113 lines
3.2 KiB
C
113 lines
3.2 KiB
C
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int
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__except_handler3(
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struct _EXCEPTION_RECORD* pExceptionRecord,
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struct EXCEPTION_REGISTRATION* pRegistrationFrame,
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struct _CONTEXT* pContextRecord,
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void* pDispatcherContext
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)
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{
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LONG filterFuncRet;
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LONG trylevel;
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EXCEPTION_POINTERS exceptPtrs;
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PSCOPETABLE pScopeTable;
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CLD // Clear the direction flag (make no assumptions!)
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// if neither the EXCEPTION_UNWINDING nor EXCEPTION_EXIT_UNWIND bit
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// is set... This is true the first time through the handler (the
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// non-unwinding case)
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if ( ! (pExceptionRecord->ExceptionFlags
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& (EXCEPTION_UNWINDING | EXCEPTION_EXIT_UNWIND)
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) )
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{
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// Build the EXCEPTION_POINTERS structure on the stack
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exceptPtrs.ExceptionRecord = pExceptionRecord;
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exceptPtrs.ContextRecord = pContextRecord;
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// Put the pointer to the EXCEPTION_POINTERS 4 bytes below the
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// establisher frame. See ASM code for GetExceptionInformation
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*(PDWORD)((PBYTE)pRegistrationFrame - 4) = &exceptPtrs;
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// Get initial "trylevel" value
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trylevel = pRegistrationFrame->trylevel
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// Get a pointer to the scopetable array
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scopeTable = pRegistrationFrame->scopetable;
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search_for_handler:
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if ( pRegistrationFrame->trylevel != TRYLEVEL_NONE )
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{
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if ( pRegistrationFrame->scopetable[trylevel].lpfnFilter )
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{
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PUSH EBP // Save this frame EBP
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// !!!Very Important!!! Switch to original EBP. This is
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// what allows all locals in the frame to have the same
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// value as before the exception occurred.
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EBP = &pRegistrationFrame->_ebp
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// Call the filter function
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filterFuncRet = scopetable[trylevel].lpfnFilter();
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POP EBP // Restore handler frame EBP
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if ( filterFuncRet != EXCEPTION_CONTINUE_SEARCH )
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{
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if ( filterFuncRet < 0 ) // EXCEPTION_CONTINUE_EXECUTION
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return ExceptionContinueExecution;
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// If we get here, EXCEPTION_EXECUTE_HANDLER was specified
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scopetable == pRegistrationFrame->scopetable
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// Does the actual OS cleanup of registration frames
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// Causes this function to recurse
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__global_unwind2( pRegistrationFrame );
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// Once we get here, everything is all cleaned up, except
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// for the last frame, where we'll continue execution
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EBP = &pRegistrationFrame->_ebp
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__local_unwind2( pRegistrationFrame, trylevel );
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// NLG == "non-local-goto" (setjmp/longjmp stuff)
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__NLG_Notify( 1 ); // EAX == scopetable->lpfnHandler
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// Set the current trylevel to whatever SCOPETABLE entry
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// was being used when a handler was found
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pRegistrationFrame->trylevel = scopetable->previousTryLevel;
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// Call the _except {} block. Never returns.
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pRegistrationFrame->scopetable[trylevel].lpfnHandler();
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}
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}
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scopeTable = pRegistrationFrame->scopetable;
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trylevel = scopeTable->previousTryLevel
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goto search_for_handler;
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}
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else // trylevel == TRYLEVEL_NONE
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{
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retvalue == DISPOSITION_CONTINUE_SEARCH;
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}
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}
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else // EXCEPTION_UNWINDING or EXCEPTION_EXIT_UNWIND flags are set
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{
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PUSH EBP // Save EBP
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EBP = pRegistrationFrame->_ebp // Set EBP for __local_unwind2
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__local_unwind2( pRegistrationFrame, TRYLEVEL_NONE )
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POP EBP // Restore EBP
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retvalue == DISPOSITION_CONTINUE_SEARCH;
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}
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}
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