view src/match.c @ 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 238ca27dbfd2
children a357a624e487
line wrap: on
line source

/* 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.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * match.c: functions for highlighting matches
 */

#include "vim.h"

#if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)

# define SEARCH_HL_PRIORITY 0

/*
 * Add match to the match list of window "wp".
 * If "pat" is not NULL the pattern will be highlighted with the group "grp"
 * with priority "prio".
 * If "pos_list" is not NULL the list of posisions defines the highlights.
 * Optionally, a desired ID "id" can be specified (greater than or equal to 1).
 * If no particular ID is desired, -1 must be specified for "id".
 * Return ID of added match, -1 on failure.
 */
    static int
match_add(
    win_T	*wp,
    char_u	*grp,
    char_u	*pat,
    int		prio,
    int		id,
    list_T	*pos_list,
    char_u      *conceal_char UNUSED) // pointer to conceal replacement char
{
    matchitem_T	*cur;
    matchitem_T	*prev;
    matchitem_T	*m;
    int		hlg_id;
    regprog_T	*regprog = NULL;
    int		rtype = UPD_SOME_VALID;

    if (*grp == NUL || (pat != NULL && *pat == NUL))
	return -1;
    if (id < -1 || id == 0)
    {
	semsg(_(e_invalid_id_nr_must_be_greater_than_or_equal_to_one_1), id);
	return -1;
    }
    if (id == -1)
    {
	// use the next available match ID
	id = wp->w_next_match_id++;
    }
    else
    {
	// check the given ID is not already in use
	for (cur = wp->w_match_head; cur != NULL; cur = cur->mit_next)
	    if (cur->mit_id == id)
	    {
		semsg(_(e_id_already_taken_nr), id);
		return -1;
	    }

	// Make sure the next match ID is always higher than the highest
	// manually selected ID.  Add some extra in case a few more IDs are
	// added soon.
	if (wp->w_next_match_id < id + 100)
	    wp->w_next_match_id = id + 100;
    }

    if ((hlg_id = syn_namen2id(grp, (int)STRLEN(grp))) == 0)
    {
	semsg(_(e_no_such_highlight_group_name_str), grp);
	return -1;
    }
    if (pat != NULL && (regprog = vim_regcomp(pat, RE_MAGIC)) == NULL)
    {
	semsg(_(e_invalid_argument_str), pat);
	return -1;
    }

    // Build new match.
    m = ALLOC_CLEAR_ONE(matchitem_T);
    if (m == NULL)
	return -1;
    if (pos_list != NULL)
    {
	m->mit_pos_array = ALLOC_CLEAR_MULT(llpos_T, pos_list->lv_len);
	if (m->mit_pos_array == NULL)
	{
	    vim_free(m);
	    return -1;
	}
	m->mit_pos_count = pos_list->lv_len;
    }
    m->mit_id = id;
    m->mit_priority = prio;
    m->mit_pattern = pat == NULL ? NULL : vim_strsave(pat);
    m->mit_hlg_id = hlg_id;
    m->mit_match.regprog = regprog;
    m->mit_match.rmm_ic = FALSE;
    m->mit_match.rmm_maxcol = 0;
# if defined(FEAT_CONCEAL)
    m->mit_conceal_char = 0;
    if (conceal_char != NULL)
	m->mit_conceal_char = (*mb_ptr2char)(conceal_char);
# endif

    // Set up position matches
    if (pos_list != NULL)
    {
	linenr_T	toplnum = 0;
	linenr_T	botlnum = 0;
	listitem_T	*li;
	int		i;

	CHECK_LIST_MATERIALIZE(pos_list);
	for (i = 0, li = pos_list->lv_first; li != NULL; i++, li = li->li_next)
	{
	    linenr_T	lnum = 0;
	    colnr_T	col = 0;
	    int		len = 1;
	    list_T	*subl;
	    listitem_T	*subli;
	    int		error = FALSE;

	    if (li->li_tv.v_type == VAR_LIST)
	    {
		subl = li->li_tv.vval.v_list;
		if (subl == NULL)
		    goto fail;
		subli = subl->lv_first;
		if (subli == NULL)
		    goto fail;
		lnum = tv_get_number_chk(&subli->li_tv, &error);
		if (error == TRUE)
		    goto fail;
		if (lnum == 0)
		{
		    --i;
		    continue;
		}
		m->mit_pos_array[i].lnum = lnum;
		subli = subli->li_next;
		if (subli != NULL)
		{
		    col = tv_get_number_chk(&subli->li_tv, &error);
		    if (error == TRUE)
			goto fail;
		    subli = subli->li_next;
		    if (subli != NULL)
		    {
			len = tv_get_number_chk(&subli->li_tv, &error);
			if (error == TRUE)
			    goto fail;
		    }
		}
		m->mit_pos_array[i].col = col;
		m->mit_pos_array[i].len = len;
	    }
	    else if (li->li_tv.v_type == VAR_NUMBER)
	    {
		if (li->li_tv.vval.v_number == 0)
		{
		    --i;
		    continue;
		}
		m->mit_pos_array[i].lnum = li->li_tv.vval.v_number;
		m->mit_pos_array[i].col = 0;
		m->mit_pos_array[i].len = 0;
	    }
	    else
	    {
		emsg(_(e_list_or_number_required));
		goto fail;
	    }
	    if (toplnum == 0 || lnum < toplnum)
		toplnum = lnum;
	    if (botlnum == 0 || lnum >= botlnum)
		botlnum = lnum + 1;
	}

	// Calculate top and bottom lines for redrawing area
	if (toplnum != 0)
	{
	    if (wp->w_buffer->b_mod_set)
	    {
		if (wp->w_buffer->b_mod_top > toplnum)
		    wp->w_buffer->b_mod_top = toplnum;
		if (wp->w_buffer->b_mod_bot < botlnum)
		    wp->w_buffer->b_mod_bot = botlnum;
	    }
	    else
	    {
		wp->w_buffer->b_mod_set = TRUE;
		wp->w_buffer->b_mod_top = toplnum;
		wp->w_buffer->b_mod_bot = botlnum;
		wp->w_buffer->b_mod_xlines = 0;
	    }
	    m->mit_toplnum = toplnum;
	    m->mit_botlnum = botlnum;
	    rtype = UPD_VALID;
	}
    }

    // Insert new match.  The match list is in ascending order with regard to
    // the match priorities.
    cur = wp->w_match_head;
    prev = cur;
    while (cur != NULL && prio >= cur->mit_priority)
    {
	prev = cur;
	cur = cur->mit_next;
    }
    if (cur == prev)
	wp->w_match_head = m;
    else
	prev->mit_next = m;
    m->mit_next = cur;

    redraw_win_later(wp, rtype);
    return id;

fail:
    vim_free(m->mit_pattern);
    vim_free(m->mit_pos_array);
    vim_free(m);
    return -1;
}

/*
 * Delete match with ID 'id' in the match list of window 'wp'.
 * Print error messages if 'perr' is TRUE.
 */
    static int
match_delete(win_T *wp, int id, int perr)
{
    matchitem_T	*cur = wp->w_match_head;
    matchitem_T	*prev = cur;
    int		rtype = UPD_SOME_VALID;

    if (id < 1)
    {
	if (perr == TRUE)
	    semsg(_(e_invalid_id_nr_must_be_greater_than_or_equal_to_one_2),
									   id);
	return -1;
    }
    while (cur != NULL && cur->mit_id != id)
    {
	prev = cur;
	cur = cur->mit_next;
    }
    if (cur == NULL)
    {
	if (perr == TRUE)
	    semsg(_(e_id_not_found_nr), id);
	return -1;
    }
    if (cur == prev)
	wp->w_match_head = cur->mit_next;
    else
	prev->mit_next = cur->mit_next;
    vim_regfree(cur->mit_match.regprog);
    vim_free(cur->mit_pattern);
    if (cur->mit_toplnum != 0)
    {
	if (wp->w_buffer->b_mod_set)
	{
	    if (wp->w_buffer->b_mod_top > cur->mit_toplnum)
		wp->w_buffer->b_mod_top = cur->mit_toplnum;
	    if (wp->w_buffer->b_mod_bot < cur->mit_botlnum)
		wp->w_buffer->b_mod_bot = cur->mit_botlnum;
	}
	else
	{
	    wp->w_buffer->b_mod_set = TRUE;
	    wp->w_buffer->b_mod_top = cur->mit_toplnum;
	    wp->w_buffer->b_mod_bot = cur->mit_botlnum;
	    wp->w_buffer->b_mod_xlines = 0;
	}
	rtype = UPD_VALID;
    }
    vim_free(cur->mit_pos_array);
    vim_free(cur);
    redraw_win_later(wp, rtype);
    return 0;
}

/*
 * Delete all matches in the match list of window 'wp'.
 */
    void
clear_matches(win_T *wp)
{
    matchitem_T *m;

    while (wp->w_match_head != NULL)
    {
	m = wp->w_match_head->mit_next;
	vim_regfree(wp->w_match_head->mit_match.regprog);
	vim_free(wp->w_match_head->mit_pattern);
	vim_free(wp->w_match_head->mit_pos_array);
	vim_free(wp->w_match_head);
	wp->w_match_head = m;
    }
    redraw_win_later(wp, UPD_SOME_VALID);
}

/*
 * Get match from ID 'id' in window 'wp'.
 * Return NULL if match not found.
 */
    static matchitem_T *
get_match(win_T *wp, int id)
{
    matchitem_T *cur = wp->w_match_head;

    while (cur != NULL && cur->mit_id != id)
	cur = cur->mit_next;
    return cur;
}

/*
 * Init for calling prepare_search_hl().
 */
    void
init_search_hl(win_T *wp, match_T *search_hl)
{
    matchitem_T *cur;

    // Setup for match and 'hlsearch' highlighting.  Disable any previous
    // match
    cur = wp->w_match_head;
    while (cur != NULL)
    {
	cur->mit_hl.rm = cur->mit_match;
	if (cur->mit_hlg_id == 0)
	    cur->mit_hl.attr = 0;
	else
	    cur->mit_hl.attr = syn_id2attr(cur->mit_hlg_id);
	cur->mit_hl.buf = wp->w_buffer;
	cur->mit_hl.lnum = 0;
	cur->mit_hl.first_lnum = 0;
	cur = cur->mit_next;
    }
    search_hl->buf = wp->w_buffer;
    search_hl->lnum = 0;
    search_hl->first_lnum = 0;
    // time limit is set at the toplevel, for all windows
}

/*
 * If there is a match fill "shl" and return one.
 * Return zero otherwise.
 */
    static int
next_search_hl_pos(
    match_T	    *shl,	// points to a match
    linenr_T	    lnum,
    matchitem_T	    *match,	// match item with positions
    colnr_T	    mincol)	// minimal column for a match
{
    int	    i;
    int	    found = -1;

    for (i = match->mit_pos_cur; i < match->mit_pos_count; i++)
    {
	llpos_T	*pos = &match->mit_pos_array[i];

	if (pos->lnum == 0)
	    break;
	if (pos->len == 0 && pos->col < mincol)
	    continue;
	if (pos->lnum == lnum)
	{
	    if (found >= 0)
	    {
		// if this match comes before the one at "found" then swap them
		if (pos->col < match->mit_pos_array[found].col)
		{
		    llpos_T	tmp = *pos;

		    *pos = match->mit_pos_array[found];
		    match->mit_pos_array[found] = tmp;
		}
	    }
	    else
		found = i;
	}
    }
    match->mit_pos_cur = 0;
    if (found >= 0)
    {
	colnr_T	start = match->mit_pos_array[found].col == 0
				     ? 0 : match->mit_pos_array[found].col - 1;
	colnr_T	end = match->mit_pos_array[found].col == 0
			    ? MAXCOL : start + match->mit_pos_array[found].len;

	shl->lnum = lnum;
	shl->rm.startpos[0].lnum = 0;
	shl->rm.startpos[0].col = start;
	shl->rm.endpos[0].lnum = 0;
	shl->rm.endpos[0].col = end;
	shl->is_addpos = TRUE;
	shl->has_cursor = FALSE;
	match->mit_pos_cur = found + 1;
	return 1;
    }
    return 0;
}

/*
 * Search for a next 'hlsearch' or match.
 * Uses shl->buf.
 * Sets shl->lnum and shl->rm contents.
 * Note: Assumes a previous match is always before "lnum", unless
 * shl->lnum is zero.
 * Careful: Any pointers for buffer lines will become invalid.
 */
    static void
next_search_hl(
    win_T	    *win,
    match_T	    *search_hl,
    match_T	    *shl,	// points to search_hl or a match
    linenr_T	    lnum,
    colnr_T	    mincol,	// minimal column for a match
    matchitem_T	    *cur)	// to retrieve match positions if any
{
    linenr_T	l;
    colnr_T	matchcol;
    long	nmatched;
    int		called_emsg_before = called_emsg;
    int		timed_out = FALSE;

    // for :{range}s/pat only highlight inside the range
    if ((lnum < search_first_line || lnum > search_last_line) && cur == NULL)
    {
	shl->lnum = 0;
	return;
    }

    if (shl->lnum != 0)
    {
	// Check for three situations:
	// 1. If the "lnum" is below a previous match, start a new search.
	// 2. If the previous match includes "mincol", use it.
	// 3. Continue after the previous match.
	l = shl->lnum + shl->rm.endpos[0].lnum - shl->rm.startpos[0].lnum;
	if (lnum > l)
	    shl->lnum = 0;
	else if (lnum < l || shl->rm.endpos[0].col > mincol)
	    return;
    }

    // Repeat searching for a match until one is found that includes "mincol"
    // or none is found in this line.
    for (;;)
    {
	// Three situations:
	// 1. No useful previous match: search from start of line.
	// 2. Not Vi compatible or empty match: continue at next character.
	//    Break the loop if this is beyond the end of the line.
	// 3. Vi compatible searching: continue at end of previous match.
	if (shl->lnum == 0)
	    matchcol = 0;
	else if (vim_strchr(p_cpo, CPO_SEARCH) == NULL
		|| (shl->rm.endpos[0].lnum == 0
		    && shl->rm.endpos[0].col <= shl->rm.startpos[0].col))
	{
	    char_u	*ml;

	    matchcol = shl->rm.startpos[0].col;
	    ml = ml_get_buf(shl->buf, lnum, FALSE) + matchcol;
	    if (*ml == NUL)
	    {
		++matchcol;
		shl->lnum = 0;
		break;
	    }
	    if (has_mbyte)
		matchcol += mb_ptr2len(ml);
	    else
		++matchcol;
	}
	else
	    matchcol = shl->rm.endpos[0].col;

	shl->lnum = lnum;
	if (shl->rm.regprog != NULL)
	{
	    // Remember whether shl->rm is using a copy of the regprog in
	    // cur->mit_match.
	    int regprog_is_copy = (shl != search_hl && cur != NULL
			  && shl == &cur->mit_hl
			  && cur->mit_match.regprog == cur->mit_hl.rm.regprog);

	    nmatched = vim_regexec_multi(&shl->rm, win, shl->buf, lnum,
							 matchcol, &timed_out);
	    // Copy the regprog, in case it got freed and recompiled.
	    if (regprog_is_copy)
		cur->mit_match.regprog = cur->mit_hl.rm.regprog;

	    if (called_emsg > called_emsg_before || got_int || timed_out)
	    {
		// Error while handling regexp: stop using this regexp.
		if (shl == search_hl)
		{
		    // don't free regprog in the match list, it's a copy
		    vim_regfree(shl->rm.regprog);
		    set_no_hlsearch(TRUE);
		}
		shl->rm.regprog = NULL;
		shl->lnum = 0;
		got_int = FALSE;  // avoid the "Type :quit to exit Vim" message
		break;
	    }
	}
	else if (cur != NULL)
	    nmatched = next_search_hl_pos(shl, lnum, cur, matchcol);
	else
	    nmatched = 0;
	if (nmatched == 0)
	{
	    shl->lnum = 0;		// no match found
	    break;
	}
	if (shl->rm.startpos[0].lnum > 0
		|| shl->rm.startpos[0].col >= mincol
		|| nmatched > 1
		|| shl->rm.endpos[0].col > mincol)
	{
	    shl->lnum += shl->rm.startpos[0].lnum;
	    break;			// useful match found
	}
    }
}

/*
 * Advance to the match in window "wp" line "lnum" or past it.
 */
    void
prepare_search_hl(win_T *wp, match_T *search_hl, linenr_T lnum)
{
    matchitem_T *cur;		// points to the match list
    match_T	*shl;		// points to search_hl or a match
    int		shl_flag;	// flag to indicate whether search_hl
				// has been processed or not
    int		pos_inprogress;	// marks that position match search is
				// in progress
    int		n;

    // When using a multi-line pattern, start searching at the top
    // of the window or just after a closed fold.
    // Do this both for search_hl and the match list.
    cur = wp->w_match_head;
    shl_flag = WIN_IS_POPUP(wp);  // skip search_hl in a popup window
    while (cur != NULL || shl_flag == FALSE)
    {
	if (shl_flag == FALSE)
	{
	    shl = search_hl;
	    shl_flag = TRUE;
	}
	else
	    shl = &cur->mit_hl;
	if (shl->rm.regprog != NULL
		&& shl->lnum == 0
		&& re_multiline(shl->rm.regprog))
	{
	    if (shl->first_lnum == 0)
	    {
# ifdef FEAT_FOLDING
		for (shl->first_lnum = lnum;
			   shl->first_lnum > wp->w_topline; --shl->first_lnum)
		    if (hasFoldingWin(wp, shl->first_lnum - 1,
						      NULL, NULL, TRUE, NULL))
			break;
# else
		shl->first_lnum = wp->w_topline;
# endif
	    }
	    if (cur != NULL)
		cur->mit_pos_cur = 0;
	    pos_inprogress = TRUE;
	    n = 0;
	    while (shl->first_lnum < lnum && (shl->rm.regprog != NULL
					  || (cur != NULL && pos_inprogress)))
	    {
		next_search_hl(wp, search_hl, shl, shl->first_lnum, (colnr_T)n,
					       shl == search_hl ? NULL : cur);
		pos_inprogress = cur == NULL || cur->mit_pos_cur == 0
							      ? FALSE : TRUE;
		if (shl->lnum != 0)
		{
		    shl->first_lnum = shl->lnum
				    + shl->rm.endpos[0].lnum
				    - shl->rm.startpos[0].lnum;
		    n = shl->rm.endpos[0].col;
		}
		else
		{
		    ++shl->first_lnum;
		    n = 0;
		}
	    }
	}
	if (shl != search_hl && cur != NULL)
	    cur = cur->mit_next;
    }
}

/*
 * Update "shl->has_cursor" based on the match in "shl" and the cursor
 * position.
 */
    static void
check_cur_search_hl(win_T *wp, match_T *shl)
{
    linenr_T linecount = shl->rm.endpos[0].lnum - shl->rm.startpos[0].lnum;

    if (wp->w_cursor.lnum >= shl->lnum
	    && wp->w_cursor.lnum <= shl->lnum + linecount
	    && (wp->w_cursor.lnum > shl->lnum
				|| wp->w_cursor.col >= shl->rm.startpos[0].col)
	    && (wp->w_cursor.lnum < shl->lnum + linecount
				  || wp->w_cursor.col < shl->rm.endpos[0].col))
	shl->has_cursor = TRUE;
    else
	shl->has_cursor = FALSE;
}

/*
 * Prepare for 'hlsearch' and match highlighting in one window line.
 * Return TRUE if there is such highlighting and set "search_attr" to the
 * current highlight attribute.
 */
    int
prepare_search_hl_line(
	win_T	    *wp,
	linenr_T    lnum,
	colnr_T	    mincol,
	char_u	    **line,
	match_T	    *search_hl,
	int	    *search_attr)
{
    matchitem_T *cur;			// points to the match list
    match_T	*shl;			// points to search_hl or a match
    int		shl_flag;		// flag to indicate whether search_hl
					// has been processed or not
    int		area_highlighting = FALSE;

    // Handle highlighting the last used search pattern and matches.
    // Do this for both search_hl and the match list.
    // Do not use search_hl in a popup window.
    cur = wp->w_match_head;
    shl_flag = WIN_IS_POPUP(wp);
    while (cur != NULL || shl_flag == FALSE)
    {
	if (shl_flag == FALSE)
	{
	    shl = search_hl;
	    shl_flag = TRUE;
	}
	else
	    shl = &cur->mit_hl;
	shl->startcol = MAXCOL;
	shl->endcol = MAXCOL;
	shl->attr_cur = 0;
	shl->is_addpos = FALSE;
	shl->has_cursor = FALSE;
	if (cur != NULL)
	    cur->mit_pos_cur = 0;
	next_search_hl(wp, search_hl, shl, lnum, mincol,
						shl == search_hl ? NULL : cur);

	// Need to get the line again, a multi-line regexp may have made it
	// invalid.
	*line = ml_get_buf(wp->w_buffer, lnum, FALSE);

	if (shl->lnum != 0 && shl->lnum <= lnum)
	{
	    if (shl->lnum == lnum)
		shl->startcol = shl->rm.startpos[0].col;
	    else
		shl->startcol = 0;
	    if (lnum == shl->lnum + shl->rm.endpos[0].lnum
						- shl->rm.startpos[0].lnum)
		shl->endcol = shl->rm.endpos[0].col;
	    else
		shl->endcol = MAXCOL;

	    // check if the cursor is in the match before changing the columns
	    if (shl == search_hl)
		check_cur_search_hl(wp, shl);

	    // Highlight one character for an empty match.
	    if (shl->startcol == shl->endcol)
	    {
		if (has_mbyte && (*line)[shl->endcol] != NUL)
		    shl->endcol += (*mb_ptr2len)((*line) + shl->endcol);
		else
		    ++shl->endcol;
	    }
	    if ((long)shl->startcol < mincol)  // match at leftcol
	    {
		shl->attr_cur = shl->attr;
		*search_attr = shl->attr;
	    }
	    area_highlighting = TRUE;
	}
	if (shl != search_hl && cur != NULL)
	    cur = cur->mit_next;
    }
    return area_highlighting;
}

/*
 * For a position in a line: Check for start/end of 'hlsearch' and other
 * matches.
 * After end, check for start/end of next match.
 * When another match, have to check for start again.
 * Watch out for matching an empty string!
 * "on_last_col" is set to TRUE with non-zero search_attr and the next column
 * is endcol.
 * Return the updated search_attr.
 */
    int
update_search_hl(
	win_T	    *wp,
	linenr_T    lnum,
	colnr_T	    col,
	char_u	    **line,
	match_T	    *search_hl,
	int	    *has_match_conc UNUSED,
	int	    *match_conc UNUSED,
	int	    did_line_attr,
	int	    lcs_eol_one,
	int	    *on_last_col)
{
    matchitem_T *cur;		    // points to the match list
    match_T	*shl;		    // points to search_hl or a match
    int		shl_flag;	    // flag to indicate whether search_hl
				    // has been processed or not
    int		pos_inprogress;	    // marks that position match search is in
				    // progress
    int		search_attr = 0;


    // Do this for 'search_hl' and the match list (ordered by priority).
    cur = wp->w_match_head;
    shl_flag = WIN_IS_POPUP(wp);
    while (cur != NULL || shl_flag == FALSE)
    {
	if (shl_flag == FALSE
		&& (cur == NULL
			|| cur->mit_priority > SEARCH_HL_PRIORITY))
	{
	    shl = search_hl;
	    shl_flag = TRUE;
	}
	else
	    shl = &cur->mit_hl;
	if (cur != NULL)
	    cur->mit_pos_cur = 0;
	pos_inprogress = TRUE;
	while (shl->rm.regprog != NULL || (cur != NULL && pos_inprogress))
	{
	    if (shl->startcol != MAXCOL
		    && col >= shl->startcol
		    && col < shl->endcol)
	    {
		int next_col = col + mb_ptr2len(*line + col);

		if (shl->endcol < next_col)
		    shl->endcol = next_col;
		shl->attr_cur = shl->attr;
# ifdef FEAT_CONCEAL
		// Match with the "Conceal" group results in hiding
		// the match.
		if (cur != NULL
			&& shl != search_hl
			&& syn_name2id((char_u *)"Conceal") == cur->mit_hlg_id)
		{
		    *has_match_conc = col == shl->startcol ? 2 : 1;
		    *match_conc = cur->mit_conceal_char;
		}
		else
		    *has_match_conc = 0;
# endif
		// Highlight the match were the cursor is using the CurSearch
		// group.
		if (shl == search_hl && shl->has_cursor)
		{
		    shl->attr_cur = HL_ATTR(HLF_LC);
		    if (shl->attr_cur != shl->attr)
			search_hl_has_cursor_lnum = lnum;
		}

	    }
	    else if (col == shl->endcol)
	    {
		shl->attr_cur = 0;
		next_search_hl(wp, search_hl, shl, lnum, col,
					       shl == search_hl ? NULL : cur);
		pos_inprogress = !(cur == NULL || cur->mit_pos_cur == 0);

		// Need to get the line again, a multi-line regexp may have
		// made it invalid.
		*line = ml_get_buf(wp->w_buffer, lnum, FALSE);

		if (shl->lnum == lnum)
		{
		    shl->startcol = shl->rm.startpos[0].col;
		    if (shl->rm.endpos[0].lnum == 0)
			shl->endcol = shl->rm.endpos[0].col;
		    else
			shl->endcol = MAXCOL;

		    // check if the cursor is in the match
		    if (shl == search_hl)
			check_cur_search_hl(wp, shl);

		    if (shl->startcol == shl->endcol)
		    {
			// highlight empty match, try again after
			// it
			if (has_mbyte)
			{
			    char_u *p = *line + shl->endcol;

			    if (*p == NUL)
				// consistent with non-mbyte
				++shl->endcol;
			    else
				shl->endcol += (*mb_ptr2len)(p);
			}
			else
			    ++shl->endcol;
		    }

		    // Loop to check if the match starts at the
		    // current position
		    continue;
		}
	    }
	    break;
	}
	if (shl != search_hl && cur != NULL)
	    cur = cur->mit_next;
    }

    // Use attributes from match with highest priority among 'search_hl' and
    // the match list.
    cur = wp->w_match_head;
    shl_flag = WIN_IS_POPUP(wp);
    while (cur != NULL || shl_flag == FALSE)
    {
	if (shl_flag == FALSE
		&& (cur == NULL ||
			cur->mit_priority > SEARCH_HL_PRIORITY))
	{
	    shl = search_hl;
	    shl_flag = TRUE;
	}
	else
	    shl = &cur->mit_hl;
	if (shl->attr_cur != 0)
	{
	    search_attr = shl->attr_cur;
	    *on_last_col = col + 1 >= shl->endcol;
	}
	if (shl != search_hl && cur != NULL)
	    cur = cur->mit_next;
    }
    // Only highlight one character after the last column.
    if (*(*line + col) == NUL && (did_line_attr >= 1
				       || (wp->w_p_list && lcs_eol_one == -1)))
	search_attr = 0;
    return search_attr;
}

    int
get_prevcol_hl_flag(win_T *wp, match_T *search_hl, long curcol)
{
    long	prevcol = curcol;
    int		prevcol_hl_flag = FALSE;
    matchitem_T *cur;			// points to the match list

#if defined(FEAT_PROP_POPUP)
    // don't do this in a popup window
    if (popup_is_popup(wp))
	return FALSE;
#endif

    // we're not really at that column when skipping some text
    if ((long)(wp->w_p_wrap ? wp->w_skipcol : wp->w_leftcol) > prevcol)
	++prevcol;

    // Highlight a character after the end of the line if the match started
    // at the end of the line or when the match continues in the next line
    // (match includes the line break).
    if (!search_hl->is_addpos && (prevcol == (long)search_hl->startcol
		|| (prevcol > (long)search_hl->startcol
					      && search_hl->endcol == MAXCOL)))
	prevcol_hl_flag = TRUE;
    else
    {
	cur = wp->w_match_head;
	while (cur != NULL)
	{
	    if (!cur->mit_hl.is_addpos && (prevcol == (long)cur->mit_hl.startcol
			|| (prevcol > (long)cur->mit_hl.startcol
					     && cur->mit_hl.endcol == MAXCOL)))
	    {
		prevcol_hl_flag = TRUE;
		break;
	    }
	    cur = cur->mit_next;
	}
    }
    return prevcol_hl_flag;
}

/*
 * Get highlighting for the char after the text in "char_attr" from 'hlsearch'
 * or match highlighting.
 */
    void
get_search_match_hl(win_T *wp, match_T *search_hl, long col, int *char_attr)
{
    matchitem_T *cur;			// points to the match list
    match_T	*shl;			// points to search_hl or a match
    int		shl_flag;		// flag to indicate whether search_hl
					// has been processed or not

    cur = wp->w_match_head;
    shl_flag = WIN_IS_POPUP(wp);
    while (cur != NULL || shl_flag == FALSE)
    {
	if (shl_flag == FALSE
		&& ((cur != NULL
			&& cur->mit_priority > SEARCH_HL_PRIORITY)
		    || cur == NULL))
	{
	    shl = search_hl;
	    shl_flag = TRUE;
	}
	else
	    shl = &cur->mit_hl;
	if (col - 1 == (long)shl->startcol
		&& (shl == search_hl || !shl->is_addpos))
	    *char_attr = shl->attr;
	if (shl != search_hl && cur != NULL)
	    cur = cur->mit_next;
    }
}

#endif // FEAT_SEARCH_EXTRA

#if defined(FEAT_EVAL) || defined(PROTO)
# ifdef FEAT_SEARCH_EXTRA
    static int
matchadd_dict_arg(typval_T *tv, char_u **conceal_char, win_T **win)
{
    dictitem_T *di;

    if (tv->v_type != VAR_DICT)
    {
	emsg(_(e_dictionary_required));
	return FAIL;
    }

    if (dict_has_key(tv->vval.v_dict, "conceal"))
	*conceal_char = dict_get_string(tv->vval.v_dict, "conceal", FALSE);

    if ((di = dict_find(tv->vval.v_dict, (char_u *)"window", -1)) == NULL)
	return OK;

    *win = find_win_by_nr_or_id(&di->di_tv);
    if (*win == NULL)
    {
	emsg(_(e_invalid_window_number));
	return FAIL;
    }

    return OK;
}
#endif

/*
 * "clearmatches()" function
 */
    void
f_clearmatches(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
{
#ifdef FEAT_SEARCH_EXTRA
    win_T   *win;

    if (in_vim9script() && check_for_opt_number_arg(argvars, 0) == FAIL)
	return;

    win = get_optional_window(argvars, 0);
    if (win != NULL)
	clear_matches(win);
#endif
}

/*
 * "getmatches()" function
 */
    void
f_getmatches(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
{
# ifdef FEAT_SEARCH_EXTRA
    dict_T	*dict;
    matchitem_T	*cur;
    int		i;
    win_T	*win;

    if (in_vim9script() && check_for_opt_number_arg(argvars, 0) == FAIL)
	return;

    win = get_optional_window(argvars, 0);
    if (rettv_list_alloc(rettv) == FAIL || win == NULL)
	return;

    cur = win->w_match_head;
    while (cur != NULL)
    {
	dict = dict_alloc();
	if (dict == NULL)
	    return;
	if (cur->mit_match.regprog == NULL)
	{
	    // match added with matchaddpos()
	    for (i = 0; i < cur->mit_pos_count; ++i)
	    {
		llpos_T	*llpos;
		char	buf[30];  // use 30 to avoid compiler warning
		list_T	*l;

		llpos = &cur->mit_pos_array[i];
		if (llpos->lnum == 0)
		    break;
		l = list_alloc();
		if (l == NULL)
		    break;
		list_append_number(l, (varnumber_T)llpos->lnum);
		if (llpos->col > 0)
		{
		    list_append_number(l, (varnumber_T)llpos->col);
		    list_append_number(l, (varnumber_T)llpos->len);
		}
		sprintf(buf, "pos%d", i + 1);
		dict_add_list(dict, buf, l);
	    }
	}
	else
	{
	    dict_add_string(dict, "pattern", cur->mit_pattern);
	}
	dict_add_string(dict, "group", syn_id2name(cur->mit_hlg_id));
	dict_add_number(dict, "priority", (long)cur->mit_priority);
	dict_add_number(dict, "id", (long)cur->mit_id);
#  if defined(FEAT_CONCEAL)
	if (cur->mit_conceal_char)
	{
	    char_u buf[MB_MAXBYTES + 1];

	    buf[(*mb_char2bytes)(cur->mit_conceal_char, buf)] = NUL;
	    dict_add_string(dict, "conceal", (char_u *)&buf);
	}
#  endif
	list_append_dict(rettv->vval.v_list, dict);
	cur = cur->mit_next;
    }
# endif
}

/*
 * "setmatches()" function
 */
    void
f_setmatches(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
{
#ifdef FEAT_SEARCH_EXTRA
    list_T	*l;
    listitem_T	*li;
    dict_T	*d;
    list_T	*s = NULL;
    win_T	*win;

    rettv->vval.v_number = -1;

    if (in_vim9script()
	    && (check_for_list_arg(argvars, 0) == FAIL
		|| check_for_opt_number_arg(argvars, 1) == FAIL))
	return;

    if (check_for_list_arg(argvars, 0) == FAIL)
	return;
    win = get_optional_window(argvars, 1);
    if (win == NULL)
	return;

    if ((l = argvars[0].vval.v_list) != NULL)
    {
	// To some extent make sure that we are dealing with a list from
	// "getmatches()".
	li = l->lv_first;
	while (li != NULL)
	{
	    if (li->li_tv.v_type != VAR_DICT
		    || (d = li->li_tv.vval.v_dict) == NULL)
	    {
		emsg(_(e_invalid_argument));
		return;
	    }
	    if (!(dict_has_key(d, "group")
			&& (dict_has_key(d, "pattern")
			    || dict_has_key(d, "pos1"))
			&& dict_has_key(d, "priority")
			&& dict_has_key(d, "id")))
	    {
		emsg(_(e_invalid_argument));
		return;
	    }
	    li = li->li_next;
	}

	clear_matches(win);
	li = l->lv_first;
	while (li != NULL)
	{
	    int		i = 0;
	    char	buf[30];  // use 30 to avoid compiler warning
	    dictitem_T  *di;
	    char_u	*group;
	    int		priority;
	    int		id;
	    char_u	*conceal;

	    d = li->li_tv.vval.v_dict;
	    if (!dict_has_key(d, "pattern"))
	    {
		if (s == NULL)
		{
		    s = list_alloc();
		    if (s == NULL)
			return;
		}

		// match from matchaddpos()
		for (i = 1; i < 9; i++)
		{
		    sprintf((char *)buf, (char *)"pos%d", i);
		    if ((di = dict_find(d, (char_u *)buf, -1)) != NULL)
		    {
			if (di->di_tv.v_type != VAR_LIST)
			    return;

			list_append_tv(s, &di->di_tv);
			s->lv_refcount++;
		    }
		    else
			break;
		}
	    }

	    group = dict_get_string(d, "group", TRUE);
	    priority = (int)dict_get_number(d, "priority");
	    id = (int)dict_get_number(d, "id");
	    conceal = dict_has_key(d, "conceal")
			      ? dict_get_string(d, "conceal", TRUE)
			      : NULL;
	    if (i == 0)
	    {
		match_add(win, group,
		    dict_get_string(d, "pattern", FALSE),
		    priority, id, NULL, conceal);
	    }
	    else
	    {
		match_add(win, group, NULL, priority, id, s, conceal);
		list_unref(s);
		s = NULL;
	    }
	    vim_free(group);
	    vim_free(conceal);

	    li = li->li_next;
	}
	rettv->vval.v_number = 0;
    }
#endif
}

/*
 * "matchadd()" function
 */
    void
f_matchadd(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
{
# ifdef FEAT_SEARCH_EXTRA
    char_u	buf[NUMBUFLEN];
    char_u	*grp;		// group
    char_u	*pat;		// pattern
    int		prio = 10;	// default priority
    int		id = -1;
    int		error = FALSE;
    char_u	*conceal_char = NULL;
    win_T	*win = curwin;

    rettv->vval.v_number = -1;

    if (in_vim9script()
	    && (check_for_string_arg(argvars, 0) == FAIL
		|| check_for_string_arg(argvars, 1) == FAIL
		|| check_for_opt_number_arg(argvars, 2) == FAIL
		|| (argvars[2].v_type != VAR_UNKNOWN
		    && (check_for_opt_number_arg(argvars, 3) == FAIL
			|| (argvars[3].v_type != VAR_UNKNOWN
			    && check_for_opt_dict_arg(argvars, 4) == FAIL)))))
	return;

    grp = tv_get_string_buf_chk(&argvars[0], buf);	// group
    pat = tv_get_string_buf_chk(&argvars[1], buf);	// pattern
    if (grp == NULL || pat == NULL)
	return;
    if (argvars[2].v_type != VAR_UNKNOWN)
    {
	prio = (int)tv_get_number_chk(&argvars[2], &error);
	if (argvars[3].v_type != VAR_UNKNOWN)
	{
	    id = (int)tv_get_number_chk(&argvars[3], &error);
	    if (argvars[4].v_type != VAR_UNKNOWN
		&& matchadd_dict_arg(&argvars[4], &conceal_char, &win) == FAIL)
		return;
	}
    }
    if (error == TRUE)
	return;
    if (id >= 1 && id <= 3)
    {
	semsg(_(e_id_is_reserved_for_match_nr), id);
	return;
    }

    rettv->vval.v_number = match_add(win, grp, pat, prio, id, NULL,
								conceal_char);
# endif
}

/*
 * "matchaddpos()" function
 */
    void
f_matchaddpos(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
{
# ifdef FEAT_SEARCH_EXTRA
    char_u	buf[NUMBUFLEN];
    char_u	*group;
    int		prio = 10;
    int		id = -1;
    int		error = FALSE;
    list_T	*l;
    char_u	*conceal_char = NULL;
    win_T	*win = curwin;

    rettv->vval.v_number = -1;

    if (in_vim9script()
	    && (check_for_string_arg(argvars, 0) == FAIL
		|| check_for_list_arg(argvars, 1) == FAIL
		|| check_for_opt_number_arg(argvars, 2) == FAIL
		|| (argvars[2].v_type != VAR_UNKNOWN
		    && (check_for_opt_number_arg(argvars, 3) == FAIL
			|| (argvars[3].v_type != VAR_UNKNOWN
			    && check_for_opt_dict_arg(argvars, 4) == FAIL)))))
	return;

    group = tv_get_string_buf_chk(&argvars[0], buf);
    if (group == NULL)
	return;

    if (argvars[1].v_type != VAR_LIST)
    {
	semsg(_(e_argument_of_str_must_be_list), "matchaddpos()");
	return;
    }
    l = argvars[1].vval.v_list;
    if (l == NULL)
	return;

    if (argvars[2].v_type != VAR_UNKNOWN)
    {
	prio = (int)tv_get_number_chk(&argvars[2], &error);
	if (argvars[3].v_type != VAR_UNKNOWN)
	{
	    id = (int)tv_get_number_chk(&argvars[3], &error);

	    if (argvars[4].v_type != VAR_UNKNOWN
		&& matchadd_dict_arg(&argvars[4], &conceal_char, &win) == FAIL)
		return;
	}
    }
    if (error == TRUE)
	return;

    // id == 3 is ok because matchaddpos() is supposed to substitute :3match
    if (id == 1 || id == 2)
    {
	semsg(_(e_id_is_reserved_for_match_nr), id);
	return;
    }

    rettv->vval.v_number = match_add(win, group, NULL, prio, id, l,
								conceal_char);
# endif
}

/*
 * "matcharg()" function
 */
    void
f_matcharg(typval_T *argvars UNUSED, typval_T *rettv)
{
    if (rettv_list_alloc(rettv) != OK)
	return;

# ifdef FEAT_SEARCH_EXTRA
    int	    id;
    matchitem_T *m;

    if (in_vim9script() && check_for_number_arg(argvars, 0) == FAIL)
	return;

    id = (int)tv_get_number(&argvars[0]);
    if (id >= 1 && id <= 3)
    {
	if ((m = get_match(curwin, id)) != NULL)
	{
	    list_append_string(rettv->vval.v_list,
		    syn_id2name(m->mit_hlg_id), -1);
	    list_append_string(rettv->vval.v_list, m->mit_pattern, -1);
	}
	else
	{
	    list_append_string(rettv->vval.v_list, NULL, -1);
	    list_append_string(rettv->vval.v_list, NULL, -1);
	}
    }
# endif
}

/*
 * "matchdelete()" function
 */
    void
f_matchdelete(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
{
# ifdef FEAT_SEARCH_EXTRA
    win_T   *win;

    if (in_vim9script()
	    && (check_for_number_arg(argvars, 0) == FAIL
		|| check_for_opt_number_arg(argvars, 1) == FAIL))
	return;

    win = get_optional_window(argvars, 1);
    if (win == NULL)
	rettv->vval.v_number = -1;
    else
	rettv->vval.v_number = match_delete(win,
				       (int)tv_get_number(&argvars[0]), TRUE);
# endif
}
#endif

#if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
/*
 * ":[N]match {group} {pattern}"
 * Sets nextcmd to the start of the next command, if any.  Also called when
 * skipping commands to find the next command.
 */
    void
ex_match(exarg_T *eap)
{
    char_u	*p;
    char_u	*g = NULL;
    char_u	*end;
    int		c;
    int		id;

    if (eap->line2 <= 3)
	id = eap->line2;
    else
    {
	emsg(_(e_invalid_command));
	return;
    }

    // First clear any old pattern.
    if (!eap->skip)
	match_delete(curwin, id, FALSE);

    if (ends_excmd2(eap->cmd, eap->arg))
	end = eap->arg;
    else if ((STRNICMP(eap->arg, "none", 4) == 0
		&& (VIM_ISWHITE(eap->arg[4])
				      || ends_excmd2(eap->arg, eap->arg + 4))))
	end = eap->arg + 4;
    else
    {
	p = skiptowhite(eap->arg);
	if (!eap->skip)
	    g = vim_strnsave(eap->arg, p - eap->arg);
	p = skipwhite(p);
	if (*p == NUL)
	{
	    // There must be two arguments.
	    vim_free(g);
	    semsg(_(e_invalid_argument_str), eap->arg);
	    return;
	}
	end = skip_regexp(p + 1, *p, TRUE);
	if (!eap->skip)
	{
	    if (*end != NUL && !ends_excmd2(end, skipwhite(end + 1)))
	    {
		vim_free(g);
		eap->errmsg = ex_errmsg(e_trailing_characters_str, end);
		return;
	    }
	    if (*end != *p)
	    {
		vim_free(g);
		semsg(_(e_invalid_argument_str), p);
		return;
	    }

	    c = *end;
	    *end = NUL;
	    match_add(curwin, g, p + 1, 10, id, NULL, NULL);
	    vim_free(g);
	    *end = c;
	}
    }
    eap->nextcmd = find_nextcmd(end);
}
#endif