Temporarily revert r244012 while we see if it's really necessary.

Add a comment explaining the current theory as to why we'd need
the -lole32 on the link line.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244015 91177308-0d34-0410-b5e6-96231b3b80d8

autoconf/configure.ac

@@ -1628,6 +1628,9 @@ dnl===-----------------------------------------------------------------------===
 
 AC_CHECK_LIB(m,sin)
 if test "$llvm_cv_os_type" = "MingW" ; then
+  dnl mingw-gcc's driver doesn't imply -lole32 by default so we may need this
+  dnl when being built with gcc for bootstrapping purposes.
+  AC_CHECK_LIB(ole32, main)
   AC_CHECK_LIB(psapi, main)
   AC_CHECK_LIB(shell32, main)
 fi

configure

@@ -8643,6 +8643,87 @@ fi
 
 if test "$llvm_cv_os_type" = "MingW" ; then
 
+{ echo "$as_me:$LINENO: checking for main in -lole32" >&5
+echo $ECHO_N "checking for main in -lole32... $ECHO_C" >&6; }
+if test "${ac_cv_lib_ole32_main+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lole32  $LIBS"
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+
+int
+main ()
+{
+return main ();
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag" || test ! -s conftest.err'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_cv_lib_ole32_main=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_cv_lib_ole32_main=no
+fi
+
+rm -f core conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv_lib_ole32_main" >&5
+echo "${ECHO_T}$ac_cv_lib_ole32_main" >&6; }
+if test $ac_cv_lib_ole32_main = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBOLE32 1
+_ACEOF
+
+  LIBS="-lole32 $LIBS"
+
+fi
+
+
 { echo "$as_me:$LINENO: checking for main in -lpsapi" >&5
 echo $ECHO_N "checking for main in -lpsapi... $ECHO_C" >&6; }
 if test "${ac_cv_lib_psapi_main+set}" = set; then

include/llvm/Config/config.h.in

@@ -140,6 +140,9 @@
 /* Define to 1 if you have the `m' library (-lm). */
 #undef HAVE_LIBM
 
+/* Define to 1 if you have the `ole32' library (-lole32). */
+#undef HAVE_LIBOLE32
+
 /* Define to 1 if you have the `psapi' library (-lpsapi). */
 #undef HAVE_LIBPSAPI