stdenv for windows: auto-link dependency DLLs

For every *.{exe,dll} in $output/bin/ we try to find all (potential)
transitive dependencies and symlink those DLLs into $output/bin
so they are found on invocation.
(DLLs are first searched in the directory of the running exe file.)

The links are relative, so relocating whole /nix/store won't break them.
The hook is activated on cygwin and when cross-compiling to mingw.

1 files changed, 7 insertions, 1 deletions

diff --git a/pkgs/stdenv/generic/default.nix b/pkgs/stdenv/generic/default.nix
index 547541d28246..e01be369f423 100644
--- a/pkgs/stdenv/generic/default.nix
+++ b/pkgs/stdenv/generic/default.nix
@@ -196,7 +196,13 @@ let
           buildInputs = if crossConfig != null then buildInputs' else [];
           propagatedBuildInputs = if crossConfig != null then propagatedBuildInputs else [];
           # Inputs built by the usual native compiler.
-          nativeBuildInputs = nativeBuildInputs ++ (if crossConfig == null then buildInputs' else []);
+          nativeBuildInputs = nativeBuildInputs
+            ++ lib.optionals (crossConfig == null) buildInputs'
+            ++ lib.optional
+                (result.isCygwin
+                  || (crossConfig != null && lib.hasSuffix "mingw32" crossConfig))
+                ../../build-support/setup-hooks/win-dll-link.sh
+            ;
           propagatedNativeBuildInputs = propagatedNativeBuildInputs ++
             (if crossConfig == null then propagatedBuildInputs else []);
         } // ifDarwin {