Problem: No support for stable Python 3 ABI
Solution: Support Python 3 stable ABI
Commits:
1) Support Python 3 stable ABI to allow mixed version interoperatbility
Vim currently supports embedding Python for use with plugins, and the
"dynamic" linking option allows the user to specify a locally installed
version of Python by setting `pythonthreedll`. However, one caveat is
that the Python 3 libs are not binary compatible across minor versions,
and mixing versions can potentially be dangerous (e.g. let's say Vim was
linked against the Python 3.10 SDK, but the user sets `pythonthreedll`
to a 3.11 lib). Usually, nothing bad happens, but in theory this could
lead to crashes, memory corruption, and other unpredictable behaviors.
It's also difficult for the user to tell something is wrong because Vim
has no way of reporting what Python 3 version Vim was linked with.
For Vim installed via a package manager, this usually isn't an issue
because all the dependencies would already be figured out. For prebuilt
Vim binaries like MacVim (my motivation for working on this), AppImage,
and Win32 installer this could potentially be an issue as usually a
single binary is distributed. This is more tricky when a new Python
version is released, as there's a chicken-and-egg issue with deciding
what Python version to build against and hard to keep in sync when a new
Python version just drops and we have a mix of users of different Python
versions, and a user just blindly upgrading to a new Python could lead to
bad interactions with Vim.
Python 3 does have a solution for this problem: stable ABI / limited API
(see https://docs.python.org/3/c-api/stable.html). The C SDK limits the
API to a set of functions that are promised to be stable across
versions. This pull request adds an ifdef config that allows us to turn
it on when building Vim. Vim binaries built with this option should be
safe to freely link with any Python 3 libraies without having the
constraint of having to use the same minor version.
Note: Python 2 has no such concept and this doesn't change how Python 2
integration works (not that there is going to be a new version of Python
2 that would cause compatibility issues in the future anyway).
---
Technical details:
======
The stable ABI can be accessed when we compile with the Python 3 limited
API (by defining `Py_LIMITED_API`). The Python 3 code (in `if_python3.c`
and `if_py_both.h`) would now handle this and switch to limited API
mode. Without it set, Vim will still use the full API as before so this
is an opt-in change.
The main difference is that `PyType_Object` is now an opaque struct that
we can't directly create "static types" out of, and we have to create
type objects as "heap types" instead. This is because the struct is not
stable and changes from version to version (e.g. 3.8 added a
`tp_vectorcall` field to it). I had to change all the types to be
allocated on the heap instead with just a pointer to them.
Other functions are also simply missing in limited API, or they are
introduced too late (e.g. `PyUnicode_AsUTF8AndSize` in 3.10) to it that
we need some other ways to do the same thing, so I had to abstract a few
things into macros, and sometimes re-implement functions like
`PyObject_NEW`.
One caveat is that in limited API, `OutputType` (used for replacing
`sys.stdout`) no longer inherits from `PyStdPrinter_Type` which I don't
think has any real issue other than minor differences in how they
convert to a string and missing a couple functions like `mode()` and
`fileno()`.
Also fixed an existing bug where `tp_basicsize` was set incorrectly for
`BufferObject`, `TabListObject, `WinListObject`.
Technically, there could be a small performance drop, there is a little
more indirection with accessing type objects, and some APIs like
`PyUnicode_AsUTF8AndSize` are missing, but in practice I didn't see any
difference, and any well-written Python plugin should try to avoid
excessing callbacks to the `vim` module in Python anyway.
I only tested limited API mode down to Python 3.7, which seemes to
compile and work fine. I haven't tried earlier Python versions.
2) Fix PyIter_Check on older Python vers / type##Ptr unused warning
For PyIter_Check, older versions exposed them as either macros (used in
full API), or a function (for use in limited API). A previous change
exposed PyIter_Check to the dynamic build because Python just moved it
to function-only in 3.10 anyway. Because of that, just make sure we
always grab the function in dynamic builds in earlier versions since
that's what Python eventually did anyway.
3) Move Py_LIMITED_API define to configure script
Can now use --with-python-stable-abi flag to customize what stable ABI
version to target. Can also use an env var to do so as well.
4) Show +python/dyn-stable in :version, and allow has() feature query
Not sure if the "/dyn-stable" suffix would break things, or whether we
should do it another way. Or just don't show it in version and rely on
has() feature checking.
5) Documentation first draft. Still need to implement v:python3_version
6) Fix PyIter_Check build breaks when compiling against Python 3.8
7) Add CI coverage stable ABI on Linux/Windows / make configurable on Windows
This adds configurable options for Windows make files (both MinGW and
MSVC). CI will also now exercise both traditional full API and stable
ABI for Linux and Windows in the matrix for coverage.
Also added a "dynamic" option to Linux matrix as a drive-by change to
make other scripting languages like Ruby / Perl testable under both
static and dynamic builds.
8) Fix inaccuracy in Windows docs
Python's own docs are confusing but you don't actually want to use
`python3.dll` for the dynamic linkage.
9) Add generated autoconf file
10) Add v:python3_version support
This variable indicates the version of Python3 that Vim was built
against (PY_VERSION_HEX), and will be useful to check whether the Python
library you are loading in dynamically actually fits it. When built with
stable ABI, it will be the limited ABI version instead
(`Py_LIMITED_API`), which indicates the minimum version of Python 3 the
user should have, rather than the exact match. When stable ABI is used,
we won't be exposing PY_VERSION_HEX in this var because it just doesn't
seem necessary to do so (the whole point of stable ABI is the promise
that it will work across versions), and I don't want to confuse the user
with too many variables.
Also, cleaned up some documentation, and added help tags.
11) Fix Python 3.7 compat issues
Fix a couple issues when using limited API < 3.8
- Crash on exit: In Python 3.7, if a heap-allocated type is destroyed
before all instances are, it would cause a crash later. This happens
when we destroyed `OptionsType` before calling `Py_Finalize` when
using the limited API. To make it worse, later versions changed the
semantics and now each instance has a strong reference to its own type
and the recommendation has changed to have each instance de-ref its
own type and have its type in GC traversal. To avoid dealing with
these cross-version variations, we just don't free the heap type. They
are static types in non-limited-API anyway and are designed to last
through the entirety of the app, and we also don't restart the Python
runtime and therefore do not need it to have absolutely 0 leaks.
See:
- https://docs.python.org/3/whatsnew/3.8.html#changes-in-the-c-api
- https://docs.python.org/3/whatsnew/3.9.html#changes-in-the-c-api
- PyIter_Check: This function is not provided in limited APIs older than
3.8. Previously I was trying to mock it out using manual
PyType_GetSlot() but it was brittle and also does not actually work
properly for static types (it will generate a Python error). Just
return false. It does mean using limited API < 3.8 is not recommended
as you lose the functionality to handle iterators, but from playing
with plugins I couldn't find it to be an issue.
- Fix loading of PyIter_Check so it will be done when limited API < 3.8.
Otherwise loading a 3.7 Python lib will fail even if limited API was
specified to use it.
12) Make sure to only load `PyUnicode_AsUTF8AndSize` in needed in limited API
We don't use this function unless limited API >= 3.10, but we were
loading it regardless. Usually it's ok in Unix-like systems where Python
just has a single lib that we load from, but in Windows where there is a
separate python3.dll this would not work as the symbol would not have
been exposed in this more limited DLL file. This makes it much clearer
under what condition is this function needed.
closes: #12032
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Yee Cheng Chin <ychin.git@gmail.com>
Problem: screenpos() may cause unnecessary redraw.
Solution: Don't unnecessarily reset VALID_WROW flag.
VALID_WROW flag is only used by two functions: validate_cursor() and
cursor_valid(), and cursor_valid() is only used once in ex_sleep().
When adjust_plines_for_skipcol() was first added in patch 9.0.0640, it
was called in two functions: comp_botline() and curs_rows().
- comp_botline() is called in two places:
- onepage(), which resets VALID_WROW flag immediately afterwards.
- validate_botline_win(), where resetting a VALID_ flag is strange.
- curs_rows() is called in two places:
- curs_columns(), which sets VALID_WROW flag afterwards.
- validate_cline_row(), which is only used by GUI mouse focus.
Therefore resetting VALID_WROW there doesn't seem to do anything useful.
Also, a w_skipcol check (which resets VALID_WROW flag) was added to
check_cursor_moved() in patch 9.0.0734, which seems to make more sense
than resetting that flag in the middle of a computation.
While at it make adjust_plines_for_skipcol() and textpos2screenpos() a
bit less confusing:
- Make adjust_plines_for_skipcol() return "off" instead of "n - off".
- Use 0-based "row" in textpos2screenpos() until W_WINROW is added.
closes: #12832
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Problem: Duplicate code to reverse a string
Solution: Move reverse_text() to strings.c and remove string_reverse().
closes: #12847
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Problem: passing multiple patterns to runtime not working
Solution: prepend prefix to each argument separately
closes: #12617
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Problem: screenpos() wrong result with w_skipcol and cpoptions+=n
Solution: Use adjust_plines_for_skipcol() instead of subtracting
w_skipcol.
closes: #12625
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Problem: incorrect heights in win_size_restore()
Solution: avoid restoring incorrect heights in win_size_restore()
Changing 'showtabline' or 'cmdheight' in the cmdwin restores incorrect
window heights after closing the cmdwin.
This may produce a gap between the cmdline and the window above.
Solution: restore window sizes only if the number of lines available for windows
changed; subtract the rows of the tabline, cmdline and last window's statusline
from 'lines' (other statuslines don't matter).
closes: #12704
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Sean Dewar <seandewar@users.noreply.github.com>
Problem: Fix regression in {func} argument of reduce()
Solution: pass function name as string again
Before patch 9.0.0548, passing a string as {func} argument of reduce()
is treated as a function name, but after patch 9.0.0548 it is treated as
an expression instead, which is useless as reduce() doesn't set any v:
variables. This PR restores the behavior of {func} before that patch.
Also correct an emsg() call, as e_string_list_or_blob_required doesn't
contain format specifiers.
closes: #12824
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Problem: wrong mapping applied when replaying a char search
Solution: Store a NOP after the ESC
closes: #12708closes: #6350
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Problem: mapset() not properly handling script ID
Solution: replace_termcodes() may accept a script ID
closes: #12699closes: #12697
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Problem: Crash syncing swapfile in new buffer when using sodium crypt.
(James McCoy)
Solution: Add checks for sodium encryption. (Christian Brabandt,
closes#12591, closes#12585)
Problem: Cursor not adjusted when near top or bottom of window and
'splitkeep' is not "cursor".
Solution: Move boundary checks to outer cursor move functions, inner
functions should only return valid cursor positions. (Luuk van
Baal, closes#12480)
Problem: Weird use of static variables for spell checking.
Solution: Move the variables to a structure and pass them from win_update()
to win_line(). (Luuk van Baal, closes#12448)
Problem: Get E304 when using 'cryptmethod' "xchacha20v2". (Steve Mynott)
Solution: Add 4th crypt method to block zero ID check. Avoid syncing a swap
file before reading the file. (closes#12433)
Problem: SpellCap highlight not always updated when needed.
Solution: Handle updating line below closed fold and other situations where
only part of the window is redrawn. (Luuk van Baal, closes#12428,
closes#12420)
Problem: Cannot use "this.member" in lambda in class method.
Solution: Adjust check for reserved keyword. (Hirohito Higashi,
closes#12416, closes#12076, closes#12336)
Problem: Position of marker for 'smoothscroll' not computed correctly.
Solution: Take 'list' and other options into account. (Luuk van Baal,
closes#12393)
Problem: no functions for converting from/to UTF-16 index.
Solution: Add UTF-16 flag to existing funtions and add strutf16len() and
utf16idx(). (Yegappan Lakshmanan, closes#12216)
Problem: Decrypting with libsodium may fail if the library changes.
Solution: Add parameters used to the encrypted file header. (Christian
Brabandt, closes#12279)
Problem: Function for setting options not used consistently.
Solution: Use a function for 'encoding' and terminal options. (Yegappan
Lakshmanan, closes#12099)
Problem: Still some "else if" constructs for setting options.
Solution: Add a few more functions for handling options. (Yegappan
Lakshmanan, closes#12090)
Problem: Too many "else if" statements in handling options.
Solution: Add more functions for handling option changes. (Yegappan
Lakshmanan, closes#12060)
Problem: Too many "else if" statements to handle option values.
Solution: Add more functions to handle option value changes. (Yegappan
Lakshmanan, closes#12058)
Problem: Checking the type of a null object causes a crash.
Solution: Don't try to get the class of a null object. (closes#12005)
Handle error from calling a user function better.
Problem: :messages behavior depends on 'fileformat' of current buffer.
Solution: Pass the buffer pointer to where it is used. (Mirko Ceroni,
closes#11995)
