1 files changed, 66 insertions, 12 deletions
diff --git a/camlp4/ocaml_src/lib/stdpp.ml b/camlp4/ocaml_src/lib/stdpp.ml
index 0830e6842..d91ee78c0 100644
--- a/camlp4/ocaml_src/lib/stdpp.ml
+++ b/camlp4/ocaml_src/lib/stdpp.ml
@@ -23,23 +23,77 @@ let raise_with_loc loc exc =
 let line_of_loc fname (bp, ep) =
   try
     let ic = open_in_bin fname in
-    let rec loop lin col cnt =
-      if cnt < bp then
-        let (lin, col) =
-          match input_char ic with
-            '\n' -> lin + 1, 0
-          | _ -> lin, col + 1
-        in
-        loop lin col (cnt + 1)
-      else lin, col, col + ep - bp
+    let strm = Stream.of_channel ic in
+    let rec loop fname lin =
+      let rec not_a_line_dir col (strm__ : _ Stream.t) =
+        let cnt = Stream.count strm__ in
+        match Stream.peek strm__ with
+          Some c ->
+            Stream.junk strm__;
+            let s = strm__ in
+            if cnt < bp then
+              if c = '\n' then loop fname (lin + 1)
+              else not_a_line_dir (col + 1) s
+            else let col = col - (cnt - bp) in fname, lin, col, col + ep - bp
+        | _ -> raise Stream.Failure
+      in
+      let rec a_line_dir str n col (strm__ : _ Stream.t) =
+        match Stream.peek strm__ with
+          Some '\n' -> Stream.junk strm__; loop str n
+        | Some _ -> Stream.junk strm__; a_line_dir str n (col + 1) strm__
+        | _ -> raise Stream.Failure
+      in
+      let rec spaces col (strm__ : _ Stream.t) =
+        match Stream.peek strm__ with
+          Some ' ' -> Stream.junk strm__; spaces (col + 1) strm__
+        | _ -> col
+      in
+      let rec check_string str n col (strm__ : _ Stream.t) =
+        match Stream.peek strm__ with
+          Some '\"' ->
+            Stream.junk strm__;
+            let col =
+              try spaces (col + 1) strm__ with
+                Stream.Failure -> raise (Stream.Error "")
+            in
+            a_line_dir str n col strm__
+        | Some c when c <> '\n' ->
+            Stream.junk strm__;
+            check_string (str ^ String.make 1 c) n (col + 1) strm__
+        | _ -> not_a_line_dir col strm__
+      in
+      let check_quote n col (strm__ : _ Stream.t) =
+        match Stream.peek strm__ with
+          Some '\"' -> Stream.junk strm__; check_string "" n (col + 1) strm__
+        | _ -> not_a_line_dir col strm__
+      in
+      let rec check_num n col (strm__ : _ Stream.t) =
+        match Stream.peek strm__ with
+          Some ('0'..'9' as c) ->
+            Stream.junk strm__;
+            check_num (10 * n + Char.code c - Char.code '0') (col + 1) strm__
+        | _ -> let col = spaces col strm__ in check_quote n col strm__
+      in
+      let begin_line (strm__ : _ Stream.t) =
+        match Stream.peek strm__ with
+          Some '#' ->
+            Stream.junk strm__;
+            let col =
+              try spaces 1 strm__ with
+                Stream.Failure -> raise (Stream.Error "")
+            in
+            check_num 0 col strm__
+        | _ -> not_a_line_dir 0 strm__
+      in
+      begin_line strm
     in
     let r =
-      try loop 1 0 0 with
-        End_of_file -> 1, bp, ep
+      try loop fname 1 with
+        Stream.Failure -> fname, 1, bp, ep
     in
     close_in ic; r
   with
-    Sys_error _ -> 1, bp, ep
+    Sys_error _ -> fname, 1, bp, ep
 ;;
 
 let loc_name = ref "loc";;