Remove unsafe arithmetic operations deprecated in 4.2 (#19426)

Author: stephentyrone

stdlib/public/core/IntegerTypes.swift.gyb

@@ -911,7 +911,7 @@ def assignmentOperatorComment(operator, fixedWidth):
 # by the related operator:
 #     +   addingReportingOverflow(_:)
 #     -   subtractingReportingOverflow(_:)
-#     *   multiplyingReportingOverflow(_:)
+#     *   multipliedReportingOverflow(by:)
 #     /   dividedReportingOverflow(by:)
 #     %   remainderReportingOverflow(dividingBy:)
 def overflowOperationComment(operator):

stdlib/public/core/Integers.swift

@@ -2995,134 +2995,6 @@ extension FixedWidthInteger {
     else { self = Self(truncatingIfNeeded: source) }
   }
 
-  /// Returns the sum of this value and the given value without checking for
-  /// arithmetic overflow.
-  ///
-  /// Use this function only to avoid the cost of overflow checking when you
-  /// are certain that the operation won't overflow. In optimized builds (`-O`)
-  /// the compiler is free to assume that overflow won't occur. Failure to
-  /// satisfy that assumption is a serious programming error and could lead to
-  /// statements being unexpectedly executed or skipped.
-  ///
-  /// In debug builds (`-Onone`) a runtime error is still triggered if the
-  /// operation overflows.
-  ///
-  /// This method is not a synonym for the masking addition operator (`&+`).
-  /// Use that operator instead of this method when you want to discard any
-  /// overflow that results from an addition operation.
-  ///
-  /// - Parameter rhs: The value to add to this value.
-  /// - Returns: The sum of this value and `rhs`.
-  @inline(__always)
-  public func unsafeAdding(_ other: Self) -> Self {
-    let (result, overflow) = self.addingReportingOverflow(other)
-
-    if overflow {
-      if (_isDebugAssertConfiguration()) {
-        _preconditionFailure("Overflow in unsafeAdding")
-      }
-      else {
-        Builtin.conditionallyUnreachable()
-      }
-    }
-    return result
-  }
-
-  /// Returns the difference obtained by subtracting the given value from this
-  /// value without checking for arithmetic overflow.
-  ///
-  /// Use this function only to avoid the cost of overflow checking when you
-  /// are certain that the operation won't overflow. In optimized builds (`-O`)
-  /// the compiler is free to assume that overflow won't occur. Failure to
-  /// satisfy that assumption is a serious programming error and could lead to
-  /// statements being unexpectedly executed or skipped.
-  ///
-  /// In debug builds (`-Onone`) a runtime error is still triggered if the
-  /// operation overflows.
-  ///
-  /// This method is not a synonym for the masking subtraction operator (`&-`).
-  /// Use that operator instead of this method when you want to discard any
-  /// overflow that results from a subtraction operation.
-  ///
-  /// - Parameter rhs: The value to subtract from this value.
-  /// - Returns: The result of subtracting `rhs` from this value.
-  @inline(__always)
-  public func unsafeSubtracting(_ other: Self) -> Self {
-    let (result, overflow) = self.subtractingReportingOverflow(other)
-
-    if overflow {
-      if (_isDebugAssertConfiguration()) {
-        _preconditionFailure("Overflow in unsafeSubtracting")
-      }
-      else {
-        Builtin.conditionallyUnreachable()
-      }
-    }
-    return result
-  }
-
-  /// Returns the product of this value and the given value without checking
-  /// for arithmetic overflow.
-  ///
-  /// Use this function only to avoid the cost of overflow checking when you
-  /// are certain that the operation won't overflow. In optimized builds (`-O`)
-  /// the compiler is free to assume that overflow won't occur. Failure to
-  /// satisfy that assumption is a serious programming error and could lead to
-  /// statements being unexpectedly executed or skipped.
-  ///
-  /// In debug builds (`-Onone`) a runtime error is still triggered if the
-  /// operation overflows.
-  ///
-  /// This method is not a synonym for the masking multiplication operator
-  /// (`&*`). Use that operator instead of this method when you want to discard
-  /// any overflow that results from an addition operation.
-  ///
-  /// - Parameter rhs: The value to multiply by this value.
-  /// - Returns: The product of this value and `rhs`.
-  @inline(__always)
-  public func unsafeMultiplied(by other: Self) -> Self {
-    let (result, overflow) = self.multipliedReportingOverflow(by: other)
-
-    if overflow {
-      if (_isDebugAssertConfiguration()) {
-        _preconditionFailure("Overflow in unsafeMultiplied")
-      }
-      else {
-        Builtin.conditionallyUnreachable()
-      }
-    }
-    return result
-  }
-
-  /// Returns the quotient obtained by dividing this value by the given value
-  /// without checking for arithmetic overflow.
-  ///
-  /// Use this function only to avoid the cost of overflow checking when you
-  /// are certain that the operation won't overflow. In optimized builds (`-O`)
-  /// the compiler is free to assume that overflow won't occur. Failure to
-  /// satisfy that assumption is a serious programming error and could lead to
-  /// statements being unexpectedly executed or skipped.
-  ///
-  /// In debug builds (`-Onone`) a runtime error is still triggered if the
-  /// operation overflows.
-  ///
-  /// - Parameter rhs: The value to divide this value by.
-  /// - Returns: The result of dividing this value by `rhs`.
-  @inline(__always)
-  public func unsafeDivided(by other: Self) -> Self {
-    let (result, overflow) = self.dividedReportingOverflow(by: other)
-
-    if overflow {
-      if (_isDebugAssertConfiguration()) {
-        _preconditionFailure("Overflow in unsafeDivided")
-      }
-      else {
-        Builtin.conditionallyUnreachable()
-      }
-    }
-    return result
-  }
-
   /// Creates a new instance from the bit pattern of the given instance by
   /// truncating or sign-extending if needed to fit this type.
   ///

stdlib/public/core/MigrationSupport.swift

@@ -383,6 +383,30 @@ extension FixedWidthInteger {
   /// The empty bitset.
   @available(swift, deprecated: 3.1, obsoleted: 4.0, message: "Use 0")
   public static var allZeros: Self { return 0 }
+  
+  @available(*, unavailable, message:
+    "Use operators or addingReportingOverflow instead.")
+  public func unsafeAdding(_ other: Self) -> Self {
+    fatalError("unavailable")
+  }
+  
+  @available(*, unavailable, message:
+    "Use operators or subtractingReportingOverflow instead.")
+  public func unsafeSubtracting(_ other: Self) -> Self {
+    fatalError("unavailable")
+  }
+  
+  @available(*, unavailable, message:
+    "Use operators or multipliedReportingOverflow(by:) instead.")
+  public func unsafeMultiplied(by other: Self) -> Self {
+    fatalError("unavailable")
+  }
+  
+  @available(*, unavailable, message:
+    "Use operators or dividedReportingOverflow(by:) instead.")
+  public func unsafeDivided(by other: Self) -> Self {
+    fatalError("unavailable")
+  }
 }
 
 extension LazyCollectionProtocol {

test/api-digester/source-stability.swift.expected

@@ -20,6 +20,10 @@ Func FixedWidthInteger.divideWithOverflow(_:_:) has been removed
 Func FixedWidthInteger.multiplyWithOverflow(_:_:) has been removed
 Func FixedWidthInteger.remainderWithOverflow(_:_:) has been removed
 Func FixedWidthInteger.subtractWithOverflow(_:_:) has been removed
+Func FixedWidthInteger.unsafeAdding(_:) has been removed
+Func FixedWidthInteger.unsafeDivided(by:) has been removed
+Func FixedWidthInteger.unsafeMultiplied(by:) has been removed
+Func FixedWidthInteger.unsafeSubtracting(_:) has been removed
 Func FloatingPoint.abs(_:) has been removed (deprecated)
 Func FloatingPoint.add(_:) has been removed
 Func FloatingPoint.adding(_:) has been removed