llvm/tools/llvm-ifs/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_LLVM_IFS_ERRORCOLLECTOR_H
  22 #define LLVM_TOOLS_LLVM_IFS_ERRORCOLLECTOR_H
  23
  24 #include "llvm/Support/Error.h"
  25 #include "llvm/Support/raw_ostream.h"
  26 #include <vector>
  27
  28 namespace llvm {
  29
  30 namespace ifs {
  31
  32 class ErrorCollector {
  33 public:
  34   /// Upon destruction, an ErrorCollector will crash if UseFatalErrors=true and
  35   /// there are remaining errors that haven't been fetched by makeError().
  36   ErrorCollector(bool UseFatalErrors = true) : ErrorsAreFatal(UseFatalErrors) {}
  37   // Don't allow copying.
  38   ErrorCollector(const ErrorCollector &Stub) = delete;
  39   ErrorCollector &operator=(const ErrorCollector &Other) = delete;
  40   ~ErrorCollector();
  41
  42   // TODO: Add move constructor and operator= when a testable situation arises.
  43
  44   /// Returns a single error that contains messages for all stored Errors.
  45   Error makeError();
  46
  47   /// Adds an error with a descriptive tag that helps with identification.
  48   /// If the error is an Error::success(), it is checked and discarded.
  49   void addError(Error &&E, StringRef Tag);
  50
  51   /// This ensures an ErrorCollector will treat unhandled errors as fatal.
  52   /// This function should be called if errors that usually can be ignored
  53   /// are suddenly of concern (i.e. attempt multiple things that return Error,
  54   /// but only care about the Errors if no attempt succeeds).
  55   void escalateToFatal();
  56
  57 private:
  58   /// Logs all errors to a raw_ostream.
  59   void log(raw_ostream &OS);
  60
  61   /// Returns true if all errors have been retrieved through makeError(), or
  62   /// false if errors have been added since the last makeError() call.
  63   bool allErrorsHandled() const;
  64
  65   /// Dump output and crash.
  66   [[noreturn]] void fatalUnhandledError();
  67
  68   bool ErrorsAreFatal;
  69   std::vector<Error> Errors;
  70   std::vector<std::string> Tags;
  71 };
  72
  73 } // end namespace ifs
  74 } // end namespace llvm
  75
  76 #endif // LLVM_TOOLS_LLVM_IFS_ERRORCOLLECTOR_H