libtraceevent: Improve tep_print_field()

The existing method tep_print_fields() gets upgraded to use the
printing formats provided by the tokens.

Link: https://lore.kernel.org/linux-trace-devel/20210823095618.138887-2-y.karadz@gmail.com

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 87 insertions, 28 deletions

diff --git a/src/event-parse.c b/src/event-parse.c
index 02ec677..6129a0c 100644
--- a/src/event-parse.c
+++ b/src/event-parse.c
@@ -3913,7 +3913,6 @@ eval_num_arg(void *data, int size, struct tep_event *event, struct tep_print_arg
 			arg->field.field = tep_find_any_field(event, arg->field.name);
 			if (!arg->field.field)
 				goto out_warning_field;
-			
 		}
 		/* must be a number */
 		val = tep_read_number(tep, data + arg->field.field->offset,
@@ -5326,8 +5325,8 @@ static int is_printable_array(char *p, unsigned int len)
 	return 1;
 }
 
-void tep_print_field(struct trace_seq *s, void *data,
-		     struct tep_format_field *field)
+static void print_field_raw(struct trace_seq *s, void *data,
+			     struct tep_format_field *field)
 {
 	struct tep_handle *tep = field->event->tep;
 	unsigned int offset, len, i;
@@ -5389,6 +5388,56 @@ void tep_print_field(struct trace_seq *s, void *data,
 	}
 }
 
+static int print_parse_data(struct tep_print_parse *parse, struct trace_seq *s,
+			    void *data, int size, struct tep_event *event);
+
+void tep_print_field(struct trace_seq *s, void *data,
+		     struct tep_format_field *field)
+{
+	struct tep_event *event = field->event;
+	struct tep_print_parse *parse;
+	bool has_0x;
+
+	parse = event->print_fmt.print_cache;
+
+	if (event->flags & TEP_EVENT_FL_FAILED)
+		goto out;
+
+	if (field->flags & (TEP_FIELD_IS_ARRAY || TEP_FIELD_IS_STRING))
+		goto out;
+
+	for (;parse; parse = parse->next) {
+		if (parse->type == PRINT_FMT_STRING) {
+			int len = strlen(parse->format);
+
+			if (len > 1 &&
+			    strcmp(parse->format + (len -2), "0x") == 0)
+				has_0x = true;
+			else
+				has_0x = false;
+
+			continue;
+		}
+
+		if (!parse->arg ||
+		    parse->arg->type != TEP_PRINT_FIELD ||
+		    parse->arg->field.field != field) {
+			has_0x = false;
+			continue;
+		}
+
+		if (has_0x)
+			trace_seq_puts(s, "0x");
+
+		print_parse_data(parse, s, data, field->size, event);
+		return;
+	}
+
+ out:
+	/* Not found. */
+	print_field_raw(s, data, field);
+}
+
 void tep_print_fields(struct trace_seq *s, void *data,
 		      int size __maybe_unused, struct tep_event *event)
 {
@@ -5908,35 +5957,45 @@ parse_args(struct tep_event *event, const char *format, struct tep_print_arg *ar
 	return parse_ret;
 }
 
-static void print_event_cache(struct tep_print_parse *parse, struct trace_seq *s,
-			      void *data, int size, struct tep_event *event)
+static int print_parse_data(struct tep_print_parse *parse, struct trace_seq *s,
+			    void *data, int size, struct tep_event *event)
 {
 	int len_arg;
 
+	if (parse->len_as_arg)
+		len_arg = eval_num_arg(data, size, event, parse->len_as_arg);
+
+	switch (parse->type) {
+	case PRINT_FMT_ARG_DIGIT:
+		print_arg_number(s, parse->format,
+				 parse->len_as_arg ? len_arg : -1, data,
+				 size, parse->ls, event, parse->arg);
+		break;
+	case PRINT_FMT_ARG_POINTER:
+		print_arg_pointer(s, parse->format,
+				  parse->len_as_arg ? len_arg : 1,
+				  data, size, event, parse->arg);
+		break;
+	case PRINT_FMT_ARG_STRING:
+		print_arg_string(s, parse->format,
+				 parse->len_as_arg ? len_arg : -1,
+				 data, size, event, parse->arg);
+		break;
+	case PRINT_FMT_STRING:
+	default:
+		trace_seq_printf(s, "%s", parse->format);
+		/* Return 1 on non field. */
+		return 1;
+	}
+	/* Return 0 on field being processed. */
+	return 0;
+}
+
+static void print_event_cache(struct tep_print_parse *parse, struct trace_seq *s,
+			      void *data, int size, struct tep_event *event)
+{
 	while (parse) {
-		if (parse->len_as_arg)
-			len_arg = eval_num_arg(data, size, event, parse->len_as_arg);
-		switch (parse->type) {
-		case PRINT_FMT_ARG_DIGIT:
-			print_arg_number(s, parse->format,
-					parse->len_as_arg ? len_arg : -1, data,
-					 size, parse->ls, event, parse->arg);
-			break;
-		case PRINT_FMT_ARG_POINTER:
-			print_arg_pointer(s, parse->format,
-					  parse->len_as_arg ? len_arg : 1,
-					  data, size, event, parse->arg);
-			break;
-		case PRINT_FMT_ARG_STRING:
-			print_arg_string(s, parse->format,
-					 parse->len_as_arg ? len_arg : -1,
-					 data, size, event, parse->arg);
-			break;
-		case PRINT_FMT_STRING:
-		default:
-			trace_seq_printf(s, "%s", parse->format);
-			break;
-		}
+		print_parse_data(parse, s, data, size, event);
 		parse = parse->next;
 	}
 }