xref: /freebsd/contrib/mandoc/man.c (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
1 /* $Id: man.c,v 1.189 2022/08/16 23:01:09 schwarze Exp $ */
2 /*
3  * Copyright (c) 2013-2015,2017-2019,2022 Ingo Schwarze <schwarze@openbsd.org>
4  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
5  * Copyright (c) 2011 Joerg Sonnenberger <joerg@netbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 #include "config.h"
20 
21 #include <sys/types.h>
22 
23 #include <assert.h>
24 #include <ctype.h>
25 #include <stdarg.h>
26 #include <stdlib.h>
27 #include <stdio.h>
28 #include <string.h>
29 
30 #include "mandoc_aux.h"
31 #include "mandoc.h"
32 #include "roff.h"
33 #include "man.h"
34 #include "libmandoc.h"
35 #include "roff_int.h"
36 #include "libman.h"
37 
38 static	char		*man_hasc(char *);
39 static	int		 man_ptext(struct roff_man *, int, char *, int);
40 static	int		 man_pmacro(struct roff_man *, int, char *, int);
41 
42 
43 int
44 man_parseln(struct roff_man *man, int ln, char *buf, int offs)
45 {
46 
47 	if (man->last->type != ROFFT_EQN || ln > man->last->line)
48 		man->flags |= MAN_NEWLINE;
49 
50 	return roff_getcontrol(man->roff, buf, &offs) ?
51 	    man_pmacro(man, ln, buf, offs) :
52 	    man_ptext(man, ln, buf, offs);
53 }
54 
55 /*
56  * If the string ends with \c, return a pointer to the backslash.
57  * Otherwise, return NULL.
58  */
59 static char *
60 man_hasc(char *start)
61 {
62 	char	*cp, *ep;
63 
64 	ep = strchr(start, '\0') - 2;
65 	if (ep < start || ep[0] != '\\' || ep[1] != 'c')
66 		return NULL;
67 	for (cp = ep; cp > start; cp--)
68 		if (cp[-1] != '\\')
69 			break;
70 	return (ep - cp) % 2 ? NULL : ep;
71 }
72 
73 /*
74  * Rewind all open next-line scopes.
75  */
76 void
77 man_descope(struct roff_man *man, int line, int offs, char *start)
78 {
79 	/* First close out all next-line element scopes, if any. */
80 
81 	if (man->flags & MAN_ELINE) {
82 		while (man->last->parent->type != ROFFT_ROOT &&
83 		    man_macro(man->last->parent->tok)->flags & MAN_ESCOPED)
84 			man_unscope(man, man->last->parent);
85 		man->flags &= ~MAN_ELINE;
86 	}
87 
88 	/* Trailing \c keeps next-line block scope open. */
89 
90 	if (start != NULL && man_hasc(start) != NULL)
91 		return;
92 
93 	/* Close out the next-line block scope, if there is one. */
94 
95 	if ( ! (man->flags & MAN_BLINE))
96 		return;
97 	man_unscope(man, man->last->parent);
98 	roff_body_alloc(man, line, offs, man->last->tok);
99 	man->flags &= ~(MAN_BLINE | ROFF_NONOFILL);
100 }
101 
102 static int
103 man_ptext(struct roff_man *man, int line, char *buf, int offs)
104 {
105 	int		 i;
106 	char		*ep;
107 
108 	/* In no-fill mode, whitespace is preserved on text lines. */
109 
110 	if (man->flags & ROFF_NOFILL) {
111 		roff_word_alloc(man, line, offs, buf + offs);
112 		man_descope(man, line, offs, buf + offs);
113 		return 1;
114 	}
115 
116 	for (i = offs; buf[i] == ' '; i++)
117 		/* Skip leading whitespace. */ ;
118 
119 	/*
120 	 * Blank lines are ignored in next line scope
121 	 * and right after headings and cancel preceding \c,
122 	 * but add a single vertical space elsewhere.
123 	 */
124 
125 	if (buf[i] == '\0') {
126 		if (man->flags & (MAN_ELINE | MAN_BLINE)) {
127 			mandoc_msg(MANDOCERR_BLK_BLANK, line, 0, NULL);
128 			return 1;
129 		}
130 		if (man->last->tok == MAN_SH || man->last->tok == MAN_SS)
131 			return 1;
132 		if (man->last->type == ROFFT_TEXT &&
133 		    ((ep = man_hasc(man->last->string)) != NULL)) {
134 			*ep = '\0';
135 			return 1;
136 		}
137 		roff_elem_alloc(man, line, offs, ROFF_sp);
138 		man->next = ROFF_NEXT_SIBLING;
139 		return 1;
140 	}
141 
142 	/*
143 	 * Warn if the last un-escaped character is whitespace. Then
144 	 * strip away the remaining spaces (tabs stay!).
145 	 */
146 
147 	i = (int)strlen(buf);
148 	assert(i);
149 
150 	if (' ' == buf[i - 1] || '\t' == buf[i - 1]) {
151 		if (i > 1 && '\\' != buf[i - 2])
152 			mandoc_msg(MANDOCERR_SPACE_EOL, line, i - 1, NULL);
153 
154 		for (--i; i && ' ' == buf[i]; i--)
155 			/* Spin back to non-space. */ ;
156 
157 		/* Jump ahead of escaped whitespace. */
158 		i += '\\' == buf[i] ? 2 : 1;
159 
160 		buf[i] = '\0';
161 	}
162 	roff_word_alloc(man, line, offs, buf + offs);
163 
164 	/*
165 	 * End-of-sentence check.  If the last character is an unescaped
166 	 * EOS character, then flag the node as being the end of a
167 	 * sentence.  The front-end will know how to interpret this.
168 	 */
169 
170 	assert(i);
171 	if (mandoc_eos(buf, (size_t)i))
172 		man->last->flags |= NODE_EOS;
173 
174 	man_descope(man, line, offs, buf + offs);
175 	return 1;
176 }
177 
178 static int
179 man_pmacro(struct roff_man *man, int ln, char *buf, int offs)
180 {
181 	struct roff_node *n;
182 	const char	*cp;
183 	size_t		 sz;
184 	enum roff_tok	 tok;
185 	int		 ppos;
186 	int		 bline;
187 
188 	/* Determine the line macro. */
189 
190 	ppos = offs;
191 	tok = TOKEN_NONE;
192 	for (sz = 0; sz < 4 && strchr(" \t\\", buf[offs]) == NULL; sz++)
193 		offs++;
194 	if (sz > 0 && sz < 4)
195 		tok = roffhash_find(man->manmac, buf + ppos, sz);
196 	if (tok == TOKEN_NONE) {
197 		mandoc_msg(MANDOCERR_MACRO, ln, ppos, "%s", buf + ppos - 1);
198 		return 1;
199 	}
200 
201 	/* Skip a leading escape sequence or tab. */
202 
203 	switch (buf[offs]) {
204 	case '\\':
205 		cp = buf + offs + 1;
206 		mandoc_escape(&cp, NULL, NULL);
207 		offs = cp - buf;
208 		break;
209 	case '\t':
210 		offs++;
211 		break;
212 	default:
213 		break;
214 	}
215 
216 	/* Jump to the next non-whitespace word. */
217 
218 	while (buf[offs] == ' ')
219 		offs++;
220 
221 	/*
222 	 * Trailing whitespace.  Note that tabs are allowed to be passed
223 	 * into the parser as "text", so we only warn about spaces here.
224 	 */
225 
226 	if (buf[offs] == '\0' && buf[offs - 1] == ' ')
227 		mandoc_msg(MANDOCERR_SPACE_EOL, ln, offs - 1, NULL);
228 
229 	/*
230 	 * Some macros break next-line scopes; otherwise, remember
231 	 * whether we are in next-line scope for a block head.
232 	 */
233 
234 	man_breakscope(man, tok);
235 	bline = man->flags & MAN_BLINE;
236 
237 	/*
238 	 * If the line in next-line scope ends with \c, keep the
239 	 * next-line scope open for the subsequent input line.
240 	 * That is not at all portable, only groff >= 1.22.4
241 	 * does it, but *if* this weird idiom occurs in a manual
242 	 * page, that's very likely what the author intended.
243 	 */
244 
245 	if (bline && man_hasc(buf + offs))
246 		bline = 0;
247 
248 	/* Call to handler... */
249 
250 	(*man_macro(tok)->fp)(man, tok, ln, ppos, &offs, buf);
251 
252 	/* In quick mode (for mandocdb), abort after the NAME section. */
253 
254 	if (man->quick && tok == MAN_SH) {
255 		n = man->last;
256 		if (n->type == ROFFT_BODY &&
257 		    strcmp(n->prev->child->string, "NAME"))
258 			return 2;
259 	}
260 
261 	/*
262 	 * If we are in a next-line scope for a block head,
263 	 * close it out now and switch to the body,
264 	 * unless the next-line scope is allowed to continue.
265 	 */
266 
267 	if (bline == 0 ||
268 	    (man->flags & MAN_BLINE) == 0 ||
269 	    man->flags & MAN_ELINE ||
270 	    man_macro(tok)->flags & MAN_NSCOPED)
271 		return 1;
272 
273 	man_unscope(man, man->last->parent);
274 	roff_body_alloc(man, ln, ppos, man->last->tok);
275 	man->flags &= ~(MAN_BLINE | ROFF_NONOFILL);
276 	return 1;
277 }
278 
279 /*
280  * Rewind open next-line scopes
281  * unless the tok request or macro is allowed inside them.
282  */
283 void
284 man_breakscope(struct roff_man *man, int tok)
285 {
286 	struct roff_node *n;
287 
288 	/*
289 	 * An element next line scope is open,
290 	 * and the new macro is not allowed inside elements.
291 	 * Delete the element that is being broken.
292 	 */
293 
294 	if (man->flags & MAN_ELINE && (tok < MAN_TH ||
295 	    (man_macro(tok)->flags & MAN_NSCOPED) == 0)) {
296 		n = man->last;
297 		if (n->type == ROFFT_TEXT)
298 			n = n->parent;
299 		if (n->tok < MAN_TH ||
300 		    (man_macro(n->tok)->flags & (MAN_NSCOPED | MAN_ESCOPED))
301 		     == MAN_NSCOPED)
302 			n = n->parent;
303 		for (;;) {
304 			mandoc_msg(MANDOCERR_BLK_LINE, n->line, n->pos,
305 			    "%s breaks %s", roff_name[tok], roff_name[n->tok]);
306 			if (n->parent->type != ROFFT_ELEM ||
307 			    (man_macro(n->parent->tok)->flags &
308 			     MAN_ESCOPED) == 0)
309 				break;
310 			n = n->parent;
311 		}
312 		roff_node_delete(man, n);
313 		man->flags &= ~MAN_ELINE;
314 	}
315 
316 	/*
317 	 * Weird special case:
318 	 * Switching fill mode closes section headers.
319 	 */
320 
321 	if (man->flags & MAN_BLINE &&
322 	    (tok == ROFF_nf || tok == ROFF_fi) &&
323 	    (man->last->tok == MAN_SH || man->last->tok == MAN_SS)) {
324 		n = man->last;
325 		man_unscope(man, n);
326 		roff_body_alloc(man, n->line, n->pos, n->tok);
327 		man->flags &= ~(MAN_BLINE | ROFF_NONOFILL);
328 	}
329 
330 	/*
331 	 * A block header next line scope is open,
332 	 * and the new macro is not allowed inside block headers.
333 	 * Delete the block that is being broken.
334 	 */
335 
336 	if (man->flags & MAN_BLINE && tok != ROFF_nf && tok != ROFF_fi &&
337 	    (tok < MAN_TH || man_macro(tok)->flags & MAN_XSCOPE)) {
338 		n = man->last;
339 		if (n->type == ROFFT_TEXT)
340 			n = n->parent;
341 		if (n->tok < MAN_TH ||
342 		    (man_macro(n->tok)->flags & MAN_XSCOPE) == 0)
343 			n = n->parent;
344 
345 		assert(n->type == ROFFT_HEAD);
346 		n = n->parent;
347 		assert(n->type == ROFFT_BLOCK);
348 		assert(man_macro(n->tok)->flags & MAN_BSCOPED);
349 
350 		mandoc_msg(MANDOCERR_BLK_LINE, n->line, n->pos,
351 		    "%s breaks %s", roff_name[tok], roff_name[n->tok]);
352 
353 		roff_node_delete(man, n);
354 		man->flags &= ~(MAN_BLINE | ROFF_NONOFILL);
355 	}
356 }
357