1 //===- Error.cpp - system_error extensions for lld --------------*- C++ -*-===//
2 //
3 //                             The LLVM Linker
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lld/Core/Error.h"
11 #include "llvm/ADT/Twine.h"
12 #include "llvm/Support/ErrorHandling.h"
13 #include <mutex>
14 #include <string>
15 #include <vector>
16 
17 using namespace lld;
18 
19 namespace {
20 class _YamlReaderErrorCategory : public std::error_category {
21 public:
name() const22   const char* name() const noexcept override {
23     return "lld.yaml.reader";
24   }
25 
message(int ev) const26   std::string message(int ev) const override {
27     switch (static_cast<YamlReaderError>(ev)) {
28     case YamlReaderError::unknown_keyword:
29       return "Unknown keyword found in yaml file";
30     case YamlReaderError::illegal_value:
31       return "Bad value found in yaml file";
32     }
33     llvm_unreachable("An enumerator of YamlReaderError does not have a "
34                      "message defined.");
35   }
36 };
37 } // end anonymous namespace
38 
YamlReaderCategory()39 const std::error_category &lld::YamlReaderCategory() {
40   static _YamlReaderErrorCategory o;
41   return o;
42 }
43 
44 namespace lld {
45 
46 /// Temporary class to enable make_dynamic_error_code() until
47 /// llvm::ErrorOr<> is updated to work with error encapsulations
48 /// other than error_code.
49 class dynamic_error_category : public std::error_category {
50 public:
51   ~dynamic_error_category() override = default;
52 
name() const53   const char *name() const noexcept override {
54     return "lld.dynamic_error";
55   }
56 
message(int ev) const57   std::string message(int ev) const override {
58     assert(ev >= 0);
59     assert(ev < (int)_messages.size());
60     // The value is an index into the string vector.
61     return _messages[ev];
62   }
63 
add(std::string msg)64   int add(std::string msg) {
65     std::lock_guard<std::recursive_mutex> lock(_mutex);
66     // Value zero is always the successs value.
67     if (_messages.empty())
68       _messages.push_back("Success");
69     _messages.push_back(msg);
70     // Return the index of the string just appended.
71     return _messages.size() - 1;
72   }
73 
74 private:
75   std::vector<std::string> _messages;
76   std::recursive_mutex _mutex;
77 };
78 
79 static dynamic_error_category categorySingleton;
80 
make_dynamic_error_code(StringRef msg)81 std::error_code make_dynamic_error_code(StringRef msg) {
82   return std::error_code(categorySingleton.add(msg), categorySingleton);
83 }
84 
85 char GenericError::ID = 0;
86 
GenericError(Twine Msg)87 GenericError::GenericError(Twine Msg) : Msg(Msg.str()) { }
88 
log(raw_ostream & OS) const89 void GenericError::log(raw_ostream &OS) const {
90   OS << Msg;
91 }
92 
93 } // namespace lld
94