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/.