Merge pull request #1841 from nojb/toplevel_include_path_env_var

Add support for OCAMLTOP_INCLUDE_PATH environment variable

Changes

@@ -213,6 +213,11 @@ Working version
 - GPR#2058: full explanation for unsafe cycles in recursive module definitions
   (Florian Angeletti, review by Gabriel Scherer, suggested by Ivan Gotovchits)
 
+- GPR#1841, MPR#7808: the environment variable OCAMLTOP_INCLUDE_PATH can now
+  specify a list of additional include directories for the ocaml toplevel.
+  (Nicolás Ojeda Bär, request by Daniel Bünzli, review by Daniel Bünzli and
+  Damien Doligez)
+
 ### Code generation and optimizations:
 
 - MPR#7725, GPR#1754: improve AFL instrumentation for objects and lazy values.

bytecomp/dll.ml

@@ -132,32 +132,15 @@ let ld_conf_contents () =
 
 (* Split the CAML_LD_LIBRARY_PATH environment variable and return
    the corresponding list of directories.  *)
-
-let split str sep =
-  let rec split_rec pos =
-    if pos >= String.length str then [] else begin
-      try
-        let newpos = String.index_from str pos sep in
-        String.sub str pos (newpos - pos) ::
-        split_rec (newpos + 1)
-      with Not_found ->
-        [String.sub str pos (String.length str - pos)]
-    end in
-  split_rec 0
-
 let ld_library_path_contents () =
-  let path_separator =
-    match Sys.os_type with
-    | "Unix" | "Cygwin" -> ':'
-    | "Win32" -> ';'
-    | _ -> assert false in
-  try
-    split (Sys.getenv "CAML_LD_LIBRARY_PATH") path_separator
-  with Not_found ->
-    []
+  match Sys.getenv "CAML_LD_LIBRARY_PATH" with
+  | exception Not_found ->
+      []
+  | s ->
+      Misc.split_path_contents s
 
 let split_dll_path path =
-  split path '\000'
+  Misc.split_path_contents ~sep:'\000' path
 
 (* Initialization for separate compilation *)
 

manual/manual/cmds/top.etex

@@ -125,6 +125,11 @@ The following command-line options are recognized by the "ocaml" command.
 \begin{unix}
 The following environment variables are also consulted:
 \begin{options}
+\item["OCAMLTOP_INCLUDE_PATH"] Additional directories to search for compiled
+  object code files (".cmi", ".cmo" and ".cma"). The specified directories are
+  considered from left to right, after the include directories specified on the
+  command line via "-I" have been searched. Available since OCaml 4.08.
+
 \item["OCAMLTOP_UTF_8"] When printing string values, non-ascii bytes
 ($ {} > "\0x7E" $) are printed as decimal escape sequence if "OCAMLTOP_UTF_8" is
 set to false. Otherwise, they are printed unescaped.
@@ -212,7 +217,7 @@ directories:
   \item Directories added with the "#directory" directive.
   \item Directories given on the command line with "-I" options.
   \item The standard library directory.
-\end{enumerate}    
+\end{enumerate}
 
 \item[Environment queries]
   \begin{options}

toplevel/opttopmain.ml

@@ -248,6 +248,14 @@ module Options = Main_args.Make_opttop_options (struct
   let anonymous = file_argument
 end);;
 
+let () =
+  let extra_paths =
+    match Sys.getenv "OCAMLTOP_INCLUDE_PATH" with
+    | exception Not_found -> []
+    | s -> Misc.split_path_contents s
+  in
+  Clflags.include_dirs := List.rev_append extra_paths !Clflags.include_dirs
+
 let main () =
   native_code := true;
   let list = ref Options.list in

toplevel/topmain.ml

@@ -156,6 +156,13 @@ module Options = Main_args.Make_bytetop_options (struct
   let anonymous s = file_argument s
 end);;
 
+let () =
+  let extra_paths =
+    match Sys.getenv "OCAMLTOP_INCLUDE_PATH" with
+    | exception Not_found -> []
+    | s -> Misc.split_path_contents s
+  in
+  Clflags.include_dirs := List.rev_append extra_paths !Clflags.include_dirs
 
 let main () =
   let ppf = Format.err_formatter in

utils/misc.ml

@@ -272,6 +272,15 @@ let expand_directory alt s =
                        (String.sub s 1 (String.length s - 1))
   else s
 
+let path_separator =
+  match Sys.os_type with
+  | "Win32" -> ';'
+  | _ -> ':'
+
+let split_path_contents ?(sep = path_separator) = function
+  | "" -> []
+  | s -> String.split_on_char sep s
+
 (* Hashtable functions *)
 
 let create_hashtable size init =

utils/misc.mli

@@ -163,6 +163,13 @@ val expand_directory: string -> string -> string
         (* [expand_directory alt file] eventually expands a [+] at the
            beginning of file into [alt] (an alternate root directory) *)
 
+val split_path_contents: ?sep:char -> string -> string list
+(* [split_path_contents ?sep s] interprets [s] as the value of a "PATH"-like
+   variable and returns the corresponding list of directories. [s] is split
+   using the platform-specific delimiter, or [~sep] if it is passed.
+
+   Returns the empty list if [s] is empty. *)
+
 val create_hashtable: int -> ('a * 'b) list -> ('a, 'b) Hashtbl.t
         (* Create a hashtable of the given size and fills it with the
            given bindings. *)