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 
17 using namespace llvm;
18 
19 namespace {
20 
21   enum class ErrorErrorCode : int {
22     MultipleErrors = 1,
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 LLVM_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       }
42       llvm_unreachable("Unhandled error code");
43     }
44   };
45 
46 }
47 
48 static ManagedStatic<ErrorErrorCategory> ErrorErrorCat;
49 
50 namespace llvm {
51 
52 void ErrorInfoBase::anchor() {}
53 char ErrorInfoBase::ID = 0;
54 char ErrorList::ID = 0;
55 char ECError::ID = 0;
56 char StringError::ID = 0;
57 
58 void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner) {
59   if (!E)
60     return;
61   OS << ErrorBanner;
62   handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
63     EI.log(OS);
64     OS << "\n";
65   });
66 }
67 
68 
69 std::error_code ErrorList::convertToErrorCode() const {
70   return std::error_code(static_cast<int>(ErrorErrorCode::MultipleErrors),
71                          *ErrorErrorCat);
72 }
73 
74 std::error_code inconvertibleErrorCode() {
75   return std::error_code(static_cast<int>(ErrorErrorCode::InconvertibleError),
76                          *ErrorErrorCat);
77 }
78 
79 Error errorCodeToError(std::error_code EC) {
80   if (!EC)
81     return Error::success();
82   return Error(llvm::make_unique<ECError>(ECError(EC)));
83 }
84 
85 std::error_code errorToErrorCode(Error Err) {
86   std::error_code EC;
87   handleAllErrors(std::move(Err), [&](const ErrorInfoBase &EI) {
88     EC = EI.convertToErrorCode();
89   });
90   if (EC == inconvertibleErrorCode())
91     report_fatal_error(EC.message());
92   return EC;
93 }
94 
95 StringError::StringError(const Twine &S, std::error_code EC)
96     : Msg(S.str()), EC(EC) {}
97 
98 void StringError::log(raw_ostream &OS) const { OS << Msg; }
99 
100 std::error_code StringError::convertToErrorCode() const {
101   return EC;
102 }
103 
104 void report_fatal_error(Error Err, bool GenCrashDiag) {
105   assert(Err && "report_fatal_error called with success value");
106   std::string ErrMsg;
107   {
108     raw_string_ostream ErrStream(ErrMsg);
109     logAllUnhandledErrors(std::move(Err), ErrStream, "");
110   }
111   report_fatal_error(ErrMsg);
112 }
113 
114 }
115