Completely get rid of first-dep

Signed-off-by: Jeremie Dimino <jeremie@dimino.org>

doc/migration.rst

@@ -169,7 +169,6 @@ Jbuild                    Dune
 ======================== ============
 ``${@}``                  ``%{targets}``
 ``${^}``                  ``%{deps}``
-``${<}``                  ``%{first-dep}``
 ``${path:file}``          ``%{dep:file}``
 ``${SCOPE_ROOT}``         ``%{project_root}``
 ``${findlib:..}``         ``%{lib:..}``
@@ -186,8 +185,26 @@ Jbuild                    Dune
 Removed Variables
 -----------------
 
-``${path-no-dep:file}`` has been removed.
+``${path-no-dep:file}`` and ``${<}`` have been removed.
 
+A named dependency should be used instead of ``${<}``. For instance
+the following jbuild file:
+
+.. code:: scheme
+
+          (alias
+           ((name   runtest)
+            (deps   (input))
+            (action (run ./test.exe %{<}))))
+
+should be rewritten to the following dune file:
+
+.. code:: scheme
+
+          (alias
+           (name   runtest)
+           (deps   (:x input))
+           (action (run ./test.exe %{x})))
 
 ``# JBUILDER_GEN`` renamed
 --------------------------

src/jbuild.ml

@@ -1307,7 +1307,7 @@ module Rule = struct
                    [ S.virt_text __POS__ "-q"
                    ; S.virt_text __POS__ "-o"
                    ; S.virt_var __POS__ "targets"
-                   ; S.virt_var __POS__"first-dep-tmp"
+                   ; S.virt_var __POS__"deps"
                    ])))
       ; mode
       ; locks = []
@@ -1328,7 +1328,7 @@ module Rule = struct
            Chdir
              (S.virt_var __POS__ "root",
               Run (S.virt_text __POS__ "ocamlyacc",
-                   [S.virt_var __POS__ "first-dep-tmp"])))
+                   [S.virt_var __POS__ "deps"])))
       ; mode
       ; locks = []
       ; loc

src/pform.ml

@@ -36,24 +36,24 @@ end
 type 'a t =
   | No_info    of 'a
   | Since      of 'a * Syntax.Version.t
-  | Deleted_in of 'a * Syntax.Version.t
+  | Deleted_in of 'a * Syntax.Version.t * string option
   | Renamed_in of Syntax.Version.t * string
 
 module Map = struct
   type nonrec 'a t = 'a t String.Map.t
 
-  let values v                      = No_info (Var.Values v)
-  let renamed_in ~new_name ~version = Renamed_in (version, new_name)
-  let deleted_in ~version kind      = Deleted_in (kind, version)
-  let since ~version v              = Since (v, version)
+  let values v                       = No_info (Var.Values v)
+  let renamed_in ~new_name ~version  = Renamed_in (version, new_name)
+  let deleted_in ~version ?repl kind = Deleted_in (kind, version, repl)
+  let since ~version v               = Since (v, version)
 
   let static_vars =
-    [ "first-dep", since ~version:(1, 0) Var.First_dep
-    ; "targets", since ~version:(1, 0) Var.Targets
+    [ "targets", since ~version:(1, 0) Var.Targets
     ; "deps", since ~version:(1, 0) Var.Deps
     ; "project_root", since ~version:(1, 0) Var.Project_root
 
-    ; "<", renamed_in ~version:(1, 0) ~new_name:"first-dep"
+    ; "<", deleted_in Var.Deps ~version:(1, 0)
+             ~repl:"Use a named dependency instead: (:<name> <dep>)"
     ; "@", renamed_in ~version:(1, 0) ~new_name:"targets"
     ; "^", renamed_in ~version:(1, 0) ~new_name:"deps"
     ; "SCOPE_ROOT", renamed_in ~version:(1, 0) ~new_name:"project_root"
@@ -167,10 +167,10 @@ module Map = struct
             expand t ~syntax_version:in_version
               ~var:(String_with_vars.Var.with_name var ~name:new_name)
         end
-      | Deleted_in (v, in_version) ->
+      | Deleted_in (v, in_version, repl) ->
         if syntax_version < in_version then
           Some v
         else
           Syntax.Error.deleted_in (String_with_vars.Var.loc var)
-            Stanza.syntax syntax_version ~what:(what var))
+            Stanza.syntax syntax_version ~what:(what var) ?repl)
 end

src/pform.mli

@@ -28,7 +28,7 @@ end
 type 'a t =
   | No_info    of 'a
   | Since      of 'a * Syntax.Version.t
-  | Deleted_in of 'a * Syntax.Version.t
+  | Deleted_in of 'a * Syntax.Version.t * string option
   | Renamed_in of Syntax.Version.t * string
 
 module Map : sig

src/syntax.ml

@@ -65,9 +65,12 @@ module Error = struct
     Loc.fail loc "%s was renamed to '%s' in the %s version of %s"
       what to_ (Version.to_string ver) t.desc
 
-  let deleted_in loc t ver ~what =
-    Loc.fail loc "%s was deleted in version %s of %s"
+  let deleted_in loc t ?repl ver ~what =
+    Loc.fail loc "%s was deleted in version %s of %s%s"
       what (Version.to_string ver) t.desc
+      (match repl with
+       | None -> ""
+       | Some s -> ".\n" ^ s)
 end
 
 

src/syntax.mli

@@ -25,7 +25,13 @@ module Error : sig
 
   val renamed_in : Loc.t -> t -> Version.t -> what:string -> to_:string -> _
 
-  val deleted_in : Loc.t -> t -> Version.t -> what:string -> _
+  val deleted_in
+    :  Loc.t
+    -> t
+    -> ?repl:string
+    -> Version.t
+    -> what:string
+    -> _
 end
 
 (** [create ~name ~desc supported_versions] defines a new

test/blackbox-tests/test-cases/syntax-versioning/run.t

@@ -16,3 +16,11 @@
   Error: 'link_executables' was deleted in version 1.0 of the dune language
   [1]
   $ rm -f dune
+
+  $ echo '(alias (name x) (deps x) (action (run %{<})))' > dune
+  $ dune build
+  File "dune", line 1, characters 40-42:
+  Error: %{<} was deleted in version 1.0 of the dune language.
+  Use a named dependency instead: (:<name> <dep>)
+  [1]
+  $ rm -f dune