executables: Allow any vars in enabled_if for executables

We allow any vars in enabled_if within the library stanza, but only
common_vars within the executable stanza. This commit fixes that and
allows any vars within the executable stanza too. The dune lang version
would need to be bumped for this to work, though.

Signed-off-by: Puneeth Chaganti <punchagan@muse-amuse.in>

Author: punchagan

src/dune_rules/stanzas/executables.ml

@@ -494,8 +494,13 @@ let common =
        fname)
   and+ project_root = Dune_project.get_exn () >>| Dune_project.root
   and+ enabled_if =
-    let allowed_vars = Enabled_if.common_vars ~since:(2, 3) in
     let is_error = Dune_lang.Syntax.Version.Infix.(dune_version >= (2, 6)) in
+    let allowed_common_vars = Enabled_if.common_vars ~since:(2, 3) in
+    let allowed_vars =
+      if Dune_lang.Syntax.Version.Infix.(dune_version >= (3, 25))
+      then Enabled_if.Any
+      else allowed_common_vars
+    in
     Enabled_if.decode ~allowed_vars ~is_error ~since:(Some (2, 3)) ()
   in
   fun names ~multi ->

test/blackbox-tests/test-cases/enabled_if/enabled_if-exec-read.t/run.t

@@ -26,23 +26,12 @@ stanza in older dune lang versions:
 
 Check that the executable is correctly enabled:
 
-  $ make_dune_project 3.24
+  $ make_dune_project 3.25
   $ dune exec ./main.exe
-  File "dune", line 5, characters 16-50:
-  5 |  (enabled_if (= %{read:./config/enable_executable} "true")))
-                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-  Error: Only architecture, system, model, os_type, ccomp_type, profile,
-  ocaml_version, context_name, arch_sixtyfour and env variables are allowed in
-  this 'enabled_if' field. Please upgrade your dune language to at least 3.15.
-  [1]
+  hello
 
 Check that the executable is correctly disabled:
 
   $ dune exec ./disabled.exe
-  File "dune", line 5, characters 16-50:
-  5 |  (enabled_if (= %{read:./config/enable_executable} "true")))
-                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-  Error: Only architecture, system, model, os_type, ccomp_type, profile,
-  ocaml_version, context_name, arch_sixtyfour and env variables are allowed in
-  this 'enabled_if' field. Please upgrade your dune language to at least 3.15.
+  Error: Program './disabled.exe' not found!
   [1]