Home | History | Annotate | Download | only in Support 
      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 
     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 LLVM_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 StringError::StringError(const Twine &S, std::error_code EC)
     95     : Msg(S.str()), EC(EC) {}
     96 
     97 void StringError::log(raw_ostream &OS) const { OS << Msg; }
     98 
     99 std::error_code StringError::convertToErrorCode() const {
    100   return EC;
    101 }
    102 
    103 void report_fatal_error(Error Err, bool GenCrashDiag) {
    104   assert(Err && "report_fatal_error called with success value");
    105   std::string ErrMsg;
    106   {
    107     raw_string_ostream ErrStream(ErrMsg);
    108     logAllUnhandledErrors(std::move(Err), ErrStream, "");
    109   }
    110   report_fatal_error(ErrMsg);
    111 }
    112 
    113 }
    114