about summary refs log tree commit diff
path: root/src/libexpr/get-drvs.cc
diff options
context:
space:
mode:
Diffstat (limited to 'src/libexpr/get-drvs.cc')
-rw-r--r--src/libexpr/get-drvs.cc4
1 files changed, 4 insertions, 0 deletions
diff --git a/src/libexpr/get-drvs.cc b/src/libexpr/get-drvs.cc
index 78edbd392d19..b101f2da30d1 100644
--- a/src/libexpr/get-drvs.cc
+++ b/src/libexpr/get-drvs.cc
@@ -45,6 +45,10 @@ MetaInfo DrvInfo::queryMetaInfo(EvalState & state) const
 }
 
 
+/* Cache for already evaluated derivations.  Usually putting ATerms in
+   a STL container is unsafe (they're not scanning for GC roots), but
+   here it doesn't matter; everything in this set is reachable from
+   the stack as well. */
 typedef set<Expr> Exprs;