diff --git a/include/swift/AST/DiagnosticsSema.def b/include/swift/AST/DiagnosticsSema.def
index 183ebdc3c3227..15f7af5f8ea1b 100644
--- a/include/swift/AST/DiagnosticsSema.def
+++ b/include/swift/AST/DiagnosticsSema.def
@@ -2192,10 +2192,16 @@ ERROR(expression_unused_function,none,
       "expression resolves to an unused function", ())
 ERROR(expression_unused_lvalue,none,
       "expression resolves to an unused l-value", ())
-WARNING(expression_unused_result,none,
+WARNING(expression_unused_result_call,none,
         "result of call to %0 is unused", (DeclName))
+WARNING(expression_unused_result_operator,none,
+        "result of operator %0 is unused", (DeclName))
+WARNING(expression_unused_result_unknown, none,
+        "result of call is unused, but produces %0", (Type))
+WARNING(expression_unused_result, none,
+        "expression of type %0 is unused", (Type))
 WARNING(expression_unused_init_result,none,
-        "result of initializer is unused", ())
+        "result of %0 initializer is unused", (Type))
 WARNING(expression_unused_optional_try,none,
         "result of 'try?' is unused", ())
 WARNING(expression_unused_selector_result, none,
diff --git a/lib/Sema/TypeCheckStmt.cpp b/lib/Sema/TypeCheckStmt.cpp
index ea15cc105b6c3..bfc590ecdd457 100644
--- a/lib/Sema/TypeCheckStmt.cpp
+++ b/lib/Sema/TypeCheckStmt.cpp
@@ -1015,6 +1015,17 @@ void TypeChecker::checkIgnoredExpr(Expr *E) {
     return;
   }
 
+  // Drill through noop expressions we don't care about, like ParanExprs.
+  auto valueE = E;
+  while (1) {
+    valueE = valueE->getValueProvidingExpr();
+    
+    if (auto *OEE = dyn_cast<OpenExistentialExpr>(valueE))
+      valueE = OEE->getSubExpr();
+    else
+      break;
+  }
+  
   // Complain about functions that aren't called.
   // TODO: What about tuples which contain functions by-value that are
   // dead?
@@ -1024,7 +1035,11 @@ void TypeChecker::checkIgnoredExpr(Expr *E) {
     return;
   }
 
-  auto valueE = E->getValueProvidingExpr();
+  // If the result of this expression is of type "()", then it is safe to
+  // ignore.
+  if (valueE->getType()->isVoid() ||
+      valueE->getType()->is<ErrorType>())
+    return;
   
   // Complain about '#selector'.
   if (auto *ObjCSE = dyn_cast<ObjCSelectorExpr>(valueE)) {
@@ -1047,15 +1062,20 @@ void TypeChecker::checkIgnoredExpr(Expr *E) {
     if (auto *IIO = dyn_cast<InjectIntoOptionalExpr>(OEE->getSubExpr()))
       return checkIgnoredExpr(IIO->getSubExpr());
 
-  // FIXME: Complain about literals
-
   // Check if we have a call to a function not marked with
   // '@discardableResult'.
   if (auto call = dyn_cast<ApplyExpr>(valueE)) {
     // Dig through all levels of calls.
-    Expr *fn = call->getFn()->getSemanticsProvidingExpr();
-    while (auto applyFn = dyn_cast<ApplyExpr>(fn)) {
-      fn = applyFn->getFn()->getSemanticsProvidingExpr();
+    Expr *fn = call->getFn();
+    while (true) {
+      fn = fn->getSemanticsProvidingExpr();
+      if (auto applyFn = dyn_cast<ApplyExpr>(fn)) {
+        fn = applyFn->getFn();
+      } else if (auto FVE = dyn_cast<ForceValueExpr>(fn)) {
+        fn = FVE->getSubExpr();
+      } else {
+        break;
+      }
     }
 
     // Find the callee.
@@ -1069,19 +1089,45 @@ void TypeChecker::checkIgnoredExpr(Expr *E) {
     else if (auto dynMemberRef = dyn_cast<DynamicMemberRefExpr>(fn))
       callee = dyn_cast<AbstractFunctionDecl>(
                  dynMemberRef->getMember().getDecl());
-
-    if (callee) {
-      if (!callee->getAttrs().getAttribute<DiscardableResultAttr>() &&
-          !valueE->getType()->isVoid()) {
-        diagnose(fn->getLoc(), diag::expression_unused_result,
-                 callee->getFullName());
-        return;
-      }
-      if (isa<ConstructorDecl>(callee) && !call->isImplicit()) {
-        diagnose(fn->getLoc(), diag::expression_unused_init_result);
-      }
+    
+    // If the callee explicitly allows its result to be ignored, then don't
+    // complain.
+    if (callee && callee->getAttrs().getAttribute<DiscardableResultAttr>())
+      return;
+
+    // Otherwise, complain.  Start with more specific diagnostics.
+    if (callee && isa<ConstructorDecl>(callee) && !call->isImplicit()) {
+      diagnose(fn->getLoc(), diag::expression_unused_init_result,
+               callee->getDeclContext()->getDeclaredTypeOfContext())
+        .highlight(call->getArg()->getSourceRange());
+      return;
     }
+    
+    SourceRange SR1 = call->getArg()->getSourceRange(), SR2;
+    if (auto *BO = dyn_cast<BinaryExpr>(call)) {
+      SR1 = BO->getArg()->getElement(0)->getSourceRange();
+      SR2 = BO->getArg()->getElement(1)->getSourceRange();
+    }
+    
+    // Otherwise, produce a generic diagnostic.
+    if (callee) {
+      auto diagID = diag::expression_unused_result_call;
+      if (callee->getFullName().isOperator())
+        diagID = diag::expression_unused_result_operator;
+      
+      diagnose(fn->getLoc(), diagID, callee->getFullName())
+        .highlight(SR1).highlight(SR2);
+    } else
+      diagnose(fn->getLoc(), diag::expression_unused_result_unknown,
+               valueE->getType())
+        .highlight(SR1).highlight(SR2);
+
+    return;
   }
+
+  // Produce a generic diagnostic.
+  diagnose(valueE->getLoc(), diag::expression_unused_result, valueE->getType())
+    .highlight(valueE->getSourceRange());
 }
 
 Stmt *StmtChecker::visitBraceStmt(BraceStmt *BS) {
diff --git a/test/ClangModules/AppKit_test.swift b/test/ClangModules/AppKit_test.swift
index 4bd589c595f80..3441362502851 100644
--- a/test/ClangModules/AppKit_test.swift
+++ b/test/ClangModules/AppKit_test.swift
@@ -15,8 +15,8 @@ class MyDocument : NSDocument {
 }
 
 func test(_ URL: NSURL, controller: NSDocumentController) {
-  try! NSDocument(contentsOf: URL, ofType: "") // expected-warning{{unused}}
-  try! MyDocument(contentsOf: URL, ofType: "")
+  try! NSDocument(contentsOf: URL, ofType: "") // expected-warning{{result of 'NSDocument' initializer is unused}}
+  try! MyDocument(contentsOf: URL, ofType: "") // expected-warning {{expression of type 'MyDocument' is unused}}
 
   try! controller.makeDocument(withContentsOf: URL, ofType: "")
 }
diff --git a/test/ClangModules/adapter.swift b/test/ClangModules/adapter.swift
index 32546e6e499f1..4e0386b6968f2 100644
--- a/test/ClangModules/adapter.swift
+++ b/test/ClangModules/adapter.swift
@@ -15,7 +15,7 @@ import Redeclaration
 let encoding: UInt = NSUTF8StringEncoding
 
 let viaTypedef: Redeclaration.NSPoint = AppKit.NSPoint(x: 0, y: 0)
-Redeclaration.NSStringToNSString(AppKit.NSStringToNSString("abc"))
+Redeclaration.NSStringToNSString(AppKit.NSStringToNSString("abc")) // expected-warning {{result of call is unused}}
 
 let viaStruct: Redeclaration.FooStruct1 = AppKit.FooStruct1()
 let forwardDecl: Redeclaration.Tribool = AppKit.Tribool() // expected-error {{no type named 'Tribool' in module 'Redeclaration'}}
diff --git a/test/ClangModules/availability.swift b/test/ClangModules/availability.swift
index ef0e158c8ba6b..f1abae4eb5ca1 100644
--- a/test/ClangModules/availability.swift
+++ b/test/ClangModules/availability.swift
@@ -14,6 +14,7 @@ func test_unavailable_instance_method(_ x : NSObject) -> Bool {
 }
 
 func test_unavailable_method_in_protocol(_ x : NSObjectProtocol) {
+  // expected-warning @+1 {{expression of type 'NSObjectProtocol' is unused}}
   x.retain() // expected-error {{'retain()' is unavailable}}
 }
 func test_unavailable_method_in_protocol_use_class_instance(_ x : NSObject) {
@@ -34,8 +35,8 @@ func test_NSInvocation(_ x: NSInvocation,         // expected-error {{'NSInvocat
 
 func test_class_avail(_ x:NSObject, obj: AnyObject) {
   x.`class`() // expected-error {{'class()' is unavailable in Swift: use 'dynamicType' instead}} expected-warning {{result of call to 'class()' is unused}}
-  NSObject.`class`() // expected-error {{'class()' is unavailable in Swift: use 'self' instead}} expected-warning {{result of call to 'class()' is unused}}
-  obj.`class`!() // expected-error {{'class()' is unavailable in Swift: use 'dynamicType' instead}}
+  _ = NSObject.`class`() // expected-error {{'class()' is unavailable in Swift: use 'self' instead}}
+  _ = obj.`class`!() // expected-error {{'class()' is unavailable in Swift: use 'dynamicType' instead}}
 }
 
 func test_unavailable_app_extension() {
@@ -100,7 +101,7 @@ func test_DistributedObjects(_ o: NSObject,
 
   let ca = NSConnectionDidDieNotification // expected-error {{'NSConnectionDidDieNotification' is unavailable in Swift: Use NSXPCConnection instead}}
   let cc = NSConnectionReplyMode // expected-error {{'NSConnectionReplyMode' is unavailable in Swift: Use NSXPCConnection instead}}
-  o.classForPortCoder // expected-error {{'classForPortCoder' is unavailable in Swift: Use NSXPCConnection instead}}
+  _ = o.classForPortCoder // expected-error {{'classForPortCoder' is unavailable in Swift: Use NSXPCConnection instead}}
 }
 
 func test_NSCalendarDate(_ o: NSCalendarDate) {} // expected-error {{'NSCalendarDate' is unavailable in Swift: Use NSCalendar and NSDateComponents and NSDateFormatter instead}}
diff --git a/test/ClangModules/foreign_errors.swift b/test/ClangModules/foreign_errors.swift
index 09c70cdbcea3c..a5200da39fd51 100644
--- a/test/ClangModules/foreign_errors.swift
+++ b/test/ClangModules/foreign_errors.swift
@@ -104,7 +104,7 @@ func testNSErrorExhaustive() {
     do {
       try ErrorProne.fail()
     } catch let e as NSError {
-      e
+      e // expected-warning {{expression of type 'NSError' is unused}}
     }
   }
 }
diff --git a/test/ClangModules/objc_parse.swift b/test/ClangModules/objc_parse.swift
index 0e527aadbcdd1..d36e971386e41 100644
--- a/test/ClangModules/objc_parse.swift
+++ b/test/ClangModules/objc_parse.swift
@@ -49,7 +49,7 @@ func instanceMethods(_ b: B) {
   b.performAdd(1, 2, 3, 4) // expected-error{{missing argument labels 'withValue:withValue:withValue2:' in call}} {{19-19=withValue: }} {{22-22=withValue: }} {{25-25=withValue2: }}
 
   // Both class and instance methods exist.
-  b.description
+  _ = b.description
   b.instanceTakesObjectClassTakesFloat(b)
   b.instanceTakesObjectClassTakesFloat(2.0) // expected-error{{cannot convert value of type 'Double' to expected argument type 'AnyObject!'}}
 
@@ -86,21 +86,21 @@ func instanceMethodsInExtensions(_ b: B) {
   b.method(1, separateExtMethod:3.5)
 
   let m1 = b.method(_:onCat1:)
-  m1(1, onCat1: 2.5)
+  _ = m1(1, onCat1: 2.5)
 
   let m2 = b.method(_:onExtA:)
-  m2(1, onExtA: 2.5)
+  _ = m2(1, onExtA: 2.5)
 
   let m3 = b.method(_:onExtB:)
-  m3(1, onExtB: 2.5)
+  _ = m3(1, onExtB: 2.5)
 
   let m4 = b.method(_:separateExtMethod:)
-  m4(1, separateExtMethod: 2.5)
+  _ = m4(1, separateExtMethod: 2.5)
 }
 
 func dynamicLookupMethod(_ b: AnyObject) {
   if let m5 = b.method(_:separateExtMethod:) {
-    m5(1, separateExtMethod: 2.5)
+    _ = m5(1, separateExtMethod: 2.5)
   }
 }
 
@@ -204,15 +204,16 @@ func testProtocolMethods(_ b: B, p2m: P2.Type) {
   // Imported constructor.
   var b2 = B(viaP2: 3.14159, second: 3.14159)
 
-  p2m.init(viaP2:3.14159, second: 3.14159)
+  _ = p2m.init(viaP2:3.14159, second: 3.14159)
 }
 
 func testId(_ x: AnyObject) {
   x.perform!("foo:", with: x) // expected-warning{{no method declared with Objective-C selector 'foo:'}}
+  // expected-warning @-1 {{result of call is unused, but produces 'Unmanaged<AnyObject>!'}}
 
-  x.performAdd(1, withValue: 2, withValue: 3, withValue2: 4)
-  x.performAdd!(1, withValue: 2, withValue: 3, withValue2: 4)
-  x.performAdd?(1, withValue: 2, withValue: 3, withValue2: 4)
+  _ = x.performAdd(1, withValue: 2, withValue: 3, withValue2: 4)
+  _ = x.performAdd!(1, withValue: 2, withValue: 3, withValue2: 4)
+  _ = x.performAdd?(1, withValue: 2, withValue: 3, withValue2: 4)
 }
 
 class MySubclass : B {
@@ -224,7 +225,7 @@ class MySubclass : B {
 }
 
 func getDescription(_ array: NSArray) {
-  array.description
+  _ = array.description
 }
 
 // Method overriding with unfortunate ordering.
@@ -257,7 +258,7 @@ func almostSubscriptableKeyMismatchInherited(_ roc: ReadOnlyCollectionChild,
 
 // Use of 'Class' via dynamic lookup.
 func classAnyObject(_ obj: NSObject) {
-  obj.myClass().description!()
+  _ = obj.myClass().description!()
 }
 
 // Protocol conformances
@@ -307,8 +308,8 @@ func customAccessors(_ hive: Hive, bee: Bee) {
   markUsed(hive.makingHoney()) // expected-error{{cannot call value of non-function type 'Bool'}}
   hive.setMakingHoney(true) // expected-error{{value of type 'Hive' has no member 'setMakingHoney'}}
 
-  hive.`guard`.description // okay
-  hive.`guard`.description! // no-warning
+  _ = hive.`guard`.description // okay
+  _ = hive.`guard`.description! // no-warning
   hive.`guard` = bee // no-warning
 }
 
@@ -339,7 +340,7 @@ func testDynamicSelf(_ queen: Bee, wobbler: NSWobbling) {
 }
 
 func testRepeatedProtocolAdoption(_ w: NSWindow) {
-  w.description
+  _ = w.description
 }
 
 class ProtocolAdopter1 : FooProto {
diff --git a/test/Constraints/construction.swift b/test/Constraints/construction.swift
index 046036d935ae7..e98b1459dc100 100644
--- a/test/Constraints/construction.swift
+++ b/test/Constraints/construction.swift
@@ -41,7 +41,7 @@ var z : Z = .none
 func acceptZ(_ z: Z) {}
 func acceptString(_ s: String) {}
 
-Point(1, 2)
+Point(1, 2) // expected-warning {{expression of type '(x: Int, y: Int)' is unused}}
 var db : Base = d
 X(i: 1, j: 2) // expected-warning{{unused}}
 Y(1, 2, "hello") // expected-warning{{unused}}
@@ -60,7 +60,7 @@ _ = .none as Optional<Int>
 Optional(.none) // expected-error{{generic parameter 'T' could not be inferred}}
 
 // Interpolation
-"\(hello), \(world) #\(i)!"
+_ = "\(hello), \(world) #\(i)!"
 
 class File {
   init() { 
@@ -86,13 +86,13 @@ extension Foo {
 
 // Downcasting
 var b : Base
-b as! Derived
+_ = b as! Derived
 
 // Construction doesn't permit conversion.
 // NOTE: Int and other integer-literal convertible types
 //  are special cased in the library.
 Int(i) // expected-warning{{unused}}
-i as Int
+_ = i as Int
 Z(z) // expected-error{{cannot invoke initializer for type 'Z' with an argument list of type '(Z)'}}
 // expected-note @-1 {{overloads for 'Z' exist with these partially matching parameter lists: (UnicodeScalar), (String)}}
 
@@ -100,7 +100,7 @@ Z.init(z)  // expected-error {{cannot invoke 'Z.Type.init' with an argument list
 // expected-note @-1 {{overloads for 'Z.Type.init' exist with these partially matching parameter lists: (UnicodeScalar), (String)}}
 
 
-z as Z
+_ = z as Z
 
 // Construction from inouts.
 struct FooRef { }
diff --git a/test/Constraints/diagnostics.swift b/test/Constraints/diagnostics.swift
index dca2351e11ccb..4d2e8a1933466 100644
--- a/test/Constraints/diagnostics.swift
+++ b/test/Constraints/diagnostics.swift
@@ -353,7 +353,7 @@ f7(1)(1.0)       // expected-error {{missing argument label 'b:' in call}}
 f7(1)(b: 1.0)       // expected-error {{cannot convert value of type 'Double' to expected argument type 'Int'}}
 
 let f8 = f7(2)
-f8(b: 1)
+_ = f8(b: 1)
 f8(10)          // expected-error {{missing argument label 'b:' in call}} {{4-4=b: }}
 f8(1.0)         // expected-error {{missing argument label 'b:' in call}}
 f8(b: 1.0)         // expected-error {{cannot convert value of type 'Double' to expected argument type 'Int'}}
diff --git a/test/Constraints/dynamic_lookup.swift b/test/Constraints/dynamic_lookup.swift
index 3348ef177c5d6..2614262e08565 100644
--- a/test/Constraints/dynamic_lookup.swift
+++ b/test/Constraints/dynamic_lookup.swift
@@ -117,7 +117,7 @@ obj.foo!(5)
 obj.foo!("hello")
 obj.wibble!()
 obj.wobble!() // expected-error{{value of type 'Id' (aka 'AnyObject') has no member 'wobble'}}
-obj.ext1!()
+obj.ext1!()  // expected-warning {{result of call is unused}}
 obj.wonka!()
 
 // Same as above but without the '!'
@@ -126,7 +126,7 @@ obj.foo(5)
 obj.foo("hello")
 obj.wibble()
 obj.wobble() // expected-error{{value of type 'Id' (aka 'AnyObject') has no member 'wobble'}}
-obj.ext1()
+obj.ext1()  // expected-warning {{result of call is unused}}
 obj.wonka()
 
 // Find class methods via dynamic method lookup.
@@ -144,7 +144,7 @@ var ovl1Result = obj.ovl1!()
 ovl1Result = A() // verify that we got an A, not a B
 
 // Same as above but without the '!'
-obj.ovl1()
+obj.ovl1()  // expected-warning {{result of call is unused}}
 
 // Don't allow overload resolution between declarations from different
 // classes.
@@ -163,7 +163,7 @@ var ovl4Result = obj.ovl4!()
 var ovl5Result = obj.ovl5!() // expected-error{{ambiguous use of 'ovl5()'}}
 
 // Same as above but without the '!'
-obj.ovl4()
+obj.ovl4()  // expected-warning {{result of call is unused}}
 
 // Generics
 
diff --git a/test/Constraints/existential_metatypes.swift b/test/Constraints/existential_metatypes.swift
index 16da85c0ffb92..6700a467e648c 100644
--- a/test/Constraints/existential_metatypes.swift
+++ b/test/Constraints/existential_metatypes.swift
@@ -69,7 +69,7 @@ extension P2 {
 }
 
 func testP2(_ pt: P2.Type) {
-  pt.init().elements
+  pt.init().elements // expected-warning {{expression of type '[P2]' is unused}}
 }
 
 // rdar://problem/21597711
diff --git a/test/Constraints/keyword_arguments.swift b/test/Constraints/keyword_arguments.swift
index e28d401b086dd..0c8f3c4073d58 100644
--- a/test/Constraints/keyword_arguments.swift
+++ b/test/Constraints/keyword_arguments.swift
@@ -282,13 +282,13 @@ func intToInt(_ i: Int) -> Int { return i }
 
 func testClosures() {
   let c0 = { (x: Int, y: Int) in x + y }
-  c0(1, 2)
+  _ = c0(1, 2)
 
   let c1 = { x, y in intToInt(x + y) }
-  c1(1, 2)
+  _ = c1(1, 2)
 
   let c2 = { intToInt($0 + $1) }
-  c2(1, 2)
+  _ = c2(1, 2)
 }
 
 func acceptAutoclosure(f: @autoclosure () -> Int) { }
diff --git a/test/Constraints/members.swift b/test/Constraints/members.swift
index d8e4232562d36..f6a1c7f3dfe23 100644
--- a/test/Constraints/members.swift
+++ b/test/Constraints/members.swift
@@ -147,7 +147,7 @@ func goo() {
 func id<T>(_ t: T) -> T { return t }
 
 func doGetLogicValue<T : Boolean>(_ t: T) {
-  t.boolValue
+  t.boolValue  // expected-warning {{expression of type 'Bool' is unused}}
 }
 
 protocol P {
diff --git a/test/Constraints/members_objc.swift b/test/Constraints/members_objc.swift
index 9b30518086ff9..2cc9b15f99a5b 100644
--- a/test/Constraints/members_objc.swift
+++ b/test/Constraints/members_objc.swift
@@ -30,5 +30,5 @@ func archetype<T: P2>(_ p2 : T) {
 
 func test_subject_ClassConstrainedSubscript() {
   let list: subject_ClassConstrainedSubscript! = test_HasSubscript()
-  list[0]
+  _ = list[0]
 }
diff --git a/test/Misc/single_expr_closure_conversion.swift b/test/Misc/single_expr_closure_conversion.swift
index 258e665c2ff81..4d9cc310f7dc1 100644
--- a/test/Misc/single_expr_closure_conversion.swift
+++ b/test/Misc/single_expr_closure_conversion.swift
@@ -45,6 +45,8 @@ class C {
 	var a = A()
 
 	func act() {
-		a.dispatch({() -> Void in self.prop})
+		a.dispatch({() -> Void in
+                  self.prop // expected-warning {{expression of type 'Int' is unused}}
+                })
 	}
 }
diff --git a/test/NameBinding/name-binding.swift b/test/NameBinding/name-binding.swift
index 0f2cea193b74c..72d421171ece8 100644
--- a/test/NameBinding/name-binding.swift
+++ b/test/NameBinding/name-binding.swift
@@ -225,7 +225,7 @@ struct Matrix4<T: FloatingPoint> {
 func r19558785() {
   let b = 10
   for b in 0...b {
-    b
+    _ = b
   }
 }
 
diff --git a/test/Parse/EOF/interpolated-string-literal.swift b/test/Parse/EOF/interpolated-string-literal.swift
index e654acd847edc..caaf0a8b6ecc6 100644
--- a/test/Parse/EOF/interpolated-string-literal.swift
+++ b/test/Parse/EOF/interpolated-string-literal.swift
@@ -3,4 +3,4 @@
 // Parser used to crash while parsing a file where the last token was an
 // interpolated string literal.
 
-"\(1)"
+_ = "\(1)"
diff --git a/test/Parse/comment_operator.swift b/test/Parse/comment_operator.swift
index f46ce7cb0c5b2..05a3cc4b3e603 100644
--- a/test/Parse/comment_operator.swift
+++ b/test/Parse/comment_operator.swift
@@ -24,6 +24,6 @@ func test5() { _ = !/* */foo }                // expected-error {{unary operator
 func test6() { _ = 1+/* */2 }                 // expected-error {{'+' is not a postfix unary operator}} expected-error {{consecutive statements on a line must be separated by ';'}} expected-warning {{result of call to 'init(_builtinIntegerLiteral:)' is unused}}
 
 // Continue to work
-foo!// this is dangerous
+_ = foo!// this is dangerous
 _ = 1 +/**/ 2
 _ = 1 +/* hi */2
diff --git a/test/Parse/consecutive_statements.swift b/test/Parse/consecutive_statements.swift
index 5c9cf3ef279c1..9fc4167e4573d 100644
--- a/test/Parse/consecutive_statements.swift
+++ b/test/Parse/consecutive_statements.swift
@@ -13,7 +13,7 @@ func statement_starts() {
   a[0] = 1
   a [0] = 1
   a // expected-error{{expression resolves to an unused l-value}}
-  [0, 1, 2]
+  [0, 1, 2] // expected-warning {{expression of type '[Int]' is unused}}
 }
 
 // Within a function
diff --git a/test/Parse/generic_disambiguation.swift b/test/Parse/generic_disambiguation.swift
index 0d43437937e7c..63c58cd6c225b 100644
--- a/test/Parse/generic_disambiguation.swift
+++ b/test/Parse/generic_disambiguation.swift
@@ -24,7 +24,7 @@ func generic<T>(_ x: T) {}
 var a, b, c, d : Int
 
 _ = a < b
-(a < b, c > d)
+_ = (a < b, c > d)
 // Parses as generic because of lparen after '>'
 (a < b, c > (d)) // expected-error{{use of undeclared type 'b'}}
 // Parses as generic because of lparen after '>'
@@ -67,6 +67,6 @@ meta2(A<B>.C<D>.self, 0)
 A<B, D>.c() // expected-error{{generic type 'A' specialized with too many type parameters (got 2, but expected 1)}}
 
 A<B?>(x: 0) // parses as type // expected-warning{{unused}}
-a < b ? c : d
+_ = a < b ? c : d
 
 A<(B) throws -> D>(x: 0) // expected-warning{{unused}}
diff --git a/test/Parse/hashbang_main.swift b/test/Parse/hashbang_main.swift
index ee4315a8e5c8b..804d5b839a34d 100644
--- a/test/Parse/hashbang_main.swift
+++ b/test/Parse/hashbang_main.swift
@@ -1,6 +1,6 @@
 #!/usr/bin/swift
 let x = 42
-x + x // expected-warning {{result of call to '+' is unused}}
+x + x // expected-warning {{result of operator '+' is unused}}
 // Check that we skip the hashbang at the beginning of the file.
 // RUN: %target-parse-verify-swift
 
diff --git a/test/Parse/line-directive.swift b/test/Parse/line-directive.swift
index f4febffc991a6..9cc3fe36896d7 100644
--- a/test/Parse/line-directive.swift
+++ b/test/Parse/line-directive.swift
@@ -17,8 +17,9 @@ x // expected-error {{parameterless closing #sourceLocation() directive without
 x x ; // should be ignored by expected_error because it is in a different file
 x
 #sourceLocation()
-x
+_ = x
 x x // expected-error{{consecutive statements}} {{2-2=;}}
+// expected-warning @-1 2 {{unused}}
 
 // rdar://19582475
 public struct S { // expected-note{{in declaration of 'S'}}
diff --git a/test/Parse/operators.swift b/test/Parse/operators.swift
index 6039c508354d9..4fe6c3faee6e8 100644
--- a/test/Parse/operators.swift
+++ b/test/Parse/operators.swift
@@ -109,5 +109,7 @@ func !!(x: Man, y: Man) {}
 let foo = Man()
 let bar = TheDevil()
 foo!!foo // expected-error{{cannot force unwrap value of non-optional type 'Man'}} {{4-5=}} expected-error{{consecutive statements}} {{6-6=;}}
-foo??bar // expected-error{{broken standard library}} expected-error{{consecutive statements}} {{6-6=;}}
+// expected-warning @-1 {{expression of type 'Man' is unused}}
 
+foo??bar // expected-error{{broken standard library}} expected-error{{consecutive statements}} {{6-6=;}}
+// expected-warning @-1 {{expression of type 'TheDevil' is unused}}
diff --git a/test/Parse/recovery.swift b/test/Parse/recovery.swift
index af0af86a803ea..6fa8f8a4e7ba9 100644
--- a/test/Parse/recovery.swift
+++ b/test/Parse/recovery.swift
@@ -128,7 +128,7 @@ func missingControllingExprInRepeatWhile() {
   }
 
   repeat {
-  } while { true }() // expected-error{{missing condition in a 'while' statement}} expected-error{{consecutive statements on a line must be separated by ';'}} {{10-10=;}}
+  } while { true }() // expected-error{{missing condition in a 'while' statement}} expected-error{{consecutive statements on a line must be separated by ';'}} {{10-10=;}} expected-warning {{result of call is unused, but produces 'Bool'}}
 }
 
 // SR-165
@@ -405,6 +405,7 @@ struct MissingInitializer1 {
 
 func exprPostfix1(x : Int) {
   x. // expected-error {{expected member name following '.'}}
+    // expected-warning @-1 {{expression of type 'Int' is unused}}
 }
 
 func exprPostfix2() {
@@ -623,6 +624,7 @@ func test23086402(a: A23086402) {
 func test23719432() {
   var x = 42
   &(Int:x)  // expected-error {{'&' can only appear immediately in a call argument list}}
+  // expected-warning @-1 {{expression of type 'inout (Int: Int)' is unused}}
 }
 
 // <rdar://problem/19911096> QoI: terrible recovery when using '·' for an operator
@@ -644,6 +646,7 @@ func postfixDot(a : String) {
   _ = a.   utf8  // expected-error {{extraneous whitespace after '.' is not permitted}} {{9-12=}}
   _ = a.       // expected-error {{expected member name following '.'}}
     a.         // expected-error {{expected member name following '.'}}
+  // expected-warning @-1 {{expression of type 'String' is unused}}
 }
 
 // <rdar://problem/23036383> QoI: Invalid trailing closures in stmt-conditions produce lowsy diagnostics
diff --git a/test/Parse/toplevel_library_invalid.swift b/test/Parse/toplevel_library_invalid.swift
index d203f0e39589a..7eaccf08544d9 100644
--- a/test/Parse/toplevel_library_invalid.swift
+++ b/test/Parse/toplevel_library_invalid.swift
@@ -1,11 +1,13 @@
 // RUN: %target-parse-verify-swift -parse-as-library
 
 let x = 42
-x + x; // expected-error {{expressions are not allowed at the top level}} expected-warning {{result of call to '+' is unused}}
-x + x; // expected-error {{expressions are not allowed at the top level}} expected-warning {{result of call to '+' is unused}}
+x + x; // expected-error {{expressions are not allowed at the top level}} expected-warning {{result of operator '+' is unused}}
+x + x; // expected-error {{expressions are not allowed at the top level}} expected-warning {{result of operator '+' is unused}}
 // Make sure we don't crash on closures at the top level
 ({ }) // expected-error {{expressions are not allowed at the top level}} expected-error{{expression resolves to an unused function}}
 ({ 5 }()) // expected-error {{expressions are not allowed at the top level}}
+// expected-warning @-1 {{result of call is unused}}
+
 
 // FIXME: Too many errors for this.
 for i // expected-error 2 {{expected ';' in 'for' statement}} 
diff --git a/test/Parse/try.swift b/test/Parse/try.swift
index 0fd62d3bad609..6d78ac5e6d614 100644
--- a/test/Parse/try.swift
+++ b/test/Parse/try.swift
@@ -14,7 +14,7 @@ func bar() throws -> Int { return 0 }
 var x = try foo() + bar()
 x = try foo() + bar()
 x += try foo() + bar()
-x += try foo() %%%% bar() // expected-error {{'try' following assignment operator does not cover everything to its right}} // expected-error {{call can throw but is not marked with 'try'}} // expected-warning {{result of call to '%%%%' is unused}}
+x += try foo() %%%% bar() // expected-error {{'try' following assignment operator does not cover everything to its right}} // expected-error {{call can throw but is not marked with 'try'}} // expected-warning {{result of operator '%%%%' is unused}}
 x += try foo() %%% bar()
 x = foo() + try bar() // expected-error {{'try' cannot appear to the right of a non-assignment operator}} // expected-error {{call can throw but is not marked with 'try'}}
 
@@ -24,7 +24,7 @@ var z = true ? try foo() : try bar() %%% 0 // expected-error {{'try' following c
 var a = try! foo() + bar()
 a = try! foo() + bar()
 a += try! foo() + bar()
-a += try! foo() %%%% bar() // expected-error {{'try!' following assignment operator does not cover everything to its right}} // expected-error {{call can throw but is not marked with 'try'}} // expected-warning {{result of call to '%%%%' is unused}}
+a += try! foo() %%%% bar() // expected-error {{'try!' following assignment operator does not cover everything to its right}} // expected-error {{call can throw but is not marked with 'try'}} // expected-warning {{result of operator '%%%%' is unused}}
 a += try! foo() %%% bar()
 a = foo() + try! bar() // expected-error {{'try!' cannot appear to the right of a non-assignment operator}} // expected-error {{call can throw but is not marked with 'try'}}
 
@@ -40,7 +40,7 @@ var i = try? foo() + bar()
 let _: Double = i // expected-error {{cannot convert value of type 'Int?' to specified type 'Double'}}
 i = try? foo() + bar()
 i ?+= try? foo() + bar()
-i ?+= try? foo() %%%% bar() // expected-error {{'try?' following assignment operator does not cover everything to its right}} // expected-error {{call can throw but is not marked with 'try'}} // expected-warning {{result of call to '%%%%' is unused}}
+i ?+= try? foo() %%%% bar() // expected-error {{'try?' following assignment operator does not cover everything to its right}} // expected-error {{call can throw but is not marked with 'try'}} // expected-warning {{result of operator '%%%%' is unused}}
 i ?+= try? foo() %%% bar()
 _ = foo() < try? bar() // expected-error {{'try?' cannot appear to the right of a non-assignment operator}} // expected-error {{call can throw but is not marked with 'try'}}
 _ = (try? foo()) < bar() // expected-error {{call can throw but is not marked with 'try'}}
@@ -100,7 +100,7 @@ struct r21432429 {
 
 // <rdar://problem/21427855> Swift 2: Omitting try from call to throwing closure in rethrowing function crashes compiler
 func callThrowingClosureWithoutTry(closure: (Int) throws -> Int) rethrows {
-  closure(0)  // expected-error {{call can throw but is not marked with 'try'}}
+  closure(0)  // expected-error {{call can throw but is not marked with 'try'}} expected-warning {{result of call is unused}}
 }
 
 func producesOptional() throws -> Int? { return nil }
diff --git a/test/SILGen/objc_blocks_bridging.swift b/test/SILGen/objc_blocks_bridging.swift
index 7333f89979234..5a541a9c2b3e5 100644
--- a/test/SILGen/objc_blocks_bridging.swift
+++ b/test/SILGen/objc_blocks_bridging.swift
@@ -42,7 +42,7 @@ import Foundation
   // CHECK:         [[NATIVE:%.*]] = function_ref @_TFC20objc_blocks_bridging3Foo16cFunctionPointer
   // CHECK:         apply [[NATIVE]]([[F]], [[X]], [[SELF]])
   dynamic func cFunctionPointer(_ fp: @convention(c) (Int) -> Int, x: Int) -> Int {
-    fp(x)
+    _ = fp(x)
   }
 
   // Blocks and C function pointers must not be reabstracted when placed in optionals.
diff --git a/test/SILOptimizer/definite_init_diagnostics.swift b/test/SILOptimizer/definite_init_diagnostics.swift
index 43f86999bc175..dc250582cd518 100644
--- a/test/SILOptimizer/definite_init_diagnostics.swift
+++ b/test/SILOptimizer/definite_init_diagnostics.swift
@@ -47,6 +47,7 @@ func test2() {
   // Address-of with Builtin.addressof.
   var a4 : Int            // expected-note {{variable defined here}}
   Builtin.addressof(&a4)  // expected-error {{address of variable 'a4' taken before it is initialized}}
+  // expected-warning @-1 {{result of call is unused, but produces 'Builtin.RawPointer'}}
 
 
   // Closures.
diff --git a/test/Sema/availability_versions.swift b/test/Sema/availability_versions.swift
index d5e772eacebfd..1996e27702bb9 100644
--- a/test/Sema/availability_versions.swift
+++ b/test/Sema/availability_versions.swift
@@ -634,8 +634,8 @@ func classAvailability() {
       // expected-note@-1 {{add @available attribute to enclosing global function}}
       // expected-note@-2 {{add 'if #available' version check}}
 
-  ClassAvailableOn10_9.self
-  ClassAvailableOn10_51.self // expected-error {{'ClassAvailableOn10_51' is only available on OS X 10.51 or newer}}
+  _ = ClassAvailableOn10_9.self
+  _ = ClassAvailableOn10_51.self // expected-error {{'ClassAvailableOn10_51' is only available on OS X 10.51 or newer}}
       // expected-note@-1 {{add @available attribute to enclosing global function}}
       // expected-note@-2 {{add 'if #available' version check}}
   
diff --git a/test/Sema/diag_values_of_module_type.swift b/test/Sema/diag_values_of_module_type.swift
index 109f9f70ab754..fe2c8d98d01ba 100644
--- a/test/Sema/diag_values_of_module_type.swift
+++ b/test/Sema/diag_values_of_module_type.swift
@@ -98,10 +98,10 @@ func badTest3() {
   var _ = Swift. // expected-error {{expected member name following '.'}} expected-error {{expected module member name after module name}}
 }
 func badTest4() {
-  Swift // expected-error {{expected module member name after module name}}
+  _ = Swift // expected-error {{expected module member name after module name}}
 }
 func badTest5() {
-  Swift. // expected-error {{expected module member name after module name}} expected-error {{expected member name following '.'}}
+  _ = Swift. // expected-error {{expected module member name after module name}} expected-error {{expected member name following '.'}}
 }
 func badTest6() {
   _ = { () -> Int in
diff --git a/test/Sema/editor_placeholders.swift b/test/Sema/editor_placeholders.swift
index d6e2b4105f325..a794a17ac303b 100644
--- a/test/Sema/editor_placeholders.swift
+++ b/test/Sema/editor_placeholders.swift
@@ -20,7 +20,7 @@ f(a2)
 <#T#> // expected-error{{editor placeholder in source file}}
 
 // FIXME: <rdar://problem/22432828> Lexer yields "editor placeholder in source file" error twice when placeholder is first token
-<#T##Int#> // expected-error 2{{editor placeholder in source file}}
+_ = <#T##Int#> // expected-error {{editor placeholder in source file}}
 
 f(<#T#> + 1) // expected-error{{editor placeholder in source file}}
 f(<#T##Int#>) // expected-error{{editor placeholder in source file}}
diff --git a/test/attr/attr_discardableResult.swift b/test/attr/attr_discardableResult.swift
index 78726704b22f2..4bf4f20c95c1b 100644
--- a/test/attr/attr_discardableResult.swift
+++ b/test/attr/attr_discardableResult.swift
@@ -52,9 +52,9 @@ func testFunctionsInClass(c1 : C1) {
   C1.f2Class()      // expected-warning {{result of call to 'f2Class()' is unused}}
   _ = C1.f2Class()  // okay
 
-  C1()              // expected-warning {{result of initializer is unused}}
+  C1()              // okay, marked @discardableResult
   _ = C1()          // okay
-  C1(foo: 5)        // expected-warning {{result of call to 'init(foo:)' is unused}}
+  C1(foo: 5)        // expected-warning {{result of 'C1' initializer is unused}}
   _ = C1(foo: 5)    // okay
 
   c1.f1()           // okay
@@ -82,12 +82,27 @@ func testFunctionsInStruct(s1 : S1) {
   S1.f2Static()     // expected-warning {{result of call to 'f2Static()' is unused}}
   _ = S1.f2Static() // okay
 
-  S1()              // expected-warning {{result of initializer is unused}}
+  S1()              // okay, marked @discardableResult
   _ = S1()          // okay
-  S1(foo: 5)        // expected-warning {{result of call to 'init(foo:)' is unused}}
+  S1(foo: 5)        // expected-warning {{result of 'S1' initializer is unused}}
   _ = S1(foo: 5)    // okay
 
   s1.f1()           // okay
   s1.f2()           // expected-warning {{result of call to 'f2()' is unused}}
   _ = s1.f2()       // okay
 }
+
+
+let x = 4
+"Hello \(x+1) world"  // expected-warning {{expression of type 'String' is unused}}
+
+func f(a : () -> Int) {
+  42  // expected-warning {{result of call to 'init(_builtinIntegerLiteral:)' is unused}}
+  
+  4 + 5 // expected-warning {{result of operator '+' is unused}}
+  a() // expected-warning {{result of call is unused, but produces 'Int'}}
+}
+
+
+
+
diff --git a/test/attr/attr_noescape.swift b/test/attr/attr_noescape.swift
index 4b2c5233118c9..1ef7949bb8d0d 100644
--- a/test/attr/attr_noescape.swift
+++ b/test/attr/attr_noescape.swift
@@ -10,7 +10,7 @@ func takesGenericClosure<T>(_ a : Int, _ fn : @noescape () -> T) {}
 func takesNoEscapeClosure(_ fn : @noescape () -> Int) {
   takesNoEscapeClosure { 4 }  // ok
 
-  fn()  // ok
+  _ = fn()  // ok
 
   var x = fn  // expected-error {{@noescape parameter 'fn' may only be called}}
 
@@ -22,7 +22,7 @@ func takesNoEscapeClosure(_ fn : @noescape () -> Int) {
 
   // This is not ok, because it escapes the 'fn' closure.
   func nested_function() {
-    fn()   // expected-error {{declaration closing over @noescape parameter 'fn' may allow it to escape}}
+    _ = fn()   // expected-error {{declaration closing over @noescape parameter 'fn' may allow it to escape}}
   }
 
   takesNoEscapeClosure(fn)  // ok
diff --git a/test/decl/enum/enumtest.swift b/test/decl/enum/enumtest.swift
index 71040e7822cae..b6c0de76a2cff 100644
--- a/test/decl/enum/enumtest.swift
+++ b/test/decl/enum/enumtest.swift
@@ -75,10 +75,12 @@ func test3(_ a: ZeroOneTwoThree) {
   var _ : Int =
      ZeroOneTwoThree.Zero // expected-error {{cannot convert value of type 'ZeroOneTwoThree' to specified type 'Int'}}
 
+  // expected-warning @+1 {{unused}}
   test3 ZeroOneTwoThree.Zero // expected-error {{expression resolves to an unused function}} expected-error{{consecutive statements}} {{8-8=;}}
   test3 (ZeroOneTwoThree.Zero)
   test3(ZeroOneTwoThree.Zero)
   test3 // expected-error {{expression resolves to an unused function}}
+  // expected-warning @+1 {{unused}}
   (ZeroOneTwoThree.Zero)
   
   var _ : ZeroOneTwoThree = .One(4)
diff --git a/test/decl/ext/generic.swift b/test/decl/ext/generic.swift
index f07e056c79465..1e4bac8e4fc65 100644
--- a/test/decl/ext/generic.swift
+++ b/test/decl/ext/generic.swift
@@ -116,10 +116,12 @@ func notHashableArray<T>(_ x: [T]) {
 }
 
 func hashableArray<T : Hashable>(_ x: [T]) {
+  // expected-warning @+1 {{unused}}
   x.worseHashEver // okay
 }
 
 func intArray(_ x: [Int]) {
+  // expected-warning @+1 {{unused}}
   x.worseHashEver
 }
 
diff --git a/test/decl/ext/protocol_objc.swift b/test/decl/ext/protocol_objc.swift
index 61c80f578de0f..9b846620841e4 100644
--- a/test/decl/ext/protocol_objc.swift
+++ b/test/decl/ext/protocol_objc.swift
@@ -16,6 +16,7 @@ class OC1 : OP1 {
 
 func testOP1(_ oc1: OC1, ao: AnyObject) {
   _ = oc1.extOP1a()
+  // expected-warning @+1 {{result of call is unused}}
   ao.reqOP1a!() // okay
 
   // Extension of @objc protocol does not have @objc members.
diff --git a/test/decl/func/functions.swift b/test/decl/func/functions.swift
index cb53e2b6229cc..5109222e81eca 100644
--- a/test/decl/func/functions.swift
+++ b/test/decl/func/functions.swift
@@ -93,7 +93,7 @@ func parenPatternInArg((a): Int) -> Int { // expected-error {{expected parameter
 parenPatternInArg(0)  // expected-error {{argument passed to call that takes no arguments}}
 
 var nullaryClosure: (Int) -> Int = {_ in 0}
-nullaryClosure(0)
+_ = nullaryClosure(0)
 
 
 // rdar://16737322 - This argument is an unnamed argument that has a labeled
diff --git a/test/decl/func/throwing_functions.swift b/test/decl/func/throwing_functions.swift
index 13726805792eb..3aa566f5a00c9 100644
--- a/test/decl/func/throwing_functions.swift
+++ b/test/decl/func/throwing_functions.swift
@@ -115,9 +115,9 @@ var c2 : () throws -> Int = c1 // ok
 var c3 : () -> Int = c1 // expected-error{{invalid conversion from throwing function of type '() throws -> Int' to non-throwing function type '() -> Int'}}
 var c4 : () -> Int = {() throws -> Int in 0} // expected-error{{invalid conversion from throwing function of type '() throws -> Int' to non-throwing function type '() -> Int'}}
 var c5 : () -> Int = { try c2() } // expected-error{{invalid conversion from throwing function of type '() throws -> Int' to non-throwing function type '() -> Int'}}
-var c6 : () throws -> Int = { do { try c2() } ; return 0 }
+var c6 : () throws -> Int = { do { _ = try c2() } ; return 0 }
 var c7 : () -> Int = { do { try c2() } ; return 0 } // expected-error{{invalid conversion from throwing function of type '() throws -> _' to non-throwing function type '() -> Int'}}
-var c8 : () -> Int = { do { try c2()  } catch _ { var x = 0 } ; return 0 }
+var c8 : () -> Int = { do { _ = try c2()  } catch _ { var x = 0 } ; return 0 }
 var c9 : () -> Int = { do { try c2()  } catch Exception.A { var x = 0 } ; return 0 }// expected-error{{invalid conversion from throwing function of type '() throws -> _' to non-throwing function type '() -> Int'}}
 var c10 : () -> Int = { throw Exception.A; return 0 } // expected-error{{invalid conversion from throwing function of type '() throws -> _' to non-throwing function type '() -> Int'}}
 var c11 : () -> Int = { try! c2() }
diff --git a/test/decl/protocol/protocols.swift b/test/decl/protocol/protocols.swift
index cd936639c7a6f..4789cee748e37 100644
--- a/test/decl/protocol/protocols.swift
+++ b/test/decl/protocol/protocols.swift
@@ -453,7 +453,7 @@ protocol SecondProtocol {
 // <rdar://problem/19495341> Can't upcast to parent types of type constraints without forcing
 class C1 : P2 {}
 func f<T : C1>(_ x : T) {
-  x as P2
+  _ = x as P2
 }
 
 class C2 {}
@@ -463,7 +463,7 @@ func g<T : C2>(_ x : T) {
 
 class C3 : P1 {} // expected-error{{type 'C3' does not conform to protocol 'P1'}}
 func h<T : C3>(_ x : T) {
-  x as P1 // expected-error{{protocol 'P1' can only be used as a generic constraint because it has Self or associated type requirements}}
+  _ = x as P1 // expected-error{{protocol 'P1' can only be used as a generic constraint because it has Self or associated type requirements}}
 }
 
 
diff --git a/test/expr/cast/array_iteration.swift b/test/expr/cast/array_iteration.swift
index ac871fc5df161..3802b8c34185b 100644
--- a/test/expr/cast/array_iteration.swift
+++ b/test/expr/cast/array_iteration.swift
@@ -10,7 +10,7 @@ var rootView = View()
 var v = [View(), View()]
 rootView.subviews = v
 
-rootView.subviews as! [View]
+_ = rootView.subviews as! [View]
 
 for view in rootView.subviews as! [View] {
   doFoo()
@@ -22,12 +22,12 @@ for view:View in rootView.subviews { // expected-error{{type 'Array<AnyObject>!'
   doFoo()
 }
 
-(rootView.subviews!) as! [View]
+_ = (rootView.subviews!) as! [View]
 
-(rootView.subviews) as! [View]
+_ = (rootView.subviews) as! [View]
 
 var ao: [AnyObject] = []
-ao as! [View] // works
+_ = ao as! [View] // works
 
 
 var b = Array<(String, Int)>()
diff --git a/test/expr/cast/as_coerce.swift b/test/expr/cast/as_coerce.swift
index ec5b4f4ba0aaa..5ca0fdb0115e9 100644
--- a/test/expr/cast/as_coerce.swift
+++ b/test/expr/cast/as_coerce.swift
@@ -59,7 +59,7 @@ if let p = cc as? P {
 
 // Test that 'as?' coercion fails.
 let strImplicitOpt: String! = nil
-strImplicitOpt as? String // expected-warning{{conditional cast from 'String!' to 'String' always succeeds}}
+_ = strImplicitOpt as? String // expected-warning{{conditional cast from 'String!' to 'String' always succeeds}}
 
 class C3 {}
 class C4 : C3 {}
@@ -92,7 +92,7 @@ Double(1) as Double as String // expected-error{{cannot convert value of type 'D
 [(1, (1, 1))] as! [(Int, (String, Int))] // expected-error{{'[(Int, (Int, Int))]' is not convertible to '[(Int, (String, Int))]'}}
 
 // <rdar://problem/19495253> Incorrect diagnostic for explicitly casting to the same type
-"hello" as! String // expected-warning{{forced cast of 'String' to same type has no effect}} {{9-20=}}
+_ = "hello" as! String // expected-warning{{forced cast of 'String' to same type has no effect}} {{13-24=}}
 
 // <rdar://problem/19499340> QoI: Nimble as -> as! changes not covered by Fix-Its
 func f(_ x : String) {}
diff --git a/test/expr/cast/dictionary_bridge.swift b/test/expr/cast/dictionary_bridge.swift
index 8c6543bf4e673..a4b4dd5a9ddba 100644
--- a/test/expr/cast/dictionary_bridge.swift
+++ b/test/expr/cast/dictionary_bridge.swift
@@ -111,19 +111,19 @@ func testDowncastBridge() {
   let dictOB = Dictionary<ObjC, BridgedToObjC>()
 
   // Downcast to bridged value types.
-  dictRR as! Dictionary<BridgedToObjC, BridgedToObjC>
-  dictRR as! Dictionary<BridgedToObjC, ObjC>
-  dictRR as! Dictionary<ObjC, BridgedToObjC>
+  _ = dictRR as! Dictionary<BridgedToObjC, BridgedToObjC>
+  _ = dictRR as! Dictionary<BridgedToObjC, ObjC>
+  _ = dictRR as! Dictionary<ObjC, BridgedToObjC>
 
-  dictRO as! Dictionary<BridgedToObjC, BridgedToObjC>
-  dictRO as! Dictionary<BridgedToObjC, ObjC>
-  dictRO as! Dictionary<ObjC, BridgedToObjC>
+  _ = dictRO as! Dictionary<BridgedToObjC, BridgedToObjC>
+  _ = dictRO as! Dictionary<BridgedToObjC, ObjC>
+  _ = dictRO as! Dictionary<ObjC, BridgedToObjC>
 
-  dictBO as! Dictionary<BridgedToObjC, BridgedToObjC>
-  dictOB as! Dictionary<BridgedToObjC, BridgedToObjC>
+  _ = dictBO as! Dictionary<BridgedToObjC, BridgedToObjC>
+  _ = dictOB as! Dictionary<BridgedToObjC, BridgedToObjC>
 
   // We don't do mixed down/upcasts.
-  dictDO as! Dictionary<BridgedToObjC, BridgedToObjC> // expected-error{{'Dictionary<DerivesObjC, ObjC>' is not convertible to 'Dictionary<BridgedToObjC, BridgedToObjC>'}}
+  _ = dictDO as! Dictionary<BridgedToObjC, BridgedToObjC> // expected-error{{'Dictionary<DerivesObjC, ObjC>' is not convertible to 'Dictionary<BridgedToObjC, BridgedToObjC>'}}
 }
 
 func testConditionalDowncastBridge() {
diff --git a/test/expr/cast/set_bridge.swift b/test/expr/cast/set_bridge.swift
index eeb9e824fe218..c569915e37f62 100644
--- a/test/expr/cast/set_bridge.swift
+++ b/test/expr/cast/set_bridge.swift
@@ -77,18 +77,18 @@ func testForcedDowncastBridge() {
   let setD = Set<DerivesObjC>()
   let setB = Set<BridgedToObjC>()
 
-  setR as! Set<BridgedToObjC>
-  setO as! Set<BridgedToObjC>
-  setD as! Set<BridgedToObjC> // expected-error {{'ObjC' is not a subtype of 'DerivesObjC'}}
+  _ = setR as! Set<BridgedToObjC>
+  _ = setO as! Set<BridgedToObjC>
+  _ = setD as! Set<BridgedToObjC> // expected-error {{'ObjC' is not a subtype of 'DerivesObjC'}}
   // expected-note @-1 {{in cast from type 'Set<DerivesObjC>' to 'Set<BridgedToObjC>'}}
 
   // TODO: the diagnostic for the below two examples should indicate that 'as'
   // should be used instead of 'as!'
-  setB as! Set<Root> // expected-error {{'Root' is not a subtype of 'BridgedToObjC'}}
+  _ = setB as! Set<Root> // expected-error {{'Root' is not a subtype of 'BridgedToObjC'}}
   // expected-note @-1 {{in cast from type 'Set<BridgedToObjC>' to 'Set<Root>'}}
-  setB as! Set<ObjC> // expected-error {{'ObjC' is not a subtype of 'BridgedToObjC'}}
+  _ = setB as! Set<ObjC> // expected-error {{'ObjC' is not a subtype of 'BridgedToObjC'}}
   // expected-note @-1 {{in cast from type 'Set<BridgedToObjC>' to 'Set<ObjC>'}}
-  setB as! Set<DerivesObjC> // expected-error {{'DerivesObjC' is not a subtype of 'BridgedToObjC'}}
+  _ = setB as! Set<DerivesObjC> // expected-error {{'DerivesObjC' is not a subtype of 'BridgedToObjC'}}
   // expected-note @-1 {{in cast from type 'Set<BridgedToObjC>' to 'Set<DerivesObjC>'}}
 }
 
diff --git a/test/expr/closure/basic.swift b/test/expr/closure/basic.swift
index 782b6b0f78224..342f18ed49c9d 100644
--- a/test/expr/closure/basic.swift
+++ b/test/expr/closure/basic.swift
@@ -22,9 +22,9 @@ func variadic() {
     }
     return result
   }
-  f(1)
-  f(1, 2)
-  f(1, 3)
+  _ = f(1)
+  _ = f(1, 2)
+  _ = f(1, 3)
 
   let D = { (Ss ...) in 1 } // expected-error{{'...' cannot be applied to a subpattern which is not explicitly typed}}, expected-error{{unable to infer closure type in the current context}}
 }
@@ -38,6 +38,6 @@ func attrs() {
 func argAndParamNames() -> Int {
   let _: (x: Int, y: Int) -> Int = { (a x, b y) in x + y }  // expected-error 2 {{closure cannot have keyword arguments}}
   let f1: (x: Int, y: Int) -> Int = { (x, y) in x + y }
-  f1(x: 1, y: 2)
+  _ = f1(x: 1, y: 2)
   return f1(x: 1, y: 2)
 }
diff --git a/test/expr/closure/closures.swift b/test/expr/closure/closures.swift
index cd2097020dd76..5b62ae190cace 100644
--- a/test/expr/closure/closures.swift
+++ b/test/expr/closure/closures.swift
@@ -244,7 +244,9 @@ func rdar19179412() -> (Int) -> Int {
 func takesVoidFunc(_ f: () -> ()) {}
 var i: Int = 1
 
+// expected-warning @+1 {{expression of type 'Int' is unused}}
 takesVoidFunc({i})
+// expected-warning @+1 {{expression of type 'Int' is unused}}
 var f1: () -> () = {i}
 var x = {return $0}(1)
 
diff --git a/test/expr/expressions.swift b/test/expr/expressions.swift
index 451eb8d454bc8..6971312a10a85 100644
--- a/test/expr/expressions.swift
+++ b/test/expr/expressions.swift
@@ -229,6 +229,7 @@ func test_lambda() {
 }
 
 func test_lambda2() {
+  // expected-warning @+1 {{result of call is unused}}
   { () -> protocol<Int> in // expected-error {{non-protocol type 'Int' cannot be used within 'protocol<...>'}}
     return 1
   }()
@@ -406,7 +407,7 @@ func stringliterals(_ d: [String: Int]) {
 
   // rdar://11385385
   let x = 4
-  "Hello \(x+1) world"
+  "Hello \(x+1) world"  // expected-warning {{expression of type 'String' is unused}}
   
   "Error: \(x+1"; // expected-error {{unterminated string literal}}
   
@@ -610,7 +611,7 @@ func lvalue_processing() {
 
   var n = 42
   fn(n, 12)  // expected-error {{passing value of type 'Int' to an inout parameter requires explicit '&'}} {{6-6=&}}
-  fn(&n, 12)
+  fn(&n, 12) // expected-warning {{result of call is unused, but produces 'Int'}}
 
   n +-+= 12
 
@@ -691,11 +692,11 @@ nil != Int.self // expected-error {{binary operator '!=' cannot be applied to op
 
 // <rdar://problem/19032294> Disallow postfix ? when not chaining
 func testOptionalChaining(_ a : Int?, b : Int!, c : Int??) {
-  a?    // expected-error {{optional chain has no effect, expression already produces 'Int?'}} {{4-5=}}
-  a?.customMirror
+  _ = a?    // expected-error {{optional chain has no effect, expression already produces 'Int?'}} {{8-9=}}
+  _ = a?.customMirror
 
-  b?   // expected-error {{'?' must be followed by a call, member lookup, or subscript}}
-  b?.customMirror
+  _ = b?   // expected-error {{'?' must be followed by a call, member lookup, or subscript}}
+  _ = b?.customMirror
 
   var _: Int? = c?   // expected-error {{'?' must be followed by a call, member lookup, or subscript}}
 }
@@ -750,6 +751,7 @@ public struct TestPropMethodOverloadGroup {
 func inoutTests(_ arr: inout Int) {
   var x = 1, y = 2
   (true ? &x : &y)  // expected-error 2 {{'&' can only appear immediately in a call argument list}}
+  // expected-warning @-1 {{expression of type 'inout Int' is unused}}
   let a = (true ? &x : &y)  // expected-error 2 {{'&' can only appear immediately in a call argument list}}
   // expected-error @-1 {{type 'inout Int' of variable is not materializable}}
 
diff --git a/test/expr/postfix/dot/init_ref_delegation.swift b/test/expr/postfix/dot/init_ref_delegation.swift
index e98b0afa0033f..67acdf7ccf211 100644
--- a/test/expr/postfix/dot/init_ref_delegation.swift
+++ b/test/expr/postfix/dot/init_ref_delegation.swift
@@ -151,7 +151,7 @@ struct RDar16603812 {
    init() {}
    func foo() {
       self.init() // expected-error {{'init' is a member of the type; insert '.dynamicType' to initialize a new object of the same dynamic type}} {{11-11=.dynamicType}}
-      self.dynamicType.init() // expected-warning{{result of call to 'init()' is unused}}
+      self.dynamicType.init() // expected-warning{{result of 'RDar16603812' initializer is unused}}
    }
 }
 
@@ -343,7 +343,7 @@ class TestNestedExpr {
   }
 
   convenience init(c: Int) {
-    ((), self.init()) // expected-error {{initializer delegation ('self.init') cannot be nested in another expression}}
+    _ = ((), self.init()) // expected-error {{initializer delegation ('self.init') cannot be nested in another expression}}
   }
 
   convenience init(d: Int) {
@@ -357,7 +357,7 @@ class TestNestedExpr {
   }
 
   convenience init(f: Int) {
-    ((), self.init(fail: true)!) // expected-error {{initializer delegation ('self.init') cannot be nested in another expression}}
+    _ = ((), self.init(fail: true)!) // expected-error {{initializer delegation ('self.init') cannot be nested in another expression}}
   }
 
   convenience init(g: Int) {
@@ -371,7 +371,7 @@ class TestNestedExpr {
   }
 
   convenience init(i: Int) {
-    ((), try! self.init(error: true)) // expected-error {{initializer delegation ('self.init') cannot be nested in another expression}}
+    _ = ((), try! self.init(error: true)) // expected-error {{initializer delegation ('self.init') cannot be nested in another expression}}
   }
 }
 
@@ -387,7 +387,7 @@ class TestNestedExprSub : TestNestedExpr {
   }
 
   init(c: Int) {
-    ((), super.init()) // expected-error {{initializer chaining ('super.init') cannot be nested in another expression}}
+    _ = ((), super.init()) // expected-error {{initializer chaining ('super.init') cannot be nested in another expression}}
   }
 
   init(d: Int) {
@@ -401,7 +401,7 @@ class TestNestedExprSub : TestNestedExpr {
   }
 
   init(f: Int) {
-    ((), super.init(fail: true)!) // expected-error {{initializer chaining ('super.init') cannot be nested in another expression}}
+    _ = ((), super.init(fail: true)!) // expected-error {{initializer chaining ('super.init') cannot be nested in another expression}}
   }
 
   init(g: Int) {
@@ -415,7 +415,7 @@ class TestNestedExprSub : TestNestedExpr {
   }
 
   init(i: Int) {
-    ((), try! super.init(error: true)) // expected-error {{initializer chaining ('super.init') cannot be nested in another expression}}
+    _ = ((), try! super.init(error: true)) // expected-error {{initializer chaining ('super.init') cannot be nested in another expression}}
   }
 }
 
diff --git a/test/stmt/statements.swift b/test/stmt/statements.swift
index f4cdaa48810a3..04cadf7e13a31 100644
--- a/test/stmt/statements.swift
+++ b/test/stmt/statements.swift
@@ -328,7 +328,7 @@ func testMyEnumWithCaseLabels(_ a : MyEnumWithCaseLabels) {
 func test_defer(_ a : Int) {
   
   defer { VoidReturn1() }
-  defer { breakContinue(1)+42 } // expected-warning {{result of call to '+' is unused}}
+  defer { breakContinue(1)+42 } // expected-warning {{result of operator '+' is unused}}
   
   // Ok:
   defer { while false { break } }
diff --git a/validation-test/Sema/OverridesAndOverloads.swift b/validation-test/Sema/OverridesAndOverloads.swift
index d1e0484acedc2..fdb8c9e42286f 100644
--- a/validation-test/Sema/OverridesAndOverloads.swift
+++ b/validation-test/Sema/OverridesAndOverloads.swift
@@ -122,10 +122,10 @@ Overrides.test("contravariant return type override, optional to non-optional") {
     }
   }
 
-  Derived().foo() as C1
+  _ = Derived().foo() as C1
   expectEqual("Derived.foo() -> C1", which)
 
-  Derived().foo() as C1?
+  _ = Derived().foo() as C1?
   expectEqual("Derived.foo() -> C1", which)
 }
 
@@ -139,10 +139,10 @@ Overrides.test("contravariant return type override, base class to derived class"
     }
   }
 
-  Derived().foo() as C1
+  _ = Derived().foo() as C1
   expectEqual("Derived.foo() -> C1x", which)
 
-  Derived().foo() as C1x
+  _ = Derived().foo() as C1x
   expectEqual("Derived.foo() -> C1x", which)
 }
 
@@ -156,10 +156,10 @@ Overrides.test("contravariant return type override, optional base class to non-o
     }
   }
 
-  Derived().foo() as C1
+  _ = Derived().foo() as C1
   expectEqual("Derived.foo() -> C1x", which)
 
-  Derived().foo() as C1x
+  _ = Derived().foo() as C1x
   expectEqual("Derived.foo() -> C1x", which)
 }
 
@@ -180,7 +180,7 @@ Overrides.test("contravariant return type override, protocol to protocol") {
   // Derived().foo() as P1 // error: ambiguous use of 'foo()'
   // expectEqual("Derived.foo() -> P1x", which)
 
-  Derived().foo() as P1x
+  _ = Derived().foo() as P1x
   expectEqual("Derived.foo() -> P1x", which)
 }
 
@@ -201,7 +201,7 @@ Overrides.test("contravariant return type override, protocol to struct") {
   // Derived().foo() as P1 // error: ambiguous use of 'foo()'
   // expectEqual("Derived.foo() -> P1ImplS1", which)
 
-  Derived().foo() as P1ImplS1
+  _ = Derived().foo() as P1ImplS1
   expectEqual("Derived.foo() -> P1ImplS1", which)
 }