic
|
| + uintptr_t classInfoOffset = readULEB128(&lsda);
|
| + classInfo = lsda + classInfoOffset;
|
| + }
|
| + // Walk call-site table looking for range that
|
| + // includes current PC.
|
| + uint8_t callSiteEncoding = *lsda++;
|
| +#if __arm__
|
| + (void)callSiteEncoding; // On arm callSiteEncoding is never used
|
| +#endif
|
| + uint32_t callSiteTableLength = static_cast<uint32_t>(readULEB128(&lsda));
|
| + const uint8_t* callSiteTableStart = lsda;
|
| + const uint8_t* callSiteTableEnd = callSiteTableStart + callSiteTableLength;
|
| + const uint8_t* actionTableStart = callSiteTableEnd;
|
| + const uint8_t* callSitePtr = callSiteTableStart;
|
| + while (callSitePtr < callSiteTableEnd)
|
| + {
|
| + // There is one entry per call site.
|
| +#if !__arm__
|
| + // The call sites are non-overlapping in [start, start+length)
|
| + // The call sites are ordered in increasing value of start
|
| + uintptr_t start = readEncodedPointer(&callSitePtr, callSiteEncoding);
|
| + uintptr_t length = readEncodedPointer(&callSitePtr, callSiteEncoding);
|
| + uintptr_t landingPad = readEncodedPointer(&callSitePtr, callSiteEncoding);
|
| + uintptr_t actionEntry = readULEB128(&callSitePtr);
|
| + if ((start <= ipOffset) && (ipOffset < (start + length)))
|
| +#else // __arm__
|
| + // ip is 1-based index into this table
|
| + uintptr_t landingPad = readULEB128(&callSitePtr);
|
| + uintptr_t actionEntry = readULEB128(&callSitePtr);
|
| + if (--ip == 0)
|
| +#endif // __arm__
|
| + {
|
| + // Found the call site containing ip.
|
| +#if !__arm__
|
| + if (landingPad == 0)
|
| + {
|
| + // No handler here
|
| + results.reason = _URC_CONTINUE_UNWIND;
|
| + return;
|
| + }
|
| + landingPad = (uintptr_t)lpStart + landingPad;
|
| +#else // __arm__
|
| + ++landingPad;
|
| +#endif // __arm__
|
| + if (actionEntry == 0)
|
| + {
|
| + // Found a cleanup
|
| + // If this is a type 1 or type 2 search, there are no handlers
|
| + // If this is a type 3 search, you want to install the cleanup.
|
| + if ((actions & _UA_CLEANUP_PHASE) && !(actions & _UA_HANDLER_FRAME))
|
| + {
|
| + results.ttypeIndex = 0; // Redundant but clarifying
|
| + results.landingPad = landingPad;
|
| + results.reason = _URC_HANDLER_FOUND;
|
| + return;
|
| + }
|
| + // No handler here
|
| + results.reason = _URC_CONTINUE_UNWIND;
|
| + return;
|
| + }
|
| + // Convert 1-based byte offset into
|
| + const uint8_t* action = actionTableStart + (actionEntry - 1);
|
| + // Scan action entries until you find a matching handler, cleanup, or the end of action list
|
| + while (true)
|
| + {
|
| + const uint8_t* actionRecord = action;
|
| + int64_t ttypeIndex = readSLEB128(&action);
|
| + if (ttypeIndex > 0)
|
| + {
|
| + // Found a catch, does it actually catch?
|
| + // First check for catch (...)
|
| + const __shim_type_info* catchType =
|
| + get_shim_type_info(static_cast<uint64_t>(ttypeIndex),
|
| + classInfo, ttypeEncoding,
|
| + native_exception, unwind_exception);
|
| + if (catchType == 0)
|
| + {
|
| + // Found catch (...) catches everything, including foreign exceptions
|
| + // If this is a type 1 search save state and return _URC_HANDLER_FOUND
|
| + // If this is a type 2 search save state and return _URC_HANDLER_FOUND
|
| + // If this is a type 3 search !_UA_FORCE_UNWIND, we should have found this in phase 1!
|
| + // If this is a type 3 search _UA_FORCE_UNWIND, ignore handler and continue scan
|
| + if ((actions & _UA_SEARCH_PHASE) || (actions & _UA_HANDLER_FRAME))
|
| + {
|
| + // Save state and return _URC_HANDLER_FOUND
|
| + results.ttypeIndex = ttypeIndex;
|
| + results.actionRecord = actionRecord;
|
| + results.landingPad = landingPad;
|
| + results.adjustedPtr = get_thrown_object_ptr(unwind_exception);
|
| + results.reason = _URC_HANDLER_FOUND;
|
| + return;
|
| + }
|
| + else if (!(actions & _UA_FORCE_UNWIND))
|
| + {
|
| + // It looks like the exception table has changed
|
| + // on us. Likely stack corruption!
|
| + call_terminate(native_exception, unwind_exception);
|
| + }
|
| + }
|
| + // Else this is a catch (T) clause and will never
|
| + // catch a foreign exception
|
| + else if (native_exception)
|
| + {
|
| + __cxa_exception* exception_header = (__cxa_exception*)(unwind_exception+1) - 1;
|
| + void* adjustedPtr = get_thrown_object_ptr(unwind_exception);
|
| + const __shim_type_info* excpType =
|
| + static_cast<const __shim_type_info*>(exception_header->exceptionType);
|
| + if (adjustedPtr == 0 || excpType == 0)
|
| + {
|
| + // Something very bad happened
|
| + call_terminate(native_exception, unwind_exception);
|
| + }
|
| + if (catchType->can_catch(excpType, adjustedPtr))
|
| + {
|
| + // Found a matching handler
|
| + // If this is a type 1 search save state and return _URC_HANDLER_FOUND
|
| + // If this is a type 3 search and !_UA_FORCE_UNWIND, we should have found this in phase 1!
|
| + // If this is a type 3 search and _UA_FORCE_UNWIND, ignore handler and continue scan
|
| + if (actions & _UA_SEARCH_PHASE)
|
| + {
|
| + // Save state and return _URC_HANDLER_FOUND
|
| + results.ttypeIndex = ttypeIndex;
|
| + results.actionRecord = actionRecord;
|
| + results.landingPad = landingPad;
|
| + results.adjustedPtr = adjustedPtr;
|
| + results.reason = _URC_HANDLER_FOUND;
|
| + return;
|
| + }
|
| + else if (!(actions & _UA_FORCE_UNWIND))
|
| + {
|
| + // It looks like the exception table has changed
|
| + // on us. Likely stack corruption!
|
| + call_terminate(native_exception, unwind_exception);
|
| + }
|
| + }
|
| + }
|
| + // Scan next action ...
|
| + }
|
| + else if (ttypeIndex < 0)
|
| + {
|
| + // Found an exception spec. If this is a foreign exception,
|
| + // it is always caught.
|
| + if (native_exception)
|
| + {
|
| + // Does the exception spec catch this native exception?
|
| + __cxa_exception* exception_header = (__cxa_exception*)(unwind_exception+1) - 1;
|
| + void* adjustedPtr = get_thrown_object_ptr(unwind_exception);
|
| + const __shim_type_info* excpType =
|
| + static_cast<const __shim_type_info*>(exception_header->exceptionType);
|
| + if (adjustedPtr == 0 || excpType == 0)
|
| + {
|
| + // Something very bad happened
|
| + call_terminate(native_exception, unwind_exception);
|
| + }
|
| + if (exception_spec_can_catch(ttypeIndex, classInfo,
|
| + ttypeEncoding, excpType,
|
| + adjustedPtr, unwind_exception))
|
| + {
|
| + // native exception caught by exception spec
|
| + // If this is a type 1 search, save state and return _URC_HANDLER_FOUND
|
| + // If this is a type 3 search !_UA_FORCE_UNWIND, we should have found this in phase 1!
|
| + // If this is a type 3 search _UA_FORCE_UNWIND, ignore handler and continue scan
|
| + if (actions & _UA_SEARCH_PHASE)
|
| + {
|
| + // Save state and return _URC_HANDLER_FOUND
|
| + results.ttypeIndex = ttypeIndex;
|
| + results.actionRecord = actionRecord;
|
| + results.landingPad = landingPad;
|
| + results.adjustedPtr = adjustedPtr;
|
| + results.reason = _URC_HANDLER_FOUND;
|
| + return;
|
| + }
|
| + else if (!(actions & _UA_FORCE_UNWIND))
|
| + {
|
| + // It looks like the exception table has changed
|
| + // on us. Likely stack corruption!
|
| + call_terminate(native_exception, unwind_exception);
|
| + }
|
| + }
|
| + }
|
| + else
|
| + {
|
| + // foreign exception caught by exception spec
|
| + // If this is a type 1 search, save state and return _URC_HANDLER_FOUND
|
| + // If this is a type 2 search, save state and return _URC_HANDLER_FOUND
|
| + // If this is a type 3 search !_UA_FORCE_UNWIND, we should have found this in phase 1!
|
| + // If this is a type 3 search _UA_FORCE_UNWIND, ignore handler and continue scan
|
| + if ((actions & _UA_SEARCH_PHASE) || (actions & _UA_HANDLER_FRAME))
|
| + {
|
| + // Save state and return _URC_HANDLER_FOUND
|
| + results.ttypeIndex = ttypeIndex;
|
| + results.actionRecord = actionRecord;
|
| + results.landingPad = landingPad;
|
| + results.adjustedPtr = get_thrown_object_ptr(unwind_exception);
|
| + results.reason = _URC_HANDLER_FOUND;
|
| + return;
|
| + }
|
| + else if (!(actions & _UA_FORCE_UNWIND))
|
| + {
|
| + // It looks like the exception table has changed
|
| + // on us. Likely stack corruption!
|
| + call_terminate(native_exception, unwind_exception);
|
| + }
|
| + }
|
| + // Scan next action ...
|
| + }
|
| + else // ttypeIndex == 0
|
| + {
|
| + // Found a cleanup
|
| + // If this is a type 1 search, ignore it and continue scan
|
| + // If this is a type 2 search, ignore it and continue scan
|
| + // If this is a type 3 search, save state and return _URC_HANDLER_FOUND
|
| + if ((actions & _UA_CLEANUP_PHASE) && !(actions & _UA_HANDLER_FRAME))
|
| + {
|
| + // Save state and return _URC_HANDLER_FOUND
|
| + results.ttypeIndex = ttypeIndex;
|
| + results.actionRecord = actionRecord;
|
| + results.landingPad = landingPad;
|
| + results.adjustedPtr = get_thrown_object_ptr(unwind_exception);
|
| + results.reason = _URC_HANDLER_FOUND;
|
| + return;
|
| + }
|
| + }
|
| + const uint8_t* temp = action;
|
| + int64_t actionOffset = readSLEB128(&temp);
|
| + if (actionOffset == 0)
|
| + {
|
| + // End of action list, no matching handler or cleanup found
|
| + results.reason = _URC_CONTINUE_UNWIND;
|
| + return;
|
| + }
|
| + // Go to next action
|
| + action += actionOffset;
|
| + } // there is no break out of this loop, only return
|
| + }
|
| +#if !__arm__
|
| + else if (ipOffset < start)
|
| + {
|
| + // There is no call site for this ip
|
| + // Something bad has happened. We should never get here.
|
| + // Possible stack corruption.
|
| + call_terminate(native_exception, unwind_exception);
|
| + }
|
| +#endif // !__arm__
|
| + } // there might be some tricky cases which break out of this loop
|
| +
|
| + // It is possible that no eh table entry specify how to handle
|
| + // this exception. By spec, terminate it immediately.
|
| + call_terminate(native_exception, unwind_exception);
|
| +}
|
| +
|
| +// public API
|
| +
|
| +/*
|
| +The personality function branches on actions like so:
|
| +
|
| +_UA_SEARCH_PHASE
|
| +
|
| + If _UA_CLEANUP_PHASE or _UA_HANDLER_FRAME or _UA_FORCE_UNWIND there's
|
| + an error from above, return _URC_FATAL_PHASE1_ERROR.
|
| +
|
| + Scan for anything that could stop unwinding:
|
| +
|
| + 1. A catch clause that will catch this exception
|
| + (will never catch foreign).
|
| + 2. A catch (...) (will always catch foreign).
|
| + 3. An exception spec that will catch this exception
|
| + (will always catch foreign).
|
| + If a handler is found
|
| + If not foreign
|
| + Save state in header
|
| + return _URC_HANDLER_FOUND
|
| + Else a handler not found
|
| + return _URC_CONTINUE_UNWIND
|
| +
|
| +_UA_CLEANUP_PHASE
|
| +
|
| + If _UA_HANDLER_FRAME
|
| + If _UA_FORCE_UNWIND
|
| + How did this happen? return _URC_FATAL_PHASE2_ERROR
|
| + If foreign
|
| + Do _UA_SEARCH_PHASE to recover state
|
| + else
|
| + Recover state from header
|
| + Transfer control to landing pad. return _URC_INSTALL_CONTEXT
|
| +
|
| + Else
|
| +
|
| + This branch handles both normal C++ non-catching handlers (cleanups)
|
| + and forced unwinding.
|
| + Scan for anything that can not stop unwinding:
|
| +
|
| + 1. A cleanup.
|
| +
|
| + If a cleanup is found
|
| + transfer control to it. return _URC_INSTALL_CONTEXT
|
| + Else a cleanup is not found: return _URC_CONTINUE_UNWIND
|
| +*/
|
| +
|
| +_Unwind_Reason_Code
|
| +#if __arm__
|
| +__gxx_personality_sj0
|
| +#else
|
| +__gxx_personality_v0
|
| +#endif
|
| + (int version, _Unwind_Action actions, uint64_t exceptionClass,
|
| + _Unwind_Exception* unwind_exception, _Unwind_Context* context)
|
| +{
|
| + if (version != 1 || unwind_exception == 0 || context == 0)
|
| + return _URC_FATAL_PHASE1_ERROR;
|
| + bool native_exception = (exceptionClass & get_vendor_and_language) ==
|
| + (kOurExceptionClass & get_vendor_and_language);
|
| + 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;
|
| + exception_header->handlerSwitchValue = static_cast<int>(results.ttypeIndex);
|
| + exception_header->actionRecord = results.actionRecord;
|
| + exception_header->languageSpecificData = results.languageSpecificData;
|
| + exception_header->catchTemp = reinterpret_cast<void*>(results.landingPad);
|
| + exception_header->adjustedPtr = results.adjustedPtr;
|
| + }
|
| + 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;
|
| + results.languageSpecificData = exception_header->languageSpecificData;
|
| + results.landingPad = reinterpret_cast<uintptr_t>(exception_header->catchTemp);
|
| + results.adjustedPtr = exception_header->adjustedPtr;
|
| + }
|
| + 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
|
| + set_registers(unwind_exception, context, results);
|
| + 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:
|
| + set_registers(unwind_exception, context, results);
|
| + 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;
|
| + }
|
| + // We were called improperly: neither a phase 1 or phase 2 search
|
| + return _URC_FATAL_PHASE1_ERROR;
|
| +}
|
| +
|
| +__attribute__((noreturn))
|
| +void
|
| +__cxa_call_unexpected(void* arg)
|
| +{
|
| + _Unwind_Exception* unwind_exception = static_cast<_Unwind_Exception*>(arg);
|
| + if (unwind_exception == 0)
|
| + call_terminate(false, unwind_exception);
|
| + __cxa_begin_catch(unwind_exception);
|
| + bool native_old_exception =
|
| + (unwind_exception->exception_class & get_vendor_and_language) ==
|
| + (kOurExceptionClass & get_vendor_and_language);
|
| + std::unexpected_handler u_handler;
|
| + std::terminate_handler t_handler;
|
| + __cxa_exception* old_exception_header = 0;
|
| + int64_t ttypeIndex;
|
| + const uint8_t* lsda;
|
| + if (native_old_exception)
|
| + {
|
| + old_exception_header = (__cxa_exception*)(unwind_exception+1) - 1;
|
| + t_handler = old_exception_header->terminateHandler;
|
| + u_handler = old_exception_header->unexpectedHandler;
|
| + // If std::__unexpected(u_handler) rethrows the same exception,
|
| + // these values get overwritten by the rethrow. So save them now:
|
| + ttypeIndex = old_exception_header->handlerSwitchValue;
|
| + lsda = old_exception_header->languageSpecificData;
|
| + }
|
| + else
|
| + {
|
| + t_handler = std::get_terminate();
|
| + u_handler = std::get_unexpected();
|
| + }
|
| + try
|
| + {
|
| + std::__unexpected(u_handler);
|
| + }
|
| + catch (...)
|
| + {
|
| + // If the old exception is foreign, then all we can do is terminate.
|
| + // We have no way to recover the needed old exception spec. There's
|
| + // no way to pass that information here. And the personality routine
|
| + // can't call us directly and do anything but terminate() if we throw
|
| + // from here.
|
| + if (native_old_exception)
|
| + {
|
| + // Have:
|
| + // old_exception_header->languageSpecificData
|
| + // old_exception_header->actionRecord
|
| + // Need
|
| + // const uint8_t* classInfo
|
| + // uint8_t ttypeEncoding
|
| + uint8_t lpStartEncoding = *lsda++;
|
| + const uint8_t* lpStart = (const uint8_t*)readEncodedPointer(&lsda, lpStartEncoding);
|
| + (void)lpStart; // purposefully unused. Just needed to increment lsda.
|
| + uint8_t ttypeEncoding = *lsda++;
|
| + if (ttypeEncoding == DW_EH_PE_omit)
|
| + std::__terminate(t_handler);
|
| + uintptr_t classInfoOffset = readULEB128(&lsda);
|
| + const uint8_t* classInfo = lsda + classInfoOffset;
|
| + // Is this new exception catchable by the exception spec at ttypeIndex?
|
| + // The answer is obviously yes if the new and old exceptions are the same exception
|
| + // If no
|
| + // throw;
|
| + __cxa_eh_globals* globals = __cxa_get_globals_fast();
|
| + __cxa_exception* new_exception_header = globals->caughtExceptions;
|
| + if (new_exception_header == 0)
|
| + // This shouldn't be able to happen!
|
| + std::__terminate(t_handler);
|
| + bool native_new_exception =
|
| + (new_exception_header->unwindHeader.exception_class & get_vendor_and_language) ==
|
| + (kOurExceptionClass & get_vendor_and_language);
|
| + void* adjustedPtr;
|
| + if (native_new_exception && (new_exception_header != old_exception_header))
|
| + {
|
| + const __shim_type_info* excpType =
|
| + static_cast<const __shim_type_info*>(new_exception_header->exceptionType);
|
| + adjustedPtr =
|
| + new_exception_header->unwindHeader.exception_class == kOurDependentExceptionClass ?
|
| + ((__cxa_dependent_exception*)new_exception_header)->primaryException :
|
| + new_exception_header + 1;
|
| + if (!exception_spec_can_catch(ttypeIndex, classInfo, ttypeEncoding,
|
| + excpType, adjustedPtr, unwind_exception))
|
| + {
|
| + // We need to __cxa_end_catch, but for the old exception,
|
| + // not the new one. This is a little tricky ...
|
| + // Disguise new_exception_header as a rethrown exception, but
|
| + // don't actually rethrow it. This means you can temporarily
|
| + // end the catch clause enclosing new_exception_header without
|
| + // __cxa_end_catch destroying new_exception_header.
|
| + new_exception_header->handlerCount = -new_exception_header->handlerCount;
|
| + globals->uncaughtExceptions += 1;
|
| + // Call __cxa_end_catch for new_exception_header
|
| + __cxa_end_catch();
|
| + // Call __cxa_end_catch for old_exception_header
|
| + __cxa_end_catch();
|
| + // Renter this catch clause with new_exception_header
|
| + __cxa_begin_catch(&new_exception_header->unwindHeader);
|
| + // Rethrow new_exception_header
|
| + throw;
|
| + }
|
| + }
|
| + // Will a std::bad_exception be catchable by the exception spec at
|
| + // ttypeIndex?
|
| + // If no
|
| + // throw std::bad_exception();
|
| + const __shim_type_info* excpType =
|
| + static_cast<const __shim_type_info*>(&typeid(std::bad_exception));
|
| + std::bad_exception be;
|
| + adjustedPtr = &be;
|
| + if (!exception_spec_can_catch(ttypeIndex, classInfo, ttypeEncoding,
|
| + excpType, adjustedPtr, unwind_exception))
|
| + {
|
| + // We need to __cxa_end_catch for both the old exception and the
|
| + // new exception. Technically we should do it in that order.
|
| + // But it is expedient to do it in the opposite order:
|
| + // Call __cxa_end_catch for new_exception_header
|
| + __cxa_end_catch();
|
| + // Throw std::bad_exception will __cxa_end_catch for
|
| + // old_exception_header
|
| + throw be;
|
| + }
|
| + }
|
| + }
|
| + std::__terminate(t_handler);
|
| +}
|
| +
|
| +} // extern "C"
|
| +
|
| +} // __cxxabiv1
|
|
|
| Property changes on: third_party/libc++abi/src/cxa_personality.cpp
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
|
|
|