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
line wrap: on
line source

*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: