Ligher weight debug instrumentation.

This speeds up the TXR Lisp interpreter, because do_eval
sets up a debug frame and uses debug_return.

* debug.c (debug_block_s): Symbol removed.
(debug_init): Remove initialization of debug_block_s.

* debug.h (debug_block_s): Declaration removed.
(debug_enter): Do not establish a named block or a catch block;
no time-wasting unwind stack manipulation at all.
The debug_depth variable is managed by the extended setjmp
context now.  Provide a return value variable, and a well-defined name to
branch to to exit from the debug block.
(debug_return): Do not use heavy-weight uw_block_return;
simply set the return variable and branch to debug_return_out
label.

* signal.h (EJ_DBG_MEMB, EJ_DBG_SAVE, EJ_DBG_REST,
EJ_OPT_MEMB, EJ_OPT_SAVE, EJ_OPT_REST): New macros.
(extended_jmp_buf): Define optional global state
variables using EJ_OPT_MEMB.
(extended_setjmp): Save and restore optional
globals using EJ_OPT_SAVE and EJ_OPT_RESTORE.
Now debug_depth is saved and restored if
debugging support is compiled in.

* match.c (open_data_source): Remove bogus debug_return
invocations which were uncovered here by changes to the macro.

* eval.c (do_eval, expand_macro): debug_return must now be after
debug_end, because it won't dynamically clean up frames that it doesn't
know about. The set_dyn_env is no longer unreachable in expand_macro;
it is now necessary because debug_return isn't doing the longjmp
that previously restored dyn_env.

1 files changed, 21 insertions, 0 deletions

diff --git a/signal.h b/signal.h
index 036475e7..4b942275 100644
--- a/signal.h
+++ b/signal.h
@@ -25,6 +25,21 @@
  */
 
 
+#if CONFIG_DEBUG_SUPPORT
+extern int debug_depth;
+#define EJ_DBG_MEMB int dbg_depth;
+#define EJ_DBG_SAVE(EJB) (EJB).dbg_depth = debug_depth,
+#define EJ_DBG_REST(EJB) debug_depth = (EJB).dbg_depth,
+#else
+#define EJ_DBG_MEMB
+#define EJ_DBG_SAVE(EJB)
+#define EJ_DBG_REST(EJB)
+#endif
+
+#define EJ_OPT_MEMB EJ_DBG_MEMB
+#define EJ_OPT_SAVE(EJB) EJ_DBG_SAVE(EJB)
+#define EJ_OPT_REST(EJB) EJ_DBG_REST(EJB)
+
 #if HAVE_POSIX_SIGS
 
 #define sig_save_enable                         \
@@ -62,6 +77,7 @@ typedef struct {
   val de;
   int gc;
   val **gc_pt;
+  EJ_OPT_MEMB
   int rv;
 } extended_jmp_buf;
 
@@ -72,12 +88,14 @@ typedef struct {
       gc_enabled = (EJB).gc,                    \
       gc_prot_top = (EJB).gc_pt,                \
       sig_mask(SIG_SETMASK, &(EJB).blocked, 0), \
+      EJ_OPT_REST(EJB)                          \
       (EJB).rv)                                 \
    : ((EJB).se = async_sig_enabled,             \
       (EJB).de = dyn_env,                       \
       (EJB).gc = gc_enabled,                    \
       (EJB).gc_pt = gc_prot_top,                \
       (EJB).blocked = sig_blocked_cache,        \
+      EJ_OPT_SAVE(EJB)                          \
       0))
 
 #define extended_longjmp(EJB, ARG)              \
@@ -99,6 +117,7 @@ typedef struct {
   val de;
   int gc;
   val **gc_pt;
+  EJ_OPT_MEMB
   int rv;
 } extended_jmp_buf;
 
@@ -107,10 +126,12 @@ typedef struct {
    ? (dyn_env = (EJB).de,                       \
       gc_enabled = ((EJB).gc),                  \
       gc_prot_top = (EJB).gc_pt,                \
+      EJ_OPT_REST(EJB)                          \
       (EJB).rv)                                 \
    : ((EJB).de = dyn_env,                       \
       (EJB).gc = gc_enabled,                    \
       (EJB).gc_pt = gc_prot_top,                \
+      EJ_OPT_SAVE(EJB)                          \
       0))
 
 #define extended_longjmp(EJB, ARG)              \