Bug Summary

File:include/llvm/Support/Error.h
Warning:line 200, column 5
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name BlockVerifier.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -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 -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-9/lib/clang/9.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-9~svn358860/build-llvm/lib/XRay -I /build/llvm-toolchain-snapshot-9~svn358860/lib/XRay -I /build/llvm-toolchain-snapshot-9~svn358860/build-llvm/include -I /build/llvm-toolchain-snapshot-9~svn358860/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/9.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-9/lib/clang/9.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-9~svn358860/build-llvm/lib/XRay -fdebug-prefix-map=/build/llvm-toolchain-snapshot-9~svn358860=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2019-04-22-050718-5320-1 -x c++ /build/llvm-toolchain-snapshot-9~svn358860/lib/XRay/BlockVerifier.cpp -faddrsig

/build/llvm-toolchain-snapshot-9~svn358860/lib/XRay/BlockVerifier.cpp

1//===- BlockVerifier.cpp - FDR Block Verifier -----------------------------===//
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#include "llvm/XRay/BlockVerifier.h"
9#include "llvm/Support/Error.h"
10
11namespace llvm {
12namespace xray {
13namespace {
14
15constexpr unsigned long long mask(BlockVerifier::State S) {
16 return 1uLL << static_cast<std::size_t>(S);
17}
18
19constexpr std::size_t number(BlockVerifier::State S) {
20 return static_cast<std::size_t>(S);
21}
22
23StringRef recordToString(BlockVerifier::State R) {
24 switch (R) {
25 case BlockVerifier::State::BufferExtents:
26 return "BufferExtents";
27 case BlockVerifier::State::NewBuffer:
28 return "NewBuffer";
29 case BlockVerifier::State::WallClockTime:
30 return "WallClockTime";
31 case BlockVerifier::State::PIDEntry:
32 return "PIDEntry";
33 case BlockVerifier::State::NewCPUId:
34 return "NewCPUId";
35 case BlockVerifier::State::TSCWrap:
36 return "TSCWrap";
37 case BlockVerifier::State::CustomEvent:
38 return "CustomEvent";
39 case BlockVerifier::State::Function:
40 return "Function";
41 case BlockVerifier::State::CallArg:
42 return "CallArg";
43 case BlockVerifier::State::EndOfBuffer:
44 return "EndOfBuffer";
45 case BlockVerifier::State::TypedEvent:
46 return "TypedEvent";
47 case BlockVerifier::State::StateMax:
48 case BlockVerifier::State::Unknown:
49 return "Unknown";
50 }
51 llvm_unreachable("Unkown state!")::llvm::llvm_unreachable_internal("Unkown state!", "/build/llvm-toolchain-snapshot-9~svn358860/lib/XRay/BlockVerifier.cpp"
, 51)
;
52}
53
54struct Transition {
55 BlockVerifier::State From;
56 std::bitset<number(BlockVerifier::State::StateMax)> ToStates;
57};
58
59} // namespace
60
61Error BlockVerifier::transition(State To) {
62 using ToSet = std::bitset<number(State::StateMax)>;
63 static constexpr std::array<const Transition, number(State::StateMax)>
64 TransitionTable{{{State::Unknown,
65 {mask(State::BufferExtents) | mask(State::NewBuffer)}},
66
67 {State::BufferExtents, {mask(State::NewBuffer)}},
68
69 {State::NewBuffer, {mask(State::WallClockTime)}},
70
71 {State::WallClockTime,
72 {mask(State::PIDEntry) | mask(State::NewCPUId)}},
73
74 {State::PIDEntry, {mask(State::NewCPUId)}},
75
76 {State::NewCPUId,
77 {mask(State::NewCPUId) | mask(State::TSCWrap) |
78 mask(State::CustomEvent) | mask(State::Function) |
79 mask(State::EndOfBuffer) | mask(State::TypedEvent)}},
80
81 {State::TSCWrap,
82 {mask(State::TSCWrap) | mask(State::NewCPUId) |
83 mask(State::CustomEvent) | mask(State::Function) |
84 mask(State::EndOfBuffer) | mask(State::TypedEvent)}},
85
86 {State::CustomEvent,
87 {mask(State::CustomEvent) | mask(State::TSCWrap) |
88 mask(State::NewCPUId) | mask(State::Function) |
89 mask(State::EndOfBuffer) | mask(State::TypedEvent)}},
90
91 {State::TypedEvent,
92 {mask(State::TypedEvent) | mask(State::TSCWrap) |
93 mask(State::NewCPUId) | mask(State::Function) |
94 mask(State::EndOfBuffer) | mask(State::CustomEvent)}},
95
96 {State::Function,
97 {mask(State::Function) | mask(State::TSCWrap) |
98 mask(State::NewCPUId) | mask(State::CustomEvent) |
99 mask(State::CallArg) | mask(State::EndOfBuffer) |
100 mask(State::TypedEvent)}},
101
102 {State::CallArg,
103 {mask(State::CallArg) | mask(State::Function) |
104 mask(State::TSCWrap) | mask(State::NewCPUId) |
105 mask(State::CustomEvent) | mask(State::EndOfBuffer) |
106 mask(State::TypedEvent)}},
107
108 {State::EndOfBuffer, {}}}};
109
110 if (CurrentRecord >= State::StateMax)
111 return createStringError(
112 std::make_error_code(std::errc::executable_format_error),
113 "BUG (BlockVerifier): Cannot find transition table entry for %s, "
114 "transitioning to %s.",
115 recordToString(CurrentRecord).data(), recordToString(To).data());
116
117 // If we're at an EndOfBuffer record, we ignore anything that follows that
118 // isn't a NewBuffer record.
119 if (CurrentRecord == State::EndOfBuffer && To != State::NewBuffer)
120 return Error::success();
121
122 auto &Mapping = TransitionTable[number(CurrentRecord)];
123 auto &Destinations = Mapping.ToStates;
124 assert(Mapping.From == CurrentRecord &&((Mapping.From == CurrentRecord && "BUG: Wrong index for record mapping."
) ? static_cast<void> (0) : __assert_fail ("Mapping.From == CurrentRecord && \"BUG: Wrong index for record mapping.\""
, "/build/llvm-toolchain-snapshot-9~svn358860/lib/XRay/BlockVerifier.cpp"
, 125, __PRETTY_FUNCTION__))
125 "BUG: Wrong index for record mapping.")((Mapping.From == CurrentRecord && "BUG: Wrong index for record mapping."
) ? static_cast<void> (0) : __assert_fail ("Mapping.From == CurrentRecord && \"BUG: Wrong index for record mapping.\""
, "/build/llvm-toolchain-snapshot-9~svn358860/lib/XRay/BlockVerifier.cpp"
, 125, __PRETTY_FUNCTION__))
;
126 if ((Destinations & ToSet(mask(To))) == 0)
127 return createStringError(
128 std::make_error_code(std::errc::executable_format_error),
129 "BlockVerifier: Invalid transition from %s to %s.",
130 recordToString(CurrentRecord).data(), recordToString(To).data());
131
132 CurrentRecord = To;
133 return Error::success();
134} // namespace xray
135
136Error BlockVerifier::visit(BufferExtents &) {
137 return transition(State::BufferExtents);
138}
139
140Error BlockVerifier::visit(WallclockRecord &) {
141 return transition(State::WallClockTime);
142}
143
144Error BlockVerifier::visit(NewCPUIDRecord &) {
145 return transition(State::NewCPUId);
146}
147
148Error BlockVerifier::visit(TSCWrapRecord &) {
149 return transition(State::TSCWrap);
150}
151
152Error BlockVerifier::visit(CustomEventRecord &) {
153 return transition(State::CustomEvent);
154}
155
156Error BlockVerifier::visit(CustomEventRecordV5 &) {
157 return transition(State::CustomEvent);
158}
159
160Error BlockVerifier::visit(TypedEventRecord &) {
161 return transition(State::TypedEvent);
162}
163
164Error BlockVerifier::visit(CallArgRecord &) {
165 return transition(State::CallArg);
166}
167
168Error BlockVerifier::visit(PIDRecord &) { return transition(State::PIDEntry); }
169
170Error BlockVerifier::visit(NewBufferRecord &) {
171 return transition(State::NewBuffer);
172}
173
174Error BlockVerifier::visit(EndBufferRecord &) {
175 return transition(State::EndOfBuffer);
176}
177
178Error BlockVerifier::visit(FunctionRecord &) {
179 return transition(State::Function);
180}
181
182Error BlockVerifier::verify() {
183 // The known terminal conditions are the following:
184 switch (CurrentRecord) {
1
Control jumps to the 'default' case at line 193
185 case State::EndOfBuffer:
186 case State::NewCPUId:
187 case State::CustomEvent:
188 case State::TypedEvent:
189 case State::Function:
190 case State::CallArg:
191 case State::TSCWrap:
192 return Error::success();
193 default:
194 return createStringError(
2
Calling 'createStringError<const char *>'
195 std::make_error_code(std::errc::executable_format_error),
196 "BlockVerifier: Invalid terminal condition %s, malformed block.",
197 recordToString(CurrentRecord).data());
198 }
199}
200
201void BlockVerifier::reset() { CurrentRecord = State::Unknown; }
202
203} // namespace xray
204} // namespace llvm

/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h

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[[clang::warn_unused_result]] Error {
158 // Both ErrorList and FileError need to be able to yank ErrorInfoBase
159 // pointers out of this class to add to the error list.
160 friend class ErrorList;
161 friend class FileError;
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);
8
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'
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_CHECKS1
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__attribute__((noreturn))
261 void fatalUncheckedError() const;
262#endif
263
264 void assertIsChecked() {
265#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
266 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
267 fatalUncheckedError();
268#endif
269 }
270
271 ErrorInfoBase *getPtr() const {
272 return reinterpret_cast<ErrorInfoBase*>(
273 reinterpret_cast<uintptr_t>(Payload) &
274 ~static_cast<uintptr_t>(0x1));
275 }
276
277 void setPtr(ErrorInfoBase *EI) {
278#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
279 Payload = reinterpret_cast<ErrorInfoBase*>(
280 (reinterpret_cast<uintptr_t>(EI) &
281 ~static_cast<uintptr_t>(0x1)) |
282 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
283#else
284 Payload = EI;
285#endif
286 }
287
288 bool getChecked() const {
289#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
290 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
291#else
292 return true;
293#endif
294 }
295
296 void setChecked(bool V) {
297 Payload = reinterpret_cast<ErrorInfoBase*>(
298 (reinterpret_cast<uintptr_t>(Payload) &
299 ~static_cast<uintptr_t>(0x1)) |
300 (V ? 0 : 1));
301 }
302
303 std::unique_ptr<ErrorInfoBase> takePayload() {
304 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
305 setPtr(nullptr);
306 setChecked(true);
307 return Tmp;
308 }
309
310 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
311 if (auto P = E.getPtr())
312 P->log(OS);
313 else
314 OS << "success";
315 return OS;
316 }
317
318 ErrorInfoBase *Payload = nullptr;
319};
320
321/// Subclass of Error for the sole purpose of identifying the success path in
322/// the type system. This allows to catch invalid conversion to Expected<T> at
323/// compile time.
324class ErrorSuccess final : public Error {};
325
326inline ErrorSuccess Error::success() { return ErrorSuccess(); }
327
328/// Make a Error instance representing failure using the given error info
329/// type.
330template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
331 return Error(llvm::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
4
Calling 'make_unique<llvm::StringError, std::__cxx11::basic_string<char> &, std::error_code &>'
6
Returned allocated memory
7
Calling constructor for 'Error'
332}
333
334/// Base class for user error types. Users should declare their error types
335/// like:
336///
337/// class MyError : public ErrorInfo<MyError> {
338/// ....
339/// };
340///
341/// This class provides an implementation of the ErrorInfoBase::kind
342/// method, which is used by the Error RTTI system.
343template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
344class ErrorInfo : public ParentErrT {
345public:
346 using ParentErrT::ParentErrT; // inherit constructors
347
348 static const void *classID() { return &ThisErrT::ID; }
349
350 const void *dynamicClassID() const override { return &ThisErrT::ID; }
351
352 bool isA(const void *const ClassID) const override {
353 return ClassID == classID() || ParentErrT::isA(ClassID);
354 }
355};
356
357/// Special ErrorInfo subclass representing a list of ErrorInfos.
358/// Instances of this class are constructed by joinError.
359class ErrorList final : public ErrorInfo<ErrorList> {
360 // handleErrors needs to be able to iterate the payload list of an
361 // ErrorList.
362 template <typename... HandlerTs>
363 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
364
365 // joinErrors is implemented in terms of join.
366 friend Error joinErrors(Error, Error);
367
368public:
369 void log(raw_ostream &OS) const override {
370 OS << "Multiple errors:\n";
371 for (auto &ErrPayload : Payloads) {
372 ErrPayload->log(OS);
373 OS << "\n";
374 }
375 }
376
377 std::error_code convertToErrorCode() const override;
378
379 // Used by ErrorInfo::classID.
380 static char ID;
381
382private:
383 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
384 std::unique_ptr<ErrorInfoBase> Payload2) {
385 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 386, __PRETTY_FUNCTION__))
386 "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 386, __PRETTY_FUNCTION__))
;
387 Payloads.push_back(std::move(Payload1));
388 Payloads.push_back(std::move(Payload2));
389 }
390
391 static Error join(Error E1, Error E2) {
392 if (!E1)
393 return E2;
394 if (!E2)
395 return E1;
396 if (E1.isA<ErrorList>()) {
397 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
398 if (E2.isA<ErrorList>()) {
399 auto E2Payload = E2.takePayload();
400 auto &E2List = static_cast<ErrorList &>(*E2Payload);
401 for (auto &Payload : E2List.Payloads)
402 E1List.Payloads.push_back(std::move(Payload));
403 } else
404 E1List.Payloads.push_back(E2.takePayload());
405
406 return E1;
407 }
408 if (E2.isA<ErrorList>()) {
409 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
410 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
411 return E2;
412 }
413 return Error(std::unique_ptr<ErrorList>(
414 new ErrorList(E1.takePayload(), E2.takePayload())));
415 }
416
417 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
418};
419
420/// Concatenate errors. The resulting Error is unchecked, and contains the
421/// ErrorInfo(s), if any, contained in E1, followed by the
422/// ErrorInfo(s), if any, contained in E2.
423inline Error joinErrors(Error E1, Error E2) {
424 return ErrorList::join(std::move(E1), std::move(E2));
425}
426
427/// Tagged union holding either a T or a Error.
428///
429/// This class parallels ErrorOr, but replaces error_code with Error. Since
430/// Error cannot be copied, this class replaces getError() with
431/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
432/// error class type.
433template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
434 template <class T1> friend class ExpectedAsOutParameter;
435 template <class OtherT> friend class Expected;
436
437 static const bool isRef = std::is_reference<T>::value;
438
439 using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
440
441 using error_type = std::unique_ptr<ErrorInfoBase>;
442
443public:
444 using storage_type = typename std::conditional<isRef, wrap, T>::type;
445 using value_type = T;
446
447private:
448 using reference = typename std::remove_reference<T>::type &;
449 using const_reference = const typename std::remove_reference<T>::type &;
450 using pointer = typename std::remove_reference<T>::type *;
451 using const_pointer = const typename std::remove_reference<T>::type *;
452
453public:
454 /// Create an Expected<T> error value from the given Error.
455 Expected(Error Err)
456 : HasError(true)
457#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
458 // Expected is unchecked upon construction in Debug builds.
459 , Unchecked(true)
460#endif
461 {
462 assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 462, __PRETTY_FUNCTION__))
;
463 new (getErrorStorage()) error_type(Err.takePayload());
464 }
465
466 /// Forbid to convert from Error::success() implicitly, this avoids having
467 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
468 /// but triggers the assertion above.
469 Expected(ErrorSuccess) = delete;
470
471 /// Create an Expected<T> success value from the given OtherT value, which
472 /// must be convertible to T.
473 template <typename OtherT>
474 Expected(OtherT &&Val,
475 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
476 * = nullptr)
477 : HasError(false)
478#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
479 // Expected is unchecked upon construction in Debug builds.
480 , Unchecked(true)
481#endif
482 {
483 new (getStorage()) storage_type(std::forward<OtherT>(Val));
484 }
485
486 /// Move construct an Expected<T> value.
487 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
488
489 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
490 /// must be convertible to T.
491 template <class OtherT>
492 Expected(Expected<OtherT> &&Other,
493 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
494 * = nullptr) {
495 moveConstruct(std::move(Other));
496 }
497
498 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
499 /// isn't convertible to T.
500 template <class OtherT>
501 explicit Expected(
502 Expected<OtherT> &&Other,
503 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
504 nullptr) {
505 moveConstruct(std::move(Other));
506 }
507
508 /// Move-assign from another Expected<T>.
509 Expected &operator=(Expected &&Other) {
510 moveAssign(std::move(Other));
511 return *this;
512 }
513
514 /// Destroy an Expected<T>.
515 ~Expected() {
516 assertIsChecked();
517 if (!HasError)
518 getStorage()->~storage_type();
519 else
520 getErrorStorage()->~error_type();
521 }
522
523 /// Return false if there is an error.
524 explicit operator bool() {
525#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
526 Unchecked = HasError;
527#endif
528 return !HasError;
529 }
530
531 /// Returns a reference to the stored T value.
532 reference get() {
533 assertIsChecked();
534 return *getStorage();
535 }
536
537 /// Returns a const reference to the stored T value.
538 const_reference get() const {
539 assertIsChecked();
540 return const_cast<Expected<T> *>(this)->get();
541 }
542
543 /// Check that this Expected<T> is an error of type ErrT.
544 template <typename ErrT> bool errorIsA() const {
545 return HasError && (*getErrorStorage())->template isA<ErrT>();
546 }
547
548 /// Take ownership of the stored error.
549 /// After calling this the Expected<T> is in an indeterminate state that can
550 /// only be safely destructed. No further calls (beside the destructor) should
551 /// be made on the Expected<T> vaule.
552 Error takeError() {
553#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
554 Unchecked = false;
555#endif
556 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
557 }
558
559 /// Returns a pointer to the stored T value.
560 pointer operator->() {
561 assertIsChecked();
562 return toPointer(getStorage());
563 }
564
565 /// Returns a const pointer to the stored T value.
566 const_pointer operator->() const {
567 assertIsChecked();
568 return toPointer(getStorage());
569 }
570
571 /// Returns a reference to the stored T value.
572 reference operator*() {
573 assertIsChecked();
574 return *getStorage();
575 }
576
577 /// Returns a const reference to the stored T value.
578 const_reference operator*() const {
579 assertIsChecked();
580 return *getStorage();
581 }
582
583private:
584 template <class T1>
585 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
586 return &a == &b;
587 }
588
589 template <class T1, class T2>
590 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
591 return false;
592 }
593
594 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
595 HasError = Other.HasError;
596#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
597 Unchecked = true;
598 Other.Unchecked = false;
599#endif
600
601 if (!HasError)
602 new (getStorage()) storage_type(std::move(*Other.getStorage()));
603 else
604 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
605 }
606
607 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
608 assertIsChecked();
609
610 if (compareThisIfSameType(*this, Other))
611 return;
612
613 this->~Expected();
614 new (this) Expected(std::move(Other));
615 }
616
617 pointer toPointer(pointer Val) { return Val; }
618
619 const_pointer toPointer(const_pointer Val) const { return Val; }
620
621 pointer toPointer(wrap *Val) { return &Val->get(); }
622
623 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
624
625 storage_type *getStorage() {
626 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 626, __PRETTY_FUNCTION__))
;
627 return reinterpret_cast<storage_type *>(TStorage.buffer);
628 }
629
630 const storage_type *getStorage() const {
631 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 631, __PRETTY_FUNCTION__))
;
632 return reinterpret_cast<const storage_type *>(TStorage.buffer);
633 }
634
635 error_type *getErrorStorage() {
636 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 636, __PRETTY_FUNCTION__))
;
637 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
638 }
639
640 const error_type *getErrorStorage() const {
641 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 641, __PRETTY_FUNCTION__))
;
642 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
643 }
644
645 // Used by ExpectedAsOutParameter to reset the checked flag.
646 void setUnchecked() {
647#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
648 Unchecked = true;
649#endif
650 }
651
652#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
653 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
654 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
655 void fatalUncheckedExpected() const {
656 dbgs() << "Expected<T> must be checked before access or destruction.\n";
657 if (HasError) {
658 dbgs() << "Unchecked Expected<T> contained error:\n";
659 (*getErrorStorage())->log(dbgs());
660 } else
661 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
662 "values in success mode must still be checked prior to being "
663 "destroyed).\n";
664 abort();
665 }
666#endif
667
668 void assertIsChecked() {
669#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
670 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
671 fatalUncheckedExpected();
672#endif
673 }
674
675 union {
676 AlignedCharArrayUnion<storage_type> TStorage;
677 AlignedCharArrayUnion<error_type> ErrorStorage;
678 };
679 bool HasError : 1;
680#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
681 bool Unchecked : 1;
682#endif
683};
684
685/// Report a serious error, calling any installed error handler. See
686/// ErrorHandling.h.
687LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
688 bool gen_crash_diag = true);
689
690/// Report a fatal error if Err is a failure value.
691///
692/// This function can be used to wrap calls to fallible functions ONLY when it
693/// is known that the Error will always be a success value. E.g.
694///
695/// @code{.cpp}
696/// // foo only attempts the fallible operation if DoFallibleOperation is
697/// // true. If DoFallibleOperation is false then foo always returns
698/// // Error::success().
699/// Error foo(bool DoFallibleOperation);
700///
701/// cantFail(foo(false));
702/// @endcode
703inline void cantFail(Error Err, const char *Msg = nullptr) {
704 if (Err) {
705 if (!Msg)
706 Msg = "Failure value returned from cantFail wrapped call";
707 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 707)
;
708 }
709}
710
711/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
712/// returns the contained value.
713///
714/// This function can be used to wrap calls to fallible functions ONLY when it
715/// is known that the Error will always be a success value. E.g.
716///
717/// @code{.cpp}
718/// // foo only attempts the fallible operation if DoFallibleOperation is
719/// // true. If DoFallibleOperation is false then foo always returns an int.
720/// Expected<int> foo(bool DoFallibleOperation);
721///
722/// int X = cantFail(foo(false));
723/// @endcode
724template <typename T>
725T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
726 if (ValOrErr)
727 return std::move(*ValOrErr);
728 else {
729 if (!Msg)
730 Msg = "Failure value returned from cantFail wrapped call";
731 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 731)
;
732 }
733}
734
735/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
736/// returns the contained reference.
737///
738/// This function can be used to wrap calls to fallible functions ONLY when it
739/// is known that the Error will always be a success value. E.g.
740///
741/// @code{.cpp}
742/// // foo only attempts the fallible operation if DoFallibleOperation is
743/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
744/// Expected<Bar&> foo(bool DoFallibleOperation);
745///
746/// Bar &X = cantFail(foo(false));
747/// @endcode
748template <typename T>
749T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
750 if (ValOrErr)
751 return *ValOrErr;
752 else {
753 if (!Msg)
754 Msg = "Failure value returned from cantFail wrapped call";
755 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 755)
;
756 }
757}
758
759/// Helper for testing applicability of, and applying, handlers for
760/// ErrorInfo types.
761template <typename HandlerT>
762class ErrorHandlerTraits
763 : public ErrorHandlerTraits<decltype(
764 &std::remove_reference<HandlerT>::type::operator())> {};
765
766// Specialization functions of the form 'Error (const ErrT&)'.
767template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
768public:
769 static bool appliesTo(const ErrorInfoBase &E) {
770 return E.template isA<ErrT>();
771 }
772
773 template <typename HandlerT>
774 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
775 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 775, __PRETTY_FUNCTION__))
;
776 return H(static_cast<ErrT &>(*E));
777 }
778};
779
780// Specialization functions of the form 'void (const ErrT&)'.
781template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
782public:
783 static bool appliesTo(const ErrorInfoBase &E) {
784 return E.template isA<ErrT>();
785 }
786
787 template <typename HandlerT>
788 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
789 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 789, __PRETTY_FUNCTION__))
;
790 H(static_cast<ErrT &>(*E));
791 return Error::success();
792 }
793};
794
795/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
796template <typename ErrT>
797class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
798public:
799 static bool appliesTo(const ErrorInfoBase &E) {
800 return E.template isA<ErrT>();
801 }
802
803 template <typename HandlerT>
804 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
805 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 805, __PRETTY_FUNCTION__))
;
806 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
807 return H(std::move(SubE));
808 }
809};
810
811/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
812template <typename ErrT>
813class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
814public:
815 static bool appliesTo(const ErrorInfoBase &E) {
816 return E.template isA<ErrT>();
817 }
818
819 template <typename HandlerT>
820 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
821 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 821, __PRETTY_FUNCTION__))
;
822 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
823 H(std::move(SubE));
824 return Error::success();
825 }
826};
827
828// Specialization for member functions of the form 'RetT (const ErrT&)'.
829template <typename C, typename RetT, typename ErrT>
830class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
831 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
832
833// Specialization for member functions of the form 'RetT (const ErrT&) const'.
834template <typename C, typename RetT, typename ErrT>
835class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
836 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
837
838// Specialization for member functions of the form 'RetT (const ErrT&)'.
839template <typename C, typename RetT, typename ErrT>
840class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
841 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
842
843// Specialization for member functions of the form 'RetT (const ErrT&) const'.
844template <typename C, typename RetT, typename ErrT>
845class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
846 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
847
848/// Specialization for member functions of the form
849/// 'RetT (std::unique_ptr<ErrT>)'.
850template <typename C, typename RetT, typename ErrT>
851class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
852 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
853
854/// Specialization for member functions of the form
855/// 'RetT (std::unique_ptr<ErrT>) const'.
856template <typename C, typename RetT, typename ErrT>
857class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
858 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
859
860inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
861 return Error(std::move(Payload));
862}
863
864template <typename HandlerT, typename... HandlerTs>
865Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
866 HandlerT &&Handler, HandlerTs &&... Handlers) {
867 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
868 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
869 std::move(Payload));
870 return handleErrorImpl(std::move(Payload),
871 std::forward<HandlerTs>(Handlers)...);
872}
873
874/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
875/// unhandled errors (or Errors returned by handlers) are re-concatenated and
876/// returned.
877/// Because this function returns an error, its result must also be checked
878/// or returned. If you intend to handle all errors use handleAllErrors
879/// (which returns void, and will abort() on unhandled errors) instead.
880template <typename... HandlerTs>
881Error handleErrors(Error E, HandlerTs &&... Hs) {
882 if (!E)
883 return Error::success();
884
885 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
886
887 if (Payload->isA<ErrorList>()) {
888 ErrorList &List = static_cast<ErrorList &>(*Payload);
889 Error R;
890 for (auto &P : List.Payloads)
891 R = ErrorList::join(
892 std::move(R),
893 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
894 return R;
895 }
896
897 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
898}
899
900/// Behaves the same as handleErrors, except that by contract all errors
901/// *must* be handled by the given handlers (i.e. there must be no remaining
902/// errors after running the handlers, or llvm_unreachable is called).
903template <typename... HandlerTs>
904void handleAllErrors(Error E, HandlerTs &&... Handlers) {
905 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
906}
907
908/// Check that E is a non-error, then drop it.
909/// If E is an error, llvm_unreachable will be called.
910inline void handleAllErrors(Error E) {
911 cantFail(std::move(E));
912}
913
914/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
915///
916/// If the incoming value is a success value it is returned unmodified. If it
917/// is a failure value then it the contained error is passed to handleErrors.
918/// If handleErrors is able to handle the error then the RecoveryPath functor
919/// is called to supply the final result. If handleErrors is not able to
920/// handle all errors then the unhandled errors are returned.
921///
922/// This utility enables the follow pattern:
923///
924/// @code{.cpp}
925/// enum FooStrategy { Aggressive, Conservative };
926/// Expected<Foo> foo(FooStrategy S);
927///
928/// auto ResultOrErr =
929/// handleExpected(
930/// foo(Aggressive),
931/// []() { return foo(Conservative); },
932/// [](AggressiveStrategyError&) {
933/// // Implicitly conusme this - we'll recover by using a conservative
934/// // strategy.
935/// });
936///
937/// @endcode
938template <typename T, typename RecoveryFtor, typename... HandlerTs>
939Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
940 HandlerTs &&... Handlers) {
941 if (ValOrErr)
942 return ValOrErr;
943
944 if (auto Err = handleErrors(ValOrErr.takeError(),
945 std::forward<HandlerTs>(Handlers)...))
946 return std::move(Err);
947
948 return RecoveryPath();
949}
950
951/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
952/// will be printed before the first one is logged. A newline will be printed
953/// after each error.
954///
955/// This function is compatible with the helpers from Support/WithColor.h. You
956/// can pass any of them as the OS. Please consider using them instead of
957/// including 'error: ' in the ErrorBanner.
958///
959/// This is useful in the base level of your program to allow clean termination
960/// (allowing clean deallocation of resources, etc.), while reporting error
961/// information to the user.
962void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
963
964/// Write all error messages (if any) in E to a string. The newline character
965/// is used to separate error messages.
966inline std::string toString(Error E) {
967 SmallVector<std::string, 2> Errors;
968 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
969 Errors.push_back(EI.message());
970 });
971 return join(Errors.begin(), Errors.end(), "\n");
972}
973
974/// Consume a Error without doing anything. This method should be used
975/// only where an error can be considered a reasonable and expected return
976/// value.
977///
978/// Uses of this method are potentially indicative of design problems: If it's
979/// legitimate to do nothing while processing an "error", the error-producer
980/// might be more clearly refactored to return an Optional<T>.
981inline void consumeError(Error Err) {
982 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
983}
984
985/// Helper for converting an Error to a bool.
986///
987/// This method returns true if Err is in an error state, or false if it is
988/// in a success state. Puts Err in a checked state in both cases (unlike
989/// Error::operator bool(), which only does this for success states).
990inline bool errorToBool(Error Err) {
991 bool IsError = static_cast<bool>(Err);
992 if (IsError)
993 consumeError(std::move(Err));
994 return IsError;
995}
996
997/// Helper for Errors used as out-parameters.
998///
999/// This helper is for use with the Error-as-out-parameter idiom, where an error
1000/// is passed to a function or method by reference, rather than being returned.
1001/// In such cases it is helpful to set the checked bit on entry to the function
1002/// so that the error can be written to (unchecked Errors abort on assignment)
1003/// and clear the checked bit on exit so that clients cannot accidentally forget
1004/// to check the result. This helper performs these actions automatically using
1005/// RAII:
1006///
1007/// @code{.cpp}
1008/// Result foo(Error &Err) {
1009/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1010/// // <body of foo>
1011/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1012/// }
1013/// @endcode
1014///
1015/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1016/// used with optional Errors (Error pointers that are allowed to be null). If
1017/// ErrorAsOutParameter took an Error reference, an instance would have to be
1018/// created inside every condition that verified that Error was non-null. By
1019/// taking an Error pointer we can just create one instance at the top of the
1020/// function.
1021class ErrorAsOutParameter {
1022public:
1023 ErrorAsOutParameter(Error *Err) : Err(Err) {
1024 // Raise the checked bit if Err is success.
1025 if (Err)
1026 (void)!!*Err;
1027 }
1028
1029 ~ErrorAsOutParameter() {
1030 // Clear the checked bit.
1031 if (Err && !*Err)
1032 *Err = Error::success();
1033 }
1034
1035private:
1036 Error *Err;
1037};
1038
1039/// Helper for Expected<T>s used as out-parameters.
1040///
1041/// See ErrorAsOutParameter.
1042template <typename T>
1043class ExpectedAsOutParameter {
1044public:
1045 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1046 : ValOrErr(ValOrErr) {
1047 if (ValOrErr)
1048 (void)!!*ValOrErr;
1049 }
1050
1051 ~ExpectedAsOutParameter() {
1052 if (ValOrErr)
1053 ValOrErr->setUnchecked();
1054 }
1055
1056private:
1057 Expected<T> *ValOrErr;
1058};
1059
1060/// This class wraps a std::error_code in a Error.
1061///
1062/// This is useful if you're writing an interface that returns a Error
1063/// (or Expected) and you want to call code that still returns
1064/// std::error_codes.
1065class ECError : public ErrorInfo<ECError> {
1066 friend Error errorCodeToError(std::error_code);
1067
1068 virtual void anchor() override;
1069
1070public:
1071 void setErrorCode(std::error_code EC) { this->EC = EC; }
1072 std::error_code convertToErrorCode() const override { return EC; }
1073 void log(raw_ostream &OS) const override { OS << EC.message(); }
1074
1075 // Used by ErrorInfo::classID.
1076 static char ID;
1077
1078protected:
1079 ECError() = default;
1080 ECError(std::error_code EC) : EC(EC) {}
1081
1082 std::error_code EC;
1083};
1084
1085/// The value returned by this function can be returned from convertToErrorCode
1086/// for Error values where no sensible translation to std::error_code exists.
1087/// It should only be used in this situation, and should never be used where a
1088/// sensible conversion to std::error_code is available, as attempts to convert
1089/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1090///error to try to convert such a value).
1091std::error_code inconvertibleErrorCode();
1092
1093/// Helper for converting an std::error_code to a Error.
1094Error errorCodeToError(std::error_code EC);
1095
1096/// Helper for converting an ECError to a std::error_code.
1097///
1098/// This method requires that Err be Error() or an ECError, otherwise it
1099/// will trigger a call to abort().
1100std::error_code errorToErrorCode(Error Err);
1101
1102/// Convert an ErrorOr<T> to an Expected<T>.
1103template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1104 if (auto EC = EO.getError())
1105 return errorCodeToError(EC);
1106 return std::move(*EO);
1107}
1108
1109/// Convert an Expected<T> to an ErrorOr<T>.
1110template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1111 if (auto Err = E.takeError())
1112 return errorToErrorCode(std::move(Err));
1113 return std::move(*E);
1114}
1115
1116/// This class wraps a string in an Error.
1117///
1118/// StringError is useful in cases where the client is not expected to be able
1119/// to consume the specific error message programmatically (for example, if the
1120/// error message is to be presented to the user).
1121///
1122/// StringError can also be used when additional information is to be printed
1123/// along with a error_code message. Depending on the constructor called, this
1124/// class can either display:
1125/// 1. the error_code message (ECError behavior)
1126/// 2. a string
1127/// 3. the error_code message and a string
1128///
1129/// These behaviors are useful when subtyping is required; for example, when a
1130/// specific library needs an explicit error type. In the example below,
1131/// PDBError is derived from StringError:
1132///
1133/// @code{.cpp}
1134/// Expected<int> foo() {
1135/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1136/// "Additional information");
1137/// }
1138/// @endcode
1139///
1140class StringError : public ErrorInfo<StringError> {
1141public:
1142 static char ID;
1143
1144 // Prints EC + S and converts to EC
1145 StringError(std::error_code EC, const Twine &S = Twine());
1146
1147 // Prints S and converts to EC
1148 StringError(const Twine &S, std::error_code EC);
1149
1150 void log(raw_ostream &OS) const override;
1151 std::error_code convertToErrorCode() const override;
1152
1153 const std::string &getMessage() const { return Msg; }
1154
1155private:
1156 std::string Msg;
1157 std::error_code EC;
1158 const bool PrintMsgOnly = false;
1159};
1160
1161/// Create formatted StringError object.
1162template <typename... Ts>
1163Error createStringError(std::error_code EC, char const *Fmt,
1164 const Ts &... Vals) {
1165 std::string Buffer;
1166 raw_string_ostream Stream(Buffer);
1167 Stream << format(Fmt, Vals...);
1168 return make_error<StringError>(Stream.str(), EC);
3
Calling 'make_error<llvm::StringError, std::__cxx11::basic_string<char> &, std::error_code &>'
1169}
1170
1171Error createStringError(std::error_code EC, char const *Msg);
1172
1173/// This class wraps a filename and another Error.
1174///
1175/// In some cases, an error needs to live along a 'source' name, in order to
1176/// show more detailed information to the user.
1177class FileError final : public ErrorInfo<FileError> {
1178
1179 friend Error createFileError(const Twine &, Error);
1180
1181public:
1182 void log(raw_ostream &OS) const override {
1183 assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 1183, __PRETTY_FUNCTION__))
;
1184 OS << "'" << FileName << "': ";
1185 Err->log(OS);
1186 }
1187
1188 Error takeError() { return Error(std::move(Err)); }
1189
1190 std::error_code convertToErrorCode() const override;
1191
1192 // Used by ErrorInfo::classID.
1193 static char ID;
1194
1195private:
1196 FileError(const Twine &F, std::unique_ptr<ErrorInfoBase> E) {
1197 assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 1197, __PRETTY_FUNCTION__))
;
1198 assert(!F.isTriviallyEmpty() &&((!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 1199, __PRETTY_FUNCTION__))
1199 "The file name provided to FileError must not be empty.")((!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/Support/Error.h"
, 1199, __PRETTY_FUNCTION__))
;
1200 FileName = F.str();
1201 Err = std::move(E);
1202 }
1203
1204 static Error build(const Twine &F, Error E) {
1205 return Error(std::unique_ptr<FileError>(new FileError(F, E.takePayload())));
1206 }
1207
1208 std::string FileName;
1209 std::unique_ptr<ErrorInfoBase> Err;
1210};
1211
1212/// Concatenate a source file path and/or name with an Error. The resulting
1213/// Error is unchecked.
1214inline Error createFileError(const Twine &F, Error E) {
1215 return FileError::build(F, std::move(E));
1216}
1217
1218/// Concatenate a source file path and/or name with a std::error_code
1219/// to form an Error object.
1220inline Error createFileError(const Twine &F, std::error_code EC) {
1221 return createFileError(F, errorCodeToError(EC));
1222}
1223
1224Error createFileError(const Twine &F, ErrorSuccess) = delete;
1225
1226/// Helper for check-and-exit error handling.
1227///
1228/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1229///
1230class ExitOnError {
1231public:
1232 /// Create an error on exit helper.
1233 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1234 : Banner(std::move(Banner)),
1235 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1236
1237 /// Set the banner string for any errors caught by operator().
1238 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1239
1240 /// Set the exit-code mapper function.
1241 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1242 this->GetExitCode = std::move(GetExitCode);
1243 }
1244
1245 /// Check Err. If it's in a failure state log the error(s) and exit.
1246 void operator()(Error Err) const { checkError(std::move(Err)); }
1247
1248 /// Check E. If it's in a success state then return the contained value. If
1249 /// it's in a failure state log the error(s) and exit.
1250 template <typename T> T operator()(Expected<T> &&E) const {
1251 checkError(E.takeError());
1252 return std::move(*E);
1253 }
1254
1255 /// Check E. If it's in a success state then return the contained reference. If
1256 /// it's in a failure state log the error(s) and exit.
1257 template <typename T> T& operator()(Expected<T&> &&E) const {
1258 checkError(E.takeError());
1259 return *E;
1260 }
1261
1262private:
1263 void checkError(Error Err) const {
1264 if (Err) {
1265 int ExitCode = GetExitCode(Err);
1266 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1267 exit(ExitCode);
1268 }
1269 }
1270
1271 std::string Banner;
1272 std::function<int(const Error &)> GetExitCode;
1273};
1274
1275/// Conversion from Error to LLVMErrorRef for C error bindings.
1276inline LLVMErrorRef wrap(Error Err) {
1277 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1278}
1279
1280/// Conversion from LLVMErrorRef to Error for C error bindings.
1281inline Error unwrap(LLVMErrorRef ErrRef) {
1282 return Error(std::unique_ptr<ErrorInfoBase>(
1283 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1284}
1285
1286} // end namespace llvm
1287
1288#endif // LLVM_SUPPORT_ERROR_H

/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h

1//===- llvm/ADT/STLExtras.h - Useful STL related functions ------*- 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 contains some templates that are useful if you are working with the
10// STL at all.
11//
12// No library is required when using these functions.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_ADT_STLEXTRAS_H
17#define LLVM_ADT_STLEXTRAS_H
18
19#include "llvm/ADT/Optional.h"
20#include "llvm/ADT/SmallVector.h"
21#include "llvm/ADT/iterator.h"
22#include "llvm/ADT/iterator_range.h"
23#include "llvm/Config/abi-breaking.h"
24#include "llvm/Support/ErrorHandling.h"
25#include <algorithm>
26#include <cassert>
27#include <cstddef>
28#include <cstdint>
29#include <cstdlib>
30#include <functional>
31#include <initializer_list>
32#include <iterator>
33#include <limits>
34#include <memory>
35#include <tuple>
36#include <type_traits>
37#include <utility>
38
39#ifdef EXPENSIVE_CHECKS
40#include <random> // for std::mt19937
41#endif
42
43namespace llvm {
44
45// Only used by compiler if both template types are the same. Useful when
46// using SFINAE to test for the existence of member functions.
47template <typename T, T> struct SameType;
48
49namespace detail {
50
51template <typename RangeT>
52using IterOfRange = decltype(std::begin(std::declval<RangeT &>()));
53
54template <typename RangeT>
55using ValueOfRange = typename std::remove_reference<decltype(
56 *std::begin(std::declval<RangeT &>()))>::type;
57
58} // end namespace detail
59
60//===----------------------------------------------------------------------===//
61// Extra additions to <type_traits>
62//===----------------------------------------------------------------------===//
63
64template <typename T>
65struct negation : std::integral_constant<bool, !bool(T::value)> {};
66
67template <typename...> struct conjunction : std::true_type {};
68template <typename B1> struct conjunction<B1> : B1 {};
69template <typename B1, typename... Bn>
70struct conjunction<B1, Bn...>
71 : std::conditional<bool(B1::value), conjunction<Bn...>, B1>::type {};
72
73template <typename T> struct make_const_ptr {
74 using type =
75 typename std::add_pointer<typename std::add_const<T>::type>::type;
76};
77
78template <typename T> struct make_const_ref {
79 using type = typename std::add_lvalue_reference<
80 typename std::add_const<T>::type>::type;
81};
82
83//===----------------------------------------------------------------------===//
84// Extra additions to <functional>
85//===----------------------------------------------------------------------===//
86
87template <class Ty> struct identity {
88 using argument_type = Ty;
89
90 Ty &operator()(Ty &self) const {
91 return self;
92 }
93 const Ty &operator()(const Ty &self) const {
94 return self;
95 }
96};
97
98template <class Ty> struct less_ptr {
99 bool operator()(const Ty* left, const Ty* right) const {
100 return *left < *right;
101 }
102};
103
104template <class Ty> struct greater_ptr {
105 bool operator()(const Ty* left, const Ty* right) const {
106 return *right < *left;
107 }
108};
109
110/// An efficient, type-erasing, non-owning reference to a callable. This is
111/// intended for use as the type of a function parameter that is not used
112/// after the function in question returns.
113///
114/// This class does not own the callable, so it is not in general safe to store
115/// a function_ref.
116template<typename Fn> class function_ref;
117
118template<typename Ret, typename ...Params>
119class function_ref<Ret(Params...)> {
120 Ret (*callback)(intptr_t callable, Params ...params) = nullptr;
121 intptr_t callable;
122
123 template<typename Callable>
124 static Ret callback_fn(intptr_t callable, Params ...params) {
125 return (*reinterpret_cast<Callable*>(callable))(
126 std::forward<Params>(params)...);
127 }
128
129public:
130 function_ref() = default;
131 function_ref(std::nullptr_t) {}
132
133 template <typename Callable>
134 function_ref(Callable &&callable,
135 typename std::enable_if<
136 !std::is_same<typename std::remove_reference<Callable>::type,
137 function_ref>::value>::type * = nullptr)
138 : callback(callback_fn<typename std::remove_reference<Callable>::type>),
139 callable(reinterpret_cast<intptr_t>(&callable)) {}
140
141 Ret operator()(Params ...params) const {
142 return callback(callable, std::forward<Params>(params)...);
143 }
144
145 operator bool() const { return callback; }
146};
147
148// deleter - Very very very simple method that is used to invoke operator
149// delete on something. It is used like this:
150//
151// for_each(V.begin(), B.end(), deleter<Interval>);
152template <class T>
153inline void deleter(T *Ptr) {
154 delete Ptr;
155}
156
157//===----------------------------------------------------------------------===//
158// Extra additions to <iterator>
159//===----------------------------------------------------------------------===//
160
161namespace adl_detail {
162
163using std::begin;
164
165template <typename ContainerTy>
166auto adl_begin(ContainerTy &&container)
167 -> decltype(begin(std::forward<ContainerTy>(container))) {
168 return begin(std::forward<ContainerTy>(container));
169}
170
171using std::end;
172
173template <typename ContainerTy>
174auto adl_end(ContainerTy &&container)
175 -> decltype(end(std::forward<ContainerTy>(container))) {
176 return end(std::forward<ContainerTy>(container));
177}
178
179using std::swap;
180
181template <typename T>
182void adl_swap(T &&lhs, T &&rhs) noexcept(noexcept(swap(std::declval<T>(),
183 std::declval<T>()))) {
184 swap(std::forward<T>(lhs), std::forward<T>(rhs));
185}
186
187} // end namespace adl_detail
188
189template <typename ContainerTy>
190auto adl_begin(ContainerTy &&container)
191 -> decltype(adl_detail::adl_begin(std::forward<ContainerTy>(container))) {
192 return adl_detail::adl_begin(std::forward<ContainerTy>(container));
193}
194
195template <typename ContainerTy>
196auto adl_end(ContainerTy &&container)
197 -> decltype(adl_detail::adl_end(std::forward<ContainerTy>(container))) {
198 return adl_detail::adl_end(std::forward<ContainerTy>(container));
199}
200
201template <typename T>
202void adl_swap(T &&lhs, T &&rhs) noexcept(
203 noexcept(adl_detail::adl_swap(std::declval<T>(), std::declval<T>()))) {
204 adl_detail::adl_swap(std::forward<T>(lhs), std::forward<T>(rhs));
205}
206
207/// Test whether \p RangeOrContainer is empty. Similar to C++17 std::empty.
208template <typename T>
209constexpr bool empty(const T &RangeOrContainer) {
210 return adl_begin(RangeOrContainer) == adl_end(RangeOrContainer);
211}
212
213// mapped_iterator - This is a simple iterator adapter that causes a function to
214// be applied whenever operator* is invoked on the iterator.
215
216template <typename ItTy, typename FuncTy,
217 typename FuncReturnTy =
218 decltype(std::declval<FuncTy>()(*std::declval<ItTy>()))>
219class mapped_iterator
220 : public iterator_adaptor_base<
221 mapped_iterator<ItTy, FuncTy>, ItTy,
222 typename std::iterator_traits<ItTy>::iterator_category,
223 typename std::remove_reference<FuncReturnTy>::type> {
224public:
225 mapped_iterator(ItTy U, FuncTy F)
226 : mapped_iterator::iterator_adaptor_base(std::move(U)), F(std::move(F)) {}
227
228 ItTy getCurrent() { return this->I; }
229
230 FuncReturnTy operator*() { return F(*this->I); }
231
232private:
233 FuncTy F;
234};
235
236// map_iterator - Provide a convenient way to create mapped_iterators, just like
237// make_pair is useful for creating pairs...
238template <class ItTy, class FuncTy>
239inline mapped_iterator<ItTy, FuncTy> map_iterator(ItTy I, FuncTy F) {
240 return mapped_iterator<ItTy, FuncTy>(std::move(I), std::move(F));
241}
242
243/// Helper to determine if type T has a member called rbegin().
244template <typename Ty> class has_rbegin_impl {
245 using yes = char[1];
246 using no = char[2];
247
248 template <typename Inner>
249 static yes& test(Inner *I, decltype(I->rbegin()) * = nullptr);
250
251 template <typename>
252 static no& test(...);
253
254public:
255 static const bool value = sizeof(test<Ty>(nullptr)) == sizeof(yes);
256};
257
258/// Metafunction to determine if T& or T has a member called rbegin().
259template <typename Ty>
260struct has_rbegin : has_rbegin_impl<typename std::remove_reference<Ty>::type> {
261};
262
263// Returns an iterator_range over the given container which iterates in reverse.
264// Note that the container must have rbegin()/rend() methods for this to work.
265template <typename ContainerTy>
266auto reverse(ContainerTy &&C,
267 typename std::enable_if<has_rbegin<ContainerTy>::value>::type * =
268 nullptr) -> decltype(make_range(C.rbegin(), C.rend())) {
269 return make_range(C.rbegin(), C.rend());
270}
271
272// Returns a std::reverse_iterator wrapped around the given iterator.
273template <typename IteratorTy>
274std::reverse_iterator<IteratorTy> make_reverse_iterator(IteratorTy It) {
275 return std::reverse_iterator<IteratorTy>(It);
276}
277
278// Returns an iterator_range over the given container which iterates in reverse.
279// Note that the container must have begin()/end() methods which return
280// bidirectional iterators for this to work.
281template <typename ContainerTy>
282auto reverse(
283 ContainerTy &&C,
284 typename std::enable_if<!has_rbegin<ContainerTy>::value>::type * = nullptr)
285 -> decltype(make_range(llvm::make_reverse_iterator(std::end(C)),
286 llvm::make_reverse_iterator(std::begin(C)))) {
287 return make_range(llvm::make_reverse_iterator(std::end(C)),
288 llvm::make_reverse_iterator(std::begin(C)));
289}
290
291/// An iterator adaptor that filters the elements of given inner iterators.
292///
293/// The predicate parameter should be a callable object that accepts the wrapped
294/// iterator's reference type and returns a bool. When incrementing or
295/// decrementing the iterator, it will call the predicate on each element and
296/// skip any where it returns false.
297///
298/// \code
299/// int A[] = { 1, 2, 3, 4 };
300/// auto R = make_filter_range(A, [](int N) { return N % 2 == 1; });
301/// // R contains { 1, 3 }.
302/// \endcode
303///
304/// Note: filter_iterator_base implements support for forward iteration.
305/// filter_iterator_impl exists to provide support for bidirectional iteration,
306/// conditional on whether the wrapped iterator supports it.
307template <typename WrappedIteratorT, typename PredicateT, typename IterTag>
308class filter_iterator_base
309 : public iterator_adaptor_base<
310 filter_iterator_base<WrappedIteratorT, PredicateT, IterTag>,
311 WrappedIteratorT,
312 typename std::common_type<
313 IterTag, typename std::iterator_traits<
314 WrappedIteratorT>::iterator_category>::type> {
315 using BaseT = iterator_adaptor_base<
316 filter_iterator_base<WrappedIteratorT, PredicateT, IterTag>,
317 WrappedIteratorT,
318 typename std::common_type<
319 IterTag, typename std::iterator_traits<
320 WrappedIteratorT>::iterator_category>::type>;
321
322protected:
323 WrappedIteratorT End;
324 PredicateT Pred;
325
326 void findNextValid() {
327 while (this->I != End && !Pred(*this->I))
328 BaseT::operator++();
329 }
330
331 // Construct the iterator. The begin iterator needs to know where the end
332 // is, so that it can properly stop when it gets there. The end iterator only
333 // needs the predicate to support bidirectional iteration.
334 filter_iterator_base(WrappedIteratorT Begin, WrappedIteratorT End,
335 PredicateT Pred)
336 : BaseT(Begin), End(End), Pred(Pred) {
337 findNextValid();
338 }
339
340public:
341 using BaseT::operator++;
342
343 filter_iterator_base &operator++() {
344 BaseT::operator++();
345 findNextValid();
346 return *this;
347 }
348};
349
350/// Specialization of filter_iterator_base for forward iteration only.
351template <typename WrappedIteratorT, typename PredicateT,
352 typename IterTag = std::forward_iterator_tag>
353class filter_iterator_impl
354 : public filter_iterator_base<WrappedIteratorT, PredicateT, IterTag> {
355 using BaseT = filter_iterator_base<WrappedIteratorT, PredicateT, IterTag>;
356
357public:
358 filter_iterator_impl(WrappedIteratorT Begin, WrappedIteratorT End,
359 PredicateT Pred)
360 : BaseT(Begin, End, Pred) {}
361};
362
363/// Specialization of filter_iterator_base for bidirectional iteration.
364template <typename WrappedIteratorT, typename PredicateT>
365class filter_iterator_impl<WrappedIteratorT, PredicateT,
366 std::bidirectional_iterator_tag>
367 : public filter_iterator_base<WrappedIteratorT, PredicateT,
368 std::bidirectional_iterator_tag> {
369 using BaseT = filter_iterator_base<WrappedIteratorT, PredicateT,
370 std::bidirectional_iterator_tag>;
371 void findPrevValid() {
372 while (!this->Pred(*this->I))
373 BaseT::operator--();
374 }
375
376public:
377 using BaseT::operator--;
378
379 filter_iterator_impl(WrappedIteratorT Begin, WrappedIteratorT End,
380 PredicateT Pred)
381 : BaseT(Begin, End, Pred) {}
382
383 filter_iterator_impl &operator--() {
384 BaseT::operator--();
385 findPrevValid();
386 return *this;
387 }
388};
389
390namespace detail {
391
392template <bool is_bidirectional> struct fwd_or_bidi_tag_impl {
393 using type = std::forward_iterator_tag;
394};
395
396template <> struct fwd_or_bidi_tag_impl<true> {
397 using type = std::bidirectional_iterator_tag;
398};
399
400/// Helper which sets its type member to forward_iterator_tag if the category
401/// of \p IterT does not derive from bidirectional_iterator_tag, and to
402/// bidirectional_iterator_tag otherwise.
403template <typename IterT> struct fwd_or_bidi_tag {
404 using type = typename fwd_or_bidi_tag_impl<std::is_base_of<
405 std::bidirectional_iterator_tag,
406 typename std::iterator_traits<IterT>::iterator_category>::value>::type;
407};
408
409} // namespace detail
410
411/// Defines filter_iterator to a suitable specialization of
412/// filter_iterator_impl, based on the underlying iterator's category.
413template <typename WrappedIteratorT, typename PredicateT>
414using filter_iterator = filter_iterator_impl<
415 WrappedIteratorT, PredicateT,
416 typename detail::fwd_or_bidi_tag<WrappedIteratorT>::type>;
417
418/// Convenience function that takes a range of elements and a predicate,
419/// and return a new filter_iterator range.
420///
421/// FIXME: Currently if RangeT && is a rvalue reference to a temporary, the
422/// lifetime of that temporary is not kept by the returned range object, and the
423/// temporary is going to be dropped on the floor after the make_iterator_range
424/// full expression that contains this function call.
425template <typename RangeT, typename PredicateT>
426iterator_range<filter_iterator<detail::IterOfRange<RangeT>, PredicateT>>
427make_filter_range(RangeT &&Range, PredicateT Pred) {
428 using FilterIteratorT =
429 filter_iterator<detail::IterOfRange<RangeT>, PredicateT>;
430 return make_range(
431 FilterIteratorT(std::begin(std::forward<RangeT>(Range)),
432 std::end(std::forward<RangeT>(Range)), Pred),
433 FilterIteratorT(std::end(std::forward<RangeT>(Range)),
434 std::end(std::forward<RangeT>(Range)), Pred));
435}
436
437/// A pseudo-iterator adaptor that is designed to implement "early increment"
438/// style loops.
439///
440/// This is *not a normal iterator* and should almost never be used directly. It
441/// is intended primarily to be used with range based for loops and some range
442/// algorithms.
443///
444/// The iterator isn't quite an `OutputIterator` or an `InputIterator` but
445/// somewhere between them. The constraints of these iterators are:
446///
447/// - On construction or after being incremented, it is comparable and
448/// dereferencable. It is *not* incrementable.
449/// - After being dereferenced, it is neither comparable nor dereferencable, it
450/// is only incrementable.
451///
452/// This means you can only dereference the iterator once, and you can only
453/// increment it once between dereferences.
454template <typename WrappedIteratorT>
455class early_inc_iterator_impl
456 : public iterator_adaptor_base<early_inc_iterator_impl<WrappedIteratorT>,
457 WrappedIteratorT, std::input_iterator_tag> {
458 using BaseT =
459 iterator_adaptor_base<early_inc_iterator_impl<WrappedIteratorT>,
460 WrappedIteratorT, std::input_iterator_tag>;
461
462 using PointerT = typename std::iterator_traits<WrappedIteratorT>::pointer;
463
464protected:
465#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
466 bool IsEarlyIncremented = false;
467#endif
468
469public:
470 early_inc_iterator_impl(WrappedIteratorT I) : BaseT(I) {}
471
472 using BaseT::operator*;
473 typename BaseT::reference operator*() {
474#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
475 assert(!IsEarlyIncremented && "Cannot dereference twice!")((!IsEarlyIncremented && "Cannot dereference twice!")
? static_cast<void> (0) : __assert_fail ("!IsEarlyIncremented && \"Cannot dereference twice!\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h"
, 475, __PRETTY_FUNCTION__))
;
476 IsEarlyIncremented = true;
477#endif
478 return *(this->I)++;
479 }
480
481 using BaseT::operator++;
482 early_inc_iterator_impl &operator++() {
483#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
484 assert(IsEarlyIncremented && "Cannot increment before dereferencing!")((IsEarlyIncremented && "Cannot increment before dereferencing!"
) ? static_cast<void> (0) : __assert_fail ("IsEarlyIncremented && \"Cannot increment before dereferencing!\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h"
, 484, __PRETTY_FUNCTION__))
;
485 IsEarlyIncremented = false;
486#endif
487 return *this;
488 }
489
490 using BaseT::operator==;
491 bool operator==(const early_inc_iterator_impl &RHS) const {
492#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
493 assert(!IsEarlyIncremented && "Cannot compare after dereferencing!")((!IsEarlyIncremented && "Cannot compare after dereferencing!"
) ? static_cast<void> (0) : __assert_fail ("!IsEarlyIncremented && \"Cannot compare after dereferencing!\""
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h"
, 493, __PRETTY_FUNCTION__))
;
494#endif
495 return BaseT::operator==(RHS);
496 }
497};
498
499/// Make a range that does early increment to allow mutation of the underlying
500/// range without disrupting iteration.
501///
502/// The underlying iterator will be incremented immediately after it is
503/// dereferenced, allowing deletion of the current node or insertion of nodes to
504/// not disrupt iteration provided they do not invalidate the *next* iterator --
505/// the current iterator can be invalidated.
506///
507/// This requires a very exact pattern of use that is only really suitable to
508/// range based for loops and other range algorithms that explicitly guarantee
509/// to dereference exactly once each element, and to increment exactly once each
510/// element.
511template <typename RangeT>
512iterator_range<early_inc_iterator_impl<detail::IterOfRange<RangeT>>>
513make_early_inc_range(RangeT &&Range) {
514 using EarlyIncIteratorT =
515 early_inc_iterator_impl<detail::IterOfRange<RangeT>>;
516 return make_range(EarlyIncIteratorT(std::begin(std::forward<RangeT>(Range))),
517 EarlyIncIteratorT(std::end(std::forward<RangeT>(Range))));
518}
519
520// forward declarations required by zip_shortest/zip_first/zip_longest
521template <typename R, typename UnaryPredicate>
522bool all_of(R &&range, UnaryPredicate P);
523template <typename R, typename UnaryPredicate>
524bool any_of(R &&range, UnaryPredicate P);
525
526template <size_t... I> struct index_sequence;
527
528template <class... Ts> struct index_sequence_for;
529
530namespace detail {
531
532using std::declval;
533
534// We have to alias this since inlining the actual type at the usage site
535// in the parameter list of iterator_facade_base<> below ICEs MSVC 2017.
536template<typename... Iters> struct ZipTupleType {
537 using type = std::tuple<decltype(*declval<Iters>())...>;
538};
539
540template <typename ZipType, typename... Iters>
541using zip_traits = iterator_facade_base<
542 ZipType, typename std::common_type<std::bidirectional_iterator_tag,
543 typename std::iterator_traits<
544 Iters>::iterator_category...>::type,
545 // ^ TODO: Implement random access methods.
546 typename ZipTupleType<Iters...>::type,
547 typename std::iterator_traits<typename std::tuple_element<
548 0, std::tuple<Iters...>>::type>::difference_type,
549 // ^ FIXME: This follows boost::make_zip_iterator's assumption that all
550 // inner iterators have the same difference_type. It would fail if, for
551 // instance, the second field's difference_type were non-numeric while the
552 // first is.
553 typename ZipTupleType<Iters...>::type *,
554 typename ZipTupleType<Iters...>::type>;
555
556template <typename ZipType, typename... Iters>
557struct zip_common : public zip_traits<ZipType, Iters...> {
558 using Base = zip_traits<ZipType, Iters...>;
559 using value_type = typename Base::value_type;
560
561 std::tuple<Iters...> iterators;
562
563protected:
564 template <size_t... Ns> value_type deref(index_sequence<Ns...>) const {
565 return value_type(*std::get<Ns>(iterators)...);
566 }
567
568 template <size_t... Ns>
569 decltype(iterators) tup_inc(index_sequence<Ns...>) const {
570 return std::tuple<Iters...>(std::next(std::get<Ns>(iterators))...);
571 }
572
573 template <size_t... Ns>
574 decltype(iterators) tup_dec(index_sequence<Ns...>) const {
575 return std::tuple<Iters...>(std::prev(std::get<Ns>(iterators))...);
576 }
577
578public:
579 zip_common(Iters &&... ts) : iterators(std::forward<Iters>(ts)...) {}
580
581 value_type operator*() { return deref(index_sequence_for<Iters...>{}); }
582
583 const value_type operator*() const {
584 return deref(index_sequence_for<Iters...>{});
585 }
586
587 ZipType &operator++() {
588 iterators = tup_inc(index_sequence_for<Iters...>{});
589 return *reinterpret_cast<ZipType *>(this);
590 }
591
592 ZipType &operator--() {
593 static_assert(Base::IsBidirectional,
594 "All inner iterators must be at least bidirectional.");
595 iterators = tup_dec(index_sequence_for<Iters...>{});
596 return *reinterpret_cast<ZipType *>(this);
597 }
598};
599
600template <typename... Iters>
601struct zip_first : public zip_common<zip_first<Iters...>, Iters...> {
602 using Base = zip_common<zip_first<Iters...>, Iters...>;
603
604 bool operator==(const zip_first<Iters...> &other) const {
605 return std::get<0>(this->iterators) == std::get<0>(other.iterators);
606 }
607
608 zip_first(Iters &&... ts) : Base(std::forward<Iters>(ts)...) {}
609};
610
611template <typename... Iters>
612class zip_shortest : public zip_common<zip_shortest<Iters...>, Iters...> {
613 template <size_t... Ns>
614 bool test(const zip_shortest<Iters...> &other, index_sequence<Ns...>) const {
615 return all_of(std::initializer_list<bool>{std::get<Ns>(this->iterators) !=
616 std::get<Ns>(other.iterators)...},
617 identity<bool>{});
618 }
619
620public:
621 using Base = zip_common<zip_shortest<Iters...>, Iters...>;
622
623 zip_shortest(Iters &&... ts) : Base(std::forward<Iters>(ts)...) {}
624
625 bool operator==(const zip_shortest<Iters...> &other) const {
626 return !test(other, index_sequence_for<Iters...>{});
627 }
628};
629
630template <template <typename...> class ItType, typename... Args> class zippy {
631public:
632 using iterator = ItType<decltype(std::begin(std::declval<Args>()))...>;
633 using iterator_category = typename iterator::iterator_category;
634 using value_type = typename iterator::value_type;
635 using difference_type = typename iterator::difference_type;
636 using pointer = typename iterator::pointer;
637 using reference = typename iterator::reference;
638
639private:
640 std::tuple<Args...> ts;
641
642 template <size_t... Ns> iterator begin_impl(index_sequence<Ns...>) const {
643 return iterator(std::begin(std::get<Ns>(ts))...);
644 }
645 template <size_t... Ns> iterator end_impl(index_sequence<Ns...>) const {
646 return iterator(std::end(std::get<Ns>(ts))...);
647 }
648
649public:
650 zippy(Args &&... ts_) : ts(std::forward<Args>(ts_)...) {}
651
652 iterator begin() const { return begin_impl(index_sequence_for<Args...>{}); }
653 iterator end() const { return end_impl(index_sequence_for<Args...>{}); }
654};
655
656} // end namespace detail
657
658/// zip iterator for two or more iteratable types.
659template <typename T, typename U, typename... Args>
660detail::zippy<detail::zip_shortest, T, U, Args...> zip(T &&t, U &&u,
661 Args &&... args) {
662 return detail::zippy<detail::zip_shortest, T, U, Args...>(
663 std::forward<T>(t), std::forward<U>(u), std::forward<Args>(args)...);
664}
665
666/// zip iterator that, for the sake of efficiency, assumes the first iteratee to
667/// be the shortest.
668template <typename T, typename U, typename... Args>
669detail::zippy<detail::zip_first, T, U, Args...> zip_first(T &&t, U &&u,
670 Args &&... args) {
671 return detail::zippy<detail::zip_first, T, U, Args...>(
672 std::forward<T>(t), std::forward<U>(u), std::forward<Args>(args)...);
673}
674
675namespace detail {
676template <typename Iter>
677static Iter next_or_end(const Iter &I, const Iter &End) {
678 if (I == End)
679 return End;
680 return std::next(I);
681}
682
683template <typename Iter>
684static auto deref_or_none(const Iter &I, const Iter &End)
685 -> llvm::Optional<typename std::remove_const<
686 typename std::remove_reference<decltype(*I)>::type>::type> {
687 if (I == End)
688 return None;
689 return *I;
690}
691
692template <typename Iter> struct ZipLongestItemType {
693 using type =
694 llvm::Optional<typename std::remove_const<typename std::remove_reference<
695 decltype(*std::declval<Iter>())>::type>::type>;
696};
697
698template <typename... Iters> struct ZipLongestTupleType {
699 using type = std::tuple<typename ZipLongestItemType<Iters>::type...>;
700};
701
702template <typename... Iters>
703class zip_longest_iterator
704 : public iterator_facade_base<
705 zip_longest_iterator<Iters...>,
706 typename std::common_type<
707 std::forward_iterator_tag,
708 typename std::iterator_traits<Iters>::iterator_category...>::type,
709 typename ZipLongestTupleType<Iters...>::type,
710 typename std::iterator_traits<typename std::tuple_element<
711 0, std::tuple<Iters...>>::type>::difference_type,
712 typename ZipLongestTupleType<Iters...>::type *,
713 typename ZipLongestTupleType<Iters...>::type> {
714public:
715 using value_type = typename ZipLongestTupleType<Iters...>::type;
716
717private:
718 std::tuple<Iters...> iterators;
719 std::tuple<Iters...> end_iterators;
720
721 template <size_t... Ns>
722 bool test(const zip_longest_iterator<Iters...> &other,
723 index_sequence<Ns...>) const {
724 return llvm::any_of(
725 std::initializer_list<bool>{std::get<Ns>(this->iterators) !=
726 std::get<Ns>(other.iterators)...},
727 identity<bool>{});
728 }
729
730 template <size_t... Ns> value_type deref(index_sequence<Ns...>) const {
731 return value_type(
732 deref_or_none(std::get<Ns>(iterators), std::get<Ns>(end_iterators))...);
733 }
734
735 template <size_t... Ns>
736 decltype(iterators) tup_inc(index_sequence<Ns...>) const {
737 return std::tuple<Iters...>(
738 next_or_end(std::get<Ns>(iterators), std::get<Ns>(end_iterators))...);
739 }
740
741public:
742 zip_longest_iterator(std::pair<Iters &&, Iters &&>... ts)
743 : iterators(std::forward<Iters>(ts.first)...),
744 end_iterators(std::forward<Iters>(ts.second)...) {}
745
746 value_type operator*() { return deref(index_sequence_for<Iters...>{}); }
747
748 value_type operator*() const { return deref(index_sequence_for<Iters...>{}); }
749
750 zip_longest_iterator<Iters...> &operator++() {
751 iterators = tup_inc(index_sequence_for<Iters...>{});
752 return *this;
753 }
754
755 bool operator==(const zip_longest_iterator<Iters...> &other) const {
756 return !test(other, index_sequence_for<Iters...>{});
757 }
758};
759
760template <typename... Args> class zip_longest_range {
761public:
762 using iterator =
763 zip_longest_iterator<decltype(adl_begin(std::declval<Args>()))...>;
764 using iterator_category = typename iterator::iterator_category;
765 using value_type = typename iterator::value_type;
766 using difference_type = typename iterator::difference_type;
767 using pointer = typename iterator::pointer;
768 using reference = typename iterator::reference;
769
770private:
771 std::tuple<Args...> ts;
772
773 template <size_t... Ns> iterator begin_impl(index_sequence<Ns...>) const {
774 return iterator(std::make_pair(adl_begin(std::get<Ns>(ts)),
775 adl_end(std::get<Ns>(ts)))...);
776 }
777
778 template <size_t... Ns> iterator end_impl(index_sequence<Ns...>) const {
779 return iterator(std::make_pair(adl_end(std::get<Ns>(ts)),
780 adl_end(std::get<Ns>(ts)))...);
781 }
782
783public:
784 zip_longest_range(Args &&... ts_) : ts(std::forward<Args>(ts_)...) {}
785
786 iterator begin() const { return begin_impl(index_sequence_for<Args...>{}); }
787 iterator end() const { return end_impl(index_sequence_for<Args...>{}); }
788};
789} // namespace detail
790
791/// Iterate over two or more iterators at the same time. Iteration continues
792/// until all iterators reach the end. The llvm::Optional only contains a value
793/// if the iterator has not reached the end.
794template <typename T, typename U, typename... Args>
795detail::zip_longest_range<T, U, Args...> zip_longest(T &&t, U &&u,
796 Args &&... args) {
797 return detail::zip_longest_range<T, U, Args...>(
798 std::forward<T>(t), std::forward<U>(u), std::forward<Args>(args)...);
799}
800
801/// Iterator wrapper that concatenates sequences together.
802///
803/// This can concatenate different iterators, even with different types, into
804/// a single iterator provided the value types of all the concatenated
805/// iterators expose `reference` and `pointer` types that can be converted to
806/// `ValueT &` and `ValueT *` respectively. It doesn't support more
807/// interesting/customized pointer or reference types.
808///
809/// Currently this only supports forward or higher iterator categories as
810/// inputs and always exposes a forward iterator interface.
811template <typename ValueT, typename... IterTs>
812class concat_iterator
813 : public iterator_facade_base<concat_iterator<ValueT, IterTs...>,
814 std::forward_iterator_tag, ValueT> {
815 using BaseT = typename concat_iterator::iterator_facade_base;
816
817 /// We store both the current and end iterators for each concatenated
818 /// sequence in a tuple of pairs.
819 ///
820 /// Note that something like iterator_range seems nice at first here, but the
821 /// range properties are of little benefit and end up getting in the way
822 /// because we need to do mutation on the current iterators.
823 std::tuple<IterTs...> Begins;
824 std::tuple<IterTs...> Ends;
825
826 /// Attempts to increment a specific iterator.
827 ///
828 /// Returns true if it was able to increment the iterator. Returns false if
829 /// the iterator is already at the end iterator.
830 template <size_t Index> bool incrementHelper() {
831 auto &Begin = std::get<Index>(Begins);
832 auto &End = std::get<Index>(Ends);
833 if (Begin == End)
834 return false;
835
836 ++Begin;
837 return true;
838 }
839
840 /// Increments the first non-end iterator.
841 ///
842 /// It is an error to call this with all iterators at the end.
843 template <size_t... Ns> void increment(index_sequence<Ns...>) {
844 // Build a sequence of functions to increment each iterator if possible.
845 bool (concat_iterator::*IncrementHelperFns[])() = {
846 &concat_iterator::incrementHelper<Ns>...};
847
848 // Loop over them, and stop as soon as we succeed at incrementing one.
849 for (auto &IncrementHelperFn : IncrementHelperFns)
850 if ((this->*IncrementHelperFn)())
851 return;
852
853 llvm_unreachable("Attempted to increment an end concat iterator!")::llvm::llvm_unreachable_internal("Attempted to increment an end concat iterator!"
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h"
, 853)
;
854 }
855
856 /// Returns null if the specified iterator is at the end. Otherwise,
857 /// dereferences the iterator and returns the address of the resulting
858 /// reference.
859 template <size_t Index> ValueT *getHelper() const {
860 auto &Begin = std::get<Index>(Begins);
861 auto &End = std::get<Index>(Ends);
862 if (Begin == End)
863 return nullptr;
864
865 return &*Begin;
866 }
867
868 /// Finds the first non-end iterator, dereferences, and returns the resulting
869 /// reference.
870 ///
871 /// It is an error to call this with all iterators at the end.
872 template <size_t... Ns> ValueT &get(index_sequence<Ns...>) const {
873 // Build a sequence of functions to get from iterator if possible.
874 ValueT *(concat_iterator::*GetHelperFns[])() const = {
875 &concat_iterator::getHelper<Ns>...};
876
877 // Loop over them, and return the first result we find.
878 for (auto &GetHelperFn : GetHelperFns)
879 if (ValueT *P = (this->*GetHelperFn)())
880 return *P;
881
882 llvm_unreachable("Attempted to get a pointer from an end concat iterator!")::llvm::llvm_unreachable_internal("Attempted to get a pointer from an end concat iterator!"
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h"
, 882)
;
883 }
884
885public:
886 /// Constructs an iterator from a squence of ranges.
887 ///
888 /// We need the full range to know how to switch between each of the
889 /// iterators.
890 template <typename... RangeTs>
891 explicit concat_iterator(RangeTs &&... Ranges)
892 : Begins(std::begin(Ranges)...), Ends(std::end(Ranges)...) {}
893
894 using BaseT::operator++;
895
896 concat_iterator &operator++() {
897 increment(index_sequence_for<IterTs...>());
898 return *this;
899 }
900
901 ValueT &operator*() const { return get(index_sequence_for<IterTs...>()); }
902
903 bool operator==(const concat_iterator &RHS) const {
904 return Begins == RHS.Begins && Ends == RHS.Ends;
905 }
906};
907
908namespace detail {
909
910/// Helper to store a sequence of ranges being concatenated and access them.
911///
912/// This is designed to facilitate providing actual storage when temporaries
913/// are passed into the constructor such that we can use it as part of range
914/// based for loops.
915template <typename ValueT, typename... RangeTs> class concat_range {
916public:
917 using iterator =
918 concat_iterator<ValueT,
919 decltype(std::begin(std::declval<RangeTs &>()))...>;
920
921private:
922 std::tuple<RangeTs...> Ranges;
923
924 template <size_t... Ns> iterator begin_impl(index_sequence<Ns...>) {
925 return iterator(std::get<Ns>(Ranges)...);
926 }
927 template <size_t... Ns> iterator end_impl(index_sequence<Ns...>) {
928 return iterator(make_range(std::end(std::get<Ns>(Ranges)),
929 std::end(std::get<Ns>(Ranges)))...);
930 }
931
932public:
933 concat_range(RangeTs &&... Ranges)
934 : Ranges(std::forward<RangeTs>(Ranges)...) {}
935
936 iterator begin() { return begin_impl(index_sequence_for<RangeTs...>{}); }
937 iterator end() { return end_impl(index_sequence_for<RangeTs...>{}); }
938};
939
940} // end namespace detail
941
942/// Concatenated range across two or more ranges.
943///
944/// The desired value type must be explicitly specified.
945template <typename ValueT, typename... RangeTs>
946detail::concat_range<ValueT, RangeTs...> concat(RangeTs &&... Ranges) {
947 static_assert(sizeof...(RangeTs) > 1,
948 "Need more than one range to concatenate!");
949 return detail::concat_range<ValueT, RangeTs...>(
950 std::forward<RangeTs>(Ranges)...);
951}
952
953//===----------------------------------------------------------------------===//
954// Extra additions to <utility>
955//===----------------------------------------------------------------------===//
956
957/// Function object to check whether the first component of a std::pair
958/// compares less than the first component of another std::pair.
959struct less_first {
960 template <typename T> bool operator()(const T &lhs, const T &rhs) const {
961 return lhs.first < rhs.first;
962 }
963};
964
965/// Function object to check whether the second component of a std::pair
966/// compares less than the second component of another std::pair.
967struct less_second {
968 template <typename T> bool operator()(const T &lhs, const T &rhs) const {
969 return lhs.second < rhs.second;
970 }
971};
972
973/// \brief Function object to apply a binary function to the first component of
974/// a std::pair.
975template<typename FuncTy>
976struct on_first {
977 FuncTy func;
978
979 template <typename T>
980 auto operator()(const T &lhs, const T &rhs) const
981 -> decltype(func(lhs.first, rhs.first)) {
982 return func(lhs.first, rhs.first);
983 }
984};
985
986// A subset of N3658. More stuff can be added as-needed.
987
988/// Represents a compile-time sequence of integers.
989template <class T, T... I> struct integer_sequence {
990 using value_type = T;
991
992 static constexpr size_t size() { return sizeof...(I); }
993};
994
995/// Alias for the common case of a sequence of size_ts.
996template <size_t... I>
997struct index_sequence : integer_sequence<std::size_t, I...> {};
998
999template <std::size_t N, std::size_t... I>
1000struct build_index_impl : build_index_impl<N - 1, N - 1, I...> {};
1001template <std::size_t... I>
1002struct build_index_impl<0, I...> : index_sequence<I...> {};
1003
1004/// Creates a compile-time integer sequence for a parameter pack.
1005template <class... Ts>
1006struct index_sequence_for : build_index_impl<sizeof...(Ts)> {};
1007
1008/// Utility type to build an inheritance chain that makes it easy to rank
1009/// overload candidates.
1010template <int N> struct rank : rank<N - 1> {};
1011template <> struct rank<0> {};
1012
1013/// traits class for checking whether type T is one of any of the given
1014/// types in the variadic list.
1015template <typename T, typename... Ts> struct is_one_of {
1016 static const bool value = false;
1017};
1018
1019template <typename T, typename U, typename... Ts>
1020struct is_one_of<T, U, Ts...> {
1021 static const bool value =
1022 std::is_same<T, U>::value || is_one_of<T, Ts...>::value;
1023};
1024
1025/// traits class for checking whether type T is a base class for all
1026/// the given types in the variadic list.
1027template <typename T, typename... Ts> struct are_base_of {
1028 static const bool value = true;
1029};
1030
1031template <typename T, typename U, typename... Ts>
1032struct are_base_of<T, U, Ts...> {
1033 static const bool value =
1034 std::is_base_of<T, U>::value && are_base_of<T, Ts...>::value;
1035};
1036
1037//===----------------------------------------------------------------------===//
1038// Extra additions for arrays
1039//===----------------------------------------------------------------------===//
1040
1041/// Find the length of an array.
1042template <class T, std::size_t N>
1043constexpr inline size_t array_lengthof(T (&)[N]) {
1044 return N;
1045}
1046
1047/// Adapt std::less<T> for array_pod_sort.
1048template<typename T>
1049inline int array_pod_sort_comparator(const void *P1, const void *P2) {
1050 if (std::less<T>()(*reinterpret_cast<const T*>(P1),
1051 *reinterpret_cast<const T*>(P2)))
1052 return -1;
1053 if (std::less<T>()(*reinterpret_cast<const T*>(P2),
1054 *reinterpret_cast<const T*>(P1)))
1055 return 1;
1056 return 0;
1057}
1058
1059/// get_array_pod_sort_comparator - This is an internal helper function used to
1060/// get type deduction of T right.
1061template<typename T>
1062inline int (*get_array_pod_sort_comparator(const T &))
1063 (const void*, const void*) {
1064 return array_pod_sort_comparator<T>;
1065}
1066
1067/// array_pod_sort - This sorts an array with the specified start and end
1068/// extent. This is just like std::sort, except that it calls qsort instead of
1069/// using an inlined template. qsort is slightly slower than std::sort, but
1070/// most sorts are not performance critical in LLVM and std::sort has to be
1071/// template instantiated for each type, leading to significant measured code
1072/// bloat. This function should generally be used instead of std::sort where
1073/// possible.
1074///
1075/// This function assumes that you have simple POD-like types that can be
1076/// compared with std::less and can be moved with memcpy. If this isn't true,
1077/// you should use std::sort.
1078///
1079/// NOTE: If qsort_r were portable, we could allow a custom comparator and
1080/// default to std::less.
1081template<class IteratorTy>
1082inline void array_pod_sort(IteratorTy Start, IteratorTy End) {
1083 // Don't inefficiently call qsort with one element or trigger undefined
1084 // behavior with an empty sequence.
1085 auto NElts = End - Start;
1086 if (NElts <= 1) return;
1087#ifdef EXPENSIVE_CHECKS
1088 std::mt19937 Generator(std::random_device{}());
1089 std::shuffle(Start, End, Generator);
1090#endif
1091 qsort(&*Start, NElts, sizeof(*Start), get_array_pod_sort_comparator(*Start));
1092}
1093
1094template <class IteratorTy>
1095inline void array_pod_sort(
1096 IteratorTy Start, IteratorTy End,
1097 int (*Compare)(
1098 const typename std::iterator_traits<IteratorTy>::value_type *,
1099 const typename std::iterator_traits<IteratorTy>::value_type *)) {
1100 // Don't inefficiently call qsort with one element or trigger undefined
1101 // behavior with an empty sequence.
1102 auto NElts = End - Start;
1103 if (NElts <= 1) return;
1104#ifdef EXPENSIVE_CHECKS
1105 std::mt19937 Generator(std::random_device{}());
1106 std::shuffle(Start, End, Generator);
1107#endif
1108 qsort(&*Start, NElts, sizeof(*Start),
1109 reinterpret_cast<int (*)(const void *, const void *)>(Compare));
1110}
1111
1112// Provide wrappers to std::sort which shuffle the elements before sorting
1113// to help uncover non-deterministic behavior (PR35135).
1114template <typename IteratorTy>
1115inline void sort(IteratorTy Start, IteratorTy End) {
1116#ifdef EXPENSIVE_CHECKS
1117 std::mt19937 Generator(std::random_device{}());
1118 std::shuffle(Start, End, Generator);
1119#endif
1120 std::sort(Start, End);
1121}
1122
1123template <typename Container> inline void sort(Container &&C) {
1124 llvm::sort(adl_begin(C), adl_end(C));
1125}
1126
1127template <typename IteratorTy, typename Compare>
1128inline void sort(IteratorTy Start, IteratorTy End, Compare Comp) {
1129#ifdef EXPENSIVE_CHECKS
1130 std::mt19937 Generator(std::random_device{}());
1131 std::shuffle(Start, End, Generator);
1132#endif
1133 std::sort(Start, End, Comp);
1134}
1135
1136template <typename Container, typename Compare>
1137inline void sort(Container &&C, Compare Comp) {
1138 llvm::sort(adl_begin(C), adl_end(C), Comp);
1139}
1140
1141//===----------------------------------------------------------------------===//
1142// Extra additions to <algorithm>
1143//===----------------------------------------------------------------------===//
1144
1145/// For a container of pointers, deletes the pointers and then clears the
1146/// container.
1147template<typename Container>
1148void DeleteContainerPointers(Container &C) {
1149 for (auto V : C)
1150 delete V;
1151 C.clear();
1152}
1153
1154/// In a container of pairs (usually a map) whose second element is a pointer,
1155/// deletes the second elements and then clears the container.
1156template<typename Container>
1157void DeleteContainerSeconds(Container &C) {
1158 for (auto &V : C)
1159 delete V.second;
1160 C.clear();
1161}
1162
1163/// Get the size of a range. This is a wrapper function around std::distance
1164/// which is only enabled when the operation is O(1).
1165template <typename R>
1166auto size(R &&Range, typename std::enable_if<
1167 std::is_same<typename std::iterator_traits<decltype(
1168 Range.begin())>::iterator_category,
1169 std::random_access_iterator_tag>::value,
1170 void>::type * = nullptr)
1171 -> decltype(std::distance(Range.begin(), Range.end())) {
1172 return std::distance(Range.begin(), Range.end());
1173}
1174
1175/// Provide wrappers to std::for_each which take ranges instead of having to
1176/// pass begin/end explicitly.
1177template <typename R, typename UnaryPredicate>
1178UnaryPredicate for_each(R &&Range, UnaryPredicate P) {
1179 return std::for_each(adl_begin(Range), adl_end(Range), P);
1180}
1181
1182/// Provide wrappers to std::all_of which take ranges instead of having to pass
1183/// begin/end explicitly.
1184template <typename R, typename UnaryPredicate>
1185bool all_of(R &&Range, UnaryPredicate P) {
1186 return std::all_of(adl_begin(Range), adl_end(Range), P);
1187}
1188
1189/// Provide wrappers to std::any_of which take ranges instead of having to pass
1190/// begin/end explicitly.
1191template <typename R, typename UnaryPredicate>
1192bool any_of(R &&Range, UnaryPredicate P) {
1193 return std::any_of(adl_begin(Range), adl_end(Range), P);
1194}
1195
1196/// Provide wrappers to std::none_of which take ranges instead of having to pass
1197/// begin/end explicitly.
1198template <typename R, typename UnaryPredicate>
1199bool none_of(R &&Range, UnaryPredicate P) {
1200 return std::none_of(adl_begin(Range), adl_end(Range), P);
1201}
1202
1203/// Provide wrappers to std::find which take ranges instead of having to pass
1204/// begin/end explicitly.
1205template <typename R, typename T>
1206auto find(R &&Range, const T &Val) -> decltype(adl_begin(Range)) {
1207 return std::find(adl_begin(Range), adl_end(Range), Val);
1208}
1209
1210/// Provide wrappers to std::find_if which take ranges instead of having to pass
1211/// begin/end explicitly.
1212template <typename R, typename UnaryPredicate>
1213auto find_if(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1214 return std::find_if(adl_begin(Range), adl_end(Range), P);
1215}
1216
1217template <typename R, typename UnaryPredicate>
1218auto find_if_not(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1219 return std::find_if_not(adl_begin(Range), adl_end(Range), P);
1220}
1221
1222/// Provide wrappers to std::remove_if which take ranges instead of having to
1223/// pass begin/end explicitly.
1224template <typename R, typename UnaryPredicate>
1225auto remove_if(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1226 return std::remove_if(adl_begin(Range), adl_end(Range), P);
1227}
1228
1229/// Provide wrappers to std::copy_if which take ranges instead of having to
1230/// pass begin/end explicitly.
1231template <typename R, typename OutputIt, typename UnaryPredicate>
1232OutputIt copy_if(R &&Range, OutputIt Out, UnaryPredicate P) {
1233 return std::copy_if(adl_begin(Range), adl_end(Range), Out, P);
1234}
1235
1236template <typename R, typename OutputIt>
1237OutputIt copy(R &&Range, OutputIt Out) {
1238 return std::copy(adl_begin(Range), adl_end(Range), Out);
1239}
1240
1241/// Wrapper function around std::find to detect if an element exists
1242/// in a container.
1243template <typename R, typename E>
1244bool is_contained(R &&Range, const E &Element) {
1245 return std::find(adl_begin(Range), adl_end(Range), Element) != adl_end(Range);
1246}
1247
1248/// Wrapper function around std::count to count the number of times an element
1249/// \p Element occurs in the given range \p Range.
1250template <typename R, typename E>
1251auto count(R &&Range, const E &Element) ->
1252 typename std::iterator_traits<decltype(adl_begin(Range))>::difference_type {
1253 return std::count(adl_begin(Range), adl_end(Range), Element);
1254}
1255
1256/// Wrapper function around std::count_if to count the number of times an
1257/// element satisfying a given predicate occurs in a range.
1258template <typename R, typename UnaryPredicate>
1259auto count_if(R &&Range, UnaryPredicate P) ->
1260 typename std::iterator_traits<decltype(adl_begin(Range))>::difference_type {
1261 return std::count_if(adl_begin(Range), adl_end(Range), P);
1262}
1263
1264/// Wrapper function around std::transform to apply a function to a range and
1265/// store the result elsewhere.
1266template <typename R, typename OutputIt, typename UnaryPredicate>
1267OutputIt transform(R &&Range, OutputIt d_first, UnaryPredicate P) {
1268 return std::transform(adl_begin(Range), adl_end(Range), d_first, P);
1269}
1270
1271/// Provide wrappers to std::partition which take ranges instead of having to
1272/// pass begin/end explicitly.
1273template <typename R, typename UnaryPredicate>
1274auto partition(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1275 return std::partition(adl_begin(Range), adl_end(Range), P);
1276}
1277
1278/// Provide wrappers to std::lower_bound which take ranges instead of having to
1279/// pass begin/end explicitly.
1280template <typename R, typename T>
1281auto lower_bound(R &&Range, T &&Value) -> decltype(adl_begin(Range)) {
1282 return std::lower_bound(adl_begin(Range), adl_end(Range),
1283 std::forward<T>(Value));
1284}
1285
1286template <typename R, typename T, typename Compare>
1287auto lower_bound(R &&Range, T &&Value, Compare C)
1288 -> decltype(adl_begin(Range)) {
1289 return std::lower_bound(adl_begin(Range), adl_end(Range),
1290 std::forward<T>(Value), C);
1291}
1292
1293/// Provide wrappers to std::upper_bound which take ranges instead of having to
1294/// pass begin/end explicitly.
1295template <typename R, typename T>
1296auto upper_bound(R &&Range, T &&Value) -> decltype(adl_begin(Range)) {
1297 return std::upper_bound(adl_begin(Range), adl_end(Range),
1298 std::forward<T>(Value));
1299}
1300
1301template <typename R, typename T, typename Compare>
1302auto upper_bound(R &&Range, T &&Value, Compare C)
1303 -> decltype(adl_begin(Range)) {
1304 return std::upper_bound(adl_begin(Range), adl_end(Range),
1305 std::forward<T>(Value), C);
1306}
1307
1308/// Binary search for the first index where a predicate is true.
1309/// Returns the first I in [Lo, Hi) where C(I) is true, or Hi if it never is.
1310/// Requires that C is always false below some limit, and always true above it.
1311///
1312/// Example:
1313/// size_t DawnModernEra = bsearch(1776, 2050, [](size_t Year){
1314/// return Presidents.for(Year).twitterHandle() != None;
1315/// });
1316///
1317/// Note the return value differs from std::binary_search!
1318template <typename Predicate>
1319size_t bsearch(size_t Lo, size_t Hi, Predicate P) {
1320 while (Lo != Hi) {
1321 assert(Hi > Lo)((Hi > Lo) ? static_cast<void> (0) : __assert_fail (
"Hi > Lo", "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h"
, 1321, __PRETTY_FUNCTION__))
;
1322 size_t Mid = Lo + (Hi - Lo) / 2;
1323 if (P(Mid))
1324 Hi = Mid;
1325 else
1326 Lo = Mid + 1;
1327 }
1328 return Hi;
1329}
1330
1331/// Binary search for the first iterator where a predicate is true.
1332/// Returns the first I in [Lo, Hi) where C(*I) is true, or Hi if it never is.
1333/// Requires that C is always false below some limit, and always true above it.
1334template <typename It, typename Predicate,
1335 typename Val = decltype(*std::declval<It>())>
1336It bsearch(It Lo, It Hi, Predicate P) {
1337 return std::lower_bound(Lo, Hi, 0u,
1338 [&](const Val &V, unsigned) { return !P(V); });
1339}
1340
1341/// Binary search for the first iterator in a range where a predicate is true.
1342/// Requires that C is always false below some limit, and always true above it.
1343template <typename R, typename Predicate>
1344auto bsearch(R &&Range, Predicate P) -> decltype(adl_begin(Range)) {
1345 return bsearch(adl_begin(Range), adl_end(Range), P);
1346}
1347
1348/// Wrapper function around std::equal to detect if all elements
1349/// in a container are same.
1350template <typename R>
1351bool is_splat(R &&Range) {
1352 size_t range_size = size(Range);
1353 return range_size != 0 && (range_size == 1 ||
1354 std::equal(adl_begin(Range) + 1, adl_end(Range), adl_begin(Range)));
1355}
1356
1357/// Given a range of type R, iterate the entire range and return a
1358/// SmallVector with elements of the vector. This is useful, for example,
1359/// when you want to iterate a range and then sort the results.
1360template <unsigned Size, typename R>
1361SmallVector<typename std::remove_const<detail::ValueOfRange<R>>::type, Size>
1362to_vector(R &&Range) {
1363 return {adl_begin(Range), adl_end(Range)};
1364}
1365
1366/// Provide a container algorithm similar to C++ Library Fundamentals v2's
1367/// `erase_if` which is equivalent to:
1368///
1369/// C.erase(remove_if(C, pred), C.end());
1370///
1371/// This version works for any container with an erase method call accepting
1372/// two iterators.
1373template <typename Container, typename UnaryPredicate>
1374void erase_if(Container &C, UnaryPredicate P) {
1375 C.erase(remove_if(C, P), C.end());
1376}
1377
1378//===----------------------------------------------------------------------===//
1379// Extra additions to <memory>
1380//===----------------------------------------------------------------------===//
1381
1382// Implement make_unique according to N3656.
1383
1384/// Constructs a `new T()` with the given args and returns a
1385/// `unique_ptr<T>` which owns the object.
1386///
1387/// Example:
1388///
1389/// auto p = make_unique<int>();
1390/// auto p = make_unique<std::tuple<int, int>>(0, 1);
1391template <class T, class... Args>
1392typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type
1393make_unique(Args &&... args) {
1394 return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
5
Memory is allocated
1395}
1396
1397/// Constructs a `new T[n]` with the given args and returns a
1398/// `unique_ptr<T[]>` which owns the object.
1399///
1400/// \param n size of the new array.
1401///
1402/// Example:
1403///
1404/// auto p = make_unique<int[]>(2); // value-initializes the array with 0's.
1405template <class T>
1406typename std::enable_if<std::is_array<T>::value && std::extent<T>::value == 0,
1407 std::unique_ptr<T>>::type
1408make_unique(size_t n) {
1409 return std::unique_ptr<T>(new typename std::remove_extent<T>::type[n]());
1410}
1411
1412/// This function isn't used and is only here to provide better compile errors.
1413template <class T, class... Args>
1414typename std::enable_if<std::extent<T>::value != 0>::type
1415make_unique(Args &&...) = delete;
1416
1417struct FreeDeleter {
1418 void operator()(void* v) {
1419 ::free(v);
1420 }
1421};
1422
1423template<typename First, typename Second>
1424struct pair_hash {
1425 size_t operator()(const std::pair<First, Second> &P) const {
1426 return std::hash<First>()(P.first) * 31 + std::hash<Second>()(P.second);
1427 }
1428};
1429
1430/// A functor like C++14's std::less<void> in its absence.
1431struct less {
1432 template <typename A, typename B> bool operator()(A &&a, B &&b) const {
1433 return std::forward<A>(a) < std::forward<B>(b);
1434 }
1435};
1436
1437/// A functor like C++14's std::equal<void> in its absence.
1438struct equal {
1439 template <typename A, typename B> bool operator()(A &&a, B &&b) const {
1440 return std::forward<A>(a) == std::forward<B>(b);
1441 }
1442};
1443
1444/// Binary functor that adapts to any other binary functor after dereferencing
1445/// operands.
1446template <typename T> struct deref {
1447 T func;
1448
1449 // Could be further improved to cope with non-derivable functors and
1450 // non-binary functors (should be a variadic template member function
1451 // operator()).
1452 template <typename A, typename B>
1453 auto operator()(A &lhs, B &rhs) const -> decltype(func(*lhs, *rhs)) {
1454 assert(lhs)((lhs) ? static_cast<void> (0) : __assert_fail ("lhs", "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h"
, 1454, __PRETTY_FUNCTION__))
;
1455 assert(rhs)((rhs) ? static_cast<void> (0) : __assert_fail ("rhs", "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h"
, 1455, __PRETTY_FUNCTION__))
;
1456 return func(*lhs, *rhs);
1457 }
1458};
1459
1460namespace detail {
1461
1462template <typename R> class enumerator_iter;
1463
1464template <typename R> struct result_pair {
1465 friend class enumerator_iter<R>;
1466
1467 result_pair() = default;
1468 result_pair(std::size_t Index, IterOfRange<R> Iter)
1469 : Index(Index), Iter(Iter) {}
1470
1471 result_pair<R> &operator=(const result_pair<R> &Other) {
1472 Index = Other.Index;
1473 Iter = Other.Iter;
1474 return *this;
1475 }
1476
1477 std::size_t index() const { return Index; }
1478 const ValueOfRange<R> &value() const { return *Iter; }
1479 ValueOfRange<R> &value() { return *Iter; }
1480
1481private:
1482 std::size_t Index = std::numeric_limits<std::size_t>::max();
1483 IterOfRange<R> Iter;
1484};
1485
1486template <typename R>
1487class enumerator_iter
1488 : public iterator_facade_base<
1489 enumerator_iter<R>, std::forward_iterator_tag, result_pair<R>,
1490 typename std::iterator_traits<IterOfRange<R>>::difference_type,
1491 typename std::iterator_traits<IterOfRange<R>>::pointer,
1492 typename std::iterator_traits<IterOfRange<R>>::reference> {
1493 using result_type = result_pair<R>;
1494
1495public:
1496 explicit enumerator_iter(IterOfRange<R> EndIter)
1497 : Result(std::numeric_limits<size_t>::max(), EndIter) {}
1498
1499 enumerator_iter(std::size_t Index, IterOfRange<R> Iter)
1500 : Result(Index, Iter) {}
1501
1502 result_type &operator*() { return Result; }
1503 const result_type &operator*() const { return Result; }
1504
1505 enumerator_iter<R> &operator++() {
1506 assert(Result.Index != std::numeric_limits<size_t>::max())((Result.Index != std::numeric_limits<size_t>::max()) ?
static_cast<void> (0) : __assert_fail ("Result.Index != std::numeric_limits<size_t>::max()"
, "/build/llvm-toolchain-snapshot-9~svn358860/include/llvm/ADT/STLExtras.h"
, 1506, __PRETTY_FUNCTION__))
;
1507 ++Result.Iter;
1508 ++Result.Index;
1509 return *this;
1510 }
1511
1512 bool operator==(const enumerator_iter<R> &RHS) const {
1513 // Don't compare indices here, only iterators. It's possible for an end
1514 // iterator to have different indices depending on whether it was created
1515 // by calling std::end() versus incrementing a valid iterator.
1516 return Result.Iter == RHS.Result.Iter;
1517 }
1518
1519 enumerator_iter<R> &operator=(const enumerator_iter<R> &Other) {
1520 Result = Other.Result;
1521 return *this;
1522 }
1523
1524private:
1525 result_type Result;
1526};
1527
1528template <typename R> class enumerator {
1529public:
1530 explicit enumerator(R &&Range) : TheRange(std::forward<R>(Range)) {}
1531
1532 enumerator_iter<R> begin() {
1533 return enumerator_iter<R>(0, std::begin(TheRange));
1534 }
1535
1536 enumerator_iter<R> end() {
1537 return enumerator_iter<R>(std::end(TheRange));
1538 }
1539
1540private:
1541 R TheRange;
1542};
1543
1544} // end namespace detail
1545
1546/// Given an input range, returns a new range whose values are are pair (A,B)
1547/// such that A is the 0-based index of the item in the sequence, and B is
1548/// the value from the original sequence. Example:
1549///
1550/// std::vector<char> Items = {'A', 'B', 'C', 'D'};
1551/// for (auto X : enumerate(Items)) {
1552/// printf("Item %d - %c\n", X.index(), X.value());
1553/// }
1554///
1555/// Output:
1556/// Item 0 - A
1557/// Item 1 - B
1558/// Item 2 - C
1559/// Item 3 - D
1560///
1561template <typename R> detail::enumerator<R> enumerate(R &&TheRange) {
1562 return detail::enumerator<R>(std::forward<R>(TheRange));
1563}
1564
1565namespace detail {
1566
1567template <typename F, typename Tuple, std::size_t... I>
1568auto apply_tuple_impl(F &&f, Tuple &&t, index_sequence<I...>)
1569 -> decltype(std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...)) {
1570 return std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...);
1571}
1572
1573} // end namespace detail
1574
1575/// Given an input tuple (a1, a2, ..., an), pass the arguments of the
1576/// tuple variadically to f as if by calling f(a1, a2, ..., an) and
1577/// return the result.
1578template <typename F, typename Tuple>
1579auto apply_tuple(F &&f, Tuple &&t) -> decltype(detail::apply_tuple_impl(
1580 std::forward<F>(f), std::forward<Tuple>(t),
1581 build_index_impl<
1582 std::tuple_size<typename std::decay<Tuple>::type>::value>{})) {
1583 using Indices = build_index_impl<
1584 std::tuple_size<typename std::decay<Tuple>::type>::value>;
1585
1586 return detail::apply_tuple_impl(std::forward<F>(f), std::forward<Tuple>(t),
1587 Indices{});
1588}
1589
1590/// Return true if the sequence [Begin, End) has exactly N items. Runs in O(N)
1591/// time. Not meant for use with random-access iterators.
1592template <typename IterTy>
1593bool hasNItems(
1594 IterTy &&Begin, IterTy &&End, unsigned N,
1595 typename std::enable_if<
1596 !std::is_same<
1597 typename std::iterator_traits<typename std::remove_reference<
1598 decltype(Begin)>::type>::iterator_category,
1599 std::random_access_iterator_tag>::value,
1600 void>::type * = nullptr) {
1601 for (; N; --N, ++Begin)
1602 if (Begin == End)
1603 return false; // Too few.
1604 return Begin == End;
1605}
1606
1607/// Return true if the sequence [Begin, End) has N or more items. Runs in O(N)
1608/// time. Not meant for use with random-access iterators.
1609template <typename IterTy>
1610bool hasNItemsOrMore(
1611 IterTy &&Begin, IterTy &&End, unsigned N,
1612 typename std::enable_if<
1613 !std::is_same<
1614 typename std::iterator_traits<typename std::remove_reference<
1615 decltype(Begin)>::type>::iterator_category,
1616 std::random_access_iterator_tag>::value,
1617 void>::type * = nullptr) {
1618 for (; N; --N, ++Begin)
1619 if (Begin == End)
1620 return false; // Too few.
1621 return true;
1622}
1623
1624/// Returns a raw pointer that represents the same address as the argument.
1625///
1626/// The late bound return should be removed once we move to C++14 to better
1627/// align with the C++20 declaration. Also, this implementation can be removed
1628/// once we move to C++20 where it's defined as std::to_addres()
1629///
1630/// The std::pointer_traits<>::to_address(p) variations of these overloads has
1631/// not been implemented.
1632template <class Ptr> auto to_address(const Ptr &P) -> decltype(P.operator->()) {
1633 return P.operator->();
1634}
1635template <class T> constexpr T *to_address(T *P) { return P; }
1636
1637} // end namespace llvm
1638
1639#endif // LLVM_ADT_STLEXTRAS_H