RFR: 8244669: convert clhsdb "mem" command from javascript to java [v3]

[Serguei Spitsyn]

On Tue, 21 Dec 2021 19:58:53 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

>> clhsdb lost support for the "mem" command when javascript support was removed from SA. This PR is re-adding it by implementing it in Java. The description of the CR contains all the details.
>> 
>> Regarding the clhsdb.html changes for the "examine" command, they are just correctly specifying the existing syntax. No change was actually made to the syntax.
>> 
>> The changes made to the "examine" command are part of a consolidation effort to better share code between "examine" and "mem". "examine" has no functional changes.
>
> Chris Plummer has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Fix issue with address range patterns. For some reason they have always allowed some extra lower case letters at the end of the pattern that just get ignored. I removed support for this since sometimes it resulted in bad address ranges producing an exception rather than a usage() message.
>  - Fix missing return after calling usage()

src/jdk.hotspot.agent/doc/clhsdb.html line 54:

> 52:   dumpreplaydata <address> | -a | <thread_id> [>replay.txt] <font color="red">dump replay data into a file</font>
> 53:   echo [ true | false ] <font color="red">turn on/off command echo mode</font>
> 54:   examine { address[/count] | address,address } <font color="red">show contents of memory from given address</font>

It would cover both input variants if to say:
  "show contents of memory range"

src/jdk.hotspot.agent/doc/clhsdb.html line 70:

> 68:   livenmethods <font color="red">show all live nmethods</font>
> 69:   longConstant [ name [ value ] ] <font color="red">print out hotspot long constant(s)s</font>
> 70:   mem [ -v ] { address[/count] | address,address } <font color="red">show contents of memory. optionally include "findpc" info for addresses</font>

The same as above.

-------------

PR: https://git.openjdk.java.net/jdk/pull/6902