configure: Expand -fvisibility checks to more compilers, test for -qvisibility

It looks like icc and sunpro both support -fvisibility=hidden and xlc supports
-qvisibility=hidden. I tested this on AIX and solaris with their proprietary
compilers as well as gcc, and with gcc or clang on freebsd, linux, macos,
netbsd and openbsd.

Apparently my prior commit fe6a64a58ab only works in combination with this
. While I tried to test them separately, an unknown caching issue
prevented me from noticing the problem.

Per discussion with Tom Lane and buildfarm member hoverfly.

Discussion: https://postgr.es/m/20220910052741.t7w7csyrggwus2ze%40awork3.anarazel.de
Discussion: https://postgr.es/m/20220820174213[email protected]

diff --git a/configure b/configure
index 613c385c480b7c414f56b4fc3ce64e6ace431b84..fd2a782454ba8ffc2ce7879bb144985e0acfaa2b 100755 (executable)
--- a/configure
+++ b/configure
@@ -6302,154 +6302,6 @@ if test x"$pgac_cv_prog_CC_cflags__ftree_vectorize" = x"yes"; then
 fi
 
 
-  #
-  # If the compiler knows how to hide symbols add the switch needed for that
-  # to CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE" >&5
-$as_echo_n "checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE... " >&6; }
-if ${pgac_cv_prog_CC_cflags__fvisibility_hidden+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  pgac_save_CFLAGS=$CFLAGS
-pgac_save_CC=$CC
-CC=${CC}
-CFLAGS="${CFLAGS_SL_MODULE} -fvisibility=hidden"
-ac_save_c_werror_flag=$ac_c_werror_flag
-ac_c_werror_flag=yes
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  pgac_cv_prog_CC_cflags__fvisibility_hidden=yes
-else
-  pgac_cv_prog_CC_cflags__fvisibility_hidden=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_c_werror_flag=$ac_save_c_werror_flag
-CFLAGS="$pgac_save_CFLAGS"
-CC="$pgac_save_CC"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__fvisibility_hidden" >&5
-$as_echo "$pgac_cv_prog_CC_cflags__fvisibility_hidden" >&6; }
-if test x"$pgac_cv_prog_CC_cflags__fvisibility_hidden" = x"yes"; then
-  CFLAGS_SL_MODULE="${CFLAGS_SL_MODULE} -fvisibility=hidden"
-fi
-
-
-  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
-
-$as_echo "#define HAVE_VISIBILITY_ATTRIBUTE 1" >>confdefs.h
-
-  fi
-  # For C++ we additionally want -fvisibility-inlines-hidden
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE" >&5
-$as_echo_n "checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE... " >&6; }
-if ${pgac_cv_prog_CXX_cxxflags__fvisibility_hidden+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  pgac_save_CXXFLAGS=$CXXFLAGS
-pgac_save_CXX=$CXX
-CXX=${CXX}
-CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
-ac_save_cxx_werror_flag=$ac_cxx_werror_flag
-ac_cxx_werror_flag=yes
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=yes
-else
-  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-
-ac_cxx_werror_flag=$ac_save_cxx_werror_flag
-CXXFLAGS="$pgac_save_CXXFLAGS"
-CXX="$pgac_save_CXX"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&5
-$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&6; }
-if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" = x"yes"; then
-  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
-fi
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE" >&5
-$as_echo_n "checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE... " >&6; }
-if ${pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  pgac_save_CXXFLAGS=$CXXFLAGS
-pgac_save_CXX=$CXX
-CXX=${CXX}
-CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
-ac_save_cxx_werror_flag=$ac_cxx_werror_flag
-ac_cxx_werror_flag=yes
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=yes
-else
-  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-
-ac_cxx_werror_flag=$ac_save_cxx_werror_flag
-CXXFLAGS="$pgac_save_CXXFLAGS"
-CXX="$pgac_save_CXX"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&5
-$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&6; }
-if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" = x"yes"; then
-  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
-fi
-
   #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
@@ -7005,6 +6857,258 @@ fi
 
 fi
 
+# If the compiler knows how to hide symbols, add the switch needed for that to
+# CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
+#
+# This is done separately from the above because -fvisibility is supported by
+# quite a few different compilers, making the required repetition bothersome.
+#
+# We might need to add a separate test to check if
+# __attribute__((visibility("hidden"))) is supported, if we encounter a
+# compiler that supports one of the supported variants of -fvisibility=hidden
+# but uses a different syntax to mark a symbol as exported.
+if test "$GCC" = yes -o "$SUN_STUDIO_CC" = yes ; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CC_cflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CC}
+CFLAGS="${CFLAGS_SL_MODULE} -fvisibility=hidden"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$pgac_save_CFLAGS"
+CC="$pgac_save_CC"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CC_cflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CC_cflags__fvisibility_hidden" = x"yes"; then
+  CFLAGS_SL_MODULE="${CFLAGS_SL_MODULE} -fvisibility=hidden"
+fi
+
+
+  # For C++ we additionally want -fvisibility-inlines-hidden
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" = x"yes"; then
+  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
+fi
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" = x"yes"; then
+  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
+fi
+
+  have_visibility_attribute=$pgac_cv_prog_CC_cflags__fvisibility_hidden
+elif test "$PORTNAME" = "aix"; then
+  # Note that xlc accepts -fvisibility=hidden as a file.
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -qvisibility=hidden, for CFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CC} supports -qvisibility=hidden, for CFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CC_cflags__qvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CC}
+CFLAGS="${CFLAGS_SL_MODULE} -qvisibility=hidden"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_prog_CC_cflags__qvisibility_hidden=yes
+else
+  pgac_cv_prog_CC_cflags__qvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$pgac_save_CFLAGS"
+CC="$pgac_save_CC"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__qvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CC_cflags__qvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CC_cflags__qvisibility_hidden" = x"yes"; then
+  CFLAGS_SL_MODULE="${CFLAGS_SL_MODULE} -qvisibility=hidden"
+fi
+
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -qvisibility=hidden, for CXXFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CXX} supports -qvisibility=hidden, for CXXFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__qvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MODULE} -qvisibility=hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__qvisibility_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__qvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__qvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__qvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__qvisibility_hidden" = x"yes"; then
+  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -qvisibility=hidden"
+fi
+
+  have_visibility_attribute=$pgac_cv_prog_CC_cflags__qvisibility_hidden
+fi
+
+if test "$have_visibility_attribute" = "yes"; then
+
+$as_echo "#define HAVE_VISIBILITY_ATTRIBUTE 1" >>confdefs.h
+
+fi
+
 
 
 

diff --git a/configure.ac b/configure.ac
index 993b5d5cb0a5c15aee40a46709f6b45cecb3f7f6..7792ae5bad34cbcbf0e1131ca999fb7f3b17e0db 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -525,17 +525,6 @@ if test "$GCC" = yes -a "$ICC" = no; then
   # Optimization flags for specific files that benefit from vectorization
   PGAC_PROG_CC_VAR_OPT(CFLAGS_VECTORIZE, [-ftree-vectorize])
   #
-  # If the compiler knows how to hide symbols add the switch needed for that
-  # to CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
-  PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MODULE, [-fvisibility=hidden])
-  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
-     AC_DEFINE([HAVE_VISIBILITY_ATTRIBUTE], 1,
-               [Define to 1 if your compiler knows the visibility("hidden") attribute.])
-  fi
-  # For C++ we additionally want -fvisibility-inlines-hidden
-  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility=hidden])
-  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility-inlines-hidden])
-  #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
   # switches, so we have to test for the positive form and if that works,
@@ -582,6 +571,34 @@ elif test "$PORTNAME" = "aix"; then
   PGAC_PROG_CXX_CFLAGS_OPT([-qlonglong])
 fi
 
+# If the compiler knows how to hide symbols, add the switch needed for that to
+# CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
+#
+# This is done separately from the above because -fvisibility is supported by
+# quite a few different compilers, making the required repetition bothersome.
+#
+# We might need to add a separate test to check if
+# __attribute__((visibility("hidden"))) is supported, if we encounter a
+# compiler that supports one of the supported variants of -fvisibility=hidden
+# but uses a different syntax to mark a symbol as exported.
+if test "$GCC" = yes -o "$SUN_STUDIO_CC" = yes ; then
+  PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MODULE, [-fvisibility=hidden])
+  # For C++ we additionally want -fvisibility-inlines-hidden
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility=hidden])
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility-inlines-hidden])
+  have_visibility_attribute=$pgac_cv_prog_CC_cflags__fvisibility_hidden
+elif test "$PORTNAME" = "aix"; then
+  # Note that xlc accepts -fvisibility=hidden as a file.
+  PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MODULE, [-qvisibility=hidden])
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-qvisibility=hidden])
+  have_visibility_attribute=$pgac_cv_prog_CC_cflags__qvisibility_hidden
+fi
+
+if test "$have_visibility_attribute" = "yes"; then
+  AC_DEFINE([HAVE_VISIBILITY_ATTRIBUTE], 1,
+            [Define to 1 if your compiler knows the visibility("hidden") attribute.])
+fi
+
 AC_SUBST(CFLAGS_UNROLL_LOOPS)
 AC_SUBST(CFLAGS_VECTORIZE)
 AC_SUBST(CFLAGS_SL_MODULE)