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1 //===- Driver.h -------------------------------------------------*- 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 #ifndef LLD_COFF_DRIVER_H
10 #define LLD_COFF_DRIVER_H
11 
12 #include "Config.h"
13 #include "SymbolTable.h"
14 #include "lld/Common/LLVM.h"
15 #include "lld/Common/Reproduce.h"
16 #include "llvm/ADT/Optional.h"
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/ADT/StringSet.h"
19 #include "llvm/Object/Archive.h"
20 #include "llvm/Object/COFF.h"
21 #include "llvm/Option/Arg.h"
22 #include "llvm/Option/ArgList.h"
23 #include "llvm/Support/FileSystem.h"
24 #include "llvm/Support/TarWriter.h"
25 #include <memory>
26 #include <set>
27 #include <vector>
28 
29 namespace lld {
30 namespace coff {
31 
32 class LinkerDriver;
33 extern LinkerDriver *driver;
34 
35 using llvm::COFF::MachineTypes;
36 using llvm::COFF::WindowsSubsystem;
37 using llvm::Optional;
38 
39 class COFFOptTable : public llvm::opt::OptTable {
40 public:
41   COFFOptTable();
42 };
43 
44 // Constructing the option table is expensive. Use a global table to avoid doing
45 // it more than once.
46 extern COFFOptTable optTable;
47 
48 // The result of parsing the .drective section. The /export: and /include:
49 // options are handled separately because they reference symbols, and the number
50 // of symbols can be quite large. The LLVM Option library will perform at least
51 // one memory allocation per argument, and that is prohibitively slow for
52 // parsing directives.
53 struct ParsedDirectives {
54   std::vector<StringRef> exports;
55   std::vector<StringRef> includes;
56   llvm::opt::InputArgList args;
57 };
58 
59 class ArgParser {
60 public:
61   // Parses command line options.
62   llvm::opt::InputArgList parse(llvm::ArrayRef<const char *> args);
63 
64   // Tokenizes a given string and then parses as command line options.
parse(StringRef s)65   llvm::opt::InputArgList parse(StringRef s) { return parse(tokenize(s)); }
66 
67   // Tokenizes a given string and then parses as command line options in
68   // .drectve section. /EXPORT options are returned in second element
69   // to be processed in fastpath.
70   ParsedDirectives parseDirectives(StringRef s);
71 
72 private:
73   // Concatenate LINK environment variable.
74   void addLINK(SmallVector<const char *, 256> &argv);
75 
76   std::vector<const char *> tokenize(StringRef s);
77 };
78 
79 class LinkerDriver {
80 public:
81   void link(llvm::ArrayRef<const char *> args);
82 
83   // Used by the resolver to parse .drectve section contents.
84   void parseDirectives(InputFile *file);
85 
86   // Used by ArchiveFile to enqueue members.
87   void enqueueArchiveMember(const Archive::Child &c, const Archive::Symbol &sym,
88                             StringRef parentName);
89 
enqueuePDB(StringRef Path)90   void enqueuePDB(StringRef Path) { enqueuePath(Path, false, false); }
91 
92   MemoryBufferRef takeBuffer(std::unique_ptr<MemoryBuffer> mb);
93 
94   void enqueuePath(StringRef path, bool wholeArchive, bool lazy);
95 
96 private:
97   std::unique_ptr<llvm::TarWriter> tar; // for /linkrepro
98 
99   // Searches a file from search paths.
100   Optional<StringRef> findFile(StringRef filename);
101   Optional<StringRef> findLib(StringRef filename);
102   StringRef doFindFile(StringRef filename);
103   StringRef doFindLib(StringRef filename);
104   StringRef doFindLibMinGW(StringRef filename);
105 
106   // Parses LIB environment which contains a list of search paths.
107   void addLibSearchPaths();
108 
109   // Library search path. The first element is always "" (current directory).
110   std::vector<StringRef> searchPaths;
111 
112   // Convert resource files and potentially merge input resource object
113   // trees into one resource tree.
114   void convertResources();
115 
116   void maybeExportMinGWSymbols(const llvm::opt::InputArgList &args);
117 
118   // We don't want to add the same file more than once.
119   // Files are uniquified by their filesystem and file number.
120   std::set<llvm::sys::fs::UniqueID> visitedFiles;
121 
122   std::set<std::string> visitedLibs;
123 
124   Symbol *addUndefined(StringRef sym);
125 
126   StringRef mangleMaybe(Symbol *s);
127 
128   // Windows specific -- "main" is not the only main function in Windows.
129   // You can choose one from these four -- {w,}{WinMain,main}.
130   // There are four different entry point functions for them,
131   // {w,}{WinMain,main}CRTStartup, respectively. The linker needs to
132   // choose the right one depending on which "main" function is defined.
133   // This function looks up the symbol table and resolve corresponding
134   // entry point name.
135   StringRef findDefaultEntry();
136   WindowsSubsystem inferSubsystem();
137 
138   void addBuffer(std::unique_ptr<MemoryBuffer> mb, bool wholeArchive,
139                  bool lazy);
140   void addArchiveBuffer(MemoryBufferRef mbref, StringRef symName,
141                         StringRef parentName, uint64_t offsetInArchive);
142 
143   void enqueueTask(std::function<void()> task);
144   bool run();
145 
146   std::list<std::function<void()>> taskQueue;
147   std::vector<StringRef> filePaths;
148   std::vector<MemoryBufferRef> resources;
149 
150   llvm::StringSet<> directivesExports;
151 };
152 
153 // Functions below this line are defined in DriverUtils.cpp.
154 
155 void printHelp(const char *argv0);
156 
157 // Parses a string in the form of "<integer>[,<integer>]".
158 void parseNumbers(StringRef arg, uint64_t *addr, uint64_t *size = nullptr);
159 
160 void parseGuard(StringRef arg);
161 
162 // Parses a string in the form of "<integer>[.<integer>]".
163 // Minor's default value is 0.
164 void parseVersion(StringRef arg, uint32_t *major, uint32_t *minor);
165 
166 // Parses a string in the form of "<subsystem>[,<integer>[.<integer>]]".
167 void parseSubsystem(StringRef arg, WindowsSubsystem *sys, uint32_t *major,
168                     uint32_t *minor, bool *gotVersion = nullptr);
169 
170 void parseAlternateName(StringRef);
171 void parseMerge(StringRef);
172 void parseSection(StringRef);
173 void parseAligncomm(StringRef);
174 
175 // Parses a string in the form of "[:<integer>]"
176 void parseFunctionPadMin(llvm::opt::Arg *a, llvm::COFF::MachineTypes machine);
177 
178 // Parses a string in the form of "EMBED[,=<integer>]|NO".
179 void parseManifest(StringRef arg);
180 
181 // Parses a string in the form of "level=<string>|uiAccess=<string>"
182 void parseManifestUAC(StringRef arg);
183 
184 // Parses a string in the form of "cd|net[,(cd|net)]*"
185 void parseSwaprun(StringRef arg);
186 
187 // Create a resource file containing a manifest XML.
188 std::unique_ptr<MemoryBuffer> createManifestRes();
189 void createSideBySideManifest();
190 
191 // Used for dllexported symbols.
192 Export parseExport(StringRef arg);
193 void fixupExports();
194 void assignExportOrdinals();
195 
196 // Parses a string in the form of "key=value" and check
197 // if value matches previous values for the key.
198 // This feature used in the directive section to reject
199 // incompatible objects.
200 void checkFailIfMismatch(StringRef arg, InputFile *source);
201 
202 // Convert Windows resource files (.res files) to a .obj file.
203 MemoryBufferRef convertResToCOFF(ArrayRef<MemoryBufferRef> mbs,
204                                  ArrayRef<ObjFile *> objs);
205 
206 // Create enum with OPT_xxx values for each option in Options.td
207 enum {
208   OPT_INVALID = 0,
209 #define OPTION(_1, _2, ID, _4, _5, _6, _7, _8, _9, _10, _11, _12) OPT_##ID,
210 #include "Options.inc"
211 #undef OPTION
212 };
213 
214 } // namespace coff
215 } // namespace lld
216 
217 #endif
218