UNW_GET_PROC_INFO(3)					       Programming Library					      UNW_GET_PROC_INFO(3)

NAME

       unw_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
       following 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 informa-
	      tion), the start_ip member is cleared to 0.

       unw_word_t end_ip
	       The address of the first instruction beyond the end of the procedure. 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 during
	      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 correct 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_FORMAT_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_create_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 available, this member must be set to NULL.  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.

       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 SAFETY

       unw_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 ALSO

       libunwind(3), unw_create_addr_space(3), unw_get_proc_name(3)

AUTHOR

       David Mosberger-Tang
       Email: dmosberger@gmail.com
       WWW: http://www.nongnu.org/libunwind/.

Programming Library						  16 August 2007					      UNW_GET_PROC_INFO(3)