ipa-utils.h (compare_virtual_tables): Declare.

	* ipa-utils.h (compare_virtual_tables): Declare.
	* ipa-devirt.c (odr_subtypes_equivalent_p): New function

	* lto-symtab.c (lto_varpool_replace_node): Call compare_virtual_tables.

From-SVN: r213990

1 files changed, 114 insertions, 0 deletions

diff --git a/gcc/ipa-devirt.c b/gcc/ipa-devirt.c
index 0f38655..2d356ad 100644
--- a/gcc/ipa-devirt.c
+++ b/gcc/ipa-devirt.c
@@ -485,6 +485,120 @@ odr_subtypes_equivalent_p (tree t1, tree t2, hash_set<tree> *visited)
   return types_same_for_odr (t1, t2);
 }
 
+/* Compare two virtual tables, PREVAILING and VTABLE and output ODR
+   violation warings.  */
+
+void
+compare_virtual_tables (varpool_node *prevailing, varpool_node *vtable)
+{
+  int n1, n2;
+  if (DECL_VIRTUAL_P (prevailing->decl) != DECL_VIRTUAL_P (vtable->decl))
+    {
+      odr_violation_reported = true;
+      if (DECL_VIRTUAL_P (prevailing->decl))
+	{
+	  varpool_node *tmp = prevailing;
+	  prevailing = vtable;
+	  vtable = tmp;
+	}
+      if (warning_at (DECL_SOURCE_LOCATION (TYPE_NAME (DECL_CONTEXT (vtable->decl))),
+		      OPT_Wodr,
+		      "virtual table of type %qD violates one definition rule",
+		      DECL_CONTEXT (vtable->decl)))
+	inform (DECL_SOURCE_LOCATION (prevailing->decl),
+		"variable of same assembler name as the virtual table is "
+		"defined in another translation unit");
+      return;
+    }
+  if (!prevailing->definition || !vtable->definition)
+    return;
+  for (n1 = 0, n2 = 0; true; n1++, n2++)
+    {
+      struct ipa_ref *ref1, *ref2;
+      bool end1, end2;
+      end1 = !prevailing->iterate_reference (n1, ref1);
+      end2 = !vtable->iterate_reference (n2, ref2);
+      if (end1 && end2)
+	return;
+      if (!end1 && !end2
+	  && DECL_ASSEMBLER_NAME (ref1->referred->decl)
+	     != DECL_ASSEMBLER_NAME (ref2->referred->decl)
+	  && !n2
+	  && !DECL_VIRTUAL_P (ref2->referred->decl)
+	  && DECL_VIRTUAL_P (ref1->referred->decl))
+	{
+	  if (warning_at (DECL_SOURCE_LOCATION (TYPE_NAME (DECL_CONTEXT (vtable->decl))), 0,
+			  "virtual table of type %qD contains RTTI information",
+			  DECL_CONTEXT (vtable->decl)))
+	    {
+	      inform (DECL_SOURCE_LOCATION (TYPE_NAME (DECL_CONTEXT (prevailing->decl))),
+		      "but is prevailed by one without from other translation unit");
+	      inform (DECL_SOURCE_LOCATION (TYPE_NAME (DECL_CONTEXT (prevailing->decl))),
+		      "RTTI will not work on this type");
+	    }
+	  n2++;
+          end2 = !vtable->iterate_reference (n2, ref2);
+	}
+      if (!end1 && !end2
+	  && DECL_ASSEMBLER_NAME (ref1->referred->decl)
+	     != DECL_ASSEMBLER_NAME (ref2->referred->decl)
+	  && !n1
+	  && !DECL_VIRTUAL_P (ref1->referred->decl)
+	  && DECL_VIRTUAL_P (ref2->referred->decl))
+	{
+	  n1++;
+          end1 = !vtable->iterate_reference (n1, ref1);
+	}
+      if (end1 || end2)
+	{
+	  if (end1)
+	    {
+	      varpool_node *tmp = prevailing;
+	      prevailing = vtable;
+	      vtable = tmp;
+	      ref1 = ref2;
+	    }
+	  if (warning_at (DECL_SOURCE_LOCATION
+			    (TYPE_NAME (DECL_CONTEXT (vtable->decl))), 0,
+			  "virtual table of type %qD violates "
+			  "one definition rule",
+			  DECL_CONTEXT (vtable->decl)))
+	    {
+	      inform (DECL_SOURCE_LOCATION
+		       (TYPE_NAME (DECL_CONTEXT (prevailing->decl))),
+		      "the conflicting type defined in another translation "
+		      "unit");
+	      inform (DECL_SOURCE_LOCATION
+		        (TYPE_NAME (DECL_CONTEXT (ref1->referring->decl))),
+		      "contains additional virtual method %qD",
+		      ref1->referred->decl);
+	    }
+	  return;
+	}
+      if (DECL_ASSEMBLER_NAME (ref1->referred->decl)
+	  != DECL_ASSEMBLER_NAME (ref2->referred->decl))
+	{
+	  if (warning_at (DECL_SOURCE_LOCATION
+			    (TYPE_NAME (DECL_CONTEXT (vtable->decl))), 0,
+			  "virtual table of type %qD violates "
+			  "one definition rule  ",
+			  DECL_CONTEXT (vtable->decl)))
+	    {
+	      inform (DECL_SOURCE_LOCATION 
+			(TYPE_NAME (DECL_CONTEXT (prevailing->decl))),
+		      "the conflicting type defined in another translation "
+		      "unit");
+	      inform (DECL_SOURCE_LOCATION (ref1->referred->decl),
+		      "virtual method %qD", ref1->referred->decl);
+	      inform (DECL_SOURCE_LOCATION (ref2->referred->decl),
+		      "ought to match virtual method %qD but does not",
+		      ref2->referred->decl);
+	      return;
+	    }
+	}
+    }
+}
+
 /* Output ODR violation warning about T1 and T2 with REASON.
    Display location of ST1 and ST2 if REASON speaks about field or
    method of the type.