From 3f17a489ef7f745f229a7562bae0053965f35709 Mon Sep 17 00:00:00 2001
From: Rodrigo Arias Mallo <rodrigo.arias@bsc.es>
Date: Tue, 21 Nov 2023 16:58:57 +0100
Subject: [PATCH] Fix clang build adding rpath to libstdc++

The binaries generated during the build process of clang are missing the
RPATH of the libstdc++.so library, which is provided by gcc libs.
Similarly, the clang binary itself also needs the rpath to the
libstdc++.so library path.

Reviewed-by: Aleix Roca Nonell <aleix.rocanonell@bsc.es>
---
 pkgs/llvm-ompss2/clang.nix | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/pkgs/llvm-ompss2/clang.nix b/pkgs/llvm-ompss2/clang.nix
index c517915..6a856af 100644
--- a/pkgs/llvm-ompss2/clang.nix
+++ b/pkgs/llvm-ompss2/clang.nix
@@ -12,6 +12,7 @@
 , zlib
 , nosv
 , pkg-config
+, gcc # needed to set the rpath of libstdc++ for clang-tblgen
 , enableDebug ? false
 , enableNosv ? false
 , useGit ? false
@@ -71,6 +72,7 @@ in stdenv.mkDerivation rec {
     libffi
     pkg-config
     zlib
+    gcc.cc.lib # Required for libstdc++.so.6
   ] ++ lib.optionals enableNosv [
     nosv
   ];
@@ -100,7 +102,7 @@ in stdenv.mkDerivation rec {
       "-DLLVM_BUILD_LLVM_DYLIB=ON"
       "-DLLVM_LINK_LLVM_DYLIB=ON"
       # Required to run clang-ast-dump and clang-tblgen during build
-      "-DCMAKE_BUILD_RPATH=$PWD/lib:${zlib}/lib"
+      "-DCMAKE_BUILD_RPATH=$PWD/lib:${zlib}/lib:${gcc.cc.lib}/lib"
       "-DLLVM_ENABLE_LLD=ON"
       "-DCMAKE_CXX_FLAGS_DEBUG=-g -ggnu-pubnames"
       "-DCMAKE_EXE_LINKER_FLAGS_DEBUG=-Wl,--gdb-index"
@@ -117,7 +119,7 @@ in stdenv.mkDerivation rec {
       # Set the rpath to include external libraries (zlib) both on build and
       # install
       "-DCMAKE_INSTALL_RPATH_USE_LINK_PATH=ON"
-      "-DCMAKE_INSTALL_RPATH=${zlib}/lib"
+      "-DCMAKE_INSTALL_RPATH=${zlib}/lib:${gcc.cc.lib}/lib"
     )
 
   '';