1. Layercake: From UNO code to Writer Core
Bjoern Michaelsen
Deputy Member, Board of Directors
The Document Foundation
Ubuntu LibreOffice package maintainer
Canonical

3. Interfaces, Services and Implementations
A quick race through some UNO concepts ...

4. Interfaces, Services and Implementations
Interfaces say what you can do with a UNO-thing
usually named com::sun::star...
and then a name prefixed with X
Services promise to provide a set of Interfaces
and then a name not prefixed with X
Implementations can provide a service or a set of Interfaces
usually named … inconsistently
have some some real core code behind it

5. XCargoStorage
XTransport

6. Lorry service
still abstract
implements XTransport and XCargoStorage

7. Lorry implementation concrete implements a service
has some real code behind it

8. UNO Runtime Reflection
How to find out what kind of UNO thing you are holding ...

9. XInterface

10. XServiceInfo

11. The css.script.theServiceDocumenter singleton
Getting to the UNO documentation from your extension or script quickly ...

12. TheServiceDocumenter.showServiceDocs(...)
void showServiceDocs( [in] com::sun::star::lang::XServiceInfo xService );
opens documentation for all services supported by this implementation in a browser

13. TheServiceDocumenter.showInterfaceDocs(...)
void showInterfaceDocs( [in] com::sun::star::lang::XTypeProvider xTypeProvider );
opens documentation for all interfaces (types) supported by this implementation in a browser

14. Example Ad-hoc StarBasic
TheServiceDocumenter =
GetDefaultContext().getValueByName(
"/singletons/com.sun.star.util.theServiceDocumenter")
' old style reflection helpers
MsgBox(TheServiceDocumenter.Dbg_Methods)
MsgBox(TheServiceDocumenter.Dbg_Properties)
MsgBox(TheServiceDocumenter.Dbg_SupportedInterfaces)
' using the Service Documenter
TheServiceDocumenter.showServiceDocs(ThisComponent)
'TheServiceDocumenter.showInterfaceDocs(ThisComponent)

15. Hard Things
There are two hard things in computer science: cache invalidation, naming things, and off-by-one errors.
– Phil Karlton

16. Interfaces, Services, UNO Wrappers and Core
Interfaces say what you can do with a UNO-thing
usually named com::sun::star...
and then a name prefixed with X
Services promise to provide a set of Interfaces
and then a name not prefixed with X
UNO Wrappers (implementations) can provide a service or a set of Interfaces
usually named … inconsistently
call real core code behind it
Core implementations do the real work and usually are older than UNO

17. Interfaces, Services, UNO Wrappers and Core
core implementation
UNO Wrapper
Interfaces and Services

18. Writer Python Tests Directory sw/qa/python has the tests
Makefile sw/PythonTest_sw_python triggers them
So, to trigger them manually: make PythonTest_sw_python

19. Debugging Python Tests: symbols
./autogen.sh --enable-symbols && make
make sw.clean && make sw DEBUG=T

20. Debugging Python Tests
Callgrinding tests:
VALGRIND=callgrind make PythonTest_sw_python
ls -lh ./workdir/PythonTest/sw_python/done.core/
callgrind_annotate $FILE \
--inclusive=yes \
--threshold=100 \
| grep sw/source/core/unocore \
| head -10
Debugging into tests:
CPPUNITTRACE="gdb --args" make PythonTest_sw_python

21. check_styles.py: callgrind
32,453,621 unostyle.cxx:sw::XStyleFamily::getByName(rtl::OUString const&) [libswlo.so]
23,155,924 unostyle.cxx:non-virtual thunk to sw::XStyleFamily::getByName(rtl::OUString const&) [libswlo.so]
11,395,863 unostyle.cxx:com::sun::star::uno::Reference<com::sun::star::style::XStyle> lcl_CreateStyle<(SfxStyleFamily)2>(SfxStyleSheetBasePool*, SwDocShell*, rtl::OUString const&) [libswlo.so]
11,132,842 unostyle.cxx:SwXStyle::SwXStyle(SfxStyleSheetBasePool*, SfxStyleFamily, SwDoc*, rtl::OUString const&) [libswlo.so]
10,673,960 unostyle.cxx:non-virtual thunk to sw::XStyleFamily::getElementNames() [libswlo.so]

22. check_styles.py: backtrace
(gdb) bt
#0 SwDocStyleSheet::PresetNameAndFamily (this=0x7fffe , rName=...) at
...sw/source/uibase/app/docstyle.cxx:2209
#1 0x00007fffdccad7f8 in SwStyleSheetIterator::Next (this=0x ) at
...sw/source/uibase/app/docstyle.cxx:3098
#2 0x00007fffdccad6df in SwStyleSheetIterator::First (this=0x ) at
...sw/source/uibase/app/docstyle.cxx:3087
#3 0x00007fffdca9da6d in sw::XStyleFamily::getElementNames (this=0x7fffd6da5998) at
...sw/source/core/unocore/unostyle.cxx:873
#4 0x00007ffff in gcc3::callVirtualMethod (pThis=0x7fffd6da59c0, nVtableIndex=6, pRegisterReturn=0x7fffffff1d40, pReturnTypeRef=0x862ed0, bSimpleReturn=false, pStack=0x7fffffff1ab0, nStack=0, pGPR=0x7fffffff1bd0, pFPR=0x7fffffff1c00) at
...bridges/source/cpp_uno/gcc3_linux_x86- 64/callvirtualmethod.cxx:133

24. Interfaces, Services, UNO Wrappers and Core
core implementation:
SwDocStyleSheet, SwStyleSheetIterator
UNO Wrapper:
SwXStyleFamily
Interfaces and Services:
com::sun::star::text::Text::ParagraphStyle

25. check_table.py: callgrind
118,911,501 unotbl.cxx:SwXTextTable::getData()
109,031,858 unotbl.cxx:SwXCellRange::getData()
107,979,526 unotext.cxx:SwXText::getString() [libswlo.so]
101,504,055 unotbl.cxx:SwXCell::getValue() [libswlo.so]
88,469,311 unoobj.cxx:SwXTextCursor::getString() [libswlo.so]

26. check_table.py: backtrace
#0 sw_GetTableBoxColStr (nCol=0, rNm=...) at
...sw/source/core/table/swtable.cxx:1793
#1 0x00007fffdc6e7526 in sw_GetCellName (nColumn=0, nRow=0) at
...sw/source/core/unocore/unotbl.cxx:522
#2 0x00007fffdc6e7955 in lcl_CreateXCell (pFormat=0x7fffd69cf000, nColumn=0, nRow=0) at
...sw/source/core/unocore/unotbl.cxx:584
#3 0x00007fffdc6f8846 in SwXCellRange::GetCells (this=0x7fffd69f4698) at
...sw/source/core/unocore/unotbl.cxx:3342
#4 0x00007fffdc570ccc in SwChartDataSequence::GetCells (this=0x7fffd ) at
...sw/source/core/unocore/unochart.cxx:2149
#5 0x00007fffdc5710af in SwChartDataSequence::getNumericalData (this=0x7fffd ) at
...sw/source/core/unocore/unochart.cxx:2184
#6 0x00007ffff in gcc3::callVirtualMethod (pThis=0x7fffd , nVtableIndex=3, pRegisterReturn=0x7fffffff1e60, pReturnTypeRef=0x , bSimpleReturn=false, pStack=0x7fffffff1bd0, nStack=0, pGPR=0x7fffffff1cf0, pFPR=0x7fffffff1d20) at
...bridges/source/cpp_uno/gcc3_linux_x86- 64/callvirtualmethod.cxx:133

28. Interfaces, Services, UNO Wrappers and Core
core implementation:
sw_GetTableBoxColString()
UNO Wrapper:
SwXCellRange
Interfaces and Services
Com::sun::star::text::XTextTable

29. Thank you!
@Sweet5hark
See you at the LibreOffice Conference in Brno 2016
Find out more at

30. Default Slide Example Here is space for your content … Some hints:
Use the master pages being the basis for the default slides
It would be useful to add your presentation title to the footer. Add it via Insert – Page Number … – Footer
Use the LibreOffice Color Palette delivered with LibreOffice (libreoffice.soc)

31. Pre-defined Shapes
Here are some pre-defined shapes for your convenience: copy the shapes, copy their formatting, or use the LibO styles.
Green Dark
Green Bright
You may add your code examples, XML statements, or debug output here ;-)
Blue Dark
Blue Bright
Orange Dark
Orange Bright
Purple Dark
Purple Bright
Yellow Dark
Yellow Bright

32. Section Header Example
You may add additional text here ...

34. XTypeProvider

35. WIP: using the css. script
WIP: using the css.script.theServiceDocumenter singleton for finding core implementations
Getting to the C++ documentation of your implementation from your extension or script quickly ...

36. clang, the Ultimate:
best solution: leak the information with a clang plugin triggering on getImplementationName(..)
There might be some cases where the implementation name is dynamically generated
That likely a bad idea anyway, so fix that then
(or worst case: fallback on the scripted solution via component files)

37. The old manual ways:
ad-hoc: Just search for the implementation name on
lots of clutter from testcode etc. though
somewhat more reliable: finding implementation in .component files, then find the implemenation in the cxx files of that library
best solution: leak the information with a clang plugin triggering on getImplementationName(..)

38. Example Ad-hoc StarBasic
TheServiceDocumenter =
GetDefaultContext().getValueByName(
"/singletons/com.sun.star.util.theServiceDocumenter")
' old style reflection helpers
MsgBox(TheServiceDocumenter.Dbg_Methods)
MsgBox(TheServiceDocumenter.Dbg_Properties)
MsgBox(TheServiceDocumenter.Dbg_SupportedInterfaces)
' using the Service Documenter
TheServiceDocumenter.CoreBaseUrl =
"
TheServiceDocumenter.showCoreDocs(ThisComponent)
WIP: only works for SwXTextDocument for now
Opens

39. Finding implementation via .component files
for f in `git ls-tree -r --name-only HEAD|grep '.component$'` do
grep 'implementation name' $f|nl -s ",$f,"
done > componentgrep.csv
In the second row, we then find the path of the component file
In the third row, we then find the implemenation name
thus we can find the ${module}/Library_${libname}.mk for each implementation and the cxx files where it could be implemented f

40. How should the Core Documentation Reference work in the end?
It just opens
“{$CoreBaseUrl}/{$ImplementationName}”
in a browser
and the URLs at ${CoreBaseUrl} are just statically generated redirects to
(possibly we could also link to github or opengrok) later