view src/syntax.c @ 32730:078630443def v9.0.1685

patch 9.0.1685: silence Python 3.11 depreciations for gcc Commit: https://github.com/vim/vim/commit/422b9dcbfadcd5c1dfad982f9782563915398430 Author: Philip H <47042125+pheiduck@users.noreply.github.com> Date: Fri Aug 11 22:38:48 2023 +0200 patch 9.0.1685: silence Python 3.11 depreciations for gcc Problem: Python 3.11 interface throws deprecation warnings Solution: ignore those warnings for gcc and clang Python 3.11 deprecation warnings are already silenced for clang using the pragma ``` # pragma clang diagnostic ignored "-Wdeprecated-declarations" ``` However those warnings are also emitted when using gcc. To avoid them for both compilers, change use the __GNUC__ ifdef, which is defined for gcc as well as clang. Additionally, instead of using the "clang diagnostic ignored" pragma, let's make use of 'GCC diagnostic ignored' which is again supported by clang and GCC closes: #12610 Signed-off-by: Christian Brabandt <cb@256bit.org> Co-authored-by: Philip H <47042125+pheiduck@users.noreply.github.com>
author Christian Brabandt <cb@256bit.org>
date Fri, 11 Aug 2023 23:00:03 +0200
parents 97255d909654
children 9e093c96dff6
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.
 */

/*
 * syntax.c: code for syntax highlighting
 */

#include "vim.h"

#if defined(FEAT_SYN_HL) || defined(PROTO)

#define SYN_NAMELEN	50		// maximum length of a syntax name

// different types of offsets that are possible
#define SPO_MS_OFF	0	// match  start offset
#define SPO_ME_OFF	1	// match  end	offset
#define SPO_HS_OFF	2	// highl. start offset
#define SPO_HE_OFF	3	// highl. end	offset
#define SPO_RS_OFF	4	// region start offset
#define SPO_RE_OFF	5	// region end	offset
#define SPO_LC_OFF	6	// leading context offset
#define SPO_COUNT	7

static char *(spo_name_tab[SPO_COUNT]) =
	    {"ms=", "me=", "hs=", "he=", "rs=", "re=", "lc="};

/*
 * The patterns that are being searched for are stored in a syn_pattern.
 * A match item consists of one pattern.
 * A start/end item consists of n start patterns and m end patterns.
 * A start/skip/end item consists of n start patterns, one skip pattern and m
 * end patterns.
 * For the latter two, the patterns are always consecutive: start-skip-end.
 *
 * A character offset can be given for the matched text (_m_start and _m_end)
 * and for the actually highlighted text (_h_start and _h_end).
 *
 * Note that ordering of members is optimized to reduce padding.
 */
typedef struct syn_pattern
{
    char	 sp_type;		// see SPTYPE_ defines below
    char	 sp_syncing;		// this item used for syncing
    short	 sp_syn_match_id;	// highlight group ID of pattern
    short	 sp_off_flags;		// see below
    int		 sp_offsets[SPO_COUNT];	// offsets
    int		 sp_flags;		// see HL_ defines below
#ifdef FEAT_CONCEAL
    int		 sp_cchar;		// conceal substitute character
#endif
    int		 sp_ic;			// ignore-case flag for sp_prog
    int		 sp_sync_idx;		// sync item index (syncing only)
    int		 sp_line_id;		// ID of last line where tried
    int		 sp_startcol;		// next match in sp_line_id line
    short	*sp_cont_list;		// cont. group IDs, if non-zero
    short	*sp_next_list;		// next group IDs, if non-zero
    struct sp_syn sp_syn;		// struct passed to in_id_list()
    char_u	*sp_pattern;		// regexp to match, pattern
    regprog_T	*sp_prog;		// regexp to match, program
#ifdef FEAT_PROFILE
    syn_time_T	 sp_time;
#endif
} synpat_T;

// The sp_off_flags are computed like this:
// offset from the start of the matched text: (1 << SPO_XX_OFF)
// offset from the end	 of the matched text: (1 << (SPO_XX_OFF + SPO_COUNT))
// When both are present, only one is used.

#define SPTYPE_MATCH	1	// match keyword with this group ID
#define SPTYPE_START	2	// match a regexp, start of item
#define SPTYPE_END	3	// match a regexp, end of item
#define SPTYPE_SKIP	4	// match a regexp, skip within item


#define SYN_ITEMS(buf)	((synpat_T *)((buf)->b_syn_patterns.ga_data))

#define NONE_IDX	(-2)	// value of sp_sync_idx for "NONE"

/*
 * Flags for b_syn_sync_flags:
 */
#define SF_CCOMMENT	0x01	// sync on a C-style comment
#define SF_MATCH	0x02	// sync by matching a pattern

#define SYN_STATE_P(ssp)    ((bufstate_T *)((ssp)->ga_data))

#define MAXKEYWLEN	80	    // maximum length of a keyword

/*
 * The attributes of the syntax item that has been recognized.
 */
static int current_attr = 0;	    // attr of current syntax word
#ifdef FEAT_EVAL
static int current_id = 0;	    // ID of current char for syn_get_id()
static int current_trans_id = 0;    // idem, transparency removed
#endif
#ifdef FEAT_CONCEAL
static int current_flags = 0;
static int current_seqnr = 0;
static int current_sub_char = 0;
#endif

typedef struct syn_cluster_S
{
    char_u	    *scl_name;	    // syntax cluster name
    char_u	    *scl_name_u;    // uppercase of scl_name
    short	    *scl_list;	    // IDs in this syntax cluster
} syn_cluster_T;

/*
 * Methods of combining two clusters
 */
#define CLUSTER_REPLACE	    1	// replace first list with second
#define CLUSTER_ADD	    2	// add second list to first
#define CLUSTER_SUBTRACT    3	// subtract second list from first

#define SYN_CLSTR(buf)	((syn_cluster_T *)((buf)->b_syn_clusters.ga_data))

/*
 * Syntax group IDs have different types:
 *     0 - 19999  normal syntax groups
 * 20000 - 20999  ALLBUT indicator (current_syn_inc_tag added)
 * 21000 - 21999  TOP indicator (current_syn_inc_tag added)
 * 22000 - 22999  CONTAINED indicator (current_syn_inc_tag added)
 * 23000 - 32767  cluster IDs (subtract SYNID_CLUSTER for the cluster ID)
 */
#define SYNID_ALLBUT	MAX_HL_ID   // syntax group ID for contains=ALLBUT
#define SYNID_TOP	21000	    // syntax group ID for contains=TOP
#define SYNID_CONTAINED	22000	    // syntax group ID for contains=CONTAINED
#define SYNID_CLUSTER	23000	    // first syntax group ID for clusters

#define MAX_SYN_INC_TAG	999	    // maximum before the above overflow
#define MAX_CLUSTER_ID  (32767 - SYNID_CLUSTER)

/*
 * Annoying Hack(TM):  ":syn include" needs this pointer to pass to
 * expand_filename().  Most of the other syntax commands don't need it, so
 * instead of passing it to them, we stow it here.
 */
static char_u **syn_cmdlinep;

/*
 * Another Annoying Hack(TM):  To prevent rules from other ":syn include"'d
 * files from leaking into ALLBUT lists, we assign a unique ID to the
 * rules in each ":syn include"'d file.
 */
static int current_syn_inc_tag = 0;
static int running_syn_inc_tag = 0;

/*
 * In a hashtable item "hi_key" points to "keyword" in a keyentry.
 * This avoids adding a pointer to the hashtable item.
 * KE2HIKEY() converts a var pointer to a hashitem key pointer.
 * HIKEY2KE() converts a hashitem key pointer to a var pointer.
 * HI2KE() converts a hashitem pointer to a var pointer.
 */
static keyentry_T dumkey;
#define KE2HIKEY(kp)  ((kp)->keyword)
#define HIKEY2KE(p)   ((keyentry_T *)((p) - (dumkey.keyword - (char_u *)&dumkey)))
#define HI2KE(hi)      HIKEY2KE((hi)->hi_key)

/*
 * To reduce the time spent in keepend(), remember at which level in the state
 * stack the first item with "keepend" is present.  When "-1", there is no
 * "keepend" on the stack.
 */
static int keepend_level = -1;

static char msg_no_items[] = N_("No Syntax items defined for this buffer");

/*
 * For the current state we need to remember more than just the idx.
 * When si_m_endpos.lnum is 0, the items other than si_idx are unknown.
 * (The end positions have the column number of the next char)
 */
typedef struct state_item
{
    int		si_idx;			// index of syntax pattern or
					// KEYWORD_IDX
    int		si_id;			// highlight group ID for keywords
    int		si_trans_id;		// idem, transparency removed
    int		si_m_lnum;		// lnum of the match
    int		si_m_startcol;		// starting column of the match
    lpos_T	si_m_endpos;		// just after end posn of the match
    lpos_T	si_h_startpos;		// start position of the highlighting
    lpos_T	si_h_endpos;		// end position of the highlighting
    lpos_T	si_eoe_pos;		// end position of end pattern
    int		si_end_idx;		// group ID for end pattern or zero
    int		si_ends;		// if match ends before si_m_endpos
    int		si_attr;		// attributes in this state
    long	si_flags;		// HL_HAS_EOL flag in this state, and
					// HL_SKIP* for si_next_list
#ifdef FEAT_CONCEAL
    int		si_seqnr;		// sequence number
    int		si_cchar;		// substitution character for conceal
#endif
    short	*si_cont_list;		// list of contained groups
    short	*si_next_list;		// nextgroup IDs after this item ends
    reg_extmatch_T *si_extmatch;	// \z(...\) matches from start
					// pattern
} stateitem_T;

#define KEYWORD_IDX	(-1)	    // value of si_idx for keywords
#define ID_LIST_ALL	((short *)-1) // valid of si_cont_list for containing all
				    // but contained groups

#ifdef FEAT_CONCEAL
static int next_seqnr = 1;		// value to use for si_seqnr
#endif

/*
 * Struct to reduce the number of arguments to get_syn_options(), it's used
 * very often.
 */
typedef struct
{
    int		flags;		// flags for contained and transparent
    int		keyword;	// TRUE for ":syn keyword"
    int		*sync_idx;	// syntax item for "grouphere" argument, NULL
				// if not allowed
    char	has_cont_list;	// TRUE if "cont_list" can be used
    short	*cont_list;	// group IDs for "contains" argument
    short	*cont_in_list;	// group IDs for "containedin" argument
    short	*next_list;	// group IDs for "nextgroup" argument
} syn_opt_arg_T;

/*
 * The next possible match in the current line for any pattern is remembered,
 * to avoid having to try for a match in each column.
 * If next_match_idx == -1, not tried (in this line) yet.
 * If next_match_col == MAXCOL, no match found in this line.
 * (All end positions have the column of the char after the end)
 */
static int next_match_col;		// column for start of next match
static lpos_T next_match_m_endpos;	// position for end of next match
static lpos_T next_match_h_startpos;	// pos. for highl. start of next match
static lpos_T next_match_h_endpos;	// pos. for highl. end of next match
static int next_match_idx;		// index of matched item
static long next_match_flags;		// flags for next match
static lpos_T next_match_eos_pos;	// end of start pattn (start region)
static lpos_T next_match_eoe_pos;	// pos. for end of end pattern
static int next_match_end_idx;		// ID of group for end pattn or zero
static reg_extmatch_T *next_match_extmatch = NULL;

/*
 * A state stack is an array of integers or stateitem_T, stored in a
 * garray_T.  A state stack is invalid if its itemsize entry is zero.
 */
#define INVALID_STATE(ssp)  ((ssp)->ga_itemsize == 0)
#define VALID_STATE(ssp)    ((ssp)->ga_itemsize != 0)

#define FOR_ALL_SYNSTATES(sb, sst) \
    for ((sst) = (sb)->b_sst_first; (sst) != NULL; (sst) = (sst)->sst_next)

/*
 * The current state (within the line) of the recognition engine.
 * When current_state.ga_itemsize is 0 the current state is invalid.
 */
static win_T	*syn_win;		// current window for highlighting
static buf_T	*syn_buf;		// current buffer for highlighting
static synblock_T *syn_block;		// current buffer for highlighting
static linenr_T current_lnum = 0;	// lnum of current state
static colnr_T	current_col = 0;	// column of current state
static int	current_state_stored = 0; // TRUE if stored current state
					  // after setting current_finished
static int	current_finished = 0;	// current line has been finished
static garray_T current_state		// current stack of state_items
		= {0, 0, 0, 0, NULL};
static short	*current_next_list = NULL; // when non-zero, nextgroup list
static int	current_next_flags = 0; // flags for current_next_list
static int	current_line_id = 0;	// unique number for current line

#define CUR_STATE(idx)	((stateitem_T *)(current_state.ga_data))[idx]

static void syn_sync(win_T *wp, linenr_T lnum, synstate_T *last_valid);
static int syn_match_linecont(linenr_T lnum);
static void syn_start_line(void);
static void syn_update_ends(int startofline);
static void syn_stack_alloc(void);
static int syn_stack_cleanup(void);
static void syn_stack_free_entry(synblock_T *block, synstate_T *p);
static synstate_T *syn_stack_find_entry(linenr_T lnum);
static synstate_T *store_current_state(void);
static void load_current_state(synstate_T *from);
static void invalidate_current_state(void);
static int syn_stack_equal(synstate_T *sp);
static void validate_current_state(void);
static int syn_finish_line(int syncing);
static int syn_current_attr(int syncing, int displaying, int *can_spell, int keep_state);
static int did_match_already(int idx, garray_T *gap);
static stateitem_T *push_next_match(stateitem_T *cur_si);
static void check_state_ends(void);
static void update_si_attr(int idx);
static void check_keepend(void);
static void update_si_end(stateitem_T *sip, int startcol, int force);
static short *copy_id_list(short *list);
static int in_id_list(stateitem_T *item, short *cont_list, struct sp_syn *ssp, int contained);
static int push_current_state(int idx);
static void pop_current_state(void);
#ifdef FEAT_PROFILE
static void syn_clear_time(syn_time_T *tt);
static void syntime_clear(void);
static void syntime_report(void);
static int syn_time_on = FALSE;
# define IF_SYN_TIME(p) (p)
#else
# define IF_SYN_TIME(p) NULL
typedef int syn_time_T;
#endif

static void syn_stack_apply_changes_block(synblock_T *block, buf_T *buf);
static void find_endpos(int idx, lpos_T *startpos, lpos_T *m_endpos, lpos_T *hl_endpos, long *flagsp, lpos_T *end_endpos, int *end_idx, reg_extmatch_T *start_ext);

static void limit_pos(lpos_T *pos, lpos_T *limit);
static void limit_pos_zero(lpos_T *pos, lpos_T *limit);
static void syn_add_end_off(lpos_T *result, regmmatch_T *regmatch, synpat_T *spp, int idx, int extra);
static void syn_add_start_off(lpos_T *result, regmmatch_T *regmatch, synpat_T *spp, int idx, int extra);
static char_u *syn_getcurline(void);
static int syn_regexec(regmmatch_T *rmp, linenr_T lnum, colnr_T col, syn_time_T *st);
static int check_keyword_id(char_u *line, int startcol, int *endcol, long *flags, short **next_list, stateitem_T *cur_si, int *ccharp);
static void syn_remove_pattern(synblock_T *block, int idx);
static void syn_clear_pattern(synblock_T *block, int i);
static void syn_clear_cluster(synblock_T *block, int i);
static void syn_clear_one(int id, int syncing);
static void syn_cmd_onoff(exarg_T *eap, char *name);
static void syn_lines_msg(void);
static void syn_match_msg(void);
static void syn_list_one(int id, int syncing, int link_only);
static void syn_list_cluster(int id);
static void put_id_list(char_u *name, short *list, int attr);
static void put_pattern(char *s, int c, synpat_T *spp, int attr);
static int syn_list_keywords(int id, hashtab_T *ht, int did_header, int attr);
static void syn_clear_keyword(int id, hashtab_T *ht);
static void clear_keywtab(hashtab_T *ht);
static int syn_scl_namen2id(char_u *linep, int len);
static int syn_check_cluster(char_u *pp, int len);
static int syn_add_cluster(char_u *name);
static void init_syn_patterns(void);
static char_u *get_syn_pattern(char_u *arg, synpat_T *ci);
static int get_id_list(char_u **arg, int keylen, short **list, int skip);
static void syn_combine_list(short **clstr1, short **clstr2, int list_op);

/*
 * Start the syntax recognition for a line.  This function is normally called
 * from the screen updating, once for each displayed line.
 * The buffer is remembered in syn_buf, because get_syntax_attr() doesn't get
 * it.	Careful: curbuf and curwin are likely to point to another buffer and
 * window.
 */
    void
syntax_start(win_T *wp, linenr_T lnum)
{
    synstate_T	*p;
    synstate_T	*last_valid = NULL;
    synstate_T	*last_min_valid = NULL;
    synstate_T	*sp, *prev = NULL;
    linenr_T	parsed_lnum;
    linenr_T	first_stored;
    int		dist;
    static varnumber_T changedtick = 0;	// remember the last change ID

#ifdef FEAT_CONCEAL
    current_sub_char = NUL;
#endif

    /*
     * After switching buffers, invalidate current_state.
     * Also do this when a change was made, the current state may be invalid
     * then.
     */
    if (syn_block != wp->w_s
	    || syn_buf != wp->w_buffer
	    || changedtick != CHANGEDTICK(syn_buf))
    {
	invalidate_current_state();
	syn_buf = wp->w_buffer;
	syn_block = wp->w_s;
    }
    changedtick = CHANGEDTICK(syn_buf);
    syn_win = wp;

    /*
     * Allocate syntax stack when needed.
     */
    syn_stack_alloc();
    if (syn_block->b_sst_array == NULL)
	return;		// out of memory
    syn_block->b_sst_lasttick = display_tick;

    /*
     * If the state of the end of the previous line is useful, store it.
     */
    if (VALID_STATE(&current_state)
	    && current_lnum < lnum
	    && current_lnum < syn_buf->b_ml.ml_line_count)
    {
	(void)syn_finish_line(FALSE);
	if (!current_state_stored)
	{
	    ++current_lnum;
	    (void)store_current_state();
	}

	/*
	 * If the current_lnum is now the same as "lnum", keep the current
	 * state (this happens very often!).  Otherwise invalidate
	 * current_state and figure it out below.
	 */
	if (current_lnum != lnum)
	    invalidate_current_state();
    }
    else
	invalidate_current_state();

    /*
     * Try to synchronize from a saved state in b_sst_array[].
     * Only do this if lnum is not before and not to far beyond a saved state.
     */
    if (INVALID_STATE(&current_state) && syn_block->b_sst_array != NULL)
    {
	// Find last valid saved state before start_lnum.
	FOR_ALL_SYNSTATES(syn_block, p)
	{
	    if (p->sst_lnum > lnum)
		break;
	    if (p->sst_lnum <= lnum && p->sst_change_lnum == 0)
	    {
		last_valid = p;
		if (p->sst_lnum >= lnum - syn_block->b_syn_sync_minlines)
		    last_min_valid = p;
	    }
	}
	if (last_min_valid != NULL)
	    load_current_state(last_min_valid);
    }

    /*
     * If "lnum" is before or far beyond a line with a saved state, need to
     * re-synchronize.
     */
    if (INVALID_STATE(&current_state))
    {
	syn_sync(wp, lnum, last_valid);
	if (current_lnum == 1)
	    // First line is always valid, no matter "minlines".
	    first_stored = 1;
	else
	    // Need to parse "minlines" lines before state can be considered
	    // valid to store.
	    first_stored = current_lnum + syn_block->b_syn_sync_minlines;
    }
    else
	first_stored = current_lnum;

    /*
     * Advance from the sync point or saved state until the current line.
     * Save some entries for syncing with later on.
     */
    if (syn_block->b_sst_len <= Rows)
	dist = 999999;
    else
	dist = syn_buf->b_ml.ml_line_count / (syn_block->b_sst_len - Rows) + 1;
    while (current_lnum < lnum)
    {
	syn_start_line();
	(void)syn_finish_line(FALSE);
	++current_lnum;

	// If we parsed at least "minlines" lines or started at a valid
	// state, the current state is considered valid.
	if (current_lnum >= first_stored)
	{
	    // Check if the saved state entry is for the current line and is
	    // equal to the current state.  If so, then validate all saved
	    // states that depended on a change before the parsed line.
	    if (prev == NULL)
		prev = syn_stack_find_entry(current_lnum - 1);
	    if (prev == NULL)
		sp = syn_block->b_sst_first;
	    else
		sp = prev;
	    while (sp != NULL && sp->sst_lnum < current_lnum)
		sp = sp->sst_next;
	    if (sp != NULL
		    && sp->sst_lnum == current_lnum
		    && syn_stack_equal(sp))
	    {
		parsed_lnum = current_lnum;
		prev = sp;
		while (sp != NULL && sp->sst_change_lnum <= parsed_lnum)
		{
		    if (sp->sst_lnum <= lnum)
			// valid state before desired line, use this one
			prev = sp;
		    else if (sp->sst_change_lnum == 0)
			// past saved states depending on change, break here.
			break;
		    sp->sst_change_lnum = 0;
		    sp = sp->sst_next;
		}
		load_current_state(prev);
	    }
	    // Store the state at this line when it's the first one, the line
	    // where we start parsing, or some distance from the previously
	    // saved state.  But only when parsed at least 'minlines'.
	    else if (prev == NULL
			|| current_lnum == lnum
			|| current_lnum >= prev->sst_lnum + dist)
		prev = store_current_state();
	}

	// This can take a long time: break when CTRL-C pressed.  The current
	// state will be wrong then.
	line_breakcheck();
	if (got_int)
	{
	    current_lnum = lnum;
	    break;
	}
    }

    syn_start_line();
}

/*
 * We cannot simply discard growarrays full of state_items or buf_states; we
 * have to manually release their extmatch pointers first.
 */
    static void
clear_syn_state(synstate_T *p)
{
    int		i;
    garray_T	*gap;

    if (p->sst_stacksize > SST_FIX_STATES)
    {
	gap = &(p->sst_union.sst_ga);
	for (i = 0; i < gap->ga_len; i++)
	    unref_extmatch(SYN_STATE_P(gap)[i].bs_extmatch);
	ga_clear(gap);
    }
    else
    {
	for (i = 0; i < p->sst_stacksize; i++)
	    unref_extmatch(p->sst_union.sst_stack[i].bs_extmatch);
    }
}

/*
 * Cleanup the current_state stack.
 */
    static void
clear_current_state(void)
{
    int		i;
    stateitem_T	*sip;

    sip = (stateitem_T *)(current_state.ga_data);
    for (i = 0; i < current_state.ga_len; i++)
	unref_extmatch(sip[i].si_extmatch);
    ga_clear(&current_state);
}

/*
 * Try to find a synchronisation point for line "lnum".
 *
 * This sets current_lnum and the current state.  One of three methods is
 * used:
 * 1. Search backwards for the end of a C-comment.
 * 2. Search backwards for given sync patterns.
 * 3. Simply start on a given number of lines above "lnum".
 */
    static void
syn_sync(
    win_T	*wp,
    linenr_T	start_lnum,
    synstate_T	*last_valid)
{
    buf_T	*curbuf_save;
    win_T	*curwin_save;
    pos_T	cursor_save;
    int		idx;
    linenr_T	lnum;
    linenr_T	end_lnum;
    linenr_T	break_lnum;
    int		had_sync_point;
    stateitem_T	*cur_si;
    synpat_T	*spp;
    char_u	*line;
    int		found_flags = 0;
    int		found_match_idx = 0;
    linenr_T	found_current_lnum = 0;
    int		found_current_col= 0;
    lpos_T	found_m_endpos;
    colnr_T	prev_current_col;

    /*
     * Clear any current state that might be hanging around.
     */
    invalidate_current_state();

    /*
     * Start at least "minlines" back.  Default starting point for parsing is
     * there.
     * Start further back, to avoid that scrolling backwards will result in
     * resyncing for every line.  Now it resyncs only one out of N lines,
     * where N is minlines * 1.5, or minlines * 2 if minlines is small.
     * Watch out for overflow when minlines is MAXLNUM.
     */
    if (syn_block->b_syn_sync_minlines > start_lnum)
	start_lnum = 1;
    else
    {
	if (syn_block->b_syn_sync_minlines == 1)
	    lnum = 1;
	else if (syn_block->b_syn_sync_minlines < 10)
	    lnum = syn_block->b_syn_sync_minlines * 2;
	else
	    lnum = syn_block->b_syn_sync_minlines * 3 / 2;
	if (syn_block->b_syn_sync_maxlines != 0
				     && lnum > syn_block->b_syn_sync_maxlines)
	    lnum = syn_block->b_syn_sync_maxlines;
	if (lnum >= start_lnum)
	    start_lnum = 1;
	else
	    start_lnum -= lnum;
    }
    current_lnum = start_lnum;

    /*
     * 1. Search backwards for the end of a C-style comment.
     */
    if (syn_block->b_syn_sync_flags & SF_CCOMMENT)
    {
	// Need to make syn_buf the current buffer for a moment, to be able to
	// use find_start_comment().
	curwin_save = curwin;
	curwin = wp;
	curbuf_save = curbuf;
	curbuf = syn_buf;

	/*
	 * Skip lines that end in a backslash.
	 */
	for ( ; start_lnum > 1; --start_lnum)
	{
	    line = ml_get(start_lnum - 1);
	    if (*line == NUL || *(line + STRLEN(line) - 1) != '\\')
		break;
	}
	current_lnum = start_lnum;

	// set cursor to start of search
	cursor_save = wp->w_cursor;
	wp->w_cursor.lnum = start_lnum;
	wp->w_cursor.col = 0;

	/*
	 * If the line is inside a comment, need to find the syntax item that
	 * defines the comment.
	 * Restrict the search for the end of a comment to b_syn_sync_maxlines.
	 */
	if (find_start_comment((int)syn_block->b_syn_sync_maxlines) != NULL)
	{
	    for (idx = syn_block->b_syn_patterns.ga_len; --idx >= 0; )
		if (SYN_ITEMS(syn_block)[idx].sp_syn.id
						   == syn_block->b_syn_sync_id
			&& SYN_ITEMS(syn_block)[idx].sp_type == SPTYPE_START)
		{
		    validate_current_state();
		    if (push_current_state(idx) == OK)
			update_si_attr(current_state.ga_len - 1);
		    break;
		}
	}

	// restore cursor and buffer
	wp->w_cursor = cursor_save;
	curwin = curwin_save;
	curbuf = curbuf_save;
    }

    /*
     * 2. Search backwards for given sync patterns.
     */
    else if (syn_block->b_syn_sync_flags & SF_MATCH)
    {
	if (syn_block->b_syn_sync_maxlines != 0
			       && start_lnum > syn_block->b_syn_sync_maxlines)
	    break_lnum = start_lnum - syn_block->b_syn_sync_maxlines;
	else
	    break_lnum = 0;

	found_m_endpos.lnum = 0;
	found_m_endpos.col = 0;
	end_lnum = start_lnum;
	lnum = start_lnum;
	while (--lnum > break_lnum)
	{
	    // This can take a long time: break when CTRL-C pressed.
	    line_breakcheck();
	    if (got_int)
	    {
		invalidate_current_state();
		current_lnum = start_lnum;
		break;
	    }

	    // Check if we have run into a valid saved state stack now.
	    if (last_valid != NULL && lnum == last_valid->sst_lnum)
	    {
		load_current_state(last_valid);
		break;
	    }

	    /*
	     * Check if the previous line has the line-continuation pattern.
	     */
	    if (lnum > 1 && syn_match_linecont(lnum - 1))
		continue;

	    /*
	     * Start with nothing on the state stack
	     */
	    validate_current_state();

	    for (current_lnum = lnum; current_lnum < end_lnum; ++current_lnum)
	    {
		syn_start_line();
		for (;;)
		{
		    had_sync_point = syn_finish_line(TRUE);
		    /*
		     * When a sync point has been found, remember where, and
		     * continue to look for another one, further on in the line.
		     */
		    if (had_sync_point && current_state.ga_len)
		    {
			cur_si = &CUR_STATE(current_state.ga_len - 1);
			if (cur_si->si_m_endpos.lnum > start_lnum)
			{
			    // ignore match that goes to after where started
			    current_lnum = end_lnum;
			    break;
			}
			if (cur_si->si_idx < 0)
			{
			    // Cannot happen?
			    found_flags = 0;
			    found_match_idx = KEYWORD_IDX;
			}
			else
			{
			    spp = &(SYN_ITEMS(syn_block)[cur_si->si_idx]);
			    found_flags = spp->sp_flags;
			    found_match_idx = spp->sp_sync_idx;
			}
			found_current_lnum = current_lnum;
			found_current_col = current_col;
			found_m_endpos = cur_si->si_m_endpos;
			/*
			 * Continue after the match (be aware of a zero-length
			 * match).
			 */
			if (found_m_endpos.lnum > current_lnum)
			{
			    current_lnum = found_m_endpos.lnum;
			    current_col = found_m_endpos.col;
			    if (current_lnum >= end_lnum)
				break;
			}
			else if (found_m_endpos.col > current_col)
			    current_col = found_m_endpos.col;
			else
			    ++current_col;

			// syn_current_attr() will have skipped the check for
			// an item that ends here, need to do that now.  Be
			// careful not to go past the NUL.
			prev_current_col = current_col;
			if (syn_getcurline()[current_col] != NUL)
			    ++current_col;
			check_state_ends();
			current_col = prev_current_col;
		    }
		    else
			break;
		}
	    }

	    /*
	     * If a sync point was encountered, break here.
	     */
	    if (found_flags)
	    {
		/*
		 * Put the item that was specified by the sync point on the
		 * state stack.  If there was no item specified, make the
		 * state stack empty.
		 */
		clear_current_state();
		if (found_match_idx >= 0
			&& push_current_state(found_match_idx) == OK)
		    update_si_attr(current_state.ga_len - 1);

		/*
		 * When using "grouphere", continue from the sync point
		 * match, until the end of the line.  Parsing starts at
		 * the next line.
		 * For "groupthere" the parsing starts at start_lnum.
		 */
		if (found_flags & HL_SYNC_HERE)
		{
		    if (current_state.ga_len)
		    {
			cur_si = &CUR_STATE(current_state.ga_len - 1);
			cur_si->si_h_startpos.lnum = found_current_lnum;
			cur_si->si_h_startpos.col = found_current_col;
			update_si_end(cur_si, (int)current_col, TRUE);
			check_keepend();
		    }
		    current_col = found_m_endpos.col;
		    current_lnum = found_m_endpos.lnum;
		    (void)syn_finish_line(FALSE);
		    ++current_lnum;
		}
		else
		    current_lnum = start_lnum;

		break;
	    }

	    end_lnum = lnum;
	    invalidate_current_state();
	}

	// Ran into start of the file or exceeded maximum number of lines
	if (lnum <= break_lnum)
	{
	    invalidate_current_state();
	    current_lnum = break_lnum + 1;
	}
    }

    validate_current_state();
}

    static void
save_chartab(char_u *chartab)
{
    if (syn_block->b_syn_isk == empty_option)
	return;

    mch_memmove(chartab, syn_buf->b_chartab, (size_t)32);
    mch_memmove(syn_buf->b_chartab, syn_win->w_s->b_syn_chartab, (size_t)32);
}

    static void
restore_chartab(char_u *chartab)
{
    if (syn_win->w_s->b_syn_isk != empty_option)
	mch_memmove(syn_buf->b_chartab, chartab, (size_t)32);
}

/*
 * Return TRUE if the line-continuation pattern matches in line "lnum".
 */
    static int
syn_match_linecont(linenr_T lnum)
{
    regmmatch_T regmatch;
    int r;
    char_u	buf_chartab[32];  // chartab array for syn iskyeyword

    if (syn_block->b_syn_linecont_prog == NULL)
	return FALSE;

    // use syntax iskeyword option
    save_chartab(buf_chartab);
    regmatch.rmm_ic = syn_block->b_syn_linecont_ic;
    regmatch.regprog = syn_block->b_syn_linecont_prog;
    r = syn_regexec(&regmatch, lnum, (colnr_T)0,
	    IF_SYN_TIME(&syn_block->b_syn_linecont_time));
    syn_block->b_syn_linecont_prog = regmatch.regprog;
    restore_chartab(buf_chartab);
    return r;
}

/*
 * Prepare the current state for the start of a line.
 */
    static void
syn_start_line(void)
{
    current_finished = FALSE;
    current_col = 0;

    /*
     * Need to update the end of a start/skip/end that continues from the
     * previous line and regions that have "keepend".
     */
    if (current_state.ga_len > 0)
    {
	syn_update_ends(TRUE);
	check_state_ends();
    }

    next_match_idx = -1;
    ++current_line_id;
#ifdef FEAT_CONCEAL
    next_seqnr = 1;
#endif
}

/*
 * Check for items in the stack that need their end updated.
 * When "startofline" is TRUE the last item is always updated.
 * When "startofline" is FALSE the item with "keepend" is forcefully updated.
 */
    static void
syn_update_ends(int startofline)
{
    stateitem_T	*cur_si;
    int		i;
    int		seen_keepend;

    if (startofline)
    {
	// Check for a match carried over from a previous line with a
	// contained region.  The match ends as soon as the region ends.
	for (i = 0; i < current_state.ga_len; ++i)
	{
	    cur_si = &CUR_STATE(i);
	    if (cur_si->si_idx >= 0
		    && (SYN_ITEMS(syn_block)[cur_si->si_idx]).sp_type
							       == SPTYPE_MATCH
		    && cur_si->si_m_endpos.lnum < current_lnum)
	    {
		cur_si->si_flags |= HL_MATCHCONT;
		cur_si->si_m_endpos.lnum = 0;
		cur_si->si_m_endpos.col = 0;
		cur_si->si_h_endpos = cur_si->si_m_endpos;
		cur_si->si_ends = TRUE;
	    }
	}
    }

    /*
     * Need to update the end of a start/skip/end that continues from the
     * previous line.  And regions that have "keepend", because they may
     * influence contained items.  If we've just removed "extend"
     * (startofline == 0) then we should update ends of normal regions
     * contained inside "keepend" because "extend" could have extended
     * these "keepend" regions as well as contained normal regions.
     * Then check for items ending in column 0.
     */
    i = current_state.ga_len - 1;
    if (keepend_level >= 0)
	for ( ; i > keepend_level; --i)
	    if (CUR_STATE(i).si_flags & HL_EXTEND)
		break;

    seen_keepend = FALSE;
    for ( ; i < current_state.ga_len; ++i)
    {
	cur_si = &CUR_STATE(i);
	if ((cur_si->si_flags & HL_KEEPEND)
			    || (seen_keepend && !startofline)
			    || (i == current_state.ga_len - 1 && startofline))
	{
	    cur_si->si_h_startpos.col = 0;	// start highl. in col 0
	    cur_si->si_h_startpos.lnum = current_lnum;

	    if (!(cur_si->si_flags & HL_MATCHCONT))
		update_si_end(cur_si, (int)current_col, !startofline);

	    if (!startofline && (cur_si->si_flags & HL_KEEPEND))
		seen_keepend = TRUE;
	}
    }
    check_keepend();
}

/////////////////////////////////////////
// Handling of the state stack cache.

/*
 * EXPLANATION OF THE SYNTAX STATE STACK CACHE
 *
 * To speed up syntax highlighting, the state stack for the start of some
 * lines is cached.  These entries can be used to start parsing at that point.
 *
 * The stack is kept in b_sst_array[] for each buffer.  There is a list of
 * valid entries.  b_sst_first points to the first one, then follow sst_next.
 * The entries are sorted on line number.  The first entry is often for line 2
 * (line 1 always starts with an empty stack).
 * There is also a list for free entries.  This construction is used to avoid
 * having to allocate and free memory blocks too often.
 *
 * When making changes to the buffer, this is logged in b_mod_*.  When calling
 * update_screen() to update the display, it will call
 * syn_stack_apply_changes() for each displayed buffer to adjust the cached
 * entries.  The entries which are inside the changed area are removed,
 * because they must be recomputed.  Entries below the changed have their line
 * number adjusted for deleted/inserted lines, and have their sst_change_lnum
 * set to indicate that a check must be made if the changed lines would change
 * the cached entry.
 *
 * When later displaying lines, an entry is stored for each line.  Displayed
 * lines are likely to be displayed again, in which case the state at the
 * start of the line is needed.
 * For not displayed lines, an entry is stored for every so many lines.  These
 * entries will be used e.g., when scrolling backwards.  The distance between
 * entries depends on the number of lines in the buffer.  For small buffers
 * the distance is fixed at SST_DIST, for large buffers there is a fixed
 * number of entries SST_MAX_ENTRIES, and the distance is computed.
 */

    static void
syn_stack_free_block(synblock_T *block)
{
    synstate_T	*p;

    if (block->b_sst_array == NULL)
	return;

    FOR_ALL_SYNSTATES(block, p)
	clear_syn_state(p);
    VIM_CLEAR(block->b_sst_array);
    block->b_sst_first = NULL;
    block->b_sst_len = 0;
}
/*
 * Free b_sst_array[] for buffer "buf".
 * Used when syntax items changed to force resyncing everywhere.
 */
    void
syn_stack_free_all(synblock_T *block)
{
#ifdef FEAT_FOLDING
    win_T	*wp;
#endif

    syn_stack_free_block(block);

#ifdef FEAT_FOLDING
    // When using "syntax" fold method, must update all folds.
    FOR_ALL_WINDOWS(wp)
    {
	if (wp->w_s == block && foldmethodIsSyntax(wp))
	    foldUpdateAll(wp);
    }
#endif
}

/*
 * Allocate the syntax state stack for syn_buf when needed.
 * If the number of entries in b_sst_array[] is much too big or a bit too
 * small, reallocate it.
 * Also used to allocate b_sst_array[] for the first time.
 */
    static void
syn_stack_alloc(void)
{
    long	len;
    synstate_T	*to, *from;
    synstate_T	*sstp;

    len = syn_buf->b_ml.ml_line_count / SST_DIST + Rows * 2;
    if (len < SST_MIN_ENTRIES)
	len = SST_MIN_ENTRIES;
    else if (len > SST_MAX_ENTRIES)
	len = SST_MAX_ENTRIES;
    if (syn_block->b_sst_len > len * 2 || syn_block->b_sst_len < len)
    {
	// Allocate 50% too much, to avoid reallocating too often.
	len = syn_buf->b_ml.ml_line_count;
	len = (len + len / 2) / SST_DIST + Rows * 2;
	if (len < SST_MIN_ENTRIES)
	    len = SST_MIN_ENTRIES;
	else if (len > SST_MAX_ENTRIES)
	    len = SST_MAX_ENTRIES;

	if (syn_block->b_sst_array != NULL)
	{
	    // When shrinking the array, cleanup the existing stack.
	    // Make sure that all valid entries fit in the new array.
	    while (syn_block->b_sst_len - syn_block->b_sst_freecount + 2 > len
		    && syn_stack_cleanup())
		;
	    if (len < syn_block->b_sst_len - syn_block->b_sst_freecount + 2)
		len = syn_block->b_sst_len - syn_block->b_sst_freecount + 2;
	}

	sstp = ALLOC_CLEAR_MULT(synstate_T, len);
	if (sstp == NULL)	// out of memory!
	    return;

	to = sstp - 1;
	if (syn_block->b_sst_array != NULL)
	{
	    // Move the states from the old array to the new one.
	    for (from = syn_block->b_sst_first; from != NULL;
							from = from->sst_next)
	    {
		++to;
		*to = *from;
		to->sst_next = to + 1;
	    }
	}
	if (to != sstp - 1)
	{
	    to->sst_next = NULL;
	    syn_block->b_sst_first = sstp;
	    syn_block->b_sst_freecount = len - (int)(to - sstp) - 1;
	}
	else
	{
	    syn_block->b_sst_first = NULL;
	    syn_block->b_sst_freecount = len;
	}

	// Create the list of free entries.
	syn_block->b_sst_firstfree = to + 1;
	while (++to < sstp + len)
	    to->sst_next = to + 1;
	(sstp + len - 1)->sst_next = NULL;

	vim_free(syn_block->b_sst_array);
	syn_block->b_sst_array = sstp;
	syn_block->b_sst_len = len;
    }
}

/*
 * Check for changes in a buffer to affect stored syntax states.  Uses the
 * b_mod_* fields.
 * Called from update_screen(), before screen is being updated, once for each
 * displayed buffer.
 */
    void
syn_stack_apply_changes(buf_T *buf)
{
    win_T	*wp;

    syn_stack_apply_changes_block(&buf->b_s, buf);

    FOR_ALL_WINDOWS(wp)
    {
	if ((wp->w_buffer == buf) && (wp->w_s != &buf->b_s))
	    syn_stack_apply_changes_block(wp->w_s, buf);
    }
}

    static void
syn_stack_apply_changes_block(synblock_T *block, buf_T *buf)
{
    synstate_T	*p, *prev, *np;
    linenr_T	n;

    prev = NULL;
    for (p = block->b_sst_first; p != NULL; )
    {
	if (p->sst_lnum + block->b_syn_sync_linebreaks > buf->b_mod_top)
	{
	    n = p->sst_lnum + buf->b_mod_xlines;
	    if (n <= buf->b_mod_bot)
	    {
		// this state is inside the changed area, remove it
		np = p->sst_next;
		if (prev == NULL)
		    block->b_sst_first = np;
		else
		    prev->sst_next = np;
		syn_stack_free_entry(block, p);
		p = np;
		continue;
	    }
	    // This state is below the changed area.  Remember the line
	    // that needs to be parsed before this entry can be made valid
	    // again.
	    if (p->sst_change_lnum != 0 && p->sst_change_lnum > buf->b_mod_top)
	    {
		if (p->sst_change_lnum + buf->b_mod_xlines > buf->b_mod_top)
		    p->sst_change_lnum += buf->b_mod_xlines;
		else
		    p->sst_change_lnum = buf->b_mod_top;
	    }
	    if (p->sst_change_lnum == 0
		    || p->sst_change_lnum < buf->b_mod_bot)
		p->sst_change_lnum = buf->b_mod_bot;

	    p->sst_lnum = n;
	}
	prev = p;
	p = p->sst_next;
    }
}

/*
 * Reduce the number of entries in the state stack for syn_buf.
 * Returns TRUE if at least one entry was freed.
 */
    static int
syn_stack_cleanup(void)
{
    synstate_T	*p, *prev;
    disptick_T	tick;
    int		above;
    int		dist;
    int		retval = FALSE;

    if (syn_block->b_sst_first == NULL)
	return retval;

    // Compute normal distance between non-displayed entries.
    if (syn_block->b_sst_len <= Rows)
	dist = 999999;
    else
	dist = syn_buf->b_ml.ml_line_count / (syn_block->b_sst_len - Rows) + 1;

    /*
     * Go through the list to find the "tick" for the oldest entry that can
     * be removed.  Set "above" when the "tick" for the oldest entry is above
     * "b_sst_lasttick" (the display tick wraps around).
     */
    tick = syn_block->b_sst_lasttick;
    above = FALSE;
    prev = syn_block->b_sst_first;
    for (p = prev->sst_next; p != NULL; prev = p, p = p->sst_next)
    {
	if (prev->sst_lnum + dist > p->sst_lnum)
	{
	    if (p->sst_tick > syn_block->b_sst_lasttick)
	    {
		if (!above || p->sst_tick < tick)
		    tick = p->sst_tick;
		above = TRUE;
	    }
	    else if (!above && p->sst_tick < tick)
		tick = p->sst_tick;
	}
    }

    /*
     * Go through the list to make the entries for the oldest tick at an
     * interval of several lines.
     */
    prev = syn_block->b_sst_first;
    for (p = prev->sst_next; p != NULL; prev = p, p = p->sst_next)
    {
	if (p->sst_tick == tick && prev->sst_lnum + dist > p->sst_lnum)
	{
	    // Move this entry from used list to free list
	    prev->sst_next = p->sst_next;
	    syn_stack_free_entry(syn_block, p);
	    p = prev;
	    retval = TRUE;
	}
    }
    return retval;
}

/*
 * Free the allocated memory for a syn_state item.
 * Move the entry into the free list.
 */
    static void
syn_stack_free_entry(synblock_T *block, synstate_T *p)
{
    clear_syn_state(p);
    p->sst_next = block->b_sst_firstfree;
    block->b_sst_firstfree = p;
    ++block->b_sst_freecount;
}

/*
 * Find an entry in the list of state stacks at or before "lnum".
 * Returns NULL when there is no entry or the first entry is after "lnum".
 */
    static synstate_T *
syn_stack_find_entry(linenr_T lnum)
{
    synstate_T	*p, *prev;

    prev = NULL;
    for (p = syn_block->b_sst_first; p != NULL; prev = p, p = p->sst_next)
    {
	if (p->sst_lnum == lnum)
	    return p;
	if (p->sst_lnum > lnum)
	    break;
    }
    return prev;
}

/*
 * Try saving the current state in b_sst_array[].
 * The current state must be valid for the start of the current_lnum line!
 */
    static synstate_T *
store_current_state(void)
{
    int		i;
    synstate_T	*p;
    bufstate_T	*bp;
    stateitem_T	*cur_si;
    synstate_T	*sp = syn_stack_find_entry(current_lnum);

    /*
     * If the current state contains a start or end pattern that continues
     * from the previous line, we can't use it.  Don't store it then.
     */
    for (i = current_state.ga_len - 1; i >= 0; --i)
    {
	cur_si = &CUR_STATE(i);
	if (cur_si->si_h_startpos.lnum >= current_lnum
		|| cur_si->si_m_endpos.lnum >= current_lnum
		|| cur_si->si_h_endpos.lnum >= current_lnum
		|| (cur_si->si_end_idx
		    && cur_si->si_eoe_pos.lnum >= current_lnum))
	    break;
    }
    if (i >= 0)
    {
	if (sp != NULL)
	{
	    // find "sp" in the list and remove it
	    if (syn_block->b_sst_first == sp)
		// it's the first entry
		syn_block->b_sst_first = sp->sst_next;
	    else
	    {
		// find the entry just before this one to adjust sst_next
		FOR_ALL_SYNSTATES(syn_block, p)
		    if (p->sst_next == sp)
			break;
		if (p != NULL)	// just in case
		    p->sst_next = sp->sst_next;
	    }
	    syn_stack_free_entry(syn_block, sp);
	    sp = NULL;
	}
    }
    else if (sp == NULL || sp->sst_lnum != current_lnum)
    {
	/*
	 * Add a new entry
	 */
	// If no free items, cleanup the array first.
	if (syn_block->b_sst_freecount == 0)
	{
	    (void)syn_stack_cleanup();
	    // "sp" may have been moved to the freelist now
	    sp = syn_stack_find_entry(current_lnum);
	}
	// Still no free items?  Must be a strange problem...
	if (syn_block->b_sst_freecount == 0)
	    sp = NULL;
	else
	{
	    // Take the first item from the free list and put it in the used
	    // list, after *sp
	    p = syn_block->b_sst_firstfree;
	    syn_block->b_sst_firstfree = p->sst_next;
	    --syn_block->b_sst_freecount;
	    if (sp == NULL)
	    {
		// Insert in front of the list
		p->sst_next = syn_block->b_sst_first;
		syn_block->b_sst_first = p;
	    }
	    else
	    {
		// insert in list after *sp
		p->sst_next = sp->sst_next;
		sp->sst_next = p;
	    }
	    sp = p;
	    sp->sst_stacksize = 0;
	    sp->sst_lnum = current_lnum;
	}
    }
    if (sp != NULL)
    {
	// When overwriting an existing state stack, clear it first
	clear_syn_state(sp);
	sp->sst_stacksize = current_state.ga_len;
	if (current_state.ga_len > SST_FIX_STATES)
	{
	    // Need to clear it, might be something remaining from when the
	    // length was less than SST_FIX_STATES.
	    ga_init2(&sp->sst_union.sst_ga, sizeof(bufstate_T), 1);
	    if (ga_grow(&sp->sst_union.sst_ga, current_state.ga_len) == FAIL)
		sp->sst_stacksize = 0;
	    else
		sp->sst_union.sst_ga.ga_len = current_state.ga_len;
	    bp = SYN_STATE_P(&(sp->sst_union.sst_ga));
	}
	else
	    bp = sp->sst_union.sst_stack;
	for (i = 0; i < sp->sst_stacksize; ++i)
	{
	    bp[i].bs_idx = CUR_STATE(i).si_idx;
	    bp[i].bs_flags = CUR_STATE(i).si_flags;
#ifdef FEAT_CONCEAL
	    bp[i].bs_seqnr = CUR_STATE(i).si_seqnr;
	    bp[i].bs_cchar = CUR_STATE(i).si_cchar;
#endif
	    bp[i].bs_extmatch = ref_extmatch(CUR_STATE(i).si_extmatch);
	}
	sp->sst_next_flags = current_next_flags;
	sp->sst_next_list = current_next_list;
	sp->sst_tick = display_tick;
	sp->sst_change_lnum = 0;
    }
    current_state_stored = TRUE;
    return sp;
}

/*
 * Copy a state stack from "from" in b_sst_array[] to current_state;
 */
    static void
load_current_state(synstate_T *from)
{
    int		i;
    bufstate_T	*bp;

    clear_current_state();
    validate_current_state();
    keepend_level = -1;
    if (from->sst_stacksize
	    && ga_grow(&current_state, from->sst_stacksize) == OK)
    {
	if (from->sst_stacksize > SST_FIX_STATES)
	    bp = SYN_STATE_P(&(from->sst_union.sst_ga));
	else
	    bp = from->sst_union.sst_stack;
	for (i = 0; i < from->sst_stacksize; ++i)
	{
	    CUR_STATE(i).si_idx = bp[i].bs_idx;
	    CUR_STATE(i).si_flags = bp[i].bs_flags;
#ifdef FEAT_CONCEAL
	    CUR_STATE(i).si_seqnr = bp[i].bs_seqnr;
	    CUR_STATE(i).si_cchar = bp[i].bs_cchar;
#endif
	    CUR_STATE(i).si_extmatch = ref_extmatch(bp[i].bs_extmatch);
	    if (keepend_level < 0 && (CUR_STATE(i).si_flags & HL_KEEPEND))
		keepend_level = i;
	    CUR_STATE(i).si_ends = FALSE;
	    CUR_STATE(i).si_m_lnum = 0;
	    if (CUR_STATE(i).si_idx >= 0)
		CUR_STATE(i).si_next_list =
		     (SYN_ITEMS(syn_block)[CUR_STATE(i).si_idx]).sp_next_list;
	    else
		CUR_STATE(i).si_next_list = NULL;
	    update_si_attr(i);
	}
	current_state.ga_len = from->sst_stacksize;
    }
    current_next_list = from->sst_next_list;
    current_next_flags = from->sst_next_flags;
    current_lnum = from->sst_lnum;
}

/*
 * Compare saved state stack "*sp" with the current state.
 * Return TRUE when they are equal.
 */
    static int
syn_stack_equal(synstate_T *sp)
{
    int		i, j;
    bufstate_T	*bp;
    reg_extmatch_T	*six, *bsx;

    // First a quick check if the stacks have the same size end nextlist.
    if (sp->sst_stacksize != current_state.ga_len
	    || sp->sst_next_list != current_next_list)
	return FALSE;

    // Need to compare all states on both stacks.
    if (sp->sst_stacksize > SST_FIX_STATES)
	bp = SYN_STATE_P(&(sp->sst_union.sst_ga));
    else
	bp = sp->sst_union.sst_stack;

    for (i = current_state.ga_len; --i >= 0; )
    {
	// If the item has another index the state is different.
	if (bp[i].bs_idx != CUR_STATE(i).si_idx)
	    break;
	if (bp[i].bs_extmatch == CUR_STATE(i).si_extmatch)
	    continue;
	// When the extmatch pointers are different, the strings in them can
	// still be the same.  Check if the extmatch references are equal.
	bsx = bp[i].bs_extmatch;
	six = CUR_STATE(i).si_extmatch;
	// If one of the extmatch pointers is NULL the states are different.
	if (bsx == NULL || six == NULL)
	    break;
	for (j = 0; j < NSUBEXP; ++j)
	{
	    // Check each referenced match string. They must all be equal.
	    if (bsx->matches[j] != six->matches[j])
	    {
		// If the pointer is different it can still be the same text.
		// Compare the strings, ignore case when the start item has the
		// sp_ic flag set.
		if (bsx->matches[j] == NULL || six->matches[j] == NULL)
		    break;
		if ((SYN_ITEMS(syn_block)[CUR_STATE(i).si_idx]).sp_ic
			? MB_STRICMP(bsx->matches[j], six->matches[j]) != 0
			: STRCMP(bsx->matches[j], six->matches[j]) != 0)
		    break;
	    }
	}
	if (j != NSUBEXP)
	    break;
    }
    return i < 0 ? TRUE : FALSE;
}

/*
 * We stop parsing syntax above line "lnum".  If the stored state at or below
 * this line depended on a change before it, it now depends on the line below
 * the last parsed line.
 * The window looks like this:
 *	    line which changed
 *	    displayed line
 *	    displayed line
 * lnum ->  line below window
 */
    void
syntax_end_parsing(win_T *wp, linenr_T lnum)
{
    synstate_T	*sp;

    if (syn_block != wp->w_s)
	return;  // not the right window
    sp = syn_stack_find_entry(lnum);
    if (sp != NULL && sp->sst_lnum < lnum)
	sp = sp->sst_next;

    if (sp != NULL && sp->sst_change_lnum != 0)
	sp->sst_change_lnum = lnum;
}

/*
 * End of handling of the state stack.
 ****************************************/

    static void
invalidate_current_state(void)
{
    clear_current_state();
    current_state.ga_itemsize = 0;	// mark current_state invalid
    current_next_list = NULL;
    keepend_level = -1;
}

    static void
validate_current_state(void)
{
    current_state.ga_itemsize = sizeof(stateitem_T);
    current_state.ga_growsize = 3;
}

/*
 * Return TRUE if the syntax at start of lnum changed since last time.
 * This will only be called just after get_syntax_attr() for the previous
 * line, to check if the next line needs to be redrawn too.
 */
    int
syntax_check_changed(linenr_T lnum)
{
    int		retval = TRUE;
    synstate_T	*sp;

    /*
     * Check the state stack when:
     * - lnum is just below the previously syntaxed line.
     * - lnum is not before the lines with saved states.
     * - lnum is not past the lines with saved states.
     * - lnum is at or before the last changed line.
     */
    if (VALID_STATE(&current_state) && lnum == current_lnum + 1)
    {
	sp = syn_stack_find_entry(lnum);
	if (sp != NULL && sp->sst_lnum == lnum)
	{
	    /*
	     * finish the previous line (needed when not all of the line was
	     * drawn)
	     */
	    (void)syn_finish_line(FALSE);

	    /*
	     * Compare the current state with the previously saved state of
	     * the line.
	     */
	    if (syn_stack_equal(sp))
		retval = FALSE;

	    /*
	     * Store the current state in b_sst_array[] for later use.
	     */
	    ++current_lnum;
	    (void)store_current_state();
	}
    }

    return retval;
}

/*
 * Finish the current line.
 * This doesn't return any attributes, it only gets the state at the end of
 * the line.  It can start anywhere in the line, as long as the current state
 * is valid.
 */
    static int
syn_finish_line(
    int	    syncing)		// called for syncing
{
    stateitem_T	*cur_si;
    colnr_T	prev_current_col;

    while (!current_finished)
    {
	(void)syn_current_attr(syncing, FALSE, NULL, FALSE);
	/*
	 * When syncing, and found some item, need to check the item.
	 */
	if (syncing && current_state.ga_len)
	{
	    /*
	     * Check for match with sync item.
	     */
	    cur_si = &CUR_STATE(current_state.ga_len - 1);
	    if (cur_si->si_idx >= 0
		    && (SYN_ITEMS(syn_block)[cur_si->si_idx].sp_flags
					  & (HL_SYNC_HERE|HL_SYNC_THERE)))
		return TRUE;

	    // syn_current_attr() will have skipped the check for an item
	    // that ends here, need to do that now.  Be careful not to go
	    // past the NUL.
	    prev_current_col = current_col;
	    if (syn_getcurline()[current_col] != NUL)
		++current_col;
	    check_state_ends();
	    current_col = prev_current_col;
	}
	++current_col;
    }
    return FALSE;
}

/*
 * Return highlight attributes for next character.
 * Must first call syntax_start() once for the line.
 * "col" is normally 0 for the first use in a line, and increments by one each
 * time.  It's allowed to skip characters and to stop before the end of the
 * line.  But only a "col" after a previously used column is allowed.
 * When "can_spell" is not NULL set it to TRUE when spell-checking should be
 * done.
 */
    int
get_syntax_attr(
    colnr_T	col,
    int		*can_spell,
    int		keep_state)	// keep state of char at "col"
{
    int	    attr = 0;

    if (can_spell != NULL)
	// Default: Only do spelling when there is no @Spell cluster or when
	// ":syn spell toplevel" was used.
	*can_spell = syn_block->b_syn_spell == SYNSPL_DEFAULT
		    ? (syn_block->b_spell_cluster_id == 0)
		    : (syn_block->b_syn_spell == SYNSPL_TOP);

    // check for out of memory situation
    if (syn_block->b_sst_array == NULL)
	return 0;

    // After 'synmaxcol' the attribute is always zero.
    if (syn_buf->b_p_smc > 0 && col >= (colnr_T)syn_buf->b_p_smc)
    {
	clear_current_state();
#ifdef FEAT_EVAL
	current_id = 0;
	current_trans_id = 0;
#endif
#ifdef FEAT_CONCEAL
	current_flags = 0;
	current_seqnr = 0;
#endif
	return 0;
    }

    // Make sure current_state is valid
    if (INVALID_STATE(&current_state))
	validate_current_state();

    /*
     * Skip from the current column to "col", get the attributes for "col".
     */
    while (current_col <= col)
    {
	attr = syn_current_attr(FALSE, TRUE, can_spell,
				     current_col == col ? keep_state : FALSE);
	++current_col;
    }

    return attr;
}

/*
 * Get syntax attributes for current_lnum, current_col.
 */
    static int
syn_current_attr(
    int		syncing,		// When 1: called for syncing
    int		displaying,		// result will be displayed
    int		*can_spell,		// return: do spell checking
    int		keep_state)		// keep syntax stack afterwards
{
    int		syn_id;
    lpos_T	endpos;		// was: char_u *endp;
    lpos_T	hl_startpos;	// was: int hl_startcol;
    lpos_T	hl_endpos;
    lpos_T	eos_pos;	// end-of-start match (start region)
    lpos_T	eoe_pos;	// end-of-end pattern
    int		end_idx;	// group ID for end pattern
    int		idx;
    synpat_T	*spp;
    stateitem_T	*cur_si, *sip = NULL;
    int		startcol;
    int		endcol;
    long	flags;
    int		cchar;
    short	*next_list;
    int		found_match;		    // found usable match
    static int	try_next_column = FALSE;    // must try in next col
    int		do_keywords;
    regmmatch_T	regmatch;
    lpos_T	pos;
    int		lc_col;
    reg_extmatch_T *cur_extmatch = NULL;
    char_u	buf_chartab[32];  // chartab array for syn iskyeyword
    char_u	*line;		// current line.  NOTE: becomes invalid after
				// looking for a pattern match!

    // variables for zero-width matches that have a "nextgroup" argument
    int		keep_next_list;
    int		zero_width_next_list = FALSE;
    garray_T	zero_width_next_ga;

    /*
     * No character, no attributes!  Past end of line?
     * Do try matching with an empty line (could be the start of a region).
     */
    line = syn_getcurline();
    if (line[current_col] == NUL && current_col != 0)
    {
	/*
	 * If we found a match after the last column, use it.
	 */
	if (next_match_idx >= 0 && next_match_col >= (int)current_col
						  && next_match_col != MAXCOL)
	    (void)push_next_match(NULL);

	current_finished = TRUE;
	current_state_stored = FALSE;
	return 0;
    }

    // if the current or next character is NUL, we will finish the line now
    if (line[current_col] == NUL || line[current_col + 1] == NUL)
    {
	current_finished = TRUE;
	current_state_stored = FALSE;
    }

    /*
     * When in the previous column there was a match but it could not be used
     * (empty match or already matched in this column) need to try again in
     * the next column.
     */
    if (try_next_column)
    {
	next_match_idx = -1;
	try_next_column = FALSE;
    }

    // Only check for keywords when not syncing and there are some.
    do_keywords = !syncing
		    && (syn_block->b_keywtab.ht_used > 0
			    || syn_block->b_keywtab_ic.ht_used > 0);

    // Init the list of zero-width matches with a nextlist.  This is used to
    // avoid matching the same item in the same position twice.
    ga_init2(&zero_width_next_ga, sizeof(int), 10);

    // use syntax iskeyword option
    save_chartab(buf_chartab);

    /*
     * Repeat matching keywords and patterns, to find contained items at the
     * same column.  This stops when there are no extra matches at the current
     * column.
     */
    do
    {
	found_match = FALSE;
	keep_next_list = FALSE;
	syn_id = 0;


	/*
	 * 1. Check for a current state.
	 *    Only when there is no current state, or if the current state may
	 *    contain other things, we need to check for keywords and patterns.
	 *    Always need to check for contained items if some item has the
	 *    "containedin" argument (takes extra time!).
	 */
	if (current_state.ga_len)
	    cur_si = &CUR_STATE(current_state.ga_len - 1);
	else
	    cur_si = NULL;

	if (syn_block->b_syn_containedin || cur_si == NULL
					      || cur_si->si_cont_list != NULL)
	{
	    /*
	     * 2. Check for keywords, if on a keyword char after a non-keyword
	     *	  char.  Don't do this when syncing.
	     */
	    if (do_keywords)
	    {
	      line = syn_getcurline();
	      if (vim_iswordp_buf(line + current_col, syn_buf)
		      && (current_col == 0
			  || !vim_iswordp_buf(line + current_col - 1
			      - (has_mbyte
				  ? (*mb_head_off)(line, line + current_col - 1)
				  : 0) , syn_buf)))
	      {
		syn_id = check_keyword_id(line, (int)current_col,
					 &endcol, &flags, &next_list, cur_si,
					 &cchar);
		if (syn_id != 0)
		{
		    if (push_current_state(KEYWORD_IDX) == OK)
		    {
			cur_si = &CUR_STATE(current_state.ga_len - 1);
			cur_si->si_m_startcol = current_col;
			cur_si->si_h_startpos.lnum = current_lnum;
			cur_si->si_h_startpos.col = 0;	// starts right away
			cur_si->si_m_endpos.lnum = current_lnum;
			cur_si->si_m_endpos.col = endcol;
			cur_si->si_h_endpos.lnum = current_lnum;
			cur_si->si_h_endpos.col = endcol;
			cur_si->si_ends = TRUE;
			cur_si->si_end_idx = 0;
			cur_si->si_flags = flags;
#ifdef FEAT_CONCEAL
			cur_si->si_seqnr = next_seqnr++;
			cur_si->si_cchar = cchar;
			if (current_state.ga_len > 1)
			    cur_si->si_flags |=
				  CUR_STATE(current_state.ga_len - 2).si_flags
								 & HL_CONCEAL;
#endif
			cur_si->si_id = syn_id;
			cur_si->si_trans_id = syn_id;
			if (flags & HL_TRANSP)
			{
			    if (current_state.ga_len < 2)
			    {
				cur_si->si_attr = 0;
				cur_si->si_trans_id = 0;
			    }
			    else
			    {
				cur_si->si_attr = CUR_STATE(
					current_state.ga_len - 2).si_attr;
				cur_si->si_trans_id = CUR_STATE(
					current_state.ga_len - 2).si_trans_id;
			    }
			}
			else
			    cur_si->si_attr = syn_id2attr(syn_id);
			cur_si->si_cont_list = NULL;
			cur_si->si_next_list = next_list;
			check_keepend();
		    }
		    else
			vim_free(next_list);
		}
	      }
	    }

	    /*
	     * 3. Check for patterns (only if no keyword found).
	     */
	    if (syn_id == 0 && syn_block->b_syn_patterns.ga_len)
	    {
		/*
		 * If we didn't check for a match yet, or we are past it, check
		 * for any match with a pattern.
		 */
		if (next_match_idx < 0 || next_match_col < (int)current_col)
		{
		    /*
		     * Check all relevant patterns for a match at this
		     * position.  This is complicated, because matching with a
		     * pattern takes quite a bit of time, thus we want to
		     * avoid doing it when it's not needed.
		     */
		    next_match_idx = 0;		// no match in this line yet
		    next_match_col = MAXCOL;
		    for (idx = syn_block->b_syn_patterns.ga_len; --idx >= 0; )
		    {
			spp = &(SYN_ITEMS(syn_block)[idx]);
			if (	   spp->sp_syncing == syncing
				&& (displaying || !(spp->sp_flags & HL_DISPLAY))
				&& (spp->sp_type == SPTYPE_MATCH
				    || spp->sp_type == SPTYPE_START)
				&& (current_next_list != NULL
				    ? in_id_list(NULL, current_next_list,
							      &spp->sp_syn, 0)
				    : (cur_si == NULL
					? !(spp->sp_flags & HL_CONTAINED)
					: in_id_list(cur_si,
					    cur_si->si_cont_list, &spp->sp_syn,
					    spp->sp_flags & HL_CONTAINED))))
			{
			    int r;

			    // If we already tried matching in this line, and
			    // there isn't a match before next_match_col, skip
			    // this item.
			    if (spp->sp_line_id == current_line_id
				    && spp->sp_startcol >= next_match_col)
				continue;
			    spp->sp_line_id = current_line_id;

			    lc_col = current_col - spp->sp_offsets[SPO_LC_OFF];
			    if (lc_col < 0)
				lc_col = 0;

			    regmatch.rmm_ic = spp->sp_ic;
			    regmatch.regprog = spp->sp_prog;
			    r = syn_regexec(&regmatch,
					     current_lnum,
					     (colnr_T)lc_col,
					     IF_SYN_TIME(&spp->sp_time));
			    spp->sp_prog = regmatch.regprog;
			    if (!r)
			    {
				// no match in this line, try another one
				spp->sp_startcol = MAXCOL;
				continue;
			    }

			    /*
			     * Compute the first column of the match.
			     */
			    syn_add_start_off(&pos, &regmatch,
							 spp, SPO_MS_OFF, -1);
			    if (pos.lnum > current_lnum)
			    {
				// must have used end of match in a next line,
				// we can't handle that
				spp->sp_startcol = MAXCOL;
				continue;
			    }
			    startcol = pos.col;

			    // remember the next column where this pattern
			    // matches in the current line
			    spp->sp_startcol = startcol;

			    /*
			     * If a previously found match starts at a lower
			     * column number, don't use this one.
			     */
			    if (startcol >= next_match_col)
				continue;

			    /*
			     * If we matched this pattern at this position
			     * before, skip it.  Must retry in the next
			     * column, because it may match from there.
			     */
			    if (did_match_already(idx, &zero_width_next_ga))
			    {
				try_next_column = TRUE;
				continue;
			    }

			    endpos.lnum = regmatch.endpos[0].lnum;
			    endpos.col = regmatch.endpos[0].col;

			    // Compute the highlight start.
			    syn_add_start_off(&hl_startpos, &regmatch,
							 spp, SPO_HS_OFF, -1);

			    // Compute the region start.
			    // Default is to use the end of the match.
			    syn_add_end_off(&eos_pos, &regmatch,
							 spp, SPO_RS_OFF, 0);

			    /*
			     * Grab the external submatches before they get
			     * overwritten.  Reference count doesn't change.
			     */
			    unref_extmatch(cur_extmatch);
			    cur_extmatch = re_extmatch_out;
			    re_extmatch_out = NULL;

			    flags = 0;
			    eoe_pos.lnum = 0;	// avoid warning
			    eoe_pos.col = 0;
			    end_idx = 0;
			    hl_endpos.lnum = 0;

			    /*
			     * For a "oneline" the end must be found in the
			     * same line too.  Search for it after the end of
			     * the match with the start pattern.  Set the
			     * resulting end positions at the same time.
			     */
			    if (spp->sp_type == SPTYPE_START
					      && (spp->sp_flags & HL_ONELINE))
			    {
				lpos_T	startpos;

				startpos = endpos;
				find_endpos(idx, &startpos, &endpos, &hl_endpos,
				    &flags, &eoe_pos, &end_idx, cur_extmatch);
				if (endpos.lnum == 0)
				    continue;	    // not found
			    }

			    /*
			     * For a "match" the size must be > 0 after the
			     * end offset needs has been added.  Except when
			     * syncing.
			     */
			    else if (spp->sp_type == SPTYPE_MATCH)
			    {
				syn_add_end_off(&hl_endpos, &regmatch, spp,
							       SPO_HE_OFF, 0);
				syn_add_end_off(&endpos, &regmatch, spp,
							       SPO_ME_OFF, 0);
				if (endpos.lnum == current_lnum
				      && (int)endpos.col + syncing < startcol)
				{
				    /*
				     * If an empty string is matched, may need
				     * to try matching again at next column.
				     */
				    if (regmatch.startpos[0].col
						    == regmatch.endpos[0].col)
					try_next_column = TRUE;
				    continue;
				}
			    }

			    /*
			     * keep the best match so far in next_match_*
			     */
			    // Highlighting must start after startpos and end
			    // before endpos.
			    if (hl_startpos.lnum == current_lnum
					   && (int)hl_startpos.col < startcol)
				hl_startpos.col = startcol;
			    limit_pos_zero(&hl_endpos, &endpos);

			    next_match_idx = idx;
			    next_match_col = startcol;
			    next_match_m_endpos = endpos;
			    next_match_h_endpos = hl_endpos;
			    next_match_h_startpos = hl_startpos;
			    next_match_flags = flags;
			    next_match_eos_pos = eos_pos;
			    next_match_eoe_pos = eoe_pos;
			    next_match_end_idx = end_idx;
			    unref_extmatch(next_match_extmatch);
			    next_match_extmatch = cur_extmatch;
			    cur_extmatch = NULL;
			}
		    }
		}

		/*
		 * If we found a match at the current column, use it.
		 */
		if (next_match_idx >= 0 && next_match_col == (int)current_col)
		{
		    synpat_T	*lspp;

		    // When a zero-width item matched which has a nextgroup,
		    // don't push the item but set nextgroup.
		    lspp = &(SYN_ITEMS(syn_block)[next_match_idx]);
		    if (next_match_m_endpos.lnum == current_lnum
			    && next_match_m_endpos.col == current_col
			    && lspp->sp_next_list != NULL)
		    {
			current_next_list = lspp->sp_next_list;
			current_next_flags = lspp->sp_flags;
			keep_next_list = TRUE;
			zero_width_next_list = TRUE;

			// Add the index to a list, so that we can check
			// later that we don't match it again (and cause an
			// endless loop).
			if (ga_grow(&zero_width_next_ga, 1) == OK)
			{
			    ((int *)(zero_width_next_ga.ga_data))
				[zero_width_next_ga.ga_len++] = next_match_idx;
			}
			next_match_idx = -1;
		    }
		    else
			cur_si = push_next_match(cur_si);
		    found_match = TRUE;
		}
	    }
	}

	/*
	 * Handle searching for nextgroup match.
	 */
	if (current_next_list != NULL && !keep_next_list)
	{
	    /*
	     * If a nextgroup was not found, continue looking for one if:
	     * - this is an empty line and the "skipempty" option was given
	     * - we are on white space and the "skipwhite" option was given
	     */
	    if (!found_match)
	    {
		line = syn_getcurline();
		if (((current_next_flags & HL_SKIPWHITE)
			    && VIM_ISWHITE(line[current_col]))
			|| ((current_next_flags & HL_SKIPEMPTY)
			    && *line == NUL))
		    break;
	    }

	    /*
	     * If a nextgroup was found: Use it, and continue looking for
	     * contained matches.
	     * If a nextgroup was not found: Continue looking for a normal
	     * match.
	     * When did set current_next_list for a zero-width item and no
	     * match was found don't loop (would get stuck).
	     */
	    current_next_list = NULL;
	    next_match_idx = -1;
	    if (!zero_width_next_list)
		found_match = TRUE;
	}

    } while (found_match);

    restore_chartab(buf_chartab);

    /*
     * Use attributes from the current state, if within its highlighting.
     * If not, use attributes from the current-but-one state, etc.
     */
    current_attr = 0;
#ifdef FEAT_EVAL
    current_id = 0;
    current_trans_id = 0;
#endif
#ifdef FEAT_CONCEAL
    current_flags = 0;
    current_seqnr = 0;
#endif
    if (cur_si != NULL)
    {
#ifndef FEAT_EVAL
	int	current_trans_id = 0;
#endif
	for (idx = current_state.ga_len - 1; idx >= 0; --idx)
	{
	    sip = &CUR_STATE(idx);
	    if ((current_lnum > sip->si_h_startpos.lnum
			|| (current_lnum == sip->si_h_startpos.lnum
			    && current_col >= sip->si_h_startpos.col))
		    && (sip->si_h_endpos.lnum == 0
			|| current_lnum < sip->si_h_endpos.lnum
			|| (current_lnum == sip->si_h_endpos.lnum
			    && current_col < sip->si_h_endpos.col)))
	    {
		current_attr = sip->si_attr;
#ifdef FEAT_EVAL
		current_id = sip->si_id;
#endif
		current_trans_id = sip->si_trans_id;
#ifdef FEAT_CONCEAL
		current_flags = sip->si_flags;
		current_seqnr = sip->si_seqnr;
		current_sub_char = sip->si_cchar;
#endif
		break;
	    }
	}

	if (can_spell != NULL)
	{
	    struct sp_syn   sps;

	    /*
	     * set "can_spell" to TRUE if spell checking is supposed to be
	     * done in the current item.
	     */
	    if (syn_block->b_spell_cluster_id == 0)
	    {
		// There is no @Spell cluster: Do spelling for items without
		// @NoSpell cluster.
		if (syn_block->b_nospell_cluster_id == 0
						     || current_trans_id == 0)
		    *can_spell = (syn_block->b_syn_spell != SYNSPL_NOTOP);
		else
		{
		    sps.inc_tag = 0;
		    sps.id = syn_block->b_nospell_cluster_id;
		    sps.cont_in_list = NULL;
		    *can_spell = !in_id_list(sip, sip->si_cont_list, &sps, 0);
		}
	    }
	    else
	    {
		// The @Spell cluster is defined: Do spelling in items with
		// the @Spell cluster.  But not when @NoSpell is also there.
		// At the toplevel only spell check when ":syn spell toplevel"
		// was used.
		if (current_trans_id == 0)
		    *can_spell = (syn_block->b_syn_spell == SYNSPL_TOP);
		else
		{
		    sps.inc_tag = 0;
		    sps.id = syn_block->b_spell_cluster_id;
		    sps.cont_in_list = NULL;
		    *can_spell = in_id_list(sip, sip->si_cont_list, &sps, 0);

		    if (syn_block->b_nospell_cluster_id != 0)
		    {
			sps.id = syn_block->b_nospell_cluster_id;
			if (in_id_list(sip, sip->si_cont_list, &sps, 0))
			    *can_spell = FALSE;
		    }
		}
	    }
	}


	/*
	 * Check for end of current state (and the states before it) at the
	 * next column.  Don't do this for syncing, because we would miss a
	 * single character match.
	 * First check if the current state ends at the current column.  It
	 * may be for an empty match and a containing item might end in the
	 * current column.
	 */
	if (!syncing && !keep_state)
	{
	    check_state_ends();
	    if (current_state.ga_len > 0
				      && syn_getcurline()[current_col] != NUL)
	    {
		++current_col;
		check_state_ends();
		--current_col;
	    }
	}
    }
    else if (can_spell != NULL)
	// Default: Only do spelling when there is no @Spell cluster or when
	// ":syn spell toplevel" was used.
	*can_spell = syn_block->b_syn_spell == SYNSPL_DEFAULT
		    ? (syn_block->b_spell_cluster_id == 0)
		    : (syn_block->b_syn_spell == SYNSPL_TOP);

    // nextgroup ends at end of line, unless "skipnl" or "skipempty" present
    if (current_next_list != NULL
	    && (line = syn_getcurline())[current_col] != NUL
	    && line[current_col + 1] == NUL
	    && !(current_next_flags & (HL_SKIPNL | HL_SKIPEMPTY)))
	current_next_list = NULL;

    if (zero_width_next_ga.ga_len > 0)
	ga_clear(&zero_width_next_ga);

    // No longer need external matches.  But keep next_match_extmatch.
    unref_extmatch(re_extmatch_out);
    re_extmatch_out = NULL;
    unref_extmatch(cur_extmatch);

    return current_attr;
}


/*
 * Check if we already matched pattern "idx" at the current column.
 */
    static int
did_match_already(int idx, garray_T *gap)
{
    int		i;

    for (i = current_state.ga_len; --i >= 0; )
	if (CUR_STATE(i).si_m_startcol == (int)current_col
		&& CUR_STATE(i).si_m_lnum == (int)current_lnum
		&& CUR_STATE(i).si_idx == idx)
	    return TRUE;

    // Zero-width matches with a nextgroup argument are not put on the syntax
    // stack, and can only be matched once anyway.
    for (i = gap->ga_len; --i >= 0; )
	if (((int *)(gap->ga_data))[i] == idx)
	    return TRUE;

    return FALSE;
}

/*
 * Push the next match onto the stack.
 */
    static stateitem_T *
push_next_match(stateitem_T *cur_si)
{
    synpat_T	*spp;
#ifdef FEAT_CONCEAL
    int		 save_flags;
#endif

    spp = &(SYN_ITEMS(syn_block)[next_match_idx]);

    /*
     * Push the item in current_state stack;
     */
    if (push_current_state(next_match_idx) == OK)
    {
	/*
	 * If it's a start-skip-end type that crosses lines, figure out how
	 * much it continues in this line.  Otherwise just fill in the length.
	 */
	cur_si = &CUR_STATE(current_state.ga_len - 1);
	cur_si->si_h_startpos = next_match_h_startpos;
	cur_si->si_m_startcol = current_col;
	cur_si->si_m_lnum = current_lnum;
	cur_si->si_flags = spp->sp_flags;
#ifdef FEAT_CONCEAL
	cur_si->si_seqnr = next_seqnr++;
	cur_si->si_cchar = spp->sp_cchar;
	if (current_state.ga_len > 1)
	    cur_si->si_flags |=
		    CUR_STATE(current_state.ga_len - 2).si_flags & HL_CONCEAL;
#endif
	cur_si->si_next_list = spp->sp_next_list;
	cur_si->si_extmatch = ref_extmatch(next_match_extmatch);
	if (spp->sp_type == SPTYPE_START && !(spp->sp_flags & HL_ONELINE))
	{
	    // Try to find the end pattern in the current line
	    update_si_end(cur_si, (int)(next_match_m_endpos.col), TRUE);
	    check_keepend();
	}
	else
	{
	    cur_si->si_m_endpos = next_match_m_endpos;
	    cur_si->si_h_endpos = next_match_h_endpos;
	    cur_si->si_ends = TRUE;
	    cur_si->si_flags |= next_match_flags;
	    cur_si->si_eoe_pos = next_match_eoe_pos;
	    cur_si->si_end_idx = next_match_end_idx;
	}
	if (keepend_level < 0 && (cur_si->si_flags & HL_KEEPEND))
	    keepend_level = current_state.ga_len - 1;
	check_keepend();
	update_si_attr(current_state.ga_len - 1);

#ifdef FEAT_CONCEAL
	save_flags = cur_si->si_flags & (HL_CONCEAL | HL_CONCEALENDS);
#endif
	/*
	 * If the start pattern has another highlight group, push another item
	 * on the stack for the start pattern.
	 */
	if (	   spp->sp_type == SPTYPE_START
		&& spp->sp_syn_match_id != 0
		&& push_current_state(next_match_idx) == OK)
	{
	    cur_si = &CUR_STATE(current_state.ga_len - 1);
	    cur_si->si_h_startpos = next_match_h_startpos;
	    cur_si->si_m_startcol = current_col;
	    cur_si->si_m_lnum = current_lnum;
	    cur_si->si_m_endpos = next_match_eos_pos;
	    cur_si->si_h_endpos = next_match_eos_pos;
	    cur_si->si_ends = TRUE;
	    cur_si->si_end_idx = 0;
	    cur_si->si_flags = HL_MATCH;
#ifdef FEAT_CONCEAL
	    cur_si->si_seqnr = next_seqnr++;
	    cur_si->si_flags |= save_flags;
	    if (cur_si->si_flags & HL_CONCEALENDS)
		cur_si->si_flags |= HL_CONCEAL;
#endif
	    cur_si->si_next_list = NULL;
	    check_keepend();
	    update_si_attr(current_state.ga_len - 1);
	}
    }

    next_match_idx = -1;	// try other match next time

    return cur_si;
}

/*
 * Check for end of current state (and the states before it).
 */
    static void
check_state_ends(void)
{
    stateitem_T	*cur_si;
    int		had_extend;

    cur_si = &CUR_STATE(current_state.ga_len - 1);
    for (;;)
    {
	if (cur_si->si_ends
		&& (cur_si->si_m_endpos.lnum < current_lnum
		    || (cur_si->si_m_endpos.lnum == current_lnum
			&& cur_si->si_m_endpos.col <= current_col)))
	{
	    /*
	     * If there is an end pattern group ID, highlight the end pattern
	     * now.  No need to pop the current item from the stack.
	     * Only do this if the end pattern continues beyond the current
	     * position.
	     */
	    if (cur_si->si_end_idx
		    && (cur_si->si_eoe_pos.lnum > current_lnum
			|| (cur_si->si_eoe_pos.lnum == current_lnum
			    && cur_si->si_eoe_pos.col > current_col)))
	    {
		cur_si->si_idx = cur_si->si_end_idx;
		cur_si->si_end_idx = 0;
		cur_si->si_m_endpos = cur_si->si_eoe_pos;
		cur_si->si_h_endpos = cur_si->si_eoe_pos;
		cur_si->si_flags |= HL_MATCH;
#ifdef FEAT_CONCEAL
		cur_si->si_seqnr = next_seqnr++;
		if (cur_si->si_flags & HL_CONCEALENDS)
		    cur_si->si_flags |= HL_CONCEAL;
#endif
		update_si_attr(current_state.ga_len - 1);

		// nextgroup= should not match in the end pattern
		current_next_list = NULL;

		// what matches next may be different now, clear it
		next_match_idx = 0;
		next_match_col = MAXCOL;
		break;
	    }

	    // handle next_list, unless at end of line and no "skipnl" or
	    // "skipempty"
	    current_next_list = cur_si->si_next_list;
	    current_next_flags = cur_si->si_flags;
	    if (!(current_next_flags & (HL_SKIPNL | HL_SKIPEMPTY))
		    && syn_getcurline()[current_col] == NUL)
		current_next_list = NULL;

	    // When the ended item has "extend", another item with
	    // "keepend" now needs to check for its end.
	    had_extend = (cur_si->si_flags & HL_EXTEND);

	    pop_current_state();

	    if (current_state.ga_len == 0)
		break;

	    if (had_extend && keepend_level >= 0)
	    {
		syn_update_ends(FALSE);
		if (current_state.ga_len == 0)
		    break;
	    }

	    cur_si = &CUR_STATE(current_state.ga_len - 1);

	    /*
	     * Only for a region the search for the end continues after
	     * the end of the contained item.  If the contained match
	     * included the end-of-line, break here, the region continues.
	     * Don't do this when:
	     * - "keepend" is used for the contained item
	     * - not at the end of the line (could be end="x$"me=e-1).
	     * - "excludenl" is used (HL_HAS_EOL won't be set)
	     */
	    if (cur_si->si_idx >= 0
		    && SYN_ITEMS(syn_block)[cur_si->si_idx].sp_type
								== SPTYPE_START
		    && !(cur_si->si_flags & (HL_MATCH | HL_KEEPEND)))
	    {
		update_si_end(cur_si, (int)current_col, TRUE);
		check_keepend();
		if ((current_next_flags & HL_HAS_EOL)
			&& keepend_level < 0
			&& syn_getcurline()[current_col] == NUL)
		    break;
	    }
	}
	else
	    break;
    }
}

/*
 * Update an entry in the current_state stack for a match or region.  This
 * fills in si_attr, si_next_list and si_cont_list.
 */
    static void
update_si_attr(int idx)
{
    stateitem_T	*sip = &CUR_STATE(idx);
    synpat_T	*spp;

    // This should not happen...
    if (sip->si_idx < 0)
	return;

    spp = &(SYN_ITEMS(syn_block)[sip->si_idx]);
    if (sip->si_flags & HL_MATCH)
	sip->si_id = spp->sp_syn_match_id;
    else
	sip->si_id = spp->sp_syn.id;
    sip->si_attr = syn_id2attr(sip->si_id);
    sip->si_trans_id = sip->si_id;
    if (sip->si_flags & HL_MATCH)
	sip->si_cont_list = NULL;
    else
	sip->si_cont_list = spp->sp_cont_list;

    /*
     * For transparent items, take attr from outer item.
     * Also take cont_list, if there is none.
     * Don't do this for the matchgroup of a start or end pattern.
     */
    if ((spp->sp_flags & HL_TRANSP) && !(sip->si_flags & HL_MATCH))
    {
	if (idx == 0)
	{
	    sip->si_attr = 0;
	    sip->si_trans_id = 0;
	    if (sip->si_cont_list == NULL)
		sip->si_cont_list = ID_LIST_ALL;
	}
	else
	{
	    sip->si_attr = CUR_STATE(idx - 1).si_attr;
	    sip->si_trans_id = CUR_STATE(idx - 1).si_trans_id;
	    if (sip->si_cont_list == NULL)
	    {
		sip->si_flags |= HL_TRANS_CONT;
		sip->si_cont_list = CUR_STATE(idx - 1).si_cont_list;
	    }
	}
    }
}

/*
 * Check the current stack for patterns with "keepend" flag.
 * Propagate the match-end to contained items, until a "skipend" item is found.
 */
    static void
check_keepend(void)
{
    int		i;
    lpos_T	maxpos;
    lpos_T	maxpos_h;
    stateitem_T	*sip;

    /*
     * This check can consume a lot of time; only do it from the level where
     * there really is a keepend.
     */
    if (keepend_level < 0)
	return;

    /*
     * Find the last index of an "extend" item.  "keepend" items before that
     * won't do anything.  If there is no "extend" item "i" will be
     * "keepend_level" and all "keepend" items will work normally.
     */
    for (i = current_state.ga_len - 1; i > keepend_level; --i)
	if (CUR_STATE(i).si_flags & HL_EXTEND)
	    break;

    maxpos.lnum = 0;
    maxpos.col = 0;
    maxpos_h.lnum = 0;
    maxpos_h.col = 0;
    for ( ; i < current_state.ga_len; ++i)
    {
	sip = &CUR_STATE(i);
	if (maxpos.lnum != 0)
	{
	    limit_pos_zero(&sip->si_m_endpos, &maxpos);
	    limit_pos_zero(&sip->si_h_endpos, &maxpos_h);
	    limit_pos_zero(&sip->si_eoe_pos, &maxpos);
	    sip->si_ends = TRUE;
	}
	if (sip->si_ends && (sip->si_flags & HL_KEEPEND))
	{
	    if (maxpos.lnum == 0
		    || maxpos.lnum > sip->si_m_endpos.lnum
		    || (maxpos.lnum == sip->si_m_endpos.lnum
			&& maxpos.col > sip->si_m_endpos.col))
		maxpos = sip->si_m_endpos;
	    if (maxpos_h.lnum == 0
		    || maxpos_h.lnum > sip->si_h_endpos.lnum
		    || (maxpos_h.lnum == sip->si_h_endpos.lnum
			&& maxpos_h.col > sip->si_h_endpos.col))
		maxpos_h = sip->si_h_endpos;
	}
    }
}

/*
 * Update an entry in the current_state stack for a start-skip-end pattern.
 * This finds the end of the current item, if it's in the current line.
 *
 * Return the flags for the matched END.
 */
    static void
update_si_end(
    stateitem_T	*sip,
    int		startcol,   // where to start searching for the end
    int		force)	    // when TRUE overrule a previous end
{
    lpos_T	startpos;
    lpos_T	endpos;
    lpos_T	hl_endpos;
    lpos_T	end_endpos;
    int		end_idx;

    // return quickly for a keyword
    if (sip->si_idx < 0)
	return;

    // Don't update when it's already done.  Can be a match of an end pattern
    // that started in a previous line.  Watch out: can also be a "keepend"
    // from a containing item.
    if (!force && sip->si_m_endpos.lnum >= current_lnum)
	return;

    /*
     * We need to find the end of the region.  It may continue in the next
     * line.
     */
    end_idx = 0;
    startpos.lnum = current_lnum;
    startpos.col = startcol;
    find_endpos(sip->si_idx, &startpos, &endpos, &hl_endpos,
		   &(sip->si_flags), &end_endpos, &end_idx, sip->si_extmatch);

    if (endpos.lnum == 0)
    {
	// No end pattern matched.
	if (SYN_ITEMS(syn_block)[sip->si_idx].sp_flags & HL_ONELINE)
	{
	    // a "oneline" never continues in the next line
	    sip->si_ends = TRUE;
	    sip->si_m_endpos.lnum = current_lnum;
	    sip->si_m_endpos.col = (colnr_T)STRLEN(syn_getcurline());
	}
	else
	{
	    // continues in the next line
	    sip->si_ends = FALSE;
	    sip->si_m_endpos.lnum = 0;
	}
	sip->si_h_endpos = sip->si_m_endpos;
    }
    else
    {
	// match within this line
	sip->si_m_endpos = endpos;
	sip->si_h_endpos = hl_endpos;
	sip->si_eoe_pos = end_endpos;
	sip->si_ends = TRUE;
	sip->si_end_idx = end_idx;
    }
}

/*
 * Add a new state to the current state stack.
 * It is cleared and the index set to "idx".
 * Return FAIL if it's not possible (out of memory).
 */
    static int
push_current_state(int idx)
{
    if (ga_grow(&current_state, 1) == FAIL)
	return FAIL;
    CLEAR_POINTER(&CUR_STATE(current_state.ga_len));
    CUR_STATE(current_state.ga_len).si_idx = idx;
    ++current_state.ga_len;
    return OK;
}

/*
 * Remove a state from the current_state stack.
 */
    static void
pop_current_state(void)
{
    if (current_state.ga_len)
    {
	unref_extmatch(CUR_STATE(current_state.ga_len - 1).si_extmatch);
	--current_state.ga_len;
    }
    // after the end of a pattern, try matching a keyword or pattern
    next_match_idx = -1;

    // if first state with "keepend" is popped, reset keepend_level
    if (keepend_level >= current_state.ga_len)
	keepend_level = -1;
}

/*
 * Find the end of a start/skip/end syntax region after "startpos".
 * Only checks one line.
 * Also handles a match item that continued from a previous line.
 * If not found, the syntax item continues in the next line.  m_endpos->lnum
 * will be 0.
 * If found, the end of the region and the end of the highlighting is
 * computed.
 */
    static void
find_endpos(
    int		idx,		// index of the pattern
    lpos_T	*startpos,	// where to start looking for an END match
    lpos_T	*m_endpos,	// return: end of match
    lpos_T	*hl_endpos,	// return: end of highlighting
    long	*flagsp,	// return: flags of matching END
    lpos_T	*end_endpos,	// return: end of end pattern match
    int		*end_idx,	// return: group ID for end pat. match, or 0
    reg_extmatch_T *start_ext)	// submatches from the start pattern
{
    colnr_T	matchcol;
    synpat_T	*spp, *spp_skip;
    int		start_idx;
    int		best_idx;
    regmmatch_T	regmatch;
    regmmatch_T	best_regmatch;	    // startpos/endpos of best match
    lpos_T	pos;
    char_u	*line;
    int		had_match = FALSE;
    char_u	buf_chartab[32];  // chartab array for syn option iskyeyword

    // just in case we are invoked for a keyword
    if (idx < 0)
	return;

    /*
     * Check for being called with a START pattern.
     * Can happen with a match that continues to the next line, because it
     * contained a region.
     */
    spp = &(SYN_ITEMS(syn_block)[idx]);
    if (spp->sp_type != SPTYPE_START)
    {
	*hl_endpos = *startpos;
	return;
    }

    /*
     * Find the SKIP or first END pattern after the last START pattern.
     */
    for (;;)
    {
	spp = &(SYN_ITEMS(syn_block)[idx]);
	if (spp->sp_type != SPTYPE_START)
	    break;
	++idx;
    }

    /*
     *	Lookup the SKIP pattern (if present)
     */
    if (spp->sp_type == SPTYPE_SKIP)
    {
	spp_skip = spp;
	++idx;
    }
    else
	spp_skip = NULL;

    // Setup external matches for syn_regexec().
    unref_extmatch(re_extmatch_in);
    re_extmatch_in = ref_extmatch(start_ext);

    matchcol = startpos->col;	// start looking for a match at sstart
    start_idx = idx;		// remember the first END pattern.
    best_regmatch.startpos[0].col = 0;		// avoid compiler warning

    // use syntax iskeyword option
    save_chartab(buf_chartab);

    for (;;)
    {
	/*
	 * Find end pattern that matches first after "matchcol".
	 */
	best_idx = -1;
	for (idx = start_idx; idx < syn_block->b_syn_patterns.ga_len; ++idx)
	{
	    int lc_col = matchcol;
	    int r;

	    spp = &(SYN_ITEMS(syn_block)[idx]);
	    if (spp->sp_type != SPTYPE_END)	// past last END pattern
		break;
	    lc_col -= spp->sp_offsets[SPO_LC_OFF];
	    if (lc_col < 0)
		lc_col = 0;

	    regmatch.rmm_ic = spp->sp_ic;
	    regmatch.regprog = spp->sp_prog;
	    r = syn_regexec(&regmatch, startpos->lnum, lc_col,
						  IF_SYN_TIME(&spp->sp_time));
	    spp->sp_prog = regmatch.regprog;
	    if (r)
	    {
		if (best_idx == -1 || regmatch.startpos[0].col
					      < best_regmatch.startpos[0].col)
		{
		    best_idx = idx;
		    best_regmatch.startpos[0] = regmatch.startpos[0];
		    best_regmatch.endpos[0] = regmatch.endpos[0];
		}
	    }
	}

	/*
	 * If all end patterns have been tried, and there is no match, the
	 * item continues until end-of-line.
	 */
	if (best_idx == -1)
	    break;

	/*
	 * If the skip pattern matches before the end pattern,
	 * continue searching after the skip pattern.
	 */
	if (spp_skip != NULL)
	{
	    int lc_col = matchcol - spp_skip->sp_offsets[SPO_LC_OFF];
	    int r;

	    if (lc_col < 0)
		lc_col = 0;
	    regmatch.rmm_ic = spp_skip->sp_ic;
	    regmatch.regprog = spp_skip->sp_prog;
	    r = syn_regexec(&regmatch, startpos->lnum, lc_col,
					      IF_SYN_TIME(&spp_skip->sp_time));
	    spp_skip->sp_prog = regmatch.regprog;
	    if (r && regmatch.startpos[0].col
					     <= best_regmatch.startpos[0].col)
	    {
		int line_len;

		// Add offset to skip pattern match
		syn_add_end_off(&pos, &regmatch, spp_skip, SPO_ME_OFF, 1);

		// If the skip pattern goes on to the next line, there is no
		// match with an end pattern in this line.
		if (pos.lnum > startpos->lnum)
		    break;

		line = ml_get_buf(syn_buf, startpos->lnum, FALSE);
		line_len = (int)STRLEN(line);

		// take care of an empty match or negative offset
		if (pos.col <= matchcol)
		    ++matchcol;
		else if (pos.col <= regmatch.endpos[0].col)
		    matchcol = pos.col;
		else
		    // Be careful not to jump over the NUL at the end-of-line
		    for (matchcol = regmatch.endpos[0].col;
			    matchcol < line_len && matchcol < pos.col;
								   ++matchcol)
			;

		// if the skip pattern includes end-of-line, break here
		if (matchcol >= line_len)
		    break;

		continue;	    // start with first end pattern again
	    }
	}

	/*
	 * Match from start pattern to end pattern.
	 * Correct for match and highlight offset of end pattern.
	 */
	spp = &(SYN_ITEMS(syn_block)[best_idx]);
	syn_add_end_off(m_endpos, &best_regmatch, spp, SPO_ME_OFF, 1);
	// can't end before the start
	if (m_endpos->lnum == startpos->lnum && m_endpos->col < startpos->col)
	    m_endpos->col = startpos->col;

	syn_add_end_off(end_endpos, &best_regmatch, spp, SPO_HE_OFF, 1);
	// can't end before the start
	if (end_endpos->lnum == startpos->lnum
					   && end_endpos->col < startpos->col)
	    end_endpos->col = startpos->col;
	// can't end after the match
	limit_pos(end_endpos, m_endpos);

	/*
	 * If the end group is highlighted differently, adjust the pointers.
	 */
	if (spp->sp_syn_match_id != spp->sp_syn.id && spp->sp_syn_match_id != 0)
	{
	    *end_idx = best_idx;
	    if (spp->sp_off_flags & (1 << (SPO_RE_OFF + SPO_COUNT)))
	    {
		hl_endpos->lnum = best_regmatch.endpos[0].lnum;
		hl_endpos->col = best_regmatch.endpos[0].col;
	    }
	    else
	    {
		hl_endpos->lnum = best_regmatch.startpos[0].lnum;
		hl_endpos->col = best_regmatch.startpos[0].col;
	    }
	    hl_endpos->col += spp->sp_offsets[SPO_RE_OFF];

	    // can't end before the start
	    if (hl_endpos->lnum == startpos->lnum
					    && hl_endpos->col < startpos->col)
		hl_endpos->col = startpos->col;
	    limit_pos(hl_endpos, m_endpos);

	    // now the match ends where the highlighting ends, it is turned
	    // into the matchgroup for the end
	    *m_endpos = *hl_endpos;
	}
	else
	{
	    *end_idx = 0;
	    *hl_endpos = *end_endpos;
	}

	*flagsp = spp->sp_flags;

	had_match = TRUE;
	break;
    }

    // no match for an END pattern in this line
    if (!had_match)
	m_endpos->lnum = 0;

    restore_chartab(buf_chartab);

    // Remove external matches.
    unref_extmatch(re_extmatch_in);
    re_extmatch_in = NULL;
}

/*
 * Limit "pos" not to be after "limit".
 */
    static void
limit_pos(lpos_T *pos, lpos_T *limit)
{
    if (pos->lnum > limit->lnum)
	*pos = *limit;
    else if (pos->lnum == limit->lnum && pos->col > limit->col)
	pos->col = limit->col;
}

/*
 * Limit "pos" not to be after "limit", unless pos->lnum is zero.
 */
    static void
limit_pos_zero(
    lpos_T	*pos,
    lpos_T	*limit)
{
    if (pos->lnum == 0)
	*pos = *limit;
    else
	limit_pos(pos, limit);
}

/*
 * Add offset to matched text for end of match or highlight.
 */
    static void
syn_add_end_off(
    lpos_T	*result,	// returned position
    regmmatch_T	*regmatch,	// start/end of match
    synpat_T	*spp,		// matched pattern
    int		idx,		// index of offset
    int		extra)		// extra chars for offset to start
{
    int		col;
    int		off;
    char_u	*base;
    char_u	*p;

    if (spp->sp_off_flags & (1 << idx))
    {
	result->lnum = regmatch->startpos[0].lnum;
	col = regmatch->startpos[0].col;
	off = spp->sp_offsets[idx] + extra;
    }
    else
    {
	result->lnum = regmatch->endpos[0].lnum;
	col = regmatch->endpos[0].col;
	off = spp->sp_offsets[idx];
    }
    // Don't go past the end of the line.  Matters for "rs=e+2" when there
    // is a matchgroup. Watch out for match with last NL in the buffer.
    if (result->lnum > syn_buf->b_ml.ml_line_count)
	col = 0;
    else if (off != 0)
    {
	base = ml_get_buf(syn_buf, result->lnum, FALSE);
	p = base + col;
	if (off > 0)
	{
	    while (off-- > 0 && *p != NUL)
		MB_PTR_ADV(p);
	}
	else if (off < 0)
	{
	    while (off++ < 0 && base < p)
		MB_PTR_BACK(base, p);
	}
	col = (int)(p - base);
    }
    result->col = col;
}

/*
 * Add offset to matched text for start of match or highlight.
 * Avoid resulting column to become negative.
 */
    static void
syn_add_start_off(
    lpos_T	*result,	// returned position
    regmmatch_T	*regmatch,	// start/end of match
    synpat_T	*spp,
    int		idx,
    int		extra)	    // extra chars for offset to end
{
    int		col;
    int		off;
    char_u	*base;
    char_u	*p;

    if (spp->sp_off_flags & (1 << (idx + SPO_COUNT)))
    {
	result->lnum = regmatch->endpos[0].lnum;
	col = regmatch->endpos[0].col;
	off = spp->sp_offsets[idx] + extra;
    }
    else
    {
	result->lnum = regmatch->startpos[0].lnum;
	col = regmatch->startpos[0].col;
	off = spp->sp_offsets[idx];
    }
    if (result->lnum > syn_buf->b_ml.ml_line_count)
    {
	// a "\n" at the end of the pattern may take us below the last line
	result->lnum = syn_buf->b_ml.ml_line_count;
	col = (int)STRLEN(ml_get_buf(syn_buf, result->lnum, FALSE));
    }
    if (off != 0)
    {
	base = ml_get_buf(syn_buf, result->lnum, FALSE);
	p = base + col;
	if (off > 0)
	{
	    while (off-- && *p != NUL)
		MB_PTR_ADV(p);
	}
	else if (off < 0)
	{
	    while (off++ && base < p)
		MB_PTR_BACK(base, p);
	}
	col = (int)(p - base);
    }
    result->col = col;
}

/*
 * Get current line in syntax buffer.
 */
    static char_u *
syn_getcurline(void)
{
    return ml_get_buf(syn_buf, current_lnum, FALSE);
}

/*
 * Call vim_regexec() to find a match with "rmp" in "syn_buf".
 * Returns TRUE when there is a match.
 */
    static int
syn_regexec(
    regmmatch_T	*rmp,
    linenr_T	lnum,
    colnr_T	col,
    syn_time_T  *st UNUSED)
{
    int		r;
    int		timed_out = FALSE;
#ifdef FEAT_PROFILE
    proftime_T	pt;

    if (syn_time_on)
	profile_start(&pt);
#endif

    if (rmp->regprog == NULL)
	// This can happen if a previous call to vim_regexec_multi() tried to
	// use the NFA engine, which resulted in NFA_TOO_EXPENSIVE, and
	// compiling the pattern with the other engine fails.
	return FALSE;

    rmp->rmm_maxcol = syn_buf->b_p_smc;
    r = vim_regexec_multi(rmp, syn_win, syn_buf, lnum, col, &timed_out);

#ifdef FEAT_PROFILE
    if (syn_time_on)
    {
	profile_end(&pt);
	profile_add(&st->total, &pt);
	if (profile_cmp(&pt, &st->slowest) < 0)
	    st->slowest = pt;
	++st->count;
	if (r > 0)
	    ++st->match;
    }
#endif
#ifdef FEAT_RELTIME
    if (timed_out && redrawtime_limit_set && !syn_win->w_s->b_syn_slow)
    {
	syn_win->w_s->b_syn_slow = TRUE;
	msg(_("'redrawtime' exceeded, syntax highlighting disabled"));
    }
#endif

    if (r > 0)
    {
	rmp->startpos[0].lnum += lnum;
	rmp->endpos[0].lnum += lnum;
	return TRUE;
    }
    return FALSE;
}

/*
 * Check one position in a line for a matching keyword.
 * The caller must check if a keyword can start at startcol.
 * Return its ID if found, 0 otherwise.
 */
    static int
check_keyword_id(
    char_u	*line,
    int		startcol,	// position in line to check for keyword
    int		*endcolp,	// return: character after found keyword
    long	*flagsp,	// return: flags of matching keyword
    short	**next_listp,	// return: next_list of matching keyword
    stateitem_T	*cur_si,	// item at the top of the stack
    int		*ccharp UNUSED)	// conceal substitution char
{
    keyentry_T	*kp;
    char_u	*kwp;
    int		round;
    int		kwlen;
    char_u	keyword[MAXKEYWLEN + 1]; // assume max. keyword len is 80
    hashtab_T	*ht;
    hashitem_T	*hi;

    // Find first character after the keyword.  First character was already
    // checked.
    kwp = line + startcol;
    kwlen = 0;
    do
    {
	if (has_mbyte)
	    kwlen += (*mb_ptr2len)(kwp + kwlen);
	else
	    ++kwlen;
    }
    while (vim_iswordp_buf(kwp + kwlen, syn_buf));

    if (kwlen > MAXKEYWLEN)
	return 0;

    /*
     * Must make a copy of the keyword, so we can add a NUL and make it
     * lowercase.
     */
    vim_strncpy(keyword, kwp, kwlen);

    /*
     * Try twice:
     * 1. matching case
     * 2. ignoring case
     */
    for (round = 1; round <= 2; ++round)
    {
	ht = round == 1 ? &syn_block->b_keywtab : &syn_block->b_keywtab_ic;
	if (ht->ht_used == 0)
	    continue;
	if (round == 2)	// ignore case
	    (void)str_foldcase(kwp, kwlen, keyword, MAXKEYWLEN + 1);

	/*
	 * Find keywords that match.  There can be several with different
	 * attributes.
	 * When current_next_list is non-zero accept only that group, otherwise:
	 *  Accept a not-contained keyword at toplevel.
	 *  Accept a keyword at other levels only if it is in the contains list.
	 */
	hi = hash_find(ht, keyword);
	if (!HASHITEM_EMPTY(hi))
	    for (kp = HI2KE(hi); kp != NULL; kp = kp->ke_next)
	    {
		if (current_next_list != 0
			? in_id_list(NULL, current_next_list, &kp->k_syn, 0)
			: (cur_si == NULL
			    ? !(kp->flags & HL_CONTAINED)
			    : in_id_list(cur_si, cur_si->si_cont_list,
				      &kp->k_syn, kp->flags & HL_CONTAINED)))
		{
		    *endcolp = startcol + kwlen;
		    *flagsp = kp->flags;
		    *next_listp = kp->next_list;
#ifdef FEAT_CONCEAL
		    *ccharp = kp->k_char;
#endif
		    return kp->k_syn.id;
		}
	    }
    }
    return 0;
}

/*
 * Handle ":syntax conceal" command.
 */
    static void
syn_cmd_conceal(exarg_T *eap UNUSED, int syncing UNUSED)
{
#ifdef FEAT_CONCEAL
    char_u	*arg = eap->arg;
    char_u	*next;

    eap->nextcmd = find_nextcmd(arg);
    if (eap->skip)
	return;

    next = skiptowhite(arg);
    if (*arg == NUL)
    {
	if (curwin->w_s->b_syn_conceal)
	    msg("syntax conceal on");
	else
	    msg("syntax conceal off");
    }
    else if (STRNICMP(arg, "on", 2) == 0 && next - arg == 2)
	curwin->w_s->b_syn_conceal = TRUE;
    else if (STRNICMP(arg, "off", 3) == 0 && next - arg == 3)
	curwin->w_s->b_syn_conceal = FALSE;
    else
	semsg(_(e_illegal_argument_str_2), arg);
#endif
}

/*
 * Handle ":syntax case" command.
 */
    static void
syn_cmd_case(exarg_T *eap, int syncing UNUSED)
{
    char_u	*arg = eap->arg;
    char_u	*next;

    eap->nextcmd = find_nextcmd(arg);
    if (eap->skip)
	return;

    next = skiptowhite(arg);
    if (*arg == NUL)
    {
	if (curwin->w_s->b_syn_ic)
	    msg("syntax case ignore");
	else
	    msg("syntax case match");
    }
    else if (STRNICMP(arg, "match", 5) == 0 && next - arg == 5)
	curwin->w_s->b_syn_ic = FALSE;
    else if (STRNICMP(arg, "ignore", 6) == 0 && next - arg == 6)
	curwin->w_s->b_syn_ic = TRUE;
    else
	semsg(_(e_illegal_argument_str_2), arg);
}

/*
 * Handle ":syntax foldlevel" command.
 */
    static void
syn_cmd_foldlevel(exarg_T *eap, int syncing UNUSED)
{
    char_u *arg = eap->arg;
    char_u *arg_end;

    eap->nextcmd = find_nextcmd(arg);
    if (eap->skip)
	return;

    if (*arg == NUL)
    {
	switch (curwin->w_s->b_syn_foldlevel)
	{
	    case SYNFLD_START:   msg("syntax foldlevel start");   break;
	    case SYNFLD_MINIMUM: msg("syntax foldlevel minimum"); break;
	    default: break;
	}
	return;
    }

    arg_end = skiptowhite(arg);
    if (STRNICMP(arg, "start", 5) == 0 && arg_end - arg == 5)
	curwin->w_s->b_syn_foldlevel = SYNFLD_START;
    else if (STRNICMP(arg, "minimum", 7) == 0 && arg_end - arg == 7)
	curwin->w_s->b_syn_foldlevel = SYNFLD_MINIMUM;
    else
    {
	semsg(_(e_illegal_argument_str_2), arg);
	return;
    }

    arg = skipwhite(arg_end);
    if (*arg != NUL)
    {
	semsg(_(e_illegal_argument_str_2), arg);
    }
}

/*
 * Handle ":syntax spell" command.
 */
    static void
syn_cmd_spell(exarg_T *eap, int syncing UNUSED)
{
    char_u	*arg = eap->arg;
    char_u	*next;

    eap->nextcmd = find_nextcmd(arg);
    if (eap->skip)
	return;

    next = skiptowhite(arg);
    if (*arg == NUL)
    {
	if (curwin->w_s->b_syn_spell == SYNSPL_TOP)
	    msg("syntax spell toplevel");
	else if (curwin->w_s->b_syn_spell == SYNSPL_NOTOP)
	    msg("syntax spell notoplevel");
	else
	    msg("syntax spell default");
    }
    else if (STRNICMP(arg, "toplevel", 8) == 0 && next - arg == 8)
	curwin->w_s->b_syn_spell = SYNSPL_TOP;
    else if (STRNICMP(arg, "notoplevel", 10) == 0 && next - arg == 10)
	curwin->w_s->b_syn_spell = SYNSPL_NOTOP;
    else if (STRNICMP(arg, "default", 7) == 0 && next - arg == 7)
	curwin->w_s->b_syn_spell = SYNSPL_DEFAULT;
    else
    {
	semsg(_(e_illegal_argument_str_2), arg);
	return;
    }

    // assume spell checking changed, force a redraw
    redraw_win_later(curwin, UPD_NOT_VALID);
}

/*
 * Handle ":syntax iskeyword" command.
 */
    static void
syn_cmd_iskeyword(exarg_T *eap, int syncing UNUSED)
{
    char_u	*arg = eap->arg;
    char_u	save_chartab[32];
    char_u	*save_isk;

    if (eap->skip)
	return;

    arg = skipwhite(arg);
    if (*arg == NUL)
    {
	msg_puts("\n");
	if (curwin->w_s->b_syn_isk != empty_option)
	{
	    msg_puts("syntax iskeyword ");
	    msg_outtrans(curwin->w_s->b_syn_isk);
	}
	else
	    msg_outtrans((char_u *)_("syntax iskeyword not set"));
    }
    else
    {
	if (STRNICMP(arg, "clear", 5) == 0)
	{
	    mch_memmove(curwin->w_s->b_syn_chartab, curbuf->b_chartab,
								  (size_t)32);
	    clear_string_option(&curwin->w_s->b_syn_isk);
	}
	else
	{
	    mch_memmove(save_chartab, curbuf->b_chartab, (size_t)32);
	    save_isk = curbuf->b_p_isk;
	    curbuf->b_p_isk = vim_strsave(arg);

	    buf_init_chartab(curbuf, FALSE);
	    mch_memmove(curwin->w_s->b_syn_chartab, curbuf->b_chartab,
								  (size_t)32);
	    mch_memmove(curbuf->b_chartab, save_chartab, (size_t)32);
	    clear_string_option(&curwin->w_s->b_syn_isk);
	    curwin->w_s->b_syn_isk = curbuf->b_p_isk;
	    curbuf->b_p_isk = save_isk;
	}
    }
    redraw_win_later(curwin, UPD_NOT_VALID);
}

/*
 * Clear all syntax info for one buffer.
 */
    void
syntax_clear(synblock_T *block)
{
    int i;

    block->b_syn_error = FALSE;	    // clear previous error
#ifdef FEAT_RELTIME
    block->b_syn_slow = FALSE;	    // clear previous timeout
#endif
    block->b_syn_ic = FALSE;	    // Use case, by default
    block->b_syn_foldlevel = SYNFLD_START;
    block->b_syn_spell = SYNSPL_DEFAULT; // default spell checking
    block->b_syn_containedin = FALSE;
#ifdef FEAT_CONCEAL
    block->b_syn_conceal = FALSE;
#endif

    // free the keywords
    clear_keywtab(&block->b_keywtab);
    clear_keywtab(&block->b_keywtab_ic);

    // free the syntax patterns
    for (i = block->b_syn_patterns.ga_len; --i >= 0; )
	syn_clear_pattern(block, i);
    ga_clear(&block->b_syn_patterns);

    // free the syntax clusters
    for (i = block->b_syn_clusters.ga_len; --i >= 0; )
	syn_clear_cluster(block, i);
    ga_clear(&block->b_syn_clusters);
    block->b_spell_cluster_id = 0;
    block->b_nospell_cluster_id = 0;

    block->b_syn_sync_flags = 0;
    block->b_syn_sync_minlines = 0;
    block->b_syn_sync_maxlines = 0;
    block->b_syn_sync_linebreaks = 0;

    vim_regfree(block->b_syn_linecont_prog);
    block->b_syn_linecont_prog = NULL;
    VIM_CLEAR(block->b_syn_linecont_pat);
#ifdef FEAT_FOLDING
    block->b_syn_folditems = 0;
#endif
    clear_string_option(&block->b_syn_isk);

    // free the stored states
    syn_stack_free_all(block);
    invalidate_current_state();

    // Reset the counter for ":syn include"
    running_syn_inc_tag = 0;
}

/*
 * Get rid of ownsyntax for window "wp".
 */
    void
reset_synblock(win_T *wp)
{
    if (wp->w_s != &wp->w_buffer->b_s)
    {
	syntax_clear(wp->w_s);
	vim_free(wp->w_s);
	wp->w_s = &wp->w_buffer->b_s;
    }
}

/*
 * Clear syncing info for one buffer.
 */
    static void
syntax_sync_clear(void)
{
    int i;

    // free the syntax patterns
    for (i = curwin->w_s->b_syn_patterns.ga_len; --i >= 0; )
	if (SYN_ITEMS(curwin->w_s)[i].sp_syncing)
	    syn_remove_pattern(curwin->w_s, i);

    curwin->w_s->b_syn_sync_flags = 0;
    curwin->w_s->b_syn_sync_minlines = 0;
    curwin->w_s->b_syn_sync_maxlines = 0;
    curwin->w_s->b_syn_sync_linebreaks = 0;

    vim_regfree(curwin->w_s->b_syn_linecont_prog);
    curwin->w_s->b_syn_linecont_prog = NULL;
    VIM_CLEAR(curwin->w_s->b_syn_linecont_pat);
    clear_string_option(&curwin->w_s->b_syn_isk);

    syn_stack_free_all(curwin->w_s);	// Need to recompute all syntax.
}

/*
 * Remove one pattern from the buffer's pattern list.
 */
    static void
syn_remove_pattern(
    synblock_T	*block,
    int		idx)
{
    synpat_T	*spp;

    spp = &(SYN_ITEMS(block)[idx]);
#ifdef FEAT_FOLDING
    if (spp->sp_flags & HL_FOLD)
	--block->b_syn_folditems;
#endif
    syn_clear_pattern(block, idx);
    mch_memmove(spp, spp + 1,
		   sizeof(synpat_T) * (block->b_syn_patterns.ga_len - idx - 1));
    --block->b_syn_patterns.ga_len;
}

/*
 * Clear and free one syntax pattern.  When clearing all, must be called from
 * last to first!
 */
    static void
syn_clear_pattern(synblock_T *block, int i)
{
    vim_free(SYN_ITEMS(block)[i].sp_pattern);
    vim_regfree(SYN_ITEMS(block)[i].sp_prog);
    // Only free sp_cont_list and sp_next_list of first start pattern
    if (i == 0 || SYN_ITEMS(block)[i - 1].sp_type != SPTYPE_START)
    {
	vim_free(SYN_ITEMS(block)[i].sp_cont_list);
	vim_free(SYN_ITEMS(block)[i].sp_next_list);
	vim_free(SYN_ITEMS(block)[i].sp_syn.cont_in_list);
    }
}

/*
 * Clear and free one syntax cluster.
 */
    static void
syn_clear_cluster(synblock_T *block, int i)
{
    vim_free(SYN_CLSTR(block)[i].scl_name);
    vim_free(SYN_CLSTR(block)[i].scl_name_u);
    vim_free(SYN_CLSTR(block)[i].scl_list);
}

/*
 * Handle ":syntax clear" command.
 */
    static void
syn_cmd_clear(exarg_T *eap, int syncing)
{
    char_u	*arg = eap->arg;
    char_u	*arg_end;
    int		id;

    eap->nextcmd = find_nextcmd(arg);
    if (eap->skip)
	return;

    /*
     * We have to disable this within ":syn include @group filename",
     * because otherwise @group would get deleted.
     * Only required for Vim 5.x syntax files, 6.0 ones don't contain ":syn
     * clear".
     */
    if (curwin->w_s->b_syn_topgrp != 0)
	return;

    if (ends_excmd2(eap->cmd, arg))
    {
	/*
	 * No argument: Clear all syntax items.
	 */
	if (syncing)
	    syntax_sync_clear();
	else
	{
	    syntax_clear(curwin->w_s);
	    if (curwin->w_s == &curwin->w_buffer->b_s)
		do_unlet((char_u *)"b:current_syntax", TRUE);
	    do_unlet((char_u *)"w:current_syntax", TRUE);
	}
    }
    else
    {
	/*
	 * Clear the group IDs that are in the argument.
	 */
	while (!ends_excmd2(eap->cmd, arg))
	{
	    arg_end = skiptowhite(arg);
	    if (*arg == '@')
	    {
		id = syn_scl_namen2id(arg + 1, (int)(arg_end - arg - 1));
		if (id == 0)
		{
		    semsg(_(e_no_such_syntax_cluster_str_1), arg);
		    break;
		}
		else
		{
		    /*
		     * We can't physically delete a cluster without changing
		     * the IDs of other clusters, so we do the next best thing
		     * and make it empty.
		     */
		    short scl_id = id - SYNID_CLUSTER;

		    VIM_CLEAR(SYN_CLSTR(curwin->w_s)[scl_id].scl_list);
		}
	    }
	    else
	    {
		id = syn_namen2id(arg, (int)(arg_end - arg));
		if (id == 0)
		{
		    semsg(_(e_no_such_highlight_group_name_str), arg);
		    break;
		}
		else
		    syn_clear_one(id, syncing);
	    }
	    arg = skipwhite(arg_end);
	}
    }
    redraw_curbuf_later(UPD_SOME_VALID);
    syn_stack_free_all(curwin->w_s);		// Need to recompute all syntax.
}

/*
 * Clear one syntax group for the current buffer.
 */
    static void
syn_clear_one(int id, int syncing)
{
    synpat_T	*spp;
    int		idx;

    // Clear keywords only when not ":syn sync clear group-name"
    if (!syncing)
    {
	(void)syn_clear_keyword(id, &curwin->w_s->b_keywtab);
	(void)syn_clear_keyword(id, &curwin->w_s->b_keywtab_ic);
    }

    // clear the patterns for "id"
    for (idx = curwin->w_s->b_syn_patterns.ga_len; --idx >= 0; )
    {
	spp = &(SYN_ITEMS(curwin->w_s)[idx]);
	if (spp->sp_syn.id != id || spp->sp_syncing != syncing)
	    continue;
	syn_remove_pattern(curwin->w_s, idx);
    }
}

/*
 * Handle ":syntax on" command.
 */
    static void
syn_cmd_on(exarg_T *eap, int syncing UNUSED)
{
    syn_cmd_onoff(eap, "syntax");
}

/*
 * Handle ":syntax enable" command.
 */
    static void
syn_cmd_enable(exarg_T *eap, int syncing UNUSED)
{
    set_internal_string_var((char_u *)"g:syntax_cmd", (char_u *)"enable");
    syn_cmd_onoff(eap, "syntax");
    do_unlet((char_u *)"g:syntax_cmd", TRUE);
}

/*
 * Handle ":syntax reset" command.
 * It actually resets highlighting, not syntax.
 */
    static void
syn_cmd_reset(exarg_T *eap, int syncing UNUSED)
{
    set_nextcmd(eap, eap->arg);
    if (!eap->skip)
    {
	set_internal_string_var((char_u *)"g:syntax_cmd", (char_u *)"reset");
	do_cmdline_cmd((char_u *)"runtime! syntax/syncolor.vim");
	do_unlet((char_u *)"g:syntax_cmd", TRUE);
    }
}

/*
 * Handle ":syntax manual" command.
 */
    static void
syn_cmd_manual(exarg_T *eap, int syncing UNUSED)
{
    syn_cmd_onoff(eap, "manual");
}

/*
 * Handle ":syntax off" command.
 */
    static void
syn_cmd_off(exarg_T *eap, int syncing UNUSED)
{
    syn_cmd_onoff(eap, "nosyntax");
}

    static void
syn_cmd_onoff(exarg_T *eap, char *name)
{
    char_u	buf[100];

    set_nextcmd(eap, eap->arg);
    if (!eap->skip)
    {
	STRCPY(buf, "so ");
	vim_snprintf((char *)buf + 3, sizeof(buf) - 3, SYNTAX_FNAME, name);
	do_cmdline_cmd(buf);
    }
}

/*
 * Handle ":syntax [list]" command: list current syntax words.
 */
    static void
syn_cmd_list(
    exarg_T	*eap,
    int		syncing)	    // when TRUE: list syncing items
{
    char_u	*arg = eap->arg;
    int		id;
    char_u	*arg_end;

    eap->nextcmd = find_nextcmd(arg);
    if (eap->skip)
	return;

    if (!syntax_present(curwin))
    {
	msg(_(msg_no_items));
	return;
    }

    if (syncing)
    {
	if (curwin->w_s->b_syn_sync_flags & SF_CCOMMENT)
	{
	    msg_puts(_("syncing on C-style comments"));
	    syn_lines_msg();
	    syn_match_msg();
	    return;
	}
	else if (!(curwin->w_s->b_syn_sync_flags & SF_MATCH))
	{
	    if (curwin->w_s->b_syn_sync_minlines == 0)
		msg_puts(_("no syncing"));
	    else
	    {
		if (curwin->w_s->b_syn_sync_minlines == MAXLNUM)
		    msg_puts(_("syncing starts at the first line"));
		else
		{
		    msg_puts(_("syncing starts "));
		    msg_outnum(curwin->w_s->b_syn_sync_minlines);
		    msg_puts(_(" lines before top line"));
		}
		syn_match_msg();
	    }
	    return;
	}
	msg_puts_title(_("\n--- Syntax sync items ---"));
	if (curwin->w_s->b_syn_sync_minlines > 0
		|| curwin->w_s->b_syn_sync_maxlines > 0
		|| curwin->w_s->b_syn_sync_linebreaks > 0)
	{
	    msg_puts(_("\nsyncing on items"));
	    syn_lines_msg();
	    syn_match_msg();
	}
    }
    else
	msg_puts_title(_("\n--- Syntax items ---"));
    if (ends_excmd2(eap->cmd, arg))
    {
	/*
	 * No argument: List all group IDs and all syntax clusters.
	 */
	for (id = 1; id <= highlight_num_groups() && !got_int; ++id)
	    syn_list_one(id, syncing, FALSE);
	for (id = 0; id < curwin->w_s->b_syn_clusters.ga_len && !got_int; ++id)
	    syn_list_cluster(id);
    }
    else
    {
	/*
	 * List the group IDs and syntax clusters that are in the argument.
	 */
	while (!ends_excmd2(eap->cmd, arg) && !got_int)
	{
	    arg_end = skiptowhite(arg);
	    if (*arg == '@')
	    {
		id = syn_scl_namen2id(arg + 1, (int)(arg_end - arg - 1));
		if (id == 0)
		    semsg(_(e_no_such_syntax_cluster_str_2), arg);
		else
		    syn_list_cluster(id - SYNID_CLUSTER);
	    }
	    else
	    {
		id = syn_namen2id(arg, (int)(arg_end - arg));
		if (id == 0)
		    semsg(_(e_no_such_highlight_group_name_str), arg);
		else
		    syn_list_one(id, syncing, TRUE);
	    }
	    arg = skipwhite(arg_end);
	}
    }
    set_nextcmd(eap, arg);
}

    static void
syn_lines_msg(void)
{
    if (curwin->w_s->b_syn_sync_maxlines > 0
				      || curwin->w_s->b_syn_sync_minlines > 0)
    {
	msg_puts("; ");
	if (curwin->w_s->b_syn_sync_minlines == MAXLNUM)
	    msg_puts(_("from the first line"));
	else
	{
	    if (curwin->w_s->b_syn_sync_minlines > 0)
	    {
		msg_puts(_("minimal "));
		msg_outnum(curwin->w_s->b_syn_sync_minlines);
		if (curwin->w_s->b_syn_sync_maxlines)
		    msg_puts(", ");
	    }
	    if (curwin->w_s->b_syn_sync_maxlines > 0)
	    {
		msg_puts(_("maximal "));
		msg_outnum(curwin->w_s->b_syn_sync_maxlines);
	    }
	    msg_puts(_(" lines before top line"));
	}
    }
}

    static void
syn_match_msg(void)
{
    if (curwin->w_s->b_syn_sync_linebreaks > 0)
    {
	msg_puts(_("; match "));
	msg_outnum(curwin->w_s->b_syn_sync_linebreaks);
	msg_puts(_(" line breaks"));
    }
}

static int  last_matchgroup;

struct name_list
{
    int		flag;
    char	*name;
};

static void syn_list_flags(struct name_list *nl, int flags, int attr);

/*
 * List one syntax item, for ":syntax" or "syntax list syntax_name".
 */
    static void
syn_list_one(
    int		id,
    int		syncing,	    // when TRUE: list syncing items
    int		link_only)	    // when TRUE; list link-only too
{
    int		attr;
    int		idx;
    int		did_header = FALSE;
    synpat_T	*spp;
    static struct name_list namelist1[] =
		{
		    {HL_DISPLAY, "display"},
		    {HL_CONTAINED, "contained"},
		    {HL_ONELINE, "oneline"},
		    {HL_KEEPEND, "keepend"},
		    {HL_EXTEND, "extend"},
		    {HL_EXCLUDENL, "excludenl"},
		    {HL_TRANSP, "transparent"},
		    {HL_FOLD, "fold"},
#ifdef FEAT_CONCEAL
		    {HL_CONCEAL, "conceal"},
		    {HL_CONCEALENDS, "concealends"},
#endif
		    {0, NULL}
		};
    static struct name_list namelist2[] =
		{
		    {HL_SKIPWHITE, "skipwhite"},
		    {HL_SKIPNL, "skipnl"},
		    {HL_SKIPEMPTY, "skipempty"},
		    {0, NULL}
		};

    attr = HL_ATTR(HLF_D);		// highlight like directories

    // list the keywords for "id"
    if (!syncing)
    {
	did_header = syn_list_keywords(id, &curwin->w_s->b_keywtab, FALSE, attr);
	did_header = syn_list_keywords(id, &curwin->w_s->b_keywtab_ic,
							    did_header, attr);
    }

    // list the patterns for "id"
    for (idx = 0; idx < curwin->w_s->b_syn_patterns.ga_len && !got_int; ++idx)
    {
	spp = &(SYN_ITEMS(curwin->w_s)[idx]);
	if (spp->sp_syn.id != id || spp->sp_syncing != syncing)
	    continue;

	(void)syn_list_header(did_header, 999, id);
	did_header = TRUE;
	last_matchgroup = 0;
	if (spp->sp_type == SPTYPE_MATCH)
	{
	    put_pattern("match", ' ', spp, attr);
	    msg_putchar(' ');
	}
	else if (spp->sp_type == SPTYPE_START)
	{
	    while (SYN_ITEMS(curwin->w_s)[idx].sp_type == SPTYPE_START)
		put_pattern("start", '=', &SYN_ITEMS(curwin->w_s)[idx++], attr);
	    if (SYN_ITEMS(curwin->w_s)[idx].sp_type == SPTYPE_SKIP)
		put_pattern("skip", '=', &SYN_ITEMS(curwin->w_s)[idx++], attr);
	    while (idx < curwin->w_s->b_syn_patterns.ga_len
			  && SYN_ITEMS(curwin->w_s)[idx].sp_type == SPTYPE_END)
		put_pattern("end", '=', &SYN_ITEMS(curwin->w_s)[idx++], attr);
	    --idx;
	    msg_putchar(' ');
	}
	syn_list_flags(namelist1, spp->sp_flags, attr);

	if (spp->sp_cont_list != NULL)
	    put_id_list((char_u *)"contains", spp->sp_cont_list, attr);

	if (spp->sp_syn.cont_in_list != NULL)
	    put_id_list((char_u *)"containedin",
					      spp->sp_syn.cont_in_list, attr);

	if (spp->sp_next_list != NULL)
	{
	    put_id_list((char_u *)"nextgroup", spp->sp_next_list, attr);
	    syn_list_flags(namelist2, spp->sp_flags, attr);
	}
	if (spp->sp_flags & (HL_SYNC_HERE|HL_SYNC_THERE))
	{
	    if (spp->sp_flags & HL_SYNC_HERE)
		msg_puts_attr("grouphere", attr);
	    else
		msg_puts_attr("groupthere", attr);
	    msg_putchar(' ');
	    if (spp->sp_sync_idx >= 0)
		msg_outtrans(highlight_group_name(SYN_ITEMS(curwin->w_s)
				   [spp->sp_sync_idx].sp_syn.id - 1));
	    else
		msg_puts("NONE");
	    msg_putchar(' ');
	}
    }

    // list the link, if there is one
    if (highlight_link_id(id - 1) && (did_header || link_only) && !got_int)
    {
	(void)syn_list_header(did_header, 999, id);
	msg_puts_attr("links to", attr);
	msg_putchar(' ');
	msg_outtrans(highlight_group_name(highlight_link_id(id - 1) - 1));
    }
}

    static void
syn_list_flags(struct name_list *nlist, int flags, int attr)
{
    int		i;

    for (i = 0; nlist[i].flag != 0; ++i)
	if (flags & nlist[i].flag)
	{
	    msg_puts_attr(nlist[i].name, attr);
	    msg_putchar(' ');
	}
}

/*
 * List one syntax cluster, for ":syntax" or "syntax list syntax_name".
 */
    static void
syn_list_cluster(int id)
{
    int	    endcol = 15;

    // slight hack:  roughly duplicate the guts of syn_list_header()
    msg_putchar('\n');
    msg_outtrans(SYN_CLSTR(curwin->w_s)[id].scl_name);

    if (msg_col >= endcol)	// output at least one space
	endcol = msg_col + 1;
    if (Columns <= endcol)	// avoid hang for tiny window
	endcol = Columns - 1;

    msg_advance(endcol);
    if (SYN_CLSTR(curwin->w_s)[id].scl_list != NULL)
    {
	put_id_list((char_u *)"cluster", SYN_CLSTR(curwin->w_s)[id].scl_list,
		    HL_ATTR(HLF_D));
    }
    else
    {
	msg_puts_attr("cluster", HL_ATTR(HLF_D));
	msg_puts("=NONE");
    }
}

    static void
put_id_list(char_u *name, short *list, int attr)
{
    short		*p;

    msg_puts_attr((char *)name, attr);
    msg_putchar('=');
    for (p = list; *p; ++p)
    {
	if (*p >= SYNID_ALLBUT && *p < SYNID_TOP)
	{
	    if (p[1])
		msg_puts("ALLBUT");
	    else
		msg_puts("ALL");
	}
	else if (*p >= SYNID_TOP && *p < SYNID_CONTAINED)
	{
	    msg_puts("TOP");
	}
	else if (*p >= SYNID_CONTAINED && *p < SYNID_CLUSTER)
	{
	    msg_puts("CONTAINED");
	}
	else if (*p >= SYNID_CLUSTER)
	{
	    short scl_id = *p - SYNID_CLUSTER;

	    msg_putchar('@');
	    msg_outtrans(SYN_CLSTR(curwin->w_s)[scl_id].scl_name);
	}
	else
	    msg_outtrans(highlight_group_name(*p - 1));
	if (p[1])
	    msg_putchar(',');
    }
    msg_putchar(' ');
}

    static void
put_pattern(
    char	*s,
    int		c,
    synpat_T	*spp,
    int		attr)
{
    long	n;
    int		mask;
    int		first;
    static char	*sepchars = "/+=-#@\"|'^&";
    int		i;

    // May have to write "matchgroup=group"
    if (last_matchgroup != spp->sp_syn_match_id)
    {
	last_matchgroup = spp->sp_syn_match_id;
	msg_puts_attr("matchgroup", attr);
	msg_putchar('=');
	if (last_matchgroup == 0)
	    msg_outtrans((char_u *)"NONE");
	else
	    msg_outtrans(highlight_group_name(last_matchgroup - 1));
	msg_putchar(' ');
    }

    // output the name of the pattern and an '=' or ' '
    msg_puts_attr(s, attr);
    msg_putchar(c);

    // output the pattern, in between a char that is not in the pattern
    for (i = 0; vim_strchr(spp->sp_pattern, sepchars[i]) != NULL; )
	if (sepchars[++i] == NUL)
	{
	    i = 0;	// no good char found, just use the first one
	    break;
	}
    msg_putchar(sepchars[i]);
    msg_outtrans(spp->sp_pattern);
    msg_putchar(sepchars[i]);

    // output any pattern options
    first = TRUE;
    for (i = 0; i < SPO_COUNT; ++i)
    {
	mask = (1 << i);
	if (spp->sp_off_flags & (mask + (mask << SPO_COUNT)))
	{
	    if (!first)
		msg_putchar(',');	// separate with commas
	    msg_puts(spo_name_tab[i]);
	    n = spp->sp_offsets[i];
	    if (i != SPO_LC_OFF)
	    {
		if (spp->sp_off_flags & mask)
		    msg_putchar('s');
		else
		    msg_putchar('e');
		if (n > 0)
		    msg_putchar('+');
	    }
	    if (n || i == SPO_LC_OFF)
		msg_outnum(n);
	    first = FALSE;
	}
    }
    msg_putchar(' ');
}

/*
 * List or clear the keywords for one syntax group.
 * Return TRUE if the header has been printed.
 */
    static int
syn_list_keywords(
    int		id,
    hashtab_T	*ht,
    int		did_header,		// header has already been printed
    int		attr)
{
    int		outlen;
    hashitem_T	*hi;
    keyentry_T	*kp;
    int		todo;
    int		prev_contained = 0;
    short	*prev_next_list = NULL;
    short	*prev_cont_in_list = NULL;
    int		prev_skipnl = 0;
    int		prev_skipwhite = 0;
    int		prev_skipempty = 0;

    /*
     * Unfortunately, this list of keywords is not sorted on alphabet but on
     * hash value...
     */
    todo = (int)ht->ht_used;
    for (hi = ht->ht_array; todo > 0 && !got_int; ++hi)
    {
	if (!HASHITEM_EMPTY(hi))
	{
	    --todo;
	    for (kp = HI2KE(hi); kp != NULL && !got_int; kp = kp->ke_next)
	    {
		if (kp->k_syn.id == id)
		{
		    if (prev_contained != (kp->flags & HL_CONTAINED)
			    || prev_skipnl != (kp->flags & HL_SKIPNL)
			    || prev_skipwhite != (kp->flags & HL_SKIPWHITE)
			    || prev_skipempty != (kp->flags & HL_SKIPEMPTY)
			    || prev_cont_in_list != kp->k_syn.cont_in_list
			    || prev_next_list != kp->next_list)
			outlen = 9999;
		    else
			outlen = (int)STRLEN(kp->keyword);
		    // output "contained" and "nextgroup" on each line
		    if (syn_list_header(did_header, outlen, id))
		    {
			prev_contained = 0;
			prev_next_list = NULL;
			prev_cont_in_list = NULL;
			prev_skipnl = 0;
			prev_skipwhite = 0;
			prev_skipempty = 0;
		    }
		    did_header = TRUE;
		    if (prev_contained != (kp->flags & HL_CONTAINED))
		    {
			msg_puts_attr("contained", attr);
			msg_putchar(' ');
			prev_contained = (kp->flags & HL_CONTAINED);
		    }
		    if (kp->k_syn.cont_in_list != prev_cont_in_list)
		    {
			put_id_list((char_u *)"containedin",
						kp->k_syn.cont_in_list, attr);
			msg_putchar(' ');
			prev_cont_in_list = kp->k_syn.cont_in_list;
		    }
		    if (kp->next_list != prev_next_list)
		    {
			put_id_list((char_u *)"nextgroup", kp->next_list, attr);
			msg_putchar(' ');
			prev_next_list = kp->next_list;
			if (kp->flags & HL_SKIPNL)
			{
			    msg_puts_attr("skipnl", attr);
			    msg_putchar(' ');
			    prev_skipnl = (kp->flags & HL_SKIPNL);
			}
			if (kp->flags & HL_SKIPWHITE)
			{
			    msg_puts_attr("skipwhite", attr);
			    msg_putchar(' ');
			    prev_skipwhite = (kp->flags & HL_SKIPWHITE);
			}
			if (kp->flags & HL_SKIPEMPTY)
			{
			    msg_puts_attr("skipempty", attr);
			    msg_putchar(' ');
			    prev_skipempty = (kp->flags & HL_SKIPEMPTY);
			}
		    }
		    msg_outtrans(kp->keyword);
		}
	    }
	}
    }

    return did_header;
}

    static void
syn_clear_keyword(int id, hashtab_T *ht)
{
    hashitem_T	*hi;
    keyentry_T	*kp;
    keyentry_T	*kp_prev;
    keyentry_T	*kp_next;
    int		todo;

    hash_lock(ht);
    todo = (int)ht->ht_used;
    FOR_ALL_HASHTAB_ITEMS(ht, hi, todo)
    {
	if (!HASHITEM_EMPTY(hi))
	{
	    --todo;
	    kp_prev = NULL;
	    for (kp = HI2KE(hi); kp != NULL; )
	    {
		if (kp->k_syn.id == id)
		{
		    kp_next = kp->ke_next;
		    if (kp_prev == NULL)
		    {
			if (kp_next == NULL)
			    hash_remove(ht, hi, "syntax clear keyword");
			else
			    hi->hi_key = KE2HIKEY(kp_next);
		    }
		    else
			kp_prev->ke_next = kp_next;
		    vim_free(kp->next_list);
		    vim_free(kp->k_syn.cont_in_list);
		    vim_free(kp);
		    kp = kp_next;
		}
		else
		{
		    kp_prev = kp;
		    kp = kp->ke_next;
		}
	    }
	}
    }
    hash_unlock(ht);
}

/*
 * Clear a whole keyword table.
 */
    static void
clear_keywtab(hashtab_T *ht)
{
    hashitem_T	*hi;
    int		todo;
    keyentry_T	*kp;
    keyentry_T	*kp_next;

    todo = (int)ht->ht_used;
    FOR_ALL_HASHTAB_ITEMS(ht, hi, todo)
    {
	if (!HASHITEM_EMPTY(hi))
	{
	    --todo;
	    for (kp = HI2KE(hi); kp != NULL; kp = kp_next)
	    {
		kp_next = kp->ke_next;
		vim_free(kp->next_list);
		vim_free(kp->k_syn.cont_in_list);
		vim_free(kp);
	    }
	}
    }
    hash_clear(ht);
    hash_init(ht);
}

/*
 * Add a keyword to the list of keywords.
 */
    static void
add_keyword(
    char_u	*name,	    // name of keyword
    int		id,	    // group ID for this keyword
    int		flags,	    // flags for this keyword
    short	*cont_in_list, // containedin for this keyword
    short	*next_list, // nextgroup for this keyword
    int		conceal_char)
{
    keyentry_T	*kp;
    hashtab_T	*ht;
    hashitem_T	*hi;
    char_u	*name_ic;
    long_u	hash;
    char_u	name_folded[MAXKEYWLEN + 1];

    if (curwin->w_s->b_syn_ic)
	name_ic = str_foldcase(name, (int)STRLEN(name),
						 name_folded, MAXKEYWLEN + 1);
    else
	name_ic = name;
    kp = alloc(offsetof(keyentry_T, keyword) + STRLEN(name_ic) + 1);
    if (kp == NULL)
	return;
    STRCPY(kp->keyword, name_ic);
    kp->k_syn.id = id;
    kp->k_syn.inc_tag = current_syn_inc_tag;
    kp->flags = flags;
    kp->k_char = conceal_char;
    kp->k_syn.cont_in_list = copy_id_list(cont_in_list);
    if (cont_in_list != NULL)
	curwin->w_s->b_syn_containedin = TRUE;
    kp->next_list = copy_id_list(next_list);

    if (curwin->w_s->b_syn_ic)
	ht = &curwin->w_s->b_keywtab_ic;
    else
	ht = &curwin->w_s->b_keywtab;

    hash = hash_hash(kp->keyword);
    hi = hash_lookup(ht, kp->keyword, hash);
    if (HASHITEM_EMPTY(hi))
    {
	// new keyword, add to hashtable
	kp->ke_next = NULL;
	hash_add_item(ht, hi, kp->keyword, hash);
    }
    else
    {
	// keyword already exists, prepend to list
	kp->ke_next = HI2KE(hi);
	hi->hi_key = KE2HIKEY(kp);
    }
}

/*
 * Get the start and end of the group name argument.
 * Return a pointer to the first argument.
 * Return NULL if the end of the command was found instead of further args.
 */
    static char_u *
get_group_name(
    char_u	*arg,		// start of the argument
    char_u	**name_end)	// pointer to end of the name
{
    char_u	*rest;

    *name_end = skiptowhite(arg);
    rest = skipwhite(*name_end);

    /*
     * Check if there are enough arguments.  The first argument may be a
     * pattern, where '|' is allowed, so only check for NUL.
     */
    if (ends_excmd(*arg) || *rest == NUL)
	return NULL;
    return rest;
}

/*
 * Check for syntax command option arguments.
 * This can be called at any place in the list of arguments, and just picks
 * out the arguments that are known.  Can be called several times in a row to
 * collect all options in between other arguments.
 * Return a pointer to the next argument (which isn't an option).
 * Return NULL for any error;
 */
    static char_u *
get_syn_options(
    char_u	    *start,		// next argument to be checked
    syn_opt_arg_T   *opt,		// various things
    int		    *conceal_char UNUSED,
    int		    skip)		// TRUE if skipping over command
{
    char_u	*arg = start;
    char_u	*gname_start, *gname;
    int		syn_id;
    int		len;
    char	*p;
    int		i;
    int		fidx;
    static struct flag
    {
	char	*name;
	int	argtype;
	int	flags;
    } flagtab[] = { {"cCoOnNtTaAiInNeEdD",	0,	HL_CONTAINED},
		    {"oOnNeElLiInNeE",		0,	HL_ONELINE},
		    {"kKeEeEpPeEnNdD",		0,	HL_KEEPEND},
		    {"eExXtTeEnNdD",		0,	HL_EXTEND},
		    {"eExXcClLuUdDeEnNlL",	0,	HL_EXCLUDENL},
		    {"tTrRaAnNsSpPaArReEnNtT",	0,	HL_TRANSP},
		    {"sSkKiIpPnNlL",		0,	HL_SKIPNL},
		    {"sSkKiIpPwWhHiItTeE",	0,	HL_SKIPWHITE},
		    {"sSkKiIpPeEmMpPtTyY",	0,	HL_SKIPEMPTY},
		    {"gGrRoOuUpPhHeErReE",	0,	HL_SYNC_HERE},
		    {"gGrRoOuUpPtThHeErReE",	0,	HL_SYNC_THERE},
		    {"dDiIsSpPlLaAyY",		0,	HL_DISPLAY},
		    {"fFoOlLdD",		0,	HL_FOLD},
		    {"cCoOnNcCeEaAlL",		0,	HL_CONCEAL},
		    {"cCoOnNcCeEaAlLeEnNdDsS",	0,	HL_CONCEALENDS},
		    {"cCcChHaArR",		11,	0},
		    {"cCoOnNtTaAiInNsS",	1,	0},
		    {"cCoOnNtTaAiInNeEdDiInN",	2,	0},
		    {"nNeExXtTgGrRoOuUpP",	3,	0},
		};
    static char *first_letters = "cCoOkKeEtTsSgGdDfFnN";

    if (arg == NULL)		// already detected error
	return NULL;

#ifdef FEAT_CONCEAL
    if (curwin->w_s->b_syn_conceal)
	opt->flags |= HL_CONCEAL;
#endif

    for (;;)
    {
	/*
	 * This is used very often when a large number of keywords is defined.
	 * Need to skip quickly when no option name is found.
	 * Also avoid tolower(), it's slow.
	 */
	if (strchr(first_letters, *arg) == NULL)
	    break;

	for (fidx = ARRAY_LENGTH(flagtab); --fidx >= 0; )
	{
	    p = flagtab[fidx].name;
	    for (i = 0, len = 0; p[i] != NUL; i += 2, ++len)
		if (arg[len] != p[i] && arg[len] != p[i + 1])
		    break;
	    if (p[i] == NUL && (VIM_ISWHITE(arg[len])
				    || (flagtab[fidx].argtype > 0
					 ? arg[len] == '='
					 : ends_excmd2(start, arg + len))))
	    {
		if (opt->keyword
			&& (flagtab[fidx].flags == HL_DISPLAY
			    || flagtab[fidx].flags == HL_FOLD
			    || flagtab[fidx].flags == HL_EXTEND))
		    // treat "display", "fold" and "extend" as a keyword
		    fidx = -1;
		break;
	    }
	}
	if (fidx < 0)	    // no match found
	    break;

	if (flagtab[fidx].argtype == 1)
	{
	    if (!opt->has_cont_list)
	    {
		emsg(_(e_contains_argument_not_accepted_here));
		return NULL;
	    }
	    if (get_id_list(&arg, 8, &opt->cont_list, skip) == FAIL)
		return NULL;
	}
	else if (flagtab[fidx].argtype == 2)
	{
	    if (get_id_list(&arg, 11, &opt->cont_in_list, skip) == FAIL)
		return NULL;
	}
	else if (flagtab[fidx].argtype == 3)
	{
	    if (get_id_list(&arg, 9, &opt->next_list, skip) == FAIL)
		return NULL;
	}
	else if (flagtab[fidx].argtype == 11 && arg[5] == '=')
	{
	    // cchar=?
	    if (has_mbyte)
	    {
#ifdef FEAT_CONCEAL
		*conceal_char = mb_ptr2char(arg + 6);
#endif
		arg += mb_ptr2len(arg + 6) - 1;
	    }
	    else
	    {
#ifdef FEAT_CONCEAL
		*conceal_char = arg[6];
#else
		;
#endif
	    }
#ifdef FEAT_CONCEAL
	    if (!vim_isprintc_strict(*conceal_char))
	    {
		emsg(_(e_invalid_cchar_value));
		return NULL;
	    }
#endif
	    arg = skipwhite(arg + 7);
	}
	else
	{
	    opt->flags |= flagtab[fidx].flags;
	    arg = skipwhite(arg + len);

	    if (flagtab[fidx].flags == HL_SYNC_HERE
		    || flagtab[fidx].flags == HL_SYNC_THERE)
	    {
		if (opt->sync_idx == NULL)
		{
		    emsg(_(e_groupthere_not_accepted_here));
		    return NULL;
		}
		gname_start = arg;
		arg = skiptowhite(arg);
		if (gname_start == arg)
		    return NULL;
		gname = vim_strnsave(gname_start, arg - gname_start);
		if (gname == NULL)
		    return NULL;
		if (STRCMP(gname, "NONE") == 0)
		    *opt->sync_idx = NONE_IDX;
		else
		{
		    syn_id = syn_name2id(gname);
		    for (i = curwin->w_s->b_syn_patterns.ga_len; --i >= 0; )
			if (SYN_ITEMS(curwin->w_s)[i].sp_syn.id == syn_id
			      && SYN_ITEMS(curwin->w_s)[i].sp_type
							       == SPTYPE_START)
			{
			    *opt->sync_idx = i;
			    break;
			}
		    if (i < 0)
		    {
			semsg(_(e_didnt_find_region_item_for_str), gname);
			vim_free(gname);
			return NULL;
		    }
		}

		vim_free(gname);
		arg = skipwhite(arg);
	    }
#ifdef FEAT_FOLDING
	    else if (flagtab[fidx].flags == HL_FOLD
						&& foldmethodIsSyntax(curwin))
		// Need to update folds later.
		foldUpdateAll(curwin);
#endif
	}
    }

    return arg;
}

/*
 * Adjustments to syntax item when declared in a ":syn include"'d file.
 * Set the contained flag, and if the item is not already contained, add it
 * to the specified top-level group, if any.
 */
    static void
syn_incl_toplevel(int id, int *flagsp)
{
    if ((*flagsp & HL_CONTAINED) || curwin->w_s->b_syn_topgrp == 0)
	return;
    *flagsp |= HL_CONTAINED;
    if (curwin->w_s->b_syn_topgrp >= SYNID_CLUSTER)
    {
	// We have to alloc this, because syn_combine_list() will free it.
	short	    *grp_list = ALLOC_MULT(short, 2);
	int	    tlg_id = curwin->w_s->b_syn_topgrp - SYNID_CLUSTER;

	if (grp_list != NULL)
	{
	    grp_list[0] = id;
	    grp_list[1] = 0;
	    syn_combine_list(&SYN_CLSTR(curwin->w_s)[tlg_id].scl_list,
						       &grp_list, CLUSTER_ADD);
	}
    }
}

/*
 * Handle ":syntax include [@{group-name}] filename" command.
 */
    static void
syn_cmd_include(exarg_T *eap, int syncing UNUSED)
{
    char_u	*arg = eap->arg;
    int		sgl_id = 1;
    char_u	*group_name_end;
    char_u	*rest;
    char	*errormsg = NULL;
    int		prev_toplvl_grp;
    int		prev_syn_inc_tag;
    int		source = FALSE;

    eap->nextcmd = find_nextcmd(arg);
    if (eap->skip)
	return;

    if (arg[0] == '@')
    {
	++arg;
	rest = get_group_name(arg, &group_name_end);
	if (rest == NULL)
	{
	    emsg(_(e_filename_required));
	    return;
	}
	sgl_id = syn_check_cluster(arg, (int)(group_name_end - arg));
	if (sgl_id == 0)
	    return;
	// separate_nextcmd() and expand_filename() depend on this
	eap->arg = rest;
    }

    /*
     * Everything that's left, up to the next command, should be the
     * filename to include.
     */
    eap->argt |= (EX_XFILE | EX_NOSPC);
    separate_nextcmd(eap, FALSE);
    if (*eap->arg == '<' || *eap->arg == '$' || mch_isFullName(eap->arg))
    {
	// For an absolute path, "$VIM/..." or "<sfile>.." we ":source" the
	// file.  Need to expand the file name first.  In other cases
	// ":runtime!" is used.
	source = TRUE;
	if (expand_filename(eap, syn_cmdlinep, &errormsg) == FAIL)
	{
	    if (errormsg != NULL)
		emsg(errormsg);
	    return;
	}
    }

    /*
     * Save and restore the existing top-level grouplist id and ":syn
     * include" tag around the actual inclusion.
     */
    if (running_syn_inc_tag >= MAX_SYN_INC_TAG)
    {
	emsg(_(e_too_many_syntax_includes));
	return;
    }
    prev_syn_inc_tag = current_syn_inc_tag;
    current_syn_inc_tag = ++running_syn_inc_tag;
    prev_toplvl_grp = curwin->w_s->b_syn_topgrp;
    curwin->w_s->b_syn_topgrp = sgl_id;
    if (source ? do_source(eap->arg, FALSE, DOSO_NONE, NULL) == FAIL
				: source_runtime(eap->arg, DIP_ALL) == FAIL)
	semsg(_(e_cant_open_file_str), eap->arg);
    curwin->w_s->b_syn_topgrp = prev_toplvl_grp;
    current_syn_inc_tag = prev_syn_inc_tag;
}

/*
 * Handle ":syntax keyword {group-name} [{option}] keyword .." command.
 */
    static void
syn_cmd_keyword(exarg_T *eap, int syncing UNUSED)
{
    char_u	*arg = eap->arg;
    char_u	*group_name_end;
    int		syn_id;
    char_u	*rest;
    char_u	*keyword_copy = NULL;
    char_u	*p;
    char_u	*kw;
    syn_opt_arg_T syn_opt_arg;
    int		cnt;
    int		conceal_char = NUL;

    rest = get_group_name(arg, &group_name_end);

    if (rest != NULL)
    {
	if (eap->skip)
	    syn_id = -1;
	else
	    syn_id = syn_check_group(arg, (int)(group_name_end - arg));
	if (syn_id != 0)
	    // allocate a buffer, for removing backslashes in the keyword
	    keyword_copy = alloc(STRLEN(rest) + 1);
	if (keyword_copy != NULL)
	{
	    syn_opt_arg.flags = 0;
	    syn_opt_arg.keyword = TRUE;
	    syn_opt_arg.sync_idx = NULL;
	    syn_opt_arg.has_cont_list = FALSE;
	    syn_opt_arg.cont_in_list = NULL;
	    syn_opt_arg.next_list = NULL;

	    /*
	     * The options given apply to ALL keywords, so all options must be
	     * found before keywords can be created.
	     * 1: collect the options and copy the keywords to keyword_copy.
	     */
	    cnt = 0;
	    p = keyword_copy;
	    for ( ; rest != NULL && !ends_excmd2(eap->arg, rest);
							rest = skipwhite(rest))
	    {
		rest = get_syn_options(rest, &syn_opt_arg, &conceal_char,
								    eap->skip);
		if (rest == NULL || ends_excmd2(eap->arg, rest))
		    break;
		// Copy the keyword, removing backslashes, and add a NUL.
		while (*rest != NUL && !VIM_ISWHITE(*rest))
		{
		    if (*rest == '\\' && rest[1] != NUL)
			++rest;
		    *p++ = *rest++;
		}
		*p++ = NUL;
		++cnt;
	    }

	    if (!eap->skip)
	    {
		// Adjust flags for use of ":syn include".
		syn_incl_toplevel(syn_id, &syn_opt_arg.flags);

		/*
		 * 2: Add an entry for each keyword.
		 */
		for (kw = keyword_copy; --cnt >= 0; kw += STRLEN(kw) + 1)
		{
		    for (p = vim_strchr(kw, '['); ; )
		    {
			if (p != NULL)
			    *p = NUL;
			add_keyword(kw, syn_id, syn_opt_arg.flags,
				syn_opt_arg.cont_in_list,
					 syn_opt_arg.next_list, conceal_char);
			if (p == NULL)
			    break;
			if (p[1] == NUL)
			{
			    semsg(_(e_error_missing_rsb_str), kw);
			    goto error;
			}
			if (p[1] == ']')
			{
			    if (p[2] != NUL)
			    {
				semsg(_(e_trailing_char_after_rsb_str_str),
								    kw, &p[2]);
				goto error;
			    }
			    kw = p + 1;		// skip over the "]"
			    break;
			}
			if (has_mbyte)
			{
			    int l = (*mb_ptr2len)(p + 1);

			    mch_memmove(p, p + 1, l);
			    p += l;
			}
			else
			{
			    p[0] = p[1];
			    ++p;
			}
		    }
		}
	    }
error:
	    vim_free(keyword_copy);
	    vim_free(syn_opt_arg.cont_in_list);
	    vim_free(syn_opt_arg.next_list);
	}
    }

    if (rest != NULL)
	set_nextcmd(eap, rest);
    else
	semsg(_(e_invalid_argument_str), arg);

    redraw_curbuf_later(UPD_SOME_VALID);
    syn_stack_free_all(curwin->w_s);		// Need to recompute all syntax.
}

/*
 * Handle ":syntax match {name} [{options}] {pattern} [{options}]".
 *
 * Also ":syntax sync match {name} [[grouphere | groupthere] {group-name}] .."
 */
    static void
syn_cmd_match(
    exarg_T	*eap,
    int		syncing)	    // TRUE for ":syntax sync match .. "
{
    char_u	*arg = eap->arg;
    char_u	*group_name_end;
    char_u	*rest;
    synpat_T	item;		// the item found in the line
    int		syn_id;
    int		idx;
    syn_opt_arg_T syn_opt_arg;
    int		sync_idx = 0;
    int		conceal_char = NUL;
    int		orig_called_emsg = called_emsg;

    // Isolate the group name, check for validity
    rest = get_group_name(arg, &group_name_end);

    // Get options before the pattern
    syn_opt_arg.flags = 0;
    syn_opt_arg.keyword = FALSE;
    syn_opt_arg.sync_idx = syncing ? &sync_idx : NULL;
    syn_opt_arg.has_cont_list = TRUE;
    syn_opt_arg.cont_list = NULL;
    syn_opt_arg.cont_in_list = NULL;
    syn_opt_arg.next_list = NULL;
    rest = get_syn_options(rest, &syn_opt_arg, &conceal_char, eap->skip);

    // get the pattern.
    init_syn_patterns();
    CLEAR_FIELD(item);
    rest = get_syn_pattern(rest, &item);
    if (vim_regcomp_had_eol() && !(syn_opt_arg.flags & HL_EXCLUDENL))
	syn_opt_arg.flags |= HL_HAS_EOL;

    // Get options after the pattern
    rest = get_syn_options(rest, &syn_opt_arg, &conceal_char, eap->skip);

    if (rest != NULL)		// all arguments are valid
    {
	/*
	 * Check for trailing command and illegal trailing arguments.
	 */
	set_nextcmd(eap, rest);
	if (!ends_excmd2(eap->cmd, rest) || eap->skip)
	    rest = NULL;
	else if (ga_grow(&curwin->w_s->b_syn_patterns, 1) == OK
		&& (syn_id = syn_check_group(arg,
					   (int)(group_name_end - arg))) != 0)
	{
	    syn_incl_toplevel(syn_id, &syn_opt_arg.flags);
	    /*
	     * Store the pattern in the syn_items list
	     */
	    idx = curwin->w_s->b_syn_patterns.ga_len;
	    SYN_ITEMS(curwin->w_s)[idx] = item;
	    SYN_ITEMS(curwin->w_s)[idx].sp_syncing = syncing;
	    SYN_ITEMS(curwin->w_s)[idx].sp_type = SPTYPE_MATCH;
	    SYN_ITEMS(curwin->w_s)[idx].sp_syn.id = syn_id;
	    SYN_ITEMS(curwin->w_s)[idx].sp_syn.inc_tag = current_syn_inc_tag;
	    SYN_ITEMS(curwin->w_s)[idx].sp_flags = syn_opt_arg.flags;
	    SYN_ITEMS(curwin->w_s)[idx].sp_sync_idx = sync_idx;
	    SYN_ITEMS(curwin->w_s)[idx].sp_cont_list = syn_opt_arg.cont_list;
	    SYN_ITEMS(curwin->w_s)[idx].sp_syn.cont_in_list =
						     syn_opt_arg.cont_in_list;
#ifdef FEAT_CONCEAL
	    SYN_ITEMS(curwin->w_s)[idx].sp_cchar = conceal_char;
#endif
	    if (syn_opt_arg.cont_in_list != NULL)
		curwin->w_s->b_syn_containedin = TRUE;
	    SYN_ITEMS(curwin->w_s)[idx].sp_next_list = syn_opt_arg.next_list;
	    ++curwin->w_s->b_syn_patterns.ga_len;

	    // remember that we found a match for syncing on
	    if (syn_opt_arg.flags & (HL_SYNC_HERE|HL_SYNC_THERE))
		curwin->w_s->b_syn_sync_flags |= SF_MATCH;
#ifdef FEAT_FOLDING
	    if (syn_opt_arg.flags & HL_FOLD)
		++curwin->w_s->b_syn_folditems;
#endif

	    redraw_curbuf_later(UPD_SOME_VALID);
	    syn_stack_free_all(curwin->w_s);	// Need to recompute all syntax.
	    return;	// don't free the progs and patterns now
	}
    }

    /*
     * Something failed, free the allocated memory.
     */
    vim_regfree(item.sp_prog);
    vim_free(item.sp_pattern);
    vim_free(syn_opt_arg.cont_list);
    vim_free(syn_opt_arg.cont_in_list);
    vim_free(syn_opt_arg.next_list);

    if (rest == NULL && called_emsg == orig_called_emsg)
	semsg(_(e_invalid_argument_str), arg);
}

/*
 * Handle ":syntax region {group-name} [matchgroup={group-name}]
 *		start {start} .. [skip {skip}] end {end} .. [{options}]".
 */
    static void
syn_cmd_region(
    exarg_T	*eap,
    int		syncing)	    // TRUE for ":syntax sync region .."
{
    char_u		*arg = eap->arg;
    char_u		*group_name_end;
    char_u		*rest;			// next arg, NULL on error
    char_u		*key_end;
    char_u		*key = NULL;
    char_u		*p;
    int			item;
#define ITEM_START	    0
#define ITEM_SKIP	    1
#define ITEM_END	    2
#define ITEM_MATCHGROUP	    3
    struct pat_ptr
    {
	synpat_T	*pp_synp;		// pointer to syn_pattern
	int		pp_matchgroup_id;	// matchgroup ID
	struct pat_ptr	*pp_next;		// pointer to next pat_ptr
    }			*(pat_ptrs[3]);
					// patterns found in the line
    struct pat_ptr	*ppp;
    struct pat_ptr	*ppp_next;
    int			pat_count = 0;		// nr of syn_patterns found
    int			syn_id;
    int			matchgroup_id = 0;
    int			not_enough = FALSE;	// not enough arguments
    int			illegal = FALSE;	// illegal arguments
    int			success = FALSE;
    int			idx;
    syn_opt_arg_T	syn_opt_arg;
    int			conceal_char = NUL;

    // Isolate the group name, check for validity
    rest = get_group_name(arg, &group_name_end);

    pat_ptrs[0] = NULL;
    pat_ptrs[1] = NULL;
    pat_ptrs[2] = NULL;

    init_syn_patterns();

    syn_opt_arg.flags = 0;
    syn_opt_arg.keyword = FALSE;
    syn_opt_arg.sync_idx = NULL;
    syn_opt_arg.has_cont_list = TRUE;
    syn_opt_arg.cont_list = NULL;
    syn_opt_arg.cont_in_list = NULL;
    syn_opt_arg.next_list = NULL;

    /*
     * get the options, patterns and matchgroup.
     */
    while (rest != NULL && !ends_excmd2(eap->cmd, rest))
    {
	// Check for option arguments
	rest = get_syn_options(rest, &syn_opt_arg, &conceal_char, eap->skip);
	if (rest == NULL || ends_excmd2(eap->cmd, rest))
	    break;

	// must be a pattern or matchgroup then
	key_end = rest;
	while (*key_end && !VIM_ISWHITE(*key_end) && *key_end != '=')
	    ++key_end;
	vim_free(key);
	key = vim_strnsave_up(rest, key_end - rest);
	if (key == NULL)			// out of memory
	{
	    rest = NULL;
	    break;
	}
	if (STRCMP(key, "MATCHGROUP") == 0)
	    item = ITEM_MATCHGROUP;
	else if (STRCMP(key, "START") == 0)
	    item = ITEM_START;
	else if (STRCMP(key, "END") == 0)
	    item = ITEM_END;
	else if (STRCMP(key, "SKIP") == 0)
	{
	    if (pat_ptrs[ITEM_SKIP] != NULL)	// one skip pattern allowed
	    {
		illegal = TRUE;
		break;
	    }
	    item = ITEM_SKIP;
	}
	else
	    break;
	rest = skipwhite(key_end);
	if (*rest != '=')
	{
	    rest = NULL;
	    semsg(_(e_missing_equal_str), arg);
	    break;
	}
	rest = skipwhite(rest + 1);
	if (*rest == NUL)
	{
	    not_enough = TRUE;
	    break;
	}

	if (item == ITEM_MATCHGROUP)
	{
	    p = skiptowhite(rest);
	    if ((p - rest == 4 && STRNCMP(rest, "NONE", 4) == 0) || eap->skip)
		matchgroup_id = 0;
	    else
	    {
		matchgroup_id = syn_check_group(rest, (int)(p - rest));
		if (matchgroup_id == 0)
		{
		    illegal = TRUE;
		    break;
		}
	    }
	    rest = skipwhite(p);
	}
	else
	{
	    /*
	     * Allocate room for a syn_pattern, and link it in the list of
	     * syn_patterns for this item, at the start (because the list is
	     * used from end to start).
	     */
	    ppp = ALLOC_ONE(struct pat_ptr);
	    if (ppp == NULL)
	    {
		rest = NULL;
		break;
	    }
	    ppp->pp_next = pat_ptrs[item];
	    pat_ptrs[item] = ppp;
	    ppp->pp_synp = ALLOC_CLEAR_ONE(synpat_T);
	    if (ppp->pp_synp == NULL)
	    {
		rest = NULL;
		break;
	    }

	    /*
	     * Get the syntax pattern and the following offset(s).
	     */
	    // Enable the appropriate \z specials.
	    if (item == ITEM_START)
		reg_do_extmatch = REX_SET;
	    else if (item == ITEM_SKIP || item == ITEM_END)
		reg_do_extmatch = REX_USE;
	    rest = get_syn_pattern(rest, ppp->pp_synp);
	    reg_do_extmatch = 0;
	    if (item == ITEM_END && vim_regcomp_had_eol()
				       && !(syn_opt_arg.flags & HL_EXCLUDENL))
		ppp->pp_synp->sp_flags |= HL_HAS_EOL;
	    ppp->pp_matchgroup_id = matchgroup_id;
	    ++pat_count;
	}
    }
    vim_free(key);
    if (illegal || not_enough)
	rest = NULL;

    /*
     * Must have a "start" and "end" pattern.
     */
    if (rest != NULL && (pat_ptrs[ITEM_START] == NULL ||
						  pat_ptrs[ITEM_END] == NULL))
    {
	not_enough = TRUE;
	rest = NULL;
    }

    if (rest != NULL)
    {
	/*
	 * Check for trailing garbage or command.
	 * If OK, add the item.
	 */
	set_nextcmd(eap, rest);
	if (!ends_excmd(*rest) || eap->skip)
	    rest = NULL;
	else if (ga_grow(&(curwin->w_s->b_syn_patterns), pat_count) == OK
		&& (syn_id = syn_check_group(arg,
					   (int)(group_name_end - arg))) != 0)
	{
	    syn_incl_toplevel(syn_id, &syn_opt_arg.flags);
	    /*
	     * Store the start/skip/end in the syn_items list
	     */
	    idx = curwin->w_s->b_syn_patterns.ga_len;
	    for (item = ITEM_START; item <= ITEM_END; ++item)
	    {
		for (ppp = pat_ptrs[item]; ppp != NULL; ppp = ppp->pp_next)
		{
		    SYN_ITEMS(curwin->w_s)[idx] = *(ppp->pp_synp);
		    SYN_ITEMS(curwin->w_s)[idx].sp_syncing = syncing;
		    SYN_ITEMS(curwin->w_s)[idx].sp_type =
			    (item == ITEM_START) ? SPTYPE_START :
			    (item == ITEM_SKIP) ? SPTYPE_SKIP : SPTYPE_END;
		    SYN_ITEMS(curwin->w_s)[idx].sp_flags |= syn_opt_arg.flags;
		    SYN_ITEMS(curwin->w_s)[idx].sp_syn.id = syn_id;
		    SYN_ITEMS(curwin->w_s)[idx].sp_syn.inc_tag =
							  current_syn_inc_tag;
		    SYN_ITEMS(curwin->w_s)[idx].sp_syn_match_id =
							ppp->pp_matchgroup_id;
#ifdef FEAT_CONCEAL
		    SYN_ITEMS(curwin->w_s)[idx].sp_cchar = conceal_char;
#endif
		    if (item == ITEM_START)
		    {
			SYN_ITEMS(curwin->w_s)[idx].sp_cont_list =
							syn_opt_arg.cont_list;
			SYN_ITEMS(curwin->w_s)[idx].sp_syn.cont_in_list =
						     syn_opt_arg.cont_in_list;
			if (syn_opt_arg.cont_in_list != NULL)
			    curwin->w_s->b_syn_containedin = TRUE;
			SYN_ITEMS(curwin->w_s)[idx].sp_next_list =
							syn_opt_arg.next_list;
		    }
		    ++curwin->w_s->b_syn_patterns.ga_len;
		    ++idx;
#ifdef FEAT_FOLDING
		    if (syn_opt_arg.flags & HL_FOLD)
			++curwin->w_s->b_syn_folditems;
#endif
		}
	    }

	    redraw_curbuf_later(UPD_SOME_VALID);
	    syn_stack_free_all(curwin->w_s);	// Need to recompute all syntax.
	    success = TRUE;	    // don't free the progs and patterns now
	}
    }

    /*
     * Free the allocated memory.
     */
    for (item = ITEM_START; item <= ITEM_END; ++item)
	for (ppp = pat_ptrs[item]; ppp != NULL; ppp = ppp_next)
	{
	    if (!success && ppp->pp_synp != NULL)
	    {
		vim_regfree(ppp->pp_synp->sp_prog);
		vim_free(ppp->pp_synp->sp_pattern);
	    }
	    vim_free(ppp->pp_synp);
	    ppp_next = ppp->pp_next;
	    vim_free(ppp);
	}

    if (!success)
    {
	vim_free(syn_opt_arg.cont_list);
	vim_free(syn_opt_arg.cont_in_list);
	vim_free(syn_opt_arg.next_list);
	if (not_enough)
	    semsg(_(e_not_enough_arguments_syntax_region_str), arg);
	else if (illegal || rest == NULL)
	    semsg(_(e_invalid_argument_str), arg);
    }
}

/*
 * A simple syntax group ID comparison function suitable for use in qsort()
 */
    static int
syn_compare_stub(const void *v1, const void *v2)
{
    const short	*s1 = v1;
    const short	*s2 = v2;

    return (*s1 > *s2 ? 1 : *s1 < *s2 ? -1 : 0);
}

/*
 * Combines lists of syntax clusters.
 * *clstr1 and *clstr2 must both be allocated memory; they will be consumed.
 */
    static void
syn_combine_list(short **clstr1, short **clstr2, int list_op)
{
    int		count1 = 0;
    int		count2 = 0;
    short	*g1;
    short	*g2;
    short	*clstr = NULL;
    int		count;
    int		round;

    /*
     * Handle degenerate cases.
     */
    if (*clstr2 == NULL)
	return;
    if (*clstr1 == NULL || list_op == CLUSTER_REPLACE)
    {
	if (list_op == CLUSTER_REPLACE)
	    vim_free(*clstr1);
	if (list_op == CLUSTER_REPLACE || list_op == CLUSTER_ADD)
	    *clstr1 = *clstr2;
	else
	    vim_free(*clstr2);
	return;
    }

    for (g1 = *clstr1; *g1; g1++)
	++count1;
    for (g2 = *clstr2; *g2; g2++)
	++count2;

    /*
     * For speed purposes, sort both lists.
     */
    qsort(*clstr1, (size_t)count1, sizeof(short), syn_compare_stub);
    qsort(*clstr2, (size_t)count2, sizeof(short), syn_compare_stub);

    /*
     * We proceed in two passes; in round 1, we count the elements to place
     * in the new list, and in round 2, we allocate and populate the new
     * list.  For speed, we use a mergesort-like method, adding the smaller
     * of the current elements in each list to the new list.
     */
    for (round = 1; round <= 2; round++)
    {
	g1 = *clstr1;
	g2 = *clstr2;
	count = 0;

	/*
	 * First, loop through the lists until one of them is empty.
	 */
	while (*g1 && *g2)
	{
	    /*
	     * We always want to add from the first list.
	     */
	    if (*g1 < *g2)
	    {
		if (round == 2)
		    clstr[count] = *g1;
		count++;
		g1++;
		continue;
	    }
	    /*
	     * We only want to add from the second list if we're adding the
	     * lists.
	     */
	    if (list_op == CLUSTER_ADD)
	    {
		if (round == 2)
		    clstr[count] = *g2;
		count++;
	    }
	    if (*g1 == *g2)
		g1++;
	    g2++;
	}

	/*
	 * Now add the leftovers from whichever list didn't get finished
	 * first.  As before, we only want to add from the second list if
	 * we're adding the lists.
	 */
	for (; *g1; g1++, count++)
	    if (round == 2)
		clstr[count] = *g1;
	if (list_op == CLUSTER_ADD)
	    for (; *g2; g2++, count++)
		if (round == 2)
		    clstr[count] = *g2;

	if (round == 1)
	{
	    /*
	     * If the group ended up empty, we don't need to allocate any
	     * space for it.
	     */
	    if (count == 0)
	    {
		clstr = NULL;
		break;
	    }
	    clstr = ALLOC_MULT(short, count + 1);
	    if (clstr == NULL)
		break;
	    clstr[count] = 0;
	}
    }

    /*
     * Finally, put the new list in place.
     */
    vim_free(*clstr1);
    vim_free(*clstr2);
    *clstr1 = clstr;
}

/*
 * Lookup a syntax cluster name and return its ID.
 * If it is not found, 0 is returned.
 */
    static int
syn_scl_name2id(char_u *name)
{
    int		i;
    char_u	*name_u;

    // Avoid using stricmp() too much, it's slow on some systems
    name_u = vim_strsave_up(name);
    if (name_u == NULL)
	return 0;
    for (i = curwin->w_s->b_syn_clusters.ga_len; --i >= 0; )
	if (SYN_CLSTR(curwin->w_s)[i].scl_name_u != NULL
		&& STRCMP(name_u, SYN_CLSTR(curwin->w_s)[i].scl_name_u) == 0)
	    break;
    vim_free(name_u);
    return (i < 0 ? 0 : i + SYNID_CLUSTER);
}

/*
 * Like syn_scl_name2id(), but take a pointer + length argument.
 */
    static int
syn_scl_namen2id(char_u *linep, int len)
{
    char_u  *name;
    int	    id = 0;

    name = vim_strnsave(linep, len);
    if (name == NULL)
	return 0;

    id = syn_scl_name2id(name);
    vim_free(name);
    return id;
}

/*
 * Find syntax cluster name in the table and return its ID.
 * The argument is a pointer to the name and the length of the name.
 * If it doesn't exist yet, a new entry is created.
 * Return 0 for failure.
 */
    static int
syn_check_cluster(char_u *pp, int len)
{
    int		id;
    char_u	*name;

    name = vim_strnsave(pp, len);
    if (name == NULL)
	return 0;

    id = syn_scl_name2id(name);
    if (id == 0)			// doesn't exist yet
	id = syn_add_cluster(name);
    else
	vim_free(name);
    return id;
}

/*
 * Add new syntax cluster and return its ID.
 * "name" must be an allocated string, it will be consumed.
 * Return 0 for failure.
 */
    static int
syn_add_cluster(char_u *name)
{
    int		len;

    /*
     * First call for this growarray: init growing array.
     */
    if (curwin->w_s->b_syn_clusters.ga_data == NULL)
    {
	curwin->w_s->b_syn_clusters.ga_itemsize = sizeof(syn_cluster_T);
	curwin->w_s->b_syn_clusters.ga_growsize = 10;
    }

    len = curwin->w_s->b_syn_clusters.ga_len;
    if (len >= MAX_CLUSTER_ID)
    {
	emsg(_(e_too_many_syntax_clusters));
	vim_free(name);
	return 0;
    }

    /*
     * Make room for at least one other cluster entry.
     */
    if (ga_grow(&curwin->w_s->b_syn_clusters, 1) == FAIL)
    {
	vim_free(name);
	return 0;
    }

    CLEAR_POINTER(&(SYN_CLSTR(curwin->w_s)[len]));
    SYN_CLSTR(curwin->w_s)[len].scl_name = name;
    SYN_CLSTR(curwin->w_s)[len].scl_name_u = vim_strsave_up(name);
    SYN_CLSTR(curwin->w_s)[len].scl_list = NULL;
    ++curwin->w_s->b_syn_clusters.ga_len;

    if (STRICMP(name, "Spell") == 0)
	curwin->w_s->b_spell_cluster_id = len + SYNID_CLUSTER;
    if (STRICMP(name, "NoSpell") == 0)
	curwin->w_s->b_nospell_cluster_id = len + SYNID_CLUSTER;

    return len + SYNID_CLUSTER;
}

/*
 * Handle ":syntax cluster {cluster-name} [contains={groupname},..]
 *		[add={groupname},..] [remove={groupname},..]".
 */
    static void
syn_cmd_cluster(exarg_T *eap, int syncing UNUSED)
{
    char_u	*arg = eap->arg;
    char_u	*group_name_end;
    char_u	*rest;
    int		scl_id;
    short	*clstr_list;
    int		got_clstr = FALSE;
    int		opt_len;
    int		list_op;

    eap->nextcmd = find_nextcmd(arg);
    if (eap->skip)
	return;

    rest = get_group_name(arg, &group_name_end);

    if (rest != NULL)
    {
	scl_id = syn_check_cluster(arg, (int)(group_name_end - arg));
	if (scl_id == 0)
	    return;
	scl_id -= SYNID_CLUSTER;

	for (;;)
	{
	    if (STRNICMP(rest, "add", 3) == 0
		    && (VIM_ISWHITE(rest[3]) || rest[3] == '='))
	    {
		opt_len = 3;
		list_op = CLUSTER_ADD;
	    }
	    else if (STRNICMP(rest, "remove", 6) == 0
		    && (VIM_ISWHITE(rest[6]) || rest[6] == '='))
	    {
		opt_len = 6;
		list_op = CLUSTER_SUBTRACT;
	    }
	    else if (STRNICMP(rest, "contains", 8) == 0
			&& (VIM_ISWHITE(rest[8]) || rest[8] == '='))
	    {
		opt_len = 8;
		list_op = CLUSTER_REPLACE;
	    }
	    else
		break;

	    clstr_list = NULL;
	    if (get_id_list(&rest, opt_len, &clstr_list, eap->skip) == FAIL)
	    {
		semsg(_(e_invalid_argument_str), rest);
		break;
	    }
	    if (scl_id >= 0)
		syn_combine_list(&SYN_CLSTR(curwin->w_s)[scl_id].scl_list,
			     &clstr_list, list_op);
	    else
		vim_free(clstr_list);
	    got_clstr = TRUE;
	}

	if (got_clstr)
	{
	    redraw_curbuf_later(UPD_SOME_VALID);
	    syn_stack_free_all(curwin->w_s);	// Need to recompute all.
	}
    }

    if (!got_clstr)
	emsg(_(e_no_cluster_specified));
    if (rest == NULL || !ends_excmd2(eap->cmd, rest))
	semsg(_(e_invalid_argument_str), arg);
}

/*
 * On first call for current buffer: Init growing array.
 */
    static void
init_syn_patterns(void)
{
    curwin->w_s->b_syn_patterns.ga_itemsize = sizeof(synpat_T);
    curwin->w_s->b_syn_patterns.ga_growsize = 10;
}

/*
 * Get one pattern for a ":syntax match" or ":syntax region" command.
 * Stores the pattern and program in a synpat_T.
 * Returns a pointer to the next argument, or NULL in case of an error.
 */
    static char_u *
get_syn_pattern(char_u *arg, synpat_T *ci)
{
    char_u	*end;
    int		*p;
    int		idx;
    char_u	*cpo_save;

    // need at least three chars
    if (arg == NULL || arg[0] == NUL || arg[1] == NUL || arg[2] == NUL)
	return NULL;

    end = skip_regexp(arg + 1, *arg, TRUE);
    if (*end != *arg)			    // end delimiter not found
    {
	semsg(_(e_pattern_delimiter_not_found_str), arg);
	return NULL;
    }
    // store the pattern and compiled regexp program
    if ((ci->sp_pattern = vim_strnsave(arg + 1, end - arg - 1)) == NULL)
	return NULL;

    // Make 'cpoptions' empty, to avoid the 'l' flag
    cpo_save = p_cpo;
    p_cpo = empty_option;
    ci->sp_prog = vim_regcomp(ci->sp_pattern, RE_MAGIC);
    p_cpo = cpo_save;

    if (ci->sp_prog == NULL)
	return NULL;
    ci->sp_ic = curwin->w_s->b_syn_ic;
#ifdef FEAT_PROFILE
    syn_clear_time(&ci->sp_time);
#endif

    /*
     * Check for a match, highlight or region offset.
     */
    ++end;
    do
    {
	for (idx = SPO_COUNT; --idx >= 0; )
	    if (STRNCMP(end, spo_name_tab[idx], 3) == 0)
		break;
	if (idx >= 0)
	{
	    p = &(ci->sp_offsets[idx]);
	    if (idx != SPO_LC_OFF)
		switch (end[3])
		{
		    case 's':   break;
		    case 'b':   break;
		    case 'e':   idx += SPO_COUNT; break;
		    default:    idx = -1; break;
		}
	    if (idx >= 0)
	    {
		ci->sp_off_flags |= (1 << idx);
		if (idx == SPO_LC_OFF)	    // lc=99
		{
		    end += 3;
		    *p = getdigits(&end);

		    // "lc=" offset automatically sets "ms=" offset
		    if (!(ci->sp_off_flags & (1 << SPO_MS_OFF)))
		    {
			ci->sp_off_flags |= (1 << SPO_MS_OFF);
			ci->sp_offsets[SPO_MS_OFF] = *p;
		    }
		}
		else			    // yy=x+99
		{
		    end += 4;
		    if (*end == '+')
		    {
			++end;
			*p = getdigits(&end);		// positive offset
		    }
		    else if (*end == '-')
		    {
			++end;
			*p = -getdigits(&end);		// negative offset
		    }
		}
		if (*end != ',')
		    break;
		++end;
	    }
	}
    } while (idx >= 0);

    if (!ends_excmd2(arg, end) && !VIM_ISWHITE(*end))
    {
	semsg(_(e_garbage_after_pattern_str), arg);
	return NULL;
    }
    return skipwhite(end);
}

/*
 * Handle ":syntax sync .." command.
 */
    static void
syn_cmd_sync(exarg_T *eap, int syncing UNUSED)
{
    char_u	*arg_start = eap->arg;
    char_u	*arg_end;
    char_u	*key = NULL;
    char_u	*next_arg;
    int		illegal = FALSE;
    int		finished = FALSE;
    long	n;
    char_u	*cpo_save;

    if (ends_excmd2(eap->cmd, arg_start))
    {
	syn_cmd_list(eap, TRUE);
	return;
    }

    while (!ends_excmd2(eap->cmd, arg_start))
    {
	arg_end = skiptowhite(arg_start);
	next_arg = skipwhite(arg_end);
	vim_free(key);
	key = vim_strnsave_up(arg_start, arg_end - arg_start);
	if (key == NULL)
	    break;
	if (STRCMP(key, "CCOMMENT") == 0)
	{
	    if (!eap->skip)
		curwin->w_s->b_syn_sync_flags |= SF_CCOMMENT;
	    if (!ends_excmd2(eap->cmd, next_arg))
	    {
		arg_end = skiptowhite(next_arg);
		if (!eap->skip)
		    curwin->w_s->b_syn_sync_id = syn_check_group(next_arg,
						   (int)(arg_end - next_arg));
		next_arg = skipwhite(arg_end);
	    }
	    else if (!eap->skip)
		curwin->w_s->b_syn_sync_id = syn_name2id((char_u *)"Comment");
	}
	else if (  STRNCMP(key, "LINES", 5) == 0
		|| STRNCMP(key, "MINLINES", 8) == 0
		|| STRNCMP(key, "MAXLINES", 8) == 0
		|| STRNCMP(key, "LINEBREAKS", 10) == 0)
	{
	    if (key[4] == 'S')
		arg_end = key + 6;
	    else if (key[0] == 'L')
		arg_end = key + 11;
	    else
		arg_end = key + 9;
	    if (arg_end[-1] != '=' || !VIM_ISDIGIT(*arg_end))
	    {
		illegal = TRUE;
		break;
	    }
	    n = getdigits(&arg_end);
	    if (!eap->skip)
	    {
		if (key[4] == 'B')
		    curwin->w_s->b_syn_sync_linebreaks = n;
		else if (key[1] == 'A')
		    curwin->w_s->b_syn_sync_maxlines = n;
		else
		    curwin->w_s->b_syn_sync_minlines = n;
	    }
	}
	else if (STRCMP(key, "FROMSTART") == 0)
	{
	    if (!eap->skip)
	    {
		curwin->w_s->b_syn_sync_minlines = MAXLNUM;
		curwin->w_s->b_syn_sync_maxlines = 0;
	    }
	}
	else if (STRCMP(key, "LINECONT") == 0)
	{
	    if (*next_arg == NUL)	   // missing pattern
	    {
		illegal = TRUE;
		break;
	    }
	    if (curwin->w_s->b_syn_linecont_pat != NULL)
	    {
		emsg(_(e_syntax_sync_line_continuations_pattern_specified_twice));
		finished = TRUE;
		break;
	    }
	    arg_end = skip_regexp(next_arg + 1, *next_arg, TRUE);
	    if (*arg_end != *next_arg)	    // end delimiter not found
	    {
		illegal = TRUE;
		break;
	    }

	    if (!eap->skip)
	    {
		// store the pattern and compiled regexp program
		if ((curwin->w_s->b_syn_linecont_pat =
			    vim_strnsave(next_arg + 1,
				      arg_end - next_arg - 1)) == NULL)
		{
		    finished = TRUE;
		    break;
		}
		curwin->w_s->b_syn_linecont_ic = curwin->w_s->b_syn_ic;

		// Make 'cpoptions' empty, to avoid the 'l' flag
		cpo_save = p_cpo;
		p_cpo = empty_option;
		curwin->w_s->b_syn_linecont_prog =
		       vim_regcomp(curwin->w_s->b_syn_linecont_pat, RE_MAGIC);
		p_cpo = cpo_save;
#ifdef FEAT_PROFILE
		syn_clear_time(&curwin->w_s->b_syn_linecont_time);
#endif

		if (curwin->w_s->b_syn_linecont_prog == NULL)
		{
		    VIM_CLEAR(curwin->w_s->b_syn_linecont_pat);
		    finished = TRUE;
		    break;
		}
	    }
	    next_arg = skipwhite(arg_end + 1);
	}
	else
	{
	    eap->arg = next_arg;
	    if (STRCMP(key, "MATCH") == 0)
		syn_cmd_match(eap, TRUE);
	    else if (STRCMP(key, "REGION") == 0)
		syn_cmd_region(eap, TRUE);
	    else if (STRCMP(key, "CLEAR") == 0)
		syn_cmd_clear(eap, TRUE);
	    else
		illegal = TRUE;
	    finished = TRUE;
	    break;
	}
	arg_start = next_arg;
    }
    vim_free(key);
    if (illegal)
	semsg(_(e_illegal_arguments_str), arg_start);
    else if (!finished)
    {
	set_nextcmd(eap, arg_start);
	redraw_curbuf_later(UPD_SOME_VALID);
	syn_stack_free_all(curwin->w_s);	// Need to recompute all syntax.
    }
}

/*
 * Convert a line of highlight group names into a list of group ID numbers.
 * "arg" should point to the "contains" or "nextgroup" keyword.
 * "arg" is advanced to after the last group name.
 * Careful: the argument is modified (NULs added).
 * returns FAIL for some error, OK for success.
 */
    static int
get_id_list(
    char_u	**arg,
    int		keylen,		// length of keyword
    short	**list,		// where to store the resulting list, if not
				// NULL, the list is silently skipped!
    int		skip)
{
    char_u	*p = NULL;
    char_u	*end;
    int		round;
    int		count;
    int		total_count = 0;
    short	*retval = NULL;
    char_u	*name;
    regmatch_T	regmatch;
    int		id;
    int		i;
    int		failed = FALSE;

    /*
     * We parse the list twice:
     * round == 1: count the number of items, allocate the array.
     * round == 2: fill the array with the items.
     * In round 1 new groups may be added, causing the number of items to
     * grow when a regexp is used.  In that case round 1 is done once again.
     */
    for (round = 1; round <= 2; ++round)
    {
	/*
	 * skip "contains"
	 */
	p = skipwhite(*arg + keylen);
	if (*p != '=')
	{
	    semsg(_(e_missing_equal_sign_str), *arg);
	    break;
	}
	p = skipwhite(p + 1);
	if (ends_excmd2(*arg, p))
	{
	    semsg(_(e_empty_argument_str), *arg);
	    break;
	}

	/*
	 * parse the arguments after "contains"
	 */
	count = 0;
	while (!ends_excmd2(*arg, p))
	{
	    for (end = p; *end && !VIM_ISWHITE(*end) && *end != ','; ++end)
		;
	    name = alloc(end - p + 3);	    // leave room for "^$"
	    if (name == NULL)
	    {
		failed = TRUE;
		break;
	    }
	    vim_strncpy(name + 1, p, end - p);
	    if (       STRCMP(name + 1, "ALLBUT") == 0
		    || STRCMP(name + 1, "ALL") == 0
		    || STRCMP(name + 1, "TOP") == 0
		    || STRCMP(name + 1, "CONTAINED") == 0)
	    {
		if (TOUPPER_ASC(**arg) != 'C')
		{
		    semsg(_(e_str_not_allowed_here), name + 1);
		    failed = TRUE;
		    vim_free(name);
		    break;
		}
		if (count != 0)
		{
		    semsg(_(e_str_must_be_first_in_contains_list), name + 1);
		    failed = TRUE;
		    vim_free(name);
		    break;
		}
		if (name[1] == 'A')
		    id = SYNID_ALLBUT + current_syn_inc_tag;
		else if (name[1] == 'T')
		{
		    if (curwin->w_s->b_syn_topgrp >= SYNID_CLUSTER)
			id = curwin->w_s->b_syn_topgrp;
		    else
			id = SYNID_TOP + current_syn_inc_tag;
		}
		else
		    id = SYNID_CONTAINED + current_syn_inc_tag;

	    }
	    else if (name[1] == '@')
	    {
		if (skip)
		    id = -1;
		else
		    id = syn_check_cluster(name + 2, (int)(end - p - 1));
	    }
	    else
	    {
		/*
		 * Handle full group name.
		 */
		if (vim_strpbrk(name + 1, (char_u *)"\\.*^$~[") == NULL)
		    id = syn_check_group(name + 1, (int)(end - p));
		else
		{
		    /*
		     * Handle match of regexp with group names.
		     */
		    *name = '^';
		    STRCAT(name, "$");
		    regmatch.regprog = vim_regcomp(name, RE_MAGIC);
		    if (regmatch.regprog == NULL)
		    {
			failed = TRUE;
			vim_free(name);
			break;
		    }

		    regmatch.rm_ic = TRUE;
		    id = 0;
		    for (i = highlight_num_groups(); --i >= 0; )
		    {
			if (vim_regexec(&regmatch, highlight_group_name(i),
								  (colnr_T)0))
			{
			    if (round == 2)
			    {
				// Got more items than expected; can happen
				// when adding items that match:
				// "contains=a.*b,axb".
				// Go back to first round
				if (count >= total_count)
				{
				    vim_free(retval);
				    round = 1;
				}
				else
				    retval[count] = i + 1;
			    }
			    ++count;
			    id = -1;	    // remember that we found one
			}
		    }
		    vim_regfree(regmatch.regprog);
		}
	    }
	    vim_free(name);
	    if (id == 0)
	    {
		semsg(_(e_unknown_group_name_str), p);
		failed = TRUE;
		break;
	    }
	    if (id > 0)
	    {
		if (round == 2)
		{
		    // Got more items than expected, go back to first round
		    if (count >= total_count)
		    {
			vim_free(retval);
			round = 1;
		    }
		    else
			retval[count] = id;
		}
		++count;
	    }
	    p = skipwhite(end);
	    if (*p != ',')
		break;
	    p = skipwhite(p + 1);	// skip comma in between arguments
	}
	if (failed)
	    break;
	if (round == 1)
	{
	    retval = ALLOC_MULT(short, count + 1);
	    if (retval == NULL)
		break;
	    retval[count] = 0;	    // zero means end of the list
	    total_count = count;
	}
    }

    *arg = p;
    if (failed || retval == NULL)
    {
	vim_free(retval);
	return FAIL;
    }

    if (*list == NULL)
	*list = retval;
    else
	vim_free(retval);	// list already found, don't overwrite it

    return OK;
}

/*
 * Make a copy of an ID list.
 */
    static short *
copy_id_list(short *list)
{
    int	    len;
    int	    count;
    short   *retval;

    if (list == NULL)
	return NULL;

    for (count = 0; list[count]; ++count)
	;
    len = (count + 1) * sizeof(short);
    retval = alloc(len);
    if (retval != NULL)
	mch_memmove(retval, list, (size_t)len);

    return retval;
}

/*
 * Check if syntax group "ssp" is in the ID list "list" of "cur_si".
 * "cur_si" can be NULL if not checking the "containedin" list.
 * Used to check if a syntax item is in the "contains" or "nextgroup" list of
 * the current item.
 * This function is called very often, keep it fast!!
 */
    static int
in_id_list(
    stateitem_T	*cur_si,	// current item or NULL
    short	*list,		// id list
    struct sp_syn *ssp,		// group id and ":syn include" tag of group
    int		contained)	// group id is contained
{
    int		retval;
    short	*scl_list;
    short	item;
    short	id = ssp->id;
    static int	depth = 0;
    int		r;

    // If ssp has a "containedin" list and "cur_si" is in it, return TRUE.
    if (cur_si != NULL && ssp->cont_in_list != NULL
					    && !(cur_si->si_flags & HL_MATCH))
    {
	// Ignore transparent items without a contains argument.  Double check
	// that we don't go back past the first one.
	while ((cur_si->si_flags & HL_TRANS_CONT)
		&& cur_si > (stateitem_T *)(current_state.ga_data))
	    --cur_si;
	// cur_si->si_idx is -1 for keywords, these never contain anything.
	if (cur_si->si_idx >= 0 && in_id_list(NULL, ssp->cont_in_list,
		&(SYN_ITEMS(syn_block)[cur_si->si_idx].sp_syn),
		  SYN_ITEMS(syn_block)[cur_si->si_idx].sp_flags & HL_CONTAINED))
	    return TRUE;
    }

    if (list == NULL)
	return FALSE;

    /*
     * If list is ID_LIST_ALL, we are in a transparent item that isn't
     * inside anything.  Only allow not-contained groups.
     */
    if (list == ID_LIST_ALL)
	return !contained;

    /*
     * If the first item is "ALLBUT", return TRUE if "id" is NOT in the
     * contains list.  We also require that "id" is at the same ":syn include"
     * level as the list.
     */
    item = *list;
    if (item >= SYNID_ALLBUT && item < SYNID_CLUSTER)
    {
	if (item < SYNID_TOP)
	{
	    // ALL or ALLBUT: accept all groups in the same file
	    if (item - SYNID_ALLBUT != ssp->inc_tag)
		return FALSE;
	}
	else if (item < SYNID_CONTAINED)
	{
	    // TOP: accept all not-contained groups in the same file
	    if (item - SYNID_TOP != ssp->inc_tag || contained)
		return FALSE;
	}
	else
	{
	    // CONTAINED: accept all contained groups in the same file
	    if (item - SYNID_CONTAINED != ssp->inc_tag || !contained)
		return FALSE;
	}
	item = *++list;
	retval = FALSE;
    }
    else
	retval = TRUE;

    /*
     * Return "retval" if id is in the contains list.
     */
    while (item != 0)
    {
	if (item == id)
	    return retval;
	if (item >= SYNID_CLUSTER)
	{
	    scl_list = SYN_CLSTR(syn_block)[item - SYNID_CLUSTER].scl_list;
	    // restrict recursiveness to 30 to avoid an endless loop for a
	    // cluster that includes itself (indirectly)
	    if (scl_list != NULL && depth < 30)
	    {
		++depth;
		r = in_id_list(NULL, scl_list, ssp, contained);
		--depth;
		if (r)
		    return retval;
	    }
	}
	item = *++list;
    }
    return !retval;
}

struct subcommand
{
    char    *name;			// subcommand name
    void    (*func)(exarg_T *, int);	// function to call
};

static struct subcommand subcommands[] =
{
    {"case",		syn_cmd_case},
    {"clear",		syn_cmd_clear},
    {"cluster",		syn_cmd_cluster},
    {"conceal",		syn_cmd_conceal},
    {"enable",		syn_cmd_enable},
    {"foldlevel",	syn_cmd_foldlevel},
    {"include",		syn_cmd_include},
    {"iskeyword",	syn_cmd_iskeyword},
    {"keyword",		syn_cmd_keyword},
    {"list",		syn_cmd_list},
    {"manual",		syn_cmd_manual},
    {"match",		syn_cmd_match},
    {"on",		syn_cmd_on},
    {"off",		syn_cmd_off},
    {"region",		syn_cmd_region},
    {"reset",		syn_cmd_reset},
    {"spell",		syn_cmd_spell},
    {"sync",		syn_cmd_sync},
    {"",		syn_cmd_list},
    {NULL, NULL}
};

/*
 * ":syntax".
 * This searches the subcommands[] table for the subcommand name, and calls a
 * syntax_subcommand() function to do the rest.
 */
    void
ex_syntax(exarg_T *eap)
{
    char_u	*arg = eap->arg;
    char_u	*subcmd_end;
    char_u	*subcmd_name;
    int		i;

    syn_cmdlinep = eap->cmdlinep;

    // isolate subcommand name
    for (subcmd_end = arg; ASCII_ISALPHA(*subcmd_end); ++subcmd_end)
	;
    subcmd_name = vim_strnsave(arg, subcmd_end - arg);
    if (subcmd_name == NULL)
	return;

    if (eap->skip)		// skip error messages for all subcommands
	++emsg_skip;
    for (i = 0; ; ++i)
    {
	if (subcommands[i].name == NULL)
	{
	    semsg(_(e_invalid_syntax_subcommand_str), subcmd_name);
	    break;
	}
	if (STRCMP(subcmd_name, (char_u *)subcommands[i].name) == 0)
	{
	    eap->arg = skipwhite(subcmd_end);
	    (subcommands[i].func)(eap, FALSE);
	    break;
	}
    }
    vim_free(subcmd_name);
    if (eap->skip)
	--emsg_skip;
}

    void
ex_ownsyntax(exarg_T *eap)
{
    char_u	*old_value;
    char_u	*new_value;

    if (curwin->w_s == &curwin->w_buffer->b_s)
    {
	curwin->w_s = ALLOC_ONE(synblock_T);
	CLEAR_POINTER(curwin->w_s);
	hash_init(&curwin->w_s->b_keywtab);
	hash_init(&curwin->w_s->b_keywtab_ic);
#ifdef FEAT_SPELL
	// TODO: keep the spell checking as it was.
	curwin->w_p_spell = FALSE;	// No spell checking
	// make sure option values are "empty_option" instead of NULL
	clear_string_option(&curwin->w_s->b_p_spc);
	clear_string_option(&curwin->w_s->b_p_spf);
	clear_string_option(&curwin->w_s->b_p_spl);
	clear_string_option(&curwin->w_s->b_p_spo);
#endif
	clear_string_option(&curwin->w_s->b_syn_isk);
    }

    // save value of b:current_syntax
    old_value = get_var_value((char_u *)"b:current_syntax");
    if (old_value != NULL)
	old_value = vim_strsave(old_value);

    // Apply the "syntax" autocommand event, this finds and loads the syntax
    // file.
    apply_autocmds(EVENT_SYNTAX, eap->arg, curbuf->b_fname, TRUE, curbuf);

    // move value of b:current_syntax to w:current_syntax
    new_value = get_var_value((char_u *)"b:current_syntax");
    if (new_value != NULL)
	set_internal_string_var((char_u *)"w:current_syntax", new_value);

    // restore value of b:current_syntax
    if (old_value == NULL)
	do_unlet((char_u *)"b:current_syntax", TRUE);
    else
    {
	set_internal_string_var((char_u *)"b:current_syntax", old_value);
	vim_free(old_value);
    }
}

    int
syntax_present(win_T *win)
{
    return (win->w_s->b_syn_patterns.ga_len != 0
	    || win->w_s->b_syn_clusters.ga_len != 0
	    || win->w_s->b_keywtab.ht_used > 0
	    || win->w_s->b_keywtab_ic.ht_used > 0);
}


static enum
{
    EXP_SUBCMD,	    // expand ":syn" sub-commands
    EXP_CASE,	    // expand ":syn case" arguments
    EXP_SPELL,	    // expand ":syn spell" arguments
    EXP_SYNC,	    // expand ":syn sync" arguments
    EXP_CLUSTER	    // expand ":syn list @cluster" arguments
} expand_what;

/*
 * Reset include_link, include_default, include_none to 0.
 * Called when we are done expanding.
 */
    void
reset_expand_highlight(void)
{
    include_link = include_default = include_none = 0;
}

/*
 * Handle command line completion for :match and :echohl command: Add "None"
 * as highlight group.
 */
    void
set_context_in_echohl_cmd(expand_T *xp, char_u *arg)
{
    xp->xp_context = EXPAND_HIGHLIGHT;
    xp->xp_pattern = arg;
    include_none = 1;
}

/*
 * Handle command line completion for :syntax command.
 */
    void
set_context_in_syntax_cmd(expand_T *xp, char_u *arg)
{
    char_u	*p;

    // Default: expand subcommands
    xp->xp_context = EXPAND_SYNTAX;
    expand_what = EXP_SUBCMD;
    xp->xp_pattern = arg;
    include_link = 0;
    include_default = 0;

    if (*arg == NUL)
	return;

    // (part of) subcommand already typed
    p = skiptowhite(arg);
    if (*p == NUL)
	return;

    // past first word
    xp->xp_pattern = skipwhite(p);
    if (*skiptowhite(xp->xp_pattern) != NUL)
	xp->xp_context = EXPAND_NOTHING;
    else if (STRNICMP(arg, "case", p - arg) == 0)
	expand_what = EXP_CASE;
    else if (STRNICMP(arg, "spell", p - arg) == 0)
	expand_what = EXP_SPELL;
    else if (STRNICMP(arg, "sync", p - arg) == 0)
	expand_what = EXP_SYNC;
    else if (STRNICMP(arg, "list", p - arg) == 0)
    {
	p = skipwhite(p);
	if (*p == '@')
	    expand_what = EXP_CLUSTER;
	else
	    xp->xp_context = EXPAND_HIGHLIGHT;
    }
    else if (STRNICMP(arg, "keyword", p - arg) == 0
	    || STRNICMP(arg, "region", p - arg) == 0
	    || STRNICMP(arg, "match", p - arg) == 0)
	xp->xp_context = EXPAND_HIGHLIGHT;
    else
	xp->xp_context = EXPAND_NOTHING;
}

/*
 * Function given to ExpandGeneric() to obtain the list syntax names for
 * expansion.
 */
    char_u *
get_syntax_name(expand_T *xp, int idx)
{
    switch (expand_what)
    {
	case EXP_SUBCMD:
	    return (char_u *)subcommands[idx].name;
	case EXP_CASE:
	{
	    static char *case_args[] = {"match", "ignore", NULL};
	    return (char_u *)case_args[idx];
	}
	case EXP_SPELL:
	{
	    static char *spell_args[] =
		{"toplevel", "notoplevel", "default", NULL};
	    return (char_u *)spell_args[idx];
	}
	case EXP_SYNC:
	{
	    static char *sync_args[] =
		{"ccomment", "clear", "fromstart",
		 "linebreaks=", "linecont", "lines=", "match",
		 "maxlines=", "minlines=", "region", NULL};
	    return (char_u *)sync_args[idx];
	}
	case EXP_CLUSTER:
	{
	    if (idx < curwin->w_s->b_syn_clusters.ga_len)
	    {
		vim_snprintf((char *)xp->xp_buf, EXPAND_BUF_LEN, "@%s",
					 SYN_CLSTR(curwin->w_s)[idx].scl_name);
		return xp->xp_buf;
	    }
	    else
		return NULL;
	}
    }
    return NULL;
}


/*
 * Function called for expression evaluation: get syntax ID at file position.
 */
    int
syn_get_id(
    win_T	*wp,
    long	lnum,
    colnr_T	col,
    int		trans,	     // remove transparency
    int		*spellp,     // return: can do spell checking
    int		keep_state)  // keep state of char at "col"
{
    // When the position is not after the current position and in the same
    // line of the same window with the same buffer, need to restart parsing.
    if (wp != syn_win
	    || wp->w_buffer != syn_buf
	    || lnum != current_lnum
	    || col < current_col)
	syntax_start(wp, lnum);
    else if (wp->w_buffer == syn_buf
	    && lnum == current_lnum
	    && col > current_col)
	// next_match may not be correct when moving around, e.g. with the
	// "skip" expression in searchpair()
	next_match_idx = -1;

    (void)get_syntax_attr(col, spellp, keep_state);

    return (trans ? current_trans_id : current_id);
}

#if defined(FEAT_CONCEAL) || defined(PROTO)
/*
 * Get extra information about the syntax item.  Must be called right after
 * get_syntax_attr().
 * Stores the current item sequence nr in "*seqnrp".
 * Returns the current flags.
 */
    int
get_syntax_info(int *seqnrp)
{
    *seqnrp = current_seqnr;
    return current_flags;
}

/*
 * Return conceal substitution character
 */
    int
syn_get_sub_char(void)
{
    return current_sub_char;
}
#endif

#if defined(FEAT_EVAL) || defined(PROTO)
/*
 * Return the syntax ID at position "i" in the current stack.
 * The caller must have called syn_get_id() before to fill the stack.
 * Returns -1 when "i" is out of range.
 */
    int
syn_get_stack_item(int i)
{
    if (i >= current_state.ga_len)
    {
	// Need to invalidate the state, because we didn't properly finish it
	// for the last character, "keep_state" was TRUE.
	invalidate_current_state();
	current_col = MAXCOL;
	return -1;
    }
    return CUR_STATE(i).si_id;
}
#endif

#if defined(FEAT_FOLDING) || defined(PROTO)
    static int
syn_cur_foldlevel(void)
{
    int		level = 0;
    int		i;

    for (i = 0; i < current_state.ga_len; ++i)
	if (CUR_STATE(i).si_flags & HL_FOLD)
	    ++level;
    return level;
}

/*
 * Function called to get folding level for line "lnum" in window "wp".
 */
    int
syn_get_foldlevel(win_T *wp, long lnum)
{
    int		level = 0;
    int		low_level;
    int		cur_level;

    // Return quickly when there are no fold items at all.
    if (wp->w_s->b_syn_folditems != 0
	    && !wp->w_s->b_syn_error
# ifdef SYN_TIME_LIMIT
	    && !wp->w_s->b_syn_slow
# endif
	    )
    {
	syntax_start(wp, lnum);

	// Start with the fold level at the start of the line.
	level = syn_cur_foldlevel();

	if (wp->w_s->b_syn_foldlevel == SYNFLD_MINIMUM)
	{
	    // Find the lowest fold level that is followed by a higher one.
	    cur_level = level;
	    low_level = cur_level;
	    while (!current_finished)
	    {
		(void)syn_current_attr(FALSE, FALSE, NULL, FALSE);
		cur_level = syn_cur_foldlevel();
		if (cur_level < low_level)
		    low_level = cur_level;
		else if (cur_level > low_level)
		    level = low_level;
		++current_col;
	    }
	}
    }
    if (level > wp->w_p_fdn)
    {
	level = wp->w_p_fdn;
	if (level < 0)
	    level = 0;
    }
    return level;
}
#endif

#if defined(FEAT_PROFILE) || defined(PROTO)
/*
 * ":syntime".
 */
    void
ex_syntime(exarg_T *eap)
{
    if (STRCMP(eap->arg, "on") == 0)
	syn_time_on = TRUE;
    else if (STRCMP(eap->arg, "off") == 0)
	syn_time_on = FALSE;
    else if (STRCMP(eap->arg, "clear") == 0)
	syntime_clear();
    else if (STRCMP(eap->arg, "report") == 0)
	syntime_report();
    else
	semsg(_(e_invalid_argument_str), eap->arg);
}

    static void
syn_clear_time(syn_time_T *st)
{
    profile_zero(&st->total);
    profile_zero(&st->slowest);
    st->count = 0;
    st->match = 0;
}

/*
 * Clear the syntax timing for the current buffer.
 */
    static void
syntime_clear(void)
{
    int		idx;
    synpat_T	*spp;

    if (!syntax_present(curwin))
    {
	msg(_(msg_no_items));
	return;
    }
    for (idx = 0; idx < curwin->w_s->b_syn_patterns.ga_len; ++idx)
    {
	spp = &(SYN_ITEMS(curwin->w_s)[idx]);
	syn_clear_time(&spp->sp_time);
    }
}

/*
 * Function given to ExpandGeneric() to obtain the possible arguments of the
 * ":syntime {on,off,clear,report}" command.
 */
    char_u *
get_syntime_arg(expand_T *xp UNUSED, int idx)
{
    switch (idx)
    {
	case 0: return (char_u *)"on";
	case 1: return (char_u *)"off";
	case 2: return (char_u *)"clear";
	case 3: return (char_u *)"report";
    }
    return NULL;
}

typedef struct
{
    proftime_T	total;
    int		count;
    int		match;
    proftime_T	slowest;
    proftime_T	average;
    int		id;
    char_u	*pattern;
} time_entry_T;

    static int
syn_compare_syntime(const void *v1, const void *v2)
{
    const time_entry_T	*s1 = v1;
    const time_entry_T	*s2 = v2;

    return profile_cmp(&s1->total, &s2->total);
}

/*
 * Clear the syntax timing for the current buffer.
 */
    static void
syntime_report(void)
{
    int		idx;
    synpat_T	*spp;
# if defined(FEAT_RELTIME)
    proftime_T	tm;
# endif
    int		len;
    proftime_T	total_total;
    int		total_count = 0;
    garray_T    ga;
    time_entry_T *p;

    if (!syntax_present(curwin))
    {
	msg(_(msg_no_items));
	return;
    }

    ga_init2(&ga, sizeof(time_entry_T), 50);
    profile_zero(&total_total);
    for (idx = 0; idx < curwin->w_s->b_syn_patterns.ga_len; ++idx)
    {
	spp = &(SYN_ITEMS(curwin->w_s)[idx]);
	if (spp->sp_time.count > 0)
	{
	    (void)ga_grow(&ga, 1);
	    p = ((time_entry_T *)ga.ga_data) + ga.ga_len;
	    p->total = spp->sp_time.total;
	    profile_add(&total_total, &spp->sp_time.total);
	    p->count = spp->sp_time.count;
	    p->match = spp->sp_time.match;
	    total_count += spp->sp_time.count;
	    p->slowest = spp->sp_time.slowest;
# if defined(FEAT_RELTIME)
	    profile_divide(&spp->sp_time.total, spp->sp_time.count, &tm);
	    p->average = tm;
# endif
	    p->id = spp->sp_syn.id;
	    p->pattern = spp->sp_pattern;
	    ++ga.ga_len;
	}
    }

    // Sort on total time. Skip if there are no items to avoid passing NULL
    // pointer to qsort().
    if (ga.ga_len > 1)
	qsort(ga.ga_data, (size_t)ga.ga_len, sizeof(time_entry_T),
							 syn_compare_syntime);

    msg_puts_title(_("  TOTAL      COUNT  MATCH   SLOWEST     AVERAGE   NAME               PATTERN"));
    msg_puts("\n");
    for (idx = 0; idx < ga.ga_len && !got_int; ++idx)
    {
	p = ((time_entry_T *)ga.ga_data) + idx;

	msg_puts(profile_msg(&p->total));
	msg_puts(" "); // make sure there is always a separating space
	msg_advance(13);
	msg_outnum(p->count);
	msg_puts(" ");
	msg_advance(20);
	msg_outnum(p->match);
	msg_puts(" ");
	msg_advance(26);
	msg_puts(profile_msg(&p->slowest));
	msg_puts(" ");
	msg_advance(38);
	msg_puts(profile_msg(&p->average));
	msg_puts(" ");
	msg_advance(50);
	msg_outtrans(highlight_group_name(p->id - 1));
	msg_puts(" ");

	msg_advance(69);
	if (Columns < 80)
	    len = 20; // will wrap anyway
	else
	    len = Columns - 70;
	if (len > (int)STRLEN(p->pattern))
	    len = (int)STRLEN(p->pattern);
	msg_outtrans_len(p->pattern, len);
	msg_puts("\n");
    }
    ga_clear(&ga);
    if (!got_int)
    {
	msg_puts("\n");
	msg_puts(profile_msg(&total_total));
	msg_advance(13);
	msg_outnum(total_count);
	msg_puts("\n");
    }
}
#endif

#endif // FEAT_SYN_HL