Re: [PATCH v2 11/16] perf parse-events: Improve error message for bad numbers

Liang, Kan
2024-04-18T20:28:07Z

On 2024-04-16 2:15 a.m., Ian Rogers wrote:
> Use the error handler from the parse_state to give a more informative
> error message.
>
> Before:
> ```
> $ perf stat -e 'cycles/period=99999999999999999999/' true
> event syntax error: 'cycles/period=99999999999999999999/'
> \___ parser error
> Run 'perf list' for a list of valid events
>
> Usage: perf stat [<options>] [<command>]
>
> -e, --event <event> event selector. use 'perf list' to list available events
> ```
>
> After:
> ```
> $ perf stat -e 'cycles/period=99999999999999999999/' true
> event syntax error: 'cycles/period=99999999999999999999/'
> \___ parser error
>
> event syntax error: '..les/period=99999999999999999999/'
> \___ Bad base 10 number "99999999999999999999"

It seems the patch only works for decimal?

./perf stat -e 'cycles/period=0xaaaaaaaaaaaaaaaaaaaaaa/' true
event syntax error: '..les/period=0xaaaaaaaaaaaaaaaaaaaaaa/'
\___ parser error
Run 'perf list' for a list of valid events

Usage: perf stat [<options>] [<command>]

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

Thanks,
Kan

> Run 'perf list' for a list of valid events
>
> Usage: perf stat [<options>] [<command>]
>
> -e, --event <event> event selector. use 'perf list' to list available events
> ```
>
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
> tools/perf/util/parse-events.l | 40 ++++++++++++++++++++--------------
> 1 file changed, 24 insertions(+), 16 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> index 6fe37003ab7b..0cd68c9f0d4f 100644
> --- a/tools/perf/util/parse-events.l
> +++ b/tools/perf/util/parse-events.l
> @@ -18,26 +18,34 @@
>
> char *parse_events_get_text(yyscan_t yyscanner);
> YYSTYPE *parse_events_get_lval(yyscan_t yyscanner);
> +int parse_events_get_column(yyscan_t yyscanner);
> +int parse_events_get_leng(yyscan_t yyscanner);
>
> -static int __value(YYSTYPE *yylval, char *str, int base, int token)
> +static int get_column(yyscan_t scanner)
> {
> - u64 num;
> -
> - errno = 0;
> - num = strtoull(str, NULL, base);
> - if (errno)
> - return PE_ERROR;
> -
> - yylval->num = num;
> - return token;
> + return parse_events_get_column(scanner) - parse_events_get_leng(scanner);
> }
>
> -static int value(yyscan_t scanner, int base)
> +static int value(struct parse_events_state *parse_state, yyscan_t scanner, int base)
> {
> YYSTYPE *yylval = parse_events_get_lval(scanner);
> char *text = parse_events_get_text(scanner);
> + u64 num;
>
> - return __value(yylval, text, base, PE_VALUE);
> + errno = 0;
> + num = strtoull(text, NULL, base);
> + if (errno) {
> + struct parse_events_error *error = parse_state->error;
> + char *help = NULL;
> +
> + if (asprintf(&help, "Bad base %d number \"%s\"", base, text) > 0)
> + parse_events_error__handle(error, get_column(scanner), help , NULL);
> +
> + return PE_ERROR;
> + }
> +
> + yylval->num = num;
> + return PE_VALUE;
> }
>
> static int str(yyscan_t scanner, int token)
> @@ -283,8 +291,8 @@ r0x{num_raw_hex} { return str(yyscanner, PE_RAW); }
> */
> "/"/{digit} { return PE_BP_SLASH; }
> "/"/{non_digit} { BEGIN(config); return '/'; }
> -{num_dec} { return value(yyscanner, 10); }
> -{num_hex} { return value(yyscanner, 16); }
> +{num_dec} { return value(_parse_state, yyscanner, 10); }
> +{num_hex} { return value(_parse_state, yyscanner, 16); }
> /*
> * We need to separate 'mem:' scanner part, in order to get specific
> * modifier bits parsed out. Otherwise we would need to handle PE_NAME
> @@ -330,8 +338,8 @@ cgroup-switches { return sym(yyscanner, PERF_COUNT_SW_CGROUP_SWITCHES); }
> {lc_type}-{lc_op_result}-{lc_op_result} { return str(yyscanner, PE_LEGACY_CACHE); }
> mem: { BEGIN(mem); return PE_PREFIX_MEM; }
> r{num_raw_hex} { return str(yyscanner, PE_RAW); }
> -{num_dec} { return value(yyscanner, 10); }
> -{num_hex} { return value(yyscanner, 16); }
> +{num_dec} { return value(_parse_state, yyscanner, 10); }
> +{num_hex} { return value(_parse_state, yyscanner, 16); }
>
> {modifier_event} { return str(yyscanner, PE_MODIFIER_EVENT); }
> {name} { return str(yyscanner, PE_NAME); }