Added initial source map position tracking for tokens.

src/compiler/printer.ts

@@ -2165,13 +2165,25 @@ function __export(m) {
                 }
             }
 
-            function writeToken(token: SyntaxKind) {
-                write(tokenToString(token));
+            function writeToken(token: SyntaxKind, pos?: number) {
+                let tokenStartPos = skipTrivia(currentSourceFile.text, pos);
+                emitPos(tokenStartPos);
+                let tokenEndPos = writeTokenText(token, pos);
+                emitPos(tokenEndPos);
+                return tokenEndPos;
+            }
+
+            function writeTokenText(token: SyntaxKind, pos?: number) {
+                let tokenString = tokenToString(token);
+                write(tokenString);
+                return positionIsSynthesized(pos) ? -1 : pos + tokenString.length;
             }
 
             function writeTokenNode(node: Node) {
                 if (node) {
-                    writeToken(node.kind);
+                    emitStart(node);
+                    writeTokenText(node.kind);
+                    emitEnd(node);
                 }
             }
 

src/compiler/scanner.ts

@@ -425,10 +425,10 @@ namespace ts {
 
       /* @internal */
       export function skipTrivia(text: string, pos: number, stopAfterLineBreak?: boolean): number {
-          if (pos < 0) {
+          if (positionIsSynthesized(pos)) {
               return pos;
           }
-          
+
           // Keep in sync with couldStartTrivia
           while (true) {
               let ch = text.charCodeAt(pos);
@@ -571,12 +571,12 @@ namespace ts {
     }
 
     /**
-     * Extract comments from text prefixing the token closest following `pos`. 
+     * Extract comments from text prefixing the token closest following `pos`.
      * The return value is an array containing a TextRange for each comment.
      * Single-line comment ranges include the beginning '//' characters but not the ending line break.
      * Multi - line comment ranges include the beginning '/* and ending '<asterisk>/' characters.
      * The return value is undefined if no comments were found.
-     * @param trailing 
+     * @param trailing
      * If false, whitespace is skipped until the first line break and comments between that location
      * and the next token are returned.
      * If true, comments occurring between the given position and the next line break are returned.

src/compiler/sourcemap.ts

@@ -7,7 +7,7 @@ namespace ts {
     export interface SourceMapWriter {
         sourceMapData?: SourceMapData;
         setSourceFile(sourceFile: SourceFile): void;
-        emitPos(pos: number, skipTrivia?: boolean): void;
+        emitPos(pos: number): void;
         emitStart(range: TextRange): void;
         emitEnd(range: TextRange): void;
         pushScope(scopeDeclaration: Node, scopeName?: string): void;
@@ -167,15 +167,11 @@ namespace ts {
             sourceMapData.sourceMapDecodedMappings.push(lastEncodedSourceMapSpan);
         }
 
-        function recordSourceMapSpan(pos: number, skipTrivia?: boolean) {
+        function recordSourceMapSpan(pos: number) {
             if (pos === -1) {
                 return;
             }
 
-            if (skipTrivia) {
-                pos = ts.skipTrivia(currentSourceFile.text, pos);
-            }
-
             let sourceLinePos = getLineAndCharacterOfPosition(currentSourceFile, pos);
 
             // Convert the location to be one-based.
@@ -215,11 +211,11 @@ namespace ts {
         }
 
         function recordEmitNodeStartSpan(range: TextRange) {
-            recordSourceMapSpan(range.pos, /*skipTrivia*/ true);
+            recordSourceMapSpan(range.pos !== -1 ? skipTrivia(currentSourceFile.text, range.pos) : -1);
         }
 
         function recordEmitNodeEndSpan(range: TextRange) {
-            recordSourceMapSpan(range.end, /*skipTrivia*/ false);
+            recordSourceMapSpan(range.end);
         }
 
         function recordNewSourceFileStart(sourceFile: SourceFile) {

src/compiler/utilities.ts

@@ -1827,11 +1827,13 @@ namespace ts {
     }
 
     export function nodeIsSynthesized(node: Node): boolean {
-        return node && node.pos === -1;
+        return node && positionIsSynthesized(node.pos);
     }
 
     export function positionIsSynthesized(pos: number): boolean {
-        return pos === -1;
+        // Using ! with a greater than test is a fast way of testing the following conditions:
+        //  pos === undefined || pos === null || isNaN(pos) || pos <= 0;
+        return !(pos > 0);
     }
 
     export function childNodeStartPositionIsOnSameLine(sourceFile: SourceFile, parent: Node, child: Node) {