Re: [Netrexx-develop] interactive trace

[René J. <rvj...@xs...>]

Wow!

René.

> 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
>>> 
>>> 
>>> 
>>> 
>>> 
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