[CS] A couple of minor improvements to operator diagnostics

- Simplify the fix locator when looking for a
fix already present in a pattern match, this
avoids us emitting both a diagnostic for the
argument conversion, and for a conformance failure.
- Include tuples in the diagnostic logic where
we emit a generic "operator cannot be applied"
diagnostic, as a conformance diagnostic is
unlikely to be helpful in that case.

Author: hamishknight

lib/Sema/CSDiagnostics.cpp

@@ -562,7 +562,10 @@ bool MissingConformanceFailure::diagnoseAsError() {
       llvm::SmallPtrSet<Expr *, 4> anchors;
       for (const auto *fix : getSolution().Fixes) {
         if (auto anchor = fix->getAnchor()) {
-          if (anchor.is<Expr *>())
+          auto path = fix->getLocator()->getPath();
+          SourceRange range;
+          simplifyLocator(anchor, path, range);
+          if (anchor && anchor.is<Expr *>())
             anchors.insert(getAsExpr(anchor));
         }
       }
@@ -703,10 +706,15 @@ bool MissingConformanceFailure::diagnoseAsAmbiguousOperatorRef() {
   if (!ODRE)
     return false;
 
+  auto isStandardType = [](Type ty) {
+    return ty->isStdlibType() || ty->is<TupleType>();
+  };
+
   auto name = ODRE->getDecls().front()->getBaseName();
-  if (!(name.isOperator() && getLHS()->isStdlibType() && getRHS()->isStdlibType()))
+  if (!(name.isOperator() && isStandardType(getLHS()) &&
+        isStandardType(getRHS()))) {
     return false;
-
+  }
   // If this is an operator reference and both types are from stdlib,
   // let's produce a generic diagnostic about invocation and a note
   // about missing conformance just in case.

test/Misc/misc_diagnostics.swift

@@ -144,9 +144,6 @@ func test17875634() {
 func test20770032() {
   if case let 1...10 = (1, 1) { // expected-warning{{'let' pattern has no effect; sub-pattern didn't bind any variables}} {{11-15=}}
     // expected-error@-1 {{expression pattern of type 'ClosedRange<Int>' cannot match values of type '(Int, Int)'}}
-    // expected-error@-2 {{type '(Int, Int)' cannot conform to 'Equatable'}}
-    // expected-note@-3 {{only concrete types such as structs, enums and classes can conform to protocols}}
-    // expected-note@-4 {{required by operator function '~=' where 'T' = '(Int, Int)'}}
   }
 }
 

test/Parse/confusables.swift

@@ -18,12 +18,8 @@ if (true ꝸꝸꝸ false) {} // expected-note {{identifier 'ꝸꝸꝸ' contains
 
 // expected-error @+3 {{invalid character in source file}}
 // expected-error @+2 {{expected ',' separator}}
-// expected-error @+1 {{type '(Int, Int)' cannot conform to 'BinaryInteger'}}
+// expected-error @+1 {{binary operator '==' cannot be applied to operands of type '(Int, Int)' and 'Int'}}
 if (5 ‒ 5) == 0 {} // expected-note {{unicode character '‒' (Figure Dash) looks similar to '-' (Hyphen Minus); did you mean to use '-' (Hyphen Minus)?}} {{7-10=-}}
-// expected-note @-1 {{operator function '=='}}
-// expected-note @-2 {{only concrete types such as structs, enums and classes can conform to protocols}}
-
-// FIXME(rdar://61028087): The above note should read "required by referencing operator function '==' on 'BinaryInteger' where 'Self' = '(Int, Int)'".
 
 // GREEK QUESTION MARK (which looks like a semicolon) 
 print("A"); print("B")

test/StringProcessing/Parse/forward-slash-regex.swift

@@ -263,8 +263,7 @@ default:
 
 do {} catch /x/ {}
 // expected-error@-1 {{expression pattern of type 'Regex<Substring>' cannot match values of type 'any Error'}}
-// expected-error@-2 {{binary operator '~=' cannot be applied to two 'any Error' operands}}
-// expected-warning@-3 {{'catch' block is unreachable because no errors are thrown in 'do' block}}
+// expected-warning@-2 {{'catch' block is unreachable because no errors are thrown in 'do' block}}
 
 switch /x/ {
 default: