From b4d6fe9fab248add7c1e93365a0c209866b70222 Mon Sep 17 00:00:00 2001
From: Julien Portalier <julien@portalier.com>
Date: Tue, 22 Oct 2024 17:59:08 +0200
Subject: [PATCH] OpenBSD: disable indirect branch tracking (#13665)

OpenBSD 7.4+ enforces Indirect Branch Tracking but we're not yet
compatible in Crystal, so we disable the feature for the time being.
---
 src/compiler/crystal/compiler.cr | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/compiler/crystal/compiler.cr b/src/compiler/crystal/compiler.cr
index 6c7664bacc25..9668fa92b423 100644
--- a/src/compiler/crystal/compiler.cr
+++ b/src/compiler/crystal/compiler.cr
@@ -500,6 +500,13 @@ module Crystal
       else
         link_flags = @link_flags || ""
         link_flags += " -rdynamic"
+
+        if program.has_flag?("openbsd")
+          # OpenBSD requires Indirect Branch Tracking by default, but we're not
+          # compatible (yet), so we disable it for now:
+          link_flags += " -Wl,-znobtcfi"
+        end
+
         {DEFAULT_LINKER, %(#{DEFAULT_LINKER} "${@}" -o #{Process.quote_posix(output_filename)} #{link_flags} #{program.lib_flags(@cross_compile)}), object_names}
       end
     end