1 files changed, 39 insertions, 16 deletions

diff --git a/gdb/alpha-osf1-tdep.c b/gdb/alpha-osf1-tdep.c
index 4eaa3c4..ca757de 100644
--- a/gdb/alpha-osf1-tdep.c
+++ b/gdb/alpha-osf1-tdep.c
@@ -24,22 +24,10 @@
 #include "value.h"
 #include "osabi.h"
 #include "gdb_string.h"
+#include "objfiles.h"
 
 #include "alpha-tdep.h"
 
-/* Under OSF/1, the __sigtramp routine is frameless and has a frame
-   size of zero, but we are able to backtrace through it.  */
-static CORE_ADDR
-alpha_osf1_skip_sigtramp_frame (struct frame_info *frame, CORE_ADDR pc)
-{
-  char *name;
-
-  find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
-  if (PC_IN_SIGTRAMP (pc, name))
-    return frame->frame;
-  return 0;
-}
-
 static int
 alpha_osf1_pc_in_sigtramp (CORE_ADDR pc, char *func_name)
 {
@@ -49,8 +37,36 @@ alpha_osf1_pc_in_sigtramp (CORE_ADDR pc, char *func_name)
 static CORE_ADDR
 alpha_osf1_sigcontext_addr (struct frame_info *frame)
 {
-  return (read_memory_integer (frame->next ? frame->next->frame
-					   : frame->frame, 8));
+  struct frame_info *next_frame = get_next_frame (frame);
+
+  if (next_frame != NULL)
+    return (read_memory_integer (get_frame_base (next_frame), 8));
+  else
+    return (read_memory_integer (get_frame_base (frame), 8));
+}
+
+/* This is the definition of CALL_DUMMY_ADDRESS.  It's a heuristic that is used
+   to find a convenient place in the text segment to stick a breakpoint to
+   detect the completion of a target function call (ala call_function_by_hand).
+ */
+
+static CORE_ADDR
+alpha_call_dummy_address (void)
+{
+  CORE_ADDR entry;
+  struct minimal_symbol *sym;
+
+  entry = entry_point_address ();
+
+  if (entry != 0)
+    return entry;
+
+  sym = lookup_minimal_symbol ("_Prelude", NULL, symfile_objfile);
+
+  if (!sym || MSYMBOL_TYPE (sym) != mst_text)
+    return 0;
+  else
+    return SYMBOL_VALUE_ADDRESS (sym) + 4;
 }
 
 static void
@@ -59,13 +75,20 @@ alpha_osf1_init_abi (struct gdbarch_info info,
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 
+  /* Hook into the MDEBUG frame unwinder.  */
+  alpha_mdebug_init_abi (info, gdbarch);
+
   set_gdbarch_pc_in_sigtramp (gdbarch, alpha_osf1_pc_in_sigtramp);
   /* The next/step support via procfs on OSF1 is broken when running
      on multi-processor machines. We need to use software single stepping
      instead.  */
   set_gdbarch_software_single_step (gdbarch, alpha_software_single_step);
 
-  tdep->skip_sigtramp_frame = alpha_osf1_skip_sigtramp_frame;
+  /* Alpha OSF/1 inhibits execution of code on the stack.  But there is
+     no need for a dummy on the Alpha.  PUSH_ARGUMENTS takes care of all
+     argument handling and bp_call_dummy takes care of stopping the dummy.  */
+  set_gdbarch_call_dummy_address (gdbarch, alpha_call_dummy_address);
+
   tdep->sigcontext_addr = alpha_osf1_sigcontext_addr;
 
   tdep->jb_pc = 2;