cpp-interop: init at 1.9.0

2026-06-30 14:23:37 -07:00
parent a85fe67ace
commit eb8494ce2e
1 changed files with 192 additions and 0 deletions
@@ -0,0 +1,192 @@
+{
+  lib,
+  fetchFromGitHub,
+  cmake,
+  ninja,
+  python3,
+  llvmPackages_21,
+  cling,
+  gcc-unwrapped,
+  libffi,
+  libxml2,
+  ncurses,
+  zlib,
+  zstd,
+
+  # tests
+  gtest,
+
+  # Which interpreter backend to build against. CppInterOp can use either
+  # clang-repl (from upstream LLVM/Clang) or Cling. They are mutually exclusive.
+  backend ? "clang-repl", # "clang-repl" | "cling"
+}:
+
+let
+  llvmPackages = llvmPackages_21;
+  inherit (llvmPackages) stdenv;
+
+  useCling = backend == "cling";
+  llvm = llvmPackages.llvm;
+  clang = llvmPackages.clang-unwrapped;
+
+  # For the cling backend we build against the LLVM/Clang/Cling that ship inside
+  # `cling` itself (its LLVM 20 fork), so the ABI matches libcling. The CMake
+  # config packages (LLVM, Clang, Cling) all live under cling.unwrapped.
+  clingRoot = cling.unwrapped;
+
+  # The Clang resource dir and standard-library include flags the JIT interpreter
+  # needs, since there is no system compiler to probe in the Nix sandbox. Both
+  # this package's own tests and xeus-cpp (via passthru) feed these to CppInterOp
+  # through CPPINTEROP_EXTRA_INTERPRETER_ARGS. The resource dir must match the
+  # Clang that CppInterOp was built against: the cling fork for the cling backend,
+  # upstream LLVM otherwise. -nostdinc(++) makes the search hermetic: only the
+  # -isystem paths below are used, never any stray host include dirs.
+  resourceDir =
+    if useCling then
+      "${clingRoot}/lib/clang/20"
+    else
+      "${lib.getLib clang}/lib/clang/${lib.versions.major llvm.version}";
+  interpreterArgs = [
+    "-nostdinc"
+    "-nostdinc++"
+    "-resource-dir"
+    resourceDir
+    "-isystem"
+    "${resourceDir}/include"
+    "-isystem"
+    "${gcc-unwrapped}/include/c++/${gcc-unwrapped.version}"
+    "-isystem"
+    "${gcc-unwrapped}/include/c++/${gcc-unwrapped.version}/${stdenv.hostPlatform.config}"
+    "-isystem"
+    "${lib.getDev stdenv.cc.libc}/include"
+  ];
+in
+
+assert lib.assertOneOf "backend" backend [
+  "clang-repl"
+  "cling"
+];
+
+stdenv.mkDerivation (finalAttrs: {
+  pname = "cpp-interop-${backend}";
+  version = "1.9.0";
+
+  src = fetchFromGitHub {
+    owner = "compiler-research";
+    repo = "CppInterOp";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-am2WObER9dlNQU/VMTY2ScMe/w8c4N8m/DVyNwHiBnw=";
+  };
+
+  strictDeps = true;
+  __structuredAttrs = true;
+
+  nativeBuildInputs = [
+    cmake
+    ninja
+    python3
+  ];
+
+  buildInputs = [
+    libffi
+    libxml2
+    ncurses
+    zlib
+    zstd
+  ]
+  ++ (
+    if useCling then
+      [ clingRoot ]
+    else
+      [
+        llvm
+        clang
+      ]
+  );
+
+  # Upstream's unittests/CMakeLists.txt only fetches GoogleTest over the network
+  # (forbidden in the sandbox) when no gtest target exists; point it at the
+  # nixpkgs gtest instead so the tests can build offline.
+  postPatch = ''
+    substituteInPlace unittests/CMakeLists.txt \
+      --replace-fail "include(GoogleTest)" "find_package(GTest REQUIRED)"
+  '';
+
+  cmakeFlags = [
+    (lib.cmakeBool "BUILD_SHARED_LIBS" true)
+    (lib.cmakeBool "CPPINTEROP_USE_CLING" useCling)
+    (lib.cmakeBool "CPPINTEROP_USE_REPL" (!useCling))
+    (lib.cmakeBool "CPPINTEROP_ENABLE_TESTING" finalAttrs.finalPackage.doCheck)
+  ]
+  ++ (
+    if useCling then
+      [
+        "-DCling_DIR=${clingRoot}/lib/cmake/cling"
+        "-DLLVM_DIR=${clingRoot}/lib/cmake/llvm"
+        "-DClang_DIR=${clingRoot}/lib/cmake/clang"
+      ]
+    else
+      [
+        "-DLLVM_DIR=${llvm.dev}/lib/cmake/llvm"
+        "-DClang_DIR=${clang.dev}/lib/cmake/clang"
+      ]
+  );
+
+  # Run the upstream GoogleTest suite. Only the clang-repl backend is exercised;
+  # the Cling backend skips many of these tests upstream.
+  doCheck = !useCling;
+  checkInputs = [ gtest ];
+  checkPhase = ''
+    runHook preCheck
+
+    export CPPINTEROP_EXTRA_INTERPRETER_ARGS="${lib.concatStringsSep " " interpreterArgs}"
+    # Upstream registers the tests only in the unittests subdir; its
+    # check-cppinterop target builds them and runs ctest from the right place.
+    ninja check-cppinterop
+
+    runHook postCheck
+  '';
+
+  # Smoke test: drive the backend to JIT-compile and run a function, proving
+  # the installed library, headers and runtime linking all work together.
+  doInstallCheck = !useCling;
+  installCheckPhase = ''
+    runHook preInstallCheck
+
+    cat > smoke.cpp <<'EOF'
+    #include "CppInterOp/CppInterOp.h"
+    #include <cstdio>
+    int main() {
+      Cpp::CreateInterpreter();
+      if (Cpp::Declare("int square(int x) { return x * x; }") != 0) return 1;
+      bool hadError = false;
+      intptr_t result = Cpp::Evaluate("square(7)", &hadError);
+      if (hadError) return 2;
+      if (result != 49) { std::printf("expected 49, got %ld\n", (long)result); return 3; }
+      if (Cpp::GetNamed("square") == nullptr) return 4;
+      return 0;
+    }
+    EOF
+
+    $CXX -std=c++17 smoke.cpp -I$out/include -L$out/lib -lclangCppInterOp -o smoke
+    LD_LIBRARY_PATH=$out/lib ./smoke
+
+    runHook postInstallCheck
+  '';
+
+  passthru = {
+    inherit backend resourceDir interpreterArgs;
+  };
+
+  meta = {
+    description = "Clang-based C++ interoperability library (${backend} backend)";
+    homepage = "https://github.com/compiler-research/CppInterOp";
+    changelog = "https://github.com/compiler-research/CppInterOp/releases/tag/v${finalAttrs.version}";
+    license = with lib.licenses; [
+      asl20
+      llvm-exception
+    ];
+    maintainers = with lib.maintainers; [ thomasjm ];
+    platforms = lib.platforms.unix;
+  };
+})