[libcxx-commits] [libcxx] [libc++][hardening] Categorize more 'valid-element-access' checks. (PR #71620)

[Louis Dionne via libcxx-commits]

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@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: has-unix-headers
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-hardening-mode=none
+// XFAIL: availability-verbose_abort-missing
+
+#include <iterator>
+
+#include "check_assertion.h"
+#include "test_iterators.h"
+
+int main(int, char**) {
+  using Iter = std::common_iterator<int*, sentinel_wrapper<int*>>;
+  int a[]    = {1, 2, 3};
+  sentinel_wrapper<int*> s;
+  Iter valid_i = a;
+
+  {
+    Iter i = s;
+
+    TEST_LIBCPP_ASSERT_FAILURE(*i, "Attempted to dereference a non-dereferenceable common_iterator");
+
+    TEST_LIBCPP_ASSERT_FAILURE(++i, "Attempted to increment a non-dereferenceable common_iterator");
+    TEST_LIBCPP_ASSERT_FAILURE(i++, "Attempted to increment a non-dereferenceable common_iterator");
+
+    TEST_LIBCPP_ASSERT_FAILURE(
+        std::ranges::iter_move(i), "Attempted to iter_move a non-dereferenceable common_iterator");
+
+    TEST_LIBCPP_ASSERT_FAILURE(
+        std::ranges::iter_swap(i, valid_i), "Attempted to iter_swap a non-dereferenceable common_iterator");
+    TEST_LIBCPP_ASSERT_FAILURE(
+        std::ranges::iter_swap(valid_i, i), "Attempted to iter_swap a non-dereferenceable common_iterator");
+    std::ranges::iter_swap(valid_i, valid_i); // Ok
+  }
+
+  { // Check the `const` overload of `operator*`.
+    const Iter i = s;
+    TEST_LIBCPP_ASSERT_FAILURE(*i, "Attempted to dereference a non-dereferenceable common_iterator");
+  }
+
+  { // Check `operator->`.
+    struct Foo {
+      int x = 0;
+    };
+
+    std::common_iterator<Foo*, sentinel_wrapper<Foo*>> i = sentinel_wrapper<Foo*>();
+    TEST_LIBCPP_ASSERT_FAILURE(i->x, "Attempted to dereference a non-dereferenceable common_iterator");
+  }
+
+  // TODO: check `valueless_by_exception
----------------
ldionne wrote:

I think it is reasonable not to test that case, since we're already pretty diligent to test these assertions in the first place. I would either add the test now, or remove the TODO and call it a day. Basically I would avoid adding a TODO for something that we don't realistically think we'll ever address (in this case because it might not be worth the trouble).

https://github.com/llvm/llvm-project/pull/71620