1 //===-- DumpRegisterValue.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/Core/DumpRegisterValue.h" 10 #include "lldb/Core/DumpDataExtractor.h" 11 #include "lldb/Core/ValueObject.h" 12 #include "lldb/Core/ValueObjectConstResult.h" 13 #include "lldb/DataFormatters/DumpValueObjectOptions.h" 14 #include "lldb/Target/RegisterFlags.h" 15 #include "lldb/Utility/DataExtractor.h" 16 #include "lldb/Utility/Endian.h" 17 #include "lldb/Utility/RegisterValue.h" 18 #include "lldb/Utility/StreamString.h" 19 #include "lldb/lldb-private-types.h" 20 #include "llvm/ADT/bit.h" 21 22 using namespace lldb; 23 24 template <typename T> 25 static void dump_type_value(lldb_private::CompilerType &fields_type, T value, 26 lldb_private::ExecutionContextScope *exe_scope, 27 const lldb_private::RegisterInfo ®_info, 28 lldb_private::Stream &strm) { 29 lldb::ByteOrder target_order = exe_scope->CalculateProcess()->GetByteOrder(); 30 31 // For the bitfield types we generate, it is expected that the fields are 32 // in what is usually a big endian order. Most significant field first. 33 // This is also clang's internal ordering and the order we want to print 34 // them. On a big endian host this all matches up, for a little endian 35 // host we have to swap the order of the fields before display. 36 if (target_order == lldb::ByteOrder::eByteOrderLittle) { 37 value = reg_info.flags_type->ReverseFieldOrder(value); 38 } 39 40 // Then we need to match the target's endian on a byte level as well. 41 if (lldb_private::endian::InlHostByteOrder() != target_order) 42 value = llvm::byteswap(value); 43 44 lldb_private::DataExtractor data_extractor{ 45 &value, sizeof(T), lldb_private::endian::InlHostByteOrder(), 8}; 46 47 lldb::ValueObjectSP vobj_sp = lldb_private::ValueObjectConstResult::Create( 48 exe_scope, fields_type, lldb_private::ConstString(), data_extractor); 49 lldb_private::DumpValueObjectOptions dump_options; 50 lldb_private::DumpValueObjectOptions::ChildPrintingDecider decider = 51 [](lldb_private::ConstString varname) { 52 // Unnamed bit-fields are padding that we don't want to show. 53 return varname.GetLength(); 54 }; 55 dump_options.SetChildPrintingDecider(decider).SetHideRootType(true); 56 57 if (llvm::Error error = vobj_sp->Dump(strm, dump_options)) 58 strm << "error: " << toString(std::move(error)); 59 } 60 61 void lldb_private::DumpRegisterValue(const RegisterValue ®_val, Stream &s, 62 const RegisterInfo ®_info, 63 bool prefix_with_name, 64 bool prefix_with_alt_name, Format format, 65 uint32_t reg_name_right_align_at, 66 ExecutionContextScope *exe_scope, 67 bool print_flags, TargetSP target_sp) { 68 DataExtractor data; 69 if (!reg_val.GetData(data)) 70 return; 71 72 bool name_printed = false; 73 // For simplicity, alignment of the register name printing applies only in 74 // the most common case where: 75 // 76 // prefix_with_name^prefix_with_alt_name is true 77 // 78 StreamString format_string; 79 if (reg_name_right_align_at && (prefix_with_name ^ prefix_with_alt_name)) 80 format_string.Printf("%%%us", reg_name_right_align_at); 81 else 82 format_string.Printf("%%s"); 83 std::string fmt = std::string(format_string.GetString()); 84 if (prefix_with_name) { 85 if (reg_info.name) { 86 s.Printf(fmt.c_str(), reg_info.name); 87 name_printed = true; 88 } else if (reg_info.alt_name) { 89 s.Printf(fmt.c_str(), reg_info.alt_name); 90 prefix_with_alt_name = false; 91 name_printed = true; 92 } 93 } 94 if (prefix_with_alt_name) { 95 if (name_printed) 96 s.PutChar('/'); 97 if (reg_info.alt_name) { 98 s.Printf(fmt.c_str(), reg_info.alt_name); 99 name_printed = true; 100 } else if (!name_printed) { 101 // No alternate name but we were asked to display a name, so show the 102 // main name 103 s.Printf(fmt.c_str(), reg_info.name); 104 name_printed = true; 105 } 106 } 107 if (name_printed) 108 s.PutCString(" = "); 109 110 if (format == eFormatDefault) 111 format = reg_info.format; 112 113 DumpDataExtractor(data, &s, 114 0, // Offset in "data" 115 format, // Format to use when dumping 116 reg_info.byte_size, // item_byte_size 117 1, // item_count 118 UINT32_MAX, // num_per_line 119 LLDB_INVALID_ADDRESS, // base_addr 120 0, // item_bit_size 121 0, // item_bit_offset 122 exe_scope); 123 124 if (!print_flags || !reg_info.flags_type || !exe_scope || !target_sp || 125 (reg_info.byte_size != 4 && reg_info.byte_size != 8)) 126 return; 127 128 CompilerType fields_type = target_sp->GetRegisterType( 129 reg_info.name, *reg_info.flags_type, reg_info.byte_size); 130 131 // Use a new stream so we can remove a trailing newline later. 132 StreamString fields_stream; 133 134 if (reg_info.byte_size == 4) { 135 dump_type_value(fields_type, reg_val.GetAsUInt32(), exe_scope, reg_info, 136 fields_stream); 137 } else { 138 dump_type_value(fields_type, reg_val.GetAsUInt64(), exe_scope, reg_info, 139 fields_stream); 140 } 141 142 // Registers are indented like: 143 // (lldb) register read foo 144 // foo = 0x12345678 145 // So we need to indent to match that. 146 147 // First drop the extra newline that the value printer added. The register 148 // command will add one itself. 149 llvm::StringRef fields_str = fields_stream.GetString().drop_back(); 150 151 // End the line that contains " foo = 0x12345678". 152 s.EOL(); 153 154 // Then split the value lines and indent each one. 155 bool first = true; 156 while (fields_str.size()) { 157 std::pair<llvm::StringRef, llvm::StringRef> split = fields_str.split('\n'); 158 fields_str = split.second; 159 // Indent as far as the register name did. 160 s.Printf(fmt.c_str(), ""); 161 162 // Lines after the first won't have " = " so compensate for that. 163 if (!first) 164 s << " "; 165 first = false; 166 167 s << split.first; 168 169 // On the last line we don't want a newline because the command will add 170 // one too. 171 if (fields_str.size()) 172 s.EOL(); 173 } 174 } 175