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, 13 insertions, 0 deletions

diff --git a/txr.c b/txr.c
index 644314f0..7a611432 100644
--- a/txr.c
+++ b/txr.c
@@ -40,6 +40,7 @@
 #include "parser.h"
 #include "match.h"
 #include "utf8.h"
+#include "debug.h"
 #include "txr.h"
 
 const wchli_t *version = wli("041");
@@ -91,6 +92,8 @@ static void help(void)
 "-q                     Quiet: don't report errors during query matching.\n"
 "-v                     Verbose: extra logging from matcher.\n"
 "-b                     Don't dump list of bindings.\n"
+"-l                     If dumping bindings, use a Lisp format.\n"
+"-d                     Debugger mode.\n"
 "-a num                 Generate array variables up to num-dimensions.\n"
 "                       Default is 1. Additional dimensions are fudged\n"
 "                       by generating numeric suffixes\n"
@@ -103,6 +106,8 @@ static void help(void)
 "                       to the utility.\n"
 "--help                 You already know!\n"
 "--version              Display program version\n"
+"--lisp-bindings        Synonym for -l\n"
+"--debugger             Synonym for -d\n"
 "\n"
 "Options that take no argument can be combined. The -q and -v options\n"
 "are mutually exclusive; the right-most one dominates.\n"
@@ -145,6 +150,7 @@ int main(int argc, char **argv)
   init(progname, oom_realloc_handler, &stack_bottom);
   match_init();
   parse_init();
+  debug_init();
   return txr_main(argc, argv);
 }
 
@@ -288,6 +294,10 @@ int txr_main(int argc, char **argv)
       opt_lisp_bindings = 1;
       argv++, argc--;
       continue;
+    } else if (!strcmp(*argv, "--debugger")) {
+      opt_debugger = 1;
+      argv++, argc--;
+      continue;
     }
 
 
@@ -307,6 +317,9 @@ int txr_main(int argc, char **argv)
         case 'l':
           opt_lisp_bindings = 1;
           break;
+        case 'd':
+          opt_debugger = 1;
+          break;
         case 'a':
         case 'c':
         case 'D':