xref: /netbsd-src/usr.bin/indent/pr_comment.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: pr_comment.c,v 1.35 2021/03/14 05:26:42 rillig Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-4-Clause
5  *
6  * Copyright (c) 1985 Sun Microsystems, Inc.
7  * Copyright (c) 1980, 1993
8  *	The Regents of the University of California.  All rights reserved.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 #if 0
41 #ifndef lint
42 static char sccsid[] = "@(#)pr_comment.c	8.1 (Berkeley) 6/6/93";
43 #endif /* not lint */
44 #endif
45 
46 #include <sys/cdefs.h>
47 #ifndef lint
48 #if defined(__NetBSD__)
49 __RCSID("$NetBSD: pr_comment.c,v 1.35 2021/03/14 05:26:42 rillig Exp $");
50 #elif defined(__FreeBSD__)
51 __FBSDID("$FreeBSD: head/usr.bin/indent/pr_comment.c 334927 2018-06-10 16:44:18Z pstef $");
52 #endif
53 #endif
54 
55 #include <err.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 
60 #include "indent.h"
61 
62 static void
63 check_size_comment(size_t desired_size)
64 {
65     if (e_com + (desired_size) < l_com)
66         return;
67 
68     size_t nsize = l_com - s_com + 400 + desired_size;
69     size_t com_len = e_com - s_com;
70     combuf = realloc(combuf, nsize);
71     if (combuf == NULL)
72 	err(1, NULL);
73     s_com = combuf + 1;
74     e_com = s_com + com_len;
75     l_com = combuf + nsize - 5;
76 }
77 
78 /*
79  * Scan, reformat and output a single comment, which is either a block comment
80  * starting with '/' '*' or an end-of-line comment starting with '//'.
81  *
82  * Try to keep comments from going over the maximum line length.  If a line is
83  * too long, move everything starting from the last blank to the next comment
84  * line.  Blanks and tabs from the beginning of the input line are removed.
85  *
86  * ALGORITHM:
87  *	1) Decide where the comment should be aligned, and if lines should
88  *	   be broken.
89  *	2) If lines should not be broken and filled, just copy up to end of
90  *	   comment.
91  *	3) If lines should be filled, then scan through the input buffer,
92  *	   copying characters to com_buf.  Remember where the last blank,
93  *	   tab, or newline was.  When line is filled, print up to last blank
94  *	   and continue copying.
95  */
96 void
97 process_comment(void)
98 {
99     int         adj_max_line_length; /* Adjusted max_line_length for comments
100 				 * that spill over the right margin */
101     ssize_t last_blank;		/* index of the last blank in combuf */
102     char       *t_ptr;		/* used for moving string */
103     int         break_delim = opt.comment_delimiter_on_blankline;
104     int         l_just_saw_decl = ps.just_saw_decl;
105 
106     adj_max_line_length = opt.max_line_length;
107     ps.just_saw_decl = 0;
108     last_blank = -1;		/* no blanks found so far */
109     ps.box_com = false;		/* at first, assume that we are not in
110 				 * a boxed comment or some other
111 				 * comment that should not be touched */
112     ++ps.out_coms;		/* keep track of number of comments */
113 
114     /* Figure where to align and how to treat the comment */
115 
116     if (ps.col_1 && !opt.format_col1_comments) { /* if the comment starts in
117 				 * column 1, it should not be touched */
118 	ps.box_com = true;
119 	break_delim = false;
120 	ps.com_col = 1;
121     } else {
122 	if (*buf_ptr == '-' || *buf_ptr == '*' || e_token[-1] == '/' ||
123 	    (*buf_ptr == '\n' && !opt.format_block_comments)) {
124 	    ps.box_com = true;	/* A comment with a '-' or '*' immediately
125 				 * after the /+* is assumed to be a boxed
126 				 * comment. A comment with a newline
127 				 * immediately after the /+* is assumed to
128 				 * be a block comment and is treated as a
129 				 * box comment unless format_block_comments
130 				 * is nonzero (the default). */
131 	    break_delim = false;
132 	}
133 	if ( /* ps.bl_line && */ s_lab == e_lab && s_code == e_code) {
134 	    /* klg: check only if this line is blank */
135 	    /*
136 	     * If this (*and previous lines are*) blank, dont put comment way
137 	     * out at left
138 	     */
139 	    ps.com_col = (ps.ind_level - opt.unindent_displace) * opt.indent_size + 1;
140 	    adj_max_line_length = opt.block_comment_max_line_length;
141 	    if (ps.com_col <= 1)
142 		ps.com_col = 1 + !opt.format_col1_comments;
143 	} else {
144 	    break_delim = false;
145 
146 	    int target_col;
147 	    if (s_code != e_code)
148 		target_col = 1 + indentation_after(compute_code_indent(), s_code);
149 	    else if (s_lab != e_lab)
150 		target_col = 1 + indentation_after(compute_label_indent(), s_lab);
151 	    else
152 		target_col = 1;
153 
154 	    ps.com_col = ps.decl_on_line || ps.ind_level == 0
155 		? opt.decl_comment_column : opt.comment_column;
156 	    if (ps.com_col <= target_col)
157 		ps.com_col = opt.tabsize * (1 + (target_col - 1) / opt.tabsize) + 1;
158 	    if (ps.com_col + 24 > adj_max_line_length)
159 	        /* XXX: mismatch between column and length */
160 		adj_max_line_length = ps.com_col + 24;
161 	}
162     }
163     if (ps.box_com) {
164 	/*
165 	 * Find out how much indentation there was originally, because that
166 	 * much will have to be ignored by pad_output() in dump_line(). This
167 	 * is a box comment, so nothing changes -- not even indentation.
168 	 *
169 	 * The comment we're about to read usually comes from in_buffer,
170 	 * unless it has been copied into save_com.
171 	 */
172 	char *start;
173 
174 	/*
175 	 * XXX: ordered comparison between pointers from different objects
176 	 * invokes undefined behavior (C99 6.5.8).
177 	 */
178 	start = buf_ptr >= save_com && buf_ptr < save_com + sc_size ?
179 	    sc_buf : in_buffer;
180 	ps.n_comment_delta = -indentation_after_range(0, start, buf_ptr - 2);
181     } else {
182 	ps.n_comment_delta = 0;
183 	while (*buf_ptr == ' ' || *buf_ptr == '\t')
184 	    buf_ptr++;
185     }
186     ps.comment_delta = 0;
187     *e_com++ = '/';
188     *e_com++ = e_token[-1];
189     if (*buf_ptr != ' ' && !ps.box_com)
190 	*e_com++ = ' ';
191 
192     /*
193      * Don't put a break delimiter if this is a one-liner that won't wrap.
194      */
195     if (break_delim)
196 	for (t_ptr = buf_ptr; *t_ptr != '\0' && *t_ptr != '\n'; t_ptr++) {
197 	    if (t_ptr >= buf_end)
198 		fill_buffer();
199 	    if (t_ptr[0] == '*' && t_ptr[1] == '/') {
200 	        /*
201 	         * XXX: This computation ignores the leading " * ", as well
202 	         * as the trailing ' ' '*' '/'.  In simple cases, these cancel
203 	         * out since they are equally long.
204 	         */
205 		int right_margin = indentation_after_range(ps.com_col - 1,
206 		    buf_ptr, t_ptr + 2);
207 		if (right_margin < adj_max_line_length)
208 		    break_delim = false;
209 		break;
210 	    }
211 	}
212 
213     if (break_delim) {
214 	char       *t = e_com;
215 	e_com = s_com + 2;
216 	*e_com = 0;
217 	if (opt.blanklines_before_blockcomments && ps.last_token != lbrace)
218 	    prefix_blankline_requested = 1;
219 	dump_line();
220 	e_com = s_com = t;
221 	if (!ps.box_com && opt.star_comment_cont)
222 	    *e_com++ = ' ', *e_com++ = '*', *e_com++ = ' ';
223     }
224 
225     /* Start to copy the comment */
226 
227     for (;;) {			/* this loop will go until the comment is
228 				 * copied */
229 	switch (*buf_ptr) {	/* this checks for various special cases */
230 	case 014:		/* check for a form feed */
231 	    check_size_comment(3);
232 	    if (!ps.box_com) {	/* in a text comment, break the line here */
233 		ps.use_ff = true;
234 		/* fix so dump_line uses a form feed */
235 		dump_line();
236 		last_blank = -1;
237 		if (!ps.box_com && opt.star_comment_cont)
238 		    *e_com++ = ' ', *e_com++ = '*', *e_com++ = ' ';
239 		while (*++buf_ptr == ' ' || *buf_ptr == '\t')
240 		    ;
241 	    } else {
242 		if (++buf_ptr >= buf_end)
243 		    fill_buffer();
244 		*e_com++ = 014;
245 	    }
246 	    break;
247 
248 	case '\n':
249 	    if (e_token[-1] == '/') {
250 		++line_no;
251 		goto end_of_comment;
252 	    }
253 	    if (had_eof) {	/* check for unexpected eof */
254 		printf("Unterminated comment\n");
255 		dump_line();
256 		return;
257 	    }
258 	    last_blank = -1;
259 	    check_size_comment(4);
260 	    if (ps.box_com || ps.last_nl) {	/* if this is a boxed comment,
261 						 * we dont ignore the newline */
262 		if (s_com == e_com)
263 		    *e_com++ = ' ';
264 		if (!ps.box_com && e_com - s_com > 3) {
265 		    dump_line();
266 		    if (opt.star_comment_cont)
267 			*e_com++ = ' ', *e_com++ = '*', *e_com++ = ' ';
268 		}
269 		dump_line();
270 		if (!ps.box_com && opt.star_comment_cont)
271 		    *e_com++ = ' ', *e_com++ = '*', *e_com++ = ' ';
272 	    } else {
273 		ps.last_nl = 1;
274 		if (!(e_com[-1] == ' ' || e_com[-1] == '\t'))
275 		    *e_com++ = ' ';
276 		last_blank = e_com - 1 - combuf;
277 	    }
278 	    ++line_no;		/* keep track of input line number */
279 	    if (!ps.box_com) {
280 		int         nstar = 1;
281 		do {		/* flush any blanks and/or tabs at start of
282 				 * next line */
283 		    if (++buf_ptr >= buf_end)
284 			fill_buffer();
285 		    if (*buf_ptr == '*' && --nstar >= 0) {
286 			if (++buf_ptr >= buf_end)
287 			    fill_buffer();
288 			if (*buf_ptr == '/')
289 			    goto end_of_comment;
290 		    }
291 		} while (*buf_ptr == ' ' || *buf_ptr == '\t');
292 	    } else if (++buf_ptr >= buf_end)
293 		fill_buffer();
294 	    break;		/* end of case for newline */
295 
296 	case '*':		/* must check for possibility of being at end
297 				 * of comment */
298 	    if (++buf_ptr >= buf_end)	/* get to next char after * */
299 		fill_buffer();
300 	    check_size_comment(4);
301 	    if (*buf_ptr == '/') {	/* it is the end!!! */
302 	end_of_comment:
303 		if (++buf_ptr >= buf_end)
304 		    fill_buffer();
305 		if (break_delim) {
306 		    if (e_com > s_com + 3)
307 			dump_line();
308 		    else
309 			s_com = e_com;
310 		    *e_com++ = ' ';
311 		}
312 		if (e_com[-1] != ' ' && e_com[-1] != '\t' && !ps.box_com)
313 		    *e_com++ = ' ';	/* ensure blank before end */
314 		if (e_token[-1] == '/')
315 		    *e_com++ = '\n', *e_com = '\0';
316 		else
317 		    *e_com++ = '*', *e_com++ = '/', *e_com = '\0';
318 		ps.just_saw_decl = l_just_saw_decl;
319 		return;
320 	    } else		/* handle isolated '*' */
321 		*e_com++ = '*';
322 	    break;
323 	default:		/* we have a random char */
324 	    ;
325 	    int now_len = indentation_after_range(ps.com_col - 1, s_com, e_com);
326 	    do {
327 		check_size_comment(1);
328 		*e_com = *buf_ptr++;
329 		if (buf_ptr >= buf_end)
330 		    fill_buffer();
331 		if (*e_com == ' ' || *e_com == '\t')
332 		    last_blank = e_com - combuf; /* remember we saw a blank */
333 		++e_com;
334 		now_len++;
335 	    } while (!memchr("*\n\r\b\t", *buf_ptr, 6) &&
336 		(now_len < adj_max_line_length || last_blank == -1));
337 	    ps.last_nl = false;
338 	    /* XXX: signed character comparison '>' does not work for UTF-8 */
339 	    if (now_len > adj_max_line_length &&
340 		    !ps.box_com && e_com[-1] > ' ') {
341 		/*
342 		 * the comment is too long, it must be broken up
343 		 */
344 		if (last_blank == -1) {
345 		    dump_line();
346 		    if (!ps.box_com && opt.star_comment_cont)
347 			*e_com++ = ' ', *e_com++ = '*', *e_com++ = ' ';
348 		    break;
349 		}
350 		*e_com = '\0';
351 		e_com = combuf + last_blank;
352 		dump_line();
353 		if (!ps.box_com && opt.star_comment_cont)
354 		    *e_com++ = ' ', *e_com++ = '*', *e_com++ = ' ';
355 		for (t_ptr = combuf + last_blank + 1;
356 		     *t_ptr == ' ' || *t_ptr == '\t'; t_ptr++)
357 		    continue;
358 		last_blank = -1;
359 		/*
360 		 * t_ptr will be somewhere between e_com (dump_line() reset)
361 		 * and l_com. So it's safe to copy byte by byte from t_ptr
362 		 * to e_com without any check_size_comment().
363 		 */
364 		while (*t_ptr != '\0') {
365 		    if (*t_ptr == ' ' || *t_ptr == '\t')
366 			last_blank = e_com - combuf;
367 		    *e_com++ = *t_ptr++;
368 		}
369 	    }
370 	    break;
371 	}
372     }
373 }
374