tools/llvm-elfabi/ErrorCollector.h

   1 //===- ErrorCollector.h -----------------------------------------*- C++ -*-===//
   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 /// This class collects errors that should be reported or ignored in aggregate.
  10 ///
  11 /// Like llvm::Error, an ErrorCollector cannot be copied. Unlike llvm::Error,
  12 /// an ErrorCollector may be destroyed if it was originally constructed to treat
  13 /// errors as non-fatal. In this case, all Errors are consumed upon destruction.
  14 /// An ErrorCollector may be initially constructed (or escalated) such that
  15 /// errors are treated as fatal. This causes a crash if an attempt is made to
  16 /// delete the ErrorCollector when some Errors have not been retrieved via
  17 /// makeError().
  18 ///
  19 //===-----------------------------------------------------------------------===/
  20
  21 #ifndef LLVM_TOOLS_ELFABI_ERRORCOLLECTOR_H
  22 #define LLVM_TOOLS_ELFABI_ERRORCOLLECTOR_H
  23
  24 #include "llvm/Support/Error.h"
  25 #include <vector>
  26
  27 namespace llvm {
  28 namespace elfabi {
  29
  30 class ErrorCollector {
  31 public:
  32   /// Upon destruction, an ErrorCollector will crash if UseFatalErrors=true and
  33   /// there are remaining errors that haven't been fetched by makeError().
  34   ErrorCollector(bool UseFatalErrors = true) : ErrorsAreFatal(UseFatalErrors) {}
  35   // Don't allow copying.
  36   ErrorCollector(const ErrorCollector &Stub) = delete;
  37   ErrorCollector &operator=(const ErrorCollector &Other) = delete;
  38   ~ErrorCollector();
  39
  40   // TODO: Add move constructor and operator= when a testable situation arises.
  41
  42   /// Returns a single error that contains messages for all stored Errors.
  43   Error makeError();
  44
  45   /// Adds an error with a descriptive tag that helps with identification.
  46   /// If the error is an Error::success(), it is checked and discarded.
  47   void addError(Error &&E, StringRef Tag);
  48
  49   /// This ensures an ErrorCollector will treat unhandled errors as fatal.
  50   /// This function should be called if errors that usually can be ignored
  51   /// are suddenly of concern (i.e. attempt multiple things that return Error,
  52   /// but only care about the Errors if no attempt succeeds).
  53   void escalateToFatal();
  54
  55 private:
  56   /// Logs all errors to a raw_ostream.
  57   void log(raw_ostream &OS);
  58
  59   /// Returns true if all errors have been retrieved through makeError(), or
  60   /// false if errors have been added since the last makeError() call.
  61   bool allErrorsHandled() const;
  62
  63   /// Dump output and crash.
  64   LLVM_ATTRIBUTE_NORETURN void fatalUnhandledError();
  65
  66   bool ErrorsAreFatal;
  67   std::vector<Error> Errors;
  68   std::vector<std::string> Tags;
  69 };
  70
  71 } // end namespace elfabi
  72 } // end namespace llvm
  73
  74 #endif // LLVM_TOOLS_ELFABI_ERRORCOLLECTOR_H