Add libcall

Author: mattn

src/cfunc_call.c

@@ -103,7 +103,93 @@ cfunc_call(mrb_state *mrb, mrb_value self)
 }
 
 
+static mrb_value
+cfunc_libcall(mrb_state *mrb, mrb_value self)
+{
+    int margc;
+    mrb_value mresult_type, mlib, mname, *margs;
+    void **values = NULL;
+    ffi_type **args = NULL;
+
+    mrb_get_args(mrb, "oSo*", &mresult_type, &mlib, &mname, &margs, &margc);
+
+    void *fp = NULL;
+    if((mrb_string_p(mname) || mrb_symbol_p(mname))) {
+        void *dlh = dlopen(mrb_string_value_ptr(mrb, mlib), RTLD_LAZY);
+        fp = dlsym(dlh, mrb_string_value_ptr(mrb, mname));
+        dlclose(dlh);
+
+        if(fp == NULL) {
+            mrb_raisef(mrb, E_NAME_ERROR, "can't find C function %s", mrb_string_value_ptr(mrb, mname));
+            goto cfunc_call_exit;
+        }
+    }
+    else {
+        fp = cfunc_pointer_ptr(mname);
+        if(fp == NULL) {
+            mrb_raisef(mrb, E_NAME_ERROR, "can't call NULL pointer");
+            goto cfunc_call_exit;
+        }
+    }
+
+    args = malloc(sizeof(ffi_type*) * margc);
+    values = malloc(sizeof(void*) * margc);
+    mrb_sym sym_to_ffi_value = mrb_intern(mrb, "to_ffi_value");
+
+    mrb_value nil_ary[1];
+    nil_ary[0] = mrb_nil_value();
+    int i;
+    for(i = 0; i < margc; ++i) {
+        if(mrb_respond_to(mrb, margs[i], sym_to_ffi_value)) {
+            args[i] = mrb_value_to_mrb_ffi_type(mrb, margs[i])->ffi_type_value;
+            values[i] = cfunc_pointer_ptr(mrb_funcall_argv(mrb, margs[i], sym_to_ffi_value, 1, nil_ary));
+        }
+        else {
+            cfunc_mrb_raise_without_jump(mrb, E_TYPE_ERROR, "ignore argument type %s", mrb_obj_classname(mrb, margs[i]));
+            goto cfunc_call_exit;
+        }
+    }
+
+    ffi_type *result_type = rclass_to_mrb_ffi_type(mrb, mrb_class_ptr(mresult_type))->ffi_type_value;
+    if (result_type == NULL) {
+        cfunc_mrb_raise_without_jump(mrb, E_ARGUMENT_ERROR, "ignore return type %s", mrb_class_name(mrb, mrb_class_ptr(mresult_type)));
+        goto cfunc_call_exit;
+    }
+
+    mrb_value mresult = mrb_nil_value();
+    ffi_cif cif;
+    if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, margc, result_type, args) == FFI_OK) {
+        void *result;
+        if(result_type->size > sizeof(long)) {
+            result = malloc(result_type->size);
+        }
+        else if(result_type->size) {
+            result = malloc(sizeof(long));
+        }
+        else {
+            result = NULL;
+        }
+        ffi_call(&cif, fp, result, values);
+
+        if(result) {
+            mrb_value result_ptr = cfunc_pointer_new_with_pointer(mrb, result, true);
+            mresult = mrb_funcall(mrb, mresult_type, "refer", 1, result_ptr);
+        }
+    }
+    else {
+        mrb_raisef(mrb, E_NAME_ERROR, "Can't find C function %s", mname);
+        goto cfunc_call_exit;
+    }
+
+cfunc_call_exit:
+    free(values);
+    free(args);
+    return mresult;
+}
+
+
 void init_cfunc_call(mrb_state *mrb, struct RClass* module)
 {
     mrb_define_class_method(mrb, module, "call", cfunc_call, ARGS_ANY());
+    mrb_define_module_function(mrb, module, "libcall", cfunc_libcall, ARGS_ANY());
 }