1*0b57cec5SDimitry Andric //===- DWARFDebugInfoEntry.cpp --------------------------------------------===// 2*0b57cec5SDimitry Andric // 3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*0b57cec5SDimitry Andric // 7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 8*0b57cec5SDimitry Andric 9*0b57cec5SDimitry Andric #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h" 10*0b57cec5SDimitry Andric #include "llvm/ADT/Optional.h" 11*0b57cec5SDimitry Andric #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h" 12*0b57cec5SDimitry Andric #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" 13*0b57cec5SDimitry Andric #include "llvm/DebugInfo/DWARF/DWARFUnit.h" 14*0b57cec5SDimitry Andric #include "llvm/Support/DataExtractor.h" 15*0b57cec5SDimitry Andric #include <cstddef> 16*0b57cec5SDimitry Andric #include <cstdint> 17*0b57cec5SDimitry Andric 18*0b57cec5SDimitry Andric using namespace llvm; 19*0b57cec5SDimitry Andric using namespace dwarf; 20*0b57cec5SDimitry Andric 21*0b57cec5SDimitry Andric bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U, 22*0b57cec5SDimitry Andric uint32_t *OffsetPtr) { 23*0b57cec5SDimitry Andric DWARFDataExtractor DebugInfoData = U.getDebugInfoExtractor(); 24*0b57cec5SDimitry Andric const uint32_t UEndOffset = U.getNextUnitOffset(); 25*0b57cec5SDimitry Andric return extractFast(U, OffsetPtr, DebugInfoData, UEndOffset, 0); 26*0b57cec5SDimitry Andric } 27*0b57cec5SDimitry Andric 28*0b57cec5SDimitry Andric bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U, uint32_t *OffsetPtr, 29*0b57cec5SDimitry Andric const DWARFDataExtractor &DebugInfoData, 30*0b57cec5SDimitry Andric uint32_t UEndOffset, uint32_t D) { 31*0b57cec5SDimitry Andric Offset = *OffsetPtr; 32*0b57cec5SDimitry Andric Depth = D; 33*0b57cec5SDimitry Andric if (Offset >= UEndOffset || !DebugInfoData.isValidOffset(Offset)) 34*0b57cec5SDimitry Andric return false; 35*0b57cec5SDimitry Andric uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr); 36*0b57cec5SDimitry Andric if (0 == AbbrCode) { 37*0b57cec5SDimitry Andric // NULL debug tag entry. 38*0b57cec5SDimitry Andric AbbrevDecl = nullptr; 39*0b57cec5SDimitry Andric return true; 40*0b57cec5SDimitry Andric } 41*0b57cec5SDimitry Andric AbbrevDecl = U.getAbbreviations()->getAbbreviationDeclaration(AbbrCode); 42*0b57cec5SDimitry Andric if (nullptr == AbbrevDecl) { 43*0b57cec5SDimitry Andric // Restore the original offset. 44*0b57cec5SDimitry Andric *OffsetPtr = Offset; 45*0b57cec5SDimitry Andric return false; 46*0b57cec5SDimitry Andric } 47*0b57cec5SDimitry Andric // See if all attributes in this DIE have fixed byte sizes. If so, we can 48*0b57cec5SDimitry Andric // just add this size to the offset to skip to the next DIE. 49*0b57cec5SDimitry Andric if (Optional<size_t> FixedSize = AbbrevDecl->getFixedAttributesByteSize(U)) { 50*0b57cec5SDimitry Andric *OffsetPtr += *FixedSize; 51*0b57cec5SDimitry Andric return true; 52*0b57cec5SDimitry Andric } 53*0b57cec5SDimitry Andric 54*0b57cec5SDimitry Andric // Skip all data in the .debug_info for the attributes 55*0b57cec5SDimitry Andric for (const auto &AttrSpec : AbbrevDecl->attributes()) { 56*0b57cec5SDimitry Andric // Check if this attribute has a fixed byte size. 57*0b57cec5SDimitry Andric if (auto FixedSize = AttrSpec.getByteSize(U)) { 58*0b57cec5SDimitry Andric // Attribute byte size if fixed, just add the size to the offset. 59*0b57cec5SDimitry Andric *OffsetPtr += *FixedSize; 60*0b57cec5SDimitry Andric } else if (!DWARFFormValue::skipValue(AttrSpec.Form, DebugInfoData, 61*0b57cec5SDimitry Andric OffsetPtr, U.getFormParams())) { 62*0b57cec5SDimitry Andric // We failed to skip this attribute's value, restore the original offset 63*0b57cec5SDimitry Andric // and return the failure status. 64*0b57cec5SDimitry Andric *OffsetPtr = Offset; 65*0b57cec5SDimitry Andric return false; 66*0b57cec5SDimitry Andric } 67*0b57cec5SDimitry Andric } 68*0b57cec5SDimitry Andric return true; 69*0b57cec5SDimitry Andric } 70