[Diagnostics] Extend argument-to-parameter mismatch note to cover inout parameters

Author: xedin

include/swift/AST/DiagnosticsSema.def

@@ -381,8 +381,8 @@ ERROR(cannot_convert_argument_value,none,
       (Type,Type))
 
 NOTE(candidate_has_invalid_argument_at_position,none,
-     "candidate expects value of type %0 for parameter #%1",
-     (Type, unsigned))
+     "candidate expects %select{|in-out }2value of type %0 for parameter #%1",
+     (Type, unsigned, bool))
 
 ERROR(cannot_convert_array_to_variadic,none,
       "cannot pass array of type %0 as variadic arguments of type %1",

lib/Sema/CSDiagnostics.cpp

@@ -5084,9 +5084,11 @@ bool ArgumentMismatchFailure::diagnoseAsError() {
 }
 
 bool ArgumentMismatchFailure::diagnoseAsNote() {
+  auto *locator = getLocator();
   if (auto *callee = getCallee()) {
     emitDiagnostic(callee, diag::candidate_has_invalid_argument_at_position,
-                   getToType(), getParamPosition());
+                   getToType(), getParamPosition(),
+                   locator->isLastElement<LocatorPathElt::LValueConversion>());
     return true;
   }
 

test/expr/postfix/dot/init_ref_delegation.swift

@@ -549,8 +549,8 @@ struct MultipleMemberAccesses {
 
 func sr10670() {
   struct S {
-    init(_ x: inout String) {} // expected-note {{candidate expects value of type 'String' for parameter #1}}
-    init(_ x: inout [Int]) {}  // expected-note {{candidate expects value of type '[Int]' for parameter #1}}
+    init(_ x: inout String) {} // expected-note {{candidate expects in-out value of type 'String' for parameter #1}}
+    init(_ x: inout [Int]) {}  // expected-note {{candidate expects in-out value of type '[Int]' for parameter #1}}
   }
   var a = 0
   S.init(&a) // expected-error {{no exact matches in call to initializer}}