[PATCH 13/14] tools lib traceevent: Refactor test_filter() to get rid of die()

[Namhyung Kim]

The test_filter() function is for testing given filter is matched to a
given record.  However it doesn't handle error cases properly so add a
new argument error_str to save error info during the test and also
pass it to internal test functions.

For now, it just save the error but does nothing with it.  Maybe it
can be given by user through pevent_filter_match() later.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
 tools/lib/traceevent/event-parse.h  |   1 +
 tools/lib/traceevent/parse-filter.c | 102 ++++++++++++++++++++++--------------
 2 files changed, 65 insertions(+), 38 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 6e23f197175f..a1d8b2792e3a 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -836,6 +836,7 @@ struct event_filter {
 
 struct event_filter *pevent_filter_alloc(struct pevent *pevent);
 
+#define FILTER_ERROR		-3
 #define FILTER_NONE		-2
 #define FILTER_NOEXIST		-1
 #define FILTER_MISS		0
diff --git a/tools/lib/traceevent/parse-filter.c b/tools/lib/traceevent/parse-filter.c
index 4d395e8b88bb..8a5b7a74b44e 100644
--- a/tools/lib/traceevent/parse-filter.c
+++ b/tools/lib/traceevent/parse-filter.c
@@ -1698,8 +1698,8 @@ int pevent_filter_event_has_trivial(struct event_filter *filter,
 	}
 }
 
-static int test_filter(struct event_format *event,
-		       struct filter_arg *arg, struct pevent_record *record);
+static int test_filter(struct event_format *event, struct filter_arg *arg,
+		       struct pevent_record *record, char **error_str);
 
 static const char *
 get_comm(struct event_format *event, struct pevent_record *record)
@@ -1745,15 +1745,17 @@ get_value(struct event_format *event,
 }
 
 static unsigned long long
-get_arg_value(struct event_format *event, struct filter_arg *arg, struct pevent_record *record);
+get_arg_value(struct event_format *event, struct filter_arg *arg,
+	      struct pevent_record *record, char **error_str);
 
 static unsigned long long
-get_exp_value(struct event_format *event, struct filter_arg *arg, struct pevent_record *record)
+get_exp_value(struct event_format *event, struct filter_arg *arg,
+	      struct pevent_record *record, char **error_str)
 {
 	unsigned long long lval, rval;
 
-	lval = get_arg_value(event, arg->exp.left, record);
-	rval = get_arg_value(event, arg->exp.right, record);
+	lval = get_arg_value(event, arg->exp.left, record, error_str);
+	rval = get_arg_value(event, arg->exp.right, record, error_str);
 
 	switch (arg->exp.type) {
 	case FILTER_EXP_ADD:
@@ -1788,39 +1790,44 @@ get_exp_value(struct event_format *event, struct filter_arg *arg, struct pevent_
 
 	case FILTER_EXP_NOT:
 	default:
-		die("error in exp");
+		if (*error_str == NULL)
+			*error_str = "invalid expression type";
 	}
 	return 0;
 }
 
 static unsigned long long
-get_arg_value(struct event_format *event, struct filter_arg *arg, struct pevent_record *record)
+get_arg_value(struct event_format *event, struct filter_arg *arg,
+	      struct pevent_record *record, char **error_str)
 {
 	switch (arg->type) {
 	case FILTER_ARG_FIELD:
 		return get_value(event, arg->field.field, record);
 
 	case FILTER_ARG_VALUE:
-		if (arg->value.type != FILTER_NUMBER)
-			die("must have number field!");
+		if (arg->value.type != FILTER_NUMBER) {
+			if (*error_str == NULL)
+				*error_str = "must have number field!";
+		}
 		return arg->value.val;
 
 	case FILTER_ARG_EXP:
-		return get_exp_value(event, arg, record);
+		return get_exp_value(event, arg, record, error_str);
 
 	default:
-		die("oops in filter");
+		if (*error_str == NULL)
+			*error_str = "invalid numeric argument type";
 	}
 	return 0;
 }
 
-static int test_num(struct event_format *event,
-		    struct filter_arg *arg, struct pevent_record *record)
+static int test_num(struct event_format *event, struct filter_arg *arg,
+		    struct pevent_record *record, char **error_str)
 {
 	unsigned long long lval, rval;
 
-	lval = get_arg_value(event, arg->num.left, record);
-	rval = get_arg_value(event, arg->num.right, record);
+	lval = get_arg_value(event, arg->num.left, record, error_str);
+	rval = get_arg_value(event, arg->num.right, record, error_str);
 
 	switch (arg->num.type) {
 	case FILTER_CMP_EQ:
@@ -1842,7 +1849,8 @@ static int test_num(struct event_format *event,
 		return lval <= rval;
 
 	default:
-		/* ?? */
+		if (*error_str == NULL)
+			*error_str = "invalid numeric comparison type";
 		return 0;
 	}
 }
@@ -1889,8 +1897,8 @@ static const char *get_field_str(struct filter_arg *arg, struct pevent_record *r
 	return val;
 }
 
-static int test_str(struct event_format *event,
-		    struct filter_arg *arg, struct pevent_record *record)
+static int test_str(struct event_format *event, struct filter_arg *arg,
+		    struct pevent_record *record, char **error_str)
 {
 	const char *val;
 
@@ -1914,48 +1922,57 @@ static int test_str(struct event_format *event,
 		return regexec(&arg->str.reg, val, 0, NULL, 0);
 
 	default:
-		/* ?? */
+		if (*error_str == NULL)
+			*error_str = "invalid string comparison type";
 		return 0;
 	}
 }
 
-static int test_op(struct event_format *event,
-		   struct filter_arg *arg, struct pevent_record *record)
+static int test_op(struct event_format *event, struct filter_arg *arg,
+		   struct pevent_record *record, char **error_str)
 {
 	switch (arg->op.type) {
 	case FILTER_OP_AND:
-		return test_filter(event, arg->op.left, record) &&
-			test_filter(event, arg->op.right, record);
+		return test_filter(event, arg->op.left, record, error_str) &&
+			test_filter(event, arg->op.right, record, error_str);
 
 	case FILTER_OP_OR:
-		return test_filter(event, arg->op.left, record) ||
-			test_filter(event, arg->op.right, record);
+		return test_filter(event, arg->op.left, record, error_str) ||
+			test_filter(event, arg->op.right, record, error_str);
 
 	case FILTER_OP_NOT:
-		return !test_filter(event, arg->op.right, record);
+		return !test_filter(event, arg->op.right, record, error_str);
 
 	default:
-		/* ?? */
+		if (*error_str == NULL)
+			*error_str = "invalid operator type";
 		return 0;
 	}
 }
 
-static int test_filter(struct event_format *event,
-		       struct filter_arg *arg, struct pevent_record *record)
+static int test_filter(struct event_format *event, struct filter_arg *arg,
+		       struct pevent_record *record, char **error_str)
 {
+	if (*error_str) {
+		/*
+		 * There was an error, no need to process anymore.
+		 */
+		return 0;
+	}
+
 	switch (arg->type) {
 	case FILTER_ARG_BOOLEAN:
 		/* easy case */
 		return arg->boolean.value;
 
 	case FILTER_ARG_OP:
-		return test_op(event, arg, record);
+		return test_op(event, arg, record, error_str);
 
 	case FILTER_ARG_NUM:
-		return test_num(event, arg, record);
+		return test_num(event, arg, record, error_str);
 
 	case FILTER_ARG_STR:
-		return test_str(event, arg, record);
+		return test_str(event, arg, record, error_str);
 
 	case FILTER_ARG_EXP:
 	case FILTER_ARG_VALUE:
@@ -1964,11 +1981,11 @@ static int test_filter(struct event_format *event,
 		 * Expressions, fields and values evaluate
 		 * to true if they return non zero
 		 */
-		return !!get_arg_value(event, arg, record);
+		return !!get_arg_value(event, arg, record, error_str);
 
 	default:
-		die("oops!");
-		/* ?? */
+		if (*error_str == NULL)
+			*error_str = "invalid argument type";
 		return 0;
 	}
 }
@@ -2004,6 +2021,7 @@ int pevent_event_filtered(struct event_filter *filter,
  *  0 - filter found for event and @record does not match
  * -1 - no filter found for @record's event
  * -2 - if no filters exist
+ * -3 - if error occurred during test
  */
 int pevent_filter_match(struct event_filter *filter,
 			struct pevent_record *record)
@@ -2011,6 +2029,8 @@ int pevent_filter_match(struct event_filter *filter,
 	struct pevent *pevent = filter->pevent;
 	struct filter_type *filter_type;
 	int event_id;
+	char *error_str = NULL;
+	int ret;
 
 	if (!filter->filters)
 		return FILTER_NONE;
@@ -2022,8 +2042,14 @@ int pevent_filter_match(struct event_filter *filter,
 	if (!filter_type)
 		return FILTER_NOEXIST;
 
-	return test_filter(filter_type->event, filter_type->filter, record) ?
-		FILTER_MATCH : FILTER_MISS;
+	ret = test_filter(filter_type->event, filter_type->filter, record,
+			  &error_str);
+	if (error_str) {
+		/* TODO: maybe we can print it or pass back to user */
+		return FILTER_ERROR;
+	}
+
+	return ret ? FILTER_MATCH : FILTER_MISS;
 }
 
 static char *op_to_str(struct event_filter *filter, struct filter_arg *arg)
-- 
1.7.11.7

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