qapi-gen: New common driver for code and doc generators

Whenever qapi-schema.json changes, we run six programs eleven times to
update eleven files.  Similar for qga/qapi-schema.json.  This is
silly.  Replace the six programs by a single program that spits out
all eleven files.

The programs become modules in new Python package qapi, along with the
helper library.  This requires moving them to scripts/qapi/.  While
moving them, consistently drop executable mode bits.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180211093607.27351-9-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
[eblake: move change to one-line 'blurb' earlier in series, mention mode
bit change as intentional, update qapi-code-gen.txt to match actual
generated events.c file]
Signed-off-by: Eric Blake <eblake@redhat.com>

1 files changed, 293 insertions, 0 deletions

diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
new file mode 100644
index 0000000000..a744611d58
--- /dev/null
+++ b/scripts/qapi/commands.py
@@ -0,0 +1,293 @@
+"""
+QAPI command marshaller generator
+
+Copyright IBM, Corp. 2011
+Copyright (C) 2014-2018 Red Hat, Inc.
+
+Authors:
+ Anthony Liguori <aliguori@us.ibm.com>
+ Michael Roth <mdroth@linux.vnet.ibm.com>
+ Markus Armbruster <armbru@redhat.com>
+
+This work is licensed under the terms of the GNU GPL, version 2.
+See the COPYING file in the top-level directory.
+"""
+
+from qapi.common import *
+
+
+def gen_command_decl(name, arg_type, boxed, ret_type):
+    return mcgen('''
+%(c_type)s qmp_%(c_name)s(%(params)s);
+''',
+                 c_type=(ret_type and ret_type.c_type()) or 'void',
+                 c_name=c_name(name),
+                 params=build_params(arg_type, boxed, 'Error **errp'))
+
+
+def gen_call(name, arg_type, boxed, ret_type):
+    ret = ''
+
+    argstr = ''
+    if boxed:
+        assert arg_type and not arg_type.is_empty()
+        argstr = '&arg, '
+    elif arg_type:
+        assert not arg_type.variants
+        for memb in arg_type.members:
+            if memb.optional:
+                argstr += 'arg.has_%s, ' % c_name(memb.name)
+            argstr += 'arg.%s, ' % c_name(memb.name)
+
+    lhs = ''
+    if ret_type:
+        lhs = 'retval = '
+
+    ret = mcgen('''
+
+    %(lhs)sqmp_%(c_name)s(%(args)s&err);
+''',
+                c_name=c_name(name), args=argstr, lhs=lhs)
+    if ret_type:
+        ret += mcgen('''
+    if (err) {
+        goto out;
+    }
+
+    qmp_marshal_output_%(c_name)s(retval, ret, &err);
+''',
+                     c_name=ret_type.c_name())
+    return ret
+
+
+def gen_marshal_output(ret_type):
+    return mcgen('''
+
+static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out, Error **errp)
+{
+    Error *err = NULL;
+    Visitor *v;
+
+    v = qobject_output_visitor_new(ret_out);
+    visit_type_%(c_name)s(v, "unused", &ret_in, &err);
+    if (!err) {
+        visit_complete(v, ret_out);
+    }
+    error_propagate(errp, err);
+    visit_free(v);
+    v = qapi_dealloc_visitor_new();
+    visit_type_%(c_name)s(v, "unused", &ret_in, NULL);
+    visit_free(v);
+}
+''',
+                 c_type=ret_type.c_type(), c_name=ret_type.c_name())
+
+
+def build_marshal_proto(name):
+    return ('void qmp_marshal_%s(QDict *args, QObject **ret, Error **errp)'
+            % c_name(name))
+
+
+def gen_marshal_decl(name):
+    return mcgen('''
+%(proto)s;
+''',
+                 proto=build_marshal_proto(name))
+
+
+def gen_marshal(name, arg_type, boxed, ret_type):
+    have_args = arg_type and not arg_type.is_empty()
+
+    ret = mcgen('''
+
+%(proto)s
+{
+    Error *err = NULL;
+''',
+                proto=build_marshal_proto(name))
+
+    if ret_type:
+        ret += mcgen('''
+    %(c_type)s retval;
+''',
+                     c_type=ret_type.c_type())
+
+    if have_args:
+        visit_members = ('visit_type_%s_members(v, &arg, &err);'
+                         % arg_type.c_name())
+        ret += mcgen('''
+    Visitor *v;
+    %(c_name)s arg = {0};
+
+''',
+                     c_name=arg_type.c_name())
+    else:
+        visit_members = ''
+        ret += mcgen('''
+    Visitor *v = NULL;
+
+    if (args) {
+''')
+        push_indent()
+
+    ret += mcgen('''
+    v = qobject_input_visitor_new(QOBJECT(args));
+    visit_start_struct(v, NULL, NULL, 0, &err);
+    if (err) {
+        goto out;
+    }
+    %(visit_members)s
+    if (!err) {
+        visit_check_struct(v, &err);
+    }
+    visit_end_struct(v, NULL);
+    if (err) {
+        goto out;
+    }
+''',
+                 visit_members=visit_members)
+
+    if not have_args:
+        pop_indent()
+        ret += mcgen('''
+    }
+''')
+
+    ret += gen_call(name, arg_type, boxed, ret_type)
+
+    ret += mcgen('''
+
+out:
+    error_propagate(errp, err);
+    visit_free(v);
+''')
+
+    if have_args:
+        visit_members = ('visit_type_%s_members(v, &arg, NULL);'
+                         % arg_type.c_name())
+    else:
+        visit_members = ''
+        ret += mcgen('''
+    if (args) {
+''')
+        push_indent()
+
+    ret += mcgen('''
+    v = qapi_dealloc_visitor_new();
+    visit_start_struct(v, NULL, NULL, 0, NULL);
+    %(visit_members)s
+    visit_end_struct(v, NULL);
+    visit_free(v);
+''',
+                 visit_members=visit_members)
+
+    if not have_args:
+        pop_indent()
+        ret += mcgen('''
+    }
+''')
+
+    ret += mcgen('''
+}
+''')
+    return ret
+
+
+def gen_register_command(name, success_response):
+    options = 'QCO_NO_OPTIONS'
+    if not success_response:
+        options = 'QCO_NO_SUCCESS_RESP'
+
+    ret = mcgen('''
+    qmp_register_command(cmds, "%(name)s",
+                         qmp_marshal_%(c_name)s, %(opts)s);
+''',
+                name=name, c_name=c_name(name),
+                opts=options)
+    return ret
+
+
+def gen_registry(registry, prefix):
+    ret = mcgen('''
+
+void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds)
+{
+    QTAILQ_INIT(cmds);
+
+''',
+                c_prefix=c_name(prefix, protect=False))
+    ret += registry
+    ret += mcgen('''
+}
+''')
+    return ret
+
+
+class QAPISchemaGenCommandVisitor(QAPISchemaVisitor):
+    def __init__(self, prefix):
+        self._prefix = prefix
+        self.decl = None
+        self.defn = None
+        self._regy = None
+        self._visited_ret_types = None
+
+    def visit_begin(self, schema):
+        self.decl = ''
+        self.defn = ''
+        self._regy = ''
+        self._visited_ret_types = set()
+
+    def visit_end(self):
+        self.defn += gen_registry(self._regy, self._prefix)
+        self._regy = None
+        self._visited_ret_types = None
+
+    def visit_command(self, name, info, arg_type, ret_type,
+                      gen, success_response, boxed):
+        if not gen:
+            return
+        self.decl += gen_command_decl(name, arg_type, boxed, ret_type)
+        if ret_type and ret_type not in self._visited_ret_types:
+            self._visited_ret_types.add(ret_type)
+            self.defn += gen_marshal_output(ret_type)
+        self.decl += gen_marshal_decl(name)
+        self.defn += gen_marshal(name, arg_type, boxed, ret_type)
+        self._regy += gen_register_command(name, success_response)
+
+
+def gen_commands(schema, output_dir, prefix):
+    blurb = ' * Schema-defined QAPI/QMP commands'
+    genc = QAPIGenC(blurb, __doc__)
+    genh = QAPIGenH(blurb, __doc__)
+
+    genc.add(mcgen('''
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qemu/module.h"
+#include "qapi/visitor.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/qobject-output-visitor.h"
+#include "qapi/qobject-input-visitor.h"
+#include "qapi/dealloc-visitor.h"
+#include "qapi/error.h"
+#include "%(prefix)sqapi-types.h"
+#include "%(prefix)sqapi-visit.h"
+#include "%(prefix)sqmp-commands.h"
+
+''',
+                   prefix=prefix))
+
+    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)))
+
+    vis = QAPISchemaGenCommandVisitor(prefix)
+    schema.visit(vis)
+    genc.add(vis.defn)
+    genh.add(vis.decl)
+    genc.write(output_dir, prefix + 'qmp-marshal.c')
+    genh.write(output_dir, prefix + 'qmp-commands.h')