[Parser] Preserve empty getter functions for indentation (#4586) (#4592)

* [Parser] Preserve empty getter functions to make sure indentation inside its body still works. rdar://28049927

* Using the consistent identifier even though they are identical.

Author: nkcsgexi

lib/Parse/ParseDecl.cpp

@@ -3522,10 +3522,19 @@ bool Parser::parseGetSetImpl(ParseDeclOptions Flags, ParameterList *Indices,
   // Otherwise, we have a normal var or subscript declaration, parse the full
   // complement of specifiers, along with their bodies.
 
-  // If the body is completely empty, reject it.  This is at best a getter with
+  // If the body is completely empty, preserve it.  This is at best a getter with
   // an implicit fallthrough off the end.
   if (Tok.is(tok::r_brace)) {
     diagnose(Tok, diag::computed_property_no_accessors);
+    auto *TheDecl = createAccessorFunc(VarLBLoc, nullptr, TypeLoc(), nullptr,
+                                       SourceLoc(), Flags,
+                                       AccessorKind::IsGetter,
+                                       AddressorKind::NotAddressor, this,
+                                       SourceLoc());
+
+    TheDecl->setBody(BraceStmt::create(Context, VarLBLoc, {}, Tok.getLoc()));
+    TheDecl->setInvalid();
+    Decls.push_back(TheDecl);
     return true;
   }
 

test/SourceKit/CodeFormat/indent-toplevel.swift

@@ -1,9 +1,14 @@
 for i in 0...5 {
 }
 
+var someProperty: String {
+
+}
 // RUN: %sourcekitd-test -req=format -line=1 -length=1 %s >%t.response
 // RUN: %sourcekitd-test -req=format -line=2 -length=1 %s >>%t.response
+// RUN: %sourcekitd-test -req=format -line=5 -length=1 %s >>%t.response
 // RUN: %FileCheck --strict-whitespace %s <%t.response
 
 // CHECK: key.sourcetext: "for i in 0...5 {"
 // CHECK: key.sourcetext: "}"
+// CHECK: key.sourcetext: "    "