From: Jason Merrill <jason@redhat.com>
Date: Tue, 12 Apr 2022 20:06:18 +0000 (-0400)
Subject: c++: non-array new alignment [PR102071]
X-Git-Tag: basepoints/gcc-13~199
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=164c6a1c5d7f99235f1a41440eacac7a977e8fbd;p=thirdparty%2Fgcc.git

c++: non-array new alignment [PR102071]

While considering the PR102071 patch for backporting, I noticed that I was
considering the alignment of the array new cookie even when there isn't one
because we aren't allocating an array.

	PR c++/102071

gcc/cp/ChangeLog:

	* init.cc (build_new_1): Check array_p for alignment.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp1z/aligned-new9.C: Add single-object test.
---

diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
index ce332c7e3292..7ce8d3a46e5b 100644
--- a/gcc/cp/init.cc
+++ b/gcc/cp/init.cc
@@ -3292,7 +3292,7 @@ build_new_1 (vec<tree, va_gc> **placement, tree type, tree nelts,
     {
       unsigned align = TYPE_ALIGN_UNIT (elt_type);
       /* Also consider the alignment of the cookie, if any.  */
-      if (TYPE_VEC_NEW_USES_COOKIE (elt_type))
+      if (array_p && 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);
     }
diff --git a/gcc/testsuite/g++.dg/cpp1z/aligned-new9.C b/gcc/testsuite/g++.dg/cpp1z/aligned-new9.C
index 7854299419a1..3fa0ed996bd3 100644
--- a/gcc/testsuite/g++.dg/cpp1z/aligned-new9.C
+++ b/gcc/testsuite/g++.dg/cpp1z/aligned-new9.C
@@ -23,4 +23,8 @@ int main()
   X *p = new X[n];
   if (nalign != align)
     __builtin_abort ();
+
+  X *p2 = new X;
+  if (nalign != alignof (X))
+    __builtin_abort ();
 }