UNW_GET_PROC_INFO_BY_IP(3)				       Programming Library					UNW_GET_PROC_INFO_BY_IP(3)

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/.

Programming Library						  16 August 2007					UNW_GET_PROC_INFO_BY_IP(3)