1 //===- yaml2obj - Convert YAML to a binary object file --------------------===//
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 program takes a YAML description of an object file and outputs the
10 // binary equivalent.
11 //
12 // This is used for writing tests that require binary files.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "llvm/ObjectYAML/yaml2obj.h"
17 #include "llvm/ADT/StringExtras.h"
18 #include "llvm/ObjectYAML/ObjectYAML.h"
19 #include "llvm/Support/CommandLine.h"
20 #include "llvm/Support/FileSystem.h"
21 #include "llvm/Support/InitLLVM.h"
22 #include "llvm/Support/MemoryBuffer.h"
23 #include "llvm/Support/ToolOutputFile.h"
24 #include "llvm/Support/WithColor.h"
25 #include "llvm/Support/YAMLTraits.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <system_error>
28 
29 using namespace llvm;
30 
31 namespace {
32 cl::OptionCategory Cat("yaml2obj Options");
33 
34 cl::opt<std::string> Input(cl::Positional, cl::desc("<input file>"),
35                            cl::init("-"), cl::cat(Cat));
36 
37 cl::list<std::string>
38     D("D", cl::Prefix,
39       cl::desc("Defined the specified macros to their specified "
40                "definition. The syntax is <macro>=<definition>"));
41 
42 cl::opt<unsigned>
43     DocNum("docnum", cl::init(1),
44            cl::desc("Read specified document from input (default = 1)"),
45            cl::cat(Cat));
46 
47 cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"),
48                                     cl::value_desc("filename"), cl::init("-"),
49                                     cl::Prefix, cl::cat(Cat));
50 } // namespace
51 
52 static Optional<std::string> preprocess(StringRef Buf,
53                                         yaml::ErrorHandler ErrHandler) {
54   DenseMap<StringRef, StringRef> Defines;
55   for (StringRef Define : D) {
56     StringRef Macro, Definition;
57     std::tie(Macro, Definition) = Define.split('=');
58     if (!Define.count('=') || Macro.empty()) {
59       ErrHandler("invalid syntax for -D: " + Define);
60       return {};
61     }
62     if (!Defines.try_emplace(Macro, Definition).second) {
63       ErrHandler("'" + Macro + "'" + " redefined");
64       return {};
65     }
66   }
67 
68   std::string Preprocessed;
69   while (!Buf.empty()) {
70     if (Buf.startswith("[[")) {
71       size_t I = Buf.find_first_of("[]", 2);
72       if (Buf.substr(I).startswith("]]")) {
73         StringRef Macro = Buf.substr(2, I - 2);
74         auto It = Defines.find(Macro);
75         if (It != Defines.end()) {
76           Preprocessed += It->second;
77           Buf = Buf.substr(I + 2);
78           continue;
79         }
80       }
81     }
82 
83     Preprocessed += Buf[0];
84     Buf = Buf.substr(1);
85   }
86 
87   return Preprocessed;
88 }
89 
90 int main(int argc, char **argv) {
91   InitLLVM X(argc, argv);
92   cl::HideUnrelatedOptions(Cat);
93   cl::ParseCommandLineOptions(
94       argc, argv, "Create an object file from a YAML description", nullptr,
95       nullptr, /*LongOptionsUseDoubleDash=*/true);
96 
97   auto ErrHandler = [](const Twine &Msg) {
98     WithColor::error(errs(), "yaml2obj") << Msg << "\n";
99   };
100 
101   std::error_code EC;
102   std::unique_ptr<ToolOutputFile> Out(
103       new ToolOutputFile(OutputFilename, EC, sys::fs::OF_None));
104   if (EC) {
105     ErrHandler("failed to open '" + OutputFilename + "': " + EC.message());
106     return 1;
107   }
108 
109   ErrorOr<std::unique_ptr<MemoryBuffer>> Buf =
110       MemoryBuffer::getFileOrSTDIN(Input);
111   if (!Buf)
112     return 1;
113 
114   Optional<std::string> Buffer = preprocess(Buf.get()->getBuffer(), ErrHandler);
115   if (!Buffer)
116     return 1;
117   yaml::Input YIn(*Buffer);
118   if (!convertYAML(YIn, Out->os(), ErrHandler, DocNum))
119     return 1;
120 
121   Out->keep();
122   Out->os().flush();
123   return 0;
124 }
125