xref: /freebsd/contrib/bc/include/status.h (revision 3332f1b444d4a73238e9f59cca27bfc95fe936bd)
1 /*
2  * *****************************************************************************
3  *
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c) 2018-2021 Gavin D. Howard and contributors.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  * * Redistributions of source code must retain the above copyright notice, this
12  *   list of conditions and the following disclaimer.
13  *
14  * * Redistributions in binary form must reproduce the above copyright notice,
15  *   this list of conditions and the following disclaimer in the documentation
16  *   and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  *
30  * *****************************************************************************
31  *
32  * All bc status codes and cross-platform portability.
33  *
34  */
35 
36 #ifndef BC_STATUS_H
37 #define BC_STATUS_H
38 
39 #include <stdint.h>
40 
41 // This is used by configure.sh to test for OpenBSD.
42 #ifdef BC_TEST_OPENBSD
43 #ifdef __OpenBSD__
44 #error On OpenBSD without _BSD_SOURCE
45 #endif // __OpenBSD__
46 #endif // BC_TEST_OPENBSD
47 
48 #ifndef BC_ENABLED
49 #define BC_ENABLED (1)
50 #endif // BC_ENABLED
51 
52 #ifndef DC_ENABLED
53 #define DC_ENABLED (1)
54 #endif // DC_ENABLED
55 
56 #ifndef BC_ENABLE_LIBRARY
57 #define BC_ENABLE_LIBRARY (0)
58 #endif // BC_ENABLE_LIBRARY
59 
60 // This is error checking for fuzz builds.
61 #if BC_ENABLE_AFL
62 #ifndef __AFL_HAVE_MANUAL_CONTROL
63 #error Must compile with afl-clang-fast or afl-clang-lto for fuzzing
64 #endif // __AFL_HAVE_MANUAL_CONTROL
65 #endif // BC_ENABLE_AFL
66 
67 #ifndef BC_ENABLE_MEMCHECK
68 #define BC_ENABLE_MEMCHECK (0)
69 #endif // BC_ENABLE_MEMCHECK
70 
71 /**
72  * Mark a variable as unused.
73  * @param e  The variable to mark as unused.
74  */
75 #define BC_UNUSED(e) ((void) (e))
76 
77 // If users want, they can define this to something like __builtin_expect(e, 1).
78 // It might give a performance improvement.
79 #ifndef BC_LIKELY
80 
81 /**
82  * Mark a branch expression as likely.
83  * @param e  The expression to mark as likely.
84  */
85 #define BC_LIKELY(e) (e)
86 
87 #endif // BC_LIKELY
88 
89 // If users want, they can define this to something like __builtin_expect(e, 0).
90 // It might give a performance improvement.
91 #ifndef BC_UNLIKELY
92 
93 /**
94  * Mark a branch expression as unlikely.
95  * @param e  The expression to mark as unlikely.
96  */
97 #define BC_UNLIKELY(e) (e)
98 
99 #endif // BC_UNLIKELY
100 
101 /**
102  * Mark a branch expression as an error, if true.
103  * @param e  The expression to mark as an error, if true.
104  */
105 #define BC_ERR(e) BC_UNLIKELY(e)
106 
107 /**
108  * Mark a branch expression as not an error, if true.
109  * @param e  The expression to mark as not an error, if true.
110  */
111 #define BC_NO_ERR(s) BC_LIKELY(s)
112 
113 // Disable extra debug code by default.
114 #ifndef BC_DEBUG_CODE
115 #define BC_DEBUG_CODE (0)
116 #endif // BC_DEBUG_CODE
117 
118 // We want to be able to use _Noreturn on C11 compilers.
119 #if __STDC_VERSION__ >= 201100L
120 
121 #include <stdnoreturn.h>
122 #define BC_NORETURN _Noreturn
123 #define BC_C11 (1)
124 
125 #else // __STDC_VERSION__
126 
127 #define BC_NORETURN
128 #define BC_MUST_RETURN
129 #define BC_C11 (0)
130 
131 #endif // __STDC_VERSION__
132 
133 #define BC_HAS_UNREACHABLE (0)
134 #define BC_HAS_COMPUTED_GOTO (0)
135 
136 // GCC and Clang complain if fallthroughs are not marked with their special
137 // attribute. Jerks. This creates a define for marking the fallthroughs that is
138 // nothing on other compilers.
139 #if defined(__clang__) || defined(__GNUC__)
140 
141 #if defined(__has_attribute)
142 
143 #if __has_attribute(fallthrough)
144 #define BC_FALLTHROUGH __attribute__((fallthrough));
145 #else // __has_attribute(fallthrough)
146 #define BC_FALLTHROUGH
147 #endif // __has_attribute(fallthrough)
148 
149 #ifdef __GNUC__
150 
151 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
152 #undef BC_HAS_UNREACHABLE
153 #define BC_HAS_UNREACHABLE (1)
154 #endif // __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
155 
156 #else // __GNUC__
157 
158 #if __clang_major__ >= 4
159 #undef BC_HAS_UNREACHABLE
160 #define BC_HAS_UNREACHABLE (1)
161 #endif // __clang_major__ >= 4
162 
163 #endif // __GNUC__
164 
165 #else // defined(__has_attribute)
166 #define BC_FALLTHROUGH
167 #endif // defined(__has_attribute)
168 #else // defined(__clang__) || defined(__GNUC__)
169 #define BC_FALLTHROUGH
170 #endif // defined(__clang__) || defined(__GNUC__)
171 
172 #if BC_HAS_UNREACHABLE
173 
174 #define BC_UNREACHABLE __builtin_unreachable();
175 
176 #else // BC_HAS_UNREACHABLE
177 
178 #ifdef _WIN32
179 
180 #define BC_UNREACHABLE __assume(0);
181 
182 #else // _WIN32
183 
184 #define BC_UNREACHABLE
185 
186 #endif // _WIN32
187 
188 #endif // BC_HAS_UNREACHABLE
189 
190 #ifdef __GNUC__
191 
192 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
193 
194 #undef BC_HAS_COMPUTED_GOTO
195 #define BC_HAS_COMPUTED_GOTO (1)
196 
197 #endif // __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
198 
199 #endif // __GNUC__
200 
201 #ifdef __clang__
202 
203 #if __clang_major__ >= 4
204 
205 #undef BC_HAS_COMPUTED_GOTO
206 #define BC_HAS_COMPUTED_GOTO (1)
207 
208 #endif // __clang_major__ >= 4
209 
210 #endif // __GNUC__
211 
212 #ifdef BC_NO_COMPUTED_GOTO
213 
214 #undef BC_HAS_COMPUTED_GOTO
215 #define BC_HAS_COMPUTED_GOTO (0)
216 
217 #endif // BC_NO_COMPUTED_GOTO
218 
219 #ifdef __GNUC__
220 #ifdef __OpenBSD__
221 // The OpenBSD GCC doesn't like inline.
222 #define inline
223 #endif // __OpenBSD__
224 #endif // __GNUC__
225 
226 // Workarounds for AIX's POSIX incompatibility.
227 #ifndef SIZE_MAX
228 #define SIZE_MAX __SIZE_MAX__
229 #endif // SIZE_MAX
230 #ifndef UINTMAX_C
231 #define UINTMAX_C __UINTMAX_C
232 #endif // UINTMAX_C
233 #ifndef UINT32_C
234 #define UINT32_C __UINT32_C
235 #endif // UINT32_C
236 #ifndef UINT_FAST32_MAX
237 #define UINT_FAST32_MAX __UINT_FAST32_MAX__
238 #endif // UINT_FAST32_MAX
239 #ifndef UINT16_MAX
240 #define UINT16_MAX __UINT16_MAX__
241 #endif // UINT16_MAX
242 #ifndef SIG_ATOMIC_MAX
243 #define SIG_ATOMIC_MAX __SIG_ATOMIC_MAX__
244 #endif // SIG_ATOMIC_MAX
245 
246 // Yes, this has to be here.
247 #include <bcl.h>
248 
249 // All of these set defaults for settings.
250 
251 #if BC_ENABLED
252 
253 #ifndef BC_DEFAULT_BANNER
254 #define BC_DEFAULT_BANNER (0)
255 #endif // BC_DEFAULT_BANNER
256 
257 #endif // BC_ENABLED
258 
259 #ifndef BC_DEFAULT_SIGINT_RESET
260 #define BC_DEFAULT_SIGINT_RESET (1)
261 #endif // BC_DEFAULT_SIGINT_RESET
262 
263 #ifndef BC_DEFAULT_TTY_MODE
264 #define BC_DEFAULT_TTY_MODE (1)
265 #endif // BC_DEFAULT_TTY_MODE
266 
267 #ifndef BC_DEFAULT_PROMPT
268 #define BC_DEFAULT_PROMPT BC_DEFAULT_TTY_MODE
269 #endif // BC_DEFAULT_PROMPT
270 
271 // All of these set defaults for settings.
272 #ifndef DC_DEFAULT_SIGINT_RESET
273 #define DC_DEFAULT_SIGINT_RESET (1)
274 #endif // DC_DEFAULT_SIGINT_RESET
275 
276 #ifndef DC_DEFAULT_TTY_MODE
277 #define DC_DEFAULT_TTY_MODE (0)
278 #endif // DC_DEFAULT_TTY_MODE
279 
280 #ifndef DC_DEFAULT_HISTORY
281 #define DC_DEFAULT_HISTORY DC_DEFAULT_TTY_MODE
282 #endif // DC_DEFAULT_HISTORY
283 
284 #ifndef DC_DEFAULT_PROMPT
285 #define DC_DEFAULT_PROMPT DC_DEFAULT_TTY_MODE
286 #endif // DC_DEFAULT_PROMPT
287 
288 /// Statuses, which mark either which category of error happened, or some other
289 /// status that matters.
290 typedef enum BcStatus {
291 
292 	/// Normal status.
293 	BC_STATUS_SUCCESS = 0,
294 
295 	/// Math error.
296 	BC_STATUS_ERROR_MATH,
297 
298 	/// Parse (and lex) error.
299 	BC_STATUS_ERROR_PARSE,
300 
301 	/// Runtime error.
302 	BC_STATUS_ERROR_EXEC,
303 
304 	/// Fatal error.
305 	BC_STATUS_ERROR_FATAL,
306 
307 	/// EOF status.
308 	BC_STATUS_EOF,
309 
310 	/// Quit status. This means that bc/dc is in the process of quitting.
311 	BC_STATUS_QUIT,
312 
313 } BcStatus;
314 
315 /// Errors, which are more specific errors.
316 typedef enum BcErr {
317 
318 	// Math errors.
319 
320 	/// Negative number used when not allowed.
321 	BC_ERR_MATH_NEGATIVE,
322 
323 	/// Non-integer used when not allowed.
324 	BC_ERR_MATH_NON_INTEGER,
325 
326 	/// Conversion to a hardware integer would overflow.
327 	BC_ERR_MATH_OVERFLOW,
328 
329 	/// Divide by zero.
330 	BC_ERR_MATH_DIVIDE_BY_ZERO,
331 
332 	// Fatal errors.
333 
334 	/// An allocation or reallocation failed.
335 	BC_ERR_FATAL_ALLOC_ERR,
336 
337 	/// I/O failure.
338 	BC_ERR_FATAL_IO_ERR,
339 
340 	/// File error, such as permissions or file does not exist.
341 	BC_ERR_FATAL_FILE_ERR,
342 
343 	/// File is binary, not text, error.
344 	BC_ERR_FATAL_BIN_FILE,
345 
346 	/// Attempted to read a directory as a file error.
347 	BC_ERR_FATAL_PATH_DIR,
348 
349 	/// Invalid option error.
350 	BC_ERR_FATAL_OPTION,
351 
352 	/// Option with required argument not given an argument.
353 	BC_ERR_FATAL_OPTION_NO_ARG,
354 
355 	/// Option with no argument given an argument.
356 	BC_ERR_FATAL_OPTION_ARG,
357 
358 	/// Option argument is invalid.
359 	BC_ERR_FATAL_ARG,
360 
361 	// Runtime errors.
362 
363 	/// Invalid ibase value.
364 	BC_ERR_EXEC_IBASE,
365 
366 	/// Invalid obase value.
367 	BC_ERR_EXEC_OBASE,
368 
369 	/// Invalid scale value.
370 	BC_ERR_EXEC_SCALE,
371 
372 	/// Invalid expression parsed by read().
373 	BC_ERR_EXEC_READ_EXPR,
374 
375 	/// read() used within an expression given to a read() call.
376 	BC_ERR_EXEC_REC_READ,
377 
378 	/// Type error.
379 	BC_ERR_EXEC_TYPE,
380 
381 	/// Stack has too few elements error.
382 	BC_ERR_EXEC_STACK,
383 
384 	/// Register stack has too few elements error.
385 	BC_ERR_EXEC_STACK_REGISTER,
386 
387 	/// Wrong number of arguments error.
388 	BC_ERR_EXEC_PARAMS,
389 
390 	/// Undefined function error.
391 	BC_ERR_EXEC_UNDEF_FUNC,
392 
393 	/// Void value used in an expression error.
394 	BC_ERR_EXEC_VOID_VAL,
395 
396 	// Parse (and lex errors).
397 
398 	/// EOF encountered when not expected error.
399 	BC_ERR_PARSE_EOF,
400 
401 	/// Invalid character error.
402 	BC_ERR_PARSE_CHAR,
403 
404 	/// Invalid string (no ending quote) error.
405 	BC_ERR_PARSE_STRING,
406 
407 	/// Invalid comment (no end found) error.
408 	BC_ERR_PARSE_COMMENT,
409 
410 	/// Invalid token encountered error.
411 	BC_ERR_PARSE_TOKEN,
412 
413 #if BC_ENABLED
414 
415 	/// Invalid expression error.
416 	BC_ERR_PARSE_EXPR,
417 
418 	/// Expression is empty error.
419 	BC_ERR_PARSE_EMPTY_EXPR,
420 
421 	/// Print statement is invalid error.
422 	BC_ERR_PARSE_PRINT,
423 
424 	/// Function definition is invalid error.
425 	BC_ERR_PARSE_FUNC,
426 
427 	/// Assignment is invalid error.
428 	BC_ERR_PARSE_ASSIGN,
429 
430 	/// No auto identifiers given for an auto statement error.
431 	BC_ERR_PARSE_NO_AUTO,
432 
433 	/// Duplicate local (parameter or auto) error.
434 	BC_ERR_PARSE_DUP_LOCAL,
435 
436 	/// Invalid block (within braces) error.
437 	BC_ERR_PARSE_BLOCK,
438 
439 	/// Invalid return statement for void functions.
440 	BC_ERR_PARSE_RET_VOID,
441 
442 	/// Reference attached to a variable, not an array, error.
443 	BC_ERR_PARSE_REF_VAR,
444 
445 	// POSIX-only errors.
446 
447 	/// Name length greater than 1 error.
448 	BC_ERR_POSIX_NAME_LEN,
449 
450 	/// Non-POSIX comment used error.
451 	BC_ERR_POSIX_COMMENT,
452 
453 	/// Non-POSIX keyword error.
454 	BC_ERR_POSIX_KW,
455 
456 	/// Non-POSIX . (last) error.
457 	BC_ERR_POSIX_DOT,
458 
459 	/// Non-POSIX return error.
460 	BC_ERR_POSIX_RET,
461 
462 	/// Non-POSIX boolean operator used error.
463 	BC_ERR_POSIX_BOOL,
464 
465 	/// POSIX relation operator used outside if, while, or for statements error.
466 	BC_ERR_POSIX_REL_POS,
467 
468 	/// Multiple POSIX relation operators used in an if, while, or for statement
469 	/// error.
470 	BC_ERR_POSIX_MULTIREL,
471 
472 	/// Empty statements in POSIX for loop error.
473 	BC_ERR_POSIX_FOR,
474 
475 	/// Non-POSIX exponential (scientific or engineering) number used error.
476 	BC_ERR_POSIX_EXP_NUM,
477 
478 	/// Non-POSIX array reference error.
479 	BC_ERR_POSIX_REF,
480 
481 	/// Non-POSIX void error.
482 	BC_ERR_POSIX_VOID,
483 
484 	/// Non-POSIX brace position used error.
485 	BC_ERR_POSIX_BRACE,
486 
487 	/// String used in expression.
488 	BC_ERR_POSIX_EXPR_STRING,
489 
490 #endif // BC_ENABLED
491 
492 	// Number of elements.
493 	BC_ERR_NELEMS,
494 
495 #if BC_ENABLED
496 
497 	/// A marker for the start of POSIX errors.
498 	BC_ERR_POSIX_START = BC_ERR_POSIX_NAME_LEN,
499 
500 	/// A marker for the end of POSIX errors.
501 	BC_ERR_POSIX_END = BC_ERR_POSIX_EXPR_STRING,
502 
503 #endif // BC_ENABLED
504 
505 } BcErr;
506 
507 // The indices of each category of error in bc_errs[], and used in bc_err_ids[]
508 // to associate actual errors with their categories.
509 
510 /// Math error category.
511 #define BC_ERR_IDX_MATH (0)
512 
513 /// Parse (and lex) error category.
514 #define BC_ERR_IDX_PARSE (1)
515 
516 /// Runtime error category.
517 #define BC_ERR_IDX_EXEC (2)
518 
519 /// Fatal error category.
520 #define BC_ERR_IDX_FATAL (3)
521 
522 /// Number of categories.
523 #define BC_ERR_IDX_NELEMS (4)
524 
525 // If bc is enabled, we add an extra category for POSIX warnings.
526 #if BC_ENABLED
527 
528 /// POSIX warning category.
529 #define BC_ERR_IDX_WARN (BC_ERR_IDX_NELEMS)
530 
531 #endif // BC_ENABLED
532 
533 /// Do a longjmp(). This is what to use when activating an "exception", i.e., a
534 /// longjmp(). With debug code, it will print the name of the function it jumped
535 /// from.
536 #if BC_DEBUG_CODE
537 #define BC_JMP bc_vm_jmp(__func__)
538 #else // BC_DEBUG_CODE
539 #define BC_JMP bc_vm_jmp()
540 #endif // BC_DEBUG_CODE
541 
542 /// Returns true if an exception is in flight, false otherwise.
543 #define BC_SIG_EXC \
544 	BC_UNLIKELY(vm.status != (sig_atomic_t) BC_STATUS_SUCCESS || vm.sig)
545 
546 /// Returns true if there is *no* exception in flight, false otherwise.
547 #define BC_NO_SIG_EXC \
548 	BC_LIKELY(vm.status == (sig_atomic_t) BC_STATUS_SUCCESS && !vm.sig)
549 
550 #ifndef NDEBUG
551 
552 /// Assert that signals are locked. There are non-async-signal-safe functions in
553 /// bc, and they *must* have signals locked. Other functions are expected to
554 /// *not* have signals locked, for reasons. So this is a pre-built assert
555 /// (no-op in non-debug mode) that check that signals are locked.
556 #define BC_SIG_ASSERT_LOCKED do { assert(vm.sig_lock); } while (0)
557 
558 /// Assert that signals are unlocked. There are non-async-signal-safe functions
559 /// in bc, and they *must* have signals locked. Other functions are expected to
560 /// *not* have signals locked, for reasons. So this is a pre-built assert
561 /// (no-op in non-debug mode) that check that signals are unlocked.
562 #define BC_SIG_ASSERT_NOT_LOCKED do { assert(vm.sig_lock == 0); } while (0)
563 
564 #else // NDEBUG
565 
566 /// Assert that signals are locked. There are non-async-signal-safe functions in
567 /// bc, and they *must* have signals locked. Other functions are expected to
568 /// *not* have signals locked, for reasons. So this is a pre-built assert
569 /// (no-op in non-debug mode) that check that signals are locked.
570 #define BC_SIG_ASSERT_LOCKED
571 
572 /// Assert that signals are unlocked. There are non-async-signal-safe functions
573 /// in bc, and they *must* have signals locked. Other functions are expected to
574 /// *not* have signals locked, for reasons. So this is a pre-built assert
575 /// (no-op in non-debug mode) that check that signals are unlocked.
576 #define BC_SIG_ASSERT_NOT_LOCKED
577 
578 #endif // NDEBUG
579 
580 /// Locks signals.
581 #define BC_SIG_LOCK               \
582 	do {                          \
583 		BC_SIG_ASSERT_NOT_LOCKED; \
584 		vm.sig_lock = 1;          \
585 	} while (0)
586 
587 /// Unlocks signals. If a signal happened, then this will cause a jump.
588 #define BC_SIG_UNLOCK         \
589 	do {                      \
590 		BC_SIG_ASSERT_LOCKED; \
591 		vm.sig_lock = 0;      \
592 		if (vm.sig) BC_JMP;   \
593 	} while (0)
594 
595 /// Locks signals, regardless of if they are already locked. This is really only
596 /// used after labels that longjmp() goes to after the jump because the cleanup
597 /// code must have signals locked, and BC_LONGJMP_CONT will unlock signals if it
598 /// doesn't jump.
599 #define BC_SIG_MAYLOCK   \
600 	do {                 \
601 		vm.sig_lock = 1; \
602 	} while (0)
603 
604 /// Unlocks signals, regardless of if they were already unlocked. If a signal
605 /// happened, then this will cause a jump.
606 #define BC_SIG_MAYUNLOCK    \
607 	do {                    \
608 		vm.sig_lock = 0;    \
609 		if (vm.sig) BC_JMP; \
610 	} while (0)
611 
612 /*
613  * Locks signals, but stores the old lock state, to be restored later by
614  * BC_SIG_TRYUNLOCK.
615  * @param v  The variable to store the old lock state to.
616  */
617 #define BC_SIG_TRYLOCK(v) \
618 	do {                  \
619 		v = vm.sig_lock;  \
620 		vm.sig_lock = 1;  \
621 	} while (0)
622 
623 /* Restores the previous state of a signal lock, and if it is now unlocked,
624  * initiates an exception/jump.
625  * @param v  The old lock state.
626  */
627 #define BC_SIG_TRYUNLOCK(v)         \
628 	do {                            \
629 		vm.sig_lock = (v);          \
630 		if (!(v) && vm.sig) BC_JMP; \
631 	} while (0)
632 
633 /**
634  * Sets a jump, and sets it up as well so that if a longjmp() happens, bc will
635  * immediately goto a label where some cleanup code is. This one assumes that
636  * signals are not locked and will lock them, set the jump, and unlock them.
637  * Setting the jump also includes pushing the jmp_buf onto the jmp_buf stack.
638  * This grows the jmp_bufs vector first to prevent a fatal error from happening
639  * after the setjmp(). This is done because BC_SETJMP(l) is assumed to be used
640  * *before* the actual initialization calls that need the setjmp().
641  * param l  The label to jump to on a longjmp().
642  */
643 #define BC_SETJMP(l)                     \
644 	do {                                 \
645 		sigjmp_buf sjb;                  \
646 		BC_SIG_LOCK;                     \
647 		bc_vec_grow(&vm.jmp_bufs, 1);    \
648 		if (sigsetjmp(sjb, 0)) {         \
649 			assert(BC_SIG_EXC);          \
650 			goto l;                      \
651 		}                                \
652 		bc_vec_push(&vm.jmp_bufs, &sjb); \
653 		BC_SIG_UNLOCK;                   \
654 	} while (0)
655 
656 /**
657  * Sets a jump like BC_SETJMP, but unlike BC_SETJMP, it assumes signals are
658  * locked and will just set the jump. This does *not* have a call to
659  * bc_vec_grow() because it is assumed that BC_SETJMP_LOCKED(l) is used *after*
660  * the initializations that need the setjmp().
661  * param l  The label to jump to on a longjmp().
662  */
663 #define BC_SETJMP_LOCKED(l)              \
664 	do {                                 \
665 		sigjmp_buf sjb;                  \
666 		BC_SIG_ASSERT_LOCKED;            \
667 		if (sigsetjmp(sjb, 0)) {         \
668 			assert(BC_SIG_EXC);          \
669 			goto l;                      \
670 		}                                \
671 		bc_vec_push(&vm.jmp_bufs, &sjb); \
672 	} while (0)
673 
674 /// Used after cleanup labels set by BC_SETJMP and BC_SETJMP_LOCKED to jump to
675 /// the next place. This is what continues the stack unwinding. This basically
676 /// copies BC_SIG_UNLOCK into itself, but that is because its condition for
677 /// jumping is BC_SIG_EXC, not just that a signal happened.
678 #define BC_LONGJMP_CONT                            \
679 	do {                                           \
680 		BC_SIG_ASSERT_LOCKED;                      \
681 		if (!vm.sig_pop) bc_vec_pop(&vm.jmp_bufs); \
682 		vm.sig_lock = 0;                           \
683 		if (BC_SIG_EXC) BC_JMP;                    \
684 	} while (0)
685 
686 /// Unsets a jump. It always assumes signals are locked. This basically just
687 /// pops a jmp_buf off of the stack of jmp_bufs, and since the jump mechanism
688 /// always jumps to the location at the top of the stack, this effectively
689 /// undoes a setjmp().
690 #define BC_UNSETJMP               \
691 	do {                          \
692 		BC_SIG_ASSERT_LOCKED;     \
693 		bc_vec_pop(&vm.jmp_bufs); \
694 	} while (0)
695 
696 /// Stops a stack unwinding. Technically, a stack unwinding needs to be done
697 /// manually, but it will always be done unless certain flags are cleared. This
698 /// clears the flags.
699 #define BC_LONGJMP_STOP \
700 	do {                \
701 		vm.sig_pop = 0; \
702 		vm.sig = 0;     \
703 	} while (0)
704 
705 // Various convenience macros for calling the bc's error handling routine.
706 #if BC_ENABLE_LIBRARY
707 
708 /**
709  * Call bc's error handling routine.
710  * @param e    The error.
711  * @param l    The line of the script that the error happened.
712  * @param ...  Extra arguments for error messages as necessary.
713  */
714 #define bc_error(e, l, ...) (bc_vm_handleError((e)))
715 
716 /**
717  * Call bc's error handling routine.
718  * @param e  The error.
719  */
720 #define bc_err(e) (bc_vm_handleError((e)))
721 
722 /**
723  * Call bc's error handling routine.
724  * @param e  The error.
725  */
726 #define bc_verr(e, ...) (bc_vm_handleError((e)))
727 
728 #else // BC_ENABLE_LIBRARY
729 
730 /**
731  * Call bc's error handling routine.
732  * @param e    The error.
733  * @param l    The line of the script that the error happened.
734  * @param ...  Extra arguments for error messages as necessary.
735  */
736 #define bc_error(e, l, ...) (bc_vm_handleError((e), (l), __VA_ARGS__))
737 
738 /**
739  * Call bc's error handling routine.
740  * @param e  The error.
741  */
742 #define bc_err(e) (bc_vm_handleError((e), 0))
743 
744 /**
745  * Call bc's error handling routine.
746  * @param e  The error.
747  */
748 #define bc_verr(e, ...) (bc_vm_handleError((e), 0, __VA_ARGS__))
749 
750 #endif // BC_ENABLE_LIBRARY
751 
752 /**
753  * Returns true if status @a s is an error, false otherwise.
754  * @param s  The status to test.
755  * @return   True if @a s is an error, false otherwise.
756  */
757 #define BC_STATUS_IS_ERROR(s) \
758 	((s) >= BC_STATUS_ERROR_MATH && (s) <= BC_STATUS_ERROR_FATAL)
759 
760 // Convenience macros that can be placed at the beginning and exits of functions
761 // for easy marking of where functions are entered and exited.
762 #if BC_DEBUG_CODE
763 #define BC_FUNC_ENTER                                              \
764 	do {                                                           \
765 		size_t bc_func_enter_i;                                    \
766 		for (bc_func_enter_i = 0; bc_func_enter_i < vm.func_depth; \
767 		     ++bc_func_enter_i)                                    \
768 		{                                                          \
769 			bc_file_puts(&vm.ferr, bc_flush_none, "  ");           \
770 		}                                                          \
771 		vm.func_depth += 1;                                        \
772 		bc_file_printf(&vm.ferr, "Entering %s\n", __func__);       \
773 		bc_file_flush(&vm.ferr, bc_flush_none);                    \
774 	} while (0);
775 
776 #define BC_FUNC_EXIT                                               \
777 	do {                                                           \
778 		size_t bc_func_enter_i;                                    \
779 		vm.func_depth -= 1;                                        \
780 		for (bc_func_enter_i = 0; bc_func_enter_i < vm.func_depth; \
781 		     ++bc_func_enter_i)                                    \
782 		{                                                          \
783 			bc_file_puts(&vm.ferr, bc_flush_none, "  ");           \
784 		}                                                          \
785 		bc_file_printf(&vm.ferr, "Leaving %s\n", __func__);        \
786 		bc_file_flush(&vm.ferr, bc_flush_none);                    \
787 	} while (0);
788 #else // BC_DEBUG_CODE
789 #define BC_FUNC_ENTER
790 #define BC_FUNC_EXIT
791 #endif // BC_DEBUG_CODE
792 
793 #endif // BC_STATUS_H
794