Re: [PATCH 2/2] perf trace/scripting: Don't display 'scripting unsupported' msg unnecessarily

[Wang Liming <liming.wang@windriver.com>]

Tom Zanussi wrote:
> The 'scripting unsupported' message should only be displayed when the
> -s or -g options are used, and not when they aren't, as the current
> code does.
> 
> Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
> ---
>  tools/perf/util/trace-event-perl.c |   64 +++++++++++++++++++++++++++++++-----
>  1 files changed, 55 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/perf/util/trace-event-perl.c b/tools/perf/util/trace-event-perl.c
> index 59564b2..a5ffe60 100644
> --- a/tools/perf/util/trace-event-perl.c
> +++ b/tools/perf/util/trace-event-perl.c
> @@ -570,26 +570,72 @@ struct scripting_ops perl_scripting_ops = {
>  	.generate_script = perl_generate_script,
>  };
>  
> -#ifdef NO_LIBPERL
> -void setup_perl_scripting(void)
> +static void print_unsupported_msg(void)
>  {
>  	fprintf(stderr, "Perl scripting not supported."
> -		"  Install libperl and rebuild perf to enable it.  e.g. "
> -		"apt-get install libperl-dev (ubuntu), yum install "
> -		"perl-ExtUtils-Embed (Fedora), etc.\n");
> +		"  Install libperl and rebuild perf to enable it.\n"
> +		"For example:\n  # apt-get install libperl-dev (ubuntu)"
> +		"\n  # yum install perl-ExtUtils-Embed (Fedora)"
> +		"\n  etc.\n");
>  }

I have one question about how to compile c program that embedded perl function:

$cat foo.c
#include <EXTERN.h>
#include <perl.h>
int main(void)
{
         perl_alloc();
         return 0;
}

$gcc  -x c foo.c `perl -MExtUtils::Embed -e ccopts 2>/dev/null`  -o foo `perl 
-MExtUtils::Embed -e ldopts 2>/dev/null`
/usr/lib/perl/5.8/auto/DynaLoader/DynaLoader.a:1: error: expected identifier or 
'(' before '!' token
/usr/lib/perl/5.8/auto/DynaLoader/DynaLoader.a:2: error: stray '`' in program
...

About thousand of error.
I'm using ubuntu 8.04. Above error leads "tools/perl/Makefile" can't find the 
libperl-dev and define "NO_LIBPERL", but I have installed "libperl-dev".

Did you ever encounter this error?
Thanks.

Liming Wang
> -#else
> -void setup_perl_scripting(void)
> +
> +static int perl_start_script_unsupported(const char *script __unused)
> +{
> +	print_unsupported_msg();
> +
> +	return -1;
> +}
> +
> +static int perl_stop_script_unsupported(void)
> +{
> +	return 0;
> +}
> +
> +static void perl_process_event_unsupported(int cpu __unused,
> +					   void *data __unused,
> +					   int size __unused,
> +					   unsigned long long nsecs __unused,
> +					   char *comm __unused)
> +{
> +}
> +
> +static int perl_generate_script_unsupported(const char *outfile __unused)
> +{
> +	print_unsupported_msg();
> +
> +	return -1;
> +}
> +
> +struct scripting_ops perl_scripting_unsupported_ops = {
> +	.name = "Perl",
> +	.start_script = perl_start_script_unsupported,
> +	.stop_script = perl_stop_script_unsupported,
> +	.process_event = perl_process_event_unsupported,
> +	.generate_script = perl_generate_script_unsupported,
> +};
> +
> +static void register_perl_scripting(struct scripting_ops *scripting_ops)
>  {
>  	int err;
> -	err = script_spec_register("Perl", &perl_scripting_ops);
> +	err = script_spec_register("Perl", scripting_ops);
>  	if (err)
>  		die("error registering Perl script extension");
>  
> -	err = script_spec_register("pl", &perl_scripting_ops);
> +	err = script_spec_register("pl", scripting_ops);
>  	if (err)
>  		die("error registering pl script extension");
>  
>  	scripting_context = malloc(sizeof(struct scripting_context));
>  }
> +
> +#ifdef NO_LIBPERL
> +void setup_perl_scripting(void)
> +{
> +	register_perl_scripting(&perl_scripting_unsupported_ops);
> +}
> +#else
> +void setup_perl_scripting(void)
> +{
> +	register_perl_scripting(&perl_scripting_ops);
> +}
>  #endif