trace: switch to modular code generation for sub-directories

Introduce rules in the top level Makefile that are able to generate
trace.[ch] files in every subdirectory which has a trace-events file.

The top level directory is handled specially, so instead of creating
trace.h, it creates trace-root.h. This allows sub-directories to
include the top level trace-root.h file, without ambiguity wrt to
the trace.g file in the current sub-dir.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170125161417.31949-7-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/scripts/tracetool.py b/scripts/tracetool.py
index 0c9d992fd8..c55a21518b 100755
--- a/scripts/tracetool.py
+++ b/scripts/tracetool.py
@@ -137,10 +137,12 @@ def main(args):
         if probe_prefix is None:
             probe_prefix = ".".join(["qemu", target_type, target_name])
 
-    if len(args) != 1:
+    if len(args) < 1:
         error_opt("missing trace-events filepath")
-    with open(args[0], "r") as fh:
-        events = tracetool.read_events(fh)
+    events = []
+    for arg in args:
+        with open(arg, "r") as fh:
+            events.extend(tracetool.read_events(fh))
 
     try:
         tracetool.generate(events, arg_group, arg_format, arg_backends,