feat: dbus error support

example/example.cc

@@ -1,6 +1,7 @@
 #include "example.h"
 
 #include <dbusx/method.h>
+#include <dbusx/error.h>
 
 example::example() {
 }
@@ -9,6 +10,10 @@ uint32_t example::string_length(const std::string &str) {
  return str.length();
 }
 
+int32_t example::always_error(int32_t) {
+ throw dbusx::error("org.freedesktop.DBus.Error.FileNotFound", "error message");
+}
+
 std::string example::interface_name() {
  return "cn.zsien.dbusx.example.control";
 }
@@ -18,6 +23,7 @@ dbusx::vtable::vtable example::exported() {
  .methods =
  {
  {"stringLength", dbusx::method<&example::string_length>::get_vtable()},
+ {"alwaysError", dbusx::method<&example::always_error>::get_vtable()},
  },
  .properties = {},
  .signals = {},

example/example.h

@@ -7,7 +7,8 @@ class example : public dbusx::interface {
 public:
  example();
 
- uint32_t string_length(const std::string &str); 
+ uint32_t string_length(const std::string &str);
+ int32_t always_error(int32_t);
 
  virtual std::string interface_name() override;
  virtual dbusx::vtable::vtable exported() override;

include/dbusx/error.h

@@ -0,0 +1,26 @@
+#ifndef DBUSX_ERROR_H
+#define DBUSX_ERROR_H
+
+#include <exception>
+#include <string>
+
+namespace dbusx {
+
+class error : public std::exception {
+ friend class message;
+
+public:
+ error(const std::string &name, const std::string &message)
+ : name_(name)
+ , message_(message) {}
+
+ const char *what() const noexcept override { return message_.c_str(); }
+
+private:
+ const std::string name_;
+ const std::string message_;
+};
+
+} // namespace dbusx
+
+#endif //! DBUSX_ERROR_H

include/dbusx/message.h

@@ -11,6 +11,8 @@ namespace dbusx {
 
 class message_private;
 
+class error;
+
 class message {
 public:
  enum class type {
@@ -64,6 +66,7 @@ class message {
  message &operator=(message &&r) noexcept;
 
  message create_return() const;
+ message create_error(const error &error) const;
 
  std::string get_destination() const;
  std::string get_path() const;

include/dbusx/method.h

@@ -9,6 +9,7 @@
 #include "message.h"
 #include "signature.h"
 #include "vtable.h"
+#include "error.h"
 
 namespace dbusx {
 
@@ -54,15 +55,22 @@ struct method<F> {
  }
 
  static void invoke(interface *o, const message &m) {
- C *obj = reinterpret_cast<C *>(o);
- OUT r = (obj->*F)(m.read<IN>()...);
- // TODO: out
+ try {
+ C *obj = reinterpret_cast<C *>(o);
+ OUT r = (obj->*F)(m.read<IN>()...);
+ // TODO: out
+ (void)r;
 
- message ret = m.create_return();
- ret.append(r);
- bool a = ret.send();
- (void)a;
- // m.reply(r);
+ message ret = m.create_return();
+ ret.append(r);
+ bool a = ret.send();
+ (void)a;
+ // m.reply(r);
+ } catch (const dbusx::error &e) {
+ message ret = m.create_error(e);
+ bool a = ret.send();
+ (void)a;
+ }
  }
 };
 

src/sdbus/message.cc

@@ -5,6 +5,7 @@
 
 #include "message_private.h"
 #include "dbusx/signature.h"
+#include "dbusx/error.h"
 
 using namespace dbusx;
 
@@ -28,6 +29,22 @@ message message::create_return() const {
  return msg;
 }
 
+message message::create_error(const error &err) const {
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wc99-extensions"
+#endif
+ auto e = SD_BUS_ERROR_MAKE_CONST(err.name_.c_str(), err.message_.c_str());
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+
+ message msg;
+ sd_bus_message_new_method_error(d_ptr_->message_, &msg.d_ptr_->message_, &e);
+
+ return msg;
+}
+
 std::string message::get_destination() const {
  return sd_bus_message_get_destination(d_ptr_->message_);
 }