Delete def_uiout

Currently, current_uiout starts out pointing to def_uiout, a dummy
ui_out implementation.

Since we create a replacement uiout early on as soon as we create the
interpreter, we never actually use def_uiout.  So this patch removes
it.

The proof that it works is that starting with current_uiout set to
NULL does not crash.

gdb/ChangeLog:
2016-06-21  Pedro Alves  <palves@redhat.com>

	* ui-out.c (default_ui_out_impl): Delete.
	(def_uiout): Delete.
	(current_uiout): Set to NULL.
	(default_table_begin, default_table_body, default_table_end)
	(default_table_header, default_begin, default_end)
	(default_field_int, default_field_skip, default_field_string)
	(default_field_fmt, default_spaces, default_text, default_message)
	(default_wrap_hint, default_flush, default_data_destroy): Delete.

2 files changed, 12 insertions, 180 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3edb6dc..ccf31f2 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,16 @@
 2016-06-21  Pedro Alves  <palves@redhat.com>
 
+	* ui-out.c (default_ui_out_impl): Delete.
+	(def_uiout): Delete.
+	(current_uiout): Set to NULL.
+	(default_table_begin, default_table_body, default_table_end)
+	(default_table_header, default_begin, default_end)
+	(default_field_int, default_field_skip, default_field_string)
+	(default_field_fmt, default_spaces, default_text, default_message)
+	(default_wrap_hint, default_flush, default_data_destroy): Delete.
+
+2016-06-21  Pedro Alves  <palves@redhat.com>
+
 	* event-top.c (gdb_setup_readline): Pass the UI's outstream and
 	errstream to stdout_fileopen and stderr_fileopen.
 	* exceptions.c: Include top.h.
diff --git a/gdb/ui-out.c b/gdb/ui-out.c
index e5a2bf1..4ea571b 100644
--- a/gdb/ui-out.c
+++ b/gdb/ui-out.c
@@ -147,84 +147,10 @@ pop_level (struct ui_out *uiout,
   return uiout->level + 1;
 }
 
-
-/* These are the default implementation functions.  */
-
-static void default_table_begin (struct ui_out *uiout, int nbrofcols,
-				 int nr_rows, const char *tblid);
-static void default_table_body (struct ui_out *uiout);
-static void default_table_end (struct ui_out *uiout);
-static void default_table_header (struct ui_out *uiout, int width,
-				  enum ui_align alig, const char *col_name,
-				  const char *colhdr);
-static void default_begin (struct ui_out *uiout,
-			   enum ui_out_type type,
-			   int level, const char *id);
-static void default_end (struct ui_out *uiout,
-			 enum ui_out_type type,
-			 int level);
-static void default_field_int (struct ui_out *uiout, int fldno, int width,
-			       enum ui_align alig,
-			       const char *fldname,
-			       int value);
-static void default_field_skip (struct ui_out *uiout, int fldno, int width,
-				enum ui_align alig,
-				const char *fldname);
-static void default_field_string (struct ui_out *uiout, int fldno, int width,
-				  enum ui_align align,
-				  const char *fldname,
-				  const char *string);
-static void default_field_fmt (struct ui_out *uiout, int fldno,
-			       int width, enum ui_align align,
-			       const char *fldname,
-			       const char *format,
-			       va_list args) ATTRIBUTE_PRINTF (6, 0);
-static void default_spaces (struct ui_out *uiout, int numspaces);
-static void default_text (struct ui_out *uiout, const char *string);
-static void default_message (struct ui_out *uiout, int verbosity,
-			     const char *format,
-			     va_list args) ATTRIBUTE_PRINTF (3, 0);
-static void default_wrap_hint (struct ui_out *uiout, char *identstring);
-static void default_flush (struct ui_out *uiout);
-static void default_data_destroy (struct ui_out *uiout);
-
-/* This is the default ui-out implementation functions vector.  */
-
-const struct ui_out_impl default_ui_out_impl =
-{
-  default_table_begin,
-  default_table_body,
-  default_table_end,
-  default_table_header,
-  default_begin,
-  default_end,
-  default_field_int,
-  default_field_skip,
-  default_field_string,
-  default_field_fmt,
-  default_spaces,
-  default_text,
-  default_message,
-  default_wrap_hint,
-  default_flush,
-  NULL, /* redirect */
-  default_data_destroy,
-  0, /* Does not need MI hacks.  */
-};
-
-/* The default ui_out */
-
-struct ui_out def_uiout =
-{
-  0,				/* flags */
-  &default_ui_out_impl,		/* impl */
-};
-
-/* Pointer to current ui_out */
 /* FIXME: This should not be a global, but something passed down from main.c
    or top.c.  */
 
-struct ui_out *current_uiout = &def_uiout;
+struct ui_out *current_uiout = NULL;
 
 /* These are the interfaces to implementation functions.  */
 
@@ -652,111 +578,6 @@ ui_out_is_mi_like_p (struct ui_out *uiout)
   return uiout->impl->is_mi_like_p;
 }
 
-/* Default gdb-out hook functions.  */
-
-static void
-default_table_begin (struct ui_out *uiout, int nbrofcols,
-		     int nr_rows,
-		     const char *tblid)
-{
-}
-
-static void
-default_table_body (struct ui_out *uiout)
-{
-}
-
-static void
-default_table_end (struct ui_out *uiout)
-{
-}
-
-static void
-default_table_header (struct ui_out *uiout, int width, enum ui_align alignment,
-		      const char *col_name,
-		      const char *colhdr)
-{
-}
-
-static void
-default_begin (struct ui_out *uiout,
-	       enum ui_out_type type,
-	       int level,
-	       const char *id)
-{
-}
-
-static void
-default_end (struct ui_out *uiout,
-	     enum ui_out_type type,
-	     int level)
-{
-}
-
-static void
-default_field_int (struct ui_out *uiout, int fldno, int width,
-		   enum ui_align align,
-		   const char *fldname, int value)
-{
-}
-
-static void
-default_field_skip (struct ui_out *uiout, int fldno, int width,
-		    enum ui_align align, const char *fldname)
-{
-}
-
-static void
-default_field_string (struct ui_out *uiout,
-		      int fldno,
-		      int width,
-		      enum ui_align align,
-		      const char *fldname,
-		      const char *string)
-{
-}
-
-static void
-default_field_fmt (struct ui_out *uiout, int fldno, int width,
-		   enum ui_align align,
-		   const char *fldname,
-		   const char *format,
-		   va_list args)
-{
-}
-
-static void
-default_spaces (struct ui_out *uiout, int numspaces)
-{
-}
-
-static void
-default_text (struct ui_out *uiout, const char *string)
-{
-}
-
-static void
-default_message (struct ui_out *uiout, int verbosity,
-		 const char *format,
-		 va_list args)
-{
-}
-
-static void
-default_wrap_hint (struct ui_out *uiout, char *identstring)
-{
-}
-
-static void
-default_flush (struct ui_out *uiout)
-{
-}
-
-static void
-default_data_destroy (struct ui_out *uiout)
-{
-}
-
 /* Interface to the implementation functions.  */
 
 void