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Re: [C++ PATCH] Fix alignment handling in build_cplus_array_type/cp_build_qualified_type_real (PR c++/65690)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Jason Merrill <jason at redhat dot com>
- Cc: Jan Hubicka <hubicka at ucw dot cz>, gcc-patches at gcc dot gnu dot org
- Date: Thu, 9 Apr 2015 17:19:22 +0200
- Subject: Re: [C++ PATCH] Fix alignment handling in build_cplus_array_type/cp_build_qualified_type_real (PR c++/65690)
- Authentication-results: sourceware.org; auth=none
- References: <20150408100239 dot GO19273 at tucnak dot redhat dot com> <55253F73 dot 1000902 at redhat dot com> <20150408150759 dot GS19273 at tucnak dot redhat dot com> <5526913D dot 4040603 at redhat dot com>
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Thu, Apr 09, 2015 at 10:48:29AM -0400, Jason Merrill wrote:
> So the first hunk of the first patch is OK.
Ok, I've committed this to fix the regression.
2015-04-09 Jakub Jelinek <jakub@redhat.com>
PR c++/65690
* tree.c (build_cplus_array_type): Layout type before variants are
set, but copy over TYPE_SIZE and TYPE_SIZE_UNIT from the main
variant.
* c-c++-common/attr-aligned-1.c: New test.
--- gcc/cp/tree.c.jj 2015-04-01 15:29:33.000000000 +0200
+++ gcc/cp/tree.c 2015-04-08 09:09:45.326939354 +0200
@@ -880,12 +880,19 @@ build_cplus_array_type (tree elt_type, t
{
t = build_min_array_type (elt_type, index_type);
set_array_type_canon (t, elt_type, index_type);
+ if (!dependent)
+ {
+ layout_type (t);
+ /* Make sure sizes are shared with the main variant.
+ layout_type can't be called after setting TYPE_NEXT_VARIANT,
+ as it will overwrite alignment etc. of all variants. */
+ TYPE_SIZE (t) = TYPE_SIZE (m);
+ TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (m);
+ }
TYPE_MAIN_VARIANT (t) = m;
TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
TYPE_NEXT_VARIANT (m) = t;
- if (!dependent)
- layout_type (t);
}
}
--- gcc/testsuite/c-c++-common/attr-aligned-1.c.jj 2015-04-08 09:22:46.181427189 +0200
+++ gcc/testsuite/c-c++-common/attr-aligned-1.c 2015-04-08 09:26:41.315627195 +0200
@@ -0,0 +1,22 @@
+/* PR c++/65690 */
+/* { dg-do run } */
+
+typedef double T[4][4] __attribute__((aligned (2 * __alignof__ (double))));
+void foo (const T);
+struct S { T s; };
+
+int
+main ()
+{
+ if (__alignof__ (struct S) != 2 * __alignof__ (double)
+ || __alignof__ (T) != 2 * __alignof__ (double)
+ || __alignof__ (const struct S) != 2 * __alignof__ (double))
+ __builtin_abort ();
+ return 0;
+}
+
+#if defined(__cplusplus) && __cplusplus >= 201103L
+static_assert (alignof (S) == 2 * alignof (double), "alignment of S");
+static_assert (alignof (T) == 2 * alignof (double), "alignment of T");
+static_assert (alignof (const S) == 2 * alignof (double), "alignment of const S");
+#endif
Jakub