Bug Summary

File:llvm/include/llvm/Bitstream/BitstreamReader.h
Warning:line 221, column 39
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SerializedDiagnosticReader.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 -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/clang/lib/Frontend -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D CLANG_ROUND_TRIP_CC1_ARGS=ON -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/clang/lib/Frontend -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/Frontend -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/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-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/clang/lib/Frontend -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-08-28-193554-24367-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/Frontend/SerializedDiagnosticReader.cpp

/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/Frontend/SerializedDiagnosticReader.cpp

→
1//===- SerializedDiagnosticReader.cpp - Reads diagnostics -----------------===//
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#include "clang/Frontend/SerializedDiagnosticReader.h"
10#include "clang/Basic/FileManager.h"
11#include "clang/Basic/FileSystemOptions.h"
12#include "clang/Frontend/SerializedDiagnostics.h"
13#include "llvm/ADT/Optional.h"
14#include "llvm/ADT/SmallVector.h"
15#include "llvm/ADT/StringRef.h"
16#include "llvm/Bitstream/BitCodes.h"
17#include "llvm/Bitstream/BitstreamReader.h"
18#include "llvm/Support/Compiler.h"
19#include "llvm/Support/ErrorHandling.h"
20#include "llvm/Support/ErrorOr.h"
21#include "llvm/Support/ManagedStatic.h"
22#include <cstdint>
23#include <system_error>
24
25using namespace clang;
26using namespace serialized_diags;
27
28std::error_code SerializedDiagnosticReader::readDiagnostics(StringRef File) {
29 // Open the diagnostics file.
30 FileSystemOptions FO;
31 FileManager FileMgr(FO);
32
33 auto Buffer = FileMgr.getBufferForFile(File);
34 if (!Buffer)
1
Taking false branch
→
35 return SDError::CouldNotLoad;
36
37 llvm::BitstreamCursor Stream(**Buffer);
38 Optional<llvm::BitstreamBlockInfo> BlockInfo;
39
40 if (Stream.AtEndOfStream())
2
←
Taking false branch
→
41 return SDError::InvalidSignature;
42
43 // Sniff for the signature.
44 for (unsigned char C : {'D', 'I', 'A', 'G'}) {
3
←
Assuming '__begin1' is not equal to '__end1'
→
45 if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = Stream.Read(8)) {
4
←
Calling 'SimpleBitstreamCursor::Read'
→
46 if (Res.get() == C)
47 continue;
48 } else {
49 // FIXME this drops the error on the floor.
50 consumeError(Res.takeError());
51 }
52 return SDError::InvalidSignature;
53 }
54
55 // Read the top level blocks.
56 while (!Stream.AtEndOfStream()) {
57 if (Expected<unsigned> Res = Stream.ReadCode()) {
58 if (Res.get() != llvm::bitc::ENTER_SUBBLOCK)
59 return SDError::InvalidDiagnostics;
60 } else {
61 // FIXME this drops the error on the floor.
62 consumeError(Res.takeError());
63 return SDError::InvalidDiagnostics;
64 }
65
66 std::error_code EC;
67 Expected<unsigned> MaybeSubBlockID = Stream.ReadSubBlockID();
68 if (!MaybeSubBlockID) {
69 // FIXME this drops the error on the floor.
70 consumeError(MaybeSubBlockID.takeError());
71 return SDError::InvalidDiagnostics;
72 }
73
74 switch (MaybeSubBlockID.get()) {
75 case llvm::bitc::BLOCKINFO_BLOCK_ID: {
76 Expected<Optional<llvm::BitstreamBlockInfo>> MaybeBlockInfo =
77 Stream.ReadBlockInfoBlock();
78 if (!MaybeBlockInfo) {
79 // FIXME this drops the error on the floor.
80 consumeError(MaybeBlockInfo.takeError());
81 return SDError::InvalidDiagnostics;
82 }
83 BlockInfo = std::move(MaybeBlockInfo.get());
84 }
85 if (!BlockInfo)
86 return SDError::MalformedBlockInfoBlock;
87 Stream.setBlockInfo(&*BlockInfo);
88 continue;
89 case BLOCK_META:
90 if ((EC = readMetaBlock(Stream)))
91 return EC;
92 continue;
93 case BLOCK_DIAG:
94 if ((EC = readDiagnosticBlock(Stream)))
95 return EC;
96 continue;
97 default:
98 if (llvm::Error Err = Stream.SkipBlock()) {
99 // FIXME this drops the error on the floor.
100 consumeError(std::move(Err));
101 return SDError::MalformedTopLevelBlock;
102 }
103 continue;
104 }
105 }
106 return {};
107}
108
109enum class SerializedDiagnosticReader::Cursor {
110 Record = 1,
111 BlockEnd,
112 BlockBegin
113};
114
115llvm::ErrorOr<SerializedDiagnosticReader::Cursor>
116SerializedDiagnosticReader::skipUntilRecordOrBlock(
117 llvm::BitstreamCursor &Stream, unsigned &BlockOrRecordID) {
118 BlockOrRecordID = 0;
119
120 while (!Stream.AtEndOfStream()) {
121 unsigned Code;
122 if (Expected<unsigned> Res = Stream.ReadCode())
123 Code = Res.get();
124 else
125 return llvm::errorToErrorCode(Res.takeError());
126
127 if (Code >= static_cast<unsigned>(llvm::bitc::FIRST_APPLICATION_ABBREV)) {
128 // We found a record.
129 BlockOrRecordID = Code;
130 return Cursor::Record;
131 }
132 switch (static_cast<llvm::bitc::FixedAbbrevIDs>(Code)) {
133 case llvm::bitc::ENTER_SUBBLOCK:
134 if (Expected<unsigned> Res = Stream.ReadSubBlockID())
135 BlockOrRecordID = Res.get();
136 else
137 return llvm::errorToErrorCode(Res.takeError());
138 return Cursor::BlockBegin;
139
140 case llvm::bitc::END_BLOCK:
141 if (Stream.ReadBlockEnd())
142 return SDError::InvalidDiagnostics;
143 return Cursor::BlockEnd;
144
145 case llvm::bitc::DEFINE_ABBREV:
146 if (llvm::Error Err = Stream.ReadAbbrevRecord())
147 return llvm::errorToErrorCode(std::move(Err));
148 continue;
149
150 case llvm::bitc::UNABBREV_RECORD:
151 return SDError::UnsupportedConstruct;
152
153 case llvm::bitc::FIRST_APPLICATION_ABBREV:
154 llvm_unreachable("Unexpected abbrev id.")::llvm::llvm_unreachable_internal("Unexpected abbrev id.", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/Frontend/SerializedDiagnosticReader.cpp"
, 154);
155 }
156 }
157
158 return SDError::InvalidDiagnostics;
159}
160
161std::error_code
162SerializedDiagnosticReader::readMetaBlock(llvm::BitstreamCursor &Stream) {
163 if (llvm::Error Err =
164 Stream.EnterSubBlock(clang::serialized_diags::BLOCK_META)) {
165 // FIXME this drops the error on the floor.
166 consumeError(std::move(Err));
167 return SDError::MalformedMetadataBlock;
168 }
169
170 bool VersionChecked = false;
171
172 while (true) {
173 unsigned BlockOrCode = 0;
174 llvm::ErrorOr<Cursor> Res = skipUntilRecordOrBlock(Stream, BlockOrCode);
175 if (!Res)
176 Res.getError();
177
178 switch (Res.get()) {
179 case Cursor::Record:
180 break;
181 case Cursor::BlockBegin:
182 if (llvm::Error Err = Stream.SkipBlock()) {
183 // FIXME this drops the error on the floor.
184 consumeError(std::move(Err));
185 return SDError::MalformedMetadataBlock;
186 }
187 LLVM_FALLTHROUGH[[gnu::fallthrough]];
188 case Cursor::BlockEnd:
189 if (!VersionChecked)
190 return SDError::MissingVersion;
191 return {};
192 }
193
194 SmallVector<uint64_t, 1> Record;
195 Expected<unsigned> MaybeRecordID = Stream.readRecord(BlockOrCode, Record);
196 if (!MaybeRecordID)
197 return errorToErrorCode(MaybeRecordID.takeError());
198 unsigned RecordID = MaybeRecordID.get();
199
200 if (RecordID == RECORD_VERSION) {
201 if (Record.size() < 1)
202 return SDError::MissingVersion;
203 if (Record[0] > VersionNumber)
204 return SDError::VersionMismatch;
205 VersionChecked = true;
206 }
207 }
208}
209
210std::error_code
211SerializedDiagnosticReader::readDiagnosticBlock(llvm::BitstreamCursor &Stream) {
212 if (llvm::Error Err =
213 Stream.EnterSubBlock(clang::serialized_diags::BLOCK_DIAG)) {
214 // FIXME this drops the error on the floor.
215 consumeError(std::move(Err));
216 return SDError::MalformedDiagnosticBlock;
217 }
218
219 std::error_code EC;
220 if ((EC = visitStartOfDiagnostic()))
221 return EC;
222
223 SmallVector<uint64_t, 16> Record;
224 while (true) {
225 unsigned BlockOrCode = 0;
226 llvm::ErrorOr<Cursor> Res = skipUntilRecordOrBlock(Stream, BlockOrCode);
227 if (!Res)
228 Res.getError();
229
230 switch (Res.get()) {
231 case Cursor::BlockBegin:
232 // The only blocks we care about are subdiagnostics.
233 if (BlockOrCode == serialized_diags::BLOCK_DIAG) {
234 if ((EC = readDiagnosticBlock(Stream)))
235 return EC;
236 } else if (llvm::Error Err = Stream.SkipBlock()) {
237 // FIXME this drops the error on the floor.
238 consumeError(std::move(Err));
239 return SDError::MalformedSubBlock;
240 }
241 continue;
242 case Cursor::BlockEnd:
243 if ((EC = visitEndOfDiagnostic()))
244 return EC;
245 return {};
246 case Cursor::Record:
247 break;
248 }
249
250 // Read the record.
251 Record.clear();
252 StringRef Blob;
253 Expected<unsigned> MaybeRecID =
254 Stream.readRecord(BlockOrCode, Record, &Blob);
255 if (!MaybeRecID)
256 return errorToErrorCode(MaybeRecID.takeError());
257 unsigned RecID = MaybeRecID.get();
258
259 if (RecID < serialized_diags::RECORD_FIRST ||
260 RecID > serialized_diags::RECORD_LAST)
261 continue;
262
263 switch ((RecordIDs)RecID) {
264 case RECORD_CATEGORY:
265 // A category has ID and name size.
266 if (Record.size() != 2)
267 return SDError::MalformedDiagnosticRecord;
268 if ((EC = visitCategoryRecord(Record[0], Blob)))
269 return EC;
270 continue;
271 case RECORD_DIAG:
272 // A diagnostic has severity, location (4), category, flag, and message
273 // size.
274 if (Record.size() != 8)
275 return SDError::MalformedDiagnosticRecord;
276 if ((EC = visitDiagnosticRecord(
277 Record[0], Location(Record[1], Record[2], Record[3], Record[4]),
278 Record[5], Record[6], Blob)))
279 return EC;
280 continue;
281 case RECORD_DIAG_FLAG:
282 // A diagnostic flag has ID and name size.
283 if (Record.size() != 2)
284 return SDError::MalformedDiagnosticRecord;
285 if ((EC = visitDiagFlagRecord(Record[0], Blob)))
286 return EC;
287 continue;
288 case RECORD_FILENAME:
289 // A filename has ID, size, timestamp, and name size. The size and
290 // timestamp are legacy fields that are always zero these days.
291 if (Record.size() != 4)
292 return SDError::MalformedDiagnosticRecord;
293 if ((EC = visitFilenameRecord(Record[0], Record[1], Record[2], Blob)))
294 return EC;
295 continue;
296 case RECORD_FIXIT:
297 // A fixit has two locations (4 each) and message size.
298 if (Record.size() != 9)
299 return SDError::MalformedDiagnosticRecord;
300 if ((EC = visitFixitRecord(
301 Location(Record[0], Record[1], Record[2], Record[3]),
302 Location(Record[4], Record[5], Record[6], Record[7]), Blob)))
303 return EC;
304 continue;
305 case RECORD_SOURCE_RANGE:
306 // A source range is two locations (4 each).
307 if (Record.size() != 8)
308 return SDError::MalformedDiagnosticRecord;
309 if ((EC = visitSourceRangeRecord(
310 Location(Record[0], Record[1], Record[2], Record[3]),
311 Location(Record[4], Record[5], Record[6], Record[7]))))
312 return EC;
313 continue;
314 case RECORD_VERSION:
315 // A version is just a number.
316 if (Record.size() != 1)
317 return SDError::MalformedDiagnosticRecord;
318 if ((EC = visitVersionRecord(Record[0])))
319 return EC;
320 continue;
321 }
322 }
323}
324
325namespace {
326
327class SDErrorCategoryType final : public std::error_category {
328 const char *name() const noexcept override {
329 return "clang.serialized_diags";
330 }
331
332 std::string message(int IE) const override {
333 auto E = static_cast<SDError>(IE);
334 switch (E) {
335 case SDError::CouldNotLoad:
336 return "Failed to open diagnostics file";
337 case SDError::InvalidSignature:
338 return "Invalid diagnostics signature";
339 case SDError::InvalidDiagnostics:
340 return "Parse error reading diagnostics";
341 case SDError::MalformedTopLevelBlock:
342 return "Malformed block at top-level of diagnostics";
343 case SDError::MalformedSubBlock:
344 return "Malformed sub-block in a diagnostic";
345 case SDError::MalformedBlockInfoBlock:
346 return "Malformed BlockInfo block";
347 case SDError::MalformedMetadataBlock:
348 return "Malformed Metadata block";
349 case SDError::MalformedDiagnosticBlock:
350 return "Malformed Diagnostic block";
351 case SDError::MalformedDiagnosticRecord:
352 return "Malformed Diagnostic record";
353 case SDError::MissingVersion:
354 return "No version provided in diagnostics";
355 case SDError::VersionMismatch:
356 return "Unsupported diagnostics version";
357 case SDError::UnsupportedConstruct:
358 return "Bitcode constructs that are not supported in diagnostics appear";
359 case SDError::HandlerFailed:
360 return "Generic error occurred while handling a record";
361 }
362 llvm_unreachable("Unknown error type!")::llvm::llvm_unreachable_internal("Unknown error type!", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/lib/Frontend/SerializedDiagnosticReader.cpp"
, 362);
363 }
364};
365
366} // namespace
367
368static llvm::ManagedStatic<SDErrorCategoryType> ErrorCategory;
369const std::error_category &clang::serialized_diags::SDErrorCategory() {
370 return *ErrorCategory;
371}
←

/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/clang/include/clang/Basic/FileManager.h

→
1//===--- FileManager.h - File System Probing and Caching --------*- 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/// \file
10/// Defines the clang::FileManager interface and associated types.
11///
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_BASIC_FILEMANAGER_H
15#define LLVM_CLANG_BASIC_FILEMANAGER_H
16
17#include "clang/Basic/DirectoryEntry.h"
18#include "clang/Basic/FileEntry.h"
19#include "clang/Basic/FileSystemOptions.h"
20#include "clang/Basic/LLVM.h"
21#include "llvm/ADT/DenseMap.h"
22#include "llvm/ADT/IntrusiveRefCntPtr.h"
23#include "llvm/ADT/PointerUnion.h"
24#include "llvm/ADT/SmallVector.h"
25#include "llvm/ADT/StringMap.h"
26#include "llvm/ADT/StringRef.h"
27#include "llvm/Support/Allocator.h"
28#include "llvm/Support/ErrorOr.h"
29#include "llvm/Support/FileSystem.h"
30#include "llvm/Support/VirtualFileSystem.h"
31#include <ctime>
32#include <map>
33#include <memory>
34#include <string>
35
36namespace llvm {
37
38class MemoryBuffer;
39
40} // end namespace llvm
41
42namespace clang {
43
44class FileSystemStatCache;
45
46/// Implements support for file system lookup, file system caching,
47/// and directory search management.
48///
49/// This also handles more advanced properties, such as uniquing files based
50/// on "inode", so that a file with two names (e.g. symlinked) will be treated
51/// as a single file.
52///
53class FileManager : public RefCountedBase<FileManager> {
54 IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS;
55 FileSystemOptions FileSystemOpts;
56
57 /// Cache for existing real directories.
58 std::map<llvm::sys::fs::UniqueID, DirectoryEntry> UniqueRealDirs;
59
60 /// Cache for existing real files.
61 std::map<llvm::sys::fs::UniqueID, FileEntry> UniqueRealFiles;
62
63 /// The virtual directories that we have allocated.
64 ///
65 /// For each virtual file (e.g. foo/bar/baz.cpp), we add all of its parent
66 /// directories (foo/ and foo/bar/) here.
67 SmallVector<std::unique_ptr<DirectoryEntry>, 4> VirtualDirectoryEntries;
68 /// The virtual files that we have allocated.
69 SmallVector<std::unique_ptr<FileEntry>, 4> VirtualFileEntries;
70
71 /// A set of files that bypass the maps and uniquing. They can have
72 /// conflicting filenames.
73 SmallVector<std::unique_ptr<FileEntry>, 0> BypassFileEntries;
74
75 /// A cache that maps paths to directory entries (either real or
76 /// virtual) we have looked up, or an error that occurred when we looked up
77 /// the directory.
78 ///
79 /// The actual Entries for real directories/files are
80 /// owned by UniqueRealDirs/UniqueRealFiles above, while the Entries
81 /// for virtual directories/files are owned by
82 /// VirtualDirectoryEntries/VirtualFileEntries above.
83 ///
84 llvm::StringMap<llvm::ErrorOr<DirectoryEntry &>, llvm::BumpPtrAllocator>
85 SeenDirEntries;
86
87 /// A cache that maps paths to file entries (either real or
88 /// virtual) we have looked up, or an error that occurred when we looked up
89 /// the file.
90 ///
91 /// \see SeenDirEntries
92 llvm::StringMap<llvm::ErrorOr<FileEntryRef::MapValue>, llvm::BumpPtrAllocator>
93 SeenFileEntries;
94
95 /// A mirror of SeenFileEntries to give fake answers for getBypassFile().
96 ///
97 /// Don't bother hooking up a BumpPtrAllocator. This should be rarely used,
98 /// and only on error paths.
99 std::unique_ptr<llvm::StringMap<llvm::ErrorOr<FileEntryRef::MapValue>>>
100 SeenBypassFileEntries;
101
102 /// The file entry for stdin, if it has been accessed through the FileManager.
103 Optional<FileEntryRef> STDIN;
104
105 /// The canonical names of files and directories .
106 llvm::DenseMap<const void *, llvm::StringRef> CanonicalNames;
107
108 /// Storage for canonical names that we have computed.
109 llvm::BumpPtrAllocator CanonicalNameStorage;
110
111 /// Each FileEntry we create is assigned a unique ID #.
112 ///
113 unsigned NextFileUID;
114
115 // Caching.
116 std::unique_ptr<FileSystemStatCache> StatCache;
117
118 std::error_code getStatValue(StringRef Path, llvm::vfs::Status &Status,
119 bool isFile,
120 std::unique_ptr<llvm::vfs::File> *F);
121
122 /// Add all ancestors of the given path (pointing to either a file
123 /// or a directory) as virtual directories.
124 void addAncestorsAsVirtualDirs(StringRef Path);
125
126 /// Fills the RealPathName in file entry.
127 void fillRealPathName(FileEntry *UFE, llvm::StringRef FileName);
128
129public:
130 /// Construct a file manager, optionally with a custom VFS.
131 ///
132 /// \param FS if non-null, the VFS to use. Otherwise uses
133 /// llvm::vfs::getRealFileSystem().
134 FileManager(const FileSystemOptions &FileSystemOpts,
135 IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS = nullptr);
136 ~FileManager();
137
138 /// Installs the provided FileSystemStatCache object within
139 /// the FileManager.
140 ///
141 /// Ownership of this object is transferred to the FileManager.
142 ///
143 /// \param statCache the new stat cache to install. Ownership of this
144 /// object is transferred to the FileManager.
145 void setStatCache(std::unique_ptr<FileSystemStatCache> statCache);
146
147 /// Removes the FileSystemStatCache object from the manager.
148 void clearStatCache();
149
150 /// Returns the number of unique real file entries cached by the file manager.
151 size_t getNumUniqueRealFiles() const { return UniqueRealFiles.size(); }
152
153 /// Lookup, cache, and verify the specified directory (real or
154 /// virtual).
155 ///
156 /// This returns a \c std::error_code if there was an error reading the
157 /// directory. On success, returns the reference to the directory entry
158 /// together with the exact path that was used to access a file by a
159 /// particular call to getDirectoryRef.
160 ///
161 /// \param CacheFailure If true and the file does not exist, we'll cache
162 /// the failure to find this file.
163 llvm::Expected<DirectoryEntryRef> getDirectoryRef(StringRef DirName,
164 bool CacheFailure = true);
165
166 /// Get a \c DirectoryEntryRef if it exists, without doing anything on error.
167 llvm::Optional<DirectoryEntryRef>
168 getOptionalDirectoryRef(StringRef DirName, bool CacheFailure = true) {
169 return llvm::expectedToOptional(getDirectoryRef(DirName, CacheFailure));
170 }
171
172 /// Lookup, cache, and verify the specified directory (real or
173 /// virtual).
174 ///
175 /// This function is deprecated and will be removed at some point in the
176 /// future, new clients should use
177 /// \c getDirectoryRef.
178 ///
179 /// This returns a \c std::error_code if there was an error reading the
180 /// directory. If there is no error, the DirectoryEntry is guaranteed to be
181 /// non-NULL.
182 ///
183 /// \param CacheFailure If true and the file does not exist, we'll cache
184 /// the failure to find this file.
185 llvm::ErrorOr<const DirectoryEntry *>
186 getDirectory(StringRef DirName, bool CacheFailure = true);
187
188 /// Lookup, cache, and verify the specified file (real or
189 /// virtual).
190 ///
191 /// This function is deprecated and will be removed at some point in the
192 /// future, new clients should use
193 /// \c getFileRef.
194 ///
195 /// This returns a \c std::error_code if there was an error loading the file.
196 /// If there is no error, the FileEntry is guaranteed to be non-NULL.
197 ///
198 /// \param OpenFile if true and the file exists, it will be opened.
199 ///
200 /// \param CacheFailure If true and the file does not exist, we'll cache
201 /// the failure to find this file.
202 llvm::ErrorOr<const FileEntry *>
203 getFile(StringRef Filename, bool OpenFile = false, bool CacheFailure = true);
204
205 /// Lookup, cache, and verify the specified file (real or virtual). Return the
206 /// reference to the file entry together with the exact path that was used to
207 /// access a file by a particular call to getFileRef. If the underlying VFS is
208 /// a redirecting VFS that uses external file names, the returned FileEntryRef
209 /// will use the external name instead of the filename that was passed to this
210 /// method.
211 ///
212 /// This returns a \c std::error_code if there was an error loading the file,
213 /// or a \c FileEntryRef otherwise.
214 ///
215 /// \param OpenFile if true and the file exists, it will be opened.
216 ///
217 /// \param CacheFailure If true and the file does not exist, we'll cache
218 /// the failure to find this file.
219 llvm::Expected<FileEntryRef> getFileRef(StringRef Filename,
220 bool OpenFile = false,
221 bool CacheFailure = true);
222
223 /// Get the FileEntryRef for stdin, returning an error if stdin cannot be
224 /// read.
225 ///
226 /// This reads and caches stdin before returning. Subsequent calls return the
227 /// same file entry, and a reference to the cached input is returned by calls
228 /// to getBufferForFile.
229 llvm::Expected<FileEntryRef> getSTDIN();
230
231 /// Get a FileEntryRef if it exists, without doing anything on error.
232 llvm::Optional<FileEntryRef> getOptionalFileRef(StringRef Filename,
233 bool OpenFile = false,
234 bool CacheFailure = true) {
235 return llvm::expectedToOptional(
236 getFileRef(Filename, OpenFile, CacheFailure));
237 }
238
239 /// Returns the current file system options
240 FileSystemOptions &getFileSystemOpts() { return FileSystemOpts; }
241 const FileSystemOptions &getFileSystemOpts() const { return FileSystemOpts; }
242
243 llvm::vfs::FileSystem &getVirtualFileSystem() const { return *FS; }
244
245 void setVirtualFileSystem(IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS) {
246 this->FS = std::move(FS);
247 }
248
249 /// Retrieve a file entry for a "virtual" file that acts as
250 /// if there were a file with the given name on disk.
251 ///
252 /// The file itself is not accessed.
253 FileEntryRef getVirtualFileRef(StringRef Filename, off_t Size,
254 time_t ModificationTime);
255
256 const FileEntry *getVirtualFile(StringRef Filename, off_t Size,
257 time_t ModificationTime);
258
259 /// Retrieve a FileEntry that bypasses VFE, which is expected to be a virtual
260 /// file entry, to access the real file. The returned FileEntry will have
261 /// the same filename as FE but a different identity and its own stat.
262 ///
263 /// This should be used only for rare error recovery paths because it
264 /// bypasses all mapping and uniquing, blindly creating a new FileEntry.
265 /// There is no attempt to deduplicate these; if you bypass the same file
266 /// twice, you get two new file entries.
267 llvm::Optional<FileEntryRef> getBypassFile(FileEntryRef VFE);
268
269 /// Open the specified file as a MemoryBuffer, returning a new
270 /// MemoryBuffer if successful, otherwise returning null.
271 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
272 getBufferForFile(const FileEntry *Entry, bool isVolatile = false,
273 bool RequiresNullTerminator = true);
274 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
275 getBufferForFile(StringRef Filename, bool isVolatile = false,
276 bool RequiresNullTerminator = true) {
277 return getBufferForFileImpl(Filename, /*FileSize=*/-1, isVolatile,
278 RequiresNullTerminator);
279 }
280
281private:
282 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
283 getBufferForFileImpl(StringRef Filename, int64_t FileSize, bool isVolatile,
284 bool RequiresNullTerminator);
285
286public:
287 /// Get the 'stat' information for the given \p Path.
288 ///
289 /// If the path is relative, it will be resolved against the WorkingDir of the
290 /// FileManager's FileSystemOptions.
291 ///
292 /// \returns a \c std::error_code describing an error, if there was one
293 std::error_code getNoncachedStatValue(StringRef Path,
294 llvm::vfs::Status &Result);
295
296 /// If path is not absolute and FileSystemOptions set the working
297 /// directory, the path is modified to be relative to the given
298 /// working directory.
299 /// \returns true if \c path changed.
300 bool FixupRelativePath(SmallVectorImpl<char> &path) const;
301
302 /// Makes \c Path absolute taking into account FileSystemOptions and the
303 /// working directory option.
304 /// \returns true if \c Path changed to absolute.
305 bool makeAbsolutePath(SmallVectorImpl<char> &Path) const;
306
307 /// Produce an array mapping from the unique IDs assigned to each
308 /// file to the corresponding FileEntry pointer.
309 void GetUniqueIDMapping(
310 SmallVectorImpl<const FileEntry *> &UIDToFiles) const;
311
312 /// Retrieve the canonical name for a given directory.
313 ///
314 /// This is a very expensive operation, despite its results being cached,
315 /// and should only be used when the physical layout of the file system is
316 /// required, which is (almost) never.
317 StringRef getCanonicalName(const DirectoryEntry *Dir);
318
319 /// Retrieve the canonical name for a given file.
320 ///
321 /// This is a very expensive operation, despite its results being cached,
322 /// and should only be used when the physical layout of the file system is
323 /// required, which is (almost) never.
324 StringRef getCanonicalName(const FileEntry *File);
325
326 void PrintStats() const;
327};
328
329} // end namespace clang
330
331#endif // LLVM_CLANG_BASIC_FILEMANAGER_H
←

/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Bitstream/BitstreamReader.h

→
1//===- BitstreamReader.h - Low-level bitstream reader interface -*- 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 header defines the BitstreamReader class. This class can be used to
10// read an arbitrary bitstream, regardless of its contents.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_BITSTREAM_BITSTREAMREADER_H
15#define LLVM_BITSTREAM_BITSTREAMREADER_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/Bitstream/BitCodes.h"
20#include "llvm/Support/Endian.h"
21#include "llvm/Support/Error.h"
22#include "llvm/Support/ErrorHandling.h"
23#include "llvm/Support/MathExtras.h"
24#include "llvm/Support/MemoryBuffer.h"
25#include <algorithm>
26#include <cassert>
27#include <climits>
28#include <cstddef>
29#include <cstdint>
30#include <memory>
31#include <string>
32#include <utility>
33#include <vector>
34
35namespace llvm {
36
37/// This class maintains the abbreviations read from a block info block.
38class BitstreamBlockInfo {
39public:
40 /// This contains information emitted to BLOCKINFO_BLOCK blocks. These
41 /// describe abbreviations that all blocks of the specified ID inherit.
42 struct BlockInfo {
43 unsigned BlockID = 0;
44 std::vector<std::shared_ptr<BitCodeAbbrev>> Abbrevs;
45 std::string Name;
46 std::vector<std::pair<unsigned, std::string>> RecordNames;
47 };
48
49private:
50 std::vector<BlockInfo> BlockInfoRecords;
51
52public:
53 /// If there is block info for the specified ID, return it, otherwise return
54 /// null.
55 const BlockInfo *getBlockInfo(unsigned BlockID) const {
56 // Common case, the most recent entry matches BlockID.
57 if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
58 return &BlockInfoRecords.back();
59
60 for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
61 i != e; ++i)
62 if (BlockInfoRecords[i].BlockID == BlockID)
63 return &BlockInfoRecords[i];
64 return nullptr;
65 }
66
67 BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
68 if (const BlockInfo *BI = getBlockInfo(BlockID))
69 return *const_cast<BlockInfo*>(BI);
70
71 // Otherwise, add a new record.
72 BlockInfoRecords.emplace_back();
73 BlockInfoRecords.back().BlockID = BlockID;
74 return BlockInfoRecords.back();
75 }
76};
77
78/// This represents a position within a bitstream. There may be multiple
79/// independent cursors reading within one bitstream, each maintaining their
80/// own local state.
81class SimpleBitstreamCursor {
82 ArrayRef<uint8_t> BitcodeBytes;
83 size_t NextChar = 0;
84
85public:
86 /// This is the current data we have pulled from the stream but have not
87 /// returned to the client. This is specifically and intentionally defined to
88 /// follow the word size of the host machine for efficiency. We use word_t in
89 /// places that are aware of this to make it perfectly explicit what is going
90 /// on.
91 using word_t = size_t;
92
93private:
94 word_t CurWord = 0;
95
96 /// This is the number of bits in CurWord that are valid. This is always from
97 /// [0...bits_of(size_t)-1] inclusive.
98 unsigned BitsInCurWord = 0;
99
100public:
101 static const constexpr size_t MaxChunkSize = sizeof(word_t) * 8;
102
103 SimpleBitstreamCursor() = default;
104 explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
105 : BitcodeBytes(BitcodeBytes) {}
106 explicit SimpleBitstreamCursor(StringRef BitcodeBytes)
107 : BitcodeBytes(arrayRefFromStringRef(BitcodeBytes)) {}
108 explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes)
109 : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {}
110
111 bool canSkipToPos(size_t pos) const {
112 // pos can be skipped to if it is a valid address or one byte past the end.
113 return pos <= BitcodeBytes.size();
114 }
115
116 bool AtEndOfStream() {
117 return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar;
118 }
119
120 /// Return the bit # of the bit we are reading.
121 uint64_t GetCurrentBitNo() const {
122 return NextChar*CHAR_BIT8 - BitsInCurWord;
123 }
124
125 // Return the byte # of the current bit.
126 uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; }
127
128 ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; }
129
130 /// Reset the stream to the specified bit number.
131 Error JumpToBit(uint64_t BitNo) {
132 size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1);
133 unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
134 assert(canSkipToPos(ByteNo) && "Invalid location")(static_cast <bool> (canSkipToPos(ByteNo) && "Invalid location"
) ? void (0) : __assert_fail ("canSkipToPos(ByteNo) && \"Invalid location\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 134, __extension__ __PRETTY_FUNCTION__));
135
136 // Move the cursor to the right word.
137 NextChar = ByteNo;
138 BitsInCurWord = 0;
139
140 // Skip over any bits that are already consumed.
141 if (WordBitNo) {
142 if (Expected<word_t> Res = Read(WordBitNo))
143 return Error::success();
144 else
145 return Res.takeError();
146 }
147
148 return Error::success();
149 }
150
151 /// Get a pointer into the bitstream at the specified byte offset.
152 const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) {
153 return BitcodeBytes.data() + ByteNo;
154 }
155
156 /// Get a pointer into the bitstream at the specified bit offset.
157 ///
158 /// The bit offset must be on a byte boundary.
159 const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) {
160 assert(!(BitNo % 8) && "Expected bit on byte boundary")(static_cast <bool> (!(BitNo % 8) && "Expected bit on byte boundary"
) ? void (0) : __assert_fail ("!(BitNo % 8) && \"Expected bit on byte boundary\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 160, __extension__ __PRETTY_FUNCTION__));
161 return getPointerToByte(BitNo / 8, NumBytes);
162 }
163
164 Error fillCurWord() {
165 if (NextChar >= BitcodeBytes.size())
166 return createStringError(std::errc::io_error,
167 "Unexpected end of file reading %u of %u bytes",
168 NextChar, BitcodeBytes.size());
169
170 // Read the next word from the stream.
171 const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar;
172 unsigned BytesRead;
173 if (BitcodeBytes.size() >= NextChar + sizeof(word_t)) {
174 BytesRead = sizeof(word_t);
175 CurWord =
176 support::endian::read<word_t, support::little, support::unaligned>(
177 NextCharPtr);
178 } else {
179 // Short read.
180 BytesRead = BitcodeBytes.size() - NextChar;
181 CurWord = 0;
182 for (unsigned B = 0; B != BytesRead; ++B)
183 CurWord |= uint64_t(NextCharPtr[B]) << (B * 8);
184 }
185 NextChar += BytesRead;
186 BitsInCurWord = BytesRead * 8;
187 return Error::success();
188 }
189
190 Expected<word_t> Read(unsigned NumBits) {
191 static const unsigned BitsInWord = MaxChunkSize;
192
193 assert(NumBits && NumBits <= BitsInWord &&(static_cast <bool> (NumBits && NumBits <= BitsInWord
&& "Cannot return zero or more than BitsInWord bits!"
) ? void (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 194, __extension__ __PRETTY_FUNCTION__))
5
←
'?' condition is true
→
194 "Cannot return zero or more than BitsInWord bits!")(static_cast <bool> (NumBits && NumBits <= BitsInWord
&& "Cannot return zero or more than BitsInWord bits!"
) ? void (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Bitstream/BitstreamReader.h"
, 194, __extension__ __PRETTY_FUNCTION__));
195
196 static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
6
←
'?' condition is true
→
197
198 // If the field is fully contained by CurWord, return it quickly.
199 if (BitsInCurWord >= NumBits) {
7
←
Assuming 'NumBits' is > field 'BitsInCurWord'
→
200 word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits));
201
202 // Use a mask to avoid undefined behavior.
203 CurWord >>= (NumBits & Mask);
204
205 BitsInCurWord -= NumBits;
206 return R;
207 }
208
209 word_t R = BitsInCurWord
8.1
Field 'BitsInCurWord' is not equal to 0
8.1
Field 'BitsInCurWord' is not equal to 0
8.1
Field 'BitsInCurWord' is not equal to 0
8.1
Field 'BitsInCurWord' is not equal to 0
 ? CurWord : 0;
8
←
Taking false branch
→
9
←
'?' condition is true
→
210 unsigned BitsLeft = NumBits - BitsInCurWord;
211
212 if (Error fillResult = fillCurWord())
10
←
Calling 'Error::operator bool'
→
12
←
Returning from 'Error::operator bool'
→
13
←
Taking false branch
→
213 return std::move(fillResult);
214
215 // If we run out of data, abort.
216 if (BitsLeft > BitsInCurWord)
14
←
Assuming 'BitsLeft' is <= field 'BitsInCurWord'
→
15
←
Taking false branch
→
217 return createStringError(std::errc::io_error,
218 "Unexpected end of file reading %u of %u bits",
219 BitsInCurWord, BitsLeft);
220
221 word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
16
←
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'
222
223 // Use a mask to avoid undefined behavior.
224 CurWord >>= (BitsLeft & Mask);
225
226 BitsInCurWord -= BitsLeft;
227
228 R |= R2 << (NumBits - BitsLeft);
229
230 return R;
231 }
232
233 Expected<uint32_t> ReadVBR(unsigned NumBits) {
234 Expected<unsigned> MaybeRead = Read(NumBits);
235 if (!MaybeRead)
236 return MaybeRead;
237 uint32_t Piece = MaybeRead.get();
238
239 if ((Piece & (1U << (NumBits-1))) == 0)
240 return Piece;
241
242 uint32_t Result = 0;
243 unsigned NextBit = 0;
244 while (true) {
245 Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
246
247 if ((Piece & (1U << (NumBits-1))) == 0)
248 return Result;
249
250 NextBit += NumBits-1;
251 MaybeRead = Read(NumBits);
252 if (!MaybeRead)
253 return MaybeRead;
254 Piece = MaybeRead.get();
255 }
256 }
257
258 // Read a VBR that may have a value up to 64-bits in size. The chunk size of
259 // the VBR must still be <= 32 bits though.
260 Expected<uint64_t> ReadVBR64(unsigned NumBits) {
261 Expected<uint64_t> MaybeRead = Read(NumBits);
262 if (!MaybeRead)
263 return MaybeRead;
264 uint32_t Piece = MaybeRead.get();
265
266 if ((Piece & (1U << (NumBits-1))) == 0)
267 return uint64_t(Piece);
268
269 uint64_t Result = 0;
270 unsigned NextBit = 0;
271 while (true) {
272 Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit;
273
274 if ((Piece & (1U << (NumBits-1))) == 0)
275 return Result;
276
277 NextBit += NumBits-1;
278 MaybeRead = Read(NumBits);
279 if (!MaybeRead)
280 return MaybeRead;
281 Piece = MaybeRead.get();
282 }
283 }
284
285 void SkipToFourByteBoundary() {
286 // If word_t is 64-bits and if we've read less than 32 bits, just dump
287 // the bits we have up to the next 32-bit boundary.
288 if (sizeof(word_t) > 4 &&
289 BitsInCurWord >= 32) {
290 CurWord >>= BitsInCurWord-32;
291 BitsInCurWord = 32;
292 return;
293 }
294
295 BitsInCurWord = 0;
296 }
297
298 /// Return the size of the stream in bytes.
299 size_t SizeInBytes() const { return BitcodeBytes.size(); }
300
301 /// Skip to the end of the file.
302 void skipToEnd() { NextChar = BitcodeBytes.size(); }
303};
304
305/// When advancing through a bitstream cursor, each advance can discover a few
306/// different kinds of entries:
307struct BitstreamEntry {
308 enum {
309 Error, // Malformed bitcode was found.
310 EndBlock, // We've reached the end of the current block, (or the end of the
311 // file, which is treated like a series of EndBlock records.
312 SubBlock, // This is the start of a new subblock of a specific ID.
313 Record // This is a record with a specific AbbrevID.
314 } Kind;
315
316 unsigned ID;
317
318 static BitstreamEntry getError() {
319 BitstreamEntry E; E.Kind = Error; return E;
320 }
321
322 static BitstreamEntry getEndBlock() {
323 BitstreamEntry E; E.Kind = EndBlock; return E;
324 }
325
326 static BitstreamEntry getSubBlock(unsigned ID) {
327 BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E;
328 }
329
330 static BitstreamEntry getRecord(unsigned AbbrevID) {
331 BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E;
332 }
333};
334
335/// This represents a position within a bitcode file, implemented on top of a
336/// SimpleBitstreamCursor.
337///
338/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not
339/// be passed by value.
340class BitstreamCursor : SimpleBitstreamCursor {
341 // This is the declared size of code values used for the current block, in
342 // bits.
343 unsigned CurCodeSize = 2;
344
345 /// Abbrevs installed at in this block.
346 std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs;
347
348 struct Block {
349 unsigned PrevCodeSize;
350 std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs;
351
352 explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
353 };
354
355 /// This tracks the codesize of parent blocks.
356 SmallVector<Block, 8> BlockScope;
357
358 BitstreamBlockInfo *BlockInfo = nullptr;
359
360public:
361 static const size_t MaxChunkSize = sizeof(word_t) * 8;
362
363 BitstreamCursor() = default;
364 explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
365 : SimpleBitstreamCursor(BitcodeBytes) {}
366 explicit BitstreamCursor(StringRef BitcodeBytes)
367 : SimpleBitstreamCursor(BitcodeBytes) {}
368 explicit BitstreamCursor(MemoryBufferRef BitcodeBytes)
369 : SimpleBitstreamCursor(BitcodeBytes) {}
370
371 using SimpleBitstreamCursor::AtEndOfStream;
372 using SimpleBitstreamCursor::canSkipToPos;
373 using SimpleBitstreamCursor::fillCurWord;
374 using SimpleBitstreamCursor::getBitcodeBytes;
375 using SimpleBitstreamCursor::GetCurrentBitNo;
376 using SimpleBitstreamCursor::getCurrentByteNo;
377 using SimpleBitstreamCursor::getPointerToByte;
378 using SimpleBitstreamCursor::JumpToBit;
379 using SimpleBitstreamCursor::Read;
380 using SimpleBitstreamCursor::ReadVBR;
381 using SimpleBitstreamCursor::ReadVBR64;
382 using SimpleBitstreamCursor::SizeInBytes;
383 using SimpleBitstreamCursor::skipToEnd;
384
385 /// Return the number of bits used to encode an abbrev #.
386 unsigned getAbbrevIDWidth() const { return CurCodeSize; }
387
388 /// Flags that modify the behavior of advance().
389 enum {
390 /// If this flag is used, the advance() method does not automatically pop
391 /// the block scope when the end of a block is reached.
392 AF_DontPopBlockAtEnd = 1,
393
394 /// If this flag is used, abbrev entries are returned just like normal
395 /// records.
396 AF_DontAutoprocessAbbrevs = 2
397 };
398
399 /// Advance the current bitstream, returning the next entry in the stream.
400 Expected<BitstreamEntry> advance(unsigned Flags = 0) {
401 while (true) {
402 if (AtEndOfStream())
403 return BitstreamEntry::getError();
404
405 Expected<unsigned> MaybeCode = ReadCode();
406 if (!MaybeCode)
407 return MaybeCode.takeError();
408 unsigned Code = MaybeCode.get();
409
410 if (Code == bitc::END_BLOCK) {
411 // Pop the end of the block unless Flags tells us not to.
412 if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd())
413 return BitstreamEntry::getError();
414 return BitstreamEntry::getEndBlock();
415 }
416
417 if (Code == bitc::ENTER_SUBBLOCK) {
418 if (Expected<unsigned> MaybeSubBlock = ReadSubBlockID())
419 return BitstreamEntry::getSubBlock(MaybeSubBlock.get());
420 else
421 return MaybeSubBlock.takeError();
422 }
423
424 if (Code == bitc::DEFINE_ABBREV &&
425 !(Flags & AF_DontAutoprocessAbbrevs)) {
426 // We read and accumulate abbrev's, the client can't do anything with
427 // them anyway.
428 if (Error Err = ReadAbbrevRecord())
429 return std::move(Err);
430 continue;
431 }
432
433 return BitstreamEntry::getRecord(Code);
434 }
435 }
436
437 /// This is a convenience function for clients that don't expect any
438 /// subblocks. This just skips over them automatically.
439 Expected<BitstreamEntry> advanceSkippingSubblocks(unsigned Flags = 0) {
440 while (true) {
441 // If we found a normal entry, return it.
442 Expected<BitstreamEntry> MaybeEntry = advance(Flags);
443 if (!MaybeEntry)
444 return MaybeEntry;
445 BitstreamEntry Entry = MaybeEntry.get();
446
447 if (Entry.Kind != BitstreamEntry::SubBlock)
448 return Entry;
449
450 // If we found a sub-block, just skip over it and check the next entry.
451 if (Error Err = SkipBlock())
452 return std::move(Err);
453 }
454 }
455
456 Expected<unsigned> ReadCode() { return Read(CurCodeSize); }
457
458 // Block header:
459 // [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
460
461 /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block.
462 Expected<unsigned> ReadSubBlockID() { return ReadVBR(bitc::BlockIDWidth); }
463
464 /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body
465 /// of this block.
466 Error SkipBlock() {
467 // Read and ignore the codelen value.
468 if (Expected<uint32_t> Res = ReadVBR(bitc::CodeLenWidth))
469 ; // Since we are skipping this block, we don't care what code widths are
470 // used inside of it.
471 else
472 return Res.takeError();
473
474 SkipToFourByteBoundary();
475 Expected<unsigned> MaybeNum = Read(bitc::BlockSizeWidth);
476 if (!MaybeNum)
477 return MaybeNum.takeError();
478 size_t NumFourBytes = MaybeNum.get();
479
480 // Check that the block wasn't partially defined, and that the offset isn't
481 // bogus.
482 size_t SkipTo = GetCurrentBitNo() + NumFourBytes * 4 * 8;
483 if (AtEndOfStream())
484 return createStringError(std::errc::illegal_byte_sequence,
485 "can't skip block: already at end of stream");
486 if (!canSkipToPos(SkipTo / 8))
487 return createStringError(std::errc::illegal_byte_sequence,
488 "can't skip to bit %zu from %" PRIu64"l" "u", SkipTo,
489 GetCurrentBitNo());
490
491 if (Error Res = JumpToBit(SkipTo))
492 return Res;
493
494 return Error::success();
495 }
496
497 /// Having read the ENTER_SUBBLOCK abbrevid, and enter the block.
498 Error EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr);
499
500 bool ReadBlockEnd() {
501 if (BlockScope.empty()) return true;
502
503 // Block tail:
504 // [END_BLOCK, <align4bytes>]
505 SkipToFourByteBoundary();
506
507 popBlockScope();
508 return false;
509 }
510
511private:
512 void popBlockScope() {
513 CurCodeSize = BlockScope.back().PrevCodeSize;
514
515 CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs);
516 BlockScope.pop_back();
517 }
518
519 //===--------------------------------------------------------------------===//
520 // Record Processing
521 //===--------------------------------------------------------------------===//
522
523public:
524 /// Return the abbreviation for the specified AbbrevId.
525 const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) {
526 unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV;
527 if (AbbrevNo >= CurAbbrevs.size())
528 report_fatal_error("Invalid abbrev number");
529 return CurAbbrevs[AbbrevNo].get();
530 }
531
532 /// Read the current record and discard it, returning the code for the record.
533 Expected<unsigned> skipRecord(unsigned AbbrevID);
534
535 Expected<unsigned> readRecord(unsigned AbbrevID,
536 SmallVectorImpl<uint64_t> &Vals,
537 StringRef *Blob = nullptr);
538
539 //===--------------------------------------------------------------------===//
540 // Abbrev Processing
541 //===--------------------------------------------------------------------===//
542 Error ReadAbbrevRecord();
543
544 /// Read and return a block info block from the bitstream. If an error was
545 /// encountered, return None.
546 ///
547 /// \param ReadBlockInfoNames Whether to read block/record name information in
548 /// the BlockInfo block. Only llvm-bcanalyzer uses this.
549 Expected<Optional<BitstreamBlockInfo>>
550 ReadBlockInfoBlock(bool ReadBlockInfoNames = false);
551
552 /// Set the block info to be used by this BitstreamCursor to interpret
553 /// abbreviated records.
554 void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; }
555};
556
557} // end llvm namespace
558
559#endif // LLVM_BITSTREAM_BITSTREAMREADER_H
←

/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/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 // ErrorList needs to be able to yank ErrorInfoBase pointers out of Errors
159 // to add to the error list. It can't rely on handleErrors for this, since
160 // handleErrors does not support ErrorList handlers.
161 friend class ErrorList;
162
163 // handleErrors needs to be able to set the Checked flag.
164 template <typename... HandlerTs>
165 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
166
167 // Expected<T> needs to be able to steal the payload when constructed from an
168 // error.
169 template <typename T> friend class Expected;
170
171 // wrap needs to be able to steal the payload.
172 friend LLVMErrorRef wrap(Error);
173
174protected:
175 /// Create a success value. Prefer using 'Error::success()' for readability
176 Error() {
177 setPtr(nullptr);
178 setChecked(false);
179 }
180
181public:
182 /// Create a success value.
183 static ErrorSuccess success();
184
185 // Errors are not copy-constructable.
186 Error(const Error &Other) = delete;
187
188 /// Move-construct an error value. The newly constructed error is considered
189 /// unchecked, even if the source error had been checked. The original error
190 /// becomes a checked Success value, regardless of its original state.
191 Error(Error &&Other) {
192 setChecked(true);
193 *this = std::move(Other);
194 }
195
196 /// Create an error value. Prefer using the 'make_error' function, but
197 /// this constructor can be useful when "re-throwing" errors from handlers.
198 Error(std::unique_ptr<ErrorInfoBase> Payload) {
199 setPtr(Payload.release());
200 setChecked(false);
201 }
202
203 // Errors are not copy-assignable.
204 Error &operator=(const Error &Other) = delete;
205
206 /// Move-assign an error value. The current error must represent success, you
207 /// you cannot overwrite an unhandled error. The current error is then
208 /// considered unchecked. The source error becomes a checked success value,
209 /// regardless of its original state.
210 Error &operator=(Error &&Other) {
211 // Don't allow overwriting of unchecked values.
212 assertIsChecked();
213 setPtr(Other.getPtr());
214
215 // This Error is unchecked, even if the source error was checked.
216 setChecked(false);
217
218 // Null out Other's payload and set its checked bit.
219 Other.setPtr(nullptr);
220 Other.setChecked(true);
221
222 return *this;
223 }
224
225 /// Destroy a Error. Fails with a call to abort() if the error is
226 /// unchecked.
227 ~Error() {
228 assertIsChecked();
229 delete getPtr();
230 }
231
232 /// Bool conversion. Returns true if this Error is in a failure state,
233 /// and false if it is in an accept state. If the error is in a Success state
234 /// it will be considered checked.
235 explicit operator bool() {
236 setChecked(getPtr() == nullptr);
237 return getPtr() != nullptr;
11
←
Returning zero, which participates in a condition later
→
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 [[noreturn]] void fatalUncheckedError() const;
261#endif
262
263 void assertIsChecked() {
264#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
265 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
266 fatalUncheckedError();
267#endif
268 }
269
270 ErrorInfoBase *getPtr() const {
271#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
272 return reinterpret_cast<ErrorInfoBase*>(
273 reinterpret_cast<uintptr_t>(Payload) &
274 ~static_cast<uintptr_t>(0x1));
275#else
276 return Payload;
277#endif
278 }
279
280 void setPtr(ErrorInfoBase *EI) {
281#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
282 Payload = reinterpret_cast<ErrorInfoBase*>(
283 (reinterpret_cast<uintptr_t>(EI) &
284 ~static_cast<uintptr_t>(0x1)) |
285 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
286#else
287 Payload = EI;
288#endif
289 }
290
291 bool getChecked() const {
292#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
293 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
294#else
295 return true;
296#endif
297 }
298
299 void setChecked(bool V) {
300#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
301 Payload = reinterpret_cast<ErrorInfoBase*>(
302 (reinterpret_cast<uintptr_t>(Payload) &
303 ~static_cast<uintptr_t>(0x1)) |
304 (V ? 0 : 1));
305#endif
306 }
307
308 std::unique_ptr<ErrorInfoBase> takePayload() {
309 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
310 setPtr(nullptr);
311 setChecked(true);
312 return Tmp;
313 }
314
315 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
316 if (auto P = E.getPtr())
317 P->log(OS);
318 else
319 OS << "success";
320 return OS;
321 }
322
323 ErrorInfoBase *Payload = nullptr;
324};
325
326/// Subclass of Error for the sole purpose of identifying the success path in
327/// the type system. This allows to catch invalid conversion to Expected<T> at
328/// compile time.
329class ErrorSuccess final : public Error {};
330
331inline ErrorSuccess Error::success() { return ErrorSuccess(); }
332
333/// Make a Error instance representing failure using the given error info
334/// type.
335template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
336 return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
337}
338
339/// Base class for user error types. Users should declare their error types
340/// like:
341///
342/// class MyError : public ErrorInfo<MyError> {
343/// ....
344/// };
345///
346/// This class provides an implementation of the ErrorInfoBase::kind
347/// method, which is used by the Error RTTI system.
348template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
349class ErrorInfo : public ParentErrT {
350public:
351 using ParentErrT::ParentErrT; // inherit constructors
352
353 static const void *classID() { return &ThisErrT::ID; }
354
355 const void *dynamicClassID() const override { return &ThisErrT::ID; }
356
357 bool isA(const void *const ClassID) const override {
358 return ClassID == classID() || ParentErrT::isA(ClassID);
359 }
360};
361
362/// Special ErrorInfo subclass representing a list of ErrorInfos.
363/// Instances of this class are constructed by joinError.
364class ErrorList final : public ErrorInfo<ErrorList> {
365 // handleErrors needs to be able to iterate the payload list of an
366 // ErrorList.
367 template <typename... HandlerTs>
368 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
369
370 // joinErrors is implemented in terms of join.
371 friend Error joinErrors(Error, Error);
372
373public:
374 void log(raw_ostream &OS) const override {
375 OS << "Multiple errors:\n";
376 for (auto &ErrPayload : Payloads) {
377 ErrPayload->log(OS);
378 OS << "\n";
379 }
380 }
381
382 std::error_code convertToErrorCode() const override;
383
384 // Used by ErrorInfo::classID.
385 static char ID;
386
387private:
388 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
389 std::unique_ptr<ErrorInfoBase> Payload2) {
390 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&(static_cast <bool> (!Payload1->isA<ErrorList>
() && !Payload2->isA<ErrorList>() &&
"ErrorList constructor payloads should be singleton errors")
? void (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 391, __extension__ __PRETTY_FUNCTION__))
391 "ErrorList constructor payloads should be singleton errors")(static_cast <bool> (!Payload1->isA<ErrorList>
() && !Payload2->isA<ErrorList>() &&
"ErrorList constructor payloads should be singleton errors")
? void (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 391, __extension__ __PRETTY_FUNCTION__));
392 Payloads.push_back(std::move(Payload1));
393 Payloads.push_back(std::move(Payload2));
394 }
395
396 static Error join(Error E1, Error E2) {
397 if (!E1)
398 return E2;
399 if (!E2)
400 return E1;
401 if (E1.isA<ErrorList>()) {
402 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
403 if (E2.isA<ErrorList>()) {
404 auto E2Payload = E2.takePayload();
405 auto &E2List = static_cast<ErrorList &>(*E2Payload);
406 for (auto &Payload : E2List.Payloads)
407 E1List.Payloads.push_back(std::move(Payload));
408 } else
409 E1List.Payloads.push_back(E2.takePayload());
410
411 return E1;
412 }
413 if (E2.isA<ErrorList>()) {
414 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
415 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
416 return E2;
417 }
418 return Error(std::unique_ptr<ErrorList>(
419 new ErrorList(E1.takePayload(), E2.takePayload())));
420 }
421
422 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
423};
424
425/// Concatenate errors. The resulting Error is unchecked, and contains the
426/// ErrorInfo(s), if any, contained in E1, followed by the
427/// ErrorInfo(s), if any, contained in E2.
428inline Error joinErrors(Error E1, Error E2) {
429 return ErrorList::join(std::move(E1), std::move(E2));
430}
431
432/// Tagged union holding either a T or a Error.
433///
434/// This class parallels ErrorOr, but replaces error_code with Error. Since
435/// Error cannot be copied, this class replaces getError() with
436/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
437/// error class type.
438///
439/// Example usage of 'Expected<T>' as a function return type:
440///
441/// @code{.cpp}
442/// Expected<int> myDivide(int A, int B) {
443/// if (B == 0) {
444/// // return an Error
445/// return createStringError(inconvertibleErrorCode(),
446/// "B must not be zero!");
447/// }
448/// // return an integer
449/// return A / B;
450/// }
451/// @endcode
452///
453/// Checking the results of to a function returning 'Expected<T>':
454/// @code{.cpp}
455/// if (auto E = Result.takeError()) {
456/// // We must consume the error. Typically one of:
457/// // - return the error to our caller
458/// // - toString(), when logging
459/// // - consumeError(), to silently swallow the error
460/// // - handleErrors(), to distinguish error types
461/// errs() << "Problem with division " << toString(std::move(E)) << "\n";
462/// return;
463/// }
464/// // use the result
465/// outs() << "The answer is " << *Result << "\n";
466/// @endcode
467///
468/// For unit-testing a function returning an 'Expceted<T>', see the
469/// 'EXPECT_THAT_EXPECTED' macros in llvm/Testing/Support/Error.h
470
471template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
472 template <class T1> friend class ExpectedAsOutParameter;
473 template <class OtherT> friend class Expected;
474
475 static constexpr bool isRef = std::is_reference<T>::value;
476
477 using wrap = std::reference_wrapper<std::remove_reference_t<T>>;
478
479 using error_type = std::unique_ptr<ErrorInfoBase>;
480
481public:
482 using storage_type = std::conditional_t<isRef, wrap, T>;
483 using value_type = T;
484
485private:
486 using reference = std::remove_reference_t<T> &;
487 using const_reference = const std::remove_reference_t<T> &;
488 using pointer = std::remove_reference_t<T> *;
489 using const_pointer = const std::remove_reference_t<T> *;
490
491public:
492 /// Create an Expected<T> error value from the given Error.
493 Expected(Error Err)
494 : HasError(true)
495#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
496 // Expected is unchecked upon construction in Debug builds.
497 , Unchecked(true)
498#endif
499 {
500 assert(Err && "Cannot create Expected<T> from Error success value.")(static_cast <bool> (Err && "Cannot create Expected<T> from Error success value."
) ? void (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 500, __extension__ __PRETTY_FUNCTION__));
501 new (getErrorStorage()) error_type(Err.takePayload());
502 }
503
504 /// Forbid to convert from Error::success() implicitly, this avoids having
505 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
506 /// but triggers the assertion above.
507 Expected(ErrorSuccess) = delete;
508
509 /// Create an Expected<T> success value from the given OtherT value, which
510 /// must be convertible to T.
511 template <typename OtherT>
512 Expected(OtherT &&Val,
513 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
514 : HasError(false)
515#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
516 // Expected is unchecked upon construction in Debug builds.
517 ,
518 Unchecked(true)
519#endif
520 {
521 new (getStorage()) storage_type(std::forward<OtherT>(Val));
522 }
523
524 /// Move construct an Expected<T> value.
525 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
526
527 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
528 /// must be convertible to T.
529 template <class OtherT>
530 Expected(
531 Expected<OtherT> &&Other,
532 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
533 moveConstruct(std::move(Other));
534 }
535
536 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
537 /// isn't convertible to T.
538 template <class OtherT>
539 explicit Expected(
540 Expected<OtherT> &&Other,
541 std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
542 moveConstruct(std::move(Other));
543 }
544
545 /// Move-assign from another Expected<T>.
546 Expected &operator=(Expected &&Other) {
547 moveAssign(std::move(Other));
548 return *this;
549 }
550
551 /// Destroy an Expected<T>.
552 ~Expected() {
553 assertIsChecked();
554 if (!HasError)
555 getStorage()->~storage_type();
556 else
557 getErrorStorage()->~error_type();
558 }
559
560 /// Return false if there is an error.
561 explicit operator bool() {
562#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
563 Unchecked = HasError;
564#endif
565 return !HasError;
566 }
567
568 /// Returns a reference to the stored T value.
569 reference get() {
570 assertIsChecked();
571 return *getStorage();
572 }
573
574 /// Returns a const reference to the stored T value.
575 const_reference get() const {
576 assertIsChecked();
577 return const_cast<Expected<T> *>(this)->get();
578 }
579
580 /// Check that this Expected<T> is an error of type ErrT.
581 template <typename ErrT> bool errorIsA() const {
582 return HasError && (*getErrorStorage())->template isA<ErrT>();
583 }
584
585 /// Take ownership of the stored error.
586 /// After calling this the Expected<T> is in an indeterminate state that can
587 /// only be safely destructed. No further calls (beside the destructor) should
588 /// be made on the Expected<T> value.
589 Error takeError() {
590#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
591 Unchecked = false;
592#endif
593 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
594 }
595
596 /// Returns a pointer to the stored T value.
597 pointer operator->() {
598 assertIsChecked();
599 return toPointer(getStorage());
600 }
601
602 /// Returns a const pointer to the stored T value.
603 const_pointer operator->() const {
604 assertIsChecked();
605 return toPointer(getStorage());
606 }
607
608 /// Returns a reference to the stored T value.
609 reference operator*() {
610 assertIsChecked();
611 return *getStorage();
612 }
613
614 /// Returns a const reference to the stored T value.
615 const_reference operator*() const {
616 assertIsChecked();
617 return *getStorage();
618 }
619
620private:
621 template <class T1>
622 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
623 return &a == &b;
624 }
625
626 template <class T1, class T2>
627 static bool compareThisIfSameType(const T1 &, const T2 &) {
628 return false;
629 }
630
631 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
632 HasError = Other.HasError;
633#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
634 Unchecked = true;
635 Other.Unchecked = false;
636#endif
637
638 if (!HasError)
639 new (getStorage()) storage_type(std::move(*Other.getStorage()));
640 else
641 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
642 }
643
644 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
645 assertIsChecked();
646
647 if (compareThisIfSameType(*this, Other))
648 return;
649
650 this->~Expected();
651 new (this) Expected(std::move(Other));
652 }
653
654 pointer toPointer(pointer Val) { return Val; }
655
656 const_pointer toPointer(const_pointer Val) const { return Val; }
657
658 pointer toPointer(wrap *Val) { return &Val->get(); }
659
660 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
661
662 storage_type *getStorage() {
663 assert(!HasError && "Cannot get value when an error exists!")(static_cast <bool> (!HasError && "Cannot get value when an error exists!"
) ? void (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 663, __extension__ __PRETTY_FUNCTION__));
664 return reinterpret_cast<storage_type *>(&TStorage);
665 }
666
667 const storage_type *getStorage() const {
668 assert(!HasError && "Cannot get value when an error exists!")(static_cast <bool> (!HasError && "Cannot get value when an error exists!"
) ? void (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 668, __extension__ __PRETTY_FUNCTION__));
669 return reinterpret_cast<const storage_type *>(&TStorage);
670 }
671
672 error_type *getErrorStorage() {
673 assert(HasError && "Cannot get error when a value exists!")(static_cast <bool> (HasError && "Cannot get error when a value exists!"
) ? void (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 673, __extension__ __PRETTY_FUNCTION__));
674 return reinterpret_cast<error_type *>(&ErrorStorage);
675 }
676
677 const error_type *getErrorStorage() const {
678 assert(HasError && "Cannot get error when a value exists!")(static_cast <bool> (HasError && "Cannot get error when a value exists!"
) ? void (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 678, __extension__ __PRETTY_FUNCTION__));
679 return reinterpret_cast<const error_type *>(&ErrorStorage);
680 }
681
682 // Used by ExpectedAsOutParameter to reset the checked flag.
683 void setUnchecked() {
684#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
685 Unchecked = true;
686#endif
687 }
688
689#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
690 [[noreturn]] LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline)) void fatalUncheckedExpected() const {
691 dbgs() << "Expected<T> must be checked before access or destruction.\n";
692 if (HasError) {
693 dbgs() << "Unchecked Expected<T> contained error:\n";
694 (*getErrorStorage())->log(dbgs());
695 } else
696 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
697 "values in success mode must still be checked prior to being "
698 "destroyed).\n";
699 abort();
700 }
701#endif
702
703 void assertIsChecked() const {
704#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
705 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
706 fatalUncheckedExpected();
707#endif
708 }
709
710 union {
711 AlignedCharArrayUnion<storage_type> TStorage;
712 AlignedCharArrayUnion<error_type> ErrorStorage;
713 };
714 bool HasError : 1;
715#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
716 bool Unchecked : 1;
717#endif
718};
719
720/// Report a serious error, calling any installed error handler. See
721/// ErrorHandling.h.
722[[noreturn]] void report_fatal_error(Error Err, bool gen_crash_diag = true);
723
724/// Report a fatal error if Err is a failure value.
725///
726/// This function can be used to wrap calls to fallible functions ONLY when it
727/// is known that the Error will always be a success value. E.g.
728///
729/// @code{.cpp}
730/// // foo only attempts the fallible operation if DoFallibleOperation is
731/// // true. If DoFallibleOperation is false then foo always returns
732/// // Error::success().
733/// Error foo(bool DoFallibleOperation);
734///
735/// cantFail(foo(false));
736/// @endcode
737inline void cantFail(Error Err, const char *Msg = nullptr) {
738 if (Err) {
739 if (!Msg)
740 Msg = "Failure value returned from cantFail wrapped call";
741#ifndef NDEBUG
742 std::string Str;
743 raw_string_ostream OS(Str);
744 OS << Msg << "\n" << Err;
745 Msg = OS.str().c_str();
746#endif
747 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 747);
748 }
749}
750
751/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
752/// returns the contained value.
753///
754/// This function can be used to wrap calls to fallible functions ONLY when it
755/// is known that the Error will always be a success value. E.g.
756///
757/// @code{.cpp}
758/// // foo only attempts the fallible operation if DoFallibleOperation is
759/// // true. If DoFallibleOperation is false then foo always returns an int.
760/// Expected<int> foo(bool DoFallibleOperation);
761///
762/// int X = cantFail(foo(false));
763/// @endcode
764template <typename T>
765T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
766 if (ValOrErr)
767 return std::move(*ValOrErr);
768 else {
769 if (!Msg)
770 Msg = "Failure value returned from cantFail wrapped call";
771#ifndef NDEBUG
772 std::string Str;
773 raw_string_ostream OS(Str);
774 auto E = ValOrErr.takeError();
775 OS << Msg << "\n" << E;
776 Msg = OS.str().c_str();
777#endif
778 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 778);
779 }
780}
781
782/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
783/// returns the contained reference.
784///
785/// This function can be used to wrap calls to fallible functions ONLY when it
786/// is known that the Error will always be a success value. E.g.
787///
788/// @code{.cpp}
789/// // foo only attempts the fallible operation if DoFallibleOperation is
790/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
791/// Expected<Bar&> foo(bool DoFallibleOperation);
792///
793/// Bar &X = cantFail(foo(false));
794/// @endcode
795template <typename T>
796T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
797 if (ValOrErr)
798 return *ValOrErr;
799 else {
800 if (!Msg)
801 Msg = "Failure value returned from cantFail wrapped call";
802#ifndef NDEBUG
803 std::string Str;
804 raw_string_ostream OS(Str);
805 auto E = ValOrErr.takeError();
806 OS << Msg << "\n" << E;
807 Msg = OS.str().c_str();
808#endif
809 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 809);
810 }
811}
812
813/// Helper for testing applicability of, and applying, handlers for
814/// ErrorInfo types.
815template <typename HandlerT>
816class ErrorHandlerTraits
817 : public ErrorHandlerTraits<decltype(
818 &std::remove_reference<HandlerT>::type::operator())> {};
819
820// Specialization functions of the form 'Error (const ErrT&)'.
821template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
822public:
823 static bool appliesTo(const ErrorInfoBase &E) {
824 return E.template isA<ErrT>();
825 }
826
827 template <typename HandlerT>
828 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
829 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 829, __extension__ __PRETTY_FUNCTION__));
830 return H(static_cast<ErrT &>(*E));
831 }
832};
833
834// Specialization functions of the form 'void (const ErrT&)'.
835template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
836public:
837 static bool appliesTo(const ErrorInfoBase &E) {
838 return E.template isA<ErrT>();
839 }
840
841 template <typename HandlerT>
842 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
843 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 843, __extension__ __PRETTY_FUNCTION__));
844 H(static_cast<ErrT &>(*E));
845 return Error::success();
846 }
847};
848
849/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
850template <typename ErrT>
851class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
852public:
853 static bool appliesTo(const ErrorInfoBase &E) {
854 return E.template isA<ErrT>();
855 }
856
857 template <typename HandlerT>
858 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
859 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 859, __extension__ __PRETTY_FUNCTION__));
860 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
861 return H(std::move(SubE));
862 }
863};
864
865/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
866template <typename ErrT>
867class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
868public:
869 static bool appliesTo(const ErrorInfoBase &E) {
870 return E.template isA<ErrT>();
871 }
872
873 template <typename HandlerT>
874 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
875 assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler"
) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 875, __extension__ __PRETTY_FUNCTION__));
876 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
877 H(std::move(SubE));
878 return Error::success();
879 }
880};
881
882// Specialization for member functions of the form 'RetT (const ErrT&)'.
883template <typename C, typename RetT, typename ErrT>
884class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
885 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
886
887// Specialization for member functions of the form 'RetT (const ErrT&) const'.
888template <typename C, typename RetT, typename ErrT>
889class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
890 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
891
892// Specialization for member functions of the form 'RetT (const ErrT&)'.
893template <typename C, typename RetT, typename ErrT>
894class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
895 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
896
897// Specialization for member functions of the form 'RetT (const ErrT&) const'.
898template <typename C, typename RetT, typename ErrT>
899class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
900 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
901
902/// Specialization for member functions of the form
903/// 'RetT (std::unique_ptr<ErrT>)'.
904template <typename C, typename RetT, typename ErrT>
905class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
906 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
907
908/// Specialization for member functions of the form
909/// 'RetT (std::unique_ptr<ErrT>) const'.
910template <typename C, typename RetT, typename ErrT>
911class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
912 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
913
914inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
915 return Error(std::move(Payload));
916}
917
918template <typename HandlerT, typename... HandlerTs>
919Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
920 HandlerT &&Handler, HandlerTs &&... Handlers) {
921 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
922 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
923 std::move(Payload));
924 return handleErrorImpl(std::move(Payload),
925 std::forward<HandlerTs>(Handlers)...);
926}
927
928/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
929/// unhandled errors (or Errors returned by handlers) are re-concatenated and
930/// returned.
931/// Because this function returns an error, its result must also be checked
932/// or returned. If you intend to handle all errors use handleAllErrors
933/// (which returns void, and will abort() on unhandled errors) instead.
934template <typename... HandlerTs>
935Error handleErrors(Error E, HandlerTs &&... Hs) {
936 if (!E)
937 return Error::success();
938
939 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
940
941 if (Payload->isA<ErrorList>()) {
942 ErrorList &List = static_cast<ErrorList &>(*Payload);
943 Error R;
944 for (auto &P : List.Payloads)
945 R = ErrorList::join(
946 std::move(R),
947 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
948 return R;
949 }
950
951 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
952}
953
954/// Behaves the same as handleErrors, except that by contract all errors
955/// *must* be handled by the given handlers (i.e. there must be no remaining
956/// errors after running the handlers, or llvm_unreachable is called).
957template <typename... HandlerTs>
958void handleAllErrors(Error E, HandlerTs &&... Handlers) {
959 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
960}
961
962/// Check that E is a non-error, then drop it.
963/// If E is an error, llvm_unreachable will be called.
964inline void handleAllErrors(Error E) {
965 cantFail(std::move(E));
966}
967
968/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
969///
970/// If the incoming value is a success value it is returned unmodified. If it
971/// is a failure value then it the contained error is passed to handleErrors.
972/// If handleErrors is able to handle the error then the RecoveryPath functor
973/// is called to supply the final result. If handleErrors is not able to
974/// handle all errors then the unhandled errors are returned.
975///
976/// This utility enables the follow pattern:
977///
978/// @code{.cpp}
979/// enum FooStrategy { Aggressive, Conservative };
980/// Expected<Foo> foo(FooStrategy S);
981///
982/// auto ResultOrErr =
983/// handleExpected(
984/// foo(Aggressive),
985/// []() { return foo(Conservative); },
986/// [](AggressiveStrategyError&) {
987/// // Implicitly conusme this - we'll recover by using a conservative
988/// // strategy.
989/// });
990///
991/// @endcode
992template <typename T, typename RecoveryFtor, typename... HandlerTs>
993Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
994 HandlerTs &&... Handlers) {
995 if (ValOrErr)
996 return ValOrErr;
997
998 if (auto Err = handleErrors(ValOrErr.takeError(),
999 std::forward<HandlerTs>(Handlers)...))
1000 return std::move(Err);
1001
1002 return RecoveryPath();
1003}
1004
1005/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
1006/// will be printed before the first one is logged. A newline will be printed
1007/// after each error.
1008///
1009/// This function is compatible with the helpers from Support/WithColor.h. You
1010/// can pass any of them as the OS. Please consider using them instead of
1011/// including 'error: ' in the ErrorBanner.
1012///
1013/// This is useful in the base level of your program to allow clean termination
1014/// (allowing clean deallocation of resources, etc.), while reporting error
1015/// information to the user.
1016void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
1017
1018/// Write all error messages (if any) in E to a string. The newline character
1019/// is used to separate error messages.
1020inline std::string toString(Error E) {
1021 SmallVector<std::string, 2> Errors;
1022 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
1023 Errors.push_back(EI.message());
1024 });
1025 return join(Errors.begin(), Errors.end(), "\n");
1026}
1027
1028/// Consume a Error without doing anything. This method should be used
1029/// only where an error can be considered a reasonable and expected return
1030/// value.
1031///
1032/// Uses of this method are potentially indicative of design problems: If it's
1033/// legitimate to do nothing while processing an "error", the error-producer
1034/// might be more clearly refactored to return an Optional<T>.
1035inline void consumeError(Error Err) {
1036 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
1037}
1038
1039/// Convert an Expected to an Optional without doing anything. This method
1040/// should be used only where an error can be considered a reasonable and
1041/// expected return value.
1042///
1043/// Uses of this method are potentially indicative of problems: perhaps the
1044/// error should be propagated further, or the error-producer should just
1045/// return an Optional in the first place.
1046template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
1047 if (E)
1048 return std::move(*E);
1049 consumeError(E.takeError());
1050 return None;
1051}
1052
1053/// Helper for converting an Error to a bool.
1054///
1055/// This method returns true if Err is in an error state, or false if it is
1056/// in a success state. Puts Err in a checked state in both cases (unlike
1057/// Error::operator bool(), which only does this for success states).
1058inline bool errorToBool(Error Err) {
1059 bool IsError = static_cast<bool>(Err);
1060 if (IsError)
1061 consumeError(std::move(Err));
1062 return IsError;
1063}
1064
1065/// Helper for Errors used as out-parameters.
1066///
1067/// This helper is for use with the Error-as-out-parameter idiom, where an error
1068/// is passed to a function or method by reference, rather than being returned.
1069/// In such cases it is helpful to set the checked bit on entry to the function
1070/// so that the error can be written to (unchecked Errors abort on assignment)
1071/// and clear the checked bit on exit so that clients cannot accidentally forget
1072/// to check the result. This helper performs these actions automatically using
1073/// RAII:
1074///
1075/// @code{.cpp}
1076/// Result foo(Error &Err) {
1077/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1078/// // <body of foo>
1079/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1080/// }
1081/// @endcode
1082///
1083/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1084/// used with optional Errors (Error pointers that are allowed to be null). If
1085/// ErrorAsOutParameter took an Error reference, an instance would have to be
1086/// created inside every condition that verified that Error was non-null. By
1087/// taking an Error pointer we can just create one instance at the top of the
1088/// function.
1089class ErrorAsOutParameter {
1090public:
1091 ErrorAsOutParameter(Error *Err) : Err(Err) {
1092 // Raise the checked bit if Err is success.
1093 if (Err)
1094 (void)!!*Err;
1095 }
1096
1097 ~ErrorAsOutParameter() {
1098 // Clear the checked bit.
1099 if (Err && !*Err)
1100 *Err = Error::success();
1101 }
1102
1103private:
1104 Error *Err;
1105};
1106
1107/// Helper for Expected<T>s used as out-parameters.
1108///
1109/// See ErrorAsOutParameter.
1110template <typename T>
1111class ExpectedAsOutParameter {
1112public:
1113 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1114 : ValOrErr(ValOrErr) {
1115 if (ValOrErr)
1116 (void)!!*ValOrErr;
1117 }
1118
1119 ~ExpectedAsOutParameter() {
1120 if (ValOrErr)
1121 ValOrErr->setUnchecked();
1122 }
1123
1124private:
1125 Expected<T> *ValOrErr;
1126};
1127
1128/// This class wraps a std::error_code in a Error.
1129///
1130/// This is useful if you're writing an interface that returns a Error
1131/// (or Expected) and you want to call code that still returns
1132/// std::error_codes.
1133class ECError : public ErrorInfo<ECError> {
1134 friend Error errorCodeToError(std::error_code);
1135
1136 virtual void anchor() override;
1137
1138public:
1139 void setErrorCode(std::error_code EC) { this->EC = EC; }
1140 std::error_code convertToErrorCode() const override { return EC; }
1141 void log(raw_ostream &OS) const override { OS << EC.message(); }
1142
1143 // Used by ErrorInfo::classID.
1144 static char ID;
1145
1146protected:
1147 ECError() = default;
1148 ECError(std::error_code EC) : EC(EC) {}
1149
1150 std::error_code EC;
1151};
1152
1153/// The value returned by this function can be returned from convertToErrorCode
1154/// for Error values where no sensible translation to std::error_code exists.
1155/// It should only be used in this situation, and should never be used where a
1156/// sensible conversion to std::error_code is available, as attempts to convert
1157/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1158///error to try to convert such a value).
1159std::error_code inconvertibleErrorCode();
1160
1161/// Helper for converting an std::error_code to a Error.
1162Error errorCodeToError(std::error_code EC);
1163
1164/// Helper for converting an ECError to a std::error_code.
1165///
1166/// This method requires that Err be Error() or an ECError, otherwise it
1167/// will trigger a call to abort().
1168std::error_code errorToErrorCode(Error Err);
1169
1170/// Convert an ErrorOr<T> to an Expected<T>.
1171template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1172 if (auto EC = EO.getError())
1173 return errorCodeToError(EC);
1174 return std::move(*EO);
1175}
1176
1177/// Convert an Expected<T> to an ErrorOr<T>.
1178template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1179 if (auto Err = E.takeError())
1180 return errorToErrorCode(std::move(Err));
1181 return std::move(*E);
1182}
1183
1184/// This class wraps a string in an Error.
1185///
1186/// StringError is useful in cases where the client is not expected to be able
1187/// to consume the specific error message programmatically (for example, if the
1188/// error message is to be presented to the user).
1189///
1190/// StringError can also be used when additional information is to be printed
1191/// along with a error_code message. Depending on the constructor called, this
1192/// class can either display:
1193/// 1. the error_code message (ECError behavior)
1194/// 2. a string
1195/// 3. the error_code message and a string
1196///
1197/// These behaviors are useful when subtyping is required; for example, when a
1198/// specific library needs an explicit error type. In the example below,
1199/// PDBError is derived from StringError:
1200///
1201/// @code{.cpp}
1202/// Expected<int> foo() {
1203/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1204/// "Additional information");
1205/// }
1206/// @endcode
1207///
1208class StringError : public ErrorInfo<StringError> {
1209public:
1210 static char ID;
1211
1212 // Prints EC + S and converts to EC
1213 StringError(std::error_code EC, const Twine &S = Twine());
1214
1215 // Prints S and converts to EC
1216 StringError(const Twine &S, std::error_code EC);
1217
1218 void log(raw_ostream &OS) const override;
1219 std::error_code convertToErrorCode() const override;
1220
1221 const std::string &getMessage() const { return Msg; }
1222
1223private:
1224 std::string Msg;
1225 std::error_code EC;
1226 const bool PrintMsgOnly = false;
1227};
1228
1229/// Create formatted StringError object.
1230template <typename... Ts>
1231inline Error createStringError(std::error_code EC, char const *Fmt,
1232 const Ts &... Vals) {
1233 std::string Buffer;
1234 raw_string_ostream Stream(Buffer);
1235 Stream << format(Fmt, Vals...);
1236 return make_error<StringError>(Stream.str(), EC);
1237}
1238
1239Error createStringError(std::error_code EC, char const *Msg);
1240
1241inline Error createStringError(std::error_code EC, const Twine &S) {
1242 return createStringError(EC, S.str().c_str());
1243}
1244
1245template <typename... Ts>
1246inline Error createStringError(std::errc EC, char const *Fmt,
1247 const Ts &... Vals) {
1248 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1249}
1250
1251/// This class wraps a filename and another Error.
1252///
1253/// In some cases, an error needs to live along a 'source' name, in order to
1254/// show more detailed information to the user.
1255class FileError final : public ErrorInfo<FileError> {
1256
1257 friend Error createFileError(const Twine &, Error);
1258 friend Error createFileError(const Twine &, size_t, Error);
1259
1260public:
1261 void log(raw_ostream &OS) const override {
1262 assert(Err && !FileName.empty() && "Trying to log after takeError().")(static_cast <bool> (Err && !FileName.empty() &&
"Trying to log after takeError().") ? void (0) : __assert_fail
("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 1262, __extension__ __PRETTY_FUNCTION__));
1263 OS << "'" << FileName << "': ";
1264 if (Line.hasValue())
1265 OS << "line " << Line.getValue() << ": ";
1266 Err->log(OS);
1267 }
1268
1269 StringRef getFileName() { return FileName; }
1270
1271 Error takeError() { return Error(std::move(Err)); }
1272
1273 std::error_code convertToErrorCode() const override;
1274
1275 // Used by ErrorInfo::classID.
1276 static char ID;
1277
1278private:
1279 FileError(const Twine &F, Optional<size_t> LineNum,
1280 std::unique_ptr<ErrorInfoBase> E) {
1281 assert(E && "Cannot create FileError from Error success value.")(static_cast <bool> (E && "Cannot create FileError from Error success value."
) ? void (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 1281, __extension__ __PRETTY_FUNCTION__));
1282 assert(!F.isTriviallyEmpty() &&(static_cast <bool> (!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? void (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 1283, __extension__ __PRETTY_FUNCTION__))
1283 "The file name provided to FileError must not be empty.")(static_cast <bool> (!F.isTriviallyEmpty() && "The file name provided to FileError must not be empty."
) ? void (0) : __assert_fail ("!F.isTriviallyEmpty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include/llvm/Support/Error.h"
, 1283, __extension__ __PRETTY_FUNCTION__));
1284 FileName = F.str();
1285 Err = std::move(E);
1286 Line = std::move(LineNum);
1287 }
1288
1289 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1290 std::unique_ptr<ErrorInfoBase> Payload;
1291 handleAllErrors(std::move(E),
1292 [&](std::unique_ptr<ErrorInfoBase> EIB) -> Error {
1293 Payload = std::move(EIB);
1294 return Error::success();
1295 });
1296 return Error(
1297 std::unique_ptr<FileError>(new FileError(F, Line, std::move(Payload))));
1298 }
1299
1300 std::string FileName;
1301 Optional<size_t> Line;
1302 std::unique_ptr<ErrorInfoBase> Err;
1303};
1304
1305/// Concatenate a source file path and/or name with an Error. The resulting
1306/// Error is unchecked.
1307inline Error createFileError(const Twine &F, Error E) {
1308 return FileError::build(F, Optional<size_t>(), std::move(E));
1309}
1310
1311/// Concatenate a source file path and/or name with line number and an Error.
1312/// The resulting Error is unchecked.
1313inline Error createFileError(const Twine &F, size_t Line, Error E) {
1314 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1315}
1316
1317/// Concatenate a source file path and/or name with a std::error_code
1318/// to form an Error object.
1319inline Error createFileError(const Twine &F, std::error_code EC) {
1320 return createFileError(F, errorCodeToError(EC));
1321}
1322
1323/// Concatenate a source file path and/or name with line number and
1324/// std::error_code to form an Error object.
1325inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1326 return createFileError(F, Line, errorCodeToError(EC));
1327}
1328
1329Error createFileError(const Twine &F, ErrorSuccess) = delete;
1330
1331/// Helper for check-and-exit error handling.
1332///
1333/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1334///
1335class ExitOnError {
1336public:
1337 /// Create an error on exit helper.
1338 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1339 : Banner(std::move(Banner)),
1340 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1341
1342 /// Set the banner string for any errors caught by operator().
1343 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1344
1345 /// Set the exit-code mapper function.
1346 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1347 this->GetExitCode = std::move(GetExitCode);
1348 }
1349
1350 /// Check Err. If it's in a failure state log the error(s) and exit.
1351 void operator()(Error Err) const { checkError(std::move(Err)); }
1352
1353 /// Check E. If it's in a success state then return the contained value. If
1354 /// it's in a failure state log the error(s) and exit.
1355 template <typename T> T operator()(Expected<T> &&E) const {
1356 checkError(E.takeError());
1357 return std::move(*E);
1358 }
1359
1360 /// Check E. If it's in a success state then return the contained reference. If
1361 /// it's in a failure state log the error(s) and exit.
1362 template <typename T> T& operator()(Expected<T&> &&E) const {
1363 checkError(E.takeError());
1364 return *E;
1365 }
1366
1367private:
1368 void checkError(Error Err) const {
1369 if (Err) {
1370 int ExitCode = GetExitCode(Err);
1371 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1372 exit(ExitCode);
1373 }
1374 }
1375
1376 std::string Banner;
1377 std::function<int(const Error &)> GetExitCode;
1378};
1379
1380/// Conversion from Error to LLVMErrorRef for C error bindings.
1381inline LLVMErrorRef wrap(Error Err) {
1382 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1383}
1384
1385/// Conversion from LLVMErrorRef to Error for C error bindings.
1386inline Error unwrap(LLVMErrorRef ErrRef) {
1387 return Error(std::unique_ptr<ErrorInfoBase>(
1388 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1389}
1390
1391} // end namespace llvm
1392
1393#endif // LLVM_SUPPORT_ERROR_H