--- Makefile.def	2017-04-19 14:49:29.000000000 -0400
+++ /scratch/kenta2/cbuild/tmp/gcc-7.1.0/Makefile.def	2017-08-01 19:28:20.599881271 -0400
@@ -49,7 +49,7 @@
 		extra_make_flags="$(EXTRA_GCC_FLAGS)"; };
 host_modules= { module= gmp; lib_path=.libs; bootstrap=true;
 		// Work around in-tree gmp configure bug with missing flex.
-		extra_configure_flags='--disable-shared LEX="touch lex.yy.c"';
+		extra_configure_flags='--enable-shared LEX="touch lex.yy.c"';
 		extra_make_flags='AM_CFLAGS="-DNO_ASM"';
 		no_install= true;
 		// none-*-* disables asm optimizations, bootstrap-testing
@@ -59,14 +59,14 @@
 		// different from host for target.
 	        target="none-${host_vendor}-${host_os}"; };
 host_modules= { module= mpfr; lib_path=src/.libs; bootstrap=true;
-		extra_configure_flags='--disable-shared @extra_mpfr_configure_flags@';
+		extra_configure_flags='--enable-shared @extra_mpfr_configure_flags@';
 		extra_make_flags='AM_CFLAGS="-DNO_ASM"';
 		no_install= true; };
 host_modules= { module= mpc; lib_path=src/.libs; bootstrap=true;
-		extra_configure_flags='--disable-shared @extra_mpc_gmp_configure_flags@ @extra_mpc_mpfr_configure_flags@ --disable-maintainer-mode';
+		extra_configure_flags='--enable-shared @extra_mpc_gmp_configure_flags@ @extra_mpc_mpfr_configure_flags@ --disable-maintainer-mode';
 		no_install= true; };
 host_modules= { module= isl; lib_path=.libs; bootstrap=true;
-		extra_configure_flags='--disable-shared @extra_isl_gmp_configure_flags@';
+		extra_configure_flags='--enable-shared @extra_isl_gmp_configure_flags@';
 		extra_make_flags='V=1';
 		no_install= true; };
 host_modules= { module= libelf; lib_path=.libs; bootstrap=true;