Sema: Remove old diagnostics for misplaced InOutExpr

Author: slavapestov

include/swift/AST/DiagnosticsSema.def

@@ -2790,8 +2790,6 @@ ERROR(object_literal_broken_proto,none,
 ERROR(discard_expr_outside_of_assignment,none,
       "'_' can only appear in a pattern or on the left side of an assignment",
       ())
-ERROR(inout_expr_outside_of_call,none,
-      "'&' can only appear immediately in a call argument list", ())
 ERROR(collection_literal_heterogeneous,none,
       "heterogeneous collection literal could only be inferred to %0; add"
       " explicit type annotation if this is intentional", (Type))

lib/Sema/MiscDiagnostics.cpp

@@ -68,9 +68,6 @@ static void diagSyntacticUseRestrictions(TypeChecker &TC, const Expr *E,
     // Keep track of acceptable DiscardAssignmentExpr's.
     SmallPtrSet<DiscardAssignmentExpr*, 2> CorrectDiscardAssignmentExprs;
 
-    /// Keep track of InOutExprs
-    SmallPtrSet<InOutExpr*, 2> AcceptableInOutExprs;
-
     /// Keep track of the arguments to CallExprs.
     SmallPtrSet<Expr *, 2> CallArgs;
 
@@ -127,15 +124,9 @@ static void diagSyntacticUseRestrictions(TypeChecker &TC, const Expr *E,
       if (isa<TypeExpr>(Base))
         checkUseOfMetaTypeName(Base);
 
-      if (auto *SE = dyn_cast<SubscriptExpr>(E)) {
+      if (auto *SE = dyn_cast<SubscriptExpr>(E))
         CallArgs.insert(SE->getIndex());
 
-        // Implicit InOutExpr's are allowed in the base of a subscript expr.
-        if (auto *IOE = dyn_cast<InOutExpr>(SE->getBase()))
-          if (IOE->isImplicit())
-            AcceptableInOutExprs.insert(IOE);
-      }
-
       if (auto *KPE = dyn_cast<KeyPathExpr>(E)) {
         for (auto Comp : KPE->getComponents()) {
           if (auto *Arg = Comp.getIndexExpr())
@@ -197,11 +188,6 @@ static void diagSyntacticUseRestrictions(TypeChecker &TC, const Expr *E,
         }
 
         visitArguments(Call, [&](unsigned argIndex, Expr *arg) {
-          // InOutExpr's are allowed in argument lists directly.
-          if (auto *IOE = dyn_cast<InOutExpr>(arg)) {
-            if (isa<CallExpr>(Call))
-              AcceptableInOutExprs.insert(IOE);
-          }
           // InOutExprs can be wrapped in some implicit casts.
           Expr *unwrapped = arg;
           if (auto *IIO = dyn_cast<InjectIntoOptionalExpr>(arg))
@@ -212,10 +198,8 @@ static void diagSyntacticUseRestrictions(TypeChecker &TC, const Expr *E,
               isa<ErasureExpr>(unwrapped)) {
             auto operand =
               cast<ImplicitConversionExpr>(unwrapped)->getSubExpr();
-            if (auto *IOE = dyn_cast<InOutExpr>(operand)) {
-              AcceptableInOutExprs.insert(IOE);
+            if (auto *IOE = dyn_cast<InOutExpr>(operand))
               operand = IOE->getSubExpr();
-            }
 
             // Also do some additional work based on how the function uses
             // the argument.
@@ -238,14 +222,6 @@ static void diagSyntacticUseRestrictions(TypeChecker &TC, const Expr *E,
           TC.diagnose(DAE->getLoc(), diag::discard_expr_outside_of_assignment);
       }
 
-      // Diagnose an '&' that isn't in an argument lists.
-      if (auto *IOE = dyn_cast<InOutExpr>(E)) {
-        if (!IOE->isImplicit() && !AcceptableInOutExprs.count(IOE) &&
-            !IOE->getType()->hasError())
-          TC.diagnose(IOE->getLoc(), diag::inout_expr_outside_of_call)
-            .highlight(IOE->getSubExpr()->getSourceRange());
-      }
-
       // Diagnose 'self.init' or 'super.init' nested in another expression
       // or closure.
       if (auto *rebindSelfExpr = dyn_cast<RebindSelfInConstructorExpr>(E)) {