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/Support/TargetRegistry.h" 16 #include "llvm/Support/TargetSelect.h" 17 #include "gtest/gtest.h" 18 19 using namespace llvm; 20 21 namespace { 22 struct Context { 23 const char *Triple = "x86_64-pc-linux"; 24 std::unique_ptr<MCRegisterInfo> MRI; 25 std::unique_ptr<MCAsmInfo> MAI; 26 std::unique_ptr<MCContext> Ctx; 27 28 Context() { 29 llvm::InitializeAllTargetInfos(); 30 llvm::InitializeAllTargetMCs(); 31 llvm::InitializeAllDisassemblers(); 32 33 // If we didn't build x86, do not run the test. 34 std::string Error; 35 const Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error); 36 if (!TheTarget) 37 return; 38 39 MRI.reset(TheTarget->createMCRegInfo(Triple)); 40 MAI.reset(TheTarget->createMCAsmInfo(*MRI, Triple)); 41 Ctx = llvm::make_unique<MCContext>(MAI.get(), MRI.get(), nullptr); 42 } 43 44 operator bool() { return Ctx.get(); } 45 operator MCContext &() { return *Ctx; }; 46 }; 47 48 Context &getContext() { 49 static Context Ctxt; 50 return Ctxt; 51 } 52 } 53 54 void verifyEncoding(MCDwarfLineTableParams Params, int LineDelta, int AddrDelta, 55 ArrayRef<uint8_t> ExpectedEncoding) { 56 SmallString<16> Buffer; 57 raw_svector_ostream EncodingOS(Buffer); 58 MCDwarfLineAddr::Encode(getContext(), Params, LineDelta, AddrDelta, 59 EncodingOS); 60 EXPECT_EQ(ExpectedEncoding, arrayRefFromStringRef(Buffer)); 61 } 62 63 TEST(DwarfLineTables, TestDefaultParams) { 64 if (!getContext()) 65 return; 66 67 MCDwarfLineTableParams Params; 68 69 // Minimal line offset expressible through extended opcode, 0 addr delta 70 const uint8_t Encoding0[] = {13}; // Special opcode Addr += 0, Line += -5 71 verifyEncoding(Params, -5, 0, Encoding0); 72 73 // Maximal line offset expressible through extended opcode, 74 const uint8_t Encoding1[] = {26}; // Special opcode Addr += 0, Line += +8 75 verifyEncoding(Params, 8, 0, Encoding1); 76 77 // Random value in the middle of the special ocode range 78 const uint8_t Encoding2[] = {146}; // Special opcode Addr += 9, Line += 2 79 verifyEncoding(Params, 2, 9, Encoding2); 80 81 // Minimal line offset expressible through extended opcode, max addr delta 82 const uint8_t Encoding3[] = {251}; // Special opcode Addr += 17, Line += -5 83 verifyEncoding(Params, -5, 17, Encoding3); 84 85 // Biggest special opcode 86 const uint8_t Encoding4[] = {255}; // Special opcode Addr += 17, Line += -1 87 verifyEncoding(Params, -1, 17, Encoding4); 88 89 // Line delta outside of the special opcode range, address delta in range 90 const uint8_t Encoding5[] = {dwarf::DW_LNS_advance_line, 9, 91 158}; // Special opcode Addr += 10, Line += 0 92 verifyEncoding(Params, 9, 10, Encoding5); 93 94 // Address delta outside of the special opcode range, but small 95 // enough to do DW_LNS_const_add_pc + special opcode. 96 const uint8_t Encoding6[] = {dwarf::DW_LNS_const_add_pc, // pc += 17 97 62}; // Special opcode Addr += 3, Line += 2 98 verifyEncoding(Params, 2, 20, Encoding6); 99 100 // Address delta big enough to require the use of DW_LNS_advance_pc 101 // Line delta in special opcode range 102 const uint8_t Encoding7[] = {dwarf::DW_LNS_advance_pc, 100, 103 20}; // Special opcode Addr += 0, Line += 2 104 verifyEncoding(Params, 2, 100, Encoding7); 105 106 // No special opcode possible. 107 const uint8_t Encoding8[] = {dwarf::DW_LNS_advance_line, 20, 108 dwarf::DW_LNS_advance_pc, 100, 109 dwarf::DW_LNS_copy}; 110 verifyEncoding(Params, 20, 100, Encoding8); 111 } 112 113 TEST(DwarfLineTables, TestCustomParams) { 114 if (!getContext()) 115 return; 116 117 // Some tests against the example values given in the standard. 118 MCDwarfLineTableParams Params; 119 Params.DWARF2LineOpcodeBase = 13; 120 Params.DWARF2LineBase = -3; 121 Params.DWARF2LineRange = 12; 122 123 // Minimal line offset expressible through extended opcode, 0 addr delta 124 const uint8_t Encoding0[] = {13}; // Special opcode Addr += 0, Line += -5 125 verifyEncoding(Params, -3, 0, Encoding0); 126 127 // Maximal line offset expressible through extended opcode, 128 const uint8_t Encoding1[] = {24}; // Special opcode Addr += 0, Line += +8 129 verifyEncoding(Params, 8, 0, Encoding1); 130 131 // Random value in the middle of the special ocode range 132 const uint8_t Encoding2[] = {126}; // Special opcode Addr += 9, Line += 2 133 verifyEncoding(Params, 2, 9, Encoding2); 134 135 // Minimal line offset expressible through extended opcode, max addr delta 136 const uint8_t Encoding3[] = {253}; // Special opcode Addr += 20, Line += -3 137 verifyEncoding(Params, -3, 20, Encoding3); 138 139 // Biggest special opcode 140 const uint8_t Encoding4[] = {255}; // Special opcode Addr += 17, Line += -1 141 verifyEncoding(Params, -1, 20, Encoding4); 142 143 // Line delta outside of the special opcode range, address delta in range 144 const uint8_t Encoding5[] = {dwarf::DW_LNS_advance_line, 9, 145 136}; // Special opcode Addr += 10, Line += 0 146 verifyEncoding(Params, 9, 10, Encoding5); 147 148 // Address delta outside of the special opcode range, but small 149 // enough to do DW_LNS_const_add_pc + special opcode. 150 const uint8_t Encoding6[] = {dwarf::DW_LNS_const_add_pc, // pc += 20 151 138}; // Special opcode Addr += 10, Line += 2 152 verifyEncoding(Params, 2, 30, Encoding6); 153 154 // Address delta big enough to require the use of DW_LNS_advance_pc 155 // Line delta in special opcode range 156 const uint8_t Encoding7[] = {dwarf::DW_LNS_advance_pc, 100, 157 18}; // Special opcode Addr += 0, Line += 2 158 verifyEncoding(Params, 2, 100, Encoding7); 159 160 // No special opcode possible. 161 const uint8_t Encoding8[] = {dwarf::DW_LNS_advance_line, 20, 162 dwarf::DW_LNS_advance_pc, 100, 163 dwarf::DW_LNS_copy}; 164 verifyEncoding(Params, 20, 100, Encoding8); 165 } 166 167 TEST(DwarfLineTables, TestCustomParams2) { 168 if (!getContext()) 169 return; 170 171 // Corner case param values. 172 MCDwarfLineTableParams Params; 173 Params.DWARF2LineOpcodeBase = 13; 174 Params.DWARF2LineBase = 1; 175 Params.DWARF2LineRange = 255; 176 177 const uint8_t Encoding0[] = {dwarf::DW_LNS_advance_line, 248, 1, 178 dwarf::DW_LNS_copy}; 179 verifyEncoding(Params, 248, 0, Encoding0); 180 } 181