Bug Summary

File:lib/DebugInfo/DWARFDebugInfoEntry.cpp
Location:line 79, column 25
Description:The result of the '<<' expression is undefined

Annotated Source Code

1//===-- DWARFDebugInfoEntry.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
10#include "DWARFDebugInfoEntry.h"
11#include "DWARFCompileUnit.h"
12#include "DWARFContext.h"
13#include "DWARFDebugAbbrev.h"
14#include "llvm/DebugInfo/DWARFFormValue.h"
15#include "llvm/Support/DataTypes.h"
16#include "llvm/Support/Debug.h"
17#include "llvm/Support/Dwarf.h"
18#include "llvm/Support/Format.h"
19#include "llvm/Support/raw_ostream.h"
20using namespace llvm;
21using namespace dwarf;
22
23// Small helper to extract a DIE pointed by a reference
24// attribute. It looks up the Unit containing the DIE and calls
25// DIE.extractFast with the right unit. Returns new unit on success,
26// nullptr otherwise.
27static const DWARFUnit *findUnitAndExtractFast(DWARFDebugInfoEntryMinimal &DIE,
28 const DWARFUnit *Unit,
29 uint32_t *Offset) {
30 Unit = Unit->getUnitSection().getUnitForOffset(*Offset);
31 return (Unit && DIE.extractFast(Unit, Offset)) ? Unit : nullptr;
32}
33
34void DWARFDebugInfoEntryMinimal::dump(raw_ostream &OS, DWARFUnit *u,
35 unsigned recurseDepth,
36 unsigned indent) const {
37 DataExtractor debug_info_data = u->getDebugInfoExtractor();
38 uint32_t offset = Offset;
39
40 if (debug_info_data.isValidOffset(offset)) {
41 uint32_t abbrCode = debug_info_data.getULEB128(&offset);
42
43 OS << format("\n0x%8.8x: ", Offset);
44 if (abbrCode) {
45 if (AbbrevDecl) {
46 const char *tagString = TagString(getTag());
47 if (tagString)
48 OS.indent(indent) << tagString;
49 else
50 OS.indent(indent) << format("DW_TAG_Unknown_%x", getTag());
51 OS << format(" [%u] %c\n", abbrCode,
52 AbbrevDecl->hasChildren() ? '*' : ' ');
53
54 // Dump all data in the DIE for the attributes.
55 for (const auto &AttrSpec : AbbrevDecl->attributes()) {
56 dumpAttribute(OS, u, &offset, AttrSpec.Attr, AttrSpec.Form, indent);
57 }
58
59 const DWARFDebugInfoEntryMinimal *child = getFirstChild();
60 if (recurseDepth > 0 && child) {
61 while (child) {
62 child->dump(OS, u, recurseDepth-1, indent+2);
63 child = child->getSibling();
64 }
65 }
66 } else {
67 OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
68 << abbrCode << '\n';
69 }
70 } else {
71 OS.indent(indent) << "NULL\n";
72 }
73 }
74}
75
76static void dumpApplePropertyAttribute(raw_ostream &OS, uint64_t Val) {
77 OS << " (";
78 do {
79 uint64_t Bit = 1ULL << countTrailingZeros(Val);
20
The result of the '<<' expression is undefined
80 if (const char *PropName = ApplePropertyString(Bit))
81 OS << PropName;
82 else
83 OS << format("DW_APPLE_PROPERTY_0x%" PRIx64"l" "x", Bit);
84 if (!(Val ^= Bit))
85 break;
86 OS << ", ";
87 } while (true);
88 OS << ")";
89}
90
91static void dumpRanges(raw_ostream &OS, const DWARFAddressRangesVector& Ranges,
92 unsigned AddressSize, unsigned Indent) {
93 if (Ranges.empty())
94 return;
95
96 for (const auto &Range: Ranges) {
97 OS << '\n';
98 OS.indent(Indent);
99 OS << format("[0x%0*" PRIx64"l" "x" " - 0x%0*" PRIx64"l" "x" ")",
100 AddressSize*2, Range.first,
101 AddressSize*2, Range.second);
102 }
103}
104
105void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
106 DWARFUnit *u,
107 uint32_t *offset_ptr,
108 uint16_t attr, uint16_t form,
109 unsigned indent) const {
110 const char BaseIndent[] = " ";
111 OS << BaseIndent;
112 OS.indent(indent+2);
113 const char *attrString = AttributeString(attr);
114 if (attrString)
1
Assuming 'attrString' is null
2
Taking false branch
115 OS << attrString;
116 else
117 OS << format("DW_AT_Unknown_%x", attr);
118 const char *formString = FormEncodingString(form);
119 if (formString)
3
Assuming 'formString' is null
4
Taking false branch
120 OS << " [" << formString << ']';
121 else
122 OS << format(" [DW_FORM_Unknown_%x]", form);
123
124 DWARFFormValue formValue(form);
125
126 if (!formValue.extractValue(u->getDebugInfoExtractor(), offset_ptr, u))
5
Taking false branch
127 return;
128
129 OS << "\t(";
130
131 const char *Name = nullptr;
132 std::string File;
133 if (attr == DW_AT_decl_file || attr == DW_AT_call_file) {
6
Assuming 'attr' is not equal to DW_AT_decl_file
7
Assuming 'attr' is not equal to DW_AT_call_file
8
Taking false branch
134 if (const auto *LT = u->getContext().getLineTableForUnit(u))
135 if (LT->getFileNameByIndex(
136 formValue.getAsUnsignedConstant().getValue(),
137 u->getCompilationDir(),
138 DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, File)) {
139 File = '"' + File + '"';
140 Name = File.c_str();
141 }
142 } else if (Optional<uint64_t> Val = formValue.getAsUnsignedConstant())
9
Taking false branch
143 Name = AttributeValueString(attr, *Val);
144
145 if (Name) {
10
Taking false branch
146 OS << Name;
147 } else if (attr == DW_AT_decl_line || attr == DW_AT_call_line) {
11
Assuming 'attr' is not equal to DW_AT_decl_line
12
Assuming 'attr' is not equal to DW_AT_call_line
13
Taking false branch
148 OS << *formValue.getAsUnsignedConstant();
149 } else {
150 formValue.dump(OS, u);
151 }
152
153 // We have dumped the attribute raw value. For some attributes
154 // having both the raw value and the pretty-printed value is
155 // interesting. These attributes are handled below.
156 if ((attr == DW_AT_specification || attr == DW_AT_abstract_origin) &&
14
Assuming 'attr' is not equal to DW_AT_specification
15
Assuming 'attr' is not equal to DW_AT_abstract_origin
157 // The signature references aren't handled.
158 formValue.getForm() != DW_FORM_ref_sig8) {
159 uint32_t Ref = formValue.getAsReference(u).getValue();
160 DWARFDebugInfoEntryMinimal DIE;
161 if (const DWARFUnit *RefU = findUnitAndExtractFast(DIE, u, &Ref))
162 if (const char *Ref = DIE.getName(RefU, DINameKind::LinkageName))
163 OS << " \"" << Ref << '\"';
164 } else if (attr == DW_AT_APPLE_property_attribute) {
16
Assuming 'attr' is equal to DW_AT_APPLE_property_attribute
17
Taking true branch
165 if (Optional<uint64_t> OptVal = formValue.getAsUnsignedConstant())
18
Taking true branch
166 dumpApplePropertyAttribute(OS, *OptVal);
19
Calling 'dumpApplePropertyAttribute'
167 } else if (attr == DW_AT_ranges) {
168 dumpRanges(OS, getAddressRanges(u), u->getAddressByteSize(),
169 sizeof(BaseIndent)+indent+4);
170 }
171
172 OS << ")\n";
173}
174
175bool DWARFDebugInfoEntryMinimal::extractFast(const DWARFUnit *U,
176 uint32_t *OffsetPtr) {
177 Offset = *OffsetPtr;
178 DataExtractor DebugInfoData = U->getDebugInfoExtractor();
179 uint32_t UEndOffset = U->getNextUnitOffset();
180 if (Offset >= UEndOffset || !DebugInfoData.isValidOffset(Offset))
181 return false;
182 uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
183 if (0 == AbbrCode) {
184 // NULL debug tag entry.
185 AbbrevDecl = nullptr;
186 return true;
187 }
188 AbbrevDecl = U->getAbbreviations()->getAbbreviationDeclaration(AbbrCode);
189 if (nullptr == AbbrevDecl) {
190 // Restore the original offset.
191 *OffsetPtr = Offset;
192 return false;
193 }
194 ArrayRef<uint8_t> FixedFormSizes = DWARFFormValue::getFixedFormSizes(
195 U->getAddressByteSize(), U->getVersion());
196 assert(FixedFormSizes.size() > 0)((FixedFormSizes.size() > 0) ? static_cast<void> (0)
: __assert_fail ("FixedFormSizes.size() > 0", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn224240/lib/DebugInfo/DWARFDebugInfoEntry.cpp"
, 196, __PRETTY_FUNCTION__))
;
197
198 // Skip all data in the .debug_info for the attributes
199 for (const auto &AttrSpec : AbbrevDecl->attributes()) {
200 uint16_t Form = AttrSpec.Form;
201
202 uint8_t FixedFormSize =
203 (Form < FixedFormSizes.size()) ? FixedFormSizes[Form] : 0;
204 if (FixedFormSize)
205 *OffsetPtr += FixedFormSize;
206 else if (!DWARFFormValue::skipValue(Form, DebugInfoData, OffsetPtr, U)) {
207 // Restore the original offset.
208 *OffsetPtr = Offset;
209 return false;
210 }
211 }
212 return true;
213}
214
215bool DWARFDebugInfoEntryMinimal::isSubprogramDIE() const {
216 return getTag() == DW_TAG_subprogram;
217}
218
219bool DWARFDebugInfoEntryMinimal::isSubroutineDIE() const {
220 uint32_t Tag = getTag();
221 return Tag == DW_TAG_subprogram ||
222 Tag == DW_TAG_inlined_subroutine;
223}
224
225bool DWARFDebugInfoEntryMinimal::getAttributeValue(
226 const DWARFUnit *U, const uint16_t Attr, DWARFFormValue &FormValue) const {
227 if (!AbbrevDecl)
228 return false;
229
230 uint32_t AttrIdx = AbbrevDecl->findAttributeIndex(Attr);
231 if (AttrIdx == -1U)
232 return false;
233
234 DataExtractor DebugInfoData = U->getDebugInfoExtractor();
235 uint32_t DebugInfoOffset = getOffset();
236
237 // Skip the abbreviation code so we are at the data for the attributes
238 DebugInfoData.getULEB128(&DebugInfoOffset);
239
240 // Skip preceding attribute values.
241 for (uint32_t i = 0; i < AttrIdx; ++i) {
242 DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(i),
243 DebugInfoData, &DebugInfoOffset, U);
244 }
245
246 FormValue = DWARFFormValue(AbbrevDecl->getFormByIndex(AttrIdx));
247 return FormValue.extractValue(DebugInfoData, &DebugInfoOffset, U);
248}
249
250const char *DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
251 const DWARFUnit *U, const uint16_t Attr, const char *FailValue) const {
252 DWARFFormValue FormValue;
253 if (!getAttributeValue(U, Attr, FormValue))
254 return FailValue;
255 Optional<const char *> Result = FormValue.getAsCString(U);
256 return Result.hasValue() ? Result.getValue() : FailValue;
257}
258
259uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsAddress(
260 const DWARFUnit *U, const uint16_t Attr, uint64_t FailValue) const {
261 DWARFFormValue FormValue;
262 if (!getAttributeValue(U, Attr, FormValue))
263 return FailValue;
264 Optional<uint64_t> Result = FormValue.getAsAddress(U);
265 return Result.hasValue() ? Result.getValue() : FailValue;
266}
267
268uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsUnsignedConstant(
269 const DWARFUnit *U, const uint16_t Attr, uint64_t FailValue) const {
270 DWARFFormValue FormValue;
271 if (!getAttributeValue(U, Attr, FormValue))
272 return FailValue;
273 Optional<uint64_t> Result = FormValue.getAsUnsignedConstant();
274 return Result.hasValue() ? Result.getValue() : FailValue;
275}
276
277uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(
278 const DWARFUnit *U, const uint16_t Attr, uint64_t FailValue) const {
279 DWARFFormValue FormValue;
280 if (!getAttributeValue(U, Attr, FormValue))
281 return FailValue;
282 Optional<uint64_t> Result = FormValue.getAsReference(U);
283 return Result.hasValue() ? Result.getValue() : FailValue;
284}
285
286uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsSectionOffset(
287 const DWARFUnit *U, const uint16_t Attr, uint64_t FailValue) const {
288 DWARFFormValue FormValue;
289 if (!getAttributeValue(U, Attr, FormValue))
290 return FailValue;
291 Optional<uint64_t> Result = FormValue.getAsSectionOffset();
292 return Result.hasValue() ? Result.getValue() : FailValue;
293}
294
295uint64_t
296DWARFDebugInfoEntryMinimal::getRangesBaseAttribute(const DWARFUnit *U,
297 uint64_t FailValue) const {
298 uint64_t Result =
299 getAttributeValueAsSectionOffset(U, DW_AT_ranges_base, -1ULL);
300 if (Result != -1ULL)
301 return Result;
302 return getAttributeValueAsSectionOffset(U, DW_AT_GNU_ranges_base, FailValue);
303}
304
305bool DWARFDebugInfoEntryMinimal::getLowAndHighPC(const DWARFUnit *U,
306 uint64_t &LowPC,
307 uint64_t &HighPC) const {
308 LowPC = getAttributeValueAsAddress(U, DW_AT_low_pc, -1ULL);
309 if (LowPC == -1ULL)
310 return false;
311 HighPC = getAttributeValueAsAddress(U, DW_AT_high_pc, -1ULL);
312 if (HighPC == -1ULL) {
313 // Since DWARF4, DW_AT_high_pc may also be of class constant, in which case
314 // it represents function size.
315 HighPC = getAttributeValueAsUnsignedConstant(U, DW_AT_high_pc, -1ULL);
316 if (HighPC != -1ULL)
317 HighPC += LowPC;
318 }
319 return (HighPC != -1ULL);
320}
321
322DWARFAddressRangesVector
323DWARFDebugInfoEntryMinimal::getAddressRanges(const DWARFUnit *U) const {
324 if (isNULL())
325 return DWARFAddressRangesVector();
326 // Single range specified by low/high PC.
327 uint64_t LowPC, HighPC;
328 if (getLowAndHighPC(U, LowPC, HighPC)) {
329 return DWARFAddressRangesVector(1, std::make_pair(LowPC, HighPC));
330 }
331 // Multiple ranges from .debug_ranges section.
332 uint32_t RangesOffset =
333 getAttributeValueAsSectionOffset(U, DW_AT_ranges, -1U);
334 if (RangesOffset != -1U) {
335 DWARFDebugRangeList RangeList;
336 if (U->extractRangeList(RangesOffset, RangeList))
337 return RangeList.getAbsoluteRanges(U->getBaseAddress());
338 }
339 return DWARFAddressRangesVector();
340}
341
342void DWARFDebugInfoEntryMinimal::collectChildrenAddressRanges(
343 const DWARFUnit *U, DWARFAddressRangesVector& Ranges) const {
344 if (isNULL())
345 return;
346 if (isSubprogramDIE()) {
347 const auto &DIERanges = getAddressRanges(U);
348 Ranges.insert(Ranges.end(), DIERanges.begin(), DIERanges.end());
349 }
350
351 const DWARFDebugInfoEntryMinimal *Child = getFirstChild();
352 while (Child) {
353 Child->collectChildrenAddressRanges(U, Ranges);
354 Child = Child->getSibling();
355 }
356}
357
358bool DWARFDebugInfoEntryMinimal::addressRangeContainsAddress(
359 const DWARFUnit *U, const uint64_t Address) const {
360 for (const auto& R : getAddressRanges(U)) {
361 if (R.first <= Address && Address < R.second)
362 return true;
363 }
364 return false;
365}
366
367const char *
368DWARFDebugInfoEntryMinimal::getSubroutineName(const DWARFUnit *U,
369 DINameKind Kind) const {
370 if (!isSubroutineDIE())
371 return nullptr;
372 return getName(U, Kind);
373}
374
375const char *
376DWARFDebugInfoEntryMinimal::getName(const DWARFUnit *U,
377 DINameKind Kind) const {
378 if (Kind == DINameKind::None)
379 return nullptr;
380 // Try to get mangled name only if it was asked for.
381 if (Kind == DINameKind::LinkageName) {
382 if (const char *name =
383 getAttributeValueAsString(U, DW_AT_MIPS_linkage_name, nullptr))
384 return name;
385 if (const char *name =
386 getAttributeValueAsString(U, DW_AT_linkage_name, nullptr))
387 return name;
388 }
389 if (const char *name = getAttributeValueAsString(U, DW_AT_name, nullptr))
390 return name;
391 // Try to get name from specification DIE.
392 uint32_t spec_ref =
393 getAttributeValueAsReference(U, DW_AT_specification, -1U);
394 if (spec_ref != -1U) {
395 DWARFDebugInfoEntryMinimal spec_die;
396 if (const DWARFUnit *RefU = findUnitAndExtractFast(spec_die, U, &spec_ref)) {
397 if (const char *name = spec_die.getName(RefU, Kind))
398 return name;
399 }
400 }
401 // Try to get name from abstract origin DIE.
402 uint32_t abs_origin_ref =
403 getAttributeValueAsReference(U, DW_AT_abstract_origin, -1U);
404 if (abs_origin_ref != -1U) {
405 DWARFDebugInfoEntryMinimal abs_origin_die;
406 if (const DWARFUnit *RefU = findUnitAndExtractFast(abs_origin_die, U,
407 &abs_origin_ref)) {
408 if (const char *name = abs_origin_die.getName(RefU, Kind))
409 return name;
410 }
411 }
412 return nullptr;
413}
414
415void DWARFDebugInfoEntryMinimal::getCallerFrame(const DWARFUnit *U,
416 uint32_t &CallFile,
417 uint32_t &CallLine,
418 uint32_t &CallColumn) const {
419 CallFile = getAttributeValueAsUnsignedConstant(U, DW_AT_call_file, 0);
420 CallLine = getAttributeValueAsUnsignedConstant(U, DW_AT_call_line, 0);
421 CallColumn = getAttributeValueAsUnsignedConstant(U, DW_AT_call_column, 0);
422}
423
424DWARFDebugInfoEntryInlinedChain
425DWARFDebugInfoEntryMinimal::getInlinedChainForAddress(
426 const DWARFUnit *U, const uint64_t Address) const {
427 DWARFDebugInfoEntryInlinedChain InlinedChain;
428 InlinedChain.U = U;
429 if (isNULL())
430 return InlinedChain;
431 for (const DWARFDebugInfoEntryMinimal *DIE = this; DIE; ) {
432 // Append current DIE to inlined chain only if it has correct tag
433 // (e.g. it is not a lexical block).
434 if (DIE->isSubroutineDIE()) {
435 InlinedChain.DIEs.push_back(*DIE);
436 }
437 // Try to get child which also contains provided address.
438 const DWARFDebugInfoEntryMinimal *Child = DIE->getFirstChild();
439 while (Child) {
440 if (Child->addressRangeContainsAddress(U, Address)) {
441 // Assume there is only one such child.
442 break;
443 }
444 Child = Child->getSibling();
445 }
446 DIE = Child;
447 }
448 // Reverse the obtained chain to make the root of inlined chain last.
449 std::reverse(InlinedChain.DIEs.begin(), InlinedChain.DIEs.end());
450 return InlinedChain;
451}