qapi: New classes QAPIGenC, QAPIGenH, QAPIGenDoc

These classes encapsulate accumulating and writing output.

Convert C code generation to QAPIGenC and QAPIGenH.  The conversion is
rather shallow: most of the output accumulation is not converted.
Left for later.

The indentation machinery uses a single global variable indent_level,
even though we generally interleave creation of a .c and its .h.  It
should become instance variable of QAPIGenC.  Also left for later.

Documentation generation isn't converted, and QAPIGenDoc isn't used.
This will change shortly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180211093607.27351-6-armbru@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
[eblake: fix nits spotted by Michael]
Signed-off-by: Eric Blake <eblake@redhat.com>

1 files changed, 12 insertions, 11 deletions

diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index 114c5ad276..8435a890ba 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -258,12 +258,10 @@ class QAPISchemaGenCommandVisitor(QAPISchemaVisitor):
 
 blurb = ' * Schema-defined QAPI/QMP commands'
 
-(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
-                            'qmp-marshal.c', 'qmp-commands.h',
-                            blurb, __doc__)
-
-fdef.write(mcgen('''
+genc = QAPIGenC(blurb, __doc__)
+genh = QAPIGenH(blurb, __doc__)
 
+genc.add(mcgen('''
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "qemu/module.h"
@@ -278,20 +276,23 @@ fdef.write(mcgen('''
 #include "%(prefix)sqmp-commands.h"
 
 ''',
-                 prefix=prefix))
+               prefix=prefix))
 
-fdecl.write(mcgen('''
+genh.add(mcgen('''
 #include "%(prefix)sqapi-types.h"
 #include "qapi/qmp/dispatch.h"
 
 void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
 ''',
-                  prefix=prefix, c_prefix=c_name(prefix, protect=False)))
+               prefix=prefix, c_prefix=c_name(prefix, protect=False)))
 
 schema = QAPISchema(input_file)
 vis = QAPISchemaGenCommandVisitor()
 schema.visit(vis)
-fdef.write(vis.defn)
-fdecl.write(vis.decl)
+genc.add(vis.defn)
+genh.add(vis.decl)
 
-close_output(fdef, fdecl)
+if do_c:
+    genc.write(output_dir, prefix + 'qmp-marshal.c')
+if do_h:
+    genh.write(output_dir, prefix + 'qmp-commands.h')