(debug_coder): Make it a static var instead of a #define.

([Decoder -_coderCreateReferenceForObject:]): Add a debugging message.
([Decoder -_coderCreateReferenceForInterconnectedObject:]):
Autorelease the placeholder object.
([Decoder -_createReferenceBeforeInit]): New method.  By default
return NO, for the GNU-style forward references.
([Decoder -decodeObjectAt:anObjPtr:name]): [CODER_OBJECT]: Use new
method; if it returns true, then we are using non-GNU, OpenStep-style
forward references.  In this case: (1) don't try to decode the object by
sending +newWithCoder:, in fact, raise an error if the object wanted
to be decoded that way; (2) call _coderInternalCreateReferenceForObject
before sending -initWithCoder, not after; unfortunately this means
that -initWithCoder methods cannot substitute another object for self.
If it returns false, use the more robust GNU style forward references.
The NSGUnarchiver overrides this method to use the OpenStep style.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@1480 72102866-910b-0410-8b05-ffd578937521

Source/Decoder.m

@@ -30,7 +30,7 @@
 #include <gnustep/base/Array.h>
 #include <Foundation/NSException.h>
 
-#define debug_coder 0
+static int debug_coder = 0;
 
 @implementation Decoder
 
@@ -109,7 +109,7 @@
 
 
 /* Functions and methods for keeping cross-references
-   so objects that were already read can be refered to again. */
+   so objects that were already read can be referred to again. */
 
 /* These _coder... methods may be overriden by subclasses so that 
    cross-references can be kept differently. */
@@ -123,6 +123,9 @@
 	 Encoders, which start at 1. */
       [xref_2_object appendObject: [NSObject new]];
     }
+  if (debug_coder)
+    fprintf (stderr, "Decoder registering object xref %u\n",
+	     [xref_2_object count] - 1);
   [xref_2_object appendObject: anObj]; // xxx but this will retain anObj.  NO.
   /* This return value should be the same as the index of anObj 
      in xref_2_object. */
@@ -161,7 +164,7 @@
       xref_2_object_root = [Array new];
       /* Append an object so our xref numbers are in sync with the 
 	 Encoders, which start at 1. */
-      [xref_2_object_root appendObject: [NSObject new]];
+      [xref_2_object_root appendObject: [[NSObject new] autorelease]];
     }
   [xref_2_object_root appendObject: anObj];
   /* This return value should be the same as the index of anObj 
@@ -276,7 +279,7 @@
 
 
 /* This is the Coder's interface to the over-ridable
-   "_coderPutObject:atReference" method.  Do not override it.  It
+   "_coderCreateReferenceForObject" method.  Do not override it.  It
    handles the xref_2_object_root. */
 
 - (unsigned) _coderInternalCreateReferenceForObject: anObj
@@ -378,7 +381,8 @@
 	  unsigned xref;
 	  xref = [self _coderCreateReferenceForConstPtr: ret];
 	  if (debug_coder)
-	    fprintf(stderr, "Coder decoding registered class xref %u\n", xref);
+	    fprintf(stderr,
+		    "Decoder decoding registered class xref %u\n", xref);
 	}
 	(*objc_free) (class_name);
 	break;
@@ -460,7 +464,8 @@
 	  unsigned xref;
 	  xref = [self _coderCreateReferenceForConstPtr: ret];
 	  if (debug_coder)
-	    fprintf(stderr, "Coder decoding registered sel xref %u\n", xref);
+	    fprintf(stderr,
+		    "Decoder decoding registered sel xref %u\n", xref);
 	}
 	(*objc_free)(sel_name);
 	(*objc_free)(sel_types);
@@ -558,6 +563,11 @@
   /* xxx We need to catch unions and make a sensible error message */
 }
 
+- (BOOL) _createReferenceBeforeInit
+{
+  return NO;
+}
+
 /* This is the designated (and one-and-only) object decoder */
 - (void) decodeObjectAt: (id*) anObjPtr withName: (id <String> *) name
 {
@@ -606,6 +616,7 @@
 	Class object_class;
 	SEL new_sel = sel_get_any_uid ("newWithCoder:");
 	Method* new_method;
+	BOOL create_ref_before_init = [self _createReferenceBeforeInit];
 
 	[self decodeIndent];
 	object_class = [self decodeClass];
@@ -614,15 +625,22 @@
 	   argument, not the metaclass! */
 	new_method = class_get_class_method(class_get_meta_class(object_class),
 					    new_sel);
-	if (new_method)
+	if (new_method && !create_ref_before_init)
 	  *anObjPtr = (*(new_method->method_imp))(object_class, new_sel, self);
 	else
 	  {
 	    SEL init_sel = sel_get_any_uid("initWithCoder:");
 	    Method *init_method = 
 	      class_get_instance_method(object_class, init_sel);
+	    
+	    NSAssert (!create_ref_before_init,
+		      @"You are trying to decode an object with the non-GNU"
+		      @"OpenStep-style of forward references, but the object's"
+		      @"decoding mechanism wants to use GNU features.");
 	    /* xxx Or should I send +alloc? */
 	    *anObjPtr = (id) NSAllocateObject (object_class, 0, zone);
+	    if (create_ref_before_init)
+	      [self _coderInternalCreateReferenceForObject: *anObjPtr];
 	    if (init_method)
 	      *anObjPtr = 
 		(*(init_method->method_imp))(*anObjPtr, init_sel, self);
@@ -640,12 +658,14 @@
 
 	/* Would get error here with Connection-wide object references
 	   because addProxy gets called in +newRemote:connection: */
-	{
-	  unsigned xref = 
-	    [self _coderInternalCreateReferenceForObject: *anObjPtr];
-	  if (debug_coder)
-	    fprintf(stderr, "Coder decoding registered class xref %u\n", xref);
-	}
+	if (!create_ref_before_init)
+	  {
+	    unsigned xref = 
+	      [self _coderInternalCreateReferenceForObject: *anObjPtr];
+	    if (debug_coder)
+	      fprintf(stderr, 
+		      "Decoder decoding registered class xref %u\n", xref);
+	  }
 	break;
       }
     case CODER_OBJECT_ROOT: