Re: [PATCH perf/core v2 3/8] perf help: Make check_emacsclient_version to check strbuf APIs

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Sat, Apr 30, 2016 at 12:10:14AM +0900, Masami Hiramatsu escreveu:
> Make check_emacsclient_version() to check the return
> value of strbuf APIs so that it can handle errors in
> strbuf.

Looks ok.

> ---
>  tools/perf/builtin-help.c |   18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/perf/builtin-help.c b/tools/perf/builtin-help.c
> index bc1de9b..f9830c9 100644
> --- a/tools/perf/builtin-help.c
> +++ b/tools/perf/builtin-help.c
> @@ -61,6 +61,7 @@ static int check_emacsclient_version(void)
>  	struct child_process ec_process;
>  	const char *argv_ec[] = { "emacsclient", "--version", NULL };
>  	int version;
> +	int ret = -1;
>  
>  	/* emacsclient prints its version number on stderr */
>  	memset(&ec_process, 0, sizeof(ec_process));
> @@ -71,7 +72,10 @@ static int check_emacsclient_version(void)
>  		fprintf(stderr, "Failed to start emacsclient.\n");
>  		return -1;
>  	}
> -	strbuf_read(&buffer, ec_process.err, 20);
> +	if (strbuf_read(&buffer, ec_process.err, 20) < 0) {
> +		fprintf(stderr, "Failed to read emacsclient version\n");
> +		goto out;
> +	}
>  	close(ec_process.err);
>  
>  	/*
> @@ -82,8 +86,7 @@ static int check_emacsclient_version(void)
>  
>  	if (prefixcmp(buffer.buf, "emacsclient")) {
>  		fprintf(stderr, "Failed to parse emacsclient version.\n");
> -		strbuf_release(&buffer);
> -		return -1;
> +		goto out;
>  	}
>  
>  	version = atoi(buffer.buf + strlen("emacsclient"));
> @@ -92,12 +95,11 @@ static int check_emacsclient_version(void)
>  		fprintf(stderr,
>  			"emacsclient version '%d' too old (< 22).\n",
>  			version);
> -		strbuf_release(&buffer);
> -		return -1;
> -	}
> -
> +	} else
> +		ret = 0;
> +out:
>  	strbuf_release(&buffer);
> -	return 0;
> +	return ret;
>  }
>  
>  static void exec_woman_emacs(const char *path, const char *page)