1 //===----- lib/Support/Error.cpp - Error and associated utilities ---------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/Support/Error.h"
11 #include "llvm/ADT/Twine.h"
12 #include "llvm/Support/ErrorHandling.h"
13 #include "llvm/Support/ManagedStatic.h"
14 #include <system_error>
15 
16 using namespace llvm;
17 
18 namespace {
19 
20   enum class ErrorErrorCode : int {
21     MultipleErrors = 1,
22     FileError,
23     InconvertibleError
24   };
25 
26   // FIXME: This class is only here to support the transition to llvm::Error. It
27   // will be removed once this transition is complete. Clients should prefer to
28   // deal with the Error value directly, rather than converting to error_code.
29   class ErrorErrorCategory : public std::error_category {
30   public:
31     const char *name() const noexcept override { return "Error"; }
32 
33     std::string message(int condition) const override {
34       switch (static_cast<ErrorErrorCode>(condition)) {
35       case ErrorErrorCode::MultipleErrors:
36         return "Multiple errors";
37       case ErrorErrorCode::InconvertibleError:
38         return "Inconvertible error value. An error has occurred that could "
39                "not be converted to a known std::error_code. Please file a "
40                "bug.";
41       case ErrorErrorCode::FileError:
42           return "A file error occurred.";
43       }
44       llvm_unreachable("Unhandled error code");
45     }
46   };
47 
48 }
49 
50 static ManagedStatic<ErrorErrorCategory> ErrorErrorCat;
51 
52 namespace llvm {
53 
54 void ErrorInfoBase::anchor() {}
55 char ErrorInfoBase::ID = 0;
56 char ErrorList::ID = 0;
57 char ECError::ID = 0;
58 char StringError::ID = 0;
59 char FileError::ID = 0;
60 
61 void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner) {
62   if (!E)
63     return;
64   OS << ErrorBanner;
65   handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
66     EI.log(OS);
67     OS << "\n";
68   });
69 }
70 
71 
72 std::error_code ErrorList::convertToErrorCode() const {
73   return std::error_code(static_cast<int>(ErrorErrorCode::MultipleErrors),
74                          *ErrorErrorCat);
75 }
76 
77 std::error_code inconvertibleErrorCode() {
78   return std::error_code(static_cast<int>(ErrorErrorCode::InconvertibleError),
79                          *ErrorErrorCat);
80 }
81 
82 std::error_code FileError::convertToErrorCode() const {
83   return std::error_code(static_cast<int>(ErrorErrorCode::FileError),
84                          *ErrorErrorCat);
85 }
86 
87 Error errorCodeToError(std::error_code EC) {
88   if (!EC)
89     return Error::success();
90   return Error(llvm::make_unique<ECError>(ECError(EC)));
91 }
92 
93 std::error_code errorToErrorCode(Error Err) {
94   std::error_code EC;
95   handleAllErrors(std::move(Err), [&](const ErrorInfoBase &EI) {
96     EC = EI.convertToErrorCode();
97   });
98   if (EC == inconvertibleErrorCode())
99     report_fatal_error(EC.message());
100   return EC;
101 }
102 
103 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
104 void Error::fatalUncheckedError() const {
105   dbgs() << "Program aborted due to an unhandled Error:\n";
106   if (getPtr())
107     getPtr()->log(dbgs());
108   else
109     dbgs() << "Error value was Success. (Note: Success values must still be "
110               "checked prior to being destroyed).\n";
111   abort();
112 }
113 #endif
114 
115 StringError::StringError(std::error_code EC, const Twine &S)
116     : Msg(S.str()), EC(EC) {}
117 
118 StringError::StringError(const Twine &S, std::error_code EC)
119     : Msg(S.str()), EC(EC), PrintMsgOnly(true) {}
120 
121 void StringError::log(raw_ostream &OS) const {
122   if (PrintMsgOnly) {
123     OS << Msg;
124   } else {
125     OS << EC.message();
126     if (!Msg.empty())
127       OS << (" " + Msg);
128   }
129 }
130 
131 std::error_code StringError::convertToErrorCode() const {
132   return EC;
133 }
134 
135 Error createStringError(std::error_code EC, char const *Msg) {
136   return make_error<StringError>(Msg, EC);
137 }
138 
139 void report_fatal_error(Error Err, bool GenCrashDiag) {
140   assert(Err && "report_fatal_error called with success value");
141   std::string ErrMsg;
142   {
143     raw_string_ostream ErrStream(ErrMsg);
144     logAllUnhandledErrors(std::move(Err), ErrStream, "");
145   }
146   report_fatal_error(ErrMsg);
147 }
148 
149 } // end namespace llvm
150 
151 LLVMErrorTypeId LLVMGetErrorTypeId(LLVMErrorRef Err) {
152   return reinterpret_cast<ErrorInfoBase *>(Err)->dynamicClassID();
153 }
154 
155 void LLVMConsumeError(LLVMErrorRef Err) { consumeError(unwrap(Err)); }
156 
157 char *LLVMGetErrorMessage(LLVMErrorRef Err) {
158   std::string Tmp = toString(unwrap(Err));
159   char *ErrMsg = new char[Tmp.size() + 1];
160   memcpy(ErrMsg, Tmp.data(), Tmp.size());
161   ErrMsg[Tmp.size()] = '\0';
162   return ErrMsg;
163 }
164 
165 void LLVMDisposeErrorMessage(char *ErrMsg) { delete[] ErrMsg; }
166 
167 LLVMErrorTypeId LLVMGetStringErrorTypeId() {
168   return reinterpret_cast<void *>(&StringError::ID);
169 }
170 
171 #ifndef _MSC_VER
172 namespace llvm {
173 
174 // One of these two variables will be referenced by a symbol defined in
175 // llvm-config.h. We provide a link-time (or load time for DSO) failure when
176 // there is a mismatch in the build configuration of the API client and LLVM.
177 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
178 int EnableABIBreakingChecks;
179 #else
180 int DisableABIBreakingChecks;
181 #endif
182 
183 } // end namespace llvm
184 #endif
185