1 //===-- Status.h ------------------------------------------------*- C++ -*-===// 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 #ifndef LLDB_UTILITY_STATUS_H 10 #define LLDB_UTILITY_STATUS_H 11 12 #include "lldb/lldb-defines.h" 13 #include "lldb/lldb-enumerations.h" 14 #include "llvm/ADT/StringRef.h" 15 #include "llvm/Support/Error.h" 16 #include "llvm/Support/FormatVariadic.h" 17 #include <cstdarg> 18 #include <cstdint> 19 #include <string> 20 #include <system_error> 21 #include <type_traits> 22 23 namespace llvm { 24 class raw_ostream; 25 } 26 27 namespace lldb_private { 28 29 /// \class Status Status.h "lldb/Utility/Status.h" An error handling class. 30 /// 31 /// This class is designed to be able to hold any error code that can be 32 /// encountered on a given platform. The errors are stored as a value of type 33 /// Status::ValueType. This value should be large enough to hold any and all 34 /// errors that the class supports. Each error has an associated type that is 35 /// of type lldb::ErrorType. New types can be added to support new error 36 /// types, and architecture specific types can be enabled. In the future we 37 /// may wish to switch to a registration mechanism where new error types can 38 /// be registered at runtime instead of a hard coded scheme. 39 /// 40 /// All errors in this class also know how to generate a string representation 41 /// of themselves for printing results and error codes. The string value will 42 /// be fetched on demand and its string value will be cached until the error 43 /// is cleared of the value of the error changes. 44 class Status { 45 public: 46 /// Every error value that this object can contain needs to be able to fit 47 /// into ValueType. 48 typedef uint32_t ValueType; 49 50 Status(); 51 52 /// Initialize the error object with a generic success value. 53 /// 54 /// \param[in] err 55 /// An error code. 56 /// 57 /// \param[in] type 58 /// The type for \a err. 59 explicit Status(ValueType err, 60 lldb::ErrorType type = lldb::eErrorTypeGeneric); 61 62 Status(std::error_code EC); 63 64 explicit Status(const char *format, ...) 65 __attribute__((format(printf, 2, 3))); 66 67 ~Status(); 68 69 // llvm::Error support 70 explicit Status(llvm::Error error) { *this = std::move(error); } 71 const Status &operator=(llvm::Error error); 72 llvm::Error ToError() const; 73 74 /// Get the error string associated with the current error. 75 // 76 /// Gets the error value as a NULL terminated C string. The error string 77 /// will be fetched and cached on demand. The error string will be retrieved 78 /// from a callback that is appropriate for the type of the error and will 79 /// be cached until the error value is changed or cleared. 80 /// 81 /// \return 82 /// The error as a NULL terminated C string value if the error 83 /// is valid and is able to be converted to a string value, 84 /// NULL otherwise. 85 const char *AsCString(const char *default_error_str = "unknown error") const; 86 87 /// Clear the object state. 88 /// 89 /// Reverts the state of this object to contain a generic success value and 90 /// frees any cached error string value. 91 void Clear(); 92 93 /// Test for error condition. 94 /// 95 /// \return 96 /// \b true if this object contains an error, \b false 97 /// otherwise. 98 bool Fail() const; 99 100 /// Access the error value. 101 /// 102 /// \return 103 /// The error value. 104 ValueType GetError() const; 105 106 /// Access the error type. 107 /// 108 /// \return 109 /// The error type enumeration value. 110 lldb::ErrorType GetType() const; 111 112 /// Set accessor from a kern_return_t. 113 /// 114 /// Set accessor for the error value to \a err and the error type to \c 115 /// MachKernel. 116 /// 117 /// \param[in] err 118 /// A mach error code. 119 void SetMachError(uint32_t err); 120 121 void SetExpressionError(lldb::ExpressionResults, const char *mssg); 122 123 int SetExpressionErrorWithFormat(lldb::ExpressionResults, const char *format, 124 ...) __attribute__((format(printf, 3, 4))); 125 126 /// Set accessor with an error value and type. 127 /// 128 /// Set accessor for the error value to \a err and the error type to \a 129 /// type. 130 /// 131 /// \param[in] err 132 /// A mach error code. 133 /// 134 /// \param[in] type 135 /// The type for \a err. 136 void SetError(ValueType err, lldb::ErrorType type); 137 138 /// Set the current error to errno. 139 /// 140 /// Update the error value to be \c errno and update the type to be \c 141 /// Status::POSIX. 142 void SetErrorToErrno(); 143 144 /// Set the current error to a generic error. 145 /// 146 /// Update the error value to be \c LLDB_GENERIC_ERROR and update the type 147 /// to be \c Status::Generic. 148 void SetErrorToGenericError(); 149 150 /// Set the current error string to \a err_str. 151 /// 152 /// Set accessor for the error string value for a generic errors, or to 153 /// supply additional details above and beyond the standard error strings 154 /// that the standard type callbacks typically provide. This allows custom 155 /// strings to be supplied as an error explanation. The error string value 156 /// will remain until the error value is cleared or a new error value/type 157 /// is assigned. 158 /// 159 /// \param err_str 160 /// The new custom error string to copy and cache. 161 void SetErrorString(llvm::StringRef err_str); 162 163 /// Set the current error string to a formatted error string. 164 /// 165 /// \param format 166 /// A printf style format string 167 int SetErrorStringWithFormat(const char *format, ...) 168 __attribute__((format(printf, 2, 3))); 169 170 int SetErrorStringWithVarArg(const char *format, va_list args); 171 172 template <typename... Args> 173 void SetErrorStringWithFormatv(const char *format, Args &&... args) { 174 SetErrorString(llvm::formatv(format, std::forward<Args>(args)...).str()); 175 } 176 177 /// Test for success condition. 178 /// 179 /// Returns true if the error code in this object is considered a successful 180 /// return value. 181 /// 182 /// \return 183 /// \b true if this object contains an value that describes 184 /// success (non-erro), \b false otherwise. 185 bool Success() const; 186 187 protected: 188 /// Member variables 189 ValueType m_code = 0; ///< Status code as an integer value. 190 lldb::ErrorType m_type = 191 lldb::eErrorTypeInvalid; ///< The type of the above error code. 192 mutable std::string m_string; ///< A string representation of the error code. 193 }; 194 195 } // namespace lldb_private 196 197 namespace llvm { 198 template <> struct format_provider<lldb_private::Status> { 199 static void format(const lldb_private::Status &error, llvm::raw_ostream &OS, 200 llvm::StringRef Options); 201 }; 202 } 203 204 #define LLDB_ERRORF(status, fmt, ...) \ 205 do { \ 206 if (status) { \ 207 (status)->SetErrorStringWithFormat((fmt), __VA_ARGS__); \ 208 } \ 209 } while (0); 210 211 #endif // LLDB_UTILITY_STATUS_H 212