[Qemu-devel] [PATCH v14 07/21] qapi: permit scalar type conversions in QObjectInputVisitor

["Daniel P. Berrange" <berrange@redhat.com>]

Currently the QObjectInputVisitor assumes that all scalar
values are directly represented as the final types declared
by the thing being visited. ie it assumes an 'int' is using
QInt, and a 'bool' is using QBool, etc.  This is good when
QObjectInputVisitor is fed a QObject that came from a JSON
document on the QMP monitor, as it will strictly validate
correctness.

To allow QObjectInputVisitor to be reused for visiting
a QObject originating from QemuOpts, an alternative mode
is needed where all the scalars types are represented as
QString and converted on the fly to the final desired
type.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 include/qapi/qobject-input-visitor.h |  32 +++++-
 qapi/qobject-input-visitor.c         | 132 ++++++++++++++++++++++++
 tests/test-qobject-input-visitor.c   | 194 ++++++++++++++++++++++++++++++++++-
 3 files changed, 350 insertions(+), 8 deletions(-)

diff --git a/include/qapi/qobject-input-visitor.h b/include/qapi/qobject-input-visitor.h
index cde328d..5022297 100644
--- a/include/qapi/qobject-input-visitor.h
+++ b/include/qapi/qobject-input-visitor.h
@@ -19,12 +19,36 @@
 
 typedef struct QObjectInputVisitor QObjectInputVisitor;
 
-/*
- * Return a new input visitor that converts a QObject to a QAPI object.
+/**
+ * Create a new input visitor that converts @obj to a QAPI object.
+ *
+ * Any scalar values in the @obj input data structure should be in the
+ * required type already. i.e. if visiting a bool, the value should
+ * already be a QBool instance.
  *
- * Set @strict to reject a parse that doesn't consume all keys of a
- * dictionary; otherwise excess input is ignored.
+ * If @strict is set to true, then an error will be reported if any
+ * dict keys are not consumed during visitation. If @strict is false
+ * then extra dict keys are silently ignored.
+ *
+ * The returned input visitor should be released by calling
+ * visit_free() when no longer required.
  */
 Visitor *qobject_input_visitor_new(QObject *obj, bool strict);
 
+/**
+ * Create a new input visitor that converts @obj to a QAPI object.
+ *
+ * Any scalar values in the @obj input data structure should always be
+ * represented as strings. i.e. if visiting a boolean, the value should
+ * be a QString whose contents represent a valid boolean.
+ *
+ * The visitor always operates in strict mode, requiring all dict keys
+ * to be consumed during visitation. An error will be reported if this
+ * does not happen.
+ *
+ * The returned input visitor should be released by calling
+ * visit_free() when no longer required.
+ */
+Visitor *qobject_input_visitor_new_autocast(QObject *obj);
+
 #endif
diff --git a/qapi/qobject-input-visitor.c b/qapi/qobject-input-visitor.c
index 5ff3db3..cf41df6 100644
--- a/qapi/qobject-input-visitor.c
+++ b/qapi/qobject-input-visitor.c
@@ -20,6 +20,7 @@
 #include "qemu-common.h"
 #include "qapi/qmp/types.h"
 #include "qapi/qmp/qerror.h"
+#include "qemu/cutils.h"
 
 #define QIV_STACK_SIZE 1024
 
@@ -263,6 +264,28 @@ static void qobject_input_type_int64(Visitor *v, const char *name, int64_t *obj,
     *obj = qint_get_int(qint);
 }
 
+
+static void qobject_input_type_int64_autocast(Visitor *v, const char *name,
+                                              int64_t *obj, Error **errp)
+{
+    QObjectInputVisitor *qiv = to_qiv(v);
+    QString *qstr = qobject_to_qstring(qobject_input_get_object(qiv, name,
+                                                                true));
+    int64_t ret;
+
+    if (!qstr || !qstr->string) {
+        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                   "string");
+        return;
+    }
+
+    if (qemu_strtoll(qstr->string, NULL, 0, &ret) < 0) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
+        return;
+    }
+    *obj = ret;
+}
+
 static void qobject_input_type_uint64(Visitor *v, const char *name,
                                       uint64_t *obj, Error **errp)
 {
@@ -279,6 +302,27 @@ static void qobject_input_type_uint64(Visitor *v, const char *name,
     *obj = qint_get_int(qint);
 }
 
+static void qobject_input_type_uint64_autocast(Visitor *v, const char *name,
+                                               uint64_t *obj, Error **errp)
+{
+    QObjectInputVisitor *qiv = to_qiv(v);
+    QString *qstr = qobject_to_qstring(qobject_input_get_object(qiv, name,
+                                                                true));
+    unsigned long long ret;
+
+    if (!qstr || !qstr->string) {
+        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                   "string");
+        return;
+    }
+
+    if (parse_uint_full(qstr->string, &ret, 0) < 0) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
+        return;
+    }
+    *obj = ret;
+}
+
 static void qobject_input_type_bool(Visitor *v, const char *name, bool *obj,
                                     Error **errp)
 {
@@ -294,6 +338,22 @@ static void qobject_input_type_bool(Visitor *v, const char *name, bool *obj,
     *obj = qbool_get_bool(qbool);
 }
 
+static void qobject_input_type_bool_autocast(Visitor *v, const char *name,
+                                             bool *obj, Error **errp)
+{
+    QObjectInputVisitor *qiv = to_qiv(v);
+    QString *qstr = qobject_to_qstring(qobject_input_get_object(qiv, name,
+                                                                true));
+
+    if (!qstr || !qstr->string) {
+        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                   "string");
+        return;
+    }
+
+    parse_option_bool(name, qstr->string, obj, errp);
+}
+
 static void qobject_input_type_str(Visitor *v, const char *name, char **obj,
                                    Error **errp)
 {
@@ -335,6 +395,30 @@ static void qobject_input_type_number(Visitor *v, const char *name, double *obj,
                "number");
 }
 
+static void qobject_input_type_number_autocast(Visitor *v, const char *name,
+                                               double *obj, Error **errp)
+{
+    QObjectInputVisitor *qiv = to_qiv(v);
+    QString *qstr = qobject_to_qstring(qobject_input_get_object(qiv, name,
+                                                                true));
+    char *endp;
+
+    if (!qstr || !qstr->string) {
+        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                   "string");
+        return;
+    }
+
+    errno = 0;
+    *obj = strtod(qstr->string, &endp);
+    if (errno == 0 && endp != qstr->string && *endp == '\0') {
+        return;
+    }
+
+    error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+               "number");
+}
+
 static void qobject_input_type_any(Visitor *v, const char *name, QObject **obj,
                                    Error **errp)
 {
@@ -356,6 +440,22 @@ static void qobject_input_type_null(Visitor *v, const char *name, Error **errp)
     }
 }
 
+static void qobject_input_type_size_autocast(Visitor *v, const char *name,
+                                             uint64_t *obj, Error **errp)
+{
+    QObjectInputVisitor *qiv = to_qiv(v);
+    QString *qstr = qobject_to_qstring(qobject_input_get_object(qiv, name,
+                                                                true));
+
+    if (!qstr || !qstr->string) {
+        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                   "string");
+        return;
+    }
+
+    parse_option_size(name, qstr->string, obj, errp);
+}
+
 static void qobject_input_optional(Visitor *v, const char *name, bool *present)
 {
     QObjectInputVisitor *qiv = to_qiv(v);
@@ -413,3 +513,35 @@ Visitor *qobject_input_visitor_new(QObject *obj, bool strict)
 
     return &v->visitor;
 }
+
+Visitor *qobject_input_visitor_new_autocast(QObject *obj)
+{
+    QObjectInputVisitor *v;
+
+    v = g_malloc0(sizeof(*v));
+
+    v->visitor.type = VISITOR_INPUT;
+    v->visitor.start_struct = qobject_input_start_struct;
+    v->visitor.check_struct = qobject_input_check_struct;
+    v->visitor.end_struct = qobject_input_pop;
+    v->visitor.start_list = qobject_input_start_list;
+    v->visitor.next_list = qobject_input_next_list;
+    v->visitor.end_list = qobject_input_pop;
+    v->visitor.start_alternate = qobject_input_start_alternate;
+    v->visitor.type_int64 = qobject_input_type_int64_autocast;
+    v->visitor.type_uint64 = qobject_input_type_uint64_autocast;
+    v->visitor.type_bool = qobject_input_type_bool_autocast;
+    v->visitor.type_str = qobject_input_type_str;
+    v->visitor.type_number = qobject_input_type_number_autocast;
+    v->visitor.type_any = qobject_input_type_any;
+    v->visitor.type_null = qobject_input_type_null;
+    v->visitor.type_size = qobject_input_type_size_autocast;
+    v->visitor.optional = qobject_input_optional;
+    v->visitor.free = qobject_input_free;
+    v->strict = true;
+
+    v->root = obj;
+    qobject_incref(obj);
+
+    return &v->visitor;
+}
diff --git a/tests/test-qobject-input-visitor.c b/tests/test-qobject-input-visitor.c
index 26c5012..d5b8044 100644
--- a/tests/test-qobject-input-visitor.c
+++ b/tests/test-qobject-input-visitor.c
@@ -41,6 +41,7 @@ static void visitor_input_teardown(TestInputVisitorData *data,
    function so that the JSON string used by the tests are kept in the test
    functions (and not in main()). */
 static Visitor *visitor_input_test_init_internal(TestInputVisitorData *data,
+                                                 bool strict, bool autocast,
                                                  const char *json_string,
                                                  va_list *ap)
 {
@@ -49,11 +50,31 @@ static Visitor *visitor_input_test_init_internal(TestInputVisitorData *data,
     data->obj = qobject_from_jsonv(json_string, ap);
     g_assert(data->obj);
 
-    data->qiv = qobject_input_visitor_new(data->obj, false);
+    if (autocast) {
+        assert(strict);
+        data->qiv = qobject_input_visitor_new_autocast(data->obj);
+    } else {
+        data->qiv = qobject_input_visitor_new(data->obj, strict);
+    }
     g_assert(data->qiv);
     return data->qiv;
 }
 
+static GCC_FMT_ATTR(4, 5)
+Visitor *visitor_input_test_init_full(TestInputVisitorData *data,
+                                      bool strict, bool autocast,
+                                      const char *json_string, ...)
+{
+    Visitor *v;
+    va_list ap;
+
+    va_start(ap, json_string);
+    v = visitor_input_test_init_internal(data, strict, autocast,
+                                         json_string, &ap);
+    va_end(ap);
+    return v;
+}
+
 static GCC_FMT_ATTR(2, 3)
 Visitor *visitor_input_test_init(TestInputVisitorData *data,
                                  const char *json_string, ...)
@@ -62,7 +83,8 @@ Visitor *visitor_input_test_init(TestInputVisitorData *data,
     va_list ap;
 
     va_start(ap, json_string);
-    v = visitor_input_test_init_internal(data, json_string, &ap);
+    v = visitor_input_test_init_internal(data, true, false,
+                                         json_string, &ap);
     va_end(ap);
     return v;
 }
@@ -77,7 +99,8 @@ Visitor *visitor_input_test_init(TestInputVisitorData *data,
 static Visitor *visitor_input_test_init_raw(TestInputVisitorData *data,
                                             const char *json_string)
 {
-    return visitor_input_test_init_internal(data, json_string, NULL);
+    return visitor_input_test_init_internal(data, true, false,
+                                            json_string, NULL);
 }
 
 static void test_visitor_in_int(TestInputVisitorData *data,
@@ -109,6 +132,45 @@ static void test_visitor_in_int_overflow(TestInputVisitorData *data,
     error_free_or_abort(&err);
 }
 
+static void test_visitor_in_int_autocast(TestInputVisitorData *data,
+                                         const void *unused)
+{
+    int64_t res = 0, value = -42;
+    Error *err = NULL;
+    Visitor *v;
+
+    v = visitor_input_test_init_full(data, true, true,
+                                     "%" PRId64, value);
+    visit_type_int(v, NULL, &res, &err);
+    error_free_or_abort(&err);
+}
+
+static void test_visitor_in_int_str_autocast(TestInputVisitorData *data,
+                                             const void *unused)
+{
+    int64_t res = 0, value = -42;
+    Visitor *v;
+
+    v = visitor_input_test_init_full(data, true, true,
+                                     "\"-42\"");
+
+    visit_type_int(v, NULL, &res, &error_abort);
+    g_assert_cmpint(res, ==, value);
+}
+
+static void test_visitor_in_int_str_noautocast(TestInputVisitorData *data,
+                                               const void *unused)
+{
+    int64_t res = 0;
+    Visitor *v;
+    Error *err = NULL;
+
+    v = visitor_input_test_init(data, "\"-42\"");
+
+    visit_type_int(v, NULL, &res, &err);
+    error_free_or_abort(&err);
+}
+
 static void test_visitor_in_bool(TestInputVisitorData *data,
                                  const void *unused)
 {
@@ -121,6 +183,44 @@ static void test_visitor_in_bool(TestInputVisitorData *data,
     g_assert_cmpint(res, ==, true);
 }
 
+static void test_visitor_in_bool_autocast(TestInputVisitorData *data,
+                                          const void *unused)
+{
+    bool res = false;
+    Error *err = NULL;
+    Visitor *v;
+
+    v = visitor_input_test_init_full(data, true, true, "true");
+
+    visit_type_bool(v, NULL, &res, &err);
+    error_free_or_abort(&err);
+}
+
+static void test_visitor_in_bool_str_autocast(TestInputVisitorData *data,
+                                              const void *unused)
+{
+    bool res = false;
+    Visitor *v;
+
+    v = visitor_input_test_init_full(data, true, true, "\"yes\"");
+
+    visit_type_bool(v, NULL, &res, &error_abort);
+    g_assert_cmpint(res, ==, true);
+}
+
+static void test_visitor_in_bool_str_noautocast(TestInputVisitorData *data,
+                                                const void *unused)
+{
+    bool res = false;
+    Visitor *v;
+    Error *err = NULL;
+
+    v = visitor_input_test_init(data, "\"true\"");
+
+    visit_type_bool(v, NULL, &res, &err);
+    error_free_or_abort(&err);
+}
+
 static void test_visitor_in_number(TestInputVisitorData *data,
                                    const void *unused)
 {
@@ -133,6 +233,69 @@ static void test_visitor_in_number(TestInputVisitorData *data,
     g_assert_cmpfloat(res, ==, value);
 }
 
+static void test_visitor_in_number_autocast(TestInputVisitorData *data,
+                                            const void *unused)
+{
+    double res = 0, value = 3.14;
+    Error *err = NULL;
+    Visitor *v;
+
+    v = visitor_input_test_init_full(data, true, true, "%f", value);
+
+    visit_type_number(v, NULL, &res, &err);
+    error_free_or_abort(&err);
+}
+
+static void test_visitor_in_number_str_autocast(TestInputVisitorData *data,
+                                                const void *unused)
+{
+    double res = 0, value = 3.14;
+    Visitor *v;
+
+    v = visitor_input_test_init_full(data, true, true, "\"3.14\"");
+
+    visit_type_number(v, NULL, &res, &error_abort);
+    g_assert_cmpfloat(res, ==, value);
+}
+
+static void test_visitor_in_number_str_noautocast(TestInputVisitorData *data,
+                                                  const void *unused)
+{
+    double res = 0;
+    Visitor *v;
+    Error *err = NULL;
+
+    v = visitor_input_test_init(data, "\"3.14\"");
+
+    visit_type_number(v, NULL, &res, &err);
+    error_free_or_abort(&err);
+}
+
+static void test_visitor_in_size_str_autocast(TestInputVisitorData *data,
+                                              const void *unused)
+{
+    uint64_t res, value = 500 * 1024 * 1024;
+    Visitor *v;
+
+    v = visitor_input_test_init_full(data, true, true, "\"500M\"");
+
+    visit_type_size(v, NULL, &res, &error_abort);
+    g_assert_cmpfloat(res, ==, value);
+}
+
+static void test_visitor_in_size_str_noautocast(TestInputVisitorData *data,
+                                                const void *unused)
+{
+    uint64_t res = 0;
+    Visitor *v;
+    Error *err = NULL;
+
+    v = visitor_input_test_init(data, "\"500M\"");
+
+    visit_type_size(v, NULL, &res, &err);
+    error_free_or_abort(&err);
+}
+
 static void test_visitor_in_string(TestInputVisitorData *data,
                                    const void *unused)
 {
@@ -289,7 +452,8 @@ static void test_visitor_in_null(TestInputVisitorData *data,
      * when input is not null.
      */
 
-    v = visitor_input_test_init(data, "{ 'a': null, 'b': '' }");
+    v = visitor_input_test_init_full(data, false, false,
+                                     "{ 'a': null, 'b': '' }");
     visit_start_struct(v, NULL, NULL, 0, &error_abort);
     visit_type_null(v, "a", &error_abort);
     visit_type_str(v, "a", &tmp, &err);
@@ -840,10 +1004,32 @@ int main(int argc, char **argv)
                            NULL, test_visitor_in_int);
     input_visitor_test_add("/visitor/input/int_overflow",
                            NULL, test_visitor_in_int_overflow);
+    input_visitor_test_add("/visitor/input/int_autocast",
+                           NULL, test_visitor_in_int_autocast);
+    input_visitor_test_add("/visitor/input/int_str_autocast",
+                           NULL, test_visitor_in_int_str_autocast);
+    input_visitor_test_add("/visitor/input/int_str_noautocast",
+                           NULL, test_visitor_in_int_str_noautocast);
     input_visitor_test_add("/visitor/input/bool",
                            NULL, test_visitor_in_bool);
+    input_visitor_test_add("/visitor/input/bool_autocast",
+                           NULL, test_visitor_in_bool_autocast);
+    input_visitor_test_add("/visitor/input/bool_str_autocast",
+                           NULL, test_visitor_in_bool_str_autocast);
+    input_visitor_test_add("/visitor/input/bool_str_noautocast",
+                           NULL, test_visitor_in_bool_str_noautocast);
     input_visitor_test_add("/visitor/input/number",
                            NULL, test_visitor_in_number);
+    input_visitor_test_add("/visitor/input/number_autocast",
+                           NULL, test_visitor_in_number_autocast);
+    input_visitor_test_add("/visitor/input/number_str_autocast",
+                           NULL, test_visitor_in_number_str_autocast);
+    input_visitor_test_add("/visitor/input/number_str_noautocast",
+                           NULL, test_visitor_in_number_str_noautocast);
+    input_visitor_test_add("/visitor/input/size_str_autocast",
+                           NULL, test_visitor_in_size_str_autocast);
+    input_visitor_test_add("/visitor/input/size_str_noautocast",
+                           NULL, test_visitor_in_size_str_noautocast);
     input_visitor_test_add("/visitor/input/string",
                            NULL, test_visitor_in_string);
     input_visitor_test_add("/visitor/input/enum",
-- 
2.7.4