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, 13 insertions, 11 deletions

diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 0e78cf3bbb..51eeaa1fc2 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -272,7 +272,7 @@ class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
     def visit_begin(self, schema):
         self.decl = ''
         self.defn = ''
-        self._btin = guardstart('QAPI_VISIT_BUILTIN')
+        self._btin = '\n' + guardstart('QAPI_VISIT_BUILTIN')
 
     def visit_end(self):
         # To avoid header dependency hell, we always generate
@@ -337,30 +337,32 @@ for o, a in opts:
 
 blurb = ' * Schema-defined QAPI visitors'
 
-(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
-                            'qapi-visit.c', 'qapi-visit.h',
-                            blurb, __doc__)
+genc = QAPIGenC(blurb, __doc__)
+genh = QAPIGenH(blurb, __doc__)
 
-fdef.write(mcgen('''
+genc.add(mcgen('''
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
 #include "%(prefix)sqapi-visit.h"
 ''',
-                 prefix=prefix))
+               prefix=prefix))
 
-fdecl.write(mcgen('''
+genh.add(mcgen('''
 #include "qapi/visitor.h"
 #include "%(prefix)sqapi-types.h"
 
 ''',
-                  prefix=prefix))
+               prefix=prefix))
 
 schema = QAPISchema(input_file)
 vis = QAPISchemaGenVisitVisitor()
 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 + 'qapi-visit.c')
+if do_h:
+    genh.write(output_dir, prefix + 'qapi-visit.h')