Add support to GDB for the Renesas rl78 architecture.

[external/binutils.git] / gdb / libunwind-frame.c

diff --git a/gdb/libunwind-frame.c b/gdb/libunwind-frame.c
index 53c42d9..893fe1e 100644 (file)
--- a/gdb/libunwind-frame.c
+++ b/gdb/libunwind-frame.c
@@ -1,7 +1,6 @@
 /* Frame unwinder for frames using the libunwind library.
 
-   Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011
-   Free Software Foundation, Inc.
+   Copyright (C) 2003-2004, 2006-2012 Free Software Foundation, Inc.
 
    Written by Jeff Johnston, contributed by Red Hat Inc.
 
@@ -162,14 +161,20 @@ libunwind_frame_cache (struct frame_info *this_frame, void **this_cache)
   /* Allocate a new cache.  */
   cache = FRAME_OBSTACK_ZALLOC (struct libunwind_frame_cache);
 
-  /* We can assume we are unwinding a normal frame.  Even if this is
-     for a signal trampoline, ia64 signal "trampolines" use a normal
-     subroutine call to start the signal handler.  */
   cache->func_addr = get_frame_func (this_frame);
-  if (cache->func_addr == 0
-      && get_next_frame (this_frame)
-      && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME)
-    return NULL;
+  if (cache->func_addr == 0)
+    /* This can happen when the frame corresponds to a function for which
+       there is no debugging information nor any entry in the symbol table.
+       This is probably a static function for which an entry in the symbol
+       table was not created when the objfile got linked (observed in
+       libpthread.so on ia64-hpux).
+
+       The best we can do, in that case, is use the frame PC as the function
+       address.  We don't need to give up since we still have the unwind
+       record to help us perform the unwinding.  There is also another
+       compelling to continue, because abandonning now means stopping
+       the backtrace, which can never be helpful for the user.  */
+    cache->func_addr = get_frame_pc (this_frame);
 
   /* Get a libunwind cursor to the previous frame.
   
@@ -231,6 +236,7 @@ libunwind_find_dyn_list (unw_addr_space_t as, unw_dyn_info_t *di, void *arg)
 static const struct frame_unwind libunwind_frame_unwind =
 {
   NORMAL_FRAME,
+  default_frame_unwind_stop_reason,
   libunwind_frame_this_id,
   libunwind_frame_prev_register,
   NULL,
@@ -502,7 +508,11 @@ libunwind_load (void)
 
   handle = dlopen (LIBUNWIND_SO, RTLD_NOW);
   if (handle == NULL)
-    return 0;
+    {
+      fprintf_unfiltered (gdb_stderr, _("[GDB failed to load %s: %s]\n"),
+                          LIBUNWIND_SO, dlerror ());
+      return 0;
+    }
 
   /* Initialize pointers to the dynamic library functions we will use.  */