From fafd52c6d2c32e24ae83b4d534c6e2f72f53795d Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Mon, 9 Sep 2013 14:28:16 +0200
Subject: [PATCH 25/38] qapi: Anonymous unions
RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1378736903-18489-26-git-send-email-kwolf@redhat.com>
Patchwork-id: 54212
O-Subject: [RHEL-7.0 qemu-kvm PATCH 25/32] qapi: Anonymous unions
Bugzilla: 1005818
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
Bugzilla: 1005818
The discriminator for anonymous unions is the data type. This allows to
have a union type that allows both of these:
{ 'file': 'my_existing_block_device_id' }
{ 'file': { 'filename': '/tmp/mydisk.qcow2', 'read-only': true } }
Unions like this are specified in the schema with an empty dict as
discriminator. For this example you could take:
{ 'union': 'BlockRef',
'discriminator': {},
'data': { 'definition': 'BlockOptions',
'reference': 'str' } }
{ 'type': 'ExampleObject',
'data: { 'file': 'BlockRef' } }
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 69dd62dfd60631ba69201d8a197fde1ece4b4df3)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
docs/qapi-code-gen.txt | 25 ++++++++++++++++++++++++
include/qapi/qmp/qobject.h | 1 +
include/qapi/visitor-impl.h | 2 ++
include/qapi/visitor.h | 3 +++
qapi/qapi-visit-core.c | 9 +++++++++
qapi/qmp-input-visitor.c | 14 ++++++++++++++
qobject/qjson.c | 2 ++
scripts/qapi-types.py | 42 ++++++++++++++++++++++++++++++++++++++++
scripts/qapi-visit.py | 47 +++++++++++++++++++++++++++++++++++++++++++++
scripts/qapi.py | 15 +++++++++++++++
10 files changed, 160 insertions(+)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
docs/qapi-code-gen.txt | 25 ++++++++++++++++++++++
include/qapi/qmp/qobject.h | 1 +
include/qapi/visitor-impl.h | 2 +
include/qapi/visitor.h | 3 ++
qapi/qapi-visit-core.c | 9 ++++++++
qapi/qmp-input-visitor.c | 14 ++++++++++++
qobject/qjson.c | 2 +
scripts/qapi-types.py | 42 ++++++++++++++++++++++++++++++++++++++
scripts/qapi-visit.py | 47 +++++++++++++++++++++++++++++++++++++++++++
scripts/qapi.py | 15 +++++++++++++
10 files changed, 160 insertions(+), 0 deletions(-)
diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt
index 11f19cf..0ce045c 100644
--- a/docs/qapi-code-gen.txt
+++ b/docs/qapi-code-gen.txt
@@ -125,6 +125,31 @@ Resulting in this JSON object:
"lazy-refcounts": true }
+A special type of unions are anonymous unions. They don't form a dictionary in
+the wire format but allow the direct use of different types in their place. As
+they aren't structured, they don't have any explicit discriminator but use
+the (QObject) data type of their value as an implicit discriminator. This means
+that they are restricted to using only one discriminator value per QObject
+type. For example, you cannot have two different complex types in an anonymous
+union, or two different integer types.
+
+Anonymous unions are declared using an empty dictionary as their discriminator.
+The discriminator values never appear on the wire, they are only used in the
+generated C code. Anonymous unions cannot have a base type.
+
+ { 'union': 'BlockRef',
+ 'discriminator': {},
+ 'data': { 'definition': 'BlockdevOptions',
+ 'reference': 'str' } }
+
+This example allows using both of the following example objects:
+
+ { "file": "my_existing_block_device_id" }
+ { "file": { "driver": "file",
+ "readonly": false,
+ 'filename': "/tmp/mydisk.qcow2" } }
+
+
=== Commands ===
Commands are defined by using a list containing three members. The first
diff --git a/include/qapi/qmp/qobject.h b/include/qapi/qmp/qobject.h
index 9124649..d0bbc7c 100644
--- a/include/qapi/qmp/qobject.h
+++ b/include/qapi/qmp/qobject.h
@@ -44,6 +44,7 @@ typedef enum {
QTYPE_QFLOAT,
QTYPE_QBOOL,
QTYPE_QERROR,
+ QTYPE_MAX,
} qtype_code;
struct QObject;
diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index 5c1297f..f3fa420 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -32,6 +32,8 @@ struct Visitor
void (*type_enum)(Visitor *v, int *obj, const char *strings[],
const char *kind, const char *name, Error **errp);
+ void (*get_next_type)(Visitor *v, int *kind, const int *qobjects,
+ const char *name, Error **errp);
void (*type_int)(Visitor *v, int64_t *obj, const char *name, Error **errp);
void (*type_bool)(Visitor *v, bool *obj, const char *name, Error **errp);
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index a1cdd81..aa9e771 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -13,6 +13,7 @@
#ifndef QAPI_VISITOR_CORE_H
#define QAPI_VISITOR_CORE_H
+#include "qapi/qmp/qobject.h"
#include "qapi/error.h"
#include <stdlib.h>
@@ -39,6 +40,8 @@ void visit_end_list(Visitor *v, Error **errp);
void visit_start_optional(Visitor *v, bool *present, const char *name,
Error **errp);
void visit_end_optional(Visitor *v, Error **errp);
+void visit_get_next_type(Visitor *v, int *obj, const int *qtypes,
+ const char *name, Error **errp);
void visit_type_enum(Visitor *v, int *obj, const char *strings[],
const char *kind, const char *name, Error **errp);
void visit_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp);
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 9b4d51b..d6a4012 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -12,6 +12,7 @@
*/
#include "qemu-common.h"
+#include "qapi/qmp/qobject.h"
#include "qapi/qmp/qerror.h"
#include "qapi/visitor.h"
#include "qapi/visitor-impl.h"
@@ -98,6 +99,14 @@ void visit_end_optional(Visitor *v, Error **errp)
}
}
+void visit_get_next_type(Visitor *v, int *obj, const int *qtypes,
+ const char *name, Error **errp)
+{
+ if (!error_is_set(errp) && v->get_next_type) {
+ v->get_next_type(v, obj, qtypes, name, errp);
+ }
+}
+
void visit_type_enum(Visitor *v, int *obj, const char *strings[],
const char *kind, const char *name, Error **errp)
{
diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
index 70864a1..bf42c04 100644
--- a/qapi/qmp-input-visitor.c
+++ b/qapi/qmp-input-visitor.c
@@ -208,6 +208,19 @@ static void qmp_input_end_list(Visitor *v, Error **errp)
qmp_input_pop(qiv, errp);
}
+static void qmp_input_get_next_type(Visitor *v, int *kind, const int *qobjects,
+ const char *name, Error **errp)
+{
+ QmpInputVisitor *qiv = to_qiv(v);
+ QObject *qobj = qmp_input_get_object(qiv, name, false);
+
+ if (!qobj) {
+ error_set(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+ return;
+ }
+ *kind = qobjects[qobject_type(qobj)];
+}
+
static void qmp_input_type_int(Visitor *v, int64_t *obj, const char *name,
Error **errp)
{
@@ -317,6 +330,7 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj)
v->visitor.type_str = qmp_input_type_str;
v->visitor.type_number = qmp_input_type_number;
v->visitor.start_optional = qmp_input_start_optional;
+ v->visitor.get_next_type = qmp_input_get_next_type;
qmp_input_push(v, obj, NULL);
qobject_incref(obj);
diff --git a/qobject/qjson.c b/qobject/qjson.c
index 19085a1..6cf2511 100644
--- a/qobject/qjson.c
+++ b/qobject/qjson.c
@@ -260,6 +260,8 @@ static void to_json(const QObject *obj, QString *str, int pretty, int indent)
/* XXX: should QError be emitted? */
case QTYPE_NONE:
break;
+ case QTYPE_MAX:
+ abort();
}
}
diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
index 3d9af3c..20f4bdf 100644
--- a/scripts/qapi-types.py
+++ b/scripts/qapi-types.py
@@ -144,6 +144,40 @@ typedef enum %(name)s
return lookup_decl + enum_decl
+def generate_anon_union_qtypes(expr):
+
+ name = expr['union']
+ members = expr['data']
+
+ ret = mcgen('''
+const int %(name)s_qtypes[QTYPE_MAX] = {
+''',
+ name=name)
+
+ for key in members:
+ qapi_type = members[key]
+ if builtin_type_qtypes.has_key(qapi_type):
+ qtype = builtin_type_qtypes[qapi_type]
+ elif find_struct(qapi_type):
+ qtype = "QTYPE_QDICT"
+ elif find_union(qapi_type):
+ qtype = "QTYPE_QDICT"
+ else:
+ assert False, "Invalid anonymous union member"
+
+ ret += mcgen('''
+ [ %(qtype)s ] = %(abbrev)s_KIND_%(enum)s,
+''',
+ qtype = qtype,
+ abbrev = de_camel_case(name).upper(),
+ enum = c_fun(de_camel_case(key),False).upper())
+
+ ret += mcgen('''
+};
+''')
+ return ret
+
+
def generate_union(expr):
name = expr['union']
@@ -184,6 +218,12 @@ struct %(name)s
ret += mcgen('''
};
''')
+ if discriminator == {}:
+ ret += mcgen('''
+extern const int %(name)s_qtypes[];
+''',
+ name=name)
+
return ret
@@ -336,6 +376,8 @@ for expr in exprs:
ret += generate_fwd_struct(expr['union'], expr['data']) + "\n"
ret += generate_enum('%sKind' % expr['union'], expr['data'].keys())
fdef.write(generate_enum_lookup('%sKind' % expr['union'], expr['data'].keys()))
+ if expr.get('discriminator') == {}:
+ fdef.write(generate_anon_union_qtypes(expr))
else:
continue
fdecl.write(ret)
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index b1c1ad6..367cf7a 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -176,6 +176,49 @@ void visit_type_%(name)s(Visitor *m, %(name)s * obj, const char *name, Error **e
''',
name=name)
+def generate_visit_anon_union(name, members):
+ ret = mcgen('''
+
+void visit_type_%(name)s(Visitor *m, %(name)s ** obj, const char *name, Error **errp)
+{
+ Error *err = NULL;
+
+ if (!error_is_set(errp)) {
+ visit_start_implicit_struct(m, (void**) obj, sizeof(%(name)s), &err);
+ visit_get_next_type(m, (int*) &(*obj)->kind, %(name)s_qtypes, name, &err);
+ switch ((*obj)->kind) {
+''',
+ name=name)
+
+ for key in members:
+ assert (members[key] in builtin_types
+ or find_struct(members[key])
+ or find_union(members[key])), "Invalid anonymous union member"
+
+ ret += mcgen('''
+ case %(abbrev)s_KIND_%(enum)s:
+ visit_type_%(c_type)s(m, &(*obj)->%(c_name)s, name, &err);
+ break;
+''',
+ abbrev = de_camel_case(name).upper(),
+ enum = c_fun(de_camel_case(key),False).upper(),
+ c_type = type_name(members[key]),
+ c_name = c_fun(key))
+
+ ret += mcgen('''
+ default:
+ abort();
+ }
+ error_propagate(errp, err);
+ err = NULL;
+ visit_end_implicit_struct(m, &err);
+ }
+}
+''')
+
+ return ret
+
+
def generate_visit_union(expr):
name = expr['union']
@@ -184,6 +227,10 @@ def generate_visit_union(expr):
base = expr.get('base')
discriminator = expr.get('discriminator')
+ if discriminator == {}:
+ assert not base
+ return generate_visit_anon_union(name, members)
+
ret = generate_visit_enum('%sKind' % name, members.keys())
if base:
diff --git a/scripts/qapi.py b/scripts/qapi.py
index 3a54c7f..38c808e 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -17,6 +17,21 @@ builtin_types = [
'uint8', 'uint16', 'uint32', 'uint64'
]
+builtin_type_qtypes = {
+ 'str': 'QTYPE_QSTRING',
+ 'int': 'QTYPE_QINT',
+ 'number': 'QTYPE_QFLOAT',
+ 'bool': 'QTYPE_QBOOL',
+ 'int8': 'QTYPE_QINT',
+ 'int16': 'QTYPE_QINT',
+ 'int32': 'QTYPE_QINT',
+ 'int64': 'QTYPE_QINT',
+ 'uint8': 'QTYPE_QINT',
+ 'uint16': 'QTYPE_QINT',
+ 'uint32': 'QTYPE_QINT',
+ 'uint64': 'QTYPE_QINT',
+}
+
def tokenize(data):
while len(data):
ch = data[0]
--
1.7.1