jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2020-2021, Itamar S. <itamar8910@gmail.com>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include "AddressRanges.h"
8#include "DwarfTypes.h"
9#include <AK/LEB128.h>
10
11namespace Debug::Dwarf {
12
13AddressRangesV5::AddressRangesV5(NonnullOwnPtr<Stream> range_lists_stream, CompilationUnit const& compilation_unit)
14 : m_range_lists_stream(move(range_lists_stream))
15 , m_compilation_unit(compilation_unit)
16{
17}
18
19ErrorOr<void> AddressRangesV5::for_each_range(Function<void(Range)> callback)
20{
21 // Dwarf version 5, section 2.17.3 "Non-Contiguous Address Ranges"
22
23 Optional<FlatPtr> current_base_address;
24 while (!m_range_lists_stream->is_eof()) {
25 auto entry_type = TRY(m_range_lists_stream->read_value<u8>());
26 switch (static_cast<RangeListEntryType>(entry_type)) {
27 case RangeListEntryType::BaseAddress: {
28 current_base_address = TRY(m_range_lists_stream->read_value<FlatPtr>());
29 break;
30 }
31 case RangeListEntryType::BaseAddressX: {
32 FlatPtr index = TRY(m_range_lists_stream->read_value<LEB128<FlatPtr>>());
33 current_base_address = TRY(m_compilation_unit.get_address(index));
34 break;
35 }
36 case RangeListEntryType::OffsetPair: {
37 Optional<FlatPtr> base_address = current_base_address;
38 if (!base_address.has_value()) {
39 base_address = TRY(m_compilation_unit.base_address());
40 }
41
42 if (!base_address.has_value())
43 return Error::from_string_literal("Expected base_address for rangelist");
44
45 size_t start_offset = TRY(m_range_lists_stream->read_value<LEB128<size_t>>());
46 size_t end_offset = TRY(m_range_lists_stream->read_value<LEB128<size_t>>());
47 callback(Range { start_offset + *base_address, end_offset + *base_address });
48 break;
49 }
50 case RangeListEntryType::StartLength: {
51 auto start = TRY(m_range_lists_stream->read_value<FlatPtr>());
52 size_t length = TRY(m_range_lists_stream->read_value<LEB128<size_t>>());
53 callback(Range { start, start + length });
54 break;
55 }
56 case RangeListEntryType::StartXEndX: {
57 size_t start = TRY(m_range_lists_stream->read_value<LEB128<size_t>>());
58 size_t end = TRY(m_range_lists_stream->read_value<LEB128<size_t>>());
59 callback(Range { TRY(m_compilation_unit.get_address(start)), TRY(m_compilation_unit.get_address(end)) });
60 break;
61 }
62 case RangeListEntryType::StartXLength: {
63 size_t start = TRY(m_range_lists_stream->read_value<LEB128<size_t>>());
64 size_t length = TRY(m_range_lists_stream->read_value<LEB128<size_t>>());
65 auto start_addr = TRY(m_compilation_unit.get_address(start));
66 callback(Range { start_addr, start_addr + length });
67 break;
68 }
69 case RangeListEntryType::EndOfList:
70 return {};
71 default:
72 dbgln("unsupported range list entry type: 0x{:x}", entry_type);
73 return Error::from_string_literal("Unsupported range list entry type");
74 }
75 }
76
77 return {};
78}
79
80AddressRangesV4::AddressRangesV4(NonnullOwnPtr<Stream> ranges_stream, CompilationUnit const& compilation_unit)
81 : m_ranges_stream(move(ranges_stream))
82 , m_compilation_unit(compilation_unit)
83{
84}
85
86ErrorOr<void> AddressRangesV4::for_each_range(Function<void(Range)> callback)
87{
88 // Dwarf version 4, section 2.17.3 "Non-Contiguous Address Ranges"
89
90 Optional<FlatPtr> current_base_address;
91 while (!m_ranges_stream->is_eof()) {
92 auto begin = TRY(m_ranges_stream->read_value<FlatPtr>());
93 auto end = TRY(m_ranges_stream->read_value<FlatPtr>());
94
95 if (begin == 0 && end == 0) {
96 // end of list entry
97 return {};
98 } else if (begin == explode_byte(0xff)) {
99 current_base_address = end;
100 } else {
101 FlatPtr base = current_base_address.value_or(TRY(m_compilation_unit.base_address()).value_or(0));
102 callback({ base + begin, base + end });
103 }
104 }
105
106 return {};
107}
108
109}