[clang] [-Wunsafe-buffer-usage] Add unique_ptr <T[]> accesses (PR #156773)

[via cfe-commits]

================
@@ -0,0 +1,62 @@
+// RUN: %clang_cc1 -Wno-unused-value -Wunsafe-buffer-usage -fsafe-buffer-usage-suggestions -std=c++20 -verify=expected %s
+
+// This debugging facility is only available in debug builds.
+//
+// REQUIRES: asserts
+
+namespace std {
+inline namespace __1 {
+template <class T> class unique_ptr {
+public:
+  T &operator[](long long i) const;
+};
+} // namespace __1
+} // namespace std
+
+int get_index() {
+  return 4;
+}
+
+void basic_unique_ptr() {
+  std::unique_ptr<int[]> p1;
+  int i = 2;
+  const int j = 3;
+  int k = 0;
+
+  p1[0];  // This is allowed
+
+  p1[k];  // expected-warning{{direct access using operator[] on std::unique_ptr<T[]> is unsafe due to lack of bounds checking}}
+
+  p1[1];  // expected-warning{{direct access using operator[] on std::unique_ptr<T[]> is unsafe due to lack of bounds checking}}
+
+  p1[1L];  // expected-warning{{direct access using operator[] on std::unique_ptr<T[]> is unsafe due to lack of bounds checking}}
+
+  p1[1LL];  // expected-warning{{direct access using operator[] on std::unique_ptr<T[]> is unsafe due to lack of bounds checking}}
+
+  p1[3 * 5];  // expected-warning{{direct access using operator[] on std::unique_ptr<T[]> is unsafe due to lack of bounds checking}}
+
+  p1[i];  // expected-warning{{direct access using operator[] on std::unique_ptr<T[]> is unsafe due to lack of bounds checking}}
+
+  p1[j];  // expected-warning{{direct access using operator[] on std::unique_ptr<T[]> is unsafe due to lack of bounds checking}}
+
+  p1[i + 5]; // expected-warning{{direct access using operator[] on std::unique_ptr<T[]> is unsafe due to lack of bounds checking}}
+
+  p1[get_index()];  // expected-warning{{direct access using operator[] on std::unique_ptr<T[]> is unsafe due to lack of bounds checking}}
+
+}
+
+// CHECK: Root # 1
----------------
shreya-jain wrote:

Removed these

https://github.com/llvm/llvm-project/pull/156773