* Maintain the references/referers relation also for derivations.

  This simplifies garbage collection and `nix-store --query
  --requisites' since we no longer need to treat derivations
  specially.

* Better maintaining of the invariants, e.g., setReferences() can only
  be called on a valid/substitutable path.

1 files changed, 9 insertions, 1 deletions

diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index 2d776fb74859..e31333e777b1 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -14,8 +14,16 @@ Hash hashTerm(ATerm t)
 
 Path writeDerivation(const Derivation & drv, const string & name)
 {
+    PathSet references;
+    references.insert(drv.inputSrcs.begin(), drv.inputSrcs.end());
+    for (DerivationInputs::const_iterator i = drv.inputDrvs.begin();
+         i != drv.inputDrvs.end(); ++i)
+        references.insert(i->first);
+    /* Note that the outputs of a derivation are *not* references
+       (that can be missing (of course) and should not necessarily be
+       held during a garbage collection). */
     return addTextToStore(name + drvExtension,
-        atPrint(unparseDerivation(drv)));
+        atPrint(unparseDerivation(drv)), references);
 }