testsuite: Change pr80334.C testcase to dg-do compile [PR102772]

The testcase has UB at runtime, placement new shouldn't construct
an object with certain alignment requirements into an unaligned buffer.

2022-03-30  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/80334
	PR target/102772
	* g++.dg/torture/pr80334.C: Change from dg-do run to dg-do compile.

diff --git a/gcc/testsuite/g++.dg/torture/pr80334.C b/gcc/testsuite/g++.dg/torture/pr80334.C
index aee1548..d25b677 100644 (file)
--- a/gcc/testsuite/g++.dg/torture/pr80334.C
+++ b/gcc/testsuite/g++.dg/torture/pr80334.C
@@ -1,4 +1,8 @@
-// { dg-do run }
+// This used to be dg-do run testcase, but it is invalid at runtime:
+// trying to do a placement new of A which is 16-byte sized and aligned
+// into a 16-byte buffer at offset 17 bytes from 16-byte aligned address
+// is UB.
+// { dg-do compile }
 
 struct A { alignas(16) char c; };
 struct B { A unpacked; char d; } __attribute__((packed));