Hacks to work around compiler/runtime bugs with protocols.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@17482 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,16 @@
+2003-08-15  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/NSObject.m: Move hacked methods for getting protocol
+	method info into functions so we can use them without going
+	through the ObjC runtime.
+	* Source/NSDistantObject.m: When attempting to check protocols,
+	use functions from NSObject.m if the protocol has not been
+	properly initialised (its class pointer is 0x2) as is the case
+	for all but very recent versions of the compiler.
+	FIXME ... this code should be removed at some future date when
+	all common systems have shipped with a working compiler for
+	a while.
+
 2003-08-13  David Ayers  <d.ayers@inode.at>
 
 	* Headers/Additions/GNUstepBase/preface.h: Remove generated

Source/NSDistantObject.m

@@ -853,10 +853,34 @@ enum
 
 	  struct objc_method_description* mth;
 
-	  mth = [_protocol descriptionForInstanceMethod: aSelector];
+	  /* Older gcc versions may not initialise Protocol objects properly
+	   * so we have an evil hack which checks for a known bad value of
+	   * the class pointer, and uses an internal function
+	   * (implemented in NSObject.m) to examine the protocol contents
+	   * without sending any ObjectiveC message to it.
+	   */
+	  if ((int)GSObjCClass(_protocol) == 0x2)
+	    {
+	      extern struct objc_method_description*
+		GSDescriptionForInstanceMethod();
+	      mth = GSDescriptionForInstanceMethod(_protocol, aSelector);
+	    }
+	  else
+	    {
+	      mth = [_protocol descriptionForInstanceMethod: aSelector];
+	    }
 	  if (mth == 0)
 	    {
-	      mth = [_protocol descriptionForClassMethod: aSelector];
+	      if ((int)GSObjCClass(_protocol) == 0x2)
+		{
+		  extern struct objc_method_description*
+		    GSDescriptionForClassMethod();
+		  mth = GSDescriptionForClassMethod(_protocol, aSelector);
+		}
+	      else
+		{
+		  mth = [_protocol descriptionForClassMethod: aSelector];
+		}
 	    }
 	  if (mth != 0)
 	    {

Source/NSObject.m

@@ -688,70 +688,88 @@ static BOOL double_release_check_enabled = NO;
 
 
 
-@implementation	Protocol (Fixup)
 struct objc_method_description_list {
-        int count;
+  int count;
-        struct objc_method_description list[1];
+  struct objc_method_description list[1];
 };
+typedef struct {
+  @defs(Protocol)
+} *pcl;
 
-- (struct objc_method_description *) descriptionForInstanceMethod:(SEL)aSel
+struct objc_method_description *
+GSDescriptionForInstanceMethod(pcl self, SEL aSel)
 {
   int i;
-  struct objc_protocol_list* proto_list;
+  struct objc_protocol_list	*p_list;
-  const char* name = sel_get_name (aSel);
+  const char			*name = sel_get_name (aSel);
   struct objc_method_description *result;
 
-  if (instance_methods != 0)
+  if (self->instance_methods != 0)
     {
-      for (i = 0; i < instance_methods->count; i++)
+      for (i = 0; i < self->instance_methods->count; i++)
 	{
-	  if (!strcmp ((char*)instance_methods->list[i].name, name))
+	  if (!strcmp ((char*)self->instance_methods->list[i].name, name))
-	    return &(instance_methods->list[i]);
+	    return &(self->instance_methods->list[i]);
 	}
     }
-  for (proto_list = protocol_list; proto_list; proto_list = proto_list->next)
+  for (p_list = self->protocol_list; p_list != 0; p_list = p_list->next)
     {
-      size_t j;
+      for (i = 0; i < p_list->count; i++)
-      for (j=0; j < proto_list->count; j++)
 	{
-	  if ((result = [proto_list->list[j]
+	  result = GSDescriptionForInstanceMethod(p_list->list[i], aSel);
-			 descriptionForInstanceMethod: aSel]))
+	  if (result)
-	    return result;
+	    {
+	      return result;
+	    }
 	}
     }
 
   return NULL;
 }
 
-- (struct objc_method_description *) descriptionForClassMethod:(SEL)aSel;
+struct objc_method_description *
+GSDescriptionForClassMethod(pcl self, SEL aSel)
 {
   int i;
-  struct objc_protocol_list* proto_list;
+  struct objc_protocol_list	*p_list;
-  const char* name = sel_get_name (aSel);
+  const char			*name = sel_get_name (aSel);
   struct objc_method_description *result;
 
-  if (class_methods != 0)
+  if (self->class_methods != 0)
     {
-      for (i = 0; i < class_methods->count; i++)
+      for (i = 0; i < self->class_methods->count; i++)
 	{
-	  if (!strcmp ((char*)class_methods->list[i].name, name))
+	  if (!strcmp ((char*)self->class_methods->list[i].name, name))
-	    return &(class_methods->list[i]);
+	    return &(self->class_methods->list[i]);
 	}
     }
-  for (proto_list = protocol_list; proto_list; proto_list = proto_list->next)
+  for (p_list = self->protocol_list; p_list != 0; p_list = p_list->next)
     {
-      size_t j;
+      for (i = 0; i < p_list->count; i++)
-      for (j=0; j < proto_list->count; j++)
 	{
-	  if ((result = [proto_list->list[j]
+	  result = GSDescriptionForClassMethod(p_list->list[i], aSel);
-			 descriptionForClassMethod: aSel]))
+	  if (result)
-	    return result;
+	    {
+	      return result;
+	    }
 	}
     }
 
   return NULL;
 }
 
+@implementation	Protocol (Fixup)
+
+- (struct objc_method_description *) descriptionForInstanceMethod:(SEL)aSel
+{
+  return GSDescriptionForInstanceMethod((pcl)self, aSel);
+}
+
+- (struct objc_method_description *) descriptionForClassMethod:(SEL)aSel;
+{
+  return GSDescriptionForClassMethod((pcl)self, aSel);
+}
+
 @end
 
 /**