Fix LuaStudio module compiling with ISO C++ strict compilers (!370) · Запросы на слияние · OpenXRay / xray-16

Закрыто xottab-duty запросил слияние github/fork/xdevelnet/xd_dev в xd_dev Мар 17, 2019

Created by: xdevelnet

Hi!

Currently (or, at least, few days ago) dev builds was failing (https://travis-ci.org/OpenXRay/xray-16/jobs/506720869) because of LuaStudio macro CS_LIBRARY_NAME, which is uses invalid tokens according to ISO C++ standard. Original developer was using Visual C++ compiler, which is shipping with Visual Studio. Such compiler is tolerant for that kind of tokens. In our case, it was tokens with dot symbol inside.

I was wondering about how I could change this macro without touching everything else. Unfortunately, after several attempts to make it looks good enough, I decided to change macro behavior:

WAS: CS_LIBRARY_NAME was concatenating several tokens first, with nested CS_STRING_CONCAT usage. Then, it was creating single C string from freshly-made big token.
NOW: CS_STRING_CONCAT is creating several C strings from available tokens. Then, it is concatenating these strings to big one.

I also made this small program for testing purposes:

#include <stdlib.h>
#include <stdio.h>

#define CS_STRING_CONCAT_HELPER(a, b) a##b
#define CS_STRING_CONCAT(a, b) CS_STRING_CONCAT_HELPER(a, b)
#define CS_MAKE_STRING_HELPER(a) #a
#define CS_MAKE_STRING(a) CS_MAKE_STRING_HELPER(a)

#define CS_LIBRARY_NAME(library, extension) \
    CS_MAKE_STRING(CS_LIBRARY_PREFIX) CS_MAKE_STRING(library) CS_MAKE_STRING(CS_PLATFORM_ID) \
        CS_MAKE_STRING(CS_SOLUTION_CONFIGURATION_ID) CS_MAKE_STRING(.) CS_MAKE_STRING(extension)

#define CS_LIBRARY_PREFIX cs.
#define CS_PLATFORM_ID
#define CS_SOLUTION_CONFIGURATION_ID

int main() {
	printf("%s\n", CS_MAKE_STRING(CS_STRING_CONCAT(hello, world)));
	//printf("%s\n", CS_MAKE_STRING(CS_STRING_CONCAT(., world)));
	printf("%s\n", CS_LIBRARY_NAME(lua_studio_backend, dll));
	return EXIT_SUCCESS;
}

Compiling and executing:

$ ./test
helloworld
cs.lua_studio_backend.dll
$

You may check out here:

How CS_STRING_CONCAT works (actually I have no idea what original developer was thinking because it is actually making one token from two, and it's widely knows as "token concatenation", not string!)
How CS_STRING_CONCAT works with dot as one of the operands (it's not working under gcc/clang and working under Visual C++ compiler)
What CS_LIBRARY_NAME returns, as in original src/xrScriptEngine/LuaStudio/Defines.hpp file

References: