1 //===- llvm/unittest/MC/DwarfLineTables.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 "llvm/Support/Dwarf.h"
11 #include "llvm/ADT/STLExtras.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/Support/TargetRegistry.h"
17 #include "llvm/Support/TargetSelect.h"
18 #include "gtest/gtest.h"
19
20 using namespace llvm;
21
22 namespace {
23 struct Context {
24 const char *Triple = "x86_64-pc-linux";
25 std::unique_ptr<MCRegisterInfo> MRI;
26 std::unique_ptr<MCAsmInfo> MAI;
27 std::unique_ptr<MCContext> Ctx;
28
Context__anon396d93a30111::Context29 Context() {
30 llvm::InitializeAllTargetInfos();
31 llvm::InitializeAllTargetMCs();
32 llvm::InitializeAllDisassemblers();
33
34 // If we didn't build x86, do not run the test.
35 std::string Error;
36 const Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
37 if (!TheTarget)
38 return;
39
40 MRI.reset(TheTarget->createMCRegInfo(Triple));
41 MAI.reset(TheTarget->createMCAsmInfo(*MRI, Triple));
42 Ctx = llvm::make_unique<MCContext>(MAI.get(), MRI.get(), nullptr);
43 }
44
operator bool__anon396d93a30111::Context45 operator bool() { return Ctx.get(); }
operator MCContext&__anon396d93a30111::Context46 operator MCContext &() { return *Ctx; };
47 };
48
49 Context Ctxt;
50 }
51
verifyEncoding(MCDwarfLineTableParams Params,int LineDelta,int AddrDelta,ArrayRef<uint8_t> ExpectedEncoding)52 void verifyEncoding(MCDwarfLineTableParams Params, int LineDelta, int AddrDelta,
53 ArrayRef<uint8_t> ExpectedEncoding) {
54 SmallString<16> Buffer;
55 raw_svector_ostream EncodingOS(Buffer);
56 MCDwarfLineAddr::Encode(Ctxt, Params, LineDelta, AddrDelta, EncodingOS);
57 ArrayRef<uint8_t> Encoding(reinterpret_cast<uint8_t *>(Buffer.data()),
58 Buffer.size());
59 EXPECT_EQ(ExpectedEncoding, Encoding);
60 }
61
TEST(DwarfLineTables,TestDefaultParams)62 TEST(DwarfLineTables, TestDefaultParams) {
63 if (!Ctxt)
64 return;
65
66 MCDwarfLineTableParams Params;
67
68 // Minimal line offset expressible through extended opcode, 0 addr delta
69 const uint8_t Encoding0[] = {13}; // Special opcode Addr += 0, Line += -5
70 verifyEncoding(Params, -5, 0, Encoding0);
71
72 // Maximal line offset expressible through extended opcode,
73 const uint8_t Encoding1[] = {26}; // Special opcode Addr += 0, Line += +8
74 verifyEncoding(Params, 8, 0, Encoding1);
75
76 // Random value in the middle of the special ocode range
77 const uint8_t Encoding2[] = {146}; // Special opcode Addr += 9, Line += 2
78 verifyEncoding(Params, 2, 9, Encoding2);
79
80 // Minimal line offset expressible through extended opcode, max addr delta
81 const uint8_t Encoding3[] = {251}; // Special opcode Addr += 17, Line += -5
82 verifyEncoding(Params, -5, 17, Encoding3);
83
84 // Biggest special opcode
85 const uint8_t Encoding4[] = {255}; // Special opcode Addr += 17, Line += -1
86 verifyEncoding(Params, -1, 17, Encoding4);
87
88 // Line delta outside of the special opcode range, address delta in range
89 const uint8_t Encoding5[] = {dwarf::DW_LNS_advance_line, 9,
90 158}; // Special opcode Addr += 10, Line += 0
91 verifyEncoding(Params, 9, 10, Encoding5);
92
93 // Address delta outside of the special opcode range, but small
94 // enough to do DW_LNS_const_add_pc + special opcode.
95 const uint8_t Encoding6[] = {dwarf::DW_LNS_const_add_pc, // pc += 17
96 62}; // Special opcode Addr += 3, Line += 2
97 verifyEncoding(Params, 2, 20, Encoding6);
98
99 // Address delta big enough to require the use of DW_LNS_advance_pc
100 // Line delta in special opcode range
101 const uint8_t Encoding7[] = {dwarf::DW_LNS_advance_pc, 100,
102 20}; // Special opcode Addr += 0, Line += 2
103 verifyEncoding(Params, 2, 100, Encoding7);
104
105 // No special opcode possible.
106 const uint8_t Encoding8[] = {dwarf::DW_LNS_advance_line, 20,
107 dwarf::DW_LNS_advance_pc, 100,
108 dwarf::DW_LNS_copy};
109 verifyEncoding(Params, 20, 100, Encoding8);
110 }
111
TEST(DwarfLineTables,TestCustomParams)112 TEST(DwarfLineTables, TestCustomParams) {
113 if (!Ctxt)
114 return;
115
116 // Some tests against the example values given in the standard.
117 MCDwarfLineTableParams Params;
118 Params.DWARF2LineOpcodeBase = 13;
119 Params.DWARF2LineBase = -3;
120 Params.DWARF2LineRange = 12;
121
122 // Minimal line offset expressible through extended opcode, 0 addr delta
123 const uint8_t Encoding0[] = {13}; // Special opcode Addr += 0, Line += -5
124 verifyEncoding(Params, -3, 0, Encoding0);
125
126 // Maximal line offset expressible through extended opcode,
127 const uint8_t Encoding1[] = {24}; // Special opcode Addr += 0, Line += +8
128 verifyEncoding(Params, 8, 0, Encoding1);
129
130 // Random value in the middle of the special ocode range
131 const uint8_t Encoding2[] = {126}; // Special opcode Addr += 9, Line += 2
132 verifyEncoding(Params, 2, 9, Encoding2);
133
134 // Minimal line offset expressible through extended opcode, max addr delta
135 const uint8_t Encoding3[] = {253}; // Special opcode Addr += 20, Line += -3
136 verifyEncoding(Params, -3, 20, Encoding3);
137
138 // Biggest special opcode
139 const uint8_t Encoding4[] = {255}; // Special opcode Addr += 17, Line += -1
140 verifyEncoding(Params, -1, 20, Encoding4);
141
142 // Line delta outside of the special opcode range, address delta in range
143 const uint8_t Encoding5[] = {dwarf::DW_LNS_advance_line, 9,
144 136}; // Special opcode Addr += 10, Line += 0
145 verifyEncoding(Params, 9, 10, Encoding5);
146
147 // Address delta outside of the special opcode range, but small
148 // enough to do DW_LNS_const_add_pc + special opcode.
149 const uint8_t Encoding6[] = {dwarf::DW_LNS_const_add_pc, // pc += 20
150 138}; // Special opcode Addr += 10, Line += 2
151 verifyEncoding(Params, 2, 30, Encoding6);
152
153 // Address delta big enough to require the use of DW_LNS_advance_pc
154 // Line delta in special opcode range
155 const uint8_t Encoding7[] = {dwarf::DW_LNS_advance_pc, 100,
156 18}; // Special opcode Addr += 0, Line += 2
157 verifyEncoding(Params, 2, 100, Encoding7);
158
159 // No special opcode possible.
160 const uint8_t Encoding8[] = {dwarf::DW_LNS_advance_line, 20,
161 dwarf::DW_LNS_advance_pc, 100,
162 dwarf::DW_LNS_copy};
163 verifyEncoding(Params, 20, 100, Encoding8);
164 }
165
TEST(DwarfLineTables,TestCustomParams2)166 TEST(DwarfLineTables, TestCustomParams2) {
167 if (!Ctxt)
168 return;
169
170 // Corner case param values.
171 MCDwarfLineTableParams Params;
172 Params.DWARF2LineOpcodeBase = 13;
173 Params.DWARF2LineBase = 1;
174 Params.DWARF2LineRange = 255;
175
176 const uint8_t Encoding0[] = {dwarf::DW_LNS_advance_line, 248, 1,
177 dwarf::DW_LNS_copy};
178 verifyEncoding(Params, 248, 0, Encoding0);
179 }
180