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linuxcode-analysislibreofficecall-graphcallgrind

LibreOffice: determine source code part responsible for printing

I am trying to implement some additional functionality to the LibreOffice printing process (some special info should be added automatically to the margins of every printed page). I am using RHEL 6.4 with LibreOffice 4.0.4 and Gnome 2.28.

My purpose is to research the data flow between LibreOffice and system components and determine which source codes are responsible for printing. After that I will have to modify these parts of code.

Now I need an advice on the methods of source code research. I found a plenty of tools and from my point of view:

  1. strace seem to be very low-level;
  2. gprof requires binaries recompiled with "-pg" CFLAGS; have no idea how to do it with LibreOffice;
  3. systemtap can probe syscalls only, isn't it?
  4. callgrind + Gprof2Dot are quite good together but perform strange results (see below);

For instance here is the call graph from callgrind output with Gprof2Dot visualisation. I started callgrind with such a command:

valgrind --tool=callgrind --dump-instr=yes --simulate-cache=yes --collect-jumps=yes /usr/lib64/libreoffice/program/soffice --writer

and received four output files:

-rw-------.   1 root  root          0 Jan  9 21:04 callgrind.out.29808
-rw-------.   1 root  root     427196 Jan  9 21:04 callgrind.out.29809
-rw-------.   1 root  root     482134 Jan  9 21:04 callgrind.out.29811
-rw-------.   1 root  root     521713 Jan  9 21:04 callgrind.out.29812

The last one (pid 29812) corresponds to the running LibreOffice Writer GUI application (i determined it with strace and ps aux). I pressed CTRL+P and OK button. Then I closed the application hoping to see the function responsible for printing process initialisation in logs.

The callgrind output was processed with a Gprof2Dot tool according to this answer. Unfortunately, I cannot see on the picture neither the actions I am interested in, nor the call graph as is.

I will appreciate for any info about the proper way of resolving such a problem. Thank you.

enter image description here

Solution

  • The proper way of solving this problem is remembering that LibreOffice is open source. The whole source code is documented and you can browse documentation at docs.libreoffice.org. Don't do that the hard way :)

    Besides, remember that the printer setup dialog is not LibreOffice-specific, rather, it is provided by the OS.