+/* Callback type for ebl_set_initial_registers_tid.
+ Register -1 is mapped to PC (if arch PC has no DWARF number).
+ If FIRSTREG is -1 then NREGS has to be 1. */
+typedef bool (ebl_tid_registers_t) (int firstreg, unsigned nregs,
+ const Dwarf_Word *regs, void *arg)
+ __nonnull_attribute__ (3);
+
+/* Callback to fetch process data from live TID.
+ EBL architecture has to have EBL_FRAME_NREGS > 0, otherwise the
+ backend doesn't support unwinding and this function call may crash. */
+extern bool ebl_set_initial_registers_tid (Ebl *ebl,
+ pid_t tid,
+ ebl_tid_registers_t *setfunc,
+ void *arg)
+ __nonnull_attribute__ (1, 3);
+
+/* Number of registers to allocate for ebl_set_initial_registers_tid.
+ EBL architecture can unwind iff EBL_FRAME_NREGS > 0. */
+extern size_t ebl_frame_nregs (Ebl *ebl)
+ __nonnull_attribute__ (1);
+
+/* Mask to use for function symbol or unwind return addresses in case
+ the architecture adds some extra non-address bits to it. This is
+ different from ebl_resolve_sym_value which only works for actual
+ symbol addresses (in non-ET_REL files) that might resolve to an
+ address in a different section. ebl_func_addr_mask is called to
+ turn a given function value into the a real address or offset (the
+ original value might not be a real address). This works for all
+ cases where an actual function address (or offset in ET_REL symbol
+ tables) is needed. */
+extern GElf_Addr ebl_func_addr_mask (Ebl *ebl);
+
+/* Convert *REGNO as is in DWARF to a lower range suitable for
+ Dwarf_Frame->REGS indexing. */
+extern bool ebl_dwarf_to_regno (Ebl *ebl, unsigned *regno)
+ __nonnull_attribute__ (1, 2);
+
+/* Modify PC as fetched from inferior data into valid PC. */
+extern void ebl_normalize_pc (Ebl *ebl, Dwarf_Addr *pc)
+ __nonnull_attribute__ (1, 2);
+
+/* Callback type for ebl_unwind's parameter getfunc. */
+typedef bool (ebl_tid_registers_get_t) (int firstreg, unsigned nregs,
+ Dwarf_Word *regs, void *arg)
+ __nonnull_attribute__ (3);
+
+/* Callback type for ebl_unwind's parameter readfunc. */
+typedef bool (ebl_pid_memory_read_t) (Dwarf_Addr addr, Dwarf_Word *data,
+ void *arg)
+ __nonnull_attribute__ (3);
+
+/* Get previous frame state for an existing frame state. Method is called only
+ if unwinder could not find CFI for current PC. PC is for the
+ existing frame. SETFUNC sets register in the previous frame. GETFUNC gets
+ register from the existing frame. Note that GETFUNC vs. SETFUNC act on
+ a disjunct set of registers. READFUNC reads memory. ARG has to be passed
+ for SETFUNC, GETFUNC and READFUNC. *SIGNAL_FRAMEP is initialized to false,
+ it can be set to true if existing frame is a signal frame. SIGNAL_FRAMEP is
+ never NULL. */
+extern bool ebl_unwind (Ebl *ebl, Dwarf_Addr pc, ebl_tid_registers_t *setfunc,
+ ebl_tid_registers_get_t *getfunc,
+ ebl_pid_memory_read_t *readfunc, void *arg,
+ bool *signal_framep)
+ __nonnull_attribute__ (1, 3, 4, 5, 7);
+
+/* Returns true if the value can be resolved to an address in an
+ allocated section, which will be returned in *ADDR
+ (e.g. function descriptor resolving) */
+extern bool ebl_resolve_sym_value (Ebl *ebl, GElf_Addr *addr)
+ __nonnull_attribute__ (2);