chore(tvix): avoid unnesscary rebuilds of protos and tvix

For the build of tvix we can safely ignore all the files in src/protos
as well as all the nix files in the root of the repository. By passing
the input sources through builtins.filterSource we can make a per-file
decision whether or not we want to copy it into the store (in other
words: if we consider it relevant for the build).

This enables much faster development on the actual build expression.

Change-Id: Ib4c01dbe9cbfa9770922f6257af2a7259814ce0d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2159
Tested-by: BuildkiteCI
Reviewed-by: glittershark <grfn@gws.fyi>
Reviewed-by: lukegb <lukegb@tvl.fyi>
This commit is contained in:
Andreas Rammhold 2020-11-27 16:31:18 +01:00 committed by andi
parent e772f38a5e
commit 9bf6eb7f82

View file

@ -12,12 +12,36 @@ let
customMemoryManagement = false;
};
src = ./.;
src = let
srcDir = ./.;
# create relative paths for all the sources we are filtering
asRelative = path:
let
srcS = toString srcDir;
pathS = toString path;
in
if ! lib.hasPrefix srcS pathS then
throw "Path is outside of the working directory."
else
lib.removePrefix srcS pathS;
in builtins.filterSource (path: type:
# Strip out .nix files that are in the root of the repository. Changing
# the expression of tvix shouldn't cause a rebuild of tvix unless really
# required.
!(dirOf (asRelative path) == "/" && lib.hasSuffix ".nix" path) &&
# remove the proto files from the repo as those are compiled separately
!(lib.hasPrefix "src/proto" (asRelative path)) &&
# ignore result symlinks
!(type == "symlink" && lib.hasPrefix "result" (baseNameOf path))
) srcDir;
# Proto generation in CMake is theoretically possible, but that is
# very theoretical - this does it in Nix instead.
protoSrcs = pkgs.runCommand "nix-proto-srcs" {} ''
export PROTO_SRCS=${src + "/src/proto"}
export PROTO_SRCS=${./src/proto}
mkdir -p $out/libproto
${pkgs.protobuf}/bin/protoc -I=$PROTO_SRCS \
--cpp_out=$out/libproto \