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/BinaryFormat/Dwarf.h" 11 #include "llvm/MC/MCAsmInfo.h" 12 #include "llvm/MC/MCContext.h" 13 #include "llvm/MC/MCDwarf.h" 14 #include "llvm/MC/MCRegisterInfo.h" 15 #include "llvm/MC/MCTargetOptions.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 *TripleName = "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(TripleName, Error); 37 if (!TheTarget) 38 return; 39 40 MRI.reset(TheTarget->createMCRegInfo(TripleName)); 41 MCTargetOptions MCOptions; 42 MAI.reset(TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions)); 43 Ctx = std::make_unique<MCContext>(Triple(TripleName), MAI.get(), MRI.get(), 44 /*MSTI=*/nullptr); 45 } 46 47 operator bool() { return Ctx.get(); } 48 operator MCContext &() { return *Ctx; }; 49 }; 50 51 Context &getContext() { 52 static Context Ctxt; 53 return Ctxt; 54 } 55 } 56 57 void verifyEncoding(MCDwarfLineTableParams Params, int LineDelta, int AddrDelta, 58 ArrayRef<uint8_t> ExpectedEncoding) { 59 SmallString<16> Buffer; 60 raw_svector_ostream EncodingOS(Buffer); 61 MCDwarfLineAddr::Encode(getContext(), Params, LineDelta, AddrDelta, 62 EncodingOS); 63 EXPECT_EQ(ExpectedEncoding, arrayRefFromStringRef(Buffer)); 64 } 65 66 TEST(DwarfLineTables, TestDefaultParams) { 67 if (!getContext()) 68 return; 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 } 115 116 TEST(DwarfLineTables, TestCustomParams) { 117 if (!getContext()) 118 return; 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 } 169 170 TEST(DwarfLineTables, TestCustomParams2) { 171 if (!getContext()) 172 return; 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