--- /dev/null
+//
+// Tests for
+// bounded_ptr& operator+=(std::ptrdiff_t n);
+//
+
+#include <libkern/c++/bounded_ptr.h>
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <limits>
+#include <darwintest.h>
+#include <darwintest_utils.h>
+#include "test_utils.h"
+
+#define _assert(...) T_ASSERT_TRUE((__VA_ARGS__), # __VA_ARGS__)
+
+struct T { int i; };
+
+namespace {
+struct tracking_policy {
+ static bool did_trap;
+ static void
+ trap(char const*)
+ {
+ did_trap = true;
+ }
+};
+bool tracking_policy::did_trap = false;
+}
+
+template <typename T, typename QualT>
+static void
+tests()
+{
+ std::array<T, 5> array = {T{0}, T{1}, T{2}, T{3}, T{4}};
+
+ // Add-assign positive offsets
+ // T{0} T{1} T{2} T{3} T{4} <one-past-last>
+ // ^ ^
+ // | |
+ // begin,ptr end
+ {
+ test_bounded_ptr<QualT> ptr(array.begin(), array.begin(), array.end());
+ auto& ref = ptr += 0;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[0]);
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.begin(), array.begin(), array.end());
+ auto& ref = ptr += 1;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[1]);
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.begin(), array.begin(), array.end());
+ auto& ref = ptr += 2;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[2]);
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.begin(), array.begin(), array.end());
+ auto& ref = ptr += 3;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[3]);
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.begin(), array.begin(), array.end());
+ auto& ref = ptr += 4;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[4]);
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.begin(), array.begin(), array.end());
+ auto& ref = ptr += 5;
+ _assert(&ref == &ptr);
+ _assert(ptr == array.end());
+ }
+
+ // Add-assign negative offsets
+ // T{0} T{1} T{2} T{3} T{4} <one-past-last>
+ // ^ ^
+ // | |
+ // begin end,ptr
+ {
+ test_bounded_ptr<QualT> ptr(array.end(), array.begin(), array.end());
+ auto& ref = ptr += 0;
+ _assert(&ref == &ptr);
+ _assert(ptr == array.end());
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.end(), array.begin(), array.end());
+ auto& ref = ptr += -1;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[4]);
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.end(), array.begin(), array.end());
+ auto& ref = ptr += -2;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[3]);
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.end(), array.begin(), array.end());
+ auto& ref = ptr += -3;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[2]);
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.end(), array.begin(), array.end());
+ auto& ref = ptr += -4;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[1]);
+ }
+ {
+ test_bounded_ptr<QualT> ptr(array.end(), array.begin(), array.end());
+ auto& ref = ptr += -5;
+ _assert(&ref == &ptr);
+ _assert(&*ptr == &array[0]);
+ }
+
+ // Make sure we trap on arithmetic overflow in the number of bytes calculation
+ {
+ std::ptrdiff_t sizeof_T = sizeof(T); // avoid promotion to unsigned in calculations
+
+ // largest (most positive) n for the number of bytes `n * sizeof(T)` not to overflow ptrdiff_t
+ std::ptrdiff_t max_n = std::numeric_limits<std::ptrdiff_t>::max() / sizeof_T;
+
+ // smallest (most negative) n for the number of bytes `n * sizeof(T)` not to overflow ptrdiff_t
+ std::ptrdiff_t min_n = std::numeric_limits<std::ptrdiff_t>::min() / sizeof_T;
+
+ // Overflow with a positive offset
+ {
+ libkern::bounded_ptr<QualT, tracking_policy> ptr(array.begin(), array.begin(), array.end());
+ tracking_policy::did_trap = false;
+ ptr += max_n + 1;
+ _assert(tracking_policy::did_trap);
+ }
+
+ // Overflow with a negative offset
+ {
+ libkern::bounded_ptr<QualT, tracking_policy> ptr(array.begin(), array.begin(), array.end());
+ tracking_policy::did_trap = false;
+ ptr += min_n - 1;
+ _assert(tracking_policy::did_trap);
+ }
+ }
+
+ // Make sure we trap on arithmetic overflow in the offset calculation
+ //
+ // To avoid running into the overflow of `n * sizeof(T)` when ptrdiff_t
+ // is the same size as int32_t, we test the offset overflow check by
+ // successive addition of smaller offsets.
+ //
+ // We basically push the offset right to its limit, and then push it
+ // past its limit to watch it overflow.
+ {
+ std::int64_t sizeof_T = sizeof(T); // avoid promotion to unsigned in calculations
+
+ // largest (most positive) n for the number of bytes `n * sizeof(T)` not to overflow the int32_t offset
+ std::int64_t max_n = std::numeric_limits<std::int32_t>::max() / sizeof_T;
+
+ // smallest (most negative) n for the number of bytes `n * sizeof(T)` not to overflow the int32_t offset
+ std::int64_t min_n = std::numeric_limits<std::int32_t>::min() / sizeof_T;
+
+ // Add positive offsets
+ {
+ libkern::bounded_ptr<QualT, tracking_policy> ptr(array.begin(), array.begin(), array.end());
+ tracking_policy::did_trap = false;
+ ptr += static_cast<ptrdiff_t>(max_n / 2);
+ _assert(!tracking_policy::did_trap);
+ ptr += static_cast<ptrdiff_t>(max_n / 2);
+ _assert(!tracking_policy::did_trap);
+ ptr += (max_n % 2);
+ _assert(!tracking_policy::did_trap); // offset is now right at its positive limit
+ ptr += 1;
+ _assert(tracking_policy::did_trap);
+ }
+
+ // Add negative offsets
+ {
+ libkern::bounded_ptr<QualT, tracking_policy> ptr(array.begin(), array.begin(), array.end());
+ tracking_policy::did_trap = false;
+ ptr += static_cast<ptrdiff_t>(min_n / 2);
+ _assert(!tracking_policy::did_trap);
+ ptr += static_cast<ptrdiff_t>(min_n / 2);
+ _assert(!tracking_policy::did_trap);
+ ptr += (min_n % 2);
+ _assert(!tracking_policy::did_trap); // offset is now right at its negative limit
+ ptr += -1;
+ _assert(tracking_policy::did_trap);
+ }
+ }
+}
+
+T_DECL(arith_add_assign, "bounded_ptr.arith.add_assign") {
+ tests<T, T>();
+ tests<T, T const>();
+ tests<T, T volatile>();
+ tests<T, T const volatile>();
+}
projects / apple / xnu.git / blobdiff