Suppress debug stepping into auto-loaded library code.

* debug.c (debug_set_state, debug_restore_state): New functions.

* debug.h (debug_state_t): New type.
(debug_set_state, debug_restore_state): Declared, and defined
as dummy macros in non-debug-support build.

* lisplib.c (opt_dbg_autoload): New global variable.
(lisplib_try_load): Disable or enable debugging around
library loading based on opt_dbg_autoload option.

* lisplib.h (opt_dbg_autoload): Declared.

* txr.c (help): List --debug-autoload option.
(no_dbg_support): New static function to avoid repeated code.
(txr_main): Add debugger option. Change duplicate no debug support
error messages into calls to no_dbg_support.

* txr.1: Document --debug-autoload

1 files changed, 14 insertions, 0 deletions

diff --git a/debug.c b/debug.c
index 00117558..0fb426b2 100644
--- a/debug.c
+++ b/debug.c
@@ -241,6 +241,20 @@ val debug(val form, val bindings, val data, val line, val pos, val base)
   }
 }
 
+debug_state_t debug_set_state(int depth, int step)
+{
+  debug_state_t old = { next_depth, step_mode };
+  next_depth = depth;
+  step_mode = step;
+  return old;
+}
+
+void debug_restore_state(debug_state_t state)
+{
+  next_depth = state.next_depth;
+  step_mode = state.step_mode;
+}
+
 void debug_init(void)
 {
   step_mode = 1;