[Buildroot] [UNSURE]Re: [PATCH 1/4] add host arch detection and Kconfig BR2_HOSTARCH

[François Perrad]

2012/7/20 Thomas Petazzoni <thomas.petazzoni at free-electrons.com>:
> Le Fri, 20 Jul 2012 13:40:14 +0200,
> François Perrad <francois.perrad at gadz.org> a écrit :
>
>> take as example a target with luajit and luasocket.
>> nothing from lua is needed at runtime.
>> but at compile time of luasocket, include files from lua (lua.h,
>> luaconf.h, lualib.h, lauxlib.h) are mandatory in staging.
>> so, luasocket.mk contains : LUASOCKET_DEPENDENCIES = lua
>>
>> so, it is useful that BR2_PACKAGE_LUA installs nothing on target.
>> the 3 sub-options BR2_PACKAGE_LUA_COMPILER,
>> BR2_PACKAGE_LUA_INTERPRETER and  BR2_PACKAGE_LUA_SHARED_LIBRARY are
>> install flags (as said in there help doc).
>> so, BR2_PACKAGE_LUA_SHARED_LIBRARY shouldn't be removed.
>
> So this means luajit is not a complete replacement for lua?
>
> Note that you did:
>
> if BR2_PACKAGE_LUA || BR2_PACKAGE_LUAJIT
> menu "LUA libraries/modules"
> source "package/cgilua/Config.in"
> source "package/copas/Config.in"
> source "package/coxpcall/Config.in"
> source "package/luacjson/Config.in"
> source "package/luaexpat/Config.in"
> source "package/luafilesystem/Config.in"
> source "package/luasocket/Config.in"
> source "package/rings/Config.in"
> source "package/wsapi/Config.in"
> source "package/xavante/Config.in"
> endmenu
>
> So this means that Lua modules can currently be compiled without the
> Lua package being selected. Of course, the Lua package will be built
> because the Lua modules packages depend on it (in terms of .mk), but
> that's really not how things are supposed to work.
>
> Thomas

LuaJIT was designed to operate with modules compiled with Lua 5.1 includes.

But LuaJIT supplies also its own set of includes (in /usr/include/luajit-2.0).

So, each Lua module could be modified with the following pattern :
    ifeq ($(BR2_PACKAGE_LUA),y)
        LUAFOO_DEPENDENCIES = lua
        LUAFOO_INCLUDES = $(STAGING_DIR)/usr/include
    else
        LUAFOO_DEPENDENCIES = luajit
        LUAFOO_INCLUDES = $(STAGING_DIR)/usr/include/luajit-2.0
    endif

instead of the current : LUAFOO_DEPENDENCIES = lua

Currently, I prefer the shortest pattern.

François

> --
> Thomas Petazzoni, Free Electrons
> Kernel, drivers, real-time and embedded Linux
> development, consulting, training and support.
> http://free-electrons.com