Previously all includes were anchored in one global mess of header
files. This moves the includes into filesystem "namespaces" (if you
will) for each sub-package of Nix.
Note: This commit does not introduce the relevant build system changes.
This applies the modernization fixes listed here:
https://clang.llvm.org/extra/clang-tidy/checks/list.html
The 'modernize-use-trailing-return-type' fix was excluded due to my
personal preference (more specifically, I think the 'auto' keyword is
misleading in that position).
This last change set was generated by a full clang-tidy run (including
compilation):
clang-tidy -p ~/projects/nix-build/ \
-checks=-*,readability-braces-around-statements -fix src/*/*.cc
Actually running clang-tidy requires some massaging to make it play
nice with Nix + meson, I'll be adding a wrapper or something for that soon.
These were not caught by the previous clang-tidy invocation, but were
instead sorted out using amber[0] as such:
ambr --regex 'if (\(.+\))\s([a-z].*;)' 'if $1 { $2 }'
[0]: https://github.com/dalance/amber
