Add variables %{lib-private} and %{libexec-private} (#2901)

Signed-off-by: Andrey Mokhov <[email protected]>

CHANGES.md

@@ -1,3 +1,10 @@
+2.1.0 (unreleased)
+------------------
+
+- Add variables `%{lib-private...}` and `%{libexec-private...}` for finding
+  build paths of files in public and private libraries within the same
+  project. (#2901, @snowleopard)
+
 2.0.0 (unreleased)
 ------------------
 

doc/concepts.rst

@@ -197,13 +197,19 @@ In addition, ``(action ...)`` fields support the following special variables:
   %{bin:program} ...)`` and ``(run program ...)`` behave in the same
   way. ``%{bin:...}`` is only necessary when you are using ``(bash
   ...)`` or ``(system ...)``
-- ``lib:<public-library-name>:<file>`` expands to a path to file ``<file>`` of
-  library ``<public-library-name>``. If ``<public-library-name>`` is available
-  in the current workspace, the local file will be used, otherwise the one from
-  the installed world will be used
+- ``lib:<public-library-name>:<file>`` expands to the installation path of
+  the file ``<file>`` in the library ``<public-library-name>``. If
+  ``<public-library-name>`` is available in the current workspace, the local
+  file will be used, otherwise the one from the installed world will be used.
+- ``lib-private:<library-name>:<file>`` expands to the build path of the file
+  ``<file>`` in the library ``<library-name>``. Both public and private library
+  names are allowed as long as they refer to libraries within the same project.
 - ``libexec:<public-library-name>:<file>`` is the same as ``lib:...`` except
   when cross-compiling, in which case it will expand to the file from the host
-  build context
+  build context.
+- ``libexec-private:<library-name>:<file>`` is the same as ``lib-private:...``
+  except when cross-compiling, in which case it will expand to the file from the
+  host build context.
 - ``lib-available:<library-name>`` expands to ``true`` or ``false`` depending on
   whether the library is available or not. A library is available iff at least
   one of the following condition holds:

src/dune/expander.ml

@@ -371,23 +371,44 @@ let expand_and_record acc ~map_exe ~dep_kind ~expansion_kind
     match resolve_binary ~loc:(Some loc) t ~prog:s with
     | Error fail -> add_fail acc fail
     | Ok path -> Some (path_exp path) )
-  | Macro (Lib, s) -> (
-    let lib_dep, file = parse_lib_file ~loc s in
-    Resolved_forms.add_lib_dep acc lib_dep dep_kind;
+  | Macro (Lib { lib_exec; lib_private }, s) -> (
+    let lib, file = parse_lib_file ~loc s in
+    Resolved_forms.add_lib_dep acc lib dep_kind;
     match
-      Artifacts.Public_libs.file_of_lib t.lib_artifacts ~loc ~lib:lib_dep ~file
-    with
-    | Ok path -> Some (path_exp path)
-    | Error e -> add_fail acc { fail = (fun () -> raise e) } )
-  | Macro (Libexec, s) -> (
-    let lib_dep, file = parse_lib_file ~loc s in
-    Resolved_forms.add_lib_dep acc lib_dep dep_kind;
-    match
-      Artifacts.Public_libs.file_of_lib t.lib_artifacts ~loc ~lib:lib_dep ~file
+      if lib_private then
+        let open Result.O in
+        let* lib = Lib.DB.resolve (Scope.libs t.scope) (loc, lib) in
+        let current_project_name = Scope.name t.scope
+        and referenced_project_name =
+          Lib.info lib |> Lib_info.status |> Lib_info.Status.project_name
+        in
+        if
+          Option.equal Dune_project.Name.equal (Some current_project_name)
+            referenced_project_name
+        then
+          Ok (Path.relative (Lib_info.src_dir (Lib.info lib)) file)
+        else
+          Error
+            (User_error.E
+               (User_error.make ~loc
+                  [ Pp.textf
+                      "The variable \"lib-private\" can only refer to \
+                       libraries within the same project. The current \
+                       project's name is %S, but the reference is to %s."
+                      (Dune_project.Name.to_string_hum current_project_name)
+                      ( match referenced_project_name with
+                      | Some name ->
+                        "\"" ^ Dune_project.Name.to_string_hum name ^ "\""
+                      | None -> "an external library" )
+                  ]))
+      else
+        Artifacts.Public_libs.file_of_lib t.lib_artifacts ~loc ~lib ~file
     with
-    | Error e -> add_fail acc { fail = (fun () -> raise e) }
     | Ok path ->
-      if (not Sys.win32) || Filename.extension s = ".exe" then
+      (* TODO: The [exec = true] case is currently not handled correctly and
+         does not match the documentation. *)
+      if (not lib_exec) || (not Sys.win32) || Filename.extension s = ".exe"
+      then
         Some (path_exp path)
       else
         let path_exe = Path.extend_basename path ~suffix:".exe" in
@@ -400,7 +421,25 @@ let expand_and_record acc ~map_exe ~dep_kind ~expansion_kind
               (let+ () = Build.path path in
                path_exp path)
         in
-        add_ddep dep )
+        add_ddep dep
+    | Error e -> (
+      match lib_private with
+      | true -> add_fail acc { fail = (fun () -> raise e) }
+      | false ->
+        if Lib.DB.available (Scope.libs t.scope) lib then
+          let fail () =
+            raise
+              (User_error.raise ~loc
+                 [ Pp.textf
+                     "The library %S is not public. The variable \"lib\" \
+                      expands to the file's installation path which is not \
+                      defined for private libraries."
+                     (Lib_name.to_string lib)
+                 ])
+          in
+          add_fail acc { fail }
+        else
+          add_fail acc { fail = (fun () -> raise e) } ) )
   | Macro (Lib_available, s) ->
     let lib = Lib_name.of_string_exn ~loc:(Some loc) s in
     Resolved_forms.add_lib_dep acc lib Optional;

src/dune/pform.ml

@@ -52,8 +52,10 @@ module Macro = struct
     | Exe
     | Dep
     | Bin
-    | Lib
-    | Libexec
+    | Lib of
+        { lib_exec : bool
+        ; lib_private : bool
+        }
     | Lib_available
     | Version
     | Read
@@ -70,8 +72,11 @@ module Macro = struct
     | Exe -> string "Exe"
     | Dep -> string "Dep"
     | Bin -> string "Bin"
-    | Lib -> string "Lib"
-    | Libexec -> string "Libexec"
+    | Lib { lib_private; lib_exec } ->
+      constr "Lib"
+        [ record
+            [ ("lib_exec", bool lib_exec); ("lib_private", bool lib_private) ]
+        ]
     | Lib_available -> string "Lib_available"
     | Version -> string "Version"
     | Read -> string "Read"
@@ -164,8 +169,14 @@ module Map = struct
     String.Map.of_list_exn
       ( [ ("exe", macro Exe)
         ; ("bin", macro Bin)
-        ; ("lib", macro Lib)
-        ; ("libexec", macro Libexec)
+        ; ("lib", macro (Lib { lib_exec = false; lib_private = false }))
+        ; ("libexec", macro (Lib { lib_exec = true; lib_private = false }))
+        ; ( "lib-private"
+          , since ~version:(2, 1)
+              (Macro.Lib { lib_exec = false; lib_private = true }) )
+        ; ( "libexec-private"
+          , since ~version:(2, 1)
+              (Macro.Lib { lib_exec = true; lib_private = true }) )
         ; ("lib-available", macro Lib_available)
         ; ("version", macro Version)
         ; ("read", macro Read)

src/dune/pform.mli

@@ -26,8 +26,12 @@ module Macro : sig
     | Exe
     | Dep
     | Bin
-    | Lib
-    | Libexec
+    (* All four combinations are allowed and correspond to variables [lib],
+       [libexec], [lib-private], and [libexec-private]. *)
+    | Lib of
+        { lib_exec : bool
+        ; lib_private : bool
+        }
     | Lib_available
     | Version
     | Read

test/blackbox-tests/dune.inc

@@ -1149,6 +1149,14 @@
     test-cases/js_of_ocaml
     (progn (run %{exe:cram.exe} -test run.t) (diff? run.t run.t.corrected))))))
 
+(rule
+ (alias lib)
+ (deps (package dune) (source_tree test-cases/lib))
+ (action
+  (chdir
+   test-cases/lib
+   (progn (run %{exe:cram.exe} -test run.t) (diff? run.t run.t.corrected)))))
+
 (rule
  (alias lib-available)
  (deps (package dune) (source_tree test-cases/lib-available))
@@ -2058,6 +2066,7 @@
   (alias install-with-var)
   (alias installable-dup-private-libs)
   (alias intf-only)
+  (alias lib)
   (alias lib-available)
   (alias lib-errors)
   (alias link-deps)
@@ -2277,6 +2286,7 @@
   (alias install-with-var)
   (alias installable-dup-private-libs)
   (alias intf-only)
+  (alias lib)
   (alias lib-available)
   (alias lib-errors)
   (alias link-deps)