Improved debugging. Debug nesting depth counter maintained

and used for next/step/finish stepping.

* Makefile (OBJS): debug.o moved to OBJS-y or OBJS-.
(OBJS-y, OBJS-): New variables.
$(PROG): Depends on OBJS-y also.
clean: clean $(OBJS-y).
depend: include $(OBJS-y) in dependency generation.

* configure: Underscores and dashes are interchangeable in
configure variables.
(yaccname_given, yacc_given): Default value is y, not yes.
(debug_support): New config variable.
(CONFIG_DEBUG_SUPPORT): New config.h symbol.

* debug.c (debug_depth): New global variable.
(debug_block_s): New symbol variable.
(next_depth): New static variable.
(debug): Renamed some commands. Introduced separate next, step
and finish.
(debug_init): debug_block_s initialized.

* debug.h (debug_depth, debug_block_s): Declared.
(debug_enter, debug_leave, debug_return): New macros.
(debug_check, debug_init): Conditionally defined based on
if this is a debug build.

* dep.mk: Regenerated.

* eval.c (eval): Instrumented with debug_enter, debug_leave,
debug_return.

* match.c (match_line, v_fun, match_files): Likewise.

* txr.c (txr_main): Bail if -d or --debug used in build
that lacks debug support.

1 files changed, 55 insertions, 2 deletions

diff --git a/debug.h b/debug.h
index b7248459..935746da 100644
--- a/debug.h
+++ b/debug.h
@@ -25,9 +25,32 @@
  */
 
 extern int opt_debugger;
+extern int debug_depth;
+extern val debug_block_s;
 
 val debug(val form, val bindings, val data, val line, val chr);
 
+#ifdef CONFIG_DEBUG_SUPPORT
+
+#define debug_enter                                     \
+  {                                                     \
+    int debug_depth_save = debug_depth++;               \
+    uw_block_begin(debug_block_s, debug_result);        \
+    uw_simple_catch_begin {
+
+#define debug_leave                                     \
+    }                                                   \
+    uw_unwind {                                         \
+      debug_depth = debug_depth_save;                   \
+    }                                                   \
+    uw_catch_end;                                       \
+    uw_block_end;                                       \
+    return debug_result;                                \
+  }
+
+#define debug_return(VAL)                               \
+  uw_block_return(debug_block_s, VAL)
+
 INLINE val debug_check(val form, val bindings, val data, val line, val chr)
 {
   return (opt_debugger) ? debug(form, bindings, data, line, chr) : nil;
@@ -40,13 +63,43 @@ void debug_init(void);
                     LINE, CHR)          \
   do {                                  \
     uw_frame_t db_env;                  \
-    if (opt_debugger)                   \
+    if (opt_debugger) {                 \
       uw_push_debug(&db_env, FUNC, ARGS,\
                     UBP, BINDINGS, DATA,\
                     LINE, CHR);         \
+    }                                   \
     (void) 0
 
 #define debug_end                       \
-    if (opt_debugger)                   \
+    if (opt_debugger) {                 \
       uw_pop_frame(&db_env);            \
+    }                                   \
   } while (0)
+
+#else
+
+#define debug_enter {
+
+#define debug_leave }
+
+#define debug_return(VAL) return VAL
+
+INLINE val debug_check(val form, val bindings, val data, val line, val chr)
+{
+  return nil;
+}
+
+#define debug_begin(FUNC, ARGS, UBP,    \
+                    BINDINGS, DATA,     \
+                    LINE, CHR)          \
+  do {                                  \
+    (void) 0
+
+#define debug_end                       \
+  } while (0)
+
+INLINE void debug_init(void)
+{
+}
+
+#endif