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