* dwarf2loc.c (dwarf_expr_frame_base): Guard against NULL.

* Makefile.in (dwarf2loc.o): Depend on gdb_assert.h.

gdb/dwarf2loc.c

@@ -37,6 +37,7 @@
 #include "dwarf2loc.h"
 
 #include "gdb_string.h"
+#include "gdb_assert.h"
 
 /* A helper function for dealing with location lists.  Given a
    symbol baton (BATON) and a pc value (PC), find the appropriate
@@ -145,6 +146,11 @@ dwarf_expr_frame_base (void *baton, gdb_byte **start, size_t * length)
 
   framefunc = get_frame_function (debaton->frame);
 
+  /* If we found a frame-relative symbol then it was certainly within
+     some function associated with a frame. If we can't find the frame,
+     something has gone wrong.  */
+  gdb_assert (framefunc != NULL);
+
   if (SYMBOL_OPS (framefunc) == &dwarf2_loclist_funcs)
     {
       struct dwarf2_loclist_baton *symbaton;