--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/langtools/tools/javac/T6406771.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,117 @@
+/*
+ * @test  /nodynamiccopyright/
+ * @bug 6406771
+ * @summary CompilationUnitTree needs access to a line map
+ * @modules jdk.compiler/com.sun.tools.javac.api
+ *          jdk.compiler/com.sun.tools.javac.file
+ *          jdk.compiler/com.sun.tools.javac.tree
+ */
+
+// WARNING: White-space and layout is important in this file, especially tab characters.
+// Editing the imports and other leading text may affect the golden text in the tests field.
+// Also beware of scripts that auto-expand tabs to spaces.
+
+
+
+import java.io.*;
+import java.util.*;
+import javax.annotation.processing.*;
+import javax.lang.model.*;
+import javax.lang.model.element.*;
+import javax.tools.*;
+
+import com.sun.source.tree.*;
+import com.sun.source.util.*;
+import com.sun.tools.javac.api.*;
+import com.sun.tools.javac.tree.JCTree;
+
+@SupportedAnnotationTypes("*")
+public class T6406771 extends AbstractProcessor {
+    String[] tests = {
+        "line:31",
+        "line:32",
+        "line:33", "line:33",
+//       1         2         3         4         5         6
+//3456789012345678901234567890123456789012345678901234567890
+      "col:7", "col:16", "col:26",                 // this line uses spaces
+        "col:9",        "col:25",       "col:41",  // this line uses tabs
+                   "col:20",              "col:43" // this line uses a mixture
+    };
+
+    // White-space after this point does not matter
+
+    public static void main(String[] args) throws IOException {
+        String self = T6406771.class.getName();
+        String testSrc = System.getProperty("test.src");
+        String testClasses = System.getProperty("test.classes");
+
+        JavaCompiler tool = ToolProvider.getSystemJavaCompiler();
+        try (StandardJavaFileManager fm = tool.getStandardFileManager(null, null, null)) {
+            JavaFileObject f = fm.getJavaFileObjectsFromFiles(Arrays.asList(new File(testSrc, self+".java"))).iterator().next();
+
+            List<String> opts = Arrays.asList(
+                "--add-exports", "jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED",
+                "--add-exports", "jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED",
+                "-XDaccessInternalAPI",
+                "-d", ".",
+                "-processorpath", testClasses,
+                "-processor", self,
+                "-proc:only");
+
+            JavacTask task = (JavacTask)tool.getTask(null, fm, null, opts, null, Arrays.asList(f));
+
+            if (!task.call())
+                throw new AssertionError("failed");
+        }
+    }
+
+    public boolean process(Set<? extends TypeElement> elems, RoundEnvironment rEnv) {
+        final String LINE = "line" + ':';   // avoid matching this string
+        final String COLUMN  = "col" + ':';
+        final Messager messager = processingEnv.getMessager();
+        final Trees trees = Trees.instance(processingEnv);
+
+        TreeScanner<Void,LineMap> s = new  TreeScanner<Void,LineMap>() {
+            public Void visitLiteral(LiteralTree tree, LineMap lineMap) {
+                if (tree.getKind() == Tree.Kind.STRING_LITERAL) {
+                    String s = (String) tree.getValue();
+                    int pos = ((JCTree) tree).pos; // can't get through public api, bug 6412669 filed
+                    String prefix;
+                    long found;
+                    if (s.startsWith(LINE)) {
+                        prefix = LINE;
+                        found = lineMap.getLineNumber(pos);
+                    }
+                    else if (s.startsWith(COLUMN)) {
+                        prefix = COLUMN;
+                        found = lineMap.getColumnNumber(pos);
+                    }
+                    else
+                        return null;
+                    int expect = Integer.parseInt(s.substring(prefix.length()));
+                    if (expect != found) {
+                        messager.printMessage(Diagnostic.Kind.ERROR,
+                                              "Error: " + prefix + " pos=" + pos
+                                              + " expect=" + expect + " found=" + found);
+                    }
+                }
+                return null;
+            }
+        };
+
+        for (Element e: rEnv.getRootElements()) {
+            System.err.println(e);
+            Tree t = trees.getTree(e);
+            TreePath p = trees.getPath(e);
+            s.scan(p.getLeaf(), p.getCompilationUnit().getLineMap());
+
+        }
+
+        return true;
+    }
+
+    @Override
+    public SourceVersion getSupportedSourceVersion() {
+        return SourceVersion.latest();
+    }
+}