108 lines
5.8 KiB
C
108 lines
5.8 KiB
C
/*++
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Copyright (c) 1990 Microsoft Corporation
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Module Name:
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chandler.c
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Abstract:
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This module implements the C specific exception handler that provides structured condition handling for the C language.
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Author:
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David N. Cutler (davec) 11-Sep-1990
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Environment:
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Any mode.
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--*/
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#include "nt.h"
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// Define procedure prototypes for exception filter and termination handler
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// execution routines defined in jmpunwnd.s
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LONG __C_ExecuteExceptionFilter (PEXCEPTION_POINTERS ExceptionPointers, EXCEPTION_FILTER ExceptionFilter, ULONG EstablisherFrame);
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VOID __C_ExecuteTerminationHandler (BOOLEAN AbnormalTermination, TERMINATION_HANDLER TerminationHandler, ULONG EstablisherFrame);
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EXCEPTION_DISPOSITION __C_specific_handler (IN PEXCEPTION_RECORD ExceptionRecord, IN PVOID EstablisherFrame, IN OUT PCONTEXT ContextRecord, IN OUT PDISPATCHER_CONTEXT DispatcherContext)
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/*++
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Routine Description:
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This function scans the scope tables associated with the specified procedure and calls exception and termination handlers as necessary.
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Arguments:
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ExceptionRecord - Supplies a pointer to an exception record.
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EstablisherFrame - Supplies a pointer to frame of the establisher function.
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ContextRecord - Supplies a pointer to a context record.
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DispatcherContext - Supplies a pointer to the exception dispatcher or unwind dispatcher context.
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Return Value:
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If the exception is handled by one of the exception filter routines, then there is no return from this routine and RtlUnwind is called.
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Otherwise, an exception disposition value of continue execution or continue search is returned.
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--*/
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{
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ULONG ControlPc;
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EXCEPTION_FILTER ExceptionFilter;
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EXCEPTION_POINTERS ExceptionPointers;
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PRUNTIME_FUNCTION FunctionEntry;
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ULONG Index;
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PSCOPE_TABLE ScopeTable;
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ULONG TargetPc;
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TERMINATION_HANDLER TerminationHandler;
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LONG Value;
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// Get address of where control left the establisher, the address of the function table entry that describes the function, and the address of the scope table.
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ControlPc = DispatcherContext->ControlPc;
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FunctionEntry = DispatcherContext->FunctionEntry;
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ScopeTable = (PSCOPE_TABLE)(FunctionEntry->HandlerData);
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// If an unwind is not in progress, then scan the scope table and call the appropriate exception filter routines. Otherwise, scan the scope
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// table and call the appropriate termination handlers using the target PC obtained from the context record.
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// are called.
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if (IS_DISPATCHING(ExceptionRecord->ExceptionFlags)) {
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// Scan the scope table and call the appropriate exception filter routines.
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ExceptionPointers.ExceptionRecord = ExceptionRecord;
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ExceptionPointers.ContextRecord = ContextRecord;
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for (Index = 0; Index < ScopeTable->Count; Index += 1) {
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if ((ControlPc >= ScopeTable->ScopeRecord[Index].BeginAddress) && (ControlPc < ScopeTable->ScopeRecord[Index].EndAddress) && (ScopeTable->ScopeRecord[Index].JumpTarget != 0)) {
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// Call the exception filter routine.
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ExceptionFilter = (EXCEPTION_FILTER)ScopeTable->ScopeRecord[Index].HandlerAddress;
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Value = __C_ExecuteExceptionFilter(&ExceptionPointers, ExceptionFilter, (ULONG)EstablisherFrame);
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// If the return value is less than zero, then dismiss the exception.
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// Otherwise, if the value is greater than zero, then unwind to the target exception handler.
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// Otherwise, continue the search for an exception filter.
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if (Value < 0) {
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return ExceptionContinueExecution;
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} else if (Value > 0) {
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RtlUnwind2(EstablisherFrame, (PVOID)ScopeTable->ScopeRecord[Index].JumpTarget, ExceptionRecord, (PVOID)ExceptionRecord->ExceptionCode, ContextRecord);
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}
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}
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}
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} else {
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// Scan the scope table and call the appropriate termination handler routines.
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TargetPc = ContextRecord->Fir;
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for (Index = 0; Index < ScopeTable->Count; Index += 1) {
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if ((ControlPc >= ScopeTable->ScopeRecord[Index].BeginAddress) && (ControlPc < ScopeTable->ScopeRecord[Index].EndAddress)) {
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// If the target PC is within the same scope the control PC is within, then this is an uplevel goto out of an inner try scope or a long jump back into a try scope.
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// Terminate the scan termination handlers.
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// N.B. The target PC can be just beyond the end of the scope, in which case it is a leave from the scope.
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if ((TargetPc >= ScopeTable->ScopeRecord[Index].BeginAddress) && (TargetPc <= ScopeTable->ScopeRecord[Index].EndAddress)) {
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break;
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} else {
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// If the scope table entry describes an exception filter and the associated exception handler is the target of
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// the unwind, then terminate the scan for termination handlers. Otherwise, if the scope table entry describes
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// a termination handler, then record the address of the end of the scope as the new control PC address and call the termination handler.
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if (ScopeTable->ScopeRecord[Index].JumpTarget != 0) {
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if (TargetPc == ScopeTable->ScopeRecord[Index].JumpTarget) {
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break;
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}
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} else {
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DispatcherContext->ControlPc = ScopeTable->ScopeRecord[Index].EndAddress + 4;
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TerminationHandler = (TERMINATION_HANDLER)ScopeTable->ScopeRecord[Index].HandlerAddress;
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__C_ExecuteTerminationHandler(TRUE, TerminationHandler, (ULONG)EstablisherFrame);
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}
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}
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}
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}
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}
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return ExceptionContinueSearch;// Continue search for exception or termination handlers.
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} |