Merge pull request #467 from ocaml/import-configurator

Import configurator

src/configurator/configurator.mli

@@ -0,0 +1,97 @@
+type t
+
+val create
+  :  ?dest_dir:string
+  -> ?ocamlc:string
+  -> ?log:(string -> unit)
+  -> string (** name, such as library name *)
+  -> t
+
+(** Return the value associated to a variable in the output of [ocamlc -config] *)
+val ocaml_config_var     : t -> string -> string option
+val ocaml_config_var_exn : t -> string -> string
+
+(** [c_test t ?c_flags ?link_flags c_code] try to compile and link the C code given in
+    [c_code]. Return whether compilation was successful. *)
+val c_test
+  :  t
+  -> ?c_flags:   string list (** default: [] *)
+  -> ?link_flags:string list (** default: [] *)
+  -> string
+  -> bool
+
+module C_define : sig
+  module Type : sig
+    type t =
+      | Switch (** defined/undefined *)
+      | Int
+      | String
+  end
+
+  module Value : sig
+    type t =
+      | Switch of bool
+      | Int    of int
+      | String of string
+  end
+
+  (** Import some #define from the given header files. For instance:
+
+      {[
+        # C.C_define.import c ~includes:"caml/config.h" ["ARCH_SIXTYFOUR", Switch];;
+        - (string * Configurator.C_define.Value.t) list = ["ARCH_SIXTYFOUR", Switch true]
+      ]}
+  *)
+  val import
+    :  t
+    -> ?c_flags:   string list
+    -> ?link_flags:string list
+    -> includes:   string list
+    -> (string * Type.t ) list
+    -> (string * Value.t) list
+
+  (** Generate a C header file containing the following #define. [protection_var] is used
+      to enclose the file with:
+
+      {[
+        #ifndef BLAH
+        #define BLAH
+        ...
+        #endif
+      ]}
+
+      If not specified, it is inferred from the name given to [create] and the
+      filename. *)
+  val gen_header_file
+    :  t
+    -> fname:string
+    -> ?protection_var:string
+    -> (string * Value.t) list -> unit
+end
+
+module Pkg_config : sig
+  type configurator = t
+  type t
+
+  (** Returns [None] if pkg-config is not installed *)
+  val get : configurator -> t option
+
+  type package_conf =
+    { libs   : string list
+    ; cflags : string list
+    }
+
+  (** Returns [None] if [package] is not available *)
+  val query : t -> package:string -> package_conf option
+end with type configurator := t
+
+(** Typical entry point for configurator programs *)
+val main
+  :  ?args:(Arg.key * Arg.spec * Arg.doc) list
+  -> name:string
+  -> (t -> unit)
+  -> unit
+
+(** Abort execution. If raised from within [main], the argument of [die] is printed as
+    [Error: <message>]. *)
+val die : ('a, unit, string, 'b) format4 -> 'a

src/configurator/jbuild

@@ -0,0 +1,7 @@
+(library
+ ((name configurator)
+  (flags (:standard -safe-string))
+  (libraries (jbuilder stdune))
+  (preprocess no_preprocessing)))
+
+(jbuild_version 1)

src/io.ml

@@ -37,15 +37,24 @@ let input_lines =
   in
   fun ic -> loop ic []
 
-let read_file fn =
-  with_file_in fn ~f:(fun ic ->
-    let len = in_channel_length ic in
-    really_input_string ic len)
+let read_all ic =
+  let len = in_channel_length ic in
+  really_input_string ic len
+
+let read_file fn = with_file_in fn ~f:read_all
 
 let lines_of_file fn = with_file_in fn ~f:input_lines ~binary:false
 
 let write_file fn data = with_file_out fn ~f:(fun oc -> output_string oc data)
 
+let write_lines fn lines =
+  with_file_out fn ~f:(fun oc ->
+    List.iter ~f:(fun line ->
+      output_string oc line;
+      output_string oc "\n"
+    ) lines
+  )
+
 let copy_channels =
   let buf_len = 65536 in
   let buf = Bytes.create buf_len in

src/io.mli

@@ -20,6 +20,10 @@ val write_file : string -> string -> unit
 
 val compare_files : string -> string -> Ordering.t
 
+val write_lines : string -> string list -> unit
+
 val copy_channels : in_channel -> out_channel -> unit
 
 val copy_file : src:string -> dst:string -> unit
+
+val read_all : in_channel -> string

src/ocamlc_config.ml

@@ -6,16 +6,16 @@ type t =
   ; ocamlc: Path.t
   }
 
+let bindings t = t.bindings
+
 let ocamlc_config_cmd ocamlc =
   sprintf "%s -config" (Path.to_string ocamlc)
 
 let sexp_of_t t =
   let open Sexp.To_sexp in
   string_map Sexp.atom_or_quoted_string t.bindings
 
-let read ~ocamlc ~env =
-  Process.run_capture_lines ~env Strict (Path.to_string ocamlc) ["-config"]
-  >>| fun lines ->
+let make ~ocamlc ~ocamlc_config_output:lines =
   List.map lines ~f:(fun line ->
     match String.index line ':' with
     | Some i ->
@@ -31,6 +31,11 @@ let read ~ocamlc ~env =
     die "variable %S present twice in the output of `%s`"
       key (ocamlc_config_cmd ocamlc)
 
+let read ~ocamlc ~env =
+  Process.run_capture_lines ~env Strict (Path.to_string ocamlc) ["-config"]
+  >>| fun lines ->
+  make ~ocamlc ~ocamlc_config_output:lines
+
 let ocaml_value t =
   let t = String_map.to_list t.bindings in
   let longest = String.longest_map t ~f:fst in

src/ocamlc_config.mli

@@ -1,8 +1,16 @@
 (** Output of [ocamlc -config] *)
+
+open Import
+
 type t
 
 val sexp_of_t : t -> Sexp.t
 
+val make
+  :  ocamlc:Path.t
+  -> ocamlc_config_output:string list
+  -> t
+
 val read : ocamlc:Path.t -> env:string array -> t Fiber.t
 
 (** Used to pass these settings to jbuild files using the OCaml syntax *)
@@ -17,3 +25,6 @@ val word_size : t -> string option
 val flambda : t -> bool
 val stdlib_dir : t -> Path.t
 val c_compiler_settings : t -> (string * string * string)
+
+(**/**)
+val bindings : t -> string String_map.t

src/stdune/string.ml

@@ -22,6 +22,8 @@ let break s ~pos =
   (sub s ~pos:0 ~len:pos,
    sub s ~pos ~len:(length s - pos))
 
+let is_empty s = length s = 0
+
 let is_prefix s ~prefix =
   let len = length s in
   let prefix_len = length prefix in
@@ -79,6 +81,11 @@ let lsplit2 s ~on =
       (sub s ~pos:0 ~len:i,
        sub s ~pos:(i + 1) ~len:(length s - i - 1))
 
+let lsplit2_exn s ~on =
+  match lsplit2 s ~on with
+  | Some s -> s
+  | None -> invalid_arg "lsplit2_exn"
+
 let rsplit2 s ~on =
   match rindex s on with
   | exception Not_found -> None
@@ -153,3 +160,12 @@ let longest_map l ~f =
     max acc (length (f x)))
 
 let longest l = longest_map l ~f:(fun x -> x)
+
+let exists s ~f =
+  try
+    for i=0 to length s - 1 do
+      if (f s.[i]) then raise_notrace Exit
+    done;
+    false
+  with Exit ->
+    true

src/stdune/string.mli

@@ -4,6 +4,7 @@ val compare : t -> t -> Ordering.t
 
 val break : t -> pos:int -> t * t
 
+val is_empty : t -> bool
 val is_prefix : t -> prefix:t -> bool
 val is_suffix : t -> suffix:t -> bool
 
@@ -22,6 +23,7 @@ val extract_comma_space_separated_words : t -> t list
 val extract_blank_separated_words : t -> t list
 
 val lsplit2 : t -> on:char -> (t * t) option
+val lsplit2_exn : t -> on:char -> t * t
 val rsplit2 : t -> on:char -> (t * t) option
 
 val split : t -> on:char -> t list
@@ -35,3 +37,5 @@ val escape_double_quote : t -> t
 (** Return the length of the longest string in the list *)
 val longest : string list -> int
 val longest_map : 'a list -> f:('a -> string) -> int
+
+val exists : t -> f:(char -> bool) -> bool

test/unit-tests/configurator/jbuild

@@ -0,0 +1,10 @@
+(jbuild_version 1)
+
+(executable
+ ((name test_configurator)
+  (libraries (configurator))))
+
+(alias
+ ((name runtest)
+  (deps (./test_configurator.exe))
+  (action (run ${<}))))

test/unit-tests/configurator/test_configurator.ml

@@ -0,0 +1 @@
+Configurator.main ~name:"test_configurator" (fun _ -> ())