From 272f4e8c8a9d77b547862fe557c85bdfce7864f5 Mon Sep 17 00:00:00 2001
From: Avimitin <dev@avimit.in>
Date: Wed, 7 Aug 2024 03:41:07 +0800
Subject: [PATCH] [nix] split buddy-mlir build

Signed-off-by: Avimitin <dev@avimit.in>
---
 nix/pkgs/buddy-llvm.nix | 33 ++++++++++++++++++++++++++-
 nix/pkgs/buddy-mlir.nix | 49 ++++++++++++++++++-----------------------
 2 files changed, 54 insertions(+), 28 deletions(-)

diff --git a/nix/pkgs/buddy-llvm.nix b/nix/pkgs/buddy-llvm.nix
index 4cbf66db77..af5bc1c867 100644
--- a/nix/pkgs/buddy-llvm.nix
+++ b/nix/pkgs/buddy-llvm.nix
@@ -39,7 +39,38 @@ stdenv.mkDerivation rec {
     "-DLLVM_ENABLE_PROJECTS=mlir"
     "-DLLVM_TARGETS_TO_BUILD=host;RISCV"
     "-DLLVM_ENABLE_ASSERTIONS=ON"
-    "-DCMAKE_BUILD_TYPE=RELEASE"
+    "-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
+  '';
 }
diff --git a/nix/pkgs/buddy-mlir.nix b/nix/pkgs/buddy-mlir.nix
index abdae657a8..7141f678b4 100644
--- a/nix/pkgs/buddy-mlir.nix
+++ b/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";
@@ -20,31 +21,25 @@ stdenv.mkDerivation {
     rev = "be2811cde9158faa0c08ad90801edf5ebfcf8e0e";
     hash = "sha256-5ZFqDZZjMbVoqbEZ1mt1RXY2oR+VSQ6wJ1dQJCGrRC4=";
   };
-  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"
+  patches = [
+    (fetchpatch {
+      url = "https://github.com/buddy-compiler/buddy-mlir/pull/359.patch";
+      hash = "sha256-j75npHWrCVUcKFfm+JGbs9/CkS51Uxi3AfI5x8o8jkc=";
+    })
   ];
 
   passthru.llvm = buddy-llvm;