Refactor: Rename Parser::consumeToken, consumeLoc. Add consumeToken API.

These APIs return SourceLocs, and eventually the Parser should consume
tokens, which now include source trivia such as whitespace and comments,
and package them into a purely syntactic tree.  Just a tiny step. NFC.

Author: bitjammer

include/swift/Parse/Parser.h

@@ -321,10 +321,10 @@ class Parser {
   void restoreParserPosition(ParserPosition PP) {
     L->restoreState(PP.LS);
 
-    // We might be at tok::eof now, so ensure that consumeToken()
+    // We might be at tok::eof now, so ensure that consumeLoc()
     // does not assert about lexing past eof.
     Tok = syntax::Token::unknown();
-    consumeToken();
+    consumeLoc();
 
     PreviousLoc = PP.PreviousLoc;
   }
@@ -334,10 +334,10 @@ class Parser {
 
     L->backtrackToState(PP.LS);
 
-    // We might be at tok::eof now, so ensure that consumeToken()
+    // We might be at tok::eof now, so ensure that consumeLoc()
     // does not assert about lexing past eof.
     Tok = syntax::Token::unknown();
-    consumeToken();
+    consumeLoc();
 
     PreviousLoc = PP.PreviousLoc;
   }
@@ -386,21 +386,22 @@ class Parser {
   //===--------------------------------------------------------------------===//
   // Utilities
 
-  /// \brief Return the next token that will be installed by \c consumeToken.
+  /// \brief Return the next token that will be installed by \c consumeLoc.
   const syntax::Token &peekToken();
 
-  SourceLoc consumeToken();
-  SourceLoc consumeToken(tok K) {
+  syntax::Token consumeToken();
+  SourceLoc consumeLoc();
+  SourceLoc consumeLoc(tok K) {
     assert(Tok.is(K) && "Consuming wrong token kind");
-    return consumeToken();
+    return consumeLoc();
   }
 
   SourceLoc consumeIdentifier(Identifier *Result = nullptr) {
     assert(Tok.isAny(tok::identifier, tok::kw_self,
                      tok::kw_Self, tok::kw_throws));
     if (Result)
       *Result = Context.getIdentifier(Tok.getText().str());
-    return consumeToken();
+    return consumeLoc();
   }
 
   /// \brief Retrieve the location just past the end of the previous
@@ -411,15 +412,15 @@ class Parser {
   /// return true.  Otherwise, return false without consuming it.
   bool consumeIf(tok K) {
     if (Tok.isNot(K)) return false;
-    consumeToken(K);
+    consumeLoc(K);
     return true;
   }
 
   /// \brief If the current token is the specified kind, consume it and
   /// return true.  Otherwise, return false without consuming it.
   bool consumeIf(tok K, SourceLoc &consumedLoc) {
     if (Tok.isNot(K)) return false;
-    consumedLoc = consumeToken(K);
+    consumedLoc = consumeLoc(K);
     return true;
   }
 

include/swift/Syntax/RawSyntax.h

@@ -0,0 +1,76 @@
+//===--- Trivia.h - Swift Raw Syntax Nodes ----------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the RawSyntax class - the immutable, persistent backing
+// for syntactic information in the AST. These are raw containers of child
+// relationships and the layout of a particular node. For example:
+//
+// func foo() {
+//   // body ...
+// }
+//
+// This function declaration is laid out as following:
+// - func token
+// - foo identifier token
+// - child: argument list
+// - child: brace statement
+//
+// And would have two children.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_SYNTAX_RAWSYNTAX_H
+#define SWIFT_SYNTAX_RAWSYNTAX_H
+
+namespace swift {
+namespace syntax {
+
+struct RawSyntax;
+using RawSyntaxRef = llvm::IntrusiveRefCntPtr<RawSyntax>;
+
+enum class RawSyntaxLayoutKind {
+  /// The layout element is a terminal token.
+  Token,
+
+  /// The layout element is a child syntax node.
+  ChildIndex,
+};
+
+struct RawSyntaxLayout {
+  const RawSyntaxLayoutKind Kind;
+private:
+  union {
+    syntax::Token Tok;
+    size_t ChildIndex;
+  } Data;
+
+public:
+  const syntax::Token &getToken() const {
+    assert(Kind == RawSyntaxLayoutKind::Token);
+    return Data.Tok;
+  }
+
+  size_t getChildIndex() const {
+    assert(Kind == RawSyntaxLayoutKind::ChildIndex);
+    return Data.ChildIndex;
+  }
+};
+
+struct RawSyntax : public llvm::ThreadSafeRefCountedBase<RawSyntax> {
+  const std::vector<RawSyntaxRef> Children;
+  const std::vector<RawSyntaxLayout> Layout;
+};
+
+} // end namespace syntax
+} // end namespace swift
+
+#endif // SWIFT_SYNTAX_RAWSYNTAX_H