jordwalke · Lupus · May 16, 2020 · May 18, 2020 · Sep 5, 2020
diff --git a/compiler/compileArg.ml b/compiler/compileArg.ml
@@ -45,6 +45,7 @@ type t =
   ; fs_output : string option
   ; fs_external : bool
   ; backend : Backend.t option
+  ; backend_flags : string option
   ; keep_unit_names : bool }
 
 (* TODO: Add these utilities into Fp.re *)
@@ -188,6 +189,13 @@ let options =
       & opt (some (enum backend)) None
       & info ["backend"] ~docs:backend_section ~doc)
   in
+  let backend_flags =
+    let doc = "Tweak backend with some specific flags." in
+    Arg.(
+      value
+      & opt (some string) None
+      & info ["backend-flags"] ~docs:backend_section ~doc)
+  in
   let build_t
       common
       set_param
@@ -200,6 +208,7 @@ let options =
       fs_files
       fs_output
       backend
+      backend_flags
       fs_external
       nocmis
       profile
@@ -299,6 +308,7 @@ let options =
       ; fs_files
       ; fs_output
       ; backend
+      ; backend_flags
       ; fs_external
       ; nocmis
       ; output_file
@@ -320,6 +330,7 @@ let options =
       $ fs_files
       $ fs_output
       $ backend
+      $ backend_flags
       $ fs_external
       $ nocmis
       $ profile

diff --git a/compiler/compileArg.mli b/compiler/compileArg.mli
@@ -43,6 +43,7 @@ type t =
   ; fs_output : string option
   ; fs_external : bool
   ; backend : Backend.t option
+  ; backend_flags : string option
   ; keep_unit_names : bool }
 
 val options : t Cmdliner.Term.t

diff --git a/compiler/js_of_ocaml.ml b/compiler/js_of_ocaml.ml
@@ -218,6 +218,7 @@ let f
      ; input_file
      ; output_file
      ; backend
+     ; backend_flags
      ; params
      ; static_env
      ; dynlink
@@ -244,7 +245,7 @@ let f
     | None -> (module Backend_js : Backend.Backend_implementation)
     | Some be -> be
   in
-  Backend.set_backend backend;
+  Backend.set_backend backend backend_flags;
   let use_hashing = common.CommonArg.use_hashing in
   let custom_header = common.CommonArg.custom_header in
   let hide_compilation_summary = common.CommonArg.hide_compilation_summary in

diff --git a/compiler/lib/RehpDriver.re b/compiler/lib/RehpDriver.re
@@ -662,4 +662,8 @@ let backends = [
     Backend_php.compiler_backend_flag(),
     (module Backend_php): (module Backend.Backend_implementation),
   ),
+  (
+    Backend_exec.compiler_backend_flag(),
+    (module Backend_exec): (module Backend.Backend_implementation),
+  ),
 ];
diff --git a/compiler/lib/backend.re b/compiler/lib/backend.re
@@ -153,6 +153,8 @@ module type Rehp_external_implementations = {};
 type runtime_getter = unit => Rehp.expression;
 
 module type Backend_implementation = {
+  /** Initialize backend with flags */
+  let init: option(string) => unit;
   /* module Rehp_external_implementations: Rehp_external_implementations; */
   let custom_module_registration:
     unit =>
@@ -201,7 +203,7 @@ type t = (module Backend_implementation);
 
 let current = ref(None);
 
-let set_backend = (backend: (module Backend_implementation)) => {
+let set_backend = (backend: (module Backend_implementation), opt_flags) => {
   if (current.contents !== None) {
     raise(
       Invalid_argument(
@@ -210,12 +212,18 @@ let set_backend = (backend: (module Backend_implementation)) => {
     );
   };
   module NewBackend = (val backend);
+  NewBackend.init(opt_flags);
   current := Some(backend);
   VarPrinter.add_reserved(StringSet.elements(NewBackend.keyword()));
   VarPrinter.add_reserved(StringSet.elements(NewBackend.provided()));
 };
 
 module Current: Backend_implementation = {
+  let init = opt_flags =>
+    switch (current^) {
+    | None => raise(Invalid_argument("Compiler backend not set"))
+    | Some((module CurrentBackend)) => CurrentBackend.init(opt_flags)
+    };
   let extension = () =>
     switch (current^) {
     | None => raise(Invalid_argument("Compiler backend not set"))

diff --git a/compiler/lib/backend_exec.re b/compiler/lib/backend_exec.re
@@ -0,0 +1,126 @@
+open Stdlib;
+
+type backend_config = {
+  extension: string,
+  keywords: list(string),
+  globals: list(string),
+  supplied_primitives: list((string, string)),
+  allow_simplify_ifdecl: bool,
+};
+
+type rpc_resp =
+  | Config(backend_config)
+  | Output(string);
+
+type rpc_req =
+  | FetchConfig
+  | ProcessTree(Rehp.program);
+
+
+module Subprocess = {
+  type t = {
+    ic: in_channel,
+    oc: out_channel,
+  };
+  let create = cmd => {
+    let (ic, oc) = Unix.open_process(cmd);
+    {ic, oc};
+  };
+  let rpc = (t, req) => {
+    Marshal.to_channel(t.oc, req, [Marshal.No_sharing]);
+    flush(t.oc);
+    let resp : rpc_resp = Marshal.from_channel(t.ic);
+    resp;
+  };
+  let fetch_config = t => {
+    switch (rpc(t, FetchConfig)) {
+    | Config(cfg) => cfg
+    | _ => failwith("unexpected rpc response for FetchConfig")
+    };
+  };
+  let process_tree = (t, tree) => {
+    switch (rpc(t, ProcessTree(tree))) {
+    | Output(str) => str
+    | _ => failwith("unexpected rpc response for ProcessIR")
+    };
+  };
+};
+
+let config = ref(None);
+let subprocess = ref(None);
+
+let get_config = () =>
+  switch (config^) {
+  | Some(cfg) => cfg
+  | None => failwith("init() was not called")
+  };
+
+let get_subprocess = () =>
+  switch (subprocess^) {
+  | Some(sp) => sp
+  | None => failwith("init() was not called")
+  };
+
+let init = flags => {
+  let cmd =
+    switch (flags) {
+    | Some(flags) => flags
+    | None =>
+      failwith(
+        "exec backend expects command line for exec passed as backend-flags",
+      )
+    };
+  let sp = Subprocess.create(cmd);
+  subprocess := Some(sp);
+  let cfg = Subprocess.fetch_config(sp);
+  config := Some(cfg);
+};
+
+let extension = () => get_config().extension;
+let compiler_backend_flag = () => "exec";
+let keyword = () =>
+  List.fold_left(
+    ~f=(acc, x) => StringSet.add(x, acc),
+    ~init=StringSet.empty,
+    get_config().keywords,
+  );
+let is_ident = () => Backend.Helpers.is_ident(keyword());
+let allow_simplify_ifdecl = () => get_config().allow_simplify_ifdecl;
+let provided = () =>
+  List.fold_left(
+    ~f=(acc, x) => StringSet.add(x, acc),
+    ~init=StringSet.empty,
+    get_config().globals,
+  );
+let object_wrapper = ((), obj: Rehp.expression) => obj;
+
+let output =
+    (
+      (),
+      formatter,
+      ~custom_header as _,
+      ~source_map as _=?,
+      ((rehp, _module_export_metadatas), _linkinfos),
+    ) => {
+  let output = Subprocess.process_tree(get_subprocess(), rehp);
+  Pretty_print.start_group(formatter, 0);
+  Pretty_print.string(formatter, output);
+  Pretty_print.end_group(formatter);
+};
+
+let is_prim_supplied = ((), s) =>
+  List.assoc_opt(s, get_config().supplied_primitives);
+
+let custom_module_registration = () =>
+  Some(
+    (_runtime_getter, module_expression, _module_export_metadatas) => {
+      Some(Rehp.ECustomRegister(module_expression))
+    },
+  );
+
+let custom_module_loader = () =>
+  Some((_runtime_getter, name) => Some(Rehp.ECustomRequire(name)));
+
+let module_require = () => Some(name => Some(Rehp.ERequire(name)));
+
+let runtime_module_var = () => Rehp.ERuntime;
diff --git a/compiler/lib/backend_js.re b/compiler/lib/backend_js.re
@@ -2,6 +2,7 @@ open Stdlib;
 module Fp = RehpFp;
 module PP = Pretty_print;
 let times = Debug.find("times");
+let init = _ => ();
 let js_keywords =
   List.fold_left(
     ~f=(acc, x) => StringSet.add(x, acc),

diff --git a/compiler/lib/backend_php.re b/compiler/lib/backend_php.re
@@ -1,6 +1,7 @@
 open Stdlib;
 module PP = Pretty_print;
 let times = Debug.find("times");
+let init = _ => ();
 let php_keywords =
   List.fold_left(
     ~f=(acc, x) => StringSet.add(x, acc),

diff --git a/rehack_tests/output/HashBugReproduce.cma.js/HashBugReproduce.js b/rehack_tests/output/HashBugReproduce.cma.js/HashBugReproduce.js
@@ -19,4 +19,4 @@ module.exports = HashBugReproduce;
 }} */
 module.exports = ((module.exports /*:: : any*/) /*:: :Exports */);
 
-/*____hashes flags: 589793685 bytecode: 4165296732 debug-data: 129913994 primitives: 1058613066*/
+/*____hashes flags: 343193019 bytecode: 4165296732 debug-data: 129913994 primitives: 1058613066*/
diff --git a/rehack_tests/output/HashBugReproduce.cma.js/HashBugReproduce__Consumer.js b/rehack_tests/output/HashBugReproduce.cma.js/HashBugReproduce__Consumer.js
@@ -25,4 +25,4 @@ module.exports = HashBugReproduce_Consumer;
 module.exports = ((module.exports /*:: : any*/) /*:: :Exports */);
 module.exports.getField = module.exports[1];
 
-/*____hashes flags: 589793685 bytecode: 7303456054 debug-data: 1066682977 primitives: 1058613066*/
+/*____hashes flags: 343193019 bytecode: 7303456054 debug-data: 1066682977 primitives: 1058613066*/
diff --git a/rehack_tests/output/HashBugReproduce.cma.js/HashBugReproduce__SeparateCompilationHashTest.js b/rehack_tests/output/HashBugReproduce.cma.js/HashBugReproduce__SeparateCompilationHashTest.js
@@ -1669,4 +1669,4 @@ module.exports.getX29 = module.exports[58];
 module.exports.getX28 = module.exports[59];
 module.exports.helperUtil = module.exports[60];
 
-/*____hashes flags: 589793685 bytecode: 729515992277 debug-data: 54564383401 primitives: 1058613066*/
+/*____hashes flags: 343193019 bytecode: 729515992277 debug-data: 54564383401 primitives: 1058613066*/
diff --git a/rehack_tests/output/HashBugReproduce.cma.php/HashBugReproduce.php b/rehack_tests/output/HashBugReproduce.cma.php/HashBugReproduce.php
@@ -19,4 +19,4 @@ public static function get() : Vector<dynamic> {
   }
 
 }
-/*____hashes flags: 1314811087 bytecode: 4165296732 debug-data: 129913994 primitives: 1058613066*/
+/*____hashes flags: 1068210421 bytecode: 4165296732 debug-data: 129913994 primitives: 1058613066*/
diff --git a/rehack_tests/output/HashBugReproduce.cma.php/HashBugReproduce__Consumer.php b/rehack_tests/output/HashBugReproduce.cma.php/HashBugReproduce__Consumer.php
@@ -23,4 +23,4 @@ public static function getField(dynamic $o): dynamic {
   }
 
 }
-/*____hashes flags: 1314811087 bytecode: 7303456054 debug-data: 1066682977 primitives: 1058613066*/
+/*____hashes flags: 1068210421 bytecode: 7303456054 debug-data: 1066682977 primitives: 1058613066*/
diff --git a/...k_tests/output/HashBugReproduce.cma.php/HashBugReproduce__SeparateCompilationHashTest.php b/...k_tests/output/HashBugReproduce.cma.php/HashBugReproduce__SeparateCompilationHashTest.php
@@ -1608,4 +1608,4 @@ public static function helperUtil(dynamic $b, dynamic $a): dynamic {
   }
 
 }
-/*____hashes flags: 1314811087 bytecode: 729515992277 debug-data: 54564383401 primitives: 1058613066*/
+/*____hashes flags: 1068210421 bytecode: 729515992277 debug-data: 54564383401 primitives: 1058613066*/
diff --git a/rehack_tests/output/SeparateCompilation.cma.js/SeparateCompilation.js b/rehack_tests/output/SeparateCompilation.cma.js/SeparateCompilation.js
@@ -34,4 +34,4 @@ module.exports = SeparateCompilation;
 }} */
 module.exports = ((module.exports /*:: : any*/) /*:: :Exports */);
 
-/*____hashes flags: 589793685 bytecode: 8090041333 debug-data: 389742017 primitives: 1058613066*/
+/*____hashes flags: 343193019 bytecode: 8090041333 debug-data: 389742017 primitives: 1058613066*/
diff --git a/rehack_tests/output/SeparateCompilation.cma.js/SeparateCompilation__.js b/rehack_tests/output/SeparateCompilation.cma.js/SeparateCompilation__.js
@@ -19,4 +19,4 @@ module.exports = SeparateCompilation;
 }} */
 module.exports = ((module.exports /*:: : any*/) /*:: :Exports */);
 
-/*____hashes flags: 589793685 bytecode: 4860596054 debug-data: 129913994 primitives: 1058613066*/
+/*____hashes flags: 343193019 bytecode: 4860596054 debug-data: 129913994 primitives: 1058613066*/
diff --git a/...tests/output/SeparateCompilation.cma.js/SeparateCompilation__SeparateCompilationHelper.js b/...tests/output/SeparateCompilation.cma.js/SeparateCompilation__SeparateCompilationHelper.js
@@ -23,4 +23,4 @@ module.exports = SeparateCompilation_SeparateCompilationHelper;
 module.exports = ((module.exports /*:: : any*/) /*:: :Exports */);
 module.exports.helperVal = module.exports[1];
 
-/*____hashes flags: 589793685 bytecode: 4371475640 debug-data: 1014914789 primitives: 1058613066*/
+/*____hashes flags: 343193019 bytecode: 4371475640 debug-data: 1014914789 primitives: 1058613066*/
diff --git a/rehack_tests/output/SeparateCompilation.cma.php/SeparateCompilation.php b/rehack_tests/output/SeparateCompilation.cma.php/SeparateCompilation.php
@@ -30,4 +30,4 @@ public static function get() : Vector<dynamic> {
   }
 
 }
-/*____hashes flags: 1314811087 bytecode: 8090041333 debug-data: 389742017 primitives: 1058613066*/
+/*____hashes flags: 1068210421 bytecode: 8090041333 debug-data: 389742017 primitives: 1058613066*/
diff --git a/rehack_tests/output/SeparateCompilation.cma.php/SeparateCompilation__.php b/rehack_tests/output/SeparateCompilation.cma.php/SeparateCompilation__.php
@@ -19,4 +19,4 @@ public static function get() : Vector<dynamic> {
   }
 
 }
-/*____hashes flags: 1314811087 bytecode: 4860596054 debug-data: 129913994 primitives: 1058613066*/
+/*____hashes flags: 1068210421 bytecode: 4860596054 debug-data: 129913994 primitives: 1058613066*/
diff --git a/...sts/output/SeparateCompilation.cma.php/SeparateCompilation__SeparateCompilationHelper.php b/...sts/output/SeparateCompilation.cma.php/SeparateCompilation__SeparateCompilationHelper.php
@@ -20,4 +20,4 @@ public static function get() : Vector<dynamic> {
   }
 
 }
-/*____hashes flags: 1314811087 bytecode: 4371475640 debug-data: 1014914789 primitives: 1058613066*/
+/*____hashes flags: 1068210421 bytecode: 4371475640 debug-data: 1014914789 primitives: 1058613066*/
diff --git a/rehack_tests/output/my-lib.cma.js/MyLib.js b/rehack_tests/output/my-lib.cma.js/MyLib.js
@@ -266,4 +266,4 @@ module.exports.get = module.exports[20];
 module.exports.construct = module.exports[22];
 module.exports.genThisShouldBeAsyncTransformed1 = module.exports[23];
 
-/*____hashes flags: 589793685 bytecode: 90287558315 debug-data: 22114087654 primitives: 314532832 rehp-hash-bust:v4*/
+/*____hashes flags: 343193019 bytecode: 90287558315 debug-data: 22114087654 primitives: 314532832 rehp-hash-bust:v4*/
diff --git a/rehack_tests/output/my-lib.cma.js/MyLib__.js b/rehack_tests/output/my-lib.cma.js/MyLib__.js
@@ -19,4 +19,4 @@ module.exports = MyLib;
 }} */
 module.exports = ((module.exports /*:: : any*/) /*:: :Exports */);
 
-/*____hashes flags: 589793685 bytecode: 4874759914 debug-data: 129913994 primitives: 1058613066 rehp-hash-bust:v4*/
+/*____hashes flags: 343193019 bytecode: 4874759914 debug-data: 129913994 primitives: 1058613066 rehp-hash-bust:v4*/
diff --git a/rehack_tests/output/my-lib.cma.js/MyLib__MyLibUtility.js b/rehack_tests/output/my-lib.cma.js/MyLib__MyLibUtility.js
@@ -31,4 +31,4 @@ module.exports = MyLib_MyLibUtility;
 module.exports = ((module.exports /*:: : any*/) /*:: :Exports */);
 module.exports.thisIsAUtilityFunction = module.exports[1];
 
-/*____hashes flags: 589793685 bytecode: 8526643038 debug-data: 1020972089 primitives: 1058613066 rehp-hash-bust:v4*/
+/*____hashes flags: 343193019 bytecode: 8526643038 debug-data: 1020972089 primitives: 1058613066 rehp-hash-bust:v4*/
diff --git a/rehack_tests/output/my-lib.cma.php/MyLib.php b/rehack_tests/output/my-lib.cma.php/MyLib.php
@@ -257,4 +257,4 @@ public static function genThisShouldBeAsyncTransformed1(): Awaitable<dynamic> {
   }
 
 }
-/*____hashes flags: 1314811087 bytecode: 90287558315 debug-data: 22114087654 primitives: 314532832 rehp-hash-bust:v4*/
+/*____hashes flags: 1068210421 bytecode: 90287558315 debug-data: 22114087654 primitives: 314532832 rehp-hash-bust:v4*/
diff --git a/rehack_tests/output/my-lib.cma.php/MyLib__.php b/rehack_tests/output/my-lib.cma.php/MyLib__.php
@@ -19,4 +19,4 @@ public static function get() : Vector<dynamic> {
   }
 
 }
-/*____hashes flags: 1314811087 bytecode: 4874759914 debug-data: 129913994 primitives: 1058613066 rehp-hash-bust:v4*/
+/*____hashes flags: 1068210421 bytecode: 4874759914 debug-data: 129913994 primitives: 1058613066 rehp-hash-bust:v4*/
diff --git a/rehack_tests/output/my-lib.cma.php/MyLib__MyLibUtility.php b/rehack_tests/output/my-lib.cma.php/MyLib__MyLibUtility.php
@@ -27,4 +27,4 @@ public static function thisIsAUtilityFunction(dynamic $param): dynamic {
   }
 
 }
-/*____hashes flags: 1314811087 bytecode: 8526643038 debug-data: 1020972089 primitives: 1058613066 rehp-hash-bust:v4*/
+/*____hashes flags: 1068210421 bytecode: 8526643038 debug-data: 1020972089 primitives: 1058613066 rehp-hash-bust:v4*/
-Original file line number
+Diff line change
@@ Expand Up / @@ -19,4 +19,4 @@ public static function get() : Vector<dynamic> { @@
       }
     }
-    /*____hashes flags: 1314811087 bytecode: 4165296732 debug-data: 129913994 primitives: 1058613066*/
+    /*____hashes flags: 1068210421 bytecode: 4165296732 debug-data: 129913994 primitives: 1058613066*/