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
20using namespace llvm;
21
22namespace {
23struct 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
29  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
45  operator bool() { return Ctx.get(); }
46  operator MCContext &() { return *Ctx; };
47};
48
49Context Ctxt;
50}
51
52void 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
62TEST(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
112TEST(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
166TEST(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