Bug Summary

File:lib/Bitcode/Reader/MetadataLoader.cpp
Warning:line 210, column 39
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'

Annotated Source Code

/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp

1//===- MetadataLoader.cpp - Internal BitcodeReader implementation ---------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "MetadataLoader.h"
11#include "ValueList.h"
12
13#include "llvm/ADT/APFloat.h"
14#include "llvm/ADT/APInt.h"
15#include "llvm/ADT/ArrayRef.h"
16#include "llvm/ADT/DenseMap.h"
17#include "llvm/ADT/DenseSet.h"
18#include "llvm/ADT/None.h"
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/ADT/SmallString.h"
21#include "llvm/ADT/SmallVector.h"
22#include "llvm/ADT/Statistic.h"
23#include "llvm/ADT/StringRef.h"
24#include "llvm/ADT/Triple.h"
25#include "llvm/ADT/Twine.h"
26#include "llvm/Bitcode/BitcodeReader.h"
27#include "llvm/Bitcode/BitstreamReader.h"
28#include "llvm/Bitcode/LLVMBitCodes.h"
29#include "llvm/IR/Argument.h"
30#include "llvm/IR/Attributes.h"
31#include "llvm/IR/AutoUpgrade.h"
32#include "llvm/IR/BasicBlock.h"
33#include "llvm/IR/CallSite.h"
34#include "llvm/IR/CallingConv.h"
35#include "llvm/IR/Comdat.h"
36#include "llvm/IR/Constant.h"
37#include "llvm/IR/Constants.h"
38#include "llvm/IR/DebugInfo.h"
39#include "llvm/IR/DebugInfoMetadata.h"
40#include "llvm/IR/DebugLoc.h"
41#include "llvm/IR/DerivedTypes.h"
42#include "llvm/IR/DiagnosticInfo.h"
43#include "llvm/IR/DiagnosticPrinter.h"
44#include "llvm/IR/Function.h"
45#include "llvm/IR/GVMaterializer.h"
46#include "llvm/IR/GlobalAlias.h"
47#include "llvm/IR/GlobalIFunc.h"
48#include "llvm/IR/GlobalIndirectSymbol.h"
49#include "llvm/IR/GlobalObject.h"
50#include "llvm/IR/GlobalValue.h"
51#include "llvm/IR/GlobalVariable.h"
52#include "llvm/IR/InlineAsm.h"
53#include "llvm/IR/InstrTypes.h"
54#include "llvm/IR/Instruction.h"
55#include "llvm/IR/Instructions.h"
56#include "llvm/IR/IntrinsicInst.h"
57#include "llvm/IR/Intrinsics.h"
58#include "llvm/IR/LLVMContext.h"
59#include "llvm/IR/Module.h"
60#include "llvm/IR/ModuleSummaryIndex.h"
61#include "llvm/IR/OperandTraits.h"
62#include "llvm/IR/Operator.h"
63#include "llvm/IR/TrackingMDRef.h"
64#include "llvm/IR/Type.h"
65#include "llvm/IR/ValueHandle.h"
66#include "llvm/Support/AtomicOrdering.h"
67#include "llvm/Support/Casting.h"
68#include "llvm/Support/CommandLine.h"
69#include "llvm/Support/Compiler.h"
70#include "llvm/Support/Debug.h"
71#include "llvm/Support/Error.h"
72#include "llvm/Support/ErrorHandling.h"
73#include "llvm/Support/ManagedStatic.h"
74#include "llvm/Support/MemoryBuffer.h"
75#include "llvm/Support/raw_ostream.h"
76#include <algorithm>
77#include <cassert>
78#include <cstddef>
79#include <cstdint>
80#include <deque>
81#include <limits>
82#include <map>
83#include <memory>
84#include <string>
85#include <system_error>
86#include <tuple>
87#include <utility>
88#include <vector>
89
90using namespace llvm;
91
92#define DEBUG_TYPE"bitcode-reader" "bitcode-reader"
93
94STATISTIC(NumMDStringLoaded, "Number of MDStrings loaded")static llvm::Statistic NumMDStringLoaded = {"bitcode-reader",
"NumMDStringLoaded", "Number of MDStrings loaded", {0}, false
}
;
95STATISTIC(NumMDNodeTemporary, "Number of MDNode::Temporary created")static llvm::Statistic NumMDNodeTemporary = {"bitcode-reader"
, "NumMDNodeTemporary", "Number of MDNode::Temporary created"
, {0}, false}
;
96STATISTIC(NumMDRecordLoaded, "Number of Metadata records loaded")static llvm::Statistic NumMDRecordLoaded = {"bitcode-reader",
"NumMDRecordLoaded", "Number of Metadata records loaded", {0
}, false}
;
97
98/// Flag whether we need to import full type definitions for ThinLTO.
99/// Currently needed for Darwin and LLDB.
100static cl::opt<bool> ImportFullTypeDefinitions(
101 "import-full-type-definitions", cl::init(false), cl::Hidden,
102 cl::desc("Import full type definitions for ThinLTO."));
103
104static cl::opt<bool> DisableLazyLoading(
105 "disable-ondemand-mds-loading", cl::init(false), cl::Hidden,
106 cl::desc("Force disable the lazy-loading on-demand of metadata when "
107 "loading bitcode for importing."));
108
109namespace {
110
111static int64_t unrotateSign(uint64_t U) { return U & 1 ? ~(U >> 1) : U >> 1; }
112
113class BitcodeReaderMetadataList {
114 /// Array of metadata references.
115 ///
116 /// Don't use std::vector here. Some versions of libc++ copy (instead of
117 /// move) on resize, and TrackingMDRef is very expensive to copy.
118 SmallVector<TrackingMDRef, 1> MetadataPtrs;
119
120 /// The set of indices in MetadataPtrs above of forward references that were
121 /// generated.
122 SmallDenseSet<unsigned, 1> ForwardReference;
123
124 /// The set of indices in MetadataPtrs above of Metadata that need to be
125 /// resolved.
126 SmallDenseSet<unsigned, 1> UnresolvedNodes;
127
128 /// Structures for resolving old type refs.
129 struct {
130 SmallDenseMap<MDString *, TempMDTuple, 1> Unknown;
131 SmallDenseMap<MDString *, DICompositeType *, 1> Final;
132 SmallDenseMap<MDString *, DICompositeType *, 1> FwdDecls;
133 SmallVector<std::pair<TrackingMDRef, TempMDTuple>, 1> Arrays;
134 } OldTypeRefs;
135
136 LLVMContext &Context;
137
138public:
139 BitcodeReaderMetadataList(LLVMContext &C) : Context(C) {}
140
141 // vector compatibility methods
142 unsigned size() const { return MetadataPtrs.size(); }
143 void resize(unsigned N) { MetadataPtrs.resize(N); }
144 void push_back(Metadata *MD) { MetadataPtrs.emplace_back(MD); }
145 void clear() { MetadataPtrs.clear(); }
146 Metadata *back() const { return MetadataPtrs.back(); }
147 void pop_back() { MetadataPtrs.pop_back(); }
148 bool empty() const { return MetadataPtrs.empty(); }
149
150 Metadata *operator[](unsigned i) const {
151 assert(i < MetadataPtrs.size())(static_cast <bool> (i < MetadataPtrs.size()) ? void
(0) : __assert_fail ("i < MetadataPtrs.size()", "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 151, __extension__ __PRETTY_FUNCTION__))
;
152 return MetadataPtrs[i];
153 }
154
155 Metadata *lookup(unsigned I) const {
156 if (I < MetadataPtrs.size())
157 return MetadataPtrs[I];
158 return nullptr;
159 }
160
161 void shrinkTo(unsigned N) {
162 assert(N <= size() && "Invalid shrinkTo request!")(static_cast <bool> (N <= size() && "Invalid shrinkTo request!"
) ? void (0) : __assert_fail ("N <= size() && \"Invalid shrinkTo request!\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 162, __extension__ __PRETTY_FUNCTION__))
;
163 assert(ForwardReference.empty() && "Unexpected forward refs")(static_cast <bool> (ForwardReference.empty() &&
"Unexpected forward refs") ? void (0) : __assert_fail ("ForwardReference.empty() && \"Unexpected forward refs\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 163, __extension__ __PRETTY_FUNCTION__))
;
164 assert(UnresolvedNodes.empty() && "Unexpected unresolved node")(static_cast <bool> (UnresolvedNodes.empty() &&
"Unexpected unresolved node") ? void (0) : __assert_fail ("UnresolvedNodes.empty() && \"Unexpected unresolved node\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 164, __extension__ __PRETTY_FUNCTION__))
;
165 MetadataPtrs.resize(N);
166 }
167
168 /// Return the given metadata, creating a replaceable forward reference if
169 /// necessary.
170 Metadata *getMetadataFwdRef(unsigned Idx);
171
172 /// Return the the given metadata only if it is fully resolved.
173 ///
174 /// Gives the same result as \a lookup(), unless \a MDNode::isResolved()
175 /// would give \c false.
176 Metadata *getMetadataIfResolved(unsigned Idx);
177
178 MDNode *getMDNodeFwdRefOrNull(unsigned Idx);
179 void assignValue(Metadata *MD, unsigned Idx);
180 void tryToResolveCycles();
181 bool hasFwdRefs() const { return !ForwardReference.empty(); }
182 int getNextFwdRef() {
183 assert(hasFwdRefs())(static_cast <bool> (hasFwdRefs()) ? void (0) : __assert_fail
("hasFwdRefs()", "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 183, __extension__ __PRETTY_FUNCTION__))
;
184 return *ForwardReference.begin();
185 }
186
187 /// Upgrade a type that had an MDString reference.
188 void addTypeRef(MDString &UUID, DICompositeType &CT);
189
190 /// Upgrade a type that had an MDString reference.
191 Metadata *upgradeTypeRef(Metadata *MaybeUUID);
192
193 /// Upgrade a type ref array that may have MDString references.
194 Metadata *upgradeTypeRefArray(Metadata *MaybeTuple);
195
196private:
197 Metadata *resolveTypeRefArray(Metadata *MaybeTuple);
198};
199
200void BitcodeReaderMetadataList::assignValue(Metadata *MD, unsigned Idx) {
201 if (auto *MDN = dyn_cast<MDNode>(MD))
202 if (!MDN->isResolved())
203 UnresolvedNodes.insert(Idx);
204
205 if (Idx == size()) {
206 push_back(MD);
207 return;
208 }
209
210 if (Idx >= size())
211 resize(Idx + 1);
212
213 TrackingMDRef &OldMD = MetadataPtrs[Idx];
214 if (!OldMD) {
215 OldMD.reset(MD);
216 return;
217 }
218
219 // If there was a forward reference to this value, replace it.
220 TempMDTuple PrevMD(cast<MDTuple>(OldMD.get()));
221 PrevMD->replaceAllUsesWith(MD);
222 ForwardReference.erase(Idx);
223}
224
225Metadata *BitcodeReaderMetadataList::getMetadataFwdRef(unsigned Idx) {
226 if (Idx >= size())
227 resize(Idx + 1);
228
229 if (Metadata *MD = MetadataPtrs[Idx])
230 return MD;
231
232 // Track forward refs to be resolved later.
233 ForwardReference.insert(Idx);
234
235 // Create and return a placeholder, which will later be RAUW'd.
236 ++NumMDNodeTemporary;
237 Metadata *MD = MDNode::getTemporary(Context, None).release();
238 MetadataPtrs[Idx].reset(MD);
239 return MD;
240}
241
242Metadata *BitcodeReaderMetadataList::getMetadataIfResolved(unsigned Idx) {
243 Metadata *MD = lookup(Idx);
244 if (auto *N = dyn_cast_or_null<MDNode>(MD))
245 if (!N->isResolved())
246 return nullptr;
247 return MD;
248}
249
250MDNode *BitcodeReaderMetadataList::getMDNodeFwdRefOrNull(unsigned Idx) {
251 return dyn_cast_or_null<MDNode>(getMetadataFwdRef(Idx));
252}
253
254void BitcodeReaderMetadataList::tryToResolveCycles() {
255 if (!ForwardReference.empty())
256 // Still forward references... can't resolve cycles.
257 return;
258
259 // Give up on finding a full definition for any forward decls that remain.
260 for (const auto &Ref : OldTypeRefs.FwdDecls)
261 OldTypeRefs.Final.insert(Ref);
262 OldTypeRefs.FwdDecls.clear();
263
264 // Upgrade from old type ref arrays. In strange cases, this could add to
265 // OldTypeRefs.Unknown.
266 for (const auto &Array : OldTypeRefs.Arrays)
267 Array.second->replaceAllUsesWith(resolveTypeRefArray(Array.first.get()));
268 OldTypeRefs.Arrays.clear();
269
270 // Replace old string-based type refs with the resolved node, if possible.
271 // If we haven't seen the node, leave it to the verifier to complain about
272 // the invalid string reference.
273 for (const auto &Ref : OldTypeRefs.Unknown) {
274 if (DICompositeType *CT = OldTypeRefs.Final.lookup(Ref.first))
275 Ref.second->replaceAllUsesWith(CT);
276 else
277 Ref.second->replaceAllUsesWith(Ref.first);
278 }
279 OldTypeRefs.Unknown.clear();
280
281 if (UnresolvedNodes.empty())
282 // Nothing to do.
283 return;
284
285 // Resolve any cycles.
286 for (unsigned I : UnresolvedNodes) {
287 auto &MD = MetadataPtrs[I];
288 auto *N = dyn_cast_or_null<MDNode>(MD);
289 if (!N)
290 continue;
291
292 assert(!N->isTemporary() && "Unexpected forward reference")(static_cast <bool> (!N->isTemporary() && "Unexpected forward reference"
) ? void (0) : __assert_fail ("!N->isTemporary() && \"Unexpected forward reference\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 292, __extension__ __PRETTY_FUNCTION__))
;
293 N->resolveCycles();
294 }
295
296 // Make sure we return early again until there's another unresolved ref.
297 UnresolvedNodes.clear();
298}
299
300void BitcodeReaderMetadataList::addTypeRef(MDString &UUID,
301 DICompositeType &CT) {
302 assert(CT.getRawIdentifier() == &UUID && "Mismatched UUID")(static_cast <bool> (CT.getRawIdentifier() == &UUID
&& "Mismatched UUID") ? void (0) : __assert_fail ("CT.getRawIdentifier() == &UUID && \"Mismatched UUID\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 302, __extension__ __PRETTY_FUNCTION__))
;
303 if (CT.isForwardDecl())
304 OldTypeRefs.FwdDecls.insert(std::make_pair(&UUID, &CT));
305 else
306 OldTypeRefs.Final.insert(std::make_pair(&UUID, &CT));
307}
308
309Metadata *BitcodeReaderMetadataList::upgradeTypeRef(Metadata *MaybeUUID) {
310 auto *UUID = dyn_cast_or_null<MDString>(MaybeUUID);
311 if (LLVM_LIKELY(!UUID)__builtin_expect((bool)(!UUID), true))
312 return MaybeUUID;
313
314 if (auto *CT = OldTypeRefs.Final.lookup(UUID))
315 return CT;
316
317 auto &Ref = OldTypeRefs.Unknown[UUID];
318 if (!Ref)
319 Ref = MDNode::getTemporary(Context, None);
320 return Ref.get();
321}
322
323Metadata *BitcodeReaderMetadataList::upgradeTypeRefArray(Metadata *MaybeTuple) {
324 auto *Tuple = dyn_cast_or_null<MDTuple>(MaybeTuple);
325 if (!Tuple || Tuple->isDistinct())
326 return MaybeTuple;
327
328 // Look through the array immediately if possible.
329 if (!Tuple->isTemporary())
330 return resolveTypeRefArray(Tuple);
331
332 // Create and return a placeholder to use for now. Eventually
333 // resolveTypeRefArrays() will be resolve this forward reference.
334 OldTypeRefs.Arrays.emplace_back(
335 std::piecewise_construct, std::forward_as_tuple(Tuple),
336 std::forward_as_tuple(MDTuple::getTemporary(Context, None)));
337 return OldTypeRefs.Arrays.back().second.get();
338}
339
340Metadata *BitcodeReaderMetadataList::resolveTypeRefArray(Metadata *MaybeTuple) {
341 auto *Tuple = dyn_cast_or_null<MDTuple>(MaybeTuple);
342 if (!Tuple || Tuple->isDistinct())
343 return MaybeTuple;
344
345 // Look through the DITypeRefArray, upgrading each DITypeRef.
346 SmallVector<Metadata *, 32> Ops;
347 Ops.reserve(Tuple->getNumOperands());
348 for (Metadata *MD : Tuple->operands())
349 Ops.push_back(upgradeTypeRef(MD));
350
351 return MDTuple::get(Context, Ops);
352}
353
354namespace {
355
356class PlaceholderQueue {
357 // Placeholders would thrash around when moved, so store in a std::deque
358 // instead of some sort of vector.
359 std::deque<DistinctMDOperandPlaceholder> PHs;
360
361public:
362 ~PlaceholderQueue() {
363 assert(empty() && "PlaceholderQueue hasn't been flushed before being destroyed")(static_cast <bool> (empty() && "PlaceholderQueue hasn't been flushed before being destroyed"
) ? void (0) : __assert_fail ("empty() && \"PlaceholderQueue hasn't been flushed before being destroyed\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 363, __extension__ __PRETTY_FUNCTION__))
;
364 }
365 bool empty() { return PHs.empty(); }
366 DistinctMDOperandPlaceholder &getPlaceholderOp(unsigned ID);
367 void flush(BitcodeReaderMetadataList &MetadataList);
368
369 /// Return the list of temporaries nodes in the queue, these need to be
370 /// loaded before we can flush the queue.
371 void getTemporaries(BitcodeReaderMetadataList &MetadataList,
372 DenseSet<unsigned> &Temporaries) {
373 for (auto &PH : PHs) {
374 auto ID = PH.getID();
375 auto *MD = MetadataList.lookup(ID);
376 if (!MD) {
377 Temporaries.insert(ID);
378 continue;
379 }
380 auto *N = dyn_cast_or_null<MDNode>(MD);
381 if (N && N->isTemporary())
382 Temporaries.insert(ID);
383 }
384 }
385};
386
387} // end anonymous namespace
388
389DistinctMDOperandPlaceholder &PlaceholderQueue::getPlaceholderOp(unsigned ID) {
390 PHs.emplace_back(ID);
391 return PHs.back();
392}
393
394void PlaceholderQueue::flush(BitcodeReaderMetadataList &MetadataList) {
395 while (!PHs.empty()) {
396 auto *MD = MetadataList.lookup(PHs.front().getID());
397 assert(MD && "Flushing placeholder on unassigned MD")(static_cast <bool> (MD && "Flushing placeholder on unassigned MD"
) ? void (0) : __assert_fail ("MD && \"Flushing placeholder on unassigned MD\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 397, __extension__ __PRETTY_FUNCTION__))
;
398#ifndef NDEBUG
399 if (auto *MDN = dyn_cast<MDNode>(MD))
400 assert(MDN->isResolved() &&(static_cast <bool> (MDN->isResolved() && "Flushing Placeholder while cycles aren't resolved"
) ? void (0) : __assert_fail ("MDN->isResolved() && \"Flushing Placeholder while cycles aren't resolved\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 401, __extension__ __PRETTY_FUNCTION__))
401 "Flushing Placeholder while cycles aren't resolved")(static_cast <bool> (MDN->isResolved() && "Flushing Placeholder while cycles aren't resolved"
) ? void (0) : __assert_fail ("MDN->isResolved() && \"Flushing Placeholder while cycles aren't resolved\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 401, __extension__ __PRETTY_FUNCTION__))
;
402#endif
403 PHs.front().replaceUseWith(MD);
404 PHs.pop_front();
405 }
406}
407
408} // anonynous namespace
409
410static Error error(const Twine &Message) {
411 return make_error<StringError>(
412 Message, make_error_code(BitcodeError::CorruptedBitcode));
413}
414
415class MetadataLoader::MetadataLoaderImpl {
416 BitcodeReaderMetadataList MetadataList;
417 BitcodeReaderValueList &ValueList;
418 BitstreamCursor &Stream;
419 LLVMContext &Context;
420 Module &TheModule;
421 std::function<Type *(unsigned)> getTypeByID;
422
423 /// Cursor associated with the lazy-loading of Metadata. This is the easy way
424 /// to keep around the right "context" (Abbrev list) to be able to jump in
425 /// the middle of the metadata block and load any record.
426 BitstreamCursor IndexCursor;
427
428 /// Index that keeps track of MDString values.
429 std::vector<StringRef> MDStringRef;
430
431 /// On-demand loading of a single MDString. Requires the index above to be
432 /// populated.
433 MDString *lazyLoadOneMDString(unsigned Idx);
434
435 /// Index that keeps track of where to find a metadata record in the stream.
436 std::vector<uint64_t> GlobalMetadataBitPosIndex;
437
438 /// Populate the index above to enable lazily loading of metadata, and load
439 /// the named metadata as well as the transitively referenced global
440 /// Metadata.
441 Expected<bool> lazyLoadModuleMetadataBlock();
442
443 /// On-demand loading of a single metadata. Requires the index above to be
444 /// populated.
445 void lazyLoadOneMetadata(unsigned Idx, PlaceholderQueue &Placeholders);
446
447 // Keep mapping of seens pair of old-style CU <-> SP, and update pointers to
448 // point from SP to CU after a block is completly parsed.
449 std::vector<std::pair<DICompileUnit *, Metadata *>> CUSubprograms;
450
451 /// Functions that need to be matched with subprograms when upgrading old
452 /// metadata.
453 SmallDenseMap<Function *, DISubprogram *, 16> FunctionsWithSPs;
454
455 // Map the bitcode's custom MDKind ID to the Module's MDKind ID.
456 DenseMap<unsigned, unsigned> MDKindMap;
457
458 bool StripTBAA = false;
459 bool HasSeenOldLoopTags = false;
460 bool NeedUpgradeToDIGlobalVariableExpression = false;
461 bool NeedDeclareExpressionUpgrade = false;
462
463 /// True if metadata is being parsed for a module being ThinLTO imported.
464 bool IsImporting = false;
465
466 Error parseOneMetadata(SmallVectorImpl<uint64_t> &Record, unsigned Code,
467 PlaceholderQueue &Placeholders, StringRef Blob,
468 unsigned &NextMetadataNo);
469 Error parseMetadataStrings(ArrayRef<uint64_t> Record, StringRef Blob,
470 function_ref<void(StringRef)> CallBack);
471 Error parseGlobalObjectAttachment(GlobalObject &GO,
472 ArrayRef<uint64_t> Record);
473 Error parseMetadataKindRecord(SmallVectorImpl<uint64_t> &Record);
474
475 void resolveForwardRefsAndPlaceholders(PlaceholderQueue &Placeholders);
476
477 /// Upgrade old-style CU <-> SP pointers to point from SP to CU.
478 void upgradeCUSubprograms() {
479 for (auto CU_SP : CUSubprograms)
480 if (auto *SPs = dyn_cast_or_null<MDTuple>(CU_SP.second))
481 for (auto &Op : SPs->operands())
482 if (auto *SP = dyn_cast_or_null<DISubprogram>(Op))
483 SP->replaceUnit(CU_SP.first);
484 CUSubprograms.clear();
485 }
486
487 /// Upgrade old-style bare DIGlobalVariables to DIGlobalVariableExpressions.
488 void upgradeCUVariables() {
489 if (!NeedUpgradeToDIGlobalVariableExpression)
490 return;
491
492 // Upgrade list of variables attached to the CUs.
493 if (NamedMDNode *CUNodes = TheModule.getNamedMetadata("llvm.dbg.cu"))
494 for (unsigned I = 0, E = CUNodes->getNumOperands(); I != E; ++I) {
495 auto *CU = cast<DICompileUnit>(CUNodes->getOperand(I));
496 if (auto *GVs = dyn_cast_or_null<MDTuple>(CU->getRawGlobalVariables()))
497 for (unsigned I = 0; I < GVs->getNumOperands(); I++)
498 if (auto *GV =
499 dyn_cast_or_null<DIGlobalVariable>(GVs->getOperand(I))) {
500 auto *DGVE = DIGlobalVariableExpression::getDistinct(
501 Context, GV, DIExpression::get(Context, {}));
502 GVs->replaceOperandWith(I, DGVE);
503 }
504 }
505
506 // Upgrade variables attached to globals.
507 for (auto &GV : TheModule.globals()) {
508 SmallVector<MDNode *, 1> MDs;
509 GV.getMetadata(LLVMContext::MD_dbg, MDs);
510 GV.eraseMetadata(LLVMContext::MD_dbg);
511 for (auto *MD : MDs)
512 if (auto *DGV = dyn_cast_or_null<DIGlobalVariable>(MD)) {
513 auto *DGVE = DIGlobalVariableExpression::getDistinct(
514 Context, DGV, DIExpression::get(Context, {}));
515 GV.addMetadata(LLVMContext::MD_dbg, *DGVE);
516 } else
517 GV.addMetadata(LLVMContext::MD_dbg, *MD);
518 }
519 }
520
521 /// Remove a leading DW_OP_deref from DIExpressions in a dbg.declare that
522 /// describes a function argument.
523 void upgradeDeclareExpressions(Function &F) {
524 if (!NeedDeclareExpressionUpgrade)
525 return;
526
527 for (auto &BB : F)
528 for (auto &I : BB)
529 if (auto *DDI = dyn_cast<DbgDeclareInst>(&I))
530 if (auto *DIExpr = DDI->getExpression())
531 if (DIExpr->startsWithDeref() &&
532 dyn_cast_or_null<Argument>(DDI->getAddress())) {
533 SmallVector<uint64_t, 8> Ops;
534 Ops.append(std::next(DIExpr->elements_begin()),
535 DIExpr->elements_end());
536 auto *E = DIExpression::get(Context, Ops);
537 DDI->setOperand(2, MetadataAsValue::get(Context, E));
538 }
539 }
540
541 /// Upgrade the expression from previous versions.
542 Error upgradeDIExpression(uint64_t FromVersion,
543 MutableArrayRef<uint64_t> &Expr,
544 SmallVectorImpl<uint64_t> &Buffer) {
545 auto N = Expr.size();
546 switch (FromVersion) {
547 default:
548 return error("Invalid record");
549 case 0:
550 if (N >= 3 && Expr[N - 3] == dwarf::DW_OP_bit_piece)
551 Expr[N - 3] = dwarf::DW_OP_LLVM_fragment;
552 LLVM_FALLTHROUGH[[clang::fallthrough]];
553 case 1:
554 // Move DW_OP_deref to the end.
555 if (N && Expr[0] == dwarf::DW_OP_deref) {
556 auto End = Expr.end();
557 if (Expr.size() >= 3 &&
558 *std::prev(End, 3) == dwarf::DW_OP_LLVM_fragment)
559 End = std::prev(End, 3);
560 std::move(std::next(Expr.begin()), End, Expr.begin());
561 *std::prev(End) = dwarf::DW_OP_deref;
562 }
563 NeedDeclareExpressionUpgrade = true;
564 LLVM_FALLTHROUGH[[clang::fallthrough]];
565 case 2: {
566 // Change DW_OP_plus to DW_OP_plus_uconst.
567 // Change DW_OP_minus to DW_OP_uconst, DW_OP_minus
568 auto SubExpr = ArrayRef<uint64_t>(Expr);
569 while (!SubExpr.empty()) {
570 // Skip past other operators with their operands
571 // for this version of the IR, obtained from
572 // from historic DIExpression::ExprOperand::getSize().
573 size_t HistoricSize;
574 switch (SubExpr.front()) {
575 default:
576 HistoricSize = 1;
577 break;
578 case dwarf::DW_OP_constu:
579 case dwarf::DW_OP_minus:
580 case dwarf::DW_OP_plus:
581 HistoricSize = 2;
582 break;
583 case dwarf::DW_OP_LLVM_fragment:
584 HistoricSize = 3;
585 break;
586 }
587
588 // If the expression is malformed, make sure we don't
589 // copy more elements than we should.
590 HistoricSize = std::min(SubExpr.size(), HistoricSize);
591 ArrayRef<uint64_t> Args = SubExpr.slice(1, HistoricSize-1);
592
593 switch (SubExpr.front()) {
594 case dwarf::DW_OP_plus:
595 Buffer.push_back(dwarf::DW_OP_plus_uconst);
596 Buffer.append(Args.begin(), Args.end());
597 break;
598 case dwarf::DW_OP_minus:
599 Buffer.push_back(dwarf::DW_OP_constu);
600 Buffer.append(Args.begin(), Args.end());
601 Buffer.push_back(dwarf::DW_OP_minus);
602 break;
603 default:
604 Buffer.push_back(*SubExpr.begin());
605 Buffer.append(Args.begin(), Args.end());
606 break;
607 }
608
609 // Continue with remaining elements.
610 SubExpr = SubExpr.slice(HistoricSize);
611 }
612 Expr = MutableArrayRef<uint64_t>(Buffer);
613 LLVM_FALLTHROUGH[[clang::fallthrough]];
614 }
615 case 3:
616 // Up-to-date!
617 break;
618 }
619
620 return Error::success();
621 }
622
623 void upgradeDebugInfo() {
624 upgradeCUSubprograms();
625 upgradeCUVariables();
626 }
627
628public:
629 MetadataLoaderImpl(BitstreamCursor &Stream, Module &TheModule,
630 BitcodeReaderValueList &ValueList,
631 std::function<Type *(unsigned)> getTypeByID,
632 bool IsImporting)
633 : MetadataList(TheModule.getContext()), ValueList(ValueList),
634 Stream(Stream), Context(TheModule.getContext()), TheModule(TheModule),
635 getTypeByID(std::move(getTypeByID)), IsImporting(IsImporting) {}
636
637 Error parseMetadata(bool ModuleLevel);
638
639 bool hasFwdRefs() const { return MetadataList.hasFwdRefs(); }
640
641 Metadata *getMetadataFwdRefOrLoad(unsigned ID) {
642 if (ID < MDStringRef.size())
643 return lazyLoadOneMDString(ID);
644 if (auto *MD = MetadataList.lookup(ID))
645 return MD;
646 // If lazy-loading is enabled, we try recursively to load the operand
647 // instead of creating a temporary.
648 if (ID < (MDStringRef.size() + GlobalMetadataBitPosIndex.size())) {
649 PlaceholderQueue Placeholders;
650 lazyLoadOneMetadata(ID, Placeholders);
651 resolveForwardRefsAndPlaceholders(Placeholders);
652 return MetadataList.lookup(ID);
653 }
654 return MetadataList.getMetadataFwdRef(ID);
655 }
656
657 MDNode *getMDNodeFwdRefOrNull(unsigned Idx) {
658 return MetadataList.getMDNodeFwdRefOrNull(Idx);
659 }
660
661 DISubprogram *lookupSubprogramForFunction(Function *F) {
662 return FunctionsWithSPs.lookup(F);
663 }
664
665 bool hasSeenOldLoopTags() { return HasSeenOldLoopTags; }
666
667 Error parseMetadataAttachment(
668 Function &F, const SmallVectorImpl<Instruction *> &InstructionList);
669
670 Error parseMetadataKinds();
671
672 void setStripTBAA(bool Value) { StripTBAA = Value; }
673 bool isStrippingTBAA() { return StripTBAA; }
674
675 unsigned size() const { return MetadataList.size(); }
676 void shrinkTo(unsigned N) { MetadataList.shrinkTo(N); }
677 void upgradeDebugIntrinsics(Function &F) { upgradeDeclareExpressions(F); }
678};
679
680Expected<bool>
681MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
682 IndexCursor = Stream;
683 SmallVector<uint64_t, 64> Record;
684 // Get the abbrevs, and preload record positions to make them lazy-loadable.
685 while (true) {
686 BitstreamEntry Entry = IndexCursor.advanceSkippingSubblocks(
687 BitstreamCursor::AF_DontPopBlockAtEnd);
688 switch (Entry.Kind) {
689 case BitstreamEntry::SubBlock: // Handled for us already.
690 case BitstreamEntry::Error:
691 return error("Malformed block");
692 case BitstreamEntry::EndBlock: {
693 return true;
694 }
695 case BitstreamEntry::Record: {
696 // The interesting case.
697 ++NumMDRecordLoaded;
698 uint64_t CurrentPos = IndexCursor.GetCurrentBitNo();
699 auto Code = IndexCursor.skipRecord(Entry.ID);
700 switch (Code) {
701 case bitc::METADATA_STRINGS: {
702 // Rewind and parse the strings.
703 IndexCursor.JumpToBit(CurrentPos);
704 StringRef Blob;
705 Record.clear();
706 IndexCursor.readRecord(Entry.ID, Record, &Blob);
707 unsigned NumStrings = Record[0];
708 MDStringRef.reserve(NumStrings);
709 auto IndexNextMDString = [&](StringRef Str) {
710 MDStringRef.push_back(Str);
711 };
712 if (auto Err = parseMetadataStrings(Record, Blob, IndexNextMDString))
713 return std::move(Err);
714 break;
715 }
716 case bitc::METADATA_INDEX_OFFSET: {
717 // This is the offset to the index, when we see this we skip all the
718 // records and load only an index to these.
719 IndexCursor.JumpToBit(CurrentPos);
720 Record.clear();
721 IndexCursor.readRecord(Entry.ID, Record);
722 if (Record.size() != 2)
723 return error("Invalid record");
724 auto Offset = Record[0] + (Record[1] << 32);
725 auto BeginPos = IndexCursor.GetCurrentBitNo();
726 IndexCursor.JumpToBit(BeginPos + Offset);
727 Entry = IndexCursor.advanceSkippingSubblocks(
728 BitstreamCursor::AF_DontPopBlockAtEnd);
729 assert(Entry.Kind == BitstreamEntry::Record &&(static_cast <bool> (Entry.Kind == BitstreamEntry::Record
&& "Corrupted bitcode: Expected `Record` when trying to find the "
"Metadata index") ? void (0) : __assert_fail ("Entry.Kind == BitstreamEntry::Record && \"Corrupted bitcode: Expected `Record` when trying to find the \" \"Metadata index\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 731, __extension__ __PRETTY_FUNCTION__))
730 "Corrupted bitcode: Expected `Record` when trying to find the "(static_cast <bool> (Entry.Kind == BitstreamEntry::Record
&& "Corrupted bitcode: Expected `Record` when trying to find the "
"Metadata index") ? void (0) : __assert_fail ("Entry.Kind == BitstreamEntry::Record && \"Corrupted bitcode: Expected `Record` when trying to find the \" \"Metadata index\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 731, __extension__ __PRETTY_FUNCTION__))
731 "Metadata index")(static_cast <bool> (Entry.Kind == BitstreamEntry::Record
&& "Corrupted bitcode: Expected `Record` when trying to find the "
"Metadata index") ? void (0) : __assert_fail ("Entry.Kind == BitstreamEntry::Record && \"Corrupted bitcode: Expected `Record` when trying to find the \" \"Metadata index\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 731, __extension__ __PRETTY_FUNCTION__))
;
732 Record.clear();
733 auto Code = IndexCursor.readRecord(Entry.ID, Record);
734 (void)Code;
735 assert(Code == bitc::METADATA_INDEX && "Corrupted bitcode: Expected "(static_cast <bool> (Code == bitc::METADATA_INDEX &&
"Corrupted bitcode: Expected " "`METADATA_INDEX` when trying "
"to find the Metadata index") ? void (0) : __assert_fail ("Code == bitc::METADATA_INDEX && \"Corrupted bitcode: Expected \" \"`METADATA_INDEX` when trying \" \"to find the Metadata index\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 737, __extension__ __PRETTY_FUNCTION__))
736 "`METADATA_INDEX` when trying "(static_cast <bool> (Code == bitc::METADATA_INDEX &&
"Corrupted bitcode: Expected " "`METADATA_INDEX` when trying "
"to find the Metadata index") ? void (0) : __assert_fail ("Code == bitc::METADATA_INDEX && \"Corrupted bitcode: Expected \" \"`METADATA_INDEX` when trying \" \"to find the Metadata index\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 737, __extension__ __PRETTY_FUNCTION__))
737 "to find the Metadata index")(static_cast <bool> (Code == bitc::METADATA_INDEX &&
"Corrupted bitcode: Expected " "`METADATA_INDEX` when trying "
"to find the Metadata index") ? void (0) : __assert_fail ("Code == bitc::METADATA_INDEX && \"Corrupted bitcode: Expected \" \"`METADATA_INDEX` when trying \" \"to find the Metadata index\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 737, __extension__ __PRETTY_FUNCTION__))
;
738
739 // Delta unpack
740 auto CurrentValue = BeginPos;
741 GlobalMetadataBitPosIndex.reserve(Record.size());
742 for (auto &Elt : Record) {
743 CurrentValue += Elt;
744 GlobalMetadataBitPosIndex.push_back(CurrentValue);
745 }
746 break;
747 }
748 case bitc::METADATA_INDEX:
749 // We don't expect to get there, the Index is loaded when we encounter
750 // the offset.
751 return error("Corrupted Metadata block");
752 case bitc::METADATA_NAME: {
753 // Named metadata need to be materialized now and aren't deferred.
754 IndexCursor.JumpToBit(CurrentPos);
755 Record.clear();
756 unsigned Code = IndexCursor.readRecord(Entry.ID, Record);
757 assert(Code == bitc::METADATA_NAME)(static_cast <bool> (Code == bitc::METADATA_NAME) ? void
(0) : __assert_fail ("Code == bitc::METADATA_NAME", "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 757, __extension__ __PRETTY_FUNCTION__))
;
758
759 // Read name of the named metadata.
760 SmallString<8> Name(Record.begin(), Record.end());
761 Code = IndexCursor.ReadCode();
762
763 // Named Metadata comes in two parts, we expect the name to be followed
764 // by the node
765 Record.clear();
766 unsigned NextBitCode = IndexCursor.readRecord(Code, Record);
767 assert(NextBitCode == bitc::METADATA_NAMED_NODE)(static_cast <bool> (NextBitCode == bitc::METADATA_NAMED_NODE
) ? void (0) : __assert_fail ("NextBitCode == bitc::METADATA_NAMED_NODE"
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 767, __extension__ __PRETTY_FUNCTION__))
;
768 (void)NextBitCode;
769
770 // Read named metadata elements.
771 unsigned Size = Record.size();
772 NamedMDNode *NMD = TheModule.getOrInsertNamedMetadata(Name);
773 for (unsigned i = 0; i != Size; ++i) {
774 // FIXME: We could use a placeholder here, however NamedMDNode are
775 // taking MDNode as operand and not using the Metadata infrastructure.
776 // It is acknowledged by 'TODO: Inherit from Metadata' in the
777 // NamedMDNode class definition.
778 MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[i]);
779 assert(MD && "Invalid record")(static_cast <bool> (MD && "Invalid record") ? void
(0) : __assert_fail ("MD && \"Invalid record\"", "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 779, __extension__ __PRETTY_FUNCTION__))
;
780 NMD->addOperand(MD);
781 }
782 break;
783 }
784 case bitc::METADATA_GLOBAL_DECL_ATTACHMENT: {
785 // FIXME: we need to do this early because we don't materialize global
786 // value explicitly.
787 IndexCursor.JumpToBit(CurrentPos);
788 Record.clear();
789 IndexCursor.readRecord(Entry.ID, Record);
790 if (Record.size() % 2 == 0)
791 return error("Invalid record");
792 unsigned ValueID = Record[0];
793 if (ValueID >= ValueList.size())
794 return error("Invalid record");
795 if (auto *GO = dyn_cast<GlobalObject>(ValueList[ValueID]))
796 if (Error Err = parseGlobalObjectAttachment(
797 *GO, ArrayRef<uint64_t>(Record).slice(1)))
798 return std::move(Err);
799 break;
800 }
801 case bitc::METADATA_KIND:
802 case bitc::METADATA_STRING_OLD:
803 case bitc::METADATA_OLD_FN_NODE:
804 case bitc::METADATA_OLD_NODE:
805 case bitc::METADATA_VALUE:
806 case bitc::METADATA_DISTINCT_NODE:
807 case bitc::METADATA_NODE:
808 case bitc::METADATA_LOCATION:
809 case bitc::METADATA_GENERIC_DEBUG:
810 case bitc::METADATA_SUBRANGE:
811 case bitc::METADATA_ENUMERATOR:
812 case bitc::METADATA_BASIC_TYPE:
813 case bitc::METADATA_DERIVED_TYPE:
814 case bitc::METADATA_COMPOSITE_TYPE:
815 case bitc::METADATA_SUBROUTINE_TYPE:
816 case bitc::METADATA_MODULE:
817 case bitc::METADATA_FILE:
818 case bitc::METADATA_COMPILE_UNIT:
819 case bitc::METADATA_SUBPROGRAM:
820 case bitc::METADATA_LEXICAL_BLOCK:
821 case bitc::METADATA_LEXICAL_BLOCK_FILE:
822 case bitc::METADATA_NAMESPACE:
823 case bitc::METADATA_MACRO:
824 case bitc::METADATA_MACRO_FILE:
825 case bitc::METADATA_TEMPLATE_TYPE:
826 case bitc::METADATA_TEMPLATE_VALUE:
827 case bitc::METADATA_GLOBAL_VAR:
828 case bitc::METADATA_LOCAL_VAR:
829 case bitc::METADATA_EXPRESSION:
830 case bitc::METADATA_OBJC_PROPERTY:
831 case bitc::METADATA_IMPORTED_ENTITY:
832 case bitc::METADATA_GLOBAL_VAR_EXPR:
833 // We don't expect to see any of these, if we see one, give up on
834 // lazy-loading and fallback.
835 MDStringRef.clear();
836 GlobalMetadataBitPosIndex.clear();
837 return false;
838 }
839 break;
840 }
841 }
842 }
843}
844
845/// Parse a METADATA_BLOCK. If ModuleLevel is true then we are parsing
846/// module level metadata.
847Error MetadataLoader::MetadataLoaderImpl::parseMetadata(bool ModuleLevel) {
848 if (!ModuleLevel && MetadataList.hasFwdRefs())
849 return error("Invalid metadata: fwd refs into function blocks");
850
851 // Record the entry position so that we can jump back here and efficiently
852 // skip the whole block in case we lazy-load.
853 auto EntryPos = Stream.GetCurrentBitNo();
854
855 if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
856 return error("Invalid record");
857
858 SmallVector<uint64_t, 64> Record;
859 PlaceholderQueue Placeholders;
860
861 // We lazy-load module-level metadata: we build an index for each record, and
862 // then load individual record as needed, starting with the named metadata.
863 if (ModuleLevel && IsImporting && MetadataList.empty() &&
864 !DisableLazyLoading) {
865 auto SuccessOrErr = lazyLoadModuleMetadataBlock();
866 if (!SuccessOrErr)
867 return SuccessOrErr.takeError();
868 if (SuccessOrErr.get()) {
869 // An index was successfully created and we will be able to load metadata
870 // on-demand.
871 MetadataList.resize(MDStringRef.size() +
872 GlobalMetadataBitPosIndex.size());
873
874 // Reading the named metadata created forward references and/or
875 // placeholders, that we flush here.
876 resolveForwardRefsAndPlaceholders(Placeholders);
877 upgradeDebugInfo();
878 // Return at the beginning of the block, since it is easy to skip it
879 // entirely from there.
880 Stream.ReadBlockEnd(); // Pop the abbrev block context.
881 Stream.JumpToBit(EntryPos);
882 if (Stream.SkipBlock())
883 return error("Invalid record");
884 return Error::success();
885 }
886 // Couldn't load an index, fallback to loading all the block "old-style".
887 }
888
889 unsigned NextMetadataNo = MetadataList.size();
890
891 // Read all the records.
892 while (true) {
893 BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
894
895 switch (Entry.Kind) {
896 case BitstreamEntry::SubBlock: // Handled for us already.
897 case BitstreamEntry::Error:
898 return error("Malformed block");
899 case BitstreamEntry::EndBlock:
900 resolveForwardRefsAndPlaceholders(Placeholders);
901 upgradeDebugInfo();
902 return Error::success();
903 case BitstreamEntry::Record:
904 // The interesting case.
905 break;
906 }
907
908 // Read a record.
909 Record.clear();
910 StringRef Blob;
911 ++NumMDRecordLoaded;
912 unsigned Code = Stream.readRecord(Entry.ID, Record, &Blob);
913 if (Error Err =
914 parseOneMetadata(Record, Code, Placeholders, Blob, NextMetadataNo))
915 return Err;
916 }
917}
918
919MDString *MetadataLoader::MetadataLoaderImpl::lazyLoadOneMDString(unsigned ID) {
920 ++NumMDStringLoaded;
921 if (Metadata *MD = MetadataList.lookup(ID))
922 return cast<MDString>(MD);
923 auto MDS = MDString::get(Context, MDStringRef[ID]);
924 MetadataList.assignValue(MDS, ID);
925 return MDS;
926}
927
928void MetadataLoader::MetadataLoaderImpl::lazyLoadOneMetadata(
929 unsigned ID, PlaceholderQueue &Placeholders) {
930 assert(ID < (MDStringRef.size()) + GlobalMetadataBitPosIndex.size())(static_cast <bool> (ID < (MDStringRef.size()) + GlobalMetadataBitPosIndex
.size()) ? void (0) : __assert_fail ("ID < (MDStringRef.size()) + GlobalMetadataBitPosIndex.size()"
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 930, __extension__ __PRETTY_FUNCTION__))
;
931 assert(ID >= MDStringRef.size() && "Unexpected lazy-loading of MDString")(static_cast <bool> (ID >= MDStringRef.size() &&
"Unexpected lazy-loading of MDString") ? void (0) : __assert_fail
("ID >= MDStringRef.size() && \"Unexpected lazy-loading of MDString\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 931, __extension__ __PRETTY_FUNCTION__))
;
932 // Lookup first if the metadata hasn't already been loaded.
933 if (auto *MD = MetadataList.lookup(ID)) {
934 auto *N = dyn_cast_or_null<MDNode>(MD);
935 if (!N->isTemporary())
936 return;
937 }
938 SmallVector<uint64_t, 64> Record;
939 StringRef Blob;
940 IndexCursor.JumpToBit(GlobalMetadataBitPosIndex[ID - MDStringRef.size()]);
941 auto Entry = IndexCursor.advanceSkippingSubblocks();
942 ++NumMDRecordLoaded;
943 unsigned Code = IndexCursor.readRecord(Entry.ID, Record, &Blob);
944 if (Error Err = parseOneMetadata(Record, Code, Placeholders, Blob, ID))
945 report_fatal_error("Can't lazyload MD");
946}
947
948/// Ensure that all forward-references and placeholders are resolved.
949/// Iteratively lazy-loading metadata on-demand if needed.
950void MetadataLoader::MetadataLoaderImpl::resolveForwardRefsAndPlaceholders(
951 PlaceholderQueue &Placeholders) {
952 DenseSet<unsigned> Temporaries;
953 while (1) {
954 // Populate Temporaries with the placeholders that haven't been loaded yet.
955 Placeholders.getTemporaries(MetadataList, Temporaries);
956
957 // If we don't have any temporary, or FwdReference, we're done!
958 if (Temporaries.empty() && !MetadataList.hasFwdRefs())
959 break;
960
961 // First, load all the temporaries. This can add new placeholders or
962 // forward references.
963 for (auto ID : Temporaries)
964 lazyLoadOneMetadata(ID, Placeholders);
965 Temporaries.clear();
966
967 // Second, load the forward-references. This can also add new placeholders
968 // or forward references.
969 while (MetadataList.hasFwdRefs())
970 lazyLoadOneMetadata(MetadataList.getNextFwdRef(), Placeholders);
971 }
972 // At this point we don't have any forward reference remaining, or temporary
973 // that haven't been loaded. We can safely drop RAUW support and mark cycles
974 // as resolved.
975 MetadataList.tryToResolveCycles();
976
977 // Finally, everything is in place, we can replace the placeholders operands
978 // with the final node they refer to.
979 Placeholders.flush(MetadataList);
980}
981
982Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
983 SmallVectorImpl<uint64_t> &Record, unsigned Code,
984 PlaceholderQueue &Placeholders, StringRef Blob, unsigned &NextMetadataNo) {
985
986 bool IsDistinct = false;
987 auto getMD = [&](unsigned ID) -> Metadata * {
988 if (ID < MDStringRef.size())
989 return lazyLoadOneMDString(ID);
990 if (!IsDistinct) {
991 if (auto *MD = MetadataList.lookup(ID))
992 return MD;
993 // If lazy-loading is enabled, we try recursively to load the operand
994 // instead of creating a temporary.
995 if (ID < (MDStringRef.size() + GlobalMetadataBitPosIndex.size())) {
996 // Create a temporary for the node that is referencing the operand we
997 // will lazy-load. It is needed before recursing in case there are
998 // uniquing cycles.
999 MetadataList.getMetadataFwdRef(NextMetadataNo);
1000 lazyLoadOneMetadata(ID, Placeholders);
1001 return MetadataList.lookup(ID);
1002 }
1003 // Return a temporary.
1004 return MetadataList.getMetadataFwdRef(ID);
1005 }
1006 if (auto *MD = MetadataList.getMetadataIfResolved(ID))
1007 return MD;
1008 return &Placeholders.getPlaceholderOp(ID);
1009 };
1010 auto getMDOrNull = [&](unsigned ID) -> Metadata * {
1011 if (ID)
1012 return getMD(ID - 1);
1013 return nullptr;
1014 };
1015 auto getMDOrNullWithoutPlaceholders = [&](unsigned ID) -> Metadata * {
1016 if (ID)
1017 return MetadataList.getMetadataFwdRef(ID - 1);
1018 return nullptr;
1019 };
1020 auto getMDString = [&](unsigned ID) -> MDString * {
1021 // This requires that the ID is not really a forward reference. In
1022 // particular, the MDString must already have been resolved.
1023 auto MDS = getMDOrNull(ID);
1024 return cast_or_null<MDString>(MDS);
1025 };
1026
1027 // Support for old type refs.
1028 auto getDITypeRefOrNull = [&](unsigned ID) {
1029 return MetadataList.upgradeTypeRef(getMDOrNull(ID));
1030 };
1031
1032#define GET_OR_DISTINCT(CLASS, ARGS) \
1033 (IsDistinct ? CLASS::getDistinct ARGS : CLASS::get ARGS)
1034
1035 switch (Code) {
1036 default: // Default behavior: ignore.
1037 break;
1038 case bitc::METADATA_NAME: {
1039 // Read name of the named metadata.
1040 SmallString<8> Name(Record.begin(), Record.end());
1041 Record.clear();
1042 Code = Stream.ReadCode();
1043
1044 ++NumMDRecordLoaded;
1045 unsigned NextBitCode = Stream.readRecord(Code, Record);
1046 if (NextBitCode != bitc::METADATA_NAMED_NODE)
1047 return error("METADATA_NAME not followed by METADATA_NAMED_NODE");
1048
1049 // Read named metadata elements.
1050 unsigned Size = Record.size();
1051 NamedMDNode *NMD = TheModule.getOrInsertNamedMetadata(Name);
1052 for (unsigned i = 0; i != Size; ++i) {
1053 MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[i]);
1054 if (!MD)
1055 return error("Invalid record");
1056 NMD->addOperand(MD);
1057 }
1058 break;
1059 }
1060 case bitc::METADATA_OLD_FN_NODE: {
1061 // FIXME: Remove in 4.0.
1062 // This is a LocalAsMetadata record, the only type of function-local
1063 // metadata.
1064 if (Record.size() % 2 == 1)
1065 return error("Invalid record");
1066
1067 // If this isn't a LocalAsMetadata record, we're dropping it. This used
1068 // to be legal, but there's no upgrade path.
1069 auto dropRecord = [&] {
1070 MetadataList.assignValue(MDNode::get(Context, None), NextMetadataNo);
1071 NextMetadataNo++;
1072 };
1073 if (Record.size() != 2) {
1074 dropRecord();
1075 break;
1076 }
1077
1078 Type *Ty = getTypeByID(Record[0]);
1079 if (Ty->isMetadataTy() || Ty->isVoidTy()) {
1080 dropRecord();
1081 break;
1082 }
1083
1084 MetadataList.assignValue(
1085 LocalAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty)),
1086 NextMetadataNo);
1087 NextMetadataNo++;
1088 break;
1089 }
1090 case bitc::METADATA_OLD_NODE: {
1091 // FIXME: Remove in 4.0.
1092 if (Record.size() % 2 == 1)
1093 return error("Invalid record");
1094
1095 unsigned Size = Record.size();
1096 SmallVector<Metadata *, 8> Elts;
1097 for (unsigned i = 0; i != Size; i += 2) {
1098 Type *Ty = getTypeByID(Record[i]);
1099 if (!Ty)
1100 return error("Invalid record");
1101 if (Ty->isMetadataTy())
1102 Elts.push_back(getMD(Record[i + 1]));
1103 else if (!Ty->isVoidTy()) {
1104 auto *MD =
1105 ValueAsMetadata::get(ValueList.getValueFwdRef(Record[i + 1], Ty));
1106 assert(isa<ConstantAsMetadata>(MD) &&(static_cast <bool> (isa<ConstantAsMetadata>(MD) &&
"Expected non-function-local metadata") ? void (0) : __assert_fail
("isa<ConstantAsMetadata>(MD) && \"Expected non-function-local metadata\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 1107, __extension__ __PRETTY_FUNCTION__))
1107 "Expected non-function-local metadata")(static_cast <bool> (isa<ConstantAsMetadata>(MD) &&
"Expected non-function-local metadata") ? void (0) : __assert_fail
("isa<ConstantAsMetadata>(MD) && \"Expected non-function-local metadata\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 1107, __extension__ __PRETTY_FUNCTION__))
;
1108 Elts.push_back(MD);
1109 } else
1110 Elts.push_back(nullptr);
1111 }
1112 MetadataList.assignValue(MDNode::get(Context, Elts), NextMetadataNo);
1113 NextMetadataNo++;
1114 break;
1115 }
1116 case bitc::METADATA_VALUE: {
1117 if (Record.size() != 2)
1118 return error("Invalid record");
1119
1120 Type *Ty = getTypeByID(Record[0]);
1121 if (Ty->isMetadataTy() || Ty->isVoidTy())
1122 return error("Invalid record");
1123
1124 MetadataList.assignValue(
1125 ValueAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty)),
1126 NextMetadataNo);
1127 NextMetadataNo++;
1128 break;
1129 }
1130 case bitc::METADATA_DISTINCT_NODE:
1131 IsDistinct = true;
1132 LLVM_FALLTHROUGH[[clang::fallthrough]];
1133 case bitc::METADATA_NODE: {
1134 SmallVector<Metadata *, 8> Elts;
1135 Elts.reserve(Record.size());
1136 for (unsigned ID : Record)
1137 Elts.push_back(getMDOrNull(ID));
1138 MetadataList.assignValue(IsDistinct ? MDNode::getDistinct(Context, Elts)
1139 : MDNode::get(Context, Elts),
1140 NextMetadataNo);
1141 NextMetadataNo++;
1142 break;
1143 }
1144 case bitc::METADATA_LOCATION: {
1145 if (Record.size() != 5)
1146 return error("Invalid record");
1147
1148 IsDistinct = Record[0];
1149 unsigned Line = Record[1];
1150 unsigned Column = Record[2];
1151 Metadata *Scope = getMD(Record[3]);
1152 Metadata *InlinedAt = getMDOrNull(Record[4]);
1153 MetadataList.assignValue(
1154 GET_OR_DISTINCT(DILocation, (Context, Line, Column, Scope, InlinedAt)),
1155 NextMetadataNo);
1156 NextMetadataNo++;
1157 break;
1158 }
1159 case bitc::METADATA_GENERIC_DEBUG: {
1160 if (Record.size() < 4)
1161 return error("Invalid record");
1162
1163 IsDistinct = Record[0];
1164 unsigned Tag = Record[1];
1165 unsigned Version = Record[2];
1166
1167 if (Tag >= 1u << 16 || Version != 0)
1168 return error("Invalid record");
1169
1170 auto *Header = getMDString(Record[3]);
1171 SmallVector<Metadata *, 8> DwarfOps;
1172 for (unsigned I = 4, E = Record.size(); I != E; ++I)
1173 DwarfOps.push_back(getMDOrNull(Record[I]));
1174 MetadataList.assignValue(
1175 GET_OR_DISTINCT(GenericDINode, (Context, Tag, Header, DwarfOps)),
1176 NextMetadataNo);
1177 NextMetadataNo++;
1178 break;
1179 }
1180 case bitc::METADATA_SUBRANGE: {
1181 if (Record.size() != 3)
1182 return error("Invalid record");
1183
1184 IsDistinct = Record[0];
1185 MetadataList.assignValue(
1186 GET_OR_DISTINCT(DISubrange,
1187 (Context, Record[1], unrotateSign(Record[2]))),
1188 NextMetadataNo);
1189 NextMetadataNo++;
1190 break;
1191 }
1192 case bitc::METADATA_ENUMERATOR: {
1193 if (Record.size() != 3)
1194 return error("Invalid record");
1195
1196 IsDistinct = Record[0];
1197 MetadataList.assignValue(
1198 GET_OR_DISTINCT(DIEnumerator, (Context, unrotateSign(Record[1]),
1199 getMDString(Record[2]))),
1200 NextMetadataNo);
1201 NextMetadataNo++;
1202 break;
1203 }
1204 case bitc::METADATA_BASIC_TYPE: {
1205 if (Record.size() != 6)
1206 return error("Invalid record");
1207
1208 IsDistinct = Record[0];
1209 MetadataList.assignValue(
1210 GET_OR_DISTINCT(DIBasicType,
1211 (Context, Record[1], getMDString(Record[2]), Record[3],
1212 Record[4], Record[5])),
1213 NextMetadataNo);
1214 NextMetadataNo++;
1215 break;
1216 }
1217 case bitc::METADATA_DERIVED_TYPE: {
1218 if (Record.size() < 12 || Record.size() > 13)
1219 return error("Invalid record");
1220
1221 // DWARF address space is encoded as N->getDWARFAddressSpace() + 1. 0 means
1222 // that there is no DWARF address space associated with DIDerivedType.
1223 Optional<unsigned> DWARFAddressSpace;
1224 if (Record.size() > 12 && Record[12])
1225 DWARFAddressSpace = Record[12] - 1;
1226
1227 IsDistinct = Record[0];
1228 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[10]);
1229 MetadataList.assignValue(
1230 GET_OR_DISTINCT(DIDerivedType,
1231 (Context, Record[1], getMDString(Record[2]),
1232 getMDOrNull(Record[3]), Record[4],
1233 getDITypeRefOrNull(Record[5]),
1234 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1235 Record[9], DWARFAddressSpace, Flags,
1236 getDITypeRefOrNull(Record[11]))),
1237 NextMetadataNo);
1238 NextMetadataNo++;
1239 break;
1240 }
1241 case bitc::METADATA_COMPOSITE_TYPE: {
1242 if (Record.size() != 16)
1243 return error("Invalid record");
1244
1245 // If we have a UUID and this is not a forward declaration, lookup the
1246 // mapping.
1247 IsDistinct = Record[0] & 0x1;
1248 bool IsNotUsedInTypeRef = Record[0] >= 2;
1249 unsigned Tag = Record[1];
1250 MDString *Name = getMDString(Record[2]);
1251 Metadata *File = getMDOrNull(Record[3]);
1252 unsigned Line = Record[4];
1253 Metadata *Scope = getDITypeRefOrNull(Record[5]);
1254 Metadata *BaseType = nullptr;
1255 uint64_t SizeInBits = Record[7];
1256 if (Record[8] > (uint64_t)std::numeric_limits<uint32_t>::max())
1257 return error("Alignment value is too large");
1258 uint32_t AlignInBits = Record[8];
1259 uint64_t OffsetInBits = 0;
1260 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[10]);
1261 Metadata *Elements = nullptr;
1262 unsigned RuntimeLang = Record[12];
1263 Metadata *VTableHolder = nullptr;
1264 Metadata *TemplateParams = nullptr;
1265 auto *Identifier = getMDString(Record[15]);
1266 // If this module is being parsed so that it can be ThinLTO imported
1267 // into another module, composite types only need to be imported
1268 // as type declarations (unless full type definitions requested).
1269 // Create type declarations up front to save memory. Also, buildODRType
1270 // handles the case where this is type ODRed with a definition needed
1271 // by the importing module, in which case the existing definition is
1272 // used.
1273 if (IsImporting && !ImportFullTypeDefinitions && Identifier &&
1274 (Tag == dwarf::DW_TAG_enumeration_type ||
1275 Tag == dwarf::DW_TAG_class_type ||
1276 Tag == dwarf::DW_TAG_structure_type ||
1277 Tag == dwarf::DW_TAG_union_type)) {
1278 Flags = Flags | DINode::FlagFwdDecl;
1279 } else {
1280 BaseType = getDITypeRefOrNull(Record[6]);
1281 OffsetInBits = Record[9];
1282 Elements = getMDOrNull(Record[11]);
1283 VTableHolder = getDITypeRefOrNull(Record[13]);
1284 TemplateParams = getMDOrNull(Record[14]);
1285 }
1286 DICompositeType *CT = nullptr;
1287 if (Identifier)
1288 CT = DICompositeType::buildODRType(
1289 Context, *Identifier, Tag, Name, File, Line, Scope, BaseType,
1290 SizeInBits, AlignInBits, OffsetInBits, Flags, Elements, RuntimeLang,
1291 VTableHolder, TemplateParams);
1292
1293 // Create a node if we didn't get a lazy ODR type.
1294 if (!CT)
1295 CT = GET_OR_DISTINCT(DICompositeType,
1296 (Context, Tag, Name, File, Line, Scope, BaseType,
1297 SizeInBits, AlignInBits, OffsetInBits, Flags,
1298 Elements, RuntimeLang, VTableHolder, TemplateParams,
1299 Identifier));
1300 if (!IsNotUsedInTypeRef && Identifier)
1301 MetadataList.addTypeRef(*Identifier, *cast<DICompositeType>(CT));
1302
1303 MetadataList.assignValue(CT, NextMetadataNo);
1304 NextMetadataNo++;
1305 break;
1306 }
1307 case bitc::METADATA_SUBROUTINE_TYPE: {
1308 if (Record.size() < 3 || Record.size() > 4)
1309 return error("Invalid record");
1310 bool IsOldTypeRefArray = Record[0] < 2;
1311 unsigned CC = (Record.size() > 3) ? Record[3] : 0;
1312
1313 IsDistinct = Record[0] & 0x1;
1314 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[1]);
1315 Metadata *Types = getMDOrNull(Record[2]);
1316 if (LLVM_UNLIKELY(IsOldTypeRefArray)__builtin_expect((bool)(IsOldTypeRefArray), false))
1317 Types = MetadataList.upgradeTypeRefArray(Types);
1318
1319 MetadataList.assignValue(
1320 GET_OR_DISTINCT(DISubroutineType, (Context, Flags, CC, Types)),
1321 NextMetadataNo);
1322 NextMetadataNo++;
1323 break;
1324 }
1325
1326 case bitc::METADATA_MODULE: {
1327 if (Record.size() != 6)
1328 return error("Invalid record");
1329
1330 IsDistinct = Record[0];
1331 MetadataList.assignValue(
1332 GET_OR_DISTINCT(DIModule,
1333 (Context, getMDOrNull(Record[1]),
1334 getMDString(Record[2]), getMDString(Record[3]),
1335 getMDString(Record[4]), getMDString(Record[5]))),
1336 NextMetadataNo);
1337 NextMetadataNo++;
1338 break;
1339 }
1340
1341 case bitc::METADATA_FILE: {
1342 if (Record.size() != 3 && Record.size() != 5)
1343 return error("Invalid record");
1344
1345 IsDistinct = Record[0];
1346 MetadataList.assignValue(
1347 GET_OR_DISTINCT(
1348 DIFile,
1349 (Context, getMDString(Record[1]), getMDString(Record[2]),
1350 Record.size() == 3 ? DIFile::CSK_None
1351 : static_cast<DIFile::ChecksumKind>(Record[3]),
1352 Record.size() == 3 ? nullptr : getMDString(Record[4]))),
1353 NextMetadataNo);
1354 NextMetadataNo++;
1355 break;
1356 }
1357 case bitc::METADATA_COMPILE_UNIT: {
1358 if (Record.size() < 14 || Record.size() > 19)
1359 return error("Invalid record");
1360
1361 // Ignore Record[0], which indicates whether this compile unit is
1362 // distinct. It's always distinct.
1363 IsDistinct = true;
1364 auto *CU = DICompileUnit::getDistinct(
1365 Context, Record[1], getMDOrNull(Record[2]), getMDString(Record[3]),
1366 Record[4], getMDString(Record[5]), Record[6], getMDString(Record[7]),
1367 Record[8], getMDOrNull(Record[9]), getMDOrNull(Record[10]),
1368 getMDOrNull(Record[12]), getMDOrNull(Record[13]),
1369 Record.size() <= 15 ? nullptr : getMDOrNull(Record[15]),
1370 Record.size() <= 14 ? 0 : Record[14],
1371 Record.size() <= 16 ? true : Record[16],
1372 Record.size() <= 17 ? false : Record[17],
1373 Record.size() <= 18 ? false : Record[18]);
1374
1375 MetadataList.assignValue(CU, NextMetadataNo);
1376 NextMetadataNo++;
1377
1378 // Move the Upgrade the list of subprograms.
1379 if (Metadata *SPs = getMDOrNullWithoutPlaceholders(Record[11]))
1380 CUSubprograms.push_back({CU, SPs});
1381 break;
1382 }
1383 case bitc::METADATA_SUBPROGRAM: {
1384 if (Record.size() < 18 || Record.size() > 21)
1385 return error("Invalid record");
1386
1387 IsDistinct =
1388 (Record[0] & 1) || Record[8]; // All definitions should be distinct.
1389 // Version 1 has a Function as Record[15].
1390 // Version 2 has removed Record[15].
1391 // Version 3 has the Unit as Record[15].
1392 // Version 4 added thisAdjustment.
1393 bool HasUnit = Record[0] >= 2;
1394 if (HasUnit && Record.size() < 19)
1395 return error("Invalid record");
1396 Metadata *CUorFn = getMDOrNull(Record[15]);
1397 unsigned Offset = Record.size() >= 19 ? 1 : 0;
1398 bool HasFn = Offset && !HasUnit;
1399 bool HasThisAdj = Record.size() >= 20;
1400 bool HasThrownTypes = Record.size() >= 21;
1401 DISubprogram *SP = GET_OR_DISTINCT(
1402 DISubprogram,
1403 (Context,
1404 getDITypeRefOrNull(Record[1]), // scope
1405 getMDString(Record[2]), // name
1406 getMDString(Record[3]), // linkageName
1407 getMDOrNull(Record[4]), // file
1408 Record[5], // line
1409 getMDOrNull(Record[6]), // type
1410 Record[7], // isLocal
1411 Record[8], // isDefinition
1412 Record[9], // scopeLine
1413 getDITypeRefOrNull(Record[10]), // containingType
1414 Record[11], // virtuality
1415 Record[12], // virtualIndex
1416 HasThisAdj ? Record[19] : 0, // thisAdjustment
1417 static_cast<DINode::DIFlags>(Record[13]), // flags
1418 Record[14], // isOptimized
1419 HasUnit ? CUorFn : nullptr, // unit
1420 getMDOrNull(Record[15 + Offset]), // templateParams
1421 getMDOrNull(Record[16 + Offset]), // declaration
1422 getMDOrNull(Record[17 + Offset]), // variables
1423 HasThrownTypes ? getMDOrNull(Record[20]) : nullptr // thrownTypes
1424 ));
1425 MetadataList.assignValue(SP, NextMetadataNo);
1426 NextMetadataNo++;
1427
1428 // Upgrade sp->function mapping to function->sp mapping.
1429 if (HasFn) {
1430 if (auto *CMD = dyn_cast_or_null<ConstantAsMetadata>(CUorFn))
1431 if (auto *F = dyn_cast<Function>(CMD->getValue())) {
1432 if (F->isMaterializable())
1433 // Defer until materialized; unmaterialized functions may not have
1434 // metadata.
1435 FunctionsWithSPs[F] = SP;
1436 else if (!F->empty())
1437 F->setSubprogram(SP);
1438 }
1439 }
1440 break;
1441 }
1442 case bitc::METADATA_LEXICAL_BLOCK: {
1443 if (Record.size() != 5)
1444 return error("Invalid record");
1445
1446 IsDistinct = Record[0];
1447 MetadataList.assignValue(
1448 GET_OR_DISTINCT(DILexicalBlock,
1449 (Context, getMDOrNull(Record[1]),
1450 getMDOrNull(Record[2]), Record[3], Record[4])),
1451 NextMetadataNo);
1452 NextMetadataNo++;
1453 break;
1454 }
1455 case bitc::METADATA_LEXICAL_BLOCK_FILE: {
1456 if (Record.size() != 4)
1457 return error("Invalid record");
1458
1459 IsDistinct = Record[0];
1460 MetadataList.assignValue(
1461 GET_OR_DISTINCT(DILexicalBlockFile,
1462 (Context, getMDOrNull(Record[1]),
1463 getMDOrNull(Record[2]), Record[3])),
1464 NextMetadataNo);
1465 NextMetadataNo++;
1466 break;
1467 }
1468 case bitc::METADATA_NAMESPACE: {
1469 // Newer versions of DINamespace dropped file and line.
1470 MDString *Name;
1471 if (Record.size() == 3)
1472 Name = getMDString(Record[2]);
1473 else if (Record.size() == 5)
1474 Name = getMDString(Record[3]);
1475 else
1476 return error("Invalid record");
1477
1478 IsDistinct = Record[0] & 1;
1479 bool ExportSymbols = Record[0] & 2;
1480 MetadataList.assignValue(
1481 GET_OR_DISTINCT(DINamespace,
1482 (Context, getMDOrNull(Record[1]), Name, ExportSymbols)),
1483 NextMetadataNo);
1484 NextMetadataNo++;
1485 break;
1486 }
1487 case bitc::METADATA_MACRO: {
1488 if (Record.size() != 5)
1489 return error("Invalid record");
1490
1491 IsDistinct = Record[0];
1492 MetadataList.assignValue(
1493 GET_OR_DISTINCT(DIMacro,
1494 (Context, Record[1], Record[2], getMDString(Record[3]),
1495 getMDString(Record[4]))),
1496 NextMetadataNo);
1497 NextMetadataNo++;
1498 break;
1499 }
1500 case bitc::METADATA_MACRO_FILE: {
1501 if (Record.size() != 5)
1502 return error("Invalid record");
1503
1504 IsDistinct = Record[0];
1505 MetadataList.assignValue(
1506 GET_OR_DISTINCT(DIMacroFile,
1507 (Context, Record[1], Record[2], getMDOrNull(Record[3]),
1508 getMDOrNull(Record[4]))),
1509 NextMetadataNo);
1510 NextMetadataNo++;
1511 break;
1512 }
1513 case bitc::METADATA_TEMPLATE_TYPE: {
1514 if (Record.size() != 3)
1515 return error("Invalid record");
1516
1517 IsDistinct = Record[0];
1518 MetadataList.assignValue(GET_OR_DISTINCT(DITemplateTypeParameter,
1519 (Context, getMDString(Record[1]),
1520 getDITypeRefOrNull(Record[2]))),
1521 NextMetadataNo);
1522 NextMetadataNo++;
1523 break;
1524 }
1525 case bitc::METADATA_TEMPLATE_VALUE: {
1526 if (Record.size() != 5)
1527 return error("Invalid record");
1528
1529 IsDistinct = Record[0];
1530 MetadataList.assignValue(
1531 GET_OR_DISTINCT(DITemplateValueParameter,
1532 (Context, Record[1], getMDString(Record[2]),
1533 getDITypeRefOrNull(Record[3]),
1534 getMDOrNull(Record[4]))),
1535 NextMetadataNo);
1536 NextMetadataNo++;
1537 break;
1538 }
1539 case bitc::METADATA_GLOBAL_VAR: {
1540 if (Record.size() < 11 || Record.size() > 12)
1541 return error("Invalid record");
1542
1543 IsDistinct = Record[0] & 1;
1544 unsigned Version = Record[0] >> 1;
1545
1546 if (Version == 1) {
1547 MetadataList.assignValue(
1548 GET_OR_DISTINCT(DIGlobalVariable,
1549 (Context, getMDOrNull(Record[1]),
1550 getMDString(Record[2]), getMDString(Record[3]),
1551 getMDOrNull(Record[4]), Record[5],
1552 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1553 getMDOrNull(Record[10]), Record[11])),
1554 NextMetadataNo);
1555 NextMetadataNo++;
1556 } else if (Version == 0) {
1557 // Upgrade old metadata, which stored a global variable reference or a
1558 // ConstantInt here.
1559 NeedUpgradeToDIGlobalVariableExpression = true;
1560 Metadata *Expr = getMDOrNull(Record[9]);
1561 uint32_t AlignInBits = 0;
1562 if (Record.size() > 11) {
1563 if (Record[11] > (uint64_t)std::numeric_limits<uint32_t>::max())
1564 return error("Alignment value is too large");
1565 AlignInBits = Record[11];
1566 }
1567 GlobalVariable *Attach = nullptr;
1568 if (auto *CMD = dyn_cast_or_null<ConstantAsMetadata>(Expr)) {
1569 if (auto *GV = dyn_cast<GlobalVariable>(CMD->getValue())) {
1570 Attach = GV;
1571 Expr = nullptr;
1572 } else if (auto *CI = dyn_cast<ConstantInt>(CMD->getValue())) {
1573 Expr = DIExpression::get(Context,
1574 {dwarf::DW_OP_constu, CI->getZExtValue(),
1575 dwarf::DW_OP_stack_value});
1576 } else {
1577 Expr = nullptr;
1578 }
1579 }
1580 DIGlobalVariable *DGV = GET_OR_DISTINCT(
1581 DIGlobalVariable,
1582 (Context, getMDOrNull(Record[1]), getMDString(Record[2]),
1583 getMDString(Record[3]), getMDOrNull(Record[4]), Record[5],
1584 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1585 getMDOrNull(Record[10]), AlignInBits));
1586
1587 DIGlobalVariableExpression *DGVE = nullptr;
1588 if (Attach || Expr)
1589 DGVE = DIGlobalVariableExpression::getDistinct(
1590 Context, DGV, Expr ? Expr : DIExpression::get(Context, {}));
1591 if (Attach)
1592 Attach->addDebugInfo(DGVE);
1593
1594 auto *MDNode = Expr ? cast<Metadata>(DGVE) : cast<Metadata>(DGV);
1595 MetadataList.assignValue(MDNode, NextMetadataNo);
1596 NextMetadataNo++;
1597 } else
1598 return error("Invalid record");
1599
1600 break;
1601 }
1602 case bitc::METADATA_LOCAL_VAR: {
1603 // 10th field is for the obseleted 'inlinedAt:' field.
1604 if (Record.size() < 8 || Record.size() > 10)
1605 return error("Invalid record");
1606
1607 IsDistinct = Record[0] & 1;
1608 bool HasAlignment = Record[0] & 2;
1609 // 2nd field used to be an artificial tag, either DW_TAG_auto_variable or
1610 // DW_TAG_arg_variable, if we have alignment flag encoded it means, that
1611 // this is newer version of record which doesn't have artificial tag.
1612 bool HasTag = !HasAlignment && Record.size() > 8;
1613 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[7 + HasTag]);
1614 uint32_t AlignInBits = 0;
1615 if (HasAlignment) {
1616 if (Record[8 + HasTag] > (uint64_t)std::numeric_limits<uint32_t>::max())
1617 return error("Alignment value is too large");
1618 AlignInBits = Record[8 + HasTag];
1619 }
1620 MetadataList.assignValue(
1621 GET_OR_DISTINCT(DILocalVariable,
1622 (Context, getMDOrNull(Record[1 + HasTag]),
1623 getMDString(Record[2 + HasTag]),
1624 getMDOrNull(Record[3 + HasTag]), Record[4 + HasTag],
1625 getDITypeRefOrNull(Record[5 + HasTag]),
1626 Record[6 + HasTag], Flags, AlignInBits)),
1627 NextMetadataNo);
1628 NextMetadataNo++;
1629 break;
1630 }
1631 case bitc::METADATA_EXPRESSION: {
1632 if (Record.size() < 1)
1633 return error("Invalid record");
1634
1635 IsDistinct = Record[0] & 1;
1636 uint64_t Version = Record[0] >> 1;
1637 auto Elts = MutableArrayRef<uint64_t>(Record).slice(1);
1638
1639 SmallVector<uint64_t, 6> Buffer;
1640 if (Error Err = upgradeDIExpression(Version, Elts, Buffer))
1641 return Err;
1642
1643 MetadataList.assignValue(
1644 GET_OR_DISTINCT(DIExpression, (Context, Elts)), NextMetadataNo);
1645 NextMetadataNo++;
1646 break;
1647 }
1648 case bitc::METADATA_GLOBAL_VAR_EXPR: {
1649 if (Record.size() != 3)
1650 return error("Invalid record");
1651
1652 IsDistinct = Record[0];
1653 Metadata *Expr = getMDOrNull(Record[2]);
1654 if (!Expr)
1655 Expr = DIExpression::get(Context, {});
1656 MetadataList.assignValue(
1657 GET_OR_DISTINCT(DIGlobalVariableExpression,
1658 (Context, getMDOrNull(Record[1]), Expr)),
1659 NextMetadataNo);
1660 NextMetadataNo++;
1661 break;
1662 }
1663 case bitc::METADATA_OBJC_PROPERTY: {
1664 if (Record.size() != 8)
1665 return error("Invalid record");
1666
1667 IsDistinct = Record[0];
1668 MetadataList.assignValue(
1669 GET_OR_DISTINCT(DIObjCProperty,
1670 (Context, getMDString(Record[1]),
1671 getMDOrNull(Record[2]), Record[3],
1672 getMDString(Record[4]), getMDString(Record[5]),
1673 Record[6], getDITypeRefOrNull(Record[7]))),
1674 NextMetadataNo);
1675 NextMetadataNo++;
1676 break;
1677 }
1678 case bitc::METADATA_IMPORTED_ENTITY: {
1679 if (Record.size() != 6 && Record.size() != 7)
1680 return error("Invalid record");
1681
1682 IsDistinct = Record[0];
1683 bool HasFile = (Record.size() == 7);
1684 MetadataList.assignValue(
1685 GET_OR_DISTINCT(DIImportedEntity,
1686 (Context, Record[1], getMDOrNull(Record[2]),
1687 getDITypeRefOrNull(Record[3]),
1688 HasFile ? getMDOrNull(Record[6]) : nullptr,
1689 HasFile ? Record[4] : 0, getMDString(Record[5]))),
1690 NextMetadataNo);
1691 NextMetadataNo++;
1692 break;
1693 }
1694 case bitc::METADATA_STRING_OLD: {
1695 std::string String(Record.begin(), Record.end());
1696
1697 // Test for upgrading !llvm.loop.
1698 HasSeenOldLoopTags |= mayBeOldLoopAttachmentTag(String);
1699 ++NumMDStringLoaded;
1700 Metadata *MD = MDString::get(Context, String);
1701 MetadataList.assignValue(MD, NextMetadataNo);
1702 NextMetadataNo++;
1703 break;
1704 }
1705 case bitc::METADATA_STRINGS: {
1706 auto CreateNextMDString = [&](StringRef Str) {
1707 ++NumMDStringLoaded;
1708 MetadataList.assignValue(MDString::get(Context, Str), NextMetadataNo);
1709 NextMetadataNo++;
1710 };
1711 if (Error Err = parseMetadataStrings(Record, Blob, CreateNextMDString))
1712 return Err;
1713 break;
1714 }
1715 case bitc::METADATA_GLOBAL_DECL_ATTACHMENT: {
1716 if (Record.size() % 2 == 0)
1717 return error("Invalid record");
1718 unsigned ValueID = Record[0];
1719 if (ValueID >= ValueList.size())
1720 return error("Invalid record");
1721 if (auto *GO = dyn_cast<GlobalObject>(ValueList[ValueID]))
1722 if (Error Err = parseGlobalObjectAttachment(
1723 *GO, ArrayRef<uint64_t>(Record).slice(1)))
1724 return Err;
1725 break;
1726 }
1727 case bitc::METADATA_KIND: {
1728 // Support older bitcode files that had METADATA_KIND records in a
1729 // block with METADATA_BLOCK_ID.
1730 if (Error Err = parseMetadataKindRecord(Record))
1731 return Err;
1732 break;
1733 }
1734 }
1735 return Error::success();
1736#undef GET_OR_DISTINCT
1737}
1738
1739Error MetadataLoader::MetadataLoaderImpl::parseMetadataStrings(
1740 ArrayRef<uint64_t> Record, StringRef Blob,
1741 function_ref<void(StringRef)> CallBack) {
1742 // All the MDStrings in the block are emitted together in a single
1743 // record. The strings are concatenated and stored in a blob along with
1744 // their sizes.
1745 if (Record.size() != 2)
1746 return error("Invalid record: metadata strings layout");
1747
1748 unsigned NumStrings = Record[0];
1749 unsigned StringsOffset = Record[1];
1750 if (!NumStrings)
1751 return error("Invalid record: metadata strings with no strings");
1752 if (StringsOffset > Blob.size())
1753 return error("Invalid record: metadata strings corrupt offset");
1754
1755 StringRef Lengths = Blob.slice(0, StringsOffset);
1756 SimpleBitstreamCursor R(Lengths);
1757
1758 StringRef Strings = Blob.drop_front(StringsOffset);
1759 do {
1760 if (R.AtEndOfStream())
1761 return error("Invalid record: metadata strings bad length");
1762
1763 unsigned Size = R.ReadVBR(6);
1764 if (Strings.size() < Size)
1765 return error("Invalid record: metadata strings truncated chars");
1766
1767 CallBack(Strings.slice(0, Size));
1768 Strings = Strings.drop_front(Size);
1769 } while (--NumStrings);
1770
1771 return Error::success();
1772}
1773
1774Error MetadataLoader::MetadataLoaderImpl::parseGlobalObjectAttachment(
1775 GlobalObject &GO, ArrayRef<uint64_t> Record) {
1776 assert(Record.size() % 2 == 0)(static_cast <bool> (Record.size() % 2 == 0) ? void (0)
: __assert_fail ("Record.size() % 2 == 0", "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 1776, __extension__ __PRETTY_FUNCTION__))
;
1777 for (unsigned I = 0, E = Record.size(); I != E; I += 2) {
1778 auto K = MDKindMap.find(Record[I]);
1779 if (K == MDKindMap.end())
1780 return error("Invalid ID");
1781 MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[I + 1]);
1782 if (!MD)
1783 return error("Invalid metadata attachment");
1784 GO.addMetadata(K->second, *MD);
1785 }
1786 return Error::success();
1787}
1788
1789/// Parse metadata attachments.
1790Error MetadataLoader::MetadataLoaderImpl::parseMetadataAttachment(
1791 Function &F, const SmallVectorImpl<Instruction *> &InstructionList) {
1792 if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
1793 return error("Invalid record");
1794
1795 SmallVector<uint64_t, 64> Record;
1796 PlaceholderQueue Placeholders;
1797
1798 while (true) {
1799 BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
1800
1801 switch (Entry.Kind) {
1802 case BitstreamEntry::SubBlock: // Handled for us already.
1803 case BitstreamEntry::Error:
1804 return error("Malformed block");
1805 case BitstreamEntry::EndBlock:
1806 resolveForwardRefsAndPlaceholders(Placeholders);
1807 return Error::success();
1808 case BitstreamEntry::Record:
1809 // The interesting case.
1810 break;
1811 }
1812
1813 // Read a metadata attachment record.
1814 Record.clear();
1815 ++NumMDRecordLoaded;
1816 switch (Stream.readRecord(Entry.ID, Record)) {
1817 default: // Default behavior: ignore.
1818 break;
1819 case bitc::METADATA_ATTACHMENT: {
1820 unsigned RecordLength = Record.size();
1821 if (Record.empty())
1822 return error("Invalid record");
1823 if (RecordLength % 2 == 0) {
1824 // A function attachment.
1825 if (Error Err = parseGlobalObjectAttachment(F, Record))
1826 return Err;
1827 continue;
1828 }
1829
1830 // An instruction attachment.
1831 Instruction *Inst = InstructionList[Record[0]];
1832 for (unsigned i = 1; i != RecordLength; i = i + 2) {
1833 unsigned Kind = Record[i];
1834 DenseMap<unsigned, unsigned>::iterator I = MDKindMap.find(Kind);
1835 if (I == MDKindMap.end())
1836 return error("Invalid ID");
1837 if (I->second == LLVMContext::MD_tbaa && StripTBAA)
1838 continue;
1839
1840 auto Idx = Record[i + 1];
1841 if (Idx < (MDStringRef.size() + GlobalMetadataBitPosIndex.size()) &&
1842 !MetadataList.lookup(Idx)) {
1843 // Load the attachment if it is in the lazy-loadable range and hasn't
1844 // been loaded yet.
1845 lazyLoadOneMetadata(Idx, Placeholders);
1846 resolveForwardRefsAndPlaceholders(Placeholders);
1847 }
1848
1849 Metadata *Node = MetadataList.getMetadataFwdRef(Idx);
1850 if (isa<LocalAsMetadata>(Node))
1851 // Drop the attachment. This used to be legal, but there's no
1852 // upgrade path.
1853 break;
1854 MDNode *MD = dyn_cast_or_null<MDNode>(Node);
1855 if (!MD)
1856 return error("Invalid metadata attachment");
1857
1858 if (HasSeenOldLoopTags && I->second == LLVMContext::MD_loop)
1859 MD = upgradeInstructionLoopAttachment(*MD);
1860
1861 if (I->second == LLVMContext::MD_tbaa) {
1862 assert(!MD->isTemporary() && "should load MDs before attachments")(static_cast <bool> (!MD->isTemporary() && "should load MDs before attachments"
) ? void (0) : __assert_fail ("!MD->isTemporary() && \"should load MDs before attachments\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/lib/Bitcode/Reader/MetadataLoader.cpp"
, 1862, __extension__ __PRETTY_FUNCTION__))
;
1863 MD = UpgradeTBAANode(*MD);
1864 }
1865 Inst->setMetadata(I->second, MD);
1866 }
1867 break;
1868 }
1869 }
1870 }
1871}
1872
1873/// Parse a single METADATA_KIND record, inserting result in MDKindMap.
1874Error MetadataLoader::MetadataLoaderImpl::parseMetadataKindRecord(
1875 SmallVectorImpl<uint64_t> &Record) {
1876 if (Record.size() < 2)
1877 return error("Invalid record");
1878
1879 unsigned Kind = Record[0];
1880 SmallString<8> Name(Record.begin() + 1, Record.end());
1881
1882 unsigned NewKind = TheModule.getMDKindID(Name.str());
1883 if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
1884 return error("Conflicting METADATA_KIND records");
1885 return Error::success();
1886}
1887
1888/// Parse the metadata kinds out of the METADATA_KIND_BLOCK.
1889Error MetadataLoader::MetadataLoaderImpl::parseMetadataKinds() {
1890 if (Stream.EnterSubBlock(bitc::METADATA_KIND_BLOCK_ID))
2
Assuming the condition is false
3
Taking false branch
1891 return error("Invalid record");
1892
1893 SmallVector<uint64_t, 64> Record;
1894
1895 // Read all the records.
1896 while (true) {
4
Loop condition is true. Entering loop body
1897 BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
5
Calling 'BitstreamCursor::advanceSkippingSubblocks'
1898
1899 switch (Entry.Kind) {
1900 case BitstreamEntry::SubBlock: // Handled for us already.
1901 case BitstreamEntry::Error:
1902 return error("Malformed block");
1903 case BitstreamEntry::EndBlock:
1904 return Error::success();
1905 case BitstreamEntry::Record:
1906 // The interesting case.
1907 break;
1908 }
1909
1910 // Read a record.
1911 Record.clear();
1912 ++NumMDRecordLoaded;
1913 unsigned Code = Stream.readRecord(Entry.ID, Record);
1914 switch (Code) {
1915 default: // Default behavior: ignore.
1916 break;
1917 case bitc::METADATA_KIND: {
1918 if (Error Err = parseMetadataKindRecord(Record))
1919 return Err;
1920 break;
1921 }
1922 }
1923 }
1924}
1925
1926MetadataLoader &MetadataLoader::operator=(MetadataLoader &&RHS) {
1927 Pimpl = std::move(RHS.Pimpl);
1928 return *this;
1929}
1930MetadataLoader::MetadataLoader(MetadataLoader &&RHS)
1931 : Pimpl(std::move(RHS.Pimpl)) {}
1932
1933MetadataLoader::~MetadataLoader() = default;
1934MetadataLoader::MetadataLoader(BitstreamCursor &Stream, Module &TheModule,
1935 BitcodeReaderValueList &ValueList,
1936 bool IsImporting,
1937 std::function<Type *(unsigned)> getTypeByID)
1938 : Pimpl(llvm::make_unique<MetadataLoaderImpl>(
1939 Stream, TheModule, ValueList, std::move(getTypeByID), IsImporting)) {}
1940
1941Error MetadataLoader::parseMetadata(bool ModuleLevel) {
1942 return Pimpl->parseMetadata(ModuleLevel);
1943}
1944
1945bool MetadataLoader::hasFwdRefs() const { return Pimpl->hasFwdRefs(); }
1946
1947/// Return the given metadata, creating a replaceable forward reference if
1948/// necessary.
1949Metadata *MetadataLoader::getMetadataFwdRefOrLoad(unsigned Idx) {
1950 return Pimpl->getMetadataFwdRefOrLoad(Idx);
1951}
1952
1953MDNode *MetadataLoader::getMDNodeFwdRefOrNull(unsigned Idx) {
1954 return Pimpl->getMDNodeFwdRefOrNull(Idx);
1955}
1956
1957DISubprogram *MetadataLoader::lookupSubprogramForFunction(Function *F) {
1958 return Pimpl->lookupSubprogramForFunction(F);
1959}
1960
1961Error MetadataLoader::parseMetadataAttachment(
1962 Function &F, const SmallVectorImpl<Instruction *> &InstructionList) {
1963 return Pimpl->parseMetadataAttachment(F, InstructionList);
1964}
1965
1966Error MetadataLoader::parseMetadataKinds() {
1967 return Pimpl->parseMetadataKinds();
1
Calling 'MetadataLoaderImpl::parseMetadataKinds'
1968}
1969
1970void MetadataLoader::setStripTBAA(bool StripTBAA) {
1971 return Pimpl->setStripTBAA(StripTBAA);
1972}
1973
1974bool MetadataLoader::isStrippingTBAA() { return Pimpl->isStrippingTBAA(); }
1975
1976unsigned MetadataLoader::size() const { return Pimpl->size(); }
1977void MetadataLoader::shrinkTo(unsigned N) { return Pimpl->shrinkTo(N); }
1978
1979void MetadataLoader::upgradeDebugIntrinsics(Function &F) {
1980 return Pimpl->upgradeDebugIntrinsics(F);
1981}

/build/llvm-toolchain-snapshot-6.0~svn318882/include/llvm/Bitcode/BitstreamReader.h

1//===- BitstreamReader.h - Low-level bitstream reader interface -*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This header defines the BitstreamReader class. This class can be used to
11// read an arbitrary bitstream, regardless of its contents.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_BITCODE_BITSTREAMREADER_H
16#define LLVM_BITCODE_BITSTREAMREADER_H
17
18#include "llvm/ADT/ArrayRef.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/Bitcode/BitCodes.h"
21#include "llvm/Support/Endian.h"
22#include "llvm/Support/ErrorHandling.h"
23#include "llvm/Support/MathExtras.h"
24#include "llvm/Support/MemoryBuffer.h"
25#include <algorithm>
26#include <cassert>
27#include <climits>
28#include <cstddef>
29#include <cstdint>
30#include <memory>
31#include <string>
32#include <utility>
33#include <vector>
34
35namespace llvm {
36
37/// This class maintains the abbreviations read from a block info block.
38class BitstreamBlockInfo {
39public:
40 /// This contains information emitted to BLOCKINFO_BLOCK blocks. These
41 /// describe abbreviations that all blocks of the specified ID inherit.
42 struct BlockInfo {
43 unsigned BlockID;
44 std::vector<std::shared_ptr<BitCodeAbbrev>> Abbrevs;
45 std::string Name;
46 std::vector<std::pair<unsigned, std::string>> RecordNames;
47 };
48
49private:
50 std::vector<BlockInfo> BlockInfoRecords;
51
52public:
53 /// If there is block info for the specified ID, return it, otherwise return
54 /// null.
55 const BlockInfo *getBlockInfo(unsigned BlockID) const {
56 // Common case, the most recent entry matches BlockID.
57 if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
58 return &BlockInfoRecords.back();
59
60 for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
61 i != e; ++i)
62 if (BlockInfoRecords[i].BlockID == BlockID)
63 return &BlockInfoRecords[i];
64 return nullptr;
65 }
66
67 BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
68 if (const BlockInfo *BI = getBlockInfo(BlockID))
69 return *const_cast<BlockInfo*>(BI);
70
71 // Otherwise, add a new record.
72 BlockInfoRecords.emplace_back();
73 BlockInfoRecords.back().BlockID = BlockID;
74 return BlockInfoRecords.back();
75 }
76};
77
78/// This represents a position within a bitstream. There may be multiple
79/// independent cursors reading within one bitstream, each maintaining their
80/// own local state.
81class SimpleBitstreamCursor {
82 ArrayRef<uint8_t> BitcodeBytes;
83 size_t NextChar = 0;
84
85public:
86 /// This is the current data we have pulled from the stream but have not
87 /// returned to the client. This is specifically and intentionally defined to
88 /// follow the word size of the host machine for efficiency. We use word_t in
89 /// places that are aware of this to make it perfectly explicit what is going
90 /// on.
91 using word_t = size_t;
92
93private:
94 word_t CurWord = 0;
95
96 /// This is the number of bits in CurWord that are valid. This is always from
97 /// [0...bits_of(size_t)-1] inclusive.
98 unsigned BitsInCurWord = 0;
99
100public:
101 static const size_t MaxChunkSize = sizeof(word_t) * 8;
102
103 SimpleBitstreamCursor() = default;
104 explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
105 : BitcodeBytes(BitcodeBytes) {}
106 explicit SimpleBitstreamCursor(StringRef BitcodeBytes)
107 : BitcodeBytes(reinterpret_cast<const uint8_t *>(BitcodeBytes.data()),
108 BitcodeBytes.size()) {}
109 explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes)
110 : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {}
111
112 bool canSkipToPos(size_t pos) const {
113 // pos can be skipped to if it is a valid address or one byte past the end.
114 return pos <= BitcodeBytes.size();
115 }
116
117 bool AtEndOfStream() {
118 return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar;
119 }
120
121 /// Return the bit # of the bit we are reading.
122 uint64_t GetCurrentBitNo() const {
123 return NextChar*CHAR_BIT8 - BitsInCurWord;
124 }
125
126 // Return the byte # of the current bit.
127 uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; }
128
129 ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; }
130
131 /// Reset the stream to the specified bit number.
132 void JumpToBit(uint64_t BitNo) {
133 size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1);
134 unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
135 assert(canSkipToPos(ByteNo) && "Invalid location")(static_cast <bool> (canSkipToPos(ByteNo) && "Invalid location"
) ? void (0) : __assert_fail ("canSkipToPos(ByteNo) && \"Invalid location\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/include/llvm/Bitcode/BitstreamReader.h"
, 135, __extension__ __PRETTY_FUNCTION__))
;
136
137 // Move the cursor to the right word.
138 NextChar = ByteNo;
139 BitsInCurWord = 0;
140
141 // Skip over any bits that are already consumed.
142 if (WordBitNo)
143 Read(WordBitNo);
144 }
145
146 /// Get a pointer into the bitstream at the specified byte offset.
147 const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) {
148 return BitcodeBytes.data() + ByteNo;
149 }
150
151 /// Get a pointer into the bitstream at the specified bit offset.
152 ///
153 /// The bit offset must be on a byte boundary.
154 const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) {
155 assert(!(BitNo % 8) && "Expected bit on byte boundary")(static_cast <bool> (!(BitNo % 8) && "Expected bit on byte boundary"
) ? void (0) : __assert_fail ("!(BitNo % 8) && \"Expected bit on byte boundary\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/include/llvm/Bitcode/BitstreamReader.h"
, 155, __extension__ __PRETTY_FUNCTION__))
;
156 return getPointerToByte(BitNo / 8, NumBytes);
157 }
158
159 void fillCurWord() {
160 if (NextChar >= BitcodeBytes.size())
161 report_fatal_error("Unexpected end of file");
162
163 // Read the next word from the stream.
164 const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar;
165 unsigned BytesRead;
166 if (BitcodeBytes.size() >= NextChar + sizeof(word_t)) {
167 BytesRead = sizeof(word_t);
168 CurWord =
169 support::endian::read<word_t, support::little, support::unaligned>(
170 NextCharPtr);
171 } else {
172 // Short read.
173 BytesRead = BitcodeBytes.size() - NextChar;
174 CurWord = 0;
175 for (unsigned B = 0; B != BytesRead; ++B)
176 CurWord |= uint64_t(NextCharPtr[B]) << (B * 8);
177 }
178 NextChar += BytesRead;
179 BitsInCurWord = BytesRead * 8;
180 }
181
182 word_t Read(unsigned NumBits) {
183 static const unsigned BitsInWord = MaxChunkSize;
184
185 assert(NumBits && NumBits <= BitsInWord &&(static_cast <bool> (NumBits && NumBits <= BitsInWord
&& "Cannot return zero or more than BitsInWord bits!"
) ? void (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/include/llvm/Bitcode/BitstreamReader.h"
, 186, __extension__ __PRETTY_FUNCTION__))
186 "Cannot return zero or more than BitsInWord bits!")(static_cast <bool> (NumBits && NumBits <= BitsInWord
&& "Cannot return zero or more than BitsInWord bits!"
) ? void (0) : __assert_fail ("NumBits && NumBits <= BitsInWord && \"Cannot return zero or more than BitsInWord bits!\""
, "/build/llvm-toolchain-snapshot-6.0~svn318882/include/llvm/Bitcode/BitstreamReader.h"
, 186, __extension__ __PRETTY_FUNCTION__))
;
187
188 static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
12
'?' condition is true
189
190 // If the field is fully contained by CurWord, return it quickly.
191 if (BitsInCurWord >= NumBits) {
13
Taking false branch
192 word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits));
193
194 // Use a mask to avoid undefined behavior.
195 CurWord >>= (NumBits & Mask);
196
197 BitsInCurWord -= NumBits;
198 return R;
199 }
200
201 word_t R = BitsInCurWord ? CurWord : 0;
14
'?' condition is true
202 unsigned BitsLeft = NumBits - BitsInCurWord;
203
204 fillCurWord();
205
206 // If we run out of data, abort.
207 if (BitsLeft > BitsInCurWord)
15
Assuming the condition is false
16
Taking false branch
208 report_fatal_error("Unexpected end of file");
209
210 word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
17
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'
211
212 // Use a mask to avoid undefined behavior.
213 CurWord >>= (BitsLeft & Mask);
214
215 BitsInCurWord -= BitsLeft;
216
217 R |= R2 << (NumBits - BitsLeft);
218
219 return R;
220 }
221
222 uint32_t ReadVBR(unsigned NumBits) {
223 uint32_t Piece = Read(NumBits);
224 if ((Piece & (1U << (NumBits-1))) == 0)
225 return Piece;
226
227 uint32_t Result = 0;
228 unsigned NextBit = 0;
229 while (true) {
230 Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
231
232 if ((Piece & (1U << (NumBits-1))) == 0)
233 return Result;
234
235 NextBit += NumBits-1;
236 Piece = Read(NumBits);
237 }
238 }
239
240 // Read a VBR that may have a value up to 64-bits in size. The chunk size of
241 // the VBR must still be <= 32 bits though.
242 uint64_t ReadVBR64(unsigned NumBits) {
243 uint32_t Piece = Read(NumBits);
244 if ((Piece & (1U << (NumBits-1))) == 0)
245 return uint64_t(Piece);
246
247 uint64_t Result = 0;
248 unsigned NextBit = 0;
249 while (true) {
250 Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit;
251
252 if ((Piece & (1U << (NumBits-1))) == 0)
253 return Result;
254
255 NextBit += NumBits-1;
256 Piece = Read(NumBits);
257 }
258 }
259
260 void SkipToFourByteBoundary() {
261 // If word_t is 64-bits and if we've read less than 32 bits, just dump
262 // the bits we have up to the next 32-bit boundary.
263 if (sizeof(word_t) > 4 &&
264 BitsInCurWord >= 32) {
265 CurWord >>= BitsInCurWord-32;
266 BitsInCurWord = 32;
267 return;
268 }
269
270 BitsInCurWord = 0;
271 }
272
273 /// Skip to the end of the file.
274 void skipToEnd() { NextChar = BitcodeBytes.size(); }
275};
276
277/// When advancing through a bitstream cursor, each advance can discover a few
278/// different kinds of entries:
279struct BitstreamEntry {
280 enum {
281 Error, // Malformed bitcode was found.
282 EndBlock, // We've reached the end of the current block, (or the end of the
283 // file, which is treated like a series of EndBlock records.
284 SubBlock, // This is the start of a new subblock of a specific ID.
285 Record // This is a record with a specific AbbrevID.
286 } Kind;
287
288 unsigned ID;
289
290 static BitstreamEntry getError() {
291 BitstreamEntry E; E.Kind = Error; return E;
292 }
293
294 static BitstreamEntry getEndBlock() {
295 BitstreamEntry E; E.Kind = EndBlock; return E;
296 }
297
298 static BitstreamEntry getSubBlock(unsigned ID) {
299 BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E;
300 }
301
302 static BitstreamEntry getRecord(unsigned AbbrevID) {
303 BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E;
304 }
305};
306
307/// This represents a position within a bitcode file, implemented on top of a
308/// SimpleBitstreamCursor.
309///
310/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not
311/// be passed by value.
312class BitstreamCursor : SimpleBitstreamCursor {
313 // This is the declared size of code values used for the current block, in
314 // bits.
315 unsigned CurCodeSize = 2;
316
317 /// Abbrevs installed at in this block.
318 std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs;
319
320 struct Block {
321 unsigned PrevCodeSize;
322 std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs;
323
324 explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
325 };
326
327 /// This tracks the codesize of parent blocks.
328 SmallVector<Block, 8> BlockScope;
329
330 BitstreamBlockInfo *BlockInfo = nullptr;
331
332public:
333 static const size_t MaxChunkSize = sizeof(word_t) * 8;
334
335 BitstreamCursor() = default;
336 explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
337 : SimpleBitstreamCursor(BitcodeBytes) {}
338 explicit BitstreamCursor(StringRef BitcodeBytes)
339 : SimpleBitstreamCursor(BitcodeBytes) {}
340 explicit BitstreamCursor(MemoryBufferRef BitcodeBytes)
341 : SimpleBitstreamCursor(BitcodeBytes) {}
342
343 using SimpleBitstreamCursor::canSkipToPos;
344 using SimpleBitstreamCursor::AtEndOfStream;
345 using SimpleBitstreamCursor::getBitcodeBytes;
346 using SimpleBitstreamCursor::GetCurrentBitNo;
347 using SimpleBitstreamCursor::getCurrentByteNo;
348 using SimpleBitstreamCursor::getPointerToByte;
349 using SimpleBitstreamCursor::JumpToBit;
350 using SimpleBitstreamCursor::fillCurWord;
351 using SimpleBitstreamCursor::Read;
352 using SimpleBitstreamCursor::ReadVBR;
353 using SimpleBitstreamCursor::ReadVBR64;
354
355 /// Return the number of bits used to encode an abbrev #.
356 unsigned getAbbrevIDWidth() const { return CurCodeSize; }
357
358 /// Flags that modify the behavior of advance().
359 enum {
360 /// If this flag is used, the advance() method does not automatically pop
361 /// the block scope when the end of a block is reached.
362 AF_DontPopBlockAtEnd = 1,
363
364 /// If this flag is used, abbrev entries are returned just like normal
365 /// records.
366 AF_DontAutoprocessAbbrevs = 2
367 };
368
369 /// Advance the current bitstream, returning the next entry in the stream.
370 BitstreamEntry advance(unsigned Flags = 0) {
371 while (true) {
8
Loop condition is true. Entering loop body
372 if (AtEndOfStream())
9
Taking false branch
373 return BitstreamEntry::getError();
374
375 unsigned Code = ReadCode();
10
Calling 'BitstreamCursor::ReadCode'
376 if (Code == bitc::END_BLOCK) {
377 // Pop the end of the block unless Flags tells us not to.
378 if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd())
379 return BitstreamEntry::getError();
380 return BitstreamEntry::getEndBlock();
381 }
382
383 if (Code == bitc::ENTER_SUBBLOCK)
384 return BitstreamEntry::getSubBlock(ReadSubBlockID());
385
386 if (Code == bitc::DEFINE_ABBREV &&
387 !(Flags & AF_DontAutoprocessAbbrevs)) {
388 // We read and accumulate abbrev's, the client can't do anything with
389 // them anyway.
390 ReadAbbrevRecord();
391 continue;
392 }
393
394 return BitstreamEntry::getRecord(Code);
395 }
396 }
397
398 /// This is a convenience function for clients that don't expect any
399 /// subblocks. This just skips over them automatically.
400 BitstreamEntry advanceSkippingSubblocks(unsigned Flags = 0) {
401 while (true) {
6
Loop condition is true. Entering loop body
402 // If we found a normal entry, return it.
403 BitstreamEntry Entry = advance(Flags);
7
Calling 'BitstreamCursor::advance'
404 if (Entry.Kind != BitstreamEntry::SubBlock)
405 return Entry;
406
407 // If we found a sub-block, just skip over it and check the next entry.
408 if (SkipBlock())
409 return BitstreamEntry::getError();
410 }
411 }
412
413 unsigned ReadCode() {
414 return Read(CurCodeSize);
11
Calling 'SimpleBitstreamCursor::Read'
415 }
416
417 // Block header:
418 // [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
419
420 /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block.
421 unsigned ReadSubBlockID() {
422 return ReadVBR(bitc::BlockIDWidth);
423 }
424
425 /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body
426 /// of this block. If the block record is malformed, return true.
427 bool SkipBlock() {
428 // Read and ignore the codelen value. Since we are skipping this block, we
429 // don't care what code widths are used inside of it.
430 ReadVBR(bitc::CodeLenWidth);
431 SkipToFourByteBoundary();
432 unsigned NumFourBytes = Read(bitc::BlockSizeWidth);
433
434 // Check that the block wasn't partially defined, and that the offset isn't
435 // bogus.
436 size_t SkipTo = GetCurrentBitNo() + NumFourBytes*4*8;
437 if (AtEndOfStream() || !canSkipToPos(SkipTo/8))
438 return true;
439
440 JumpToBit(SkipTo);
441 return false;
442 }
443
444 /// Having read the ENTER_SUBBLOCK abbrevid, enter the block, and return true
445 /// if the block has an error.
446 bool EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr);
447
448 bool ReadBlockEnd() {
449 if (BlockScope.empty()) return true;
450
451 // Block tail:
452 // [END_BLOCK, <align4bytes>]
453 SkipToFourByteBoundary();
454
455 popBlockScope();
456 return false;
457 }
458
459private:
460 void popBlockScope() {
461 CurCodeSize = BlockScope.back().PrevCodeSize;
462
463 CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs);
464 BlockScope.pop_back();
465 }
466
467 //===--------------------------------------------------------------------===//
468 // Record Processing
469 //===--------------------------------------------------------------------===//
470
471public:
472 /// Return the abbreviation for the specified AbbrevId.
473 const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) {
474 unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV;
475 if (AbbrevNo >= CurAbbrevs.size())
476 report_fatal_error("Invalid abbrev number");
477 return CurAbbrevs[AbbrevNo].get();
478 }
479
480 /// Read the current record and discard it, returning the code for the record.
481 unsigned skipRecord(unsigned AbbrevID);
482
483 unsigned readRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals,
484 StringRef *Blob = nullptr);
485
486 //===--------------------------------------------------------------------===//
487 // Abbrev Processing
488 //===--------------------------------------------------------------------===//
489 void ReadAbbrevRecord();
490
491 /// Read and return a block info block from the bitstream. If an error was
492 /// encountered, return None.
493 ///
494 /// \param ReadBlockInfoNames Whether to read block/record name information in
495 /// the BlockInfo block. Only llvm-bcanalyzer uses this.
496 Optional<BitstreamBlockInfo>
497 ReadBlockInfoBlock(bool ReadBlockInfoNames = false);
498
499 /// Set the block info to be used by this BitstreamCursor to interpret
500 /// abbreviated records.
501 void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; }
502};
503
504} // end llvm namespace
505
506#endif // LLVM_BITCODE_BITSTREAMREADER_H