Merge pull request #197478 from CobaltCause/add-cargo-llvm-cov

# If the tests are broken, it's probably for one of two reasons:

#

# 1. The version of llvm used doesn't match the expectations of rustc and/or

#    cargo-llvm-cov. This is relatively unlikely because we pull llvm out of

#    rustc's attrset, so it *should* be the right version as long as this is the

#    case.

# 2. Nixpkgs has changed its rust infrastructure in a way that causes

#    cargo-llvm-cov to misbehave under test. It's likely that even though the

#    tests are failing, cargo-llvm-cov will still function properly in actual

#    use. This has happened before, and is described [here][0] (along with a

#    feature request that would fix this instance of the problem).

#

# For previous test-troubleshooting discussion, see [here][1].

#

# [0]: https://github.com/taiki-e/cargo-llvm-cov/issues/242

# [1]: https://github.com/NixOS/nixpkgs/pull/197478

{ stdenv

, lib

, fetchCrate

, fetchurl

, fetchFromGitHub

, rustPlatform

, rustc

}:

rustPlatform.buildRustPackage rec {

let

  pname = "cargo-llvm-cov";

  version = "0.5.31";

  src = fetchCrate {

  owner = "taiki-e";

  homepage = "https://github.com/${owner}/${pname}";

  llvm = rustc.llvmPackages.llvm;

  # Download `Cargo.lock` from crates.io so we don't clutter up Nixpkgs

  cargoLock = fetchurl {

    name = "Cargo.lock";

    url = "https://crates.io/api/v1/crates/${pname}/${version}/download";

    sha256 = "sha256-BbrdyJgZSIz6GaTdQv1GiFHufRBSbcoHcqqEmr/HvAM=";

    downloadToTemp = true;

    postFetch = ''

      tar xzf $downloadedFile ${pname}-${version}/Cargo.lock

      mv ${pname}-${version}/Cargo.lock $out

    '';

  };

in

rustPlatform.buildRustPackage {

  inherit pname version;

    sha256 = "sha256-HjnP9H1t660PJ5eXzgAhrdDEgqdzzb+9Dbk5RGUPjaQ=";

  # Use `fetchFromGitHub` instead of `fetchCrate` because the latter does not

  # pull in fixtures needed for the test suite

  src = fetchFromGitHub {

    inherit owner;

    repo = pname;

    rev = "v${version}";

    sha256 = "sha256-wRo94JVn4InkhrMHFSsEvm2FFIxUsltA57sMMOcL8b0=";

  };

  cargoSha256 = "sha256-p6zpRRNX4g+jESNSwouWMjZlFhTBFJhe7LirYtFrZ1g=";

  # skip tests which require llvm-tools-preview

  checkFlags = [

    "--skip bin_crate"

    "--skip cargo_config"

    "--skip clean_ws"

    "--skip instantiations"

    "--skip merge"

    "--skip merge_failure_mode_all"

    "--skip no_test"

    "--skip open_report"

    "--skip real1"

    "--skip show_env"

    "--skip virtual1"

  ];

  meta = rec {

    homepage = "https://github.com/taiki-e/${pname}";

  # Upstream doesn't include the lockfile so we need to add it back

  postUnpack = ''

    cp ${cargoLock} source/Cargo.lock

  '';

  cargoSha256 = "sha256-XcsognndhHenYnlJCNMbrNh+S8FX7qxXUjuV1j2qsmY=";

  # `cargo-llvm-cov` reads these environment variables to find these binaries,

  # which are needed to run the tests

  LLVM_COV = "${llvm}/bin/llvm-cov";

  LLVM_PROFDATA = "${llvm}/bin/llvm-profdata";

  meta = {

    inherit homepage;

    changelog = homepage + "/blob/v${version}/CHANGELOG.md";

    description = "Cargo subcommand to easily use LLVM source-based code coverage";

    longDescription = ''

      library (e.g. fenix or rust-overlay)

    '';

    license = with lib.licenses; [ asl20 /* or */ mit ];

    maintainers = with lib.maintainers; [ wucke13 matthiasbeyer ];

    maintainers = with lib.maintainers; [ wucke13 matthiasbeyer CobaltCause ];

    # The profiler runtime is (currently) disabled on non-Linux platforms

    broken = !(stdenv.isLinux && !stdenv.targetPlatform.isRedox);

  };

}