diff --git a/src/compiler/comments.ts b/src/compiler/comments.ts
index d44b3c9d80257..d926107d62bec 100644
--- a/src/compiler/comments.ts
+++ b/src/compiler/comments.ts
@@ -260,15 +260,9 @@ namespace ts {
             }
         }
 
-        function isJSDocLikeText(text: string, start: number) {
-            return text.charCodeAt(start + 1) === CharacterCodes.asterisk &&
-                text.charCodeAt(start + 2) === CharacterCodes.asterisk &&
-                text.charCodeAt(start + 3) !== CharacterCodes.slash;
-        }
-
         function shouldWriteComment(text: string, pos: number) {
             if (printerOptions.onlyPrintJsDocStyle) {
-                return (isJSDocLikeText(text, pos) || isPinnedComment(text, pos));
+                return (isJsDocStart(text, pos) || isPinnedComment(text, pos));
             }
             return true;
         }
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 52e4d5acf6a06..0d4f87744f5ba 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -43,7 +43,7 @@ namespace ts {
     }
 
     /*@internal*/
-    export function getOutputPathsFor(sourceFile: SourceFile | Bundle, host: EmitHost, forceDtsPaths?: boolean) {
+    export function getOutputPathsFor(sourceFile: SourceFile | Bundle, host: EmitHost, forceDtsPaths: boolean) {
         const options = host.getCompilerOptions();
         if (sourceFile.kind === SyntaxKind.Bundle) {
             const jsFilePath = options.outFile || options.out;
@@ -129,7 +129,8 @@ namespace ts {
         let declarationPrinter: Printer;
         if (emitOnlyDtsFiles || compilerOptions.declaration) {
             const nonJsFiles = filter(sourceFiles, isSourceFileNotJavaScript);
-            declarationTransform = transformNodes(resolver, host, compilerOptions, (compilerOptions.outFile || compilerOptions.out) ? [createBundle(nonJsFiles)] : nonJsFiles, [transformDeclarations], /*allowDtsFiles*/ false);
+            const inputListOrBundle = (compilerOptions.outFile || compilerOptions.out) ? [createBundle(nonJsFiles)] : nonJsFiles;
+            declarationTransform = transformNodes(resolver, host, compilerOptions, inputListOrBundle, [transformDeclarations], /*allowDtsFiles*/ false);
             declarationPrinter = createPrinter({ ...compilerOptions, onlyPrintJsDocStyle: true } as PrinterOptions, {
                 // resolver hooks
                 hasGlobalName: resolver.hasGlobalName,
@@ -182,9 +183,9 @@ namespace ts {
                         return getOriginalNode(n) === getOriginalNode(sourceFileOrBundle);
                     });
                     if (associatedDeclarationTree) {
-                        const previousState = sourceMap.setDisabled(true);
+                        const previousState = sourceMap.setState(/*disabled*/ true);
                         printSourceFileOrBundle(declarationFilePath, /*sourceMapFilePath*/ undefined, associatedDeclarationTree, declarationPrinter, /*shouldSkipSourcemap*/ true);
-                        sourceMap.setDisabled(previousState);
+                        sourceMap.setState(previousState);
                     }
                     else {
                         Debug.fail(`No declaration output found for path "${declarationFilePath}" for js output file: "${jsFilePath}".`);
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 70ddb7b791df1..147ac6f12a4c9 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -6416,13 +6416,6 @@ namespace ts {
                     }
                 }
 
-                function isJsDocStart(content: string, start: number) {
-                    return content.charCodeAt(start) === CharacterCodes.slash &&
-                        content.charCodeAt(start + 1) === CharacterCodes.asterisk &&
-                        content.charCodeAt(start + 2) === CharacterCodes.asterisk &&
-                        content.charCodeAt(start + 3) !== CharacterCodes.asterisk;
-                }
-
                 function createJSDocComment(): JSDoc {
                     const result = <JSDoc>createNode(SyntaxKind.JSDocComment, start);
                     result.tags = tags && createNodeArray(tags, tagsPos, tagsEnd);
diff --git a/src/compiler/sourcemap.ts b/src/compiler/sourcemap.ts
index 76656f9235375..14ecbce997cb0 100644
--- a/src/compiler/sourcemap.ts
+++ b/src/compiler/sourcemap.ts
@@ -71,7 +71,7 @@ namespace ts {
         /**
          * @returns the previous disabled state
          */
-        setDisabled(state: boolean): boolean;
+        setState(disabled: boolean): boolean;
     }
 
     // Used for initialize lastEncodedSourceMapSpan and reset lastEncodedSourceMapSpan when updateLastEncodedAndRecordedSpans
@@ -112,10 +112,10 @@ namespace ts {
             emitTokenWithSourceMap,
             getText,
             getSourceMappingURL,
-            setDisabled,
+            setState,
         };
 
-        function setDisabled(state: boolean) {
+        function setState(state: boolean) {
             const last = disabled;
             disabled = state;
             return last;
diff --git a/src/compiler/transformers/declarations.ts b/src/compiler/transformers/declarations.ts
index c970dbc08b9d8..d715bed1924e1 100644
--- a/src/compiler/transformers/declarations.ts
+++ b/src/compiler/transformers/declarations.ts
@@ -184,7 +184,7 @@ namespace ts {
             possibleImports = undefined;
             importDeclarationMap = createMap();
             necessaryTypeRefernces = undefined;
-            const refs = collectReferences(currentSourceFile);
+            const refs = collectReferences(currentSourceFile, createMap());
             const references: FileReference[] = [];
             const outputFilePath = getDirectoryPath(normalizeSlashes(getOutputPathsFor(node, host, /*forceDtsPaths*/ true).declarationFilePath));
             const referenceVisitor = mapReferencesIntoArray(references, outputFilePath);
@@ -234,7 +234,7 @@ namespace ts {
             }
         }
 
-        function collectReferences(sourceFile: SourceFile, ret = createMap<SourceFile>()) {
+        function collectReferences(sourceFile: SourceFile, ret: Map<SourceFile>) {
             if (noResolve || isSourceFileJavaScript(sourceFile)) return ret;
             forEach(sourceFile.referencedFiles, f => {
                 const elem = tryResolveScriptReference(host, sourceFile, f);
@@ -797,7 +797,7 @@ namespace ts {
 
             switch (input.kind) {
                 case SyntaxKind.ExportDeclaration: {
-                    if (!resultHasExternalModuleIndicator && isSourceFile(input.parent)) {
+                    if (isSourceFile(input.parent)) {
                         resultHasExternalModuleIndicator = true;
                     }
                     // Always visible if the parent node isn't dropped for being not visible
@@ -806,7 +806,7 @@ namespace ts {
                 }
                 case SyntaxKind.ExportAssignment: {
                     // Always visible if the parent node isn't dropped for being not visible
-                    if (!resultHasExternalModuleIndicator && isSourceFile(input.parent)) {
+                    if (isSourceFile(input.parent)) {
                         resultHasExternalModuleIndicator = true;
                     }
                     if (input.expression.kind === SyntaxKind.Identifier) {
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index e3518fdc196b2..6b9eef0202951 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -274,6 +274,13 @@ namespace ts {
         return false;
     }
 
+    export function isJsDocStart(content: string, start: number) {
+        return content.charCodeAt(start) === CharacterCodes.slash &&
+            content.charCodeAt(start + 1) === CharacterCodes.asterisk &&
+            content.charCodeAt(start + 2) === CharacterCodes.asterisk &&
+            content.charCodeAt(start + 3) !== CharacterCodes.asterisk;
+    }
+
     export function isPinnedComment(text: string, start: number) {
         return text.charCodeAt(start + 1) === CharacterCodes.asterisk &&
             text.charCodeAt(start + 2) === CharacterCodes.exclamation;