From 053225431604d09cbe1d1495581b71a85a72dd1f Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Mon, 20 Jun 2011 10:40:19 -0400
Subject: [PATCH] re PR c++/48138 (__attribute__((aligned)) should give an
 error when applied to a typedef or template parameter, at least in C++0x
 mode.)

	PR c++/48138
	* tree.c (strip_typedefs): Use build_aligned_type.

From-SVN: r175215
---
 gcc/cp/ChangeLog                          |  3 +++
 gcc/cp/tree.c                             | 10 ++++++++++
 gcc/testsuite/ChangeLog                   |  3 +++
 gcc/testsuite/g++.dg/ext/attr-aligned01.C | 20 ++++++++++++++++++++
 4 files changed, 36 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/ext/attr-aligned01.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 87e5164d9b6..d88dc6089da 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2011-06-20  Jason Merrill  <jason@redhat.com>
 
+	PR c++/48138
+	* tree.c (strip_typedefs): Use build_aligned_type.
+
 	PR c++/49205
 	* call.c (sufficient_parms_p): Allow parameter packs too.
 
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index c1824b4626b..31005084b3c 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -1167,6 +1167,16 @@ strip_typedefs (tree t)
 
   if (!result)
       result = TYPE_MAIN_VARIANT (t);
+  if (TYPE_USER_ALIGN (t) != TYPE_USER_ALIGN (result)
+      || TYPE_ALIGN (t) != TYPE_ALIGN (result))
+    {
+      gcc_assert (TYPE_USER_ALIGN (t));
+      if (TYPE_ALIGN (t) == TYPE_ALIGN (result))
+	result = build_variant_type_copy (result);
+      else
+	result = build_aligned_type (result, TYPE_ALIGN (t));
+      TYPE_USER_ALIGN (result) = true;
+    }
   if (TYPE_ATTRIBUTES (t))
     result = cp_build_type_attribute_variant (result, TYPE_ATTRIBUTES (t));
   return cp_build_qualified_type (result, cp_type_quals (t));
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index abc624597da..99d4d3d410a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2011-06-20  Jason Merrill  <jason@redhat.com>
 
+	PR c++/48138
+	* g++.dg/ext/attr-aligned01.C: New.
+
 	PR c++/49205
 	* g++.dg/cpp0x/variadic-default.C: New.
 
diff --git a/gcc/testsuite/g++.dg/ext/attr-aligned01.C b/gcc/testsuite/g++.dg/ext/attr-aligned01.C
new file mode 100644
index 00000000000..a051c6e98d3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attr-aligned01.C
@@ -0,0 +1,20 @@
+// PR c++/48138
+// { dg-options -std=c++0x }
+
+#define ALIGNED(x) __attribute__((aligned(x)))
+#define SA(X) static_assert ((X),#X)
+
+template<typename T>
+void type_alignment(const T&) {
+  struct { char c; T t; } s;
+  SA((char*)&s.t - (char*)&s.c == 8);
+}
+
+int main() {
+  typedef char unaligned[15];
+  typedef char aligned[15] ALIGNED(8);
+
+  aligned z;
+  type_alignment(z);
+  type_alignment<unaligned ALIGNED(8)>(z);
+}
-- 
2.30.2