gdb: Remove deprecated_set_gdbarch_data

There are currently two remaining uses of deprecated_set_gdbarch_data,
both of which are needed because during gdbarch initialisation we call
gdbarch_data for a data field that is registered using:

  gdbarch_data_register_post_init (....)

However, in both of these cases, the only thing that the call back
needs from the gdbarch struct is its obstack.  Given this there is
nothing stopping us changing the post-init hooks into pre-init hooks.
The pre-init hooks don't get passed the full gdbarch, they only get
passed its obstack.

The IA64 change is completely untested.  The user-regs change has been
tested a little by locally adding some user-regs to the x86-64 target,
and also by running the RISC-V tests, which do use user-regs.

gdb/ChangeLog:

	* gdbarch.c: Regenerate.
	* gdbarch.h: Regenerate.
	* gdbarch.sh (deprecated_set_gdbarch_data): Delete.
	(gdbarch_data): Use internal_error for the case where
	deprecated_set_gdbarch_data was originally needed.
	* ia64-libunwind-tdep.c (libunwind_descr_init): Update parameters,
	and use passed in obstack.
	(libunwind_frame_set_descr): Should no longer get back NULL from
	gdbarch_data.
	(_initialize_libunwind_frame): Register as a pre-init gdbarch data
	type.
	* user-regs.c (user_regs_init): Update parameters, and use passed
	in obstack.
	(user_reg_add): Should no longer get back NULL from gdbarch_data.
	(_initialize_user_regs): Register as a pre-init gdbarch data type.

6 files changed, 33 insertions, 68 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a07dd38..0b73be8 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,21 @@
+2020-07-06  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* gdbarch.c: Regenerate.
+	* gdbarch.h: Regenerate.
+	* gdbarch.sh (deprecated_set_gdbarch_data): Delete.
+	(gdbarch_data): Use internal_error for the case where
+	deprecated_set_gdbarch_data was originally needed.
+	* ia64-libunwind-tdep.c (libunwind_descr_init): Update parameters,
+	and use passed in obstack.
+	(libunwind_frame_set_descr): Should no longer get back NULL from
+	gdbarch_data.
+	(_initialize_libunwind_frame): Register as a pre-init gdbarch data
+	type.
+	* user-regs.c (user_regs_init): Update parameters, and use passed
+	in obstack.
+	(user_reg_add): Should no longer get back NULL from gdbarch_data.
+	(_initialize_user_regs): Register as a pre-init gdbarch data type.
+
 2020-07-06  Tom de Vries  <tdevries@suse.de>
 
 	* buildsym.c (buildsym_compunit::end_symtab_with_blockvector): Handle
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index 6d1bb0d..21ee840 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -5208,20 +5208,6 @@ alloc_gdbarch_data (struct gdbarch *gdbarch)
   gdbarch->data = GDBARCH_OBSTACK_CALLOC (gdbarch, gdbarch->nr_data, void *);
 }
 
-/* Initialize the current value of the specified per-architecture
-   data-pointer.  */
-
-void
-deprecated_set_gdbarch_data (struct gdbarch *gdbarch,
-			     struct gdbarch_data *data,
-			     void *pointer)
-{
-  gdb_assert (data->index < gdbarch->nr_data);
-  gdb_assert (gdbarch->data[data->index] == NULL);
-  gdb_assert (data->pre_init == NULL);
-  gdbarch->data[data->index] = pointer;
-}
-
 /* Return the current value of the specified per-architecture
    data-pointer.  */
 
@@ -5251,11 +5237,9 @@ gdbarch_data (struct gdbarch *gdbarch, struct gdbarch_data *data)
 	  data->init_p = 1;
 	}
       else
-	/* The architecture initialization hasn't completed - punt -
-	 hope that the caller knows what they are doing.  Once
-	 deprecated_set_gdbarch_data has been initialized, this can be
-	 changed to an internal error.  */
-	return NULL;
+	internal_error (__FILE__, __LINE__,
+			_("gdbarch post-init data field can only be used "
+			  "after gdbarch is fully initialised"));
       gdb_assert (gdbarch->data[data->index] != NULL);
     }
   return gdbarch->data[data->index];
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 4e51c29..0940156 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -1839,9 +1839,6 @@ typedef void *(gdbarch_data_pre_init_ftype) (struct obstack *obstack);
 extern struct gdbarch_data *gdbarch_data_register_pre_init (gdbarch_data_pre_init_ftype *init);
 typedef void *(gdbarch_data_post_init_ftype) (struct gdbarch *gdbarch);
 extern struct gdbarch_data *gdbarch_data_register_post_init (gdbarch_data_post_init_ftype *init);
-extern void deprecated_set_gdbarch_data (struct gdbarch *gdbarch,
-                                         struct gdbarch_data *data,
-			                 void *pointer);
 
 extern void *gdbarch_data (struct gdbarch *gdbarch, struct gdbarch_data *);
 
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index ad27a4e..41e7b8d 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -1630,9 +1630,6 @@ typedef void *(gdbarch_data_pre_init_ftype) (struct obstack *obstack);
 extern struct gdbarch_data *gdbarch_data_register_pre_init (gdbarch_data_pre_init_ftype *init);
 typedef void *(gdbarch_data_post_init_ftype) (struct gdbarch *gdbarch);
 extern struct gdbarch_data *gdbarch_data_register_post_init (gdbarch_data_post_init_ftype *init);
-extern void deprecated_set_gdbarch_data (struct gdbarch *gdbarch,
-                                         struct gdbarch_data *data,
-			                 void *pointer);
 
 extern void *gdbarch_data (struct gdbarch *gdbarch, struct gdbarch_data *);
 
@@ -2237,20 +2234,6 @@ alloc_gdbarch_data (struct gdbarch *gdbarch)
   gdbarch->data = GDBARCH_OBSTACK_CALLOC (gdbarch, gdbarch->nr_data, void *);
 }
 
-/* Initialize the current value of the specified per-architecture
-   data-pointer.  */
-
-void
-deprecated_set_gdbarch_data (struct gdbarch *gdbarch,
-			     struct gdbarch_data *data,
-			     void *pointer)
-{
-  gdb_assert (data->index < gdbarch->nr_data);
-  gdb_assert (gdbarch->data[data->index] == NULL);
-  gdb_assert (data->pre_init == NULL);
-  gdbarch->data[data->index] = pointer;
-}
-
 /* Return the current value of the specified per-architecture
    data-pointer.  */
 
@@ -2280,11 +2263,9 @@ gdbarch_data (struct gdbarch *gdbarch, struct gdbarch_data *data)
 	  data->init_p = 1;
 	}
       else
-	/* The architecture initialization hasn't completed - punt -
-	 hope that the caller knows what they are doing.  Once
-	 deprecated_set_gdbarch_data has been initialized, this can be
-	 changed to an internal error.  */
-	return NULL;
+	internal_error (__FILE__, __LINE__,
+			_("gdbarch post-init data field can only be used "
+			  "after gdbarch is fully initialised"));
       gdb_assert (gdbarch->data[data->index] != NULL);
     }
   return gdbarch->data[data->index];
diff --git a/gdb/ia64-libunwind-tdep.c b/gdb/ia64-libunwind-tdep.c
index 59b7df1..94881bb 100644
--- a/gdb/ia64-libunwind-tdep.c
+++ b/gdb/ia64-libunwind-tdep.c
@@ -133,10 +133,10 @@ libunwind_descr (struct gdbarch *gdbarch)
 }
 
 static void *
-libunwind_descr_init (struct gdbarch *gdbarch)
+libunwind_descr_init (struct obstack *obstack)
 {
   struct libunwind_descr *descr
-    = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct libunwind_descr);
+    = OBSTACK_ZALLOC (obstack, struct libunwind_descr);
 
   return descr;
 }
@@ -151,14 +151,7 @@ libunwind_frame_set_descr (struct gdbarch *gdbarch,
 
   arch_descr = ((struct libunwind_descr *)
 		gdbarch_data (gdbarch, libunwind_descr_handle));
-
-  if (arch_descr == NULL)
-    {
-      /* First time here.  Must initialize data area.  */
-      arch_descr = (struct libunwind_descr *) libunwind_descr_init (gdbarch);
-      deprecated_set_gdbarch_data (gdbarch,
-				   libunwind_descr_handle, arch_descr);
-    }
+  gdb_assert (arch_descr != NULL);
 
   /* Copy new descriptor info into arch descriptor.  */
   arch_descr->gdb2uw = descr->gdb2uw;
@@ -596,7 +589,7 @@ void
 _initialize_libunwind_frame ()
 {
   libunwind_descr_handle
-    = gdbarch_data_register_post_init (libunwind_descr_init);
+    = gdbarch_data_register_pre_init (libunwind_descr_init);
 
   libunwind_initialized = libunwind_load ();
 }
diff --git a/gdb/user-regs.c b/gdb/user-regs.c
index cb92231..d461f85 100644
--- a/gdb/user-regs.c
+++ b/gdb/user-regs.c
@@ -98,16 +98,15 @@ user_reg_add_builtin (const char *name, user_reg_read_ftype *xread,
 static struct gdbarch_data *user_regs_data;
 
 static void *
-user_regs_init (struct gdbarch *gdbarch)
+user_regs_init (struct obstack *obstack)
 {
   struct user_reg *reg;
-  struct gdb_user_regs *regs 
-    = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct gdb_user_regs);
+  struct gdb_user_regs *regs = OBSTACK_ZALLOC (obstack, struct gdb_user_regs);
 
   regs->last = &regs->first;
   for (reg = builtin_user_regs.first; reg != NULL; reg = reg->next)
     append_user_reg (regs, reg->name, reg->xread, reg->baton,
-		     GDBARCH_OBSTACK_ZALLOC (gdbarch, struct user_reg));
+		     OBSTACK_ZALLOC (obstack, struct user_reg));
   return regs;
 }
 
@@ -117,14 +116,7 @@ user_reg_add (struct gdbarch *gdbarch, const char *name,
 {
   struct gdb_user_regs *regs
     = (struct gdb_user_regs *) gdbarch_data (gdbarch, user_regs_data);
-
-  if (regs == NULL)
-    {
-      /* ULGH, called during architecture initialization.  Patch
-         things up.  */
-      regs = (struct gdb_user_regs *) user_regs_init (gdbarch);
-      deprecated_set_gdbarch_data (gdbarch, user_regs_data, regs);
-    }
+  gdb_assert (regs != NULL);
   append_user_reg (regs, name, xread, baton,
 		   GDBARCH_OBSTACK_ZALLOC (gdbarch, struct user_reg));
 }
@@ -240,7 +232,7 @@ void _initialize_user_regs ();
 void
 _initialize_user_regs ()
 {
-  user_regs_data = gdbarch_data_register_post_init (user_regs_init);
+  user_regs_data = gdbarch_data_register_pre_init (user_regs_init);
 
   add_cmd ("user-registers", class_maintenance,
 	   maintenance_print_user_registers,