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