trace log build option

[David Mathog]

Working in mingw I am finding it almost impossible to trace the execution within Inkscape. For instance, if it is run in GDB
and an exception occurs a backtrace will typically show a few steps, but no module names, not even mangled ones. (Yes, gdb
was run with: file inkscape.exe inkscape.dbg).

Working this way in Mingw is pretty much the worst development environment I have ever had to deal with. It would be immensely helpful if there was a build option that implemented the following:

1. TRACELOG=""
(This is the default, no trace logging. However, if it is set to something, like "C:\TEMP\inktrace.log" then wherever main/initialization that file is opened.)

2. In every method/function:

void Objectname::Methodname
...
#ifdef TRACELOG tlog << "TRACE: Objectname::Methodname" << std::endl

With that I could keep one copy with trace enabled, for development, and another copy with it disabled, for testing/normal use. That would save having to recompile everything when a trace is needed, and it would skip the overhead of doing this via something like:

  if(global_trace){ tlog << "TRACE: Objectname::Methodname" << std::endl; }

The way I have been dealing with this issue so far has been find a problem, search all of the source code for locations that might call the method/function, put print statements in all of them, rinse and repeat. There have been cases where I could not figure out the path to an execution point, probably because it passed through some external library. (Most recently, Layout::print in layout-TNG-Output.cpp seems only to be called on EMF output, not ps, pdf, or cairo-png, but I could not determine why, since I did not find the caller.) This would at least show me the path above and below such "outside the debuggable arena" paths.

[Kris (kris-degussem)]

Is this a windows/win32 specific issue?
I would consider it a more general, that is a multi-platform request to be able to log function calls ...

As a side note: when debugging some functionality I'm working on, I use temporary g_message calls to see which step is failing as an alternative to the wishlist item described here.

[David Mathog (mathog)]

I think the development environments on Mac or Linux nay already have a satisfactory trace function like this. If not, then it is not Win32 specific.

I also use (the equivalent of) g_message calls for debugging, but those are not of much help if you don't already know where to put them in.

[[e-mail] (movgp0)]

I think there should be no trace build option. instead, tracing and logging should be enabled and disabled via a config file.

also, the output should be put onto the console and into a log file. ideally it would be configurable what to log where in an XML file.