Bug Summary

File:include/llvm/Support/Error.h
Warning:line 201, column 5
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name DWARFVerifier.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/lib/DebugInfo/DWARF -I /build/llvm-toolchain-snapshot-8~svn345461/lib/DebugInfo/DWARF -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/lib/DebugInfo/DWARF -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/lib/DebugInfo/DWARF/DWARFVerifier.cpp -faddrsig

/build/llvm-toolchain-snapshot-8~svn345461/lib/DebugInfo/DWARF/DWARFVerifier.cpp

1//===- DWARFVerifier.cpp --------------------------------------------------===//
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#include "llvm/DebugInfo/DWARF/DWARFVerifier.h"
10#include "llvm/ADT/SmallSet.h"
11#include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
12#include "llvm/DebugInfo/DWARF/DWARFContext.h"
13#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
14#include "llvm/DebugInfo/DWARF/DWARFDie.h"
15#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
16#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
17#include "llvm/DebugInfo/DWARF/DWARFSection.h"
18#include "llvm/Support/DJB.h"
19#include "llvm/Support/FormatVariadic.h"
20#include "llvm/Support/WithColor.h"
21#include "llvm/Support/raw_ostream.h"
22#include <map>
23#include <set>
24#include <vector>
25
26using namespace llvm;
27using namespace dwarf;
28using namespace object;
29
30DWARFVerifier::DieRangeInfo::address_range_iterator
31DWARFVerifier::DieRangeInfo::insert(const DWARFAddressRange &R) {
32 auto Begin = Ranges.begin();
33 auto End = Ranges.end();
34 auto Pos = std::lower_bound(Begin, End, R);
35
36 if (Pos != End) {
37 if (Pos->intersects(R))
38 return Pos;
39 if (Pos != Begin) {
40 auto Iter = Pos - 1;
41 if (Iter->intersects(R))
42 return Iter;
43 }
44 }
45
46 Ranges.insert(Pos, R);
47 return Ranges.end();
48}
49
50DWARFVerifier::DieRangeInfo::die_range_info_iterator
51DWARFVerifier::DieRangeInfo::insert(const DieRangeInfo &RI) {
52 auto End = Children.end();
53 auto Iter = Children.begin();
54 while (Iter != End) {
55 if (Iter->intersects(RI))
56 return Iter;
57 ++Iter;
58 }
59 Children.insert(RI);
60 return Children.end();
61}
62
63bool DWARFVerifier::DieRangeInfo::contains(const DieRangeInfo &RHS) const {
64 // Both list of ranges are sorted so we can make this fast.
65
66 if (Ranges.empty() || RHS.Ranges.empty())
67 return false;
68
69 // Since the ranges are sorted we can advance where we start searching with
70 // this object's ranges as we traverse RHS.Ranges.
71 auto End = Ranges.end();
72 auto Iter = findRange(RHS.Ranges.front());
73
74 // Now linearly walk the ranges in this object and see if they contain each
75 // ranges from RHS.Ranges.
76 for (const auto &R : RHS.Ranges) {
77 while (Iter != End) {
78 if (Iter->contains(R))
79 break;
80 ++Iter;
81 }
82 if (Iter == End)
83 return false;
84 }
85 return true;
86}
87
88bool DWARFVerifier::DieRangeInfo::intersects(const DieRangeInfo &RHS) const {
89 if (Ranges.empty() || RHS.Ranges.empty())
90 return false;
91
92 auto End = Ranges.end();
93 auto Iter = findRange(RHS.Ranges.front());
94 for (const auto &R : RHS.Ranges) {
95 if (Iter == End)
96 return false;
97 if (R.HighPC <= Iter->LowPC)
98 continue;
99 while (Iter != End) {
100 if (Iter->intersects(R))
101 return true;
102 ++Iter;
103 }
104 }
105
106 return false;
107}
108
109bool DWARFVerifier::verifyUnitHeader(const DWARFDataExtractor DebugInfoData,
110 uint32_t *Offset, unsigned UnitIndex,
111 uint8_t &UnitType, bool &isUnitDWARF64) {
112 uint32_t AbbrOffset, Length;
113 uint8_t AddrSize = 0;
114 uint16_t Version;
115 bool Success = true;
116
117 bool ValidLength = false;
118 bool ValidVersion = false;
119 bool ValidAddrSize = false;
120 bool ValidType = true;
121 bool ValidAbbrevOffset = true;
122
123 uint32_t OffsetStart = *Offset;
124 Length = DebugInfoData.getU32(Offset);
125 if (Length == UINT32_MAX(4294967295U)) {
126 isUnitDWARF64 = true;
127 OS << format(
128 "Unit[%d] is in 64-bit DWARF format; cannot verify from this point.\n",
129 UnitIndex);
130 return false;
131 }
132 Version = DebugInfoData.getU16(Offset);
133
134 if (Version >= 5) {
135 UnitType = DebugInfoData.getU8(Offset);
136 AddrSize = DebugInfoData.getU8(Offset);
137 AbbrOffset = DebugInfoData.getU32(Offset);
138 ValidType = dwarf::isUnitType(UnitType);
139 } else {
140 UnitType = 0;
141 AbbrOffset = DebugInfoData.getU32(Offset);
142 AddrSize = DebugInfoData.getU8(Offset);
143 }
144
145 if (!DCtx.getDebugAbbrev()->getAbbreviationDeclarationSet(AbbrOffset))
146 ValidAbbrevOffset = false;
147
148 ValidLength = DebugInfoData.isValidOffset(OffsetStart + Length + 3);
149 ValidVersion = DWARFContext::isSupportedVersion(Version);
150 ValidAddrSize = AddrSize == 4 || AddrSize == 8;
151 if (!ValidLength || !ValidVersion || !ValidAddrSize || !ValidAbbrevOffset ||
152 !ValidType) {
153 Success = false;
154 error() << format("Units[%d] - start offset: 0x%08x \n", UnitIndex,
155 OffsetStart);
156 if (!ValidLength)
157 note() << "The length for this unit is too "
158 "large for the .debug_info provided.\n";
159 if (!ValidVersion)
160 note() << "The 16 bit unit header version is not valid.\n";
161 if (!ValidType)
162 note() << "The unit type encoding is not valid.\n";
163 if (!ValidAbbrevOffset)
164 note() << "The offset into the .debug_abbrev section is "
165 "not valid.\n";
166 if (!ValidAddrSize)
167 note() << "The address size is unsupported.\n";
168 }
169 *Offset = OffsetStart + Length + 4;
170 return Success;
171}
172
173unsigned DWARFVerifier::verifyUnitContents(DWARFUnit &Unit) {
174 unsigned NumUnitErrors = 0;
175 unsigned NumDies = Unit.getNumDIEs();
176 for (unsigned I = 0; I < NumDies; ++I) {
7
Assuming 'I' is >= 'NumDies'
8
Loop condition is false. Execution continues on line 200
177 auto Die = Unit.getDIEAtIndex(I);
178
179 if (Die.getTag() == DW_TAG_null)
180 continue;
181
182 bool HasTypeAttr = false;
183 for (auto AttrValue : Die.attributes()) {
184 NumUnitErrors += verifyDebugInfoAttribute(Die, AttrValue);
185 NumUnitErrors += verifyDebugInfoForm(Die, AttrValue);
186 HasTypeAttr |= (AttrValue.Attr == DW_AT_type);
187 }
188
189 if (!HasTypeAttr && (Die.getTag() == DW_TAG_formal_parameter ||
190 Die.getTag() == DW_TAG_variable ||
191 Die.getTag() == DW_TAG_array_type)) {
192 error() << "DIE with tag " << TagString(Die.getTag())
193 << " is missing type attribute:\n";
194 dump(Die) << '\n';
195 NumUnitErrors++;
196 }
197 NumUnitErrors += verifyDebugInfoCallSite(Die);
198 }
199
200 DWARFDie Die = Unit.getUnitDIE(/* ExtractUnitDIEOnly = */ false);
201 if (!Die) {
9
Assuming the condition is false
10
Taking false branch
202 error() << "Compilation unit without DIE.\n";
203 NumUnitErrors++;
204 return NumUnitErrors;
205 }
206
207 if (!dwarf::isUnitType(Die.getTag())) {
11
Taking true branch
208 error() << "Compilation unit root DIE is not a unit DIE: "
209 << dwarf::TagString(Die.getTag()) << ".\n";
210 NumUnitErrors++;
211 }
212
213 uint8_t UnitType = Unit.getUnitType();
214 if (!DWARFUnit::isMatchingUnitTypeAndTag(UnitType, Die.getTag())) {
12
Taking false branch
215 error() << "Compilation unit type (" << dwarf::UnitTypeString(UnitType)
216 << ") and root DIE (" << dwarf::TagString(Die.getTag())
217 << ") do not match.\n";
218 NumUnitErrors++;
219 }
220
221 DieRangeInfo RI;
222 NumUnitErrors += verifyDieRanges(Die, RI);
13
Calling 'DWARFVerifier::verifyDieRanges'
223
224 return NumUnitErrors;
225}
226
227unsigned DWARFVerifier::verifyDebugInfoCallSite(const DWARFDie &Die) {
228 if (Die.getTag() != DW_TAG_call_site)
229 return 0;
230
231 DWARFDie Curr = Die.getParent();
232 for (; Curr.isValid() && !Curr.isSubprogramDIE(); Curr = Die.getParent()) {
233 if (Curr.getTag() == DW_TAG_inlined_subroutine) {
234 error() << "Call site entry nested within inlined subroutine:";
235 Curr.dump(OS);
236 return 1;
237 }
238 }
239
240 if (!Curr.isValid()) {
241 error() << "Call site entry not nested within a valid subprogram:";
242 Die.dump(OS);
243 return 1;
244 }
245
246 Optional<DWARFFormValue> CallAttr =
247 Curr.find({DW_AT_call_all_calls, DW_AT_call_all_source_calls,
248 DW_AT_call_all_tail_calls});
249 if (!CallAttr) {
250 error() << "Subprogram with call site entry has no DW_AT_call attribute:";
251 Curr.dump(OS);
252 Die.dump(OS, /*indent*/ 1);
253 return 1;
254 }
255
256 return 0;
257}
258
259unsigned DWARFVerifier::verifyAbbrevSection(const DWARFDebugAbbrev *Abbrev) {
260 unsigned NumErrors = 0;
261 if (Abbrev) {
262 const DWARFAbbreviationDeclarationSet *AbbrDecls =
263 Abbrev->getAbbreviationDeclarationSet(0);
264 for (auto AbbrDecl : *AbbrDecls) {
265 SmallDenseSet<uint16_t> AttributeSet;
266 for (auto Attribute : AbbrDecl.attributes()) {
267 auto Result = AttributeSet.insert(Attribute.Attr);
268 if (!Result.second) {
269 error() << "Abbreviation declaration contains multiple "
270 << AttributeString(Attribute.Attr) << " attributes.\n";
271 AbbrDecl.dump(OS);
272 ++NumErrors;
273 }
274 }
275 }
276 }
277 return NumErrors;
278}
279
280bool DWARFVerifier::handleDebugAbbrev() {
281 OS << "Verifying .debug_abbrev...\n";
282
283 const DWARFObject &DObj = DCtx.getDWARFObj();
284 bool noDebugAbbrev = DObj.getAbbrevSection().empty();
285 bool noDebugAbbrevDWO = DObj.getAbbrevDWOSection().empty();
286
287 if (noDebugAbbrev && noDebugAbbrevDWO) {
288 return true;
289 }
290
291 unsigned NumErrors = 0;
292 if (!noDebugAbbrev)
293 NumErrors += verifyAbbrevSection(DCtx.getDebugAbbrev());
294
295 if (!noDebugAbbrevDWO)
296 NumErrors += verifyAbbrevSection(DCtx.getDebugAbbrevDWO());
297 return NumErrors == 0;
298}
299
300unsigned DWARFVerifier::verifyUnitSection(const DWARFSection &S,
301 DWARFSectionKind SectionKind) {
302 const DWARFObject &DObj = DCtx.getDWARFObj();
303 DWARFDataExtractor DebugInfoData(DObj, S, DCtx.isLittleEndian(), 0);
304 unsigned NumDebugInfoErrors = 0;
305 uint32_t OffsetStart = 0, Offset = 0, UnitIdx = 0;
306 uint8_t UnitType = 0;
307 bool isUnitDWARF64 = false;
308 bool isHeaderChainValid = true;
309 bool hasDIE = DebugInfoData.isValidOffset(Offset);
310 DWARFUnitVector TypeUnitVector;
311 DWARFUnitVector CompileUnitVector;
312 while (hasDIE) {
2
Loop condition is true. Entering loop body
313 OffsetStart = Offset;
314 if (!verifyUnitHeader(DebugInfoData, &Offset, UnitIdx, UnitType,
3
Taking false branch
315 isUnitDWARF64)) {
316 isHeaderChainValid = false;
317 if (isUnitDWARF64)
318 break;
319 } else {
320 DWARFUnitHeader Header;
321 Header.extract(DCtx, DebugInfoData, &OffsetStart, SectionKind);
322 DWARFUnit *Unit;
323 switch (UnitType) {
4
Control jumps to 'case 0:' at line 339
324 case dwarf::DW_UT_type:
325 case dwarf::DW_UT_split_type: {
326 Unit = TypeUnitVector.addUnit(llvm::make_unique<DWARFTypeUnit>(
327 DCtx, S, Header, DCtx.getDebugAbbrev(), &DObj.getRangeSection(),
328 &DObj.getLocSection(), DObj.getStringSection(),
329 DObj.getStringOffsetSection(), &DObj.getAppleObjCSection(),
330 DObj.getLineSection(), DCtx.isLittleEndian(), false,
331 TypeUnitVector));
332 break;
333 }
334 case dwarf::DW_UT_skeleton:
335 case dwarf::DW_UT_split_compile:
336 case dwarf::DW_UT_compile:
337 case dwarf::DW_UT_partial:
338 // UnitType = 0 means that we are verifying a compile unit in DWARF v4.
339 case 0: {
340 Unit = CompileUnitVector.addUnit(llvm::make_unique<DWARFCompileUnit>(
341 DCtx, S, Header, DCtx.getDebugAbbrev(), &DObj.getRangeSection(),
342 &DObj.getLocSection(), DObj.getStringSection(),
343 DObj.getStringOffsetSection(), &DObj.getAppleObjCSection(),
344 DObj.getLineSection(), DCtx.isLittleEndian(), false,
345 CompileUnitVector));
346 break;
5
Execution continues on line 350
347 }
348 default: { llvm_unreachable("Invalid UnitType.")::llvm::llvm_unreachable_internal("Invalid UnitType.", "/build/llvm-toolchain-snapshot-8~svn345461/lib/DebugInfo/DWARF/DWARFVerifier.cpp"
, 348)
; }
349 }
350 NumDebugInfoErrors += verifyUnitContents(*Unit);
6
Calling 'DWARFVerifier::verifyUnitContents'
351 }
352 hasDIE = DebugInfoData.isValidOffset(Offset);
353 ++UnitIdx;
354 }
355 if (UnitIdx == 0 && !hasDIE) {
356 warn() << "Section is empty.\n";
357 isHeaderChainValid = true;
358 }
359 if (!isHeaderChainValid)
360 ++NumDebugInfoErrors;
361 NumDebugInfoErrors += verifyDebugInfoReferences();
362 return NumDebugInfoErrors;
363}
364
365bool DWARFVerifier::handleDebugInfo() {
366 const DWARFObject &DObj = DCtx.getDWARFObj();
367
368 OS << "Verifying .debug_info Unit Header Chain...\n";
369 unsigned result = verifyUnitSection(DObj.getInfoSection(), DW_SECT_INFO);
370
371 OS << "Verifying .debug_types Unit Header Chain...\n";
372 DObj.forEachTypesSections([&](const DWARFSection &S) {
373 result += verifyUnitSection(S, DW_SECT_TYPES);
1
Calling 'DWARFVerifier::verifyUnitSection'
374 });
375 return result == 0;
376}
377
378unsigned DWARFVerifier::verifyDieRanges(const DWARFDie &Die,
379 DieRangeInfo &ParentRI) {
380 unsigned NumErrors = 0;
381
382 if (!Die.isValid())
14
Assuming the condition is false
15
Taking false branch
383 return NumErrors;
384
385 auto RangesOrError = Die.getAddressRanges();
386 if (!RangesOrError) {
16
Taking true branch
387 // FIXME: Report the error.
388 ++NumErrors;
389 llvm::consumeError(RangesOrError.takeError());
17
Calling 'consumeError'
390 return NumErrors;
391 }
392
393 DWARFAddressRangesVector Ranges = RangesOrError.get();
394 // Build RI for this DIE and check that ranges within this DIE do not
395 // overlap.
396 DieRangeInfo RI(Die);
397 for (auto Range : Ranges) {
398 if (!Range.valid()) {
399 ++NumErrors;
400 error() << "Invalid address range " << Range << "\n";
401 continue;
402 }
403
404 // Verify that ranges don't intersect.
405 const auto IntersectingRange = RI.insert(Range);
406 if (IntersectingRange != RI.Ranges.end()) {
407 ++NumErrors;
408 error() << "DIE has overlapping address ranges: " << Range << " and "
409 << *IntersectingRange << "\n";
410 break;
411 }
412 }
413
414 // Verify that children don't intersect.
415 const auto IntersectingChild = ParentRI.insert(RI);
416 if (IntersectingChild != ParentRI.Children.end()) {
417 ++NumErrors;
418 error() << "DIEs have overlapping address ranges:";
419 dump(Die);
420 dump(IntersectingChild->Die) << '\n';
421 }
422
423 // Verify that ranges are contained within their parent.
424 bool ShouldBeContained = !Ranges.empty() && !ParentRI.Ranges.empty() &&
425 !(Die.getTag() == DW_TAG_subprogram &&
426 ParentRI.Die.getTag() == DW_TAG_subprogram);
427 if (ShouldBeContained && !ParentRI.contains(RI)) {
428 ++NumErrors;
429 error() << "DIE address ranges are not contained in its parent's ranges:";
430 dump(ParentRI.Die);
431 dump(Die, 2) << '\n';
432 }
433
434 // Recursively check children.
435 for (DWARFDie Child : Die)
436 NumErrors += verifyDieRanges(Child, RI);
437
438 return NumErrors;
439}
440
441unsigned DWARFVerifier::verifyDebugInfoAttribute(const DWARFDie &Die,
442 DWARFAttribute &AttrValue) {
443 unsigned NumErrors = 0;
444 auto ReportError = [&](const Twine &TitleMsg) {
445 ++NumErrors;
446 error() << TitleMsg << '\n';
447 dump(Die) << '\n';
448 };
449
450 const DWARFObject &DObj = DCtx.getDWARFObj();
451 const auto Attr = AttrValue.Attr;
452 switch (Attr) {
453 case DW_AT_ranges:
454 // Make sure the offset in the DW_AT_ranges attribute is valid.
455 if (auto SectionOffset = AttrValue.Value.getAsSectionOffset()) {
456 if (*SectionOffset >= DObj.getRangeSection().Data.size())
457 ReportError("DW_AT_ranges offset is beyond .debug_ranges bounds:");
458 break;
459 }
460 ReportError("DIE has invalid DW_AT_ranges encoding:");
461 break;
462 case DW_AT_stmt_list:
463 // Make sure the offset in the DW_AT_stmt_list attribute is valid.
464 if (auto SectionOffset = AttrValue.Value.getAsSectionOffset()) {
465 if (*SectionOffset >= DObj.getLineSection().Data.size())
466 ReportError("DW_AT_stmt_list offset is beyond .debug_line bounds: " +
467 llvm::formatv("{0:x8}", *SectionOffset));
468 break;
469 }
470 ReportError("DIE has invalid DW_AT_stmt_list encoding:");
471 break;
472 case DW_AT_location: {
473 auto VerifyLocationExpr = [&](StringRef D) {
474 DWARFUnit *U = Die.getDwarfUnit();
475 DataExtractor Data(D, DCtx.isLittleEndian(), 0);
476 DWARFExpression Expression(Data, U->getVersion(),
477 U->getAddressByteSize());
478 bool Error = llvm::any_of(Expression, [](DWARFExpression::Operation &Op) {
479 return Op.isError();
480 });
481 if (Error)
482 ReportError("DIE contains invalid DWARF expression:");
483 };
484 if (Optional<ArrayRef<uint8_t>> Expr = AttrValue.Value.getAsBlock()) {
485 // Verify inlined location.
486 VerifyLocationExpr(llvm::toStringRef(*Expr));
487 } else if (auto LocOffset = AttrValue.Value.getAsSectionOffset()) {
488 // Verify location list.
489 if (auto DebugLoc = DCtx.getDebugLoc())
490 if (auto LocList = DebugLoc->getLocationListAtOffset(*LocOffset))
491 for (const auto &Entry : LocList->Entries)
492 VerifyLocationExpr({Entry.Loc.data(), Entry.Loc.size()});
493 }
494 break;
495 }
496 case DW_AT_specification:
497 case DW_AT_abstract_origin: {
498 if (auto ReferencedDie = Die.getAttributeValueAsReferencedDie(Attr)) {
499 auto DieTag = Die.getTag();
500 auto RefTag = ReferencedDie.getTag();
501 if (DieTag == RefTag)
502 break;
503 if (DieTag == DW_TAG_inlined_subroutine && RefTag == DW_TAG_subprogram)
504 break;
505 if (DieTag == DW_TAG_variable && RefTag == DW_TAG_member)
506 break;
507 ReportError("DIE with tag " + TagString(DieTag) + " has " +
508 AttributeString(Attr) +
509 " that points to DIE with "
510 "incompatible tag " +
511 TagString(RefTag));
512 }
513 break;
514 }
515 case DW_AT_type: {
516 DWARFDie TypeDie = Die.getAttributeValueAsReferencedDie(DW_AT_type);
517 if (TypeDie && !isType(TypeDie.getTag())) {
518 ReportError("DIE has " + AttributeString(Attr) +
519 " with incompatible tag " + TagString(TypeDie.getTag()));
520 }
521 break;
522 }
523 default:
524 break;
525 }
526 return NumErrors;
527}
528
529unsigned DWARFVerifier::verifyDebugInfoForm(const DWARFDie &Die,
530 DWARFAttribute &AttrValue) {
531 const DWARFObject &DObj = DCtx.getDWARFObj();
532 unsigned NumErrors = 0;
533 const auto Form = AttrValue.Value.getForm();
534 switch (Form) {
535 case DW_FORM_ref1:
536 case DW_FORM_ref2:
537 case DW_FORM_ref4:
538 case DW_FORM_ref8:
539 case DW_FORM_ref_udata: {
540 // Verify all CU relative references are valid CU offsets.
541 Optional<uint64_t> RefVal = AttrValue.Value.getAsReference();
542 assert(RefVal)((RefVal) ? static_cast<void> (0) : __assert_fail ("RefVal"
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/DebugInfo/DWARF/DWARFVerifier.cpp"
, 542, __PRETTY_FUNCTION__))
;
543 if (RefVal) {
544 auto DieCU = Die.getDwarfUnit();
545 auto CUSize = DieCU->getNextUnitOffset() - DieCU->getOffset();
546 auto CUOffset = AttrValue.Value.getRawUValue();
547 if (CUOffset >= CUSize) {
548 ++NumErrors;
549 error() << FormEncodingString(Form) << " CU offset "
550 << format("0x%08" PRIx64"l" "x", CUOffset)
551 << " is invalid (must be less than CU size of "
552 << format("0x%08" PRIx32"x", CUSize) << "):\n";
553 Die.dump(OS, 0, DumpOpts);
554 dump(Die) << '\n';
555 } else {
556 // Valid reference, but we will verify it points to an actual
557 // DIE later.
558 ReferenceToDIEOffsets[*RefVal].insert(Die.getOffset());
559 }
560 }
561 break;
562 }
563 case DW_FORM_ref_addr: {
564 // Verify all absolute DIE references have valid offsets in the
565 // .debug_info section.
566 Optional<uint64_t> RefVal = AttrValue.Value.getAsReference();
567 assert(RefVal)((RefVal) ? static_cast<void> (0) : __assert_fail ("RefVal"
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/DebugInfo/DWARF/DWARFVerifier.cpp"
, 567, __PRETTY_FUNCTION__))
;
568 if (RefVal) {
569 if (*RefVal >= DObj.getInfoSection().Data.size()) {
570 ++NumErrors;
571 error() << "DW_FORM_ref_addr offset beyond .debug_info "
572 "bounds:\n";
573 dump(Die) << '\n';
574 } else {
575 // Valid reference, but we will verify it points to an actual
576 // DIE later.
577 ReferenceToDIEOffsets[*RefVal].insert(Die.getOffset());
578 }
579 }
580 break;
581 }
582 case DW_FORM_strp: {
583 auto SecOffset = AttrValue.Value.getAsSectionOffset();
584 assert(SecOffset)((SecOffset) ? static_cast<void> (0) : __assert_fail ("SecOffset"
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/DebugInfo/DWARF/DWARFVerifier.cpp"
, 584, __PRETTY_FUNCTION__))
; // DW_FORM_strp is a section offset.
585 if (SecOffset && *SecOffset >= DObj.getStringSection().size()) {
586 ++NumErrors;
587 error() << "DW_FORM_strp offset beyond .debug_str bounds:\n";
588 dump(Die) << '\n';
589 }
590 break;
591 }
592 default:
593 break;
594 }
595 return NumErrors;
596}
597
598unsigned DWARFVerifier::verifyDebugInfoReferences() {
599 // Take all references and make sure they point to an actual DIE by
600 // getting the DIE by offset and emitting an error
601 OS << "Verifying .debug_info references...\n";
602 unsigned NumErrors = 0;
603 for (auto Pair : ReferenceToDIEOffsets) {
604 auto Die = DCtx.getDIEForOffset(Pair.first);
605 if (Die)
606 continue;
607 ++NumErrors;
608 error() << "invalid DIE reference " << format("0x%08" PRIx64"l" "x", Pair.first)
609 << ". Offset is in between DIEs:\n";
610 for (auto Offset : Pair.second)
611 dump(DCtx.getDIEForOffset(Offset)) << '\n';
612 OS << "\n";
613 }
614 return NumErrors;
615}
616
617void DWARFVerifier::verifyDebugLineStmtOffsets() {
618 std::map<uint64_t, DWARFDie> StmtListToDie;
619 for (const auto &CU : DCtx.compile_units()) {
620 auto Die = CU->getUnitDIE();
621 // Get the attribute value as a section offset. No need to produce an
622 // error here if the encoding isn't correct because we validate this in
623 // the .debug_info verifier.
624 auto StmtSectionOffset = toSectionOffset(Die.find(DW_AT_stmt_list));
625 if (!StmtSectionOffset)
626 continue;
627 const uint32_t LineTableOffset = *StmtSectionOffset;
628 auto LineTable = DCtx.getLineTableForUnit(CU.get());
629 if (LineTableOffset < DCtx.getDWARFObj().getLineSection().Data.size()) {
630 if (!LineTable) {
631 ++NumDebugLineErrors;
632 error() << ".debug_line[" << format("0x%08" PRIx32"x", LineTableOffset)
633 << "] was not able to be parsed for CU:\n";
634 dump(Die) << '\n';
635 continue;
636 }
637 } else {
638 // Make sure we don't get a valid line table back if the offset is wrong.
639 assert(LineTable == nullptr)((LineTable == nullptr) ? static_cast<void> (0) : __assert_fail
("LineTable == nullptr", "/build/llvm-toolchain-snapshot-8~svn345461/lib/DebugInfo/DWARF/DWARFVerifier.cpp"
, 639, __PRETTY_FUNCTION__))
;
640 // Skip this line table as it isn't valid. No need to create an error
641 // here because we validate this in the .debug_info verifier.
642 continue;
643 }
644 auto Iter = StmtListToDie.find(LineTableOffset);
645 if (Iter != StmtListToDie.end()) {
646 ++NumDebugLineErrors;
647 error() << "two compile unit DIEs, "
648 << format("0x%08" PRIx32"x", Iter->second.getOffset()) << " and "
649 << format("0x%08" PRIx32"x", Die.getOffset())
650 << ", have the same DW_AT_stmt_list section offset:\n";
651 dump(Iter->second);
652 dump(Die) << '\n';
653 // Already verified this line table before, no need to do it again.
654 continue;
655 }
656 StmtListToDie[LineTableOffset] = Die;
657 }
658}
659
660void DWARFVerifier::verifyDebugLineRows() {
661 for (const auto &CU : DCtx.compile_units()) {
662 auto Die = CU->getUnitDIE();
663 auto LineTable = DCtx.getLineTableForUnit(CU.get());
664 // If there is no line table we will have created an error in the
665 // .debug_info verifier or in verifyDebugLineStmtOffsets().
666 if (!LineTable)
667 continue;
668
669 // Verify prologue.
670 uint32_t MaxFileIndex = LineTable->Prologue.FileNames.size();
671 uint32_t MaxDirIndex = LineTable->Prologue.IncludeDirectories.size();
672 uint32_t FileIndex = 1;
673 StringMap<uint16_t> FullPathMap;
674 for (const auto &FileName : LineTable->Prologue.FileNames) {
675 // Verify directory index.
676 if (FileName.DirIdx > MaxDirIndex) {
677 ++NumDebugLineErrors;
678 error() << ".debug_line["
679 << format("0x%08" PRIx64"l" "x",
680 *toSectionOffset(Die.find(DW_AT_stmt_list)))
681 << "].prologue.file_names[" << FileIndex
682 << "].dir_idx contains an invalid index: " << FileName.DirIdx
683 << "\n";
684 }
685
686 // Check file paths for duplicates.
687 std::string FullPath;
688 const bool HasFullPath = LineTable->getFileNameByIndex(
689 FileIndex, CU->getCompilationDir(),
690 DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, FullPath);
691 assert(HasFullPath && "Invalid index?")((HasFullPath && "Invalid index?") ? static_cast<void
> (0) : __assert_fail ("HasFullPath && \"Invalid index?\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/DebugInfo/DWARF/DWARFVerifier.cpp"
, 691, __PRETTY_FUNCTION__))
;
692 (void)HasFullPath;
693 auto It = FullPathMap.find(FullPath);
694 if (It == FullPathMap.end())
695 FullPathMap[FullPath] = FileIndex;
696 else if (It->second != FileIndex) {
697 warn() << ".debug_line["
698 << format("0x%08" PRIx64"l" "x",
699 *toSectionOffset(Die.find(DW_AT_stmt_list)))
700 << "].prologue.file_names[" << FileIndex
701 << "] is a duplicate of file_names[" << It->second << "]\n";
702 }
703
704 FileIndex++;
705 }
706
707 // Verify rows.
708 uint64_t PrevAddress = 0;
709 uint32_t RowIndex = 0;
710 for (const auto &Row : LineTable->Rows) {
711 // Verify row address.
712 if (Row.Address < PrevAddress) {
713 ++NumDebugLineErrors;
714 error() << ".debug_line["
715 << format("0x%08" PRIx64"l" "x",
716 *toSectionOffset(Die.find(DW_AT_stmt_list)))
717 << "] row[" << RowIndex
718 << "] decreases in address from previous row:\n";
719
720 DWARFDebugLine::Row::dumpTableHeader(OS);
721 if (RowIndex > 0)
722 LineTable->Rows[RowIndex - 1].dump(OS);
723 Row.dump(OS);
724 OS << '\n';
725 }
726
727 // Verify file index.
728 if (Row.File > MaxFileIndex) {
729 ++NumDebugLineErrors;
730 error() << ".debug_line["
731 << format("0x%08" PRIx64"l" "x",
732 *toSectionOffset(Die.find(DW_AT_stmt_list)))
733 << "][" << RowIndex << "] has invalid file index " << Row.File
734 << " (valid values are [1," << MaxFileIndex << "]):\n";
735 DWARFDebugLine::Row::dumpTableHeader(OS);
736 Row.dump(OS);
737 OS << '\n';
738 }
739 if (Row.EndSequence)
740 PrevAddress = 0;
741 else
742 PrevAddress = Row.Address;
743 ++RowIndex;
744 }
745 }
746}
747
748bool DWARFVerifier::handleDebugLine() {
749 NumDebugLineErrors = 0;
750 OS << "Verifying .debug_line...\n";
751 verifyDebugLineStmtOffsets();
752 verifyDebugLineRows();
753 return NumDebugLineErrors == 0;
754}
755
756unsigned DWARFVerifier::verifyAppleAccelTable(const DWARFSection *AccelSection,
757 DataExtractor *StrData,
758 const char *SectionName) {
759 unsigned NumErrors = 0;
760 DWARFDataExtractor AccelSectionData(DCtx.getDWARFObj(), *AccelSection,
761 DCtx.isLittleEndian(), 0);
762 AppleAcceleratorTable AccelTable(AccelSectionData, *StrData);
763
764 OS << "Verifying " << SectionName << "...\n";
765
766 // Verify that the fixed part of the header is not too short.
767 if (!AccelSectionData.isValidOffset(AccelTable.getSizeHdr())) {
768 error() << "Section is too small to fit a section header.\n";
769 return 1;
770 }
771
772 // Verify that the section is not too short.
773 if (Error E = AccelTable.extract()) {
774 error() << toString(std::move(E)) << '\n';
775 return 1;
776 }
777
778 // Verify that all buckets have a valid hash index or are empty.
779 uint32_t NumBuckets = AccelTable.getNumBuckets();
780 uint32_t NumHashes = AccelTable.getNumHashes();
781
782 uint32_t BucketsOffset =
783 AccelTable.getSizeHdr() + AccelTable.getHeaderDataLength();
784 uint32_t HashesBase = BucketsOffset + NumBuckets * 4;
785 uint32_t OffsetsBase = HashesBase + NumHashes * 4;
786 for (uint32_t BucketIdx = 0; BucketIdx < NumBuckets; ++BucketIdx) {
787 uint32_t HashIdx = AccelSectionData.getU32(&BucketsOffset);
788 if (HashIdx >= NumHashes && HashIdx != UINT32_MAX(4294967295U)) {
789 error() << format("Bucket[%d] has invalid hash index: %u.\n", BucketIdx,
790 HashIdx);
791 ++NumErrors;
792 }
793 }
794 uint32_t NumAtoms = AccelTable.getAtomsDesc().size();
795 if (NumAtoms == 0) {
796 error() << "No atoms: failed to read HashData.\n";
797 return 1;
798 }
799 if (!AccelTable.validateForms()) {
800 error() << "Unsupported form: failed to read HashData.\n";
801 return 1;
802 }
803
804 for (uint32_t HashIdx = 0; HashIdx < NumHashes; ++HashIdx) {
805 uint32_t HashOffset = HashesBase + 4 * HashIdx;
806 uint32_t DataOffset = OffsetsBase + 4 * HashIdx;
807 uint32_t Hash = AccelSectionData.getU32(&HashOffset);
808 uint32_t HashDataOffset = AccelSectionData.getU32(&DataOffset);
809 if (!AccelSectionData.isValidOffsetForDataOfSize(HashDataOffset,
810 sizeof(uint64_t))) {
811 error() << format("Hash[%d] has invalid HashData offset: 0x%08x.\n",
812 HashIdx, HashDataOffset);
813 ++NumErrors;
814 }
815
816 uint32_t StrpOffset;
817 uint32_t StringOffset;
818 uint32_t StringCount = 0;
819 unsigned Offset;
820 unsigned Tag;
821 while ((StrpOffset = AccelSectionData.getU32(&HashDataOffset)) != 0) {
822 const uint32_t NumHashDataObjects =
823 AccelSectionData.getU32(&HashDataOffset);
824 for (uint32_t HashDataIdx = 0; HashDataIdx < NumHashDataObjects;
825 ++HashDataIdx) {
826 std::tie(Offset, Tag) = AccelTable.readAtoms(HashDataOffset);
827 auto Die = DCtx.getDIEForOffset(Offset);
828 if (!Die) {
829 const uint32_t BucketIdx =
830 NumBuckets ? (Hash % NumBuckets) : UINT32_MAX(4294967295U);
831 StringOffset = StrpOffset;
832 const char *Name = StrData->getCStr(&StringOffset);
833 if (!Name)
834 Name = "<NULL>";
835
836 error() << format(
837 "%s Bucket[%d] Hash[%d] = 0x%08x "
838 "Str[%u] = 0x%08x "
839 "DIE[%d] = 0x%08x is not a valid DIE offset for \"%s\".\n",
840 SectionName, BucketIdx, HashIdx, Hash, StringCount, StrpOffset,
841 HashDataIdx, Offset, Name);
842
843 ++NumErrors;
844 continue;
845 }
846 if ((Tag != dwarf::DW_TAG_null) && (Die.getTag() != Tag)) {
847 error() << "Tag " << dwarf::TagString(Tag)
848 << " in accelerator table does not match Tag "
849 << dwarf::TagString(Die.getTag()) << " of DIE[" << HashDataIdx
850 << "].\n";
851 ++NumErrors;
852 }
853 }
854 ++StringCount;
855 }
856 }
857 return NumErrors;
858}
859
860unsigned
861DWARFVerifier::verifyDebugNamesCULists(const DWARFDebugNames &AccelTable) {
862 // A map from CU offset to the (first) Name Index offset which claims to index
863 // this CU.
864 DenseMap<uint32_t, uint32_t> CUMap;
865 const uint32_t NotIndexed = std::numeric_limits<uint32_t>::max();
866
867 CUMap.reserve(DCtx.getNumCompileUnits());
868 for (const auto &CU : DCtx.compile_units())
869 CUMap[CU->getOffset()] = NotIndexed;
870
871 unsigned NumErrors = 0;
872 for (const DWARFDebugNames::NameIndex &NI : AccelTable) {
873 if (NI.getCUCount() == 0) {
874 error() << formatv("Name Index @ {0:x} does not index any CU\n",
875 NI.getUnitOffset());
876 ++NumErrors;
877 continue;
878 }
879 for (uint32_t CU = 0, End = NI.getCUCount(); CU < End; ++CU) {
880 uint32_t Offset = NI.getCUOffset(CU);
881 auto Iter = CUMap.find(Offset);
882
883 if (Iter == CUMap.end()) {
884 error() << formatv(
885 "Name Index @ {0:x} references a non-existing CU @ {1:x}\n",
886 NI.getUnitOffset(), Offset);
887 ++NumErrors;
888 continue;
889 }
890
891 if (Iter->second != NotIndexed) {
892 error() << formatv("Name Index @ {0:x} references a CU @ {1:x}, but "
893 "this CU is already indexed by Name Index @ {2:x}\n",
894 NI.getUnitOffset(), Offset, Iter->second);
895 continue;
896 }
897 Iter->second = NI.getUnitOffset();
898 }
899 }
900
901 for (const auto &KV : CUMap) {
902 if (KV.second == NotIndexed)
903 warn() << formatv("CU @ {0:x} not covered by any Name Index\n", KV.first);
904 }
905
906 return NumErrors;
907}
908
909unsigned
910DWARFVerifier::verifyNameIndexBuckets(const DWARFDebugNames::NameIndex &NI,
911 const DataExtractor &StrData) {
912 struct BucketInfo {
913 uint32_t Bucket;
914 uint32_t Index;
915
916 constexpr BucketInfo(uint32_t Bucket, uint32_t Index)
917 : Bucket(Bucket), Index(Index) {}
918 bool operator<(const BucketInfo &RHS) const { return Index < RHS.Index; };
919 };
920
921 uint32_t NumErrors = 0;
922 if (NI.getBucketCount() == 0) {
923 warn() << formatv("Name Index @ {0:x} does not contain a hash table.\n",
924 NI.getUnitOffset());
925 return NumErrors;
926 }
927
928 // Build up a list of (Bucket, Index) pairs. We use this later to verify that
929 // each Name is reachable from the appropriate bucket.
930 std::vector<BucketInfo> BucketStarts;
931 BucketStarts.reserve(NI.getBucketCount() + 1);
932 for (uint32_t Bucket = 0, End = NI.getBucketCount(); Bucket < End; ++Bucket) {
933 uint32_t Index = NI.getBucketArrayEntry(Bucket);
934 if (Index > NI.getNameCount()) {
935 error() << formatv("Bucket {0} of Name Index @ {1:x} contains invalid "
936 "value {2}. Valid range is [0, {3}].\n",
937 Bucket, NI.getUnitOffset(), Index, NI.getNameCount());
938 ++NumErrors;
939 continue;
940 }
941 if (Index > 0)
942 BucketStarts.emplace_back(Bucket, Index);
943 }
944
945 // If there were any buckets with invalid values, skip further checks as they
946 // will likely produce many errors which will only confuse the actual root
947 // problem.
948 if (NumErrors > 0)
949 return NumErrors;
950
951 // Sort the list in the order of increasing "Index" entries.
952 array_pod_sort(BucketStarts.begin(), BucketStarts.end());
953
954 // Insert a sentinel entry at the end, so we can check that the end of the
955 // table is covered in the loop below.
956 BucketStarts.emplace_back(NI.getBucketCount(), NI.getNameCount() + 1);
957
958 // Loop invariant: NextUncovered is the (1-based) index of the first Name
959 // which is not reachable by any of the buckets we processed so far (and
960 // hasn't been reported as uncovered).
961 uint32_t NextUncovered = 1;
962 for (const BucketInfo &B : BucketStarts) {
963 // Under normal circumstances B.Index be equal to NextUncovered, but it can
964 // be less if a bucket points to names which are already known to be in some
965 // bucket we processed earlier. In that case, we won't trigger this error,
966 // but report the mismatched hash value error instead. (We know the hash
967 // will not match because we have already verified that the name's hash
968 // puts it into the previous bucket.)
969 if (B.Index > NextUncovered) {
970 error() << formatv("Name Index @ {0:x}: Name table entries [{1}, {2}] "
971 "are not covered by the hash table.\n",
972 NI.getUnitOffset(), NextUncovered, B.Index - 1);
973 ++NumErrors;
974 }
975 uint32_t Idx = B.Index;
976
977 // The rest of the checks apply only to non-sentinel entries.
978 if (B.Bucket == NI.getBucketCount())
979 break;
980
981 // This triggers if a non-empty bucket points to a name with a mismatched
982 // hash. Clients are likely to interpret this as an empty bucket, because a
983 // mismatched hash signals the end of a bucket, but if this is indeed an
984 // empty bucket, the producer should have signalled this by marking the
985 // bucket as empty.
986 uint32_t FirstHash = NI.getHashArrayEntry(Idx);
987 if (FirstHash % NI.getBucketCount() != B.Bucket) {
988 error() << formatv(
989 "Name Index @ {0:x}: Bucket {1} is not empty but points to a "
990 "mismatched hash value {2:x} (belonging to bucket {3}).\n",
991 NI.getUnitOffset(), B.Bucket, FirstHash,
992 FirstHash % NI.getBucketCount());
993 ++NumErrors;
994 }
995
996 // This find the end of this bucket and also verifies that all the hashes in
997 // this bucket are correct by comparing the stored hashes to the ones we
998 // compute ourselves.
999 while (Idx <= NI.getNameCount()) {
1000 uint32_t Hash = NI.getHashArrayEntry(Idx);
1001 if (Hash % NI.getBucketCount() != B.Bucket)
1002 break;
1003
1004 const char *Str = NI.getNameTableEntry(Idx).getString();
1005 if (caseFoldingDjbHash(Str) != Hash) {
1006 error() << formatv("Name Index @ {0:x}: String ({1}) at index {2} "
1007 "hashes to {3:x}, but "
1008 "the Name Index hash is {4:x}\n",
1009 NI.getUnitOffset(), Str, Idx,
1010 caseFoldingDjbHash(Str), Hash);
1011 ++NumErrors;
1012 }
1013
1014 ++Idx;
1015 }
1016 NextUncovered = std::max(NextUncovered, Idx);
1017 }
1018 return NumErrors;
1019}
1020
1021unsigned DWARFVerifier::verifyNameIndexAttribute(
1022 const DWARFDebugNames::NameIndex &NI, const DWARFDebugNames::Abbrev &Abbr,
1023 DWARFDebugNames::AttributeEncoding AttrEnc) {
1024 StringRef FormName = dwarf::FormEncodingString(AttrEnc.Form);
1025 if (FormName.empty()) {
1026 error() << formatv("NameIndex @ {0:x}: Abbreviation {1:x}: {2} uses an "
1027 "unknown form: {3}.\n",
1028 NI.getUnitOffset(), Abbr.Code, AttrEnc.Index,
1029 AttrEnc.Form);
1030 return 1;
1031 }
1032
1033 if (AttrEnc.Index == DW_IDX_type_hash) {
1034 if (AttrEnc.Form != dwarf::DW_FORM_data8) {
1035 error() << formatv(
1036 "NameIndex @ {0:x}: Abbreviation {1:x}: DW_IDX_type_hash "
1037 "uses an unexpected form {2} (should be {3}).\n",
1038 NI.getUnitOffset(), Abbr.Code, AttrEnc.Form, dwarf::DW_FORM_data8);
1039 return 1;
1040 }
1041 }
1042
1043 // A list of known index attributes and their expected form classes.
1044 // DW_IDX_type_hash is handled specially in the check above, as it has a
1045 // specific form (not just a form class) we should expect.
1046 struct FormClassTable {
1047 dwarf::Index Index;
1048 DWARFFormValue::FormClass Class;
1049 StringLiteral ClassName;
1050 };
1051 static constexpr FormClassTable Table[] = {
1052 {dwarf::DW_IDX_compile_unit, DWARFFormValue::FC_Constant, {"constant"}},
1053 {dwarf::DW_IDX_type_unit, DWARFFormValue::FC_Constant, {"constant"}},
1054 {dwarf::DW_IDX_die_offset, DWARFFormValue::FC_Reference, {"reference"}},
1055 {dwarf::DW_IDX_parent, DWARFFormValue::FC_Constant, {"constant"}},
1056 };
1057
1058 ArrayRef<FormClassTable> TableRef(Table);
1059 auto Iter = find_if(TableRef, [AttrEnc](const FormClassTable &T) {
1060 return T.Index == AttrEnc.Index;
1061 });
1062 if (Iter == TableRef.end()) {
1063 warn() << formatv("NameIndex @ {0:x}: Abbreviation {1:x} contains an "
1064 "unknown index attribute: {2}.\n",
1065 NI.getUnitOffset(), Abbr.Code, AttrEnc.Index);
1066 return 0;
1067 }
1068
1069 if (!DWARFFormValue(AttrEnc.Form).isFormClass(Iter->Class)) {
1070 error() << formatv("NameIndex @ {0:x}: Abbreviation {1:x}: {2} uses an "
1071 "unexpected form {3} (expected form class {4}).\n",
1072 NI.getUnitOffset(), Abbr.Code, AttrEnc.Index,
1073 AttrEnc.Form, Iter->ClassName);
1074 return 1;
1075 }
1076 return 0;
1077}
1078
1079unsigned
1080DWARFVerifier::verifyNameIndexAbbrevs(const DWARFDebugNames::NameIndex &NI) {
1081 if (NI.getLocalTUCount() + NI.getForeignTUCount() > 0) {
1082 warn() << formatv("Name Index @ {0:x}: Verifying indexes of type units is "
1083 "not currently supported.\n",
1084 NI.getUnitOffset());
1085 return 0;
1086 }
1087
1088 unsigned NumErrors = 0;
1089 for (const auto &Abbrev : NI.getAbbrevs()) {
1090 StringRef TagName = dwarf::TagString(Abbrev.Tag);
1091 if (TagName.empty()) {
1092 warn() << formatv("NameIndex @ {0:x}: Abbreviation {1:x} references an "
1093 "unknown tag: {2}.\n",
1094 NI.getUnitOffset(), Abbrev.Code, Abbrev.Tag);
1095 }
1096 SmallSet<unsigned, 5> Attributes;
1097 for (const auto &AttrEnc : Abbrev.Attributes) {
1098 if (!Attributes.insert(AttrEnc.Index).second) {
1099 error() << formatv("NameIndex @ {0:x}: Abbreviation {1:x} contains "
1100 "multiple {2} attributes.\n",
1101 NI.getUnitOffset(), Abbrev.Code, AttrEnc.Index);
1102 ++NumErrors;
1103 continue;
1104 }
1105 NumErrors += verifyNameIndexAttribute(NI, Abbrev, AttrEnc);
1106 }
1107
1108 if (NI.getCUCount() > 1 && !Attributes.count(dwarf::DW_IDX_compile_unit)) {
1109 error() << formatv("NameIndex @ {0:x}: Indexing multiple compile units "
1110 "and abbreviation {1:x} has no {2} attribute.\n",
1111 NI.getUnitOffset(), Abbrev.Code,
1112 dwarf::DW_IDX_compile_unit);
1113 ++NumErrors;
1114 }
1115 if (!Attributes.count(dwarf::DW_IDX_die_offset)) {
1116 error() << formatv(
1117 "NameIndex @ {0:x}: Abbreviation {1:x} has no {2} attribute.\n",
1118 NI.getUnitOffset(), Abbrev.Code, dwarf::DW_IDX_die_offset);
1119 ++NumErrors;
1120 }
1121 }
1122 return NumErrors;
1123}
1124
1125static SmallVector<StringRef, 2> getNames(const DWARFDie &DIE,
1126 bool IncludeLinkageName = true) {
1127 SmallVector<StringRef, 2> Result;
1128 if (const char *Str = DIE.getName(DINameKind::ShortName))
1129 Result.emplace_back(Str);
1130 else if (DIE.getTag() == dwarf::DW_TAG_namespace)
1131 Result.emplace_back("(anonymous namespace)");
1132
1133 if (IncludeLinkageName) {
1134 if (const char *Str = DIE.getName(DINameKind::LinkageName)) {
1135 if (Result.empty() || Result[0] != Str)
1136 Result.emplace_back(Str);
1137 }
1138 }
1139
1140 return Result;
1141}
1142
1143unsigned DWARFVerifier::verifyNameIndexEntries(
1144 const DWARFDebugNames::NameIndex &NI,
1145 const DWARFDebugNames::NameTableEntry &NTE) {
1146 // Verifying type unit indexes not supported.
1147 if (NI.getLocalTUCount() + NI.getForeignTUCount() > 0)
1148 return 0;
1149
1150 const char *CStr = NTE.getString();
1151 if (!CStr) {
1152 error() << formatv(
1153 "Name Index @ {0:x}: Unable to get string associated with name {1}.\n",
1154 NI.getUnitOffset(), NTE.getIndex());
1155 return 1;
1156 }
1157 StringRef Str(CStr);
1158
1159 unsigned NumErrors = 0;
1160 unsigned NumEntries = 0;
1161 uint32_t EntryID = NTE.getEntryOffset();
1162 uint32_t NextEntryID = EntryID;
1163 Expected<DWARFDebugNames::Entry> EntryOr = NI.getEntry(&NextEntryID);
1164 for (; EntryOr; ++NumEntries, EntryID = NextEntryID,
1165 EntryOr = NI.getEntry(&NextEntryID)) {
1166 uint32_t CUIndex = *EntryOr->getCUIndex();
1167 if (CUIndex > NI.getCUCount()) {
1168 error() << formatv("Name Index @ {0:x}: Entry @ {1:x} contains an "
1169 "invalid CU index ({2}).\n",
1170 NI.getUnitOffset(), EntryID, CUIndex);
1171 ++NumErrors;
1172 continue;
1173 }
1174 uint32_t CUOffset = NI.getCUOffset(CUIndex);
1175 uint64_t DIEOffset = CUOffset + *EntryOr->getDIEUnitOffset();
1176 DWARFDie DIE = DCtx.getDIEForOffset(DIEOffset);
1177 if (!DIE) {
1178 error() << formatv("Name Index @ {0:x}: Entry @ {1:x} references a "
1179 "non-existing DIE @ {2:x}.\n",
1180 NI.getUnitOffset(), EntryID, DIEOffset);
1181 ++NumErrors;
1182 continue;
1183 }
1184 if (DIE.getDwarfUnit()->getOffset() != CUOffset) {
1185 error() << formatv("Name Index @ {0:x}: Entry @ {1:x}: mismatched CU of "
1186 "DIE @ {2:x}: index - {3:x}; debug_info - {4:x}.\n",
1187 NI.getUnitOffset(), EntryID, DIEOffset, CUOffset,
1188 DIE.getDwarfUnit()->getOffset());
1189 ++NumErrors;
1190 }
1191 if (DIE.getTag() != EntryOr->tag()) {
1192 error() << formatv("Name Index @ {0:x}: Entry @ {1:x}: mismatched Tag of "
1193 "DIE @ {2:x}: index - {3}; debug_info - {4}.\n",
1194 NI.getUnitOffset(), EntryID, DIEOffset, EntryOr->tag(),
1195 DIE.getTag());
1196 ++NumErrors;
1197 }
1198
1199 auto EntryNames = getNames(DIE);
1200 if (!is_contained(EntryNames, Str)) {
1201 error() << formatv("Name Index @ {0:x}: Entry @ {1:x}: mismatched Name "
1202 "of DIE @ {2:x}: index - {3}; debug_info - {4}.\n",
1203 NI.getUnitOffset(), EntryID, DIEOffset, Str,
1204 make_range(EntryNames.begin(), EntryNames.end()));
1205 ++NumErrors;
1206 }
1207 }
1208 handleAllErrors(EntryOr.takeError(),
1209 [&](const DWARFDebugNames::SentinelError &) {
1210 if (NumEntries > 0)
1211 return;
1212 error() << formatv("Name Index @ {0:x}: Name {1} ({2}) is "
1213 "not associated with any entries.\n",
1214 NI.getUnitOffset(), NTE.getIndex(), Str);
1215 ++NumErrors;
1216 },
1217 [&](const ErrorInfoBase &Info) {
1218 error()
1219 << formatv("Name Index @ {0:x}: Name {1} ({2}): {3}\n",
1220 NI.getUnitOffset(), NTE.getIndex(), Str,
1221 Info.message());
1222 ++NumErrors;
1223 });
1224 return NumErrors;
1225}
1226
1227static bool isVariableIndexable(const DWARFDie &Die, DWARFContext &DCtx) {
1228 Optional<DWARFFormValue> Location = Die.findRecursively(DW_AT_location);
1229 if (!Location)
1230 return false;
1231
1232 auto ContainsInterestingOperators = [&](StringRef D) {
1233 DWARFUnit *U = Die.getDwarfUnit();
1234 DataExtractor Data(D, DCtx.isLittleEndian(), U->getAddressByteSize());
1235 DWARFExpression Expression(Data, U->getVersion(), U->getAddressByteSize());
1236 return any_of(Expression, [](DWARFExpression::Operation &Op) {
1237 return !Op.isError() && (Op.getCode() == DW_OP_addr ||
1238 Op.getCode() == DW_OP_form_tls_address ||
1239 Op.getCode() == DW_OP_GNU_push_tls_address);
1240 });
1241 };
1242
1243 if (Optional<ArrayRef<uint8_t>> Expr = Location->getAsBlock()) {
1244 // Inlined location.
1245 if (ContainsInterestingOperators(toStringRef(*Expr)))
1246 return true;
1247 } else if (Optional<uint64_t> Offset = Location->getAsSectionOffset()) {
1248 // Location list.
1249 if (const DWARFDebugLoc *DebugLoc = DCtx.getDebugLoc()) {
1250 if (const DWARFDebugLoc::LocationList *LocList =
1251 DebugLoc->getLocationListAtOffset(*Offset)) {
1252 if (any_of(LocList->Entries, [&](const DWARFDebugLoc::Entry &E) {
1253 return ContainsInterestingOperators({E.Loc.data(), E.Loc.size()});
1254 }))
1255 return true;
1256 }
1257 }
1258 }
1259 return false;
1260}
1261
1262unsigned DWARFVerifier::verifyNameIndexCompleteness(
1263 const DWARFDie &Die, const DWARFDebugNames::NameIndex &NI) {
1264
1265 // First check, if the Die should be indexed. The code follows the DWARF v5
1266 // wording as closely as possible.
1267
1268 // "All non-defining declarations (that is, debugging information entries
1269 // with a DW_AT_declaration attribute) are excluded."
1270 if (Die.find(DW_AT_declaration))
1271 return 0;
1272
1273 // "DW_TAG_namespace debugging information entries without a DW_AT_name
1274 // attribute are included with the name “(anonymous namespace)”.
1275 // All other debugging information entries without a DW_AT_name attribute
1276 // are excluded."
1277 // "If a subprogram or inlined subroutine is included, and has a
1278 // DW_AT_linkage_name attribute, there will be an additional index entry for
1279 // the linkage name."
1280 auto IncludeLinkageName = Die.getTag() == DW_TAG_subprogram ||
1281 Die.getTag() == DW_TAG_inlined_subroutine;
1282 auto EntryNames = getNames(Die, IncludeLinkageName);
1283 if (EntryNames.empty())
1284 return 0;
1285
1286 // We deviate from the specification here, which says:
1287 // "The name index must contain an entry for each debugging information entry
1288 // that defines a named subprogram, label, variable, type, or namespace,
1289 // subject to ..."
1290 // Instead whitelisting all TAGs representing a "type" or a "subprogram", to
1291 // make sure we catch any missing items, we instead blacklist all TAGs that we
1292 // know shouldn't be indexed.
1293 switch (Die.getTag()) {
1294 // Compile units and modules have names but shouldn't be indexed.
1295 case DW_TAG_compile_unit:
1296 case DW_TAG_module:
1297 return 0;
1298
1299 // Function and template parameters are not globally visible, so we shouldn't
1300 // index them.
1301 case DW_TAG_formal_parameter:
1302 case DW_TAG_template_value_parameter:
1303 case DW_TAG_template_type_parameter:
1304 case DW_TAG_GNU_template_parameter_pack:
1305 case DW_TAG_GNU_template_template_param:
1306 return 0;
1307
1308 // Object members aren't globally visible.
1309 case DW_TAG_member:
1310 return 0;
1311
1312 // According to a strict reading of the specification, enumerators should not
1313 // be indexed (and LLVM currently does not do that). However, this causes
1314 // problems for the debuggers, so we may need to reconsider this.
1315 case DW_TAG_enumerator:
1316 return 0;
1317
1318 // Imported declarations should not be indexed according to the specification
1319 // and LLVM currently does not do that.
1320 case DW_TAG_imported_declaration:
1321 return 0;
1322
1323 // "DW_TAG_subprogram, DW_TAG_inlined_subroutine, and DW_TAG_label debugging
1324 // information entries without an address attribute (DW_AT_low_pc,
1325 // DW_AT_high_pc, DW_AT_ranges, or DW_AT_entry_pc) are excluded."
1326 case DW_TAG_subprogram:
1327 case DW_TAG_inlined_subroutine:
1328 case DW_TAG_label:
1329 if (Die.findRecursively(
1330 {DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_entry_pc}))
1331 break;
1332 return 0;
1333
1334 // "DW_TAG_variable debugging information entries with a DW_AT_location
1335 // attribute that includes a DW_OP_addr or DW_OP_form_tls_address operator are
1336 // included; otherwise, they are excluded."
1337 //
1338 // LLVM extension: We also add DW_OP_GNU_push_tls_address to this list.
1339 case DW_TAG_variable:
1340 if (isVariableIndexable(Die, DCtx))
1341 break;
1342 return 0;
1343
1344 default:
1345 break;
1346 }
1347
1348 // Now we know that our Die should be present in the Index. Let's check if
1349 // that's the case.
1350 unsigned NumErrors = 0;
1351 uint64_t DieUnitOffset = Die.getOffset() - Die.getDwarfUnit()->getOffset();
1352 for (StringRef Name : EntryNames) {
1353 if (none_of(NI.equal_range(Name), [&](const DWARFDebugNames::Entry &E) {
1354 return E.getDIEUnitOffset() == DieUnitOffset;
1355 })) {
1356 error() << formatv("Name Index @ {0:x}: Entry for DIE @ {1:x} ({2}) with "
1357 "name {3} missing.\n",
1358 NI.getUnitOffset(), Die.getOffset(), Die.getTag(),
1359 Name);
1360 ++NumErrors;
1361 }
1362 }
1363 return NumErrors;
1364}
1365
1366unsigned DWARFVerifier::verifyDebugNames(const DWARFSection &AccelSection,
1367 const DataExtractor &StrData) {
1368 unsigned NumErrors = 0;
1369 DWARFDataExtractor AccelSectionData(DCtx.getDWARFObj(), AccelSection,
1370 DCtx.isLittleEndian(), 0);
1371 DWARFDebugNames AccelTable(AccelSectionData, StrData);
1372
1373 OS << "Verifying .debug_names...\n";
1374
1375 // This verifies that we can read individual name indices and their
1376 // abbreviation tables.
1377 if (Error E = AccelTable.extract()) {
1378 error() << toString(std::move(E)) << '\n';
1379 return 1;
1380 }
1381
1382 NumErrors += verifyDebugNamesCULists(AccelTable);
1383 for (const auto &NI : AccelTable)
1384 NumErrors += verifyNameIndexBuckets(NI, StrData);
1385 for (const auto &NI : AccelTable)
1386 NumErrors += verifyNameIndexAbbrevs(NI);
1387
1388 // Don't attempt Entry validation if any of the previous checks found errors
1389 if (NumErrors > 0)
1390 return NumErrors;
1391 for (const auto &NI : AccelTable)
1392 for (DWARFDebugNames::NameTableEntry NTE : NI)
1393 NumErrors += verifyNameIndexEntries(NI, NTE);
1394
1395 if (NumErrors > 0)
1396 return NumErrors;
1397
1398 for (const std::unique_ptr<DWARFUnit> &U : DCtx.compile_units()) {
1399 if (const DWARFDebugNames::NameIndex *NI =
1400 AccelTable.getCUNameIndex(U->getOffset())) {
1401 auto *CU = cast<DWARFCompileUnit>(U.get());
1402 for (const DWARFDebugInfoEntry &Die : CU->dies())
1403 NumErrors += verifyNameIndexCompleteness(DWARFDie(CU, &Die), *NI);
1404 }
1405 }
1406 return NumErrors;
1407}
1408
1409bool DWARFVerifier::handleAccelTables() {
1410 const DWARFObject &D = DCtx.getDWARFObj();
1411 DataExtractor StrData(D.getStringSection(), DCtx.isLittleEndian(), 0);
1412 unsigned NumErrors = 0;
1413 if (!D.getAppleNamesSection().Data.empty())
1414 NumErrors += verifyAppleAccelTable(&D.getAppleNamesSection(), &StrData,
1415 ".apple_names");
1416 if (!D.getAppleTypesSection().Data.empty())
1417 NumErrors += verifyAppleAccelTable(&D.getAppleTypesSection(), &StrData,
1418 ".apple_types");
1419 if (!D.getAppleNamespacesSection().Data.empty())
1420 NumErrors += verifyAppleAccelTable(&D.getAppleNamespacesSection(), &StrData,
1421 ".apple_namespaces");
1422 if (!D.getAppleObjCSection().Data.empty())
1423 NumErrors += verifyAppleAccelTable(&D.getAppleObjCSection(), &StrData,
1424 ".apple_objc");
1425
1426 if (!D.getDebugNamesSection().Data.empty())
1427 NumErrors += verifyDebugNames(D.getDebugNamesSection(), StrData);
1428 return NumErrors == 0;
1429}
1430
1431raw_ostream &DWARFVerifier::error() const { return WithColor::error(OS); }
1432
1433raw_ostream &DWARFVerifier::warn() const { return WithColor::warning(OS); }
1434
1435raw_ostream &DWARFVerifier::note() const { return WithColor::note(OS); }
1436
1437raw_ostream &DWARFVerifier::dump(const DWARFDie &Die, unsigned indent) const {
1438 Die.dump(OS, indent, DumpOpts);
1439 return OS;
1440}

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- 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 file defines an API used to report recoverable errors.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_ERROR_H
15#define LLVM_SUPPORT_ERROR_H
16
17#include "llvm-c/Error.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/ADT/StringExtras.h"
21#include "llvm/ADT/Twine.h"
22#include "llvm/Config/abi-breaking.h"
23#include "llvm/Support/AlignOf.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/Debug.h"
26#include "llvm/Support/ErrorHandling.h"
27#include "llvm/Support/ErrorOr.h"
28#include "llvm/Support/Format.h"
29#include "llvm/Support/raw_ostream.h"
30#include <algorithm>
31#include <cassert>
32#include <cstdint>
33#include <cstdlib>
34#include <functional>
35#include <memory>
36#include <new>
37#include <string>
38#include <system_error>
39#include <type_traits>
40#include <utility>
41#include <vector>
42
43namespace llvm {
44
45class ErrorSuccess;
46
47/// Base class for error info classes. Do not extend this directly: Extend
48/// the ErrorInfo template subclass instead.
49class ErrorInfoBase {
50public:
51 virtual ~ErrorInfoBase() = default;
52
53 /// Print an error message to an output stream.
54 virtual void log(raw_ostream &OS) const = 0;
55
56 /// Return the error message as a string.
57 virtual std::string message() const {
58 std::string Msg;
59 raw_string_ostream OS(Msg);
60 log(OS);
61 return OS.str();
62 }
63
64 /// Convert this error to a std::error_code.
65 ///
66 /// This is a temporary crutch to enable interaction with code still
67 /// using std::error_code. It will be removed in the future.
68 virtual std::error_code convertToErrorCode() const = 0;
69
70 // Returns the class ID for this type.
71 static const void *classID() { return &ID; }
72
73 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
74 virtual const void *dynamicClassID() const = 0;
75
76 // Check whether this instance is a subclass of the class identified by
77 // ClassID.
78 virtual bool isA(const void *const ClassID) const {
79 return ClassID == classID();
80 }
81
82 // Check whether this instance is a subclass of ErrorInfoT.
83 template <typename ErrorInfoT> bool isA() const {
84 return isA(ErrorInfoT::classID());
85 }
86
87private:
88 virtual void anchor();
89
90 static char ID;
91};
92
93/// Lightweight error class with error context and mandatory checking.
94///
95/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
96/// are represented by setting the pointer to a ErrorInfoBase subclass
97/// instance containing information describing the failure. Success is
98/// represented by a null pointer value.
99///
100/// Instances of Error also contains a 'Checked' flag, which must be set
101/// before the destructor is called, otherwise the destructor will trigger a
102/// runtime error. This enforces at runtime the requirement that all Error
103/// instances be checked or returned to the caller.
104///
105/// There are two ways to set the checked flag, depending on what state the
106/// Error instance is in. For Error instances indicating success, it
107/// is sufficient to invoke the boolean conversion operator. E.g.:
108///
109/// @code{.cpp}
110/// Error foo(<...>);
111///
112/// if (auto E = foo(<...>))
113/// return E; // <- Return E if it is in the error state.
114/// // We have verified that E was in the success state. It can now be safely
115/// // destroyed.
116/// @endcode
117///
118/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
119/// without testing the return value will raise a runtime error, even if foo
120/// returns success.
121///
122/// For Error instances representing failure, you must use either the
123/// handleErrors or handleAllErrors function with a typed handler. E.g.:
124///
125/// @code{.cpp}
126/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
127/// // Custom error info.
128/// };
129///
130/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
131///
132/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
133/// auto NewE =
134/// handleErrors(E,
135/// [](const MyErrorInfo &M) {
136/// // Deal with the error.
137/// },
138/// [](std::unique_ptr<OtherError> M) -> Error {
139/// if (canHandle(*M)) {
140/// // handle error.
141/// return Error::success();
142/// }
143/// // Couldn't handle this error instance. Pass it up the stack.
144/// return Error(std::move(M));
145/// );
146/// // Note - we must check or return NewE in case any of the handlers
147/// // returned a new error.
148/// @endcode
149///
150/// The handleAllErrors function is identical to handleErrors, except
151/// that it has a void return type, and requires all errors to be handled and
152/// no new errors be returned. It prevents errors (assuming they can all be
153/// handled) from having to be bubbled all the way to the top-level.
154///
155/// *All* Error instances must be checked before destruction, even if
156/// they're moved-assigned or constructed from Success values that have already
157/// been checked. This enforces checking through all levels of the call stack.
158class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
159 // Both ErrorList and FileError need to be able to yank ErrorInfoBase
160 // pointers out of this class to add to the error list.
161 friend class ErrorList;
162 friend class FileError;
163
164 // handleErrors needs to be able to set the Checked flag.
165 template <typename... HandlerTs>
166 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
167
168 // Expected<T> needs to be able to steal the payload when constructed from an
169 // error.
170 template <typename T> friend class Expected;
171
172 // wrap needs to be able to steal the payload.
173 friend LLVMErrorRef wrap(Error);
174
175protected:
176 /// Create a success value. Prefer using 'Error::success()' for readability
177 Error() {
178 setPtr(nullptr);
179 setChecked(false);
180 }
181
182public:
183 /// Create a success value.
184 static ErrorSuccess success();
185
186 // Errors are not copy-constructable.
187 Error(const Error &Other) = delete;
188
189 /// Move-construct an error value. The newly constructed error is considered
190 /// unchecked, even if the source error had been checked. The original error
191 /// becomes a checked Success value, regardless of its original state.
192 Error(Error &&Other) {
193 setChecked(true);
194 *this = std::move(Other);
195 }
196
197 /// Create an error value. Prefer using the 'make_error' function, but
198 /// this constructor can be useful when "re-throwing" errors from handlers.
199 Error(std::unique_ptr<ErrorInfoBase> Payload) {
200 setPtr(Payload.release());
201 setChecked(false);
32
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'
202 }
203
204 // Errors are not copy-assignable.
205 Error &operator=(const Error &Other) = delete;
206
207 /// Move-assign an error value. The current error must represent success, you
208 /// you cannot overwrite an unhandled error. The current error is then
209 /// considered unchecked. The source error becomes a checked success value,
210 /// regardless of its original state.
211 Error &operator=(Error &&Other) {
212 // Don't allow overwriting of unchecked values.
213 assertIsChecked();
214 setPtr(Other.getPtr());
215
216 // This Error is unchecked, even if the source error was checked.
217 setChecked(false);
218
219 // Null out Other's payload and set its checked bit.
220 Other.setPtr(nullptr);
221 Other.setChecked(true);
222
223 return *this;
224 }
225
226 /// Destroy a Error. Fails with a call to abort() if the error is
227 /// unchecked.
228 ~Error() {
229 assertIsChecked();
230 delete getPtr();
231 }
232
233 /// Bool conversion. Returns true if this Error is in a failure state,
234 /// and false if it is in an accept state. If the error is in a Success state
235 /// it will be considered checked.
236 explicit operator bool() {
237 setChecked(getPtr() == nullptr);
238 return getPtr() != nullptr;
239 }
240
241 /// Check whether one error is a subclass of another.
242 template <typename ErrT> bool isA() const {
243 return getPtr() && getPtr()->isA(ErrT::classID());
244 }
245
246 /// Returns the dynamic class id of this error, or null if this is a success
247 /// value.
248 const void* dynamicClassID() const {
249 if (!getPtr())
250 return nullptr;
251 return getPtr()->dynamicClassID();
252 }
253
254private:
255#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
256 // assertIsChecked() happens very frequently, but under normal circumstances
257 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
258 // of debug prints can cause the function to be too large for inlining. So
259 // it's important that we define this function out of line so that it can't be
260 // inlined.
261 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
262 void fatalUncheckedError() const;
263#endif
264
265 void assertIsChecked() {
266#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
267 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
268 fatalUncheckedError();
269#endif
270 }
271
272 ErrorInfoBase *getPtr() const {
273 return reinterpret_cast<ErrorInfoBase*>(
274 reinterpret_cast<uintptr_t>(Payload) &
275 ~static_cast<uintptr_t>(0x1));
276 }
277
278 void setPtr(ErrorInfoBase *EI) {
279#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
280 Payload = reinterpret_cast<ErrorInfoBase*>(
281 (reinterpret_cast<uintptr_t>(EI) &
282 ~static_cast<uintptr_t>(0x1)) |
283 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
284#else
285 Payload = EI;
286#endif
287 }
288
289 bool getChecked() const {
290#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
291 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
292#else
293 return true;
294#endif
295 }
296
297 void setChecked(bool V) {
298 Payload = reinterpret_cast<ErrorInfoBase*>(
299 (reinterpret_cast<uintptr_t>(Payload) &
300 ~static_cast<uintptr_t>(0x1)) |
301 (V ? 0 : 1));
302 }
303
304 std::unique_ptr<ErrorInfoBase> takePayload() {
305 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
306 setPtr(nullptr);
307 setChecked(true);
308 return Tmp;
309 }
310
311 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
312 if (auto P = E.getPtr())
313 P->log(OS);
314 else
315 OS << "success";
316 return OS;
317 }
318
319 ErrorInfoBase *Payload = nullptr;
320};
321
322/// Subclass of Error for the sole purpose of identifying the success path in
323/// the type system. This allows to catch invalid conversion to Expected<T> at
324/// compile time.
325class ErrorSuccess final : public Error {};
326
327inline ErrorSuccess Error::success() { return ErrorSuccess(); }
328
329/// Make a Error instance representing failure using the given error info
330/// type.
331template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
332 return Error(llvm::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
333}
334
335/// Base class for user error types. Users should declare their error types
336/// like:
337///
338/// class MyError : public ErrorInfo<MyError> {
339/// ....
340/// };
341///
342/// This class provides an implementation of the ErrorInfoBase::kind
343/// method, which is used by the Error RTTI system.
344template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
345class ErrorInfo : public ParentErrT {
346public:
347 using ParentErrT::ParentErrT; // inherit constructors
348
349 static const void *classID() { return &ThisErrT::ID; }
350
351 const void *dynamicClassID() const override { return &ThisErrT::ID; }
352
353 bool isA(const void *const ClassID) const override {
354 return ClassID == classID() || ParentErrT::isA(ClassID);
355 }
356};
357
358/// Special ErrorInfo subclass representing a list of ErrorInfos.
359/// Instances of this class are constructed by joinError.
360class ErrorList final : public ErrorInfo<ErrorList> {
361 // handleErrors needs to be able to iterate the payload list of an
362 // ErrorList.
363 template <typename... HandlerTs>
364 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
365
366 // joinErrors is implemented in terms of join.
367 friend Error joinErrors(Error, Error);
368
369public:
370 void log(raw_ostream &OS) const override {
371 OS << "Multiple errors:\n";
372 for (auto &ErrPayload : Payloads) {
373 ErrPayload->log(OS);
374 OS << "\n";
375 }
376 }
377
378 std::error_code convertToErrorCode() const override;
379
380 // Used by ErrorInfo::classID.
381 static char ID;
382
383private:
384 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
385 std::unique_ptr<ErrorInfoBase> Payload2) {
386 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
387 "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
;
388 Payloads.push_back(std::move(Payload1));
389 Payloads.push_back(std::move(Payload2));
390 }
391
392 static Error join(Error E1, Error E2) {
393 if (!E1)
24
Taking false branch
394 return E2;
395 if (!E2)
25
Taking false branch
396 return E1;
397 if (E1.isA<ErrorList>()) {
26
Assuming the condition is false
27
Taking false branch
398 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
399 if (E2.isA<ErrorList>()) {
400 auto E2Payload = E2.takePayload();
401 auto &E2List = static_cast<ErrorList &>(*E2Payload);
402 for (auto &Payload : E2List.Payloads)
403 E1List.Payloads.push_back(std::move(Payload));
404 } else
405 E1List.Payloads.push_back(E2.takePayload());
406
407 return E1;
408 }
409 if (E2.isA<ErrorList>()) {
28
Assuming the condition is false
29
Taking false branch
410 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
411 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
412 return E2;
413 }
414 return Error(std::unique_ptr<ErrorList>(
31
Calling constructor for 'Error'
415 new ErrorList(E1.takePayload(), E2.takePayload())));
30
Memory is allocated
416 }
417
418 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
419};
420
421/// Concatenate errors. The resulting Error is unchecked, and contains the
422/// ErrorInfo(s), if any, contained in E1, followed by the
423/// ErrorInfo(s), if any, contained in E2.
424inline Error joinErrors(Error E1, Error E2) {
425 return ErrorList::join(std::move(E1), std::move(E2));
426}
427
428/// Tagged union holding either a T or a Error.
429///
430/// This class parallels ErrorOr, but replaces error_code with Error. Since
431/// Error cannot be copied, this class replaces getError() with
432/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
433/// error class type.
434template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
435 template <class T1> friend class ExpectedAsOutParameter;
436 template <class OtherT> friend class Expected;
437
438 static const bool isRef = std::is_reference<T>::value;
439
440 using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
441
442 using error_type = std::unique_ptr<ErrorInfoBase>;
443
444public:
445 using storage_type = typename std::conditional<isRef, wrap, T>::type;
446 using value_type = T;
447
448private:
449 using reference = typename std::remove_reference<T>::type &;
450 using const_reference = const typename std::remove_reference<T>::type &;
451 using pointer = typename std::remove_reference<T>::type *;
452 using const_pointer = const typename std::remove_reference<T>::type *;
453
454public:
455 /// Create an Expected<T> error value from the given Error.
456 Expected(Error Err)
457 : HasError(true)
458#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
459 // Expected is unchecked upon construction in Debug builds.
460 , Unchecked(true)
461#endif
462 {
463 assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 463, __PRETTY_FUNCTION__))
;
464 new (getErrorStorage()) error_type(Err.takePayload());
465 }
466
467 /// Forbid to convert from Error::success() implicitly, this avoids having
468 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
469 /// but triggers the assertion above.
470 Expected(ErrorSuccess) = delete;
471
472 /// Create an Expected<T> success value from the given OtherT value, which
473 /// must be convertible to T.
474 template <typename OtherT>
475 Expected(OtherT &&Val,
476 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
477 * = nullptr)
478 : HasError(false)
479#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
480 // Expected is unchecked upon construction in Debug builds.
481 , Unchecked(true)
482#endif
483 {
484 new (getStorage()) storage_type(std::forward<OtherT>(Val));
485 }
486
487 /// Move construct an Expected<T> value.
488 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
489
490 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
491 /// must be convertible to T.
492 template <class OtherT>
493 Expected(Expected<OtherT> &&Other,
494 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
495 * = nullptr) {
496 moveConstruct(std::move(Other));
497 }
498
499 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
500 /// isn't convertible to T.
501 template <class OtherT>
502 explicit Expected(
503 Expected<OtherT> &&Other,
504 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
505 nullptr) {
506 moveConstruct(std::move(Other));
507 }
508
509 /// Move-assign from another Expected<T>.
510 Expected &operator=(Expected &&Other) {
511 moveAssign(std::move(Other));
512 return *this;
513 }
514
515 /// Destroy an Expected<T>.
516 ~Expected() {
517 assertIsChecked();
518 if (!HasError)
519 getStorage()->~storage_type();
520 else
521 getErrorStorage()->~error_type();
522 }
523
524 /// Return false if there is an error.
525 explicit operator bool() {
526#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
527 Unchecked = HasError;
528#endif
529 return !HasError;
530 }
531
532 /// Returns a reference to the stored T value.
533 reference get() {
534 assertIsChecked();
535 return *getStorage();
536 }
537
538 /// Returns a const reference to the stored T value.
539 const_reference get() const {
540 assertIsChecked();
541 return const_cast<Expected<T> *>(this)->get();
542 }
543
544 /// Check that this Expected<T> is an error of type ErrT.
545 template <typename ErrT> bool errorIsA() const {
546 return HasError && (*getErrorStorage())->template isA<ErrT>();
547 }
548
549 /// Take ownership of the stored error.
550 /// After calling this the Expected<T> is in an indeterminate state that can
551 /// only be safely destructed. No further calls (beside the destructor) should
552 /// be made on the Expected<T> vaule.
553 Error takeError() {
554#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
555 Unchecked = false;
556#endif
557 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
558 }
559
560 /// Returns a pointer to the stored T value.
561 pointer operator->() {
562 assertIsChecked();
563 return toPointer(getStorage());
564 }
565
566 /// Returns a const pointer to the stored T value.
567 const_pointer operator->() const {
568 assertIsChecked();
569 return toPointer(getStorage());
570 }
571
572 /// Returns a reference to the stored T value.
573 reference operator*() {
574 assertIsChecked();
575 return *getStorage();
576 }
577
578 /// Returns a const reference to the stored T value.
579 const_reference operator*() const {
580 assertIsChecked();
581 return *getStorage();
582 }
583
584private:
585 template <class T1>
586 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
587 return &a == &b;
588 }
589
590 template <class T1, class T2>
591 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
592 return false;
593 }
594
595 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
596 HasError = Other.HasError;
597#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
598 Unchecked = true;
599 Other.Unchecked = false;
600#endif
601
602 if (!HasError)
603 new (getStorage()) storage_type(std::move(*Other.getStorage()));
604 else
605 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
606 }
607
608 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
609 assertIsChecked();
610
611 if (compareThisIfSameType(*this, Other))
612 return;
613
614 this->~Expected();
615 new (this) Expected(std::move(Other));
616 }
617
618 pointer toPointer(pointer Val) { return Val; }
619
620 const_pointer toPointer(const_pointer Val) const { return Val; }
621
622 pointer toPointer(wrap *Val) { return &Val->get(); }
623
624 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
625
626 storage_type *getStorage() {
627 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 627, __PRETTY_FUNCTION__))
;
628 return reinterpret_cast<storage_type *>(TStorage.buffer);
629 }
630
631 const storage_type *getStorage() const {
632 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 632, __PRETTY_FUNCTION__))
;
633 return reinterpret_cast<const storage_type *>(TStorage.buffer);
634 }
635
636 error_type *getErrorStorage() {
637 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 637, __PRETTY_FUNCTION__))
;
638 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
639 }
640
641 const error_type *getErrorStorage() const {
642 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 642, __PRETTY_FUNCTION__))
;
643 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
644 }
645
646 // Used by ExpectedAsOutParameter to reset the checked flag.
647 void setUnchecked() {
648#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
649 Unchecked = true;
650#endif
651 }
652
653#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
654 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
655 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
656 void fatalUncheckedExpected() const {
657 dbgs() << "Expected<T> must be checked before access or destruction.\n";
658 if (HasError) {
659 dbgs() << "Unchecked Expected<T> contained error:\n";
660 (*getErrorStorage())->log(dbgs());
661 } else
662 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
663 "values in success mode must still be checked prior to being "
664 "destroyed).\n";
665 abort();
666 }
667#endif
668
669 void assertIsChecked() {
670#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
671 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
672 fatalUncheckedExpected();
673#endif
674 }
675
676 union {
677 AlignedCharArrayUnion<storage_type> TStorage;
678 AlignedCharArrayUnion<error_type> ErrorStorage;
679 };
680 bool HasError : 1;
681#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
682 bool Unchecked : 1;
683#endif
684};
685
686/// Report a serious error, calling any installed error handler. See
687/// ErrorHandling.h.
688LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
689 bool gen_crash_diag = true);
690
691/// Report a fatal error if Err is a failure value.
692///
693/// This function can be used to wrap calls to fallible functions ONLY when it
694/// is known that the Error will always be a success value. E.g.
695///
696/// @code{.cpp}
697/// // foo only attempts the fallible operation if DoFallibleOperation is
698/// // true. If DoFallibleOperation is false then foo always returns
699/// // Error::success().
700/// Error foo(bool DoFallibleOperation);
701///
702/// cantFail(foo(false));
703/// @endcode
704inline void cantFail(Error Err, const char *Msg = nullptr) {
705 if (Err) {
706 if (!Msg)
707 Msg = "Failure value returned from cantFail wrapped call";
708 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 708)
;
709 }
710}
711
712/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
713/// returns the contained value.
714///
715/// This function can be used to wrap calls to fallible functions ONLY when it
716/// is known that the Error will always be a success value. E.g.
717///
718/// @code{.cpp}
719/// // foo only attempts the fallible operation if DoFallibleOperation is
720/// // true. If DoFallibleOperation is false then foo always returns an int.
721/// Expected<int> foo(bool DoFallibleOperation);
722///
723/// int X = cantFail(foo(false));
724/// @endcode
725template <typename T>
726T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
727 if (ValOrErr)
728 return std::move(*ValOrErr);
729 else {
730 if (!Msg)
731 Msg = "Failure value returned from cantFail wrapped call";
732 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 732)
;
733 }
734}
735
736/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
737/// returns the contained reference.
738///
739/// This function can be used to wrap calls to fallible functions ONLY when it
740/// is known that the Error will always be a success value. E.g.
741///
742/// @code{.cpp}
743/// // foo only attempts the fallible operation if DoFallibleOperation is
744/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
745/// Expected<Bar&> foo(bool DoFallibleOperation);
746///
747/// Bar &X = cantFail(foo(false));
748/// @endcode
749template <typename T>
750T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
751 if (ValOrErr)
752 return *ValOrErr;
753 else {
754 if (!Msg)
755 Msg = "Failure value returned from cantFail wrapped call";
756 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 756)
;
757 }
758}
759
760/// Helper for testing applicability of, and applying, handlers for
761/// ErrorInfo types.
762template <typename HandlerT>
763class ErrorHandlerTraits
764 : public ErrorHandlerTraits<decltype(
765 &std::remove_reference<HandlerT>::type::operator())> {};
766
767// Specialization functions of the form 'Error (const ErrT&)'.
768template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
769public:
770 static bool appliesTo(const ErrorInfoBase &E) {
771 return E.template isA<ErrT>();
772 }
773
774 template <typename HandlerT>
775 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
776 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 776, __PRETTY_FUNCTION__))
;
777 return H(static_cast<ErrT &>(*E));
778 }
779};
780
781// Specialization functions of the form 'void (const ErrT&)'.
782template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
783public:
784 static bool appliesTo(const ErrorInfoBase &E) {
785 return E.template isA<ErrT>();
786 }
787
788 template <typename HandlerT>
789 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
790 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 790, __PRETTY_FUNCTION__))
;
791 H(static_cast<ErrT &>(*E));
792 return Error::success();
793 }
794};
795
796/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
797template <typename ErrT>
798class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
799public:
800 static bool appliesTo(const ErrorInfoBase &E) {
801 return E.template isA<ErrT>();
802 }
803
804 template <typename HandlerT>
805 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
806 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 806, __PRETTY_FUNCTION__))
;
807 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
808 return H(std::move(SubE));
809 }
810};
811
812/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
813template <typename ErrT>
814class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
815public:
816 static bool appliesTo(const ErrorInfoBase &E) {
817 return E.template isA<ErrT>();
818 }
819
820 template <typename HandlerT>
821 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
822 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 822, __PRETTY_FUNCTION__))
;
823 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
824 H(std::move(SubE));
825 return Error::success();
826 }
827};
828
829// Specialization for member functions of the form 'RetT (const ErrT&)'.
830template <typename C, typename RetT, typename ErrT>
831class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
832 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
833
834// Specialization for member functions of the form 'RetT (const ErrT&) const'.
835template <typename C, typename RetT, typename ErrT>
836class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
837 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
838
839// Specialization for member functions of the form 'RetT (const ErrT&)'.
840template <typename C, typename RetT, typename ErrT>
841class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
842 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
843
844// Specialization for member functions of the form 'RetT (const ErrT&) const'.
845template <typename C, typename RetT, typename ErrT>
846class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
847 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
848
849/// Specialization for member functions of the form
850/// 'RetT (std::unique_ptr<ErrT>)'.
851template <typename C, typename RetT, typename ErrT>
852class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
853 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
854
855/// Specialization for member functions of the form
856/// 'RetT (std::unique_ptr<ErrT>) const'.
857template <typename C, typename RetT, typename ErrT>
858class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
859 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
860
861inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
862 return Error(std::move(Payload));
863}
864
865template <typename HandlerT, typename... HandlerTs>
866Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
867 HandlerT &&Handler, HandlerTs &&... Handlers) {
868 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
869 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
870 std::move(Payload));
871 return handleErrorImpl(std::move(Payload),
872 std::forward<HandlerTs>(Handlers)...);
873}
874
875/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
876/// unhandled errors (or Errors returned by handlers) are re-concatenated and
877/// returned.
878/// Because this function returns an error, its result must also be checked
879/// or returned. If you intend to handle all errors use handleAllErrors
880/// (which returns void, and will abort() on unhandled errors) instead.
881template <typename... HandlerTs>
882Error handleErrors(Error E, HandlerTs &&... Hs) {
883 if (!E)
20
Taking false branch
884 return Error::success();
885
886 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
887
888 if (Payload->isA<ErrorList>()) {
21
Assuming the condition is true
22
Taking true branch
889 ErrorList &List = static_cast<ErrorList &>(*Payload);
890 Error R;
891 for (auto &P : List.Payloads)
892 R = ErrorList::join(
23
Calling 'ErrorList::join'
893 std::move(R),
894 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
895 return R;
896 }
897
898 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
899}
900
901/// Behaves the same as handleErrors, except that by contract all errors
902/// *must* be handled by the given handlers (i.e. there must be no remaining
903/// errors after running the handlers, or llvm_unreachable is called).
904template <typename... HandlerTs>
905void handleAllErrors(Error E, HandlerTs &&... Handlers) {
906 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
19
Calling 'handleErrors<(lambda at /build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h:979:35)>'
907}
908
909/// Check that E is a non-error, then drop it.
910/// If E is an error, llvm_unreachable will be called.
911inline void handleAllErrors(Error E) {
912 cantFail(std::move(E));
913}
914
915/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
916///
917/// If the incoming value is a success value it is returned unmodified. If it
918/// is a failure value then it the contained error is passed to handleErrors.
919/// If handleErrors is able to handle the error then the RecoveryPath functor
920/// is called to supply the final result. If handleErrors is not able to
921/// handle all errors then the unhandled errors are returned.
922///
923/// This utility enables the follow pattern:
924///
925/// @code{.cpp}
926/// enum FooStrategy { Aggressive, Conservative };
927/// Expected<Foo> foo(FooStrategy S);
928///
929/// auto ResultOrErr =
930/// handleExpected(
931/// foo(Aggressive),
932/// []() { return foo(Conservative); },
933/// [](AggressiveStrategyError&) {
934/// // Implicitly conusme this - we'll recover by using a conservative
935/// // strategy.
936/// });
937///
938/// @endcode
939template <typename T, typename RecoveryFtor, typename... HandlerTs>
940Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
941 HandlerTs &&... Handlers) {
942 if (ValOrErr)
943 return ValOrErr;
944
945 if (auto Err = handleErrors(ValOrErr.takeError(),
946 std::forward<HandlerTs>(Handlers)...))
947 return std::move(Err);
948
949 return RecoveryPath();
950}
951
952/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
953/// will be printed before the first one is logged. A newline will be printed
954/// after each error.
955///
956/// This is useful in the base level of your program to allow clean termination
957/// (allowing clean deallocation of resources, etc.), while reporting error
958/// information to the user.
959void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner);
960
961/// Write all error messages (if any) in E to a string. The newline character
962/// is used to separate error messages.
963inline std::string toString(Error E) {
964 SmallVector<std::string, 2> Errors;
965 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
966 Errors.push_back(EI.message());
967 });
968 return join(Errors.begin(), Errors.end(), "\n");
969}
970
971/// Consume a Error without doing anything. This method should be used
972/// only where an error can be considered a reasonable and expected return
973/// value.
974///
975/// Uses of this method are potentially indicative of design problems: If it's
976/// legitimate to do nothing while processing an "error", the error-producer
977/// might be more clearly refactored to return an Optional<T>.
978inline void consumeError(Error Err) {
979 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
18
Calling 'handleAllErrors<(lambda at /build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h:979:35)>'
980}
981
982/// Helper for converting an Error to a bool.
983///
984/// This method returns true if Err is in an error state, or false if it is
985/// in a success state. Puts Err in a checked state in both cases (unlike
986/// Error::operator bool(), which only does this for success states).
987inline bool errorToBool(Error Err) {
988 bool IsError = static_cast<bool>(Err);
989 if (IsError)
990 consumeError(std::move(Err));
991 return IsError;
992}
993
994/// Helper for Errors used as out-parameters.
995///
996/// This helper is for use with the Error-as-out-parameter idiom, where an error
997/// is passed to a function or method by reference, rather than being returned.
998/// In such cases it is helpful to set the checked bit on entry to the function
999/// so that the error can be written to (unchecked Errors abort on assignment)
1000/// and clear the checked bit on exit so that clients cannot accidentally forget
1001/// to check the result. This helper performs these actions automatically using
1002/// RAII:
1003///
1004/// @code{.cpp}
1005/// Result foo(Error &Err) {
1006/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1007/// // <body of foo>
1008/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1009/// }
1010/// @endcode
1011///
1012/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1013/// used with optional Errors (Error pointers that are allowed to be null). If
1014/// ErrorAsOutParameter took an Error reference, an instance would have to be
1015/// created inside every condition that verified that Error was non-null. By
1016/// taking an Error pointer we can just create one instance at the top of the
1017/// function.
1018class ErrorAsOutParameter {
1019public:
1020 ErrorAsOutParameter(Error *Err) : Err(Err) {
1021 // Raise the checked bit if Err is success.
1022 if (Err)
1023 (void)!!*Err;
1024 }
1025
1026 ~ErrorAsOutParameter() {
1027 // Clear the checked bit.
1028 if (Err && !*Err)
1029 *Err = Error::success();
1030 }
1031
1032private:
1033 Error *Err;
1034};
1035
1036/// Helper for Expected<T>s used as out-parameters.
1037///
1038/// See ErrorAsOutParameter.
1039template <typename T>
1040class ExpectedAsOutParameter {
1041public:
1042 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1043 : ValOrErr(ValOrErr) {
1044 if (ValOrErr)
1045 (void)!!*ValOrErr;
1046 }
1047
1048 ~ExpectedAsOutParameter() {
1049 if (ValOrErr)
1050 ValOrErr->setUnchecked();
1051 }
1052
1053private:
1054 Expected<T> *ValOrErr;
1055};
1056
1057/// This class wraps a std::error_code in a Error.
1058///
1059/// This is useful if you're writing an interface that returns a Error
1060/// (or Expected) and you want to call code that still returns
1061/// std::error_codes.
1062class ECError : public ErrorInfo<ECError> {
1063 friend Error errorCodeToError(std::error_code);
1064
1065public:
1066 void setErrorCode(std::error_code EC) { this->EC = EC; }
1067 std::error_code convertToErrorCode() const override { return EC; }
1068 void log(raw_ostream &OS) const override { OS << EC.message(); }
1069
1070 // Used by ErrorInfo::classID.
1071 static char ID;
1072
1073protected:
1074 ECError() = default;
1075 ECError(std::error_code EC) : EC(EC) {}
1076
1077 std::error_code EC;
1078};
1079
1080/// The value returned by this function can be returned from convertToErrorCode
1081/// for Error values where no sensible translation to std::error_code exists.
1082/// It should only be used in this situation, and should never be used where a
1083/// sensible conversion to std::error_code is available, as attempts to convert
1084/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1085///error to try to convert such a value).
1086std::error_code inconvertibleErrorCode();
1087
1088/// Helper for converting an std::error_code to a Error.
1089Error errorCodeToError(std::error_code EC);
1090
1091/// Helper for converting an ECError to a std::error_code.
1092///
1093/// This method requires that Err be Error() or an ECError, otherwise it
1094/// will trigger a call to abort().
1095std::error_code errorToErrorCode(Error Err);
1096
1097/// Convert an ErrorOr<T> to an Expected<T>.
1098template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1099 if (auto EC = EO.getError())
1100 return errorCodeToError(EC);
1101 return std::move(*EO);
1102}
1103
1104/// Convert an Expected<T> to an ErrorOr<T>.
1105template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1106 if (auto Err = E.takeError())
1107 return errorToErrorCode(std::move(Err));
1108 return std::move(*E);
1109}
1110
1111/// This class wraps a string in an Error.
1112///
1113/// StringError is useful in cases where the client is not expected to be able
1114/// to consume the specific error message programmatically (for example, if the
1115/// error message is to be presented to the user).
1116///
1117/// StringError can also be used when additional information is to be printed
1118/// along with a error_code message. Depending on the constructor called, this
1119/// class can either display:
1120/// 1. the error_code message (ECError behavior)
1121/// 2. a string
1122/// 3. the error_code message and a string
1123///
1124/// These behaviors are useful when subtyping is required; for example, when a
1125/// specific library needs an explicit error type. In the example below,
1126/// PDBError is derived from StringError:
1127///
1128/// @code{.cpp}
1129/// Expected<int> foo() {
1130/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1131/// "Additional information");
1132/// }
1133/// @endcode
1134///
1135class StringError : public ErrorInfo<StringError> {
1136public:
1137 static char ID;
1138
1139 // Prints EC + S and converts to EC
1140 StringError(std::error_code EC, const Twine &S = Twine());
1141
1142 // Prints S and converts to EC
1143 StringError(const Twine &S, std::error_code EC);
1144
1145 void log(raw_ostream &OS) const override;
1146 std::error_code convertToErrorCode() const override;
1147
1148 const std::string &getMessage() const { return Msg; }
1149
1150private:
1151 std::string Msg;
1152 std::error_code EC;
1153 const bool PrintMsgOnly = false;
1154};
1155
1156/// Create formatted StringError object.
1157template <typename... Ts>
1158Error createStringError(std::error_code EC, char const *Fmt,
1159 const Ts &... Vals) {
1160 std::string Buffer;
1161 raw_string_ostream Stream(Buffer);
1162 Stream << format(Fmt, Vals...);
1163 return make_error<StringError>(Stream.str(), EC);
1164}
1165
1166Error createStringError(std::error_code EC, char const *Msg);
1167
1168/// This class wraps a filename and another Error.
1169///
1170/// In some cases, an error needs to live along a 'source' name, in order to
1171/// show more detailed information to the user.
1172class FileError final : public ErrorInfo<FileError> {
1173
1174 friend Error createFileError(std::string, Error);
1175
1176public:
1177 void log(raw_ostream &OS) const override {
1178 assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1178, __PRETTY_FUNCTION__))
;
1179 OS << "'" << FileName << "': ";
1180 Err->log(OS);
1181 }
1182
1183 Error takeError() { return Error(std::move(Err)); }
1184
1185 std::error_code convertToErrorCode() const override;
1186
1187 // Used by ErrorInfo::classID.
1188 static char ID;
1189
1190private:
1191 FileError(std::string F, std::unique_ptr<ErrorInfoBase> E) {
1192 assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1192, __PRETTY_FUNCTION__))
;
1193 assert(!F.empty() &&((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
1194 "The file name provided to FileError must not be empty.")((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
;
1195 FileName = F;
1196 Err = std::move(E);
1197 }
1198
1199 static Error build(std::string F, Error E) {
1200 return Error(std::unique_ptr<FileError>(new FileError(F, E.takePayload())));
1201 }
1202
1203 std::string FileName;
1204 std::unique_ptr<ErrorInfoBase> Err;
1205};
1206
1207/// Concatenate a source file path and/or name with an Error. The resulting
1208/// Error is unchecked.
1209inline Error createFileError(std::string F, Error E) {
1210 return FileError::build(F, std::move(E));
1211}
1212
1213Error createFileError(std::string F, ErrorSuccess) = delete;
1214
1215/// Helper for check-and-exit error handling.
1216///
1217/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1218///
1219class ExitOnError {
1220public:
1221 /// Create an error on exit helper.
1222 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1223 : Banner(std::move(Banner)),
1224 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1225
1226 /// Set the banner string for any errors caught by operator().
1227 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1228
1229 /// Set the exit-code mapper function.
1230 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1231 this->GetExitCode = std::move(GetExitCode);
1232 }
1233
1234 /// Check Err. If it's in a failure state log the error(s) and exit.
1235 void operator()(Error Err) const { checkError(std::move(Err)); }
1236
1237 /// Check E. If it's in a success state then return the contained value. If
1238 /// it's in a failure state log the error(s) and exit.
1239 template <typename T> T operator()(Expected<T> &&E) const {
1240 checkError(E.takeError());
1241 return std::move(*E);
1242 }
1243
1244 /// Check E. If it's in a success state then return the contained reference. If
1245 /// it's in a failure state log the error(s) and exit.
1246 template <typename T> T& operator()(Expected<T&> &&E) const {
1247 checkError(E.takeError());
1248 return *E;
1249 }
1250
1251private:
1252 void checkError(Error Err) const {
1253 if (Err) {
1254 int ExitCode = GetExitCode(Err);
1255 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1256 exit(ExitCode);
1257 }
1258 }
1259
1260 std::string Banner;
1261 std::function<int(const Error &)> GetExitCode;
1262};
1263
1264/// Conversion from Error to LLVMErrorRef for C error bindings.
1265inline LLVMErrorRef wrap(Error Err) {
1266 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1267}
1268
1269/// Conversion from LLVMErrorRef to Error for C error bindings.
1270inline Error unwrap(LLVMErrorRef ErrRef) {
1271 return Error(std::unique_ptr<ErrorInfoBase>(
1272 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1273}
1274
1275} // end namespace llvm
1276
1277#endif // LLVM_SUPPORT_ERROR_H