Following legacy packing conventions, `isArm` was defined just for
32-bit ARM instruction set. This is confusing to non packagers though,
because Aarch64 is an ARM instruction set.
The official ARM overview for ARMv8[1] is surprisingly not confusing,
given the overall state of affairs for ARM naming conventions, and
offers us a solution. It divides the nomenclature into three levels:
```
ISA: ARMv8 {-A, -R, -M}
/ \
Mode: Aarch32 Aarch64
| / \
Encoding: A64 A32 T32
```
At the top is the overall v8 instruction set archicture. Second are the
two modes, defined by bitwidth but differing in other semantics too, and
buttom are the encodings, (hopefully?) isomorphic if they encode the
same mode.
The 32 bit encodings are mostly backwards compatible with previous
non-Thumb and Thumb encodings, and if so we can pun the mode names to
instead mean "sets of compatable or isomorphic encodings", and then
voilà we have nice names for 32-bit and 64-bit arm instruction sets
which do not use the word ARM so as to not confused either laymen or
experienced ARM packages.
[1]: https://developer.arm.com/products/architecture/a-profile
In anticipation of what I outline in #33599, I only simplify exactly those
`doCheck`s which are equal to `hostPlatform != buildPlatform`. I also stick a
comment next to them so I can grep for them later.
* pkgs: refactor needless quoting of homepage meta attribute
A lot of packages are needlessly quoting the homepage meta attribute
(about 1400, 22%), this commit refactors all of those instances.
* pkgs: Fixing some links that were wrongfully unquoted in the previous
commit
* Fixed some instances
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 most complex problems were from dealing with switches reverted in
the meantime (gcc5, gmp6, ncurses6).
It's likely that darwin is (still) broken nontrivially.
The config.guess script tries to detect various ARM optimization flags
via /proc/cpuinfo. This is not only impure, but the detection is also
broken on multicore machines; on my quad-core system the machine type is
autodetected as 'neon neon neon neon-unknown-linux-gnueabihf':
checking build system type... Invalid configuration `neon': machine `neon' not recognized
configure: error: /nix/store/bafimhdj1yaxj6m1hvq7wvhwwizc939x-bootstrap-tools/bin/sh ./config.sub neon
neon
neon
neon-unknown-linux-gnueabihf failed
builder for ‘/nix/store/1npm2358bpvclj5w7fqjjwg72vbb0d79-gmp-6.0.0a.drv’ failed with exit code 1
Override the system type with the output of GNU config.guess to avoid
the autodetection.
