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