From dc0f7d8f9652ba4fb18096e93fd50bd63ec35ad7 Mon Sep 17 00:00:00 2001
From: Yorick van Pelt <yorick@yorickvanpelt.nl>
Date: Mon, 7 Aug 2023 15:41:21 +0200
Subject: [PATCH] initPlugins: run nix_plugin_entry() on dlopen'd plugins

Only when it exists.
---
 src/libstore/globals.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc
index b9ad8ac18..afb6039f3 100644
--- a/src/libstore/globals.cc
+++ b/src/libstore/globals.cc
@@ -346,6 +346,12 @@ void initPlugins()
                 dlopen(file.c_str(), RTLD_LAZY | RTLD_LOCAL);
             if (!handle)
                 throw Error("could not dynamically open plugin file '%s': %s", file, dlerror());
+
+            /* Older plugins use a statically initialized object to run their code.
+               Newer plugins can also export nix_plugin_entry() */
+            void (*nix_plugin_entry)() = (void (*)())dlsym(handle, "nix_plugin_entry");
+            if (nix_plugin_entry)
+                nix_plugin_entry();
         }
     }