1 //===-- Status.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/Utility/Status.h" 10 11 #include "lldb/Utility/VASPrintf.h" 12 #include "lldb/lldb-defines.h" 13 #include "lldb/lldb-enumerations.h" 14 #include "llvm/ADT/SmallString.h" 15 #include "llvm/ADT/StringRef.h" 16 #include "llvm/Support/Errno.h" 17 #include "llvm/Support/FormatProviders.h" 18 19 #include <cerrno> 20 #include <cstdarg> 21 #include <string> 22 #include <system_error> 23 24 #ifdef __APPLE__ 25 #include <mach/mach.h> 26 #endif 27 28 #ifdef _WIN32 29 #include <windows.h> 30 #endif 31 #include <cstdint> 32 33 namespace llvm { 34 class raw_ostream; 35 } 36 37 using namespace lldb; 38 using namespace lldb_private; 39 40 Status::Status() : m_string() {} 41 42 Status::Status(ValueType err, ErrorType type) 43 : m_code(err), m_type(type), m_string() {} 44 45 // This logic is confusing because c++ calls the traditional (posix) errno codes 46 // "generic errors", while we use the term "generic" to mean completely 47 // arbitrary (text-based) errors. 48 Status::Status(std::error_code EC) 49 : m_code(EC.value()), 50 m_type(EC.category() == std::generic_category() ? eErrorTypePOSIX 51 : eErrorTypeGeneric), 52 m_string(EC.message()) {} 53 54 Status::Status(const char *format, ...) : m_string() { 55 va_list args; 56 va_start(args, format); 57 SetErrorToGenericError(); 58 SetErrorStringWithVarArg(format, args); 59 va_end(args); 60 } 61 62 const Status &Status::operator=(llvm::Error error) { 63 if (!error) { 64 Clear(); 65 return *this; 66 } 67 68 // if the error happens to be a errno error, preserve the error code 69 error = llvm::handleErrors( 70 std::move(error), [&](std::unique_ptr<llvm::ECError> e) -> llvm::Error { 71 std::error_code ec = e->convertToErrorCode(); 72 if (ec.category() == std::generic_category()) { 73 m_code = ec.value(); 74 m_type = ErrorType::eErrorTypePOSIX; 75 return llvm::Error::success(); 76 } 77 return llvm::Error(std::move(e)); 78 }); 79 80 // Otherwise, just preserve the message 81 if (error) { 82 SetErrorToGenericError(); 83 SetErrorString(llvm::toString(std::move(error))); 84 } 85 86 return *this; 87 } 88 89 llvm::Error Status::ToError() const { 90 if (Success()) 91 return llvm::Error::success(); 92 if (m_type == ErrorType::eErrorTypePOSIX) 93 return llvm::errorCodeToError( 94 std::error_code(m_code, std::generic_category())); 95 return llvm::make_error<llvm::StringError>(AsCString(), 96 llvm::inconvertibleErrorCode()); 97 } 98 99 Status::~Status() = default; 100 101 #ifdef _WIN32 102 static std::string RetrieveWin32ErrorString(uint32_t error_code) { 103 char *buffer = nullptr; 104 std::string message; 105 // Retrieve win32 system error. 106 // First, attempt to load a en-US message 107 if (::FormatMessageA( 108 FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | 109 FORMAT_MESSAGE_MAX_WIDTH_MASK, 110 NULL, error_code, MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US), 111 (LPSTR)&buffer, 0, NULL)) { 112 message.assign(buffer); 113 ::LocalFree(buffer); 114 } 115 // If the previous didn't work, use the default OS language 116 else if (::FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | 117 FORMAT_MESSAGE_FROM_SYSTEM | 118 FORMAT_MESSAGE_MAX_WIDTH_MASK, 119 NULL, error_code, 0, (LPSTR)&buffer, 0, NULL)) { 120 message.assign(buffer); 121 ::LocalFree(buffer); 122 } 123 return message; 124 } 125 #endif 126 127 // Get the error value as a NULL C string. The error string will be fetched and 128 // cached on demand. The cached error string value will remain until the error 129 // value is changed or cleared. 130 const char *Status::AsCString(const char *default_error_str) const { 131 if (Success()) 132 return nullptr; 133 134 if (m_string.empty()) { 135 switch (m_type) { 136 case eErrorTypeMachKernel: 137 #if defined(__APPLE__) 138 if (const char *s = ::mach_error_string(m_code)) 139 m_string.assign(s); 140 #endif 141 break; 142 143 case eErrorTypePOSIX: 144 m_string = llvm::sys::StrError(m_code); 145 break; 146 147 case eErrorTypeWin32: 148 #if defined(_WIN32) 149 m_string = RetrieveWin32ErrorString(m_code); 150 #endif 151 break; 152 153 default: 154 break; 155 } 156 } 157 if (m_string.empty()) { 158 if (default_error_str) 159 m_string.assign(default_error_str); 160 else 161 return nullptr; // User wanted a nullptr string back... 162 } 163 return m_string.c_str(); 164 } 165 166 // Clear the error and any cached error string that it might contain. 167 void Status::Clear() { 168 m_code = 0; 169 m_type = eErrorTypeInvalid; 170 m_string.clear(); 171 } 172 173 // Access the error value. 174 Status::ValueType Status::GetError() const { return m_code; } 175 176 // Access the error type. 177 ErrorType Status::GetType() const { return m_type; } 178 179 // Returns true if this object contains a value that describes an error or 180 // otherwise non-success result. 181 bool Status::Fail() const { return m_code != 0; } 182 183 // Set accessor for the error value to "err" and the type to 184 // "eErrorTypeMachKernel" 185 void Status::SetMachError(uint32_t err) { 186 m_code = err; 187 m_type = eErrorTypeMachKernel; 188 m_string.clear(); 189 } 190 191 void Status::SetExpressionError(lldb::ExpressionResults result, 192 const char *mssg) { 193 m_code = result; 194 m_type = eErrorTypeExpression; 195 m_string = mssg; 196 } 197 198 int Status::SetExpressionErrorWithFormat(lldb::ExpressionResults result, 199 const char *format, ...) { 200 int length = 0; 201 202 if (format != nullptr && format[0]) { 203 va_list args; 204 va_start(args, format); 205 length = SetErrorStringWithVarArg(format, args); 206 va_end(args); 207 } else { 208 m_string.clear(); 209 } 210 m_code = result; 211 m_type = eErrorTypeExpression; 212 return length; 213 } 214 215 // Set accessor for the error value and type. 216 void Status::SetError(ValueType err, ErrorType type) { 217 m_code = err; 218 m_type = type; 219 m_string.clear(); 220 } 221 222 // Update the error value to be "errno" and update the type to be "POSIX". 223 void Status::SetErrorToErrno() { 224 m_code = errno; 225 m_type = eErrorTypePOSIX; 226 m_string.clear(); 227 } 228 229 // Update the error value to be LLDB_GENERIC_ERROR and update the type to be 230 // "Generic". 231 void Status::SetErrorToGenericError() { 232 m_code = LLDB_GENERIC_ERROR; 233 m_type = eErrorTypeGeneric; 234 m_string.clear(); 235 } 236 237 // Set accessor for the error string value for a specific error. This allows 238 // any string to be supplied as an error explanation. The error string value 239 // will remain until the error value is cleared or a new error value/type is 240 // assigned. 241 void Status::SetErrorString(llvm::StringRef err_str) { 242 if (!err_str.empty()) { 243 // If we have an error string, we should always at least have an error set 244 // to a generic value. 245 if (Success()) 246 SetErrorToGenericError(); 247 } 248 m_string = std::string(err_str); 249 } 250 251 /// Set the current error string to a formatted error string. 252 /// 253 /// \param format 254 /// A printf style format string 255 int Status::SetErrorStringWithFormat(const char *format, ...) { 256 if (format != nullptr && format[0]) { 257 va_list args; 258 va_start(args, format); 259 int length = SetErrorStringWithVarArg(format, args); 260 va_end(args); 261 return length; 262 } else { 263 m_string.clear(); 264 } 265 return 0; 266 } 267 268 int Status::SetErrorStringWithVarArg(const char *format, va_list args) { 269 if (format != nullptr && format[0]) { 270 // If we have an error string, we should always at least have an error set 271 // to a generic value. 272 if (Success()) 273 SetErrorToGenericError(); 274 275 llvm::SmallString<1024> buf; 276 VASprintf(buf, format, args); 277 m_string = std::string(buf.str()); 278 return buf.size(); 279 } else { 280 m_string.clear(); 281 } 282 return 0; 283 } 284 285 // Returns true if the error code in this object is considered a successful 286 // return value. 287 bool Status::Success() const { return m_code == 0; } 288 289 void llvm::format_provider<lldb_private::Status>::format( 290 const lldb_private::Status &error, llvm::raw_ostream &OS, 291 llvm::StringRef Options) { 292 llvm::format_provider<llvm::StringRef>::format(error.AsCString(), OS, 293 Options); 294 } 295