view runtime/doc/usr_45.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 f8116058ca76
children 4635e43f2c6f
line wrap: on
line source

*usr_45.txt*	For Vim version 9.0.  Last change: 2022 May 13

		     VIM USER MANUAL - by Bram Moolenaar

			Select your language (locale)


The messages in Vim can be given in several languages.  This chapter explains
how to change which one is used.  Also, the different ways to work with files
in various languages is explained.

|45.1|	Language for Messages
|45.2|	Language for Menus
|45.3|	Using another encoding
|45.4|	Editing files with a different encoding
|45.5|	Entering language text

     Next chapter: |usr_50.txt|  Advanced Vim script writing
 Previous chapter: |usr_44.txt|  Your own syntax highlighted
Table of contents: |usr_toc.txt|

==============================================================================
*45.1*	Language for Messages

When you start Vim, it checks the environment to find out what language you
are using.  Mostly this should work fine, and you get the messages in your
language (if they are available).  To see what the current language is, use
this command: >

	:language

If it replies with "C", this means the default is being used, which is
English.

	Note:
	Using different languages only works when Vim was compiled to handle
	it.  To find out if it works, use the ":version" command and check the
	output for "+gettext" and "+multi_lang".  If they are there, you are
	OK.  If you see "-gettext" or "-multi_lang" you will have to find
	another Vim.

What if you would like your messages in a different language?  There are
several ways.  Which one you should use depends on the capabilities of your
system.
   The first way is to set the environment to the desired language before
starting Vim.  Example for Unix: >

	env LANG=de_DE.ISO_8859-1  vim

This only works if the language is available on your system.  The advantage is
that all the GUI messages and things in libraries will use the right language
as well.  A disadvantage is that you must do this before starting Vim.  If you
want to change language while Vim is running, you can use the second method: >

	:language fr_FR.ISO_8859-1

This way you can try out several names for your language.  You will get an
error message when it's not supported on your system.  You don't get an error
when translated messages are not available.  Vim will silently fall back to
using English.
   To find out which languages are supported on your system, find the
directory where they are listed.  On my system it is "/usr/share/locale".  On
some systems it's in "/usr/lib/locale".  The manual page for "setlocale"
should give you a hint where it is found on your system.
   Be careful to type the name exactly as it should be.  Upper and lowercase
matter, and the '-' and '_' characters are easily confused.

You can also set the language separately for messages, edited text and the
time format.  See |:language|.


DO-IT-YOURSELF MESSAGE TRANSLATION

If translated messages are not available for your language, you could write
them yourself.  To do this, get the source code for Vim and the GNU gettext
package.  After unpacking the sources, instructions can be found in the
directory src/po/README.txt.
   It's not too difficult to do the translation.  You don't need to be a
programmer.  You must know both English and the language you are translating
to, of course.
   When you are satisfied with the translation, consider making it available
to others.  Upload it at vim-online (http://vim.sf.net) or e-mail it to
the Vim maintainer <maintainer@vim.org>.  Or both.

==============================================================================
*45.2*	Language for Menus

The default menus are in English.  To be able to use your local language, they
must be translated.  Normally this is automatically done for you if the
environment is set for your language, just like with messages.  You don't need
to do anything extra for this.  But it only works if translations for the
language are available.
   Suppose you are in Germany, with the language set to German, but prefer to
use "File" instead of "Datei".  You can switch back to using the English menus
this way: >

	:set langmenu=none

It is also possible to specify a language: >

	:set langmenu=nl_NL.ISO_8859-1

Like above, differences between "-" and "_" matter.  However, upper/lowercase
differences are ignored here.
   The 'langmenu' option must be set before the menus are loaded.  Once the
menus have been defined changing 'langmenu' has no direct effect.  Therefore,
put the command to set 'langmenu' in your vimrc file.
   If you really want to switch menu language while running Vim, you can do it
this way: >

	:source $VIMRUNTIME/delmenu.vim
	:set langmenu=de_DE.ISO_8859-1
	:source $VIMRUNTIME/menu.vim

There is one drawback: All menus that you defined yourself will be gone.  You
will need to redefine them as well.


DO-IT-YOURSELF MENU TRANSLATION

To see which menu translations are available, look in this directory:

	$VIMRUNTIME/lang ~

The files are called menu_{language}.vim.  If you don't see the language you
want to use, you can do your own translations.  The simplest way to do this is
by copying one of the existing language files, and change it.
   First find out the name of your language with the ":language" command.  Use
this name, but with all letters made lowercase.  Then copy the file to your
own runtime directory, as found early in 'runtimepath'.  For example, for Unix
you would do: >

	:!cp $VIMRUNTIME/lang/menu_ko_kr.euckr.vim ~/.vim/lang/menu_nl_be.iso_8859-1.vim

You will find hints for the translation in "$VIMRUNTIME/lang/README.txt".

==============================================================================
*45.3*	Using another encoding

Vim guesses that the files you are going to edit are encoded for your
language.  For many European languages this is "latin1".  Then each byte is
one character.  That means there are 256 different characters possible.  For
Asian languages this is not sufficient.  These mostly use a double-byte
encoding, providing for over ten thousand possible characters.  This still
isn't enough when a text is to contain several different languages.  This is
where Unicode comes in.  It was designed to include all characters used in
commonly used languages.  This is the "Super encoding that replaces all
others".  But it isn't used that much yet.
   Fortunately, Vim supports these three kinds of encodings.  And, with some
restrictions, you can use them even when your environment uses another
language than the text.
   Nevertheless, when you only edit files that are in the encoding of your
language, the default should work fine and you don't need to do anything.  The
following is only relevant when you want to edit different languages.


USING UNICODE IN THE GUI

The nice thing about Unicode is that other encodings can be converted to it
and back without losing information.  When you make Vim use Unicode
internally, you will be able to edit files in any encoding.
   Unfortunately, the number of systems supporting Unicode is still limited.
Thus it's unlikely that your language uses it.  You need to tell Vim you want
to use Unicode, and how to handle interfacing with the rest of the system.
   Let's start with the GUI version of Vim, which is able to display Unicode
characters.  This should work: >

	:set encoding=utf-8
	:set guifont=-misc-fixed-medium-r-normal--18-120-100-100-c-90-iso10646-1

The 'encoding' option tells Vim the encoding of the characters that you use.
This applies to the text in buffers (files you are editing), registers, Vim
script files, etc.  You can regard 'encoding' as the setting for the internals
of Vim.
   This example assumes you have this font on your system.  The name in the
example is for the X Window System.  This font is in a package that is used to
enhance xterm with Unicode support.  If you don't have this font, you might
find it here:

	http://www.cl.cam.ac.uk/~mgk25/download/ucs-fonts.tar.gz ~

For MS-Windows, some fonts have a limited number of Unicode characters.  Try
using the "Courier New" font.  You can use the Edit/Select Font... menu to
select and try out the fonts available.  Only fixed-width fonts can be used
though.  Example: >

	:set guifont=courier_new:h12

If it doesn't work well, try getting a fontpack.  If Microsoft didn't move it,
you can find it here:

	http://www.microsoft.com/typography/fonts/default.aspx ~

Now you have told Vim to use Unicode internally and display text with a
Unicode font.  Typed characters still arrive in the encoding of your original
language.  This requires converting them to Unicode.  Tell Vim the language
from which to convert with the 'termencoding' option.  You can do it like
this: >

	:let &termencoding = &encoding
	:set encoding=utf-8

This assigns the old value of 'encoding' to 'termencoding' before setting
'encoding' to utf-8.  You will have to try out if this really works for your
setup.  It should work especially well when using an input method for an Asian
language, and you want to edit Unicode text.


USING UNICODE IN A UNICODE TERMINAL

There are terminals that support Unicode directly.  The standard xterm that
comes with XFree86 is one of them.  Let's use that as an example.
   First of all, the xterm must have been compiled with Unicode support.  See
|UTF8-xterm| how to check that and how to compile it when needed.
   Start the xterm with the "-u8" argument.  You might also need so specify a
font.  Example: >

   xterm -u8 -fn -misc-fixed-medium-r-normal--18-120-100-100-c-90-iso10646-1

Now you can run Vim inside this terminal.  Set 'encoding' to "utf-8" as
before.  That's all.


USING UNICODE IN AN ORDINARY TERMINAL

Suppose you want to work with Unicode files, but don't have a terminal with
Unicode support.  You can do this with Vim, although characters that are not
supported by the terminal will not be displayed.  The layout of the text
will be preserved.  >

	:let &termencoding = &encoding
	:set encoding=utf-8

This is the same as what was used for the GUI.  But it works differently: Vim
will convert the displayed text before sending it to the terminal.  That
avoids that the display is messed up with strange characters.
   For this to work the conversion between 'termencoding' and 'encoding' must
be possible.  Vim will convert from latin1 to Unicode, thus that always works.
For other conversions the |+iconv| feature is required.
   Try editing a file with Unicode characters in it.  You will notice that Vim
will put a question mark (or underscore or some other character) in places
where a character should be that the terminal can't display.  Move the cursor
to a question mark and use this command: >

	ga

Vim will display a line with the code of the character.  This gives you a hint
about what character it is.  You can look it up in a Unicode table.  You could
actually view a file that way, if you have lots of time at hand.

	Note:
	Since 'encoding' is used for all text inside Vim, changing it makes
	all non-ASCII text invalid.  You will notice this when using registers
	and the 'viminfo' file (e.g., a remembered search pattern).  It's
	recommended to set 'encoding' in your vimrc file, and leave it alone.

==============================================================================
*45.4*	Editing files with a different encoding

Suppose you have setup Vim to use Unicode, and you want to edit a file that is
in 16-bit Unicode.  Sounds simple, right?  Well, Vim actually uses utf-8
encoding internally, thus the 16-bit encoding must be converted, since there
is a difference between the character set (Unicode) and the encoding (utf-8 or
16-bit).
   Vim will try to detect what kind of file you are editing.  It uses the
encoding names in the 'fileencodings' option.  When using Unicode, the default
value is: "ucs-bom,utf-8,latin1".  This means that Vim checks the file to see
if it's one of these encodings:

	ucs-bom		File must start with a Byte Order Mark (BOM).  This
			allows detection of 16-bit, 32-bit and utf-8 Unicode
			encodings.
	utf-8		utf-8 Unicode.  This is rejected when a sequence of
			bytes is illegal in utf-8.
	latin1		The good old 8-bit encoding.  Always works.

When you start editing that 16-bit Unicode file, and it has a BOM, Vim will
detect this and convert the file to utf-8 when reading it.  The 'fileencoding'
option (without s at the end) is set to the detected value.  In this case it
is "utf-16le".  That means it's Unicode, 16-bit and little-endian.  This
file format is common on MS-Windows (e.g., for registry files).
   When writing the file, Vim will compare 'fileencoding' with 'encoding'.  If
they are different, the text will be converted.
   An empty value for 'fileencoding' means that no conversion is to be done.
Thus the text is assumed to be encoded with 'encoding'.

If the default 'fileencodings' value is not good for you, set it to the
encodings you want Vim to try.  Only when a value is found to be invalid will
the next one be used.  Putting "latin1" first doesn't work, because it is
never illegal.  An example, to fall back to Japanese when the file doesn't
have a BOM and isn't utf-8: >

	:set fileencodings=ucs-bom,utf-8,sjis

See |encoding-values| for suggested values.  Other values may work as well.
This depends on the conversion available.


FORCING AN ENCODING

If the automatic detection doesn't work you must tell Vim what encoding the
file is.  Example: >

	:edit ++enc=koi8-r russian.txt

The "++enc" part specifies the name of the encoding to be used for this file
only.  Vim will convert the file from the specified encoding, Russian in this
example, to 'encoding'.  'fileencoding' will also be set to the specified
encoding, so that the reverse conversion can be done when writing the file.
   The same argument can be used when writing the file.  This way you can
actually use Vim to convert a file.  Example: >

	:write ++enc=utf-8 russian.txt
<
	Note:
	Conversion may result in lost characters.  Conversion from an encoding
	to Unicode and back is mostly free of this problem, unless there are
	illegal characters.  Conversion from Unicode to other encodings often
	loses information when there was more than one language in the file.

==============================================================================
*45.5*	Entering language text

Computer keyboards don't have much more than a hundred keys.  Some languages
have thousands of characters, Unicode has over hundred thousand.  So how do
you type these characters?
   First of all, when you don't use too many of the special characters, you
can use digraphs.  This was already explained in |24.9|.
   When you use a language that uses many more characters than keys on your
keyboard, you will want to use an Input Method (IM).  This requires learning
the translation from typed keys to resulting character.  When you need an IM
you probably already have one on your system.  It should work with Vim like
with other programs.  For details see |mbyte-XIM| for the X Window system and
|mbyte-IME| for MS-Windows.


KEYMAPS

For some languages the character set is different from latin, but uses a
similar number of characters.  It's possible to map keys to characters.  Vim
uses keymaps for this.
   Suppose you want to type Hebrew.  You can load the keymap like this: >

	:set keymap=hebrew

Vim will try to find a keymap file for you.  This depends on the value of
'encoding'.  If no matching file was found, you will get an error message.

Now you can type Hebrew in Insert mode.  In Normal mode, and when typing a ":"
command, Vim automatically switches to English.  You can use this command to
switch between Hebrew and English: >

	CTRL-^

This only works in Insert mode and Command-line mode.  In Normal mode it does
something completely different (jumps to alternate file).
   The usage of the keymap is indicated in the mode message, if you have the
'showmode' option set.  In the GUI Vim will indicate the usage of keymaps with
a different cursor color.
   You can also change the usage of the keymap with the 'iminsert' and
'imsearch' options.

To see the list of mappings, use this command: >

	:lmap

To find out which keymap files are available, in the GUI you can use the
Edit/Keymap menu.  Otherwise you can use this command: >

	:echo globpath(&rtp, "keymap/*.vim")


DO-IT-YOURSELF KEYMAPS

You can create your own keymap file.  It's not very difficult.  Start with
a keymap file that is similar to the language you want to use.  Copy it to the
"keymap" directory in your runtime directory.  For example, for Unix, you
would use the directory "~/.vim/keymap".
   The name of the keymap file must look like this:

	keymap/{name}.vim ~
or
	keymap/{name}_{encoding}.vim ~

{name} is the name of the keymap.  Chose a name that is obvious, but different
from existing keymaps (unless you want to replace an existing keymap file).
{name} cannot contain an underscore.  Optionally, add the encoding used after
an underscore.  Examples:

	keymap/hebrew.vim ~
	keymap/hebrew_utf-8.vim ~

The contents of the file should be self-explanatory.  Look at a few of the
keymaps that are distributed with Vim.  For the details, see |mbyte-keymap|.


LAST RESORT

If all other methods fail, you can enter any character with CTRL-V:

	encoding   type			range ~
	8-bit	   CTRL-V 123		decimal 0-255
	8-bit	   CTRL-V x a1		hexadecimal 00-ff
	16-bit     CTRL-V u 013b	hexadecimal 0000-ffff
	31-bit	   CTRL-V U 001303a4	hexadecimal 00000000-7fffffff

Don't type the spaces.  See |i_CTRL-V_digit| for the details.

==============================================================================

Next chapter: |usr_50.txt|  Advanced Vim script writing

Copyright: see |manual-copyright|  vim:tw=78:ts=8:noet:ft=help:norl: