[Diagnostics] Adjust getCallInfo to accept TypedNode instead of expression

Author: xedin

lib/Sema/CSDiagnostics.cpp

@@ -3909,9 +3909,8 @@ bool MissingArgumentsFailure::diagnoseAsError() {
   unsigned numArguments = 0;
   bool hasTrailingClosure = false;
 
-  auto *rawAnchor = getRawAnchor().get<const Expr *>();
   std::tie(fnExpr, argExpr, numArguments, hasTrailingClosure) =
-      getCallInfo(const_cast<Expr *>(rawAnchor));
+      getCallInfo(getRawAnchor());
 
   // TODO(diagnostics): We should be able to suggest this fix-it
   // unconditionally.
@@ -3987,7 +3986,7 @@ bool MissingArgumentsFailure::diagnoseSingleMissingArgument() const {
   bool hasTrailingClosure = false;
 
   std::tie(fnExpr, argExpr, insertableEndIdx, hasTrailingClosure) =
-      getCallInfo(const_cast<Expr *>(anchor.get<const Expr *>()));
+      getCallInfo(anchor);
 
   if (!argExpr)
     return false;
@@ -4293,17 +4292,17 @@ bool MissingArgumentsFailure::isMisplacedMissingArgument(
 }
 
 std::tuple<Expr *, Expr *, unsigned, bool>
-MissingArgumentsFailure::getCallInfo(Expr *anchor) const {
-  if (auto *call = dyn_cast<CallExpr>(anchor)) {
+MissingArgumentsFailure::getCallInfo(TypedNode anchor) const {
+  if (auto *call = getAsExpr<CallExpr>(anchor)) {
     return std::make_tuple(call->getFn(), call->getArg(),
                            call->getNumArguments(), call->hasTrailingClosure());
-  } else if (auto *UME = dyn_cast<UnresolvedMemberExpr>(anchor)) {
+  } else if (auto *UME = getAsExpr<UnresolvedMemberExpr>(anchor)) {
     return std::make_tuple(UME, UME->getArgument(), UME->getNumArguments(),
                            UME->hasTrailingClosure());
-  } else if (auto *SE = dyn_cast<SubscriptExpr>(anchor)) {
+  } else if (auto *SE = getAsExpr<SubscriptExpr>(anchor)) {
     return std::make_tuple(SE, SE->getIndex(), SE->getNumArguments(),
                            SE->hasTrailingClosure());
-  } else if (auto *OLE = dyn_cast<ObjectLiteralExpr>(anchor)) {
+  } else if (auto *OLE = getAsExpr<ObjectLiteralExpr>(anchor)) {
     return std::make_tuple(OLE, OLE->getArg(), OLE->getNumArguments(),
                            OLE->hasTrailingClosure());
   }

lib/Sema/CSDiagnostics.h

@@ -1278,10 +1278,11 @@ class MissingArgumentsFailure final : public FailureDiagnostic {
   /// `@Foo(answer: 42) var question = "ultimate question"`
   bool isPropertyWrapperInitialization() const;
 
-  /// Gather informatioin associated with expression that represents
+  /// Gather information associated with expression that represents
   /// a call - function, arguments, # of arguments and whether it has
   /// a trailing closure.
-  std::tuple<Expr *, Expr *, unsigned, bool> getCallInfo(Expr *anchor) const;
+  std::tuple<Expr *, Expr *, unsigned, bool>
+  getCallInfo(TypedNode anchor) const;
 
   /// Transform given argument into format suitable for a fix-it
   /// text e.g. `[<label>:]? <#<type#>`