From efc51afc7c8298ecd3b511b8d0faf9ff6d2df22e Mon Sep 17 00:00:00 2001
From: Xavier Leroy <xavier.leroy@college-de-france.fr>
Date: Tue, 27 Sep 2022 12:04:31 +0200
Subject: Revised passing of options to `Parse.preprocessed_file`

Instead of passing a string that encodes the optional source-to-source
transformations to perform, just pass one optional, named argument for
each transformation.  It is clearer and easier to extend this way.
---
 cparser/Parse.ml   | 45 ++++++++++++++++-----------------------------
 cparser/Parse.mli  | 17 ++++++++++++-----
 driver/Frontend.ml | 12 +++++-------
 3 files changed, 33 insertions(+), 41 deletions(-)

diff --git a/cparser/Parse.ml b/cparser/Parse.ml
index a54af0cc..c0419301 100644
--- a/cparser/Parse.ml
+++ b/cparser/Parse.ml
@@ -16,33 +16,16 @@
 
 (* Entry point for the library: parse, elaborate, and transform *)
 
-module CharSet = Set.Make(struct type t = char let compare = compare end)
-
-let transform_program t p =
-  let run_pass pass flag p =
-    if CharSet.mem flag t then begin
-      let p = pass p in
-      Diagnostics.check_errors ();
-      p
-    end else
-      p
-  in
-    p
-    |> run_pass Unblock.program 'b'
-    |> run_pass PackedStructs.program 'p'
-    |> run_pass StructPassing.program 's'
-    |> Rename.program
-
-let parse_transformations s =
-  let t = ref CharSet.empty in
-  let set s = String.iter (fun c -> t := CharSet.add c !t) s in
-  String.iter
-    (function 'b' -> set "b"
-            | 's' -> set "s"
-            | 'p' -> set "bp"
-            |  _  -> ())
-    s;
-  !t
+let transform_program ~unblock ~struct_passing ~packed_structs p =
+  let run_pass pass p =
+    let p' = pass p in Diagnostics.check_errors (); p' in
+  let run_opt_pass pass flag p =
+    if flag then run_pass pass p else p in
+  p
+  |> run_opt_pass Unblock.program (unblock || packed_structs)
+  |> run_opt_pass PackedStructs.program packed_structs
+  |> run_opt_pass StructPassing.program struct_passing
+  |> Rename.program
 
 let read_file sourcefile =
   let ic = open_in_bin sourcefile in
@@ -65,7 +48,10 @@ let parse_string name text =
             Timeout_pr means that we ran for 2^50 steps. *)
       Diagnostics.fatal_error Diagnostics.no_loc "internal error while parsing"
 
-let preprocessed_file transfs name sourcefile =
+let preprocessed_file ?(unblock = false)
+                      ?(struct_passing = false)
+                      ?(packed_structs = false)
+                      name sourcefile =
   Diagnostics.reset();
   let check_errors x =
     Diagnostics.check_errors(); x in
@@ -79,5 +65,6 @@ let preprocessed_file transfs name sourcefile =
   |> Timing.time2 "Parsing" parse_string name
   |> Timing.time "Elaboration" Elab.elab_file
   |> check_errors
-  |> Timing.time2 "Emulations" transform_program (parse_transformations transfs)
+  |> Timing.time "Emulations"
+                (transform_program ~unblock ~struct_passing ~packed_structs)
   |> check_errors
diff --git a/cparser/Parse.mli b/cparser/Parse.mli
index c406d96c..7b33cc5b 100644
--- a/cparser/Parse.mli
+++ b/cparser/Parse.mli
@@ -16,8 +16,15 @@
 
 (* Entry point for the library: parse, elaborate, and transform *)
 
-val preprocessed_file: string -> string -> string -> C.program
-
-(* first arg: desired transformations
-   second arg: source file name before preprocessing
-   third arg: file after preprocessing *)
+val preprocessed_file:
+  ?unblock: bool -> 
+  ?struct_passing: bool ->
+  ?packed_structs: bool ->
+  string -> string -> C.program
+      (** [preprocessed_file filename sourcetext] performs parsing,
+          elaboration, and optional source-to-source transformations.
+          [filename] is the name of the source file, for error messages.
+          [sourcetext] is the text of the source file after preprocessing.
+          The optional arguments indicate which source-to-source
+          transformations to perform.  They default to [false] (don't perform).
+      *)
diff --git a/driver/Frontend.ml b/driver/Frontend.ml
index 5d45306d..5132f730 100644
--- a/driver/Frontend.ml
+++ b/driver/Frontend.ml
@@ -79,14 +79,12 @@ let parse_c_file sourcename ifile =
   Debug.init_compile_unit sourcename;
   Sections.initialize();
   CPragmas.reset();
-  (* Simplification options *)
-  let simplifs =
-    "b" (* blocks: mandatory *)
-  ^ (if !option_fstruct_passing then "s" else "")
-  ^ (if !option_fpacked_structs then "p" else "")
-  in
   (* Parsing and production of a simplified C AST *)
-  let ast = Parse.preprocessed_file simplifs sourcename ifile in
+  let ast = Parse.preprocessed_file
+              ~unblock: true
+              ~struct_passing: !option_fstruct_passing
+              ~packed_structs: !option_fpacked_structs
+              sourcename ifile in
   (* Save C AST if requested *)
   Cprint.print_if ast;
   (* Conversion to Csyntax *)
-- 
cgit