NativeWrapperDefns.h

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/* Copyright (C) 2009 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */
 #include "ps/GameSetup/Config.h"

// (NativeWrapperDecls.h set up a lot of the macros we use here)

// ScriptInterface_NativeWrapper<T>::call(cx, rval, fptr, args...) will call fptr(cbdata, args...),
// and if T != void then it will store the result in rval:

// Templated on the return type so void can be handled separately
template <typename R>
struct ScriptInterface_NativeWrapper {
    #define OVERLOADS(z, i, data) \
        template<TYPENAME_T0_HEAD(z,i)  typename F> \
        static void call(JSContext* cx, jsval& rval, F fptr  T0_A0(z,i)) { \
            rval = ScriptInterface::ToJSVal<R>(cx, fptr(ScriptInterface::GetCallbackData(cx)  A0_TAIL(z,i))); \
        }

    BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
    #undef OVERLOADS
};

// Overloaded to ignore the return value from void functions
template <>
struct ScriptInterface_NativeWrapper<void> {
    #define OVERLOADS(z, i, data) \
        template<TYPENAME_T0_HEAD(z,i)  typename F> \
        static void call(JSContext* cx, jsval& /*rval*/, F fptr  T0_A0(z,i)) { \
            fptr(ScriptInterface::GetCallbackData(cx)  A0_TAIL(z,i)); \
        }
    BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
    #undef OVERLOADS
};

// Same idea but for method calls:

template <typename R, typename TC>
struct ScriptInterface_NativeMethodWrapper {
    #define OVERLOADS(z, i, data) \
        template<TYPENAME_T0_HEAD(z,i)  typename F> \
        static void call(JSContext* cx, jsval& rval, TC* c, F fptr  T0_A0(z,i)) { \
            rval = ScriptInterface::ToJSVal<R>(cx, (c->*fptr)( A0(z,i) )); \
        }

    BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
    #undef OVERLOADS
};

template <typename TC>
struct ScriptInterface_NativeMethodWrapper<void, TC> {
    #define OVERLOADS(z, i, data) \
        template<TYPENAME_T0_HEAD(z,i)  typename F> \
        static void call(JSContext* /*cx*/, jsval& /*rval*/, TC* c, F fptr  T0_A0(z,i)) { \
            (c->*fptr)( A0(z,i) ); \
        }
    BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
    #undef OVERLOADS
};

// Fast natives don't trigger the hook we use for profiling, so explicitly
// notify the profiler when these functions are being called.
// ScriptInterface_impl::Register stores the name in a reserved slot.
// (TODO: this doesn't work for functions registered via InterfaceScripted.h.
// Maybe we should do some interned JS_GetFunctionId thing.)
#define SCRIPT_PROFILE \
    if (g_ScriptProfilingEnabled) \
    { \
        ENSURE(JSVAL_IS_OBJECT(JS_CALLEE(cx, vp)) && JS_ObjectIsFunction(cx, JSVAL_TO_OBJECT(JS_CALLEE(cx, vp)))); \
        const char* name = "(unknown)"; \
        jsval nameval; \
        if (JS_GetReservedSlot(cx, JSVAL_TO_OBJECT(JS_CALLEE(cx, vp)), 0, &nameval) \
            && !JSVAL_IS_VOID(nameval)) \
            name = static_cast<const char*>(JSVAL_TO_PRIVATE(nameval)); \
        CProfileSampleScript profile(name); \
    }

// JSFastNative-compatible function that wraps the function identified in the template argument list
#define OVERLOADS(z, i, data) \
    template <typename R, TYPENAME_T0_HEAD(z,i)  R (*fptr) ( void* T0_TAIL(z,i) )> \
    JSBool ScriptInterface::call(JSContext* cx, uintN argc, jsval* vp) { \
        UNUSED2(argc); \
        SCRIPT_PROFILE \
        BOOST_PP_REPEAT_##z (i, CONVERT_ARG, ~) \
        jsval rval = JSVAL_VOID; \
        ScriptInterface_NativeWrapper<R>::call(cx, rval, fptr  A0_TAIL(z,i)); \
        JS_SET_RVAL(cx, vp, rval); \
        return (ScriptInterface::IsExceptionPending(cx) ? JS_FALSE : JS_TRUE); \
    }
BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
#undef OVERLOADS

// Same idea but for methods
#define OVERLOADS(z, i, data) \
    template <typename R, TYPENAME_T0_HEAD(z,i)  JSClass* CLS, typename TC, R (TC::*fptr) ( T0(z,i) )> \
    JSBool ScriptInterface::callMethod(JSContext* cx, uintN argc, jsval* vp) { \
        UNUSED2(argc); \
        SCRIPT_PROFILE \
        if (ScriptInterface::GetClass(cx, JS_THIS_OBJECT(cx, vp)) != CLS) return JS_FALSE; \
        TC* c = static_cast<TC*>(ScriptInterface::GetPrivate(cx, JS_THIS_OBJECT(cx, vp))); \
        if (! c) return JS_FALSE; \
        BOOST_PP_REPEAT_##z (i, CONVERT_ARG, ~) \
        jsval rval = JSVAL_VOID; \
        ScriptInterface_NativeMethodWrapper<R, TC>::call(cx, rval, c, fptr  A0_TAIL(z,i)); \
        JS_SET_RVAL(cx, vp, rval); \
        return (ScriptInterface::IsExceptionPending(cx) ? JS_FALSE : JS_TRUE); \
    }
BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
#undef OVERLOADS

// Clean up our mess
#undef SCRIPT_PROFILE
#undef NUMBERED_LIST_HEAD
#undef NUMBERED_LIST_TAIL
#undef NUMBERED_LIST_BALANCED
#undef TYPED_ARGS
#undef CONVERT_ARG
#undef TYPENAME_T0_HEAD
#undef TYPENAME_T0_TAIL
#undef T0
#undef T0_HEAD
#undef T0_TAIL
#undef T0_A0
#undef A0
#undef A0_TAIL