Re: [PATCH 5/6] perf-probe: don't always consider EOF as an error when listing source code

[Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>]

(2010/12/20 23:18), Franck Bui-Huu wrote:
> From: Franck Bui-Huu <fbuihuu@gmail.com>
> 
> When listing a whole file or a function which is located at the end,
> perf-probe -L output wrongly: "Source file is shorter than expected.".
> 
> This is because show_one_line() always consider EOF as an error.

Right, that was a wrong behavior.

> 
> This patch fixes this by not considering EOF as an error when dumping
> the trailing lines. Otherwise it's still an error and perf-probe still
> outputs its warning.

Thank you for fixing the bug! :)

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

> 
> Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
> ---
>  tools/perf/util/probe-event.c |   38 ++++++++++++++++++++++++++------------
>  1 files changed, 26 insertions(+), 12 deletions(-)
> 
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index 8e5f5ff..1e81936 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -297,7 +297,7 @@ static int get_real_path(const char *raw_path, const char *comp_dir,
>  #define LINEBUF_SIZE 256
>  #define NR_ADDITIONAL_LINES 2
>  
> -static int show_one_line(FILE *fp, int l, bool skip, bool show_num)
> +static int __show_one_line(FILE *fp, int l, bool skip, bool show_num)
>  {
>  	char buf[LINEBUF_SIZE];
>  	const char *color = show_num ? "" : PERF_COLOR_BLUE;
> @@ -316,16 +316,30 @@ static int show_one_line(FILE *fp, int l, bool skip, bool show_num)
>  
>  	} while (strchr(buf, '\n') == NULL);
>  
> -	return 0;
> +	return 1;
>  error:
> -	if (feof(fp))
> +	if (ferror(fp)) {
>  		pr_warning("Source file is shorter than expected.\n");
> -	else
> -		pr_warning("File read error: %s\n", strerror(errno));
> +		return -1;
> +	}
> +	return 0;
> +}
>  
> -	return -1;
> +static int _show_one_line(FILE *fp, int l, bool skip, bool show_num)
> +{
> +	int rv = __show_one_line(fp, l, skip, show_num);
> +	if (rv == 0) {
> +		pr_warning("Source file is shorter than expected.\n");
> +		rv = -1;
> +	}
> +	return rv;
>  }
>  
> +#define show_one_line_with_num(f,l)	_show_one_line(f,l,false,true)
> +#define show_one_line(f,l)		_show_one_line(f,l,false,false)
> +#define skip_one_line(f,l)		_show_one_line(f,l,true,false)
> +#define show_one_line_or_eof(f,l)	__show_one_line(f,l,false,false)
> +
>  /*
>   * Show line-range always requires debuginfo to find source file and
>   * line number.
> @@ -384,27 +398,27 @@ int show_line_range(struct line_range *lr, const char *module)
>  	}
>  	/* Skip to starting line number */
>  	while (l < lr->start) {
> -		ret = show_one_line(fp, l++, true, false);
> +		ret = skip_one_line(fp, l++);
>  		if (ret < 0)
>  			goto end;
>  	}
>  
>  	list_for_each_entry(ln, &lr->line_list, list) {
>  		for (; ln->line > l; l++) {
> -			ret = show_one_line(fp, l - lr->offset, false, false);
> +			ret = show_one_line(fp, l - lr->offset);
>  			if (ret < 0)
>  				goto end;
>  		}
> -		ret = show_one_line(fp, l++ - lr->offset, false, true);
> +		ret = show_one_line_with_num(fp, l++ - lr->offset);
>  		if (ret < 0)
>  			goto end;
>  	}
>  
>  	if (lr->end == INT_MAX)
>  		lr->end = l + NR_ADDITIONAL_LINES;
> -	while (l <= lr->end && !feof(fp)) {
> -		ret = show_one_line(fp, l++ - lr->offset, false, false);
> -		if (ret < 0)
> +	while (l <= lr->end) {
> +		ret = show_one_line_or_eof(fp, l++ - lr->offset);
> +		if (ret <= 0)
>  			break;
>  	}
>  end:


-- 
Masami HIRAMATSU
2nd Dept. Linux Technology Center
Hitachi, Ltd., Systems Development Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com