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