Re: "Unrecognized demangle component" error

[Ian Lance Taylor <ian at wasabisystems dot com>]

"Dave Korn" <dk@artimi.com> writes:

> > I wonder which component it was.  I should have had the error message
> > print it out the number.  It would probably also be friendlier to
> > print a warning and then return debug_make_void_type (dhandle).
> 
>   OK, I quickly plumbed in those changes (using 2.15 release sources), and see
> that they're all without exception references to type #34 which I make out to be
> DEMANGLE_COMPONENT_FUNCTION_TYPE.  Ummm.  I would imagine that's a slightly
> surprising result, perhaps?

That's what I would expect from a static method which takes a function
pointer as a parameter.  For example, I can recreate the problem with
this one-liner:
    class C { static int foo(int (*pfn)(int)); };
So it's not especially unlikely, it's just not handled.

Since you bring it up, I just checked in this patch to handle it.

Ian

Index: stabs.c
===================================================================
RCS file: /cvs/src/src/binutils/stabs.c,v
retrieving revision 1.20
diff -u -p -r1.20 stabs.c
--- stabs.c	12 Jan 2004 21:08:00 -0000	1.20
+++ stabs.c	25 Oct 2004 15:24:44 -0000
@@ -203,6 +203,8 @@ static debug_type *stab_demangle_argtype
   (void *, struct stab_handle *, const char *, bfd_boolean *, unsigned int);
 static debug_type *stab_demangle_v3_argtypes
   (void *, struct stab_handle *, const char *, bfd_boolean *);
+static debug_type *stab_demangle_v3_arglist
+  (void *, struct stab_handle *, struct demangle_component *, bfd_boolean *);
 static debug_type stab_demangle_v3_arg
   (void *, struct stab_handle *, struct demangle_component *, debug_type,
    bfd_boolean *);
@@ -5073,7 +5075,6 @@ stab_demangle_v3_argtypes (void *dhandle
 {
   struct demangle_component *dc;
   void *mem;
-  unsigned int alloc, count;
   debug_type *pargs;
 
   dc = cplus_demangle_v3_components (physname, DMGL_PARAMS | DMGL_ANSI, &mem);
@@ -5093,13 +5094,35 @@ stab_demangle_v3_argtypes (void *dhandle
       return NULL;
     }
 
+  pargs = stab_demangle_v3_arglist (dhandle, info,
+				    dc->u.s_binary.right->u.s_binary.right,
+				    pvarargs);
+
+  free (mem);
+
+  return pargs;
+}
+
+/* Demangle an argument list in a struct demangle_component tree.
+   Returns a DEBUG_TYPE_NULL terminated array of argument types, and
+   sets *PVARARGS to indicate whether this is a varargs function.  */
+
+static debug_type *
+stab_demangle_v3_arglist (void *dhandle, struct stab_handle *info,
+			  struct demangle_component *arglist,
+			  bfd_boolean *pvarargs)
+{
+  struct demangle_component *dc;
+  unsigned int alloc, count;
+  debug_type *pargs;
+
   alloc = 10;
   pargs = (debug_type *) xmalloc (alloc * sizeof *pargs);
   *pvarargs = FALSE;
 
   count = 0;
 
-  for (dc = dc->u.s_binary.right->u.s_binary.right;
+  for (dc = arglist;
        dc != NULL;
        dc = dc->u.s_binary.right)
     {
@@ -5108,8 +5131,8 @@ stab_demangle_v3_argtypes (void *dhandle
 
       if (dc->type != DEMANGLE_COMPONENT_ARGLIST)
 	{
-	  fprintf (stderr, _("Unexpected type in demangle tree\n"));
-	  free (mem);
+	  fprintf (stderr, _("Unexpected type in v3 arglist demangling\n"));
+	  free (pargs);
 	  return NULL;
 	}
 
@@ -5122,7 +5145,7 @@ stab_demangle_v3_argtypes (void *dhandle
 	      *pvarargs = TRUE;
 	      continue;
 	    }
-	  free (mem);
+	  free (pargs);
 	  return NULL;
 	}
 
@@ -5138,8 +5161,6 @@ stab_demangle_v3_argtypes (void *dhandle
 
   pargs[count] = DEBUG_TYPE_NULL;
 
-  free (mem);
-
   return pargs;
 }
 
@@ -5173,12 +5194,12 @@ stab_demangle_v3_arg (void *dhandle, str
     case DEMANGLE_COMPONENT_COMPLEX:
     case DEMANGLE_COMPONENT_IMAGINARY:
     case DEMANGLE_COMPONENT_VENDOR_TYPE:
-    case DEMANGLE_COMPONENT_FUNCTION_TYPE:
     case DEMANGLE_COMPONENT_ARRAY_TYPE:
     case DEMANGLE_COMPONENT_PTRMEM_TYPE:
     case DEMANGLE_COMPONENT_ARGLIST:
     default:
-      fprintf (stderr, _("Unrecognized demangle component\n"));
+      fprintf (stderr, _("Unrecognized demangle component %d\n"),
+	       (int) dc->type);
       return NULL;
 
     case DEMANGLE_COMPONENT_NAME:
@@ -5269,6 +5290,34 @@ stab_demangle_v3_arg (void *dhandle, str
 	  return debug_make_reference_type (dhandle, dt);
 	}
 
+    case DEMANGLE_COMPONENT_FUNCTION_TYPE:
+      {
+	debug_type *pargs;
+	bfd_boolean varargs;
+
+	if (dc->u.s_binary.left == NULL)
+	  {
+	    /* In this case the return type is actually unknown.
+	       However, I'm not sure this will ever arise in practice;
+	       normally an unknown return type would only appear at
+	       the top level, which is handled above.  */
+	    dt = debug_make_void_type (dhandle);
+	  }
+	else
+	  dt = stab_demangle_v3_arg (dhandle, info, dc->u.s_binary.left, NULL,
+				     NULL);
+	if (dt == NULL)
+	  return NULL;
+
+	pargs = stab_demangle_v3_arglist (dhandle, info,
+					  dc->u.s_binary.right,
+					  &varargs);
+	if (pargs == NULL)
+	  return NULL;
+
+	return debug_make_function_type (dhandle, dt, pargs, varargs);
+      }
+
     case DEMANGLE_COMPONENT_BUILTIN_TYPE:
       {
 	char *p;