Re: [OB PATCH] Avoid testcase build failures with -Wunused-value

[Pedro Alves <palves@redhat.com>]

On 6/23/20 12:26 PM, Gary Benson via Gdb-patches wrote:
> --- a/gdb/testsuite/gdb.cp/namespace.cc
> +++ b/gdb/testsuite/gdb.cp/namespace.cc
> @@ -150,22 +150,22 @@ namespace C
>        // plan to have GDB try to print out, just to make sure that the
>        // compiler and I agree which ones should be legal!  It's easy
>        // to screw up when testing the boundaries of namespace stuff.
> -      c;
> +      int unused1 = c;

It looks like such a fix will only work until the compiler decides
to enable -Wunused-variable by default too:

testsuite/gdb.cp/namespace.cc:153:11: warning: unused variable 'unused' [-Wunused-variable]
      int unused = c;
          ^

Try compiling the testcase with -Wall, with both g++ and clang++:

 $ clang++ testsuite/gdb.cp/namespace.cc -Wall

I think we should fix this with the more usual cast-to-void way:

 (void) c;

etc.