lkml.org 
[lkml]   [2012]   [Jun]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 3/3] tools lib traceevent: Introduce pevent_strerror
Date
Steven Rostedt <rostedt@goodmis.org> writes:

> On Tue, 2012-06-12 at 16:42 +0900, Namhyung Kim wrote:
>
>> +/*
>> + * This must have a same ordering as the enum pevent_errno.
>> + */
>> +static const char * const pevent_error_str[] = {
>> + "failed to allocate memory",
>> + "failed to parse event",
>> + "failed to read event id",
>> + "failed to read event format",
>> + "failed to read event print fmt",
>> + "failed to allocate field name for ftrace",
>> +};
>> +
>
> Here's a little macro trick to keep the strings and enums always in
> sync:
>
> #define __PEVENT_ERRNO_CODES \
> _C(PEVENT_ERRNO__MEM_ALLOC_FAILED, "failed to allocate memory"), \
> _C(PEVENT_ERRNO__PARSE_EVENT_FAILED, "failed to parse event"), \
> _C(PEVENT_ERRNO__READ_ID_FAILED, "failed to read event id"), \
> _C(PEVENT_ERRNO__READ_FORMAT_FAILED, "failed to read event format"), \
> _C(PEVENT_ERRNO__READ_PRINT_FAILED, "failed to read event print fmt"),\
> _C(PEVENT_ERRNO__OLD_FTRACE_ARG_FAILED,"failed to allocate field name for ftrace"),
>
> #undef _C
> #define _C(a,b) b
> static const char * const pevent_error_str[] = { __PEVENT_ERROR_CODES };
>

Cool. Maybe even shorter:

#define __PEVENT_ERRNO_CODES \
_C(MEM_ALLOC_FAILED, "failed to allocate memory"), \
_C(PARSE_EVENT_FAILED, "failed to parse event"), \
_C(READ_ID_FAILED, "failed to read event id"), \
_C(READ_FORMAT_FAILED, "failed to read event format"), \
_C(READ_PRINT_FAILED, "failed to read event print fmt"), \
_C(OLD_FTRACE_ARG_FAILED, "failed to allocate field name for ftrace"),

#undef _C
#define _C(a,b) PEVENT_ERRNO__ ## a
static const char * const pevent_error_str[] = { __PEVENT_ERROR_CODES };

But it make them less grep-able?

Thanks,
Namhyung


> #undef _C
> #define _C(a, b) a
>
> enum pevent_errno {
> __PEVENT_ERRNO__BEFORE_START = -100000 - 1,
> __PEVENT_ERRNO_CODES
> __PEVENT_ERRNO__END,
> };
>
> #define __PEVENT_ERRNO__START (__PEVENT_ERRNO__BEFORE_START + 1)
>
> Just saying ;-)
>
> -- Steve


\
 
 \ /
  Last update: 2012-06-16 05:01    [W:0.103 / U:0.724 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site