Use dune-configurator to set C flags (#216)

* Use dune-configurator to set C flags

* Upgrade to dune language version 3.0

This automatically has the `(use_standard_c_and_cxx_flags true)` set.

* add dune-configurator

* dune-configurator in dune-project

* wip

* fmt

---------

Co-authored-by: Antonio Nuno Monteiro <[email protected]>

dune-project

@@ -1,4 +1,4 @@
-(lang dune 2.8)
+(lang dune 3.0)
 
 (using dune_site 0.1)
 
@@ -27,6 +27,7 @@
  (depends
   (ocaml
    (>= "5.1"))
+  dune-configurator
   logs
   (eio-ssl
    (>= 0.3.0))

lib/cflags/cflags.ml

@@ -0,0 +1,28 @@
+module C = Configurator.V1
+
+let directory_exists fsp = Sys.file_exists fsp && Sys.is_directory fsp
+
+let default c : C.Pkg_config.package_conf =
+  if C.ocaml_config_var_exn c "system" = "macosx"
+  then
+    if directory_exists "/usr/local/opt/openssl"
+    then
+      { libs = [ "-L/usr/local/opt/openssl/lib" ]
+      ; cflags = [ "-I/usr/local/opt/openssl/include" ]
+      }
+    else { libs = [ "-L/opt/local/lib" ]; cflags = [ "-I/opt/local/include" ] }
+  else { libs = [ "-lssl"; "-lcrypto" ]; cflags = [] }
+
+let () =
+  C.main ~name:"ssl" (fun c ->
+    let default = default c in
+    let conf =
+      match C.Pkg_config.get c with
+      | None -> default
+      | Some pc ->
+        (match C.Pkg_config.query pc ~package:"openssl" with
+        | Some s -> s
+        | None -> default)
+    in
+    C.Flags.write_sexp "c_library_flags.sexp" conf.libs;
+    C.Flags.write_sexp "c_flags.sexp" conf.cflags)

lib/cflags/dune

@@ -0,0 +1,3 @@
+(executable
+ (name cflags)
+ (libraries dune-configurator))

lib/dune

@@ -21,4 +21,13 @@
   piaf.stream)
  (foreign_stubs
   (language c)
-  (names piaf_bigarray_read piaf_openssl_rand piaf_openssl_sha piaf_fdutils)))
+  (names piaf_bigarray_read piaf_openssl_rand piaf_openssl_sha piaf_fdutils)
+  (flags
+   (:include c_flags.sexp)))
+ (c_library_flags
+  (:include c_library_flags.sexp)))
+
+(rule
+ (targets c_flags.sexp c_library_flags.sexp)
+ (action
+  (run ./cflags/cflags.exe)))

nix/ci/test.nix

@@ -94,6 +94,7 @@ let
         dune
         findlib
         ocamlformat
+        dune-configurator
       ]);
       doCheck = true;
       checkPhase = ''

nix/default.nix

@@ -22,6 +22,8 @@ rec {
       ];
     };
 
+    buildInputs = with ocamlPackages; [ dune-configurator ];
+
     propagatedBuildInputs = with ocamlPackages; [
       logs
       eio-ssl

piaf.opam

@@ -9,8 +9,9 @@ license: "BSD-3-clause"
 homepage: "https://github.com/anmonteiro/piaf"
 bug-reports: "https://github.com/anmonteiro/piaf/issues"
 depends: [
-  "dune" {>= "2.8"}
+  "dune" {>= "3.0"}
   "ocaml" {>= "5.1"}
+  "dune-configurator"
   "logs"
   "eio-ssl" {>= "0.3.0"}
   "magic-mime"
@@ -38,9 +39,11 @@ build: [
     name
     "-j"
     jobs
+    "--promote-install-files=false"
     "@install"
     "@runtest" {with-test}
     "@doc" {with-doc}
   ]
+  ["dune" "install" "-p" name "--create-install-files" name]
 ]
 dev-repo: "git+https://github.com/anmonteiro/piaf.git"