Re: [RFC] Use macro for void typecast necessary for ncurses library.

[Joel Brobecker <brobecker at adacore dot com>]

> > Suggestion (which you are free to ignore): Would it make sense to
> > define
> > a new function or macro to have the cast (and therefore the comment) in
> > only one place?
>   Here is an implementation of your idea.

Argh - I didn't realize that two "routines" where involved. For some
reason, when I looked at the initial patch, I only noticed wstandout,
and I thought it was used 4 times.

For the record - my idea was to define a macro such as unchecked_wstandout
that contains the cast, but if we have to do it for at least 2 routines,
there is no real benefit.

I ended up checking in the attached patch.  Sorry about the screwup,
and thanks for giving it a try...

-- 
Joel

commit e0737f6d628f1aa573cc2d1fd827be90b5d48a09
Author: Joel Brobecker <brobecker@adacore.com>
Date:   Thu Apr 15 21:32:52 2010 -0700

            * tui/tui-regs.c (tui_display_register): Add comment about
            a couple of casts.
            * tui/tui-stack.c (tui_show_locator_content): Ditto.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0a8f5b1..7c2ec94 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2010-04-16  Joel Brobecker  <brobecker@adacore.com>
+
+	* tui/tui-regs.c (tui_display_register): Add comment about
+	a couple of casts.
+	* tui/tui-stack.c (tui_show_locator_content): Ditto.
+
 2010-04-15  Stan Shebs  <stan@codesourcery.com>
 
 	* frame.c: Include tracepoint.h.
diff --git a/gdb/tui/tui-regs.c b/gdb/tui/tui-regs.c
index 8cbd338..a339bea 100644
--- a/gdb/tui/tui-regs.c
+++ b/gdb/tui/tui-regs.c
@@ -541,6 +541,11 @@ tui_display_register (struct tui_data_element *data,
       int i;
 
       if (data->highlight)
+	/* We ignore the return value, casting it to void in order to avoid
+	   a compiler warning.  The warning itself was introduced by a patch
+	   to ncurses 5.7 dated 2009-08-29, changing this macro to expand
+	   to code that causes the compiler to generate an unused-value
+	   warning.  */
 	(void) wstandout (win_info->handle);
       
       wmove (win_info->handle, 0, 0);
@@ -551,6 +556,11 @@ tui_display_register (struct tui_data_element *data,
         waddstr (win_info->handle, data->content);
 
       if (data->highlight)
+	/* We ignore the return value, casting it to void in order to avoid
+	   a compiler warning.  The warning itself was introduced by a patch
+	   to ncurses 5.7 dated 2009-08-29, changing this macro to expand
+	   to code that causes the compiler to generate an unused-value
+	   warning.  */
 	(void) wstandend (win_info->handle);
       tui_refresh_win (win_info);
     }
diff --git a/gdb/tui/tui-stack.c b/gdb/tui/tui-stack.c
index 1630bea..d6b514d 100644
--- a/gdb/tui/tui-stack.c
+++ b/gdb/tui/tui-stack.c
@@ -256,6 +256,11 @@ tui_show_locator_content (void)
 
       string = tui_make_status_line (&element->which_element.locator);
       wmove (locator->handle, 0, 0);
+      /* We ignore the return value from wstandout and wstandend, casting
+	 them to void in order to avoid a compiler warning.  The warning
+	 itself was introduced by a patch to ncurses 5.7 dated 2009-08-29,
+	 changing these macro to expand to code that causes the compiler
+	 to generate an unused-value warning.  */
       (void) wstandout (locator->handle);
       waddstr (locator->handle, string);
       wclrtoeol (locator->handle);