unikernel/duniverse/dune_/test/blackbox-tests/test-cases/ppx/ppx-runtime-dependencies.t/gen_c.ml

@@ -0,0 +1,10 @@
+open Ppxlib
+
+let rules =
+  let extension =
+    Extension.declare "c" Expression Ast_pattern.__ (fun ~loc ~path:_ _ ->
+        Ast_builder.Default.eint ~loc [%get_c])
+  in
+  [ Context_free.Rule.extension extension ]
+
+let () = Ppxlib.Driver.register_transformation "rules" ~rules

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/ppx/ppx-runtime-dependencies.t/ppx.ml

@@ -0,0 +1,10 @@
+open Ppxlib
+
+let rules =
+  let extension =
+    Extension.declare "get_c" Expression Ast_pattern.__ (fun ~loc ~path:_ _ ->
+        Ast_builder.Default.evar ~loc "C.c")
+  in
+  [ Context_free.Rule.extension extension ]
+
+let () = Ppxlib.Driver.register_transformation "rules" ~rules

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/ppx/ppx-runtime-dependencies.t/run.t

@@ -0,0 +1,168 @@
+----------------------------------------------------------------------------------
+Handling ppx_runtime_libraries dependencies correctly
+
+  $ cat >sdune <<'EOF'
+  > #!/usr/bin/env bash
+  > DUNE_SANDBOX=symlink dune "$@"
+  > EOF
+  $ chmod +x sdune
+
+----------------------------------------------------------------------------------
+* Incorrect cycle detection due to ppx_runtime_libraries (TODO: fix this bug!)
+
+  $ cat >dune-project <<EOF
+  > (lang dune 2.0)
+  > (implicit_transitive_deps true)
+  > EOF
+
+  $ cat >dune <<EOF
+  > (library
+  >  (name a)
+  >  (modules a)
+  >  (libraries b))
+  > (library
+  >  (name b)
+  >  (kind ppx_rewriter)
+  >  (modules b ppx)
+  >  (libraries ppxlib)
+  >  (ppx_runtime_libraries c))
+  > (library
+  >  (name c)
+  >  (modules c)
+  >  (libraries a))
+  > EOF
+
+  $ mkdir -p bin
+  $ cat >bin/dune <<EOF
+  > (executable
+  >  (name main)
+  >  (preprocess (pps b))
+  >  (modules main))
+  > EOF
+
+  $ cat >a.ml <<EOF
+  > include B
+  > let a = B.b - 1
+  > EOF
+
+  $ cat >b.ml <<EOF
+  > let b = 2
+  > EOF
+
+  $ cat >c.ml <<EOF
+  > include A
+  > let c = A.a + 2
+  > EOF
+
+  $ cat >bin/main.ml <<EOF
+  > let () = Printf.printf "Should print 3: %d\n" [%get_c]
+  > EOF
+
+  $ ./sdune exec bin/main.exe
+  Error: Dependency cycle between:
+     library "b" in _build/default
+  -> library "a" in _build/default
+  -> library "c" in _build/default
+  -> library "b" in _build/default
+  [1]
+
+----------------------------------------------------------------------------------
+* Ppx rewriters (and their ppx_runtime_libraries information) are collected recursively
+In this case we have the following dependency graph:
+main --[pps]--> b ---> ppx --[runtime]--> c ---> a
+Note the direct dependency b ---> ppx that separates pps and runtime dependencies.
+
+  $ cat >dune <<EOF
+  > (library
+  >  (name a)
+  >  (modules a))
+  > (library
+  >  (name b)
+  >  (modules b)
+  >  (libraries ppx))
+  > (library
+  >  (name ppx)
+  >  (modules ppx)
+  >  (kind ppx_rewriter)
+  >  (libraries ppxlib)
+  >  (ppx_runtime_libraries c))
+  > (library
+  >  (name c)
+  >  (modules c)
+  >  (libraries a))
+  > EOF
+
+  $ cat >a.ml <<EOF
+  > let a = 2 - 1
+  > EOF
+
+  $ ./sdune exec bin/main.exe
+  Should print 3: 3
+
+----------------------------------------------------------------------------------
+* Since Dune 2.2, it is not allowed to have a pps dependency on a library that has
+not been marked with (kind ppx_rewriter).
+
+  $ cat >dune-project <<EOF
+  > (lang dune 2.2)
+  > (implicit_transitive_deps true)
+  > EOF
+
+  $ ./sdune exec bin/main.exe
+  File "bin/dune", line 3, characters 18-19:
+  3 |  (preprocess (pps b))
+                        ^
+  Error: Ppx dependency on a non-ppx library "b". If "b" is in fact a ppx
+  rewriter library, it should have (kind ppx_rewriter) in its dune file.
+  -> required by _build/default/bin/.main.eobjs/native/dune__exe__Main.cmx
+  -> required by _build/default/bin/main.exe
+  [1]
+
+----------------------------------------------------------------------------------
+* Dependency cycle between ppx rewriters created via [ppx_runtime_libraries]
+In this case we have the following dependency graph:
+gen_c --[pps]--> ppx --[runtime]--> c --[pps]--> gen_c
+Note that pps dependencies are separated by a runtime dependency.
+
+  $ cat >dune <<EOF
+  > (library
+  >  (name gen_c)
+  >  (modules gen_c)
+  >  (kind ppx_rewriter)
+  >  (libraries ppxlib)
+  >  (preprocess (pps ppx)))
+  > (library
+  >  (name ppx)
+  >  (modules ppx)
+  >  (kind ppx_rewriter)
+  >  (libraries ppxlib)
+  >  (ppx_runtime_libraries c))
+  > (library
+  >  (name c)
+  >  (modules c)
+  >  (libraries ppxlib)
+  >  (preprocess (pps gen_c)))
+  > EOF
+
+  $ cat >c.ml <<EOF
+  > let c = [%c]
+  > EOF
+
+  $ cat >bin/dune <<EOF
+  > (executable
+  >  (name main)
+  >  (libraries c)
+  >  (modules main))
+  > EOF
+
+  $ cat >bin/main.ml <<EOF
+  > let () = Printf.printf "Should be impossible: %d\n" C.c
+  > EOF
+
+  $ ./sdune exec bin/main.exe
+  Error: Dependency cycle between:
+     library "c" in _build/default
+  -> library "ppx" in _build/default
+  -> library "gen_c" in _build/default
+  -> library "c" in _build/default
+  [1]