diff mbox series

[pushed] c++: low -faligned-new [PR102071]

Message ID 20220328133525.2586952-1-jason@redhat.com
State Committed
Commit 19b87a06482756739087283cd8b884cb3de693f9
Headers
Series [pushed] c++: low -faligned-new [PR102071] |

Commit Message

Jason Merrill March 28, 2022, 1:35 p.m. UTC 
  This test ICEd after the constexpr new patch (r10-3661) because alloc_call
had a NOP_EXPR around it; fixed by moving the NOP_EXPR to alloc_expr.  And
the PR pointed out that the size_t cookie might need more alignment, so I
fix that as well.

Tested x86_64-pc-linux-gnu, applying to trunk.

	PR c++/102071

gcc/cp/ChangeLog:

	* init.cc (build_new_1): Include cookie in alignment.  Omit
	constexpr wrapper from alloc_call.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp1z/aligned-new9.C: New test.
---
 gcc/cp/init.cc                            | 15 +++++++++----
 gcc/testsuite/g++.dg/cpp1z/aligned-new9.C | 26 +++++++++++++++++++++++
 2 files changed, 37 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp1z/aligned-new9.C


base-commit: bc86a86a4f2c057bc0e0be94dcbb8c128ae7f717
prerequisite-patch-id: 09e711b54e7911a4a04bd7808abc1b73ae4482ba
prerequisite-patch-id: 566cf0772894d0c6a842b2e0ca62eb1d5ae8ad33
prerequisite-patch-id: b1def7e83e76c1652efb483cb2b67e472d15b720
prerequisite-patch-id: 12973b1310781ff6ce5c9792ea689f0673fc5251
prerequisite-patch-id: 8dcc4ecc29dbe7b290325412af70613171456714
prerequisite-patch-id: 0e11ad2f06a4b425182bca51bd5a85eedd3ce8cd
prerequisite-patch-id: 1c17a86736dd239bc62ee4619599fc89f0cf5908
prerequisite-patch-id: e62940b6d46209e9c0af369d9eff7351d9a94775
diff mbox series

Patch

diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
index 08767679dd4..91b5c2c0f69 100644
--- a/gcc/cp/init.cc
+++ b/gcc/cp/init.cc
@@ -3284,7 +3284,13 @@  build_new_1 (vec<tree, va_gc> **placement, tree type, tree nelts,
 
   tree align_arg = NULL_TREE;
   if (type_has_new_extended_alignment (elt_type))
-    align_arg = build_int_cst (align_type_node, TYPE_ALIGN_UNIT (elt_type));
+    {
+      unsigned align = TYPE_ALIGN_UNIT (elt_type);
+      /* Also consider the alignment of the cookie, if any.  */
+      if (TYPE_VEC_NEW_USES_COOKIE (elt_type))
+	align = MAX (align, TYPE_ALIGN_UNIT (size_type_node));
+      align_arg = build_int_cst (align_type_node, align);
+    }
 
   alloc_fn = NULL_TREE;
 
@@ -3473,18 +3479,19 @@  build_new_1 (vec<tree, va_gc> **placement, tree type, tree nelts,
 	}
     }
 
+  alloc_expr = alloc_call;
   if (cookie_size)
-    alloc_call = maybe_wrap_new_for_constexpr (alloc_call, type,
+    alloc_expr = maybe_wrap_new_for_constexpr (alloc_expr, type,
 					       cookie_size);
 
   /* In the simple case, we can stop now.  */
   pointer_type = build_pointer_type (type);
   if (!cookie_size && !is_initialized && !member_delete_p)
-    return build_nop (pointer_type, alloc_call);
+    return build_nop (pointer_type, alloc_expr);
 
   /* Store the result of the allocation call in a variable so that we can
      use it more than once.  */
-  alloc_expr = get_target_expr (alloc_call);
+  alloc_expr = get_target_expr (alloc_expr);
   alloc_node = TARGET_EXPR_SLOT (alloc_expr);
 
   /* Strip any COMPOUND_EXPRs from ALLOC_CALL.  */
diff --git a/gcc/testsuite/g++.dg/cpp1z/aligned-new9.C b/gcc/testsuite/g++.dg/cpp1z/aligned-new9.C
new file mode 100644
index 00000000000..7854299419a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/aligned-new9.C
@@ -0,0 +1,26 @@ 
+// PR c++/102071
+// { dg-do run { target c++17 } }
+// { dg-additional-options -faligned-new=2 }
+
+#include <new>
+
+int nalign;
+void *operator new (std::size_t s, std::align_val_t a)
+{
+  nalign = (int)a;
+  return operator new (s);
+}
+
+struct X { ~X(); int c; };
+
+int align = (alignof (X) > alignof (std::size_t)
+	     ? alignof (X) : alignof (std::size_t));
+
+int n = 4;
+
+int main()
+{
+  X *p = new X[n];
+  if (nalign != align)
+    __builtin_abort ();
+}