[libcxx-commits] [libcxx] [ASan][libc++] Turn on ASan annotations for short strings (PR #75882)

[Louis Dionne via libcxx-commits]

================
@@ -0,0 +1,181 @@
+//===----------------------------------------------------------------------===//
+//
+// 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: asan
+// UNSUPPORTED: c++03
+
+#include <cassert>
+#include <array>
+#include "test_macros.h"
+#include "asan_testing.h" // includes vector and string - don't do it before
+#include "min_allocator.h"
+
+// This tests exists to check if strings work well with vector, as those
+// may be partialy annotated, we cannot simply call
+// is_contiguous_container_asan_correct, as it assumes that
+// object memory inside is not annotated, so we check everything in a more careful way.
+
+template <typename D>
+bool verify_inside(D const& d) {
+  for (size_t i = 0; i < d.size(); ++i) {
+    if (!is_string_asan_correct(d[i]))
+      return false;
+  }
+
+  return true;
+}
+
+template <typename S, size_t N>
+S get_s(char c) {
+  S s;
+  for (size_t i = 0; i < N; ++i)
+    s.push_back(c);
+
+  return s;
+}
+
+template <class C, class S>
+void test_string() {
+  size_t const N = sizeof(S) < 256 ? (4096 / sizeof(S)) : 16;
+
+  {
+    C d1a(1), d1b(N), d1c(N + 1), d1d(32 * N);
+    assert(verify_inside(d1a));
+    assert(verify_inside(d1b));
+    assert(verify_inside(d1c));
+    assert(verify_inside(d1d));
+  }
+  {
+    C d2;
+    for (size_t i = 0; i < 16 * N; ++i) {
+      d2.push_back(get_s<S, 1>(i % 10 + 'a'));
+      assert(verify_inside(d2));
+      d2.push_back(get_s<S, 222>(i % 10 + 'b'));
+      assert(verify_inside(d2));
+
+      d2.erase(d2.cbegin());
+      assert(verify_inside(d2));
+    }
+  }
+  {
+    C d3;
+    for (size_t i = 0; i < 16 * N; ++i) {
+      d3.push_back(get_s<S, 1>(i % 10 + 'a'));
+      assert(verify_inside(d3));
+      d3.push_back(get_s<S, 222>(i % 10 + 'b'));
+      assert(verify_inside(d3));
+
+      d3.pop_back();
+      assert(verify_inside(d3));
+    }
+  }
+  {
+    C d4;
+    for (size_t i = 0; i < 16 * N; ++i) {
+      // When there is no SSO, all elements inside should not be poisoned,
+      // so we can verify vector poisoning.
+      d4.push_back(get_s<S, 333>(i % 10 + 'a'));
+      assert(verify_inside(d4));
+      assert(is_contiguous_container_asan_correct(d4));
+      d4.push_back(get_s<S, 222>(i % 10 + 'b'));
+      assert(verify_inside(d4));
+      assert(is_contiguous_container_asan_correct(d4));
+    }
+  }
+  {
+    C d5;
+    for (size_t i = 0; i < 5 * N; ++i) {
+      // In d4 we never had poisoned memory inside vector.
+      // Here we start with SSO, so part of the inside of the container,
+      // will be poisoned.
+      d5.push_back(S());
+      assert(verify_inside(d5));
+    }
+    for (size_t i = 0; i < d5.size(); ++i) {
+      // We change the size to have long string.
+      // Memory owne by vector should not be poisoned by string.
+      d5[i].resize(1000);
+      assert(verify_inside(d5));
+    }
+
+    assert(is_contiguous_container_asan_correct(d5));
+
+    d5.erase(d5.begin() + 2);
+    assert(verify_inside(d5));
+
+    d5.erase(d5.end() - 2);
+    assert(verify_inside(d5));
+
+    assert(is_contiguous_container_asan_correct(d5));
+  }
+  {
+    C d6a;
+    assert(is_contiguous_container_asan_correct(d6a));
+
+    C d6b(N + 2, get_s<S, 1000>('a'));
+    d6b.push_back(get_s<S, 1001>('b'));
+    while (!d6b.empty()) {
+      d6b.pop_back();
+      assert(is_contiguous_container_asan_correct(d6b));
+    }
+
+    C d6c(N + 2, get_s<S, 1002>('c'));
+    while (!d6c.empty()) {
+      d6c.pop_back();
+      assert(is_contiguous_container_asan_correct(d6c));
+    }
+  }
+  {
+    C d7(9 * N + 2);
+
+    d7.insert(d7.begin() + 1, S());
+    assert(verify_inside(d7));
+
+    d7.insert(d7.end() - 3, S());
+    assert(verify_inside(d7));
+
+    d7.insert(d7.begin() + 2 * N, get_s<S, 1>('a'));
+    assert(verify_inside(d7));
+
+    d7.insert(d7.end() - 2 * N, get_s<S, 1>('b'));
+    assert(verify_inside(d7));
+
+    d7.insert(d7.begin() + 2 * N, 3 * N, get_s<S, 1>('c'));
+    assert(verify_inside(d7));
+
+    // It may not be short for big element types, but it will be checked correctly:
+    d7.insert(d7.end() - 2 * N, 3 * N, get_s<S, 2>('d'));
+    assert(verify_inside(d7));
+
+    d7.erase(d7.begin() + 2);
+    assert(verify_inside(d7));
+
+    d7.erase(d7.end() - 2);
+    assert(verify_inside(d7));
+  }
+}
+
+template <class S>
+void test_container() {
+  test_string<std::vector<S, std::allocator<S>>, S>();
+  test_string<std::vector<S, min_allocator<S>>, S>();
+  test_string<std::vector<S, safe_allocator<S>>, S>();
+}
+
+int main(int, char**) {
+  // Those tests support only types based on std::basic_string.
+  test_container<std::string>();
+  test_container<std::wstring>();
+#if TEST_STD_VER >= 11
+  test_container<std::u16string>();
+  test_container<std::u32string>();
+#endif
+#if TEST_STD_VER >= 20
+  test_container<std::u8string>();
+#endif
+}
----------------
ldionne wrote:

`return 0` 🙂

https://github.com/llvm/llvm-project/pull/75882