Sun Studio 11 "Warning (Anachronism)"

Question

Hello,
Compiling a C++ program using Sun Studio 11 compiler on Solaris, I get warnings like this:
Warning (Anachronism): Using blabla(*)(<params>) to initialize extern "C" blabla(*)(<params>).
For example, this happens passing a callback of type jvmtiHeapObjectCallback to IterateOverHeap (both defined in Sun's jvmti.h):
typedef jvmtiIterationControl (JNICALL *jvmtiHeapObjectCallback)
(jlong class_tag, jlong size, jlong* tag_ptr, void* user_data);
jvmtiError (JNICALL IterateOverHeap) (jvmtiEnv env,
jvmtiHeapObjectFilter object_filter,
jvmtiHeapObjectCallback heap_object_callback,
const void* user_data);
What does this warning mean?
I checked that JNICALL is defined in Solaris jni_md.h as empty string, so it seems strange for me that the compiler wants extern "C" here.
The same code compiles with no problems on Solaris with gcc, as well as with Visual Studio on Windows and with gcc on Linux and Mac.
Best regards,
Anton

Answer 1

Thank you for your prompt reply.
In the guide, it is said:
"The Sun implementation of C and C++ function linkage is binary-compatible. That is not the case with every C++ implementation, although it is reasonably common".
I believe that for all other platforms that we support - Linux, Mac OS X, Windows - the only difference in C and C++ linkage is C++ name mangling.
I'm not 100% sure (just curious, do you know any implementations where C and C++ functions are not linkage compatible?), but there never were runtime problems with such C/C++ function mixing in our code.
Actually, the mixing happens in our code because we declare class with single static function (callback implemetation) right in the function where function requiring callback parameter is used. This is similar to Java anonymous classes, and helps to write simpler code (especially when callback code is short, and there are many different callbacks in different places of the code):
void qqq() {
struct Tmp {
static void myCallback() { ... }
foo(&Tmp::myCallback);
So, unfortunately, the offered solutions (wrapping) will not work in our case, unless we simply rewrite our callbacks as regular C functions.
Is there a compiler option (or a pragma) to suppress this warning?