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/FormatProviders.h" // for format_provider
19 
20 #include <cerrno>
21 #include <cstdarg>
22 #include <string> // for string
23 #include <system_error>
24 
25 #ifdef __APPLE__
26 #include <mach/mach.h>
27 #endif
28 
29 #include <stdint.h> // for uint32_t
30 #include <string.h> // for strerror
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     const char *s = nullptr;
125     switch (m_type) {
126     case eErrorTypeMachKernel:
127 #if defined(__APPLE__)
128       s = ::mach_error_string(m_code);
129 #endif
130       break;
131 
132     case eErrorTypePOSIX:
133       s = ::strerror(m_code);
134       break;
135 
136     default:
137       break;
138     }
139     if (s != nullptr)
140       m_string.assign(s);
141   }
142   if (m_string.empty()) {
143     if (default_error_str)
144       m_string.assign(default_error_str);
145     else
146       return nullptr; // User wanted a nullptr string back...
147   }
148   return m_string.c_str();
149 }
150 
151 //----------------------------------------------------------------------
152 // Clear the error and any cached error string that it might contain.
153 //----------------------------------------------------------------------
154 void Status::Clear() {
155   m_code = 0;
156   m_type = eErrorTypeInvalid;
157   m_string.clear();
158 }
159 
160 //----------------------------------------------------------------------
161 // Access the error value.
162 //----------------------------------------------------------------------
163 Status::ValueType Status::GetError() const { return m_code; }
164 
165 //----------------------------------------------------------------------
166 // Access the error type.
167 //----------------------------------------------------------------------
168 ErrorType Status::GetType() const { return m_type; }
169 
170 //----------------------------------------------------------------------
171 // Returns true if this object contains a value that describes an
172 // error or otherwise non-success result.
173 //----------------------------------------------------------------------
174 bool Status::Fail() const { return m_code != 0; }
175 
176 //----------------------------------------------------------------------
177 // Set accesssor for the error value to "err" and the type to
178 // "eErrorTypeMachKernel"
179 //----------------------------------------------------------------------
180 void Status::SetMachError(uint32_t err) {
181   m_code = err;
182   m_type = eErrorTypeMachKernel;
183   m_string.clear();
184 }
185 
186 void Status::SetExpressionError(lldb::ExpressionResults result,
187                                 const char *mssg) {
188   m_code = result;
189   m_type = eErrorTypeExpression;
190   m_string = mssg;
191 }
192 
193 int Status::SetExpressionErrorWithFormat(lldb::ExpressionResults result,
194                                          const char *format, ...) {
195   int length = 0;
196 
197   if (format != nullptr && format[0]) {
198     va_list args;
199     va_start(args, format);
200     length = SetErrorStringWithVarArg(format, args);
201     va_end(args);
202   } else {
203     m_string.clear();
204   }
205   m_code = result;
206   m_type = eErrorTypeExpression;
207   return length;
208 }
209 
210 //----------------------------------------------------------------------
211 // Set accesssor for the error value and type.
212 //----------------------------------------------------------------------
213 void Status::SetError(ValueType err, ErrorType type) {
214   m_code = err;
215   m_type = type;
216   m_string.clear();
217 }
218 
219 //----------------------------------------------------------------------
220 // Update the error value to be "errno" and update the type to
221 // be "POSIX".
222 //----------------------------------------------------------------------
223 void Status::SetErrorToErrno() {
224   m_code = errno;
225   m_type = eErrorTypePOSIX;
226   m_string.clear();
227 }
228 
229 //----------------------------------------------------------------------
230 // Update the error value to be LLDB_GENERIC_ERROR and update the type
231 // to be "Generic".
232 //----------------------------------------------------------------------
233 void Status::SetErrorToGenericError() {
234   m_code = LLDB_GENERIC_ERROR;
235   m_type = eErrorTypeGeneric;
236   m_string.clear();
237 }
238 
239 //----------------------------------------------------------------------
240 // Set accessor for the error string value for a specific error.
241 // This allows any string to be supplied as an error explanation.
242 // The error string value will remain until the error value is
243 // cleared or a new error value/type is assigned.
244 //----------------------------------------------------------------------
245 void Status::SetErrorString(llvm::StringRef err_str) {
246   if (!err_str.empty()) {
247     // If we have an error string, we should always at least have an error
248     // set to a generic value.
249     if (Success())
250       SetErrorToGenericError();
251   }
252   m_string = err_str;
253 }
254 
255 //------------------------------------------------------------------
256 /// Set the current error string to a formatted error string.
257 ///
258 /// @param format
259 ///     A printf style format string
260 //------------------------------------------------------------------
261 int Status::SetErrorStringWithFormat(const char *format, ...) {
262   if (format != nullptr && format[0]) {
263     va_list args;
264     va_start(args, format);
265     int length = SetErrorStringWithVarArg(format, args);
266     va_end(args);
267     return length;
268   } else {
269     m_string.clear();
270   }
271   return 0;
272 }
273 
274 int Status::SetErrorStringWithVarArg(const char *format, va_list args) {
275   if (format != nullptr && format[0]) {
276     // If we have an error string, we should always at least have
277     // an error set to a generic value.
278     if (Success())
279       SetErrorToGenericError();
280 
281     llvm::SmallString<1024> buf;
282     VASprintf(buf, format, args);
283     m_string = buf.str();
284     return buf.size();
285   } else {
286     m_string.clear();
287   }
288   return 0;
289 }
290 
291 //----------------------------------------------------------------------
292 // Returns true if the error code in this object is considered a
293 // successful return value.
294 //----------------------------------------------------------------------
295 bool Status::Success() const { return m_code == 0; }
296 
297 bool Status::WasInterrupted() const {
298   return (m_type == eErrorTypePOSIX && m_code == EINTR);
299 }
300 
301 void llvm::format_provider<lldb_private::Status>::format(
302     const lldb_private::Status &error, llvm::raw_ostream &OS,
303     llvm::StringRef Options) {
304   llvm::format_provider<llvm::StringRef>::format(error.AsCString(), OS,
305                                                  Options);
306 }
307