Merge pull request #275947 from SomeoneSerge/fix/cuda-cc-wrapper

cudaPackages.backendStdenv.cc: gccForLibs

1 files changed, 30 insertions, 1 deletions

diff --git a/pkgs/build-support/cc-wrapper/default.nix b/pkgs/build-support/cc-wrapper/default.nix
index 56075a032971..0b25d70b14a2 100644
--- a/pkgs/build-support/cc-wrapper/default.nix
+++ b/pkgs/build-support/cc-wrapper/default.nix
@@ -110,6 +110,9 @@ let
   gccForLibs_solib = getLib gccForLibs
     + optionalString (targetPlatform != hostPlatform) "/${targetPlatform.config}";
 
+  # Analogously to cc_solib and gccForLibs_solib
+  libcxx_solib = "${lib.getLib libcxx}/lib";
+
   # The following two functions, `isGccArchSupported` and
   # `isGccTuneSupported`, only handle those situations where a flag
   # (`-march` or `-mtune`) is accepted by one compiler but rejected
@@ -261,6 +264,25 @@ stdenv.mkDerivation {
     inherit bintools;
     inherit cc libc libcxx nativeTools nativeLibc nativePrefix isGNU isClang;
 
+    # Expose the C++ standard library we're using. See the comments on "General
+    # libc++ support". This is also relevant when using older gcc than the
+    # stdenv's, as may be required e.g. by CUDAToolkit's nvcc.
+    cxxStdlib =
+      let
+        givenLibcxx = libcxx.isLLVM or false;
+        givenGccForLibs = useGccForLibs && gccForLibs.langCC or false;
+      in
+      if (!givenLibcxx) && givenGccForLibs then
+        { kind = "libstdc++"; package = gccForLibs; solib = gccForLibs_solib; }
+      else if givenLibcxx then
+        { kind = "libc++"; package = libcxx;  solib = libcxx_solib;}
+      else
+      # We're probably using the `libstdc++` that came with our `gcc`.
+      # TODO: this is maybe not always correct?
+      # TODO: what happens when `nativeTools = true`?
+        { kind = "libstdc++"; package = cc; solib = cc_solib; }
+    ;
+
     emacsBufferSetup = pkgs: ''
       ; We should handle propagation here too
       (mapc
@@ -440,6 +462,13 @@ stdenv.mkDerivation {
       echo "-L${gccForLibs}/lib/gcc/${targetPlatform.config}/${gccForLibs.version}" >> $out/nix-support/cc-ldflags
       echo "-L${gccForLibs_solib}/lib" >> $out/nix-support/cc-ldflags
     ''
+    # The above "fix" may be incorrect; gcc.cc.lib doesn't contain a
+    # `target-triple` dir but the correct fix may be to just remove the above?
+    #
+    # For clang it's not necessary (see `--gcc-toolchain` below) and for other
+    # situations adding in the above will bring in lots of other gcc libraries
+    # (i.e. sanitizer libraries, `libatomic`, `libquadmath`) besides just
+    # `libstdc++`; this may actually break clang.
 
     # TODO We would like to connect this to `useGccForLibs`, but we cannot yet
     # because `libcxxStdenv` on linux still needs this. Maybe someday we'll
@@ -564,7 +593,7 @@ stdenv.mkDerivation {
       echo "$ccLDFlags" >> $out/nix-support/cc-ldflags
       echo "$ccCFlags" >> $out/nix-support/cc-cflags
     '' + optionalString (targetPlatform.isDarwin && (libcxx != null) && (cc.isClang or false)) ''
-      echo " -L${lib.getLib libcxx}/lib" >> $out/nix-support/cc-ldflags
+      echo " -L${libcxx_solib}" >> $out/nix-support/cc-ldflags
     ''
 
     ##