From ab348e2dc2527cb2f052d28b248427eb49689d66 Mon Sep 17 00:00:00 2001
From: aaravrav <37036762+aaravrav@users.noreply.github.com>
Date: Fri, 16 Oct 2026 23:20:55 +0530
Subject: [PATCH] llvmPackages_23.openmp: fix build for LLVM 23+

---
 .../compilers/llvm/common/openmp/default.nix  | 32 +++++++++++++++----
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/pkgs/development/compilers/llvm/common/openmp/default.nix b/pkgs/development/compilers/llvm/common/openmp/default.nix
index 2601e294fccf..d6792fa1a94b 100644
--- a/pkgs/development/compilers/llvm/common/openmp/default.nix
+++ b/pkgs/development/compilers/llvm/common/openmp/default.nix
@@ -36,15 +36,28 @@ stdenv.mkDerivation (finalAttrs: {
           strictDeps = true;
           __structuredAttrs = true;
         }
-        ''
-          mkdir -p "$out"
-          cp -r ${monorepoSrc}/cmake "$out"
-          cp -r ${monorepoSrc}/openmp "$out"
-        ''
+        (
+          ''
+            mkdir -p "$out"
+            cp -r ${monorepoSrc}/cmake "$out"
+            cp -r ${monorepoSrc}/openmp "$out"
+          ''
+          + lib.optionalString (lib.versionAtLeast release_version "23") ''
+            mkdir -p "$out/llvm"
+            cp -r ${monorepoSrc}/llvm/cmake "$out/llvm"
+            cp -r ${monorepoSrc}/llvm/utils "$out/llvm"
+            cp -r ${monorepoSrc}/third-party "$out"
+            cp -r ${monorepoSrc}/runtimes "$out"
+          ''
+        )
     else
       src;
 
-  sourceRoot = "${finalAttrs.src.name}/openmp";
+  # LLVM 23 removed OpenMP's standalone build
+  # https://openmp.llvm.org/Building.html
+  sourceRoot =
+    "${finalAttrs.src.name}/"
+    + (if lib.versionAtLeast release_version "23" then "runtimes" else "openmp");
 
   outputs = [
     "out"
@@ -89,6 +102,9 @@ stdenv.mkDerivation (finalAttrs: {
     (lib.cmakeFeature "OPT_TOOL" "${llvm}/bin/opt")
     (lib.cmakeFeature "LINK_TOOL" "${llvm}/bin/llvm-link")
   ]
+  ++ lib.optionals (lib.versionAtLeast release_version "23") [
+    (lib.cmakeFeature "LLVM_ENABLE_RUNTIMES" "openmp")
+  ]
   ++ devExtraCmakeFlags;
 
   doCheck = false;
@@ -96,7 +112,9 @@ stdenv.mkDerivation (finalAttrs: {
   checkTarget = "check-openmp";
 
   preCheck = ''
-    patchShebangs ../tools/archer/tests/deflake.bash
+    patchShebangs ${
+      if lib.versionAtLeast release_version "23" then "../../openmp" else ".."
+    }/tools/archer/tests/deflake.bash
   '';
 
   __structuredAttrs = true;