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14c48b3d51
init_local, but *not* setting use_prev_instr. This is necessary to correctly unwind using ucontext argument to signal handlers.
122 lines
2.6 KiB
Groff
122 lines
2.6 KiB
Groff
'\" t
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.\" Manual page created with latex2man on Thu Mar 30 16:13:10 PDT 2017
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.\" NOTE: This file is generated, DO NOT EDIT.
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.de Vb
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.ft CW
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..
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..
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.TH "UNW\\_INIT\\_LOCAL" "3" "30 March 2017" "Programming Library " "Programming Library "
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.SH NAME
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unw_init_local
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\-\- initialize cursor for local unwinding
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.PP
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.SH SYNOPSIS
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.PP
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#include <libunwind.h>
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.br
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.PP
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int
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unw_init_local(unw_cursor_t *c,
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unw_context_t *ctxt);
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.br
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int
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unw_init_local_signal(unw_cursor_t *c,
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unw_context_t *ctxt);
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.br
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.PP
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.SH DESCRIPTION
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.PP
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The unw_init_local()
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routine initializes the unwind cursor
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pointed to by c
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with the machine\-state in the context structure
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pointed to by ctxt\&.
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As such, the machine\-state pointed to by
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ctxt
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identifies the initial stack frame at which unwinding
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starts. The machine\-state is expected to be one provided by a call to
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unw_getcontext; as such, the instruction pointer may point to the
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instruction after the last instruction of a function, and libunwind
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will back\-up the instruction pointer before beginning a walk up the
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call stack. The machine\-state must remain valid for the duration for
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which the cursor c
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is in use.
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.PP
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The unw_init_local()
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routine can be used only for unwinding in
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the address space of the current process (i.e., for local unwinding).
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For all other cases, unw_init_remote()
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must be used instead.
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However, unwind performance may be better when using
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unw_init_local().
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Also, unw_init_local()
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is
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available even when UNW_LOCAL_ONLY
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has been defined before
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including <libunwind.h>,
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whereas unw_init_remote()
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is not.
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.PP
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If the unw_context_t is known to be a signal frame (i.e., from the
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third argument in a sigaction handler on linux),
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unw_init_local_signal()
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should be used for correct
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initialization on some platforms.
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.PP
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.SH RETURN VALUE
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.PP
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On successful completion, unw_init_local()
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returns 0.
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Otherwise the negative value of one of the error\-codes below is
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returned.
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.PP
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.SH THREAD AND SIGNAL SAFETY
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.PP
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unw_init_local()
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is thread\-safe as well as safe to use from a
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signal handler.
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.PP
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.SH ERRORS
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.PP
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.TP
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UNW_EINVAL
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unw_init_local()
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was called in a
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version of libunwind
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which supports remote unwinding only
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(this normally happens when calling unw_init_local()
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for a
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cross\-platform version of libunwind).
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.TP
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UNW_EUNSPEC
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An unspecified error occurred.
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.TP
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UNW_EBADREG
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A register needed by unw_init_local()
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wasn\&'t accessible.
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.PP
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.SH SEE ALSO
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.PP
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libunwind(3),
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unw_init_remote(3)
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.PP
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.SH AUTHOR
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.PP
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David Mosberger\-Tang
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.br
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Email: \fBdmosberger@gmail.com\fP
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.br
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WWW: \fBhttp://www.nongnu.org/libunwind/\fP\&.
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.\" NOTE: This file is generated, DO NOT EDIT.
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