Make sure the "all" alias is defined in directories without dune files

CHANGES.md

@@ -32,6 +32,9 @@
 - Introduce a `strict_package_deps` mode that verifies that dependencies between
   packages in the workspace are specified correctly. (@rgrinberg, #3117)
 
+- Make sure the `@all` alias is defined when no `dune` file is present
+  in a directory (#2946, fix #2927, @diml)
+
 2.2.0 (06/02/2020)
 ------------------
 

src/dune/gen_rules.ml

@@ -164,6 +164,34 @@ let lib_src_dirs ~dir_contents =
 
 (* Stanza *)
 
+let define_all_alias ~dir ~scope ~js_targets =
+  let dyn_deps =
+    let pred =
+      let id =
+        lazy
+          (let open Dyn.Encoder in
+          constr "exclude"
+            (List.map ~f:(fun p -> Path.Build.to_dyn p) js_targets))
+      in
+      List.iter js_targets ~f:(fun js_target ->
+          assert (Path.Build.equal (Path.Build.parent_exn js_target) dir));
+      let f =
+        if Dune_project.explicit_js_mode (Scope.project scope) then
+          fun _ ->
+        true
+        else
+          fun basename ->
+        not
+          (List.exists js_targets ~f:(fun js_target ->
+               String.equal (Path.Build.basename js_target) basename))
+      in
+      Predicate.create ~id ~f
+    in
+    File_selector.create ~dir:(Path.build dir) pred
+    |> Build.paths_matching ~loc:Loc.none
+  in
+  Rules.Produce.Alias.add_deps ~dyn_deps (Alias.all ~dir) Path.Set.empty
+
 let gen_rules sctx dir_contents cctxs
     { Dir_with_dune.src_dir; ctx_dir; data = stanzas; scope; dune_version = _ }
     =
@@ -246,39 +274,17 @@ let gen_rules sctx dir_contents cctxs
         Coq_rules.coqpp_rules ~sctx ~build_dir ~dir:ctx_dir m
         |> Super_context.add_rules ~dir:ctx_dir sctx
       | _ -> ());
-  let dyn_deps =
-    let pred =
-      let id =
-        lazy
-          (let open Dyn.Encoder in
-          constr "exclude"
-            (List.map ~f:(fun p -> Path.Build.to_dyn p) js_targets))
-      in
-      List.iter js_targets ~f:(fun js_target ->
-          assert (Path.Build.equal (Path.Build.parent_exn js_target) ctx_dir));
-      let f =
-        if Dune_project.explicit_js_mode (Scope.project scope) then
-          fun _ ->
-        true
-        else
-          fun basename ->
-        not
-          (List.exists js_targets ~f:(fun js_target ->
-               String.equal (Path.Build.basename js_target) basename))
-      in
-      Predicate.create ~id ~f
-    in
-    File_selector.create ~dir:(Path.build ctx_dir) pred
-    |> Build.paths_matching ~loc:Loc.none
-  in
-  Rules.Produce.Alias.add_deps ~dyn_deps (Alias.all ~dir:ctx_dir) Path.Set.empty;
+  define_all_alias ~dir:ctx_dir ~scope ~js_targets;
   cctxs
 
 let gen_rules sctx dir_contents cctxs ~dir :
     (Loc.t * Compilation_context.t) list =
   with_format sctx ~dir ~f:(fun _ -> Format_rules.gen_rules ~dir);
   match Super_context.stanzas_in sctx ~dir with
-  | None -> []
+  | None ->
+    define_all_alias ~dir ~js_targets:[]
+      ~scope:(Super_context.find_scope_by_dir sctx dir);
+    []
   | Some d -> gen_rules sctx dir_contents cctxs d
 
 let gen_rules ~sctx ~dir components : Build_system.extra_sub_directories_to_keep

test/blackbox-tests/dune.inc

@@ -511,6 +511,16 @@
     (run %{exe:cram.exe} run.t -sanitizer %{bin:sanitizer})
     (diff? run.t run.t.corrected)))))
 
+(rule
+ (alias dune-project-meta-github2927)
+ (deps (package dune) (source_tree test-cases/dune-project-meta/github2927))
+ (action
+  (chdir
+   test-cases/dune-project-meta/github2927
+   (progn
+    (run %{exe:cram.exe} run.t -sanitizer %{bin:sanitizer})
+    (diff? run.t run.t.corrected)))))
+
 (rule
  (alias dune-project-no-opam)
  (deps (package dune) (source_tree test-cases/dune-project-no-opam))
@@ -2698,6 +2708,7 @@
   (alias dune-ppx-driver-system)
   (alias dune-project-edition)
   (alias dune-project-meta)
+  (alias dune-project-meta-github2927)
   (alias dune-project-no-opam)
   (alias dune_memory-and-the-universe)
   (alias dup-fields)
@@ -2953,6 +2964,7 @@
   (alias dune-package)
   (alias dune-project-edition)
   (alias dune-project-meta)
+  (alias dune-project-meta-github2927)
   (alias dune-project-no-opam)
   (alias dune_memory-and-the-universe)
   (alias dup-fields)

test/blackbox-tests/test-cases/byte-code-only/run.t

@@ -1,4 +1,10 @@
   $ env ORIG_PATH="$PATH" PATH="$PWD/ocaml-bin:$PATH" dune build @all --display short
+      ocamldep bin/.toto.eobjs/toto.ml.d
+        ocamlc bin/.toto.eobjs/byte/dune__exe__Toto.{cmi,cmo,cmt}
+        ocamlc bin/toto.bc
+      ocamldep src/.foo.objs/foo.ml.d
+        ocamlc src/.foo.objs/byte/foo.{cmi,cmo,cmt}
+        ocamlc src/foo.cma
         ocamlc build-info/.build_info.objs/byte/build_info.{cmi,cmo,cmt}
         ocamlc build-info/build_info.cma
       ocamldep build-info/.build_info.objs/build_info_data.mli.d
@@ -7,14 +13,8 @@
       ocamldep bin-with-build-info/.print_version.eobjs/print_version.ml.d
         ocamlc bin-with-build-info/.print_version.eobjs/byte/dune__exe__Print_version.{cmi,cmo,cmt}
         ocamlc bin-with-build-info/print_version.exe
-      ocamldep bin/.toto.eobjs/toto.ml.d
-        ocamlc bin/.toto.eobjs/byte/dune__exe__Toto.{cmi,cmo,cmt}
-        ocamlc bin/toto.bc
-      ocamldep src/.foo.objs/foo.ml.d
-        ocamlc src/.foo.objs/byte/foo.{cmi,cmo,cmt}
-        ocamlc src/foo.cma
-        ocamlc bin-with-build-info/print_version.bc
         ocamlc bin/toto.exe
+        ocamlc bin-with-build-info/print_version.bc
 
   $ _build/default/bin-with-build-info/print_version.exe
   <version missing>

test/blackbox-tests/test-cases/dune-project-meta/github2927/run.t

@@ -0,0 +1,16 @@
+Generation of opam files is attached to @all
+--------------------------------------------
+Reproduction case for #2927
+
+  $ mkdir attached-to-all
+  $ cat >attached-to-all/dune-project <<EOF
+  > (lang dune 2.0)
+  > (generate_opam_files true)
+  > (package (name foo))
+  > EOF
+
+  $ cd attached-to-all && dune build
+
+  $ cat attached-to-all/foo.opam
+  cat: attached-to-all/foo.opam: No such file or directory
+  [1]