Sync with gcc-toplevel

configure

@@ -4920,15 +4920,34 @@ trap 'rm -f $CONFIG_STATUS conftest*; exit 1' 1 2 15
 # Transform confdefs.h into DEFS.
 # Protect against shell expansion while executing Makefile rules.
 # Protect against Makefile macro expansion.
-cat > conftest.defs <<\EOF
-s%#define \([A-Za-z_][A-Za-z0-9_]*\) *\(.*\)%-D\1=\2%g
-s%[ 	`~#$^&*(){}\\|;'"<>?]%\\&%g
-s%\[%\\&%g
-s%\]%\\&%g
-s%\$%$$%g
-EOF
-DEFS=`sed -f conftest.defs confdefs.h | tr '\012' ' '`
-rm -f conftest.defs
+#
+# If the first sed substitution is executed (which looks for macros that
+# take arguments), then we branch to the quote section.  Otherwise,
+# look for a macro that doesn't take arguments.
+cat >confdef2opt.sed <<\_ACEOF
+t clear
+: clear
+s,^[ 	]*#[ 	]*define[ 	][ 	]*\([^ 	(][^ 	(]*([^)]*)\)[ 	]*\(.*\),-D\1=\2,g
+t quote
+s,^[ 	]*#[ 	]*define[ 	][ 	]*\([^ 	][^ 	]*\)[ 	]*\(.*\),-D\1=\2,g
+t quote
+d
+: quote
+s,[ 	`~#$^&*(){}\\|;'"<>?],\\&,g
+s,\[,\\&,g
+s,\],\\&,g
+s,\$,$$,g
+p
+_ACEOF
+# We use echo to avoid assuming a particular line-breaking character.
+# The extra dot is to prevent the shell from consuming trailing
+# line-breaks from the sub-command output.  A line-break within
+# single-quotes doesn't work because, if this script is created in a
+# platform that uses two characters for line-breaks (e.g., DOS), tr
+# would break.
+ac_LF_and_DOT=`echo; echo .`
+DEFS=`sed -n -f confdef2opt.sed confdefs.h | tr "$ac_LF_and_DOT" ' .'`
+rm -f confdef2opt.sed
 
 
 # Without the "./", some shells look in PATH for config.status.