lua-bit32: new package

[mstorchak]

provides bit32, a replacement for luabitops

Signed-off-by: Maxim Storchak [email protected]

Maintainer: me
Compile tested: ath79, WNDR3800, r10703+3-e1f588e446
Run tested: ath79, WNDR3800, base system r9880+3-bd3a18bbe4, actually tested in a chroot with r10703+3-e1f588e446

Description:
This package provides bit32, a backport of Lua 5.2 bit manipulation library. It's required for new luaposix.

[neheb]

Please rebase against current master to fix the buildbot.

[mstorchak]

@neheb , done.

[neheb]

Place above PKG_SOURCE_URL.

[karlp]

why? based on what?

[neheb]

#9682

[karlp]

That hasn't even merged yet!

[neheb]

get rid of PKG_SRC_NAME. variables are normally not used in URLs unless they change (the version).

[karlp]

what requirement is this? where is it documented for contributors?

[neheb]

f82287c

I've done this before but was told to replace with normal name.

[cotequeiroz]

@neheb, I think you are overextending this requirement. It is only for call, eval or define lines. Note that f82287c does not touch any other lines, and that
git grep '^PKG_SOURCE_URL.*PKG_NAME' f82287c will return 34 lines that were left unchanged.

[hnyman]

Let's merge this.
luaposix that was already merged for some reason, depends on this and is now broken.

Although package name variables are frowned upon on most of the declarations, I see no real problem this time, as the variable is used just as part of the download path to identify the lua compatibility version.

[mstorchak]

I'm sorry for not responding in time, I was traveling and didn't have access to internet.
@hnyman , thank you for merging this PR!
@neheb , I introduced PKG_SRC_* variables to avoid duplication. In this case package name doesn't match the name of the repo, and it appears that some parts of the build process depend on repo name.

[PolynomialDivision]

Can we please backport this package to 19.07.4?

[karlp]

@PolynomialDivision lua bitop is already available, this bit32 package is only for the major version bump in luaposix, which will not be backported. Is lua bitop not sufficient?

[PolynomialDivision]

Ah okay. Thanks!
I have to look. I wrote an exporter that uses bit32. I wanted to make it available under 19.07.4. Maybe I have to change the lib. Thanks for the hint. :)

#13606

[karlp]

Here's some code that will automatically use native (on lua 5.3) or lua bitop, or whwatever else you plugin)

-- Try and figure out a bitop library...
local bitnative, err = loadstring("if 2 & 1<<1 then return true end")
band = nil
bor = nil
lshift = nil
rshift = nil

if bitnative then
        local magic_str = [[
        bor = function(a,b) return a | b end
        band = function(a,b) return a & b end
        lshift = function(a,b) return a << b end
        rshift = function(a,b) return a >> b end
        ]]
        local f, err = loadstring(magic_str)
        if f then f() else print("loadstring failed?!", err) end
        -- sanity
        if band(0xfff, 0x2) ~= 0x2 then error("wat") end
else
	-- try bitop, it's common too
	local hasbit, bit = pcall(require, "bit")
	if hasbit then
		bor = bit.bor
		band = bit.band
		lshift = bit.lshift
		rshift = bit.rshift
	end
end