[PATCH] Check DECL_CONTEXT of new/delete operators.

Jan Hubicka hubicka@ucw.cz
Fri Apr 3 15:42:12 GMT 2020


Hi,
and this is the streaming fix

diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index e4077b58890..dd9645723c1 100644
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -646,6 +647,19 @@ degenerate_phi_p (gimple *phi)
   return true;
 }
 
+/* Return true if C1 and C2 are matching contexts (both translation unit decls
+   or both types.  */
+
+bool
+matching_contexts_p (tree c1, tree c2)
+{
+  if (TREE_CODE (c1) == TRANSLATION_UNIT_DECL)
+    return TREE_CODE (c2) == TRANSLATION_UNIT_DECL;
+  if (TREE_CODE (c2) == TRANSLATION_UNIT_DECL)
+    return TREE_CODE (c1) == TRANSLATION_UNIT_DECL;
+  return types_same_for_odr (c1, c2);
+}
+
 /* Propagate necessity using the operands of necessary statements.
    Process the uses on each statement in the worklist, and add all
    feeding statements which contribute to the calculation of this
@@ -824,16 +838,28 @@ propagate_necessity (bool aggressive)
 			   || DECL_FUNCTION_CODE (def_callee) == BUILT_IN_CALLOC))
 		      || DECL_IS_REPLACEABLE_OPERATOR_NEW_P (def_callee)))
 		{
-		  /* Delete operators can have alignment and (or) size as next
-		     arguments.  When being a SSA_NAME, they must be marked
-		     as necessary.  */
-		  if (is_delete_operator && gimple_call_num_args (stmt) >= 2)
-		    for (unsigned i = 1; i < gimple_call_num_args (stmt); i++)
-		      {
-			tree arg = gimple_call_arg (stmt, i);
-			if (TREE_CODE (arg) == SSA_NAME)
-			  mark_operand_necessary (arg);
-		      }
+		  if (is_delete_operator)
+		    {
+		      /* Verify that new and delete operators have the same
+			 context.  */
+		      if (DECL_IS_REPLACEABLE_OPERATOR_NEW_P (def_callee)
+			  && !matching_contexts_p
+				 (DECL_CONTEXT (def_callee),
+				  DECL_CONTEXT (gimple_call_fndecl (stmt))))
+			mark_operand_necessary (gimple_call_arg (stmt, 0));
+
+		      /* Delete operators can have alignment and (or) size
+			 as next arguments.  When being a SSA_NAME, they
+			 must be marked as necessary.  */
+		      if (gimple_call_num_args (stmt) >= 2)
+			for (unsigned i = 1; i < gimple_call_num_args (stmt);
+			     i++)
+			  {
+			    tree arg = gimple_call_arg (stmt, i);
+			    if (TREE_CODE (arg) == SSA_NAME)
+			      mark_operand_necessary (arg);
+			  }
+		    }
 
 		  continue;
 		}
diff --git a/gcc/tree.c b/gcc/tree.c
index 63dc6730b2b..cd608a9c878 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -5879,6 +5879,9 @@ free_lang_data_in_decl (tree decl, class free_lang_data_d *fld)
      merging may merge some fileds and keep others disjoint wich in turn will
      not do well with TREE_CHAIN pointers linking them.
 
+     tree-ssa-dce is using context to match new and delete operators (which may
+     be static functions).
+
      Also do not drop containing types for virtual methods and tables because
      these are needed by devirtualization.
      C++ destructors are special because C++ frontends sometimes produces
@@ -5886,6 +5889,9 @@ free_lang_data_in_decl (tree decl, class free_lang_data_d *fld)
      devirutalization code we always walk through aliases and we need
      context to be preserved too.  See PR89335  */
   if (TREE_CODE (decl) != FIELD_DECL
+      && (TREE_CODE (decl) != FUNCTION_DECL
+	  || (!DECL_IS_REPLACEABLE_OPERATOR_NEW_P (decl)
+	      && !DECL_IS_OPERATOR_DELETE_P (decl)))
       && ((TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)
           || (!DECL_VIRTUAL_P (decl)
 	      && (TREE_CODE (decl) != FUNCTION_DECL


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