Patchwork [C++,Patch/RFC] PR 55951

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Submitter Paolo Carlini
Date March 26, 2013, 3 p.m.
Message ID <5151B7F8.6060503@oracle.com>
Download mbox | patch
Permalink /patch/231251/
State New
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Comments

Paolo Carlini - March 26, 2013, 3 p.m.
Hi,

On 03/26/2013 03:15 PM, Jason Merrill wrote:
> On 03/26/2013 10:14 AM, Jason Merrill wrote:
>> On 03/26/2013 09:17 AM, Paolo Carlini wrote:
>>> +      if (identifier_p (ce->index))
>>> +    {
>>> +      error ("name %qD used in a GNU-style designated "
>>> +         "initializer for an array", ce->index);
>>> +      return false;
>>> +    }
>>> +
>>> +      tree ce_index = cxx_constant_value (ce->index);
>>> +
>>>         /* The parser only allows identifiers as designated
>>>        initializers.  */
>>>         if (ce->index == error_mark_node)
>>>       error ("name used in a GNU-style designated "
>>>              "initializer for an array");
>>
>> Let's also combine these two instances of the same error.
> Or at any rate move the error_mark_node case above cxx_constant_value 
> as well.
Indeed. Thus I'm finishing testing the below.

Thanks,
Paolo.

////////////////////
Jason Merrill - March 26, 2013, 3:10 p.m.
On 03/26/2013 11:00 AM, Paolo Carlini wrote:
> +      tree ce_index = cxx_constant_value (ce->index);
> +
> +      if (TREE_CODE (ce_index) == INTEGER_CST)
> +	{
>   	  /* A C99 designator is OK if it matches the current index.  */
> -	  if (TREE_INT_CST_LOW (ce->index) == index)
> +	  if (TREE_INT_CST_LOW (ce_index) == index)
>   	    return true;

Hmm, it occurs to me that we probably want to replace ce->index with the 
constant value for the benefit of varasm.  I'm surprised that the 
testcase passes without doing that.

Jason

Patch

Index: cp/decl.c
===================================================================
--- cp/decl.c	(revision 197097)
+++ cp/decl.c	(working copy)
@@ -4769,22 +4769,31 @@  check_array_designated_initializer (const construc
       /* The parser only allows identifiers as designated
 	 initializers.  */
       if (ce->index == error_mark_node)
-	error ("name used in a GNU-style designated "
-	       "initializer for an array");
-      else if (TREE_CODE (ce->index) == INTEGER_CST)
 	{
+	  error ("name used in a GNU-style designated "
+		 "initializer for an array");
+	  return false;
+	}
+      else if (identifier_p (ce->index))
+	{
+	  error ("name %qD used in a GNU-style designated "
+		 "initializer for an array", ce->index);
+	  return false;
+	}
+
+      tree ce_index = cxx_constant_value (ce->index);
+
+      if (TREE_CODE (ce_index) == INTEGER_CST)
+	{
 	  /* A C99 designator is OK if it matches the current index.  */
-	  if (TREE_INT_CST_LOW (ce->index) == index)
+	  if (TREE_INT_CST_LOW (ce_index) == index)
 	    return true;
 	  else
 	    sorry ("non-trivial designated initializers not supported");
 	}
       else
-	{
-	  gcc_assert (identifier_p (ce->index));
-	  error ("name %qD used in a GNU-style designated "
-		 "initializer for an array", ce->index);
-	}
+	gcc_unreachable ();
+
       return false;
     }
 
Index: testsuite/g++.dg/ext/desig5.C
===================================================================
--- testsuite/g++.dg/ext/desig5.C	(revision 0)
+++ testsuite/g++.dg/ext/desig5.C	(working copy)
@@ -0,0 +1,7 @@ 
+// PR c++/55951
+
+enum { A };
+
+static const char *a[] = {
+  [A] = "a"
+};