1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines an API used to report recoverable errors.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_ERROR_H
14#define LLVM_SUPPORT_ERROR_H
15
16#include "llvm-c/Error.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/ADT/Twine.h"
21#include "llvm/Config/abi-breaking.h"
22#include "llvm/Support/AlignOf.h"
23#include "llvm/Support/Compiler.h"
24#include "llvm/Support/Debug.h"
25#include "llvm/Support/ErrorHandling.h"
26#include "llvm/Support/ErrorOr.h"
27#include "llvm/Support/Format.h"
28#include "llvm/Support/raw_ostream.h"
29#include <algorithm>
30#include <cassert>
31#include <cstdint>
32#include <cstdlib>
33#include <functional>
34#include <memory>
35#include <new>
36#include <string>
37#include <system_error>
38#include <type_traits>
39#include <utility>
40#include <vector>
41
42namespace llvm {
43
44class ErrorSuccess;
45
46/// Base class for error info classes. Do not extend this directly: Extend
47/// the ErrorInfo template subclass instead.
48class ErrorInfoBase {
49public:
50 virtual ~ErrorInfoBase() = default;
51
52 /// Print an error message to an output stream.
53 virtual void log(raw_ostream &OS) const = 0;
54
55 /// Return the error message as a string.
56 virtual std::string message() const {
57 std::string Msg;
58 raw_string_ostream OS(Msg);
59 log(OS);
60 return OS.str();
61 }
62
63 /// Convert this error to a std::error_code.
64 ///
65 /// This is a temporary crutch to enable interaction with code still
66 /// using std::error_code. It will be removed in the future.
67 virtual std::error_code convertToErrorCode() const = 0;
68
69 // Returns the class ID for this type.
70 static const void *classID() { return &ID; }
71
72 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
73 virtual const void *dynamicClassID() const = 0;
74
75 // Check whether this instance is a subclass of the class identified by
76 // ClassID.
77 virtual bool isA(const void *const ClassID) const {
78 return ClassID == classID();
79 }
80
81 // Check whether this instance is a subclass of ErrorInfoT.
82 template <typename ErrorInfoT> bool isA() const {
83 return isA(ErrorInfoT::classID());
84 }
85
86private:
87 virtual void anchor();
88
89 static char ID;
90};
91
92/// Lightweight error class with error context and mandatory checking.
93///
94/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
95/// are represented by setting the pointer to a ErrorInfoBase subclass
96/// instance containing information describing the failure. Success is
97/// represented by a null pointer value.
98///
99/// Instances of Error also contains a 'Checked' flag, which must be set
100/// before the destructor is called, otherwise the destructor will trigger a
101/// runtime error. This enforces at runtime the requirement that all Error
102/// instances be checked or returned to the caller.
103///
104/// There are two ways to set the checked flag, depending on what state the
105/// Error instance is in. For Error instances indicating success, it
106/// is sufficient to invoke the boolean conversion operator. E.g.:
107///
108/// @code{.cpp}
109/// Error foo(<...>);
110///
111/// if (auto E = foo(<...>))
112/// return E; // <- Return E if it is in the error state.
113/// // We have verified that E was in the success state. It can now be safely
114/// // destroyed.
115/// @endcode
116///
117/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
118/// without testing the return value will raise a runtime error, even if foo
119/// returns success.
120///
121/// For Error instances representing failure, you must use either the
122/// handleErrors or handleAllErrors function with a typed handler. E.g.:
123///
124/// @code{.cpp}
125/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
126/// // Custom error info.
127/// };
128///
129/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
130///
131/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
132/// auto NewE =
133/// handleErrors(E,
134/// [](const MyErrorInfo &M) {
135/// // Deal with the error.
136/// },
137/// [](std::unique_ptr<OtherError> M) -> Error {
138/// if (canHandle(*M)) {
139/// // handle error.
140/// return Error::success();
141/// }
142/// // Couldn't handle this error instance. Pass it up the stack.
143/// return Error(std::move(M));
144/// );
145/// // Note - we must check or return NewE in case any of the handlers
146/// // returned a new error.
147/// @endcode
148///
149/// The handleAllErrors function is identical to handleErrors, except
150/// that it has a void return type, and requires all errors to be handled and
151/// no new errors be returned. It prevents errors (assuming they can all be
152/// handled) from having to be bubbled all the way to the top-level.
153///
154/// *All* Error instances must be checked before destruction, even if
155/// they're moved-assigned or constructed from Success values that have already
156/// been checked. This enforces checking through all levels of the call stack.
157class LLVM_NODISCARD Error {
158 // ErrorList needs to be able to yank ErrorInfoBase pointers out of Errors
159 // to add to the error list. It can't rely on handleErrors for this, since
160 // handleErrors does not support ErrorList handlers.
161 friend class ErrorList;
162
163 // handleErrors needs to be able to set the Checked flag.
164 template <typename... HandlerTs>
165 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
166
167 // Expected<T> needs to be able to steal the payload when constructed from an
168 // error.
169 template <typename T> friend class Expected;
170
171 // wrap needs to be able to steal the payload.
172 friend LLVMErrorRef wrap(Error);
173
174protected:
175 /// Create a success value. Prefer using 'Error::success()' for readability
176 Error() {
177 setPtr(nullptr);
178 setChecked(false);
179 }
180
181public:
182 /// Create a success value.
183 static ErrorSuccess success();
184
185 // Errors are not copy-constructable.
186 Error(const Error &Other) = delete;
187
188 /// Move-construct an error value. The newly constructed error is considered
189 /// unchecked, even if the source error had been checked. The original error
190 /// becomes a checked Success value, regardless of its original state.
191 Error(Error &&Other) {
192 setChecked(true);
193 *this = std::move(Other);
194 }
195
196 /// Create an error value. Prefer using the 'make_error' function, but
197 /// this constructor can be useful when "re-throwing" errors from handlers.
198 Error(std::unique_ptr<ErrorInfoBase> Payload) {
199 setPtr(Payload.release());
200 setChecked(false);
201 }
202
203 // Errors are not copy-assignable.
204 Error &operator=(const Error &Other) = delete;
205
206 /// Move-assign an error value. The current error must represent success, you
207 /// you cannot overwrite an unhandled error. The current error is then
208 /// considered unchecked. The source error becomes a checked success value,
209 /// regardless of its original state.
210 Error &operator=(Error &&Other) {
211 // Don't allow overwriting of unchecked values.
212 assertIsChecked();
213 setPtr(Other.getPtr());
214
215 // This Error is unchecked, even if the source error was checked.
216 setChecked(false);
217
218 // Null out Other's payload and set its checked bit.
219 Other.setPtr(nullptr);
220 Other.setChecked(true);
221
222 return *this;
223 }
224
225 /// Destroy a Error. Fails with a call to abort() if the error is
226 /// unchecked.
227 ~Error() {
228 assertIsChecked();
229 delete getPtr();
230 }
231
232 /// Bool conversion. Returns true if this Error is in a failure state,
233 /// and false if it is in an accept state. If the error is in a Success state
234 /// it will be considered checked.
235 explicit operator bool() {
236 setChecked(getPtr() == nullptr);
237 return getPtr() != nullptr;
238 }
239
240 /// Check whether one error is a subclass of another.
241 template <typename ErrT> bool isA() const {
242 return getPtr() && getPtr()->isA(ErrT::classID());
243 }
244
245 /// Returns the dynamic class id of this error, or null if this is a success
246 /// value.
247 const void* dynamicClassID() const {
248 if (!getPtr())
249 return nullptr;
250 return getPtr()->dynamicClassID();
251 }
252
253private:
254#if LLVM_ENABLE_ABI_BREAKING_CHECKS
255 // assertIsChecked() happens very frequently, but under normal circumstances
256 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
257 // of debug prints can cause the function to be too large for inlining. So
258 // it's important that we define this function out of line so that it can't be
259 // inlined.
260 LLVM_ATTRIBUTE_NORETURN
261 void fatalUncheckedError() const;
262#endif
263
264 void assertIsChecked() {
265#if LLVM_ENABLE_ABI_BREAKING_CHECKS
266 if (LLVM_UNLIKELY(!getChecked() || getPtr()))
267 fatalUncheckedError();
268#endif
269 }
270
271 ErrorInfoBase *getPtr() const {
272#if LLVM_ENABLE_ABI_BREAKING_CHECKS
273 return reinterpret_cast<ErrorInfoBase*>(
274 reinterpret_cast<uintptr_t>(Payload) &
275 ~static_cast<uintptr_t>(0x1));
276#else
277 return Payload;
278#endif
279 }
280
281 void setPtr(ErrorInfoBase *EI) {
282#if LLVM_ENABLE_ABI_BREAKING_CHECKS
283 Payload = reinterpret_cast<ErrorInfoBase*>(
284 (reinterpret_cast<uintptr_t>(EI) &
285 ~static_cast<uintptr_t>(0x1)) |
286 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
287#else
288 Payload = EI;
289#endif
290 }
291
292 bool getChecked() const {
293#if LLVM_ENABLE_ABI_BREAKING_CHECKS
294 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
295#else
296 return true;
297#endif
298 }
299
300 void setChecked(bool V) {
301#if LLVM_ENABLE_ABI_BREAKING_CHECKS
302 Payload = reinterpret_cast<ErrorInfoBase*>(
303 (reinterpret_cast<uintptr_t>(Payload) &
304 ~static_cast<uintptr_t>(0x1)) |
305 (V ? 0 : 1));
306#endif
307 }
308
309 std::unique_ptr<ErrorInfoBase> takePayload() {
310 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
311 setPtr(nullptr);
312 setChecked(true);
313 return Tmp;
314 }
315
316 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
317 if (auto P = E.getPtr())
318 P->log(OS);
319 else
320 OS << "success";
321 return OS;
322 }
323
324 ErrorInfoBase *Payload = nullptr;
325};
326
327/// Subclass of Error for the sole purpose of identifying the success path in
328/// the type system. This allows to catch invalid conversion to Expected<T> at
329/// compile time.
330class ErrorSuccess final : public Error {};
331
332inline ErrorSuccess Error::success() { return ErrorSuccess(); }
333
334/// Make a Error instance representing failure using the given error info
335/// type.
336template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
337 return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
338}
339
340/// Base class for user error types. Users should declare their error types
341/// like:
342///
343/// class MyError : public ErrorInfo<MyError> {
344/// ....
345/// };
346///
347/// This class provides an implementation of the ErrorInfoBase::kind
348/// method, which is used by the Error RTTI system.
349template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
350class ErrorInfo : public ParentErrT {
351public:
352 using ParentErrT::ParentErrT; // inherit constructors
353
354 static const void *classID() { return &ThisErrT::ID; }
355
356 const void *dynamicClassID() const override { return &ThisErrT::ID; }
357
358 bool isA(const void *const ClassID) const override {
359 return ClassID == classID() || ParentErrT::isA(ClassID);
360 }
361};
362
363/// Special ErrorInfo subclass representing a list of ErrorInfos.
364/// Instances of this class are constructed by joinError.
365class ErrorList final : public ErrorInfo<ErrorList> {
366 // handleErrors needs to be able to iterate the payload list of an
367 // ErrorList.
368 template <typename... HandlerTs>
369 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
370
371 // joinErrors is implemented in terms of join.
372 friend Error joinErrors(Error, Error);
373
374public:
375 void log(raw_ostream &OS) const override {
376 OS << "Multiple errors:\n";
377 for (auto &ErrPayload : Payloads) {
378 ErrPayload->log(OS);
379 OS << "\n";
380 }
381 }
382
383 std::error_code convertToErrorCode() const override;
384
385 // Used by ErrorInfo::classID.
386 static char ID;
387
388private:
389 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
390 std::unique_ptr<ErrorInfoBase> Payload2) {
391 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&
392 "ErrorList constructor payloads should be singleton errors");
393 Payloads.push_back(std::move(Payload1));
394 Payloads.push_back(std::move(Payload2));
395 }
396
397 static Error join(Error E1, Error E2) {
398 if (!E1)
399 return E2;
400 if (!E2)
401 return E1;
402 if (E1.isA<ErrorList>()) {
403 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
404 if (E2.isA<ErrorList>()) {
405 auto E2Payload = E2.takePayload();
406 auto &E2List = static_cast<ErrorList &>(*E2Payload);
407 for (auto &Payload : E2List.Payloads)
408 E1List.Payloads.push_back(std::move(Payload));
409 } else
410 E1List.Payloads.push_back(E2.takePayload());
411
412 return E1;
413 }
414 if (E2.isA<ErrorList>()) {
415 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
416 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
417 return E2;
418 }
419 return Error(std::unique_ptr<ErrorList>(
420 new ErrorList(E1.takePayload(), E2.takePayload())));
421 }
422
423 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
424};
425
426/// Concatenate errors. The resulting Error is unchecked, and contains the
427/// ErrorInfo(s), if any, contained in E1, followed by the
428/// ErrorInfo(s), if any, contained in E2.
429inline Error joinErrors(Error E1, Error E2) {
430 return ErrorList::join(std::move(E1), std::move(E2));
431}
432
433/// Tagged union holding either a T or a Error.
434///
435/// This class parallels ErrorOr, but replaces error_code with Error. Since
436/// Error cannot be copied, this class replaces getError() with
437/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
438/// error class type.
439template <class T> class LLVM_NODISCARD Expected {
440 template <class T1> friend class ExpectedAsOutParameter;
441 template <class OtherT> friend class Expected;
442
443 static constexpr bool isRef = std::is_reference<T>::value;
444
445 using wrap = std::reference_wrapper<std::remove_reference_t<T>>;
446
447 using error_type = std::unique_ptr<ErrorInfoBase>;
448
449public:
450 using storage_type = std::conditional_t<isRef, wrap, T>;
451 using value_type = T;
452
453private:
454 using reference = std::remove_reference_t<T> &;
455 using const_reference = const std::remove_reference_t<T> &;
456 using pointer = std::remove_reference_t<T> *;
457 using const_pointer = const std::remove_reference_t<T> *;
458
459public:
460 /// Create an Expected<T> error value from the given Error.
461 Expected(Error Err)
462 : HasError(true)
463#if LLVM_ENABLE_ABI_BREAKING_CHECKS
464 // Expected is unchecked upon construction in Debug builds.
465 , Unchecked(true)
466#endif
467 {
468 assert(Err && "Cannot create Expected<T> from Error success value.");
469 new (getErrorStorage()) error_type(Err.takePayload());
470 }
471
472 /// Forbid to convert from Error::success() implicitly, this avoids having
473 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
474 /// but triggers the assertion above.
475 Expected(ErrorSuccess) = delete;
476
477 /// Create an Expected<T> success value from the given OtherT value, which
478 /// must be convertible to T.
479 template <typename OtherT>
480 Expected(OtherT &&Val,
481 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
482 : HasError(false)
483#if LLVM_ENABLE_ABI_BREAKING_CHECKS
484 // Expected is unchecked upon construction in Debug builds.
485 ,
486 Unchecked(true)
487#endif
488 {
489 new (getStorage()) storage_type(std::forward<OtherT>(Val));
490 }
491
492 /// Move construct an Expected<T> value.
493 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
494
495 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
496 /// must be convertible to T.
497 template <class OtherT>
498 Expected(
499 Expected<OtherT> &&Other,
500 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
501 moveConstruct(std::move(Other));
502 }
503
504 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
505 /// isn't convertible to T.
506 template <class OtherT>
507 explicit Expected(
508 Expected<OtherT> &&Other,
509 std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
510 moveConstruct(std::move(Other));
511 }
512
513 /// Move-assign from another Expected<T>.
514 Expected &operator=(Expected &&Other) {
515 moveAssign(std::move(Other));
516 return *this;
517 }
518
519 /// Destroy an Expected<T>.
520 ~Expected() {
521 assertIsChecked();
522 if (!HasError)
523 getStorage()->~storage_type();
524 else
525 getErrorStorage()->~error_type();
526 }
527
528 /// Return false if there is an error.
529 explicit operator bool() {
530#if LLVM_ENABLE_ABI_BREAKING_CHECKS
531 Unchecked = HasError;
532#endif
533 return !HasError;
534 }
535
536 /// Returns a reference to the stored T value.
537 reference get() {
538 assertIsChecked();
539 return *getStorage();
540 }
541
542 /// Returns a const reference to the stored T value.
543 const_reference get() const {
544 assertIsChecked();
545 return const_cast<Expected<T> *>(this)->get();
546 }
547
548 /// Check that this Expected<T> is an error of type ErrT.
549 template <typename ErrT> bool errorIsA() const {
550 return HasError && (*getErrorStorage())->template isA<ErrT>();
551 }
552
553 /// Take ownership of the stored error.
554 /// After calling this the Expected<T> is in an indeterminate state that can
555 /// only be safely destructed. No further calls (beside the destructor) should
556 /// be made on the Expected<T> value.
557 Error takeError() {
558#if LLVM_ENABLE_ABI_BREAKING_CHECKS
559 Unchecked = false;
560#endif
561 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
562 }
563
564 /// Returns a pointer to the stored T value.
565 pointer operator->() {
566 assertIsChecked();
567 return toPointer(getStorage());
568 }
569
570 /// Returns a const pointer to the stored T value.
571 const_pointer operator->() const {
572 assertIsChecked();
573 return toPointer(getStorage());
574 }
575
576 /// Returns a reference to the stored T value.
577 reference operator*() {
578 assertIsChecked();
579 return *getStorage();
580 }
581
582 /// Returns a const reference to the stored T value.
583 const_reference operator*() const {
584 assertIsChecked();
585 return *getStorage();
586 }
587
588private:
589 template <class T1>
590 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
591 return &a == &b;
592 }
593
594 template <class T1, class T2>
595 static bool compareThisIfSameType(const T1 &, const T2 &) {
596 return false;
597 }
598
599 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
600 HasError = Other.HasError;
601#if LLVM_ENABLE_ABI_BREAKING_CHECKS
602 Unchecked = true;
603 Other.Unchecked = false;
604#endif
605
606 if (!HasError)
607 new (getStorage()) storage_type(std::move(*Other.getStorage()));
608 else
609 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
610 }
611
612 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
613 assertIsChecked();
614
615 if (compareThisIfSameType(*this, Other))
616 return;
617
618 this->~Expected();
619 new (this) Expected(std::move(Other));
620 }
621
622 pointer toPointer(pointer Val) { return Val; }
623
624 const_pointer toPointer(const_pointer Val) const { return Val; }
625
626 pointer toPointer(wrap *Val) { return &Val->get(); }
627
628 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
629
630 storage_type *getStorage() {
631 assert(!HasError && "Cannot get value when an error exists!");
632 return reinterpret_cast<storage_type *>(&TStorage);
633 }
634
635 const storage_type *getStorage() const {
636 assert(!HasError && "Cannot get value when an error exists!");
637 return reinterpret_cast<const storage_type *>(&TStorage);
638 }
639
640 error_type *getErrorStorage() {
641 assert(HasError && "Cannot get error when a value exists!");
642 return reinterpret_cast<error_type *>(&ErrorStorage);
643 }
644
645 const error_type *getErrorStorage() const {
646 assert(HasError && "Cannot get error when a value exists!");
647 return reinterpret_cast<const error_type *>(&ErrorStorage);
648 }
649
650 // Used by ExpectedAsOutParameter to reset the checked flag.
651 void setUnchecked() {
652#if LLVM_ENABLE_ABI_BREAKING_CHECKS
653 Unchecked = true;
654#endif
655 }
656
657#if LLVM_ENABLE_ABI_BREAKING_CHECKS
658 LLVM_ATTRIBUTE_NORETURN
659 LLVM_ATTRIBUTE_NOINLINE
660 void fatalUncheckedExpected() const {
661 dbgs() << "Expected<T> must be checked before access or destruction.\n";
662 if (HasError) {
663 dbgs() << "Unchecked Expected<T> contained error:\n";
664 (*getErrorStorage())->log(dbgs());
665 } else
666 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
667 "values in success mode must still be checked prior to being "
668 "destroyed).\n";
669 abort();
670 }
671#endif
672
673 void assertIsChecked() {
674#if LLVM_ENABLE_ABI_BREAKING_CHECKS
675 if (LLVM_UNLIKELY(Unchecked))
676 fatalUncheckedExpected();
677#endif
678 }
679
680 union {
681 AlignedCharArrayUnion<storage_type> TStorage;
682 AlignedCharArrayUnion<error_type> ErrorStorage;
683 };
684 bool HasError : 1;
685#if LLVM_ENABLE_ABI_BREAKING_CHECKS
686 bool Unchecked : 1;
687#endif
688};
689
690/// Report a serious error, calling any installed error handler. See
691/// ErrorHandling.h.
692LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err,
693 bool gen_crash_diag = true);
694
695/// Report a fatal error if Err is a failure value.
696///
697/// This function can be used to wrap calls to fallible functions ONLY when it
698/// is known that the Error will always be a success value. E.g.
699///
700/// @code{.cpp}
701/// // foo only attempts the fallible operation if DoFallibleOperation is
702/// // true. If DoFallibleOperation is false then foo always returns
703/// // Error::success().
704/// Error foo(bool DoFallibleOperation);
705///
706/// cantFail(foo(false));
707/// @endcode
708inline void cantFail(Error Err, const char *Msg = nullptr) {
709 if (Err) {
710 if (!Msg)
711 Msg = "Failure value returned from cantFail wrapped call";
712#ifndef NDEBUG
713 std::string Str;
714 raw_string_ostream OS(Str);
715 OS << Msg << "\n" << Err;
716 Msg = OS.str().c_str();
717#endif
718 llvm_unreachable(Msg);
719 }
720}
721
722/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
723/// returns the contained value.
724///
725/// This function can be used to wrap calls to fallible functions ONLY when it
726/// is known that the Error will always be a success value. E.g.
727///
728/// @code{.cpp}
729/// // foo only attempts the fallible operation if DoFallibleOperation is
730/// // true. If DoFallibleOperation is false then foo always returns an int.
731/// Expected<int> foo(bool DoFallibleOperation);
732///
733/// int X = cantFail(foo(false));
734/// @endcode
735template <typename T>
736T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
737 if (ValOrErr)
738 return std::move(*ValOrErr);
739 else {
740 if (!Msg)
741 Msg = "Failure value returned from cantFail wrapped call";
742#ifndef NDEBUG
743 std::string Str;
744 raw_string_ostream OS(Str);
745 auto E = ValOrErr.takeError();
746 OS << Msg << "\n" << E;
747 Msg = OS.str().c_str();
748#endif
749 llvm_unreachable(Msg);
750 }
751}
752
753/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
754/// returns the contained reference.
755///
756/// This function can be used to wrap calls to fallible functions ONLY when it
757/// is known that the Error will always be a success value. E.g.
758///
759/// @code{.cpp}
760/// // foo only attempts the fallible operation if DoFallibleOperation is
761/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
762/// Expected<Bar&> foo(bool DoFallibleOperation);
763///
764/// Bar &X = cantFail(foo(false));
765/// @endcode
766template <typename T>
767T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
768 if (ValOrErr)
769 return *ValOrErr;
770 else {
771 if (!Msg)
772 Msg = "Failure value returned from cantFail wrapped call";
773#ifndef NDEBUG
774 std::string Str;
775 raw_string_ostream OS(Str);
776 auto E = ValOrErr.takeError();
777 OS << Msg << "\n" << E;
778 Msg = OS.str().c_str();
779#endif
780 llvm_unreachable(Msg);
781 }
782}
783
784/// Helper for testing applicability of, and applying, handlers for
785/// ErrorInfo types.
786template <typename HandlerT>
787class ErrorHandlerTraits
788 : public ErrorHandlerTraits<decltype(
789 &std::remove_reference<HandlerT>::type::operator())> {};
790
791// Specialization functions of the form 'Error (const ErrT&)'.
792template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
793public:
794 static bool appliesTo(const ErrorInfoBase &E) {
795 return E.template isA<ErrT>();
796 }
797
798 template <typename HandlerT>
799 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
800 assert(appliesTo(*E) && "Applying incorrect handler");
801 return H(static_cast<ErrT &>(*E));
802 }
803};
804
805// Specialization functions of the form 'void (const ErrT&)'.
806template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
807public:
808 static bool appliesTo(const ErrorInfoBase &E) {
809 return E.template isA<ErrT>();
810 }
811
812 template <typename HandlerT>
813 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
814 assert(appliesTo(*E) && "Applying incorrect handler");
815 H(static_cast<ErrT &>(*E));
816 return Error::success();
817 }
818};
819
820/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
821template <typename ErrT>
822class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
823public:
824 static bool appliesTo(const ErrorInfoBase &E) {
825 return E.template isA<ErrT>();
826 }
827
828 template <typename HandlerT>
829 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
830 assert(appliesTo(*E) && "Applying incorrect handler");
831 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
832 return H(std::move(SubE));
833 }
834};
835
836/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
837template <typename ErrT>
838class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
839public:
840 static bool appliesTo(const ErrorInfoBase &E) {
841 return E.template isA<ErrT>();
842 }
843
844 template <typename HandlerT>
845 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
846 assert(appliesTo(*E) && "Applying incorrect handler");
847 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
848 H(std::move(SubE));
849 return Error::success();
850 }
851};
852
853// Specialization for member functions of the form 'RetT (const ErrT&)'.
854template <typename C, typename RetT, typename ErrT>
855class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
856 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
857
858// Specialization for member functions of the form 'RetT (const ErrT&) const'.
859template <typename C, typename RetT, typename ErrT>
860class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
861 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
862
863// Specialization for member functions of the form 'RetT (const ErrT&)'.
864template <typename C, typename RetT, typename ErrT>
865class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
866 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
867
868// Specialization for member functions of the form 'RetT (const ErrT&) const'.
869template <typename C, typename RetT, typename ErrT>
870class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
871 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
872
873/// Specialization for member functions of the form
874/// 'RetT (std::unique_ptr<ErrT>)'.
875template <typename C, typename RetT, typename ErrT>
876class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
877 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
878
879/// Specialization for member functions of the form
880/// 'RetT (std::unique_ptr<ErrT>) const'.
881template <typename C, typename RetT, typename ErrT>
882class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
883 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
884
885inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
886 return Error(std::move(Payload));
887}
888
889template <typename HandlerT, typename... HandlerTs>
890Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
891 HandlerT &&Handler, HandlerTs &&... Handlers) {
892 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
893 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
894 std::move(Payload));
895 return handleErrorImpl(std::move(Payload),
896 std::forward<HandlerTs>(Handlers)...);
897}
898
899/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
900/// unhandled errors (or Errors returned by handlers) are re-concatenated and
901/// returned.
902/// Because this function returns an error, its result must also be checked
903/// or returned. If you intend to handle all errors use handleAllErrors
904/// (which returns void, and will abort() on unhandled errors) instead.
905template <typename... HandlerTs>
906Error handleErrors(Error E, HandlerTs &&... Hs) {
907 if (!E)
908 return Error::success();
909
910 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
911
912 if (Payload->isA<ErrorList>()) {
913 ErrorList &List = static_cast<ErrorList &>(*Payload);
914 Error R;
915 for (auto &P : List.Payloads)
916 R = ErrorList::join(
917 std::move(R),
918 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
919 return R;
920 }
921
922 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
923}
924
925/// Behaves the same as handleErrors, except that by contract all errors
926/// *must* be handled by the given handlers (i.e. there must be no remaining
927/// errors after running the handlers, or llvm_unreachable is called).
928template <typename... HandlerTs>
929void handleAllErrors(Error E, HandlerTs &&... Handlers) {
930 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
931}
932
933/// Check that E is a non-error, then drop it.
934/// If E is an error, llvm_unreachable will be called.
935inline void handleAllErrors(Error E) {
936 cantFail(std::move(E));
937}
938
939/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
940///
941/// If the incoming value is a success value it is returned unmodified. If it
942/// is a failure value then it the contained error is passed to handleErrors.
943/// If handleErrors is able to handle the error then the RecoveryPath functor
944/// is called to supply the final result. If handleErrors is not able to
945/// handle all errors then the unhandled errors are returned.
946///
947/// This utility enables the follow pattern:
948///
949/// @code{.cpp}
950/// enum FooStrategy { Aggressive, Conservative };
951/// Expected<Foo> foo(FooStrategy S);
952///
953/// auto ResultOrErr =
954/// handleExpected(
955/// foo(Aggressive),
956/// []() { return foo(Conservative); },
957/// [](AggressiveStrategyError&) {
958/// // Implicitly conusme this - we'll recover by using a conservative
959/// // strategy.
960/// });
961///
962/// @endcode
963template <typename T, typename RecoveryFtor, typename... HandlerTs>
964Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
965 HandlerTs &&... Handlers) {
966 if (ValOrErr)
967 return ValOrErr;
968
969 if (auto Err = handleErrors(ValOrErr.takeError(),
970 std::forward<HandlerTs>(Handlers)...))
971 return std::move(Err);
972
973 return RecoveryPath();
974}
975
976/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
977/// will be printed before the first one is logged. A newline will be printed
978/// after each error.
979///
980/// This function is compatible with the helpers from Support/WithColor.h. You
981/// can pass any of them as the OS. Please consider using them instead of
982/// including 'error: ' in the ErrorBanner.
983///
984/// This is useful in the base level of your program to allow clean termination
985/// (allowing clean deallocation of resources, etc.), while reporting error
986/// information to the user.
987void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
988
989/// Write all error messages (if any) in E to a string. The newline character
990/// is used to separate error messages.
991inline std::string toString(Error E) {
992 SmallVector<std::string, 2> Errors;
993 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
994 Errors.push_back(EI.message());
995 });
996 return join(Errors.begin(), Errors.end(), "\n");
997}
998
999/// Consume a Error without doing anything. This method should be used
1000/// only where an error can be considered a reasonable and expected return
1001/// value.
1002///
1003/// Uses of this method are potentially indicative of design problems: If it's
1004/// legitimate to do nothing while processing an "error", the error-producer
1005/// might be more clearly refactored to return an Optional<T>.
1006inline void consumeError(Error Err) {
1007 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
1008}
1009
1010/// Convert an Expected to an Optional without doing anything. This method
1011/// should be used only where an error can be considered a reasonable and
1012/// expected return value.
1013///
1014/// Uses of this method are potentially indicative of problems: perhaps the
1015/// error should be propagated further, or the error-producer should just
1016/// return an Optional in the first place.
1017template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
1018 if (E)
1019 return std::move(*E);
1020 consumeError(E.takeError());
1021 return None;
1022}
1023
1024/// Helper for converting an Error to a bool.
1025///
1026/// This method returns true if Err is in an error state, or false if it is
1027/// in a success state. Puts Err in a checked state in both cases (unlike
1028/// Error::operator bool(), which only does this for success states).
1029inline bool errorToBool(Error Err) {
1030 bool IsError = static_cast<bool>(Err);
1031 if (IsError)
1032 consumeError(std::move(Err));
1033 return IsError;
1034}
1035
1036/// Helper for Errors used as out-parameters.
1037///
1038/// This helper is for use with the Error-as-out-parameter idiom, where an error
1039/// is passed to a function or method by reference, rather than being returned.
1040/// In such cases it is helpful to set the checked bit on entry to the function
1041/// so that the error can be written to (unchecked Errors abort on assignment)
1042/// and clear the checked bit on exit so that clients cannot accidentally forget
1043/// to check the result. This helper performs these actions automatically using
1044/// RAII:
1045///
1046/// @code{.cpp}
1047/// Result foo(Error &Err) {
1048/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1049/// // <body of foo>
1050/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1051/// }
1052/// @endcode
1053///
1054/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1055/// used with optional Errors (Error pointers that are allowed to be null). If
1056/// ErrorAsOutParameter took an Error reference, an instance would have to be
1057/// created inside every condition that verified that Error was non-null. By
1058/// taking an Error pointer we can just create one instance at the top of the
1059/// function.
1060class ErrorAsOutParameter {
1061public:
1062 ErrorAsOutParameter(Error *Err) : Err(Err) {
1063 // Raise the checked bit if Err is success.
1064 if (Err)
1065 (void)!!*Err;
1066 }
1067
1068 ~ErrorAsOutParameter() {
1069 // Clear the checked bit.
1070 if (Err && !*Err)
1071 *Err = Error::success();
1072 }
1073
1074private:
1075 Error *Err;
1076};
1077
1078/// Helper for Expected<T>s used as out-parameters.
1079///
1080/// See ErrorAsOutParameter.
1081template <typename T>
1082class ExpectedAsOutParameter {
1083public:
1084 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1085 : ValOrErr(ValOrErr) {
1086 if (ValOrErr)
1087 (void)!!*ValOrErr;
1088 }
1089
1090 ~ExpectedAsOutParameter() {
1091 if (ValOrErr)
1092 ValOrErr->setUnchecked();
1093 }
1094
1095private:
1096 Expected<T> *ValOrErr;
1097};
1098
1099/// This class wraps a std::error_code in a Error.
1100///
1101/// This is useful if you're writing an interface that returns a Error
1102/// (or Expected) and you want to call code that still returns
1103/// std::error_codes.
1104class ECError : public ErrorInfo<ECError> {
1105 friend Error errorCodeToError(std::error_code);
1106
1107 virtual void anchor() override;
1108
1109public:
1110 void setErrorCode(std::error_code EC) { this->EC = EC; }
1111 std::error_code convertToErrorCode() const override { return EC; }
1112 void log(raw_ostream &OS) const override { OS << EC.message(); }
1113
1114 // Used by ErrorInfo::classID.
1115 static char ID;
1116
1117protected:
1118 ECError() = default;
1119 ECError(std::error_code EC) : EC(EC) {}
1120
1121 std::error_code EC;
1122};
1123
1124/// The value returned by this function can be returned from convertToErrorCode
1125/// for Error values where no sensible translation to std::error_code exists.
1126/// It should only be used in this situation, and should never be used where a
1127/// sensible conversion to std::error_code is available, as attempts to convert
1128/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1129///error to try to convert such a value).
1130std::error_code inconvertibleErrorCode();
1131
1132/// Helper for converting an std::error_code to a Error.
1133Error errorCodeToError(std::error_code EC);
1134
1135/// Helper for converting an ECError to a std::error_code.
1136///
1137/// This method requires that Err be Error() or an ECError, otherwise it
1138/// will trigger a call to abort().
1139std::error_code errorToErrorCode(Error Err);
1140
1141/// Convert an ErrorOr<T> to an Expected<T>.
1142template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1143 if (auto EC = EO.getError())
1144 return errorCodeToError(EC);
1145 return std::move(*EO);
1146}
1147
1148/// Convert an Expected<T> to an ErrorOr<T>.
1149template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1150 if (auto Err = E.takeError())
1151 return errorToErrorCode(std::move(Err));
1152 return std::move(*E);
1153}
1154
1155/// This class wraps a string in an Error.
1156///
1157/// StringError is useful in cases where the client is not expected to be able
1158/// to consume the specific error message programmatically (for example, if the
1159/// error message is to be presented to the user).
1160///
1161/// StringError can also be used when additional information is to be printed
1162/// along with a error_code message. Depending on the constructor called, this
1163/// class can either display:
1164/// 1. the error_code message (ECError behavior)
1165/// 2. a string
1166/// 3. the error_code message and a string
1167///
1168/// These behaviors are useful when subtyping is required; for example, when a
1169/// specific library needs an explicit error type. In the example below,
1170/// PDBError is derived from StringError:
1171///
1172/// @code{.cpp}
1173/// Expected<int> foo() {
1174/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1175/// "Additional information");
1176/// }
1177/// @endcode
1178///
1179class StringError : public ErrorInfo<StringError> {
1180public:
1181 static char ID;
1182
1183 // Prints EC + S and converts to EC
1184 StringError(std::error_code EC, const Twine &S = Twine());
1185
1186 // Prints S and converts to EC
1187 StringError(const Twine &S, std::error_code EC);
1188
1189 void log(raw_ostream &OS) const override;
1190 std::error_code convertToErrorCode() const override;
1191
1192 const std::string &getMessage() const { return Msg; }
1193
1194private:
1195 std::string Msg;
1196 std::error_code EC;
1197 const bool PrintMsgOnly = false;
1198};
1199
1200/// Create formatted StringError object.
1201template <typename... Ts>
1202inline Error createStringError(std::error_code EC, char const *Fmt,
1203 const Ts &... Vals) {
1204 std::string Buffer;
1205 raw_string_ostream Stream(Buffer);
1206 Stream << format(Fmt, Vals...);
1207 return make_error<StringError>(Stream.str(), EC);
1208}
1209
1210Error createStringError(std::error_code EC, char const *Msg);
1211
1212inline Error createStringError(std::error_code EC, const Twine &S) {
1213 return createStringError(EC, S.str().c_str());
1214}
1215
1216template <typename... Ts>
1217inline Error createStringError(std::errc EC, char const *Fmt,
1218 const Ts &... Vals) {
1219 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1220}
1221
1222/// This class wraps a filename and another Error.
1223///
1224/// In some cases, an error needs to live along a 'source' name, in order to
1225/// show more detailed information to the user.
1226class FileError final : public ErrorInfo<FileError> {
1227
1228 friend Error createFileError(const Twine &, Error);
1229 friend Error createFileError(const Twine &, size_t, Error);
1230
1231public:
1232 void log(raw_ostream &OS) const override {
1233 assert(Err && !FileName.empty() && "Trying to log after takeError().");
1234 OS << "'" << FileName << "': ";
1235 if (Line.hasValue())
1236 OS << "line " << Line.getValue() << ": ";
1237 Err->log(OS);
1238 }
1239
1240 StringRef getFileName() { return FileName; }
1241
1242 Error takeError() { return Error(std::move(Err)); }
1243
1244 std::error_code convertToErrorCode() const override;
1245
1246 // Used by ErrorInfo::classID.
1247 static char ID;
1248
1249private:
1250 FileError(const Twine &F, Optional<size_t> LineNum,
1251 std::unique_ptr<ErrorInfoBase> E) {
1252 assert(E && "Cannot create FileError from Error success value.");
1253 assert(!F.isTriviallyEmpty() &&
1254 "The file name provided to FileError must not be empty.");
1255 FileName = F.str();
1256 Err = std::move(E);
1257 Line = std::move(LineNum);
1258 }
1259
1260 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1261 std::unique_ptr<ErrorInfoBase> Payload;
1262 handleAllErrors(std::move(E),
1263 [&](std::unique_ptr<ErrorInfoBase> EIB) -> Error {
1264 Payload = std::move(EIB);
1265 return Error::success();
1266 });
1267 return Error(
1268 std::unique_ptr<FileError>(new FileError(F, Line, std::move(Payload))));
1269 }
1270
1271 std::string FileName;
1272 Optional<size_t> Line;
1273 std::unique_ptr<ErrorInfoBase> Err;
1274};
1275
1276/// Concatenate a source file path and/or name with an Error. The resulting
1277/// Error is unchecked.
1278inline Error createFileError(const Twine &F, Error E) {
1279 return FileError::build(F, Optional<size_t>(), std::move(E));
1280}
1281
1282/// Concatenate a source file path and/or name with line number and an Error.
1283/// The resulting Error is unchecked.
1284inline Error createFileError(const Twine &F, size_t Line, Error E) {
1285 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1286}
1287
1288/// Concatenate a source file path and/or name with a std::error_code
1289/// to form an Error object.
1290inline Error createFileError(const Twine &F, std::error_code EC) {
1291 return createFileError(F, errorCodeToError(EC));
1292}
1293
1294/// Concatenate a source file path and/or name with line number and
1295/// std::error_code to form an Error object.
1296inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1297 return createFileError(F, Line, errorCodeToError(EC));
1298}
1299
1300Error createFileError(const Twine &F, ErrorSuccess) = delete;
1301
1302/// Helper for check-and-exit error handling.
1303///
1304/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1305///
1306class ExitOnError {
1307public:
1308 /// Create an error on exit helper.
1309 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1310 : Banner(std::move(Banner)),
1311 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1312
1313 /// Set the banner string for any errors caught by operator().
1314 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1315
1316 /// Set the exit-code mapper function.
1317 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1318 this->GetExitCode = std::move(GetExitCode);
1319 }
1320
1321 /// Check Err. If it's in a failure state log the error(s) and exit.
1322 void operator()(Error Err) const { checkError(std::move(Err)); }
1323
1324 /// Check E. If it's in a success state then return the contained value. If
1325 /// it's in a failure state log the error(s) and exit.
1326 template <typename T> T operator()(Expected<T> &&E) const {
1327 checkError(E.takeError());
1328 return std::move(*E);
1329 }
1330
1331 /// Check E. If it's in a success state then return the contained reference. If
1332 /// it's in a failure state log the error(s) and exit.
1333 template <typename T> T& operator()(Expected<T&> &&E) const {
1334 checkError(E.takeError());
1335 return *E;
1336 }
1337
1338private:
1339 void checkError(Error Err) const {
1340 if (Err) {
1341 int ExitCode = GetExitCode(Err);
1342 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1343 exit(ExitCode);
1344 }
1345 }
1346
1347 std::string Banner;
1348 std::function<int(const Error &)> GetExitCode;
1349};
1350
1351/// Conversion from Error to LLVMErrorRef for C error bindings.
1352inline LLVMErrorRef wrap(Error Err) {
1353 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1354}
1355
1356/// Conversion from LLVMErrorRef to Error for C error bindings.
1357inline Error unwrap(LLVMErrorRef ErrRef) {
1358 return Error(std::unique_ptr<ErrorInfoBase>(
1359 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1360}
1361
1362} // end namespace llvm
1363
1364#endif // LLVM_SUPPORT_ERROR_H
1365