Re: [Netrexx-develop] interactive trace

[Rony G. F. <Ron...@wu...>]

On 17.06.2022 18:20, René Jansen wrote:
> Wow!

+1

Very nice!

---rony

>> On 17 Jun 2022, at 16:38, Marc Remes <re...@gm...> wrote:
>>
>> Latest push fixes access to properties
>>
>>> On 6/17/22 10:49, Marc Remes wrote:
>>> I've updated branch interactive-trace.
>>> You now have access to method variables and arguments, you can view or modify their values. Accessing properties still throws an exception.
>>> On the interactive trace *-> prompt you can now:
>>>    press [Enter] to trace interactively
>>>    type '=' to reinterpret current clause
>>>    type '-[n]' to show previous n clause(s), shows current clause if n is absent
>>>    type '+[n]' to show next n clause(s), shows next clause if n is absent
>>>    type 'trace off' to stop tracing
>>>    any other clause entered must be either an assignment or a SAY instruction
>>> I've turned away of touching existing code as much as possible, so albeit experimental, impact on existing code is limited to nonexistent.
>>> A sample run :
>>> <<
>>> $ cat trace.nrx
>>> class trace
>>>    method main(args=String[]) static
>>>      say 'interactively tracing..'
>>>      trace int
>>>      i=0
>>>      say 'i='i
>>>      do
>>>        say 'Hello world'||'!'.copies(i)
>>>      end
>>>      trace off
>>>      x=traces(9)
>>>      say 'x:'x
>>>      xx=traced(9)
>>>      say 'xx.prop:'xx.prop
>>>      loop while i < 5
>>>        trace int
>>>        i=i+1
>>>        say 'i='i
>>>        say 'Hello world'||'!'.copies(i)
>>>      end
>>>    method traces(arg=Rexx) static
>>>      trace int
>>>      say 'method traced called'
>>>      say 'traced:'arg
>>>      return arg
>>> class traced
>>>    properties public
>>>    prop = 9
>>>    method traced(arg=Rexx)
>>>      trace int
>>>      say 'prop:'prop
>>>      say 'class traced constructed'
>>>      say 'traced:'arg
>>> $ nrc -exec trace
>>> NetRexx portable processor 4.04-alpha build 1,558-20220616-1912
>>> Copyright (c) RexxLA, 2011,2022.   All rights reserved.
>>> Parts Copyright (c) IBM Corporation, 1995,2008.
>>> Program trace.nrx
>>>    === class trace ===
>>>      function main(String[])
>>>      function traces(Rexx)
>>>    === class traced ===
>>>      constructor traced(Rexx)
>>> ===== Exec: trace =====
>>> interactively tracing..
>>>      *->
>>>      --- trace.nrx
>>>    6 *=*     i=0
>>>      >v> i "0"
>>>      *-> say i
>>> 0
>>>      *-> i=3
>>>      *-> say i
>>> 3
>>>      *->
>>>    7 *=*     say 'i='i
>>>      >>> "i=3"
>>> i=3
>>>      *->
>>>    8 *=*     do
>>>      *->
>>>    9 *=*       say 'Hello world'||'!'.copies(i)
>>>      >>> "3"
>>>      >>> "Hello world!!!"
>>> Hello world!!!
>>>      *->
>>>   10 *=*     end
>>>      *->
>>>   11 *=*     trace off
>>>      *->
>>>   25 *=*     say 'method traced called'
>>>      >>> "method traced called"
>>> method traced called
>>>      *-> -3
>>> method traces(arg=Rexx) static
>>> trace int
>>> say "method traced called"
>>>      *-> say arg
>>> 9
>>>      *-> arg=8
>>>      *->
>>>   26 *=*     say 'traced:'arg
>>>      >>> "traced:8"
>>> traced:8
>>>      *->
>>>   27 *=*     return arg
>>>      >>> "8"
>>>      *->
>>> x:8
>>>      *->
>>>   35 *=*     say 'prop:'prop
>>>      >>> "prop:9"
>>> prop:9
>>>      *->
>>>   36 *=*     say 'class traced constructed'
>>>      >>> "class traced constructed"
>>> class traced constructed
>>>      *-> -3
>>> trace int
>>> say "prop:"prop
>>> say "class traced constructed"
>>>      *-> -5
>>> prop=9
>>> method traced(arg=Rexx)
>>> trace int
>>> say "prop:"prop
>>> say "class traced constructed"
>>>      *-> say arg
>>> 9
>>>      *-> arg=8
>>>      *-> say arg
>>> 8
>>>      *->
>>>   37 *=*     say 'traced:'arg
>>>      >>> "traced:8"
>>> traced:8
>>>      *->
>>> xx.prop:9
>>>      *->
>>>   18 *=*       i=i+1
>>>      >v> i "4"
>>>      *->
>>>   19 *=*       say 'i='i
>>>      >>> "i=4"
>>> i=4
>>>      *-> trace off
>>> Hello world!!!!
>>>      *->
>>>   18 *=*       i=i+1
>>>      >v> i "5"
>>>      *->
>>>   19 *=*       say 'i='i
>>>      >>> "i=5"
>>> i=5
>>>      *->
>>>   20 *=*       say 'Hello world'||'!'.copies(i)
>>>      >>> "5"
>>>      >>> "Hello world!!!!!"
>>> Hello world!!!!!
>>>      *->
>>>   16 *=*     loop while i < 5
>>>      >>> "0"
>>>      *->
>>>   21 *=*     end
>>>      *->
>>> Processing of 'trace.nrx' complete [2 classes]
>>> Please test;
>>> Marc
>>>> On 6/7/22 13:42, Marc Remes wrote:
>>>> I've submitted branch interactive-trace, an *experimental* *experiment* to mimic Classic Rexx interactive trace capabilities.
>>>>
>>>> The new 'TRACE INT' instruction will intercept and pause execution during interpretation and present a '*->' prompt to the user.
>>>> Pressing [Enter] will interpret next clause
>>>> Typing '=' will reinterpret current clause
>>>> Typing '?' will show usage
>>>> Typing 'TRACE OFF' will stop interactive trace and will continue normally with next clause
>>>> Typing anything else is currently 'not supported'.
>>>>
>>>> TRACE INT is only active when interpreting NetRexx code, otherwise a warning 'TRACE INT ignored when compiling' is shown.
>>>>
>>>> An example:
>>>> <<
>>>> $ cat trace.nrx
>>>>
>>>> class trace
>>>>
>>>>      method main(args=String[]) static
>>>>        say 'interactively tracing..'
>>>>        trace int
>>>>        i=0
>>>>        say 'i='i
>>>>        do
>>>>          say 'Hello world'||'!'.copies(i)
>>>>        end
>>>>        trace off
>>>>        loop while i < 5
>>>>          trace int
>>>>          i=i+1
>>>>          say 'i='i
>>>>          say 'Hello world'||'!'.copies(i)
>>>>        end
>>>> Sample run:
>>>> <<
>>>> $ nrc -exec trace
>>>> NetRexx portable processor 4.04-alpha build 1,400-20220530-2046
>>>> Copyright (c) RexxLA, 2011,2022.   All rights reserved.
>>>> Parts Copyright (c) IBM Corporation, 1995,2008.
>>>> Program trace.nrx
>>>>      === class trace ===
>>>>        function main(String[])
>>>> ===== Exec: trace =====
>>>> interactively tracing..
>>>>     *->
>>>>        --- trace.nrx
>>>>      6 *=*     i=0
>>>>        >v> i "0"
>>>>     *->
>>>>      7 *=*     say 'i='i
>>>>        >>> "i=0"
>>>> i=0
>>>>     *-> trace off
>>>> Hello world
>>>>     *->
>>>>     14 *=*       i=i+1
>>>>        >v> i "1"
>>>>     *-> trace off
>>>> i=1
>>>> Hello world!
>>>>     *->
>>>>     14 *=*       i=i+1
>>>>        >v> i "2"
>>>>     *-> =
>>>>        *=*       i=i+1
>>>>        >v> i "3"
>>>>     *->
>>>>     15 *=*       say 'i='i
>>>>        >>> "i=3"
>>>> i=3
>>>>     *->
>>>>     16 *=*       say 'Hello world'||'!'.copies(i)
>>>>        >>> "3"
>>>>        >>> "Hello world!!!"
>>>> Hello world!!!
>>>>     *->
>>>>     12 *=*     loop while i < 5
>>>>        >>> "1"
>>>>     *-> trace off
>>>>     *->
>>>>     14 *=*       i=i+1
>>>>        >v> i "4"
>>>>     *-> trace off
>>>> i=4
>>>> Hello world!!!!
>>>>     *-> trace off
>>>> i=5
>>>> Hello world!!!!!
>>>> Processing of 'trace.nrx' complete
>>>> Do not reinterprete a clause that changes 'level' depth:
>>>> <<
>>>> $ nrc -exec trace
>>>> NetRexx portable processor 4.04-alpha build 1,400-20220530-2046
>>>> Copyright (c) RexxLA, 2011,2022.   All rights reserved.
>>>> Parts Copyright (c) IBM Corporation, 1995,2008.
>>>> Program trace.nrx
>>>>      === class trace ===
>>>>        function main(String[])
>>>> ===== Exec: trace =====
>>>> interactively tracing..
>>>>     *->
>>>>        --- trace.nrx
>>>>      6 *=*     i=0
>>>>        >v> i "0"
>>>>     *->
>>>>      7 *=*     say 'i='i
>>>>        >>> "i=0"
>>>> i=0
>>>>     *->
>>>>      8 *=*     do
>>>>     *->
>>>>      9 *=*       say 'Hello world'||'!'.copies(i)
>>>>        >>> "0"
>>>>        >>> "Hello world"
>>>> Hello world
>>>>     *->
>>>>     10 *=*     end
>>>>     *-> =
>>>>        *=*     end
>>>>     *-> =
>>>>        *=*     end
>>>> Exception in thread "main" java.lang.NullPointerException: Cannot read field "prev" because "<parameter1>.curlevel" is null
>>>>       at org.netrexx.process.RxInterpreter.poplevel(RxInterpreter.java:1590)
>>>>       at org.netrexx.process.NrEnd.interpret(NrEnd.java:174)
>>>>       at org.netrexx.process.RxInterpreter.runfree(RxInterpreter.java:1314)
>>>>       at org.netrexx.process.RxInterpreter.callMethod(RxInterpreter.java:1180)
>>>>       at org.netrexx.process.RxInterpreter.callMethod(RxInterpreter.java:835)
>>>>       at org.netrexx.process.RxTranslator.exec(RxTranslator.java:791)
>>>>       at org.netrexx.process.NetRexxC.process(NetRexxC.java:536)
>>>>       at org.netrexx.process.NetRexxC.main2(NetRexxC.java:345)
>>>>       at org.netrexx.process.NetRexxC.main2(NetRexxC.java:324)
>>>>       at org.netrexx.process.NetRexxC.main2(NetRexxC.java:320)
>>>>       at org.netrexx.process.NetRexxC.main(NetRexxC.java:174)
>>>> As such, the code is to be considered experimental..
>>>>
>>>> Pressing [Enter] without interfering with execution should not have other impact than 'pausing' execution.
>>>>
>>>> Obviously, 'not supported' should be replaced by interpreting the provided 'trace' clause in the context of the current program with access to the current varpool.
>>>> Unfortunately, this is not trivial, at least with my understanding of Mike's code.
>>>>
>>>> Marc
>>>>
>>>>
>>>>