1 //===-- DWARFDebugArangeSet.cpp -------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "DWARFDebugArangeSet.h" 11 #include "llvm/Support/Format.h" 12 #include "llvm/Support/raw_ostream.h" 13 #include <algorithm> 14 #include <cassert> 15 using namespace llvm; 16 17 void DWARFDebugArangeSet::clear() { 18 Offset = -1U; 19 std::memset(&HeaderData, 0, sizeof(Header)); 20 ArangeDescriptors.clear(); 21 } 22 23 bool 24 DWARFDebugArangeSet::extract(DataExtractor data, uint32_t *offset_ptr) { 25 if (data.isValidOffset(*offset_ptr)) { 26 ArangeDescriptors.clear(); 27 Offset = *offset_ptr; 28 29 // 7.20 Address Range Table 30 // 31 // Each set of entries in the table of address ranges contained in 32 // the .debug_aranges section begins with a header consisting of: a 33 // 4-byte length containing the length of the set of entries for this 34 // compilation unit, not including the length field itself; a 2-byte 35 // version identifier containing the value 2 for DWARF Version 2; a 36 // 4-byte offset into the.debug_infosection; a 1-byte unsigned integer 37 // containing the size in bytes of an address (or the offset portion of 38 // an address for segmented addressing) on the target system; and a 39 // 1-byte unsigned integer containing the size in bytes of a segment 40 // descriptor on the target system. This header is followed by a series 41 // of tuples. Each tuple consists of an address and a length, each in 42 // the size appropriate for an address on the target architecture. 43 HeaderData.Length = data.getU32(offset_ptr); 44 HeaderData.Version = data.getU16(offset_ptr); 45 HeaderData.CuOffset = data.getU32(offset_ptr); 46 HeaderData.AddrSize = data.getU8(offset_ptr); 47 HeaderData.SegSize = data.getU8(offset_ptr); 48 49 // Perform basic validation of the header fields. 50 if (!data.isValidOffsetForDataOfSize(Offset, HeaderData.Length) || 51 (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8)) { 52 clear(); 53 return false; 54 } 55 56 // The first tuple following the header in each set begins at an offset 57 // that is a multiple of the size of a single tuple (that is, twice the 58 // size of an address). The header is padded, if necessary, to the 59 // appropriate boundary. 60 const uint32_t header_size = *offset_ptr - Offset; 61 const uint32_t tuple_size = HeaderData.AddrSize * 2; 62 uint32_t first_tuple_offset = 0; 63 while (first_tuple_offset < header_size) 64 first_tuple_offset += tuple_size; 65 66 *offset_ptr = Offset + first_tuple_offset; 67 68 Descriptor arangeDescriptor; 69 70 static_assert(sizeof(arangeDescriptor.Address) == 71 sizeof(arangeDescriptor.Length), 72 "Different datatypes for addresses and sizes!"); 73 assert(sizeof(arangeDescriptor.Address) >= HeaderData.AddrSize); 74 75 while (data.isValidOffset(*offset_ptr)) { 76 arangeDescriptor.Address = data.getUnsigned(offset_ptr, HeaderData.AddrSize); 77 arangeDescriptor.Length = data.getUnsigned(offset_ptr, HeaderData.AddrSize); 78 79 // Each set of tuples is terminated by a 0 for the address and 0 80 // for the length. 81 if (arangeDescriptor.Address || arangeDescriptor.Length) 82 ArangeDescriptors.push_back(arangeDescriptor); 83 else 84 break; // We are done if we get a zero address and length 85 } 86 87 return !ArangeDescriptors.empty(); 88 } 89 return false; 90 } 91 92 void DWARFDebugArangeSet::dump(raw_ostream &OS) const { 93 OS << format("Address Range Header: length = 0x%8.8x, version = 0x%4.4x, ", 94 HeaderData.Length, HeaderData.Version) 95 << format("cu_offset = 0x%8.8x, addr_size = 0x%2.2x, seg_size = 0x%2.2x\n", 96 HeaderData.CuOffset, HeaderData.AddrSize, HeaderData.SegSize); 97 98 const uint32_t hex_width = HeaderData.AddrSize * 2; 99 for (const auto &Desc : ArangeDescriptors) { 100 OS << format("[0x%*.*" PRIx64 " -", hex_width, hex_width, Desc.Address) 101 << format(" 0x%*.*" PRIx64 ")\n", 102 hex_width, hex_width, Desc.getEndAddress()); 103 } 104 } 105
