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, ...) 55 : m_code(0), m_type(eErrorTypeInvalid), m_string() { 56 va_list args; 57 va_start(args, format); 58 SetErrorToGenericError(); 59 SetErrorStringWithVarArg(format, args); 60 va_end(args); 61 } 62 63 const Status &Status::operator=(llvm::Error error) { 64 if (!error) { 65 Clear(); 66 return *this; 67 } 68 69 // if the error happens to be a errno error, preserve the error code 70 error = llvm::handleErrors( 71 std::move(error), [&](std::unique_ptr<llvm::ECError> e) -> llvm::Error { 72 std::error_code ec = e->convertToErrorCode(); 73 if (ec.category() == std::generic_category()) { 74 m_code = ec.value(); 75 m_type = ErrorType::eErrorTypePOSIX; 76 return llvm::Error::success(); 77 } 78 return llvm::Error(std::move(e)); 79 }); 80 81 // Otherwise, just preserve the message 82 if (error) { 83 SetErrorToGenericError(); 84 SetErrorString(llvm::toString(std::move(error))); 85 } 86 87 return *this; 88 } 89 90 llvm::Error Status::ToError() const { 91 if (Success()) 92 return llvm::Error::success(); 93 if (m_type == ErrorType::eErrorTypePOSIX) 94 return llvm::errorCodeToError( 95 std::error_code(m_code, std::generic_category())); 96 return llvm::make_error<llvm::StringError>(AsCString(), 97 llvm::inconvertibleErrorCode()); 98 } 99 100 Status::~Status() = default; 101 102 #ifdef _WIN32 103 static std::string RetrieveWin32ErrorString(uint32_t error_code) { 104 char *buffer = nullptr; 105 std::string message; 106 // Retrieve win32 system error. 107 // First, attempt to load a en-US message 108 if (::FormatMessageA( 109 FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | 110 FORMAT_MESSAGE_MAX_WIDTH_MASK, 111 NULL, error_code, MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US), 112 (LPSTR)&buffer, 0, NULL)) { 113 message.assign(buffer); 114 ::LocalFree(buffer); 115 } 116 // If the previous didn't work, use the default OS language 117 else if (::FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | 118 FORMAT_MESSAGE_FROM_SYSTEM | 119 FORMAT_MESSAGE_MAX_WIDTH_MASK, 120 NULL, error_code, 0, (LPSTR)&buffer, 0, NULL)) { 121 message.assign(buffer); 122 ::LocalFree(buffer); 123 } 124 return message; 125 } 126 #endif 127 128 // Get the error value as a NULL C string. The error string will be fetched and 129 // cached on demand. The cached error string value will remain until the error 130 // value is changed or cleared. 131 const char *Status::AsCString(const char *default_error_str) const { 132 if (Success()) 133 return nullptr; 134 135 if (m_string.empty()) { 136 switch (m_type) { 137 case eErrorTypeMachKernel: 138 #if defined(__APPLE__) 139 if (const char *s = ::mach_error_string(m_code)) 140 m_string.assign(s); 141 #endif 142 break; 143 144 case eErrorTypePOSIX: 145 m_string = llvm::sys::StrError(m_code); 146 break; 147 148 case eErrorTypeWin32: 149 #if defined(_WIN32) 150 m_string = RetrieveWin32ErrorString(m_code); 151 #endif 152 break; 153 154 default: 155 break; 156 } 157 } 158 if (m_string.empty()) { 159 if (default_error_str) 160 m_string.assign(default_error_str); 161 else 162 return nullptr; // User wanted a nullptr string back... 163 } 164 return m_string.c_str(); 165 } 166 167 // Clear the error and any cached error string that it might contain. 168 void Status::Clear() { 169 m_code = 0; 170 m_type = eErrorTypeInvalid; 171 m_string.clear(); 172 } 173 174 // Access the error value. 175 Status::ValueType Status::GetError() const { return m_code; } 176 177 // Access the error type. 178 ErrorType Status::GetType() const { return m_type; } 179 180 // Returns true if this object contains a value that describes an error or 181 // otherwise non-success result. 182 bool Status::Fail() const { return m_code != 0; } 183 184 // Set accessor for the error value to "err" and the type to 185 // "eErrorTypeMachKernel" 186 void Status::SetMachError(uint32_t err) { 187 m_code = err; 188 m_type = eErrorTypeMachKernel; 189 m_string.clear(); 190 } 191 192 void Status::SetExpressionError(lldb::ExpressionResults result, 193 const char *mssg) { 194 m_code = result; 195 m_type = eErrorTypeExpression; 196 m_string = mssg; 197 } 198 199 int Status::SetExpressionErrorWithFormat(lldb::ExpressionResults result, 200 const char *format, ...) { 201 int length = 0; 202 203 if (format != nullptr && format[0]) { 204 va_list args; 205 va_start(args, format); 206 length = SetErrorStringWithVarArg(format, args); 207 va_end(args); 208 } else { 209 m_string.clear(); 210 } 211 m_code = result; 212 m_type = eErrorTypeExpression; 213 return length; 214 } 215 216 // Set accessor for the error value and type. 217 void Status::SetError(ValueType err, ErrorType type) { 218 m_code = err; 219 m_type = type; 220 m_string.clear(); 221 } 222 223 // Update the error value to be "errno" and update the type to be "POSIX". 224 void Status::SetErrorToErrno() { 225 m_code = errno; 226 m_type = eErrorTypePOSIX; 227 m_string.clear(); 228 } 229 230 // Update the error value to be LLDB_GENERIC_ERROR and update the type to be 231 // "Generic". 232 void Status::SetErrorToGenericError() { 233 m_code = LLDB_GENERIC_ERROR; 234 m_type = eErrorTypeGeneric; 235 m_string.clear(); 236 } 237 238 // Set accessor for the error string value for a specific error. This allows 239 // any string to be supplied as an error explanation. The error string value 240 // will remain until the error value is cleared or a new error value/type is 241 // assigned. 242 void Status::SetErrorString(llvm::StringRef err_str) { 243 if (!err_str.empty()) { 244 // If we have an error string, we should always at least have an error set 245 // to a generic value. 246 if (Success()) 247 SetErrorToGenericError(); 248 } 249 m_string = std::string(err_str); 250 } 251 252 /// Set the current error string to a formatted error string. 253 /// 254 /// \param format 255 /// A printf style format string 256 int Status::SetErrorStringWithFormat(const char *format, ...) { 257 if (format != nullptr && format[0]) { 258 va_list args; 259 va_start(args, format); 260 int length = SetErrorStringWithVarArg(format, args); 261 va_end(args); 262 return length; 263 } else { 264 m_string.clear(); 265 } 266 return 0; 267 } 268 269 int Status::SetErrorStringWithVarArg(const char *format, va_list args) { 270 if (format != nullptr && format[0]) { 271 // If we have an error string, we should always at least have an error set 272 // to a generic value. 273 if (Success()) 274 SetErrorToGenericError(); 275 276 llvm::SmallString<1024> buf; 277 VASprintf(buf, format, args); 278 m_string = std::string(buf.str()); 279 return buf.size(); 280 } else { 281 m_string.clear(); 282 } 283 return 0; 284 } 285 286 // Returns true if the error code in this object is considered a successful 287 // return value. 288 bool Status::Success() const { return m_code == 0; } 289 290 bool Status::WasInterrupted() const { 291 return (m_type == eErrorTypePOSIX && m_code == EINTR); 292 } 293 294 void llvm::format_provider<lldb_private::Status>::format( 295 const lldb_private::Status &error, llvm::raw_ostream &OS, 296 llvm::StringRef Options) { 297 llvm::format_provider<llvm::StringRef>::format(error.AsCString(), OS, 298 Options); 299 } 300