Disable Compmisc.auto_include: do not add the directory, do not alert.

driver/flambda_backend_args.ml

@@ -144,6 +144,13 @@ let mk_internal_assembler f =
 let mk_gc_timings f =
   "-dgc-timings", Arg.Unit f, "Output information about time spent in the GC"
 
+let mk_no_auto_include_otherlibs f =
+  "-no-auto-include-otherlibs", Arg.Unit f,
+  "Add only stdlib to the list of include directories (unless -nostdlib is \
+   specified). Do not add subdirectories of other libraries distributed with \
+   the compiler (such as unix, str, dynlink). Do not alert when \
+   they are missing."
+
 module Flambda2 = Flambda_backend_flags.Flambda2
 
 let mk_flambda2_result_types_functors_only f =
@@ -603,6 +610,7 @@ module type Flambda_backend_options = sig
   val internal_assembler : unit -> unit
 
   val gc_timings : unit -> unit
+  val no_auto_include_otherlibs : unit -> unit
 
   val flambda2_debug : unit -> unit
   val no_flambda2_debug : unit -> unit
@@ -708,6 +716,7 @@ struct
     mk_internal_assembler F.internal_assembler;
 
     mk_gc_timings F.gc_timings;
+    mk_no_auto_include_otherlibs F.no_auto_include_otherlibs;
 
     mk_flambda2_debug F.flambda2_debug;
     mk_no_flambda2_debug F.no_flambda2_debug;
@@ -867,6 +876,7 @@ module Flambda_backend_options_impl = struct
   let internal_assembler = set' Flambda_backend_flags.internal_assembler
 
   let gc_timings = set' Flambda_backend_flags.gc_timings
+  let no_auto_include_otherlibs = set' Clflags.no_auto_include_otherlibs
 
   let flambda2_debug = set' Flambda_backend_flags.Flambda2.debug
   let no_flambda2_debug = clear' Flambda_backend_flags.Flambda2.debug
@@ -1088,6 +1098,7 @@ module Extra_params = struct
     match name with
     | "internal-assembler" -> set' Flambda_backend_flags.internal_assembler
     | "dgc-timings" -> set' Flambda_backend_flags.gc_timings
+    | "no-auto-include-otherlibs" -> set' Clflags.no_auto_include_otherlibs
     | "ocamlcfg" -> set' Flambda_backend_flags.use_ocamlcfg
     | "cfg-invariants" -> set' Flambda_backend_flags.cfg_invariants
     | "cfg-equivalence-check" -> set' Flambda_backend_flags.cfg_equivalence_check

driver/flambda_backend_args.mli

@@ -59,6 +59,7 @@ module type Flambda_backend_options = sig
   val internal_assembler : unit -> unit
 
   val gc_timings : unit -> unit
+  val no_auto_include_otherlibs : unit -> unit
 
   val flambda2_debug : unit -> unit
   val no_flambda2_debug : unit -> unit

ocaml/driver/compmisc.ml

@@ -14,7 +14,7 @@
 (**************************************************************************)
 
 let auto_include find_in_dir fn =
-  if !Clflags.no_std_include then
+  if !Clflags.no_auto_include_otherlibs || !Clflags.no_std_include then
     raise Not_found
   else
     let alert = Location.auto_include_alert in

ocaml/parsing/ast_mapper.ml

@@ -1201,7 +1201,7 @@ module PpxContext = struct
           (* Duplicates Compmisc.auto_include, since we can't reference Compmisc
              from this module. *)
           let auto_include find_in_dir fn =
-            if !Clflags.no_std_include then
+            if !Clflags.no_auto_include_otherlibs || !Clflags.no_std_include then
               raise Not_found
             else
               let alert = Location.auto_include_alert in

ocaml/utils/clflags.ml

@@ -673,3 +673,5 @@ end
 
 let zero_alloc_check = ref Annotations.No_check         (* -zero-alloc-check *)
 let zero_alloc_check_assert_all = ref false (* -zero-alloc-check-assert-all *)
+
+let no_auto_include_otherlibs = ref false      (* -no-auto-include-otherlibs *)

ocaml/utils/clflags.mli

@@ -301,3 +301,4 @@ end
 val zero_alloc_check : Annotations.t ref
 val zero_alloc_check_assert_all : bool ref
 
+val no_auto_include_otherlibs : bool ref