[PATCH 2/4] ld/testsuite: don't output to /dev/null on mingw hosts

[Alan Modra]

On Mon, Feb 20, 2023 at 09:22:22AM +0100, Clément Chigot via Binutils wrote:
> Mingw doesn't have /dev/null and thus "-o /dev/null" will fail.
> Currently, all the options are checked using this "-o /dev/null",
> resulting in them being disabled on mingw hosts. Fix that by
> outputting to a real .exe file.
> 
> ld/ChangeLog:
> 
> 	* testsuite/config/default.exp: Replace "-o /dev/null" by a file
> 	on mingw hosts.

I think I'd prefer this to always output to a file, which you should
delete afterwards.

> ---
>  ld/testsuite/config/default.exp | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/ld/testsuite/config/default.exp b/ld/testsuite/config/default.exp
> index 257fd4ba985..776b33842c2 100644
> --- a/ld/testsuite/config/default.exp
> +++ b/ld/testsuite/config/default.exp
> @@ -383,6 +383,9 @@ proc compiler_supports { flag args } {
>  	    append flags " [board_info [target_info name] ldflags]"
>  	}
>  	set fn "cs[pid].c"
> +	if [ishost "*-*-mingw*"] {
> +	    set fno "cs[pid].exe"
> +	}
>  	set f [open $fn "w"]
>  	if { [llength $args] > 0 } {
>  	    puts $f [lindex $args 0]
> @@ -391,7 +394,12 @@ proc compiler_supports { flag args } {
>  	}
>  	close $f
>  	set rfn [remote_download host $fn]
> -	set avail [run_host_cmd_yesno "$CC_FOR_TARGET" "$flags $flag $rfn -o /dev/null"]
> +	if [ishost "*-*-mingw*"] {
> +	    set avail [run_host_cmd_yesno "$CC_FOR_TARGET" "$flags $flag $rfn -o $fno"]
> +	    file delete $fno
> +	} else {
> +	    set avail [run_host_cmd_yesno "$CC_FOR_TARGET" "$flags $flag $rfn -o /dev/null"]
> +	}
>  	remote_file host delete $rfn
>  	file delete $fn
>  	return $avail
> -- 
> 2.25.1

-- 
Alan Modra
Australia Development Lab, IBM