Added traces for system and command errors. Added handling of #include.

src/ligo/contracts/included.ligo

@@ -0,0 +1 @@
+const foo : int = 144

src/ligo/contracts/includer.ligo

@@ -0,0 +1,3 @@
+#include "included.ligo"
+
+const bar : int = foo

src/ligo/ligo-helpers/trace.ml

@@ -153,6 +153,18 @@ let specific_try handler f =
     ok @@ f ()
   ) with exn -> fail (handler exn)
 
+let sys_try f =
+  let handler = function
+    | Sys_error str -> error "Sys_error" str
+    | exn -> raise exn
+  in
+  specific_try handler f
+
+let sys_command command =
+  sys_try (fun () -> Sys.command command) >>? function
+  | 0 -> ok ()
+  | n -> fail (error "Nonzero return code" (string_of_int n))
+
 let sequence f lst =
   let rec aux acc = function
     | hd :: tl -> (

src/ligo/ligo-parser/ParserMain.ml

@@ -98,21 +98,3 @@ let () =
       let () = close_all () in
       print_error ~offsets EvalOpt.mode error
   | Sys_error msg -> Utils.highlight msg
-
-                                    (*
-(* Temporary: force dune to build AST2.ml *)
-let () =
-  let open AST2 in
-  let _ = s_ast in
-  ()
-
-    (*
-(* Temporary: force dune to build AST2.ml *)
-let () =
-  if false then
-    let _ = Typecheck2.annotate in
-    ()
-  else
-    ()
-     *)
-     *)

src/ligo/ligo.ml

@@ -10,10 +10,20 @@ module Typer = Typer
 module Transpiler = Transpiler
 
 open Ligo_helpers.Trace
+
 let parse_file (source: string) : AST_Raw.t result =
+  let pp_input =
+    let prefix = Filename.(source |> basename |> remove_extension)
+    and suffix = ".pp.ligo"
+    in prefix ^ suffix in
+
+  let cpp_cmd = Printf.sprintf "cpp -traditional-cpp %s -o %s"
+                               source pp_input in
+  let%bind () = sys_command cpp_cmd in
+
   let%bind channel =
     generic_try (simple_error "error opening file") @@
-    (fun () -> open_in source) in
+    (fun () -> open_in pp_input) in
   let lexbuf = Lexing.from_channel channel in
   let module Lexer = Lexer.Make(LexToken) in
   let Lexer.{read ; close} =

src/ligo/test/integration_tests.ml

@@ -76,6 +76,14 @@ let unit_expression () : unit result =
     get_a_unit result in
   ok ()
 
+let include_ () : unit result =
+  let%bind program = type_file "./contracts/includer.ligo" in
+  let%bind result = easy_evaluate_typed "bar" program in
+  let%bind n =
+    trace (simple_error "Include failed") @@
+    AST_Typed.Combinators.get_a_int result in
+  Assert.assert_equal_int 144 n
+
 let record_ez_int names n =
   let open AST_Typed.Combinators in
   ez_e_a_record @@ List.map (fun x -> x, e_a_int n) names
@@ -337,4 +345,5 @@ let main = "Integration (End to End)", [
     test "declarations" declarations ;
     test "quote declaration" quote_declaration ;
     test "quote declarations" quote_declarations ;
+    test "#include directives" include_ ;
   ]