bugGNU Octave - Bugs: bug #50312, dbstep fails when combined with...


bug #50312: dbstep fails when combined with another command: "dbstep; cmd2"

Submitted by:  nicodemus <nicmus>
Submitted on:  Wed 15 Feb 2017 10:59:15 AM UTC  
Category: InterpreterSeverity: 2 - Minor
Priority: 3 - LowItem Group: Incorrect Result
Status: ConfirmedAssigned to: None
Originator Name: Open/Closed: Open
Release: 4.2.0Operating System: GNU/Linux

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Thu 16 Feb 2017 05:24:19 PM UTC, comment #2:

Changing the priority to Low. The debug path is only occasionally used so it makes more sense to spend time fixing bugs on the default execution path. And there is an easy workaround of using just one dbnext command per line.

When it comes to debugging this, the issue is the dbnext command itself. It wants to stop after every single command execution.

For example,

As you can see, the debugger stops in the middle of the pipeline "cmd1; cmd2". If I use dbnext once more in this intermediate context then it executes cmd2 (sin (1)) and then line 3 from the script.

Obviously the Octave parser is confused about what stack frame it is located in. If I use the command "dbnext; dbnext" you might think that from the example above it would halt after the first "dbnext", and that typing "dbnext" would cause it to execute the second half. Instead, there is as an error issued.

Rik <rik5>
Project Administrator
Wed 15 Feb 2017 05:48:52 PM UTC, comment #1:

Confirmed here when using dbstep on the same line as another debug command. This goes back to at least version 3.8, this is not a recent change.

Easy workaround is to not use more than one debugging command per entry at the debug prompt.

Mike Miller <mtmiller>
Project Administrator
Wed 15 Feb 2017 10:59:15 AM UTC, original submission:

Hi when I run the debug octave --no-gui console a strange behaviour shows up by concatanating dbstep and other commands.

Here is an example which best explain the problem

nicodemus <nicmus>


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    Follow 5 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Thu 16 Feb 2017 05:25:35 PM UTCrik5Summarydebug: combining dbstep and dblist=>dbstep fails when combined with another command: "dbstep; cmd2"
    Thu 16 Feb 2017 05:24:19 PM UTCrik5Severity3 - Normal=>2 - Minor
      Priority5 - Normal=>3 - Low
    Wed 15 Feb 2017 05:48:52 PM UTCmtmillerItem GroupSegfault, Bus Error, etc.=>Incorrect Result

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