1 //===- DriverUtils.cpp ----------------------------------------------------===//
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 #include "Driver.h"
10 #include "Config.h"
11 #include "InputFiles.h"
12 
13 #include "lld/Common/Args.h"
14 #include "lld/Common/ErrorHandler.h"
15 #include "lld/Common/Memory.h"
16 #include "lld/Common/Reproduce.h"
17 #include "llvm/ADT/CachedHashString.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/Option/Arg.h"
20 #include "llvm/Option/ArgList.h"
21 #include "llvm/Option/Option.h"
22 #include "llvm/Support/CommandLine.h"
23 #include "llvm/Support/Path.h"
24 #include "llvm/TextAPI/MachO/TextAPIReader.h"
25 
26 using namespace llvm;
27 using namespace llvm::MachO;
28 using namespace llvm::opt;
29 using namespace llvm::sys;
30 using namespace lld;
31 using namespace lld::macho;
32 
33 // Create prefix string literals used in Options.td
34 #define PREFIX(NAME, VALUE) const char *NAME[] = VALUE;
35 #include "Options.inc"
36 #undef PREFIX
37 
38 // Create table mapping all options defined in Options.td
39 static const opt::OptTable::Info optInfo[] = {
40 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12)      \
41   {X1, X2, X10,         X11,         OPT_##ID, opt::Option::KIND##Class,       \
42    X9, X8, OPT_##GROUP, OPT_##ALIAS, X7,       X12},
43 #include "Options.inc"
44 #undef OPTION
45 };
46 
MachOOptTable()47 MachOOptTable::MachOOptTable() : OptTable(optInfo) {}
48 
49 // Set color diagnostics according to --color-diagnostics={auto,always,never}
50 // or --no-color-diagnostics flags.
handleColorDiagnostics(opt::InputArgList & args)51 static void handleColorDiagnostics(opt::InputArgList &args) {
52   auto *arg = args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
53                               OPT_no_color_diagnostics);
54   if (!arg)
55     return;
56   if (arg->getOption().getID() == OPT_color_diagnostics) {
57     lld::errs().enable_colors(true);
58   } else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
59     lld::errs().enable_colors(false);
60   } else {
61     StringRef s = arg->getValue();
62     if (s == "always")
63       lld::errs().enable_colors(true);
64     else if (s == "never")
65       lld::errs().enable_colors(false);
66     else if (s != "auto")
67       error("unknown option: --color-diagnostics=" + s);
68   }
69 }
70 
parse(ArrayRef<const char * > argv)71 opt::InputArgList MachOOptTable::parse(ArrayRef<const char *> argv) {
72   // Make InputArgList from string vectors.
73   unsigned missingIndex;
74   unsigned missingCount;
75   SmallVector<const char *, 256> vec(argv.data(), argv.data() + argv.size());
76 
77   // Expand response files (arguments in the form of @<filename>)
78   // and then parse the argument again.
79   cl::ExpandResponseFiles(saver, cl::TokenizeGNUCommandLine, vec);
80   opt::InputArgList args = ParseArgs(vec, missingIndex, missingCount);
81 
82   // Handle -fatal_warnings early since it converts missing argument warnings
83   // to errors.
84   errorHandler().fatalWarnings = args.hasArg(OPT_fatal_warnings);
85 
86   if (missingCount)
87     error(Twine(args.getArgString(missingIndex)) + ": missing argument");
88 
89   handleColorDiagnostics(args);
90 
91   for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
92     std::string nearest;
93     if (findNearest(arg->getAsString(args), nearest) > 1)
94       error("unknown argument '" + arg->getAsString(args) + "'");
95     else
96       error("unknown argument '" + arg->getAsString(args) +
97             "', did you mean '" + nearest + "'");
98   }
99   return args;
100 }
101 
printHelp(const char * argv0,bool showHidden) const102 void MachOOptTable::printHelp(const char *argv0, bool showHidden) const {
103   PrintHelp(lld::outs(), (std::string(argv0) + " [options] file...").c_str(),
104             "LLVM Linker", showHidden);
105   lld::outs() << "\n";
106 }
107 
rewritePath(StringRef s)108 static std::string rewritePath(StringRef s) {
109   if (fs::exists(s))
110     return relativeToRoot(s);
111   return std::string(s);
112 }
113 
114 // Reconstructs command line arguments so that so that you can re-run
115 // the same command with the same inputs. This is for --reproduce.
createResponseFile(const opt::InputArgList & args)116 std::string macho::createResponseFile(const opt::InputArgList &args) {
117   SmallString<0> data;
118   raw_svector_ostream os(data);
119 
120   // Copy the command line to the output while rewriting paths.
121   for (auto *arg : args) {
122     switch (arg->getOption().getID()) {
123     case OPT_reproduce:
124       break;
125     case OPT_INPUT:
126       os << quote(rewritePath(arg->getValue())) << "\n";
127       break;
128     case OPT_o:
129       os << "-o " << quote(path::filename(arg->getValue())) << "\n";
130       break;
131     case OPT_filelist:
132       if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
133         for (StringRef path : args::getLines(*buffer))
134           os << quote(rewritePath(path)) << "\n";
135       break;
136     case OPT_force_load:
137     case OPT_rpath:
138     case OPT_syslibroot:
139     case OPT_F:
140     case OPT_L:
141     case OPT_order_file:
142       os << arg->getSpelling() << " " << quote(rewritePath(arg->getValue()))
143          << "\n";
144       break;
145     case OPT_sectcreate:
146       os << arg->getSpelling() << " " << quote(arg->getValue(0)) << " "
147          << quote(arg->getValue(1)) << " "
148          << quote(rewritePath(arg->getValue(2))) << "\n";
149       break;
150     default:
151       os << toString(*arg) << "\n";
152     }
153   }
154   return std::string(data.str());
155 }
156 
resolveDylibPath(StringRef path)157 Optional<std::string> macho::resolveDylibPath(StringRef path) {
158   // TODO: if a tbd and dylib are both present, we should check to make sure
159   // they are consistent.
160   if (fs::exists(path))
161     return std::string(path);
162 
163   SmallString<261> location = path;
164   path::replace_extension(location, ".tbd");
165   if (fs::exists(location))
166     return std::string(location);
167 
168   return {};
169 }
170 
171 // It's not uncommon to have multiple attempts to load a single dylib,
172 // especially if it's a commonly re-exported core library.
173 static DenseMap<CachedHashStringRef, DylibFile *> loadedDylibs;
174 
loadDylib(MemoryBufferRef mbref,DylibFile * umbrella)175 Optional<DylibFile *> macho::loadDylib(MemoryBufferRef mbref,
176                                        DylibFile *umbrella) {
177   StringRef path = mbref.getBufferIdentifier();
178   DylibFile *&file = loadedDylibs[CachedHashStringRef(path)];
179   if (file)
180     return file;
181 
182   file_magic magic = identify_magic(mbref.getBuffer());
183   if (magic == file_magic::tapi_file) {
184     Expected<std::unique_ptr<InterfaceFile>> result = TextAPIReader::get(mbref);
185     if (!result) {
186       error("could not load TAPI file at " + mbref.getBufferIdentifier() +
187             ": " + toString(result.takeError()));
188       return {};
189     }
190     file = make<DylibFile>(**result, umbrella);
191   } else {
192     assert(magic == file_magic::macho_dynamically_linked_shared_lib ||
193            magic == file_magic::macho_dynamically_linked_shared_lib_stub);
194     file = make<DylibFile>(mbref, umbrella);
195   }
196   return file;
197 }
198 
getModTime(StringRef path)199 uint32_t macho::getModTime(StringRef path) {
200   fs::file_status stat;
201   if (!fs::status(path, stat))
202     if (fs::exists(stat))
203       return toTimeT(stat.getLastModificationTime());
204 
205   warn("failed to get modification time of " + path);
206   return 0;
207 }
208 
printArchiveMemberLoad(StringRef reason,const InputFile * f)209 void macho::printArchiveMemberLoad(StringRef reason, const InputFile *f) {
210   if (config->printEachFile)
211     message(toString(f));
212   if (config->printWhyLoad)
213     message(reason + " forced load of " + toString(f));
214 }
215