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Re: SIGTRAP crash with ngspice


The issue was discussed here:


If you tell me what my "coding policy errors" are, or point me to something I should read, then I can do better next time.

I've attached a new copy of the patch - the code change is identical, the only difference is that it has the commit message prepended.


On 1/14/19 12:50 PM, Wayne Stambaugh wrote:
> Steve,
> Please include the bug report link so I can link the patch to the bug
> report.  I'll fix the coding policy errors since I'm assuming this is as
> one a done patch for you.
> Tom or Orson,
> Any objections to this patch.  I didn't test it but on the surface it
> appears to resolve the issue.
> Cheers,
> Wayne
> On 1/14/2019 10:30 AM, Steven A. Falco wrote:
>> I wanted to close the loop on the SIGTRAP crash that I reported a few days ago.
>> The issue is probably unique to Fedora, and stems from a huge quantity of "percent complete" messages that the ngspice library passes back to KiCad.  I'm not kidding when I say huge - it amounts to over 1 megabyte of text, including many backspace characters.  When I try to select the text, it probably blows up the clipboard and causes the crash.
>> The ideal fix will be to have the Fedora ngspice maintainer remove a flag, which in turn will disable the "percent complete" messages.
>> In the interim, I have a patch that filters out any line containing a string of backspaces.  I don't know if there is any interest in applying this patch to the official KiCad sources, but I've attached it here in case there is interest.  I see it as defensive programming. :-)
>> I'll wait a bit to see what happens with the ngspice library.  If it looks like there will be a substantial delay in having the flag removed, I can always apply my patch and push that as the next official Fedora build.
>> 	Steve
>> On 1/11/19 2:25 PM, Steven A. Falco wrote:
>>> On 1/11/19 1:51 PM, Steven A. Falco wrote:
>>>> On 1/11/19 1:21 PM, Seth Hillbrand wrote:
>>>>> Am 2019-01-11 12:18, schrieb Steven A. Falco:
>>>>>> I tried another ngspice experiment.  I ran a simulation, and it
>>>>>> worked, albeit with the data size warning I asked about earlier.  So
>>>>>> far so good.
>>>>> That warning was saying that it ran out of memory and had overwritten unplanned space.  I would expect a crash after that.  I'm not sure that KiCad can trap that kind of error as it occurred inside the library.
>>>> Ok, but I'm concerned about the bug reports I'll get if I were to enable ngspice and push the build to the Fedora community.
>>>> I'll wait to see if the forum has any thoughts on the warning.  I'll only enable ngspice in the official Fedora builds if I can get to where the examples run cleanly.
>>> I saved the netlist from the simple example I've been running:
>>> .title KiCad schematic
>>> V101 in 0 PULSE (0 5 1u 1u 1u 1 1)
>>> C101 Net-_C101-Pad1_ 0 1u
>>> C102 out 0 100n
>>> R101 Net-_C101-Pad1_ in 10k
>>> R102 out Net-_C101-Pad1_ 1k
>>> .save @v101[i]
>>> .save @c101[i]
>>> .save @c102[i]
>>> .save @r101[i]
>>> .save @r102[i]
>>> .save V(0)
>>> .save V(GND)
>>> .save V(Net-_C101-Pad1_)
>>> .save V(in)
>>> .save V(out)
>>> .tran 1u 100m
>>> .end
>>> When I run this circuit in stand-alone ngspice, it does a lot of overprinting, apparently to indicate the run-time of the job.  Here is a small example of the character stream, where there are tons of backspaces as part of the overprinting:
>>> saf$ od -c foo
>>> 0000000   %   0   .   0   0  \b  \b  \b  \b  \b   %   0   .   0   0  \b
>>> 0000020  \b  \b  \b  \b   %   0   .   0   0  \b  \b  \b  \b  \b   %   0
>>> 0000040   .   0   0  \b  \b  \b  \n
>>> 0000047
>>> The stand-alone captured output from this simple circuit is around 1 Mbyte!  I'm guessing that this huge amount of data is blowing up the window and showing all of the strange characters.
>>> I'm not sure of the division of labor here.  Is that something that a KiCad developer should address, or is it a library issue?  Hopefully there is a flag that can be passed to the library to suppress the overprinted text.
>>> 	Steve
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>From d8d2b70eab51656a8805461f3a8c8fd207519e86 Mon Sep 17 00:00:00 2001
From: "Steven A. Falco" <stevenfalco@xxxxxxxxx>
Date: Mon, 14 Jan 2019 10:39:17 -0500
Subject: [PATCH] Filter out ngspice status lines containing backspaces.

The ngspice library can output "percent complete" status lines, and the
amount of status produced can exceed 1 megabyte.  Those lines contain
embedded backspaces, and don't print correctly.  Therefore, we filter
them out.
 eeschema/sim/sim_plot_frame.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/eeschema/sim/sim_plot_frame.cpp b/eeschema/sim/sim_plot_frame.cpp
index 3812d0c3b..aa1d6b465 100644
--- a/eeschema/sim/sim_plot_frame.cpp
+++ b/eeschema/sim/sim_plot_frame.cpp
@@ -1282,8 +1282,14 @@ void SIM_PLOT_FRAME::onSimUpdate( wxCommandEvent& aEvent )
 void SIM_PLOT_FRAME::onSimReport( wxCommandEvent& aEvent )
-    m_simConsole->AppendText( aEvent.GetString() + "\n" );
-    m_simConsole->SetInsertionPointEnd();
+    wxString t = aEvent.GetString();
+    // Toss any text with a string of embedded backspaces, as these are
+    // progress status lines that don't print properly.
+    if( t.find("\b\b\b") == wxString::npos ) {
+        m_simConsole->AppendText( t + "\n" );
+        m_simConsole->SetInsertionPointEnd();
+    }

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