NAME
unw_get_proc_info_by_ip -- get procedure info by IP
SYNOPSIS
#include <libunwind.h>
int unw_get_proc_info_by_ip(unw_addr_space_t as, unw_word_t ip,
unw_proc_info_t *pip, void *arg);
DESCRIPTION
The unw_get_proc_info_by_ip() routine returns the same kind of
auxiliary information about a procedure as unw_get_proc_info(), except
that the info is looked up by instruction-pointer (IP) instead of a
cursor. This is more flexible because it is possible to look up the
info for an arbitrary procedure, even if it is not part of the current
call-chain. However, since it is more flexible, it also tends to run
slower (and often much slower) than unw_get_proc_info().
The routine expects the followins arguments: as is the address-space in
which the instruction-pointer should be looked up. For a look-up in
the local address-space, unw_local_addr_space can be passed for this
argument. Argument ip is the instruction-pointer for which the
procedure info should be looked up and pip is a pointer to a structure
of type unw_proc_info_t which is used to return the info. Lastly, arg
is the address-space argument that should be used when accessing the
address-space. It has the same purpose as the argument of the same name
for unw_init_remote(). When accessing the local address-space (first
argument is unw_local_addr_space), NULL must be passed for this
argument.
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_by_ip() returns 0.
Otherwise the negative value of one of the error-codes below is
returned.
THREAD AND SIGNAL SAFETY
unw_get_proc_info() is thread-safe. If the local address-space is
passed in argument as, 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 ALSO
libunwind(3), unw_create_addr_space(3), unw_get_proc_name(3),
unw_get_proc_info(3), unw_init_remote(3)
AUTHOR
David Mosberger-Tang
Email: dmosberger@gmail.com
WWW: http://www.nongnu.org/libunwind/.