/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1985 Sun Microsystems, Inc.
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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 <err.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>

#include "indent_globs.h"
#include "indent_codes.h"
#include "indent.h"

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

/*
 * This table has to be sorted alphabetically, because it'll be used in binary
 * search. For the same reason, string must be the first thing in struct templ.
 */
struct templ specials[] =
{
    {"_Bool", 4},
    {"_Complex", 4},
    {"_Imaginary", 4},
    {"auto", 10},
    {"bool", 4},
    {"break", 9},
    {"case", 8},
    {"char", 4},
    {"complex", 4},
    {"const", 4},
    {"continue", 12},
    {"default", 8},
    {"do", 6},
    {"double", 4},
    {"else", 6},
    {"enum", 3},
    {"extern", 10},
    {"float", 4},
    {"for", 5},
    {"global", 4},
    {"goto", 9},
    {"if", 5},
    {"imaginary", 4},
    {"inline", 12},
    {"int", 4},
    {"long", 4},
    {"offsetof", 1},
    {"register", 10},
    {"restrict", 12},
    {"return", 9},
    {"short", 4},
    {"signed", 4},
    {"sizeof", 2},
    {"static", 10},
    {"struct", 3},
    {"switch", 7},
    {"typedef", 11},
    {"union", 3},
    {"unsigned", 4},
    {"void", 4},
    {"volatile", 4},
    {"while", 5}
};

const char **typenames;
int         typename_count;
int         typename_top = -1;

/*
 * The transition table below was rewritten by hand from lx's output, given
 * the following definitions. lx is Katherine Flavel's lexer generator.
 *
 * O  = /[0-7]/;        D  = /[0-9]/;          NZ = /[1-9]/;
 * H  = /[a-f0-9]/i;    B  = /[0-1]/;          HP = /0x/i;
 * BP = /0b/i;          E  = /e[+\-]?/i D+;    P  = /p[+\-]?/i D+;
 * FS = /[fl]/i;        IS = /u/i /(l|L|ll|LL)/? | /(l|L|ll|LL)/ /u/i?;
 *
 * D+           E  FS? -> $float;
 * D*    "." D+ E? FS? -> $float;
 * D+    "."    E? FS? -> $float;    HP H+           IS? -> $int;
 * HP H+        P  FS? -> $float;    NZ D*           IS? -> $int;
 * HP H* "." H+ P  FS? -> $float;    "0" O*          IS? -> $int;
 * HP H+ "."    P  FS  -> $float;    BP B+           IS? -> $int;
 */
static char const *table[] = {
    /*                examples:
                                     00
             s                      0xx
             t                    00xaa
             a     11       101100xxa..
             r   11ee0001101lbuuxx.a.pp
             t.01.e+008bLuxll0Ll.aa.p+0
    states:  ABCDEFGHIJKLMNOPQRSTUVWXYZ */
    ['0'] = "CEIDEHHHIJQ  U  Q  VUVVZZZ",
    ['1'] = "DEIDEHHHIJQ  U  Q  VUVVZZZ",
    ['7'] = "DEIDEHHHIJ   U     VUVVZZZ",
    ['9'] = "DEJDEHHHJJ   U     VUVVZZZ",
    ['a'] = "             U     VUVV   ",
    ['b'] = "  K          U     VUVV   ",
    ['e'] = "  FFF   FF   U     VUVV   ",
    ['f'] = "    f  f     U     VUVV  f",
    ['u'] = "  MM    M  i  iiM   M     ",
    ['x'] = "  N                       ",
    ['p'] = "                    FFX   ",
    ['L'] = "  LLf  fL  PR   Li  L    f",
    ['l'] = "  OOf  fO   S P O i O    f",
    ['+'] = "     G                 Y  ",
    ['.'] = "B EE    EE   T      W     ",
    /*       ABCDEFGHIJKLMNOPQRSTUVWXYZ */
    [0]   = "uuiifuufiuuiiuiiiiiuiuuuuu",
};

static int
strcmp_type(const void *e1, const void *e2)
{
    return (strcmp(e1, *(const char * const *)e2));
}

int
lexi(struct parser_state *state)
{
    int         unary_delim;    /* this is set to 1 if the current token
                                 * forces a following operator to be unary */
    int         code;           /* internal code to be returned */
    char        qchar;          /* the delimiter character for a string */

    e_token = s_token;          /* point to start of place to save token */
    unary_delim = false;
    state->col_1 = state->last_nl;      /* tell world that this token started
                                         * in column 1 iff the last thing
                                         * scanned was a newline */
    state->last_nl = false;

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

    /* Scan an alphanumeric token */
    if (isalnum((unsigned char)*buf_ptr) ||
        *buf_ptr == '_' || *buf_ptr == '$' ||
        (buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
        /*
         * we have a character or number
         */
        struct templ *p;

        if (isdigit((unsigned char)*buf_ptr) ||
            (buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
            char s;
            unsigned char i;

            for (s = 'A'; s != 'f' && s != 'i' && s != 'u'; ) {
                i = (unsigned char)*buf_ptr;
                if (i >= nitems(table) || table[i] == NULL ||
                    table[i][s - 'A'] == ' ') {
                    s = table[0][s - 'A'];
                    break;
                }
                s = table[i][s - 'A'];
                CHECK_SIZE_TOKEN(1);
                *e_token++ = *buf_ptr++;
                if (buf_ptr >= buf_end)
                    fill_buffer();
            }
            /* s now indicates the type: f(loating), i(integer), u(nknown) */
        }
        else
            while (isalnum((unsigned char)*buf_ptr) ||
                *buf_ptr == BACKSLASH ||
                *buf_ptr == '_' || *buf_ptr == '$') {
                /* fill_buffer() terminates buffer with newline */
                if (*buf_ptr == BACKSLASH) {
                    if (*(buf_ptr + 1) == '\n') {
                        buf_ptr += 2;
                        if (buf_ptr >= buf_end)
                            fill_buffer();
                        } else
                            break;
                }
                CHECK_SIZE_TOKEN(1);
                /* copy it over */
                *e_token++ = *buf_ptr++;
                if (buf_ptr >= buf_end)
                    fill_buffer();
            }
        *e_token = '\0';

        if (s_token[0] == 'L' && s_token[1] == '\0' &&
              (*buf_ptr == '"' || *buf_ptr == '\''))
            return (strpfx);

        while (*buf_ptr == ' ' || *buf_ptr == '\t') {   /* get rid of blanks */
            if (++buf_ptr >= buf_end)
                fill_buffer();
        }
        state->keyword = 0;
        if (state->last_token == structure && !state->p_l_follow) {
                                /* if last token was 'struct' and we're not
                                 * in parentheses, then this token
                                 * should be treated as a declaration */
            state->last_u_d = true;
            return (decl);
        }
        /*
         * Operator after identifier is binary unless last token was 'struct'
         */
        state->last_u_d = (state->last_token == structure);

        p = bsearch(s_token,
            specials,
            sizeof(specials) / sizeof(specials[0]),
            sizeof(specials[0]),
            strcmp_type);
        if (p == NULL) {        /* not a special keyword... */
            char *u;

            /* ... so maybe a type_t or a typedef */
            if ((opt.auto_typedefs && ((u = strrchr(s_token, '_')) != NULL) &&
                strcmp(u, "_t") == 0) || (typename_top >= 0 &&
                  bsearch(s_token, typenames, typename_top + 1,
                    sizeof(typenames[0]), strcmp_type))) {
                state->keyword = 4;     /* a type name */
                state->last_u_d = true;
                goto found_typename;
            }
        } else {                        /* we have a keyword */
            state->keyword = p->rwcode;
            state->last_u_d = true;
            switch (p->rwcode) {
            case 7:             /* it is a switch */
                return (swstmt);
            case 8:             /* a case or default */
                return (casestmt);

            case 3:             /* a "struct" */
                /* FALLTHROUGH */
            case 4:             /* one of the declaration keywords */
            found_typename:
                if (state->p_l_follow) {
                    /* inside parens: cast, param list, offsetof or sizeof */
                    state->cast_mask |= (1 << state->p_l_follow) & ~state->not_cast_mask;
                }
                if (state->last_token == period || state->last_token == unary_op) {
                    state->keyword = 0;
                    break;
                }
                if (p != NULL && p->rwcode == 3)
                    return (structure);
                if (state->p_l_follow)
                    break;
                return (decl);

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

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

            case 10:            /* storage class specifier */
                return (storage);

            case 11:            /* typedef */
                return (type_def);

            default:            /* all others are treated like any other
                                 * identifier */
                return (ident);
            }                   /* end of switch */
        }                       /* end of if (found_it) */
        if (*buf_ptr == '(' && state->tos <= 1 && state->ind_level == 0 &&
            state->in_parameter_declaration == 0 && state->block_init == 0) {
            char *tp = buf_ptr;
            while (tp < buf_end)
                if (*tp++ == ')' && (*tp == ';' || *tp == ','))
                    goto not_proc;
            strncpy(state->procname, token, sizeof state->procname - 1);
            if (state->in_decl)
                state->in_parameter_declaration = 1;
            return (funcname);
    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
         */
        else if (!state->p_l_follow && !state->block_init &&
            !state->in_stmt &&
            ((*buf_ptr == '*' && buf_ptr[1] != '=') ||
                isalpha((unsigned char)*buf_ptr)) &&
            (state->last_token == semicolon || state->last_token == lbrace ||
                state->last_token == rbrace)) {
            state->keyword = 4; /* a type name */
            state->last_u_d = true;
            return decl;
        }
        if (state->last_token == decl)  /* if this is a declared variable,
                                         * then following sign is unary */
            state->last_u_d = true;     /* will make "int a -1" work */
        return (ident);         /* the ident is not in the list */
    }                           /* end of processing for alpanum character */

    /* Scan a non-alphanumeric token */

    CHECK_SIZE_TOKEN(3);                /* things like "<<=" */
    *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 = state->last_u_d;
        state->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;
        do {                    /* copy the string */
            while (1) {         /* move one character or [/<char>]<char> */
                if (*buf_ptr == '\n') {
                    diag2(1, "Unterminated literal");
                    goto stop_lit;
                }
                CHECK_SIZE_TOKEN(2);
                *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;
                    *++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);
stop_lit:
        code = ident;
        break;

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

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

    case '#':
        unary_delim = state->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 (state->in_or_st) state->block_init = 1;
         */
        /* ?    code = state->block_init ? lparen : lbrace; */
        code = lbrace;
        break;

    case ('}'):
        unary_delim = true;
        /* ?    code = state->block_init ? rparen : rbrace; */
        code = rbrace;
        break;

    case 014:                   /* a form feed */
        unary_delim = state->last_u_d;
        state->last_nl = true;  /* remember this so we can set 'state->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 = (state->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 (state->last_token == ident || state->last_token == rparen) {
                code = (state->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 (!opt.pointer_as_binop) {
                unary_delim = false;
                code = unary_op;
                state->want_blank = false;
            }
        }
        break;                  /* buffer overflow will be checked at end of
                                 * switch */

    case '=':
        if (state->in_or_st)
            state->block_init = 1;
        if (*buf_ptr == '=') {/* == */
            *e_token++ = '=';   /* Flip =+ to += */
            buf_ptr++;
            *e_token = 0;
        }
        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 = (state->last_u_d ? unary_op : binary_op);
        unary_delim = true;
        break;

    case '*':
        unary_delim = true;
        if (!state->last_u_d) {
            if (*buf_ptr == '=')
                *e_token++ = *buf_ptr++;
            code = binary_op;
            break;
        }
        while (*buf_ptr == '*' || isspace((unsigned char)*buf_ptr)) {
            if (*buf_ptr == '*') {
                CHECK_SIZE_TOKEN(1);
                *e_token++ = *buf_ptr;
            }
            if (++buf_ptr >= buf_end)
                fill_buffer();
        }
        if (ps.in_decl) {
            char *tp = buf_ptr;

            while (isalpha((unsigned char)*tp) ||
                   isspace((unsigned char)*tp)) {
                if (++tp >= buf_end)
                    fill_buffer();
            }
            if (*tp == '(')
                ps.procname[0] = ' ';
        }
        code = unary_op;
        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 = state->last_u_d;
            break;
        }
        while (*(e_token - 1) == *buf_ptr || *buf_ptr == '=') {
            /*
             * handle ||, &&, etc, and also things as in int *****i
             */
            CHECK_SIZE_TOKEN(1);
            *e_token++ = *buf_ptr;
            if (++buf_ptr >= buf_end)
                fill_buffer();
        }
        code = (state->last_u_d ? unary_op : binary_op);
        unary_delim = true;


    }                           /* end of switch */
    if (buf_ptr >= buf_end)     /* check for input buffer empty */
        fill_buffer();
    state->last_u_d = unary_delim;
    CHECK_SIZE_TOKEN(1);
    *e_token = '\0';            /* null terminate the token */
    return (code);
}

/* Initialize constant transition table */
void
init_constant_tt(void)
{
    table['-'] = table['+'];
    table['8'] = table['9'];
    table['2'] = table['3'] = table['4'] = table['5'] = table['6'] = table['7'];
    table['A'] = table['C'] = table['D'] = table['c'] = table['d'] = table['a'];
    table['B'] = table['b'];
    table['E'] = table['e'];
    table['U'] = table['u'];
    table['X'] = table['x'];
    table['P'] = table['p'];
    table['F'] = table['f'];
}

void
alloc_typenames(void)
{

    typenames = (const char **)malloc(sizeof(typenames[0]) *
        (typename_count = 16));
    if (typenames == NULL)
        err(1, NULL);
}

void
add_typename(const char *key)
{
    int comparison;
    const char *copy;

    if (typename_top + 1 >= typename_count) {
        typenames = realloc((void *)typenames,
            sizeof(typenames[0]) * (typename_count *= 2));
        if (typenames == NULL)
            err(1, NULL);
    }
    if (typename_top == -1)
        typenames[++typename_top] = copy = strdup(key);
    else if ((comparison = strcmp(key, typenames[typename_top])) >= 0) {
        /* take advantage of sorted input */
        if (comparison == 0)    /* remove duplicates */
            return;
        typenames[++typename_top] = copy = strdup(key);
    }
    else {
        int p;

        for (p = 0; (comparison = strcmp(key, typenames[p])) > 0; p++)
            /* find place for the new key */;
        if (comparison == 0)    /* remove duplicates */
            return;
        memmove(&typenames[p + 1], &typenames[p],
            sizeof(typenames[0]) * (++typename_top - p));
        typenames[p] = copy = strdup(key);
    }

    if (copy == NULL)
        err(1, NULL);
}