/* $OpenBSD: comp_parse.c,v 1.13 2023/10/17 09:52:09 nicm Exp $ */

/****************************************************************************
 * Copyright 2018-2022,2023 Thomas E. Dickey                                *
 * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
 *                                                                          *
 * Permission is hereby granted, free of charge, to any person obtaining a  *
 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
 *                                                                          *
 * Except as contained in this notice, the name(s) of the above copyright   *
 * holders shall not be used in advertising or otherwise to promote the     *
 * sale, use or other dealings in this Software without prior written       *
 * authorization.                                                           *
 ****************************************************************************/

/****************************************************************************
 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
 *     and: Thomas E. Dickey                        1996-on                 *
 ****************************************************************************/

/*
 *      comp_parse.c -- parser driver loop and use handling.
 *
 *      Use this code by calling _nc_read_entry_source() on as many source
 *      files as you like (either terminfo or termcap syntax).  If you
 *      want use-resolution, call _nc_resolve_uses2().  To free the list
 *      storage, do _nc_free_entries().
 */

#include <curses.priv.h>

#include <ctype.h>

#include <tic.h>

MODULE_ID("$Id: comp_parse.c,v 1.13 2023/10/17 09:52:09 nicm Exp $")

static void sanity_check2(TERMTYPE2 *, bool);
NCURSES_IMPEXP void (NCURSES_API *_nc_check_termtype2) (TERMTYPE2 *, bool) = sanity_check2;

static void fixup_acsc(TERMTYPE2 *, int);

static void
enqueue(ENTRY * ep)
/* add an entry to the in-core list */
{
    ENTRY *newp;

    DEBUG(2, (T_CALLED("enqueue(ep=%p)"), (void *) ep));

    newp = _nc_copy_entry(ep);
    if (newp == 0)
        _nc_err_abort(MSG_NO_MEMORY);

    newp->last = _nc_tail;
    _nc_tail = newp;

    newp->next = 0;
    if (newp->last)
        newp->last->next = newp;
    DEBUG(2, (T_RETURN("")));
}

#define NAMEBUFFER_SIZE (MAX_NAME_SIZE + 2)

static char *
force_bar(char *dst, char *src)
{
    if (strchr(src, '|') == 0) {
        size_t len = strlen(src);
        if (len > MAX_NAME_SIZE)
            len = MAX_NAME_SIZE;
        _nc_STRNCPY(dst, src, MAX_NAME_SIZE);
        _nc_STRCPY(dst + len, "|", NAMEBUFFER_SIZE - len);
        src = dst;
    }
    return src;
}
#define ForceBar(dst, src) ((strchr(src, '|') == 0) ? force_bar(dst, src) : src)

#if NCURSES_USE_TERMCAP && NCURSES_XNAMES
static char *
skip_index(char *name)
{
    char *bar = strchr(name, '|');

    if (bar != 0 && (bar - name) == 2)
        name = bar + 1;

    return name;
}
#endif

static bool
check_collisions(char *n1, char *n2, int counter)
{
    char *pstart, *qstart, *pend, *qend;
    char nc1[NAMEBUFFER_SIZE];
    char nc2[NAMEBUFFER_SIZE];

    n1 = ForceBar(nc1, n1);
    n2 = ForceBar(nc2, n2);

#if NCURSES_USE_TERMCAP && NCURSES_XNAMES
    if ((_nc_syntax == SYN_TERMCAP) && _nc_user_definable) {
        n1 = skip_index(n1);
        n2 = skip_index(n2);
    }
#endif

    for (pstart = n1; (pend = strchr(pstart, '|')); pstart = pend + 1) {
        for (qstart = n2; (qend = strchr(qstart, '|')); qstart = qend + 1) {
            if ((pend - pstart == qend - qstart)
                && memcmp(pstart, qstart, (size_t) (pend - pstart)) == 0) {
                if (counter > 0)
                    (void) fprintf(stderr, "Name collision '%.*s' between\n",
                                   (int) (pend - pstart), pstart);
                return (TRUE);
            }
        }
    }

    return (FALSE);
}

static char *
next_name(char *name)
{
    if (*name != '\0')
        ++name;
    return name;
}

static char *
name_ending(char *name)
{
    if (*name == '\0') {
        name = 0;
    } else {
        while (*name != '\0' && *name != '|')
            ++name;
    }
    return name;
}

/*
 * Essentially, find the conflict reported in check_collisions() and remove
 * it from the second name, unless that happens to be the last alias.
 */
static bool
remove_collision(char *n1, char *n2)
{
    char *p2 = n2;
    char *pstart, *qstart, *pend, *qend;
    bool removed = FALSE;

#if NCURSES_USE_TERMCAP && NCURSES_XNAMES
    if ((_nc_syntax == SYN_TERMCAP) && _nc_user_definable) {
        n1 = skip_index(n1);
        p2 = n2 = skip_index(n2);
    }
#endif

    for (pstart = n1; (pend = name_ending(pstart)); pstart = next_name(pend)) {
        for (qstart = n2; (qend = name_ending(qstart)); qstart = next_name(qend)) {
            if ((pend - pstart == qend - qstart)
                && memcmp(pstart, qstart, (size_t) (pend - pstart)) == 0) {
                if (qstart != p2 || *qend == '|') {
                    if (*qend == '|')
                        ++qend;
                    while ((*qstart++ = *qend++) != '\0') ;
                    fprintf(stderr, "...now\t%s\n", p2);
                    removed = TRUE;
                } else {
                    fprintf(stderr, "Cannot remove alias '%.*s'\n",
                            (int) (qend - qstart), qstart);
                }
                break;
            }
        }
    }

    return removed;
}

/* do any of the aliases in a pair of terminal names match? */
NCURSES_EXPORT(bool)
_nc_entry_match(char *n1, char *n2)
{
    return check_collisions(n1, n2, 0);
}

/****************************************************************************
 *
 * Entry compiler and resolution logic
 *
 ****************************************************************************/

NCURSES_EXPORT(void)
_nc_read_entry_source(FILE *fp, char *buf,
                      int literal, bool silent,
                      bool(*hook) (ENTRY *))
/* slurp all entries in the given file into core */
{
    ENTRY thisentry;
    bool oldsuppress = _nc_suppress_warnings;
    int immediate = 0;

    DEBUG(2,
          (T_CALLED("_nc_read_entry_source("
                    "file=%p, buf=%p, literal=%d, silent=%d, hook=%#"
                    PRIxPTR ")"),
           (void *) fp, buf, literal, silent, CASTxPTR(hook)));

    if (silent)
        _nc_suppress_warnings = TRUE;   /* shut the lexer up, too */

    _nc_reset_input(fp, buf);
    for (;;) {
        memset(&thisentry, 0, sizeof(thisentry));
        if (_nc_parse_entry(&thisentry, literal, silent) == ERR)
            break;
        if (!isalnum(UChar(thisentry.tterm.term_names[0])))
            _nc_err_abort("terminal names must start with letter or digit");

        /*
         * This can be used for immediate compilation of entries with no "use="
         * references to disk.  That avoids consuming a lot of memory when the
         * resolution code could fetch entries off disk.
         */
        if (hook != NULLHOOK && (*hook) (&thisentry)) {
            immediate++;
        } else {
            enqueue(&thisentry);
            /*
             * The enqueued entry is copied with _nc_copy_termtype(), so we can
             * free some of the data from thisentry, i.e., the arrays.
             */
            FreeIfNeeded(thisentry.tterm.Booleans);
            FreeIfNeeded(thisentry.tterm.Numbers);
            FreeIfNeeded(thisentry.tterm.Strings);
            FreeIfNeeded(thisentry.tterm.str_table);
#if NCURSES_XNAMES
            FreeIfNeeded(thisentry.tterm.ext_Names);
            FreeIfNeeded(thisentry.tterm.ext_str_table);
#endif
        }
    }

    if (_nc_tail) {
        /* set up the head pointer */
        for (_nc_head = _nc_tail; _nc_head->last; _nc_head = _nc_head->last) {
            /* EMPTY */ ;
        }

        DEBUG(2, ("head = %s", _nc_head->tterm.term_names));
        DEBUG(2, ("tail = %s", _nc_tail->tterm.term_names));
    }
#ifdef TRACE
    else if (!immediate)
        DEBUG(2, ("no entries parsed"));
#endif

    _nc_suppress_warnings = oldsuppress;
    DEBUG(2, (T_RETURN("")));
}

#if 0 && NCURSES_XNAMES
static unsigned
find_capname(TERMTYPE2 *p, const char *name)
{
    unsigned num_names = NUM_EXT_NAMES(p);
    unsigned n;
    if (name != 0) {
        for (n = 0; n < num_names; ++n) {
            if (!strcmp(p->ext_Names[n], name))
                break;
        }
    } else {
        n = num_names + 1;
    }
    return n;
}

static int
extended_captype(TERMTYPE2 *p, unsigned which)
{
    int result = UNDEF;
    unsigned limit = 0;
    limit += p->ext_Booleans;
    if (limit != 0 && which < limit) {
        result = BOOLEAN;
    } else {
        limit += p->ext_Numbers;
        if (limit != 0 && which < limit) {
            result = NUMBER;
        } else {
            limit += p->ext_Strings;
            if (limit != 0 && which < limit) {
                result = ((p->Strings[STRCOUNT + which] != CANCELLED_STRING)
                          ? STRING
                          : CANCEL);
            } else if (which >= limit) {
                result = CANCEL;
            }
        }
    }
    return result;
}

static const char *
name_of_captype(int which)
{
    const char *result = "?";
    switch (which) {
    case BOOLEAN:
        result = "boolean";
        break;
    case NUMBER:
        result = "number";
        break;
    case STRING:
        result = "string";
        break;
    }
    return result;
}

#define valid_TERMTYPE2(p) \
        ((p) != 0 && \
         (p)->term_names != 0 && \
         (p)->ext_Names != 0)

/*
 * Disallow changing the type of an extended capability when doing a "use"
 * if one or the other is a string.
 */
static int
invalid_merge(TERMTYPE2 *to, TERMTYPE2 *from)
{
    int rc = FALSE;
    if (valid_TERMTYPE2(to)
        && valid_TERMTYPE2(from)) {
        char *to_name = _nc_first_name(to->term_names);
        char *from_name = strdup(_nc_first_name(from->term_names));
        unsigned num_names = NUM_EXT_NAMES(from);
        unsigned n;

        for (n = 0; n < num_names; ++n) {
            const char *capname = from->ext_Names[n];
            int tt = extended_captype(to, find_capname(to, capname));
            int tf = extended_captype(from, n);

            if (tt <= STRING
                && tf <= STRING
                && (tt == STRING) != (tf == STRING)) {
                if (from_name != 0 && strcmp(to_name, from_name)) {
                    _nc_warning("merge of %s to %s changes type of %s from %s to %s",
                                from_name,
                                to_name,
                                from->ext_Names[n],
                                name_of_captype(tf),
                                name_of_captype(tt));
                } else {
                    _nc_warning("merge of %s changes type of %s from %s to %s",
                                to_name,
                                from->ext_Names[n],
                                name_of_captype(tf),
                                name_of_captype(tt));
                }
                rc = TRUE;
            }
        }
        free(from_name);
    }
    return rc;
}
#define validate_merge(p, q) \
        if (invalid_merge(&((p)->tterm), &((q)->tterm))) \
                return FALSE
#else
#define validate_merge(p, q)    /* nothing */
#endif

NCURSES_EXPORT(int)
_nc_resolve_uses2(bool fullresolve, bool literal)
/* try to resolve all use capabilities */
{
    ENTRY *qp, *rp, *lastread = 0;
    bool keepgoing;
    unsigned i, j;
    int unresolved, total_unresolved, multiples;

    DEBUG(2, (T_CALLED("_nc_resolve_uses2")));

    /*
     * Check for multiple occurrences of the same name.
     */
    multiples = 0;
    for_entry_list(qp) {
        int matchcount = 0;

        for_entry_list2(rp, qp->next) {
            if (qp > rp
                && check_collisions(qp->tterm.term_names,
                                    rp->tterm.term_names,
                                    matchcount + 1)) {
                if (!matchcount++) {
                    (void) fprintf(stderr, "\t%s\n", rp->tterm.term_names);
                }
                (void) fprintf(stderr, "and\t%s\n", qp->tterm.term_names);
                if (!remove_collision(rp->tterm.term_names,
                                      qp->tterm.term_names)) {
                    ++multiples;
                }
            }
        }
    }
    if (multiples > 0) {
        DEBUG(2, (T_RETURN("false")));
        return (FALSE);
    }

    DEBUG(2, ("NO MULTIPLE NAME OCCURRENCES"));

    /*
     * First resolution stage: compute link pointers corresponding to names.
     */
    total_unresolved = 0;
    _nc_curr_col = -1;
    for_entry_list(qp) {
        unresolved = 0;
        for (i = 0; i < qp->nuses; i++) {
            bool foundit;
            char *child = _nc_first_name(qp->tterm.term_names);
            char *lookfor = qp->uses[i].name;
            long lookline = qp->uses[i].line;

            if (lookfor == 0)
                continue;

            foundit = FALSE;

            _nc_set_type(child);

            /* first, try to resolve from in-core records */
            for_entry_list(rp) {
                if (rp != qp
                    && _nc_name_match(rp->tterm.term_names, lookfor, "|")) {
                    DEBUG(2, ("%s: resolving use=%s %p (in core)",
                              child, lookfor, lookfor));

                    qp->uses[i].link = rp;
                    foundit = TRUE;

                    /* verify that there are no earlier uses */
                    for (j = 0; j < i; ++j) {
                        if (qp->uses[j].link != NULL
                            && !strcmp(qp->uses[j].link->tterm.term_names,
                                       rp->tterm.term_names)) {
                            _nc_warning("duplicate use=%s", lookfor);
                            break;
                        }
                    }
                }
            }

            /* if that didn't work, try to merge in a compiled entry */
            if (!foundit) {
                TERMTYPE2 thisterm;
                char filename[PATH_MAX];

                memset(&thisterm, 0, sizeof(thisterm));
                if (_nc_read_entry2(lookfor, filename, &thisterm) == 1) {
                    DEBUG(2, ("%s: resolving use=%s (compiled)",
                              child, lookfor));

                    TYPE_MALLOC(ENTRY, 1, rp);
                    rp->tterm = thisterm;
                    rp->nuses = 0;
                    rp->next = lastread;
                    lastread = rp;

                    qp->uses[i].link = rp;
                    foundit = TRUE;

                    /* verify that there are no earlier uses */
                    for (j = 0; j < i; ++j) {
                        if (qp->uses[j].link != NULL
                            && !strcmp(qp->uses[j].link->tterm.term_names,
                                       rp->tterm.term_names)) {
                            _nc_warning("duplicate use=%s", lookfor);
                            break;
                        }
                    }
                }
            }

            /* no good, mark this one unresolvable and complain */
            if (!foundit) {
                unresolved++;
                total_unresolved++;

                _nc_curr_line = (int) lookline;
                _nc_warning("resolution of use=%s failed", lookfor);
                qp->uses[i].link = 0;
            }
        }
    }
    if (total_unresolved) {
        /* free entries read in off disk */
        _nc_free_entries(lastread);
        DEBUG(2, (T_RETURN("false")));
        return (FALSE);
    }

    DEBUG(2, ("NAME RESOLUTION COMPLETED OK"));

    /*
     * OK, at this point all (char *) references in `name' members
     * have been successfully converted to (ENTRY *) pointers in
     * `link' members.  Time to do the actual merges.
     */
    if (fullresolve) {
        do {
            ENTRY merged;

            keepgoing = FALSE;

            for_entry_list(qp) {
                if (qp->nuses > 0) {
                    DEBUG(2, ("%s: attempting merge of %d entries",
                              _nc_first_name(qp->tterm.term_names),
                              qp->nuses));
                    /*
                     * If any of the use entries we're looking for is
                     * incomplete, punt.  We'll catch this entry on a
                     * subsequent pass.
                     */
                    for (i = 0; i < qp->nuses; i++) {
                        if (qp->uses[i].link
                            && qp->uses[i].link->nuses) {
                            DEBUG(2, ("%s: use entry %d unresolved",
                                      _nc_first_name(qp->tterm.term_names), i));
                            goto incomplete;
                        }
                    }

                    /*
                     * First, make sure there is no garbage in the
                     * merge block.  As a side effect, copy into
                     * the merged entry the name field and string
                     * table pointer.
                     */
                    _nc_copy_termtype2(&(merged.tterm), &(qp->tterm));

                    /*
                     * Now merge in each use entry in the proper
                     * (reverse) order.
                     */
                    for (; qp->nuses; qp->nuses--) {
                        int n = (int) (qp->nuses - 1);
                        validate_merge(&merged, qp->uses[n].link);
                        _nc_merge_entry(&merged, qp->uses[n].link);
                        free(qp->uses[n].name);
                    }

                    /*
                     * Now merge in the original entry.
                     */
                    validate_merge(&merged, qp);
                    _nc_merge_entry(&merged, qp);

                    /*
                     * Replace the original entry with the merged one.
                     */
                    FreeIfNeeded(qp->tterm.Booleans);
                    FreeIfNeeded(qp->tterm.Numbers);
                    FreeIfNeeded(qp->tterm.Strings);
                    FreeIfNeeded(qp->tterm.str_table);
#if NCURSES_XNAMES
                    FreeIfNeeded(qp->tterm.ext_Names);
                    FreeIfNeeded(qp->tterm.ext_str_table);
#endif
                    qp->tterm = merged.tterm;
                    _nc_wrap_entry(qp, TRUE);

                    /*
                     * We know every entry is resolvable because name resolution
                     * didn't bomb.  So go back for another pass.
                     */
                    /* FALLTHRU */
                  incomplete:
                    keepgoing = TRUE;
                }
            }
        } while
            (keepgoing);

        DEBUG(2, ("MERGES COMPLETED OK"));
    }

    DEBUG(2, ("RESOLUTION FINISHED"));

    if (fullresolve) {
        _nc_curr_col = -1;
        for_entry_list(qp) {
            _nc_curr_line = (int) qp->startline;
            _nc_set_type(_nc_first_name(qp->tterm.term_names));
            /*
             * tic overrides this function pointer to provide more verbose
             * checking.
             */
            if (_nc_check_termtype2 != sanity_check2) {
                SCREEN *save_SP = SP;
                SCREEN fake_sp;
                TERMINAL fake_tm;
                TERMINAL *save_tm = cur_term;

                /*
                 * Setup so that tic can use ordinary terminfo interface to
                 * obtain capability information.
                 */
                memset(&fake_sp, 0, sizeof(fake_sp));
                memset(&fake_tm, 0, sizeof(fake_tm));
                fake_sp._term = &fake_tm;
                TerminalType(&fake_tm) = qp->tterm;
                _nc_set_screen(&fake_sp);
                set_curterm(&fake_tm);

                _nc_check_termtype2(&qp->tterm, literal);

                /*
                 * Checking calls tparm, which can allocate memory.  Fix leaks.
                 */
#define TPS(name) fake_tm.tparm_state.name
                FreeAndNull(TPS(out_buff));
                FreeAndNull(TPS(fmt_buff));
#undef TPS

                _nc_set_screen(save_SP);
                set_curterm(save_tm);
            } else {
                fixup_acsc(&qp->tterm, literal);
            }
        }
        DEBUG(2, ("SANITY CHECK FINISHED"));
    }

    DEBUG(2, (T_RETURN("true")));
    return (TRUE);
}

/*
 * This bit of legerdemain turns all the terminfo variable names into
 * references to locations in the arrays Booleans, Numbers, and Strings ---
 * precisely what's needed.
 */

#undef CUR
#define CUR tp->

static void
fixup_acsc(TERMTYPE2 *tp, int literal)
{
    if (!literal) {
        if (acs_chars == ABSENT_STRING
            && PRESENT(enter_alt_charset_mode)
            && PRESENT(exit_alt_charset_mode))
            acs_chars = strdup(VT_ACSC);
    }
}

static void
sanity_check2(TERMTYPE2 *tp, bool literal)
{
    if (!PRESENT(exit_attribute_mode)) {
#ifdef __UNUSED__               /* this casts too wide a net */
        bool terminal_entry = !strchr(tp->term_names, '+');
        if (terminal_entry &&
            (PRESENT(set_attributes)
             || PRESENT(enter_standout_mode)
             || PRESENT(enter_underline_mode)
             || PRESENT(enter_blink_mode)
             || PRESENT(enter_bold_mode)
             || PRESENT(enter_dim_mode)
             || PRESENT(enter_secure_mode)
             || PRESENT(enter_protected_mode)
             || PRESENT(enter_reverse_mode)))
            _nc_warning("no exit_attribute_mode");
#endif /* __UNUSED__ */
        PAIRED(enter_standout_mode, exit_standout_mode);
        PAIRED(enter_underline_mode, exit_underline_mode);
#if defined(enter_italics_mode) && defined(exit_italics_mode)
        PAIRED(enter_italics_mode, exit_italics_mode);
#endif
    }

    /* we do this check/fix in postprocess_termcap(), but some packagers
     * prefer to bypass it...
     */
    if (!literal) {
        fixup_acsc(tp, literal);
        ANDMISSING(enter_alt_charset_mode, acs_chars);
        ANDMISSING(exit_alt_charset_mode, acs_chars);
    }

    /* listed in structure-member order of first argument */
    PAIRED(enter_alt_charset_mode, exit_alt_charset_mode);
    ANDMISSING(enter_blink_mode, exit_attribute_mode);
    ANDMISSING(enter_bold_mode, exit_attribute_mode);
    PAIRED(exit_ca_mode, enter_ca_mode);
    PAIRED(enter_delete_mode, exit_delete_mode);
    ANDMISSING(enter_dim_mode, exit_attribute_mode);
    PAIRED(enter_insert_mode, exit_insert_mode);
    ANDMISSING(enter_secure_mode, exit_attribute_mode);
    ANDMISSING(enter_protected_mode, exit_attribute_mode);
    ANDMISSING(enter_reverse_mode, exit_attribute_mode);
    PAIRED(from_status_line, to_status_line);
    PAIRED(meta_off, meta_on);

    PAIRED(prtr_on, prtr_off);
    PAIRED(save_cursor, restore_cursor);
    PAIRED(enter_xon_mode, exit_xon_mode);
    PAIRED(enter_am_mode, exit_am_mode);
    ANDMISSING(label_off, label_on);
#if defined(display_clock) && defined(remove_clock)
    PAIRED(display_clock, remove_clock);
#endif
    ANDMISSING(set_color_pair, initialize_pair);
}

#if NO_LEAKS
NCURSES_EXPORT(void)
_nc_leaks_tic(void)
{
    T((T_CALLED("_nc_leaks_tic()")));
    _nc_globals.leak_checking = TRUE;
    _nc_alloc_entry_leaks();
    _nc_captoinfo_leaks();
    _nc_comp_scan_leaks();
#if BROKEN_LINKER || USE_REENTRANT
    _nc_names_leaks();
    _nc_codes_leaks();
#endif
    _nc_tic_expand(0, FALSE, 0);
    T((T_RETURN("")));
}

NCURSES_EXPORT(void)
_nc_free_tic(int code)
{
    T((T_CALLED("_nc_free_tic(%d)"), code));
    _nc_leaks_tic();
    exit_terminfo(code);
}
#endif