Implement system.MsgBoxOkCancel

src/instructions.c

@@ -54,7 +54,7 @@ const struct syscall syscalls[NR_SYSCALLS] = {
 	SYS  ( SYS_ERROR,                Error ),
 	SYS  ( SYS_EXISTS_SAVE_FILE,     ExistsSaveFile ),
 	SYS  ( SYS_IS_DEBUG_MODE,        IsDebugMode ),
-	TODO ( SYS_MSGBOX_OK_CANCEL,     MsgBoxOkCancel ),
+	SYS  ( SYS_MSGBOX_OK_CANCEL,     MsgBoxOkCancel ),
 	SYS  ( SYS_GET_FUNC_STACK_NAME,  GetFuncStackName ),
 	SYS  ( SYS_PEEK,                 Peek ),
 	SYS  ( SYS_SLEEP,                Sleep ),
@@ -243,7 +243,7 @@ struct instruction instructions[NR_OPCODES] = {
         TODO ( R_NOTE,         0 ),
         OP   ( SH_LOCALCREATE, 2, T_LOCAL, T_STRUCT ),
         OP   ( SH_LOCALDELETE, 1, T_LOCAL ),
-        TODO ( STOI,           0 ),
+        OP   ( STOI,           0 ),
         OP   ( A_PUSHBACK,     0 ),
         OP   ( A_POPBACK,      0 ),
         OP   ( S_EMPTY,        0 ),

src/vm.c

@@ -328,6 +328,11 @@ static void function_return(void)
 	call_stack_ptr--;
 }
 
+static const SDL_MessageBoxButtonData buttons[] = {
+	{ SDL_MESSAGEBOX_BUTTON_RETURNKEY_DEFAULT, 1, "OK" },
+	{ SDL_MESSAGEBOX_BUTTON_ESCAPEKEY_DEFAULT, 0, "Cancel" },
+};
+
 static void system_call(enum syscall_code code)
 {
 	switch (code) {
@@ -372,6 +377,29 @@ static void system_call(enum syscall_code code)
 		// XXX: caller S_POPs
 		break;
 	}
+	case SYS_MSGBOX_OK_CANCEL: {
+		int result = 0;
+		struct string *str = stack_peek_string(0);
+		char *utf = sjis2utf(str->text, str->size);
+
+		const SDL_MessageBoxData mbox = {
+			SDL_MESSAGEBOX_INFORMATION,
+			NULL,
+			"xsystem4",
+			str->text,
+			SDL_arraysize(buttons),
+			buttons,
+			NULL
+		};
+		if (SDL_ShowMessageBox(&mbox, &result)) {
+			WARNING("Error displaying message box");
+		}
+		// ...
+		free(utf);
+		heap_unref(stack_pop().i);
+		stack_push(result);
+		break;
+	}
 	case SYS_RESUME_SAVE: {
 		union vm_value *success = stack_pop_var();
 		struct string *filename = stack_peek_string(0);