UNW_REG_STATES_ITERATE(3libunwind)                        Programming Library

NAME
       unw_reg_states_iterate -- get register state info on current procedure

SYNOPSIS
       #include <libunwind.h>

       int unw_reg_states_iterate(unw_cursor_t *cp, unw_reg_states_callbackcb,
       void *token);

DESCRIPTION
       The unw_reg_states_iterate() routine provides information about the
       procedure that created the stack frame identified by argument cp.  The
       cb argument is a pointer to a function of type unw_reg_states_callback
       which is used to return the information. The function
       unw_reg_states_callback has the following definition:

       int ( *unw_reg_states_callback)(void *token, void *reg_states_data,
       size_t reg_states_data_size, unw_word_t start_ip, unw_word_t end_ip);

       The callback function may be invoked several times for each call of
       unw_reg_states_iterate.  Each call is associated with an instruction
       address range and a set of instructions on how to update register
       values when returning from the procedure in that address range. For
       each invocation, the arguments to the callback function are:

       void * token
               The token value passed to unw_reg_states_callback.

       void * reg_states_data
               A pointer to data about updating register values. This data, or
              a copy of it, can be passed to unw_apply_reg_state.

       int reg_states_data_size
               The size of the register update data.

       unw_word_t start_ip
               The address of the first instruction of the address range.

       unw_word_t end_ip
               The address of the first instruction beyond the end of the
              address range.

RETURN VALUE
       On successful completion, unw_reg_states_iterate() returns 0. If the
       callback function returns a nonzero value, that indicates failure and
       the function returns immediately. Otherwise the negative value of one
       of the error codes below is returned.

THREAD AND SIGNAL SAFETY
       unw_reg_states_iterate() 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_reg_states_iterate() may return any error returned by
       the access_mem() call-back (see unw_create_addr_space(3libunwind)).

SEE ALSO
       libunwind(3libunwind), unw_apply_reg_state(3libunwind)

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

Programming Library             29 August 2023
                                            UNW_REG_STATES_ITERATE(3libunwind)