1 files changed, 86 insertions, 0 deletions
diff --git a/libstdc++-v3/testsuite/19_diagnostics/stacktrace/current.cc b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/current.cc
new file mode 100644
index 00000000000..184e23b460e
--- /dev/null
+++ b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/current.cc
@@ -0,0 +1,86 @@
+// { dg-options "-std=gnu++23 -lstdc++_libbacktrace" }
+// { dg-do run { target c++23 } }
+// { dg-require-effective-target stacktrace }
+
+#include <stacktrace>
+#include <memory>
+#include <new>
+#include "testsuite_hooks.h"
+
+template<typename T>
+struct Allocator
+{
+  using value_type = T;
+  using propagate_on_container_move_assignment = std::true_type;
+
+  explicit
+  Allocator(unsigned max = -1u) : max_size(max) { }
+
+  template<typename U>
+    Allocator(const Allocator<U>& a) : max_size(a.max_size) { }
+
+  T*
+  allocate(std::size_t n)
+  {
+    if (n > max_size)
+      throw std::bad_alloc();
+
+    return std::allocator<T>().allocate(n);
+  }
+
+  void
+  deallocate(T* p, std::size_t n) noexcept
+  {
+    std::allocator<T>().deallocate(p, n);
+  }
+
+  bool operator==(const Allocator&) const = default;
+
+private:
+  unsigned max_size;
+};
+
+[[gnu::optimize("O0")]]
+void
+test_max_depth()
+{
+  using Stacktrace = std::basic_stacktrace<Allocator<std::stacktrace_entry>>;
+  using Alloc = typename Stacktrace::allocator_type;
+
+  [] { [] { [] { [] { [] { [] { [] { [] {
+    auto t = Stacktrace::current();
+    VERIFY( ! t.empty() );
+    const auto n = t.size(); // total number of frames
+    t = Stacktrace::current(8);
+    VERIFY( t.size() == (n - 8) );
+    t = Stacktrace::current(n);
+    VERIFY( t.empty() );
+    t = Stacktrace::current(n - 2);
+    VERIFY( t.size() == 2 );
+    t = Stacktrace::current(2, 6);
+    VERIFY( t.size() == 6 );
+    t = Stacktrace::current(n - 2, 6);
+    VERIFY( t.size() == 2 );
+
+    t = Stacktrace::current(Alloc(3));
+    // Full stacktrace is larger than 3 frames, so allocation fails:
+    VERIFY( t.empty() );
+    t = Stacktrace::current(3, Alloc(2));
+    // Stacktrace still too large after skipping 3 frames, so allocation fails:
+    VERIFY( t.empty() );
+    t = Stacktrace::current(0, 3, Alloc(3));
+    // Capacity for exactly 3 frames is allocated:
+    VERIFY( t.size() == 3 );
+    t = Stacktrace::current(2, 4, Alloc(4));
+    // Capacity for exactly 4 frames is allocated:
+    VERIFY( t.size() == 4 );
+    t = Stacktrace::current(0, 4, Alloc(3));
+    // Capacity for exactly 4 frames is requested, but allocation fails:
+    VERIFY( t.empty() );
+  }(); }(); }(); }(); }(); }(); }(); }();
+}
+
+int main()
+{
+  test_max_depth();
+}