ffi: retain some functionality if libffi missing.

The FFI module is more than just foreign calls and callbacks;
it provides a type system and operations for working with
binary data. None of it depends on libffi being present and so
shouldn't be disabled if libffi is not available.

* Makefile (ffi.o): Unconditionally link this object file,
not subject to the have_libffi variable.

* configure (have_libffi): Variable removed.
(gen_config_make): Do not generate a have_libffi
variable into config.make, since nothing needs it.

* ffi.c (ffi_type): Fake ffi_type defined if libffi is
missing.
(FFI_TYPE_STRUCT): Fake macro.
(ffi_type ffi_type_void, ffi_type_pointer, ffi_type_sint,
ffi_type ffi_type_schar, ffi_type_uchar, ffi_type
ffi_type_sshort, ffi_type_ushort, ffi_type ffi_type_sint,
ffi_type_uint, ffi_type ffi_type_slong, ffi_type_ulong,
ffi_type ffi_type_sint8, ffi_type_uint8, ffi_type
ffi_type_sint16, ffi_type_uint16, ffi_type ffi_type_sint32,
ffi_type_uint32, ffi_type ffi_type_sint64, ffi_type_uint64,
ffi_type ffi_type_float, ffi_type_double): Fake libffi type
objects, so that code which references these things will
build without modification.
(ffi_get_type): Function only defined if we have libffi.
(ffi_type_struct_destroy_op, ffi_struct_clone,
make_ffi_type_struct, ffi_array_clone, make_ffi_type_array):
Don't work with ffi_type's element array if we don't have
libffi; our fake ffi_type doesn't have such an array.
(struct txr_ffi_closure): Type only defined if we have libffi.
(ffi_closure_struct, ffi_closure_struct_checked,
ffi_closure_print_op, ffi_closure_destroy_op,
ffi_closure_mark_op, ffi_closure_put): Functions only defined
if we have libffi.
(ffi_closure_ops): Static structure only defined if we have
libffi.
(ffi_init_types): Don't register a closure type if we don't
have libffi.
(struct txr_ffi_call_desc): Don't define type if we don't have
libffi.
(ffi_call_desc, ffi_call_desc_checked, ffi_call_desc_print_op,
ffi_call_desc_destroy_op, ffi_call_desc_mark_op,
ffi_make_call_desc, ffi_call_wrap, ffi_closure_dispatch,
ffi_closure_dispatch_safe, ffi_make_closure,
ffi_closure_get_fptr): Functions only defined if we have
libffi.
(ffi_call_desc_ops): Static structure only defined if we have
libffi.
(ffi_init): Only register ffi-make-call-desc, ffi-call, and
ffi-make-closure if we have libffi.

* lib.c: Include "ffi.h" header unconditionally.
(generic_funcall, ref, refset, int): Remove #if HAVE_LIBFFI.

1 files changed, 1 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index 531395cd..ae3c7fd3 100644
--- a/Makefile
+++ b/Makefile
@@ -49,7 +49,7 @@ EXTRA_OBJS-y :=
 
 OBJS := txr.o lex.yy.o y.tab.o match.o lib.o regex.o gc.o unwind.o stream.o
 OBJS += arith.o hash.o utf8.o filter.o eval.o parser.o rand.o combi.o sysif.o
-OBJS += args.o lisplib.o cadr.o struct.o itypes.o buf.o jmp.o protsym.o
+OBJS += args.o lisplib.o cadr.o struct.o itypes.o buf.o jmp.o protsym.o ffi.o
 OBJS-$(debug_support) += debug.o
 OBJS-$(have_syslog) += syslog.o
 OBJS-$(have_glob) += glob.o
@@ -58,7 +58,6 @@ OBJS-$(have_posix_sigs) += signal.o
 OBJS-$(have_sockets) += socket.o
 OBJS-$(have_termios) += termios.o
 OBJS-$(have_termios) += linenoise/linenoise.o
-OBJS-$(have_libffi) += ffi.o
 EXTRA_OBJS-$(add_win_res) += win/txr.res
 
 ifneq ($(have_git),)