[libcxx-commits] [libcxx] d3b9855 - Add exception guard for constructor vector(n, x, a) (#113086)

[via libcxx-commits]

Author: Peng Liu
Date: 2024-10-29T13:29:37+08:00
New Revision: d3b98559be72682da45df73522173cb315912f6f

URL: https://github.com/llvm/llvm-project/commit/d3b98559be72682da45df73522173cb315912f6f
DIFF: https://github.com/llvm/llvm-project/commit/d3b98559be72682da45df73522173cb315912f6f.diff

LOG: Add exception guard for constructor vector(n, x, a) (#113086)

Added exception guard to the `vector(n, x, a)` constructor to enhance
exception safety. This change ensures that the `vector(n, x, a)`
constructor is consistent with other constructors, such as `vector(n)`,
`vector(n, x)`, `vector(n, a)`, in terms of exception safety.

Added: 
    

Modified: 
    libcxx/include/__vector/vector.h
    libcxx/test/std/containers/sequences/vector/vector.cons/exceptions.pass.cpp

Removed: 
    


################################################################################
diff  --git a/libcxx/include/__vector/vector.h b/libcxx/include/__vector/vector.h
index 7889e8c2201ac1..844e5d6a210568 100644
--- a/libcxx/include/__vector/vector.h
+++ b/libcxx/include/__vector/vector.h
@@ -165,10 +165,12 @@ class _LIBCPP_TEMPLATE_VIS vector {
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
   vector(size_type __n, const value_type& __x, const allocator_type& __a)
       : __alloc_(__a) {
+    auto __guard = std::__make_exception_guard(__destroy_vector(*this));
     if (__n > 0) {
       __vallocate(__n);
       __construct_at_end(__n, __x);
     }
+    __guard.__complete();
   }
 
   template <class _InputIterator,

diff  --git a/libcxx/test/std/containers/sequences/vector/vector.cons/exceptions.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.cons/exceptions.pass.cpp
index 3ef5aeecc1b0c9..c9c1bac2fb4a0c 100644
--- a/libcxx/test/std/containers/sequences/vector/vector.cons/exceptions.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.cons/exceptions.pass.cpp
@@ -139,6 +139,14 @@ int main(int, char**) {
   check_new_delete_called();
 #endif  // TEST_STD_VER >= 14
 
+  try { // Throw in vector(size_type, value_type, const allocator_type&) from the type
+    int throw_after = 1;
+    ThrowingT v(throw_after);
+    std::vector<ThrowingT> vec(1, v, std::allocator<ThrowingT>());
+  } catch (int) {
+  }
+  check_new_delete_called();
+
   try { // Throw in vector(InputIterator, InputIterator) from input iterator
     std::vector<int> vec((Iterator<std::input_iterator_tag>()), Iterator<std::input_iterator_tag>(2));
   } catch (int) {