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
28namespace llvm {
29
30namespace ifs {
31
32class ErrorCollector {
33public:
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
57private:
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
77