From 5f67d82896a918aef2c70b6974da1fef26183d22 Mon Sep 17 00:00:00 2001
From: Gabriel Scherer <gabriel.scherer@gmail.com>
Date: Thu, 20 Mar 2014 15:54:10 +0000
Subject: [PATCH] PR#6187: Add a warning when using -plugin-tag(s) without
 myocamlbuild.ml

(Patch by Jacques-Pascal Deplaix)

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14475 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
---
 Changes                          |  2 ++
 ocamlbuild/plugin.ml             |  3 +++
 ocamlbuild/testsuite/internal.ml | 12 +++++++++++-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Changes b/Changes
index ddcfcb86d..068d22f1e 100644
--- a/Changes
+++ b/Changes
@@ -92,6 +92,8 @@ Features wishes:
 - PR#6064: GADT representation for Bigarray.kind + CAML_BA_CHAR runtime kind
 - PR#6071: Add a -noinit option to the toplevel (patch by David Sheets)
 - PR#6166: document -ocamldoc option of ocamlbuild
+- PR#6187: ocamlbuild: warn when using -plugin-tag(s) without myocamlbuild.ml
+	   (patch by Jacques-Pascal Deplaix)
 - PR#6246: allow wilcard _ as for-loop index
 - ocamllex: user-definable refill action
 	    (patch by Frédéric Bour, review by Gabriel Scherer and Luc Maranget)
diff --git a/ocamlbuild/plugin.ml b/ocamlbuild/plugin.ml
index 6e533bb90..eb831e722 100644
--- a/ocamlbuild/plugin.ml
+++ b/ocamlbuild/plugin.ml
@@ -248,6 +248,9 @@ module Make(U:sig end) =
           let rc = sys_command (Command.string_of_command_spec spec) in
           raise (Exit_silently_with_code rc);
         end
+      else if not (sys_file_exists plugin_file) && !Options.plugin_tags <> [] then
+        eprintf "Warning: option -plugin-tag(s) has no effect \
+                 in absence of plugin file %S" plugin_file
       else
         ()
   end
diff --git a/ocamlbuild/testsuite/internal.ml b/ocamlbuild/testsuite/internal.ml
index b25594f88..5d3c28840 100644
--- a/ocamlbuild/testsuite/internal.ml
+++ b/ocamlbuild/testsuite/internal.ml
@@ -239,6 +239,16 @@ let () = test "PluginCompilation3"
          T.f "myocamlbuild.ml" ~content:"print_endline \"foo\";;"]
   (* if the plugin were executed we'd get "foo" in failing_msg *)
   ~failing_msg:""
-  ~targets:("main,byte", []) ();;
+  ~targets:("main.byte", []) ();;
+
+let () = test "PluginTagsWarning"
+  ~description:"check that a warning is raised if -plugin-tags \
+                is used without a plugin file"
+  ~options:[`no_ocamlfind; `plugin_tag "use_str"]
+  ~tree:[T.f "main.ml" ~content:""]
+  ~matching:[_build [M.f "main.cmo"]]
+  ~failing_msg:"Warning: option -plugin-tag(s) has no effect \
+                in absence of plugin file \"myocamlbuild.ml\""
+  ~targets:("main.ml", []) ();;
 
 run ~root:"_test_internal";;