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::string toStringWithoutConsuming(const Error &E) {
  86   SmallVector<std::string, 2> Errors;
  87   visitErrors(E, [&Errors](const ErrorInfoBase &EI) {
  88     Errors.push_back(EI.message());
  89   });
  90   return join(Errors.begin(), Errors.end(), "\n");
  91 }
  92
  93 std::error_code ErrorList::convertToErrorCode() const {
  94   return std::error_code(static_cast<int>(ErrorErrorCode::MultipleErrors),
  95                          getErrorErrorCat());
  96 }
  97
  98 std::error_code inconvertibleErrorCode() {
  99   return std::error_code(static_cast<int>(ErrorErrorCode::InconvertibleError),
 100                          getErrorErrorCat());
 101 }
 102
 103 std::error_code FileError::convertToErrorCode() const {
 104   std::error_code NestedEC = Err->convertToErrorCode();
 105   if (NestedEC == inconvertibleErrorCode())
 106     return std::error_code(static_cast<int>(ErrorErrorCode::FileError),
 107                            getErrorErrorCat());
 108   return NestedEC;
 109 }
 110
 111 Error errorCodeToError(std::error_code EC) {
 112   if (!EC)
 113     return Error::success();
 114   return Error(std::make_unique<ECError>(ECError(EC)));
 115 }
 116
 117 std::error_code errorToErrorCode(Error Err) {
 118   std::error_code EC;
 119   handleAllErrors(std::move(Err), [&](const ErrorInfoBase &EI) {
 120     EC = EI.convertToErrorCode();
 121   });
 122   if (EC == inconvertibleErrorCode())
 123     report_fatal_error(Twine(EC.message()));
 124   return EC;
 125 }
 126
 127 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
 128 void Error::fatalUncheckedError() const {
 129   dbgs() << "Program aborted due to an unhandled Error:\n";
 130   if (getPtr()) {
 131     getPtr()->log(dbgs());
 132     dbgs() << "\n";
 133   }else
 134     dbgs() << "Error value was Success. (Note: Success values must still be "
 135               "checked prior to being destroyed).\n";
 136   abort();
 137 }
 138 #endif
 139
 140 StringError::StringError(std::error_code EC, const Twine &S)
 141     : Msg(S.str()), EC(EC) {}
 142
 143 StringError::StringError(const Twine &S, std::error_code EC)
 144     : Msg(S.str()), EC(EC), PrintMsgOnly(true) {}
 145
 146 StringError::StringError(std::string &&S, std::error_code EC, bool PrintMsgOnly)
 147     : Msg(S), EC(EC), PrintMsgOnly(PrintMsgOnly) {}
 148
 149 void StringError::log(raw_ostream &OS) const {
 150   if (PrintMsgOnly) {
 151     OS << Msg;
 152   } else {
 153     OS << EC.message();
 154     if (!Msg.empty())
 155       OS << (" " + Msg);
 156   }
 157 }
 158
 159 std::error_code StringError::convertToErrorCode() const {
 160   return EC;
 161 }
 162
 163 Error createStringError(std::string &&Msg, std::error_code EC) {
 164   return make_error<StringError>(Msg, EC);
 165 }
 166
 167 void report_fatal_error(Error Err, bool GenCrashDiag) {
 168   assert(Err && "report_fatal_error called with success value");
 169   std::string ErrMsg;
 170   {
 171     raw_string_ostream ErrStream(ErrMsg);
 172     logAllUnhandledErrors(std::move(Err), ErrStream);
 173   }
 174   report_fatal_error(Twine(ErrMsg), GenCrashDiag);
 175 }
 176
 177 } // end namespace llvm
 178
 179 LLVMErrorTypeId LLVMGetErrorTypeId(LLVMErrorRef Err) {
 180   return reinterpret_cast<ErrorInfoBase *>(Err)->dynamicClassID();
 181 }
 182
 183 void LLVMConsumeError(LLVMErrorRef Err) { consumeError(unwrap(Err)); }
 184
 185
 186
 187 void LLVMCantFail(LLVMErrorRef Err) {
 188   cantFail(unwrap(Err));
 189 }
 190
 191 char *LLVMGetErrorMessage(LLVMErrorRef Err) {
 192   std::string Tmp = toString(unwrap(Err));
 193   char *ErrMsg = new char[Tmp.size() + 1];
 194   memcpy(ErrMsg, Tmp.data(), Tmp.size());
 195   ErrMsg[Tmp.size()] = '\0';
 196   return ErrMsg;
 197 }
 198
 199 void LLVMDisposeErrorMessage(char *ErrMsg) { delete[] ErrMsg; }
 200
 201 LLVMErrorTypeId LLVMGetStringErrorTypeId() {
 202   return reinterpret_cast<void *>(&StringError::ID);
 203 }
 204
 205 LLVMErrorRef LLVMCreateStringError(const char *ErrMsg) {
 206   return wrap(make_error<StringError>(ErrMsg, inconvertibleErrorCode()));
 207 }