* README: Added description of compat.

* compat/acconfig.h, compat/acinclude.m4, compat.h, configure.in:
New files.

6 files changed, 230 insertions, 0 deletions

diff --git a/examples/ChangeLog b/examples/ChangeLog
index f70742449..db8e0ec2f 100644
--- a/examples/ChangeLog
+++ b/examples/ChangeLog
@@ -1,3 +1,10 @@
+2002-11-17  Mikael Djurfeldt  <mdj@linnaeus>
+
+	* README: Added description of compat.
+
+	* compat/acconfig.h, compat/acinclude.m4, compat.h, configure.in:
+	New files.
+
 2001-07-24  Martin Grabmueller  <mgrabmue@cs.tu-berlin.de>
 
 	All examples are now built and tested on `make installcheck'
diff --git a/examples/README b/examples/README
index 793d131c8..f6d645cec 100644
--- a/examples/README
+++ b/examples/README
@@ -34,3 +34,7 @@ box-dynamic-module  Combination of `box-module' and `box-dynamic':
 modules		    Examples for writing and using Guile modules.
 
 safe		    Examples for creating and using safe environments.
+
+compat		    autoconf code for making a Guile extension
+		    compatible with older versions of Guile.
+
diff --git a/examples/compat/acconfig.h b/examples/compat/acconfig.h
new file mode 100644
index 000000000..c7f8304ca
--- /dev/null
+++ b/examples/compat/acconfig.h
@@ -0,0 +1 @@
+#undef HAVE_SCM_T_BITS
diff --git a/examples/compat/acinclude.m4 b/examples/compat/acinclude.m4
new file mode 100644
index 000000000..9560e0b93
--- /dev/null
+++ b/examples/compat/acinclude.m4
@@ -0,0 +1,18 @@
+AC_DEFUN([GUILE_COMPAT],
+ [guile_compat_save_CFLAGS="$CFLAGS"
+  guile_compat_save_LIBS="$LIBS"
+  CFLAGS="$GUILE_CFLAGS"
+  LIBS="$GUILE_LDFLAGS"
+  AC_CHECK_FUNCS([scm_c_define_module scm_c_read_string scm_gc_protect_object scm_list_1 scm_c_register_extension scm_make_real scm_num2double scm_c_define_gsubr])
+  AC_MSG_CHECKING(for scm_t_bits)
+  AC_CACHE_VAL(ac_cv_have_scm_t_bits,
+               [AC_TRY_COMPILE([#include <libguile.h>],
+                               [scm_t_bits a;],
+                               ac_cv_have_scm_t_bits=yes,
+                               ac_cv_have_scm_t_bits=no)])
+  AC_MSG_RESULT($ac_cv_have_scm_t_bits)
+  if test $ac_cv_have_scm_t_bits = yes; then
+    AC_DEFINE(HAVE_SCM_T_BITS)
+  fi
+  LIBS="$guile_compat_save_LIBS"
+  CFLAGS="$guile_compat_save_CFLAGS"])
diff --git a/examples/compat/compat.h b/examples/compat/compat.h
new file mode 100644
index 000000000..20cc566c4
--- /dev/null
+++ b/examples/compat/compat.h
@@ -0,0 +1,185 @@
+/* classes: h_files */
+
+#ifndef COMPATH
+#define COMPATH
+/*	Copyright (C) 2001, 2002 Free Software Foundation, Inc.
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ * 
+ * This program 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307 USA
+ *
+ * As a special exception, the Free Software Foundation gives permission
+ * for additional uses of the text contained in its release of GUILE.
+ *
+ * The exception is that, if you link the GUILE library with other files
+ * to produce an executable, this does not by itself cause the
+ * resulting executable to be covered by the GNU General Public License.
+ * Your use of that executable is in no way restricted on account of
+ * linking the GUILE library code into it.
+ *
+ * This exception does not however invalidate any other reasons why
+ * the executable file might be covered by the GNU General Public License.
+ *
+ * This exception applies only to the code released by the
+ * Free Software Foundation under the name GUILE.  If you copy
+ * code from other Free Software Foundation releases into a copy of
+ * GUILE, as the General Public License permits, the exception does
+ * not apply to the code that you add in this way.  To avoid misleading
+ * anyone as to the status of such modified files, you must delete
+ * this exception notice from them.
+ *
+ * If you write modifications of your own for GUILE, it is your choice
+ * whether to permit this exception to apply to your modifications.
+ * If you do not wish that, delete this exception notice.  */
+
+
+#ifndef SCM_GC8MARKP
+#  define SCM_GC8MARKP(X) SCM_GC_MARK_P(X)
+#  define SCM_SETGC8MARK(X) SCM_SET_GC_MARK(X)
+#endif
+
+#ifndef SCM_GC_MARK_P
+#  define SCM_GC_MARK_P(X) SCM_GCMARKP(X)
+#  define SCM_SET_GC_MARK(X) SCM_SETGCMARK(X)
+#endif
+
+#ifndef SCM_ARRAY_FLAG_CONTIGUOUS
+#  define SCM_ARRAY_FLAG_CONTIGUOUS SCM_ARRAY_CONTIGUOUS
+#endif
+
+#ifndef HAVE_SCM_T_BITS
+typedef scm_bits_t scm_t_bits;
+typedef scm_array scm_t_array;
+typedef scm_array_dim scm_t_array_dim;
+typedef scm_mutex_t scm_t_mutex;
+typedef scm_cond_t scm_t_cond;
+typedef scm_key_t scm_t_key;
+typedef scm_catch_body_t scm_t_catch_body;
+typedef scm_catch_handler_t scm_t_catch_handler;
+typedef scm_rstate scm_t_rstate;
+typedef scm_port scm_t_port;
+typedef scm_fport scm_t_fport;
+#endif
+
+#ifndef SCM_VALIDATE_DOUBLE_COPY
+#define SCM_VALIDATE_DOUBLE_COPY SCM_VALIDATE_NUMBER_COPY
+#endif
+
+#ifndef HAVE_SCM_C_DEFINE_MODULE
+#define scm_c_define_module(NAME,INIT,DATA) \
+  scm_make_module (scm_read_0str ("(" NAME ")"))
+#endif
+
+#ifndef SCM_MAKE_CHAR
+#define SCM_MAKE_CHAR SCM_MAKICHR
+#define SCM_CHAR SCM_ICHR
+#define SCM_CHARP SCM_ICHRP
+#endif
+
+#ifndef SCM_ROSTRINGP
+#define SCM_ROSTRINGP(x) (SCM_STRINGP (x) || SCM_SYMBOLP (x))
+#define SCM_RWSTRINGP(x) SCM_STRINGP (x)
+#define SCM_ROCHARS(x) \
+  (SCM_STRINGP (x) ? SCM_STRING_CHARS (x) : SCM_SYMBOL_CHARS (x))
+#define SCM_ROLENGTH(x) \
+  (SCM_STRINGP (x) ? SCM_STRING_LENGTH (x) : SCM_SYMBOL_LENGTH (x))
+#endif
+
+#ifndef SCM_STRING_COERCE_0TERMINATION_X
+#ifdef SCM_COERCE_SUBSTR
+#define SCM_STRING_COERCE_0TERMINATION_X SCM_COERCE_SUBSTR
+#else
+#define SCM_STRING_COERCE_0TERMINATION_X(x) (x)
+#endif
+#endif
+
+#ifndef HAVE_SCM_C_READ_STRING
+#define scm_c_read_string scm_read_0str
+#define scm_c_eval_string scm_eval_0str
+#define scm_str2symbol(X) SCM_CAR (scm_intern0 (X))
+#define scm_mem2string(X, Y) scm_makfromstr ((X), (Y), 0)
+#endif
+
+#ifndef HAVE_SCM_MAKE_REAL
+#define scm_make_real(X) scm_makdbl ((X), 0.0)
+#endif
+
+#ifdef HAVE_SCM_NUM2DOUBLE
+#define scm_real2double scm_num2double
+#define SCM_REAL2DOUBLE SCM_NUM2DOUBLE
+#else
+#define scm_real2double(X, POS, WHERE) scm_num2dbl ((X), (WHERE))
+#define SCM_REAL2DOUBLE(X, POS) scm_num2dbl ((X), FUNC_NAME)
+#endif
+
+#ifndef SCM_VALIDATE_DOUBLE_DEF_COPY
+#define SCM_VALIDATE_DOUBLE_DEF_COPY SCM_VALIDATE_NUMBER_DEF_COPY
+#endif
+
+#ifndef HAVE_SCM_GC_PROTECT_OBJECT
+#define scm_gc_protect_object scm_protect_object
+#endif
+
+#ifndef HAVE_SCM_C_DEFINE_GSUBR
+#define scm_c_define_gsubr scm_make_gsubr
+#endif
+
+#ifndef SCM_STRING_CHARS
+#define SCM_STRING_CHARS SCM_CHARS
+#define SCM_STRING_UCHARS SCM_UCHARS
+#define SCM_STRING_LENGTH SCM_LENGTH
+#endif
+
+#ifndef SCM_SUBSTRP
+#define SCM_SUBSTRP(X) 0
+#endif
+
+#ifndef SCM_VECTOR_LENGTH
+#define SCM_VECTOR_LENGTH SCM_LENGTH
+#define SCM_UVECTOR_LENGTH SCM_LENGTH
+#endif
+
+#ifndef SCM_SET_VECTOR_LENGTH
+#define SCM_SET_VECTOR_LENGTH SCM_SETLENGTH
+#define SCM_SET_UVECTOR_LENGTH SCM_SETLENGTH
+#endif
+
+#ifndef SCM_VECTOR_BASE
+#define SCM_VECTOR_BASE SCM_CHARS
+#define SCM_UVECTOR_BASE SCM_CHARS
+#endif
+
+#ifndef SCM_SET_VECTOR_BASE
+#define SCM_SET_VECTOR_BASE SCM_SETCHARS
+#define SCM_SET_UVECTOR_BASE SCM_SETCHARS
+#endif
+
+#ifndef SCM_UVECTOR_MAX_LENGTH
+#define SCM_UVECTOR_MAX_LENGTH SCM_LENGTH_MAX
+#endif
+
+#ifndef HAVE_SCM_LIST_1
+#define scm_list_1 SCM_LIST1
+#define scm_list_2 SCM_LIST2
+#define scm_list_3 SCM_LIST3
+#define scm_list_4 SCM_LIST4
+#define scm_list_5 SCM_LIST5
+#define scm_list_n scm_listify
+#endif
+
+#ifndef SCM_SYMBOL_CHARS
+#define SCM_SYMBOL_CHARS SCM_CHARS
+#endif
+
+#endif /* COMPATH */
diff --git a/examples/compat/configure.in b/examples/compat/configure.in
new file mode 100644
index 000000000..2e6be259d
--- /dev/null
+++ b/examples/compat/configure.in
@@ -0,0 +1,15 @@
+### BEGIN compatibility checks ###
+
+AC_CHECK_FUNCS(scm_c_define_module scm_c_read_string scm_gc_protect_object scm_list_1)
+
+AC_MSG_CHECKING(for scm_t_bits)
+AC_CACHE_VAL(ac_cv_have_scm_t_bits,
+[AC_TRY_COMPILE([#include <libguile.h>],
+[scm_t_bits a;],
+ac_cv_have_scm_t_bits=yes, ac_cv_have_scm_t_bits=no)])
+AC_MSG_RESULT($ac_cv_have_scm_t_bits)
+if test $ac_cv_have_scm_t_bits = yes; then
+  AC_DEFINE(HAVE_SCM_T_BITS)
+fi
+
+### END compatibility checks ###