re PR c++/79380 (ICE on C++11 code with illegal alignas specifier on…

re PR c++/79380 (ICE on C++11 code with illegal alignas specifier on x86_64-linux-gnu: unexpected expression ‘f’ of kind overload)

/cp
2017-02-19  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/79380
	* typeck.c (cxx_alignas_expr): Reject a non-integral alignas
	argument.

/testsuite
2017-02-19  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/79380
	* g++.dg/cpp0x/alignas8.C: New.

From-SVN: r245578

gcc/cp/ChangeLog

+2017-02-19  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/79380
+	* typeck.c (cxx_alignas_expr): Reject a non-integral alignas
+	argument.
+
 2017-02-19  Eric Fiselier  <eric@efcs.ca>
 	    Jonathan Wakely  <jwakely@redhat.com>
 

gcc/cp/typeck.c

@@ -1796,6 +1796,12 @@ cxx_alignas_expr (tree e)
          the assignment-expression shall be an integral constant
 	 expression.  */
 
+  if (!INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (e)))
+    {
+      error ("%<alignas%> argument has non-integral type %qT", TREE_TYPE (e));
+      return error_mark_node;
+    }
+  
   return cxx_constant_value (e);
 }
 

gcc/testsuite/ChangeLog

+2017-02-19  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/79380
+	* g++.dg/cpp0x/alignas8.C: New.
+
 2017-02-19  Eric Fiselier  <eric@efcs.ca>
 	    Jonathan Wakely  <jwakely@redhat.com>
 

gcc/testsuite/g++.dg/cpp0x/alignas8.C

+// PR c++/79380
+// { dg-do compile { target c++11 } }
+
+template < typename > constexpr int f () {  return 8;  }
+
+// should have been: struct alignas (f<int>()) S {};
+struct alignas (f) S {};  // { dg-error "17:'alignas' argument has non-integral type" }