Track differences between the various ocaml parsers (ocaml-ppx#1783)

Author: gpetiot

tools/diff-parsers/diff_parsers.ml

@@ -0,0 +1,61 @@
+let diff d1 d2 f =
+  let f1 = Filename.concat d1 f in
+  let f2 = Filename.concat d2 f in
+  if Sys.file_exists f2 then
+    Sys.command
+      (Printf.sprintf
+         {|diff -U 5 -L %s %s -L %s %s | sed 's/^@@ .* @@$/@@@@/g'|} f1 f1 f2
+         f2 )
+  else 0
+
+let import version dir f =
+  Sys.command
+    (Printf.sprintf
+       "curl -s -o %s \
+        https://raw.githubusercontent.com/ocaml/ocaml/%s/parsing/%s"
+       (Filename.concat dir f) version f )
+
+let files =
+  [ "ast_helper.ml"
+  ; "ast_helper.mli"
+  ; "ast_mapper.ml"
+  ; "ast_mapper.mli"
+  ; "asttypes.mli"
+  ; "docstrings.ml"
+  ; "docstrings.mli"
+  ; "lexer.mll"
+  ; "parse.ml"
+  ; "parse.mli"
+  ; "parser.mly"
+  ; "parsetree.mli"
+  ; "pprintast.ml"
+  ; "pprintast.mli" ]
+
+let usage () =
+  let exe = Filename.basename Sys.executable_name in
+  Printf.printf "usage:\n\n%s diff DIR1 DIR2\n\n%s import VERSION DIR" exe
+    exe ;
+  exit 1
+
+let () =
+  let l = List.tl (Array.to_list Sys.argv) in
+  match l with
+  | "diff" :: args -> (
+    match args with
+    | [d1; d2] -> (
+        let codes = List.map (diff d1 d2) files in
+        let non_zero =
+          List.filter (function 0 | 1 -> false | _ -> true) codes
+        in
+        match non_zero with [] -> () | first :: _ -> exit first )
+    | _ -> usage () )
+  | "import" :: args -> (
+    match args with
+    | [version; dir] -> (
+        let codes = List.map (import version dir) files in
+        let non_zero =
+          List.filter (function 0 -> false | _ -> true) codes
+        in
+        match non_zero with [] -> () | first :: _ -> exit first )
+    | _ -> usage () )
+  | _ -> usage ()

tools/diff-parsers/dune

@@ -0,0 +1,2 @@
+(executable
+ (name diff_parsers))