From 06aa1fc5d43e2e6ea5b39e150fbf0fbea4baa893 Mon Sep 17 00:00:00 2001
From: Aleix Roca Nonell <aleix.rocanonell@bsc.es>
Date: Tue, 15 Jul 2025 17:12:29 +0200
Subject: [PATCH] Fix clang cross-build

---
 overlay.nix                  |  8 ++++----
 pkgs/llvm-ompss2/clang.nix   | 27 +++++++++++++++++----------
 pkgs/llvm-ompss2/default.nix |  3 ++-
 3 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/overlay.nix b/overlay.nix
index 27d92c5e..ea44f869 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -56,10 +56,10 @@ let
     #psmpi = callPackage ./pkgs/parastation/psmpi.nix { }; # Unmaintaned
     slurm = import ./pkgs/slurm/default.nix { slurm = prev.slurm; };
     sonar = callPackage ./pkgs/sonar/default.nix { };
-    stdenvClangOmpss2 = final.stdenv.override { cc = final.clangOmpss2; allowedRequisites = null; };
-    stdenvClangOmpss2Nanos6 = final.stdenv.override { cc = final.clangOmpss2Nanos6; allowedRequisites = null; };
-    stdenvClangOmpss2Nodes = final.stdenv.override { cc = final.clangOmpss2Nodes; allowedRequisites = null; };
-    stdenvClangOmpss2NodesOmpv = final.stdenv.override { cc = final.clangOmpss2NodesOmpv; allowedRequisites = null; };
+    stdenvClangOmpss2 = final.stdenv.override { cc = final.buildPackages.clangOmpss2; allowedRequisites = null; };
+    stdenvClangOmpss2Nanos6 = final.stdenv.override { cc = final.buildPackages.clangOmpss2Nanos6; allowedRequisites = null; };
+    stdenvClangOmpss2Nodes = final.stdenv.override { cc = final.buildPackages.clangOmpss2Nodes; allowedRequisites = null; };
+    stdenvClangOmpss2NodesOmpv = final.stdenv.override { cc = final.buildPackages.clangOmpss2NodesOmpv; allowedRequisites = null; };
     tagaspi = callPackage ./pkgs/tagaspi/default.nix { };
     tampi = callPackage ./pkgs/tampi/default.nix { };
     upc-qaire-exporter = prev.callPackage ./pkgs/upc-qaire-exporter/default.nix { };
diff --git a/pkgs/llvm-ompss2/clang.nix b/pkgs/llvm-ompss2/clang.nix
index 05af0f27..9a1b7654 100644
--- a/pkgs/llvm-ompss2/clang.nix
+++ b/pkgs/llvm-ompss2/clang.nix
@@ -1,9 +1,9 @@
 {
-  llvmPackages_latest
+  stdenv
+, llvmPackages_latest
 , lib
 , fetchFromGitHub
 , cmake
-, bash
 , python3
 , perl
 , which
@@ -11,7 +11,6 @@
 , libffi
 , zlib
 , pkg-config
-, gcc # needed to set the rpath of libstdc++ for clang-tblgen
 , enableDebug ? false
 , useGit ? false
 , gitUrl ? "ssh://git@bscpm04.bsc.es/llvm-ompss/llvm-mono.git"
@@ -20,7 +19,10 @@
 }:
 
 let
-  stdenv = llvmPackages_latest.stdenv;
+  llvmPackages = llvmPackages_latest;
+  llvmStdenv = llvmPackages.stdenv;
+  # needed to set the rpath of libstdc++ for clang-tblgen
+  gcc = stdenv.cc;
 
   release = rec {
     version = "2025.11";
@@ -43,7 +45,7 @@ let
 
   source = if (useGit) then git else release;
 
-in stdenv.mkDerivation {
+in llvmStdenv.mkDerivation {
   pname = "clang-ompss2";
   inherit (source) src version;
 
@@ -61,13 +63,12 @@ in stdenv.mkDerivation {
   };
 
   nativeBuildInputs = [
-    bash
     cmake
     elfutils
-    llvmPackages_latest.lld
+    llvmPackages.lld
+    perl
     pkg-config
     python3
-    perl
     which
     zlib
   ];
@@ -98,8 +99,13 @@ in stdenv.mkDerivation {
     cd build
     cmakeDir="../llvm"
     cmakeFlagsArray=(
-      "-DLLVM_HOST_TRIPLE=${stdenv.targetPlatform.config}"
+      "-DLLVM_HOST_TRIPLE=${llvmStdenv.targetPlatform.config}"
+    '' + (if "${llvmStdenv.targetPlatform.config}" == "riscv64-unknown-linux-gnu" then ''
+      "-DLLVM_DEFAULT_TARGET_TRIPLE=riscv64-unknown-linux-gnu"
+      "-DLLVM_TARGETS_TO_BUILD=RISCV"
+    '' else ''
       "-DLLVM_TARGETS_TO_BUILD=host"
+    '') + ''
       "-DLLVM_BUILD_LLVM_DYLIB=ON"
       "-DLLVM_LINK_LLVM_DYLIB=ON"
       # Required to run clang-ast-dump and clang-tblgen during build
@@ -108,7 +114,8 @@ in stdenv.mkDerivation {
       "-DCMAKE_CXX_FLAGS_DEBUG=-g -ggnu-pubnames"
       "-DCMAKE_EXE_LINKER_FLAGS_DEBUG=-Wl,--gdb-index"
       "-DLLVM_LIT_ARGS=-sv --xunit-xml-output=xunit.xml"
-      "-DLLVM_ENABLE_PROJECTS=clang;compiler-rt;lld"
+      "-DLLVM_ENABLE_PROJECTS=clang;lld"
+      "-DLLVM_ENABLE_RUNTIMES=compiler-rt"
       "-DLLVM_ENABLE_ASSERTIONS=ON"
       "-DLLVM_INSTALL_TOOLCHAIN_ONLY=ON"
       "-DCMAKE_INSTALL_BINDIR=bin"
diff --git a/pkgs/llvm-ompss2/default.nix b/pkgs/llvm-ompss2/default.nix
index 9a812693..bee0d548 100644
--- a/pkgs/llvm-ompss2/default.nix
+++ b/pkgs/llvm-ompss2/default.nix
@@ -56,7 +56,8 @@ in wrapCCWith {
 
     echo "--gcc-toolchain=${gcc}" >> $out/nix-support/cc-cflags
 
-    wrap clang++  $wrapper $ccPath/clang++
+    wrap ${targetConfig}clang++  $wrapper $ccPath/clang++
+    wrap ${targetConfig}clang    $wrapper $ccPath/clang
 
   '' + optionalString (openmp != null) ''
     echo "export OPENMP_RUNTIME=${ompname}" >> $out/nix-support/cc-wrapper-hook