1 | //===- bolt/Core/AddressMap.h - Input-output address map --------*- C++ -*-===// |
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 | // This file contains the declaration of the AddressMap class used for looking |
10 | // up addresses in the output object. |
11 | // |
12 | //===----------------------------------------------------------------------===// |
13 | |
14 | #ifndef BOLT_CORE_ADDRESS_MAP_H |
15 | #define BOLT_CORE_ADDRESS_MAP_H |
16 | |
17 | #include "llvm/MC/MCSymbol.h" |
18 | |
19 | #include <optional> |
20 | #include <unordered_map> |
21 | |
22 | namespace llvm { |
23 | |
24 | class MCStreamer; |
25 | |
26 | namespace bolt { |
27 | |
28 | class BinaryContext; |
29 | |
30 | /// Helper class to create a mapping from input entities to output addresses |
31 | /// needed for updating debugging symbols and BAT. We emit a section containing |
32 | /// <Input entity, Output MCSymbol> pairs to the object file and JITLink will |
33 | /// transform this in <Input entity, Output address> pairs. The linker output |
34 | /// can then be parsed and used to establish the mapping. |
35 | /// |
36 | /// The entities that can be mapped to output address are input addresses and |
37 | /// labels (MCSymbol). Input addresses support one-to-many mapping. |
38 | class AddressMap { |
39 | static const char *const AddressSectionName; |
40 | static const char *const LabelSectionName; |
41 | |
42 | /// Map multiple <input address> to <output address>. |
43 | using Addr2AddrMapTy = std::unordered_multimap<uint64_t, uint64_t>; |
44 | Addr2AddrMapTy Address2AddressMap; |
45 | |
46 | /// Map MCSymbol to its output address. Normally used for temp symbols that |
47 | /// are not updated by the linker. |
48 | using Label2AddrMapTy = DenseMap<const MCSymbol *, uint64_t>; |
49 | Label2AddrMapTy Label2AddrMap; |
50 | |
51 | public: |
52 | static void emit(MCStreamer &Streamer, BinaryContext &BC); |
53 | static std::optional<AddressMap> parse(BinaryContext &BC); |
54 | |
55 | std::optional<uint64_t> lookup(uint64_t InputAddress) const { |
56 | auto It = Address2AddressMap.find(x: InputAddress); |
57 | if (It != Address2AddressMap.end()) |
58 | return It->second; |
59 | return std::nullopt; |
60 | } |
61 | |
62 | std::optional<uint64_t> lookup(const MCSymbol *Symbol) const { |
63 | auto It = Label2AddrMap.find(Val: Symbol); |
64 | if (It != Label2AddrMap.end()) |
65 | return It->second; |
66 | return std::nullopt; |
67 | } |
68 | |
69 | std::pair<Addr2AddrMapTy::const_iterator, Addr2AddrMapTy::const_iterator> |
70 | lookupAll(uint64_t InputAddress) const { |
71 | return Address2AddressMap.equal_range(x: InputAddress); |
72 | } |
73 | }; |
74 | |
75 | } // namespace bolt |
76 | } // namespace llvm |
77 | |
78 | #endif |
79 | |