1 //===- DWARFDebugArangeSet.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/DWARFDebugArangeSet.h" 10 #include "llvm/Support/Format.h" 11 #include "llvm/Support/raw_ostream.h" 12 #include <cassert> 13 #include <cinttypes> 14 #include <cstdint> 15 #include <cstring> 16 17 using namespace llvm; 18 19 void DWARFDebugArangeSet::Descriptor::dump(raw_ostream &OS, 20 uint32_t AddressSize) const { 21 OS << format("[0x%*.*" PRIx64 ", ", AddressSize * 2, AddressSize * 2, Address) 22 << format(" 0x%*.*" PRIx64 ")", AddressSize * 2, AddressSize * 2, 23 getEndAddress()); 24 } 25 26 void DWARFDebugArangeSet::clear() { 27 Offset = -1ULL; 28 std::memset(&HeaderData, 0, sizeof(Header)); 29 ArangeDescriptors.clear(); 30 } 31 32 bool 33 DWARFDebugArangeSet::extract(DataExtractor data, uint64_t *offset_ptr) { 34 if (data.isValidOffset(*offset_ptr)) { 35 ArangeDescriptors.clear(); 36 Offset = *offset_ptr; 37 38 // 7.20 Address Range Table 39 // 40 // Each set of entries in the table of address ranges contained in 41 // the .debug_aranges section begins with a header consisting of: a 42 // 4-byte length containing the length of the set of entries for this 43 // compilation unit, not including the length field itself; a 2-byte 44 // version identifier containing the value 2 for DWARF Version 2; a 45 // 4-byte offset into the.debug_infosection; a 1-byte unsigned integer 46 // containing the size in bytes of an address (or the offset portion of 47 // an address for segmented addressing) on the target system; and a 48 // 1-byte unsigned integer containing the size in bytes of a segment 49 // descriptor on the target system. This header is followed by a series 50 // of tuples. Each tuple consists of an address and a length, each in 51 // the size appropriate for an address on the target architecture. 52 HeaderData.Length = data.getU32(offset_ptr); 53 HeaderData.Version = data.getU16(offset_ptr); 54 HeaderData.CuOffset = data.getU32(offset_ptr); 55 HeaderData.AddrSize = data.getU8(offset_ptr); 56 HeaderData.SegSize = data.getU8(offset_ptr); 57 58 // Perform basic validation of the header fields. 59 if (!data.isValidOffsetForDataOfSize(Offset, HeaderData.Length) || 60 (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8)) { 61 clear(); 62 return false; 63 } 64 65 // The first tuple following the header in each set begins at an offset 66 // that is a multiple of the size of a single tuple (that is, twice the 67 // size of an address). The header is padded, if necessary, to the 68 // appropriate boundary. 69 const uint32_t header_size = *offset_ptr - Offset; 70 const uint32_t tuple_size = HeaderData.AddrSize * 2; 71 uint32_t first_tuple_offset = 0; 72 while (first_tuple_offset < header_size) 73 first_tuple_offset += tuple_size; 74 75 *offset_ptr = Offset + first_tuple_offset; 76 77 Descriptor arangeDescriptor; 78 79 static_assert(sizeof(arangeDescriptor.Address) == 80 sizeof(arangeDescriptor.Length), 81 "Different datatypes for addresses and sizes!"); 82 assert(sizeof(arangeDescriptor.Address) >= HeaderData.AddrSize); 83 84 while (data.isValidOffset(*offset_ptr)) { 85 arangeDescriptor.Address = data.getUnsigned(offset_ptr, HeaderData.AddrSize); 86 arangeDescriptor.Length = data.getUnsigned(offset_ptr, HeaderData.AddrSize); 87 88 // Each set of tuples is terminated by a 0 for the address and 0 89 // for the length. 90 if (arangeDescriptor.Address || arangeDescriptor.Length) 91 ArangeDescriptors.push_back(arangeDescriptor); 92 else 93 break; // We are done if we get a zero address and length 94 } 95 96 return !ArangeDescriptors.empty(); 97 } 98 return false; 99 } 100 101 void DWARFDebugArangeSet::dump(raw_ostream &OS) const { 102 OS << format("Address Range Header: length = 0x%8.8x, version = 0x%4.4x, ", 103 HeaderData.Length, HeaderData.Version) 104 << format("cu_offset = 0x%8.8x, addr_size = 0x%2.2x, seg_size = 0x%2.2x\n", 105 HeaderData.CuOffset, HeaderData.AddrSize, HeaderData.SegSize); 106 107 for (const auto &Desc : ArangeDescriptors) { 108 Desc.dump(OS, HeaderData.AddrSize); 109 OS << '\n'; 110 } 111 } 112