mirror of http://192.168.1.51:8099/lmh188/twain3.0
141 lines
3.7 KiB
C
141 lines
3.7 KiB
C
/*++
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Copyright (c) 1994 Microsoft Corporation
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Module Name:
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Except.h
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Abstract:
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This module prototypes the macros and routines used for exception handling.
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Author:
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Revision History:
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--*/
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#ifndef _EXCEPTION_STUFF_DEFINED_
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#define _EXCEPTION_STUFF_DEFINED_
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//
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// The following two macro are used by the Fsd/Fsp exception handlers to
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// process an exception. The first macro is the exception filter used in the
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// Fsd/Fsp to decide if an exception should be handled at this level.
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// The second macro decides if the exception is to be finished off by
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// completing the IRP, and cleaning up the Irp Context, or if we should
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// bugcheck. Exception values such as RxStatus(FILE_INVALID) (raised by
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// VerfySup.c) cause us to complete the Irp and cleanup, while exceptions
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// such as accvio cause us to bugcheck.
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//
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// The basic structure for fsd/fsp exception handling is as follows:
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//
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// RxFsdXxx(...)
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// {
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// try {
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//
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// ...
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//
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// } except(RxExceptionFilter( RxContext, GetExceptionCode() )) {
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//
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// Status = RxProcessException( RxContext, GetExceptionCode() );
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// }
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//
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// Return Status;
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// }
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//
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// To explicitly raise an exception that we expect, such as
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// RxStatus(FILE_INVALID), use the below macro RxRaiseStatus(). To raise a
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// status from an unknown origin (such as CcFlushCache()), use the macro
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// RxNormalizeAndRaiseStatus. This will raise the status if it is expected,
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// or raise RxStatus(UNEXPECTED_IO_ERROR) if it is not.
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//
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// Note that when using these two macros, the original status is placed in
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// RxContext->ExceptionStatus, signaling RxExceptionFilter and
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// RxProcessException that the status we actually raise is by definition
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// expected.
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//
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LONG
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RxExceptionFilter (
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IN PRX_CONTEXT RxContext,
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IN PEXCEPTION_POINTERS ExceptionPointer
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);
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NTSTATUS
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RxProcessException (
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IN PRX_CONTEXT RxContext,
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IN NTSTATUS ExceptionCode
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);
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#define CATCH_EXPECTED_EXCEPTIONS (FsRtlIsNtstatusExpected(GetExceptionCode()) ? \
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EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH )
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//
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// VOID
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// RxRaiseStatus (
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// IN PRIP_CONTEXT RxContext,
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// IN NT_STATUS Status
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// );
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//
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//
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#define RxRaiseStatus(RXCONTEXT,STATUS) { \
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ASSERT((RXCONTEXT)!=NULL); \
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if (RxContext!=NULL) {(RXCONTEXT)->StoredStatus = (STATUS); } \
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ExRaiseStatus( (STATUS) ); \
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}
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//
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// VOID
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// RxNormalAndRaiseStatus (
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// IN PRIP_CONTEXT RxContext,
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// IN NT_STATUS Status
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// );
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//
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#define RxNormalizeAndRaiseStatus(RXCONTEXT,STATUS) { \
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ASSERT((RXCONTEXT)!=NULL); \
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if (RxContext!=NULL) {(RXCONTEXT)->StoredStatus = (STATUS); } \
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if ((STATUS) == (STATUS_VERIFY_REQUIRED)) { ExRaiseStatus((STATUS)); } \
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ExRaiseStatus(FsRtlNormalizeNtstatus((STATUS),(STATUS_UNEXPECTED_IO_ERROR))); \
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}
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//
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// The following macros are used to establish the semantics needed
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// to do a return from within a try-finally clause. As a rule every
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// try clause must end with a label call try_exit. For example,
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//
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// try {
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// :
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// :
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//
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// try_exit: NOTHING;
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// } finally {
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//
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// :
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// :
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// }
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//
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// Every return statement executed inside of a try clause should use the
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// try_return macro. If the compiler fully supports the try-finally construct
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// then the macro should be
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//
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// #define try_return(S) { return(S); }
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//
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// If the compiler does not support the try-finally construct then the macro
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// should be
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//
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// #define try_return(S) { S; goto try_exit; }
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//
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#define try_return(S) { S; goto try_exit; }
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#endif // _EXCEPTION_STUFF_DEFINED_
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