[Spice-devel] [RFC PATCH spice-protocol] codegen: Filter not defined messages from protocol

[Pavel Grunt]

Do not create functions for a message which doesn't have a definition
in the included header file.

Make spice-protocol again compatible with older spice-common.
---
Hi, this is an attemp to make spice-protocol compatible with older releases of spice / spice-gtk

Currently released versions of spice and spice-gtk are failing to build
using spice-protocol from git master:
  CC       libspice_common_server_la-generated_server_demarshallers.lo
generated_server_demarshallers.c: In function 'parse_msgc_display_gl_draw_done':
generated_server_demarshallers.c:767:23: error: 'SpiceMsgcDisplayGlDrawDone' undeclared (first use in this function)
     mem_size = sizeof(SpiceMsgcDisplayGlDrawDone);
                       ^
It is due to the fact that spice-common calls spice_codegen.py from spice-protocol
to generated marshallers from spice.proto (which is included in spice-protocol).
However structures defining messages from spice.proto are in "common/messages.h"
which is in spice-common. So generated code contains new messages but the header doesn't.

To fix the issue I took advantage of spice-common calling the codegen with the header file,
see spice-common/common/Makefile.am:

	spice_codegen.py --generate-demarshallers --client --include common/messages.h

Codegen then opens the header, gets its content and checks if messages defined in spice.proto
are also defined in the header. If not the message is discarded.

The code needs some improvements (the find_file() function), but what do you think about the approach?

Thanks for any comments,
Pavel

---
 spice_codegen.py | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/spice_codegen.py b/spice_codegen.py
index 569cccc..06f8fe1 100755
--- a/spice_codegen.py
+++ b/spice_codegen.py
@@ -105,6 +105,30 @@ def write_enums(writer, describe=False):
 
     writer.writeln("#endif /* _H_SPICE_ENUMS */")
 
+def filter_protocol_messages(proto, headers):
+    """ Remove messages which don't have the definition in a header"""
+    def find_file(name):
+        fname = os.path.basename(name)
+        for root, dirs, files in os.walk(os.getcwd()):
+            if fname in files:
+                return os.path.join(root, fname)
+        return None
+
+    if headers == None:
+        return
+
+    filesstr = ""
+    for f in headers:
+        path_to_file = find_file(f)
+        if path_to_file != None:
+            with open(path_to_file) as content_file:
+                filesstr += content_file.read()
+
+    filter_func = lambda msg : msg.message_type.c_type().replace("Temp","Spice") in filesstr
+    for channel in proto.channels:
+        channel.channel_type.client_messages = filter(filter_func, channel.channel_type.client_messages)
+        channel.channel_type.server_messages = filter(filter_func, channel.channel_type.server_messages)
+
 parser = OptionParser(usage="usage: %prog [options] <protocol_file> <destination file>")
 parser.add_option("-e", "--generate-enums",
                   action="store_true", dest="generate_enums", default=False,
@@ -209,6 +233,7 @@ if options.print_error:
     writer.set_option("print_error")
 
 if options.includes:
+    filter_protocol_messages(proto, options.includes)
     for i in options.includes:
         writer.header.writeln('#include <%s>' % i)
         writer.writeln('#include <%s>' % i)
-- 
2.5.0