/*      $OpenBSD: lexi.c,v 1.21 2022/12/26 19:16:01 jmc Exp $   */

/*
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.
 * Copyright (c) 1976 Board of Trustees of the University of Illinois.
 * Copyright (c) 1985 Sun Microsystems, Inc.
 * All rights reserved.
 *
 * 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.
 */

/*
 * Here we have the token scanner for indent.  It scans off one token and puts
 * it in the global variable "token".  It returns a code, indicating the type
 * of token scanned.
 */

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include "indent_globs.h"
#include "indent_codes.h"

#define alphanum 1
#define opchar 3

struct templ {
    char       *rwd;
    int         rwcode;
};

struct templ specialsinit[] = {
        { "switch", 1 },
        { "case", 2 },
        { "break", 0 },
        { "struct", 3 },
        { "union", 3 },
        { "enum", 3 },
        { "default", 2 },
        { "int", 4 },
        { "char", 4 },
        { "float", 4 },
        { "double", 4 },
        { "long", 4 },
        { "short", 4 },
        { "typedef", 4 },
        { "unsigned", 4 },
        { "register", 4 },
        { "static", 4 },
        { "global", 4 },
        { "extern", 4 },
        { "void", 4 },
        { "goto", 0 },
        { "return", 0 },
        { "if", 5 },
        { "while", 5 },
        { "for", 5 },
        { "else", 6 },
        { "do", 6 },
        { "sizeof", 7 },
};

struct templ *specials = specialsinit;
int     nspecials = sizeof(specialsinit) / sizeof(specialsinit[0]);
int     maxspecials;

char        chartype[128] =
{                               /* this is used to facilitate the decision of
                                 * what type (alphanumeric, operator) each
                                 * character is */
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 3, 0, 0, 1, 3, 3, 0,
    0, 0, 3, 3, 0, 3, 0, 3,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 0, 0, 3, 3, 3, 3,
    0, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 0, 0, 0, 3, 1,
    0, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 0, 3, 0, 3, 0
};




int
lexi(void)
{
    int         unary_delim;    /* this is set to 1 if the current token
                                 * forces a following operator to be unary */
    static int  last_code;      /* the last token type returned */
    static int  l_struct;       /* set to 1 if the last token was 'struct' */
    int         code;           /* internal code to be returned */
    char        qchar;          /* the delimiter character for a string */
    int         i;

    e_token = s_token;          /* point to start of place to save token */
    unary_delim = false;
    ps.col_1 = ps.last_nl;      /* tell world that this token started in
                                 * column 1 iff the last thing scanned was nl */
    ps.last_nl = false;

    while (*buf_ptr == ' ' || *buf_ptr == '\t') {       /* get rid of blanks */
        ps.col_1 = false;       /* leading blanks imply token is not in column
                                 * 1 */
        if (++buf_ptr >= buf_end)
            fill_buffer();
    }

    /* Scan an alphanumeric token */
    if (chartype[(int)*buf_ptr] == alphanum ||
        (buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
        /*
         * we have a character or number
         */
        char *j;        /* used for searching thru list of
                         * reserved words */
        if (isdigit((unsigned char)*buf_ptr) ||
            (buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
            int         seendot = 0,
                        seenexp = 0,
                        seensfx = 0;
            if (*buf_ptr == '0' &&
                    (buf_ptr[1] == 'x' || buf_ptr[1] == 'X')) {
                *e_token++ = *buf_ptr++;
                *e_token++ = *buf_ptr++;
                while (isxdigit(*buf_ptr)) {
                    CHECK_SIZE_TOKEN;
                    *e_token++ = *buf_ptr++;
                }
            }
            else
                while (1) {
                    if (*buf_ptr == '.') {
                        if (seendot)
                            break;
                        else
                            seendot++;
                    }
                    CHECK_SIZE_TOKEN;
                    *e_token++ = *buf_ptr++;
                    if (!isdigit((unsigned char)*buf_ptr) && *buf_ptr != '.') {
                        if ((*buf_ptr != 'E' && *buf_ptr != 'e') || seenexp)
                            break;
                        else {
                            seenexp++;
                            seendot++;
                            CHECK_SIZE_TOKEN;
                            *e_token++ = *buf_ptr++;
                            if (*buf_ptr == '+' || *buf_ptr == '-')
                                *e_token++ = *buf_ptr++;
                        }
                    }
                }
            while (1) {
                if (!(seensfx & 1) &&
                        (*buf_ptr == 'U' || *buf_ptr == 'u')) {
                    CHECK_SIZE_TOKEN;
                    *e_token++ = *buf_ptr++;
                    seensfx |= 1;
                    continue;
                }
                if (!(seensfx & 2) &&
                        (*buf_ptr == 'L' || *buf_ptr == 'l')) {
                    CHECK_SIZE_TOKEN;
                    if (buf_ptr[1] == buf_ptr[0])
                        *e_token++ = *buf_ptr++;
                    *e_token++ = *buf_ptr++;
                    seensfx |= 2;
                    continue;
                }
                break;
            }
            if (!(seensfx & 1) &&    
                (*buf_ptr == 'F' || *buf_ptr == 'f')) {
                CHECK_SIZE_TOKEN;
                *e_token++ = *buf_ptr++;
                seensfx |= 1;
            }
        }
        else
            while (chartype[(int)*buf_ptr] == alphanum) {       /* copy it over */
                CHECK_SIZE_TOKEN;
                *e_token++ = *buf_ptr++;
                if (buf_ptr >= buf_end)
                    fill_buffer();
            }
        *e_token++ = '\0';
        while (*buf_ptr == ' ' || *buf_ptr == '\t') {   /* get rid of blanks */
            if (++buf_ptr >= buf_end)
                fill_buffer();
        }
        ps.its_a_keyword = false;
        ps.sizeof_keyword = false;
        if (l_struct) {         /* if last token was 'struct', then this token
                                 * should be treated as a declaration */
            l_struct = false;
            last_code = ident;
            ps.last_u_d = true;
            return (decl);
        }
        ps.last_u_d = false;    /* Operator after identifier is binary */
        last_code = ident;      /* Remember that this is the code we will
                                 * return */

        /*
         * This loop will check if the token is a keyword.
         */
        for (i = 0; i < nspecials; i++) {
            char *p = s_token;  /* point at scanned token */
            j = specials[i].rwd;
            if (*j++ != *p++ || *j++ != *p++)
                continue;       /* This test depends on the fact that
                                 * identifiers are always at least 1 character
                                 * long (ie. the first two bytes of the
                                 * identifier are always meaningful) */
            if (p[-1] == 0)
                break;          /* If its a one-character identifier */
            while (*p++ == *j)
                if (*j++ == 0)
                    goto found_keyword; /* I wish that C had a multi-level
                                         * break... */
        }
        if (i < nspecials) {            /* we have a keyword */
    found_keyword:
            ps.its_a_keyword = true;
            ps.last_u_d = true;
            switch (specials[i].rwcode) {
            case 1:             /* it is a switch */
                return (swstmt);
            case 2:             /* a case or default */
                return (casestmt);

            case 3:             /* a "struct" */
                if (ps.p_l_follow)
                    break;      /* inside parens: cast */
                l_struct = true;

                /*
                 * Next time around, we will want to know that we have had a
                 * 'struct'
                 */
            case 4:             /* one of the declaration keywords */
                if (ps.p_l_follow) {
                    ps.cast_mask |= 1 << ps.p_l_follow;
                    break;      /* inside parens: cast */
                }
                last_code = decl;
                return (decl);

            case 5:             /* if, while, for */
                return (sp_paren);

            case 6:             /* do, else */
                return (sp_nparen);

            case 7:
                ps.sizeof_keyword = true;
            default:            /* all others are treated like any other
                                 * identifier */
                return (ident);
            }                   /* end of switch */
        }                       /* end of if (found_it) */
        if (*buf_ptr == '(' && ps.tos <= 1 && ps.ind_level == 0) {
            char *tp = buf_ptr;
            while (tp < buf_end)
                if (*tp++ == ')' && (*tp == ';' || *tp == ','))
                    goto not_proc;
            strlcpy(ps.procname, token, sizeof ps.procname);
            ps.in_parameter_declaration = 1;
            rparen_count = 1;
    not_proc:;
        }
        /*
         * The following hack attempts to guess whether or not the current
         * token is in fact a declaration keyword -- one that has been
         * typedefd
         */
        if (((*buf_ptr == '*' && buf_ptr[1] != '=') ||
            isalpha((unsigned char)*buf_ptr) || *buf_ptr == '_')
                && !ps.p_l_follow
                && !ps.block_init
                && (ps.last_token == rparen || ps.last_token == semicolon ||
                    ps.last_token == decl ||
                    ps.last_token == lbrace || ps.last_token == rbrace)) {
            ps.its_a_keyword = true;
            ps.last_u_d = true;
            last_code = decl;
            return decl;
        }
        if (last_code == decl)  /* if this is a declared variable, then
                                 * following sign is unary */
            ps.last_u_d = true; /* will make "int a -1" work */
        last_code = ident;
        return (ident);         /* the ident is not in the list */
    }                           /* end of processing for alpanum character */

    /* Scan a non-alphanumeric token */

    *e_token++ = *buf_ptr;              /* if it is only a one-character token, it is
                                 * moved here */
    *e_token = '\0';
    if (++buf_ptr >= buf_end)
        fill_buffer();

    switch (*token) {
    case '\n':
        unary_delim = ps.last_u_d;
        ps.last_nl = true;      /* remember that we just had a newline */
        code = (had_eof ? 0 : newline);

        /*
         * if data has been exhausted, the newline is a dummy, and we should
         * return code to stop
         */
        break;

    case '\'':                  /* start of quoted character */
    case '"':                   /* start of string */
        qchar = *token;
        if (troff) {
            e_token[-1] = '`';
            if (qchar == '"')
                *e_token++ = '`';
            e_token = chfont(&bodyf, &stringf, e_token);
        }
        do {                    /* copy the string */
            while (1) {         /* move one character or [/<char>]<char> */
                if (*buf_ptr == '\n') {
                    printf("%d: Unterminated literal\n", line_no);
                    goto stop_lit;
                }
                CHECK_SIZE_TOKEN;       /* Only have to do this once in this loop,
                                         * since CHECK_SIZE guarantees that there
                                         * are at least 5 entries left */
                *e_token = *buf_ptr++;
                if (buf_ptr >= buf_end)
                    fill_buffer();
                if (*e_token == BACKSLASH) {    /* if escape, copy extra char */
                    if (*buf_ptr == '\n')       /* check for escaped newline */
                        ++line_no;
                    if (troff) {
                        *++e_token = BACKSLASH;
                        if (*buf_ptr == BACKSLASH)
                            *++e_token = BACKSLASH;
                    }
                    *++e_token = *buf_ptr++;
                    ++e_token;  /* we must increment this again because we
                                 * copied two chars */
                    if (buf_ptr >= buf_end)
                        fill_buffer();
                }
                else
                    break;      /* we copied one character */
            }                   /* end of while (1) */
        } while (*e_token++ != qchar);
        if (troff) {
            e_token = chfont(&stringf, &bodyf, e_token - 1);
            if (qchar == '"')
                *e_token++ = '\'';
        }
stop_lit:
        code = ident;
        break;

    case ('('):
    case ('['):
        unary_delim = true;
        code = lparen;
        break;

    case (')'):
    case (']'):
        code = rparen;
        break;

    case '#':
        unary_delim = ps.last_u_d;
        code = preesc;
        break;

    case '?':
        unary_delim = true;
        code = question;
        break;

    case (':'):
        code = colon;
        unary_delim = true;
        break;

    case (';'):
        unary_delim = true;
        code = semicolon;
        break;

    case ('{'):
        unary_delim = true;

        /*
         * if (ps.in_or_st) ps.block_init = 1;
         */
        /* ?    code = ps.block_init ? lparen : lbrace; */
        code = lbrace;
        break;

    case ('}'):
        unary_delim = true;
        /* ?    code = ps.block_init ? rparen : rbrace; */
        code = rbrace;
        break;

    case 014:                   /* a form feed */
        unary_delim = ps.last_u_d;
        ps.last_nl = true;      /* remember this so we can set 'ps.col_1'
                                 * right */
        code = form_feed;
        break;

    case (','):
        unary_delim = true;
        code = comma;
        break;

    case '.':
        unary_delim = false;
        code = period;
        break;

    case '-':
    case '+':                   /* check for -, +, --, ++ */
        code = (ps.last_u_d ? unary_op : binary_op);
        unary_delim = true;

        if (*buf_ptr == token[0]) {
            /* check for doubled character */
            *e_token++ = *buf_ptr++;
            /* buffer overflow will be checked at end of loop */
            if (last_code == ident || last_code == rparen) {
                code = (ps.last_u_d ? unary_op : postop);
                /* check for following ++ or -- */
                unary_delim = false;
            }
        }
        else if (*buf_ptr == '=')
            /* check for operator += */
            *e_token++ = *buf_ptr++;
        else if (*buf_ptr == '>') {
            /* check for operator -> */
            *e_token++ = *buf_ptr++;
            if (!pointer_as_binop) {
                unary_delim = false;
                code = unary_op;
                ps.want_blank = false;
            }
        }
        break;                  /* buffer overflow will be checked at end of
                                 * switch */

    case '=':
        if (ps.in_or_st)
            ps.block_init = 1;
#ifdef undef
        if (chartype[*buf_ptr] == opchar) {     /* we have two char assignment */
            e_token[-1] = *buf_ptr++;
            if ((e_token[-1] == '<' || e_token[-1] == '>') && e_token[-1] == *buf_ptr)
                *e_token++ = *buf_ptr++;
            *e_token++ = '=';   /* Flip =+ to += */
            *e_token = 0;
        }
#else
        if (*buf_ptr == '=') {/* == */
            *e_token++ = '=';   /* Flip =+ to += */
            buf_ptr++;
            *e_token = 0;
        }
#endif
        code = binary_op;
        unary_delim = true;
        break;
        /* can drop thru!!! */

    case '>':
    case '<':
    case '!':                   /* ops like <, <<, <=, !=, etc */
        if (*buf_ptr == '>' || *buf_ptr == '<' || *buf_ptr == '=') {
            *e_token++ = *buf_ptr;
            if (++buf_ptr >= buf_end)
                fill_buffer();
        }
        if (*buf_ptr == '=')
            *e_token++ = *buf_ptr++;
        code = (ps.last_u_d ? unary_op : binary_op);
        unary_delim = true;
        break;

    default:
        if (token[0] == '/' && *buf_ptr == '*') {
            /* it is start of comment */
            *e_token++ = '*';

            if (++buf_ptr >= buf_end)
                fill_buffer();

            code = comment;
            unary_delim = ps.last_u_d;
            break;
        }
        while (*(e_token - 1) == *buf_ptr || *buf_ptr == '=') {
            /*
             * handle ||, &&, etc, and also things as in int *****i
             */
            *e_token++ = *buf_ptr;
            if (++buf_ptr >= buf_end)
                fill_buffer();
        }
        code = (ps.last_u_d ? unary_op : binary_op);
        unary_delim = true;


    }                           /* end of switch */
    if (code != newline) {
        l_struct = false;
        last_code = code;
    }
    if (buf_ptr >= buf_end)     /* check for input buffer empty */
        fill_buffer();
    ps.last_u_d = unary_delim;
    *e_token = '\0';            /* null terminate the token */
    return (code);
}

/*
 * Add the given keyword to the keyword table, using val as the keyword type
 */
void
addkey(char *key, int val)
{
    struct templ *p;
    int i;

    for (i = 0; i < nspecials; i++) {
        p = &specials[i];
        if (p->rwd[0] == key[0] && strcmp(p->rwd, key) == 0)
            return;
    }

    if (specials == specialsinit) {
        /*
         * Whoa. Must reallocate special table.
         */
        nspecials = sizeof (specialsinit) / sizeof (specialsinit[0]);
        maxspecials = nspecials + (nspecials >> 2);
        specials = calloc(maxspecials, sizeof specials[0]);
        if (specials == NULL)
            err(1, NULL);
        memcpy(specials, specialsinit, sizeof specialsinit);
    } else if (nspecials >= maxspecials) {
        int newspecials = maxspecials + (maxspecials >> 2);
        struct templ *specials2;

        specials2 = reallocarray(specials, newspecials, sizeof(specials[0]));
        if (specials2 == NULL)
            err(1, NULL);
        specials = specials2;
        maxspecials = newspecials;
    }

    p = &specials[nspecials];
    p->rwd = key;
    p->rwcode = val;
    nspecials++;
    return;
}