Merge pull request #223664 from SomeoneSerge/cuda-libstdcpp

cudaPackages: use the same libstdc++ as the rest of nixpkgs

pkgs/development/compilers/cudatoolkit/common.nix

···
 , python3 # FIXME: CUDAToolkit 10 may still need python27
 , pulseaudio
 , requireFile
+, stdenv
 , backendStdenv # E.g. gcc11Stdenv, set in extension.nix
 , unixODBC
 , wayland
···
     (placeholder "lib")
     (placeholder "out")
     "${placeholder "out"}/nvvm"
-    # Is it not handled by autoPatchelf automatically?
-    "${lib.getLib backendStdenv.cc.cc}/lib64"
+    # NOTE: use the same libstdc++ as the rest of nixpkgs, not from backendStdenv
+    "${lib.getLib stdenv.cc.cc}/lib64"
     "${placeholder "out"}/jre/lib/amd64/jli"
     "${placeholder "out"}/lib64"
     "${placeholder "out"}/nvvm/lib64"
···
 
       mv pkg/builds/nsight_systems/target-linux-x64 $out/target-linux-x64
       mv pkg/builds/nsight_systems/host-linux-x64 $out/host-linux-x64
+      rm $out/host-linux-x64/libstdc++.so*
     ''}
       ${lib.optionalString (lib.versionAtLeast version "11.8")
       # error: auto-patchelf could not satisfy dependency libtiff.so.5 wanted by /nix/store/.......-cudatoolkit-12.0.1/host-linux-x64/Plugins/imageformats/libqtiff.so

pkgs/development/compilers/cudatoolkit/extension.nix

···
   finalVersion = cudatoolkitVersions.${final.cudaVersion};
 
   # Exposed as cudaPackages.backendStdenv.
-  # We don't call it just "stdenv" to avoid confusion: e.g. this toolchain doesn't contain nvcc.
-  # Instead, it's the back-end toolchain for nvcc to use.
-  # We also use this to link a compatible libstdc++ (backendStdenv.cc.cc.lib)
+  # This is what nvcc uses as a backend,
+  # and it has to be an officially supported one (e.g. gcc11 for cuda11).
+  #
+  # It, however, propagates current stdenv's libstdc++ to avoid "GLIBCXX_* not found errors"
+  # when linked with other C++ libraries.
+  # E.g. for cudaPackages_11_8 we use gcc11 with gcc12's libstdc++
   # Cf. https://github.com/NixOS/nixpkgs/pull/218265 for context
-  backendStdenv = prev.pkgs."${finalVersion.gcc}Stdenv";
+  backendStdenv = final.callPackage ./stdenv.nix {
+    nixpkgsStdenv = prev.pkgs.stdenv;
+    nvccCompatibleStdenv = prev.pkgs.buildPackages."${finalVersion.gcc}Stdenv";
+  };
 
   ### Add classic cudatoolkit package
   cudatoolkit =

pkgs/development/compilers/cudatoolkit/redist/build-cuda-redist-package.nix

···
 { lib
+, stdenv
 , backendStdenv
 , fetchurl
 , autoPatchelfHook
···
   ];
 
   buildInputs = [
-    # autoPatchelfHook will search for a libstdc++ and we're giving it a
-    # "compatible" libstdc++ from the same toolchain that NVCC uses.
-    #
+    # autoPatchelfHook will search for a libstdc++ and we're giving it
+    # one that is compatible with the rest of nixpkgs, even when
+    # nvcc forces us to use an older gcc
     # NB: We don't actually know if this is the right thing to do
-    backendStdenv.cc.cc.lib
+    stdenv.cc.cc.lib
   ];
 
   dontBuild = true;

pkgs/development/compilers/cudatoolkit/stdenv.nix

···
+{ nixpkgsStdenv
+, nvccCompatibleStdenv
+, overrideCC
+, wrapCCWith
+}:
+
+overrideCC nixpkgsStdenv (wrapCCWith {
+  cc = nvccCompatibleStdenv.cc.cc;
+
+  # This option is for clang's libcxx, but we (ab)use it for gcc's libstdc++.
+  # Note that libstdc++ maintains forward-compatibility: if we load a newer
+  # libstdc++ into the process, we can still use libraries built against an
+  # older libstdc++. This, in practice, means that we should use libstdc++ from
+  # the same stdenv that the rest of nixpkgs uses.
+  # We currently do not try to support anything other than gcc and linux.
+  libcxx = nixpkgsStdenv.cc.cc.lib;
+})

pkgs/development/libraries/science/math/cudnn/generic.nix

···
-{
+{ stdenv,
   backendStdenv,
   lib,
   zlib,
···
   maxCudaVersion,
 }:
 assert useCudatoolkitRunfile || (libcublas != null); let
-  inherit (backendStdenv) cc;
   inherit (lib) lists strings trivial versions;
 
   # majorMinorPatch :: String -> String
···
 
     # Used by autoPatchelfHook
     buildInputs = [
-      cc.cc.lib # libstdc++
+      # Note this libstdc++ isn't from the (possibly older) nvcc-compatible
+      # stdenv, but from the (newer) stdenv that the rest of nixpkgs uses
+      stdenv.cc.cc.lib
+
       zlib
       cudatoolkit_root
     ];

pkgs/development/libraries/science/math/faiss/default.nix

···
   builtins.head optLevels
 , faiss # To run demos in the tests
 , runCommand
-}:
+}@inputs:
 
 assert cudaSupport -> nvidia-thrust.cudaSupport;
 
···
   pname = "faiss";
   version = "1.7.2";
 
-  inherit (cudaPackages) cudaFlags;
+  inherit (cudaPackages) cudaFlags backendStdenv;
   inherit (cudaFlags) cudaCapabilities dropDot;
+
+  stdenv = if cudaSupport then backendStdenv else inputs.stdenv;
 
   cudaJoined = symlinkJoin {
     name = "cuda-packages-unsplit";