From: Matt Birkholz <matt@birchwood-abbey.net>
Date: Sat, 16 Sep 2017 21:56:31 +0000 (-0700)
Subject: microcode/debug: Add ustring support, Stack(), Print(), brevity.
X-Git-Tag: mit-scheme-pucked-9.2.12~14^2~26
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=2be32584a814e3a5be6fe0ddc5d613026861d8d1;p=mit-scheme.git

microcode/debug: Add ustring support, Stack(), Print(), brevity.

Print is just the renamed Debug_Print, renamed for brevity in debugger
commands.  Rename do_printing to print_object and punt the detailed_p
parameter, and the gotos, and handled_p.  Move the bulky compiled
entry handling to a separate function: print_compiled_entry.  Punt
checking for a "closed" stack frame in verify_stack().
---

diff --git a/src/microcode/debug.c b/src/microcode/debug.c
index 9f0888a86..26fe18fce 100644
--- a/src/microcode/debug.c
+++ b/src/microcode/debug.c
@@ -36,7 +36,7 @@ USA.
    static SCHEME_OBJECT compiled_block_debug_filename (SCHEME_OBJECT);
 #endif
 
-static void do_printing (outf_channel, SCHEME_OBJECT, bool);
+static void print_object (outf_channel, SCHEME_OBJECT);
 static bool print_primitive_name (outf_channel, SCHEME_OBJECT);
 static void print_expression (outf_channel, SCHEME_OBJECT, const char *);
 
@@ -186,45 +186,106 @@ Print_Return (const char * String)
   outf_error ("\n");
 }
 
+static void
+print_simple (outf_channel stream, SCHEME_OBJECT object)
+{
+  unsigned int type = (OBJECT_TYPE (object));
+  const char * name = 0;
+  if (type < TYPE_CODE_LIMIT)
+    name = (type_names[type]);
+  if (name != 0)
+    outf (stream, "[%s", name);
+  else
+    outf (stream, "[%#02x", type);
+  outf (stream, " %#lx]", OBJECT_DATUM (object));
+}
+
+static void
+print_char (outf_channel stream, unsigned int cp)
+{
+  switch (cp)
+    {
+    case '\\':
+      outf (stream, "\\\\");
+      break;
+    case '"':
+      outf (stream, "\\\"");
+      break;
+    case '\t':
+      outf (stream, "\\t");
+      break;
+    case '\n':
+      outf (stream, "\\n");
+      break;
+    case '\f':
+      outf (stream, "\\f");
+      break;
+    default:
+      if ((cp >= ' ') && (cp <= '~'))
+	outf (stream, "%c", cp);
+      else
+	outf (stream, "\\%03o", cp);
+      break;
+    }
+}
+
 static void
 print_string (outf_channel stream, SCHEME_OBJECT string)
 {
   long length, long_enough;
   long i;
   char * next;
-  char this;
 
   outf (stream, "\"");
   length = (STRING_LENGTH (string));
   long_enough = (length < 100 ? length : 90);
   next = (STRING_POINTER (string));
   for (i = 0; (i < long_enough); i += 1)
+    print_char (stream, *next++);
+  if (length != long_enough)
+    outf (stream, "...[%ld total chars]", length);
+  outf (stream, "\"");
+}
+
+static void
+print_ustring (outf_channel stream, SCHEME_OBJECT string)
+{
+  long length, long_enough;
+  long i;
+  unsigned char * next;
+  unsigned int cp;
+  unsigned char cp_size;
+
+  length = (STRING_LENGTH (string));
+  long_enough = (length < 100 ? length : 90);
+  next = (STRING_LOC (string, 0));
+
+  cp_size = ((OBJECT_TYPE (MEMORY_REF (string, BYTEVECTOR_LENGTH_INDEX)))
+	     && 0x03);
+  if (cp_size == 0)
     {
-      this = (*next++);
-      switch (this)
-	{
-	case '\\':
-	  outf (stream, "\\\\");
-	  break;
-	case '"':
-	  outf (stream, "\\\"");
-	  break;
-	case '\t':
-	  outf (stream, "\\t");
-	  break;
-	case '\n':
-	  outf (stream, "\\n");
-	  break;
-	case '\f':
-	  outf (stream, "\\f");
-	  break;
-	default:
-	  if ((this >= ' ') && (this <= '~'))
-	    outf (stream, "%c", this);
-	  else
-	    outf (stream, "\\%03o", this);
-	  break;
-	}
+      print_simple (stream, string);
+      return;
+    }
+
+  outf (stream, "\"");
+  for (i = 0; (i < long_enough); i += 1)
+    {
+      switch (cp_size) {
+      case 1:
+	cp = *next++;
+	break;
+      case 2:
+	cp = *next++;
+	cp |= (*next++ << 8);
+	break;
+      case 3:
+	cp = *next++;
+	cp |= (*next++ << 8);
+	cp |= (*next++ << 16);
+	break;
+      }
+      print_char (stream, cp);
     }
   if (length != long_enough)
     outf (stream, "...[%ld total chars]", length);
@@ -276,20 +337,12 @@ print_filename (outf_channel stream, SCHEME_OBJECT filename)
 }
 #endif
 
-static void
-print_object (SCHEME_OBJECT object)
-{
-  do_printing (ERROR_OUTPUT, object, true);
-  outf_error ("\n");
-  outf_flush_error();
-}
-
 DEFINE_PRIMITIVE ("DEBUGGING-PRINTER", Prim_debugging_printer, 1, 1,
   "A cheap, built-in printer intended for debugging the interpreter.")
 {
   PRIMITIVE_HEADER (1);
 
-  print_object (ARG_REF (1));
+  print_object (ERROR_OUTPUT, ARG_REF (1));
   return (SHARP_F);
 }
 
@@ -303,15 +356,14 @@ print_objects (SCHEME_OBJECT * objects, int n)
   end = (objects + n);
   while (scan < end)
     {
-      outf_error
-	("%4lx: ", ((unsigned long) (((char *) scan) - ((char *) objects))));
-      do_printing (ERROR_OUTPUT, (*scan++), true);
+      outf_error ("%#lx: ", ((unsigned long) scan));
+      print_object (ERROR_OUTPUT, (*scan++));
       outf_error ("\n");
     }
   outf_flush_error();
 }
 
-/* This is useful because `do_printing' doesn't print the contents of
+/* This is useful because `print_object' doesn't print the contents of
    vectors.  The reason that it doesn't is because vectors are used to
    represent named structures, and most named structures don't want to
    be printed out explicitly.  */
@@ -324,11 +376,12 @@ Print_Vector (SCHEME_OBJECT vector)
 }
 
 static void
-print_expression (outf_channel stream, SCHEME_OBJECT expression, const char * string)
+print_expression (outf_channel stream,
+		  SCHEME_OBJECT expression, const char * string)
 {
   if ((string [0]) != 0)
     outf (stream, "%s: ", string);
-  do_printing (stream, expression, true);
+  print_object (stream, expression);
 }
 
 void
@@ -338,277 +391,250 @@ Print_Expression (SCHEME_OBJECT expression, const char * string)
 }
 
 static void
-do_printing (outf_channel stream, SCHEME_OBJECT Expr, bool Detailed)
+print_compiled_entry (outf_channel stream, SCHEME_OBJECT entry)
 {
-  long Temp_Address = (OBJECT_DATUM (Expr));
-  bool handled_p = false;
+  bool closure_p = false;
+  cc_entry_type_t cet;
+  const char * type_string;
+  SCHEME_OBJECT filename;
 
-  if (EMPTY_LIST_P (Expr))	{ outf (stream, "()");	return; }
-  else if (Expr == SHARP_F)	{ outf (stream, "#F");	return; }
-  else if (Expr == SHARP_T)	{ outf (stream, "#T");	return; }
-  else if (Expr == UNSPECIFIC)	{ outf (stream, "[UNSPECIFIC]"); return; }
+  if (read_cc_entry_type ((&cet), (CC_ENTRY_ADDRESS (entry))))
+    type_string = "UNKNOWN";
+  else
+    switch (cet.marker)
+      {
+      case CET_PROCEDURE:
+      case CET_CLOSURE:
+	if (cc_entry_closure_p (entry))
+	  {
+	    type_string = "compiled-closure";
+	    entry = (cc_closure_to_entry (entry));
+	    closure_p = true;
+	  }
+	else
+	  type_string = "compiled-procedure";
+	break;
 
-  else if (Expr == return_to_interpreter)
+      case CET_CONTINUATION:
+	type_string = "compiled-return-address";
+	break;
+
+      case CET_EXPRESSION:
+	type_string = "compiled-expression";
+	break;
+
+      case CET_INTERNAL_CONTINUATION:
+	type_string = "compiled-return-address";
+	break;
+
+      case CET_INTERNAL_PROCEDURE:
+      case CET_TRAMPOLINE:
+	type_string = "compiled-entry";
+	break;
+
+      case CET_RETURN_TO_INTERPRETER:
+	type_string = "compiled-return-address";
+	break;
+
+      default:
+	type_string = "compiled-entry";
+	break;
+      }
+
+  outf (stream, "[%s offset: %#lx entry: %#lx",
+	type_string,
+	(cc_entry_to_block_offset (entry)),
+	(OBJECT_DATUM (entry)));
+  if (closure_p)
+    outf (stream, " address: %#lx", (OBJECT_DATUM (entry)));
+
+  filename = (compiled_entry_debug_filename (entry));
+  if (STRING_P (filename))
     {
-      outf (stream, "[RETURN_TO_INTERPRETER]");
-      return;
+      outf (stream, " file: ");
+      print_filename (stream, filename);
+    }
+  else if (PAIR_P (filename))
+    {
+      outf (stream, " file: ");
+      print_filename (stream, (PAIR_CAR (filename)));
+      outf (stream, " block: %ld",
+	    ((long) (FIXNUM_TO_LONG (PAIR_CDR (filename)))));
     }
+  outf (stream, "]");
+}
 
-  else if (Expr == reflect_to_interface)
+static void
+print_object (outf_channel stream, SCHEME_OBJECT obj)
+{
+  if (EMPTY_LIST_P (obj))	{ outf (stream, "()");	return; }
+  else if (obj == SHARP_F)	{ outf (stream, "#F");	return; }
+  else if (obj == SHARP_T)	{ outf (stream, "#T");	return; }
+  else if (obj == UNSPECIFIC){ outf (stream, "[unspecific]"); return; }
+
+  else if (obj == return_to_interpreter)
     {
-      outf (stream, "[REFLECT_TO_INTERFACE]");
+      outf (stream, "[return-to-interpreter]");
       return;
     }
 
+  else if (obj == reflect_to_interface)
+    {
+      outf (stream, "[reflect-to-interface]");
+      return;
+    }
 
-  switch (OBJECT_TYPE (Expr))
+  switch (OBJECT_TYPE (obj))
     {
     case TC_ACCESS:
-      {
-	outf (stream, "[ACCESS (");
-	Expr = (MEMORY_REF (Expr, ACCESS_NAME));
-      SPrint:
-	print_symbol (stream, Expr);
-	handled_p = true;
-	outf (stream, ")");
-	break;
-      }
+      outf (stream, "[access ");
+      print_symbol (stream, (MEMORY_REF (obj, ACCESS_NAME)));
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
+      return;
 
     case TC_ASSIGNMENT:
-      outf (stream, "[SET! (");
-      Expr = (MEMORY_REF ((MEMORY_REF (Expr, ASSIGN_NAME)), VARIABLE_SYMBOL));
-      goto SPrint;
+      outf (stream, "[set! ");
+      print_symbol (stream, (MEMORY_REF ((MEMORY_REF (obj, ASSIGN_NAME)),
+					 VARIABLE_SYMBOL)));
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
+      return;
+
+    case TC_DEFINITION:
+      outf (stream, "[define ");
+      print_symbol (stream, (MEMORY_REF (obj, DEFINE_NAME)));
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
+      return;
 
     case TC_CHARACTER_STRING:
     case TC_BYTEVECTOR:
-      print_string (stream, Expr);
+      print_string (stream, obj);
       return;
 
-    case TC_DEFINITION:
-      outf (stream, "[DEFINE (");
-      Expr = (MEMORY_REF (Expr, DEFINE_NAME));
-      goto SPrint;
+    case TC_UNICODE_STRING:
+      print_ustring (stream, obj);
+      return;
 
     case TC_FIXNUM:
-      outf (stream, "%ld", ((long) (FIXNUM_TO_LONG (Expr))));
+      outf (stream, "%ld", ((long) (FIXNUM_TO_LONG (obj))));
       return;
 
     case TC_BIG_FLONUM:
-      outf (stream, "%lf", (FLONUM_TO_DOUBLE (Expr)));
+      outf (stream, "%lf", (FLONUM_TO_DOUBLE (obj)));
       return;
 
     case TC_WEAK_CONS:
     case TC_LIST:
-      print_list (stream, Expr);
+      print_list (stream, obj);
       return;
 
     case TC_FALSE:
-      break;
+      print_simple (stream, obj);
+      return;
 
     case TC_UNINTERNED_SYMBOL:
-      outf (stream, "[UNINTERNED_SYMBOL (");
-      goto SPrint;
+      outf (stream, "[uninterned ");
+      print_symbol (stream, obj);
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
+      return;
 
     case TC_INTERNED_SYMBOL:
-      print_symbol (stream, Expr);
+      print_symbol (stream, obj);
       return;
 
     case TC_VARIABLE:
-      Expr = (MEMORY_REF (Expr, VARIABLE_SYMBOL));
-      if (Detailed)
-	{
-	  outf (stream, "[VARIABLE (");
-	  goto SPrint;
-	}
-      print_symbol (stream, Expr);
+      outf (stream, "[variable ");
+      print_symbol (stream, (MEMORY_REF (obj, VARIABLE_SYMBOL)));
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
       return;
 
     case TC_COMBINATION:
-      outf (stream, "[COMBINATION (%ld args) 0x%lx]",
-	      ((long) ((VECTOR_LENGTH (Expr)) - 1)),
-	      ((long) Temp_Address));
-      if (Detailed)
-	{
-	  outf (stream, " (");
-	  do_printing (stream, (MEMORY_REF (Expr, COMB_FN_SLOT)), false);
-	  outf (stream, " ...)");
-	}
+      outf (stream, "[combination ");
+      print_object (stream, (MEMORY_REF (obj, COMB_FN_SLOT)));
+      outf (stream, " ... (%ld args)", (VECTOR_LENGTH (obj)) - 1);
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
       return;
 
     case TC_ENVIRONMENT:
+      outf (stream, "[environment from ");
       {
 	SCHEME_OBJECT procedure;
-
-	outf (stream, "[ENVIRONMENT 0x%lx]", ((long) Temp_Address));
-	outf (stream, " (from ");
-	procedure = (MEMORY_REF (Expr, ENVIRONMENT_FUNCTION));
+	procedure = (MEMORY_REF (obj, ENVIRONMENT_FUNCTION));
 	if ((OBJECT_TYPE (procedure)) == TC_QUAD)
 	  procedure = (MEMORY_REF (procedure, ENV_EXTENSION_PROCEDURE));
-	do_printing (stream, procedure, false);
-	outf (stream, ")");
-	return;
+	print_object (stream, procedure);
       }
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
+      return;
 
     case TC_EXTENDED_LAMBDA:
-      if (Detailed)
-	outf (stream, "[EXTENDED_LAMBDA (");
-      do_printing (stream,
-		   (MEMORY_REF ((MEMORY_REF (Expr, ELAMBDA_NAMES)), 1)),
-		   false);
-      if (Detailed)
-	outf (stream, ") 0x%lx", ((long) Temp_Address));
+      outf (stream, "[extended-lambda ");
+      print_object (stream, (MEMORY_REF ((MEMORY_REF (obj, ELAMBDA_NAMES)),
+					 1)));
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
       return;
 
     case TC_EXTENDED_PROCEDURE:
-      if (Detailed)
-	outf (stream, "[EXTENDED_PROCEDURE (");
-      do_printing (stream, (MEMORY_REF (Expr, PROCEDURE_LAMBDA_EXPR)), false);
-      if (Detailed)
-	outf (stream, ") 0x%lx]", ((long) Temp_Address));
-      break;
+      outf (stream, "[extended-procedure ");
+      print_object (stream, (MEMORY_REF (obj, PROCEDURE_LAMBDA_EXPR)));
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
+      return;
 
     case TC_LAMBDA:
-      if (Detailed)
-	outf (stream, "[LAMBDA (");
-      do_printing (stream,
-		   (MEMORY_REF ((MEMORY_REF (Expr, LAMBDA_FORMALS)), 1)),
-		  false);
-      if (Detailed)
-	outf (stream, ") 0x%lx]", ((long) Temp_Address));
+      outf (stream, "[lambda ");
+      print_object (stream, (MEMORY_REF ((MEMORY_REF (obj, LAMBDA_FORMALS)),
+					 1)));
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
       return;
 
     case TC_PRIMITIVE:
-      outf (stream, "[PRIMITIVE ");
-      print_primitive_name (stream, Expr);
+      outf (stream, "[primitive ");
+      print_primitive_name (stream, obj);
       outf (stream, "]");
       return;
 
     case TC_PROCEDURE:
-      if (Detailed)
-	outf (stream, "[PROCEDURE (");
-      do_printing (stream, (MEMORY_REF (Expr, PROCEDURE_LAMBDA_EXPR)), false);
-      if (Detailed)
-	outf (stream, ") 0x%lx]", ((long) Temp_Address));
+      outf (stream, "[procedure ");
+      print_object (stream, (MEMORY_REF (obj, PROCEDURE_LAMBDA_EXPR)));
+      outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
       return;
 
     case TC_REFERENCE_TRAP:
-      {
-	if ((OBJECT_DATUM (Expr)) <= TRAP_MAX_IMMEDIATE)
-	  break;
-	outf (stream, "[REFERENCE-TRAP");
-	print_expression (stream, (MEMORY_REF (Expr, TRAP_TAG)), " tag");
-	print_expression (stream, (MEMORY_REF (Expr, TRAP_EXTRA)), " extra");
-	outf (stream, "]");
-	return;
-      }
+      if ((OBJECT_DATUM (obj)) <= TRAP_MAX_IMMEDIATE)
+	print_simple (stream, obj);
+      else
+	{
+	  outf (stream, "[reference-trap");
+	  print_expression (stream, (MEMORY_REF (obj, TRAP_TAG)), " tag");
+	  print_expression (stream, (MEMORY_REF (obj, TRAP_EXTRA)), " extra");
+	  outf (stream, " %#lx]", (OBJECT_DATUM (obj)));
+	}
+      return;
 
     case TC_RETURN_CODE:
-      outf (stream, "[RETURN_CODE ");
-      print_return_name (stream, Expr);
+      outf (stream, "[return-code ");
+      print_return_name (stream, obj);
       outf (stream, "]");
       return;
 
     case TC_CONSTANT:
-      break;
+      print_simple (stream, obj);
+      return;
 
 #ifdef CC_SUPPORT_P
     case TC_COMPILED_ENTRY:
-      {
-	SCHEME_OBJECT entry = Expr;
-	bool closure_p = false;
-	cc_entry_type_t cet;
-	const char * type_string;
-	SCHEME_OBJECT filename;
-
-	if (read_cc_entry_type ((&cet), (CC_ENTRY_ADDRESS (entry))))
-	  type_string = "UNKNOWN";
-	else
-	  switch (cet.marker)
-	    {
-	    case CET_PROCEDURE:
-	    case CET_CLOSURE:
-	      if (cc_entry_closure_p (entry))
-		{
-		  type_string = "COMPILED_CLOSURE";
-		  entry = (cc_closure_to_entry (entry));
-		  closure_p = true;
-		}
-	      else
-		type_string = "COMPILED_PROCEDURE";
-	      break;
-
-	    case CET_CONTINUATION:
-	      type_string = "COMPILED_RETURN_ADDRESS";
-	      break;
-
-	    case CET_EXPRESSION:
-	      type_string = "COMPILED_EXPRESSION";
-	      break;
-
-	    case CET_INTERNAL_CONTINUATION:
-	      type_string = "COMPILED_RETURN_ADDRESS";
-	      break;
-
-	    case CET_INTERNAL_PROCEDURE:
-	    case CET_TRAMPOLINE:
-	      type_string = "COMPILED_ENTRY";
-	      break;
-
-	    case CET_RETURN_TO_INTERPRETER:
-	      type_string = "COMPILED_RETURN_ADDRESS";
-	      break;
-
-	    default:
-	      type_string = "COMPILED_ENTRY";
-	      break;
-	    }
-
-	outf (stream, "[%s offset: %#lx entry: %#lx",
-	      type_string,
-	      (cc_entry_to_block_offset (entry)),
-	      (OBJECT_DATUM (entry)));
-	if (closure_p)
-	  outf (stream, " address: 0x%lx", ((long) Temp_Address));
-
-	filename = (compiled_entry_debug_filename (entry));
-	if (STRING_P (filename))
-	  {
-	    outf (stream, " file: ");
-	    print_filename (stream, filename);
-	  }
-	else if (PAIR_P (filename))
-	  {
-	    outf (stream, " file: ");
-	    print_filename (stream, (PAIR_CAR (filename)));
-	    outf (stream, " block: %ld",
-		    ((long) (FIXNUM_TO_LONG (PAIR_CDR (filename)))));
-	  }
-	outf (stream, "]");
-	return;
-      }
+      print_compiled_entry (stream, obj);
+      return;
 #endif
 
     default:
-      break;
+      print_simple (stream, obj);
     }
-  if (!handled_p)
-    {
-      unsigned int type = (OBJECT_TYPE (Expr));
-      const char * name = 0;
-      if ((OBJECT_TYPE (Expr)) < TYPE_CODE_LIMIT)
-	name = (type_names[type]);
-      if (name != 0)
-	outf (stream, "[%s", name);
-      else
-	outf (stream, "[%#02x", type);
-    }
-  outf (stream, " %#lx]", ((unsigned long) Temp_Address));
 }
 
-extern void
-Debug_Print (SCHEME_OBJECT Expr, bool Detailed)
+void
+Print (SCHEME_OBJECT Expr)
 {
-  do_printing (ERROR_OUTPUT, Expr, Detailed);
+  print_object (ERROR_OUTPUT, Expr);
   outf_error ("\n");
   outf_flush_error ();
 }
@@ -640,6 +666,40 @@ Print_One_Continuation_Frame (SCHEME_OBJECT Temp)
   return (print_one_continuation_frame (ERROR_OUTPUT, Temp));
 }
 
+/* Code to dump the Scheme stack. */
+
+static void
+dump_stack (outf_channel stream,
+	    SCHEME_OBJECT *sp,
+	    SCHEME_OBJECT *limit,
+	    int count)
+{
+  int done = 0;
+  while (((count == 0) || (done < count))
+	 && (STACK_LOCATIVE_ABOVE_P (sp, limit)))
+    {
+      SCHEME_OBJECT obj;
+      outf (stream, "%#lx: ", ((unsigned long) sp));
+      obj = (STACK_LOCATIVE_POP (sp));
+      print_object (stream, obj);
+      outf (stream, "\n");
+      done += 1;
+      if ((RETURN_CODE_P (obj))
+	  && ((OBJECT_DATUM (obj)) == RC_JOIN_STACKLETS))
+	{
+	  SCHEME_OBJECT cp = (STACK_LOCATIVE_POP (sp));
+	  sp = (control_point_start (cp));
+	  limit = (control_point_end (cp));
+	}
+    }
+}
+
+void
+Stack (int count)
+{
+  dump_stack (ERROR_OUTPUT, stack_pointer, stack_end, count);
+}
+
 /* Back_Trace relies on (a) only a call to SAVE_CONT puts a return code on the
    stack; (b) SAVE_CONT pushes the expression first.  */
 
@@ -738,6 +798,8 @@ Print_Primitive (SCHEME_OBJECT primitive)
   }
 }
 
+/* Code for scanning the heap for obviously broken or invalid objects. */
+
 #ifdef ENABLE_DEBUGGING_TOOLS
 
 static void
@@ -803,7 +865,7 @@ dump_object (SCHEME_OBJECT * addr)
 {
   SCHEME_OBJECT object = *addr;
   outf_error ("%#lx: ", (unsigned long)addr);
-  do_printing (ERROR_OUTPUT, object, true);
+  print_object (ERROR_OUTPUT, object);
   outf_error ("\n");
   {
     SCHEME_OBJECT * end = next_addr (addr);
@@ -1185,39 +1247,25 @@ verify_heap_area (const char * name, SCHEME_OBJECT * area, SCHEME_OBJECT * end)
 bool
 verify_stack (SCHEME_OBJECT * sp, SCHEME_OBJECT * bottom)
 {
-  /* Check that the stack is "sealed" -- the top is an interpreter
-     return code or a compiled entry point (return address). */
-
   int complaints = 0;
-  unsigned long addr = (unsigned long)sp;
-  SCHEME_OBJECT object = STACK_LOCATIVE_POP (sp);
-  unsigned int type = OBJECT_TYPE (object);
-  if (! (type == TC_RETURN_CODE || type == TC_COMPILED_ENTRY))
-    {
-      outf_error ("%#lx: Invalid stack top: ", addr);
-      do_printing (ERROR_OUTPUT, object, true);
-      outf_error ("\n");
-      complaints += 1;
-    }
   while (STACK_LOCATIVE_ABOVE_P (sp, bottom))
     {
-      addr = (unsigned long)sp;
-      object = STACK_LOCATIVE_POP (sp);
-      type = OBJECT_TYPE (object);
+      SCHEME_OBJECT object = STACK_LOCATIVE_POP (sp);
+      unsigned int type = OBJECT_TYPE (object);
       if (type == TC_MANIFEST_NM_VECTOR)
 	{
 	  unsigned long n_words = (OBJECT_DATUM (object));
 	  if (n_words > 1000)
 	    outf_error ("%#lx: Extraordinary finger size: %ld\n",
-			addr, n_words);
+			((unsigned long)sp), n_words);
 	  sp = STACK_LOCATIVE_OFFSET (sp, n_words);
 	}
       else if (type == TC_MANIFEST_CLOSURE
 	       || type == TC_BROKEN_HEART
 	       || gc_type_code (type) == GC_UNDEFINED)
 	{
-	  outf_error ("%#lx: Invalid stack slot: ", addr);
-	  do_printing (ERROR_OUTPUT, object, true);
+	  outf_error ("%#lx: Invalid stack slot: ", ((unsigned long)sp));
+	  print_object (ERROR_OUTPUT, object);
 	  outf_error ("\n");
 	  complaints += 1;
 	}