Online Developer Meeting (2021-10-26)
- Date: Tuesday, October 26, 2021 @ 18:00 UTC
- Location: https://meet.jit.si/octave-dev-2021-10-26
- Meet and greet 5 minutes before meeting (audio testing).
Progress of Octave 6.4.0 release
- State of OpenBLAS compilation bug(?): bug #61246: matrix inversions give wrong results (inv, lu, mldivide)
pkg test sparsersbcrashes Octave (only when installed to read-only directory?). Needs further investigation.
- Which version numbers to update in which files on (minor) release? (CITATION file?)
- Update of merge date for Octave 7.x?
Importance of allowing Octave headers in C language sources
Some header files in Octave have been written to allow them to be compiled by a C compiler. It is not clear whether anyone really needs to do that and it adds somewhat to the cost of maintaining Octave to ensure that this goal is met, even for just a few of the public header files. Would it be OK to change Octave so that public header files require a C++ compiler? And would it be OK to make this change in version 7 without deprecating and preserving the current coding style for two release cycles?
See bug report 61370 and also comments 39 and 40 in this discourse discussion for some motivating examples of cases where it might be simpler to expect that Octave header files will be compiled by a C++ compiler.
P_OVERLAY works differently on POSIX and Windows
(Only if there is nothing else to talk about.)
Markus' current understanding:
P_OVERLAYreplaces the current process with a new one. On POSIX, another process waiting for the original process (like a terminal) will wait for the replacing process instead.
- On Windows,
P_OVERLAYalso replaces the current process. But each process has a distinct id on Windows. I.e., the new process gets a different process id from the original one. Another process (like a terminal) waiting for the original process id will resume once the original process terminates. (The same happens with
exec.) That leads to issues when trying to use the
octave.exewrapper on Windows.
- Could we use
P_WAITinstead? IIUC, that would require passing the return code from the spawned process. What else?
- [jwe] We have too many different ways of starting and interacting with subprocesses (popen, popen2, system, spawn, procbuf, procstream, etc.). Is it possible to use just one C++ function to provide all the public functions we need to support?
- The following items were not discussed. Just some links to progress on those items are displayed.
- Last(?) Octave 6 release?
- Background: 12 changes on the stable branch (~10 on the release branch of MXE Octave) since the last release. Most important ones:
- Octave GUI doesn't start for some Windows users. Bug in Qt 5.14 that is fixed in Qt 5.15.
- Crash to desktop fixed in Octave core (bug #61191).
- Crash to desktop fixed in librsb (bug #60042, only affects Windows bundle).
- Command line arguments with parameters (e.g.
--path) can't be combined with
- Ask on discourse for pending changes and do a new release.
Approximate release date for Octave 7?
- Last few cycles: merge to stable and release date of first stable version:
- 6.x: merge to stable: 2020-02-17 --- release: 2020-11-26 (~ 9.5 month)
- 5.x: merge to stable: 2018-12-20 --- release: 2019-02-23 (~ 2 month)
- 4.4.x: merge to stable: 2018-04-04 --- release: 2018-04-30 (< 1 month)
- 4.2.x: merge to stable: 2016-09-28 --- release: 2016-11-13 (~ 1.5 month)
- Unfinished projects:
- Symbol visibility breaks tests for indexing expressions on macOS. Also many linker warnings similar to this (see bug #59820):
ld: warning: direct access in function 'conv_to_int_array(Array<octave::idx_vector> const&)' from file 'liboctave/array/.libs/libarray.a(libarray_la-Array-util.o)' to global weak symbol 'vtable for Array<long long>' from file 'liboctave/array/.libs/libarray.a(libarray_la-Array-i.o)' means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.
- Support paths including spaces (mostly for Windows - not relying on short file names). What about package Makefiles? Probably best if we defer that one to later.
- more efficient mex file interface with direct pointers to data in Octave arrays (jwe)
- Prefer OCTAVE_LOCAL_BUFFER over Array objects where possible (Rik, not a blocker)
- Probably merge default to stable some time in November
- Probably release Octave 7 around the end of this year or early 2022.
CamelCase in Octave functions?
- What is our current stance on that? --> Avoid it for consistency. Allowed for compatibility.
Octave released on MSYS2
- Not aiming to replace MXE Octave (more reliable, tested, stable(?)). Rather complement it.
- Target group:
- Users that want to use e.g. Octave packages that depends on third party packages not included in MXE Octave.
- Users that need features of newer versions of packages that are included in MXE Octave.
- Call out to anyone who has experience with compiler plugins
- Is it possible to write a compiler plugin that identifies variables that match certain conditions? E.g.,
m_prefix for member variables.
- Might allow other analysis of the code: E.g., are static or global variables used in a thread-safe manner?
Convenience function to check for integer property
- Add a function that checks if a double has an integer value.
- Also return true for integer type input.
- What is a good name (in Octave and C++ code)?
Broadcasting with special matrix types
- Topic comes up repeatedly in bug reports.
- Add convenience option to disable support for these types (range, diagonal matrix, permutation matrix)?
- Cast to full matrices before broadcasting? Special handling for NaN and Inf values!