[WIP] Add initial version of luasocket

[tpimh]

Do not merge this yet, this is still WIP. I am now building with Lua 5.1, and it seems to work fine.

[tpimh]

@sharkwouter my "AR-in-place-of-LD hack" is not very reliable with the latest toolchain. I can remember it worked every time about 3 months ago, and now it only works every other time. Can't figure out why it is doing this, and what the success depends on.

Also now I started thinking, why am I building it as a static library anyway? I should try to build prx instead and load it dynamically.

[sharkwouter]

I'm going to need a bit more context for the "AR-in-place-of-LD hack" then I can help look into it. What is the problem you're running into?

I do think having luasocket as a library would be really cool.

[sharkwouter]

You might want to rebase on the latest commit to main, then the automated build should work again.

[tpimh]

The whole hack looks like this:

LDFLAGS_psp=$(LUALIB) && mv templib.a 
LD_psp=psp-ar rcs templib.a

When building dynamic libraries, LD is fine with the last argument being the output file name. When building static libraries, the output file name must be the first argument to ar after rcs flags. So for every static library to be built, I create a temporary file, then move it to the correct file name, because mv accepts the target file name as the last argument.

The order of arguments is $(LD) $(OBJECTS) $(LDFLAGS) $(OUTFILE) which expands to gcc obj1.o obj2.o -llua -o libluasocket.so (when LD is gcc and LDFLAGS is -llua -o), but with the variables above it expands to ar rcs templib.a obj1.o obj2.o /path/to/lua.a && mv templib.a libluasocket.a. Ideally I'd like to just have ar rcs libluasocket.a obj1.o obj2.o /path/to/lua.a without the extra mv call, but it's not possible to implement without seriously rewriting the makefile.

Not sure why it was failing, but after updating, the reason is obvious: https://github.com/pspdev/pspsdk/pull/205 (I'll fix it).

[tpimh]

Quick overview of the patch:

• getaddrinfo
• gethostname (just returns "psp", needs to be improved)
• servent, protoent with related functions and hstrerror
• sockaddr_un
• sockaddr_storage (needs to be removed since https://github.com/pspdev/pspsdk/pull/205)
• IPv6 support removed

The other patch just fixes the incorrect version number reported.

[tpimh]

Here is a simple script that can simplify using AR-in-place-of-LD:

#!/bin/sh

for last; do true; done
args="$last $(echo $@ | sed 's@ '$last'$@@')"

psp-ar rcs $args

[tpimh]

Alright, now it's somewhat usable. In order to use it, do this:

#include "luasocket.h"
#include "mime.h" // (optional)

// init Lua and load all libraries
lua_State *L = luaL_newstate();
luaL_openlibs(L);

// Load LuaSocket into Lua core
lua_getglobal(L, "package");
lua_getfield(L, -1, "preload");
lua_pushcfunction(L, luaopen_socket_core);
lua_setfield(L, -2, "socket.core");
lua_pushcfunction(L, luaopen_mime_core); // (optional)
lua_setfield(L, -2, "mime.core"); // (optional)
lua_pop(L, 2);

Then files copied from psp/share/lua/5.1 can be used from lua. A bit cumbersome, but I don't really know how can I make it any better at the moment.

[sharkwouter]

Thanks for working on this. I'm mostly happy with this. I'm a little bit worried about the compat.h and mime.h files being in $PSPDEV/psp/include, though. Those are very generic names. Would it be possible to give them their own directory or give luasocket an own directory for now?

[tpimh]

I'm a little bit worried about the compat.h and mime.h files being in $PSPDEV/psp/include, though. Those are very generic names. Would it be possible to give them their own directory or give luasocket an own directory for now?

Yes, I was also thinking about this. I don't really like the "compat" header, and it is only included, because it's referenced from luasocket.h, so maybe the two can be merged? mime.h can be renamed to luasocket_mime.h, maybe? Or just move all the headers to $PSPDEV/psp/include/luasocket. There's no standard way of handling this as far as I know, this library is only supposed to be compiled dynamically (which is really cool, and I want to do it, but unfortunately, there's no way to load dynamic libraries at runtime from Lua at the moment), however a handful of projects link luasocket statically and they all just invent their own way. I wish something like this actually went upstream, I might break my PSP support patch into smaller pieces, and submit them separately.

[sharkwouter]

Such an odd library, I think putting it in lib/luasocket probably makes the most sense.

[tpimh]

I am sure lib/libluasocket.a and include/luasocket.h (a single combined header) wouldn't collide with anything.

[sharkwouter]

Yeah, that would be great

[sharkwouter]

Thanks for the work on this, this was an impressive feat. You should probably update your pull request to upstream to have more information on what was changed. Maybe they'll look into it then.