1 //===- Error.h - system_error extensions for Object -------------*- 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 declares a new error_category for the Object library.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_OBJECT_ERROR_H
14 #define LLVM_OBJECT_ERROR_H
15 
16 #include "llvm/Support/Error.h"
17 #include <system_error>
18 
19 namespace llvm {
20 
21 class Twine;
22 
23 namespace object {
24 
25 const std::error_category &object_category();
26 
27 enum class object_error {
28   // Error code 0 is absent. Use std::error_code() instead.
29   arch_not_found = 1,
30   invalid_file_type,
31   parse_failed,
32   unexpected_eof,
33   string_table_non_null_end,
34   invalid_section_index,
35   bitcode_section_not_found,
36   invalid_symbol_index,
37 };
38 
39 inline std::error_code make_error_code(object_error e) {
40   return std::error_code(static_cast<int>(e), object_category());
41 }
42 
43 /// Base class for all errors indicating malformed binary files.
44 ///
45 /// Having a subclass for all malformed binary files allows archive-walking
46 /// code to skip malformed files without having to understand every possible
47 /// way that a binary file might be malformed.
48 ///
49 /// Currently inherits from ECError for easy interoperability with
50 /// std::error_code, but this will be removed in the future.
51 class BinaryError : public ErrorInfo<BinaryError, ECError> {
52   void anchor() override;
53 public:
54   static char ID;
55   BinaryError() {
56     // Default to parse_failed, can be overridden with setErrorCode.
57     setErrorCode(make_error_code(object_error::parse_failed));
58   }
59 };
60 
61 /// Generic binary error.
62 ///
63 /// For errors that don't require their own specific sub-error (most errors)
64 /// this class can be used to describe the error via a string message.
65 class GenericBinaryError : public ErrorInfo<GenericBinaryError, BinaryError> {
66 public:
67   static char ID;
68   GenericBinaryError(const Twine &Msg);
69   GenericBinaryError(const Twine &Msg, object_error ECOverride);
70   const std::string &getMessage() const { return Msg; }
71   void log(raw_ostream &OS) const override;
72 private:
73   std::string Msg;
74 };
75 
76 /// isNotObjectErrorInvalidFileType() is used when looping through the children
77 /// of an archive after calling getAsBinary() on the child and it returns an
78 /// llvm::Error.  In the cases we want to loop through the children and ignore the
79 /// non-objects in the archive this is used to test the error to see if an
80 /// error() function needs to called on the llvm::Error.
81 Error isNotObjectErrorInvalidFileType(llvm::Error Err);
82 
83 inline Error createError(const Twine &Err) {
84   return make_error<StringError>(Err, object_error::parse_failed);
85 }
86 
87 } // end namespace object.
88 
89 } // end namespace llvm.
90 
91 namespace std {
92 template <>
93 struct is_error_code_enum<llvm::object::object_error> : std::true_type {};
94 }
95 
96 #endif
97