Certain tools, e.g. compilers, are customarily prefixed with the name of
their target platform so that multiple builds can be used at once
without clobbering each other on the PATH. I was using identifiers named
`prefix` for this purpose, but that conflicts with the standard use of
`prefix` to mean the directory where something is installed. To avoid
conflict and confusion, I renamed those to `targetPrefix`.
https://github.com/NixOS/nixpkgs/pull/30484#issuecomment-345472766
Since [1] libbfd is compiled with support for all available targets. However, it
can not choose whether an ARM ELF file is elf32-littlearm,
elf32-littlearm-symbian, or elf32-littlearm-vxworks, and fails with the "File
format is ambiguous" error. Here [2] Alan Modra intended to prioritize the
first of the three, but although his patch was merged and reportedly solved the
issue, currently glibc 2.28.1 and 2.29.1 again fail to disambiguate these
targets. This commit makes it prioritize elf32-littlearm over the other two.
[1] f8741c38cd
[2] https://sourceware.org/ml/binutils/2013-05/msg00271.html
There are separate derivations for these libraries and we don't want
conflict. Multitarget is generally more useful, and will eventually
speed up cross builds, so why not?!
On most distros, these are just built and distributed as part of
binutils. We don't use binutils across the board, however, but rather
switch between binutils and a cctools-binutils mashup, and change the
outputs on binutils too. This creates a combinatorial conditional soup
which is hard to maintain.
My hope is to lower the the state space. While my patch isn't the most
maintainable, they make downstream packages become more maintainable to
compensate. The additional derivations themselves are completely
platform-agnostic, always they always supports all possible target
platforms, and always yield "out" and "dev" outputs. That, in turn,
allows downstream packages to not worry about a dependency
shape-shifting under them.
In fact, the actual binutils package can avoid needing multiple outputs
now that these serve the requisite libraries, so that also can become
simpler on all platforms, too, removing the original wart this PR
circumnavigates for now. Actually changing the binutils package to
leverage is a mass rebuild, however, so I'll leave that for a separate
PR.
I do hope to upstream something like my patch too, but until then I'll
make myself maintainer of these derivations
This is needed for build != host == target builds. Moreoever, we want
to move towards always passing all 3, and the previous change to
unbreak Arm moved us away from that.
We want platform triple prefixes and suffixes on derivation names to
be used consistently. The ideom this commit strives for is
- suffix means build != host, i.e. cross *built* packages. This is
already done.
- prefix means build != target, i.e. cross tools. This matches the
tradition of such binaries themselves being prefixed to disambiguate.]
Binutils and cctools, as build tools, now use the latter
- No more *Cross duplication for binutils on darwin either.
`cctools_cross` is merged into plain `cctools`, so `buildPackages`
chains alone are used to disambiguate.
- Always use a mashup of cctools and actual GNU Binutils as `binutils`.
Previously, this was only done in the native case as nobody had
bothered to implement the masher in the cross case. Implemented it
basically consisted of extending the wrapper to deal with prefixed
binaries.
The old forms presumably predates, or were made in ignorance of,
`let inherit`. This way is better style as the scoping as more lexical,
something which Nix can (or might already!) take advantage of.
The following parameters are now available:
* hardeningDisable
To disable specific hardening flags
* hardeningEnable
To enable specific hardening flags
Only the cc-wrapper supports this right now, but these may be reused by
other wrappers, builders or setup hooks.
cc-wrapper supports the following flags:
* fortify
* stackprotector
* pie (disabled by default)
* pic
* strictoverflow
* format
* relro
* bindnow
