Re: [PATCH] GDB testsuite: Suppress GCC's colored output

[Simon Marchi <simon dot marchi at polymtl dot ca>]

On 2017-08-02 19:35, Andreas Arnez wrote:
> Newer GCC versions yield colored diagnostic messages by default, which 
> may
> be useful when executing GDB interactively from a terminal.  But when 
> run
> from a GDB test case, the compiler output is written into gdb.log, 
> where
> such escape sequences are usually more inhibiting than helpful to the
> evaluation of test results.  So this patch suppresses that.

That's because you are not using the right viewer :).  Try "less -R 
gdb.log", you should see the rainbow.

> gdb/testsuite/ChangeLog:
>
> 	* lib/gdb.exp (gdb_compile): Suppress GCC's coloring of messages.
> ---
>  gdb/testsuite/lib/gdb.exp | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
> index 3d3eaab..9a5c27f 100644
> --- a/gdb/testsuite/lib/gdb.exp
> +++ b/gdb/testsuite/lib/gdb.exp
> @@ -3552,6 +3552,9 @@ proc gdb_compile {source dest type options} {
>  	}
>      }
>
> +    # Stop the compiler from producing colored output.
> +    setenv GCC_COLORS ""
> +
>      set result [target_compile $source $dest $type $options]
>
>      # Prune uninteresting compiler (and linker) output.

I was wondering why GCC showed colors even though it's not invoked 
"interactively".  Dejagnu uses expect's spawn to spawn processes, 
including the compiler.  spawn allocates a tty for the subprocess, which 
is what GCC checks to determine whether or not to enable colors.

You patch LGTM, but please leave the patch for review for a few days, 
then push it if nobody says anything.

Thanks!

Simon