Prototyping DCE tool for JS

js/js.parser/src/com/google/gwt/dev/js/JsAstMapper.java

@@ -32,9 +32,13 @@ public class JsAstMapper {
     private final JsProgram program;
     private final ScopeContext scopeContext;
 
-    public JsAstMapper(@NotNull JsScope scope) {
+    @NotNull
+    private final String fileName;
+
+    public JsAstMapper(@NotNull JsScope scope, @NotNull String fileName) {
         scopeContext = new ScopeContext(scope);
         program = scope.getProgram();
+        this.fileName = fileName;
     }
 
     private static JsParserException createParserException(String msg, Node offender) {
@@ -43,6 +47,10 @@ public class JsAstMapper {
     }
 
     private JsNode map(Node node) throws JsParserException {
+        return withLocation(mapWithoutLocation(node), node);
+    }
+
+    private JsNode mapWithoutLocation(Node node) throws JsParserException {
         switch (node.getType()) {
             case TokenStream.SCRIPT: {
                 JsBlock block = new JsBlock();
@@ -1115,4 +1123,18 @@ public class JsAstMapper {
         int type = jsNode.getType();
         return type == TokenStream.NUMBER || type == TokenStream.NUMBER;
     }
+
+    private <T extends JsNode> T withLocation(T astNode, Node node) {
+        int lineNumber = node.getLineno();
+        if (lineNumber >= 0) {
+            JsLocation location = new JsLocation(fileName, lineNumber, 0);
+            if (astNode instanceof SourceInfoAwareJsNode) {
+                astNode.setSource(location);
+            }
+            else if (astNode instanceof JsExpressionStatement) {
+                ((JsExpressionStatement) astNode).getExpression().setSource(location);
+            }
+        }
+        return astNode;
+    }
 }

js/js.parser/src/org/jetbrains/kotlin/js/parser/parserUtils.kt

@@ -29,17 +29,19 @@ import java.util.*
 
 private val FAKE_SOURCE_INFO = SourceInfoImpl(null, 0, 0, 0, 0)
 
-fun parse(code: String, reporter: ErrorReporter, scope: JsScope): List<JsStatement> {
+fun parse(code: String, reporter: ErrorReporter, scope: JsScope, fileName: String): List<JsStatement> {
         val insideFunction = scope is JsFunctionScope
         val node = parse(code, 0, reporter, insideFunction, Parser::parse)
-        return node.toJsAst(scope, JsAstMapper::mapStatements)
+        return node.toJsAst(scope, fileName) {
+            mapStatements(it)
+        }
 }
 
-fun parseFunction(code: String, offset: Int, reporter: ErrorReporter, scope: JsScope): JsFunction =
+fun parseFunction(code: String, fileName: String, offset: Int, reporter: ErrorReporter, scope: JsScope): JsFunction =
         parse(code, offset, reporter, insideFunction = false) {
             addObserver(FunctionParsingObserver())
             primaryExpr(it)
-        }.toJsAst(scope, JsAstMapper::mapFunction)
+        }.toJsAst(scope, fileName, JsAstMapper::mapFunction)
 
 private class FunctionParsingObserver : Observer {
     var functionsStarted = 0
@@ -80,8 +82,8 @@ private fun parse(
 }
 
 inline
-private fun <T> Node.toJsAst(scope: JsScope, mapAction: JsAstMapper.(Node)->T): T =
-        JsAstMapper(scope).mapAction(this)
+private fun <T> Node.toJsAst(scope: JsScope, fileName: String, mapAction: JsAstMapper.(Node)->T): T =
+        JsAstMapper(scope, fileName).mapAction(this)
 
 private fun StringReader(string: String, offset: Int): Reader {
     val reader = StringReader(string)