Add plugins to make Nix more extensible.

All plugins in plugin-files will be dlopened, allowing them to
statically construct instances of the various Register* types Nix
supports.

2 files changed, 19 insertions, 0 deletions

diff --git a/tests/plugins/local.mk b/tests/plugins/local.mk
new file mode 100644
index 000000000000..a5f19b087c82
--- /dev/null
+++ b/tests/plugins/local.mk
@@ -0,0 +1,9 @@
+libraries += plugintest
+
+plugintest_DIR := $(d)
+
+plugintest_SOURCES := $(d)/plugintest.cc
+
+plugintest_ALLOW_UNDEFINED := 1
+
+plugintest_EXCLUDE_FROM_LIBRARY_LIST := 1
diff --git a/tests/plugins/plugintest.cc b/tests/plugins/plugintest.cc
new file mode 100644
index 000000000000..f788c4814322
--- /dev/null
+++ b/tests/plugins/plugintest.cc
@@ -0,0 +1,10 @@
+#include "primops.hh"
+
+using namespace nix;
+
+static void prim_constNull (EvalState & state, const Pos & pos, Value ** args, Value & v)
+{
+    mkNull(v);
+}
+
+static RegisterPrimOp r("constNull", 1, prim_constNull);