Enable LTO again.

NOTE: I did not build this in Rawhide, because building it appears to
change some of the ocamlx() dependencies, which would require
everything in Rawhide to be rebuilt.  I will build all OCaml packages
in Rawhide once OCaml 4.11.0 has been released which should be in a
week or two.

0001-Don-t-add-rpaths-to-libraries.patch

@@ -1,7 +1,7 @@
 From 1b1a2ad3294327e5bbbc753f306d1199b0a2a583 Mon Sep 17 00:00:00 2001
 From: "Richard W.M. Jones" <rjones@redhat.com>
 Date: Tue, 24 Jun 2014 10:00:15 +0100
-Subject: [PATCH 1/7] Don't add rpaths to libraries.
+Subject: [PATCH 1/8] Don't add rpaths to libraries.
 
 ---
  tools/Makefile | 4 ++--
@@ -23,5 +23,5 @@ index 96a4244cc..076411a91 100644
          > ocamlmklibconfig.ml
  
 -- 
-2.24.1
+2.28.0.rc2
 

0002-configure-Allow-user-defined-C-compiler-flags.patch

@@ -1,7 +1,7 @@
 From 8ea0bc7713a89cd6340e35b4dae048be63c50aec Mon Sep 17 00:00:00 2001
 From: "Richard W.M. Jones" <rjones@redhat.com>
 Date: Tue, 29 May 2012 20:44:18 +0100
-Subject: [PATCH 2/7] configure: Allow user defined C compiler flags.
+Subject: [PATCH 2/8] configure: Allow user defined C compiler flags.
 
 ---
  configure.ac | 4 ++++
@@ -23,5 +23,5 @@ index fbd49c1ee..a35da2040 100644
  
  # Enable SSE2 on x86 mingw to avoid using 80-bit registers.
 -- 
-2.24.1
+2.28.0.rc2
 

0003-configure-Remove-incorrect-assumption-about-cross-co.patch

@@ -1,7 +1,7 @@
 From 39df379f1aa139a073d7b436bb9bd33ef2f70caf Mon Sep 17 00:00:00 2001
 From: "Richard W.M. Jones" <rjones@redhat.com>
 Date: Fri, 26 Apr 2019 16:16:29 +0100
-Subject: [PATCH 3/7] configure: Remove incorrect assumption about
+Subject: [PATCH 3/8] configure: Remove incorrect assumption about
  cross-compiling.
 
 See https://github.com/ocaml/ocaml/issues/8647#issuecomment-487094390
@@ -39,5 +39,5 @@ index a35da2040..4c9358897 100644
  # We first compute default values for as and aspp
  # If values have been given by the user then they take precedence over
 -- 
-2.24.1
+2.28.0.rc2
 

0004-Remove-configure-from-.gitattributes.patch

@@ -1,7 +1,7 @@
 From e829051c3b35920db3c5e0dd913026f556448675 Mon Sep 17 00:00:00 2001
 From: "Richard W.M. Jones" <rjones@redhat.com>
 Date: Sat, 18 Jan 2020 11:31:27 +0000
-Subject: [PATCH 4/7] Remove configure from .gitattributes.
+Subject: [PATCH 4/8] Remove configure from .gitattributes.
 
 It's not a binary file.
 ---
@@ -24,5 +24,5 @@ index 200eb49c6..d871764de 100644
  #   http://krlmlr.github.io/using-gitattributes-to-avoid-merge-conflicts/
  /.mailmap                merge=union
 -- 
-2.24.1
+2.28.0.rc2
 

0005-Add-RISC-V-native-code-backend-9441.patch

@@ -1,7 +1,7 @@
 From 1a0ca036e40cbd701cbe3f0e5cf5e2a6b6d4c804 Mon Sep 17 00:00:00 2001
 From: =?UTF-8?q?Nicol=C3=A1s=20Ojeda=20B=C3=A4r?= <n.oje.bar@gmail.com>
 Date: Fri, 24 Apr 2020 16:04:50 +0200
-Subject: [PATCH 5/7] Add RISC-V native-code backend (#9441)
+Subject: [PATCH 5/8] Add RISC-V native-code backend (#9441)
 
 This is a port of ocamlopt for the RISC-V processor in 64-bit mode.
 
@@ -2008,5 +2008,5 @@ index 000000000..efb30a80f
 +caml_c_call:
 +        jr      t2
 -- 
-2.24.1
+2.28.0.rc2
 

0006-Support-FP-reg-int-reg-moves.patch

@@ -1,7 +1,7 @@
 From d26a313ae92bb515b04865b6a71a63701dd1fe41 Mon Sep 17 00:00:00 2001
 From: Xavier Leroy <xavier.leroy@college-de-france.fr>
 Date: Thu, 30 Apr 2020 16:18:06 +0200
-Subject: [PATCH 6/7] Support FP reg -> int reg moves
+Subject: [PATCH 6/8] Support FP reg -> int reg moves
 
 Using instruction fmv.x.d.
 
@@ -30,5 +30,5 @@ index dc652de42..dbfdc2d40 100644
              let ofs = slot_offset s (register_class dst) in
              emit_store src ofs
 -- 
-2.24.1
+2.28.0.rc2
 

0007-Update-C-calling-conventions-to-the-RISC-V-ELF-psABI.patch

@@ -1,7 +1,7 @@
 From 5bc92d0cdb5cb26b8d8d517f30914c2b18e85f2b Mon Sep 17 00:00:00 2001
 From: Xavier Leroy <xavier.leroy@college-de-france.fr>
 Date: Thu, 30 Apr 2020 16:19:16 +0200
-Subject: [PATCH 7/7] Update C calling conventions to the RISC-V ELF psABI
+Subject: [PATCH 7/8] Update C calling conventions to the RISC-V ELF psABI
 
 The original implementation of loc_external_arguments and
 loc_external_results was following an older ABI,
@@ -55,5 +55,5 @@ index 70909cd83..4c7b58612 100644
                loc.(i) <- [| stack_slot (make_stack !ofs) Float |];
                ofs := !ofs + size_float
 -- 
-2.24.1
+2.28.0.rc2
 

0008-runtime-major_gc.c-Declare-caml_fl_merge-with-proper.patch

@@ -0,0 +1,49 @@
+From 7364f5081851fe306802883d9a8069da559d4973 Mon Sep 17 00:00:00 2001
+From: "Richard W.M. Jones" <rjones@redhat.com>
+Date: Tue, 4 Aug 2020 12:26:12 +0100
+Subject: [PATCH 8/8] runtime/major_gc.c: Declare caml_fl_merge with proper
+ type.
+
+When compiling OCaml with LTO enabled (as is now done routinely in
+Fedora and OpenSUSE) we got a failure because the caml_fl_merge symbol
+is not declared identically across compilation units.  The simple fix
+is to make sure the declarations are identical, although probably
+moving the definition to a common header file would be a better
+long-term fix.
+
+major_gc.c:66:14: warning: type of 'caml_fl_merge' does not match original declaration [-Wlto-type-mismatch]
+   66 | extern char *caml_fl_merge;  /* Defined in freelist.c. */
+      |              ^
+freelist.c:47:7: note: 'caml_fl_merge' was previously declared here
+   47 | value caml_fl_merge = Val_NULL;  /* Current insertion pointer.  Managed
+      |       ^
+freelist.c:47:7: note: code may be misoptimized unless '-fno-strict-aliasing' is used
+---
+ runtime/major_gc.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/runtime/major_gc.c b/runtime/major_gc.c
+index 5e4f06bce..c8f5a3281 100644
+--- a/runtime/major_gc.c
++++ b/runtime/major_gc.c
+@@ -63,7 +63,7 @@ uintnat caml_dependent_size, caml_dependent_allocated;
+ double caml_extra_heap_resources;
+ uintnat caml_fl_wsz_at_phase_change = 0;
+ 
+-extern char *caml_fl_merge;  /* Defined in freelist.c. */
++extern value caml_fl_merge;  /* Defined in freelist.c. */
+ 
+ static char *markhp, *chunk, *limit;
+ static double p_backlog = 0.0; /* backlog for the gc speedup parameter */
+@@ -570,7 +570,7 @@ static void sweep_slice (intnat work)
+         break;
+       case Caml_blue:
+         /* Only the blocks of the free-list are blue.  See [freelist.c]. */
+-        caml_fl_merge = Bp_hp (hp);
++        caml_fl_merge = (value) Bp_hp (hp);
+         break;
+       default:          /* gray or black */
+         CAMLassert (Color_hd (hd) == Caml_black);
+-- 
+2.28.0.rc2
+

ocaml.spec

@@ -31,7 +31,7 @@
 
 Name:           ocaml
 Version:        4.11.0
-Release:        0.8.dev2%{?dist}
+Release:        0.9.dev2%{?dist}
 
 Summary:        OCaml compiler and programming environment
 
@@ -69,6 +69,9 @@ Patch0005:      0005-Add-RISC-V-native-code-backend-9441.patch
 Patch0006:      0006-Support-FP-reg-int-reg-moves.patch
 Patch0007:      0007-Update-C-calling-conventions-to-the-RISC-V-ELF-psABI.patch
 
+# Fix compilation with LTO (sent upstream 2020-08-04).
+Patch0008:      0008-runtime-major_gc.c-Declare-caml_fl_merge-with-proper.patch
+
 BuildRequires:  git
 BuildRequires:  gcc
 BuildRequires:  autoconf
@@ -174,12 +177,6 @@ autoconf --force
 
 
 %build
-# This package fails to build with LTO due to undefined symbols.  LTO
-# was disabled in OpenSuSE as well, but with no real explanation why
-# beyond the undefined symbols.  It really shold be investigated further.
-# Disable LTO
-%define _lto_cflags %{nil}
-
 %ifnarch %{no_parallel_build_arches}
 make="%make_build"
 %else
@@ -381,8 +378,9 @@ rm -f $RPM_BUILD_ROOT%{_libdir}/ocaml/eventlog_metadata
 
 
 %changelog
-* Tue Aug 04 2020 Richard W.M. Jones <rjones@redhat.com> - 4.11.0-0.8.dev2
+* Tue Aug 04 2020 Richard W.M. Jones <rjones@redhat.com> - 4.11.0-0.9.dev2
 - Bump and rebuild to fix DWARF versioning issues.
+- Enable LTO again.
 
 * Tue Jul 28 2020 Fedora Release Engineering <releng@fedoraproject.org> - 4.11.0-0.7.dev2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild