Adding a debugger. This is an experimental prototype.

* Makefile (OBJS): New object file debug.o.

* dep.mk: Updated.

* match.c (h_fun): Use debug_begin and debug_end macros
to set up a debug frame for backtracing.
(match_line, match_files): Call debug_check to give debugger a chance
to instrument call.
(v_fun): Use debug_begin and debug_end macros to set up a debug frame
for backtracing. Call debug_check to give debugger a chance to
instrument call.

* stream.c (struct strm_ops): New function pointer, flush.
(stdio_maybe_write_error): Wrong word in error message corrected.
(stdio_flush): New static function.
(stdio_ops, pipe_ops): New function entered into tables.
(flush_stream): New function.

* stream.h (flush_stream): Declared.

* txr.c (help): New options documented.
(main): call to debug_init added. New debug options parsed and
opt_debugger set accordingly.

* unwind.c (uw_push_debug, uw_current_frame): New function.

* unwind.h (uw_frtype): New enumeration member UW_DBG.
(struct uw_debug): New frame variant.
(union uw_frame): New member, db.
(uw_push_debug, uw_current_frame): Declared,

* debug.c: New file.

* debug.h: New file.

1 files changed, 52 insertions, 0 deletions

diff --git a/debug.h b/debug.h
new file mode 100644
index 00000000..b7248459
--- /dev/null
+++ b/debug.h
@@ -0,0 +1,52 @@
+/* Copyright 2011
+ * Kaz Kylheku <kaz@kylheku.com>
+ * Vancouver, Canada
+ * All rights reserved.
+ *
+ * BSD License:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in
+ *      the documentation and/or other materials provided with the
+ *      distribution.
+ *   3. The name of the author may not be used to endorse or promote
+ *      products derived from this software without specific prior
+ *      written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+extern int opt_debugger;
+
+val debug(val form, val bindings, val data, val line, val chr);
+
+INLINE val debug_check(val form, val bindings, val data, val line, val chr)
+{
+  return (opt_debugger) ? debug(form, bindings, data, line, chr) : nil;
+}
+
+void debug_init(void);
+
+#define debug_begin(FUNC, ARGS, UBP,    \
+                    BINDINGS, DATA,     \
+                    LINE, CHR)          \
+  do {                                  \
+    uw_frame_t db_env;                  \
+    if (opt_debugger)                   \
+      uw_push_debug(&db_env, FUNC, ARGS,\
+                    UBP, BINDINGS, DATA,\
+                    LINE, CHR);         \
+    (void) 0
+
+#define debug_end                       \
+    if (opt_debugger)                   \
+      uw_pop_frame(&db_env);            \
+  } while (0)