[PATCH v3 2/4] perf tools: Prompt proper error message for wrong terms of hw/sw events

He Kuang
2015-09-28T03:53:42Z

Prompt proper error message and show valid terms when wrong config
terms is specificed for hw/sw type perf events. This patch makes the
original error prompt function formats_error_string() more generic,
which only outputs the static config terms for hw/sw perf events, and
prepends pmu formats for pmu events.

Before this patch:

$ perf record -e 'cpu-clock/freqx=200/' -a sleep 1
invalid or unsupported event: 'cpu-clock/freqx=200/'
Run 'perf list' for a list of valid events

usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]

-e, --event <event> event selector. use 'perf list' to list available events

After this patch:

$ perf record -e 'cpu-clock/freqx=200/' -a sleep 1
event syntax error: 'cpu-clock/freqx=200/'
\___ unknown term

valid terms: config,config1,config2,name,period,freq,branch_type,time,call-graph,stack-size

Run 'perf list' for a list of valid events

usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]

-e, --event <event> event selector. use 'perf list' to list available events

Signed-off-by: He Kuang <hekuang@huawei.com>
---

Changes v2-v3:
- Change example in commit message.
- Update comment in flex file.
- Move freeing additional_terms outside.

---
tools/perf/util/parse-events.c | 29 +++++++++++++++++++++++++++++
tools/perf/util/parse-events.h | 1 +
tools/perf/util/parse-events.l | 2 +-
tools/perf/util/pmu.c | 37 ++++++++++++++-----------------------
4 files changed, 45 insertions(+), 24 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 9dc3fb6..ea64ec07 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -656,6 +656,9 @@ do { \
CHECK_TYPE_VAL(STR);
break;
default:
+ err->str = strdup("unknown term");
+ err->idx = term->err_term;
+ err->help = parse_events_formats_error_string(NULL);
return -EINVAL;
}

@@ -1875,3 +1878,29 @@ void parse_events_evlist_error(struct parse_events_evlist *data,
err->str = strdup(str);
WARN_ONCE(!err->str, "WARNING: failed to allocate error string");
}
+
+/*
+ * Return string contains valid config terms of an event.
+ * @additional_terms: For terms such as PMU sysfs terms.
+ */
+char *parse_events_formats_error_string(char *additional_terms)
+{
+ char *str;
+ static const char *static_terms = "config,config1,config2,name,"
+ "period,freq,branch_type,time,"
+ "call-graph,stack-size\n";
+
+ /* valid terms */
+ if (additional_terms) {
+ if (!asprintf(&str, "valid terms: %s,%s",
+ additional_terms, static_terms))
+ goto fail;
+ } else {
+ if (!asprintf(&str, "valid terms: %s", static_terms))
+ goto fail;
+ }
+ return str;
+
+fail:
+ return NULL;
+}
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index ffee7ec..c7b904a 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -156,5 +156,6 @@ int print_hwcache_events(const char *event_glob, bool name_only);
extern int is_valid_tracepoint(const char *event_string);

int valid_event_mount(const char *eventfs);
+char *parse_events_formats_error_string(char *additional_terms);

#endif /* __PERF_PARSE_EVENTS_H */
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 936d566..c29832b 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -174,7 +174,7 @@ modifier_bp [rwx]{1,3}

<config>{
/*
- * Please update formats_error_string any time
+ * Please update parse_events_formats_error_string any time
* new static term is added.
*/
config { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CONFIG); }
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 89c91a1..ac42c97 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -626,38 +626,26 @@ static int pmu_resolve_param_term(struct parse_events_term *term,
return -1;
}

-static char *formats_error_string(struct list_head *formats)
+static char *pmu_formats_string(struct list_head *formats)
{
struct perf_pmu_format *format;
- char *err, *str;
- static const char *static_terms = "config,config1,config2,name,"
- "period,freq,branch_type,time,"
- "call-graph,stack-size\n";
+ char *str;
+ struct strbuf buf;
unsigned i = 0;

- if (!asprintf(&str, "valid terms:"))
+ if (!formats)
return NULL;

+ strbuf_init(&buf, 0);
/* sysfs exported terms */
- list_for_each_entry(format, formats, list) {
- char c = i++ ? ',' : ' ';
-
- err = str;
- if (!asprintf(&str, "%s%c%s", err, c, format->name))
- goto fail;
- free(err);
- }
+ list_for_each_entry(format, formats, list)
+ strbuf_addf(&buf, i++ ? ",%s" : "%s",
+ format->name);

- /* static terms */
- err = str;
- if (!asprintf(&str, "%s,%s", err, static_terms))
- goto fail;
+ str = strbuf_detach(&buf, NULL);
+ strbuf_release(&buf);

- free(err);
return str;
-fail:
- free(err);
- return NULL;
}

/*
@@ -693,9 +681,12 @@ static int pmu_config_term(struct list_head *formats,
if (verbose)
printf("Invalid event/parameter '%s'\n", term->config);
if (err) {
+ char *pmu_term = pmu_formats_string(formats);
+
err->idx = term->err_term;
err->str = strdup("unknown term");
- err->help = formats_error_string(formats);
+ err->help = parse_events_formats_error_string(pmu_term);
+ free(pmu_term);
}
return -EINVAL;
}
--
1.8.5.2