1 //===- COFFImportFile.h - COFF short import file implementation -*- 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 // COFF short import file is a special kind of file which contains
10 // only symbol names for DLL-exported symbols. This class implements
11 // exporting of Symbols to create libraries and a SymbolicFile
12 // interface for the file type.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_OBJECT_COFFIMPORTFILE_H
17 #define LLVM_OBJECT_COFFIMPORTFILE_H
18 
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/Object/COFF.h"
21 #include "llvm/Object/ObjectFile.h"
22 #include "llvm/Object/SymbolicFile.h"
23 #include "llvm/Support/MemoryBufferRef.h"
24 #include "llvm/Support/raw_ostream.h"
25 
26 namespace llvm {
27 namespace object {
28 
29 class COFFImportFile : public SymbolicFile {
30 public:
31   COFFImportFile(MemoryBufferRef Source)
32       : SymbolicFile(ID_COFFImportFile, Source) {}
33 
34   static bool classof(Binary const *V) { return V->isCOFFImportFile(); }
35 
36   void moveSymbolNext(DataRefImpl &Symb) const override { ++Symb.p; }
37 
38   Error printSymbolName(raw_ostream &OS, DataRefImpl Symb) const override {
39     if (Symb.p == 0)
40       OS << "__imp_";
41     OS << StringRef(Data.getBufferStart() + sizeof(coff_import_header));
42     return Error::success();
43   }
44 
45   Expected<uint32_t> getSymbolFlags(DataRefImpl Symb) const override {
46     return SymbolRef::SF_Global;
47   }
48 
49   basic_symbol_iterator symbol_begin() const override {
50     return BasicSymbolRef(DataRefImpl(), this);
51   }
52 
53   basic_symbol_iterator symbol_end() const override {
54     DataRefImpl Symb;
55     Symb.p = isData() ? 1 : 2;
56     return BasicSymbolRef(Symb, this);
57   }
58 
59   bool is64Bit() const override { return false; }
60 
61   const coff_import_header *getCOFFImportHeader() const {
62     return reinterpret_cast<const object::coff_import_header *>(
63         Data.getBufferStart());
64   }
65 
66 private:
67   bool isData() const {
68     return getCOFFImportHeader()->getType() == COFF::IMPORT_DATA;
69   }
70 };
71 
72 struct COFFShortExport {
73   /// The name of the export as specified in the .def file or on the command
74   /// line, i.e. "foo" in "/EXPORT:foo", and "bar" in "/EXPORT:foo=bar". This
75   /// may lack mangling, such as underscore prefixing and stdcall suffixing.
76   std::string Name;
77 
78   /// The external, exported name. Only non-empty when export renaming is in
79   /// effect, i.e. "foo" in "/EXPORT:foo=bar".
80   std::string ExtName;
81 
82   /// The real, mangled symbol name from the object file. Given
83   /// "/export:foo=bar", this could be "_bar@8" if bar is stdcall.
84   std::string SymbolName;
85 
86   /// Creates a weak alias. This is the name of the weak aliasee. In a .def
87   /// file, this is "baz" in "EXPORTS\nfoo = bar == baz".
88   std::string AliasTarget;
89 
90   uint16_t Ordinal = 0;
91   bool Noname = false;
92   bool Data = false;
93   bool Private = false;
94   bool Constant = false;
95 
96   friend bool operator==(const COFFShortExport &L, const COFFShortExport &R) {
97     return L.Name == R.Name && L.ExtName == R.ExtName &&
98             L.Ordinal == R.Ordinal && L.Noname == R.Noname &&
99             L.Data == R.Data && L.Private == R.Private;
100   }
101 
102   friend bool operator!=(const COFFShortExport &L, const COFFShortExport &R) {
103     return !(L == R);
104   }
105 };
106 
107 Error writeImportLibrary(StringRef ImportName, StringRef Path,
108                          ArrayRef<COFFShortExport> Exports,
109                          COFF::MachineTypes Machine, bool MinGW);
110 
111 } // namespace object
112 } // namespace llvm
113 
114 #endif
115