Make -fcompact-unwind the default

This is a follow-up to !7247 (closed) making the inclusion of compact unwinding
sections the default.

Also a slight refactoring/simplification of the flag handling to add
-fno-compact-unwind.

3 files changed, 13 insertions, 11 deletions

diff --git a/compiler/GHC/Driver/Session.hs b/compiler/GHC/Driver/Session.hs
index f765bb44ce..e200bd46bb 100644
--- a/compiler/GHC/Driver/Session.hs
+++ b/compiler/GHC/Driver/Session.hs
@@ -2121,12 +2121,6 @@ dynamic_flags_deps = [
       (NoArg (setGeneralFlag Opt_SingleLibFolder))
   , make_ord_flag defGhcFlag "pie"            (NoArg (setGeneralFlag Opt_PICExecutable))
   , make_ord_flag defGhcFlag "no-pie"         (NoArg (unSetGeneralFlag Opt_PICExecutable))
-  , make_ord_flag defGhcFlag "fcompact-unwind"
-      (noArgM (\dflags -> do
-       if platformOS (targetPlatform dflags) == OSDarwin
-          then return (gopt_set dflags Opt_CompactUnwind)
-          else do addWarn "-compact-unwind is only implemented by the darwin platform. Ignoring."
-                  return dflags))
 
         ------- Specific phases  --------------------------------------------
     -- need to appear before -pgmL to be parsed as LLVM flags.
@@ -3498,7 +3492,13 @@ fFlagsDeps = [
   flagSpec "show-loaded-modules"              Opt_ShowLoadedModules,
   flagSpec "whole-archive-hs-libs"            Opt_WholeArchiveHsLibs,
   flagSpec "keep-cafs"                        Opt_KeepCAFs,
-  flagSpec "link-rts"                         Opt_LinkRts
+  flagSpec "link-rts"                         Opt_LinkRts,
+  flagSpec' "compact-unwind"                   Opt_CompactUnwind
+      (\turn_on -> updM (\dflags -> do
+        unless (platformOS (targetPlatform dflags) == OSDarwin && turn_on)
+               (addWarn "-compact-unwind is only implemented by the darwin platform. Ignoring.")
+        return dflags))
+
   ]
   ++ fHoleFlags
 
@@ -3787,7 +3787,8 @@ defaultFlags settings
       Opt_SimplPreInlining,
       Opt_VersionMacros,
       Opt_RPath,
-      Opt_DumpWithWays
+      Opt_DumpWithWays,
+      Opt_CompactUnwind
     ]
 
     ++ [f | (ns,f) <- optLevelFlags, 0 `elem` ns]
diff --git a/docs/users_guide/phases.rst b/docs/users_guide/phases.rst
index b784fa7662..fb635531e3 100644
--- a/docs/users_guide/phases.rst
+++ b/docs/users_guide/phases.rst
@@ -1330,6 +1330,8 @@ for example).
     :type: dynamic
     :category: linking
 
+    :default: on
+
     :since: 9.4.1
 
     This instructs the linker to produce an executable that supports Apple's
diff --git a/testsuite/tests/rts/all.T b/testsuite/tests/rts/all.T
index d907ceff62..0c541dd480 100644
--- a/testsuite/tests/rts/all.T
+++ b/testsuite/tests/rts/all.T
@@ -473,9 +473,8 @@ test('keep-cafs',
 
 # Test proper functioning of C++ exceptions within a C++ program.
 # On darwin, this requires -fcompact-unwind.
-# When -fcompact-unwind becomes default, generalize test to all platforms.
-test('T11829', unless(opsys('darwin'), skip), compile_and_run,
-     ['T11829_c.cpp -l{} -fcompact-unwind'.format(config.stdcxx_impl)])
+test('T11829', [ check_errmsg("This is a test") ], compile_and_run,
+     ['T11829_c.cpp -l{}'.format(config.stdcxx_impl)])
 
 test('T16514', normal, compile_and_run, ['T16514_c.c'])
 test('test-zeroongc', extra_run_opts('-DZ'), compile_and_run, ['-debug'])