xref: /freebsd/contrib/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp (revision 9f44a47fd07924afc035991af15d84e6585dea4f)
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/DWARFDataExtractor.h"
13 #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
14 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
15 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
16 #include "llvm/Support/Errc.h"
17 #include <cstddef>
18 #include <cstdint>
19 
20 using namespace llvm;
21 using namespace dwarf;
22 
23 bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U, uint64_t *OffsetPtr,
24                                       const DWARFDataExtractor &DebugInfoData,
25                                       uint64_t UEndOffset, uint32_t ParentIdx) {
26   Offset = *OffsetPtr;
27   this->ParentIdx = ParentIdx;
28   if (Offset >= UEndOffset) {
29     U.getContext().getWarningHandler()(
30         createStringError(errc::invalid_argument,
31                           "DWARF unit from offset 0x%8.8" PRIx64 " incl. "
32                           "to offset 0x%8.8" PRIx64 " excl. "
33                           "tries to read DIEs at offset 0x%8.8" PRIx64,
34                           U.getOffset(), U.getNextUnitOffset(), *OffsetPtr));
35     return false;
36   }
37   assert(DebugInfoData.isValidOffset(UEndOffset - 1));
38   uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
39   if (0 == AbbrCode) {
40     // NULL debug tag entry.
41     AbbrevDecl = nullptr;
42     return true;
43   }
44   const auto *AbbrevSet = U.getAbbreviations();
45   if (!AbbrevSet) {
46     U.getContext().getWarningHandler()(
47         createStringError(errc::invalid_argument,
48                           "DWARF unit at offset 0x%8.8" PRIx64 " "
49                           "contains invalid abbreviation set offset 0x%" PRIx64,
50                           U.getOffset(), U.getAbbreviationsOffset()));
51     // Restore the original offset.
52     *OffsetPtr = Offset;
53     return false;
54   }
55   AbbrevDecl = AbbrevSet->getAbbreviationDeclaration(AbbrCode);
56   if (!AbbrevDecl) {
57     U.getContext().getWarningHandler()(
58         createStringError(errc::invalid_argument,
59                           "DWARF unit at offset 0x%8.8" PRIx64 " "
60                           "contains invalid abbreviation %" PRIu64 " at "
61                           "offset 0x%8.8" PRIx64 ", valid abbreviations are %s",
62                           U.getOffset(), AbbrCode, *OffsetPtr,
63                           AbbrevSet->getCodeRange().c_str()));
64     // Restore the original offset.
65     *OffsetPtr = Offset;
66     return false;
67   }
68   // See if all attributes in this DIE have fixed byte sizes. If so, we can
69   // just add this size to the offset to skip to the next DIE.
70   if (Optional<size_t> FixedSize = AbbrevDecl->getFixedAttributesByteSize(U)) {
71     *OffsetPtr += *FixedSize;
72     return true;
73   }
74 
75   // Skip all data in the .debug_info for the attributes
76   for (const auto &AttrSpec : AbbrevDecl->attributes()) {
77     // Check if this attribute has a fixed byte size.
78     if (auto FixedSize = AttrSpec.getByteSize(U)) {
79       // Attribute byte size if fixed, just add the size to the offset.
80       *OffsetPtr += *FixedSize;
81     } else if (!DWARFFormValue::skipValue(AttrSpec.Form, DebugInfoData,
82                                           OffsetPtr, U.getFormParams())) {
83       // We failed to skip this attribute's value, restore the original offset
84       // and return the failure status.
85       U.getContext().getWarningHandler()(createStringError(
86           errc::invalid_argument,
87           "DWARF unit at offset 0x%8.8" PRIx64 " "
88           "contains invalid FORM_* 0x%" PRIx16 " at offset 0x%8.8" PRIx64,
89           U.getOffset(), AttrSpec.Form, *OffsetPtr));
90       *OffsetPtr = Offset;
91       return false;
92     }
93   }
94   return true;
95 }
96