[Qemu-devel] [PATCH 10/12] qapi: AllocVisitor

[Kővágó, Zoltán]

Simple visitor that recursively allocates structures with only optional
variables. Unions are initialized to the first type specified. Other non
optional types are not supported.

Signed-off-by: Kővágó, Zoltán <address@hidden>
---
 include/qapi/alloc-visitor.h | 18 +++++++++++++
 qapi/Makefile.objs           |  1 +
 qapi/alloc-visitor.c         | 62 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+)
 create mode 100644 include/qapi/alloc-visitor.h
 create mode 100644 qapi/alloc-visitor.c

diff --git a/include/qapi/alloc-visitor.h b/include/qapi/alloc-visitor.h
new file mode 100644
index 0000000..3d54295
--- /dev/null
+++ b/include/qapi/alloc-visitor.h
@@ -0,0 +1,18 @@
+/*
+ * Alloc Visitor.
+ * Recursively allocates structs, leaving all optional fields unset. In case of
+ * a non-optional field it fails.
+ */
+
+#ifndef ALLOC_VISITOR_H
+#define ALLOC_VISITOR_H
+
+#include "qapi/visitor.h"
+
+typedef struct AllocVisitor AllocVisitor;
+
+AllocVisitor *alloc_visitor_new(void);
+void alloc_visitor_cleanup(AllocVisitor *v);
+Visitor *alloc_visitor_get_visitor(AllocVisitor *v);
+
+#endif
diff --git a/qapi/Makefile.objs b/qapi/Makefile.objs
index 2278970..7bc26a3 100644
--- a/qapi/Makefile.objs
+++ b/qapi/Makefile.objs
@@ -4,3 +4,4 @@ util-obj-y += string-input-visitor.o string-output-visitor.o
 util-obj-y += opts-visitor.o
 util-obj-y += qmp-event.o
 util-obj-y += qapi-util.o
+util-obj-y += alloc-visitor.o
diff --git a/qapi/alloc-visitor.c b/qapi/alloc-visitor.c
new file mode 100644
index 0000000..dbb83af
--- /dev/null
+++ b/qapi/alloc-visitor.c
@@ -0,0 +1,62 @@
+#include "qapi/alloc-visitor.h"
+#include "qemu-common.h"
+#include "qapi/visitor-impl.h"
+
+struct AllocVisitor {
+    Visitor visitor;
+};
+
+static void alloc_start_struct(Visitor *v, void **obj, const char* kind,
+                               const char *name, size_t size, Error **errp)
+{
+    if (obj) {
+        *obj = g_malloc0(size);
+    }
+}
+
+static void alloc_end_struct(Visitor *v, Error **errp)
+{
+}
+
+static void alloc_start_implicit_struct(Visitor *v, void **obj, size_t size,
+                                        Error **errp)
+{
+    if (obj) {
+        *obj = g_malloc0(size);
+    }
+}
+
+static void alloc_end_implicit_struct(Visitor *v, Error **errp)
+{
+}
+
+static void alloc_type_enum(Visitor *v, int *obj, const char *strings[],
+                            const char *kind, const char *name, Error **errp)
+{
+    assert(*strings); /* there is at least one valid enum value... */
+    *obj = 0;
+}
+
+AllocVisitor *alloc_visitor_new(void)
+{
+    AllocVisitor *v = g_malloc0(sizeof(AllocVisitor));
+
+    v->visitor.start_struct = alloc_start_struct;
+    v->visitor.end_struct = alloc_end_struct;
+    v->visitor.start_implicit_struct = alloc_start_implicit_struct;
+    v->visitor.end_implicit_struct = alloc_end_implicit_struct;
+
+    v->visitor.type_enum = alloc_type_enum;
+
+    return v;
+}
+
+void alloc_visitor_cleanup(AllocVisitor *v)
+{
+    g_free(v);
+}
+
+Visitor *alloc_visitor_get_visitor(AllocVisitor *v)
+{
+    return &v->visitor;
+}
-- 
2.4.2