add foreign value wrapper

* libguile/foreign.h:
* libguile/foreign.c: New files, implementing simple wrappers around
  foreign values, such as those that one might link in dynamically from
  a library.

* libguile/tags.h (scm_tc7_foreign): Take a tc7 for foreign values.

* libguile.h:
* libguile/init.c: Add foreign.h to headers and init.

* libguile/print.c (iprin1): Add printer for foreign values.

* libguile/gc.c (scm_i_tag_name): Case for foreign values.
* libguile/goops.c (scm_class_of, create_standard_classes): Add a class
  for foreign values.

* libguile/evalext.c (scm_self_evaluating_p): Add case for foreign
  values.

* libguile/Makefile.am: Add foreign.[ch] to the build.

1 files changed, 87 insertions, 0 deletions

diff --git a/libguile/foreign.h b/libguile/foreign.h
new file mode 100644
index 000000000..954c1c5b3
--- /dev/null
+++ b/libguile/foreign.h
@@ -0,0 +1,87 @@
+/* Copyright (C) 2010  Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef SCM_FOREIGN_H
+#define SCM_FOREIGN_H
+
+
+
+/* A subset of libffi's types. */
+typedef enum
+  {
+    SCM_FOREIGN_TYPE_VOID,
+    SCM_FOREIGN_TYPE_FLOAT,    
+    SCM_FOREIGN_TYPE_DOUBLE,
+    SCM_FOREIGN_TYPE_UINT8,
+    SCM_FOREIGN_TYPE_INT8,
+    SCM_FOREIGN_TYPE_UINT16,
+    SCM_FOREIGN_TYPE_INT16,
+    SCM_FOREIGN_TYPE_UINT32,
+    SCM_FOREIGN_TYPE_INT32,
+    SCM_FOREIGN_TYPE_UINT64,
+    SCM_FOREIGN_TYPE_INT64,
+    SCM_FOREIGN_TYPE_STRUCT,
+    SCM_FOREIGN_TYPE_POINTER
+  } scm_t_foreign_type;
+
+
+typedef void (*scm_t_foreign_finalizer) (void *);
+
+#define SCM_FOREIGN_P(x)                                                \
+  (!SCM_IMP (x) && SCM_TYP7(x) == scm_tc7_foreign)
+#define SCM_VALIDATE_FOREIGN(pos, x)					\
+  SCM_MAKE_VALIDATE (pos, x, FOREIGN_P)
+#define SCM_FOREIGN_TYPE(x)                                             \
+  ((scm_t_foreign_type)((SCM_CELL_WORD_0 (x) >> 8)&0xff))
+#define SCM_FOREIGN_OBJECT(x, ctype)                                    \
+  ((ctype*)SCM_CELL_OBJECT_1 (x))
+#define SCM_FOREIGN_OBJECT_REF(x, ctype)                                \
+  (*SCM_FOREIGN_OBJECT (x, ctype))
+#define SCM_FOREIGN_OBJECT_SET(x, ctype, val)                           \
+  (*SCM_FOREIGN_OBJECT (x, ctype) = (val))
+
+#define SCM_FOREIGN_TYPED_P(x, type)					\
+  (SCM_FOREIGN_P (x) && SCM_FOREIGN_TYPE (x) == SCM_FOREIGN_TYPE_##type)
+#define SCM_VALIDATE_FOREIGN_TYPED(pos, x, type)                        \
+  do {                                                                  \
+    SCM_ASSERT_TYPE (SCM_FOREIGN_TYPED_P (x, type), x, pos, FUNC_NAME,  \
+                     "FOREIGN_"#type"_P");                              \
+  } while (0)
+
+#define SCM_FOREIGN_SIMPLE_P(x)                                         \
+  (SCM_FOREIGN_P (x)                                                    \
+   && SCM_FOREIGN_TYPE (x) != SCM_FOREIGN_TYPE_VOID                     \
+   && SCM_FOREIGN_TYPE (x) != SCM_FOREIGN_TYPE_STRUCT                   \
+   && SCM_FOREIGN_TYPE (x) != SCM_FOREIGN_TYPE_POINTER)
+#define SCM_VALIDATE_FOREIGN_SIMPLE(pos, x)				\
+  SCM_MAKE_VALIDATE (pos, x, FOREIGN_SIMPLE_P)
+
+SCM_API SCM scm_c_from_foreign (scm_t_foreign_type type, void *val, size_t size,
+                                scm_t_foreign_finalizer finalizer);
+SCM_API SCM scm_c_take_foreign (scm_t_foreign_type type, void *val,
+                                scm_t_foreign_finalizer finalizer);
+
+SCM_API SCM scm_foreign_ref (SCM foreign);
+SCM_API SCM scm_foreign_set_x (SCM foreign, SCM val);
+
+SCM_INTERNAL void scm_i_foreign_print (SCM foreign, SCM port,
+                                       scm_print_state *pstate);
+SCM_INTERNAL void scm_init_foreign (void);
+
+
+#endif /* SCM_FOREIGN_H */