PR c++/12698, c++/12699, c++/12700, c++/12566

cp:
	PR c++/12698, c++/12699, c++/12700, c++/12566
	* cp-tree.h (THUNK_ALIAS_P, THUNK_ALIAS): New.
	(debug_class, debug_thunks): New.
	* class.c (dump_class_hierarchy_1): New break out from ...
	(dump_class_hierarchy): ... here.
	(dump_thunk, debug_thunks, debug_class): New.
	(update_vtable_entry_for_fn): Add ssizetype casts. Correct
	continued search for primary binfo via virtual.
	(build_vtbl_initializer): Follow covariant thunk alias.
	* method.c (make_thunk): Clear DECL_THUNKS of the thunk.
	(finish_thunk): Look for an alias of the covariant thunk and point
	to it.
	(use_thunk): We should never use an alias.
	* semantics.c (emit_associated_thunks): Do not emit aliases.

	PR c++/12566
	* cp-tree.h (cp_fname_init): Add TYPE pointer param.
	* decl.c (cp_fname_init): Add TYPE pointer param. Set it. Don't
	create an ad-hoc ERROR_MARK.
	(cp_make_fname_decl): Adjust.
	* pt.c (tsubst_expr): Adjust.
testsuite:
	PR c++/12698, c++/12699, c++/12700, c++/12566
	* g++.dg/inherit/covariant9.C: New test.
	* g++.dg/inherit/covariant10.C: New test.
	* g++.dg/inherit/covariant11.C: New test.

From-SVN: r72882

1 files changed, 30 insertions, 0 deletions

diff --git a/gcc/cp/method.c b/gcc/cp/method.c
index 5277004..c6651e8 100644
--- a/gcc/cp/method.c
+++ b/gcc/cp/method.c
@@ -107,6 +107,8 @@ make_thunk (tree function, bool this_adjusting,
   my_friendly_assert (TREE_CODE (function) == FUNCTION_DECL, 20021025);
   /* We can have this thunks to covariant thunks, but not vice versa.  */
   my_friendly_assert (!DECL_THIS_THUNK_P (function), 20021127);
+  my_friendly_assert (!DECL_RESULT_THUNK_P (function) || this_adjusting,
+		      20031123);
   
   /* Scale the VIRTUAL_OFFSET to be in terms of bytes.  */
   if (this_adjusting && virtual_offset)
@@ -140,6 +142,8 @@ make_thunk (tree function, bool this_adjusting,
   thunk = build_decl (FUNCTION_DECL, NULL_TREE, TREE_TYPE (function));
   DECL_LANG_SPECIFIC (thunk) = DECL_LANG_SPECIFIC (function);
   cxx_dup_lang_specific_decl (thunk);
+  DECL_THUNKS (thunk) = NULL_TREE;
+  
   DECL_CONTEXT (thunk) = DECL_CONTEXT (function);
   TREE_READONLY (thunk) = TREE_READONLY (function);
   TREE_THIS_VOLATILE (thunk) = TREE_THIS_VOLATILE (function);
@@ -171,6 +175,7 @@ make_thunk (tree function, bool this_adjusting,
   DECL_DECLARED_INLINE_P (thunk) = 0;
   /* Nor has it been deferred.  */
   DECL_DEFERRED_FN (thunk) = 0;
+  
   /* Add it to the list of thunks associated with FUNCTION.  */
   TREE_CHAIN (thunk) = DECL_THUNKS (function);
   DECL_THUNKS (function) = thunk;
@@ -193,6 +198,27 @@ finish_thunk (tree thunk)
   function = THUNK_TARGET (thunk);
   name = mangle_thunk (function, DECL_THIS_THUNK_P (thunk),
 		       fixed_offset, virtual_offset);
+
+  /* We can end up with declarations of (logically) different
+     covariant thunks, that do identical adjustments.  The two thunks
+     will be adjusting between within different hierarchies, which
+     happen to have the same layout.  We must nullify one of them to
+     refer to the other.  */
+  if (DECL_RESULT_THUNK_P (thunk))
+    {
+      tree cov_probe;
+
+      for (cov_probe = DECL_THUNKS (function);
+	   cov_probe; cov_probe = TREE_CHAIN (cov_probe))
+	if (DECL_NAME (cov_probe) == name)
+	  {
+	    my_friendly_assert (!DECL_THUNKS (thunk), 20031023);
+	    THUNK_ALIAS (thunk) = (THUNK_ALIAS_P (cov_probe)
+				   ? THUNK_ALIAS (cov_probe) : cov_probe);
+	    break;
+	  }
+    }
+  
   DECL_NAME (thunk) = name;
   SET_DECL_ASSEMBLER_NAME (thunk, name);
 }
@@ -307,6 +333,10 @@ use_thunk (tree thunk_fndecl, bool emit_p)
   /* We should have called finish_thunk to give it a name.  */
   my_friendly_assert (DECL_NAME (thunk_fndecl), 20021127);
 
+  /* We should never be using an alias, always refer to the
+     aliased thunk.  */
+  my_friendly_assert (!THUNK_ALIAS_P (thunk_fndecl), 20031023);
+
   if (TREE_ASM_WRITTEN (thunk_fndecl))
     return;