1 //===- llvm/unittest/MC/DwarfLineTables.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/ADT/STLExtras.h"
10 #include "llvm/ADT/StringExtras.h"
11 #include "llvm/BinaryFormat/Dwarf.h"
12 #include "llvm/MC/MCAsmInfo.h"
13 #include "llvm/MC/MCContext.h"
14 #include "llvm/MC/MCDwarf.h"
15 #include "llvm/MC/MCRegisterInfo.h"
16 #include "llvm/MC/MCTargetOptions.h"
17 #include "llvm/MC/TargetRegistry.h"
18 #include "llvm/Support/TargetSelect.h"
19 #include "gtest/gtest.h"
20
21 using namespace llvm;
22
23 namespace {
24 struct Context {
25 const char *TripleName = "x86_64-pc-linux";
26 std::unique_ptr<MCRegisterInfo> MRI;
27 std::unique_ptr<MCAsmInfo> MAI;
28 std::unique_ptr<MCContext> Ctx;
29
Context__anond3adc5b50111::Context30 Context() {
31 llvm::InitializeAllTargetInfos();
32 llvm::InitializeAllTargetMCs();
33 llvm::InitializeAllDisassemblers();
34
35 // If we didn't build x86, do not run the test.
36 std::string Error;
37 const Target *TheTarget = TargetRegistry::lookupTarget(TripleName, Error);
38 if (!TheTarget)
39 return;
40
41 MRI.reset(TheTarget->createMCRegInfo(TripleName));
42 MCTargetOptions MCOptions;
43 MAI.reset(TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
44 Ctx = std::make_unique<MCContext>(Triple(TripleName), MAI.get(), MRI.get(),
45 /*MSTI=*/nullptr);
46 }
47
operator bool__anond3adc5b50111::Context48 operator bool() { return Ctx.get(); }
operator MCContext&__anond3adc5b50111::Context49 operator MCContext &() { return *Ctx; };
50 };
51
getContext()52 Context &getContext() {
53 static Context Ctxt;
54 return Ctxt;
55 }
56 }
57
verifyEncoding(MCDwarfLineTableParams Params,int LineDelta,int AddrDelta,ArrayRef<uint8_t> ExpectedEncoding)58 void verifyEncoding(MCDwarfLineTableParams Params, int LineDelta, int AddrDelta,
59 ArrayRef<uint8_t> ExpectedEncoding) {
60 SmallString<16> Buffer;
61 MCDwarfLineAddr::encode(getContext(), Params, LineDelta, AddrDelta,
62 Buffer);
63 EXPECT_EQ(ExpectedEncoding, arrayRefFromStringRef(Buffer));
64 }
65
TEST(DwarfLineTables,TestDefaultParams)66 TEST(DwarfLineTables, TestDefaultParams) {
67 if (!getContext())
68 GTEST_SKIP();
69
70 MCDwarfLineTableParams Params;
71
72 // Minimal line offset expressible through extended opcode, 0 addr delta
73 const uint8_t Encoding0[] = {13}; // Special opcode Addr += 0, Line += -5
74 verifyEncoding(Params, -5, 0, Encoding0);
75
76 // Maximal line offset expressible through extended opcode,
77 const uint8_t Encoding1[] = {26}; // Special opcode Addr += 0, Line += +8
78 verifyEncoding(Params, 8, 0, Encoding1);
79
80 // Random value in the middle of the special ocode range
81 const uint8_t Encoding2[] = {146}; // Special opcode Addr += 9, Line += 2
82 verifyEncoding(Params, 2, 9, Encoding2);
83
84 // Minimal line offset expressible through extended opcode, max addr delta
85 const uint8_t Encoding3[] = {251}; // Special opcode Addr += 17, Line += -5
86 verifyEncoding(Params, -5, 17, Encoding3);
87
88 // Biggest special opcode
89 const uint8_t Encoding4[] = {255}; // Special opcode Addr += 17, Line += -1
90 verifyEncoding(Params, -1, 17, Encoding4);
91
92 // Line delta outside of the special opcode range, address delta in range
93 const uint8_t Encoding5[] = {dwarf::DW_LNS_advance_line, 9,
94 158}; // Special opcode Addr += 10, Line += 0
95 verifyEncoding(Params, 9, 10, Encoding5);
96
97 // Address delta outside of the special opcode range, but small
98 // enough to do DW_LNS_const_add_pc + special opcode.
99 const uint8_t Encoding6[] = {dwarf::DW_LNS_const_add_pc, // pc += 17
100 62}; // Special opcode Addr += 3, Line += 2
101 verifyEncoding(Params, 2, 20, Encoding6);
102
103 // Address delta big enough to require the use of DW_LNS_advance_pc
104 // Line delta in special opcode range
105 const uint8_t Encoding7[] = {dwarf::DW_LNS_advance_pc, 100,
106 20}; // Special opcode Addr += 0, Line += 2
107 verifyEncoding(Params, 2, 100, Encoding7);
108
109 // No special opcode possible.
110 const uint8_t Encoding8[] = {dwarf::DW_LNS_advance_line, 20,
111 dwarf::DW_LNS_advance_pc, 100,
112 dwarf::DW_LNS_copy};
113 verifyEncoding(Params, 20, 100, Encoding8);
114 }
115
TEST(DwarfLineTables,TestCustomParams)116 TEST(DwarfLineTables, TestCustomParams) {
117 if (!getContext())
118 GTEST_SKIP();
119
120 // Some tests against the example values given in the standard.
121 MCDwarfLineTableParams Params;
122 Params.DWARF2LineOpcodeBase = 13;
123 Params.DWARF2LineBase = -3;
124 Params.DWARF2LineRange = 12;
125
126 // Minimal line offset expressible through extended opcode, 0 addr delta
127 const uint8_t Encoding0[] = {13}; // Special opcode Addr += 0, Line += -5
128 verifyEncoding(Params, -3, 0, Encoding0);
129
130 // Maximal line offset expressible through extended opcode,
131 const uint8_t Encoding1[] = {24}; // Special opcode Addr += 0, Line += +8
132 verifyEncoding(Params, 8, 0, Encoding1);
133
134 // Random value in the middle of the special ocode range
135 const uint8_t Encoding2[] = {126}; // Special opcode Addr += 9, Line += 2
136 verifyEncoding(Params, 2, 9, Encoding2);
137
138 // Minimal line offset expressible through extended opcode, max addr delta
139 const uint8_t Encoding3[] = {253}; // Special opcode Addr += 20, Line += -3
140 verifyEncoding(Params, -3, 20, Encoding3);
141
142 // Biggest special opcode
143 const uint8_t Encoding4[] = {255}; // Special opcode Addr += 17, Line += -1
144 verifyEncoding(Params, -1, 20, Encoding4);
145
146 // Line delta outside of the special opcode range, address delta in range
147 const uint8_t Encoding5[] = {dwarf::DW_LNS_advance_line, 9,
148 136}; // Special opcode Addr += 10, Line += 0
149 verifyEncoding(Params, 9, 10, Encoding5);
150
151 // Address delta outside of the special opcode range, but small
152 // enough to do DW_LNS_const_add_pc + special opcode.
153 const uint8_t Encoding6[] = {dwarf::DW_LNS_const_add_pc, // pc += 20
154 138}; // Special opcode Addr += 10, Line += 2
155 verifyEncoding(Params, 2, 30, Encoding6);
156
157 // Address delta big enough to require the use of DW_LNS_advance_pc
158 // Line delta in special opcode range
159 const uint8_t Encoding7[] = {dwarf::DW_LNS_advance_pc, 100,
160 18}; // Special opcode Addr += 0, Line += 2
161 verifyEncoding(Params, 2, 100, Encoding7);
162
163 // No special opcode possible.
164 const uint8_t Encoding8[] = {dwarf::DW_LNS_advance_line, 20,
165 dwarf::DW_LNS_advance_pc, 100,
166 dwarf::DW_LNS_copy};
167 verifyEncoding(Params, 20, 100, Encoding8);
168 }
169
TEST(DwarfLineTables,TestCustomParams2)170 TEST(DwarfLineTables, TestCustomParams2) {
171 if (!getContext())
172 GTEST_SKIP();
173
174 // Corner case param values.
175 MCDwarfLineTableParams Params;
176 Params.DWARF2LineOpcodeBase = 13;
177 Params.DWARF2LineBase = 1;
178 Params.DWARF2LineRange = 255;
179
180 const uint8_t Encoding0[] = {dwarf::DW_LNS_advance_line, 248, 1,
181 dwarf::DW_LNS_copy};
182 verifyEncoding(Params, 248, 0, Encoding0);
183 }
184