From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753839Ab2FLSB5 (ORCPT ); Tue, 12 Jun 2012 14:01:57 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:27932 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751847Ab2FLSBz (ORCPT ); Tue, 12 Jun 2012 14:01:55 -0400 X-Authority-Analysis: v=2.0 cv=T6AOvo2Q c=1 sm=0 a=ZycB6UtQUfgMyuk2+PxD7w==:17 a=XQbtiDEiEegA:10 a=ag8JG7z7P3cA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=meVymXHHAAAA:8 a=ayC55rCoAAAA:8 a=57SyGIRnAAAA:8 a=pGLkceISAAAA:8 a=VwQbUJbxAAAA:8 a=xOx-NkpWTd6BDVzQWhAA:9 a=PUjeQqilurYA:10 a=TIV7c6GJmisA:10 a=MSl-tDqOz04A:10 a=jeBq3FmKZ4MA:10 a=LI9Vle30uBYA:10 a=ZycB6UtQUfgMyuk2+PxD7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.80.29 Message-ID: <1339524114.13377.140.camel@gandalf.stny.rr.com> Subject: Re: [PATCH 3/3] tools lib traceevent: Introduce pevent_strerror From: Steven Rostedt To: Namhyung Kim Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , Paul Mackerras , Ingo Molnar , LKML , Frederic Weisbecker , Namhyung Kim Date: Tue, 12 Jun 2012 14:01:54 -0400 In-Reply-To: <1339486959-25241-4-git-send-email-namhyung@kernel.org> References: <1339486959-25241-1-git-send-email-namhyung@kernel.org> <1339486959-25241-4-git-send-email-namhyung@kernel.org> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.2.2-1+b1 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2012-06-12 at 16:42 +0900, Namhyung Kim wrote: > From: Namhyung Kim > > The pevent_strerror() sets @buf to a string that describes the > (libtraceevent-specific) error condition that is passed via @errnum. > > This is similar to strerror_r() and does same thing if @errnum has a > standard errno value. > > Cc: Frederic Weisbecker > Cc: Steven Rostedt > Signed-off-by: Namhyung Kim > --- > tools/lib/traceevent/event-parse.c | 48 ++++++++++++++++++++++++++++++++++++ > tools/lib/traceevent/event-parse.h | 2 ++ > 2 files changed, 50 insertions(+) > > diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c > index 866bdca4825d..3ed2d9362e69 100644 > --- a/tools/lib/traceevent/event-parse.c > +++ b/tools/lib/traceevent/event-parse.c > @@ -4706,6 +4706,54 @@ enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf, > return ret; > } > > +/* > + * 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", > +}; > + > +int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum, > + char *buf, size_t buflen) Hmm, actually I wonder if we should put the error into the pevent structure. Then we wouldn't even need to waste time to pass the data through. That is, you can simply do: ret = pevent_foo(); if (ret < 0) { pevent_strerr(pevent, buf, buflen); printf("%s\n", buf); } Perhaps even include a pevent_perror(), to just do: if (ret < 0) { pevent_perror(pevent); return ret; } -- Steve > +{ > + int idx; > + const char *msg; > + > + if (errnum >= 0) { > + strerror_r(errnum, buf, buflen); > + return 0; > + } > + > + if (errnum < __PEVENT_ERRNO__START || > + errnum >= __PEVENT_ERRNO__END) > + return -1; > + > + idx = errnum - __PEVENT_ERRNO__START; > + msg = pevent_error_str[idx]; > + > + switch (errnum) { > + case PEVENT_ERRNO__MEM_ALLOC_FAILED: > + case PEVENT_ERRNO__PARSE_EVENT_FAILED: > + case PEVENT_ERRNO__READ_ID_FAILED: > + case PEVENT_ERRNO__READ_FORMAT_FAILED: > + case PEVENT_ERRNO__READ_PRINT_FAILED: > + case PEVENT_ERRNO__OLD_FTRACE_ARG_FAILED: > + snprintf(buf, buflen, "%s", msg); > + break; > + > + default: > + /* cannot reach here */ > + break; > + } > + > + return 0; > +} > + > int get_field_val(struct trace_seq *s, struct format_field *field, > const char *name, struct pevent_record *record, > unsigned long long *val, int err) > diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h > index 24b7649d530b..7e90aba20850 100644 > --- a/tools/lib/traceevent/event-parse.h > +++ b/tools/lib/traceevent/event-parse.h > @@ -576,6 +576,8 @@ int pevent_data_pid(struct pevent *pevent, struct pevent_record *rec); > const char *pevent_data_comm_from_pid(struct pevent *pevent, int pid); > void pevent_event_info(struct trace_seq *s, struct event_format *event, > struct pevent_record *record); > +int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum, > + char *buf, size_t buflen); > > struct event_format **pevent_list_events(struct pevent *pevent, enum event_sort_type); > struct format_field **pevent_event_common_fields(struct event_format *event);