From 7eb779860dafba203b048a56c0ee29ed5fb4303b Mon Sep 17 00:00:00 2001
From: Reno Dakota <paparodeo@proton.me>
Date: Mon, 4 Nov 2024 10:13:20 -0800
Subject: [PATCH] llvmPackages_19.libclc: use unwrapped clang only

The build requires an unwrapped clang due to passing in --arch flags.
However, for c++ it doesn't pass in --arch and requires standard headers
so which requires the wrapped compiler.
---
 pkgs/development/compilers/llvm/common/libclc.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/compilers/llvm/common/libclc.nix b/pkgs/development/compilers/llvm/common/libclc.nix
index c24fc6e3b4c0..d20e6877019b 100644
--- a/pkgs/development/compilers/llvm/common/libclc.nix
+++ b/pkgs/development/compilers/llvm/common/libclc.nix
@@ -17,6 +17,14 @@ let
   spirv-llvm-translator = buildPackages.spirv-llvm-translator.override {
     inherit (buildLlvmTools) llvm;
   };
+
+  # The build requires an unwrapped clang but wrapped clang++ thus we need to
+  # split the unwrapped clang out to prevent the build from finding the
+  # unwrapped clang++
+  clang-only = runCommand "clang-only" { } ''
+    mkdir -p "$out"/bin
+    ln -s "${lib.getExe' buildLlvmTools.clang.cc "clang"}" "$out"/bin
+  '';
 in
 stdenv.mkDerivation rec {
   pname = "libclc";
@@ -78,7 +86,7 @@ stdenv.mkDerivation rec {
       python3
     ]
     ++ lib.optional (lib.versionAtLeast release_version "19") [
-      buildLlvmTools.clang.cc
+      clang-only
       buildLlvmTools.llvm
       spirv-llvm-translator
     ];