What Do You Think? JDK-8213084: Rework and enhance Print[Opto]Assembly output
Schmidt, Lutz
lutz.schmidt at sap.com
Fri Nov 30 16:13:16 UTC 2018
Sorry,
hit the wrong reply button. Wasn't meant to be hidden communication.
Regards,
Lutz
On 30.11.18, 15:51, "Schmidt, Lutz" <lutz.schmidt at sap.com> wrote:
Hi Andrew,
I assume you read my response to Andrew Haley as well. I will therefore
restrict my comments here on what to do if no hsdis.so is available.
I can't comment on your customers. Ours are extremely reluctant when it
comes to adding libraries of "unknown origin" to their landscape. For us
it boils down to getting a hex byte dump or nothing.
I agree, manually disassembling the hex dump isn't a sexy task. We have
a homegrown tool for that. It could be contributed to OpenJDK, but as a
separate enhancement.
Thank you,
Lutz
On 30.11.18, 11:30, "Andrew Dinn" <adinn at redhat.com> wrote:
I am entirely in agreement with Andrew Haley:
The blank lines in the original format are critical to conspicuity of
independent groups of information. Gestalt matters.
The additional detail (keywords, brackets offset, insn bytes) add almost
zero /useful/ information, effectively blotting the original signal with
noise.
Also, I'm also dubious over the utility of providing a hex byte dump of
the code when no hsdis.so is available. I say that having written a
simulator for AArch64 (including, therefore, a decode unit) and coded &
debugged a lot of AArch4 and x86 assembler and, occasionally, machine
code. So, I'm probably one of your most promising potential customers
for such a feature and I'm (at best) lukewarm.
I'll allow that there /may/ be situations where one could arrange for
PrintAsssembly to be enabled on a java command line but could not
arrange for an hsdis.so to be installed in the LD_LIBRARY_PATH yet I'm
struggling to think of one. Faced with the task of decoding the hex I'd
much rather spend time working on whatever problems were involved in
building and/or installing the library.
regards,
Andrew Dinn
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