Hi Vivin,
What you see is some fuzziness in the translation from JS functions to
Java methods and from there to the stack traces you see.
When we compile a JS function, we create a Java method with the name of
the function concatenated to the names of its parent functions, using
'$' as separator. For anonymous functions we use something like L:123 as
name where 123 is the line of code where the function begins.
This method naming scheme helps a lot in making bytecode easier to
debug, and to create unique method names within a compilation unit.
However, it also leads to the stack traces you see, getting f$foo in the
first case and something like L1:foo in the second case, which is
rendered as <anonymous> in the stack trace.
Ideally we should reverse this when printing stack traces, displaying
only the name of the function itself, e.g. "bar" for "foo$bar" and
"<anonymous>" for "foo$L:3". Unfortunately, "$" is a valid character in
a JS identifier, so it's not that easy, "foo$bar" may also be the name
of the original function.
I'm thinking about how to solve this and will probably file an issue for it.
Hannes
Am 2016-05-12 um 15:59 schrieb Vivin Suresh Paliath:
I tried this out on in chrome and I get the expected stack trace there. Is
this a bug?
On May 6, 2016 3:39 PM, "Vivin Suresh Paliath" <vivin.pali...@gmail.com>
wrote:
I have the following code:
*var f = (function() {*
* return function foo() {*
* try {*
* throw new Error();*
* } catch(e) {*
* print(e.stack);*
* }*
* }*
*})();*
When I call the function, I get the following stacktrace as expected
(mostly; I was expecting *foo* instead of *f$foo*).
*Error*
* at f$foo (<shell>:1)*
* at <program> (<shell>:1)*
However, if I dynamically construct the function as follows:
*var f = new Function([], "return function foo() { try { throw new
Error(); } catch(e) { print(e.stack); } }")()*
I get:
*Error*
* at <anonymous> (<function>:2)*
* at <program> (<shell>:1)*
Is there a reason for this discrepancy? Isn't the second version
effectively the same as the first? Also, why is it *f$foo* instead of
*foo* in the first case?
I am running jdk8u92.
Thanks!
--
Ruin untold;
And thine own sadness,
Sing in the grass,
When eve has forgot, that no more hear common things that gleam and pass;
But seek alone to lip, sad Rose of love and ruin untold;
And thine own mother
Can know it as I know
More than another
What makes your own sadness,
Set in her eyes.
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