From 9349acf148080faf29feadbff84d183c16bad681 Mon Sep 17 00:00:00 2001
From: Rudi Grinberg <me@rgrinberg.com>
Date: Sat, 14 Mar 2020 18:32:15 +0100
Subject: [PATCH] Remove wrong validation for switch names

Previously, switch names were validated to be valid context names. This
is wrong as it prevent us from using local switches which are in fact
specified by their path. We remove this unnecessary validation and now
we can use local switches to define contexts.

Signed-off-by: Rudi Grinberg <me@rgrinberg.com>
---
 CHANGES.md             |  6 ++++++
 src/dune/context.ml    |  9 +++------
 src/dune/context.mli   |  2 +-
 src/dune/workspace.ml  | 11 ++++++-----
 src/dune/workspace.mli |  4 +++-
 5 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index 76c4b7468bf..bbf5c568af2 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,9 @@
+Unreleased
+----------
+
+- Allow contexts to be defined with local switches in workspace files (#3265,
+  fix #3264, @rgrinberg)
+
 2.4.0 (06/03/2020)
 ------------------
 
diff --git a/src/dune/context.ml b/src/dune/context.ml
index b20100af556..a293d063740 100644
--- a/src/dune/context.ml
+++ b/src/dune/context.ml
@@ -6,7 +6,7 @@ module Kind = struct
   module Opam = struct
     type t =
       { root : string option
-      ; switch : Context_name.t
+      ; switch : string
       }
   end
 
@@ -18,10 +18,7 @@ module Kind = struct
     | Default -> Dyn.Encoder.string "default"
     | Opam o ->
       Dyn.Encoder.(
-        record
-          [ ("root", option string o.root)
-          ; ("switch", Context_name.to_dyn o.switch)
-          ])
+        record [ ("root", option string o.root); ("switch", string o.switch) ])
 end
 
 module Env_nodes = struct
@@ -643,7 +640,7 @@ let create_for_opam ~root ~env ~env_nodes ~targets ~profile ~switch ~name
       ; ( match root with
         | None -> []
         | Some root -> [ "--root"; root ] )
-      ; [ "--switch"; Context_name.to_string switch; "--sexp" ]
+      ; [ "--switch"; switch; "--sexp" ]
       ; ( if version < (2, 0, 0) then
           []
         else
diff --git a/src/dune/context.mli b/src/dune/context.mli
index fa2c02d6653..9922023f980 100644
--- a/src/dune/context.mli
+++ b/src/dune/context.mli
@@ -26,7 +26,7 @@ module Kind : sig
   module Opam : sig
     type t =
       { root : string option
-      ; switch : Context_name.t
+      ; switch : string
       }
   end
 
diff --git a/src/dune/workspace.ml b/src/dune/workspace.ml
index 4506314976d..5a61458a2f4 100644
--- a/src/dune/workspace.ml
+++ b/src/dune/workspace.ml
@@ -156,7 +156,7 @@ module Context = struct
   module Opam = struct
     type t =
       { base : Common.t
-      ; switch : Context_name.t
+      ; switch : string
       ; root : string option
       ; merlin : bool
       }
@@ -165,26 +165,27 @@ module Context = struct
       let open Dyn.Encoder in
       record
         [ ("base", Common.to_dyn base)
-        ; ("switch", Context_name.to_dyn switch)
+        ; ("switch", string switch)
         ; ("root", option string root)
         ; ("merlin", bool merlin)
         ]
 
     let equal { base; switch; root; merlin } t =
       Common.equal base t.base
-      && Context_name.equal switch t.switch
+      && String.equal switch t.switch
       && Option.equal String.equal root t.root
       && Bool.equal merlin t.merlin
 
     let t ~profile ~x =
-      let+ switch = field "switch" Context_name.decode
+      let+ switch = field "switch" string
       and+ name = field_o "name" Context_name.decode
       and+ root = field_o "root" string
       and+ merlin = field_b "merlin"
       and+ base = Common.t ~profile in
       let default =
         (* TODO this needs proper error handling with locations *)
-        let name = Context_name.to_string switch ^ Common.fdo_suffix base in
+        (* TODO Does this work when the switch is local? *)
+        let name = switch ^ Common.fdo_suffix base in
         Context_name.parse_string_exn (Loc.none, name)
       in
       let name = Option.value ~default name in
diff --git a/src/dune/workspace.mli b/src/dune/workspace.mli
index b6bc12a1bb7..0f4b57ff706 100644
--- a/src/dune/workspace.mli
+++ b/src/dune/workspace.mli
@@ -34,7 +34,9 @@ module Context : sig
   module Opam : sig
     type t =
       { base : Common.t
-      ; switch : Context_name.t
+      ; (** Either a switch name or a path to a local switch. This argument is
+            left opaque as we leave to opam to interpret it. *)
+        switch : string
       ; root : string option
       ; merlin : bool
       }