Mercurial > vim
view runtime/doc/if_ole.txt @ 32936:c517845bd10e v9.0.1776
patch 9.0.1776: No support for stable Python 3 ABI
Commit: https://github.com/vim/vim/commit/c13b3d1350b60b94fe87f0761ea31c0e7fb6ebf3
Author: Yee Cheng Chin <ychin.git@gmail.com>
Date: Sun Aug 20 21:18:38 2023 +0200
patch 9.0.1776: No support for stable Python 3 ABI
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>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Sun, 20 Aug 2023 21:30:04 +0200 |
parents | 645722244c3f |
children | 199e0d672feb |
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*if_ole.txt* For Vim version 9.0. Last change: 2022 Oct 08 VIM REFERENCE MANUAL by Paul Moore The OLE Interface to Vim *ole-interface* 1. Activation |ole-activation| 2. Methods |ole-methods| 3. The "normal" command |ole-normal| 4. Registration |ole-registration| 5. MS Visual Studio integration |MSVisualStudio| {only available when compiled with the |+ole| feature. See src/if_ole.INSTALL} An alternative is using the client-server communication |clientserver|. ============================================================================== 1. Activation *ole-activation* Vim acts as an OLE automation server, accessible from any automation client, for example, Visual Basic, Python, or Perl. The Vim application "name" (its "ProgID", in OLE terminology) is "Vim.Application". Hence, in order to start a Vim instance (or connect to an already running instance), code similar to the following should be used: [Visual Basic] > Dim Vim As Object Set Vim = CreateObject("Vim.Application") [Python] > from win32com.client.dynamic import Dispatch vim = Dispatch('Vim.Application') [Perl] > use Win32::OLE; $vim = new Win32::OLE 'Vim.Application'; [C#] > // Add a reference to Vim in your project. // Choose the COM tab. // Select "Vim Ole Interface 1.1 Type Library" Vim.Vim vimobj = new Vim.Vim(); Vim does not support acting as a "hidden" OLE server, like some other OLE Automation servers. When a client starts up an instance of Vim, that instance is immediately visible. Simply closing the OLE connection to the Vim instance is not enough to shut down the Vim instance - it is necessary to explicitly execute a quit command (for example, :qa!, :wqa). ============================================================================== 2. Methods *ole-methods* Vim exposes four methods for use by clients. *ole-sendkeys* SendKeys(keys) Execute a series of keys. This method takes a single parameter, which is a string of keystrokes. These keystrokes are executed exactly as if they had been types in at the keyboard. Special keys can be given using their <..> names, as for the right hand side of a mapping. Note: Execution of the Ex "normal" command is not supported - see below |ole-normal|. Examples (Visual Basic syntax) > Vim.SendKeys "ihello<Esc>" Vim.SendKeys "ma1GV4jy`a" These examples assume that Vim starts in Normal mode. To force Normal mode, start the key sequence with CTRL-\ CTRL-N as in > Vim.SendKeys "<C-\><C-N>ihello<Esc>" CTRL-\ CTRL-N returns Vim to Normal mode, when in Insert or Command-line mode. Note that this doesn't work halfway a Vim command *ole-eval* Eval(expr) Evaluate an expression. This method takes a single parameter, which is an expression in Vim's normal format (see |expression|). It returns a string, which is the result of evaluating the expression. A |List| is turned into a string by joining the items and inserting line breaks. Examples (Visual Basic syntax) > Line20 = Vim.Eval("getline(20)") Twelve = Vim.Eval("6 + 6") ' Note this is a STRING Font = Vim.Eval("&guifont") < *ole-setforeground* SetForeground() Make the Vim window come to the foreground This method takes no arguments. No value is returned. Example (Visual Basic syntax) > Vim.SetForeground < *ole-gethwnd* GetHwnd() Return the handle of the Vim window. This method takes no arguments. It returns the hwnd of the main Vimwindow. You can use this if you are writing something which needs to manipulate the Vim window, or to track it in the z-order, etc. Example (Visual Basic syntax) > Vim_Hwnd = Vim.GetHwnd < ============================================================================== 3. The "normal" command *ole-normal* Due to the way Vim processes OLE Automation commands, combined with the method of implementation of the Ex command :normal, it is not possible to execute the :normal command via OLE automation. Any attempt to do so will fail, probably harmlessly, although possibly in unpredictable ways. There is currently no practical way to trap this situation, and users must simply be aware of the limitation. ============================================================================== 4. Registration *ole-registration* *E243* Before Vim will act as an OLE server, it must be registered in the system registry. In order to do this, Vim should be run with a single parameter of "-register". *-register* > gvim -register If gvim with OLE support is run and notices that no Vim OLE server has been registered, it will present a dialog and offers you the choice to register by clicking "Yes". In some situations registering is not possible. This happens when the registry is not writable. If you run into this problem you need to run gvim as "Administrator". Once vim is registered, the application path is stored in the registry. Before moving, deleting, or upgrading Vim, the registry entries should be removed using the "-unregister" switch. *-unregister* > gvim -unregister The OLE mechanism will use the first registered Vim it finds. If a Vim is already running, this one will be used. If you want to have (several) Vim sessions open that should not react to OLE commands, use the non-OLE version, and put it in a different directory. The OLE version should then be put in a directory that is not in your normal path, so that typing "gvim" will start the non-OLE version. *-silent* To avoid the message box that pops up to report the result, prepend "-silent": > gvim -silent -register gvim -silent -unregister ============================================================================== 5. MS Visual Studio integration *MSVisualStudio* The old "VisVim" integration was removed from Vim in patch 9.0.0698. Using Vim with Visual Studio .Net~ .Net studio has support for external editors. Follow these directions: In .Net Studio choose from the menu Tools->External Tools... Add Title - Vim Command - c:\vim\vim63\gvim.exe Arguments - --servername VS_NET --remote-silent "+call cursor($(CurLine), $(CurCol))" $(ItemPath) Init Dir - Empty Now, when you open a file in .Net, you can choose from the .Net menu: Tools->Vim That will open the file in Vim. You can then add this external command as an icon and place it anywhere you like. You might also be able to set this as your default editor. If you refine this further, please post back to the Vim maillist so we have a record of it. --servername VS_NET This will create a new instance of vim called VS_NET. So if you open multiple files from VS, they will use the same instance of Vim. This allows you to have multiple copies of Vim running, but you can control which one has VS files in it. --remote-silent "+call cursor(10, 27)" - Places the cursor on line 10 column 27 In Vim > :h --remote-silent for more details [.Net remarks provided by Dave Fishburn and Brian Sturk] ============================================================================== vim:tw=78:ts=8:noet:ft=help:norl: