Re: [PATCH] perf tools: Fix line number in the config file error message

[Namhyung Kim <namhyung@kernel.org>]

Hi Jiri,

On Tue, 23 Sep 2014 13:56:56 +0200, Jiri Olsa wrote:
> On Tue, Sep 23, 2014 at 10:01:39AM +0900, Namhyung Kim wrote:
>> Hello,
>> 
>> This is patchset to add new callchain related config options so that
>> users don't need to pass their preference to the cmdline everytime.
>> 
>> Following config options will be added, and users can set appropriate
>> values to ~/.perfconfig file.  Note that the dump-size option is
>> meaningful only if record-mode = dwarf.
>> 
>>   $ cat ~/.perfconfig
>>   [call-graph]
>>     record-mode = dwarf
>>     dump-size = 4096
>>     print-type = graph
>>     order = callee
>>     threshold = 0.5
>>     print-limit = 128
>>     sort-key = function
>> 
>>   $ perf record -vg sleep 1
>>   callchain: type DWARF
>>   callchain: stack dump size 4096
>>   mmap size 528384B
>>   [ perf record: Woken up 1 times to write data ]
>>   [ perf record: Captured and wrote 0.054 MB perf.data (~2378 samples) ]
>>   Looking at the vmlinux_path (7 entries long)
>>   Using /lib/modules/3.16.3-1-ARCH/build/vmlinux for symbols
>> 
>> 
>> Jiri and David, I kept your Acked-by and Reviewed-by in this version.
>> Please take a look at the patch 4/5 which splits parser functions that
>> it still looks okay to you.
>
> looks ok to me, ACK for the patchset

Thanks!

>
> During the testing I found wrong line is displayed in the parsing
> error message. It's bug in the config code, attached patch should
> fix it.

Didn't notice that.. thanks for the quick fix. :)

>
>
> ---
> If we fail to parse the config file within the callback function,
> the line number counter 'could be' already on the next line.
>
> This results in wrong line number report like:
>
>   $ cat ~/.perfconfig
>   [call-graph]
>           sort-key = krava
>   $ perf record ls
>   Fatal: bad config file line 3 in /home/jolsa/.perfconfig
>
> Fixing this by saving the current line number for this case.
>
> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung


> ---
>  tools/perf/util/config.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
> index 953512ed72ba..57ff826f150b 100644
> --- a/tools/perf/util/config.c
> +++ b/tools/perf/util/config.c
> @@ -222,7 +222,8 @@ static int perf_parse_file(config_fn_t fn, void *data)
>  	const unsigned char *bomptr = utf8_bom;
>  
>  	for (;;) {
> -		int c = get_next_char();
> +		int line, c = get_next_char();
> +
>  		if (bomptr && *bomptr) {
>  			/* We are at the file beginning; skip UTF8-encoded BOM
>  			 * if present. Sane editors won't put this in on their
> @@ -261,8 +262,16 @@ static int perf_parse_file(config_fn_t fn, void *data)
>  		if (!isalpha(c))
>  			break;
>  		var[baselen] = tolower(c);
> -		if (get_value(fn, data, var, baselen+1) < 0)
> +
> +		/*
> +		 * The get_value function might or might not reach the '\n',
> +		 * so saving the current line number for error reporting.
> +		 */
> +		line = config_linenr;
> +		if (get_value(fn, data, var, baselen+1) < 0) {
> +			config_linenr = line;
>  			break;
> +		}
>  	}
>  	die("bad config file line %d in %s", config_linenr, config_file_name);
>  }