1 //===-- DWARFExpressionTest.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 "lldb/Expression/DWARFExpression.h" 10 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h" 11 #include "TestingSupport/Symbol/YAMLModuleTester.h" 12 #include "lldb/Core/Value.h" 13 #include "lldb/Core/dwarf.h" 14 #include "lldb/Symbol/ObjectFile.h" 15 #include "lldb/Utility/StreamString.h" 16 #include "llvm/ADT/StringExtras.h" 17 #include "llvm/Testing/Support/Error.h" 18 #include "gtest/gtest.h" 19 20 using namespace lldb_private; 21 22 static llvm::Expected<Scalar> Evaluate(llvm::ArrayRef<uint8_t> expr, 23 lldb::ModuleSP module_sp = {}, 24 DWARFUnit *unit = nullptr) { 25 DataExtractor extractor(expr.data(), expr.size(), lldb::eByteOrderLittle, 26 /*addr_size*/ 4); 27 Value result; 28 Status status; 29 if (!DWARFExpression::Evaluate( 30 /*exe_ctx*/ nullptr, /*reg_ctx*/ nullptr, module_sp, extractor, unit, 31 lldb::eRegisterKindLLDB, 32 /*initial_value_ptr*/ nullptr, 33 /*object_address_ptr*/ nullptr, result, &status)) 34 return status.ToError(); 35 36 switch (result.GetValueType()) { 37 case Value::eValueTypeScalar: 38 return result.GetScalar(); 39 case Value::eValueTypeHostAddress: { 40 // Convert small buffers to scalars to simplify the tests. 41 DataBufferHeap &buf = result.GetBuffer(); 42 if (buf.GetByteSize() <= 8) { 43 uint64_t val = 0; 44 memcpy(&val, buf.GetBytes(), buf.GetByteSize()); 45 return Scalar(llvm::APInt(buf.GetByteSize()*8, val, false)); 46 } 47 } 48 LLVM_FALLTHROUGH; 49 default: 50 return status.ToError(); 51 } 52 } 53 54 class DWARFExpressionTester : public YAMLModuleTester { 55 public: 56 using YAMLModuleTester::YAMLModuleTester; 57 llvm::Expected<Scalar> Eval(llvm::ArrayRef<uint8_t> expr) { 58 return ::Evaluate(expr, m_module_sp, m_dwarf_unit.get()); 59 } 60 }; 61 62 /// Unfortunately Scalar's operator==() is really picky. 63 static Scalar GetScalar(unsigned bits, uint64_t value, bool sign) { 64 Scalar scalar(value); 65 scalar.TruncOrExtendTo(bits, sign); 66 return scalar; 67 } 68 69 TEST(DWARFExpression, DW_OP_pick) { 70 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_lit1, DW_OP_lit0, DW_OP_pick, 0}), 71 llvm::HasValue(0)); 72 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_lit1, DW_OP_lit0, DW_OP_pick, 1}), 73 llvm::HasValue(1)); 74 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_lit1, DW_OP_lit0, DW_OP_pick, 2}), 75 llvm::Failed()); 76 } 77 78 TEST(DWARFExpression, DW_OP_convert) { 79 /// Auxiliary debug info. 80 const char *yamldata = 81 "debug_abbrev:\n" 82 " - Table:\n" 83 " - Code: 0x00000001\n" 84 " Tag: DW_TAG_compile_unit\n" 85 " Children: DW_CHILDREN_yes\n" 86 " Attributes:\n" 87 " - Attribute: DW_AT_language\n" 88 " Form: DW_FORM_data2\n" 89 " - Code: 0x00000002\n" 90 " Tag: DW_TAG_base_type\n" 91 " Children: DW_CHILDREN_no\n" 92 " Attributes:\n" 93 " - Attribute: DW_AT_encoding\n" 94 " Form: DW_FORM_data1\n" 95 " - Attribute: DW_AT_byte_size\n" 96 " Form: DW_FORM_data1\n" 97 "debug_info:\n" 98 " - Version: 4\n" 99 " AddrSize: 8\n" 100 " Entries:\n" 101 " - AbbrCode: 0x00000001\n" 102 " Values:\n" 103 " - Value: 0x000000000000000C\n" 104 // 0x0000000e: 105 " - AbbrCode: 0x00000002\n" 106 " Values:\n" 107 " - Value: 0x0000000000000007\n" // DW_ATE_unsigned 108 " - Value: 0x0000000000000004\n" 109 // 0x00000011: 110 " - AbbrCode: 0x00000002\n" 111 " Values:\n" 112 " - Value: 0x0000000000000007\n" // DW_ATE_unsigned 113 " - Value: 0x0000000000000008\n" 114 // 0x00000014: 115 " - AbbrCode: 0x00000002\n" 116 " Values:\n" 117 " - Value: 0x0000000000000005\n" // DW_ATE_signed 118 " - Value: 0x0000000000000008\n" 119 // 0x00000017: 120 " - AbbrCode: 0x00000002\n" 121 " Values:\n" 122 " - Value: 0x0000000000000008\n" // DW_ATE_unsigned_char 123 " - Value: 0x0000000000000001\n" 124 // 0x0000001a: 125 " - AbbrCode: 0x00000002\n" 126 " Values:\n" 127 " - Value: 0x0000000000000006\n" // DW_ATE_signed_char 128 " - Value: 0x0000000000000001\n" 129 // 0x0000001d: 130 " - AbbrCode: 0x00000002\n" 131 " Values:\n" 132 " - Value: 0x000000000000000b\n" // DW_ATE_numeric_string 133 " - Value: 0x0000000000000001\n" 134 " - AbbrCode: 0x00000000\n"; 135 uint8_t offs_uint32_t = 0x0000000e; 136 uint8_t offs_uint64_t = 0x00000011; 137 uint8_t offs_sint64_t = 0x00000014; 138 uint8_t offs_uchar = 0x00000017; 139 uint8_t offs_schar = 0x0000001a; 140 141 DWARFExpressionTester t(yamldata, "i386-unknown-linux"); 142 ASSERT_TRUE((bool)t.GetDwarfUnit()); 143 144 // Constant is given as little-endian. 145 bool is_signed = true; 146 bool not_signed = false; 147 148 // 149 // Positive tests. 150 // 151 152 // Truncate to default unspecified (pointer-sized) type. 153 EXPECT_THAT_EXPECTED( 154 t.Eval({DW_OP_const8u, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, // 155 DW_OP_convert, 0x00}), 156 llvm::HasValue(GetScalar(32, 0x44332211, not_signed))); 157 // Truncate to 32 bits. 158 EXPECT_THAT_EXPECTED(t.Eval({DW_OP_const8u, // 159 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88,// 160 DW_OP_convert, offs_uint32_t}), 161 llvm::HasValue(GetScalar(32, 0x44332211, not_signed))); 162 163 // Leave as is. 164 EXPECT_THAT_EXPECTED( 165 t.Eval({DW_OP_const8u, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, // 166 DW_OP_convert, offs_uint64_t}), 167 llvm::HasValue(GetScalar(64, 0x8877665544332211, not_signed))); 168 169 // Sign-extend to 64 bits. 170 EXPECT_THAT_EXPECTED( 171 t.Eval({DW_OP_const4s, 0xcc, 0xdd, 0xee, 0xff, // 172 DW_OP_convert, offs_sint64_t}), 173 llvm::HasValue(GetScalar(64, 0xffffffffffeeddcc, is_signed))); 174 175 // Truncate to 8 bits. 176 EXPECT_THAT_EXPECTED( 177 t.Eval({DW_OP_const4s, 'A', 'B', 'C', 'D', DW_OP_convert, offs_uchar}), 178 llvm::HasValue(GetScalar(8, 'A', not_signed))); 179 180 // Also truncate to 8 bits. 181 EXPECT_THAT_EXPECTED( 182 t.Eval({DW_OP_const4s, 'A', 'B', 'C', 'D', DW_OP_convert, offs_schar}), 183 llvm::HasValue(GetScalar(8, 'A', is_signed))); 184 185 // 186 // Errors. 187 // 188 189 // No Module. 190 EXPECT_THAT_ERROR(Evaluate({DW_OP_const1s, 'X', DW_OP_convert, 0x00}, nullptr, 191 t.GetDwarfUnit().get()) 192 .takeError(), 193 llvm::Failed()); 194 195 // No DIE. 196 EXPECT_THAT_ERROR( 197 t.Eval({DW_OP_const1s, 'X', DW_OP_convert, 0x01}).takeError(), 198 llvm::Failed()); 199 200 // Unsupported. 201 EXPECT_THAT_ERROR( 202 t.Eval({DW_OP_const1s, 'X', DW_OP_convert, 0x1d}).takeError(), 203 llvm::Failed()); 204 } 205 206 TEST(DWARFExpression, DW_OP_stack_value) { 207 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_stack_value}), llvm::Failed()); 208 } 209 210 TEST(DWARFExpression, DW_OP_piece) { 211 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_const2u, 0x11, 0x22, DW_OP_piece, 2, 212 DW_OP_const2u, 0x33, 0x44, DW_OP_piece, 2}), 213 llvm::HasValue(GetScalar(32, 0x44332211, true))); 214 EXPECT_THAT_EXPECTED( 215 Evaluate({DW_OP_piece, 1, DW_OP_const1u, 0xff, DW_OP_piece, 1}), 216 // Note that the "00" should really be "undef", but we can't 217 // represent that yet. 218 llvm::HasValue(GetScalar(16, 0xff00, true))); 219 } 220 221 TEST(DWARFExpression, DW_OP_implicit_value) { 222 unsigned char bytes = 4; 223 224 EXPECT_THAT_EXPECTED( 225 Evaluate({DW_OP_implicit_value, bytes, 0x11, 0x22, 0x33, 0x44}), 226 llvm::HasValue(GetScalar(8 * bytes, 0x44332211, true))); 227 } 228 229 TEST(DWARFExpression, DW_OP_unknown) { 230 EXPECT_THAT_EXPECTED( 231 Evaluate({0xff}), 232 llvm::FailedWithMessage( 233 "Unhandled opcode DW_OP_unknown_ff in DWARFExpression")); 234 } 235