местный goto (local goto)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
_longjmp, _setjmp — non-local goto
Синопсис (Synopsis)
#include <setjmp.h>
void _longjmp(jmp_buf env, int val);
int _setjmp(jmp_buf env);
Описание (Description)
The _longjmp() and _setjmp() functions shall be equivalent to
longjmp() and setjmp(), respectively, with the additional
restriction that _longjmp() and _setjmp() shall not manipulate
the signal mask.
If _longjmp() is called even though env was never initialized by
a call to _setjmp(), or when the last such call was in a function
that has since returned, the results are undefined.
Возвращаемое значение (Return value)
Refer to longjmp(3p) and setjmp(3p).
Ошибки (Error)
No errors are defined.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
If _longjmp() is executed and the environment in which _setjmp()
was executed no longer exists, errors can occur. The conditions
under which the environment of the _setjmp() no longer exists
include exiting the function that contains the _setjmp() call,
and exiting an inner block with temporary storage. This condition
might not be detectable, in which case the _longjmp() occurs and,
if the environment no longer exists, the contents of the
temporary storage of an inner block are unpredictable. This
condition might also cause unexpected process termination. If the
function has returned, the results are undefined.
Passing longjmp() a pointer to a buffer not created by setjmp(),
passing _longjmp() a pointer to a buffer not created by
_setjmp(), passing siglongjmp() a pointer to a buffer not created
by sigsetjmp(), or passing any of these three functions a buffer
that has been modified by the user can cause all the problems
listed above, and more.
The _longjmp() and _setjmp() functions are included to support
programs written to historical system interfaces. New
applications should use siglongjmp() and sigsetjmp()
respectively.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
The _longjmp() and _setjmp() functions may be removed in a future
version.
Смотри также (See also)
longjmp(3p), setjmp(3p), siglongjmp(3p), sigsetjmp(3p)
The Base Definitions volume of POSIX.1‐2017, setjmp.h(0p)
