[libcxx-commits] [libcxx] [libc++][test] Fix and refactor exception tests for std::vector (PR #117662)

[Peng Liu via libcxx-commits]

================
@@ -17,145 +17,65 @@
 #include <vector>
 
 #include "count_new.h"
+#include "exception_test_helpers.h"
+#include "test_allocator.h"
 #include "test_iterators.h"
 
-template <class T>
-struct Allocator {
-  using value_type      = T;
-  using is_always_equal = std::false_type;
-
-  template <class U>
-  Allocator(const Allocator<U>&) {}
-
-  Allocator(bool should_throw = true) {
-    if (should_throw)
-      throw 0;
-  }
-
-  T* allocate(std::size_t n) { return std::allocator<T>().allocate(n); }
-  void deallocate(T* ptr, std::size_t n) { std::allocator<T>().deallocate(ptr, n); }
-
-  template <class U>
-  friend bool operator==(const Allocator&, const Allocator<U>&) { return true; }
-};
-
-struct ThrowingT {
-  int* throw_after_n_ = nullptr;
-  ThrowingT() { throw 0; }
-
-  ThrowingT(int& throw_after_n) : throw_after_n_(&throw_after_n) {
-    if (throw_after_n == 0)
-      throw 0;
-    --throw_after_n;
-  }
-
-  ThrowingT(const ThrowingT& rhs) : throw_after_n_(rhs.throw_after_n_) {
-    if (throw_after_n_ == nullptr || *throw_after_n_ == 0)
-      throw 1;
-    --*throw_after_n_;
-  }
-
-  ThrowingT& operator=(const ThrowingT& rhs) {
-    throw_after_n_ = rhs.throw_after_n_;
-    if (throw_after_n_ == nullptr || *throw_after_n_ == 0)
-      throw 1;
-    --*throw_after_n_;
-    return *this;
-  }
-};
-
-template <class IterCat>
-struct Iterator {
-  using iterator_category = IterCat;
-  using difference_type   = std::ptrdiff_t;
-  using value_type        = int;
-  using reference         = int&;
-  using pointer           = int*;
-
-  int i_;
-  Iterator(int i = 0) : i_(i) {}
-  int& operator*() {
-    if (i_ == 1)
-      throw 1;
-    return i_;
-  }
-
-  friend bool operator==(const Iterator& lhs, const Iterator& rhs) { return lhs.i_ == rhs.i_; }
-
-  friend bool operator!=(const Iterator& lhs, const Iterator& rhs) { return lhs.i_ != rhs.i_; }
-
-  Iterator& operator++() {
-    ++i_;
-    return *this;
-  }
-
-  Iterator operator++(int) {
-    auto tmp = *this;
-    ++i_;
-    return tmp;
-  }
-};
-
-void check_new_delete_called() {
-  assert(globalMemCounter.new_called == globalMemCounter.delete_called);
-  assert(globalMemCounter.new_array_called == globalMemCounter.delete_array_called);
-  assert(globalMemCounter.aligned_new_called == globalMemCounter.aligned_delete_called);
-  assert(globalMemCounter.aligned_new_array_called == globalMemCounter.aligned_delete_array_called);
-}
-
 int main(int, char**) {
-  using AllocVec = std::vector<int, Allocator<int> >;
+  using AllocVec = std::vector<int, throwing_allocator<int> >;
   try { // vector()
     AllocVec vec;
   } catch (int) {
   }
   check_new_delete_called();
 
   try { // Throw in vector(size_type) from type
-    std::vector<ThrowingT> get_alloc(1);
+    std::vector<throwing_t> get_alloc(1);
   } catch (int) {
   }
   check_new_delete_called();
 
 #if TEST_STD_VER >= 14
   try { // Throw in vector(size_type, value_type) from type
     int throw_after = 1;
-    ThrowingT v(throw_after);
-    std::vector<ThrowingT> get_alloc(1, v);
+    throwing_t v(throw_after);
+    std::vector<throwing_t> get_alloc(1, v);
   } catch (int) {
   }
   check_new_delete_called();
 
-  try { // Throw in vector(size_type, const allocator_type&) from allocator
-    Allocator<int> alloc(false);
+  try {                                         // Throw in vector(size_type, const allocator_type&) from allocator
+    throwing_allocator<int> alloc(false, true); // throw on copy only
     AllocVec get_alloc(0, alloc);
   } catch (int) {
   }
----------------
winner245 wrote:

I think the original test passed false to the constructor to avoid an immediate exception throw. However, the issue is that no exceptions were being thrown elsewhere. That's why I added the throw_on_copy_ flag, allowing us to trigger an exception later when the allocator is copied.

https://github.com/llvm/llvm-project/pull/117662