[fedora-java] line numbers

[Bryce McKinlay]

Andrew Haley wrote:
> Anthony Green writes:
>  > Now that we have a new libgcj in FC-5, azureus logging seems to be
>  > working.  I've been comparing log files between Sun JRE and gcj runs,
>  > and have filed 1 GNU Classpath bug so far.
>  > 
>  > One thing that is annoying is that I'm not getting line numbers in the
>  > azureus debug output.  Azureus' calls to
>  > StackTraceElement.getLineNumber() always result in -1.  I have the
>  > azureus debug RPM installed, and just assumed that this would be enough
>  > to get line number info.  Maybe I'm misremembering all this.  Should
>  > StackTraceElement.getLineNumber() return good info for bc-compiled code?
>
> Yes, it should.  However, StackTraceElement.getLineNumber() doesn't
> work with separate debuginfo.
>   
We could also solve this by having the Java RPMs strip the rest of the 
debug info, but NOT the .debug_line section. .debug_line is quite 
compact compared to the rest of the debug info: it adds less than 1MB to 
libgcj.so. Is this extra size worth it to always have stack trace line 
numbers?

We would want to make sure that we have a fast line number lookup before 
doing that, though. Currently, line number lookups have a big negative 
performance impact on certain applications that log stack traces frequently.

Bryce