flambda-backend: Create object files internally to avoid invoking GAS (…

…ocaml-flambda#757)

otherlibs/unix/dune

@@ -22,6 +22,10 @@
  ))
  (ocamlopt_flags (:include %{project_root}/ocamlopt_flags.sexp))
  (library_flags (:standard -linkall))
+ ; UnixLabels is compiled separately as it needs the -nolabels flag.  We can't
+ ; currently use an attribute in the .ml file to enable this behaviour as
+ ; the system compiler used to build the boot compiler won't understand it.
+ (modules (:standard \ unixLabels))
  (foreign_stubs (language c) (names
    accept access addrofstr alarm bind channels chdir chmod chown chroot close
    fsync closedir connect cst2constr cstringv dup dup2 envir errmsg execv execve
@@ -39,17 +43,58 @@
            (:include %{project_root}/oc_cppflags.sexp)))
  ))
 
+(library
+ (name unixlabels)
+ (libraries unix)
+ (wrapped false)
+ (modes byte native)
+ (flags (
+   -absname -w +a-4-9-41-42-44-45-48 -warn-error A -bin-annot
+   -g -safe-string -strict-sequence -strict-formats -nolabels
+ ))
+ (ocamlopt_flags (:include %{project_root}/ocamlopt_flags.sexp))
+ (modules unixLabels)
+)
+
+(rule
+ (targets unix_merged.a)
+ (action
+  (run
+   %{dep:../../../tools/merge_dot_a_files.sh}
+   %{targets}
+   %{dep:unix.a}
+   %{dep:unixlabels.a})))
+
+(rule
+ (targets unix_merged.cma)
+ (action
+  (run
+   %{dep:../../../tools/merge_archives.exe}
+   %{targets}
+   %{dep:unix.cma}
+   %{dep:unixlabels.cma})))
+
+(rule
+ (targets unix_merged.cmxa)
+ (action
+  (run
+   %{dep:../../../tools/merge_archives.exe}
+   %{targets}
+   %{dep:unix.cmxa}
+   %{dep:unixlabels.cmxa})))
+
 (install
   (files
     .unix.objs/native/unix.cmx
-    .unix.objs/native/unixLabels.cmx
-    unix.cmxa
-    unix.a
-    unix.cma
+    .unixlabels.objs/native/unixLabels.cmx
+    (unix_merged.cmxa as unix.cmxa)
+    (unix_merged.a as unix.a)
+    (unix_merged.cma as unix.cma)
     .unix.objs/byte/unix.cmi
     .unix.objs/byte/unix.cmti
-    .unix.objs/byte/unixLabels.cmi
-    .unix.objs/byte/unixLabels.cmti
+    .unixlabels.objs/byte/unixLabels.cmi
+    .unixlabels.objs/byte/unixLabels.cmti
+    ; For the moment unix.cmxs does not include UnixLabels.
     unix.cmxs
     unix.mli
     unixLabels.mli

otherlibs/unix/unixLabels.ml

@@ -15,6 +15,4 @@
 
 (* Module [UnixLabels]: labelled Unix module *)
 
-[@@@ocaml.nolabels]
-
 include Unix

otherlibs/unix/unixLabels.mli

@@ -40,7 +40,6 @@
 
 (** {1 Error report} *)
 
-
 type error = Unix.error =
     E2BIG               (** Argument list too long *)
   | EACCES              (** Permission denied *)