[gardening] Clean up do catch blocks

Foundation/FileManager.swift

@@ -957,11 +957,7 @@ open class FileManager : NSObject {
     /* These methods are provided here for compatibility. The corresponding methods on NSData which return NSErrors should be regarded as the primary method of creating a file from an NSData or retrieving the contents of a file as an NSData.
      */
     open func contents(atPath path: String) -> Data? {
-        do {
-            return try Data(contentsOf: URL(fileURLWithPath: path))
-        } catch {
-            return nil
-        }
+        return try? Data(contentsOf: URL(fileURLWithPath: path))
     }
 
     open func createFile(atPath path: String, contents data: Data?, attributes attr: [FileAttributeKey : Any]? = nil) -> Bool {
@@ -971,7 +967,7 @@ open class FileManager : NSObject {
                 try self.setAttributes(attr, ofItemAtPath: path)
             }
             return true
-        } catch _ {
+        } catch {
             return false
         }
     }

Foundation/NSData.swift

@@ -579,22 +579,18 @@ open class NSData : NSObject, NSCopying, NSMutableCopying, NSSecureCoding {
                         if fsync(fd) < 0 {
                             throw _NSErrorWithErrno(errno, reading: false, path: path)
                         }
-                    } catch let err {
+                    } catch {
                         if let auxFilePath = auxFilePath {
-                            do {
-                                try FileManager.default.removeItem(atPath: auxFilePath)
-                            } catch _ {}
+                            try? FileManager.default.removeItem(atPath: auxFilePath)
                         }
-                        throw err
+                        throw error
                     }
                 }
             }
             if let auxFilePath = auxFilePath {
                 try fm._fileSystemRepresentation(withPath: auxFilePath, { auxFilePathFsRep in
                     if rename(auxFilePathFsRep, pathFsRep) != 0 {
-                        do {
-                            try FileManager.default.removeItem(atPath: auxFilePath)
-                        } catch _ {}
+                        try? FileManager.default.removeItem(atPath: auxFilePath)
                         throw _NSErrorWithErrno(errno, reading: false, path: path)
                     }
                     if let mode = mode {
@@ -705,8 +701,8 @@ open class NSData : NSObject, NSCopying, NSMutableCopying, NSSecureCoding {
         self.enumerateBytes() { (buf, range, stop) -> Void in
             do {
                 try block(buf, range, stop)
-            } catch let e {
-                err = e
+            } catch {
+                err = error
             }
         }
         if let err = err {

Foundation/NSKeyedArchiver.swift

@@ -138,18 +138,15 @@ open class NSKeyedArchiver : NSCoder {
 
         do {
             (fd, auxFilePath) = try _NSCreateTemporaryFile(path)
-        } catch _ {
+        } catch {
             return false
         }
 
         defer {
-            do {
-                if finishedEncoding {
-                    try _NSCleanupTemporaryFile(auxFilePath, path)
-                } else {
-                    try FileManager.default.removeItem(atPath: auxFilePath)
-                }
-            } catch _ {
+            if finishedEncoding {
+                try? _NSCleanupTemporaryFile(auxFilePath, path)
+            } else {
+                try? FileManager.default.removeItem(atPath: auxFilePath)
             }
         }
 

Foundation/NSKeyedUnarchiver.swift

@@ -58,11 +58,7 @@ open class NSKeyedUnarchiver : NSCoder {
     }
 
     open class func unarchiveObject(with data: Data) -> Any? {
-        do {
-            return try unarchiveTopLevelObjectWithData(data)
-        } catch {
-        }
-        return nil
+        return try? unarchiveTopLevelObjectWithData(data)
     }
 
     open class func unarchiveObject(withFile path: String) -> Any? {

Foundation/NSString.swift

@@ -122,15 +122,13 @@ internal func _createRegexForPattern(_ pattern: String, _ options: NSRegularExpr
     if let regex = local.__NSRegularExpressionCache.object(forKey: key._nsObject) {
         return regex
     }
-    do {
-        let regex = try NSRegularExpression(pattern: pattern, options: options)
-        local.__NSRegularExpressionCache.setObject(regex, forKey: key._nsObject)
-        return regex
-    } catch {
-
+
+    guard let regex = try? NSRegularExpression(pattern: pattern, options: options) else {
+        return nil
     }
-
-    return nil
+
+    local.__NSRegularExpressionCache.setObject(regex, forKey: key._nsObject)
+    return regex
 }
 
 internal func _bytesInEncoding(_ str: NSString, _ encoding: String.Encoding, _ fatalOnError: Bool, _ externalRep: Bool, _ lossy: Bool) -> UnsafePointer<Int8>? {

TestFoundation/TestBundle.swift

@@ -133,7 +133,7 @@ class BundlePlayground {
                 }
 
                 self.bundlePath = bundleURL.path
-            } catch _ {
+            } catch {
                 return false
             }
 
@@ -176,7 +176,7 @@ class BundlePlayground {
                 }
 
                 self.bundlePath = resourcesDirectory.path
-            } catch _ {
+            } catch {
                 return false
             }
 
@@ -210,7 +210,7 @@ class BundlePlayground {
                 }
 
                 self.bundlePath = resourcesDirectory.path
-            } catch _ {
+            } catch {
                 return false
             }
         }
@@ -222,12 +222,8 @@ class BundlePlayground {
     func destroy() {
         guard let path = self.playgroundPath else { return }
         self.playgroundPath = nil
-
-        do {
-            try FileManager.default.removeItem(atPath: path)
-        } catch _ {
-            // ¯\_(ツ)_/¯ We did what we could.
-        }
+
+        try? FileManager.default.removeItem(atPath: path)
     }
 
     deinit {
@@ -363,11 +359,7 @@ class TestBundle : XCTestCase {
     }
 
     private func _cleanupPlayground(_ location: String) {
-        do {
-            try FileManager.default.removeItem(atPath: location)
-        } catch _ {
-            // Oh well
-        }
+        try? FileManager.default.removeItem(atPath: location)
     }
 
     func test_URLsForResourcesWithExtension() {

TestFoundation/TestCodable.swift

@@ -84,7 +84,7 @@ class TestCodable : XCTestCase {
         for components in personNameComponentsValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: components)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(components)")
             }
         }
@@ -103,7 +103,7 @@ class TestCodable : XCTestCase {
             // We have to wrap the UUID since we cannot have a top-level string.
             do {
                 try expectRoundTripEqualityThroughJSON(for: UUIDCodingWrapper(uuid))
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(uuid)")
             }
         }
@@ -122,7 +122,7 @@ class TestCodable : XCTestCase {
         for url in urlValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: url)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(url)")
             }
         }
@@ -139,7 +139,7 @@ class TestCodable : XCTestCase {
         for range in nsrangeValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: range)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(range)")
             }
         }
@@ -161,7 +161,7 @@ class TestCodable : XCTestCase {
         for locale in localeValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: locale)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(locale)")
             }
         }
@@ -178,7 +178,7 @@ class TestCodable : XCTestCase {
         for indexSet in indexSetValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: indexSet)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(indexSet)")
             }
         }
@@ -196,7 +196,7 @@ class TestCodable : XCTestCase {
         for indexPath in indexPathValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: indexPath)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(indexPath)")
             }
         }
@@ -224,7 +224,7 @@ class TestCodable : XCTestCase {
         for transform in affineTransformValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: transform)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(transform)")
             }
         }
@@ -244,7 +244,7 @@ class TestCodable : XCTestCase {
         for decimal in decimalValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: decimal)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(decimal)")
             }
         }
@@ -264,7 +264,7 @@ class TestCodable : XCTestCase {
         for point in cgpointValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: point)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(point)")
             }
         }
@@ -284,7 +284,7 @@ class TestCodable : XCTestCase {
         for size in cgsizeValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: size)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(size)")
             }
         }
@@ -305,7 +305,7 @@ class TestCodable : XCTestCase {
         for rect in cgrectValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: rect)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(rect)")
             }
         }
@@ -335,7 +335,7 @@ class TestCodable : XCTestCase {
         for characterSet in characterSetValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: characterSet)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(characterSet)")
             }
         }
@@ -366,7 +366,7 @@ class TestCodable : XCTestCase {
         for timeZone in timeZoneValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: timeZone)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(timeZone)")
             }
         }
@@ -404,7 +404,7 @@ class TestCodable : XCTestCase {
         for calendar in calendarValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: calendar)
-            } catch let error {
+            } catch {
                 XCTFail("\(error) for \(calendar)")
             }
         }
@@ -441,7 +441,7 @@ class TestCodable : XCTestCase {
         let components = calendar.dateComponents(dateComponents, from: Date(timeIntervalSince1970: 1501283776))
         do {
             try expectRoundTripEqualityThroughJSON(for: components)
-        } catch let error {
+        } catch {
             XCTFail("\(error)")
         }
     }
@@ -452,7 +452,7 @@ class TestCodable : XCTestCase {
             try expectRoundTripEqualityThroughJSON(for: Measurement(value: 42, unit: UnitAcceleration.metersPerSecondSquared))
             try expectRoundTripEqualityThroughJSON(for: Measurement(value: 42, unit: UnitMass.kilograms))
             try expectRoundTripEqualityThroughJSON(for: Measurement(value: 42, unit: UnitLength.miles))
-        } catch let error {
+        } catch {
             XCTFail("\(error)")
         }
     }
@@ -548,7 +548,7 @@ class TestCodable : XCTestCase {
         for (components) in urlComponentsValues {
             do {
                 try expectRoundTripEqualityThroughJSON(for: components)
-            } catch let error {
+            } catch {
                 XCTFail("\(error)")
             }
         }