Re: [PATCH v2] perf pmu: Make parser reentrant

[Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>]

On April 5, 2023 4:25:18 AM GMT-03:00, Jiri Olsa <olsajiri@gmail.com> wrote:
>On Tue, Apr 04, 2023 at 06:36:30AM -0700, Ian Rogers wrote:
>> By default bison uses global state for compatibility with yacc. Make
>> the parser reentrant so that it may be used in asynchronous and
>> multithreaded situations.
>> 
>> Signed-off-by: Ian Rogers <irogers@google.com>
>
>hum I can't apply this version on Arnaldo's perf/core:

Try on tmp.perf-tools-next

>
>patching file tools/perf/util/pmu.c
>Hunk #2 succeeded at 59 with fuzz 1.
>Hunk #3 FAILED at 80.
>Hunk #4 FAILED at 90.
>2 out of 4 hunks FAILED -- saving rejects to file tools/perf/util/pmu.c.rej
>patching file tools/perf/util/pmu.h
>patching file tools/perf/util/pmu.l
>patching file tools/perf/util/pmu.y
>
>jirka
>
>
>> ---
>>  tools/perf/util/pmu.c | 24 ++++++++++++++++++------
>>  tools/perf/util/pmu.h |  2 +-
>>  tools/perf/util/pmu.l | 17 ++++++++++++-----
>>  tools/perf/util/pmu.y |  5 ++++-
>>  4 files changed, 35 insertions(+), 13 deletions(-)
>> 
>> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
>> index 78a407b42ad1..f603cdabf797 100644
>> --- a/tools/perf/util/pmu.c
>> +++ b/tools/perf/util/pmu.c
>> @@ -24,6 +24,8 @@
>>  #include "evsel.h"
>>  #include "pmu.h"
>>  #include "pmus.h"
>> +#include "pmu-bison.h"
>> +#include "pmu-flex.h"
>>  #include "parse-events.h"
>>  #include "print-events.h"
>>  #include "header.h"
>> @@ -57,9 +59,6 @@ struct perf_pmu_format {
>>  	struct list_head list;
>>  };
>>  
>> -int perf_pmu_parse(struct list_head *list, char *name);
>> -extern FILE *perf_pmu_in;
>> -
>>  static bool hybrid_scanned;
>>  
>>  static struct perf_pmu *perf_pmu__find2(int dirfd, const char *name);
>> @@ -81,6 +80,8 @@ int perf_pmu__format_parse(int dirfd, struct list_head *head)
>>  	while (!ret && (evt_ent = readdir(format_dir))) {
>>  		char *name = evt_ent->d_name;
>>  		int fd;
>> +		void *scanner;
>> +		FILE *file;
>>  
>>  		if (!strcmp(name, ".") || !strcmp(name, ".."))
>>  			continue;
>> @@ -91,9 +92,20 @@ int perf_pmu__format_parse(int dirfd, struct list_head *head)
>>  		if (fd < 0)
>>  			break;
>>  
>> -		perf_pmu_in = fdopen(fd, "r");
>> -		ret = perf_pmu_parse(head, name);
>> -		fclose(perf_pmu_in);
>> +		file = fdopen(fd, "r");
>> +		if (!file)
>> +			break;
>> +
>> +		ret = perf_pmu_lex_init(&scanner);
>> +		if (ret) {
>> +			fclose(file);
>> +			break;
>> +		}
>> +
>> +		perf_pmu_set_in(file, scanner);
>> +		ret = perf_pmu_parse(head, name, scanner);
>> +		perf_pmu_lex_destroy(scanner);
>> +		fclose(file);
>>  	}
>>  
>>  	closedir(format_dir);
>> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
>> index 32c3a75bca0e..d53618c65c92 100644
>> --- a/tools/perf/util/pmu.h
>> +++ b/tools/perf/util/pmu.h
>> @@ -206,7 +206,7 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
>>  			  struct perf_pmu_info *info);
>>  struct list_head *perf_pmu__alias(struct perf_pmu *pmu,
>>  				  struct list_head *head_terms);
>> -void perf_pmu_error(struct list_head *list, char *name, char const *msg);
>> +void perf_pmu_error(struct list_head *list, char *name, void *scanner, char const *msg);
>>  
>>  int perf_pmu__new_format(struct list_head *list, char *name,
>>  			 int config, unsigned long *bits);
>> diff --git a/tools/perf/util/pmu.l b/tools/perf/util/pmu.l
>> index 58b4926cfaca..67b247be693b 100644
>> --- a/tools/perf/util/pmu.l
>> +++ b/tools/perf/util/pmu.l
>> @@ -1,4 +1,6 @@
>>  %option prefix="perf_pmu_"
>> +%option reentrant
>> +%option bison-bridge
>>  
>>  %{
>>  #include <stdlib.h>
>> @@ -6,16 +8,21 @@
>>  #include "pmu.h"
>>  #include "pmu-bison.h"
>>  
>> -static int value(int base)
>> +char *perf_pmu_get_text(yyscan_t yyscanner);
>> +YYSTYPE *perf_pmu_get_lval(yyscan_t yyscanner);
>> +
>> +static int value(yyscan_t scanner, int base)
>>  {
>> +	YYSTYPE *yylval = perf_pmu_get_lval(scanner);
>> +	char *text = perf_pmu_get_text(scanner);
>>  	long num;
>>  
>>  	errno = 0;
>> -	num = strtoul(perf_pmu_text, NULL, base);
>> +	num = strtoul(text, NULL, base);
>>  	if (errno)
>>  		return PP_ERROR;
>>  
>> -	perf_pmu_lval.num = num;
>> +	yylval->num = num;
>>  	return PP_VALUE;
>>  }
>>  
>> @@ -25,7 +32,7 @@ num_dec         [0-9]+
>>  
>>  %%
>>  
>> -{num_dec}	{ return value(10); }
>> +{num_dec}	{ return value(yyscanner, 10); }
>>  config		{ return PP_CONFIG; }
>>  -		{ return '-'; }
>>  :		{ return ':'; }
>> @@ -35,7 +42,7 @@ config		{ return PP_CONFIG; }
>>  
>>  %%
>>  
>> -int perf_pmu_wrap(void)
>> +int perf_pmu_wrap(void *scanner __maybe_unused)
>>  {
>>  	return 1;
>>  }
>> diff --git a/tools/perf/util/pmu.y b/tools/perf/util/pmu.y
>> index e675d79a0274..dff4e892ac4d 100644
>> --- a/tools/perf/util/pmu.y
>> +++ b/tools/perf/util/pmu.y
>> @@ -1,6 +1,8 @@
>> -
>> +%define api.pure full
>>  %parse-param {struct list_head *format}
>>  %parse-param {char *name}
>> +%parse-param {void *scanner}
>> +%lex-param {void* scanner}
>>  
>>  %{
>>  
>> @@ -78,6 +80,7 @@ PP_VALUE
>>  
>>  void perf_pmu_error(struct list_head *list __maybe_unused,
>>  		    char *name __maybe_unused,
>> +		    void *scanner __maybe_unused,
>>  		    char const *msg __maybe_unused)
>>  {
>>  }
>> -- 
>> 2.40.0.348.gf938b09366-goog
>>