1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "delta_encoder.h"
6
7 #include <vector>
8 #include "elf.h"
9 #include "elf_traits.h"
10 #include "testing/gtest/include/gtest/gtest.h"
11
12 namespace {
13
AddRelocation(ELF::Addr addr,ELF::Sxword addend,std::vector<ELF::Rela> * relocations)14 void AddRelocation(ELF::Addr addr,
15 ELF::Sxword addend,
16 std::vector<ELF::Rela>* relocations) {
17 ELF::Rela relocation;
18 relocation.r_offset = addr;
19 relocation.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode);
20 relocation.r_addend = addend;
21 relocations->push_back(relocation);
22 }
23
CheckRelocation(ELF::Addr addr,ELF::Sxword addend,const ELF::Rela & relocation)24 bool CheckRelocation(ELF::Addr addr,
25 ELF::Sxword addend,
26 const ELF::Rela& relocation) {
27 return relocation.r_offset == addr &&
28 ELF_R_SYM(relocation.r_info) == 0 &&
29 ELF_R_TYPE(relocation.r_info) == ELF::kRelativeRelocationCode &&
30 relocation.r_addend == addend;
31 }
32
33 } // namespace
34
35 namespace relocation_packer {
36
TEST(Delta,Encode)37 TEST(Delta, Encode) {
38 std::vector<ELF::Rela> relocations;
39 std::vector<ELF::Sxword> packed;
40
41 RelocationDeltaCodec codec;
42
43 packed.clear();
44 codec.Encode(relocations, &packed);
45
46 EXPECT_EQ(0, packed.size());
47
48 // Initial relocation.
49 AddRelocation(0xf00d0000, 10000, &relocations);
50
51 packed.clear();
52 codec.Encode(relocations, &packed);
53
54 EXPECT_EQ(3, packed.size());
55 // One pair present.
56 EXPECT_EQ(1, packed[0]);
57 // Delta from the neutral element is the initial relocation.
58 EXPECT_EQ(0xf00d0000, packed[1]);
59 EXPECT_EQ(10000, packed[2]);
60
61 // Add a second relocation, 4 byte offset delta, 12 byte addend delta.
62 AddRelocation(0xf00d0004, 10012, &relocations);
63
64 packed.clear();
65 codec.Encode(relocations, &packed);
66
67 EXPECT_EQ(5, packed.size());
68 // Two pairs present.
69 EXPECT_EQ(2, packed[0]);
70 // Delta from the neutral element is the initial relocation.
71 EXPECT_EQ(0xf00d0000, packed[1]);
72 EXPECT_EQ(10000, packed[2]);
73 // 4 byte offset delta, 12 byte addend delta.
74 EXPECT_EQ(4, packed[3]);
75 EXPECT_EQ(12, packed[4]);
76
77 // Add a third relocation, 4 byte offset delta, 12 byte addend delta.
78 AddRelocation(0xf00d0008, 10024, &relocations);
79
80 // Add three more relocations, 8 byte offset deltas, -24 byte addend deltas.
81 AddRelocation(0xf00d0010, 10000, &relocations);
82 AddRelocation(0xf00d0018, 9976, &relocations);
83 AddRelocation(0xf00d0020, 9952, &relocations);
84
85 packed.clear();
86 codec.Encode(relocations, &packed);
87
88 EXPECT_EQ(13, packed.size());
89 // Six pairs present.
90 EXPECT_EQ(6, packed[0]);
91 // Initial relocation.
92 EXPECT_EQ(0xf00d0000, packed[1]);
93 EXPECT_EQ(10000, packed[2]);
94 // Two relocations, 4 byte offset deltas, 12 byte addend deltas.
95 EXPECT_EQ(4, packed[3]);
96 EXPECT_EQ(12, packed[4]);
97 EXPECT_EQ(4, packed[5]);
98 EXPECT_EQ(12, packed[6]);
99 // Three relocations, 8 byte offset deltas, -24 byte addend deltas.
100 EXPECT_EQ(8, packed[7]);
101 EXPECT_EQ(-24, packed[8]);
102 EXPECT_EQ(8, packed[9]);
103 EXPECT_EQ(-24, packed[10]);
104 EXPECT_EQ(8, packed[11]);
105 EXPECT_EQ(-24, packed[12]);
106 }
107
TEST(Delta,Decode)108 TEST(Delta, Decode) {
109 std::vector<ELF::Sxword> packed;
110 std::vector<ELF::Rela> relocations;
111
112 RelocationDeltaCodec codec;
113 codec.Decode(packed, &relocations);
114
115 EXPECT_EQ(0, relocations.size());
116
117 // Six pairs.
118 packed.push_back(6);
119 // Initial relocation.
120 packed.push_back(0xc0de0000);
121 packed.push_back(10000);
122 // Two relocations, 4 byte offset deltas, 12 byte addend deltas.
123 packed.push_back(4);
124 packed.push_back(12);
125 packed.push_back(4);
126 packed.push_back(12);
127 // Three relocations, 8 byte offset deltas, -24 byte addend deltas.
128 packed.push_back(8);
129 packed.push_back(-24);
130 packed.push_back(8);
131 packed.push_back(-24);
132 packed.push_back(8);
133 packed.push_back(-24);
134
135 relocations.clear();
136 codec.Decode(packed, &relocations);
137
138 EXPECT_EQ(6, relocations.size());
139 // Initial relocation.
140 EXPECT_TRUE(CheckRelocation(0xc0de0000, 10000, relocations[0]));
141 // Two relocations, 4 byte offset deltas, 12 byte addend deltas.
142 EXPECT_TRUE(CheckRelocation(0xc0de0004, 10012, relocations[1]));
143 EXPECT_TRUE(CheckRelocation(0xc0de0008, 10024, relocations[2]));
144 // Three relocations, 8 byte offset deltas, -24 byte addend deltas.
145 EXPECT_TRUE(CheckRelocation(0xc0de0010, 10000, relocations[3]));
146 EXPECT_TRUE(CheckRelocation(0xc0de0018, 9976, relocations[4]));
147 EXPECT_TRUE(CheckRelocation(0xc0de0020, 9952, relocations[5]));
148 }
149
150 } // namespace relocation_packer
151