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/Twine.h"
  11 #include "llvm/Support/ErrorHandling.h"
  12 #include "llvm/Support/ManagedStatic.h"
  13 #include <system_error>
  14
  15 using namespace llvm;
  16
  17 namespace {
  18
  19   enum class ErrorErrorCode : int {
  20     MultipleErrors = 1,
  21     FileError,
  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       case ErrorErrorCode::FileError:
  41           return "A file error occurred.";
  42       }
  43       llvm_unreachable("Unhandled error code");
  44     }
  45   };
  46
  47 }
  48
  49 static ManagedStatic<ErrorErrorCategory> ErrorErrorCat;
  50
  51 namespace llvm {
  52
  53 void ErrorInfoBase::anchor() {}
  54 char ErrorInfoBase::ID = 0;
  55 char ErrorList::ID = 0;
  56 void ECError::anchor() {}
  57 char ECError::ID = 0;
  58 char StringError::ID = 0;
  59 char FileError::ID = 0;
  60
  61 void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner) {
  62   if (!E)
  63     return;
  64   OS << ErrorBanner;
  65   handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
  66     EI.log(OS);
  67     OS << "\n";
  68   });
  69 }
  70
  71
  72 std::error_code ErrorList::convertToErrorCode() const {
  73   return std::error_code(static_cast<int>(ErrorErrorCode::MultipleErrors),
  74                          *ErrorErrorCat);
  75 }
  76
  77 std::error_code inconvertibleErrorCode() {
  78   return std::error_code(static_cast<int>(ErrorErrorCode::InconvertibleError),
  79                          *ErrorErrorCat);
  80 }
  81
  82 std::error_code FileError::convertToErrorCode() const {
  83   return std::error_code(static_cast<int>(ErrorErrorCode::FileError),
  84                          *ErrorErrorCat);
  85 }
  86
  87 Error errorCodeToError(std::error_code EC) {
  88   if (!EC)
  89     return Error::success();
  90   return Error(std::make_unique<ECError>(ECError(EC)));
  91 }
  92
  93 std::error_code errorToErrorCode(Error Err) {
  94   std::error_code EC;
  95   handleAllErrors(std::move(Err), [&](const ErrorInfoBase &EI) {
  96     EC = EI.convertToErrorCode();
  97   });
  98   if (EC == inconvertibleErrorCode())
  99     report_fatal_error(EC.message());
 100   return EC;
 101 }
 102
 103 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
 104 void Error::fatalUncheckedError() const {
 105   dbgs() << "Program aborted due to an unhandled Error:\n";
 106   if (getPtr())
 107     getPtr()->log(dbgs());
 108   else
 109     dbgs() << "Error value was Success. (Note: Success values must still be "
 110               "checked prior to being destroyed).\n";
 111   abort();
 112 }
 113 #endif
 114
 115 StringError::StringError(std::error_code EC, const Twine &S)
 116     : Msg(S.str()), EC(EC) {}
 117
 118 StringError::StringError(const Twine &S, std::error_code EC)
 119     : Msg(S.str()), EC(EC), PrintMsgOnly(true) {}
 120
 121 void StringError::log(raw_ostream &OS) const {
 122   if (PrintMsgOnly) {
 123     OS << Msg;
 124   } else {
 125     OS << EC.message();
 126     if (!Msg.empty())
 127       OS << (" " + Msg);
 128   }
 129 }
 130
 131 std::error_code StringError::convertToErrorCode() const {
 132   return EC;
 133 }
 134
 135 Error createStringError(std::error_code EC, char const *Msg) {
 136   return make_error<StringError>(Msg, EC);
 137 }
 138
 139 void report_fatal_error(Error Err, bool GenCrashDiag) {
 140   assert(Err && "report_fatal_error called with success value");
 141   std::string ErrMsg;
 142   {
 143     raw_string_ostream ErrStream(ErrMsg);
 144     logAllUnhandledErrors(std::move(Err), ErrStream);
 145   }
 146   report_fatal_error(ErrMsg);
 147 }
 148
 149 } // end namespace llvm
 150
 151 LLVMErrorTypeId LLVMGetErrorTypeId(LLVMErrorRef Err) {
 152   return reinterpret_cast<ErrorInfoBase *>(Err)->dynamicClassID();
 153 }
 154
 155 void LLVMConsumeError(LLVMErrorRef Err) { consumeError(unwrap(Err)); }
 156
 157 char *LLVMGetErrorMessage(LLVMErrorRef Err) {
 158   std::string Tmp = toString(unwrap(Err));
 159   char *ErrMsg = new char[Tmp.size() + 1];
 160   memcpy(ErrMsg, Tmp.data(), Tmp.size());
 161   ErrMsg[Tmp.size()] = '\0';
 162   return ErrMsg;
 163 }
 164
 165 void LLVMDisposeErrorMessage(char *ErrMsg) { delete[] ErrMsg; }
 166
 167 LLVMErrorTypeId LLVMGetStringErrorTypeId() {
 168   return reinterpret_cast<void *>(&StringError::ID);
 169 }
 170
 171 #ifndef _MSC_VER
 172 namespace llvm {
 173
 174 // One of these two variables will be referenced by a symbol defined in
 175 // llvm-config.h. We provide a link-time (or load time for DSO) failure when
 176 // there is a mismatch in the build configuration of the API client and LLVM.
 177 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
 178 int EnableABIBreakingChecks;
 179 #else
 180 int DisableABIBreakingChecks;
 181 #endif
 182
 183 } // end namespace llvm
 184 #endif