indent/pr_comment.c

/*  $OpenBSD: pr_comment.c,v 1.7 2009/10/27 23:59:39 deraadt 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.
 */

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include "indent_globs.h"

/*
 * NAME:
 *  pr_comment
 *
 * FUNCTION:
 *  This routine takes care of scanning and printing comments.
 *
 * ALGORITHM:
 *  1) Decide where the comment should be aligned, and if lines should
 *     be broken.
 *  2) If lines should not be broken and filled, just copy up to end of
 *     comment.
 *  3) If lines should be filled, then scan thru input_buffer copying
 *     characters to com_buf.  Remember where the last blank, tab, or
 *     newline was.  When line is filled, print up to last blank and
 *     continue copying.
 *
 * HISTORY:
 *  November 1976   D A Willcox of CAC  Initial coding
 *  12/6/76     D A Willcox of CAC  Modification to handle
 *                      UNIX-style comments
 *
 */

/*
 * this routine processes comments.  It makes an attempt to keep comments from
 * going over the max line length.  If a line is too long, it moves everything
 * from the last blank to the next comment line.  Blanks and tabs from the
 * beginning of the input line are removed
 */

void
pr_comment(void)
{
    int         now_col;    /* column we are in now */
    int         adj_max_col;    /* Adjusted max_col for when we decide to
                 * spill comments over the right margin */
    char       *last_bl;    /* points to the last blank in the output
                 * buffer */
    char       *t_ptr;      /* used for moving string */
    int         unix_comment;   /* tri-state variable used to decide if it is
                 * a unix-style comment. 0 means only blanks
                 * since / *, 1 means regular style comment, 2
                 * means unix style comment */
    int         break_delim = comment_delimiter_on_blankline;
    int         l_just_saw_decl = ps.just_saw_decl;
    /*
     * int         ps.last_nl = 0;   true iff the last significant thing
     * we've seen is a newline
     */
    int         one_liner = 1;  /* true iff this comment is a one-liner */
    adj_max_col = max_col;
    ps.just_saw_decl = 0;
    last_bl = 0;        /* no blanks found so far */
    ps.box_com = false;     /* at first, assume that we are not in
                 * a boxed comment or some other
                 * comment that should not be touched */
    ++ps.out_coms;      /* keep track of number of comments */
    unix_comment = 1;       /* set flag to let us figure out if there is a
                 * unix-style comment ** DISABLED: use 0 to
                 * reenable this hack! */

    /* Figure where to align and how to treat the comment */

    if (ps.col_1 && !format_col1_comments) {    /* if comment starts in column
                         * 1 it should not be touched */
    ps.box_com = true;
    ps.com_col = 1;
    }
    else {
    if (*buf_ptr == '-' || *buf_ptr == '*' || *buf_ptr == '\n') {
        ps.box_com = true;  /* a comment with a '-', '*' or newline
                 * immediately after the / * is assumed to be
                 * a boxed comment */
        break_delim = 0;
    }
    if ( /* ps.bl_line && */ (s_lab == e_lab) && (s_code == e_code)) {
        /* klg: check only if this line is blank */
        /*
         * If this (*and previous lines are*) blank, don't put comment way
         * out at left
         */
        ps.com_col = (ps.ind_level - ps.unindent_displace) * ps.ind_size + 1;
        adj_max_col = block_comment_max_col;
        if (ps.com_col <= 1)
        ps.com_col = 1 + !format_col1_comments;
    }
    else {
        int    target_col;
        break_delim = 0;
        if (s_code != e_code)
        target_col = count_spaces(compute_code_target(), s_code);
        else {
        target_col = 1;
        if (s_lab != e_lab)
            target_col = count_spaces(compute_label_target(), s_lab);
        }
        ps.com_col = ps.decl_on_line || ps.ind_level == 0 ? ps.decl_com_ind : ps.com_ind;
        if (ps.com_col < target_col)
        ps.com_col = ((target_col + 7) & ~7) + 1;
        if (ps.com_col + 24 > adj_max_col)
        adj_max_col = ps.com_col + 24;
    }
    }
    if (ps.box_com) {
    buf_ptr[-2] = 0;
    ps.n_comment_delta = 1 - count_spaces(1, in_buffer);
    buf_ptr[-2] = '/';
    }
    else {
    ps.n_comment_delta = 0;
    while (*buf_ptr == ' ' || *buf_ptr == '\t')
        buf_ptr++;
    }
    ps.comment_delta = 0;
    *e_com++ = '/';     /* put '/ *' into buffer */
    *e_com++ = '*';
    if (*buf_ptr != ' ' && !ps.box_com)
    *e_com++ = ' ';

    *e_com = '\0';
    if (troff) {
    now_col = 1;
    adj_max_col = 80;
    }
    else
    now_col = count_spaces(ps.com_col, s_com);  /* figure what column we
                             * would be in if we
                             * printed the comment
                             * now */

    /* Start to copy the comment */

    while (1) {         /* this loop will go until the comment is
                 * copied */
    if (*buf_ptr > 040 && *buf_ptr != '*')
        ps.last_nl = 0;
    CHECK_SIZE_COM;
    switch (*buf_ptr) { /* this checks for various spcl cases */
    case 014:       /* check for a form feed */
        if (!ps.box_com) {  /* in a text comment, break the line here */
        ps.use_ff = true;
        /* fix so dump_line uses a form feed */
        dump_line();
        last_bl = 0;
        *e_com++ = ' ';
        *e_com++ = '*';
        *e_com++ = ' ';
        while (*++buf_ptr == ' ' || *buf_ptr == '\t');
        }
        else {
        if (++buf_ptr >= buf_end)
            fill_buffer();
        *e_com++ = 014;
        }
        break;

    case '\n':
        if (had_eof) {  /* check for unexpected eof */
        printf("Unterminated comment\n");
        *e_com = '\0';
        dump_line();
        return;
        }
        one_liner = 0;
        if (ps.box_com || ps.last_nl) { /* if this is a boxed comment,
                         * we don't ignore the newline
                         */
        if (s_com == e_com) {
            *e_com++ = ' ';
            *e_com++ = ' ';
        }
        *e_com = '\0';
        if (!ps.box_com && e_com - s_com > 3) {
            if (break_delim == 1 && s_com[0] == '/'
                && s_com[1] == '*' && s_com[2] == ' ') {
            char       *t = e_com;
            break_delim = 2;
            e_com = s_com + 2;
            *e_com = 0;
            if (blanklines_before_blockcomments)
                prefix_blankline_requested = 1;
            dump_line();
            e_com = t;
            s_com[0] = s_com[1] = s_com[2] = ' ';
            }
            dump_line();
            CHECK_SIZE_COM;
            *e_com++ = ' ';
            *e_com++ = ' ';
        }
        dump_line();
        now_col = ps.com_col;
        }
        else {
        ps.last_nl = 1;
        if (unix_comment != 1) {    /* we not are in unix_style
                         * comment */
            if (unix_comment == 0 && s_code == e_code) {
            /*
             * if it is a UNIX-style comment, ignore the
             * requirement that previous line be blank for
             * unindention
             */
            ps.com_col = (ps.ind_level - ps.unindent_displace) * ps.ind_size + 1;
            if (ps.com_col <= 1)
                ps.com_col = 2;
            }
            unix_comment = 2;   /* permanently remember that we are in
                     * this type of comment */
            dump_line();
            ++line_no;
            now_col = ps.com_col;
            *e_com++ = ' ';
            /*
             * fix so that the star at the start of the line will line
             * up
             */
            do      /* flush leading white space */
            if (++buf_ptr >= buf_end)
                fill_buffer();
            while (*buf_ptr == ' ' || *buf_ptr == '\t');
            break;
        }
        if (*(e_com - 1) == ' ' || *(e_com - 1) == '\t')
            last_bl = e_com - 1;
        /*
         * if there was a space at the end of the last line, remember
         * where it was
         */
        else {      /* otherwise, insert one */
            last_bl = e_com;
            CHECK_SIZE_COM;
            *e_com++ = ' ';
            ++now_col;
        }
        }
        ++line_no;      /* keep track of input line number */
        if (!ps.box_com) {
        int         nstar = 1;
        do {        /* flush any blanks and/or tabs at start of
                 * next line */
            if (++buf_ptr >= buf_end)
            fill_buffer();
            if (*buf_ptr == '*' && --nstar >= 0) {
            if (++buf_ptr >= buf_end)
                fill_buffer();
            if (*buf_ptr == '/')
                goto end_of_comment;
            }
        } while (*buf_ptr == ' ' || *buf_ptr == '\t');
        }
        else if (++buf_ptr >= buf_end)
        fill_buffer();
        break;      /* end of case for newline */

    case '*':       /* must check for possibility of being at end
                 * of comment */
        if (++buf_ptr >= buf_end)   /* get to next char after * */
        fill_buffer();

        if (unix_comment == 0)  /* set flag to show we are not in
                     * unix-style comment */
        unix_comment = 1;

        if (*buf_ptr == '/') {  /* it is the end!!! */
    end_of_comment:
        if (++buf_ptr >= buf_end)
            fill_buffer();

        if (*(e_com - 1) != ' ' && !ps.box_com) {   /* insure blank before
                                 * end */
            *e_com++ = ' ';
            ++now_col;
        }
        if (break_delim == 1 && !one_liner && s_com[0] == '/'
            && s_com[1] == '*' && s_com[2] == ' ') {
            char       *t = e_com;
            break_delim = 2;
            e_com = s_com + 2;
            *e_com = 0;
            if (blanklines_before_blockcomments)
            prefix_blankline_requested = 1;
            dump_line();
            e_com = t;
            s_com[0] = s_com[1] = s_com[2] = ' ';
        }
        if (break_delim == 2 && e_com > s_com + 3
            /* now_col > adj_max_col - 2 && !ps.box_com */ ) {
            *e_com = '\0';
            dump_line();
            now_col = ps.com_col;
        }
        CHECK_SIZE_COM;
        *e_com++ = '*';
        *e_com++ = '/';
        *e_com = '\0';
        ps.just_saw_decl = l_just_saw_decl;
        return;
        }
        else {      /* handle isolated '*' */
        *e_com++ = '*';
        ++now_col;
        }
        break;
    default:        /* we have a random char */
        if (unix_comment == 0 && *buf_ptr != ' ' && *buf_ptr != '\t')
        unix_comment = 1;   /* we are not in unix-style comment */

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

        if (*e_com == '\t') /* keep track of column */
        now_col = ((now_col - 1) & tabmask) + tabsize + 1;
        else if (*e_com == '\b')    /* this is a backspace */
        --now_col;
        else
        ++now_col;

        if (*e_com == ' ' || *e_com == '\t')
        last_bl = e_com;
        /* remember we saw a blank */

        ++e_com;
        if (now_col > adj_max_col && !ps.box_com && unix_comment == 1 && e_com[-1] > ' ') {
        /*
         * the comment is too long, it must be broken up
         */
        if (break_delim == 1 && s_com[0] == '/'
            && s_com[1] == '*' && s_com[2] == ' ') {
            char       *t = e_com;
            break_delim = 2;
            e_com = s_com + 2;
            *e_com = 0;
            if (blanklines_before_blockcomments)
            prefix_blankline_requested = 1;
            dump_line();
            e_com = t;
            s_com[0] = s_com[1] = s_com[2] = ' ';
        }
        if (last_bl == 0) { /* we have seen no blanks */
            last_bl = e_com;    /* fake it */
            *e_com++ = ' ';
        }
        *e_com = '\0';  /* print what we have */
        *last_bl = '\0';
        while (last_bl > s_com && last_bl[-1] < 040)
            *--last_bl = 0;
        e_com = last_bl;
        dump_line();

        *e_com++ = ' '; /* add blanks for continuation */
        *e_com++ = ' ';
        *e_com++ = ' ';

        t_ptr = last_bl + 1;
        last_bl = 0;
        if (t_ptr >= e_com) {
            while (*t_ptr == ' ' || *t_ptr == '\t')
            t_ptr++;
            while (*t_ptr != '\0') {    /* move unprinted part of
                         * comment down in buffer */
            if (*t_ptr == ' ' || *t_ptr == '\t')
                last_bl = e_com;
            *e_com++ = *t_ptr++;
            }
        }
        *e_com = '\0';
        now_col = count_spaces(ps.com_col, s_com);  /* recompute current
                                 * position */
        }
        break;
    }
    }
}