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-rw-r--r--system/lib/libcxxabi/src/cxa_personality.cpp987
1 files changed, 987 insertions, 0 deletions
diff --git a/system/lib/libcxxabi/src/cxa_personality.cpp b/system/lib/libcxxabi/src/cxa_personality.cpp
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+++ b/system/lib/libcxxabi/src/cxa_personality.cpp
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+//===------------------------- 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 wtih 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 |
++---------------------+-----------+------------------------------------------------+--+
+| Beginning of Call Site Table If 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) | lenght of code fragment | |
+| | landingPad | (encoded with callSiteEncoding) | offset relative to lpStart | |
+| | actionEntry | (ULEB128) | Action Table Index 1-based | |
+| | | | actionEntry == 0 -> cleanup | |
+| +-------------+---------------------------------+------------------------------+ |
+| ... |
++---------------------------------------------------------------------+------------+
+| 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 Applendix 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
+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 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 = 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 = *((uint64_t*)p);
+ p += sizeof(uint64_t);
+ break;
+ case DW_EH_PE_sdata2:
+ result = *((int16_t*)p);
+ p += sizeof(int16_t);
+ break;
+ case DW_EH_PE_sdata4:
+ result = *((int32_t*)p);
+ p += sizeof(int32_t);
+ break;
+ case DW_EH_PE_sdata8:
+ result = *((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(int64_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 posibly 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;
+}
+
+/*
+ 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
+*/
+
+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
+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 // Niether _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);
+ uintptr_t ipOffset = ip - funcStart;
+ 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++;
+ uint32_t callSiteTableLength = readULEB128(&lsda);
+ const uint8_t* callSiteTableStart = lsda;
+ const uint8_t* callSiteTableEnd = callSiteTableStart + callSiteTableLength;
+ const uint8_t* actionTableStart = callSiteTableEnd;
+ const uint8_t* callSitePtr = callSiteTableStart;
+ while (true)
+ {
+ // There is one entry per call site.
+ // 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)))
+ {
+ // Found the call site containing ip.
+ if (landingPad == 0)
+ {
+ // No handler here
+ results.reason = _URC_CONTINUE_UNWIND;
+ return;
+ }
+ landingPad = (uintptr_t)lpStart + landingPad;
+ 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(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
+ }
+ 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);
+ }
+ } // there is no break out of this loop, only return
+}
+
+// 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
+__gxx_personality_v0(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
+ _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;
+ }
+ // 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,
+