UNW_GET_PROC_INFO(3) Programming Library UNW_GET_PROC_INFO(3)NAMEunw_get_proc_info-- get info on current procedure
SYNOPSIS
#include <libunwind.h>
int unw_get_proc_info(unw_cursor_t *cp, unw_proc_info_t *pip);
DESCRIPTION
The unw_get_proc_info() routine returns auxiliary information about the
procedure that created the stack frame identified by argument cp. The
pip argument is a pointer to a structure of type unw_proc_info_t which
is used to return the information. The unw_proc_info_t has the follow‐
ing members:
unw_word_t start_ip
The address of the first instruction of the procedure. If this
address cannot be determined (e.g., due to lack of unwind infor‐
mation), the start_ip member is cleared to 0.
unw_word_t end_ip
The address of the first instruction beyond the end of the pro‐
cedure. If this address cannot be determined (e.g., due to lack
of unwind information), the end_ip member is cleared to 0.
unw_word_t lsda
The address of the language-specific data-area (LSDA). This
area normally contains language-specific information needed dur‐
ing exception handling. If the procedure has no such area, this
member is cleared to 0.
unw_word_t handler
The address of the exception handler routine. This is sometimes
called the personality routine. If the procedure does not define
a personality routine, the handler member is cleared to 0.
unw_word_t gp
The global-pointer of the procedure. On platforms that do not
use a global pointer, this member may contain an undefined
value. On all other platforms, it must be set either to the cor‐
rect global-pointer value of the procedure or to 0 if the proper
global-pointer cannot be obtained for some reason.
unw_word_t flags
A set of flags. There are currently no target-independent
flags. For the IA-64 target, the flag
UNW_PI_FLAG_IA64_RBS_SWITCH is set if the procedure may switch
the register-backing store.
int format
The format of the unwind-info for this procedure. If the
unwind-info consists of dynamic procedure info, format is equal
to UNW_INFO_FORMAT_DYNAMIC. If the unwind-info consists of a
(target-specific) unwind table, it is equal to to UNW_INFO_FOR‐
MAT_TABLE. All other values are reserved for future use by
libunwind. This member exists for use by the find_proc_info()
call-back (see unw_create_addr_space(3)). The
unw_get_proc_info() routine may return an undefined value in
this member.
int unwind_info_size
The size of the unwind-info in bytes. This member exists for
use by the find_proc_info() call-back (see unw_cre‐
ate_addr_space(3)). The unw_get_proc_info() routine may return
an undefined value in this member.
void *unwind_info
The pointer to the unwind-info. If no unwind info is avail‐
able, this member must be set to NULL. This member exists for
use by the find_proc_info() call-back (see unw_cre‐
ate_addr_space(3)). The unw_get_proc_info() routine may return
an undefined value in this member.
Note that for the purposes of libunwind, the code of a procedure is
assumed to occupy a single, contiguous range of addresses. For this
reason, it is alwas possible to describe the extent of a procedure with
the start_ip and end_ip members. If a single function/routine is split
into multiple, discontiguous pieces, libunwind will treat each piece as
a separate procedure.
RETURN VALUE
On successful completion, unw_get_proc_info() returns 0. Otherwise the
negative value of one of the error-codes below is returned.
THREAD AND SIGNAL SAFETYunw_get_proc_info() is thread-safe. If cursor cp is in the local
address-space, this routine is also safe to use from a signal handler.
ERRORS
UNW_EUNSPEC
An unspecified error occurred.
UNW_ENOINFO
Libunwind was unable to locate unwind-info for the procedure.
UNW_EBADVERSION
The unwind-info for the procedure has version or format that is
not understood by libunwind.
In addition, unw_get_proc_info() may return any error returned by the
access_mem() call-back (see unw_create_addr_space(3)).
SEE ALSOlibunwind(3), unw_create_addr_space(3), unw_get_proc_name(3)AUTHOR
David Mosberger-Tang
Hewlett-Packard Labs
Palo-Alto, CA 94304
Email: davidm@hpl.hp.com
WWW: http://www.hpl.hp.com/research/linux/libunwind/.
Programming Library 05 August 2004 UNW_GET_PROC_INFO(3)
