From 69da78025ec5e1408576eda81cb97d2e53cdace8 Mon Sep 17 00:00:00 2001
From: Martin Sebor <msebor@redhat.com>
Date: Sat, 23 Jan 2016 16:01:47 +0000
Subject: [PATCH] PR c++/58109 - alignas() fails to compile with constant
 expression

PR c++/58109 - alignas() fails to compile with constant expression
PR c++/69022 - attribute vector_size ignored with dependent bytes

gcc/testsuite/ChangeLog:
2016-01-23  Martin Sebor  <msebor@redhat.com>

	PR c++/58109
	PR c++/69022
	* g++.dg/cpp0x/alignas5.C: New test.
	* g++.dg/ext/vector29.C: Same.

gcc/cp/ChangeLog:
2016-01-23  Martin Sebor  <msebor@redhat.com>

	PR c++/58109
	PR c++/69022
	* decl2.c (is_late_template_attribute): Handle dependent argument
 	to attribute align and attribute vector_size.

From-SVN: r232766
---
 gcc/cp/ChangeLog                      |  7 ++++
 gcc/cp/decl2.c                        |  3 +-
 gcc/testsuite/ChangeLog               |  7 ++++
 gcc/testsuite/g++.dg/cpp0x/alignas5.C | 47 ++++++++++++++++++++++--
 gcc/testsuite/g++.dg/ext/vector29.C   | 53 +++++++++++++++++++++++++++
 5 files changed, 112 insertions(+), 5 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/ext/vector29.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 05ca52a2cbc..07fcef44987 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2016-01-23  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/58109
+	PR c++/69022
+	* decl2.c (is_late_template_attribute): Handle dependent argument
+	to attribute align and attribute vector_size.
+
 2016-01-21  Jason Merrill  <jason@redhat.com>
 
 	PR c++/69392
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index a7212ca05bb..7d68961cd20 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -1193,7 +1193,8 @@ is_late_template_attribute (tree attr, tree decl)
 	 second and following arguments.  Attributes like mode, format,
 	 cleanup and several target specific attributes aren't late
 	 just because they have an IDENTIFIER_NODE as first argument.  */
-      if (arg == args && identifier_p (t))
+      if (arg == args && attribute_takes_identifier_p (name)
+	  && identifier_p (t))
 	continue;
 
       if (value_dependent_expression_p (t)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f6f0fdba59b..27d03891419 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2016-01-23  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/58109
+	PR c++/69022
+	* g++.dg/cpp0x/alignas5.C: New test.
+	* g++.dg/ext/vector29.C: Same.
+
 2016-01-23  Uros Bizjak  <ubizjak@gmail.com>
 
 	* gcc.target/i386/chkp-strlen-2.c: Define _GNU_SOURCE.
diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas5.C b/gcc/testsuite/g++.dg/cpp0x/alignas5.C
index 2820ca716f6..2dcc41fae8a 100644
--- a/gcc/testsuite/g++.dg/cpp0x/alignas5.C
+++ b/gcc/testsuite/g++.dg/cpp0x/alignas5.C
@@ -1,6 +1,45 @@
-// { dg-do compile { target c++11 } }
+// PR c++/58109  - alignas() fails to compile with constant expression
+// { dg-do compile }
 
-#define SA(X) static_assert(X,#X)
+template <typename T>
+struct Base {
+  static const int Align = sizeof (T);
+};
 
-enum alignas(16) E {};
-SA(alignof(E) == 16);
+// 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;
diff --git a/gcc/testsuite/g++.dg/ext/vector29.C b/gcc/testsuite/g++.dg/ext/vector29.C
new file mode 100644
index 00000000000..4a130092a3f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/vector29.C
@@ -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 ();
+}