Allow cross-compiling bootstrapping without ipopt

Makefile.in

@@ -43,7 +43,7 @@ LIBCMINPACKLIB=@LIBCMINPACKLIB@
 LD_LAPACK=@LD_LAPACK@
 LAPACK_TARGET=@LAPACK_TARGET@
 OPENBLAS_EXTRA_ARGS=@OPENBLAS_EXTRA_ARGS@
-IPOPT_TARGET=ipopt
+IPOPT_TARGET=@IPOPT_TARGET@
 UMFPACK_TARGET=@UMFPACK_TARGET@
 UMFPACK_SHARED=@UMFPACK_SHARED@
 # We don't want the shared version, but symbols are not exported if we use the static version

configure.ac

@@ -37,6 +37,7 @@ AC_SUBST(OMCRUNTIME_SHARED_LDFLAGS)
 AC_SUBST(SUNDIALS_LDFLAGS)
 AC_SUBST(IPOPT_LDFLAGS)
 AC_SUBST(IPOPT_CFLAGS)
+AC_SUBST(IPOPT_TARGET)
 AC_SUBST(QMAKE)
 AC_SUBST(EXE)
 AC_SUBST(SOURCE_REVISION)
@@ -597,6 +598,17 @@ AS_IF([test "x$with_UMFPACK" = xyes],
   UMFPACK_LDFLAGS=""
 ])
 
+# check for ipopt
+AC_ARG_WITH(ipopt, [  --without-ipopt              Disable compilation with IPOPT (only for bootstrapping; required for simulations)],
+[],[with_ipopt=yes])
+
+AS_IF([test "x$with_ipopt" = xyes],
+[
+  IPOPT_TARGET="ipopt";
+],[
+  IPOPT_TARGET=""
+])
+
 m4_include([common/m4/corba.m4])
 
 AC_MSG_CHECKING([for OpenCL])