GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/lex/filter.c Lines: 130 179 72.6 %
Date: 2016-12-06 Branches: 72 126 57.1 %

Line Branch Exec Source
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/* $OpenBSD: filter.c,v 1.6 2015/11/19 23:28:03 tedu Exp $ */
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3
/* filter - postprocessing of flex output through filters */
4
5
/*  This file is part of flex. */
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7
/*  Redistribution and use in source and binary forms, with or without */
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/*  modification, are permitted provided that the following conditions */
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/*  are met: */
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/*  1. Redistributions of source code must retain the above copyright */
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/*     notice, this list of conditions and the following disclaimer. */
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/*  2. Redistributions in binary form must reproduce the above copyright */
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/*     notice, this list of conditions and the following disclaimer in the */
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/*     documentation and/or other materials provided with the distribution. */
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/*  Neither the name of the University nor the names of its contributors */
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/*  may be used to endorse or promote products derived from this software */
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/*  without specific prior written permission. */
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/*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
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/*  IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
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/*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
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/*  PURPOSE. */
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#include "flexdef.h"
27
static const char *check_4_gnu_m4 =
28
"m4_dnl ifdef(`__gnu__', ,"
29
"`errprint(Flex requires GNU M4. Set the PATH or set the M4 environment variable to its path name.)"
30
" m4exit(2)')\n";
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32
33
/** global chain. */
34
struct filter *output_chain = NULL;
35
36
/* Allocate and initialize an external filter.
37
 * @param chain the current chain or NULL for new chain
38
 * @param cmd the command to execute.
39
 * @param ... a NULL terminated list of (const char*) arguments to command,
40
 *            not including argv[0].
41
 * @return newest filter in chain
42
 */
43
struct filter *
44
filter_create_ext(struct filter * chain, const char *cmd,
45
    ...)
46
5
{
47
	struct filter *f;
48
	int max_args;
49
	const char *s;
50
	va_list ap;
51
52
	/* allocate and initialize new filter */
53
5
	f = malloc(sizeof(struct filter));
54
5
	if (!f)
55
		flexerror(_("malloc failed (f) in filter_create_ext"));
56
5
	memset(f, 0, sizeof(*f));
57
5
	f->filter_func = NULL;
58
5
	f->extra = NULL;
59
5
	f->next = NULL;
60
5
	f->argc = 0;
61
62
5
	if (chain != NULL) {
63
		/* append f to end of chain */
64
5
		while (chain->next)
65
			chain = chain->next;
66
5
		chain->next = f;
67
	}
68
	/* allocate argv, and populate it with the argument list. */
69
5
	max_args = 8;
70
5
	f->argv = malloc(sizeof(char *) * (max_args + 1));
71
5
	if (!f->argv)
72
		flexerror(_("malloc failed (f->argv) in filter_create_ext"));
73
5
	f->argv[f->argc++] = cmd;
74
75
5
	va_start(ap, cmd);
76

15
	while ((s = va_arg(ap, const char *)) != NULL) {
77
5
		if (f->argc >= max_args) {
78
			max_args += 8;
79
			f->argv = realloc(f->argv,
80
			    sizeof(char *) * (max_args + 1));
81
		}
82
5
		f->argv[f->argc++] = s;
83
	}
84
5
	f->argv[f->argc] = NULL;
85
86
5
	va_end(ap);
87
5
	return f;
88
}
89
90
/* Allocate and initialize an internal filter.
91
 * @param chain the current chain or NULL for new chain
92
 * @param filter_func The function that will perform the filtering.
93
 *        filter_func should return 0 if successful, and -1
94
 *        if an error occurs -- or it can simply exit().
95
 * @param extra optional user-defined data to pass to the filter.
96
 * @return newest filter in chain
97
 */
98
struct filter *
99
filter_create_int(struct filter * chain,
100
    int (*filter_func) (struct filter *),
101
    void *extra)
102
10
{
103
	struct filter *f;
104
105
	/* allocate and initialize new filter */
106
10
	f = malloc(sizeof(struct filter));
107
10
	if (!f)
108
		flexerror(_("malloc failed in filter_create_int"));
109
10
	memset(f, 0, sizeof(*f));
110
10
	f->next = NULL;
111
10
	f->argc = 0;
112
10
	f->argv = NULL;
113
114
10
	f->filter_func = filter_func;
115
10
	f->extra = extra;
116
117
10
	if (chain != NULL) {
118
		/* append f to end of chain */
119
10
		while (chain->next)
120
5
			chain = chain->next;
121
5
		chain->next = f;
122
	}
123
10
	return f;
124
}
125
126
/** Fork and exec entire filter chain.
127
 *  @param chain The head of the chain.
128
 *  @return true on success.
129
 */
130
bool
131
filter_apply_chain(struct filter * chain)
132
20
{
133
	int pid, pipes[2];
134
	int r;
135
20
	const int readsz = 512;
136
	char *buf;
137
138
139
	/*
140
	 * Tricky recursion, since we want to begin the chain at the END.
141
	 * Why? Because we need all the forked processes to be children of
142
	 * the main flex process.
143
	 */
144
20
	if (chain)
145
15
		filter_apply_chain(chain->next);
146
	else
147
5
		return true;
148
149
	/*
150
	 * Now we are the right-most unprocessed link in the chain.
151
	 */
152
153
15
	fflush(stdout);
154
15
	fflush(stderr);
155
156
157
15
	if (pipe(pipes) == -1)
158
		flexerror(_("pipe failed"));
159
160
15
	if ((pid = fork()) == -1)
161
		flexerror(_("fork failed"));
162
163
30
	if (pid == 0) {
164
		/* child */
165
166
		/*
167
		 * We need stdin (the FILE* stdin) to connect to this new
168
		 * pipe. There is no portable way to set stdin to a new file
169
		 * descriptor, as stdin is not an lvalue on some systems
170
		 * (BSD). So we dup the new pipe onto the stdin descriptor
171
		 * and use a no-op fseek to sync the stream. This is a Hail
172
		 * Mary situation. It seems to work.
173
		 */
174
15
		close(pipes[1]);
175
15
		clearerr(stdin);
176

15
		if (dup2(pipes[0], fileno(stdin)) == -1)
177
			flexfatal(_("dup2(pipes[0],0)"));
178
15
		close(pipes[0]);
179
15
		fseek(stdin, 0, SEEK_CUR);
180
181
		/* run as a filter, either internally or by exec */
182
15
		if (chain->filter_func) {
183
			int r;
184
185
10
			if ((r = chain->filter_func(chain)) == -1)
186
				flexfatal(_("filter_func failed"));
187
5
			exit(0);
188
		} else {
189
5
			execvp(chain->argv[0],
190
			    (char **const) (chain->argv));
191
			lerrsf_fatal(_("exec of %s failed"),
192
			    chain->argv[0]);
193
		}
194
195
		exit(1);
196
	}
197
	/* Parent */
198
15
	close(pipes[0]);
199

15
	if (dup2(pipes[1], fileno(stdout)) == -1)
200
		flexfatal(_("dup2(pipes[1],1)"));
201
15
	close(pipes[1]);
202
15
	fseek(stdout, 0, SEEK_CUR);
203
204
15
	return true;
205
}
206
207
/** Truncate the chain to max_len number of filters.
208
 * @param chain the current chain.
209
 * @param max_len the maximum length of the chain.
210
 * @return the resulting length of the chain.
211
 */
212
int
213
filter_truncate(struct filter * chain, int max_len)
214
5
{
215
5
	int len = 1;
216
217
5
	if (!chain)
218
		return 0;
219
220
15
	while (chain->next && len < max_len) {
221
10
		chain = chain->next;
222
10
		++len;
223
	}
224
225
5
	chain->next = NULL;
226
5
	return len;
227
}
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229
/** Splits the chain in order to write to a header file.
230
 *  Similar in spirit to the 'tee' program.
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 *  The header file name is in extra.
232
 *  @return 0 (zero) on success, and -1 on failure.
233
 */
234
int
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filter_tee_header(struct filter * chain)
236
5
{
237
	/*
238
	 * This function reads from stdin and writes to both the C file and
239
	 * the header file at the same time.
240
	 */
241
242
5
	const int readsz = 512;
243
	char *buf;
244
5
	int to_cfd = -1;
245
5
	FILE *to_c = NULL, *to_h = NULL;
246
	bool write_header;
247
248
5
	write_header = (chain->extra != NULL);
249
250
	/*
251
	 * Store a copy of the stdout pipe, which is already piped to C file
252
	 * through the running chain. Then create a new pipe to the H file as
253
	 * stdout, and fork the rest of the chain again.
254
	 */
255
256
5
	if ((to_cfd = dup(1)) == -1)
257
		flexfatal(_("dup(1) failed"));
258
5
	to_c = fdopen(to_cfd, "w");
259
260
5
	if (write_header) {
261
		if (freopen((char *) chain->extra, "w", stdout) == NULL)
262
			flexfatal(_("freopen(headerfilename) failed"));
263
264
		filter_apply_chain(chain->next);
265
		to_h = stdout;
266
	}
267
	/*
268
	 * Now to_c is a pipe to the C branch, and to_h is a pipe to the H
269
	 * branch.
270
	 */
271
272
5
	if (write_header) {
273
		fputs(check_4_gnu_m4, to_h);
274
		fputs("m4_changecom`'m4_dnl\n", to_h);
275
		fputs("m4_changequote`'m4_dnl\n", to_h);
276
		fputs("m4_changequote([[,]])[[]]m4_dnl\n", to_h);
277
		fputs("m4_define([[M4_YY_NOOP]])[[]]m4_dnl\n", to_h);
278
		fputs("m4_define( [[M4_YY_IN_HEADER]],[[]])m4_dnl\n",
279
		    to_h);
280
		fprintf(to_h, "#ifndef %sHEADER_H\n", prefix);
281
		fprintf(to_h, "#define %sHEADER_H 1\n", prefix);
282
		fprintf(to_h, "#define %sIN_HEADER 1\n\n", prefix);
283
		fprintf(to_h,
284
		    "m4_define( [[M4_YY_OUTFILE_NAME]],[[%s]])m4_dnl\n",
285
		    headerfilename ? headerfilename : "<stdout>");
286
287
	}
288
5
	fputs(check_4_gnu_m4, to_c);
289
5
	fputs("m4_changecom`'m4_dnl\n", to_c);
290
5
	fputs("m4_changequote`'m4_dnl\n", to_c);
291
5
	fputs("m4_changequote([[,]])[[]]m4_dnl\n", to_c);
292
5
	fputs("m4_define([[M4_YY_NOOP]])[[]]m4_dnl\n", to_c);
293
5
	fprintf(to_c, "m4_define( [[M4_YY_OUTFILE_NAME]],[[%s]])m4_dnl\n",
294
	    outfilename ? outfilename : "<stdout>");
295
296
5
	buf = malloc(readsz);
297
5
	if (!buf)
298
		flexerror(_("malloc failed in filter_tee_header"));
299
15509
	while (fgets(buf, readsz, stdin)) {
300
15504
		fputs(buf, to_c);
301
15504
		if (write_header)
302
			fputs(buf, to_h);
303
	}
304
305
5
	if (write_header) {
306
		fprintf(to_h, "\n");
307
308
		/*
309
		 * write a fake line number. It will get fixed by the linedir
310
		 * filter.
311
		 */
312
		fprintf(to_h, "#line 4000 \"M4_YY_OUTFILE_NAME\"\n");
313
314
		fprintf(to_h, "#undef %sIN_HEADER\n", prefix);
315
		fprintf(to_h, "#endif /* %sHEADER_H */\n", prefix);
316
		fputs("m4_undefine( [[M4_YY_IN_HEADER]])m4_dnl\n", to_h);
317
318
		fflush(to_h);
319
		if (ferror(to_h))
320
			lerrsf(_("error writing output file %s"),
321
			    (char *) chain->extra);
322
323
		else if (fclose(to_h))
324
			lerrsf(_("error closing output file %s"),
325
			    (char *) chain->extra);
326
	}
327
5
	fflush(to_c);
328

5
	if (ferror(to_c))
329
		lerrsf(_("error writing output file %s"),
330
		    outfilename ? outfilename : "<stdout>");
331
332
5
	else if (fclose(to_c))
333
		lerrsf(_("error closing output file %s"),
334
		    outfilename ? outfilename : "<stdout>");
335
336
5
	while (wait(0) > 0);
337
338
5
	exit(0);
339
	return 0;
340
}
341
342
/** Adjust the line numbers in the #line directives of the generated scanner.
343
 * After the m4 expansion, the line numbers are incorrect since the m4 macros
344
 * can add or remove lines.  This only adjusts line numbers for generated code,
345
 * not user code. This also happens to be a good place to squeeze multiple
346
 * blank lines into a single blank line.
347
 */
348
int
349
filter_fix_linedirs(struct filter * chain)
350
5
{
351
	char *buf;
352
5
	const int readsz = 512;
353
5
	int lineno = 1;
354
5
	bool in_gen = true;	/* in generated code */
355
5
	bool last_was_blank = false;
356
357
5
	if (!chain)
358
		return 0;
359
360
5
	buf = malloc(readsz);
361
5
	if (!buf)
362
		flexerror(_("malloc failed in filter_fix_linedirs"));
363
364
13151
	while (fgets(buf, readsz, stdin)) {
365
366
		regmatch_t m[10];
367
368
		/* Check for #line directive. */
369

13368
		if (buf[0] == '#'
370
		    && regexec(&regex_linedir, buf, 3, m, 0) == 0) {
371
372
			int num;
373
			char *fname;
374
375
			/* extract the line number and filename */
376
222
			num = regmatch_strtol(&m[1], buf, NULL, 0);
377
222
			fname = regmatch_dup(&m[2], buf);
378
379


242
			if (strcmp(fname,
380
				outfilename ? outfilename : "<stdout>") == 0 ||
381
			    strcmp(fname, headerfilename ? headerfilename :
382
				"<stdout>") == 0) {
383
384
				char *s1, *s2;
385
				char filename[MAXLINE];
386
387
20
				s1 = fname;
388
20
				s2 = filename;
389
390

200
				while ((s2 - filename) < (MAXLINE - 1) && *s1) {
391
					/* Escape the backslash */
392
160
					if (*s1 == '\\')
393
						*s2++ = '\\';
394
					/* Escape the double quote */
395
160
					if (*s1 == '\"')
396
						*s2++ = '\\';
397
					/* Copy the character as usual */
398
160
					*s2++ = *s1++;
399
				}
400
401
20
				*s2 = '\0';
402
403
				/* Adjust the line directives. */
404
20
				in_gen = true;
405
20
				snprintf(buf, readsz, "#line %d \"%s\"\n",
406
				    lineno + 1, filename);
407
			} else {
408
				/*
409
				 * it's a #line directive for code we didn't
410
				 * write
411
				 */
412
202
				in_gen = false;
413
			}
414
415
222
			free(fname);
416
222
			last_was_blank = false;
417
		}
418
		/* squeeze blank lines from generated code */
419

14642
		else if (in_gen &&
420
		    regexec(&regex_blank_line, buf, 0, NULL, 0) == 0) {
421
3622
			if (last_was_blank)
422
1904
				continue;
423
			else
424
1718
				last_was_blank = true;
425
		} else {
426
			/* it's a line of normal, non-empty code. */
427
9302
			last_was_blank = false;
428
		}
429
430
11242
		fputs(buf, stdout);
431
11242
		lineno++;
432
	}
433
5
	fflush(stdout);
434

5
	if (ferror(stdout))
435
		lerrsf(_("error writing output file %s"),
436
		    outfilename ? outfilename : "<stdout>");
437
438
5
	else if (fclose(stdout))
439
		lerrsf(_("error closing output file %s"),
440
		    outfilename ? outfilename : "<stdout>");
441
442
5
	return 0;
443
}