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>

/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 */

#ifndef OS_MAC__H
#define OS_MAC__H

// Before Including the MacOS specific files,
// let's set the OPAQUE_TOOLBOX_STRUCTS to 0 so we
// can access the internal structures.
// (Until fully Carbon compliant)
// TODO: Can we remove this? (Dany)
#if 0
# define OPAQUE_TOOLBOX_STRUCTS 0
#endif

// Include MAC_OS_X_VERSION_* macros
#ifdef HAVE_AVAILABILITYMACROS_H
# include <AvailabilityMacros.h>
#endif

/*
 * Unix interface
 */
#if defined(__APPLE_CC__) // for Project Builder and ...
# include <unistd.h>
// Get stat.h or something similar. Comment: How come some OS get in vim.h
# include <sys/stat.h>
// && defined(HAVE_CURSE)
// The curses.h from MacOS X provides by default some BACKWARD compatibility
// definition which can cause us problem later on. So we undefine a few of them.
# include <curses.h>
# undef reg
# undef ospeed
// OK defined to 0 in MacOS X 10.2 curses!  Remove it, we define it to be 1.
# undef OK
#endif
#include <signal.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <dirent.h>

/*
 * MacOS specific #define
 */

// This will go away when CMD_KEY fully tested
#define USE_CMD_KEY
// On MacOS X use the / not the :
// TODO: Should file such as ~/.vimrc reside instead in
//       ~/Library/Vim or ~/Library/Preferences/org.vim.vim/ ? (Dany)
// When compiled under MacOS X (including CARBON version)
// we use the Unix File path style.  Also when UNIX is defined.
#define USE_UNIXFILENAME


/*
 * Generic Vim #define for Mac
 */

#define FEAT_SOURCE_FFS
#define FEAT_SOURCE_FF_MAC

#define USE_EXE_NAME		    // to find  $VIM
#define CASE_INSENSITIVE_FILENAME   // ignore case when comparing file names
#define SPACE_IN_FILENAME

#define USE_FNAME_CASE		// make ":e os_Mac.c" open the file in its
				// original case, as "os_mac.c"
#define BINARY_FILE_IO
#define EOL_DEFAULT EOL_MAC
#define HAVE_AVAIL_MEM

#ifndef HAVE_CONFIG_H
# define HAVE_STRING_H
# define HAVE_STRCSPN
# define HAVE_MEMSET
# define USE_TMPNAM		// use tmpnam() instead of mktemp()
# define HAVE_FCNTL_H
# define HAVE_QSORT
# define HAVE_ST_MODE		// have stat.st_mode
# define HAVE_MATH_H

# if defined(__DATE__) && defined(__TIME__)
#  define HAVE_DATE_TIME
# endif
# define HAVE_STRFTIME
#endif

/*
 * Names for the EXRC, HELP and temporary files.
 * Some of these may have been defined in the makefile.
 */

#ifndef SYS_VIMRC_FILE
# define SYS_VIMRC_FILE "$VIM/vimrc"
#endif
#ifndef SYS_GVIMRC_FILE
# define SYS_GVIMRC_FILE "$VIM/gvimrc"
#endif
#ifndef SYS_MENU_FILE
# define SYS_MENU_FILE	"$VIMRUNTIME/menu.vim"
#endif
#ifndef SYS_OPTWIN_FILE
# define SYS_OPTWIN_FILE "$VIMRUNTIME/optwin.vim"
#endif
#ifndef VIM_DEFAULTS_FILE
# define VIM_DEFAULTS_FILE "$VIMRUNTIME/defaults.vim"
#endif
#ifndef EVIM_FILE
# define EVIM_FILE	"$VIMRUNTIME/evim.vim"
#endif

#ifdef FEAT_GUI
# ifndef USR_GVIMRC_FILE
#  define USR_GVIMRC_FILE "~/.gvimrc"
# endif
# ifndef GVIMRC_FILE
#  define GVIMRC_FILE	"_gvimrc"
# endif
#endif
#ifndef USR_VIMRC_FILE
# define USR_VIMRC_FILE	"~/.vimrc"
#endif

#ifndef USR_EXRC_FILE
# define USR_EXRC_FILE	"~/.exrc"
#endif

#ifndef VIMRC_FILE
# define VIMRC_FILE	"_vimrc"
#endif

#ifndef EXRC_FILE
# define EXRC_FILE	"_exrc"
#endif

#ifndef DFLT_HELPFILE
# define DFLT_HELPFILE	"$VIMRUNTIME/doc/help.txt"
#endif

#ifndef SYNTAX_FNAME
# define SYNTAX_FNAME	"$VIMRUNTIME/syntax/%s.vim"
#endif

#ifdef FEAT_VIMINFO
# ifndef VIMINFO_FILE
#  define VIMINFO_FILE	"~/.viminfo"
# endif
#endif // FEAT_VIMINFO

#ifndef DFLT_BDIR
# define DFLT_BDIR	"."	// default for 'backupdir'
#endif

#ifndef DFLT_DIR
# define DFLT_DIR	"."	// default for 'directory'
#endif

#ifndef DFLT_VDIR
# define DFLT_VDIR	"$VIM/vimfiles/view"	// default for 'viewdir'
#endif

#define DFLT_ERRORFILE		"errors.err"

#ifndef DFLT_RUNTIMEPATH
# define DFLT_RUNTIMEPATH	"~/.vim,$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after,~/.vim/after"
#endif
#ifndef CLEAN_RUNTIMEPATH
# define CLEAN_RUNTIMEPATH	"$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after"
#endif

/*
 * Macintosh has plenty of memory, use large buffers
 */
#define CMDBUFFSIZE 1024	// size of the command processing buffer

#ifndef DFLT_MAXMEM
# define DFLT_MAXMEM	512	// use up to  512 Kbyte for buffer
#endif

#ifndef DFLT_MAXMEMTOT
# define DFLT_MAXMEMTOT	2048	// use up to 2048 Kbyte for Vim
#endif

#define WILDCHAR_LIST "*?[{`$"

/**************/
#define mch_rename(src, dst) rename(src, dst)
#define mch_remove(x) unlink((char *)(x))
#ifndef mch_getenv
# if defined(__APPLE_CC__)
#  define mch_getenv(name)  ((char_u *)getenv((char *)(name)))
#  define mch_setenv(name, val, x) setenv(name, val, x)
# else
  // vim_getenv() is in pty.c
#  define USE_VIMPTY_GETENV
#  define mch_getenv(x) vimpty_getenv(x)
#  define mch_setenv(name, val, x) setenv(name, val, x)
# endif
#endif

#ifndef HAVE_CONFIG_H
# ifdef __APPLE_CC__
// Assuming compiling for MacOS X
// Trying to take advantage of the prebinding
#  define HAVE_TGETENT
#  define OSPEED_EXTERN
#  define UP_BC_PC_EXTERN
# endif
#endif

// Some "prep work" definition to be able to compile the MacOS X
// version with os_unix.c instead of os_mac.c. Based on the result
// of ./configure for console MacOS X.

#ifndef SIGPROTOARG
# define SIGPROTOARG	(int)
#endif
#ifndef SIGDEFARG
# define SIGDEFARG(s)	(s) int s UNUSED;
#endif
#ifndef SIGDUMMYARG
# define SIGDUMMYARG	0
#endif
#undef  HAVE_AVAIL_MEM
#ifndef HAVE_CONFIG_H
//# define USE_SYSTEM  // Output ship do debugger :(, but not compile
# define HAVE_SYS_WAIT_H 1 // Attempt
# define HAVE_TERMIOS_H 1
# define SYS_SELECT_WITH_SYS_TIME 1
# define HAVE_SELECT 1
# define HAVE_SYS_SELECT_H 1
# define HAVE_PUTENV
# define HAVE_SETENV
# define HAVE_RENAME
#endif

#if !defined(HAVE_CONFIG_H)
# define HAVE_PUTENV
#endif

// A Mac constant causing big problem to syntax highlighting
#define UNKNOWN_CREATOR '\?\?\?\?'

#ifdef FEAT_RELTIME

# include <dispatch/dispatch.h>

# if !defined(MAC_OS_X_VERSION_10_12) \
	|| (MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_12)
typedef int clockid_t;
# endif
# ifndef CLOCK_REALTIME
#  define CLOCK_REALTIME 0
# endif
# ifndef CLOCK_MONOTONIC
#  define CLOCK_MONOTONIC 1
# endif

struct itimerspec
{
    struct timespec it_interval;  // timer period
    struct timespec it_value;	  // initial expiration
};

struct sigevent;

struct macos_timer
{
    dispatch_queue_t tim_queue;
    dispatch_source_t tim_timer;
    void (*tim_func)(union sigval);
    void *tim_arg;
};

typedef struct macos_timer *timer_t;

extern int timer_create(
    clockid_t clockid,
    struct sigevent *sevp,
    timer_t *timerid);

extern int timer_delete(timer_t timerid);

extern int timer_settime(
    timer_t timerid, int flags,
    const struct itimerspec *new_value,
    struct itimerspec *unused);

#endif // FEAT_RELTIME

#endif // OS_MAC__H