1 //===- DWARFDebugInfoEntry.cpp --------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
10 #include "llvm/ADT/Optional.h"
11 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
12 #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
13 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
14 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
15 #include "llvm/Support/DataExtractor.h"
16 #include <cstddef>
17 #include <cstdint>
18
19 using namespace llvm;
20 using namespace dwarf;
21
extractFast(const DWARFUnit & U,uint64_t * OffsetPtr)22 bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U,
23 uint64_t *OffsetPtr) {
24 DWARFDataExtractor DebugInfoData = U.getDebugInfoExtractor();
25 const uint64_t UEndOffset = U.getNextUnitOffset();
26 return extractFast(U, OffsetPtr, DebugInfoData, UEndOffset, 0);
27 }
28
extractFast(const DWARFUnit & U,uint64_t * OffsetPtr,const DWARFDataExtractor & DebugInfoData,uint64_t UEndOffset,uint32_t D)29 bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U, uint64_t *OffsetPtr,
30 const DWARFDataExtractor &DebugInfoData,
31 uint64_t UEndOffset, uint32_t D) {
32 Offset = *OffsetPtr;
33 Depth = D;
34 if (Offset >= UEndOffset) {
35 U.getContext().getWarningHandler()(
36 createStringError(errc::invalid_argument,
37 "DWARF unit from offset 0x%8.8" PRIx64 " incl. "
38 "to offset 0x%8.8" PRIx64 " excl. "
39 "tries to read DIEs at offset 0x%8.8" PRIx64,
40 U.getOffset(), U.getNextUnitOffset(), *OffsetPtr));
41 return false;
42 }
43 assert(DebugInfoData.isValidOffset(UEndOffset - 1));
44 uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
45 if (0 == AbbrCode) {
46 // NULL debug tag entry.
47 AbbrevDecl = nullptr;
48 return true;
49 }
50 const auto *AbbrevSet = U.getAbbreviations();
51 if (!AbbrevSet) {
52 U.getContext().getWarningHandler()(
53 createStringError(errc::invalid_argument,
54 "DWARF unit at offset 0x%8.8" PRIx64 " "
55 "contains invalid abbreviation set offset 0x%" PRIx64,
56 U.getOffset(), U.getAbbreviationsOffset()));
57 // Restore the original offset.
58 *OffsetPtr = Offset;
59 return false;
60 }
61 AbbrevDecl = AbbrevSet->getAbbreviationDeclaration(AbbrCode);
62 if (!AbbrevDecl) {
63 U.getContext().getWarningHandler()(
64 createStringError(errc::invalid_argument,
65 "DWARF unit at offset 0x%8.8" PRIx64 " "
66 "contains invalid abbreviation %" PRIu64 " at "
67 "offset 0x%8.8" PRIx64 ", valid abbreviations are %s",
68 U.getOffset(), AbbrCode, *OffsetPtr,
69 AbbrevSet->getCodeRange().c_str()));
70 // Restore the original offset.
71 *OffsetPtr = Offset;
72 return false;
73 }
74 // See if all attributes in this DIE have fixed byte sizes. If so, we can
75 // just add this size to the offset to skip to the next DIE.
76 if (Optional<size_t> FixedSize = AbbrevDecl->getFixedAttributesByteSize(U)) {
77 *OffsetPtr += *FixedSize;
78 return true;
79 }
80
81 // Skip all data in the .debug_info for the attributes
82 for (const auto &AttrSpec : AbbrevDecl->attributes()) {
83 // Check if this attribute has a fixed byte size.
84 if (auto FixedSize = AttrSpec.getByteSize(U)) {
85 // Attribute byte size if fixed, just add the size to the offset.
86 *OffsetPtr += *FixedSize;
87 } else if (!DWARFFormValue::skipValue(AttrSpec.Form, DebugInfoData,
88 OffsetPtr, U.getFormParams())) {
89 // We failed to skip this attribute's value, restore the original offset
90 // and return the failure status.
91 U.getContext().getWarningHandler()(createStringError(
92 errc::invalid_argument,
93 "DWARF unit at offset 0x%8.8" PRIx64 " "
94 "contains invalid FORM_* 0x%" PRIx16 " at offset 0x%8.8" PRIx64,
95 U.getOffset(), AttrSpec.Form, *OffsetPtr));
96 *OffsetPtr = Offset;
97 return false;
98 }
99 }
100 return true;
101 }
102