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); 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 = R"( 81 --- !ELF 82 FileHeader: 83 Class: ELFCLASS64 84 Data: ELFDATA2LSB 85 Type: ET_EXEC 86 Machine: EM_386 87 DWARF: 88 debug_abbrev: 89 - Table: 90 - Code: 0x00000001 91 Tag: DW_TAG_compile_unit 92 Children: DW_CHILDREN_yes 93 Attributes: 94 - Attribute: DW_AT_language 95 Form: DW_FORM_data2 96 - Code: 0x00000002 97 Tag: DW_TAG_base_type 98 Children: DW_CHILDREN_no 99 Attributes: 100 - Attribute: DW_AT_encoding 101 Form: DW_FORM_data1 102 - Attribute: DW_AT_byte_size 103 Form: DW_FORM_data1 104 debug_info: 105 - Version: 4 106 AddrSize: 8 107 Entries: 108 - AbbrCode: 0x00000001 109 Values: 110 - Value: 0x000000000000000C 111 # 0x0000000e: 112 - AbbrCode: 0x00000002 113 Values: 114 - Value: 0x0000000000000007 # DW_ATE_unsigned 115 - Value: 0x0000000000000004 116 # 0x00000011: 117 - AbbrCode: 0x00000002 118 Values: 119 - Value: 0x0000000000000007 # DW_ATE_unsigned 120 - Value: 0x0000000000000008 121 # 0x00000014: 122 - AbbrCode: 0x00000002 123 Values: 124 - Value: 0x0000000000000005 # DW_ATE_signed 125 - Value: 0x0000000000000008 126 # 0x00000017: 127 - AbbrCode: 0x00000002 128 Values: 129 - Value: 0x0000000000000008 # DW_ATE_unsigned_char 130 - Value: 0x0000000000000001 131 # 0x0000001a: 132 - AbbrCode: 0x00000002 133 Values: 134 - Value: 0x0000000000000006 # DW_ATE_signed_char 135 - Value: 0x0000000000000001 136 # 0x0000001d: 137 - AbbrCode: 0x00000002 138 Values: 139 - Value: 0x000000000000000b # DW_ATE_numeric_string 140 - Value: 0x0000000000000001 141 - AbbrCode: 0x00000000 142 )"; 143 uint8_t offs_uint32_t = 0x0000000e; 144 uint8_t offs_uint64_t = 0x00000011; 145 uint8_t offs_sint64_t = 0x00000014; 146 uint8_t offs_uchar = 0x00000017; 147 uint8_t offs_schar = 0x0000001a; 148 149 DWARFExpressionTester t(yamldata); 150 ASSERT_TRUE((bool)t.GetDwarfUnit()); 151 152 // Constant is given as little-endian. 153 bool is_signed = true; 154 bool not_signed = false; 155 156 // 157 // Positive tests. 158 // 159 160 // Truncate to default unspecified (pointer-sized) type. 161 EXPECT_THAT_EXPECTED( 162 t.Eval({DW_OP_const8u, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, // 163 DW_OP_convert, 0x00}), 164 llvm::HasValue(GetScalar(32, 0x44332211, not_signed))); 165 // Truncate to 32 bits. 166 EXPECT_THAT_EXPECTED(t.Eval({DW_OP_const8u, // 167 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88,// 168 DW_OP_convert, offs_uint32_t}), 169 llvm::HasValue(GetScalar(32, 0x44332211, not_signed))); 170 171 // Leave as is. 172 EXPECT_THAT_EXPECTED( 173 t.Eval({DW_OP_const8u, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, // 174 DW_OP_convert, offs_uint64_t}), 175 llvm::HasValue(GetScalar(64, 0x8877665544332211, not_signed))); 176 177 // Sign-extend to 64 bits. 178 EXPECT_THAT_EXPECTED( 179 t.Eval({DW_OP_const4s, 0xcc, 0xdd, 0xee, 0xff, // 180 DW_OP_convert, offs_sint64_t}), 181 llvm::HasValue(GetScalar(64, 0xffffffffffeeddcc, is_signed))); 182 183 // Truncate to 8 bits. 184 EXPECT_THAT_EXPECTED( 185 t.Eval({DW_OP_const4s, 'A', 'B', 'C', 'D', DW_OP_convert, offs_uchar}), 186 llvm::HasValue(GetScalar(8, 'A', not_signed))); 187 188 // Also truncate to 8 bits. 189 EXPECT_THAT_EXPECTED( 190 t.Eval({DW_OP_const4s, 'A', 'B', 'C', 'D', DW_OP_convert, offs_schar}), 191 llvm::HasValue(GetScalar(8, 'A', is_signed))); 192 193 // 194 // Errors. 195 // 196 197 // No Module. 198 EXPECT_THAT_ERROR(Evaluate({DW_OP_const1s, 'X', DW_OP_convert, 0x00}, nullptr, 199 t.GetDwarfUnit()) 200 .takeError(), 201 llvm::Failed()); 202 203 // No DIE. 204 EXPECT_THAT_ERROR( 205 t.Eval({DW_OP_const1s, 'X', DW_OP_convert, 0x01}).takeError(), 206 llvm::Failed()); 207 208 // Unsupported. 209 EXPECT_THAT_ERROR( 210 t.Eval({DW_OP_const1s, 'X', DW_OP_convert, 0x1d}).takeError(), 211 llvm::Failed()); 212 } 213 214 TEST(DWARFExpression, DW_OP_stack_value) { 215 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_stack_value}), llvm::Failed()); 216 } 217 218 TEST(DWARFExpression, DW_OP_piece) { 219 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_const2u, 0x11, 0x22, DW_OP_piece, 2, 220 DW_OP_const2u, 0x33, 0x44, DW_OP_piece, 2}), 221 llvm::HasValue(GetScalar(32, 0x44332211, true))); 222 EXPECT_THAT_EXPECTED( 223 Evaluate({DW_OP_piece, 1, DW_OP_const1u, 0xff, DW_OP_piece, 1}), 224 // Note that the "00" should really be "undef", but we can't 225 // represent that yet. 226 llvm::HasValue(GetScalar(16, 0xff00, true))); 227 } 228 229 TEST(DWARFExpression, DW_OP_implicit_value) { 230 unsigned char bytes = 4; 231 232 EXPECT_THAT_EXPECTED( 233 Evaluate({DW_OP_implicit_value, bytes, 0x11, 0x22, 0x33, 0x44}), 234 llvm::HasValue(GetScalar(8 * bytes, 0x44332211, true))); 235 } 236 237 TEST(DWARFExpression, DW_OP_unknown) { 238 EXPECT_THAT_EXPECTED( 239 Evaluate({0xff}), 240 llvm::FailedWithMessage( 241 "Unhandled opcode DW_OP_unknown_ff in DWARFExpression")); 242 } 243