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>

*pi_tar.txt*	For Vim version 9.0.  Last change: 2022 Oct 17

		       +====================+
		       | Tar File Interface |
		       +====================+

Author:  Charles E. Campbell  <NcampObell@SdrPchip.AorgM-NOSPAM>
	  (remove NOSPAM from Campbell's email first)
Copyright 2005-2017:					*tar-copyright*
	The VIM LICENSE (see |copyright|) applies to the files in this
	package, including tarPlugin.vim, tar.vim, and pi_tar.txt.  Like
	anything else that's except use "tar.vim" instead of "VIM".  Like
	anything else that's free, tar.vim and its associated files are
	provided *as is* and comes with no warranty of any kind, either
	expressed or implied.  No guarantees of merchantability.  No
	guarantees of suitability for any purpose.  By using this plugin, you
	agree that in no event will the copyright holder be liable for any
	damages resulting from the use of this software. Use at your own risk!

==============================================================================
1. Contents					*tar* *tar-contents*
   1. Contents..................................................|tar-contents|
   2. Usage.....................................................|tar-usage|
   3. Options...................................................|tar-options|
   4. History...................................................|tar-history|

==============================================================================
2. Usage					*tar-usage* *tar-manual*

   When one edits a *.tar file, this plugin will handle displaying a
   contents page.  Select a file to edit by moving the cursor atop
   the desired file, then hit the <return> key.  After editing, one may
   also write to the file.  Currently, one may not make a new file in
   tar archives via the plugin.

						*:Vimuntar*
   VIMUNTAR~

   :Vimuntar [vimhome]

	This command copies, if necessary, the tarball to the .vim or vimfiles
	directory using the first writable directory in the |'runtimepath'|
	when no [vimhome] is specified.  Otherwise, the [vimhome] argument
	allows the user to specify that directory, instead.

	The copy is done using the command in *g:tar_copycmd* , which is >
		cp   for cygwin, unix, macunix
		copy for windows (32, 95, 64, 16)
<	The extraction is done with the command specified with
	*g:tar_extractcmd* , which by default is >
		"tar -xf"
<
						*:TarDiff*
   DIFFERENCING SUPPORT~

   :TarDiff [filename]

	This command will attempt to show the differences between the tarball
	version of a file and the associated file on the system.  In order to
	find that file on the system, the script uses the path associated with
	the file mentioned in the tarball.  If the current directory is not
	correct for that path, :TarDiff will fail to find the associated file.

	If the [filename] is given, that that filename (and path) will be used
	to specify the associated file.


   PREVENTING LOADING~

   If for some reason you do not wish to use vim to examine tar'd files,
   you may put the following two variables into your <.vimrc> to prevent
   the tar plugin from loading: >

	let g:loaded_tarPlugin= 1
	let g:loaded_tar      = 1
<

==============================================================================
3. Options						*tar-options*

   These options are variables that one may change, typically in one's
   <.vimrc> file.
			 Default
   Variable		  Value   Explanation
   *g:tar_browseoptions*    "Ptf"   used to get a list of contents
   *g:tar_readoptions*	  "OPxf"  used to extract a file from a tarball
   *g:tar_cmd*		  "tar"   the name of the tar program
   *g:tar_nomax*	    0	  if true, file window will not be maximized
   *g:tar_secure*	  undef   if exists:
					"--"s will be used to prevent unwanted
					option expansion in tar commands.
					Please be sure that your tar command
					accepts "--"; Posix compliant tar
					utilities do accept them.
				  if not exists:
					The tar plugin will reject any tar
					files or member files that begin with
					"-"
				  Not all tar's support the "--" which is why
				  it isn't default.
   *g:tar_writeoptions*	  "uf"    used to update/replace a file


==============================================================================
4. History						*tar-history*

	v31	Apr 02, 2017	* (klartext) reported that browsing encrypted
				  files in a zip archive created unencrypted
				  swap files.  I am applying a similar fix
				  used on zip.vim to tar.vim: new buffers
				  are opened with |:noswapfile|.
		May 16, 2017	* When the mouse option isn't empty, the
				  leftmouse can be used to select a file
				  in the tar-file listing.
	v30	Apr 22, 2014	* .tgz files are ambiguous: they may have been
				  compressed with either gzip or bzip2.  Tar.vim
				  disambiguates by using unix's "file" command.
		Feb 18, 2016	* Changed =~ to =~# where appropriate
		Feb 18, 2017	* Now also permits xz decompression
	v28	Jun 23, 2011	* a few more decompression options (tbz tb2 txz)
	v27	May 31, 2011	* moved cygwin detection before g:tar_copycmd
				  handling
				* inserted additional |:keepj| modifiers
				* changed silent  to  sil!  (|:silent|)
	v26	Aug 09, 2010	* uses buffer-local instead of window variables
				  to hold tarfile name
				* inserted keepj before 0d to protect jump list
	v25	Jun 19, 2010	* (Jan Steffens) added support for xz
				  compression
	v24	Apr 07, 2009	* :Untarvim command implemented
		Sep 28, 2009	* Added lzma support
	v22	Aug 08, 2008	* security fixes
	v16	Jun 06, 2008	* tarfile:: used instead of tarfile: when
				  editing files inside tarballs.  Fixes a
				  problem with tarballs called things like
				  c:\abc.tar. (tnx to Bill McCarthy)
	v14	May 09, 2008	* arno caught a security bug
		May 28, 2008	* various security improvements.  Now requires
				  patch 299 which provides the fnameescape()
				  function
		May 30, 2008	* allows one to view *.gz and *.bz2 files that
				  are in *.tar files.
	v12	Sep 07, 2007	* &shq now used if not the empty string for
				  g:tar_shq
	v10	May 02, 2006	* now using "redraw then echo" to show messages,
				  instead of "echo and prompt user"
	v9	May 02, 2006	* improved detection of masquerading as tar file
	v8	May 02, 2006	* allows editing of files that merely masquerade
				  as tar files
	v7	Mar 22, 2006	* work on making tar plugin work across network
		Mar 27, 2006	* g:tar_cmd now available for users to change
				  the name of the tar program to be used.  By
				  default, of course, it's "tar".
	v6	Dec 21, 2005	* writing to files not in directories caused
				  problems - fixed (pointed out by
				  Christian Robinson)
	v5	Nov 22, 2005	* report option workaround installed
	v3	Sep 16, 2005	* handles writing files in an archive back to
				  the archive
		Oct 18, 2005	* <amatch> used instead of <afile> in autocmds
		Oct 18, 2005	* handles writing to compressed archives
		Nov 03, 2005	* handles writing tarfiles across a network
				  using netrw#NetWrite()
	v2			* converted to use Vim7's new autoload feature
				  by Bram Moolenaar
	v1	(original)	* Michael Toren
				  (see http://michael.toren.net/code/)

==============================================================================
vim:tw=78:ts=8:noet:ft=help