Merge changes from topic "libutil-split" into main

* changes:
  util.hh: Delete remaining file and clean up headers
  util.hh: Move nativeSystem to local-derivation-goal.cc
  util.hh: Move stuff to types.hh
  util.cc: Delete remaining file
  util.{hh,cc}: Move ignoreException to error.{hh,cc}
  util.{hh,cc}: Split out namespaces.{hh,cc}
  util.{hh,cc}: Split out users.{hh,cc}
  util.{hh,cc}: Split out strings.{hh,cc}
  util.{hh,cc}: Split out unix-domain-socket.{hh,cc}
  util.{hh,cc}: Split out child.{hh,cc}
  util.{hh,cc}: Split out current-process.{hh,cc}
  util.{hh,cc}: Split out processes.{hh,cc}
  util.{hh,cc}: Split out file-descriptor.{hh,cc}
  util.{hh,cc}: Split out file-system.{hh,cc}
  util.{hh,cc}: Split out terminal.{hh,cc}
  util.{hh,cc}: Split out environment-variables.{hh,cc}

1 files changed, 20 insertions, 0 deletions

diff --git a/src/libutil/namespaces.hh b/src/libutil/namespaces.hh
index 0b7eeb66c..3a920e665 100644
--- a/src/libutil/namespaces.hh
+++ b/src/libutil/namespaces.hh
@@ -3,6 +3,26 @@
 
 namespace nix {
 
+/**
+ * Save the current mount namespace. Ignored if called more than
+ * once.
+ */
+void saveMountNamespace();
+
+/**
+ * Restore the mount namespace saved by saveMountNamespace(). Ignored
+ * if saveMountNamespace() was never called.
+ */
+void restoreMountNamespace();
+
+/**
+ * Cause this thread to not share any FS attributes with the main
+ * thread, because this causes setns() in restoreMountNamespace() to
+ * fail.
+ */
+void unshareFilesystem();
+
+
 #if __linux__
 
 bool userNamespacesSupported();