qapi: add string-based visitors

String based visitors provide a consistent interface for parsing
strings to C values, as well as consuming C values as strings.
They will be used to parse command-line options.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c
new file mode 100644
index 0000000000..92b0305212
--- /dev/null
+++ b/qapi/string-output-visitor.c
@@ -0,0 +1,89 @@
+/*
+ * String printing Visitor
+ *
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Author: Paolo Bonzini <pbonzini@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "qemu-common.h"
+#include "string-output-visitor.h"
+#include "qapi/qapi-visit-impl.h"
+#include "qerror.h"
+
+struct StringOutputVisitor
+{
+    Visitor visitor;
+    char *string;
+};
+
+static void string_output_set(StringOutputVisitor *sov, char *string)
+{
+    g_free(sov->string);
+    sov->string = string;
+}
+
+static void print_type_int(Visitor *v, int64_t *obj, const char *name,
+                           Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    string_output_set(sov, g_strdup_printf("%lld", (long long) *obj));
+}
+
+static void print_type_bool(Visitor *v, bool *obj, const char *name,
+                            Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    string_output_set(sov, g_strdup(*obj ? "true" : "false"));
+}
+
+static void print_type_str(Visitor *v, char **obj, const char *name,
+                           Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    string_output_set(sov, g_strdup(*obj ? *obj : ""));
+}
+
+static void print_type_number(Visitor *v, double *obj, const char *name,
+                              Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    string_output_set(sov, g_strdup_printf("%g", *obj));
+}
+
+char *string_output_get_string(StringOutputVisitor *sov)
+{
+    char *string = sov->string;
+    sov->string = NULL;
+    return string;
+}
+
+Visitor *string_output_get_visitor(StringOutputVisitor *sov)
+{
+    return &sov->visitor;
+}
+
+void string_output_visitor_cleanup(StringOutputVisitor *sov)
+{
+    g_free(sov->string);
+    g_free(sov);
+}
+
+StringOutputVisitor *string_output_visitor_new(void)
+{
+    StringOutputVisitor *v;
+
+    v = g_malloc0(sizeof(*v));
+
+    v->visitor.type_enum = output_type_enum;
+    v->visitor.type_int = print_type_int;
+    v->visitor.type_bool = print_type_bool;
+    v->visitor.type_str = print_type_str;
+    v->visitor.type_number = print_type_number;
+
+    return v;
+}