The attached patch adds handling of dependent arguments to
attribute aligned and attribute vector_size, fixing c++/58109
and 69022 - attribute vector_size ignored with dependent bytes.
Tested on x86_64.
Martin
gcc/testsuite/ChangeLog:
2015-12-22 Martin Sebor <mse...@redhat.com>
PR c++/58109
PR c++/69022
* g++.dg/cpp0x/alignas5.C: New test.
* g++.dg/ext/vector29.C: Same.
gcc/cp/ChangeLog:
2015-12-22 Martin Sebor <mse...@redhat.com>
PR c++/58109
PR c++/69022
* decl2.c (is_late_template_attribute): Handle dependent argument
to attribute align and attribute vector_size.
Index: gcc/cp/decl2.c
===================================================================
--- gcc/cp/decl2.c (revision 231903)
+++ gcc/cp/decl2.c (working copy)
@@ -1183,6 +1183,16 @@
if (args && PACK_EXPANSION_P (args))
return true;
+ if (is_attribute_p ("aligned", name)
+ || is_attribute_p ("vector_size", name))
+ {
+ /* Attribute argument may be a dependent indentifier. */
+ if (tree t = args ? TREE_VALUE (args) : NULL_TREE)
+ if (value_dependent_expression_p (t)
+ || type_dependent_expression_p (t))
+ return true;
+ }
+
/* If any of the arguments are dependent expressions, we can't evaluate
the attribute until instantiation time. */
for (arg = args; arg; arg = TREE_CHAIN (arg))
Index: gcc/testsuite/g++.dg/cpp0x/alignas5.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/alignas5.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/alignas5.C (working copy)
@@ -0,0 +1,45 @@
+// PR c++/58109 - alignas() fails to compile with constant expression
+// { dg-do compile }
+
+template <typename T>
+struct Base {
+ static const int Align = sizeof (T);
+};
+
+// Never instantiated.
+template <typename T>
+struct Derived: Base<T>
+{
+#if __cplusplus >= 201102L
+ // This is the meat of the (simplified) regression test for c++/58109.
+ using B = Base<T>;
+ using B::Align;
+
+ alignas (Align) char a [1];
+ alignas (Align) T b [1];
+#else
+ // Fake the test for C++ 98.
+# define Align Base<T>::Align
+#endif
+
+ char __attribute__ ((aligned (Align))) c [1];
+ T __attribute__ ((aligned (Align))) d [1];
+};
+
+// Instantiated to verify that the code is accepted even when instantiated.
+template <typename T>
+struct InstDerived: Base<T>
+{
+#if __cplusplus >= 201102L
+ using B = Base<T>;
+ using B::Align;
+
+ alignas (Align) char a [1];
+ alignas (Align) T b [1];
+#endif
+
+ char __attribute__ ((aligned (Align))) c [1];
+ T __attribute__ ((aligned (Align))) d [1];
+};
+
+InstDerived<int> dx;
Index: gcc/testsuite/g++.dg/ext/vector29.C
===================================================================
--- gcc/testsuite/g++.dg/ext/vector29.C (revision 0)
+++ gcc/testsuite/g++.dg/ext/vector29.C (working copy)
@@ -0,0 +1,53 @@
+// PR c++/69022 - attribute vector_size ignored with dependent bytes
+// { dg-do compile }
+
+template <int N>
+struct A { static const int X = N; };
+
+#if __cplusplus >= 201202L
+# define ASSERT(e) static_assert (e, #e)
+#else
+# define ASSERT(e) \
+ do { struct S { bool: !!(e); } asrt; (void)&asrt; } while (0)
+#endif
+
+template <class T, int N>
+struct B: A<N>
+{
+#if __cplusplus >= 201202L
+ using A<N>::X;
+# define VecSize X
+#else
+# define VecSize A<N>::X
+#endif
+
+ static void foo ()
+ {
+ char a __attribute__ ((vector_size (N)));
+ ASSERT (sizeof a == N);
+
+ T b __attribute__ ((vector_size (N)));
+ ASSERT (sizeof b == N);
+ }
+
+ static void bar ()
+ {
+ char c1 __attribute__ ((vector_size (VecSize)));
+ ASSERT (sizeof c1 == VecSize);
+
+ char c2 __attribute__ ((vector_size (A<N>::X)));
+ ASSERT (sizeof c2 == A<N>::X);
+
+ T d1 __attribute__ ((vector_size (VecSize)));
+ ASSERT (sizeof d1 == VecSize);
+
+ T d2 __attribute__ ((vector_size (A<N>::X)));
+ ASSERT (sizeof d2 == A<N>::X);
+ }
+};
+
+void bar ()
+{
+ B<int, 16>::foo ();
+ B<int, 16>::bar ();
+}
