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/.