[nix] add standalone LLVM build for buddy-mlir

Signed-off-by: Avimitin <[email protected]>

nix/pkgs/buddy-llvm.nix

@@ -0,0 +1,76 @@
+{ stdenv
+, cmake
+, ninja
+, python3
+, fetchFromGitHub
+}:
+
+let
+  pythonEnv = python3.withPackages (ps: [
+    ps.numpy
+    ps.pybind11
+    ps.pyyaml
+    ps.ml-dtypes
+  ]);
+in
+stdenv.mkDerivation rec {
+  name = "llvm-for-buddy-mlir";
+  version = "6c59f0e1b0fb56c909ad7c9aad4bde37dc006ae0";
+  src = fetchFromGitHub {
+    owner = "llvm";
+    repo = "llvm-project";
+    rev = version;
+    hash = "sha256-bMJJ2q1hSh7m0ewclHOmIe7lOHv110rz/P7D3pw8Uiw=";
+  };
+
+  requiredSystemFeatures = [ "big-parallel" ];
+
+  propagatedBuildInputs = [
+    pythonEnv
+  ];
+
+  nativeBuildInputs = [
+    cmake
+    ninja
+  ];
+
+  cmakeDir = "../llvm";
+  cmakeFlags = [
+    "-DLLVM_ENABLE_PROJECTS=mlir"
+    "-DLLVM_TARGETS_TO_BUILD=host;RISCV"
+    "-DLLVM_ENABLE_ASSERTIONS=ON"
+    "-DCMAKE_BUILD_TYPE=Release"
+    # required for MLIR python binding
+    "-DMLIR_ENABLE_BINDINGS_PYTHON=ON"
+    # required for not, FileCheck...
+    "-DLLVM_INSTALL_UTILS=ON"
+  ];
+
+  outputs = [ "out" "lib" "dev" ];
+
+  postInstall = ''
+    # buddy-mlir have custom RVV backend that required LLVM backend,
+    # and those LLVM backend headers require this config.h header file.
+    # However for LLVM, this config.h is meant to be used on build phase only,
+    # so it will not be installed for cmake install.
+    # We have to do some hack 
+    cp -v "include/llvm/Config/config.h" "$dev/include/llvm/Config/config.h"
+
+    # move llvm-config to $dev to resolve a circular dependency
+    moveToOutput "bin/llvm-config*" "$dev"
+
+    # move all lib files to $lib except lib/cmake
+    moveToOutput "lib" "$lib"
+    moveToOutput "lib/cmake" "$dev"
+
+    # patch configuration files so each path points to the new $lib or $dev paths
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
+      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "'"$lib"'")'
+    substituteInPlace \
+      "$dev/lib/cmake/llvm/LLVMExports-release.cmake" \
+      "$dev/lib/cmake/mlir/MLIRTargets-release.cmake" \
+      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
+      --replace "\''${_IMPORT_PREFIX}/lib/objects-Release" "$lib/lib/objects-Release" \
+      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config" # patch path for llvm-config
+  '';
+}

nix/pkgs/buddy-mlir.nix

@@ -1,14 +1,15 @@
-{ cmake, ninja, python3, llvmPackages_17, fetchFromGitHub, fetchpatch }:
+{ cmake
+, ninja
+, llvmPackages_17
+, fetchFromGitHub
+, fetchpatch
+, callPackage
+}:
 let
   stdenv = llvmPackages_17.stdenv;
   bintools = llvmPackages_17.bintools;
 
-  buddy-llvm = fetchFromGitHub {
-    owner = "llvm";
-    repo = "llvm-project";
-    rev = "6c59f0e1b0fb56c909ad7c9aad4bde37dc006ae0";
-    hash = "sha256-bMJJ2q1hSh7m0ewclHOmIe7lOHv110rz/P7D3pw8Uiw=";
-  };
+  buddy-llvm = callPackage ./buddy-llvm.nix { inherit stdenv; };
 in
 stdenv.mkDerivation {
   pname = "buddy-mlir";
@@ -17,38 +18,23 @@ stdenv.mkDerivation {
   src = fetchFromGitHub {
     owner = "buddy-compiler";
     repo = "buddy-mlir";
-    rev = "be2811cde9158faa0c08ad90801edf5ebfcf8e0e";
-    hash = "sha256-5ZFqDZZjMbVoqbEZ1mt1RXY2oR+VSQ6wJ1dQJCGrRC4=";
+    rev = "d7d90a488ac0d6fc1e700e932f842c7b2bcad816";
+    hash = "sha256-MhykCa6Z7Z8PpAlNh+vMuWYEOZZDyWhtMzMnFlNbGIk=";
   };
-  unpackPhase = ''
-    # We can only use one-step build now...buddy-mlir have bad build system that always
-    # assume the build artifacts are inside of the LLVM sources. And it also relies on
-    # some LLVM Cpp source that are configured to be installed by default.
-    cp -r ${buddy-llvm} llvm-project
-    cp -r $src buddy-mlir
-
-    # Directories copied from nix store are read only
-    chmod -R u+w llvm-project buddy-mlir
-  '';
-  sourceRoot = "llvm-project";
 
-  nativeBuildInputs = [ cmake ninja python3 bintools ];
+  nativeBuildInputs = [ cmake ninja bintools ];
+  buildInputs = [
+    buddy-llvm
+  ];
 
-  cmakeDir = "../llvm";
   cmakeFlags = [
+    "-DMLIR_DIR=${buddy-llvm.dev}/lib/cmake/mlir"
+    "-DLLVM_DIR=${buddy-llvm.dev}/lib/cmake/llvm"
+    "-DLLVM_MAIN_SRC_DIR=${buddy-llvm.src}/llvm"
+    "-DBUDDY_MLIR_ENABLE_PYTHON_PACKAGES=ON"
     "-DCMAKE_BUILD_TYPE=Release"
-    "-DLLVM_INSTALL_UTILS=ON"
-    "-DLLVM_ENABLE_PROJECTS=mlir"
-    "-DLLVM_TARGETS_TO_BUILD=host;RISCV"
-    "-DLLVM_ENABLE_ASSERTIONS=ON"
-    "-DLLVM_USE_LINKER=lld"
-
-    "-DLLVM_EXTERNAL_PROJECTS=buddy-mlir"
-    "-DLLVM_EXTERNAL_BUDDY_MLIR_SOURCE_DIR=../../buddy-mlir"
   ];
 
-  passthru.llvm = buddy-llvm;
-
   # No need to do check, and it also takes too much time to finish.
   doCheck = false;
 }