/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1992 Diomidis Spinellis.
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Diomidis Spinellis of Imperial College, University of London.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Types of address specifications
 */
enum e_atype {
        AT_RE       = 1,                        /* Line that match RE */
        AT_LINE,                                /* Specific line */
        AT_RELLINE,                             /* Relative line */
        AT_LAST,                                /* Last line */
};

/*
 * Format of an address
 */
struct s_addr {
        enum e_atype type;                      /* Address type */
        union {
                u_long l;                       /* Line number */
                regex_t *r;                     /* Regular expression */
        } u;
};

/*
 * Substitution command
 */
struct s_subst {
        int n;                                  /* Occurrence to subst. */
        int p;                                  /* True if p flag */
        int icase;                              /* True if I flag */
        char *wfile;                            /* NULL if no wfile */
        int wfd;                                /* Cached file descriptor */
        regex_t *re;                            /* Regular expression */
        unsigned int maxbref;                   /* Largest backreference. */
        u_long linenum;                         /* Line number. */
        char *new;                              /* Replacement text */
};

/*
 * Translate command.
 */
struct s_tr {
        unsigned char bytetab[256];
        struct trmulti {
                size_t fromlen;
                char from[MB_LEN_MAX];
                size_t tolen;
                char to[MB_LEN_MAX];
        } *multis;
        int nmultis;
};

/*
 * An internally compiled command.
 * Initially, label references are stored in t, on a second pass they
 * are updated to pointers.
 */
struct s_command {
        struct s_command *next;                 /* Pointer to next command */
        struct s_addr *a1, *a2;                 /* Start and end address */
        u_long startline;                       /* Start line number or zero */
        char *t;                                /* Text for : a c i r w */
        union {
                struct s_command *c;            /* Command(s) for b t { */
                struct s_subst *s;              /* Substitute command */
                struct s_tr *y;                 /* Replace command array */
                int fd;                         /* File descriptor for w */
        } u;
        char code;                              /* Command code */
        u_int nonsel:1;                         /* True if ! */
};

/*
 * Types of command arguments recognised by the parser
 */
enum e_args {
        EMPTY,                  /* d D g G h H l n N p P q x = \0 */
        TEXT,                   /* a c i */
        NONSEL,                 /* ! */
        GROUP,                  /* { */
        ENDGROUP,               /* } */
        COMMENT,                /* # */
        BRANCH,                 /* b t */
        LABEL,                  /* : */
        RFILE,                  /* r */
        WFILE,                  /* w */
        SUBST,                  /* s */
        TR                      /* y */
};

/*
 * Structure containing things to append before a line is read
 */
struct s_appends {
        enum {AP_STRING, AP_FILE} type;
        char *s;
        size_t len;
};

enum e_spflag {
        APPEND,                                 /* Append to the contents. */
        REPLACE,                                /* Replace the contents. */
};

/*
 * Structure for a space (process, hold, otherwise).
 */
typedef struct {
        char *space;            /* Current space pointer. */
        size_t len;             /* Current length. */
        int deleted;            /* If deleted. */
        int append_newline;     /* If originally terminated by \n. */
        char *back;             /* Backing memory. */
        size_t blen;            /* Backing memory length. */
} SPACE;