1 //===- lib/Core/Reader.cpp ------------------------------------------------===//
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/Reader.h"
11 #include "lld/Core/File.h"
12 #include "lld/Core/Reference.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/BinaryFormat/Magic.h"
15 #include "llvm/Support/Errc.h"
16 #include "llvm/Support/FileSystem.h"
17 #include "llvm/Support/MemoryBuffer.h"
18 #include <algorithm>
19 #include <memory>
20 
21 using llvm::file_magic;
22 using llvm::identify_magic;
23 
24 namespace lld {
25 
26 YamlIOTaggedDocumentHandler::~YamlIOTaggedDocumentHandler() = default;
27 
28 void Registry::add(std::unique_ptr<Reader> reader) {
29   _readers.push_back(std::move(reader));
30 }
31 
32 void Registry::add(std::unique_ptr<YamlIOTaggedDocumentHandler> handler) {
33   _yamlHandlers.push_back(std::move(handler));
34 }
35 
36 ErrorOr<std::unique_ptr<File>>
37 Registry::loadFile(std::unique_ptr<MemoryBuffer> mb) const {
38   // Get file magic.
39   StringRef content(mb->getBufferStart(), mb->getBufferSize());
40   file_magic fileType = identify_magic(content);
41 
42   // Ask each registered reader if it can handle this file type or extension.
43   for (const std::unique_ptr<Reader> &reader : _readers) {
44     if (!reader->canParse(fileType, mb->getMemBufferRef()))
45       continue;
46     return reader->loadFile(std::move(mb), *this);
47   }
48 
49   // No Reader could parse this file.
50   return make_error_code(llvm::errc::executable_format_error);
51 }
52 
53 static const Registry::KindStrings kindStrings[] = {
54     {Reference::kindLayoutAfter, "layout-after"},
55     {Reference::kindAssociate, "associate"},
56     LLD_KIND_STRING_END};
57 
58 Registry::Registry() {
59   addKindTable(Reference::KindNamespace::all, Reference::KindArch::all,
60                kindStrings);
61 }
62 
63 bool Registry::handleTaggedDoc(llvm::yaml::IO &io,
64                                const lld::File *&file) const {
65   for (const std::unique_ptr<YamlIOTaggedDocumentHandler> &h : _yamlHandlers)
66     if (h->handledDocTag(io, file))
67       return true;
68   return false;
69 }
70 
71 void Registry::addKindTable(Reference::KindNamespace ns,
72                             Reference::KindArch arch,
73                             const KindStrings array[]) {
74   KindEntry entry = { ns, arch, array };
75   _kindEntries.push_back(entry);
76 }
77 
78 bool Registry::referenceKindFromString(StringRef inputStr,
79                                        Reference::KindNamespace &ns,
80                                        Reference::KindArch &arch,
81                                        Reference::KindValue &value) const {
82   for (const KindEntry &entry : _kindEntries) {
83     for (const KindStrings *pair = entry.array; !pair->name.empty(); ++pair) {
84       if (!inputStr.equals(pair->name))
85         continue;
86       ns = entry.ns;
87       arch = entry.arch;
88       value = pair->value;
89       return true;
90     }
91   }
92   return false;
93 }
94 
95 bool Registry::referenceKindToString(Reference::KindNamespace ns,
96                                      Reference::KindArch arch,
97                                      Reference::KindValue value,
98                                      StringRef &str) const {
99   for (const KindEntry &entry : _kindEntries) {
100     if (entry.ns != ns)
101       continue;
102     if (entry.arch != arch)
103       continue;
104     for (const KindStrings *pair = entry.array; !pair->name.empty(); ++pair) {
105       if (pair->value != value)
106         continue;
107       str = pair->name;
108       return true;
109     }
110   }
111   return false;
112 }
113 
114 } // end namespace lld
115