[libc++][hardening] Categorize assertions related to strict weak ordering

libcxx/include/__algorithm/comp_ref_type.h

@@ -44,7 +44,7 @@ struct __debug_less {
   _LIBCPP_CONSTEXPR_SINCE_CXX14 inline _LIBCPP_HIDE_FROM_ABI decltype((void)std::declval<_Compare&>()(
       std::declval<_LHS&>(), std::declval<_RHS&>()))
   __do_compare_assert(int, _LHS& __l, _RHS& __r) {
-    _LIBCPP_ASSERT_UNCATEGORIZED(!__comp_(__l, __r), "Comparator does not induce a strict weak ordering");
+    _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(!__comp_(__l, __r), "Comparator does not induce a strict weak ordering");
     (void)__l;
     (void)__r;
   }
@@ -53,8 +53,7 @@ struct __debug_less {
   _LIBCPP_CONSTEXPR_SINCE_CXX14 inline _LIBCPP_HIDE_FROM_ABI void __do_compare_assert(long, _LHS&, _RHS&) {}
 };
 
-// Pass the comparator by lvalue reference. Or in debug mode, using a
-// debugging wrapper that stores a reference.
+// Pass the comparator by lvalue reference. Or in the debug mode, using a debugging wrapper that stores a reference.
 #if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG
 template <class _Comp>
 using __comp_ref_type = __debug_less<_Comp>;

libcxx/include/__algorithm/nth_element.h

@@ -114,12 +114,12 @@ __nth_element(
         while (true) {
           while (!__comp(*__first, *__i)) {
             ++__i;
-            _LIBCPP_ASSERT_UNCATEGORIZED(
+            _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
                 __i != __last,
                 "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
           }
           do {
-            _LIBCPP_ASSERT_UNCATEGORIZED(
+            _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
                 __j != __first,
                 "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
             --__j;
@@ -150,13 +150,13 @@ __nth_element(
         // __m still guards upward moving __i
         while (__comp(*__i, *__m)) {
           ++__i;
-          _LIBCPP_ASSERT_UNCATEGORIZED(
+          _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
               __i != __last,
               "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
         }
         // It is now known that a guard exists for downward moving __j
         do {
-          _LIBCPP_ASSERT_UNCATEGORIZED(
+          _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
               __j != __first,
               "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
           --__j;

libcxx/include/__algorithm/sort.h

@@ -325,7 +325,7 @@ __insertion_sort_unguarded(_RandomAccessIterator const __first, _RandomAccessIte
       do {
         *__j = _Ops::__iter_move(__k);
         __j  = __k;
-        _LIBCPP_ASSERT_UNCATEGORIZED(
+        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
             __k != __leftmost,
             "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
       } while (__comp(__t, *--__k)); // No need for bounds check due to the assumption stated above.
@@ -544,7 +544,7 @@ __bitset_partition(_RandomAccessIterator __first, _RandomAccessIterator __last,
     // Not guarded since we know the last element is greater than the pivot.
     do {
       ++__first;
-      _LIBCPP_ASSERT_UNCATEGORIZED(
+      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
           __first != __end,
           "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
     } while (!__comp(__pivot, *__first));
@@ -557,7 +557,7 @@ __bitset_partition(_RandomAccessIterator __first, _RandomAccessIterator __last,
     // It will be always guarded because __introsort will do the median-of-three
     // before calling this.
     do {
-      _LIBCPP_ASSERT_UNCATEGORIZED(
+      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
           __last != __begin,
           "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
       --__last;
@@ -635,7 +635,7 @@ __partition_with_equals_on_right(_RandomAccessIterator __first, _RandomAccessIte
   // this.
   do {
     ++__first;
-    _LIBCPP_ASSERT_UNCATEGORIZED(
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
         __first != __end,
         "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
   } while (__comp(*__first, __pivot));
@@ -647,7 +647,7 @@ __partition_with_equals_on_right(_RandomAccessIterator __first, _RandomAccessIte
   } else {
     // Guarded.
     do {
-      _LIBCPP_ASSERT_UNCATEGORIZED(
+      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
           __last != __begin,
           "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
       --__last;
@@ -665,12 +665,12 @@ __partition_with_equals_on_right(_RandomAccessIterator __first, _RandomAccessIte
     _Ops::iter_swap(__first, __last);
     do {
       ++__first;
-      _LIBCPP_ASSERT_UNCATEGORIZED(
+      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
           __first != __end,
           "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
     } while (__comp(*__first, __pivot));
     do {
-      _LIBCPP_ASSERT_UNCATEGORIZED(
+      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
           __last != __begin,
           "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
       --__last;
@@ -702,7 +702,7 @@ __partition_with_equals_on_left(_RandomAccessIterator __first, _RandomAccessIter
     // Guarded.
     do {
       ++__first;
-      _LIBCPP_ASSERT_UNCATEGORIZED(
+      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
           __first != __end,
           "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
     } while (!__comp(__pivot, *__first));
@@ -715,7 +715,7 @@ __partition_with_equals_on_left(_RandomAccessIterator __first, _RandomAccessIter
     // It will be always guarded because __introsort will do the
     // median-of-three before calling this.
     do {
-      _LIBCPP_ASSERT_UNCATEGORIZED(
+      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
           __last != __begin,
           "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
       --__last;
@@ -725,12 +725,12 @@ __partition_with_equals_on_left(_RandomAccessIterator __first, _RandomAccessIter
     _Ops::iter_swap(__first, __last);
     do {
       ++__first;
-      _LIBCPP_ASSERT_UNCATEGORIZED(
+      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
           __first != __end,
           "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
     } while (!__comp(__pivot, *__first));
     do {
-      _LIBCPP_ASSERT_UNCATEGORIZED(
+      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
           __last != __begin,
           "Would read out of bounds, does your comparator satisfy the strict-weak ordering requirement?");
       --__last;

libcxx/include/__algorithm/three_way_comp_ref_type.h

@@ -50,14 +50,14 @@ struct __debug_three_way_comp {
       __expected = _Order::greater;
     if (__o == _Order::greater)
       __expected = _Order::less;
-    _LIBCPP_ASSERT_UNCATEGORIZED(__comp_(__l, __r) == __expected, "Comparator does not induce a strict weak ordering");
+    _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(
+        __comp_(__l, __r) == __expected, "Comparator does not induce a strict weak ordering");
     (void)__l;
     (void)__r;
   }
 };
 
-// Pass the comparator by lvalue reference. Or in debug mode, using a
-// debugging wrapper that stores a reference.
+// Pass the comparator by lvalue reference. Or in the debug mode, using a debugging wrapper that stores a reference.
 #  if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG
 template <class _Comp>
 using __three_way_comp_ref_type = __debug_three_way_comp<_Comp>;

libcxx/include/__config

@@ -313,6 +313,10 @@
 // - `_LIBCPP_ASSERT_PEDANTIC` -- checks prerequisites which are imposed by the Standard, but violating which happens to
 //   be benign in our implementation.
 //
+// - `_LIBCPP_ASSERT_SEMANTIC_REQUIREMENT` -- checks that the given argument satisfies the semantic requirements imposed
+//   by the Standard. Typically, there is no simple way to completely prove that a semantic requirement is satisfied;
+//   thus, this would often be a heuristic check and it might be quite expensive.
+//
 // - `_LIBCPP_ASSERT_INTERNAL` -- checks that internal invariants of the library hold. These assertions don't depend on
 //   user input.
 //
@@ -359,6 +363,7 @@ _LIBCPP_HARDENING_MODE_DEBUG
 #    define _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(expression, message)     _LIBCPP_ASSUME(expression)
 #    define _LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN(expression, message)   _LIBCPP_ASSUME(expression)
 #    define _LIBCPP_ASSERT_PEDANTIC(expression, message)                 _LIBCPP_ASSUME(expression)
+#    define _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(expression, message)     _LIBCPP_ASSUME(expression)
 #    define _LIBCPP_ASSERT_INTERNAL(expression, message)                 _LIBCPP_ASSUME(expression)
 #    define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message)            _LIBCPP_ASSUME(expression)
 
@@ -378,6 +383,7 @@ _LIBCPP_HARDENING_MODE_DEBUG
 #    define _LIBCPP_ASSERT_PEDANTIC(expression, message)                 _LIBCPP_ASSERT(expression, message)
 #    define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message)            _LIBCPP_ASSERT(expression, message)
 // Disabled checks.
+#    define _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(expression, message)     _LIBCPP_ASSUME(expression)
 #    define _LIBCPP_ASSERT_INTERNAL(expression, message)                 _LIBCPP_ASSUME(expression)
 
 // Debug hardening mode checks.
@@ -394,6 +400,7 @@ _LIBCPP_HARDENING_MODE_DEBUG
 #    define _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(expression, message)      _LIBCPP_ASSERT(expression, message)
 #    define _LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN(expression, message)    _LIBCPP_ASSERT(expression, message)
 #    define _LIBCPP_ASSERT_PEDANTIC(expression, message)                  _LIBCPP_ASSERT(expression, message)
+#    define _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(expression, message)      _LIBCPP_ASSERT(expression, message)
 #    define _LIBCPP_ASSERT_INTERNAL(expression, message)                  _LIBCPP_ASSERT(expression, message)
 #    define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message)             _LIBCPP_ASSERT(expression, message)
 
@@ -411,6 +418,7 @@ _LIBCPP_HARDENING_MODE_DEBUG
 #    define _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(expression, message)      _LIBCPP_ASSUME(expression)
 #    define _LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN(expression, message)    _LIBCPP_ASSUME(expression)
 #    define _LIBCPP_ASSERT_PEDANTIC(expression, message)                  _LIBCPP_ASSUME(expression)
+#    define _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(expression, message)      _LIBCPP_ASSUME(expression)
 #    define _LIBCPP_ASSERT_INTERNAL(expression, message)                  _LIBCPP_ASSUME(expression)
 #    define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message)             _LIBCPP_ASSUME(expression)
 

libcxx/include/__debug_utils/strict_weak_ordering_check.h

@@ -26,12 +26,12 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 template <class _RandomAccessIterator, class _Comp>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void
 __check_strict_weak_ordering_sorted(_RandomAccessIterator __first, _RandomAccessIterator __last, _Comp& __comp) {
-#ifdef _LIBCPP_DEBUG_STRICT_WEAK_ORDERING_CHECK
+#if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG
   using __diff_t  = __iter_diff_t<_RandomAccessIterator>;
   using _Comp_ref = __comp_ref_type<_Comp>;
   if (!__libcpp_is_constant_evaluated()) {
     // Check if the range is actually sorted.
-    _LIBCPP_ASSERT_UNCATEGORIZED(
+    _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(
         (std::is_sorted<_RandomAccessIterator, _Comp_ref>(__first, __last, _Comp_ref(__comp))),
         "The range is not sorted after the sort, your comparator is not a valid strict-weak ordering");
     // Limit the number of elements we need to check.
@@ -46,18 +46,18 @@ __check_strict_weak_ordering_sorted(_RandomAccessIterator __first, _RandomAccess
       // Check that the elements from __p to __q are equal between each other.
       for (__diff_t __b = __p; __b < __q; ++__b) {
         for (__diff_t __a = __p; __a <= __b; ++__a) {
-          _LIBCPP_ASSERT_UNCATEGORIZED(
+          _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(
               !__comp(*(__first + __a), *(__first + __b)), "Your comparator is not a valid strict-weak ordering");
-          _LIBCPP_ASSERT_UNCATEGORIZED(
+          _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(
               !__comp(*(__first + __b), *(__first + __a)), "Your comparator is not a valid strict-weak ordering");
         }
       }
       // Check that elements between __p and __q are less than between __q and __size.
       for (__diff_t __a = __p; __a < __q; ++__a) {
         for (__diff_t __b = __q; __b < __size; ++__b) {
-          _LIBCPP_ASSERT_UNCATEGORIZED(
+          _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(
               __comp(*(__first + __a), *(__first + __b)), "Your comparator is not a valid strict-weak ordering");
-          _LIBCPP_ASSERT_UNCATEGORIZED(
+          _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(
               !__comp(*(__first + __b), *(__first + __a)), "Your comparator is not a valid strict-weak ordering");
         }
       }
@@ -69,7 +69,7 @@ __check_strict_weak_ordering_sorted(_RandomAccessIterator __first, _RandomAccess
   (void)__first;
   (void)__last;
   (void)__comp;
-#endif
+#endif // _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG
 }
 
 _LIBCPP_END_NAMESPACE_STD