[PATCH v2 5/7] trace-cmd library: Select the file version when writing trace file

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

When a new output handler to trace file is allocated, select the proper
file version. If this output handler is based on an existing input trace
file handler, inherit the trace file version.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 lib/trace-cmd/trace-output.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index 9231c319..f36718f1 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -57,6 +57,7 @@ struct tracecmd_output {
 	int			nr_options;
 	bool			quiet;
 	unsigned long		file_state;
+	unsigned long		file_version;
 	struct list_head	options;
 	struct tracecmd_msg_handle *msg_handle;
 	char			*trace_clock;
@@ -907,6 +908,17 @@ out_free:
 	return ret;
 }
 
+static int select_file_version(struct tracecmd_output *handle,
+				struct tracecmd_input *ihandle)
+{
+	if (ihandle)
+		handle->file_version = tracecmd_get_file_version(ihandle);
+	else
+		handle->file_version = FILE_VERSION;
+
+	return 0;
+}
+
 static struct tracecmd_output *
 create_file_fd(int fd, struct tracecmd_input *ihandle,
 	       const char *tracing_dir,
@@ -933,6 +945,9 @@ create_file_fd(int fd, struct tracecmd_input *ihandle,
 
 	handle->msg_handle = msg_handle;
 
+	if (select_file_version(handle, ihandle))
+		goto out_free;
+
 	list_head_init(&handle->options);
 
 	buf[0] = 23;
@@ -943,7 +958,8 @@ create_file_fd(int fd, struct tracecmd_input *ihandle,
 	if (do_write_check(handle, buf, 10))
 		goto out_free;
 
-	if (do_write_check(handle, FILE_VERSION_STRING, strlen(FILE_VERSION_STRING) + 1))
+	sprintf(buf, "%lu", handle->file_version);
+	if (do_write_check(handle, buf, strlen(buf) + 1))
 		goto out_free;
 
 	/* get endian and page size */
@@ -1602,6 +1618,7 @@ struct tracecmd_output *tracecmd_get_output_handle_fd(int fd)
 	handle->pevent = tracecmd_get_tep(ihandle);
 	tep_ref(handle->pevent);
 	handle->page_size = tracecmd_page_size(ihandle);
+	handle->file_version = tracecmd_get_file_version(ihandle);
 	list_head_init(&handle->options);
 
 	tracecmd_close(ihandle);
-- 
2.30.2