* configure.ac: Use AC_CHECK_DECLS instead of gcc_AC_CHECK_DECLS

[deliverable/binutils-gdb.git] / gdb / frame-unwind.h

diff --git a/gdb/frame-unwind.h b/gdb/frame-unwind.h
index 49f28896ffe602c4103eaaee2e08d60123dcbb43..74c0a4aa9b4e05f79df179e8e27e3553fa1ed0f4 100644 (file)
--- a/gdb/frame-unwind.h
+++ b/gdb/frame-unwind.h
@@ -118,6 +118,14 @@ typedef void (frame_prev_register_ftype) (struct frame_info *next_frame,
                                          CORE_ADDR *addrp,
                                          int *realnump, void *valuep);
 
+/* Assuming the frame chain: (outer) prev <-> this <-> next (inner);
+   use the NEXT frame, and its register unwind method, to return the PREV
+   frame's program-counter.  */
+
+typedef CORE_ADDR (frame_prev_pc_ftype) (struct frame_info *next_frame,
+                                        void **this_prologue_cache);
+
+
 struct frame_unwind
 {
   /* The frame's type.  Should this instead be a collection of
@@ -129,13 +137,17 @@ struct frame_unwind
   frame_prev_register_ftype *prev_register;
   const struct frame_data *unwind_data;
   frame_sniffer_ftype *sniffer;
+  frame_prev_pc_ftype *prev_pc;
 };
 
-/* Register a frame unwinder, _appending_ it to the end of the search
-   list.  */
-extern void frame_unwind_register_unwinder (struct gdbarch *gdbarch,
-                                           const struct frame_unwind *unwinder);
-
+/* Register a frame unwinder, _prepending_ it to the front of the
+   search list (so it is sniffed before previously registered
+   unwinders).  By using a prepend, later calls can install unwinders
+   that override earlier calls.  This allows, for instance, an OSABI
+   to install a a more specific sigtramp unwinder that overrides the
+   traditional brute-force unwinder.  */
+extern void frame_unwind_prepend_unwinder (struct gdbarch *gdbarch,
+                                          const struct frame_unwind *unwinder);
 
 /* Given the NEXT frame, take a wiff of THIS frame's registers (namely
    the PC and attributes) and if it is the applicable unwinder return