[libcxx-commits] [libcxx] [libc++] Correctly handle custom deleters in hardened unique_ptr<T[]> (PR #110685)

[Louis Dionne via libcxx-commits]

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@@ -112,12 +117,33 @@ TEST_CONSTEXPR_CXX23 bool test() {
         WithNonTrivialDtor<16>,
         WithNonTrivialDtor<256>>;
     types::for_each(TrickyCookieTypes(), []<class T> {
-      types::for_each(types::type_list<std::default_delete<T[]>, CustomDeleter<T[]>>(), []<class Deleter> {
-        std::unique_ptr<T[], Deleter> p(new T[3]);
+      // Array allocated with `new T[n]`, default deleter
+      {
+        std::unique_ptr<T[], std::default_delete<T[]>> p(new T[3]);
+        assert(p[0] == T());
+        assert(p[1] == T());
+        assert(p[2] == T());
+      }
+
+      // Array allocated with `new T[n]`, custom deleter
+      {
+        std::unique_ptr<T[], CustomDeleter<T[]>> p(new T[3]);
+        assert(p[0] == T());
+        assert(p[1] == T());
+        assert(p[2] == T());
+      }
+
+      // Array not allocated with `new T[n]`, custom deleter
+      //
+      // This test aims to ensure that the implementation doesn't try to use an array cookie
+      // when there is none.
+      {
+        T array[50] = {};
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ldionne wrote:

@nico I verified locally and this test breaks down without my patch. That's a smaller version of your reproducer.

https://github.com/llvm/llvm-project/pull/110685