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 <stdint.h>
32
33 namespace llvm {
34 class raw_ostream;
35 }
36
37 using namespace lldb;
38 using namespace lldb_private;
39
Status()40 Status::Status() : m_code(0), m_type(eErrorTypeInvalid), m_string() {}
41
Status(ValueType err,ErrorType type)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.
Status(std::error_code EC)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
Status(const char * format,...)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
operator =(llvm::Error error)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
ToError() const90 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
RetrieveWin32ErrorString(uint32_t error_code)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.
AsCString(const char * default_error_str) const131 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.
Clear()168 void Status::Clear() {
169 m_code = 0;
170 m_type = eErrorTypeInvalid;
171 m_string.clear();
172 }
173
174 // Access the error value.
GetError() const175 Status::ValueType Status::GetError() const { return m_code; }
176
177 // Access the error type.
GetType() const178 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.
Fail() const182 bool Status::Fail() const { return m_code != 0; }
183
184 // Set accessor for the error value to "err" and the type to
185 // "eErrorTypeMachKernel"
SetMachError(uint32_t err)186 void Status::SetMachError(uint32_t err) {
187 m_code = err;
188 m_type = eErrorTypeMachKernel;
189 m_string.clear();
190 }
191
SetExpressionError(lldb::ExpressionResults result,const char * mssg)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
SetExpressionErrorWithFormat(lldb::ExpressionResults result,const char * format,...)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.
SetError(ValueType err,ErrorType 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".
SetErrorToErrno()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".
SetErrorToGenericError()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.
SetErrorString(llvm::StringRef err_str)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
SetErrorStringWithFormat(const char * format,...)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
SetErrorStringWithVarArg(const char * format,va_list args)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.
Success() const288 bool Status::Success() const { return m_code == 0; }
289
WasInterrupted() const290 bool Status::WasInterrupted() const {
291 return (m_type == eErrorTypePOSIX && m_code == EINTR);
292 }
293
format(const lldb_private::Status & error,llvm::raw_ostream & OS,llvm::StringRef Options)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