lib.systems.elaborate: expose canExecute predicate over isCompatible

canExecute is like isCompatible, but also checks that the Kernels are
_equal_, i.e. that both platforms use the same syscall interface. This
is crucial in order to actually be able to execute binaries for the
other platform.

isCompatible is dropped, since it has changed semantically and there's
no use case left in nixpkgs.
This commit is contained in:
sternenseemann 2022-04-26 22:17:48 +02:00
parent fe836f3564
commit acb063701a
3 changed files with 7 additions and 5 deletions

View file

@ -34,8 +34,10 @@ rec {
# Either of these can be losslessly-extracted from `parsed` iff parsing succeeds.
system = parse.doubleFromSystem final.parsed;
config = parse.tripleFromSystem final.parsed;
# Determine whether we are compatible with the provided CPU
isCompatible = platform: parse.isCompatible final.parsed.cpu platform.parsed.cpu;
# Determine whether we can execute binaries built for the provided platform.
canExecute = platform:
parse.isCompatible final.parsed.cpu platform.parsed.cpu
&& final.parsed.kernel == platform.parsed.kernel;
# Derived meta-data
libc =
/**/ if final.isDarwin then "libSystem"

View file

@ -17,9 +17,9 @@ stdenv.mkDerivation rec {
};
nativeBuildInputs = [ cmake ]
++ lib.optional (!(stdenv.hostPlatform.isCompatible stdenv.buildPlatform)) capnproto;
++ lib.optional (!(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) capnproto;
cmakeFlags = lib.optional (!(stdenv.hostPlatform.isCompatible stdenv.buildPlatform)) "-DEXTERNAL_CAPNP";
cmakeFlags = lib.optional (!(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) "-DEXTERNAL_CAPNP";
# Upstream 77ac9154440bcc216fda1092fd5bb51da62ae09c, modified to apply to v0.9.1. Drop on update.
patches = lib.optional stdenv.hostPlatform.isMusl ./musl-no-fibers.patch;

View file

@ -31,7 +31,7 @@
# compatible with or current architecture.
getCompatibleTools = lib.foldl (v: system:
if v != null then v
else if localSystem.isCompatible (lib.systems.elaborate { inherit system; }) then archLookupTable.${system}
else if localSystem.canExecute (lib.systems.elaborate { inherit system; }) then archLookupTable.${system}
else null) null (lib.attrNames archLookupTable);
archLookupTable = table.${localSystem.libc}