From 5ee8a5b5c07ce40e3f5e0a089476a8d16518defe Mon Sep 17 00:00:00 2001
From: ivg <ivg@ieee.org>
Date: Wed, 17 Aug 2022 16:05:33 -0400
Subject: [PATCH] adds support for loading plugins in toplevels

Uses virtual libraries to select the proper dynamic linker
facility. To load in the toplevel add `dune-site.toplevel` library as
the dependency to your toplevel.

Signed-off-by: ivg <ivg@ieee.org>
---
 otherlibs/site/src/plugins/dune                      | 2 +-
 otherlibs/site/src/plugins/linker/dune               | 5 +++++
 otherlibs/site/src/plugins/linker/dynlink/dune       | 5 +++++
 otherlibs/site/src/plugins/linker/dynlink/linker.ml  | 1 +
 otherlibs/site/src/plugins/linker/linker.mli         | 1 +
 otherlibs/site/src/plugins/linker/toplevel/dune      | 6 ++++++
 otherlibs/site/src/plugins/linker/toplevel/linker.ml | 1 +
 otherlibs/site/src/plugins/plugins.ml                | 2 +-
 8 files changed, 21 insertions(+), 2 deletions(-)
 create mode 100644 otherlibs/site/src/plugins/linker/dune
 create mode 100644 otherlibs/site/src/plugins/linker/dynlink/dune
 create mode 100644 otherlibs/site/src/plugins/linker/dynlink/linker.ml
 create mode 100644 otherlibs/site/src/plugins/linker/linker.mli
 create mode 100644 otherlibs/site/src/plugins/linker/toplevel/dune
 create mode 100644 otherlibs/site/src/plugins/linker/toplevel/linker.ml

diff --git a/otherlibs/site/src/plugins/dune b/otherlibs/site/src/plugins/dune
index 378af3bb8750..cbaf5cd3efac 100644
--- a/otherlibs/site/src/plugins/dune
+++ b/otherlibs/site/src/plugins/dune
@@ -6,6 +6,6 @@
   (dune_site
    (plugins)
    (data_module dune_site_plugins_data)))
- (libraries dune-site dune-private-libs.meta_parser dynlink)
+ (libraries dune-site dune-private-libs.meta_parser linker)
  (instrumentation
   (backend bisect_ppx)))
diff --git a/otherlibs/site/src/plugins/linker/dune b/otherlibs/site/src/plugins/linker/dune
new file mode 100644
index 000000000000..ce852a1e35b5
--- /dev/null
+++ b/otherlibs/site/src/plugins/linker/dune
@@ -0,0 +1,5 @@
+(library
+ (name linker)
+ (public_name dune-site.linker)
+ (virtual_modules linker)
+ (default_implementation dune-site.dynlink))
diff --git a/otherlibs/site/src/plugins/linker/dynlink/dune b/otherlibs/site/src/plugins/linker/dynlink/dune
new file mode 100644
index 000000000000..851802c02d98
--- /dev/null
+++ b/otherlibs/site/src/plugins/linker/dynlink/dune
@@ -0,0 +1,5 @@
+(library
+ (name dune_site_dynlink_linker)
+ (public_name dune-site.dynlink)
+ (implements dune-site.linker)
+ (libraries dynlink))
diff --git a/otherlibs/site/src/plugins/linker/dynlink/linker.ml b/otherlibs/site/src/plugins/linker/dynlink/linker.ml
new file mode 100644
index 000000000000..73bf7a03a50f
--- /dev/null
+++ b/otherlibs/site/src/plugins/linker/dynlink/linker.ml
@@ -0,0 +1 @@
+let load = Dynlink.loadfile
diff --git a/otherlibs/site/src/plugins/linker/linker.mli b/otherlibs/site/src/plugins/linker/linker.mli
new file mode 100644
index 000000000000..63fbb5a31860
--- /dev/null
+++ b/otherlibs/site/src/plugins/linker/linker.mli
@@ -0,0 +1 @@
+val load : string -> unit
diff --git a/otherlibs/site/src/plugins/linker/toplevel/dune b/otherlibs/site/src/plugins/linker/toplevel/dune
new file mode 100644
index 000000000000..c56cd49f8249
--- /dev/null
+++ b/otherlibs/site/src/plugins/linker/toplevel/dune
@@ -0,0 +1,6 @@
+(library
+ (name dune_site_toplevel_linker)
+ (modes byte)
+ (public_name dune-site.toplevel)
+ (implements dune-site.linker)
+ (libraries compiler-libs.toplevel))
diff --git a/otherlibs/site/src/plugins/linker/toplevel/linker.ml b/otherlibs/site/src/plugins/linker/toplevel/linker.ml
new file mode 100644
index 000000000000..563590db4366
--- /dev/null
+++ b/otherlibs/site/src/plugins/linker/toplevel/linker.ml
@@ -0,0 +1 @@
+let load = Topdirs.dir_load Format.err_formatter
diff --git a/otherlibs/site/src/plugins/plugins.ml b/otherlibs/site/src/plugins/plugins.ml
index 581a8b9f803a..7d848890f7bd 100644
--- a/otherlibs/site/src/plugins/plugins.ml
+++ b/otherlibs/site/src/plugins/plugins.ml
@@ -256,7 +256,7 @@ let load_gen ~load_requires dirs name =
     List.iter
       (fun p ->
         let file = Filename.concat directory p in
-        Dynlink.loadfile file)
+        Linker.load file)
       plugins)
 
 let rec load_requires name =