#include "moar.h"

#ifndef _WIN32

#include <dlfcn.h>

#endif

/* Maps a calling convention name to an ID. */

MVMint16 MVM_nativecall_get_calling_convention(MVMThreadContext *tc, MVMString *name) {

    MVMint16 result = DC_CALL_C_DEFAULT;

    if (name && MVM_string_graphs(tc, name) > 0) {

        char *cname = MVM_string_utf8_encode_C_string(tc, name);

        if (strcmp(cname, "cdecl") == 0)

            result = DC_CALL_C_X86_CDECL;

        else if (strcmp(cname, "stdcall") == 0)

            result = DC_CALL_C_X86_WIN32_STD;

        else if (strcmp(cname, "thisgnu") == 0)

            result = DC_CALL_C_X86_WIN32_THIS_GNU;

        else if (strcmp(cname, "thisms") == 0)

            result = DC_CALL_C_X86_WIN32_THIS_MS;

        else if (strcmp(cname, "stdcall") == 0)

            result = DC_CALL_C_X64_WIN64;

        else {

            char *waste[] = { cname, NULL };

            MVM_exception_throw_adhoc_free(tc, waste,

                "Unknown calling convention '%s' used for native call", cname);

        }

        MVM_free(cname);

    }

    return result;

}

/* Map argument type ID to dyncall character ID. */

static char get_signature_char(MVMint16 type_id) {

    if ( (type_id & MVM_NATIVECALL_ARG_RW_MASK) == MVM_NATIVECALL_ARG_RW)

        return 'p';

    switch (type_id & MVM_NATIVECALL_ARG_TYPE_MASK) {

        case MVM_NATIVECALL_ARG_VOID:

            return 'v';

        case MVM_NATIVECALL_ARG_CHAR:

            return 'c';

        case MVM_NATIVECALL_ARG_SHORT:

            return 's';

        case MVM_NATIVECALL_ARG_INT:

            return 'i';

        case MVM_NATIVECALL_ARG_LONG:

            return 'j';

        case MVM_NATIVECALL_ARG_LONGLONG:

            return 'l';

        case MVM_NATIVECALL_ARG_FLOAT:

            return 'f';

        case MVM_NATIVECALL_ARG_DOUBLE:

            return 'd';

        case MVM_NATIVECALL_ARG_ASCIISTR:

        case MVM_NATIVECALL_ARG_UTF8STR:

        case MVM_NATIVECALL_ARG_UTF16STR:

        case MVM_NATIVECALL_ARG_CSTRUCT:

        case MVM_NATIVECALL_ARG_CPPSTRUCT:

        case MVM_NATIVECALL_ARG_CPOINTER:

        case MVM_NATIVECALL_ARG_CARRAY:

        case MVM_NATIVECALL_ARG_CUNION:

        case MVM_NATIVECALL_ARG_VMARRAY:

        case MVM_NATIVECALL_ARG_CALLBACK:

            return 'p';

        case MVM_NATIVECALL_ARG_UCHAR:

            return 'C';

        case MVM_NATIVECALL_ARG_USHORT:

            return 'S';

        case MVM_NATIVECALL_ARG_UINT:

            return 'I';

        case MVM_NATIVECALL_ARG_ULONG:

            return 'J';

        case MVM_NATIVECALL_ARG_ULONGLONG:

            return 'L';

        default:

            return '\0';

    }

}

/* Sets up a callback, caching the information to avoid duplicate work. */

static char callback_handler(DCCallback *cb, DCArgs *args, DCValue *result, MVMNativeCallback *data);

static void * unmarshal_callback(MVMThreadContext *tc, MVMObject *callback, MVMObject *sig_info) {

    MVMNativeCallbackCacheHead *callback_data_head = NULL;

    MVMNativeCallback **callback_data_handle;

    MVMString          *cuid;

    if (!IS_CONCRETE(callback))

        return NULL;

    /* Try to locate existing cached callback info. */

    callback = MVM_frame_find_invokee(tc, callback, NULL);

    cuid     = ((MVMCode *)callback)->body.sf->body.cuuid;

    MVM_HASH_GET(tc, tc->native_callback_cache, cuid, callback_data_head);

    if (!callback_data_head) {

        callback_data_head = MVM_malloc(sizeof(MVMNativeCallbackCacheHead));

        callback_data_head->head = NULL;

        MVM_HASH_BIND(tc, tc->native_callback_cache, cuid, callback_data_head);

    }

    callback_data_handle = &(callback_data_head->head);

    while (*callback_data_handle) {

        if ((*callback_data_handle)->target == callback) /* found it, break */

            break;

        callback_data_handle = &((*callback_data_handle)->next);

    }

    if (!*callback_data_handle) {

        /* First, build the MVMNativeCallback */

        MVMCallsite *cs;

        char        *signature;

        MVMObject   *typehash;

        MVMint64     num_info, i;

        MVMNativeCallback *callback_data;

        num_info                 = MVM_repr_elems(tc, sig_info);

        callback_data            = MVM_malloc(sizeof(MVMNativeCallback));

        callback_data->num_types = num_info;

        callback_data->typeinfos = MVM_malloc(num_info * sizeof(MVMint16));

        callback_data->types     = MVM_malloc(num_info * sizeof(MVMObject *));

        callback_data->next      = NULL;

        /* A dyncall signature looks like this: xxx)x

        * Argument types before the ) and return type after it. Thus,

        * num_info+1 must be NULL (zero-terminated string) and num_info-1

        * must be the ).

        */

        signature = MVM_malloc(num_info + 2);

        signature[num_info + 1] = '\0';

        signature[num_info - 1] = ')';

        /* We'll also build up a MoarVM callsite as we go. */

        cs                 = MVM_calloc(1, sizeof(MVMCallsite));

        cs->flag_count     = num_info - 1;

        cs->arg_flags      = MVM_malloc(cs->flag_count * sizeof(MVMCallsiteEntry));

        cs->arg_count      = num_info - 1;

        cs->num_pos        = num_info - 1;

        cs->has_flattening = 0;

        cs->is_interned    = 0;

        cs->with_invocant  = NULL;

        typehash = MVM_repr_at_pos_o(tc, sig_info, 0);

        callback_data->types[0] = MVM_repr_at_key_o(tc, typehash,

            tc->instance->str_consts.typeobj);

        callback_data->typeinfos[0] = MVM_nativecall_get_arg_type(tc, typehash, 1);

        signature[num_info] = get_signature_char(callback_data->typeinfos[0]);

        for (i = 1; i < num_info; i++) {

            typehash = MVM_repr_at_pos_o(tc, sig_info, i);

            callback_data->types[i] = MVM_repr_at_key_o(tc, typehash,

                tc->instance->str_consts.typeobj);

            callback_data->typeinfos[i] = MVM_nativecall_get_arg_type(tc, typehash, 0) & ~MVM_NATIVECALL_ARG_FREE_STR;

            signature[i - 1] = get_signature_char(callback_data->typeinfos[i]);

            switch (callback_data->typeinfos[i] & MVM_NATIVECALL_ARG_TYPE_MASK) {

                case MVM_NATIVECALL_ARG_CHAR:

                case MVM_NATIVECALL_ARG_SHORT:

                case MVM_NATIVECALL_ARG_INT:

                case MVM_NATIVECALL_ARG_LONG:

                case MVM_NATIVECALL_ARG_LONGLONG:

                    cs->arg_flags[i - 1] = MVM_CALLSITE_ARG_INT;

                    break;

                case MVM_NATIVECALL_ARG_UCHAR:

                case MVM_NATIVECALL_ARG_USHORT:

                case MVM_NATIVECALL_ARG_UINT:

                case MVM_NATIVECALL_ARG_ULONG:

                case MVM_NATIVECALL_ARG_ULONGLONG:

                    /* TODO: should probably be UINT, when we can support that. */

                    cs->arg_flags[i - 1] = MVM_CALLSITE_ARG_INT;

                    break;

                case MVM_NATIVECALL_ARG_FLOAT:

                case MVM_NATIVECALL_ARG_DOUBLE:

                    cs->arg_flags[i - 1] = MVM_CALLSITE_ARG_NUM;

                    break;

                default:

                    cs->arg_flags[i - 1] = MVM_CALLSITE_ARG_OBJ;

                    break;

            }

        }

        MVM_callsite_try_intern(tc, &cs);

        callback_data->instance  = tc->instance;

        callback_data->cs        = cs;

        callback_data->target    = callback;

        callback_data->cb        = dcbNewCallback(signature, (DCCallbackHandler *)callback_handler, callback_data);

        if (!callback_data->cb)

            MVM_panic(1, "Unable to allocate memory for callback closure");

        /* Now insert the MVMCallback into the linked list. */

        *callback_data_handle = callback_data;

        MVM_free(signature);

    }

    return (*callback_data_handle)->cb;

}

/* Called to handle a callback. */

typedef struct {

    MVMObject   *invokee;

    MVMRegister *args;

    MVMCallsite *cs;

} CallbackInvokeData;

static void callback_invoke(MVMThreadContext *tc, void *data) {

    /* Invoke the coderef, to set up the nested interpreter. */

    CallbackInvokeData *cid = (CallbackInvokeData *)data;

    STABLE(cid->invokee)->invoke(tc, cid->invokee, cid->cs, cid->args);

    /* Ensure we exit interp after callback. */

    tc->thread_entry_frame = tc->cur_frame;

}

static char callback_handler(DCCallback *cb, DCArgs *cb_args, DCValue *cb_result, MVMNativeCallback *data) {

    CallbackInvokeData cid;

    MVMint32 num_roots, i;

    MVMRegister res;

    MVMRegister *args;

    unsigned int interval_id;

    /* Locate the MoarVM thread this callback is being run on. */

    MVMThreadContext *tc = MVM_nativecall_find_thread_context(data->instance);

    /* Unblock GC if needed, so this thread can do work. */

    MVMint32 was_blocked = MVM_gc_is_thread_blocked(tc);

    if (was_blocked)

        MVM_gc_mark_thread_unblocked(tc);

    interval_id = MVM_telemetry_interval_start(tc, "nativecall callback handler");

    /* Build a callsite and arguments buffer. */

    args = MVM_malloc(data->num_types * sizeof(MVMRegister));

    num_roots = 0;

    for (i = 1; i < data->num_types; i++) {

        MVMObject *type     = data->types[i];

        MVMint16   typeinfo = data->typeinfos[i];

        switch (typeinfo & MVM_NATIVECALL_ARG_TYPE_MASK) {

            case MVM_NATIVECALL_ARG_CHAR:

                args[i - 1].i64 = dcbArgChar(cb_args);

                break;

            case MVM_NATIVECALL_ARG_SHORT:

                args[i - 1].i64 = dcbArgShort(cb_args);

                break;

            case MVM_NATIVECALL_ARG_INT:

                args[i - 1].i64 = dcbArgInt(cb_args);

                break;

            case MVM_NATIVECALL_ARG_LONG:

                args[i - 1].i64 = dcbArgLong(cb_args);

                break;

            case MVM_NATIVECALL_ARG_LONGLONG:

                args[i - 1].i64 = dcbArgLongLong(cb_args);

                break;

            case MVM_NATIVECALL_ARG_FLOAT:

                args[i - 1].n64 = dcbArgFloat(cb_args);

                break;

            case MVM_NATIVECALL_ARG_DOUBLE:

                args[i - 1].n64 = dcbArgDouble(cb_args);

                break;

            case MVM_NATIVECALL_ARG_ASCIISTR:

            case MVM_NATIVECALL_ARG_UTF8STR:

            case MVM_NATIVECALL_ARG_UTF16STR:

                args[i - 1].o = MVM_nativecall_make_str(tc, type, typeinfo,

                    (char *)dcbArgPointer(cb_args));

                MVM_gc_root_temp_push(tc, (MVMCollectable **)&(args[i - 1].o));

                num_roots++;

                break;

            case MVM_NATIVECALL_ARG_CSTRUCT:

                args[i - 1].o = MVM_nativecall_make_cstruct(tc, type,

                    dcbArgPointer(cb_args));

                MVM_gc_root_temp_push(tc, (MVMCollectable **)&(args[i - 1].o));

                num_roots++;

                break;

            case MVM_NATIVECALL_ARG_CPPSTRUCT:

                args[i - 1].o = MVM_nativecall_make_cppstruct(tc, type,

                    dcbArgPointer(cb_args));

                MVM_gc_root_temp_push(tc, (MVMCollectable **)&(args[i - 1].o));

                num_roots++;

                break;

            case MVM_NATIVECALL_ARG_CPOINTER:

                args[i - 1].o = MVM_nativecall_make_cpointer(tc, type,

                    dcbArgPointer(cb_args));

                MVM_gc_root_temp_push(tc, (MVMCollectable **)&(args[i - 1].o));

                num_roots++;

                break;

            case MVM_NATIVECALL_ARG_CARRAY:

                args[i - 1].o = MVM_nativecall_make_carray(tc, type,

                    dcbArgPointer(cb_args));

                MVM_gc_root_temp_push(tc, (MVMCollectable **)&(args[i - 1].o));

                num_roots++;

                break;

            case MVM_NATIVECALL_ARG_CUNION:

                args[i - 1].o = MVM_nativecall_make_cunion(tc, type,

                    dcbArgPointer(cb_args));

                MVM_gc_root_temp_push(tc, (MVMCollectable **)&(args[i - 1].o));

                num_roots++;

                break;

            case MVM_NATIVECALL_ARG_CALLBACK:

                /* TODO: A callback -return- value means that we have a C method

                * that needs to be wrapped similarly to a is native(...) Perl 6

                * sub. */

                dcbArgPointer(cb_args);

                args[i - 1].o = type;

                MVM_gc_root_temp_push(tc, (MVMCollectable **)&(args[i - 1].o));

                num_roots++;

                break;

            case MVM_NATIVECALL_ARG_UCHAR:

                args[i - 1].i64 = dcbArgUChar(cb_args);

                break;

            case MVM_NATIVECALL_ARG_USHORT:

                args[i - 1].i64 = dcbArgUShort(cb_args);

                break;

            case MVM_NATIVECALL_ARG_UINT:

                args[i - 1].i64 = dcbArgUInt(cb_args);

                break;

            case MVM_NATIVECALL_ARG_ULONG:

                args[i - 1].i64 = dcbArgULong(cb_args);

                break;

            case MVM_NATIVECALL_ARG_ULONGLONG:

                args[i - 1].i64 = dcbArgULongLong(cb_args);

                break;

            default:

                MVM_telemetry_interval_stop(tc, interval_id, "nativecall callback handler failed");

                MVM_exception_throw_adhoc(tc,

                    "Internal error: unhandled dyncall callback argument type");

        }

    }

    /* Call into a nested interpreter (since we already are in one). Need to

     * save a bunch of state around each side of this. */

    cid.invokee = data->target;

    cid.args    = args;

    cid.cs      = data->cs;

    {

        MVMuint8 **backup_interp_cur_op         = tc->interp_cur_op;

        MVMuint8 **backup_interp_bytecode_start = tc->interp_bytecode_start;

        MVMRegister **backup_interp_reg_base    = tc->interp_reg_base;

        MVMCompUnit **backup_interp_cu          = tc->interp_cu;

        MVMFrame *backup_cur_frame              = MVM_frame_force_to_heap(tc, tc->cur_frame);

        MVMFrame *backup_thread_entry_frame     = tc->thread_entry_frame;

        void **backup_jit_return_address        = tc->jit_return_address;

        tc->jit_return_address                  = NULL;

        MVMROOT2(tc, backup_cur_frame, backup_thread_entry_frame, {

            MVMuint32 backup_mark                   = MVM_gc_root_temp_mark(tc);

            jmp_buf backup_interp_jump;

            memcpy(backup_interp_jump, tc->interp_jump, sizeof(jmp_buf));

            tc->cur_frame->return_value = &res;

            tc->cur_frame->return_type  = MVM_RETURN_OBJ;

            MVM_interp_run(tc, callback_invoke, &cid);

            tc->interp_cur_op         = backup_interp_cur_op;

            tc->interp_bytecode_start = backup_interp_bytecode_start;

            tc->interp_reg_base       = backup_interp_reg_base;

            tc->interp_cu             = backup_interp_cu;

            tc->cur_frame             = backup_cur_frame;

            tc->current_frame_nr      = backup_cur_frame->sequence_nr;

            tc->thread_entry_frame    = backup_thread_entry_frame;

            tc->jit_return_address    = backup_jit_return_address;

            memcpy(tc->interp_jump, backup_interp_jump, sizeof(jmp_buf));

            MVM_gc_root_temp_mark_reset(tc, backup_mark);

        });

    }

    /* Handle return value. */

    if (res.o) {

        MVMContainerSpec const *contspec = STABLE(res.o)->container_spec;

        if (contspec && contspec->fetch_never_invokes)

            contspec->fetch(tc, res.o, &res);

    }

    switch (data->typeinfos[0] & MVM_NATIVECALL_ARG_TYPE_MASK) {

        case MVM_NATIVECALL_ARG_VOID:

            break;

        case MVM_NATIVECALL_ARG_CHAR:

            cb_result->c = (signed char)MVM_nativecall_unmarshal_char(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_SHORT:

            cb_result->s = MVM_nativecall_unmarshal_short(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_INT:

            cb_result->i = MVM_nativecall_unmarshal_int(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_LONG:

            cb_result->j = MVM_nativecall_unmarshal_long(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_LONGLONG:

            cb_result->l = MVM_nativecall_unmarshal_longlong(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_FLOAT:

            cb_result->f = MVM_nativecall_unmarshal_float(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_DOUBLE:

            cb_result->d = MVM_nativecall_unmarshal_double(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_ASCIISTR:

        case MVM_NATIVECALL_ARG_UTF8STR:

        case MVM_NATIVECALL_ARG_UTF16STR:

            cb_result->Z = MVM_nativecall_unmarshal_string(tc, res.o, data->typeinfos[0], NULL);

            break;

        case MVM_NATIVECALL_ARG_CSTRUCT:

            cb_result->p = MVM_nativecall_unmarshal_cstruct(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_CPPSTRUCT:

            cb_result->p = MVM_nativecall_unmarshal_cppstruct(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_CPOINTER:

            cb_result->p = MVM_nativecall_unmarshal_cpointer(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_CARRAY:

            cb_result->p = MVM_nativecall_unmarshal_carray(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_CUNION:

            cb_result->p = MVM_nativecall_unmarshal_cunion(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_VMARRAY:

            cb_result->p = MVM_nativecall_unmarshal_vmarray(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_CALLBACK:

            cb_result->p = unmarshal_callback(tc, res.o, data->types[0]);

            break;

        case MVM_NATIVECALL_ARG_UCHAR:

            cb_result->c = MVM_nativecall_unmarshal_uchar(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_USHORT:

            cb_result->s = MVM_nativecall_unmarshal_ushort(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_UINT:

            cb_result->i = MVM_nativecall_unmarshal_uint(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_ULONG:

            cb_result->j = MVM_nativecall_unmarshal_ulong(tc, res.o);

            break;

        case MVM_NATIVECALL_ARG_ULONGLONG:

            cb_result->l = MVM_nativecall_unmarshal_ulonglong(tc, res.o);

            break;

        default:

            MVM_telemetry_interval_stop(tc, interval_id, "nativecall callback handler failed");

            MVM_exception_throw_adhoc(tc,

                "Internal error: unhandled dyncall callback return type");

    }

    /* Clean up. */

    MVM_gc_root_temp_pop_n(tc, num_roots);

    MVM_free(args);

    /* Re-block GC if needed, so other threads will be able to collect. */

    if (was_blocked)

        MVM_gc_mark_thread_blocked(tc);

    MVM_telemetry_interval_stop(tc, interval_id, "nativecall callback handler");

    /* Indicate what we're producing as a result. */

    return get_signature_char(data->typeinfos[0]);

}

#define handle_arg(what, cont_X, dc_type, reg_slot, dc_fun, unmarshal_fun) do { \

    MVMRegister r; \

    if ((arg_types[i] & MVM_NATIVECALL_ARG_RW_MASK) == MVM_NATIVECALL_ARG_RW) { \

        if (MVM_6model_container_is ## cont_X(tc, value)) { \

            dc_type *rw = (dc_type *)MVM_malloc(sizeof(dc_type)); \

            MVM_6model_container_de ## cont_X(tc, value, &r); \

            *rw = (dc_type)r. reg_slot ; \

            if (!free_rws) \

                free_rws = (void **)MVM_malloc(num_args * sizeof(void *)); \

            free_rws[num_rws] = rw; \

            num_rws++; \

            dcArgPointer(vm, rw); \

        } \

        else \

            MVM_exception_throw_adhoc(tc, \

                "Native call expected argument that references a native %s, but got %s", \

                what, REPR(value)->name); \

    } \

    else { \

        if (value && IS_CONCRETE(value) && STABLE(value)->container_spec) { \

            STABLE(value)->container_spec->fetch(tc, value, &r); \

            dc_fun(vm, unmarshal_fun(tc, r.o)); \

        } \

        else { \

            dc_fun(vm, unmarshal_fun(tc, value)); \

        } \

    } \

} while (0)

MVMObject * MVM_nativecall_invoke(MVMThreadContext *tc, MVMObject *res_type,

        MVMObject *site, MVMObject *args) {

    MVMObject  *result = NULL;

    char      **free_strs = NULL;

    void      **free_rws  = NULL;

    MVMint16    num_strs  = 0;

    MVMint16    num_rws   = 0;

    MVMint16    i;

    /* Get native call body, so we can locate the call info. Read out all we

     * shall need, since later we may allocate a result and and move it. */

    MVMNativeCallBody *body = MVM_nativecall_get_nc_body(tc, site);

    MVMint16  num_args    = body->num_args;

    MVMint16 *arg_types   = body->arg_types;

    MVMint16  ret_type    = body->ret_type;

    void     *entry_point = body->entry_point;

    void     *ptr         = NULL;

    unsigned int interval_id;

    DCCallVM *vm;

    /* Create and set up call VM. */

    vm = dcNewCallVM(8192);

    dcMode(vm, body->convention);

    dcReset(vm);

    interval_id = MVM_telemetry_interval_start(tc, "nativecall invoke");

    MVM_telemetry_interval_annotate((intptr_t)entry_point, interval_id, "nc entrypoint");

    /* Process arguments. */

    for (i = 0; i < num_args; i++) {

        MVMObject *value = MVM_repr_at_pos_o(tc, args, i);

        switch (arg_types[i] & MVM_NATIVECALL_ARG_TYPE_MASK) {

            case MVM_NATIVECALL_ARG_CHAR:

                handle_arg("integer", cont_i, DCchar, i64, dcArgChar, MVM_nativecall_unmarshal_char);

                break;

            case MVM_NATIVECALL_ARG_SHORT:

                handle_arg("integer", cont_i, DCshort, i64, dcArgShort, MVM_nativecall_unmarshal_short);

                break;

            case MVM_NATIVECALL_ARG_INT:

                handle_arg("integer", cont_i, DCint, i64, dcArgInt, MVM_nativecall_unmarshal_int);

                break;

            case MVM_NATIVECALL_ARG_LONG:

                handle_arg("integer", cont_i, DClong, i64, dcArgLong, MVM_nativecall_unmarshal_long);

                break;

            case MVM_NATIVECALL_ARG_LONGLONG:

                handle_arg("integer", cont_i, DClonglong, i64, dcArgLongLong, MVM_nativecall_unmarshal_longlong);

                break;

            case MVM_NATIVECALL_ARG_FLOAT:

                handle_arg("number", cont_n, DCfloat, n64, dcArgFloat, MVM_nativecall_unmarshal_float);

                break;

            case MVM_NATIVECALL_ARG_DOUBLE:

                handle_arg("number", cont_n, DCdouble, n64, dcArgDouble, MVM_nativecall_unmarshal_double);

                break;

            case MVM_NATIVECALL_ARG_ASCIISTR:

            case MVM_NATIVECALL_ARG_UTF8STR:

            case MVM_NATIVECALL_ARG_UTF16STR:

                {

                    MVMint16 free = 0;

                    char *str = MVM_nativecall_unmarshal_string(tc, value, arg_types[i], &free);

                    if (free) {

                        if (!free_strs)

                            free_strs = (char**)MVM_malloc(num_args * sizeof(char *));

                        free_strs[num_strs] = str;

                        num_strs++;

                    }

                    dcArgPointer(vm, str);

                }

                break;

            case MVM_NATIVECALL_ARG_CSTRUCT:

                dcArgPointer(vm, MVM_nativecall_unmarshal_cstruct(tc, value));

                break;

            case MVM_NATIVECALL_ARG_CPPSTRUCT: {

                    /* We need to allocate the struct (THIS) for C++ constructor before passing it along. */

                    if (i == 0 && !IS_CONCRETE(value)) {

                        MVMCPPStructREPRData *repr_data = (MVMCPPStructREPRData *)STABLE(res_type)->REPR_data;

                        /* Allocate a full byte aligned area where the C++ structure fits into. */

                        ptr    = MVM_malloc(repr_data->struct_size > 0 ? repr_data->struct_size : 1);

                        result = MVM_nativecall_make_cppstruct(tc, res_type, ptr);

                        dcArgPointer(vm, ptr);

                    }

                    else {

                        dcArgPointer(vm, MVM_nativecall_unmarshal_cppstruct(tc, value));

                    }

                }

                break;

            case MVM_NATIVECALL_ARG_CPOINTER:

                if ((arg_types[i] & MVM_NATIVECALL_ARG_RW_MASK) == MVM_NATIVECALL_ARG_RW) {

                    DCpointer *rw = (DCpointer *)MVM_malloc(sizeof(DCpointer *));

                    *rw           = (DCpointer)MVM_nativecall_unmarshal_cpointer(tc, value);

                    if (!free_rws)

                        free_rws = (void **)MVM_malloc(num_args * sizeof(void *));

                    free_rws[num_rws] = rw;

                    num_rws++;

                    dcArgPointer(vm, rw);

                }

                else {

                    dcArgPointer(vm, MVM_nativecall_unmarshal_cpointer(tc, value));

                }

                break;

            case MVM_NATIVECALL_ARG_CARRAY:

                dcArgPointer(vm, MVM_nativecall_unmarshal_carray(tc, value));

                break;

            case MVM_NATIVECALL_ARG_CUNION:

                dcArgPointer(vm, MVM_nativecall_unmarshal_cunion(tc, value));

                break;

            case MVM_NATIVECALL_ARG_VMARRAY:

                dcArgPointer(vm, MVM_nativecall_unmarshal_vmarray(tc, value));

                break;

            case MVM_NATIVECALL_ARG_CALLBACK:

                dcArgPointer(vm, unmarshal_callback(tc, value, body->arg_info[i]));

                break;

            case MVM_NATIVECALL_ARG_UCHAR:

                handle_arg("integer", cont_i, DCuchar, i64, dcArgChar, MVM_nativecall_unmarshal_uchar);

                break;

            case MVM_NATIVECALL_ARG_USHORT:

                handle_arg("integer", cont_i, DCushort, i64, dcArgShort, MVM_nativecall_unmarshal_ushort);

                break;

            case MVM_NATIVECALL_ARG_UINT:

                handle_arg("integer", cont_i, DCuint, i64, dcArgInt, MVM_nativecall_unmarshal_uint);

                break;

            case MVM_NATIVECALL_ARG_ULONG:

                handle_arg("integer", cont_i, DCulong, i64, dcArgLong, MVM_nativecall_unmarshal_ulong);

                break;

            case MVM_NATIVECALL_ARG_ULONGLONG:

                handle_arg("integer", cont_i, DCulonglong, i64, dcArgLongLong, MVM_nativecall_unmarshal_ulonglong);

                break;

            default:

                MVM_telemetry_interval_stop(tc, interval_id, "nativecall invoke failed");

                MVM_exception_throw_adhoc(tc, "Internal error: unhandled dyncall argument type");

        }

    }

    MVMROOT2(tc, args, res_type, {

        MVM_gc_mark_thread_blocked(tc);

        if (result) {

            /* We are calling a C++ constructor so we hand back the invocant (THIS) we recorded earlier. */

            dcCallVoid(vm, body->entry_point);

            MVM_gc_mark_thread_unblocked(tc);

        }

        else {

            /* Call and process return values. */

            switch (ret_type & MVM_NATIVECALL_ARG_TYPE_MASK) {

                case MVM_NATIVECALL_ARG_VOID:

                    dcCallVoid(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = res_type;

                    break;

                case MVM_NATIVECALL_ARG_CHAR: {

                    MVMint64 native_result = (signed char)dcCallChar(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_int(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_SHORT: {

                    MVMint64 native_result = dcCallShort(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_int(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_INT: {

                    MVMint64 native_result = dcCallInt(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_int(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_LONG: {

                    MVMint64 native_result = dcCallLong(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_int(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_LONGLONG: {

                    MVMint64 native_result = dcCallLongLong(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_int(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_FLOAT: {

                    MVMnum64 native_result = dcCallFloat(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_num(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_DOUBLE: {

                    MVMnum64 native_result = dcCallDouble(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_num(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_ASCIISTR:

                case MVM_NATIVECALL_ARG_UTF8STR:

                case MVM_NATIVECALL_ARG_UTF16STR: {

                    char *native_result = (char *)dcCallPointer(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_str(tc, res_type, body->ret_type,

                        native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_CSTRUCT: {

                    void *native_result = dcCallPointer(vm, body->entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_cstruct(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_CPPSTRUCT: {

                    void *native_result = dcCallPointer(vm, body->entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_cppstruct(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_CPOINTER: {

                    void *native_result = dcCallPointer(vm, body->entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_cpointer(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_CARRAY: {

                    void *native_result = dcCallPointer(vm, body->entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_carray(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_CUNION: {

                    void *native_result = dcCallPointer(vm, body->entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_cunion(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_CALLBACK:

                    /* TODO: A callback -return- value means that we have a C method

                    * that needs to be wrapped similarly to a is native(...) Perl 6

                    * sub. */

                    dcCallPointer(vm, body->entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = res_type;

                    break;

                case MVM_NATIVECALL_ARG_UCHAR: {

                    MVMuint64 native_result = (DCuchar)dcCallChar(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_uint(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_USHORT: {

                    MVMuint64 native_result = (DCushort)dcCallShort(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_uint(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_UINT: {

                    MVMuint64 native_result = (DCuint)dcCallInt(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_uint(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_ULONG: {

                    MVMuint64 native_result = (DCulong)dcCallLong(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_uint(tc, res_type, native_result);

                    break;

                }

                case MVM_NATIVECALL_ARG_ULONGLONG: {

                    MVMuint64 native_result = (DCulonglong)dcCallLongLong(vm, entry_point);

                    MVM_gc_mark_thread_unblocked(tc);

                    result = MVM_nativecall_make_uint(tc, res_type, native_result);

                    break;

                }

                default:

                    MVM_telemetry_interval_stop(tc, interval_id, "nativecall invoke failed");

                    MVM_exception_throw_adhoc(tc, "Internal error: unhandled dyncall return type");

            }

        }

    });

    num_rws = 0;

    for (i = 0; i < num_args; i++) {

        MVMObject *value = MVM_repr_at_pos_o(tc, args, i);

        if ((arg_types[i] & MVM_NATIVECALL_ARG_RW_MASK) == MVM_NATIVECALL_ARG_RW) {

            switch (arg_types[i] & MVM_NATIVECALL_ARG_TYPE_MASK) {

                case MVM_NATIVECALL_ARG_CHAR:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DCchar *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_SHORT:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DCshort *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_INT:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DCint *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_LONG:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DClong *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_LONGLONG:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DClonglong *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_FLOAT:

                    MVM_6model_container_assign_n(tc, value, (MVMnum64)*(DCfloat *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_DOUBLE:

                    MVM_6model_container_assign_n(tc, value, (MVMnum64)*(DCdouble *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_UCHAR:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DCuchar *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_USHORT:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DCushort *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_UINT:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DCuint *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_ULONG:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DCulong *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_ULONGLONG:

                    MVM_6model_container_assign_i(tc, value, (MVMint64)*(DCulonglong *)free_rws[num_rws]);

                    break;

                case MVM_NATIVECALL_ARG_CPOINTER:

                    REPR(value)->box_funcs.set_int(tc, STABLE(value), value, OBJECT_BODY(value),

                        (MVMint64)*(DCpointer *)free_rws[num_rws]);

                    break;

                default:

                    MVM_telemetry_interval_stop(tc, interval_id, "nativecall invoke failed");

                    MVM_exception_throw_adhoc(tc, "Internal error: unhandled dyncall argument type");

            }

            num_rws++;

        }

        /* Perform CArray/CStruct write barriers. */

        MVM_nativecall_refresh(tc, value);

    }

    /* Free any memory that we need to. */

    if (free_strs) {

        for (i = 0; i < num_strs; i++)

            MVM_free(free_strs[i]);

        MVM_free(free_strs);

    }

    if (free_rws) {

        for (i = 0; i < num_rws; i++)

            MVM_free(free_rws[i]);

        MVM_free(free_rws);

    }

    /* Finally, free call VM. */

    dcFree(vm);

    MVM_telemetry_interval_stop(tc, interval_id, "nativecall invoke");

    return result;

}