Move "how to add a new flag" to HACKING

Author: gretay-js

HACKING.md

@@ -16,6 +16,7 @@ want to modify the Flambda backend.  Jump to:
   - [Pulling changes onto a release branch](#pulling-changes-onto-a-release-branch)
   - [Rebasing to a new major version of the upstream compiler](#rebasing-to-a-new-major-version-of-the-upstream-compiler)
   - [How to add a new intrinsic to the compiler](#how-to-add-a-new-intrinsic-to-the-compiler)
+  - [How to add a new command line option](#how-to-add-a-new-command-line-option)
   - [Installation tree comparison script](#installation-tree-comparison-script)
 
 ## Branches, pull requests, etc.
@@ -293,6 +294,17 @@ library, and then the compiler.
   relies on the library tests to avoid duplication. Library tests use
   `Core`, but the library itself does not.
 
+## How to add a new command line option
+
+1) Add a ref to `flambda_backend_flags.ml{i}`
+2) Add the flag's constructor `mk_<flag>` in `flambda_backend_args.ml`
+3) Add the callback for the new flag to `Flambda_backend_options` module type
+   in `flambda_backend_args.ml{i}`
+4) List the flag in the body of `Make_flambda_backend_options` functor
+5) Implement the flag in `Flambda_backend_options_impl`
+   by setting the corresponding ref in Flambda_backend_flags
+6) Add the flag to `Extra_params` if it can be set via `OCAMLPARAM`
+
 ## Installation tree comparison script
 
 A target `make compare` exists to run a comparison script that finds differences

driver/flambda_backend_args.mli

@@ -18,17 +18,6 @@
     different installable tools and (b) override default implementations
     of arguments. *)
 
-(** Steps for adding a new flag:
-    1) add a ref to flambda_backend_flags.ml{i}
-    2) add the flag's constructor "mk_<flag>" in flambda_backend_args.ml
-    3) add the callback for the new flag to Flambda_backend_options module type
-       in flambda_backend_args.ml{i}
-    4) list the flag in the body of Make_flambda_backend_options functor
-    5) implement the flag in Flambda_backend_options_impl
-       by setting the corresponding ref in Flambda_backend_flags
-    6) add the flag to Extra_params if it can be set via OCAMLPARAM
-*)
-
 (** Command line arguments required for flambda backend.  *)
 module type Flambda_backend_options = sig
   val ocamlcfg : unit -> unit