Merge tag 'upstream/4.14' into tizentizen_6.5.m2_releasetizen_6.0.m2_releasetizen_5.5.m2_releasesubmit/tizen_6.5/20211028.163501submit/tizen_6.0_hotfix/20201103.115102submit/tizen_6.0_hotfix/20201102.192902submit/tizen_6.0/20201029.205502submit/tizen_5.5_wearable_hotfix/20201026.184307submit/tizen_5.5_mobile_hotfix/20201026.185107submit/tizen_5.5/20191031.000007submit/tizen/20190904.070216submit/tizen/20190829.061506accepted/tizen/unified/20190904.110630accepted/tizen/6.5/unified/20211029.014057accepted/tizen/6.0/unified/hotfix/20201103.050702accepted/tizen/6.0/unified/hotfix/20201102.234932accepted/tizen/6.0/unified/20201030.110146accepted/tizen/5.5/unified/wearable/hotfix/20201027.100357accepted/tizen/5.5/unified/mobile/hotfix/20201027.074057accepted/tizen/5.5/unified/20191031.011500tizen_6.5tizen_6.0_hotfixtizen_6.0tizen_5.5_wearable_hotfixtizen_5.5_tvtizen_5.5_mobile_hotfixtizen_5.5accepted/tizen_6.5_unifiedaccepted/tizen_6.0_unified_hotfixaccepted/tizen_6.0_unifiedaccepted/tizen_5.5_unified_wearable_hotfixaccepted/tizen_5.5_unified_mobile_hotfixaccepted/tizen_5.5_unified

Change-Id: I6d4b47b2072db8e7c45daa6e269e2f0cc6f54a7f

1 files changed, 77 insertions, 0 deletions

diff --git a/m4-gl/visibility.m4 b/m4-gl/visibility.m4
new file mode 100644
index 0000000..8c266a8
--- /dev/null
+++ b/m4-gl/visibility.m4
@@ -0,0 +1,77 @@
+# visibility.m4 serial 6
+dnl Copyright (C) 2005, 2008, 2010-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl Tests whether the compiler supports the command-line option
+dnl -fvisibility=hidden and the function and variable attributes
+dnl __attribute__((__visibility__("hidden"))) and
+dnl __attribute__((__visibility__("default"))).
+dnl Does *not* test for __visibility__("protected") - which has tricky
+dnl semantics (see the 'vismain' test in glibc) and does not exist e.g. on
+dnl Mac OS X.
+dnl Does *not* test for __visibility__("internal") - which has processor
+dnl dependent semantics.
+dnl Does *not* test for #pragma GCC visibility push(hidden) - which is
+dnl "really only recommended for legacy code".
+dnl Set the variable CFLAG_VISIBILITY.
+dnl Defines and sets the variable HAVE_VISIBILITY.
+
+AC_DEFUN([gl_VISIBILITY],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  CFLAG_VISIBILITY=
+  HAVE_VISIBILITY=0
+  if test -n "$GCC"; then
+    dnl First, check whether -Werror can be added to the command line, or
+    dnl whether it leads to an error because of some other option that the
+    dnl user has put into $CC $CFLAGS $CPPFLAGS.
+    AC_CACHE_CHECK([whether the -Werror option is usable],
+      [gl_cv_cc_vis_werror],
+      [gl_save_CFLAGS="$CFLAGS"
+       CFLAGS="$CFLAGS -Werror"
+       AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM([[]], [[]])],
+         [gl_cv_cc_vis_werror=yes],
+         [gl_cv_cc_vis_werror=no])
+       CFLAGS="$gl_save_CFLAGS"
+      ])
+    dnl Now check whether visibility declarations are supported.
+    AC_CACHE_CHECK([for simple visibility declarations],
+      [gl_cv_cc_visibility],
+      [gl_save_CFLAGS="$CFLAGS"
+       CFLAGS="$CFLAGS -fvisibility=hidden"
+       dnl We use the option -Werror and a function dummyfunc, because on some
+       dnl platforms (Cygwin 1.7) the use of -fvisibility triggers a warning
+       dnl "visibility attribute not supported in this configuration; ignored"
+       dnl at the first function definition in every compilation unit, and we
+       dnl don't want to use the option in this case.
+       if test $gl_cv_cc_vis_werror = yes; then
+         CFLAGS="$CFLAGS -Werror"
+       fi
+       AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[extern __attribute__((__visibility__("hidden"))) int hiddenvar;
+              extern __attribute__((__visibility__("default"))) int exportedvar;
+              extern __attribute__((__visibility__("hidden"))) int hiddenfunc (void);
+              extern __attribute__((__visibility__("default"))) int exportedfunc (void);
+              void dummyfunc (void) {}
+            ]],
+            [[]])],
+         [gl_cv_cc_visibility=yes],
+         [gl_cv_cc_visibility=no])
+       CFLAGS="$gl_save_CFLAGS"
+      ])
+    if test $gl_cv_cc_visibility = yes; then
+      CFLAG_VISIBILITY="-fvisibility=hidden"
+      HAVE_VISIBILITY=1
+    fi
+  fi
+  AC_SUBST([CFLAG_VISIBILITY])
+  AC_SUBST([HAVE_VISIBILITY])
+  AC_DEFINE_UNQUOTED([HAVE_VISIBILITY], [$HAVE_VISIBILITY],
+    [Define to 1 or 0, depending whether the compiler supports simple visibility declarations.])
+])