Allow callback raw access to message

In some cases, the callback may care where the message came from. Allow
the callback to receive the raw sdbusplus::message along with the
automatically extracted arguments.

This means that the registration mechanism as well as the callback
mechanism need to be aware of a 'message as a first parameter' situation
and behave accordingly. The registration needs to strip the message
parameter off in order to expose a correct DBus signature. The callback
mechanism needs to strip of the message parameter in order to properly
unpack the message, but add it back in before calling apply to execute
the function.

Tested: Added an example to example/asio-example.cpp and checked to see
	that it builds. Was able to extract sender from message passed
	into the IPMI handler.

Change-Id: I520e494d3baad34271e748465f30274353554728
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/example/asio-example.cpp b/example/asio-example.cpp
index 82d713e..7477357 100644
--- a/example/asio-example.cpp
+++ b/example/asio-example.cpp
@@ -12,6 +12,11 @@ int foo(int test)
     return ++test;
 }
 
+int methodWithMessage(sdbusplus::message::message& m, int test)
+{
+    return ++test;
+}
+
 int main()
 {
     using GetSubTreeType = std::vector<std::pair<
@@ -60,7 +65,6 @@ int main()
             {
                 std::cout << item.first << "\n";
             }
-
         },
         "xyz.openbmc_project.ObjectMapper",
         "/xyz/openbmc_project/object_mapper",
@@ -115,6 +119,8 @@ int main()
 
     iface->register_method("TestFunction", foo);
 
+    iface->register_method("TestMethodWithMessage", methodWithMessage);
+
     iface->initialize();
     iface->set_property("int", 45);
     io.run();