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