llvm/lib/Support/Error.cpp

   1 //===----- lib/Support/Error.cpp - Error and associated utilities ---------===//
   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 "llvm/Support/Error.h"
  10 #include "llvm/ADT/SmallVector.h"
  11 #include "llvm/ADT/StringExtras.h"
  12 #include "llvm/ADT/Twine.h"
  13 #include "llvm/Support/ErrorHandling.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 ErrorErrorCategory &getErrorErrorCat() {
  51   static ErrorErrorCategory ErrorErrorCat;
  52   return ErrorErrorCat;
  53 }
  54
  55 namespace llvm {
  56
  57 void ErrorInfoBase::anchor() {}
  58 char ErrorInfoBase::ID = 0;
  59 char ErrorList::ID = 0;
  60 void ECError::anchor() {}
  61 char ECError::ID = 0;
  62 char StringError::ID = 0;
  63 char FileError::ID = 0;
  64
  65 void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner) {
  66   if (!E)
  67     return;
  68   OS << ErrorBanner;
  69   handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
  70     EI.log(OS);
  71     OS << "\n";
  72   });
  73 }
  74
  75 /// Write all error messages (if any) in E to a string. The newline character
  76 /// is used to separate error messages.
  77 std::string toString(Error E) {
  78   SmallVector<std::string, 2> Errors;
  79   handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
  80     Errors.push_back(EI.message());
  81   });
  82   return join(Errors.begin(), Errors.end(), "\n");
  83 }
  84
  85 std::error_code ErrorList::convertToErrorCode() const {
  86   return std::error_code(static_cast<int>(ErrorErrorCode::MultipleErrors),
  87                          getErrorErrorCat());
  88 }
  89
  90 std::error_code inconvertibleErrorCode() {
  91   return std::error_code(static_cast<int>(ErrorErrorCode::InconvertibleError),
  92                          getErrorErrorCat());
  93 }
  94
  95 std::error_code FileError::convertToErrorCode() const {
  96   std::error_code NestedEC = Err->convertToErrorCode();
  97   if (NestedEC == inconvertibleErrorCode())
  98     return std::error_code(static_cast<int>(ErrorErrorCode::FileError),
  99                            getErrorErrorCat());
 100   return NestedEC;
 101 }
 102
 103 Error errorCodeToError(std::error_code EC) {
 104   if (!EC)
 105     return Error::success();
 106   return Error(std::make_unique<ECError>(ECError(EC)));
 107 }
 108
 109 std::error_code errorToErrorCode(Error Err) {
 110   std::error_code EC;
 111   handleAllErrors(std::move(Err), [&](const ErrorInfoBase &EI) {
 112     EC = EI.convertToErrorCode();
 113   });
 114   if (EC == inconvertibleErrorCode())
 115     report_fatal_error(Twine(EC.message()));
 116   return EC;
 117 }
 118
 119 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
 120 void Error::fatalUncheckedError() const {
 121   dbgs() << "Program aborted due to an unhandled Error:\n";
 122   if (getPtr()) {
 123     getPtr()->log(dbgs());
 124     dbgs() << "\n";
 125   }else
 126     dbgs() << "Error value was Success. (Note: Success values must still be "
 127               "checked prior to being destroyed).\n";
 128   abort();
 129 }
 130 #endif
 131
 132 StringError::StringError(std::error_code EC, const Twine &S)
 133     : Msg(S.str()), EC(EC) {}
 134
 135 StringError::StringError(const Twine &S, std::error_code EC)
 136     : Msg(S.str()), EC(EC), PrintMsgOnly(true) {}
 137
 138 void StringError::log(raw_ostream &OS) const {
 139   if (PrintMsgOnly) {
 140     OS << Msg;
 141   } else {
 142     OS << EC.message();
 143     if (!Msg.empty())
 144       OS << (" " + Msg);
 145   }
 146 }
 147
 148 std::error_code StringError::convertToErrorCode() const {
 149   return EC;
 150 }
 151
 152 Error createStringError(std::error_code EC, char const *Msg) {
 153   return make_error<StringError>(Msg, EC);
 154 }
 155
 156 void report_fatal_error(Error Err, bool GenCrashDiag) {
 157   assert(Err && "report_fatal_error called with success value");
 158   std::string ErrMsg;
 159   {
 160     raw_string_ostream ErrStream(ErrMsg);
 161     logAllUnhandledErrors(std::move(Err), ErrStream);
 162   }
 163   report_fatal_error(Twine(ErrMsg), GenCrashDiag);
 164 }
 165
 166 } // end namespace llvm
 167
 168 LLVMErrorTypeId LLVMGetErrorTypeId(LLVMErrorRef Err) {
 169   return reinterpret_cast<ErrorInfoBase *>(Err)->dynamicClassID();
 170 }
 171
 172 void LLVMConsumeError(LLVMErrorRef Err) { consumeError(unwrap(Err)); }
 173
 174 char *LLVMGetErrorMessage(LLVMErrorRef Err) {
 175   std::string Tmp = toString(unwrap(Err));
 176   char *ErrMsg = new char[Tmp.size() + 1];
 177   memcpy(ErrMsg, Tmp.data(), Tmp.size());
 178   ErrMsg[Tmp.size()] = '\0';
 179   return ErrMsg;
 180 }
 181
 182 void LLVMDisposeErrorMessage(char *ErrMsg) { delete[] ErrMsg; }
 183
 184 LLVMErrorTypeId LLVMGetStringErrorTypeId() {
 185   return reinterpret_cast<void *>(&StringError::ID);
 186 }
 187
 188 LLVMErrorRef LLVMCreateStringError(const char *ErrMsg) {
 189   return wrap(make_error<StringError>(ErrMsg, inconvertibleErrorCode()));
 190 }