[CSStep] Skip disabled overloads only if there are no fixes in diagnostic mode

Author: xedin

lib/Sema/CSStep.cpp

@@ -598,10 +598,6 @@ bool TypeChecker::isDeclRefinementOf(ValueDecl *declA, ValueDecl *declB) {
 bool DisjunctionStep::shouldSkip(const DisjunctionChoice &choice) const {
   auto &ctx = CS.getASTContext();
 
-  // Never skip disjunction choices in diagnostic mode.
-  if (CS.shouldAttemptFixes())
-    return false;
-
   auto skip = [&](std::string reason) -> bool {
     if (CS.isDebugMode()) {
       auto &log = getDebugLogger();
@@ -613,11 +609,14 @@ bool DisjunctionStep::shouldSkip(const DisjunctionChoice &choice) const {
     return true;
   };
 
-  if (choice.isDisabled())
+
+  // Skip disabled overloads in the diagnostic mode if they do not have a
+  // fix attached to them e.g. overloads where labels didn't match up.
+  if (choice.isDisabled() && !(CS.shouldAttemptFixes() && choice.hasFix()))
     return skip("disabled");
 
-  // Skip unavailable overloads.
-  if (choice.isUnavailable())
+  // Skip unavailable overloads (unless in dignostic mode).
+  if (choice.isUnavailable() && !CS.shouldAttemptFixes())
     return skip("unavailable");
 
   if (ctx.TypeCheckerOpts.DisableConstraintSolverPerformanceHacks)

test/Constraints/generics.swift

@@ -648,7 +648,7 @@ let arr = [BottleLayout]()
 let layout = BottleLayout(count:1)
 let ix = arr.firstIndex(of:layout) // expected-error {{referencing instance method 'firstIndex(of:)' on 'Collection' requires that 'BottleLayout' conform to 'Equatable'}}
 
-let _: () -> UInt8 = { .init("a" as Unicode.Scalar) } // expected-error {{missing argument label 'ascii:' in call}}
+let _: () -> UInt8 = { .init("a" as Unicode.Scalar) } // expected-error {{initializer 'init(_:)' requires that 'Unicode.Scalar' conform to 'BinaryInteger'}}
 
 // https://bugs.swift.org/browse/SR-9068
 func compare<C: Collection, Key: Hashable, Value: Equatable>(c: C)

test/stdlib/UnsafePointerDiagnostics.swift

@@ -113,7 +113,7 @@ func unsafeRawBufferPointerConversions(
   _ = UnsafeRawBufferPointer(start: rp, count: 1)
   _ = UnsafeMutableRawBufferPointer(mrbp)
   _ = UnsafeRawBufferPointer(mrbp)
-  _ = UnsafeMutableRawBufferPointer(rbp) // expected-error {{missing argument label 'mutating:' in call}}
+  _ = UnsafeMutableRawBufferPointer(rbp) // expected-error {{cannot convert value of type 'UnsafeRawBufferPointer' to expected argument type 'UnsafeMutableRawBufferPointer'}}
   _ = UnsafeRawBufferPointer(rbp)
   _ = UnsafeMutableRawBufferPointer(mbpi)
   _ = UnsafeRawBufferPointer(mbpi)

validation-test/Sema/type_checker_crashers_fixed/rdar45470505.swift

@@ -4,7 +4,6 @@ extension BinaryInteger {
   init(bytes: [UInt8]) { fatalError() }
 
   init<S: Sequence>(bytes: S) where S.Iterator.Element == UInt8 {
-    // expected-note@-1 {{incorrect labels for candidate (have: '(_:)', expected: '(bytes:)')}}
     self.init(bytes // expected-error {{no exact matches in call to initializer}}
     // expected-note@-1 {{}}