xref: /llvm-project/llvm/tools/llvm-ifs/ErrorCollector.h (revision ccde601f140c79344e67e3a5164524ea3d8f43aa)
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().
ErrorsAreFatal(UseFatalErrors)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
77