Remove unnecessary casts of NULL

I noticed some unnecessary casts of NULL.  This removes all the
unnecessary ones, leaving only ones where we must ensure that NULL has
pointer type for passing through varargs.

I removed a couple of useless casts of 0 that I noticed while writing
this.

Tested by rebuilding.

gdb/ChangeLog
2019-06-16  Tom Tromey  <tom@tromey.com>

	* valops.c (value_cast, value_slice): Remove unnecessary cast.
	* breakpoint.c (stopin_command, stopat_command)
	(until_break_command, decode_location_default): Remove unnecessary
	cast.
	* utils.c (subset_compare): Remove unnecessary cast.
	* ada-lang.c (ada_update_initial_language): Remove unnecessary
	cast.
	* linespec.c (decode_line_with_last_displayed): Remove unnecessary
	cast.
	* infcmd.c (path_command): Remove unnecessary cast.
	* coffread.c (decode_type): Remove unnecessary cast.
	* xcoffread.c (read_xcoff_symtab): Remove unnecessary cast.
	* mipsread.c (mipscoff_symfile_read): Remove unnecessary cast.
	* tui/tui-stack.c (tui_show_locator_content)
	(tui_show_frame_info): Remove unnecessary cast.
	* tui/tui-win.c (tui_scroll_forward_command)
	(tui_scroll_backward_command, tui_set_focus, tui_set_win_height)
	(parse_scrolling_args): Remove unnecessary cast.
	* tui/tui-data.c (init_win_info, tui_del_window)
	(tui_free_window, tui_del_data_windows, tui_free_data_content)
	(free_content_elements): Remove unnecessary cast.
	* tui/tui-windata.c (tui_first_data_item_displayed): Remove
	unnecessary cast.
	* tui/tui-source.c (tui_set_source_content)
	(tui_vertical_source_scroll): Remove unnecessary cast.
	* tui/tui-layout.c (tui_default_win_height): Remove unnecessary
	cast.
	* tui/tui-io.c (tui_initialize_io): Remove unnecessary cast.
	* tui/tui-regs.c (tui_display_registers_from)
	(tui_display_register): Remove unnecessary cast.
	* tui/tui-wingeneral.c (tui_refresh_win, tui_delete_win)
	(tui_unhighlight_win, tui_highlight_win, tui_make_window)
	(make_visible): Remove unnecessary cast.
	* tui/tui-winsource.c (tui_erase_source_content)
	(tui_update_breakpoint_info, tui_set_exec_info_content): Remove
	unnecessary cast.
	* ax-gdb.c (agent_command_1): Remove unnecessary cast.
	* cli/cli-setshow.c (cmd_show_list): Remove unnecessary cast.
	* stabsread.c (read_type, read_array_type, read_range_type):
	Remove unnecessary cast.
	* mdebugread.c (mdebug_build_psymtabs): Remove unnecessary cast.
	(parse_symbol, parse_type, upgrade_type, parse_external)
	(parse_partial_symbols, psymtab_to_symtab_1, cross_ref): Remove
	unnecessary cast.
	* gdb_bfd.c (gdb_bfd_map_section): Remove unnecessary cast.

1 files changed, 7 insertions, 7 deletions

diff --git a/gdb/tui/tui-wingeneral.c b/gdb/tui/tui-wingeneral.c
index b1ed0f4..b474aa0 100644
--- a/gdb/tui/tui-wingeneral.c
+++ b/gdb/tui/tui-wingeneral.c
@@ -45,7 +45,7 @@ tui_refresh_win (struct tui_gen_win_info *win_info)
 
 	  data_item_win_ptr = &win_info->content[i]->which_element.data_window;
 	  if (data_item_win_ptr != NULL
-	      && data_item_win_ptr->handle != (WINDOW *) NULL)
+	      && data_item_win_ptr->handle != NULL)
 	    wrefresh (data_item_win_ptr->handle);
 	}
     }
@@ -55,7 +55,7 @@ tui_refresh_win (struct tui_gen_win_info *win_info)
     }
   else
     {
-      if (win_info->handle != (WINDOW *) NULL)
+      if (win_info->handle != NULL)
 	wrefresh (win_info->handle);
     }
 
@@ -67,7 +67,7 @@ tui_refresh_win (struct tui_gen_win_info *win_info)
 void
 tui_delete_win (WINDOW *window)
 {
-  if (window != (WINDOW *) NULL)
+  if (window != NULL)
     delwin (window);
 
   return;
@@ -110,7 +110,7 @@ void
 tui_unhighlight_win (struct tui_win_info *win_info)
 {
   if (win_info != NULL 
-      && win_info->generic.handle != (WINDOW *) NULL)
+      && win_info->generic.handle != NULL)
     {
       box_win ((struct tui_gen_win_info *) win_info, NO_HILITE);
       wrefresh (win_info->generic.handle);
@@ -124,7 +124,7 @@ tui_highlight_win (struct tui_win_info *win_info)
 {
   if (win_info != NULL
       && win_info->can_highlight
-      && win_info->generic.handle != (WINDOW *) NULL)
+      && win_info->generic.handle != NULL)
     {
       box_win ((struct tui_gen_win_info *) win_info, HILITE);
       wrefresh (win_info->generic.handle);
@@ -157,7 +157,7 @@ tui_make_window (struct tui_gen_win_info *win_info, int box_it)
 		   win_info->origin.y,
 		   win_info->origin.x);
   win_info->handle = handle;
-  if (handle != (WINDOW *) NULL)
+  if (handle != NULL)
     {
       if (box_it == BOX_WINDOW)
 	box_win (win_info, NO_HILITE);
@@ -189,7 +189,7 @@ make_visible (struct tui_gen_win_info *win_info, int visible)
     }
   else if (!visible
 	   && win_info->is_visible
-	   && win_info->handle != (WINDOW *) NULL)
+	   && win_info->handle != NULL)
     {
       win_info->is_visible = FALSE;
       tui_delete_win (win_info->handle);