Write abritrary printable objects into Xml_generator

Fix #3161

repos/base/include/util/xml_generator.h

@@ -248,6 +248,16 @@ class Genode::Xml_generator
 					_commit_content(content_buffer);
 				}
 
+				/**
+				 * Append character, sanitize it if needed
+				 */
+				void append_sanitized(char const c)
+				{
+					Out_buffer content_buffer = _content_buffer(false);
+					content_buffer.append_sanitized(c);
+					_commit_content(content_buffer);
+				}
+
 				void append_sanitized(char const *src, size_t src_len)
 				{
 					Out_buffer content_buffer = _content_buffer(false);
@@ -417,6 +427,33 @@ class Genode::Xml_generator
 			_curr_node->append_sanitized(str, str_len == ~0UL ? strlen(str) : str_len);
 		}
 
+		/**
+		 * Append printable objects to XML node as sanitized content
+		 *
+		 * This method must not be followed by calls of 'attribute'.
+		 */
+		template <typename... ARGS>
+		void append_content(ARGS &&... args)
+		{
+			struct Node_output : Genode::Output
+			{
+				Node &node; Node_output(Node &n) : node(n) { }
+
+				/******************************
+				 ** Genode::Output interface **
+				 ******************************/
+
+				void out_char(char c) override {
+					node.append_sanitized(c); }
+
+				void out_string(char const *str, size_t n) override {
+					node.append_sanitized(str, n); }
+
+			} output { *_curr_node };
+
+			Output::out_args(output, args...);
+		}
+
 		size_t used() const { return _out_buffer.used(); }
 };
 

repos/base/src/test/xml_generator/main.cc

@@ -226,6 +226,22 @@ void Component::construct(Genode::Env &env)
 		}
 	}
 
+	/*
+	 * Test arbitrary content
+	 */
+	{
+		Xml_generator xml(dst, sizeof(dst), "data", [&] () {
+			xml.append_content(" ", 2 + 2, " == 2 + 2 == ", 4.0, " ");
+		});
+
+		Xml_node node(dst);
+		auto s = node.decoded_content<String<32>>();
+		if (s != " 4 == 2 + 2 == 4.0 ") {
+			error("decoded content does not match expect content");
+			return;
+		}
+	}
+
 	log("--- XML generator test finished ---");
 	genode_exit(0);
 }