Bug Summary

File:src/lib/libedit/read.c
Warning:line 166, column 8
Although the value stored to 'num' is used in the enclosing expression, the value is never actually read from 'num'

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name read.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/lib/libedit/obj -resource-dir /usr/local/lib/clang/13.0.0 -I . -I /usr/src/lib/libedit -I . -I /usr/src/lib/libedit -D PIC -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/lib/libedit/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/lib/libedit/read.c
1/* $OpenBSD: read.c,v 1.49 2021/08/13 10:21:25 schwarze Exp $ */
2/* $NetBSD: read.c,v 1.100 2016/05/24 19:31:27 christos Exp $ */
3
4/*-
5 * Copyright (c) 1992, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Christos Zoulas of Cornell University.
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. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include "config.h"
37
38/*
39 * read.c: Clean this junk up! This is horrible code.
40 * Terminal read functions
41 */
42#include <sys/ioctl.h>
43
44#include <ctype.h>
45#include <errno(*__errno()).h>
46#include <limits.h>
47#include <stdlib.h>
48#include <string.h>
49#include <unistd.h>
50
51#include "el.h"
52#include "fcns.h"
53#include "read.h"
54
55#define EL_MAXMACRO10 10
56
57struct macros {
58 wchar_t **macro;
59 int level;
60 int offset;
61};
62
63struct el_read_t {
64 struct macros macros;
65 el_rfunc_t read_char; /* Function to read a character. */
66 int read_errno;
67};
68
69static int read_char(EditLine *, wchar_t *);
70static int read_getcmd(EditLine *, el_action_t *, wchar_t *);
71static void read_clearmacros(struct macros *);
72static void read_pop(struct macros *);
73
74/* read_init():
75 * Initialize the read stuff
76 */
77protected__attribute__((__visibility__("hidden"))) int
78read_init(EditLine *el)
79{
80 struct macros *ma;
81
82 if ((el->el_read = malloc(sizeof(*el->el_read))) == NULL((void *)0))
83 return -1;
84
85 ma = &el->el_read->macros;
86 if ((ma->macro = reallocarray(NULL((void *)0), EL_MAXMACRO10,
87 sizeof(*ma->macro))) == NULL((void *)0)) {
88 free(el->el_read);
89 return -1;
90 }
91 ma->level = -1;
92 ma->offset = 0;
93
94 /* builtin read_char */
95 el->el_read->read_char = read_char;
96 return 0;
97}
98
99/* el_read_end():
100 * Free the data structures used by the read stuff.
101 */
102protected__attribute__((__visibility__("hidden"))) void
103read_end(struct el_read_t *el_read)
104{
105 read_clearmacros(&el_read->macros);
106 free(el_read->macros.macro);
107 el_read->macros.macro = NULL((void *)0);
108}
109
110/* el_read_setfn():
111 * Set the read char function to the one provided.
112 * If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
113 */
114protected__attribute__((__visibility__("hidden"))) int
115el_read_setfn(struct el_read_t *el_read, el_rfunc_t rc)
116{
117 el_read->read_char = (rc == EL_BUILTIN_GETCFN(((void *)0))) ? read_char : rc;
118 return 0;
119}
120
121
122/* el_read_getfn():
123 * return the current read char function, or EL_BUILTIN_GETCFN
124 * if it is the default one
125 */
126protected__attribute__((__visibility__("hidden"))) el_rfunc_t
127el_read_getfn(struct el_read_t *el_read)
128{
129 return el_read->read_char == read_char ?
130 EL_BUILTIN_GETCFN(((void *)0)) : el_read->read_char;
131}
132
133
134/* el_push():
135 * Push a macro
136 */
137void
138el_wpush(EditLine *el, const wchar_t *str)
139{
140 struct macros *ma = &el->el_read->macros;
141
142 if (str != NULL((void *)0) && ma->level + 1 < EL_MAXMACRO10) {
143 ma->level++;
144 if ((ma->macro[ma->level] = wcsdup(str)) != NULL((void *)0))
145 return;
146 ma->level--;
147 }
148 terminal_beep(el);
149 terminal__flush(el);
150}
151
152
153/* read_getcmd():
154 * Get next command from the input stream,
155 * return 0 on success or -1 on EOF or error.
156 * Character values > 255 are not looked up in the map, but inserted.
157 */
158static int
159read_getcmd(EditLine *el, el_action_t *cmdnum, wchar_t *ch)
160{
161 static const wchar_t meta = (wchar_t)0x80;
162 el_action_t cmd;
163 int num;
164
165 do {
166 if ((num = el_wgetc(el, ch)) != 1)
Although the value stored to 'num' is used in the enclosing expression, the value is never actually read from 'num'
167 return -1;
168
169#ifdef KANJI
170 if ((*ch & meta)) {
171 el->el_state.metanext = 0;
172 cmd = CcViMap[' '];
173 break;
174 } else
175#endif /* KANJI */
176
177 if (el->el_state.metanext) {
178 el->el_state.metanext = 0;
179 *ch |= meta;
180 }
181 if (*ch >= N_KEYS256)
182 cmd = ED_INSERT9;
183 else
184 cmd = el->el_map.current[(unsigned char) *ch];
185 if (cmd == ED_SEQUENCE_LEAD_IN25) {
186 keymacro_value_t val;
187 switch (keymacro_get(el, ch, &val)) {
188 case XK_CMD0:
189 cmd = val.cmd;
190 break;
191 case XK_STR1:
192 el_wpush(el, val.str);
193 break;
194 case XK_NOD2:
195 return -1;
196 default:
197 EL_ABORT((el->el_errfile, "Bad XK_ type \n"))abort();
198 break;
199 }
200 }
201 } while (cmd == ED_SEQUENCE_LEAD_IN25);
202 *cmdnum = cmd;
203 return 0;
204}
205
206/* read_char():
207 * Read a character from the tty.
208 */
209static int
210read_char(EditLine *el, wchar_t *cp)
211{
212 char cbuf[MB_LEN_MAX4];
213 int cbp = 0;
214
215 again:
216 el->el_signal->sig_no = 0;
217 switch (read(el->el_infd, cbuf + cbp, 1)) {
218 case -1:
219 if (errno(*__errno()) == EINTR4) {
220 switch (el->el_signal->sig_no) {
221 case SIGCONT19:
222 el_set(el, EL_REFRESH20);
223 /*FALLTHROUGH*/
224 case SIGWINCH28:
225 sig_set(el);
226 goto again;
227 default:
228 break;
229 }
230 }
231 *cp = L'\0';
232 return -1;
233 case 0:
234 *cp = L'\0';
235 return 0;
236 default:
237 break;
238 }
239
240 for (;;) {
241 mbstate_t mbs;
242
243 ++cbp;
244 /* This only works because UTF8 is stateless. */
245 memset(&mbs, 0, sizeof(mbs));
246 switch (mbrtowc(cp, cbuf, cbp, &mbs)) {
247 case (size_t)-1:
248 if (cbp > 1) {
249 /*
250 * Invalid sequence, discard all bytes
251 * except the last one.
252 */
253 cbuf[0] = cbuf[cbp - 1];
254 cbp = 0;
255 break;
256 } else {
257 /* Invalid byte, discard it. */
258 cbp = 0;
259 goto again;
260 }
261 case (size_t)-2:
262 /*
263 * We don't support other multibyte charsets.
264 * The second condition shouldn't happen
265 * and is here merely for additional safety.
266 */
267 if ((el->el_flags & CHARSET_IS_UTF80x10) == 0 ||
268 cbp >= MB_LEN_MAX4) {
269 errno(*__errno()) = EILSEQ84;
270 *cp = L'\0';
271 return -1;
272 }
273 /* Incomplete sequence, read another byte. */
274 goto again;
275 default:
276 /* Valid character, process it. */
277 return 1;
278 }
279 }
280}
281
282/* read_pop():
283 * Pop a macro from the stack
284 */
285static void
286read_pop(struct macros *ma)
287{
288 int i;
289
290 free(ma->macro[0]);
291 for (i = 0; i < ma->level; i++)
292 ma->macro[i] = ma->macro[i + 1];
293 ma->level--;
294 ma->offset = 0;
295}
296
297static void
298read_clearmacros(struct macros *ma)
299{
300 while (ma->level >= 0)
301 free(ma->macro[ma->level--]);
302 ma->offset = 0;
303}
304
305/* el_wgetc():
306 * Read a wide character
307 */
308int
309el_wgetc(EditLine *el, wchar_t *cp)
310{
311 struct macros *ma = &el->el_read->macros;
312 int num_read;
313
314 terminal__flush(el);
315 for (;;) {
316 if (ma->level < 0)
317 break;
318
319 if (ma->macro[0][ma->offset] == '\0') {
320 read_pop(ma);
321 continue;
322 }
323
324 *cp = ma->macro[0][ma->offset++];
325
326 if (ma->macro[0][ma->offset] == '\0') {
327 /* Needed for QuoteMode On */
328 read_pop(ma);
329 }
330
331 return 1;
332 }
333
334 if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
335 return 0;
336
337 num_read = (*el->el_read->read_char)(el, cp);
338
339 /*
340 * Remember the original reason of a read failure
341 * such that el_wgets() can restore it after doing
342 * various cleanup operation that might change errno.
343 */
344 if (num_read < 0)
345 el->el_read->read_errno = errno(*__errno());
346
347 return num_read;
348}
349
350protected__attribute__((__visibility__("hidden"))) void
351read_prepare(EditLine *el)
352{
353 if (el->el_flags & HANDLE_SIGNALS0x01)
354 sig_set(el);
355 if (el->el_flags & NO_TTY0x02)
356 return;
357 if ((el->el_flags & (UNBUFFERED0x08|EDIT_DISABLED0x04)) == UNBUFFERED0x08)
358 tty_rawmode(el);
359
360 /* This is relatively cheap, and things go terribly wrong if
361 we have the wrong size. */
362 el_resize(el);
363 re_clear_display(el); /* reset the display stuff */
364 ch_reset(el);
365 re_refresh(el); /* print the prompt */
366
367 if (el->el_flags & UNBUFFERED0x08)
368 terminal__flush(el);
369}
370
371protected__attribute__((__visibility__("hidden"))) void
372read_finish(EditLine *el)
373{
374 if ((el->el_flags & UNBUFFERED0x08) == 0)
375 (void) tty_cookedmode(el);
376 if (el->el_flags & HANDLE_SIGNALS0x01)
377 sig_clr(el);
378}
379
380const wchar_t *
381el_wgets(EditLine *el, int *nread)
382{
383 int retval;
384 el_action_t cmdnum = 0;
385 int num; /* how many chars we have read at NL */
386 wchar_t wc;
387 wchar_t ch, *cp;
388 int crlf = 0;
389 int nrb;
390
391 if (nread == NULL((void *)0))
392 nread = &nrb;
393 *nread = 0;
394 el->el_read->read_errno = 0;
395
396 if (el->el_flags & NO_TTY0x02) {
397 size_t idx;
398
399 cp = el->el_line.buffer;
400 while ((num = (*el->el_read->read_char)(el, &wc)) == 1) {
401 *cp = wc;
402 /* make sure there is space for next character */
403 if (cp + 1 >= el->el_line.limit) {
404 idx = (cp - el->el_line.buffer);
405 if (!ch_enlargebufs(el, 2))
406 break;
407 cp = &el->el_line.buffer[idx];
408 }
409 cp++;
410 if (el->el_flags & UNBUFFERED0x08)
411 break;
412 if (cp[-1] == '\r' || cp[-1] == '\n')
413 break;
414 }
415 if (num == -1 && errno(*__errno()) == EINTR4)
416 cp = el->el_line.buffer;
417 goto noedit;
418 }
419
420
421#ifdef FIONREAD((unsigned long)0x40000000 | ((sizeof(int) & 0x1fff) <<
16) | ((('f')) << 8) | ((127)))
422 if (el->el_tty.t_mode == EX_IO0 && el->el_read->macros.level < 0) {
423 int chrs = 0;
424
425 (void) ioctl(el->el_infd, FIONREAD((unsigned long)0x40000000 | ((sizeof(int) & 0x1fff) <<
16) | ((('f')) << 8) | ((127))), &chrs);
426 if (chrs == 0) {
427 if (tty_rawmode(el) < 0) {
428 errno(*__errno()) = 0;
429 *nread = 0;
430 return NULL((void *)0);
431 }
432 }
433 }
434#endif /* FIONREAD */
435
436 if ((el->el_flags & UNBUFFERED0x08) == 0)
437 read_prepare(el);
438
439 if (el->el_flags & EDIT_DISABLED0x04) {
440 size_t idx;
441
442 if ((el->el_flags & UNBUFFERED0x08) == 0)
443 cp = el->el_line.buffer;
444 else
445 cp = el->el_line.lastchar;
446
447 terminal__flush(el);
448
449 while ((num = (*el->el_read->read_char)(el, &wc)) == 1) {
450 *cp = wc;
451 /* make sure there is space next character */
452 if (cp + 1 >= el->el_line.limit) {
453 idx = (cp - el->el_line.buffer);
454 if (!ch_enlargebufs(el, 2))
455 break;
456 cp = &el->el_line.buffer[idx];
457 }
458 cp++;
459 crlf = cp[-1] == '\r' || cp[-1] == '\n';
460 if (el->el_flags & UNBUFFERED0x08)
461 break;
462 if (crlf)
463 break;
464 }
465 if (num == -1 && errno(*__errno()) == EINTR4)
466 cp = el->el_line.buffer;
467 goto noedit;
468 }
469
470 for (num = -1; num == -1;) { /* while still editing this line */
471 /* if EOF or error */
472 if (read_getcmd(el, &cmdnum, &ch) == -1)
473 break;
474 if ((int)cmdnum >= el->el_map.nfunc) /* BUG CHECK command */
475 continue; /* try again */
476 /* now do the real command */
477 /* vi redo needs these way down the levels... */
478 el->el_state.thiscmd = cmdnum;
479 el->el_state.thisch = ch;
480 if (el->el_map.type == MAP_VI1 &&
481 el->el_map.current == el->el_map.key &&
482 el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
483 if (cmdnum == VI_DELETE_PREV_CHAR58 &&
484 el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
485 && iswprint(el->el_chared.c_redo.pos[-1]))
486 el->el_chared.c_redo.pos--;
487 else
488 *el->el_chared.c_redo.pos++ = ch;
489 }
490 retval = (*el->el_map.func[cmdnum]) (el, ch);
491
492 /* save the last command here */
493 el->el_state.lastcmd = cmdnum;
494
495 /* use any return value */
496 switch (retval) {
497 case CC_CURSOR5:
498 re_refresh_cursor(el);
499 break;
500
501 case CC_REDISPLAY8:
502 re_clear_lines(el);
503 re_clear_display(el);
504 /* FALLTHROUGH */
505
506 case CC_REFRESH4:
507 re_refresh(el);
508 break;
509
510 case CC_REFRESH_BEEP9:
511 re_refresh(el);
512 terminal_beep(el);
513 break;
514
515 case CC_NORM0: /* normal char */
516 break;
517
518 case CC_ARGHACK3: /* Suggested by Rich Salz */
519 /* <rsalz@pineapple.bbn.com> */
520 continue; /* keep going... */
521
522 case CC_EOF2: /* end of file typed */
523 if ((el->el_flags & UNBUFFERED0x08) == 0)
524 num = 0;
525 else if (num == -1) {
526 *el->el_line.lastchar++ = CONTROL('d')(('d') & 037);
527 el->el_line.cursor = el->el_line.lastchar;
528 num = 1;
529 }
530 break;
531
532 case CC_NEWLINE1: /* normal end of line */
533 num = (int)(el->el_line.lastchar - el->el_line.buffer);
534 break;
535
536 case CC_FATAL7: /* fatal error, reset to known state */
537 /* put (real) cursor in a known place */
538 re_clear_display(el); /* reset the display stuff */
539 ch_reset(el); /* reset the input pointers */
540 read_clearmacros(&el->el_read->macros);
541 re_refresh(el); /* print the prompt again */
542 break;
543
544 case CC_ERROR6:
545 default: /* functions we don't know about */
546 terminal_beep(el);
547 terminal__flush(el);
548 break;
549 }
550 el->el_state.argument = 1;
551 el->el_state.doingarg = 0;
552 el->el_chared.c_vcmd.action = NOP0x00;
553 if (el->el_flags & UNBUFFERED0x08)
554 break;
555 }
556
557 terminal__flush(el); /* flush any buffered output */
558 /* make sure the tty is set up correctly */
559 if ((el->el_flags & UNBUFFERED0x08) == 0) {
560 read_finish(el);
561 *nread = num != -1 ? num : 0;
562 } else {
563 *nread = (int)(el->el_line.lastchar - el->el_line.buffer);
564 }
565 goto done;
566noedit:
567 el->el_line.cursor = el->el_line.lastchar = cp;
568 *cp = '\0';
569 *nread = (int)(el->el_line.cursor - el->el_line.buffer);
570done:
571 if (*nread == 0) {
572 if (num == -1) {
573 *nread = -1;
574 if (el->el_read->read_errno)
575 errno(*__errno()) = el->el_read->read_errno;
576 }
577 return NULL((void *)0);
578 } else
579 return el->el_line.buffer;
580}