Bug Summary

File:llvm/lib/Bitcode/Reader/MetadataLoader.cpp
Warning:line 771, column 17
1st function call argument is an uninitialized value

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 MetadataLoader.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 -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~++20210903100615+fd66b44ec19e/build-llvm/lib/Bitcode/Reader -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Bitcode/Reader -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Bitcode/Reader -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/include -D 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~++20210903100615+fd66b44ec19e/build-llvm/lib/Bitcode/Reader -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e=. -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-2021-09-04-040900-46481-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Bitcode/Reader/MetadataLoader.cpp

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Bitcode/Reader/MetadataLoader.cpp

1//===- MetadataLoader.cpp - Internal BitcodeReader implementation ---------===//
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 "MetadataLoader.h"
10#include "ValueList.h"
11
12#include "llvm/ADT/APFloat.h"
13#include "llvm/ADT/APInt.h"
14#include "llvm/ADT/ArrayRef.h"
15#include "llvm/ADT/DenseMap.h"
16#include "llvm/ADT/DenseSet.h"
17#include "llvm/ADT/None.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/SmallString.h"
20#include "llvm/ADT/Statistic.h"
21#include "llvm/ADT/StringRef.h"
22#include "llvm/ADT/Twine.h"
23#include "llvm/Bitcode/BitcodeReader.h"
24#include "llvm/Bitstream/BitstreamReader.h"
25#include "llvm/Bitcode/LLVMBitCodes.h"
26#include "llvm/IR/Argument.h"
27#include "llvm/IR/Attributes.h"
28#include "llvm/IR/AutoUpgrade.h"
29#include "llvm/IR/BasicBlock.h"
30#include "llvm/IR/CallingConv.h"
31#include "llvm/IR/Comdat.h"
32#include "llvm/IR/Constant.h"
33#include "llvm/IR/Constants.h"
34#include "llvm/IR/DebugInfo.h"
35#include "llvm/IR/DebugInfoMetadata.h"
36#include "llvm/IR/DebugLoc.h"
37#include "llvm/IR/DerivedTypes.h"
38#include "llvm/IR/DiagnosticPrinter.h"
39#include "llvm/IR/Function.h"
40#include "llvm/IR/GVMaterializer.h"
41#include "llvm/IR/GlobalAlias.h"
42#include "llvm/IR/GlobalIFunc.h"
43#include "llvm/IR/GlobalIndirectSymbol.h"
44#include "llvm/IR/GlobalObject.h"
45#include "llvm/IR/GlobalValue.h"
46#include "llvm/IR/GlobalVariable.h"
47#include "llvm/IR/InlineAsm.h"
48#include "llvm/IR/InstrTypes.h"
49#include "llvm/IR/Instruction.h"
50#include "llvm/IR/Instructions.h"
51#include "llvm/IR/IntrinsicInst.h"
52#include "llvm/IR/Intrinsics.h"
53#include "llvm/IR/LLVMContext.h"
54#include "llvm/IR/Module.h"
55#include "llvm/IR/ModuleSummaryIndex.h"
56#include "llvm/IR/OperandTraits.h"
57#include "llvm/IR/TrackingMDRef.h"
58#include "llvm/IR/Type.h"
59#include "llvm/IR/ValueHandle.h"
60#include "llvm/Support/AtomicOrdering.h"
61#include "llvm/Support/Casting.h"
62#include "llvm/Support/CommandLine.h"
63#include "llvm/Support/Compiler.h"
64#include "llvm/Support/Debug.h"
65#include "llvm/Support/ErrorHandling.h"
66#include "llvm/Support/ManagedStatic.h"
67#include "llvm/Support/MemoryBuffer.h"
68#include "llvm/Support/raw_ostream.h"
69#include <algorithm>
70#include <cassert>
71#include <cstddef>
72#include <cstdint>
73#include <deque>
74#include <limits>
75#include <map>
76#include <string>
77#include <system_error>
78#include <tuple>
79#include <utility>
80#include <vector>
81
82using namespace llvm;
83
84#define DEBUG_TYPE"bitcode-reader" "bitcode-reader"
85
86STATISTIC(NumMDStringLoaded, "Number of MDStrings loaded")static llvm::Statistic NumMDStringLoaded = {"bitcode-reader",
"NumMDStringLoaded", "Number of MDStrings loaded"}
;
87STATISTIC(NumMDNodeTemporary, "Number of MDNode::Temporary created")static llvm::Statistic NumMDNodeTemporary = {"bitcode-reader"
, "NumMDNodeTemporary", "Number of MDNode::Temporary created"
}
;
88STATISTIC(NumMDRecordLoaded, "Number of Metadata records loaded")static llvm::Statistic NumMDRecordLoaded = {"bitcode-reader",
"NumMDRecordLoaded", "Number of Metadata records loaded"}
;
89
90/// Flag whether we need to import full type definitions for ThinLTO.
91/// Currently needed for Darwin and LLDB.
92static cl::opt<bool> ImportFullTypeDefinitions(
93 "import-full-type-definitions", cl::init(false), cl::Hidden,
94 cl::desc("Import full type definitions for ThinLTO."));
95
96static cl::opt<bool> DisableLazyLoading(
97 "disable-ondemand-mds-loading", cl::init(false), cl::Hidden,
98 cl::desc("Force disable the lazy-loading on-demand of metadata when "
99 "loading bitcode for importing."));
100
101namespace {
102
103static int64_t unrotateSign(uint64_t U) { return (U & 1) ? ~(U >> 1) : U >> 1; }
104
105class BitcodeReaderMetadataList {
106 /// Array of metadata references.
107 ///
108 /// Don't use std::vector here. Some versions of libc++ copy (instead of
109 /// move) on resize, and TrackingMDRef is very expensive to copy.
110 SmallVector<TrackingMDRef, 1> MetadataPtrs;
111
112 /// The set of indices in MetadataPtrs above of forward references that were
113 /// generated.
114 SmallDenseSet<unsigned, 1> ForwardReference;
115
116 /// The set of indices in MetadataPtrs above of Metadata that need to be
117 /// resolved.
118 SmallDenseSet<unsigned, 1> UnresolvedNodes;
119
120 /// Structures for resolving old type refs.
121 struct {
122 SmallDenseMap<MDString *, TempMDTuple, 1> Unknown;
123 SmallDenseMap<MDString *, DICompositeType *, 1> Final;
124 SmallDenseMap<MDString *, DICompositeType *, 1> FwdDecls;
125 SmallVector<std::pair<TrackingMDRef, TempMDTuple>, 1> Arrays;
126 } OldTypeRefs;
127
128 LLVMContext &Context;
129
130 /// Maximum number of valid references. Forward references exceeding the
131 /// maximum must be invalid.
132 unsigned RefsUpperBound;
133
134public:
135 BitcodeReaderMetadataList(LLVMContext &C, size_t RefsUpperBound)
136 : Context(C),
137 RefsUpperBound(std::min((size_t)std::numeric_limits<unsigned>::max(),
138 RefsUpperBound)) {}
139
140 // vector compatibility methods
141 unsigned size() const { return MetadataPtrs.size(); }
142 void resize(unsigned N) { MetadataPtrs.resize(N); }
143 void push_back(Metadata *MD) { MetadataPtrs.emplace_back(MD); }
144 void clear() { MetadataPtrs.clear(); }
145 Metadata *back() const { return MetadataPtrs.back(); }
146 void pop_back() { MetadataPtrs.pop_back(); }
147 bool empty() const { return MetadataPtrs.empty(); }
148
149 Metadata *operator[](unsigned i) const {
150 assert(i < MetadataPtrs.size())(static_cast<void> (0));
151 return MetadataPtrs[i];
152 }
153
154 Metadata *lookup(unsigned I) const {
155 if (I < MetadataPtrs.size())
156 return MetadataPtrs[I];
157 return nullptr;
158 }
159
160 void shrinkTo(unsigned N) {
161 assert(N <= size() && "Invalid shrinkTo request!")(static_cast<void> (0));
162 assert(ForwardReference.empty() && "Unexpected forward refs")(static_cast<void> (0));
163 assert(UnresolvedNodes.empty() && "Unexpected unresolved node")(static_cast<void> (0));
164 MetadataPtrs.resize(N);
165 }
166
167 /// Return the given metadata, creating a replaceable forward reference if
168 /// necessary.
169 Metadata *getMetadataFwdRef(unsigned Idx);
170
171 /// Return the given metadata only if it is fully resolved.
172 ///
173 /// Gives the same result as \a lookup(), unless \a MDNode::isResolved()
174 /// would give \c false.
175 Metadata *getMetadataIfResolved(unsigned Idx);
176
177 MDNode *getMDNodeFwdRefOrNull(unsigned Idx);
178 void assignValue(Metadata *MD, unsigned Idx);
179 void tryToResolveCycles();
180 bool hasFwdRefs() const { return !ForwardReference.empty(); }
181 int getNextFwdRef() {
182 assert(hasFwdRefs())(static_cast<void> (0));
183 return *ForwardReference.begin();
184 }
185
186 /// Upgrade a type that had an MDString reference.
187 void addTypeRef(MDString &UUID, DICompositeType &CT);
188
189 /// Upgrade a type that had an MDString reference.
190 Metadata *upgradeTypeRef(Metadata *MaybeUUID);
191
192 /// Upgrade a type ref array that may have MDString references.
193 Metadata *upgradeTypeRefArray(Metadata *MaybeTuple);
194
195private:
196 Metadata *resolveTypeRefArray(Metadata *MaybeTuple);
197};
198
199void BitcodeReaderMetadataList::assignValue(Metadata *MD, unsigned Idx) {
200 if (auto *MDN = dyn_cast<MDNode>(MD))
201 if (!MDN->isResolved())
202 UnresolvedNodes.insert(Idx);
203
204 if (Idx == size()) {
205 push_back(MD);
206 return;
207 }
208
209 if (Idx >= size())
210 resize(Idx + 1);
211
212 TrackingMDRef &OldMD = MetadataPtrs[Idx];
213 if (!OldMD) {
214 OldMD.reset(MD);
215 return;
216 }
217
218 // If there was a forward reference to this value, replace it.
219 TempMDTuple PrevMD(cast<MDTuple>(OldMD.get()));
220 PrevMD->replaceAllUsesWith(MD);
221 ForwardReference.erase(Idx);
222}
223
224Metadata *BitcodeReaderMetadataList::getMetadataFwdRef(unsigned Idx) {
225 // Bail out for a clearly invalid value.
226 if (Idx >= RefsUpperBound)
227 return nullptr;
228
229 if (Idx >= size())
230 resize(Idx + 1);
231
232 if (Metadata *MD = MetadataPtrs[Idx])
233 return MD;
234
235 // Track forward refs to be resolved later.
236 ForwardReference.insert(Idx);
237
238 // Create and return a placeholder, which will later be RAUW'd.
239 ++NumMDNodeTemporary;
240 Metadata *MD = MDNode::getTemporary(Context, None).release();
241 MetadataPtrs[Idx].reset(MD);
242 return MD;
243}
244
245Metadata *BitcodeReaderMetadataList::getMetadataIfResolved(unsigned Idx) {
246 Metadata *MD = lookup(Idx);
247 if (auto *N = dyn_cast_or_null<MDNode>(MD))
248 if (!N->isResolved())
249 return nullptr;
250 return MD;
251}
252
253MDNode *BitcodeReaderMetadataList::getMDNodeFwdRefOrNull(unsigned Idx) {
254 return dyn_cast_or_null<MDNode>(getMetadataFwdRef(Idx));
255}
256
257void BitcodeReaderMetadataList::tryToResolveCycles() {
258 if (!ForwardReference.empty())
259 // Still forward references... can't resolve cycles.
260 return;
261
262 // Give up on finding a full definition for any forward decls that remain.
263 for (const auto &Ref : OldTypeRefs.FwdDecls)
264 OldTypeRefs.Final.insert(Ref);
265 OldTypeRefs.FwdDecls.clear();
266
267 // Upgrade from old type ref arrays. In strange cases, this could add to
268 // OldTypeRefs.Unknown.
269 for (const auto &Array : OldTypeRefs.Arrays)
270 Array.second->replaceAllUsesWith(resolveTypeRefArray(Array.first.get()));
271 OldTypeRefs.Arrays.clear();
272
273 // Replace old string-based type refs with the resolved node, if possible.
274 // If we haven't seen the node, leave it to the verifier to complain about
275 // the invalid string reference.
276 for (const auto &Ref : OldTypeRefs.Unknown) {
277 if (DICompositeType *CT = OldTypeRefs.Final.lookup(Ref.first))
278 Ref.second->replaceAllUsesWith(CT);
279 else
280 Ref.second->replaceAllUsesWith(Ref.first);
281 }
282 OldTypeRefs.Unknown.clear();
283
284 if (UnresolvedNodes.empty())
285 // Nothing to do.
286 return;
287
288 // Resolve any cycles.
289 for (unsigned I : UnresolvedNodes) {
290 auto &MD = MetadataPtrs[I];
291 auto *N = dyn_cast_or_null<MDNode>(MD);
292 if (!N)
293 continue;
294
295 assert(!N->isTemporary() && "Unexpected forward reference")(static_cast<void> (0));
296 N->resolveCycles();
297 }
298
299 // Make sure we return early again until there's another unresolved ref.
300 UnresolvedNodes.clear();
301}
302
303void BitcodeReaderMetadataList::addTypeRef(MDString &UUID,
304 DICompositeType &CT) {
305 assert(CT.getRawIdentifier() == &UUID && "Mismatched UUID")(static_cast<void> (0));
306 if (CT.isForwardDecl())
307 OldTypeRefs.FwdDecls.insert(std::make_pair(&UUID, &CT));
308 else
309 OldTypeRefs.Final.insert(std::make_pair(&UUID, &CT));
310}
311
312Metadata *BitcodeReaderMetadataList::upgradeTypeRef(Metadata *MaybeUUID) {
313 auto *UUID = dyn_cast_or_null<MDString>(MaybeUUID);
314 if (LLVM_LIKELY(!UUID)__builtin_expect((bool)(!UUID), true))
315 return MaybeUUID;
316
317 if (auto *CT = OldTypeRefs.Final.lookup(UUID))
318 return CT;
319
320 auto &Ref = OldTypeRefs.Unknown[UUID];
321 if (!Ref)
322 Ref = MDNode::getTemporary(Context, None);
323 return Ref.get();
324}
325
326Metadata *BitcodeReaderMetadataList::upgradeTypeRefArray(Metadata *MaybeTuple) {
327 auto *Tuple = dyn_cast_or_null<MDTuple>(MaybeTuple);
328 if (!Tuple || Tuple->isDistinct())
329 return MaybeTuple;
330
331 // Look through the array immediately if possible.
332 if (!Tuple->isTemporary())
333 return resolveTypeRefArray(Tuple);
334
335 // Create and return a placeholder to use for now. Eventually
336 // resolveTypeRefArrays() will be resolve this forward reference.
337 OldTypeRefs.Arrays.emplace_back(
338 std::piecewise_construct, std::forward_as_tuple(Tuple),
339 std::forward_as_tuple(MDTuple::getTemporary(Context, None)));
340 return OldTypeRefs.Arrays.back().second.get();
341}
342
343Metadata *BitcodeReaderMetadataList::resolveTypeRefArray(Metadata *MaybeTuple) {
344 auto *Tuple = dyn_cast_or_null<MDTuple>(MaybeTuple);
345 if (!Tuple || Tuple->isDistinct())
346 return MaybeTuple;
347
348 // Look through the DITypeRefArray, upgrading each DIType *.
349 SmallVector<Metadata *, 32> Ops;
350 Ops.reserve(Tuple->getNumOperands());
351 for (Metadata *MD : Tuple->operands())
352 Ops.push_back(upgradeTypeRef(MD));
353
354 return MDTuple::get(Context, Ops);
355}
356
357namespace {
358
359class PlaceholderQueue {
360 // Placeholders would thrash around when moved, so store in a std::deque
361 // instead of some sort of vector.
362 std::deque<DistinctMDOperandPlaceholder> PHs;
363
364public:
365 ~PlaceholderQueue() {
366 assert(empty() && "PlaceholderQueue hasn't been flushed before being destroyed")(static_cast<void> (0));
367 }
368 bool empty() const { return PHs.empty(); }
369 DistinctMDOperandPlaceholder &getPlaceholderOp(unsigned ID);
370 void flush(BitcodeReaderMetadataList &MetadataList);
371
372 /// Return the list of temporaries nodes in the queue, these need to be
373 /// loaded before we can flush the queue.
374 void getTemporaries(BitcodeReaderMetadataList &MetadataList,
375 DenseSet<unsigned> &Temporaries) {
376 for (auto &PH : PHs) {
377 auto ID = PH.getID();
378 auto *MD = MetadataList.lookup(ID);
379 if (!MD) {
380 Temporaries.insert(ID);
381 continue;
382 }
383 auto *N = dyn_cast_or_null<MDNode>(MD);
384 if (N && N->isTemporary())
385 Temporaries.insert(ID);
386 }
387 }
388};
389
390} // end anonymous namespace
391
392DistinctMDOperandPlaceholder &PlaceholderQueue::getPlaceholderOp(unsigned ID) {
393 PHs.emplace_back(ID);
394 return PHs.back();
395}
396
397void PlaceholderQueue::flush(BitcodeReaderMetadataList &MetadataList) {
398 while (!PHs.empty()) {
399 auto *MD = MetadataList.lookup(PHs.front().getID());
400 assert(MD && "Flushing placeholder on unassigned MD")(static_cast<void> (0));
401#ifndef NDEBUG1
402 if (auto *MDN = dyn_cast<MDNode>(MD))
403 assert(MDN->isResolved() &&(static_cast<void> (0))
404 "Flushing Placeholder while cycles aren't resolved")(static_cast<void> (0));
405#endif
406 PHs.front().replaceUseWith(MD);
407 PHs.pop_front();
408 }
409}
410
411} // anonymous namespace
412
413static Error error(const Twine &Message) {
414 return make_error<StringError>(
415 Message, make_error_code(BitcodeError::CorruptedBitcode));
416}
417
418class MetadataLoader::MetadataLoaderImpl {
419 BitcodeReaderMetadataList MetadataList;
420 BitcodeReaderValueList &ValueList;
421 BitstreamCursor &Stream;
422 LLVMContext &Context;
423 Module &TheModule;
424 std::function<Type *(unsigned)> getTypeByID;
425
426 /// Cursor associated with the lazy-loading of Metadata. This is the easy way
427 /// to keep around the right "context" (Abbrev list) to be able to jump in
428 /// the middle of the metadata block and load any record.
429 BitstreamCursor IndexCursor;
430
431 /// Index that keeps track of MDString values.
432 std::vector<StringRef> MDStringRef;
433
434 /// On-demand loading of a single MDString. Requires the index above to be
435 /// populated.
436 MDString *lazyLoadOneMDString(unsigned Idx);
437
438 /// Index that keeps track of where to find a metadata record in the stream.
439 std::vector<uint64_t> GlobalMetadataBitPosIndex;
440
441 /// Cursor position of the start of the global decl attachments, to enable
442 /// loading using the index built for lazy loading, instead of forward
443 /// references.
444 uint64_t GlobalDeclAttachmentPos = 0;
445
446#ifndef NDEBUG1
447 /// Sanity check that we end up parsing all of the global decl attachments.
448 unsigned NumGlobalDeclAttachSkipped = 0;
449 unsigned NumGlobalDeclAttachParsed = 0;
450#endif
451
452 /// Load the global decl attachments, using the index built for lazy loading.
453 Expected<bool> loadGlobalDeclAttachments();
454
455 /// Populate the index above to enable lazily loading of metadata, and load
456 /// the named metadata as well as the transitively referenced global
457 /// Metadata.
458 Expected<bool> lazyLoadModuleMetadataBlock();
459
460 /// On-demand loading of a single metadata. Requires the index above to be
461 /// populated.
462 void lazyLoadOneMetadata(unsigned Idx, PlaceholderQueue &Placeholders);
463
464 // Keep mapping of seens pair of old-style CU <-> SP, and update pointers to
465 // point from SP to CU after a block is completly parsed.
466 std::vector<std::pair<DICompileUnit *, Metadata *>> CUSubprograms;
467
468 /// Functions that need to be matched with subprograms when upgrading old
469 /// metadata.
470 SmallDenseMap<Function *, DISubprogram *, 16> FunctionsWithSPs;
471
472 // Map the bitcode's custom MDKind ID to the Module's MDKind ID.
473 DenseMap<unsigned, unsigned> MDKindMap;
474
475 bool StripTBAA = false;
476 bool HasSeenOldLoopTags = false;
477 bool NeedUpgradeToDIGlobalVariableExpression = false;
478 bool NeedDeclareExpressionUpgrade = false;
479
480 /// True if metadata is being parsed for a module being ThinLTO imported.
481 bool IsImporting = false;
482
483 Error parseOneMetadata(SmallVectorImpl<uint64_t> &Record, unsigned Code,
484 PlaceholderQueue &Placeholders, StringRef Blob,
485 unsigned &NextMetadataNo);
486 Error parseMetadataStrings(ArrayRef<uint64_t> Record, StringRef Blob,
487 function_ref<void(StringRef)> CallBack);
488 Error parseGlobalObjectAttachment(GlobalObject &GO,
489 ArrayRef<uint64_t> Record);
490 Error parseMetadataKindRecord(SmallVectorImpl<uint64_t> &Record);
491
492 void resolveForwardRefsAndPlaceholders(PlaceholderQueue &Placeholders);
493
494 /// Upgrade old-style CU <-> SP pointers to point from SP to CU.
495 void upgradeCUSubprograms() {
496 for (auto CU_SP : CUSubprograms)
497 if (auto *SPs = dyn_cast_or_null<MDTuple>(CU_SP.second))
498 for (auto &Op : SPs->operands())
499 if (auto *SP = dyn_cast_or_null<DISubprogram>(Op))
500 SP->replaceUnit(CU_SP.first);
501 CUSubprograms.clear();
502 }
503
504 /// Upgrade old-style bare DIGlobalVariables to DIGlobalVariableExpressions.
505 void upgradeCUVariables() {
506 if (!NeedUpgradeToDIGlobalVariableExpression)
507 return;
508
509 // Upgrade list of variables attached to the CUs.
510 if (NamedMDNode *CUNodes = TheModule.getNamedMetadata("llvm.dbg.cu"))
511 for (unsigned I = 0, E = CUNodes->getNumOperands(); I != E; ++I) {
512 auto *CU = cast<DICompileUnit>(CUNodes->getOperand(I));
513 if (auto *GVs = dyn_cast_or_null<MDTuple>(CU->getRawGlobalVariables()))
514 for (unsigned I = 0; I < GVs->getNumOperands(); I++)
515 if (auto *GV =
516 dyn_cast_or_null<DIGlobalVariable>(GVs->getOperand(I))) {
517 auto *DGVE = DIGlobalVariableExpression::getDistinct(
518 Context, GV, DIExpression::get(Context, {}));
519 GVs->replaceOperandWith(I, DGVE);
520 }
521 }
522
523 // Upgrade variables attached to globals.
524 for (auto &GV : TheModule.globals()) {
525 SmallVector<MDNode *, 1> MDs;
526 GV.getMetadata(LLVMContext::MD_dbg, MDs);
527 GV.eraseMetadata(LLVMContext::MD_dbg);
528 for (auto *MD : MDs)
529 if (auto *DGV = dyn_cast<DIGlobalVariable>(MD)) {
530 auto *DGVE = DIGlobalVariableExpression::getDistinct(
531 Context, DGV, DIExpression::get(Context, {}));
532 GV.addMetadata(LLVMContext::MD_dbg, *DGVE);
533 } else
534 GV.addMetadata(LLVMContext::MD_dbg, *MD);
535 }
536 }
537
538 /// Remove a leading DW_OP_deref from DIExpressions in a dbg.declare that
539 /// describes a function argument.
540 void upgradeDeclareExpressions(Function &F) {
541 if (!NeedDeclareExpressionUpgrade)
542 return;
543
544 for (auto &BB : F)
545 for (auto &I : BB)
546 if (auto *DDI = dyn_cast<DbgDeclareInst>(&I))
547 if (auto *DIExpr = DDI->getExpression())
548 if (DIExpr->startsWithDeref() &&
549 dyn_cast_or_null<Argument>(DDI->getAddress())) {
550 SmallVector<uint64_t, 8> Ops;
551 Ops.append(std::next(DIExpr->elements_begin()),
552 DIExpr->elements_end());
553 DDI->setExpression(DIExpression::get(Context, Ops));
554 }
555 }
556
557 /// Upgrade the expression from previous versions.
558 Error upgradeDIExpression(uint64_t FromVersion,
559 MutableArrayRef<uint64_t> &Expr,
560 SmallVectorImpl<uint64_t> &Buffer) {
561 auto N = Expr.size();
562 switch (FromVersion) {
563 default:
564 return error("Invalid record");
565 case 0:
566 if (N >= 3 && Expr[N - 3] == dwarf::DW_OP_bit_piece)
567 Expr[N - 3] = dwarf::DW_OP_LLVM_fragment;
568 LLVM_FALLTHROUGH[[gnu::fallthrough]];
569 case 1:
570 // Move DW_OP_deref to the end.
571 if (N && Expr[0] == dwarf::DW_OP_deref) {
572 auto End = Expr.end();
573 if (Expr.size() >= 3 &&
574 *std::prev(End, 3) == dwarf::DW_OP_LLVM_fragment)
575 End = std::prev(End, 3);
576 std::move(std::next(Expr.begin()), End, Expr.begin());
577 *std::prev(End) = dwarf::DW_OP_deref;
578 }
579 NeedDeclareExpressionUpgrade = true;
580 LLVM_FALLTHROUGH[[gnu::fallthrough]];
581 case 2: {
582 // Change DW_OP_plus to DW_OP_plus_uconst.
583 // Change DW_OP_minus to DW_OP_uconst, DW_OP_minus
584 auto SubExpr = ArrayRef<uint64_t>(Expr);
585 while (!SubExpr.empty()) {
586 // Skip past other operators with their operands
587 // for this version of the IR, obtained from
588 // from historic DIExpression::ExprOperand::getSize().
589 size_t HistoricSize;
590 switch (SubExpr.front()) {
591 default:
592 HistoricSize = 1;
593 break;
594 case dwarf::DW_OP_constu:
595 case dwarf::DW_OP_minus:
596 case dwarf::DW_OP_plus:
597 HistoricSize = 2;
598 break;
599 case dwarf::DW_OP_LLVM_fragment:
600 HistoricSize = 3;
601 break;
602 }
603
604 // If the expression is malformed, make sure we don't
605 // copy more elements than we should.
606 HistoricSize = std::min(SubExpr.size(), HistoricSize);
607 ArrayRef<uint64_t> Args = SubExpr.slice(1, HistoricSize-1);
608
609 switch (SubExpr.front()) {
610 case dwarf::DW_OP_plus:
611 Buffer.push_back(dwarf::DW_OP_plus_uconst);
612 Buffer.append(Args.begin(), Args.end());
613 break;
614 case dwarf::DW_OP_minus:
615 Buffer.push_back(dwarf::DW_OP_constu);
616 Buffer.append(Args.begin(), Args.end());
617 Buffer.push_back(dwarf::DW_OP_minus);
618 break;
619 default:
620 Buffer.push_back(*SubExpr.begin());
621 Buffer.append(Args.begin(), Args.end());
622 break;
623 }
624
625 // Continue with remaining elements.
626 SubExpr = SubExpr.slice(HistoricSize);
627 }
628 Expr = MutableArrayRef<uint64_t>(Buffer);
629 LLVM_FALLTHROUGH[[gnu::fallthrough]];
630 }
631 case 3:
632 // Up-to-date!
633 break;
634 }
635
636 return Error::success();
637 }
638
639 void upgradeDebugInfo() {
640 upgradeCUSubprograms();
641 upgradeCUVariables();
642 }
643
644public:
645 MetadataLoaderImpl(BitstreamCursor &Stream, Module &TheModule,
646 BitcodeReaderValueList &ValueList,
647 std::function<Type *(unsigned)> getTypeByID,
648 bool IsImporting)
649 : MetadataList(TheModule.getContext(), Stream.SizeInBytes()),
650 ValueList(ValueList), Stream(Stream), Context(TheModule.getContext()),
651 TheModule(TheModule), getTypeByID(std::move(getTypeByID)),
652 IsImporting(IsImporting) {}
653
654 Error parseMetadata(bool ModuleLevel);
655
656 bool hasFwdRefs() const { return MetadataList.hasFwdRefs(); }
657
658 Metadata *getMetadataFwdRefOrLoad(unsigned ID) {
659 if (ID < MDStringRef.size())
660 return lazyLoadOneMDString(ID);
661 if (auto *MD = MetadataList.lookup(ID))
662 return MD;
663 // If lazy-loading is enabled, we try recursively to load the operand
664 // instead of creating a temporary.
665 if (ID < (MDStringRef.size() + GlobalMetadataBitPosIndex.size())) {
666 PlaceholderQueue Placeholders;
667 lazyLoadOneMetadata(ID, Placeholders);
668 resolveForwardRefsAndPlaceholders(Placeholders);
669 return MetadataList.lookup(ID);
670 }
671 return MetadataList.getMetadataFwdRef(ID);
672 }
673
674 DISubprogram *lookupSubprogramForFunction(Function *F) {
675 return FunctionsWithSPs.lookup(F);
676 }
677
678 bool hasSeenOldLoopTags() const { return HasSeenOldLoopTags; }
679
680 Error parseMetadataAttachment(
681 Function &F, const SmallVectorImpl<Instruction *> &InstructionList);
682
683 Error parseMetadataKinds();
684
685 void setStripTBAA(bool Value) { StripTBAA = Value; }
686 bool isStrippingTBAA() const { return StripTBAA; }
687
688 unsigned size() const { return MetadataList.size(); }
689 void shrinkTo(unsigned N) { MetadataList.shrinkTo(N); }
690 void upgradeDebugIntrinsics(Function &F) { upgradeDeclareExpressions(F); }
691};
692
693Expected<bool>
694MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
695 IndexCursor = Stream;
696 SmallVector<uint64_t, 64> Record;
697 GlobalDeclAttachmentPos = 0;
698 // Get the abbrevs, and preload record positions to make them lazy-loadable.
699 while (true) {
1
Loop condition is true. Entering loop body
700 uint64_t SavedPos = IndexCursor.GetCurrentBitNo();
701 Expected<BitstreamEntry> MaybeEntry = IndexCursor.advanceSkippingSubblocks(
702 BitstreamCursor::AF_DontPopBlockAtEnd);
703 if (!MaybeEntry)
2
Calling 'Expected::operator bool'
4
Returning from 'Expected::operator bool'
5
Taking false branch
704 return MaybeEntry.takeError();
705 BitstreamEntry Entry = MaybeEntry.get();
706
707 switch (Entry.Kind) {
6
Control jumps to 'case Record:' at line 714
708 case BitstreamEntry::SubBlock: // Handled for us already.
709 case BitstreamEntry::Error:
710 return error("Malformed block");
711 case BitstreamEntry::EndBlock: {
712 return true;
713 }
714 case BitstreamEntry::Record: {
715 // The interesting case.
716 ++NumMDRecordLoaded;
717 uint64_t CurrentPos = IndexCursor.GetCurrentBitNo();
718 Expected<unsigned> MaybeCode = IndexCursor.skipRecord(Entry.ID);
719 if (!MaybeCode)
7
Calling 'Expected::operator bool'
10
Returning from 'Expected::operator bool'
11
Taking false branch
720 return MaybeCode.takeError();
721 unsigned Code = MaybeCode.get();
722 switch (Code) {
12
Control jumps to 'case METADATA_INDEX_OFFSET:' at line 743
723 case bitc::METADATA_STRINGS: {
724 // Rewind and parse the strings.
725 if (Error Err = IndexCursor.JumpToBit(CurrentPos))
726 return std::move(Err);
727 StringRef Blob;
728 Record.clear();
729 if (Expected<unsigned> MaybeRecord =
730 IndexCursor.readRecord(Entry.ID, Record, &Blob))
731 ;
732 else
733 return MaybeRecord.takeError();
734 unsigned NumStrings = Record[0];
735 MDStringRef.reserve(NumStrings);
736 auto IndexNextMDString = [&](StringRef Str) {
737 MDStringRef.push_back(Str);
738 };
739 if (auto Err = parseMetadataStrings(Record, Blob, IndexNextMDString))
740 return std::move(Err);
741 break;
742 }
743 case bitc::METADATA_INDEX_OFFSET: {
744 // This is the offset to the index, when we see this we skip all the
745 // records and load only an index to these.
746 if (Error Err = IndexCursor.JumpToBit(CurrentPos))
13
Calling 'Error::operator bool'
15
Returning from 'Error::operator bool'
16
Taking false branch
747 return std::move(Err);
748 Record.clear();
749 if (Expected<unsigned> MaybeRecord =
17
Calling 'Expected::operator bool'
20
Returning from 'Expected::operator bool'
21
Taking true branch
750 IndexCursor.readRecord(Entry.ID, Record))
751 ;
752 else
753 return MaybeRecord.takeError();
754 if (Record.size() != 2)
22
Assuming the condition is false
23
Taking false branch
755 return error("Invalid record");
756 auto Offset = Record[0] + (Record[1] << 32);
757 auto BeginPos = IndexCursor.GetCurrentBitNo();
758 if (Error Err = IndexCursor.JumpToBit(BeginPos + Offset))
24
Calling 'Error::operator bool'
26
Returning from 'Error::operator bool'
27
Taking false branch
759 return std::move(Err);
760 Expected<BitstreamEntry> MaybeEntry =
761 IndexCursor.advanceSkippingSubblocks(
762 BitstreamCursor::AF_DontPopBlockAtEnd);
763 if (!MaybeEntry)
28
Calling 'Expected::operator bool'
30
Returning from 'Expected::operator bool'
31
Taking false branch
764 return MaybeEntry.takeError();
765 Entry = MaybeEntry.get();
32
Uninitialized value stored to 'Entry.ID'
766 assert(Entry.Kind == BitstreamEntry::Record &&(static_cast<void> (0))
767 "Corrupted bitcode: Expected `Record` when trying to find the "(static_cast<void> (0))
768 "Metadata index")(static_cast<void> (0));
769 Record.clear();
770 if (Expected<unsigned> MaybeCode =
771 IndexCursor.readRecord(Entry.ID, Record))
33
1st function call argument is an uninitialized value
772 assert(MaybeCode.get() == bitc::METADATA_INDEX &&(static_cast<void> (0))
773 "Corrupted bitcode: Expected `METADATA_INDEX` when trying to "(static_cast<void> (0))
774 "find the Metadata index")(static_cast<void> (0));
775 else
776 return MaybeCode.takeError();
777 // Delta unpack
778 auto CurrentValue = BeginPos;
779 GlobalMetadataBitPosIndex.reserve(Record.size());
780 for (auto &Elt : Record) {
781 CurrentValue += Elt;
782 GlobalMetadataBitPosIndex.push_back(CurrentValue);
783 }
784 break;
785 }
786 case bitc::METADATA_INDEX:
787 // We don't expect to get there, the Index is loaded when we encounter
788 // the offset.
789 return error("Corrupted Metadata block");
790 case bitc::METADATA_NAME: {
791 // Named metadata need to be materialized now and aren't deferred.
792 if (Error Err = IndexCursor.JumpToBit(CurrentPos))
793 return std::move(Err);
794 Record.clear();
795
796 unsigned Code;
797 if (Expected<unsigned> MaybeCode =
798 IndexCursor.readRecord(Entry.ID, Record)) {
799 Code = MaybeCode.get();
800 assert(Code == bitc::METADATA_NAME)(static_cast<void> (0));
801 } else
802 return MaybeCode.takeError();
803
804 // Read name of the named metadata.
805 SmallString<8> Name(Record.begin(), Record.end());
806 if (Expected<unsigned> MaybeCode = IndexCursor.ReadCode())
807 Code = MaybeCode.get();
808 else
809 return MaybeCode.takeError();
810
811 // Named Metadata comes in two parts, we expect the name to be followed
812 // by the node
813 Record.clear();
814 if (Expected<unsigned> MaybeNextBitCode =
815 IndexCursor.readRecord(Code, Record))
816 assert(MaybeNextBitCode.get() == bitc::METADATA_NAMED_NODE)(static_cast<void> (0));
817 else
818 return MaybeNextBitCode.takeError();
819
820 // Read named metadata elements.
821 unsigned Size = Record.size();
822 NamedMDNode *NMD = TheModule.getOrInsertNamedMetadata(Name);
823 for (unsigned i = 0; i != Size; ++i) {
824 // FIXME: We could use a placeholder here, however NamedMDNode are
825 // taking MDNode as operand and not using the Metadata infrastructure.
826 // It is acknowledged by 'TODO: Inherit from Metadata' in the
827 // NamedMDNode class definition.
828 MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[i]);
829 assert(MD && "Invalid metadata: expect fwd ref to MDNode")(static_cast<void> (0));
830 NMD->addOperand(MD);
831 }
832 break;
833 }
834 case bitc::METADATA_GLOBAL_DECL_ATTACHMENT: {
835 if (!GlobalDeclAttachmentPos)
836 GlobalDeclAttachmentPos = SavedPos;
837#ifndef NDEBUG1
838 NumGlobalDeclAttachSkipped++;
839#endif
840 break;
841 }
842 case bitc::METADATA_KIND:
843 case bitc::METADATA_STRING_OLD:
844 case bitc::METADATA_OLD_FN_NODE:
845 case bitc::METADATA_OLD_NODE:
846 case bitc::METADATA_VALUE:
847 case bitc::METADATA_DISTINCT_NODE:
848 case bitc::METADATA_NODE:
849 case bitc::METADATA_LOCATION:
850 case bitc::METADATA_GENERIC_DEBUG:
851 case bitc::METADATA_SUBRANGE:
852 case bitc::METADATA_ENUMERATOR:
853 case bitc::METADATA_BASIC_TYPE:
854 case bitc::METADATA_STRING_TYPE:
855 case bitc::METADATA_DERIVED_TYPE:
856 case bitc::METADATA_COMPOSITE_TYPE:
857 case bitc::METADATA_SUBROUTINE_TYPE:
858 case bitc::METADATA_MODULE:
859 case bitc::METADATA_FILE:
860 case bitc::METADATA_COMPILE_UNIT:
861 case bitc::METADATA_SUBPROGRAM:
862 case bitc::METADATA_LEXICAL_BLOCK:
863 case bitc::METADATA_LEXICAL_BLOCK_FILE:
864 case bitc::METADATA_NAMESPACE:
865 case bitc::METADATA_COMMON_BLOCK:
866 case bitc::METADATA_MACRO:
867 case bitc::METADATA_MACRO_FILE:
868 case bitc::METADATA_TEMPLATE_TYPE:
869 case bitc::METADATA_TEMPLATE_VALUE:
870 case bitc::METADATA_GLOBAL_VAR:
871 case bitc::METADATA_LOCAL_VAR:
872 case bitc::METADATA_LABEL:
873 case bitc::METADATA_EXPRESSION:
874 case bitc::METADATA_OBJC_PROPERTY:
875 case bitc::METADATA_IMPORTED_ENTITY:
876 case bitc::METADATA_GLOBAL_VAR_EXPR:
877 case bitc::METADATA_GENERIC_SUBRANGE:
878 // We don't expect to see any of these, if we see one, give up on
879 // lazy-loading and fallback.
880 MDStringRef.clear();
881 GlobalMetadataBitPosIndex.clear();
882 return false;
883 }
884 break;
885 }
886 }
887 }
888}
889
890// Load the global decl attachments after building the lazy loading index.
891// We don't load them "lazily" - all global decl attachments must be
892// parsed since they aren't materialized on demand. However, by delaying
893// their parsing until after the index is created, we can use the index
894// instead of creating temporaries.
895Expected<bool> MetadataLoader::MetadataLoaderImpl::loadGlobalDeclAttachments() {
896 // Nothing to do if we didn't find any of these metadata records.
897 if (!GlobalDeclAttachmentPos)
898 return true;
899 // Use a temporary cursor so that we don't mess up the main Stream cursor or
900 // the lazy loading IndexCursor (which holds the necessary abbrev ids).
901 BitstreamCursor TempCursor = Stream;
902 SmallVector<uint64_t, 64> Record;
903 // Jump to the position before the first global decl attachment, so we can
904 // scan for the first BitstreamEntry record.
905 if (Error Err = TempCursor.JumpToBit(GlobalDeclAttachmentPos))
906 return std::move(Err);
907 while (true) {
908 Expected<BitstreamEntry> MaybeEntry = TempCursor.advanceSkippingSubblocks(
909 BitstreamCursor::AF_DontPopBlockAtEnd);
910 if (!MaybeEntry)
911 return MaybeEntry.takeError();
912 BitstreamEntry Entry = MaybeEntry.get();
913
914 switch (Entry.Kind) {
915 case BitstreamEntry::SubBlock: // Handled for us already.
916 case BitstreamEntry::Error:
917 return error("Malformed block");
918 case BitstreamEntry::EndBlock:
919 // Sanity check that we parsed them all.
920 assert(NumGlobalDeclAttachSkipped == NumGlobalDeclAttachParsed)(static_cast<void> (0));
921 return true;
922 case BitstreamEntry::Record:
923 break;
924 }
925 uint64_t CurrentPos = TempCursor.GetCurrentBitNo();
926 Expected<unsigned> MaybeCode = TempCursor.skipRecord(Entry.ID);
927 if (!MaybeCode)
928 return MaybeCode.takeError();
929 if (MaybeCode.get() != bitc::METADATA_GLOBAL_DECL_ATTACHMENT) {
930 // Anything other than a global decl attachment signals the end of
931 // these records. sanity check that we parsed them all.
932 assert(NumGlobalDeclAttachSkipped == NumGlobalDeclAttachParsed)(static_cast<void> (0));
933 return true;
934 }
935#ifndef NDEBUG1
936 NumGlobalDeclAttachParsed++;
937#endif
938 // FIXME: we need to do this early because we don't materialize global
939 // value explicitly.
940 if (Error Err = TempCursor.JumpToBit(CurrentPos))
941 return std::move(Err);
942 Record.clear();
943 if (Expected<unsigned> MaybeRecord =
944 TempCursor.readRecord(Entry.ID, Record))
945 ;
946 else
947 return MaybeRecord.takeError();
948 if (Record.size() % 2 == 0)
949 return error("Invalid record");
950 unsigned ValueID = Record[0];
951 if (ValueID >= ValueList.size())
952 return error("Invalid record");
953 if (auto *GO = dyn_cast<GlobalObject>(ValueList[ValueID])) {
954 // Need to save and restore the current position since
955 // parseGlobalObjectAttachment will resolve all forward references which
956 // would require parsing from locations stored in the index.
957 CurrentPos = TempCursor.GetCurrentBitNo();
958 if (Error Err = parseGlobalObjectAttachment(
959 *GO, ArrayRef<uint64_t>(Record).slice(1)))
960 return std::move(Err);
961 if (Error Err = TempCursor.JumpToBit(CurrentPos))
962 return std::move(Err);
963 }
964 }
965}
966
967/// Parse a METADATA_BLOCK. If ModuleLevel is true then we are parsing
968/// module level metadata.
969Error MetadataLoader::MetadataLoaderImpl::parseMetadata(bool ModuleLevel) {
970 if (!ModuleLevel && MetadataList.hasFwdRefs())
971 return error("Invalid metadata: fwd refs into function blocks");
972
973 // Record the entry position so that we can jump back here and efficiently
974 // skip the whole block in case we lazy-load.
975 auto EntryPos = Stream.GetCurrentBitNo();
976
977 if (Error Err = Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
978 return Err;
979
980 SmallVector<uint64_t, 64> Record;
981 PlaceholderQueue Placeholders;
982
983 // We lazy-load module-level metadata: we build an index for each record, and
984 // then load individual record as needed, starting with the named metadata.
985 if (ModuleLevel && IsImporting && MetadataList.empty() &&
986 !DisableLazyLoading) {
987 auto SuccessOrErr = lazyLoadModuleMetadataBlock();
988 if (!SuccessOrErr)
989 return SuccessOrErr.takeError();
990 if (SuccessOrErr.get()) {
991 // An index was successfully created and we will be able to load metadata
992 // on-demand.
993 MetadataList.resize(MDStringRef.size() +
994 GlobalMetadataBitPosIndex.size());
995
996 // Now that we have built the index, load the global decl attachments
997 // that were deferred during that process. This avoids creating
998 // temporaries.
999 SuccessOrErr = loadGlobalDeclAttachments();
1000 if (!SuccessOrErr)
1001 return SuccessOrErr.takeError();
1002 assert(SuccessOrErr.get())(static_cast<void> (0));
1003
1004 // Reading the named metadata created forward references and/or
1005 // placeholders, that we flush here.
1006 resolveForwardRefsAndPlaceholders(Placeholders);
1007 upgradeDebugInfo();
1008 // Return at the beginning of the block, since it is easy to skip it
1009 // entirely from there.
1010 Stream.ReadBlockEnd(); // Pop the abbrev block context.
1011 if (Error Err = IndexCursor.JumpToBit(EntryPos))
1012 return Err;
1013 if (Error Err = Stream.SkipBlock()) {
1014 // FIXME this drops the error on the floor, which
1015 // ThinLTO/X86/debuginfo-cu-import.ll relies on.
1016 consumeError(std::move(Err));
1017 return Error::success();
1018 }
1019 return Error::success();
1020 }
1021 // Couldn't load an index, fallback to loading all the block "old-style".
1022 }
1023
1024 unsigned NextMetadataNo = MetadataList.size();
1025
1026 // Read all the records.
1027 while (true) {
1028 Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
1029 if (!MaybeEntry)
1030 return MaybeEntry.takeError();
1031 BitstreamEntry Entry = MaybeEntry.get();
1032
1033 switch (Entry.Kind) {
1034 case BitstreamEntry::SubBlock: // Handled for us already.
1035 case BitstreamEntry::Error:
1036 return error("Malformed block");
1037 case BitstreamEntry::EndBlock:
1038 resolveForwardRefsAndPlaceholders(Placeholders);
1039 upgradeDebugInfo();
1040 return Error::success();
1041 case BitstreamEntry::Record:
1042 // The interesting case.
1043 break;
1044 }
1045
1046 // Read a record.
1047 Record.clear();
1048 StringRef Blob;
1049 ++NumMDRecordLoaded;
1050 if (Expected<unsigned> MaybeCode =
1051 Stream.readRecord(Entry.ID, Record, &Blob)) {
1052 if (Error Err = parseOneMetadata(Record, MaybeCode.get(), Placeholders,
1053 Blob, NextMetadataNo))
1054 return Err;
1055 } else
1056 return MaybeCode.takeError();
1057 }
1058}
1059
1060MDString *MetadataLoader::MetadataLoaderImpl::lazyLoadOneMDString(unsigned ID) {
1061 ++NumMDStringLoaded;
1062 if (Metadata *MD = MetadataList.lookup(ID))
1063 return cast<MDString>(MD);
1064 auto MDS = MDString::get(Context, MDStringRef[ID]);
1065 MetadataList.assignValue(MDS, ID);
1066 return MDS;
1067}
1068
1069void MetadataLoader::MetadataLoaderImpl::lazyLoadOneMetadata(
1070 unsigned ID, PlaceholderQueue &Placeholders) {
1071 assert(ID < (MDStringRef.size()) + GlobalMetadataBitPosIndex.size())(static_cast<void> (0));
1072 assert(ID >= MDStringRef.size() && "Unexpected lazy-loading of MDString")(static_cast<void> (0));
1073 // Lookup first if the metadata hasn't already been loaded.
1074 if (auto *MD = MetadataList.lookup(ID)) {
1075 auto *N = cast<MDNode>(MD);
1076 if (!N->isTemporary())
1077 return;
1078 }
1079 SmallVector<uint64_t, 64> Record;
1080 StringRef Blob;
1081 if (Error Err = IndexCursor.JumpToBit(
1082 GlobalMetadataBitPosIndex[ID - MDStringRef.size()]))
1083 report_fatal_error("lazyLoadOneMetadata failed jumping: " +
1084 toString(std::move(Err)));
1085 Expected<BitstreamEntry> MaybeEntry = IndexCursor.advanceSkippingSubblocks();
1086 if (!MaybeEntry)
1087 // FIXME this drops the error on the floor.
1088 report_fatal_error("lazyLoadOneMetadata failed advanceSkippingSubblocks: " +
1089 toString(MaybeEntry.takeError()));
1090 BitstreamEntry Entry = MaybeEntry.get();
1091 ++NumMDRecordLoaded;
1092 if (Expected<unsigned> MaybeCode =
1093 IndexCursor.readRecord(Entry.ID, Record, &Blob)) {
1094 if (Error Err =
1095 parseOneMetadata(Record, MaybeCode.get(), Placeholders, Blob, ID))
1096 report_fatal_error("Can't lazyload MD, parseOneMetadata: " +
1097 toString(std::move(Err)));
1098 } else
1099 report_fatal_error("Can't lazyload MD: " + toString(MaybeCode.takeError()));
1100}
1101
1102/// Ensure that all forward-references and placeholders are resolved.
1103/// Iteratively lazy-loading metadata on-demand if needed.
1104void MetadataLoader::MetadataLoaderImpl::resolveForwardRefsAndPlaceholders(
1105 PlaceholderQueue &Placeholders) {
1106 DenseSet<unsigned> Temporaries;
1107 while (1) {
1108 // Populate Temporaries with the placeholders that haven't been loaded yet.
1109 Placeholders.getTemporaries(MetadataList, Temporaries);
1110
1111 // If we don't have any temporary, or FwdReference, we're done!
1112 if (Temporaries.empty() && !MetadataList.hasFwdRefs())
1113 break;
1114
1115 // First, load all the temporaries. This can add new placeholders or
1116 // forward references.
1117 for (auto ID : Temporaries)
1118 lazyLoadOneMetadata(ID, Placeholders);
1119 Temporaries.clear();
1120
1121 // Second, load the forward-references. This can also add new placeholders
1122 // or forward references.
1123 while (MetadataList.hasFwdRefs())
1124 lazyLoadOneMetadata(MetadataList.getNextFwdRef(), Placeholders);
1125 }
1126 // At this point we don't have any forward reference remaining, or temporary
1127 // that haven't been loaded. We can safely drop RAUW support and mark cycles
1128 // as resolved.
1129 MetadataList.tryToResolveCycles();
1130
1131 // Finally, everything is in place, we can replace the placeholders operands
1132 // with the final node they refer to.
1133 Placeholders.flush(MetadataList);
1134}
1135
1136Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
1137 SmallVectorImpl<uint64_t> &Record, unsigned Code,
1138 PlaceholderQueue &Placeholders, StringRef Blob, unsigned &NextMetadataNo) {
1139
1140 bool IsDistinct = false;
1141 auto getMD = [&](unsigned ID) -> Metadata * {
1142 if (ID < MDStringRef.size())
1143 return lazyLoadOneMDString(ID);
1144 if (!IsDistinct) {
1145 if (auto *MD = MetadataList.lookup(ID))
1146 return MD;
1147 // If lazy-loading is enabled, we try recursively to load the operand
1148 // instead of creating a temporary.
1149 if (ID < (MDStringRef.size() + GlobalMetadataBitPosIndex.size())) {
1150 // Create a temporary for the node that is referencing the operand we
1151 // will lazy-load. It is needed before recursing in case there are
1152 // uniquing cycles.
1153 MetadataList.getMetadataFwdRef(NextMetadataNo);
1154 lazyLoadOneMetadata(ID, Placeholders);
1155 return MetadataList.lookup(ID);
1156 }
1157 // Return a temporary.
1158 return MetadataList.getMetadataFwdRef(ID);
1159 }
1160 if (auto *MD = MetadataList.getMetadataIfResolved(ID))
1161 return MD;
1162 return &Placeholders.getPlaceholderOp(ID);
1163 };
1164 auto getMDOrNull = [&](unsigned ID) -> Metadata * {
1165 if (ID)
1166 return getMD(ID - 1);
1167 return nullptr;
1168 };
1169 auto getMDOrNullWithoutPlaceholders = [&](unsigned ID) -> Metadata * {
1170 if (ID)
1171 return MetadataList.getMetadataFwdRef(ID - 1);
1172 return nullptr;
1173 };
1174 auto getMDString = [&](unsigned ID) -> MDString * {
1175 // This requires that the ID is not really a forward reference. In
1176 // particular, the MDString must already have been resolved.
1177 auto MDS = getMDOrNull(ID);
1178 return cast_or_null<MDString>(MDS);
1179 };
1180
1181 // Support for old type refs.
1182 auto getDITypeRefOrNull = [&](unsigned ID) {
1183 return MetadataList.upgradeTypeRef(getMDOrNull(ID));
1184 };
1185
1186#define GET_OR_DISTINCT(CLASS, ARGS) \
1187 (IsDistinct ? CLASS::getDistinct ARGS : CLASS::get ARGS)
1188
1189 switch (Code) {
1190 default: // Default behavior: ignore.
1191 break;
1192 case bitc::METADATA_NAME: {
1193 // Read name of the named metadata.
1194 SmallString<8> Name(Record.begin(), Record.end());
1195 Record.clear();
1196 Expected<unsigned> MaybeCode = Stream.ReadCode();
1197 if (!MaybeCode)
1198 return MaybeCode.takeError();
1199 Code = MaybeCode.get();
1200
1201 ++NumMDRecordLoaded;
1202 if (Expected<unsigned> MaybeNextBitCode = Stream.readRecord(Code, Record)) {
1203 if (MaybeNextBitCode.get() != bitc::METADATA_NAMED_NODE)
1204 return error("METADATA_NAME not followed by METADATA_NAMED_NODE");
1205 } else
1206 return MaybeNextBitCode.takeError();
1207
1208 // Read named metadata elements.
1209 unsigned Size = Record.size();
1210 NamedMDNode *NMD = TheModule.getOrInsertNamedMetadata(Name);
1211 for (unsigned i = 0; i != Size; ++i) {
1212 MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[i]);
1213 if (!MD)
1214 return error("Invalid named metadata: expect fwd ref to MDNode");
1215 NMD->addOperand(MD);
1216 }
1217 break;
1218 }
1219 case bitc::METADATA_OLD_FN_NODE: {
1220 // Deprecated, but still needed to read old bitcode files.
1221 // This is a LocalAsMetadata record, the only type of function-local
1222 // metadata.
1223 if (Record.size() % 2 == 1)
1224 return error("Invalid record");
1225
1226 // If this isn't a LocalAsMetadata record, we're dropping it. This used
1227 // to be legal, but there's no upgrade path.
1228 auto dropRecord = [&] {
1229 MetadataList.assignValue(MDNode::get(Context, None), NextMetadataNo);
1230 NextMetadataNo++;
1231 };
1232 if (Record.size() != 2) {
1233 dropRecord();
1234 break;
1235 }
1236
1237 Type *Ty = getTypeByID(Record[0]);
1238 if (Ty->isMetadataTy() || Ty->isVoidTy()) {
1239 dropRecord();
1240 break;
1241 }
1242
1243 MetadataList.assignValue(
1244 LocalAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty)),
1245 NextMetadataNo);
1246 NextMetadataNo++;
1247 break;
1248 }
1249 case bitc::METADATA_OLD_NODE: {
1250 // Deprecated, but still needed to read old bitcode files.
1251 if (Record.size() % 2 == 1)
1252 return error("Invalid record");
1253
1254 unsigned Size = Record.size();
1255 SmallVector<Metadata *, 8> Elts;
1256 for (unsigned i = 0; i != Size; i += 2) {
1257 Type *Ty = getTypeByID(Record[i]);
1258 if (!Ty)
1259 return error("Invalid record");
1260 if (Ty->isMetadataTy())
1261 Elts.push_back(getMD(Record[i + 1]));
1262 else if (!Ty->isVoidTy()) {
1263 auto *MD =
1264 ValueAsMetadata::get(ValueList.getValueFwdRef(Record[i + 1], Ty));
1265 assert(isa<ConstantAsMetadata>(MD) &&(static_cast<void> (0))
1266 "Expected non-function-local metadata")(static_cast<void> (0));
1267 Elts.push_back(MD);
1268 } else
1269 Elts.push_back(nullptr);
1270 }
1271 MetadataList.assignValue(MDNode::get(Context, Elts), NextMetadataNo);
1272 NextMetadataNo++;
1273 break;
1274 }
1275 case bitc::METADATA_VALUE: {
1276 if (Record.size() != 2)
1277 return error("Invalid record");
1278
1279 Type *Ty = getTypeByID(Record[0]);
1280 if (Ty->isMetadataTy() || Ty->isVoidTy())
1281 return error("Invalid record");
1282
1283 MetadataList.assignValue(
1284 ValueAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty)),
1285 NextMetadataNo);
1286 NextMetadataNo++;
1287 break;
1288 }
1289 case bitc::METADATA_DISTINCT_NODE:
1290 IsDistinct = true;
1291 LLVM_FALLTHROUGH[[gnu::fallthrough]];
1292 case bitc::METADATA_NODE: {
1293 SmallVector<Metadata *, 8> Elts;
1294 Elts.reserve(Record.size());
1295 for (unsigned ID : Record)
1296 Elts.push_back(getMDOrNull(ID));
1297 MetadataList.assignValue(IsDistinct ? MDNode::getDistinct(Context, Elts)
1298 : MDNode::get(Context, Elts),
1299 NextMetadataNo);
1300 NextMetadataNo++;
1301 break;
1302 }
1303 case bitc::METADATA_LOCATION: {
1304 if (Record.size() != 5 && Record.size() != 6)
1305 return error("Invalid record");
1306
1307 IsDistinct = Record[0];
1308 unsigned Line = Record[1];
1309 unsigned Column = Record[2];
1310 Metadata *Scope = getMD(Record[3]);
1311 Metadata *InlinedAt = getMDOrNull(Record[4]);
1312 bool ImplicitCode = Record.size() == 6 && Record[5];
1313 MetadataList.assignValue(
1314 GET_OR_DISTINCT(DILocation, (Context, Line, Column, Scope, InlinedAt,
1315 ImplicitCode)),
1316 NextMetadataNo);
1317 NextMetadataNo++;
1318 break;
1319 }
1320 case bitc::METADATA_GENERIC_DEBUG: {
1321 if (Record.size() < 4)
1322 return error("Invalid record");
1323
1324 IsDistinct = Record[0];
1325 unsigned Tag = Record[1];
1326 unsigned Version = Record[2];
1327
1328 if (Tag >= 1u << 16 || Version != 0)
1329 return error("Invalid record");
1330
1331 auto *Header = getMDString(Record[3]);
1332 SmallVector<Metadata *, 8> DwarfOps;
1333 for (unsigned I = 4, E = Record.size(); I != E; ++I)
1334 DwarfOps.push_back(getMDOrNull(Record[I]));
1335 MetadataList.assignValue(
1336 GET_OR_DISTINCT(GenericDINode, (Context, Tag, Header, DwarfOps)),
1337 NextMetadataNo);
1338 NextMetadataNo++;
1339 break;
1340 }
1341 case bitc::METADATA_SUBRANGE: {
1342 Metadata *Val = nullptr;
1343 // Operand 'count' is interpreted as:
1344 // - Signed integer (version 0)
1345 // - Metadata node (version 1)
1346 // Operand 'lowerBound' is interpreted as:
1347 // - Signed integer (version 0 and 1)
1348 // - Metadata node (version 2)
1349 // Operands 'upperBound' and 'stride' are interpreted as:
1350 // - Metadata node (version 2)
1351 switch (Record[0] >> 1) {
1352 case 0:
1353 Val = GET_OR_DISTINCT(DISubrange,
1354 (Context, Record[1], unrotateSign(Record[2])));
1355 break;
1356 case 1:
1357 Val = GET_OR_DISTINCT(DISubrange, (Context, getMDOrNull(Record[1]),
1358 unrotateSign(Record[2])));
1359 break;
1360 case 2:
1361 Val = GET_OR_DISTINCT(
1362 DISubrange, (Context, getMDOrNull(Record[1]), getMDOrNull(Record[2]),
1363 getMDOrNull(Record[3]), getMDOrNull(Record[4])));
1364 break;
1365 default:
1366 return error("Invalid record: Unsupported version of DISubrange");
1367 }
1368
1369 MetadataList.assignValue(Val, NextMetadataNo);
1370 IsDistinct = Record[0] & 1;
1371 NextMetadataNo++;
1372 break;
1373 }
1374 case bitc::METADATA_GENERIC_SUBRANGE: {
1375 Metadata *Val = nullptr;
1376 Val = GET_OR_DISTINCT(DIGenericSubrange,
1377 (Context, getMDOrNull(Record[1]),
1378 getMDOrNull(Record[2]), getMDOrNull(Record[3]),
1379 getMDOrNull(Record[4])));
1380
1381 MetadataList.assignValue(Val, NextMetadataNo);
1382 IsDistinct = Record[0] & 1;
1383 NextMetadataNo++;
1384 break;
1385 }
1386 case bitc::METADATA_ENUMERATOR: {
1387 if (Record.size() < 3)
1388 return error("Invalid record");
1389
1390 IsDistinct = Record[0] & 1;
1391 bool IsUnsigned = Record[0] & 2;
1392 bool IsBigInt = Record[0] & 4;
1393 APInt Value;
1394
1395 if (IsBigInt) {
1396 const uint64_t BitWidth = Record[1];
1397 const size_t NumWords = Record.size() - 3;
1398 Value = readWideAPInt(makeArrayRef(&Record[3], NumWords), BitWidth);
1399 } else
1400 Value = APInt(64, unrotateSign(Record[1]), !IsUnsigned);
1401
1402 MetadataList.assignValue(
1403 GET_OR_DISTINCT(DIEnumerator,
1404 (Context, Value, IsUnsigned, getMDString(Record[2]))),
1405 NextMetadataNo);
1406 NextMetadataNo++;
1407 break;
1408 }
1409 case bitc::METADATA_BASIC_TYPE: {
1410 if (Record.size() < 6 || Record.size() > 7)
1411 return error("Invalid record");
1412
1413 IsDistinct = Record[0];
1414 DINode::DIFlags Flags = (Record.size() > 6) ?
1415 static_cast<DINode::DIFlags>(Record[6]) : DINode::FlagZero;
1416
1417 MetadataList.assignValue(
1418 GET_OR_DISTINCT(DIBasicType,
1419 (Context, Record[1], getMDString(Record[2]), Record[3],
1420 Record[4], Record[5], Flags)),
1421 NextMetadataNo);
1422 NextMetadataNo++;
1423 break;
1424 }
1425 case bitc::METADATA_STRING_TYPE: {
1426 if (Record.size() != 8)
1427 return error("Invalid record");
1428
1429 IsDistinct = Record[0];
1430 MetadataList.assignValue(
1431 GET_OR_DISTINCT(DIStringType,
1432 (Context, Record[1], getMDString(Record[2]),
1433 getMDOrNull(Record[3]), getMDOrNull(Record[4]),
1434 Record[5], Record[6], Record[7])),
1435 NextMetadataNo);
1436 NextMetadataNo++;
1437 break;
1438 }
1439 case bitc::METADATA_DERIVED_TYPE: {
1440 if (Record.size() < 12 || Record.size() > 14)
1441 return error("Invalid record");
1442
1443 // DWARF address space is encoded as N->getDWARFAddressSpace() + 1. 0 means
1444 // that there is no DWARF address space associated with DIDerivedType.
1445 Optional<unsigned> DWARFAddressSpace;
1446 if (Record.size() > 12 && Record[12])
1447 DWARFAddressSpace = Record[12] - 1;
1448
1449 Metadata *Annotations = nullptr;
1450 if (Record.size() > 13 && Record[13])
1451 Annotations = getMDOrNull(Record[13]);
1452
1453 IsDistinct = Record[0];
1454 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[10]);
1455 MetadataList.assignValue(
1456 GET_OR_DISTINCT(DIDerivedType,
1457 (Context, Record[1], getMDString(Record[2]),
1458 getMDOrNull(Record[3]), Record[4],
1459 getDITypeRefOrNull(Record[5]),
1460 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1461 Record[9], DWARFAddressSpace, Flags,
1462 getDITypeRefOrNull(Record[11]), Annotations)),
1463 NextMetadataNo);
1464 NextMetadataNo++;
1465 break;
1466 }
1467 case bitc::METADATA_COMPOSITE_TYPE: {
1468 if (Record.size() < 16 || Record.size() > 22)
1469 return error("Invalid record");
1470
1471 // If we have a UUID and this is not a forward declaration, lookup the
1472 // mapping.
1473 IsDistinct = Record[0] & 0x1;
1474 bool IsNotUsedInTypeRef = Record[0] >= 2;
1475 unsigned Tag = Record[1];
1476 MDString *Name = getMDString(Record[2]);
1477 Metadata *File = getMDOrNull(Record[3]);
1478 unsigned Line = Record[4];
1479 Metadata *Scope = getDITypeRefOrNull(Record[5]);
1480 Metadata *BaseType = nullptr;
1481 uint64_t SizeInBits = Record[7];
1482 if (Record[8] > (uint64_t)std::numeric_limits<uint32_t>::max())
1483 return error("Alignment value is too large");
1484 uint32_t AlignInBits = Record[8];
1485 uint64_t OffsetInBits = 0;
1486 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[10]);
1487 Metadata *Elements = nullptr;
1488 unsigned RuntimeLang = Record[12];
1489 Metadata *VTableHolder = nullptr;
1490 Metadata *TemplateParams = nullptr;
1491 Metadata *Discriminator = nullptr;
1492 Metadata *DataLocation = nullptr;
1493 Metadata *Associated = nullptr;
1494 Metadata *Allocated = nullptr;
1495 Metadata *Rank = nullptr;
1496 Metadata *Annotations = nullptr;
1497 auto *Identifier = getMDString(Record[15]);
1498 // If this module is being parsed so that it can be ThinLTO imported
1499 // into another module, composite types only need to be imported
1500 // as type declarations (unless full type definitions requested).
1501 // Create type declarations up front to save memory. Also, buildODRType
1502 // handles the case where this is type ODRed with a definition needed
1503 // by the importing module, in which case the existing definition is
1504 // used.
1505 if (IsImporting && !ImportFullTypeDefinitions && Identifier &&
1506 (Tag == dwarf::DW_TAG_enumeration_type ||
1507 Tag == dwarf::DW_TAG_class_type ||
1508 Tag == dwarf::DW_TAG_structure_type ||
1509 Tag == dwarf::DW_TAG_union_type)) {
1510 Flags = Flags | DINode::FlagFwdDecl;
1511 } else {
1512 BaseType = getDITypeRefOrNull(Record[6]);
1513 OffsetInBits = Record[9];
1514 Elements = getMDOrNull(Record[11]);
1515 VTableHolder = getDITypeRefOrNull(Record[13]);
1516 TemplateParams = getMDOrNull(Record[14]);
1517 if (Record.size() > 16)
1518 Discriminator = getMDOrNull(Record[16]);
1519 if (Record.size() > 17)
1520 DataLocation = getMDOrNull(Record[17]);
1521 if (Record.size() > 19) {
1522 Associated = getMDOrNull(Record[18]);
1523 Allocated = getMDOrNull(Record[19]);
1524 }
1525 if (Record.size() > 20) {
1526 Rank = getMDOrNull(Record[20]);
1527 }
1528 if (Record.size() > 21) {
1529 Annotations = getMDOrNull(Record[21]);
1530 }
1531 }
1532 DICompositeType *CT = nullptr;
1533 if (Identifier)
1534 CT = DICompositeType::buildODRType(
1535 Context, *Identifier, Tag, Name, File, Line, Scope, BaseType,
1536 SizeInBits, AlignInBits, OffsetInBits, Flags, Elements, RuntimeLang,
1537 VTableHolder, TemplateParams, Discriminator, DataLocation, Associated,
1538 Allocated, Rank, Annotations);
1539
1540 // Create a node if we didn't get a lazy ODR type.
1541 if (!CT)
1542 CT = GET_OR_DISTINCT(DICompositeType,
1543 (Context, Tag, Name, File, Line, Scope, BaseType,
1544 SizeInBits, AlignInBits, OffsetInBits, Flags,
1545 Elements, RuntimeLang, VTableHolder, TemplateParams,
1546 Identifier, Discriminator, DataLocation, Associated,
1547 Allocated, Rank, Annotations));
1548 if (!IsNotUsedInTypeRef && Identifier)
1549 MetadataList.addTypeRef(*Identifier, *cast<DICompositeType>(CT));
1550
1551 MetadataList.assignValue(CT, NextMetadataNo);
1552 NextMetadataNo++;
1553 break;
1554 }
1555 case bitc::METADATA_SUBROUTINE_TYPE: {
1556 if (Record.size() < 3 || Record.size() > 4)
1557 return error("Invalid record");
1558 bool IsOldTypeRefArray = Record[0] < 2;
1559 unsigned CC = (Record.size() > 3) ? Record[3] : 0;
1560
1561 IsDistinct = Record[0] & 0x1;
1562 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[1]);
1563 Metadata *Types = getMDOrNull(Record[2]);
1564 if (LLVM_UNLIKELY(IsOldTypeRefArray)__builtin_expect((bool)(IsOldTypeRefArray), false))
1565 Types = MetadataList.upgradeTypeRefArray(Types);
1566
1567 MetadataList.assignValue(
1568 GET_OR_DISTINCT(DISubroutineType, (Context, Flags, CC, Types)),
1569 NextMetadataNo);
1570 NextMetadataNo++;
1571 break;
1572 }
1573
1574 case bitc::METADATA_MODULE: {
1575 if (Record.size() < 5 || Record.size() > 9)
1576 return error("Invalid record");
1577
1578 unsigned Offset = Record.size() >= 8 ? 2 : 1;
1579 IsDistinct = Record[0];
1580 MetadataList.assignValue(
1581 GET_OR_DISTINCT(
1582 DIModule,
1583 (Context, Record.size() >= 8 ? getMDOrNull(Record[1]) : nullptr,
1584 getMDOrNull(Record[0 + Offset]), getMDString(Record[1 + Offset]),
1585 getMDString(Record[2 + Offset]), getMDString(Record[3 + Offset]),
1586 getMDString(Record[4 + Offset]),
1587 Record.size() <= 7 ? 0 : Record[7],
1588 Record.size() <= 8 ? false : Record[8])),
1589 NextMetadataNo);
1590 NextMetadataNo++;
1591 break;
1592 }
1593
1594 case bitc::METADATA_FILE: {
1595 if (Record.size() != 3 && Record.size() != 5 && Record.size() != 6)
1596 return error("Invalid record");
1597
1598 IsDistinct = Record[0];
1599 Optional<DIFile::ChecksumInfo<MDString *>> Checksum;
1600 // The BitcodeWriter writes null bytes into Record[3:4] when the Checksum
1601 // is not present. This matches up with the old internal representation,
1602 // and the old encoding for CSK_None in the ChecksumKind. The new
1603 // representation reserves the value 0 in the ChecksumKind to continue to
1604 // encode None in a backwards-compatible way.
1605 if (Record.size() > 4 && Record[3] && Record[4])
1606 Checksum.emplace(static_cast<DIFile::ChecksumKind>(Record[3]),
1607 getMDString(Record[4]));
1608 MetadataList.assignValue(
1609 GET_OR_DISTINCT(
1610 DIFile,
1611 (Context, getMDString(Record[1]), getMDString(Record[2]), Checksum,
1612 Record.size() > 5 ? Optional<MDString *>(getMDString(Record[5]))
1613 : None)),
1614 NextMetadataNo);
1615 NextMetadataNo++;
1616 break;
1617 }
1618 case bitc::METADATA_COMPILE_UNIT: {
1619 if (Record.size() < 14 || Record.size() > 22)
1620 return error("Invalid record");
1621
1622 // Ignore Record[0], which indicates whether this compile unit is
1623 // distinct. It's always distinct.
1624 IsDistinct = true;
1625 auto *CU = DICompileUnit::getDistinct(
1626 Context, Record[1], getMDOrNull(Record[2]), getMDString(Record[3]),
1627 Record[4], getMDString(Record[5]), Record[6], getMDString(Record[7]),
1628 Record[8], getMDOrNull(Record[9]), getMDOrNull(Record[10]),
1629 getMDOrNull(Record[12]), getMDOrNull(Record[13]),
1630 Record.size() <= 15 ? nullptr : getMDOrNull(Record[15]),
1631 Record.size() <= 14 ? 0 : Record[14],
1632 Record.size() <= 16 ? true : Record[16],
1633 Record.size() <= 17 ? false : Record[17],
1634 Record.size() <= 18 ? 0 : Record[18],
1635 Record.size() <= 19 ? 0 : Record[19],
1636 Record.size() <= 20 ? nullptr : getMDString(Record[20]),
1637 Record.size() <= 21 ? nullptr : getMDString(Record[21]));
1638
1639 MetadataList.assignValue(CU, NextMetadataNo);
1640 NextMetadataNo++;
1641
1642 // Move the Upgrade the list of subprograms.
1643 if (Metadata *SPs = getMDOrNullWithoutPlaceholders(Record[11]))
1644 CUSubprograms.push_back({CU, SPs});
1645 break;
1646 }
1647 case bitc::METADATA_SUBPROGRAM: {
1648 if (Record.size() < 18 || Record.size() > 21)
1649 return error("Invalid record");
1650
1651 bool HasSPFlags = Record[0] & 4;
1652
1653 DINode::DIFlags Flags;
1654 DISubprogram::DISPFlags SPFlags;
1655 if (!HasSPFlags)
1656 Flags = static_cast<DINode::DIFlags>(Record[11 + 2]);
1657 else {
1658 Flags = static_cast<DINode::DIFlags>(Record[11]);
1659 SPFlags = static_cast<DISubprogram::DISPFlags>(Record[9]);
1660 }
1661
1662 // Support for old metadata when
1663 // subprogram specific flags are placed in DIFlags.
1664 const unsigned DIFlagMainSubprogram = 1 << 21;
1665 bool HasOldMainSubprogramFlag = Flags & DIFlagMainSubprogram;
1666 if (HasOldMainSubprogramFlag)
1667 // Remove old DIFlagMainSubprogram from DIFlags.
1668 // Note: This assumes that any future use of bit 21 defaults to it
1669 // being 0.
1670 Flags &= ~static_cast<DINode::DIFlags>(DIFlagMainSubprogram);
1671
1672 if (HasOldMainSubprogramFlag && HasSPFlags)
1673 SPFlags |= DISubprogram::SPFlagMainSubprogram;
1674 else if (!HasSPFlags)
1675 SPFlags = DISubprogram::toSPFlags(
1676 /*IsLocalToUnit=*/Record[7], /*IsDefinition=*/Record[8],
1677 /*IsOptimized=*/Record[14], /*Virtuality=*/Record[11],
1678 /*DIFlagMainSubprogram*/HasOldMainSubprogramFlag);
1679
1680 // All definitions should be distinct.
1681 IsDistinct = (Record[0] & 1) || (SPFlags & DISubprogram::SPFlagDefinition);
1682 // Version 1 has a Function as Record[15].
1683 // Version 2 has removed Record[15].
1684 // Version 3 has the Unit as Record[15].
1685 // Version 4 added thisAdjustment.
1686 // Version 5 repacked flags into DISPFlags, changing many element numbers.
1687 bool HasUnit = Record[0] & 2;
1688 if (!HasSPFlags && HasUnit && Record.size() < 19)
1689 return error("Invalid record");
1690 if (HasSPFlags && !HasUnit)
1691 return error("Invalid record");
1692 // Accommodate older formats.
1693 bool HasFn = false;
1694 bool HasThisAdj = true;
1695 bool HasThrownTypes = true;
1696 bool HasAnnotations = false;
1697 unsigned OffsetA = 0;
1698 unsigned OffsetB = 0;
1699 if (!HasSPFlags) {
1700 OffsetA = 2;
1701 OffsetB = 2;
1702 if (Record.size() >= 19) {
1703 HasFn = !HasUnit;
1704 OffsetB++;
1705 }
1706 HasThisAdj = Record.size() >= 20;
1707 HasThrownTypes = Record.size() >= 21;
1708 } else {
1709 HasAnnotations = Record.size() >= 19;
1710 }
1711 Metadata *CUorFn = getMDOrNull(Record[12 + OffsetB]);
1712 DISubprogram *SP = GET_OR_DISTINCT(
1713 DISubprogram,
1714 (Context,
1715 getDITypeRefOrNull(Record[1]), // scope
1716 getMDString(Record[2]), // name
1717 getMDString(Record[3]), // linkageName
1718 getMDOrNull(Record[4]), // file
1719 Record[5], // line
1720 getMDOrNull(Record[6]), // type
1721 Record[7 + OffsetA], // scopeLine
1722 getDITypeRefOrNull(Record[8 + OffsetA]), // containingType
1723 Record[10 + OffsetA], // virtualIndex
1724 HasThisAdj ? Record[16 + OffsetB] : 0, // thisAdjustment
1725 Flags, // flags
1726 SPFlags, // SPFlags
1727 HasUnit ? CUorFn : nullptr, // unit
1728 getMDOrNull(Record[13 + OffsetB]), // templateParams
1729 getMDOrNull(Record[14 + OffsetB]), // declaration
1730 getMDOrNull(Record[15 + OffsetB]), // retainedNodes
1731 HasThrownTypes ? getMDOrNull(Record[17 + OffsetB])
1732 : nullptr, // thrownTypes
1733 HasAnnotations ? getMDOrNull(Record[18 + OffsetB])
1734 : nullptr // annotations
1735 ));
1736 MetadataList.assignValue(SP, NextMetadataNo);
1737 NextMetadataNo++;
1738
1739 // Upgrade sp->function mapping to function->sp mapping.
1740 if (HasFn) {
1741 if (auto *CMD = dyn_cast_or_null<ConstantAsMetadata>(CUorFn))
1742 if (auto *F = dyn_cast<Function>(CMD->getValue())) {
1743 if (F->isMaterializable())
1744 // Defer until materialized; unmaterialized functions may not have
1745 // metadata.
1746 FunctionsWithSPs[F] = SP;
1747 else if (!F->empty())
1748 F->setSubprogram(SP);
1749 }
1750 }
1751 break;
1752 }
1753 case bitc::METADATA_LEXICAL_BLOCK: {
1754 if (Record.size() != 5)
1755 return error("Invalid record");
1756
1757 IsDistinct = Record[0];
1758 MetadataList.assignValue(
1759 GET_OR_DISTINCT(DILexicalBlock,
1760 (Context, getMDOrNull(Record[1]),
1761 getMDOrNull(Record[2]), Record[3], Record[4])),
1762 NextMetadataNo);
1763 NextMetadataNo++;
1764 break;
1765 }
1766 case bitc::METADATA_LEXICAL_BLOCK_FILE: {
1767 if (Record.size() != 4)
1768 return error("Invalid record");
1769
1770 IsDistinct = Record[0];
1771 MetadataList.assignValue(
1772 GET_OR_DISTINCT(DILexicalBlockFile,
1773 (Context, getMDOrNull(Record[1]),
1774 getMDOrNull(Record[2]), Record[3])),
1775 NextMetadataNo);
1776 NextMetadataNo++;
1777 break;
1778 }
1779 case bitc::METADATA_COMMON_BLOCK: {
1780 IsDistinct = Record[0] & 1;
1781 MetadataList.assignValue(
1782 GET_OR_DISTINCT(DICommonBlock,
1783 (Context, getMDOrNull(Record[1]),
1784 getMDOrNull(Record[2]), getMDString(Record[3]),
1785 getMDOrNull(Record[4]), Record[5])),
1786 NextMetadataNo);
1787 NextMetadataNo++;
1788 break;
1789 }
1790 case bitc::METADATA_NAMESPACE: {
1791 // Newer versions of DINamespace dropped file and line.
1792 MDString *Name;
1793 if (Record.size() == 3)
1794 Name = getMDString(Record[2]);
1795 else if (Record.size() == 5)
1796 Name = getMDString(Record[3]);
1797 else
1798 return error("Invalid record");
1799
1800 IsDistinct = Record[0] & 1;
1801 bool ExportSymbols = Record[0] & 2;
1802 MetadataList.assignValue(
1803 GET_OR_DISTINCT(DINamespace,
1804 (Context, getMDOrNull(Record[1]), Name, ExportSymbols)),
1805 NextMetadataNo);
1806 NextMetadataNo++;
1807 break;
1808 }
1809 case bitc::METADATA_MACRO: {
1810 if (Record.size() != 5)
1811 return error("Invalid record");
1812
1813 IsDistinct = Record[0];
1814 MetadataList.assignValue(
1815 GET_OR_DISTINCT(DIMacro,
1816 (Context, Record[1], Record[2], getMDString(Record[3]),
1817 getMDString(Record[4]))),
1818 NextMetadataNo);
1819 NextMetadataNo++;
1820 break;
1821 }
1822 case bitc::METADATA_MACRO_FILE: {
1823 if (Record.size() != 5)
1824 return error("Invalid record");
1825
1826 IsDistinct = Record[0];
1827 MetadataList.assignValue(
1828 GET_OR_DISTINCT(DIMacroFile,
1829 (Context, Record[1], Record[2], getMDOrNull(Record[3]),
1830 getMDOrNull(Record[4]))),
1831 NextMetadataNo);
1832 NextMetadataNo++;
1833 break;
1834 }
1835 case bitc::METADATA_TEMPLATE_TYPE: {
1836 if (Record.size() < 3 || Record.size() > 4)
1837 return error("Invalid record");
1838
1839 IsDistinct = Record[0];
1840 MetadataList.assignValue(
1841 GET_OR_DISTINCT(DITemplateTypeParameter,
1842 (Context, getMDString(Record[1]),
1843 getDITypeRefOrNull(Record[2]),
1844 (Record.size() == 4) ? getMDOrNull(Record[3])
1845 : getMDOrNull(false))),
1846 NextMetadataNo);
1847 NextMetadataNo++;
1848 break;
1849 }
1850 case bitc::METADATA_TEMPLATE_VALUE: {
1851 if (Record.size() < 5 || Record.size() > 6)
1852 return error("Invalid record");
1853
1854 IsDistinct = Record[0];
1855
1856 MetadataList.assignValue(
1857 GET_OR_DISTINCT(
1858 DITemplateValueParameter,
1859 (Context, Record[1], getMDString(Record[2]),
1860 getDITypeRefOrNull(Record[3]),
1861 (Record.size() == 6) ? getMDOrNull(Record[4]) : getMDOrNull(false),
1862 (Record.size() == 6) ? getMDOrNull(Record[5])
1863 : getMDOrNull(Record[4]))),
1864 NextMetadataNo);
1865 NextMetadataNo++;
1866 break;
1867 }
1868 case bitc::METADATA_GLOBAL_VAR: {
1869 if (Record.size() < 11 || Record.size() > 13)
1870 return error("Invalid record");
1871
1872 IsDistinct = Record[0] & 1;
1873 unsigned Version = Record[0] >> 1;
1874
1875 if (Version == 2) {
1876 Metadata *Annotations = nullptr;
1877 if (Record.size() > 12)
1878 Annotations = getMDOrNull(Record[12]);
1879
1880 MetadataList.assignValue(
1881 GET_OR_DISTINCT(
1882 DIGlobalVariable,
1883 (Context, getMDOrNull(Record[1]), getMDString(Record[2]),
1884 getMDString(Record[3]), getMDOrNull(Record[4]), Record[5],
1885 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1886 getMDOrNull(Record[9]), getMDOrNull(Record[10]), Record[11],
1887 Annotations)),
1888 NextMetadataNo);
1889
1890 NextMetadataNo++;
1891 } else if (Version == 1) {
1892 // No upgrade necessary. A null field will be introduced to indicate
1893 // that no parameter information is available.
1894 MetadataList.assignValue(
1895 GET_OR_DISTINCT(DIGlobalVariable,
1896 (Context, getMDOrNull(Record[1]),
1897 getMDString(Record[2]), getMDString(Record[3]),
1898 getMDOrNull(Record[4]), Record[5],
1899 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1900 getMDOrNull(Record[10]), nullptr, Record[11],
1901 nullptr)),
1902 NextMetadataNo);
1903
1904 NextMetadataNo++;
1905 } else if (Version == 0) {
1906 // Upgrade old metadata, which stored a global variable reference or a
1907 // ConstantInt here.
1908 NeedUpgradeToDIGlobalVariableExpression = true;
1909 Metadata *Expr = getMDOrNull(Record[9]);
1910 uint32_t AlignInBits = 0;
1911 if (Record.size() > 11) {
1912 if (Record[11] > (uint64_t)std::numeric_limits<uint32_t>::max())
1913 return error("Alignment value is too large");
1914 AlignInBits = Record[11];
1915 }
1916 GlobalVariable *Attach = nullptr;
1917 if (auto *CMD = dyn_cast_or_null<ConstantAsMetadata>(Expr)) {
1918 if (auto *GV = dyn_cast<GlobalVariable>(CMD->getValue())) {
1919 Attach = GV;
1920 Expr = nullptr;
1921 } else if (auto *CI = dyn_cast<ConstantInt>(CMD->getValue())) {
1922 Expr = DIExpression::get(Context,
1923 {dwarf::DW_OP_constu, CI->getZExtValue(),
1924 dwarf::DW_OP_stack_value});
1925 } else {
1926 Expr = nullptr;
1927 }
1928 }
1929 DIGlobalVariable *DGV = GET_OR_DISTINCT(
1930 DIGlobalVariable,
1931 (Context, getMDOrNull(Record[1]), getMDString(Record[2]),
1932 getMDString(Record[3]), getMDOrNull(Record[4]), Record[5],
1933 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1934 getMDOrNull(Record[10]), nullptr, AlignInBits, nullptr));
1935
1936 DIGlobalVariableExpression *DGVE = nullptr;
1937 if (Attach || Expr)
1938 DGVE = DIGlobalVariableExpression::getDistinct(
1939 Context, DGV, Expr ? Expr : DIExpression::get(Context, {}));
1940 if (Attach)
1941 Attach->addDebugInfo(DGVE);
1942
1943 auto *MDNode = Expr ? cast<Metadata>(DGVE) : cast<Metadata>(DGV);
1944 MetadataList.assignValue(MDNode, NextMetadataNo);
1945 NextMetadataNo++;
1946 } else
1947 return error("Invalid record");
1948
1949 break;
1950 }
1951 case bitc::METADATA_LOCAL_VAR: {
1952 // 10th field is for the obseleted 'inlinedAt:' field.
1953 if (Record.size() < 8 || Record.size() > 10)
1954 return error("Invalid record");
1955
1956 IsDistinct = Record[0] & 1;
1957 bool HasAlignment = Record[0] & 2;
1958 // 2nd field used to be an artificial tag, either DW_TAG_auto_variable or
1959 // DW_TAG_arg_variable, if we have alignment flag encoded it means, that
1960 // this is newer version of record which doesn't have artificial tag.
1961 bool HasTag = !HasAlignment && Record.size() > 8;
1962 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[7 + HasTag]);
1963 uint32_t AlignInBits = 0;
1964 Metadata *Annotations = nullptr;
1965 if (HasAlignment) {
1966 if (Record[8] > (uint64_t)std::numeric_limits<uint32_t>::max())
1967 return error("Alignment value is too large");
1968 AlignInBits = Record[8];
1969 if (Record.size() > 9)
1970 Annotations = getMDOrNull(Record[9]);
1971 }
1972
1973 MetadataList.assignValue(
1974 GET_OR_DISTINCT(DILocalVariable,
1975 (Context, getMDOrNull(Record[1 + HasTag]),
1976 getMDString(Record[2 + HasTag]),
1977 getMDOrNull(Record[3 + HasTag]), Record[4 + HasTag],
1978 getDITypeRefOrNull(Record[5 + HasTag]),
1979 Record[6 + HasTag], Flags, AlignInBits,
1980 Annotations)),
1981 NextMetadataNo);
1982 NextMetadataNo++;
1983 break;
1984 }
1985 case bitc::METADATA_LABEL: {
1986 if (Record.size() != 5)
1987 return error("Invalid record");
1988
1989 IsDistinct = Record[0] & 1;
1990 MetadataList.assignValue(
1991 GET_OR_DISTINCT(DILabel,
1992 (Context, getMDOrNull(Record[1]),
1993 getMDString(Record[2]),
1994 getMDOrNull(Record[3]), Record[4])),
1995 NextMetadataNo);
1996 NextMetadataNo++;
1997 break;
1998 }
1999 case bitc::METADATA_EXPRESSION: {
2000 if (Record.size() < 1)
2001 return error("Invalid record");
2002
2003 IsDistinct = Record[0] & 1;
2004 uint64_t Version = Record[0] >> 1;
2005 auto Elts = MutableArrayRef<uint64_t>(Record).slice(1);
2006
2007 SmallVector<uint64_t, 6> Buffer;
2008 if (Error Err = upgradeDIExpression(Version, Elts, Buffer))
2009 return Err;
2010
2011 MetadataList.assignValue(
2012 GET_OR_DISTINCT(DIExpression, (Context, Elts)), NextMetadataNo);
2013 NextMetadataNo++;
2014 break;
2015 }
2016 case bitc::METADATA_GLOBAL_VAR_EXPR: {
2017 if (Record.size() != 3)
2018 return error("Invalid record");
2019
2020 IsDistinct = Record[0];
2021 Metadata *Expr = getMDOrNull(Record[2]);
2022 if (!Expr)
2023 Expr = DIExpression::get(Context, {});
2024 MetadataList.assignValue(
2025 GET_OR_DISTINCT(DIGlobalVariableExpression,
2026 (Context, getMDOrNull(Record[1]), Expr)),
2027 NextMetadataNo);
2028 NextMetadataNo++;
2029 break;
2030 }
2031 case bitc::METADATA_OBJC_PROPERTY: {
2032 if (Record.size() != 8)
2033 return error("Invalid record");
2034
2035 IsDistinct = Record[0];
2036 MetadataList.assignValue(
2037 GET_OR_DISTINCT(DIObjCProperty,
2038 (Context, getMDString(Record[1]),
2039 getMDOrNull(Record[2]), Record[3],
2040 getMDString(Record[4]), getMDString(Record[5]),
2041 Record[6], getDITypeRefOrNull(Record[7]))),
2042 NextMetadataNo);
2043 NextMetadataNo++;
2044 break;
2045 }
2046 case bitc::METADATA_IMPORTED_ENTITY: {
2047 if (Record.size() != 6 && Record.size() != 7)
2048 return error("Invalid record");
2049
2050 IsDistinct = Record[0];
2051 bool HasFile = (Record.size() == 7);
2052 MetadataList.assignValue(
2053 GET_OR_DISTINCT(DIImportedEntity,
2054 (Context, Record[1], getMDOrNull(Record[2]),
2055 getDITypeRefOrNull(Record[3]),
2056 HasFile ? getMDOrNull(Record[6]) : nullptr,
2057 HasFile ? Record[4] : 0, getMDString(Record[5]))),
2058 NextMetadataNo);
2059 NextMetadataNo++;
2060 break;
2061 }
2062 case bitc::METADATA_STRING_OLD: {
2063 std::string String(Record.begin(), Record.end());
2064
2065 // Test for upgrading !llvm.loop.
2066 HasSeenOldLoopTags |= mayBeOldLoopAttachmentTag(String);
2067 ++NumMDStringLoaded;
2068 Metadata *MD = MDString::get(Context, String);
2069 MetadataList.assignValue(MD, NextMetadataNo);
2070 NextMetadataNo++;
2071 break;
2072 }
2073 case bitc::METADATA_STRINGS: {
2074 auto CreateNextMDString = [&](StringRef Str) {
2075 ++NumMDStringLoaded;
2076 MetadataList.assignValue(MDString::get(Context, Str), NextMetadataNo);
2077 NextMetadataNo++;
2078 };
2079 if (Error Err = parseMetadataStrings(Record, Blob, CreateNextMDString))
2080 return Err;
2081 break;
2082 }
2083 case bitc::METADATA_GLOBAL_DECL_ATTACHMENT: {
2084 if (Record.size() % 2 == 0)
2085 return error("Invalid record");
2086 unsigned ValueID = Record[0];
2087 if (ValueID >= ValueList.size())
2088 return error("Invalid record");
2089 if (auto *GO = dyn_cast<GlobalObject>(ValueList[ValueID]))
2090 if (Error Err = parseGlobalObjectAttachment(
2091 *GO, ArrayRef<uint64_t>(Record).slice(1)))
2092 return Err;
2093 break;
2094 }
2095 case bitc::METADATA_KIND: {
2096 // Support older bitcode files that had METADATA_KIND records in a
2097 // block with METADATA_BLOCK_ID.
2098 if (Error Err = parseMetadataKindRecord(Record))
2099 return Err;
2100 break;
2101 }
2102 case bitc::METADATA_ARG_LIST: {
2103 SmallVector<ValueAsMetadata *, 4> Elts;
2104 Elts.reserve(Record.size());
2105 for (uint64_t Elt : Record) {
2106 Metadata *MD = getMD(Elt);
2107 if (isa<MDNode>(MD) && cast<MDNode>(MD)->isTemporary())
2108 return error(
2109 "Invalid record: DIArgList should not contain forward refs");
2110 if (!isa<ValueAsMetadata>(MD))
2111 return error("Invalid record");
2112 Elts.push_back(cast<ValueAsMetadata>(MD));
2113 }
2114
2115 MetadataList.assignValue(DIArgList::get(Context, Elts), NextMetadataNo);
2116 NextMetadataNo++;
2117 break;
2118 }
2119 }
2120 return Error::success();
2121#undef GET_OR_DISTINCT
2122}
2123
2124Error MetadataLoader::MetadataLoaderImpl::parseMetadataStrings(
2125 ArrayRef<uint64_t> Record, StringRef Blob,
2126 function_ref<void(StringRef)> CallBack) {
2127 // All the MDStrings in the block are emitted together in a single
2128 // record. The strings are concatenated and stored in a blob along with
2129 // their sizes.
2130 if (Record.size() != 2)
2131 return error("Invalid record: metadata strings layout");
2132
2133 unsigned NumStrings = Record[0];
2134 unsigned StringsOffset = Record[1];
2135 if (!NumStrings)
2136 return error("Invalid record: metadata strings with no strings");
2137 if (StringsOffset > Blob.size())
2138 return error("Invalid record: metadata strings corrupt offset");
2139
2140 StringRef Lengths = Blob.slice(0, StringsOffset);
2141 SimpleBitstreamCursor R(Lengths);
2142
2143 StringRef Strings = Blob.drop_front(StringsOffset);
2144 do {
2145 if (R.AtEndOfStream())
2146 return error("Invalid record: metadata strings bad length");
2147
2148 Expected<uint32_t> MaybeSize = R.ReadVBR(6);
2149 if (!MaybeSize)
2150 return MaybeSize.takeError();
2151 uint32_t Size = MaybeSize.get();
2152 if (Strings.size() < Size)
2153 return error("Invalid record: metadata strings truncated chars");
2154
2155 CallBack(Strings.slice(0, Size));
2156 Strings = Strings.drop_front(Size);
2157 } while (--NumStrings);
2158
2159 return Error::success();
2160}
2161
2162Error MetadataLoader::MetadataLoaderImpl::parseGlobalObjectAttachment(
2163 GlobalObject &GO, ArrayRef<uint64_t> Record) {
2164 assert(Record.size() % 2 == 0)(static_cast<void> (0));
2165 for (unsigned I = 0, E = Record.size(); I != E; I += 2) {
2166 auto K = MDKindMap.find(Record[I]);
2167 if (K == MDKindMap.end())
2168 return error("Invalid ID");
2169 MDNode *MD =
2170 dyn_cast_or_null<MDNode>(getMetadataFwdRefOrLoad(Record[I + 1]));
2171 if (!MD)
2172 return error("Invalid metadata attachment: expect fwd ref to MDNode");
2173 GO.addMetadata(K->second, *MD);
2174 }
2175 return Error::success();
2176}
2177
2178/// Parse metadata attachments.
2179Error MetadataLoader::MetadataLoaderImpl::parseMetadataAttachment(
2180 Function &F, const SmallVectorImpl<Instruction *> &InstructionList) {
2181 if (Error Err = Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
2182 return Err;
2183
2184 SmallVector<uint64_t, 64> Record;
2185 PlaceholderQueue Placeholders;
2186
2187 while (true) {
2188 Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
2189 if (!MaybeEntry)
2190 return MaybeEntry.takeError();
2191 BitstreamEntry Entry = MaybeEntry.get();
2192
2193 switch (Entry.Kind) {
2194 case BitstreamEntry::SubBlock: // Handled for us already.
2195 case BitstreamEntry::Error:
2196 return error("Malformed block");
2197 case BitstreamEntry::EndBlock:
2198 resolveForwardRefsAndPlaceholders(Placeholders);
2199 return Error::success();
2200 case BitstreamEntry::Record:
2201 // The interesting case.
2202 break;
2203 }
2204
2205 // Read a metadata attachment record.
2206 Record.clear();
2207 ++NumMDRecordLoaded;
2208 Expected<unsigned> MaybeRecord = Stream.readRecord(Entry.ID, Record);
2209 if (!MaybeRecord)
2210 return MaybeRecord.takeError();
2211 switch (MaybeRecord.get()) {
2212 default: // Default behavior: ignore.
2213 break;
2214 case bitc::METADATA_ATTACHMENT: {
2215 unsigned RecordLength = Record.size();
2216 if (Record.empty())
2217 return error("Invalid record");
2218 if (RecordLength % 2 == 0) {
2219 // A function attachment.
2220 if (Error Err = parseGlobalObjectAttachment(F, Record))
2221 return Err;
2222 continue;
2223 }
2224
2225 // An instruction attachment.
2226 Instruction *Inst = InstructionList[Record[0]];
2227 for (unsigned i = 1; i != RecordLength; i = i + 2) {
2228 unsigned Kind = Record[i];
2229 DenseMap<unsigned, unsigned>::iterator I = MDKindMap.find(Kind);
2230 if (I == MDKindMap.end())
2231 return error("Invalid ID");
2232 if (I->second == LLVMContext::MD_tbaa && StripTBAA)
2233 continue;
2234
2235 auto Idx = Record[i + 1];
2236 if (Idx < (MDStringRef.size() + GlobalMetadataBitPosIndex.size()) &&
2237 !MetadataList.lookup(Idx)) {
2238 // Load the attachment if it is in the lazy-loadable range and hasn't
2239 // been loaded yet.
2240 lazyLoadOneMetadata(Idx, Placeholders);
2241 resolveForwardRefsAndPlaceholders(Placeholders);
2242 }
2243
2244 Metadata *Node = MetadataList.getMetadataFwdRef(Idx);
2245 if (isa<LocalAsMetadata>(Node))
2246 // Drop the attachment. This used to be legal, but there's no
2247 // upgrade path.
2248 break;
2249 MDNode *MD = dyn_cast_or_null<MDNode>(Node);
2250 if (!MD)
2251 return error("Invalid metadata attachment");
2252
2253 if (HasSeenOldLoopTags && I->second == LLVMContext::MD_loop)
2254 MD = upgradeInstructionLoopAttachment(*MD);
2255
2256 if (I->second == LLVMContext::MD_tbaa) {
2257 assert(!MD->isTemporary() && "should load MDs before attachments")(static_cast<void> (0));
2258 MD = UpgradeTBAANode(*MD);
2259 }
2260 Inst->setMetadata(I->second, MD);
2261 }
2262 break;
2263 }
2264 }
2265 }
2266}
2267
2268/// Parse a single METADATA_KIND record, inserting result in MDKindMap.
2269Error MetadataLoader::MetadataLoaderImpl::parseMetadataKindRecord(
2270 SmallVectorImpl<uint64_t> &Record) {
2271 if (Record.size() < 2)
2272 return error("Invalid record");
2273
2274 unsigned Kind = Record[0];
2275 SmallString<8> Name(Record.begin() + 1, Record.end());
2276
2277 unsigned NewKind = TheModule.getMDKindID(Name.str());
2278 if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
2279 return error("Conflicting METADATA_KIND records");
2280 return Error::success();
2281}
2282
2283/// Parse the metadata kinds out of the METADATA_KIND_BLOCK.
2284Error MetadataLoader::MetadataLoaderImpl::parseMetadataKinds() {
2285 if (Error Err = Stream.EnterSubBlock(bitc::METADATA_KIND_BLOCK_ID))
2286 return Err;
2287
2288 SmallVector<uint64_t, 64> Record;
2289
2290 // Read all the records.
2291 while (true) {
2292 Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
2293 if (!MaybeEntry)
2294 return MaybeEntry.takeError();
2295 BitstreamEntry Entry = MaybeEntry.get();
2296
2297 switch (Entry.Kind) {
2298 case BitstreamEntry::SubBlock: // Handled for us already.
2299 case BitstreamEntry::Error:
2300 return error("Malformed block");
2301 case BitstreamEntry::EndBlock:
2302 return Error::success();
2303 case BitstreamEntry::Record:
2304 // The interesting case.
2305 break;
2306 }
2307
2308 // Read a record.
2309 Record.clear();
2310 ++NumMDRecordLoaded;
2311 Expected<unsigned> MaybeCode = Stream.readRecord(Entry.ID, Record);
2312 if (!MaybeCode)
2313 return MaybeCode.takeError();
2314 switch (MaybeCode.get()) {
2315 default: // Default behavior: ignore.
2316 break;
2317 case bitc::METADATA_KIND: {
2318 if (Error Err = parseMetadataKindRecord(Record))
2319 return Err;
2320 break;
2321 }
2322 }
2323 }
2324}
2325
2326MetadataLoader &MetadataLoader::operator=(MetadataLoader &&RHS) {
2327 Pimpl = std::move(RHS.Pimpl);
2328 return *this;
2329}
2330MetadataLoader::MetadataLoader(MetadataLoader &&RHS)
2331 : Pimpl(std::move(RHS.Pimpl)) {}
2332
2333MetadataLoader::~MetadataLoader() = default;
2334MetadataLoader::MetadataLoader(BitstreamCursor &Stream, Module &TheModule,
2335 BitcodeReaderValueList &ValueList,
2336 bool IsImporting,
2337 std::function<Type *(unsigned)> getTypeByID)
2338 : Pimpl(std::make_unique<MetadataLoaderImpl>(
2339 Stream, TheModule, ValueList, std::move(getTypeByID), IsImporting)) {}
2340
2341Error MetadataLoader::parseMetadata(bool ModuleLevel) {
2342 return Pimpl->parseMetadata(ModuleLevel);
2343}
2344
2345bool MetadataLoader::hasFwdRefs() const { return Pimpl->hasFwdRefs(); }
2346
2347/// Return the given metadata, creating a replaceable forward reference if
2348/// necessary.
2349Metadata *MetadataLoader::getMetadataFwdRefOrLoad(unsigned Idx) {
2350 return Pimpl->getMetadataFwdRefOrLoad(Idx);
2351}
2352
2353DISubprogram *MetadataLoader::lookupSubprogramForFunction(Function *F) {
2354 return Pimpl->lookupSubprogramForFunction(F);
2355}
2356
2357Error MetadataLoader::parseMetadataAttachment(
2358 Function &F, const SmallVectorImpl<Instruction *> &InstructionList) {
2359 return Pimpl->parseMetadataAttachment(F, InstructionList);
2360}
2361
2362Error MetadataLoader::parseMetadataKinds() {
2363 return Pimpl->parseMetadataKinds();
2364}
2365
2366void MetadataLoader::setStripTBAA(bool StripTBAA) {
2367 return Pimpl->setStripTBAA(StripTBAA);
2368}
2369
2370bool MetadataLoader::isStrippingTBAA() { return Pimpl->isStrippingTBAA(); }
2371
2372unsigned MetadataLoader::size() const { return Pimpl->size(); }
2373void MetadataLoader::shrinkTo(unsigned N) { return Pimpl->shrinkTo(N); }
2374
2375void MetadataLoader::upgradeDebugIntrinsics(Function &F) {
2376 return Pimpl->upgradeDebugIntrinsics(F);
2377}

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/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;
14
Returning zero, which participates in a condition later
25
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_CHECKS0
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_CHECKS0
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_CHECKS0
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_CHECKS0
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_CHECKS0
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_CHECKS0
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<void> (0))
391 "ErrorList constructor payloads should be singleton errors")(static_cast<void> (0));
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_CHECKS0
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<void> (0));
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_CHECKS0
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_CHECKS0
563 Unchecked = HasError;
564#endif
565 return !HasError;
3
Returning the value 1, which participates in a condition later
8
Assuming field 'HasError' is false, which participates in a condition later
9
Returning the value 1, which participates in a condition later
18
Assuming field 'HasError' is false, which participates in a condition later
19
Returning the value 1, which participates in a condition later
29
Returning the value 1, which participates in a condition later
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_CHECKS0
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_CHECKS0
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<void> (0));
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<void> (0));
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<void> (0));
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<void> (0));
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_CHECKS0
685 Unchecked = true;
686#endif
687 }
688
689#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
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_CHECKS0
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_CHECKS0
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 NDEBUG1
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)__builtin_unreachable();
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 NDEBUG1
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)__builtin_unreachable();
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 NDEBUG1
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)__builtin_unreachable();
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<void> (0));
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<void> (0));
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<void> (0));
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<void> (0));
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<void> (0));
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<void> (0));
1282 assert(!F.isTriviallyEmpty() &&(static_cast<void> (0))
1283 "The file name provided to FileError must not be empty.")(static_cast<void> (0));
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