1 //===-- Status.cpp -----------------------------------------------*- C++
2 //-*-===//
3 //
4 //                     The LLVM Compiler Infrastructure
5 //
6 // This file is distributed under the University of Illinois Open Source
7 // License. See LICENSE.TXT for details.
8 //
9 //===----------------------------------------------------------------------===//
10 
11 #include "lldb/Utility/Status.h"
12 
13 #include "lldb/Utility/VASPrintf.h"
14 #include "lldb/lldb-defines.h"      // for LLDB_GENERIC_ERROR
15 #include "lldb/lldb-enumerations.h" // for ErrorType, ErrorType::eErr...
16 #include "llvm/ADT/SmallString.h"   // for SmallString
17 #include "llvm/ADT/StringRef.h"     // for StringRef
18 #include "llvm/Support/Errno.h"
19 #include "llvm/Support/FormatProviders.h" // for format_provider
20 
21 #include <cerrno>
22 #include <cstdarg>
23 #include <string> // for string
24 #include <system_error>
25 
26 #ifdef __APPLE__
27 #include <mach/mach.h>
28 #endif
29 
30 #include <stdint.h> // for uint32_t
31 
32 namespace llvm {
33 class raw_ostream;
34 }
35 
36 using namespace lldb;
37 using namespace lldb_private;
38 
39 Status::Status() : m_code(0), m_type(eErrorTypeInvalid), m_string() {}
40 
41 Status::Status(ValueType err, ErrorType type)
42     : m_code(err), m_type(type), m_string() {}
43 
44 Status::Status(std::error_code EC)
45     : m_code(EC.value()), m_type(ErrorType::eErrorTypeGeneric),
46       m_string(EC.message()) {}
47 
48 Status::Status(const Status &rhs) = default;
49 
50 Status::Status(const char *format, ...)
51     : m_code(0), m_type(eErrorTypeInvalid), m_string() {
52   va_list args;
53   va_start(args, format);
54   SetErrorToGenericError();
55   SetErrorStringWithVarArg(format, args);
56   va_end(args);
57 }
58 
59 Status::Status(llvm::Error error)
60     : m_code(0), m_type(ErrorType::eErrorTypeGeneric) {
61   if (!error)
62     return;
63 
64   // if the error happens to be a errno error, preserve the error code
65   error = llvm::handleErrors(
66       std::move(error), [&](std::unique_ptr<llvm::ECError> e) -> llvm::Error {
67         std::error_code ec = e->convertToErrorCode();
68         if (ec.category() == std::generic_category()) {
69           m_code = ec.value();
70           m_type = ErrorType::eErrorTypePOSIX;
71           return llvm::Error::success();
72         }
73         return llvm::Error(std::move(e));
74       });
75 
76   // Otherwise, just preserve the message
77   if (error)
78     SetErrorString(llvm::toString(std::move(error)));
79 }
80 
81 llvm::Error Status::ToError() const {
82   if (Success())
83     return llvm::Error::success();
84   if (m_type == ErrorType::eErrorTypePOSIX)
85     return llvm::errorCodeToError(std::error_code(m_code, std::generic_category()));
86   return llvm::make_error<llvm::StringError>(AsCString(),
87                                              llvm::inconvertibleErrorCode());
88 }
89 
90 //----------------------------------------------------------------------
91 // Assignment operator
92 //----------------------------------------------------------------------
93 const Status &Status::operator=(const Status &rhs) {
94   if (this != &rhs) {
95     m_code = rhs.m_code;
96     m_type = rhs.m_type;
97     m_string = rhs.m_string;
98   }
99   return *this;
100 }
101 
102 //----------------------------------------------------------------------
103 // Assignment operator
104 //----------------------------------------------------------------------
105 const Status &Status::operator=(uint32_t err) {
106   m_code = err;
107   m_type = eErrorTypeMachKernel;
108   m_string.clear();
109   return *this;
110 }
111 
112 Status::~Status() = default;
113 
114 //----------------------------------------------------------------------
115 // Get the error value as a NULL C string. The error string will be
116 // fetched and cached on demand. The cached error string value will
117 // remain until the error value is changed or cleared.
118 //----------------------------------------------------------------------
119 const char *Status::AsCString(const char *default_error_str) const {
120   if (Success())
121     return nullptr;
122 
123   if (m_string.empty()) {
124     switch (m_type) {
125     case eErrorTypeMachKernel:
126 #if defined(__APPLE__)
127       if (const char *s = ::mach_error_string(m_code))
128         m_string.assign(s);
129 #endif
130       break;
131 
132     case eErrorTypePOSIX:
133       m_string = llvm::sys::StrError(m_code);
134       break;
135 
136     default:
137       break;
138     }
139   }
140   if (m_string.empty()) {
141     if (default_error_str)
142       m_string.assign(default_error_str);
143     else
144       return nullptr; // User wanted a nullptr string back...
145   }
146   return m_string.c_str();
147 }
148 
149 //----------------------------------------------------------------------
150 // Clear the error and any cached error string that it might contain.
151 //----------------------------------------------------------------------
152 void Status::Clear() {
153   m_code = 0;
154   m_type = eErrorTypeInvalid;
155   m_string.clear();
156 }
157 
158 //----------------------------------------------------------------------
159 // Access the error value.
160 //----------------------------------------------------------------------
161 Status::ValueType Status::GetError() const { return m_code; }
162 
163 //----------------------------------------------------------------------
164 // Access the error type.
165 //----------------------------------------------------------------------
166 ErrorType Status::GetType() const { return m_type; }
167 
168 //----------------------------------------------------------------------
169 // Returns true if this object contains a value that describes an
170 // error or otherwise non-success result.
171 //----------------------------------------------------------------------
172 bool Status::Fail() const { return m_code != 0; }
173 
174 //----------------------------------------------------------------------
175 // Set accesssor for the error value to "err" and the type to
176 // "eErrorTypeMachKernel"
177 //----------------------------------------------------------------------
178 void Status::SetMachError(uint32_t err) {
179   m_code = err;
180   m_type = eErrorTypeMachKernel;
181   m_string.clear();
182 }
183 
184 void Status::SetExpressionError(lldb::ExpressionResults result,
185                                 const char *mssg) {
186   m_code = result;
187   m_type = eErrorTypeExpression;
188   m_string = mssg;
189 }
190 
191 int Status::SetExpressionErrorWithFormat(lldb::ExpressionResults result,
192                                          const char *format, ...) {
193   int length = 0;
194 
195   if (format != nullptr && format[0]) {
196     va_list args;
197     va_start(args, format);
198     length = SetErrorStringWithVarArg(format, args);
199     va_end(args);
200   } else {
201     m_string.clear();
202   }
203   m_code = result;
204   m_type = eErrorTypeExpression;
205   return length;
206 }
207 
208 //----------------------------------------------------------------------
209 // Set accesssor for the error value and type.
210 //----------------------------------------------------------------------
211 void Status::SetError(ValueType err, ErrorType type) {
212   m_code = err;
213   m_type = type;
214   m_string.clear();
215 }
216 
217 //----------------------------------------------------------------------
218 // Update the error value to be "errno" and update the type to
219 // be "POSIX".
220 //----------------------------------------------------------------------
221 void Status::SetErrorToErrno() {
222   m_code = errno;
223   m_type = eErrorTypePOSIX;
224   m_string.clear();
225 }
226 
227 //----------------------------------------------------------------------
228 // Update the error value to be LLDB_GENERIC_ERROR and update the type
229 // to be "Generic".
230 //----------------------------------------------------------------------
231 void Status::SetErrorToGenericError() {
232   m_code = LLDB_GENERIC_ERROR;
233   m_type = eErrorTypeGeneric;
234   m_string.clear();
235 }
236 
237 //----------------------------------------------------------------------
238 // Set accessor for the error string value for a specific error.
239 // This allows any string to be supplied as an error explanation.
240 // The error string value will remain until the error value is
241 // cleared or a new error value/type is assigned.
242 //----------------------------------------------------------------------
243 void Status::SetErrorString(llvm::StringRef err_str) {
244   if (!err_str.empty()) {
245     // If we have an error string, we should always at least have an error
246     // set to a generic value.
247     if (Success())
248       SetErrorToGenericError();
249   }
250   m_string = err_str;
251 }
252 
253 //------------------------------------------------------------------
254 /// Set the current error string to a formatted error string.
255 ///
256 /// @param format
257 ///     A printf style format string
258 //------------------------------------------------------------------
259 int Status::SetErrorStringWithFormat(const char *format, ...) {
260   if (format != nullptr && format[0]) {
261     va_list args;
262     va_start(args, format);
263     int length = SetErrorStringWithVarArg(format, args);
264     va_end(args);
265     return length;
266   } else {
267     m_string.clear();
268   }
269   return 0;
270 }
271 
272 int Status::SetErrorStringWithVarArg(const char *format, va_list args) {
273   if (format != nullptr && format[0]) {
274     // If we have an error string, we should always at least have
275     // an error set to a generic value.
276     if (Success())
277       SetErrorToGenericError();
278 
279     llvm::SmallString<1024> buf;
280     VASprintf(buf, format, args);
281     m_string = buf.str();
282     return buf.size();
283   } else {
284     m_string.clear();
285   }
286   return 0;
287 }
288 
289 //----------------------------------------------------------------------
290 // Returns true if the error code in this object is considered a
291 // successful return value.
292 //----------------------------------------------------------------------
293 bool Status::Success() const { return m_code == 0; }
294 
295 bool Status::WasInterrupted() const {
296   return (m_type == eErrorTypePOSIX && m_code == EINTR);
297 }
298 
299 void llvm::format_provider<lldb_private::Status>::format(
300     const lldb_private::Status &error, llvm::raw_ostream &OS,
301     llvm::StringRef Options) {
302   llvm::format_provider<llvm::StringRef>::format(error.AsCString(), OS,
303                                                  Options);
304 }
305