1 //===- DlltoolDriver.cpp - dlltool.exe-compatible driver ------------------===//
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 // Defines an interface to a dlltool.exe-compatible driver.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ToolDrivers/llvm-dlltool/DlltoolDriver.h"
14 #include "llvm/Object/COFF.h"
15 #include "llvm/Object/COFFImportFile.h"
16 #include "llvm/Object/COFFModuleDefinition.h"
17 #include "llvm/Option/Arg.h"
18 #include "llvm/Option/ArgList.h"
19 #include "llvm/Option/Option.h"
20 #include "llvm/Support/Path.h"
21 
22 #include <vector>
23 
24 using namespace llvm;
25 using namespace llvm::object;
26 using namespace llvm::COFF;
27 
28 namespace {
29 
30 enum {
31   OPT_INVALID = 0,
32 #define OPTION(_1, _2, ID, _4, _5, _6, _7, _8, _9, _10, _11, _12) OPT_##ID,
33 #include "Options.inc"
34 #undef OPTION
35 };
36 
37 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
38 #include "Options.inc"
39 #undef PREFIX
40 
41 static const llvm::opt::OptTable::Info InfoTable[] = {
42 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12)      \
43   {X1, X2, X10,         X11,         OPT_##ID, llvm::opt::Option::KIND##Class, \
44    X9, X8, OPT_##GROUP, OPT_##ALIAS, X7,       X12},
45 #include "Options.inc"
46 #undef OPTION
47 };
48 
49 class DllOptTable : public llvm::opt::OptTable {
50 public:
51   DllOptTable() : OptTable(InfoTable, false) {}
52 };
53 
54 } // namespace
55 
56 // Opens a file. Path has to be resolved already.
57 static std::unique_ptr<MemoryBuffer> openFile(const Twine &Path) {
58   ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MB = MemoryBuffer::getFile(Path);
59 
60   if (std::error_code EC = MB.getError()) {
61     llvm::errs() << "cannot open file " << Path << ": " << EC.message() << "\n";
62     return nullptr;
63   }
64 
65   return std::move(*MB);
66 }
67 
68 static MachineTypes getEmulation(StringRef S) {
69   return StringSwitch<MachineTypes>(S)
70       .Case("i386", IMAGE_FILE_MACHINE_I386)
71       .Case("i386:x86-64", IMAGE_FILE_MACHINE_AMD64)
72       .Case("arm", IMAGE_FILE_MACHINE_ARMNT)
73       .Case("arm64", IMAGE_FILE_MACHINE_ARM64)
74       .Default(IMAGE_FILE_MACHINE_UNKNOWN);
75 }
76 
77 int llvm::dlltoolDriverMain(llvm::ArrayRef<const char *> ArgsArr) {
78   DllOptTable Table;
79   unsigned MissingIndex;
80   unsigned MissingCount;
81   llvm::opt::InputArgList Args =
82       Table.ParseArgs(ArgsArr.slice(1), MissingIndex, MissingCount);
83   if (MissingCount) {
84     llvm::errs() << Args.getArgString(MissingIndex) << ": missing argument\n";
85     return 1;
86   }
87 
88   // Handle when no input or output is specified
89   if (Args.hasArgNoClaim(OPT_INPUT) ||
90       (!Args.hasArgNoClaim(OPT_d) && !Args.hasArgNoClaim(OPT_l))) {
91     Table.PrintHelp(outs(), "llvm-dlltool [options] file...", "llvm-dlltool",
92                     false);
93     llvm::outs() << "\nTARGETS: i386, i386:x86-64, arm, arm64\n";
94     return 1;
95   }
96 
97   if (!Args.hasArgNoClaim(OPT_m) && Args.hasArgNoClaim(OPT_d)) {
98     llvm::errs() << "error: no target machine specified\n"
99                  << "supported targets: i386, i386:x86-64, arm, arm64\n";
100     return 1;
101   }
102 
103   for (auto *Arg : Args.filtered(OPT_UNKNOWN))
104     llvm::errs() << "ignoring unknown argument: " << Arg->getAsString(Args)
105                  << "\n";
106 
107   if (!Args.hasArg(OPT_d)) {
108     llvm::errs() << "no definition file specified\n";
109     return 1;
110   }
111 
112   std::unique_ptr<MemoryBuffer> MB =
113       openFile(Args.getLastArg(OPT_d)->getValue());
114   if (!MB)
115     return 1;
116 
117   if (!MB->getBufferSize()) {
118     llvm::errs() << "definition file empty\n";
119     return 1;
120   }
121 
122   COFF::MachineTypes Machine = IMAGE_FILE_MACHINE_UNKNOWN;
123   if (auto *Arg = Args.getLastArg(OPT_m))
124     Machine = getEmulation(Arg->getValue());
125 
126   if (Machine == IMAGE_FILE_MACHINE_UNKNOWN) {
127     llvm::errs() << "unknown target\n";
128     return 1;
129   }
130 
131   Expected<COFFModuleDefinition> Def =
132       parseCOFFModuleDefinition(*MB, Machine, true);
133 
134   if (!Def) {
135     llvm::errs() << "error parsing definition\n"
136                  << errorToErrorCode(Def.takeError()).message();
137     return 1;
138   }
139 
140   // Do this after the parser because parseCOFFModuleDefinition sets OutputFile.
141   if (auto *Arg = Args.getLastArg(OPT_D))
142     Def->OutputFile = Arg->getValue();
143 
144   if (Def->OutputFile.empty()) {
145     llvm::errs() << "no DLL name specified\n";
146     return 1;
147   }
148 
149   std::string Path = std::string(Args.getLastArgValue(OPT_l));
150 
151   // If ExtName is set (if the "ExtName = Name" syntax was used), overwrite
152   // Name with ExtName and clear ExtName. When only creating an import
153   // library and not linking, the internal name is irrelevant. This avoids
154   // cases where writeImportLibrary tries to transplant decoration from
155   // symbol decoration onto ExtName.
156   for (COFFShortExport& E : Def->Exports) {
157     if (!E.ExtName.empty()) {
158       E.Name = E.ExtName;
159       E.ExtName.clear();
160     }
161   }
162 
163   if (Machine == IMAGE_FILE_MACHINE_I386 && Args.getLastArg(OPT_k)) {
164     for (COFFShortExport& E : Def->Exports) {
165       if (!E.AliasTarget.empty() || (!E.Name.empty() && E.Name[0] == '?'))
166         continue;
167       E.SymbolName = E.Name;
168       // Trim off the trailing decoration. Symbols will always have a
169       // starting prefix here (either _ for cdecl/stdcall, @ for fastcall
170       // or ? for C++ functions). Vectorcall functions won't have any
171       // fixed prefix, but the function base name will still be at least
172       // one char.
173       E.Name = E.Name.substr(0, E.Name.find('@', 1));
174       // By making sure E.SymbolName != E.Name for decorated symbols,
175       // writeImportLibrary writes these symbols with the type
176       // IMPORT_NAME_UNDECORATE.
177     }
178   }
179 
180   if (!Path.empty() &&
181       writeImportLibrary(Def->OutputFile, Path, Def->Exports, Machine, true))
182     return 1;
183   return 0;
184 }
185