perf parse-events: Improvements to modifier parsing

Use a struct/bitmap rather than a copied string from lexer.

In lexer give improved error message when too many precise flags are
given or repeated modifiers.

Before:

  $ perf stat -e 'cycles:kuk' true
  event syntax error: 'cycles:kuk'
                              \___ Bad modifier
  ...
  $ perf stat -e 'cycles:pppp' true
  event syntax error: 'cycles:pppp'
                              \___ Bad modifier
  ...
  $ perf stat -e '{instructions:p,cycles:pp}:pp' -a true
  event syntax error: '..cycles:pp}:pp'
                                    \___ Bad modifier
  ...

After:

  $ perf stat -e 'cycles:kuk' true
  event syntax error: 'cycles:kuk'
                                \___ Duplicate modifier 'k' (kernel)
  ...
  $ perf stat -e 'cycles:pppp' true
  event syntax error: 'cycles:pppp'
                                 \___ Maximum precise value is 3
  ...
  $ perf stat -e '{instructions:p,cycles:pp}:pp' true
  event syntax error: '..cycles:pp}:pp'
                                    \___ Maximum combined precise value is 3, adding precision to "cycles:pp"
  ...

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Beeman Strong <beeman@rivosinc.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240416061533.921723-14-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 21 insertions, 2 deletions

diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 290ae6c72ec5..f104faef1a78 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -186,8 +186,27 @@ void parse_events_terms__init(struct parse_events_terms *terms);
 void parse_events_terms__exit(struct parse_events_terms *terms);
 int parse_events_terms(struct parse_events_terms *terms, const char *str, FILE *input);
 int parse_events_terms__to_strbuf(const struct parse_events_terms *terms, struct strbuf *sb);
-int parse_events__modifier_event(struct list_head *list, char *str, bool add);
-int parse_events__modifier_group(struct list_head *list, char *event_mod);
+
+struct parse_events_modifier {
+	u8 precise;	/* Number of repeated 'p' for precision. */
+	bool precise_max : 1;	/* 'P' */
+	bool non_idle : 1;	/* 'I' */
+	bool sample_read : 1;	/* 'S' */
+	bool pinned : 1;	/* 'D' */
+	bool exclusive : 1;	/* 'e' */
+	bool weak : 1;		/* 'W' */
+	bool bpf : 1;		/* 'b' */
+	bool user : 1;		/* 'u' */
+	bool kernel : 1;	/* 'k' */
+	bool hypervisor : 1;	/* 'h' */
+	bool guest : 1;		/* 'G' */
+	bool host : 1;		/* 'H' */
+};
+
+int parse_events__modifier_event(struct parse_events_state *parse_state, void *loc,
+				 struct list_head *list, struct parse_events_modifier mod);
+int parse_events__modifier_group(struct parse_events_state *parse_state, void *loc,
+				 struct list_head *list, struct parse_events_modifier mod);
 int parse_events_name(struct list_head *list, const char *name);
 int parse_events_add_tracepoint(struct list_head *list, int *idx,
 				const char *sys, const char *event,