Hi Wim, After reviewing your comments, I propose to check out rootcling. I initially had some trouble using pip3 to install the newer code, but that seems to have been resolved as of yesterday's 0.2.3 build. I did notice one message during the install which seems to be benign, so I mention it here merely in passing:
Running command /usr/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-spz01kkp/cppyy-backend/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d /tmp/tmpe2h6yls0pip-wheel- --python-tag cp36 running bdist_wheel running build running build_ext error: [Errno 2] No such file or directory: 'cling-config': 'cling-config' error Failed building wheel for cppyy-backend Running setup.py clean for cppyy-backend I'll no doubt be back with questions :-). Thanks for all the good work, Shaheed On 23 September 2017 at 06:24, Shaheed Haque <srha...@theiet.org> wrote: > Wim, > > Thanks for the detailed and thoughtful reply. I will digest and > respond when I am properly back in circulation. > > On 15 September 2017 at 07:43, <wlavrij...@lbl.gov> wrote: >> Shaheed, >> >>> Ah, I had not realised rootcling existed. I've seen that I can invoke >>> it using Python version-specific paths...is this the correct way to >>> invoke it: >>> >>> ROOTCLING=/usr/local/lib/python3.6/dist-packages/cppyy_backend >>> LD_LIBRARY_PATH=$ROOTCLING/lib $ROOTCLING/bin/rootcling -h >> >> >> Yes, and here's a description of the LinkDef.h format: >> >> >> https://root.cern.ch/root/html/guides/users-guide/AddingaClass.html#the-linkdef.h-file >> >>> or is there a recommended wrapper? >> >> >> No, but I'm going to add one for pip, same as I did for genreflex. I've >> been fleshing out the backend generation, taken over from Anto: >> >> https://bitbucket.org/wlav/cppyy-backend >> >> where all that can live. I'm told that I'll need rootcling anyway for >> use of modules (see below). >> >>> I actually get some warnings and then the error: >> >> >> Add this set of exclusions to the selection.xml: >> >> <exclusion> >> <class pattern="*thread_mutex*" /> >> <class pattern="*new_allocator*" /> >> <class pattern="*Alloc_hider*" /> >> </exclusion> >> >> Of course, the larger problem of pulling in these standard libs over and >> over again is that it is a waste of cpu and memory, so I do want to see >> the file_name attribute fixed. As it stands, I'd simply exclude: >> >> <class pattern="std::*" /> >> <class pattern="__gnu_cxx::*" /> >> >> especially since they are already available by default. Note that those two >> rules cover the ones needed for new_allocator and Alloc_hider. >> >> However, there is a more efficient approach that is right around the corner >> (and has been right about the corner for a long time, so don't hold me to >> that). Next release now seems likely though. >> >> The long term goal has always been to use modules: >> >> http://clang.llvm.org/docs/Modules.html >> >> but the original drivers (Apple, Google, and the C++ standards committee) >> have been going back and forth on it. Now, things are finally falling into >> place. Here's Google: >> >> https://www.youtube.com/watch?v=dHFNpBfemDI >> >> And here's ROOT: >> >> >> https://indico.cern.ch/event/643728/contributions/2612822/attachments/1494074/2323893/ROOTs_C_modules_status_report.pdf >> >> The big deal is that C++ developers have an incentive to deploy modules, so >> being able to patch into that should be a huge time saver (and where they >> don't, rootcling will soon be able to create modules from headers). Note >> that modules don't come for free: it will require some ambiguity resolution, >> but that is typically a Good Thing (code-quality wise). >> >> Modules allow deserialization of only the piece of the AST that is actually >> being requested, saving memory. This as opposed to header files (whether or >> not precompiled) which pull in everything before them. See the status report >> above for the improvements in memory usage. >> >> And with modules, of course, selection becomes unnecessary (markup for >> automatic streamers may still be useful, but that is not relevant for >> bindings generation). >> >>> I did wonder if I was missing some "-isystem" includes, and tried >>> adding them but the --debug output from genreflex seemed to suggest >>> they were being ignored. >> >> >> Some flags are ignored as no-one was using them (so far). Some others >> are definitely obsolete by now. >> >>> What is interesting, and might possibly throw light on the selection >>> filter issue, is that the file name for the classes in >>> kjsinterpreter.h itself is always the empty string ''. Classes that >>> come from included files return non-empty strings such as >>> 'kjsobject.h' for 'KJSObject'. >> >> >> That's after the fact (i.e. what is stored); I don't see the rule being >> respected/used at all. >> >>> BTW, the reason for doing this is that lots of KDE code has multiple >>> classes and even namespaces in a single header file. Now, for >>> discoverability of the loaded objects, I find the incremental "pop >>> into cppyy,gbl on demand" somewhat limiting and I wanted to play about >>> with that. I could also workaround the filter issue if I precomputed >>> the needed names in a precursor pass. >> >> >> The issue here is the memory cost of loading things that won't get used >> in the end. This is why a functional dir() (which needs nothing but >> strings, after all), in conjunction with lazy loading/creation when a >> real access happens work well. LLVM is fully lookup based, btw. There >> is a custom layer on top of Cling to make enumeration possible. >> >>> Finally, and most importantly given the fidelity with which cppyy >>> renders the C++ code, I'm think about how Pythonisation customisation >>> might be handled: e.g. a Python wrapper layer to allow a >>> pointer-plus-size to render as a Python list/tuple, or generate a dict >>> mapping fora QSet, and so on. (I'm dimly aware of the >>> boost-recognition logic you have alluded to, this is specifically more >>> about Qt-specific patterns and ad-hoc scenarios). >> >> >> In 2015, a GSoC student fleshed this out. I never put it into PyPy b/c of >> a lack of test coverage, but did put in in PyROOT. Here's an example of >> the "pointer-plus-size" pythonization (from ROOT.py): >> >> # python side pythonizations (should live in their own file, if we get >> many) >> def set_size(self, buf): >> buf.SetSize(self.GetN()) >> return buf >> >> # TODO: add pythonization API to pypy-c >> if not PYPY_CPPYY_COMPATIBILITY_FIXME: >> cppyy.add_pythonization( >> cppyy.compose_method("^TGraph(2D)?$|^TGraph.*Errors$", >> "GetE?[XYZ]$", set_size)) >> >> The functions selected by the regexps return naked pointers, but the object >> can be queried for the size (all have a consistent GetN() function). So the >> method composer patches up the return value, making it a sized array, >> instead of an "open-ended" one. >> >> I'm sitting on some patches as I wanted to tweak his APIs a bit. There >> was some ordering that I felt didn't compose well, but that is minor. >> >> Similarly, there's code to apply ownership rules, mapping exceptions, >> the new C++11 smartptrs, controlling auto-casting, handling the GIL, making >> properties, and adding overloads. All driven by regexp matching of patterns. >> See here: >> >> >> https://bitbucket.org/wlav/cppyy/src/4d14ba325e494f13cc11f3f11cbb87b44048b256/python/cppyy/_pythonization.py?at=master >> >> (plus further support inside the bindings layer itself). >> >> Of course, one can hook up completely custom functions, and he made it so >> that that is per C++ namespace, so nicely self-contained. >> >> Again, this is currently only partly available, as I need to write a lot >> more tests for PyPy (which are bound to unearth some problems along the >> way). And then there is documentation to be written ... >> >>> P.S. Please note that after today, I'll likely not have much Internet >>> access for a couple of weeks, so any responses may be limited. >> >> >> I'll make sure I have at least all my local changes pushed by then. :) >> >> >> Best regards, >> Wim >> -- >> wlavrij...@lbl.gov -- +1 (510) 486 6411 -- www.lavrijsen.net _______________________________________________ pypy-dev mailing list pypy-dev@python.org https://mail.python.org/mailman/listinfo/pypy-dev