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