nixpkgs/lib/systems/default.nix
Matthew Bauer 45cc6e2a42 lib/systems: use lookup for uname.system
This is a little bit cleaner and avoids the if ... else if ... chain.
2018-10-17 14:43:49 -05:00

80 lines
2.8 KiB
Nix

{ lib }:
let inherit (lib.attrsets) mapAttrs; in
rec {
doubles = import ./doubles.nix { inherit lib; };
forMeta = import ./for-meta.nix { inherit lib; };
parse = import ./parse.nix { inherit lib; };
inspect = import ./inspect.nix { inherit lib; };
platforms = import ./platforms.nix { inherit lib; };
examples = import ./examples.nix { inherit lib; };
# Elaborate a `localSystem` or `crossSystem` so that it contains everything
# necessary.
#
# `parsed` is inferred from args, both because there are two options with one
# clearly prefered, and to prevent cycles. A simpler fixed point where the RHS
# always just used `final.*` would fail on both counts.
elaborate = args: let
final = {
# Prefer to parse `config` as it is strictly more informative.
parsed = parse.mkSystemFromString (if args ? config then args.config else args.system);
# Either of these can be losslessly-extracted from `parsed` iff parsing succeeds.
system = parse.doubleFromSystem final.parsed;
config = parse.tripleFromSystem final.parsed;
# Just a guess, based on `system`
platform = platforms.selectBySystem final.system;
# Derived meta-data
libc =
/**/ if final.isDarwin then "libSystem"
else if final.isMinGW then "msvcrt"
else if final.isMusl then "musl"
else if final.isUClibc then "uclibc"
else if final.isAndroid then "bionic"
else if final.isLinux /* default */ then "glibc"
# TODO(@Ericson2314) think more about other operating systems
else "native/impure";
extensions = {
sharedLibrary =
/**/ if final.isDarwin then ".dylib"
else if final.isWindows then ".dll"
else ".so";
executable =
/**/ if final.isWindows then ".exe"
else "";
};
# Misc boolean options
useAndroidPrebuilt = false;
useiOSPrebuilt = false;
# Output from uname
uname = {
# uname -s
system = {
"linux" = "Linux";
"windows" = "Windows";
"darwin" = "Darwin";
"netbsd" = "NetBSD";
"freebsd" = "FreeBSD";
"openbsd" = "OpenBSD";
}.${final.parsed.kernel.name} or null;
# uname -p
processor = final.parsed.cpu.name;
# uname -r
release = null;
};
} // mapAttrs (n: v: v final.parsed) inspect.predicates
// args;
in assert final.useAndroidPrebuilt -> final.isAndroid;
assert lib.foldl
(pass: { assertion, message }:
if assertion final
then pass
else throw message)
true
(final.parsed.abi.assertions or []);
final;
}