Telescope Browser

Blame

Date:: Tue Jun 18 11:38:54 2024 UTC
Message:: code: add wrappers for common failure cases Certain calls to well-known functions sometimes result in similar error handling across the code base. Sometimes there's a need to centralise the failure case. Achieve this for common wrappers to often-used functions. The transformation is achieved via coccinelle, commited with this patch. Note that coccinelle can be told to ignore code blocks with comment delimiters. This transformation applies just to telescope's code, and not any of the bundled depdencies in telescope (libgrapheme).
Actions:: History | Blob | Raw File
  1 1ac119fb 2024-01-23 op /*
  2 1ac119fb 2024-01-23 op  * Copyright (c) 2021, 2022 Omar Polo <op@omarpolo.com>
  3 1ac119fb 2024-01-23 op  *
  4 1ac119fb 2024-01-23 op  * Permission to use, copy, modify, and distribute this software for any
  5 1ac119fb 2024-01-23 op  * purpose with or without fee is hereby granted, provided that the above
  6 1ac119fb 2024-01-23 op  * copyright notice and this permission notice appear in all copies.
  7 1ac119fb 2024-01-23 op  *
  8 1ac119fb 2024-01-23 op  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  9 1ac119fb 2024-01-23 op  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 10 1ac119fb 2024-01-23 op  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 11 1ac119fb 2024-01-23 op  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 12 1ac119fb 2024-01-23 op  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 13 1ac119fb 2024-01-23 op  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 14 1ac119fb 2024-01-23 op  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 15 1ac119fb 2024-01-23 op  */
 16 1ac119fb 2024-01-23 op 
 17 1ac119fb 2024-01-23 op /*
 18 1ac119fb 2024-01-23 op  * A streaming gemtext parser.
 19 1ac119fb 2024-01-23 op  *
 20 1ac119fb 2024-01-23 op  * TODO:
 21 1ac119fb 2024-01-23 op  *  - handle NULs
 22 1ac119fb 2024-01-23 op  *  - UTF8
 23 1ac119fb 2024-01-23 op  */
 24 1ac119fb 2024-01-23 op 
 25 1ac119fb 2024-01-23 op #include "compat.h"
 26 1ac119fb 2024-01-23 op 
 27 1ac119fb 2024-01-23 op #include <ctype.h>
 28 1ac119fb 2024-01-23 op #include <string.h>
 29 1ac119fb 2024-01-23 op #include <stdlib.h>
 30 1ac119fb 2024-01-23 op 
 31 1ac119fb 2024-01-23 op #include "defaults.h"
 32 1ac119fb 2024-01-23 op #include "parser.h"
 33 c1d27b0e 2024-06-14 op #include "telescope.h"
 34 1ac119fb 2024-01-23 op #include "utf8.h"
 35 3d89457c 2024-06-18 thomas.ad #include "xwrapper.h"
 36 1ac119fb 2024-01-23 op 
 37 c1d27b0e 2024-06-14 op static int	gemtext_parse_line(struct buffer *, const char *, size_t);
 38 c1d27b0e 2024-06-14 op static int	gemtext_free(struct buffer *);
 39 c1d27b0e 2024-06-14 op static int	gemtext_serialize(struct buffer *, FILE *);
 40 1ac119fb 2024-01-23 op 
 41 c1d27b0e 2024-06-14 op static int	parse_link(struct buffer *, const char*, size_t);
 42 c1d27b0e 2024-06-14 op static int	parse_title(struct buffer *, const char*, size_t);
 43 c1d27b0e 2024-06-14 op static void	search_title(struct buffer *, enum line_type);
 44 1ac119fb 2024-01-23 op 
 45 fd1c80ce 2024-06-14 op const struct parser gemtext_parser = {
 46 c1d27b0e 2024-06-14 op 	.name = "text/gemini",
 47 c1d27b0e 2024-06-14 op 	.parseline = &gemtext_parse_line,
 48 c1d27b0e 2024-06-14 op 	.free = &gemtext_free,
 49 c1d27b0e 2024-06-14 op 	.serialize = &gemtext_serialize,
 50 c1d27b0e 2024-06-14 op };
 51 1ac119fb 2024-01-23 op 
 52 1ac119fb 2024-01-23 op static inline int
 53 c1d27b0e 2024-06-14 op emit_line(struct buffer *b, enum line_type type, char *line, char *alt)
 54 1ac119fb 2024-01-23 op {
 55 1ac119fb 2024-01-23 op 	struct line *l;
 56 1ac119fb 2024-01-23 op 
 57 3d89457c 2024-06-18 thomas.ad 	l = xcalloc(1, sizeof(*l));
 58 1ac119fb 2024-01-23 op 
 59 1ac119fb 2024-01-23 op 	l->type = type;
 60 1ac119fb 2024-01-23 op 	l->line = line;
 61 1ac119fb 2024-01-23 op 	l->alt = alt;
 62 1ac119fb 2024-01-23 op 
 63 1ac119fb 2024-01-23 op 	switch (l->type) {
 64 1ac119fb 2024-01-23 op 	case LINE_PRE_START:
 65 1ac119fb 2024-01-23 op 	case LINE_PRE_END:
 66 1ac119fb 2024-01-23 op 		if (hide_pre_context)
 67 1ac119fb 2024-01-23 op 			l->flags = L_HIDDEN;
 68 1ac119fb 2024-01-23 op 		if (l->type == LINE_PRE_END &&
 69 1ac119fb 2024-01-23 op 		    hide_pre_closing_line)
 70 1ac119fb 2024-01-23 op 			l->flags = L_HIDDEN;
 71 1ac119fb 2024-01-23 op 		break;
 72 1ac119fb 2024-01-23 op 	case LINE_PRE_CONTENT:
 73 1ac119fb 2024-01-23 op 		if (hide_pre_blocks)
 74 1ac119fb 2024-01-23 op 			l->flags = L_HIDDEN;
 75 1ac119fb 2024-01-23 op 		break;
 76 1ac119fb 2024-01-23 op 	case LINE_LINK:
 77 1ac119fb 2024-01-23 op 		if (emojify_link &&
 78 1ac119fb 2024-01-23 op 		    !emojied_line(line, (const char **)&l->data))
 79 1ac119fb 2024-01-23 op 			l->data = NULL;
 80 1ac119fb 2024-01-23 op 		break;
 81 1ac119fb 2024-01-23 op 	default:
 82 1ac119fb 2024-01-23 op 		break;
 83 1ac119fb 2024-01-23 op 	}
 84 1ac119fb 2024-01-23 op 
 85 f350bc73 2024-05-27 thomas.ad 	if (dont_apply_styling)
 86 f350bc73 2024-05-27 thomas.ad 		l->flags &= ~L_HIDDEN;
 87 f350bc73 2024-05-27 thomas.ad 
 88 c1d27b0e 2024-06-14 op 	TAILQ_INSERT_TAIL(&b->head, l, lines);
 89 1ac119fb 2024-01-23 op 
 90 1ac119fb 2024-01-23 op 	return 1;
 91 1ac119fb 2024-01-23 op }
 92 1ac119fb 2024-01-23 op 
 93 1ac119fb 2024-01-23 op static int
 94 c1d27b0e 2024-06-14 op parse_link(struct buffer *b, const char *line, size_t len)
 95 1ac119fb 2024-01-23 op {
 96 32c44488 2024-06-05 op 	char *label, *url;
 97 32c44488 2024-06-05 op 	const char *start;
 98 1ac119fb 2024-01-23 op 
 99 1ac119fb 2024-01-23 op 	if (len <= 2)
100 c1d27b0e 2024-06-14 op 		return emit_line(b, LINE_TEXT, NULL, NULL);
101 1ac119fb 2024-01-23 op 
102 32c44488 2024-06-05 op 	line += 2, len -= 2;
103 32c44488 2024-06-05 op 	while (len > 0 && isspace((unsigned char)line[0]))
104 32c44488 2024-06-05 op 		line++, len--;
105 1ac119fb 2024-01-23 op 
106 1ac119fb 2024-01-23 op 	if (len == 0)
107 c1d27b0e 2024-06-14 op 		return emit_line(b, LINE_TEXT, NULL, NULL);
108 1ac119fb 2024-01-23 op 
109 32c44488 2024-06-05 op 	start = line;
110 32c44488 2024-06-05 op 	while (len > 0 && !isspace((unsigned char)line[0]))
111 32c44488 2024-06-05 op 		line++, len--;
112 1ac119fb 2024-01-23 op 
113 3d89457c 2024-06-18 thomas.ad 	url = xstrndup(start, line - start);
114 1ac119fb 2024-01-23 op 
115 32c44488 2024-06-05 op 	while (len > 0 && isspace(line[0]))
116 32c44488 2024-06-05 op 		line++, len--;
117 1ac119fb 2024-01-23 op 
118 32c44488 2024-06-05 op 	if (len == 0) {
119 3d89457c 2024-06-18 thomas.ad 		label = xstrdup(url);
120 32c44488 2024-06-05 op 	} else {
121 3d89457c 2024-06-18 thomas.ad 		label = xstrndup(line, len);
122 1ac119fb 2024-01-23 op 	}
123 1ac119fb 2024-01-23 op 
124 c1d27b0e 2024-06-14 op 	return emit_line(b, LINE_LINK, label, url);
125 1ac119fb 2024-01-23 op }
126 1ac119fb 2024-01-23 op 
127 1ac119fb 2024-01-23 op static int
128 c1d27b0e 2024-06-14 op parse_title(struct buffer *b, const char *line, size_t len)
129 1ac119fb 2024-01-23 op {
130 32c44488 2024-06-05 op 	enum line_type t = LINE_TITLE_1;
131 1ac119fb 2024-01-23 op 	char *l;
132 1ac119fb 2024-01-23 op 
133 dfc5d927 2024-06-05 op 	line++, len--;
134 32c44488 2024-06-05 op 	while (len > 0 && *line == '#') {
135 32c44488 2024-06-05 op 		line++, len--;
136 32c44488 2024-06-05 op 		t++;
137 32c44488 2024-06-05 op 		if (t == LINE_TITLE_3)
138 32c44488 2024-06-05 op 			break;
139 1ac119fb 2024-01-23 op 	}
140 1ac119fb 2024-01-23 op 
141 32c44488 2024-06-05 op 	while (len > 0 && isspace((unsigned char)*line))
142 32c44488 2024-06-05 op 		line++, len--;
143 1ac119fb 2024-01-23 op 
144 1ac119fb 2024-01-23 op 	if (len == 0)
145 c1d27b0e 2024-06-14 op 		return emit_line(b, t, NULL, NULL);
146 1ac119fb 2024-01-23 op 
147 c1d27b0e 2024-06-14 op 	if (t == LINE_TITLE_1 && *b->title == '\0')
148 c1d27b0e 2024-06-14 op 		strncpy(b->title, line, MIN(sizeof(b->title)-1, len));
149 1ac119fb 2024-01-23 op 
150 3d89457c 2024-06-18 thomas.ad 	l = xstrndup(line, len);
151 c1d27b0e 2024-06-14 op 	return emit_line(b, t, l, NULL);
152 1ac119fb 2024-01-23 op }
153 1ac119fb 2024-01-23 op 
154 1ac119fb 2024-01-23 op static int
155 c1d27b0e 2024-06-14 op gemtext_parse_line(struct buffer *b, const char *line, size_t len)
156 1ac119fb 2024-01-23 op {
157 1ac119fb 2024-01-23 op 	char *l;
158 1ac119fb 2024-01-23 op 
159 c1d27b0e 2024-06-14 op 	if (b->parser_flags & PARSER_IN_PRE) {
160 32c44488 2024-06-05 op 		if (len >= 3 && !strncmp(line, "```", 3)) {
161 c1d27b0e 2024-06-14 op 			b->parser_flags ^= PARSER_IN_PRE;
162 c1d27b0e 2024-06-14 op 			return emit_line(b, LINE_PRE_END, NULL, NULL);
163 32c44488 2024-06-05 op 		}
164 1ac119fb 2024-01-23 op 
165 32c44488 2024-06-05 op 		if (len == 0)
166 c1d27b0e 2024-06-14 op 			return emit_line(b, LINE_PRE_CONTENT, NULL, NULL);
167 3d89457c 2024-06-18 thomas.ad 		l = xstrndup(line, len);
168 c1d27b0e 2024-06-14 op 		return emit_line(b, LINE_PRE_CONTENT, l, NULL);
169 1ac119fb 2024-01-23 op 	}
170 1ac119fb 2024-01-23 op 
171 1ac119fb 2024-01-23 op 	if (len == 0)
172 c1d27b0e 2024-06-14 op 		return emit_line(b, LINE_TEXT, NULL, NULL);
173 1ac119fb 2024-01-23 op 
174 32c44488 2024-06-05 op 	switch (*line) {
175 32c44488 2024-06-05 op 	case '*':
176 32c44488 2024-06-05 op 		if (len < 1 || line[1] != ' ')
177 32c44488 2024-06-05 op 			break;
178 1ac119fb 2024-01-23 op 
179 32c44488 2024-06-05 op 		line += 2, len -= 2;
180 32c44488 2024-06-05 op 		while (len > 0 && isspace((unsigned char)*line))
181 32c44488 2024-06-05 op 			line++, len--;
182 32c44488 2024-06-05 op 		if (len == 0)
183 c1d27b0e 2024-06-14 op 			return emit_line(b, LINE_ITEM, NULL, NULL);
184 3d89457c 2024-06-18 thomas.ad 		l = xstrndup(line, len);
185 c1d27b0e 2024-06-14 op 		return emit_line(b, LINE_ITEM, l, NULL);
186 1ac119fb 2024-01-23 op 
187 32c44488 2024-06-05 op 	case '>':
188 32c44488 2024-06-05 op 		line++, len--;
189 32c44488 2024-06-05 op 		while (len > 0 && isspace((unsigned char)*line))
190 32c44488 2024-06-05 op 			line++, len--;
191 32c44488 2024-06-05 op 		if (len == 0)
192 c1d27b0e 2024-06-14 op 			return emit_line(b, LINE_QUOTE, NULL, NULL);
193 3d89457c 2024-06-18 thomas.ad 		l = xstrndup(line, len);
194 c1d27b0e 2024-06-14 op 		return emit_line(b, LINE_QUOTE, l, NULL);
195 1ac119fb 2024-01-23 op 
196 32c44488 2024-06-05 op 	case '=':
197 32c44488 2024-06-05 op 		if (len > 1 && line[1] == '>')
198 c1d27b0e 2024-06-14 op 			return parse_link(b, line, len);
199 32c44488 2024-06-05 op 		break;
200 1ac119fb 2024-01-23 op 
201 32c44488 2024-06-05 op 	case '#':
202 c1d27b0e 2024-06-14 op 		return parse_title(b, line, len);
203 1ac119fb 2024-01-23 op 
204 32c44488 2024-06-05 op 	case '`':
205 32c44488 2024-06-05 op 		if (len < 3 || strncmp(line, "```", 3) != 0)
206 32c44488 2024-06-05 op 			break;
207 1ac119fb 2024-01-23 op 
208 c1d27b0e 2024-06-14 op 		b->parser_flags |= PARSER_IN_PRE;
209 32c44488 2024-06-05 op 		line += 3, len -= 3;
210 32c44488 2024-06-05 op 		while (len > 0 && isspace((unsigned char)*line))
211 32c44488 2024-06-05 op 			line++, len--;
212 32c44488 2024-06-05 op 		if (len == 0)
213 c1d27b0e 2024-06-14 op 			return emit_line(b, LINE_PRE_START,
214 32c44488 2024-06-05 op 			    NULL, NULL);
215 3d89457c 2024-06-18 thomas.ad 		l = xstrndup(line, len);
216 c1d27b0e 2024-06-14 op 		return emit_line(b, LINE_PRE_START, l, NULL);
217 1ac119fb 2024-01-23 op 	}
218 1ac119fb 2024-01-23 op 
219 3d89457c 2024-06-18 thomas.ad 	l = xstrndup(line, len);
220 c1d27b0e 2024-06-14 op 	return emit_line(b, LINE_TEXT, l, NULL);
221 1ac119fb 2024-01-23 op }
222 1ac119fb 2024-01-23 op 
223 1ac119fb 2024-01-23 op static int
224 c1d27b0e 2024-06-14 op gemtext_free(struct buffer *b)
225 1ac119fb 2024-01-23 op {
226 1ac119fb 2024-01-23 op 	/* flush the buffer */
227 c1d27b0e 2024-06-14 op 	if (b->len != 0) {
228 c1d27b0e 2024-06-14 op 		if (!gemtext_parse_line(b, b->buf, b->len))
229 1ac119fb 2024-01-23 op 			return 0;
230 c1d27b0e 2024-06-14 op 		if ((b->parser_flags & PARSER_IN_PRE) &&
231 c1d27b0e 2024-06-14 op 		    !emit_line(b, LINE_PRE_END, NULL, NULL))
232 1ac119fb 2024-01-23 op 			return 0;
233 1ac119fb 2024-01-23 op 	}
234 1ac119fb 2024-01-23 op 
235 1ac119fb 2024-01-23 op 	/*
236 1ac119fb 2024-01-23 op 	 * use the first level 2 or 3 header as page title if none
237 1ac119fb 2024-01-23 op 	 * found yet.
238 1ac119fb 2024-01-23 op 	 */
239 c1d27b0e 2024-06-14 op 	if (*b->title == '\0')
240 c1d27b0e 2024-06-14 op 		search_title(b, LINE_TITLE_2);
241 c1d27b0e 2024-06-14 op 	if (*b->title == '\0')
242 c1d27b0e 2024-06-14 op 		search_title(b, LINE_TITLE_3);
243 1ac119fb 2024-01-23 op 
244 1ac119fb 2024-01-23 op 	return 1;
245 1ac119fb 2024-01-23 op }
246 1ac119fb 2024-01-23 op 
247 1ac119fb 2024-01-23 op static void
248 c1d27b0e 2024-06-14 op search_title(struct buffer *b, enum line_type level)
249 1ac119fb 2024-01-23 op {
250 1ac119fb 2024-01-23 op 	struct line *l;
251 1ac119fb 2024-01-23 op 
252 c1d27b0e 2024-06-14 op 	TAILQ_FOREACH(l, &b->head, lines) {
253 1ac119fb 2024-01-23 op 		if (l->type == level) {
254 1ac119fb 2024-01-23 op 			if (l->line == NULL)
255 1ac119fb 2024-01-23 op 				continue;
256 c1d27b0e 2024-06-14 op 			strlcpy(b->title, l->line, sizeof(b->title));
257 1ac119fb 2024-01-23 op 			break;
258 1ac119fb 2024-01-23 op 		}
259 1ac119fb 2024-01-23 op 	}
260 1ac119fb 2024-01-23 op }
261 1ac119fb 2024-01-23 op 
262 1ac119fb 2024-01-23 op static const char *gemtext_prefixes[] = {
263 1ac119fb 2024-01-23 op 	[LINE_TEXT] = "",
264 1ac119fb 2024-01-23 op 	[LINE_TITLE_1] = "# ",
265 1ac119fb 2024-01-23 op 	[LINE_TITLE_2] = "## ",
266 1ac119fb 2024-01-23 op 	[LINE_TITLE_3] = "### ",
267 1ac119fb 2024-01-23 op 	[LINE_ITEM] = "* ",
268 1ac119fb 2024-01-23 op 	[LINE_QUOTE] = "> ",
269 1ac119fb 2024-01-23 op 	[LINE_PRE_START] = "``` ",
270 1ac119fb 2024-01-23 op 	[LINE_PRE_CONTENT] = "",
271 1ac119fb 2024-01-23 op 	[LINE_PRE_END] = "```",
272 1ac119fb 2024-01-23 op };
273 1ac119fb 2024-01-23 op 
274 1ac119fb 2024-01-23 op static int
275 c1d27b0e 2024-06-14 op gemtext_serialize(struct buffer *b, FILE *fp)
276 1ac119fb 2024-01-23 op {
277 1ac119fb 2024-01-23 op 	struct line	*line;
278 1ac119fb 2024-01-23 op 	const char	*text;
279 1ac119fb 2024-01-23 op 	const char	*alt;
280 1ac119fb 2024-01-23 op 	int		 r;
281 1ac119fb 2024-01-23 op 
282 c1d27b0e 2024-06-14 op 	TAILQ_FOREACH(line, &b->head, lines) {
283 1ac119fb 2024-01-23 op 		if ((text = line->line) == NULL)
284 1ac119fb 2024-01-23 op 			text = "";
285 1ac119fb 2024-01-23 op 
286 1ac119fb 2024-01-23 op 		if ((alt = line->alt) == NULL)
287 1ac119fb 2024-01-23 op 			alt = "";
288 1ac119fb 2024-01-23 op 
289 1ac119fb 2024-01-23 op 		switch (line->type) {
290 1ac119fb 2024-01-23 op 		case LINE_TEXT:
291 1ac119fb 2024-01-23 op 		case LINE_TITLE_1:
292 1ac119fb 2024-01-23 op 		case LINE_TITLE_2:
293 1ac119fb 2024-01-23 op 		case LINE_TITLE_3:
294 1ac119fb 2024-01-23 op 		case LINE_ITEM:
295 1ac119fb 2024-01-23 op 		case LINE_QUOTE:
296 1ac119fb 2024-01-23 op 		case LINE_PRE_START:
297 1ac119fb 2024-01-23 op 		case LINE_PRE_CONTENT:
298 1ac119fb 2024-01-23 op 		case LINE_PRE_END:
299 1ac119fb 2024-01-23 op 			r = fprintf(fp, "%s%s\n", gemtext_prefixes[line->type],
300 1ac119fb 2024-01-23 op 			    text);
301 1ac119fb 2024-01-23 op 			break;
302 1ac119fb 2024-01-23 op 
303 1ac119fb 2024-01-23 op 		case LINE_LINK:
304 1ac119fb 2024-01-23 op 			r = fprintf(fp, "=> %s %s\n", alt, text);
305 1ac119fb 2024-01-23 op 			break;
306 1ac119fb 2024-01-23 op 
307 1ac119fb 2024-01-23 op 		default:
308 1ac119fb 2024-01-23 op 			/* not reached */
309 1ac119fb 2024-01-23 op 			abort();
310 1ac119fb 2024-01-23 op 		}
311 1ac119fb 2024-01-23 op 
312 1ac119fb 2024-01-23 op 		if (r == -1)
313 1ac119fb 2024-01-23 op 			return 0;
314 1ac119fb 2024-01-23 op 	}
315 1ac119fb 2024-01-23 op 
316 1ac119fb 2024-01-23 op 	return 1;
317 1ac119fb 2024-01-23 op }