Nashorn comment nodes in the syntax tree

[Emilian Bold]

Yes, it must be a bug: comments are certainly swallowed in the nodes on my
JRE. I see this for FunctionNode but also for IdentNode and perhaps more.

It makes getting actual offsets a pain and I would strip-out comments from
the text before sending it to the parser, but I need those too.

$ uname -a
Darwin mac.local 15.5.0 Darwin Kernel Version 15.5.0: Tue Apr 19 18:36:36
PDT 2016; root:xnu-3248.50.21~8/RELEASE_X86_64 x86_64

$ java -version
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode)

Java 1.8.0_66

Script text:
--begin--
function hello(){
 return 'world';
}

//some comment
hello();
--end--

[<unknown>] function {U%}hello()
Function text:
--begin--
{
 return 'world';
}

//some comment
--end-


junit.framework.AssertionFailedError: The function should not swallow the
comment


Test:

package com; import jdk.nashorn.internal.ir.FunctionNode; import
jdk.nashorn.internal.ir.LexicalContext; import
jdk.nashorn.internal.ir.visitor.NodeVisitor; import
jdk.nashorn.internal.runtime.ErrorManager; import
jdk.nashorn.internal.runtime.ScriptEnvironment; import
jdk.nashorn.internal.runtime.Source; import
jdk.nashorn.internal.runtime.options.Options; import
junit.framework.TestCase; import java.io.PrintWriter; public class
NashornCommentBugTest extends TestCase { public void testComment(){
System.out.println("Java " + System.getProperty("java.version"));
System.out.println(); String text = "function hello(){ \n" + " return
'world';\n" + "}\n\n" + "" + "//some comment\n" + "hello();"; Source source
= Source.sourceFor("test.js", text); //NOI18N Options options = new
Options("nashorn"); // NOI18N options.process(new String[]{
"--parse-only=true", // NOI18N "--empty-statements=true", // NOI18N
"--debug-lines=false"}); // NOI18N ScriptEnvironment env = new
ScriptEnvironment(options, new PrintWriter(System.out), new
PrintWriter(System.err)); ErrorManager errorManager = new ErrorManager();
jdk.nashorn.internal.parser.Parser parser = new
jdk.nashorn.internal.parser.Parser(env, source, errorManager); FunctionNode
root = parser.parse(); System.out.println("Script text:\n--begin--\n" +
text+"\n--end--\n"); root.accept(new NodeVisitor<LexicalContext>(new
LexicalContext()) { @Override public boolean enterFunctionNode(FunctionNode
functionNode) { if
(!functionNode.getKind().equals(FunctionNode.Kind.SCRIPT)) {
System.out.println(functionNode.toString()); String functionText =
text.substring(functionNode.getStart(), functionNode.getFinish());
System.out.println("Function text:\n--begin--\n" +
functionText+"\n--end-\n"); assertFalse("The function should not swallow
the comment", functionText.contains("some comment")); } return
super.enterFunctionNode(functionNode); } }); } }






--emi

On Mon, Jun 13, 2016 at 6:31 AM, Sundararajan Athijegannathan <
sundararajan.athijegannathan at oracle.com> wrote:

> start and finish should not include comments around. If it does, it is a
> bug. Please do file a bug and send us test case here and we'll file a bug
>
> Thanks,
>
> -Sundar
>
> On 6/10/2016 9:05 PM, Emilian Bold wrote:
>
> BTW, jdk.nashorn.internal.ir.IdentNode (and other classes) seem to have
> the habit of "absorbing" the nearby comments and have incorrect
> start/finish offsets.
>
> Is this intentional or a bug?
>
> I haven't tested yet but I wonder if it propagates to the TreeAPI (ie.
> does IdentifierTree also swallow adjacent comments?)
>
>
>
> --emi
>
> On Wed, Apr 27, 2016 at 5:18 PM, Sundararajan Athijegannathan <
> <sundararajan.athijegannathan at oracle.com>
> sundararajan.athijegannathan at oracle.com> wrote:
>
>> Hi,
>>
>> I filed an enhancement request:
>> https://bugs.openjdk.java.net/browse/JDK-8155242
>>
>> Thanks,
>>
>> -Sundar
>>
>>
>> On 4/27/2016 12:40 AM, Emilian Bold wrote:
>> > Hello,
>> >
>> > NetBeans used a modified Rhino that had useful features for an IDE like
>> > comment nodes and parser-level sanitization.
>> >
>> > As far as I know there is no way to get the comments in the Nashorn Tree
>> > API (created as part of JEP 236) or in the jdk.nashorn.internal.ir Node
>> > subclasses.
>> >
>> > Obviously having access to comment contents and comment offsets is very
>> > useful. An IDE, for example, would provide code folding for the
>> multiline
>> > comment.
>> >
>> > Am I missing some proper way to get this information?
>> >
>> > I believe an extra option for Parser.create() would be nice (plus a
>> > CommentTree and a visitComment method).
>> >
>> > --emi
>>
>>
>
>