[Qemu-devel] [PATCH v4 27/28] qapi: Add 'any' support to JSON output

[Eric Blake <eblake@redhat.com>]

Now that we can visit any QObject, it's easy to add support
for visit_type_any() in the JSON output visitor.

Signed-off-by: Eric Blake <eblake@redhat.com>

---
v4: new patch, split out of v3 7/18, but made simpler by
not requiring v3 12/18
---
 include/qapi/json-output-visitor.h |  2 --
 qapi/json-output-visitor.c         |  7 ++++++
 tests/test-json-output-visitor.c   | 50 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/include/qapi/json-output-visitor.h b/include/qapi/json-output-visitor.h
index 94c9e0f..414f91b 100644
--- a/include/qapi/json-output-visitor.h
+++ b/include/qapi/json-output-visitor.h
@@ -23,8 +23,6 @@ typedef struct JsonOutputVisitor JsonOutputVisitor;
  *
  * If @pretty, make the output legible with newlines and indentation;
  * otherwise the output uses a single line.
- *
- * For now, this cannot be used to visit the 'any' type.
  */
 Visitor *json_output_visitor_new(bool pretty, char **result);

diff --git a/qapi/json-output-visitor.c b/qapi/json-output-visitor.c
index 881c9ee..ba647d3 100644
--- a/qapi/json-output-visitor.c
+++ b/qapi/json-output-visitor.c
@@ -147,6 +147,12 @@ static void json_output_type_number(Visitor *v, const char *name, double *obj,
     qstring_append_json_number(jov->str, *obj);
 }

+static void json_output_type_any(Visitor *v, const char *name, QObject **obj,
+                                 Error **errp)
+{
+    qobject_visit_output(v, name, *obj);
+}
+
 static void json_output_type_null(Visitor *v, const char *name, Error **errp)
 {
     JsonOutputVisitor *jov = to_jov(v);
@@ -196,6 +202,7 @@ Visitor *json_output_visitor_new(bool pretty, char **result)
     v->visitor.type_bool = json_output_type_bool;
     v->visitor.type_str = json_output_type_str;
     v->visitor.type_number = json_output_type_number;
+    v->visitor.type_any = json_output_type_any;
     v->visitor.type_null = json_output_type_null;
     v->visitor.complete = json_output_complete;
     v->visitor.free = json_output_free;
diff --git a/tests/test-json-output-visitor.c b/tests/test-json-output-visitor.c
index 5073715..fd14e26 100644
--- a/tests/test-json-output-visitor.c
+++ b/tests/test-json-output-visitor.c
@@ -316,6 +316,52 @@ static void test_visitor_out_list(TestOutputVisitorData *data,
     qapi_free_TestStructList(head);
 }

+static void test_visitor_out_any(TestOutputVisitorData *data,
+                                 const void *arg)
+{
+    const bool *pretty = arg;
+    QObject *qobj;
+    QDict *qdict;
+    const char *out;
+
+    qobj = QOBJECT(qint_from_int(-42));
+    visit_type_any(data->ov, NULL, &qobj, &error_abort);
+    out = visitor_get(data);
+    g_assert_cmpstr(out, ==, "-42");
+    qobject_decref(qobj);
+
+    visitor_reset(data);
+    qdict = qdict_new();
+    /* Ordering here is sensitive to the hashing chosen by QDict. */
+    qdict_put(qdict, "integer", qint_from_int(-42));
+    qdict_put(qdict, "list", qlist_new());
+    qdict_put(qdict, "boolean", qbool_from_bool(true));
+    qdict_put(qdict, "string", qstring_from_str("foo"));
+    qobj = QOBJECT(qdict);
+    visit_type_any(data->ov, NULL, &qobj, &error_abort);
+    qobject_decref(qobj);
+    out = visitor_get(data);
+
+    if (*pretty) {
+        g_assert_cmpstr(out, ==,
+                        "{\n"
+                        "    \"integer\": -42,\n"
+                        "    \"list\": [\n"
+                        "    ],\n"
+                        "    \"boolean\": true,\n"
+                        "    \"string\": \"foo\"\n"
+                        "}");
+    } else {
+        g_assert_cmpstr(out, ==,
+                        "{"
+                         "\"integer\": -42, "
+                         "\"list\": [], "
+                         "\"boolean\": true, "
+                         "\"string\": \"foo\""
+                        "}");
+    }
+}
+
 static void test_visitor_out_union_flat(TestOutputVisitorData *data,
                                         const void *unused)
 {
@@ -412,6 +458,10 @@ int main(int argc, char **argv)
                             test_visitor_out_struct_errors);
     output_visitor_test_add("/visitor/json/list", &plain,
                             test_visitor_out_list);
+    output_visitor_test_add("/visitor/json/any", &plain,
+                            test_visitor_out_any);
+    output_visitor_test_add("/visitor/json-pretty/any", &pretty,
+                            test_visitor_out_any);
     output_visitor_test_add("/visitor/json/union-flat", &plain,
                             test_visitor_out_union_flat);
     output_visitor_test_add("/visitor/json/alternate", &plain,
-- 
2.5.5