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 // This file contains utility functions for the driver. Because there
10 // are so many small functions, we created this separate file to make
11 // Driver.cpp less cluttered.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "Driver.h"
16 #include "lld/Common/ErrorHandler.h"
17 #include "lld/Common/Memory.h"
18 #include "lld/Common/Reproduce.h"
19 #include "lld/Common/Version.h"
20 #include "llvm/ADT/Optional.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/Option/Option.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/Host.h"
27 #include "llvm/Support/Path.h"
28 #include "llvm/Support/Process.h"
29 #include "llvm/Support/TimeProfiler.h"
30
31 using namespace llvm;
32 using namespace llvm::sys;
33 using namespace llvm::opt;
34 using namespace lld;
35 using namespace lld::elf;
36
37 // Create OptTable
38
39 // Create prefix string literals used in Options.td
40 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
41 #include "Options.inc"
42 #undef PREFIX
43
44 // Create table mapping all options defined in Options.td
45 static const opt::OptTable::Info optInfo[] = {
46 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12) \
47 {X1, X2, X10, X11, OPT_##ID, opt::Option::KIND##Class, \
48 X9, X8, OPT_##GROUP, OPT_##ALIAS, X7, X12},
49 #include "Options.inc"
50 #undef OPTION
51 };
52
ELFOptTable()53 ELFOptTable::ELFOptTable() : OptTable(optInfo) {}
54
55 // Set color diagnostics according to -color-diagnostics={auto,always,never}
56 // or -no-color-diagnostics flags.
handleColorDiagnostics(opt::InputArgList & args)57 static void handleColorDiagnostics(opt::InputArgList &args) {
58 auto *arg = args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
59 OPT_no_color_diagnostics);
60 if (!arg)
61 return;
62 if (arg->getOption().getID() == OPT_color_diagnostics) {
63 lld::errs().enable_colors(true);
64 } else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
65 lld::errs().enable_colors(false);
66 } else {
67 StringRef s = arg->getValue();
68 if (s == "always")
69 lld::errs().enable_colors(true);
70 else if (s == "never")
71 lld::errs().enable_colors(false);
72 else if (s != "auto")
73 error("unknown option: --color-diagnostics=" + s);
74 }
75 }
76
getQuotingStyle(opt::InputArgList & args)77 static cl::TokenizerCallback getQuotingStyle(opt::InputArgList &args) {
78 if (auto *arg = args.getLastArg(OPT_rsp_quoting)) {
79 StringRef s = arg->getValue();
80 if (s != "windows" && s != "posix")
81 error("invalid response file quoting: " + s);
82 if (s == "windows")
83 return cl::TokenizeWindowsCommandLine;
84 return cl::TokenizeGNUCommandLine;
85 }
86 if (Triple(sys::getProcessTriple()).isOSWindows())
87 return cl::TokenizeWindowsCommandLine;
88 return cl::TokenizeGNUCommandLine;
89 }
90
91 // Gold LTO plugin takes a `--plugin-opt foo=bar` option as an alias for
92 // `--plugin-opt=foo=bar`. We want to handle `--plugin-opt=foo=` as an
93 // option name and `bar` as a value. Unfortunately, OptParser cannot
94 // handle an option with a space in it.
95 //
96 // In this function, we concatenate command line arguments so that
97 // `--plugin-opt <foo>` is converted to `--plugin-opt=<foo>`. This is a
98 // bit hacky, but looks like it is still better than handling --plugin-opt
99 // options by hand.
concatLTOPluginOptions(SmallVectorImpl<const char * > & args)100 static void concatLTOPluginOptions(SmallVectorImpl<const char *> &args) {
101 SmallVector<const char *, 256> v;
102 for (size_t i = 0, e = args.size(); i != e; ++i) {
103 StringRef s = args[i];
104 if ((s == "-plugin-opt" || s == "--plugin-opt") && i + 1 != e) {
105 v.push_back(saver.save(s + "=" + args[i + 1]).data());
106 ++i;
107 } else {
108 v.push_back(args[i]);
109 }
110 }
111 args = std::move(v);
112 }
113
114 // Parses a given list of options.
parse(ArrayRef<const char * > argv)115 opt::InputArgList ELFOptTable::parse(ArrayRef<const char *> argv) {
116 // Make InputArgList from string vectors.
117 unsigned missingIndex;
118 unsigned missingCount;
119 SmallVector<const char *, 256> vec(argv.data(), argv.data() + argv.size());
120
121 // We need to get the quoting style for response files before parsing all
122 // options so we parse here before and ignore all the options but
123 // --rsp-quoting.
124 opt::InputArgList args = this->ParseArgs(vec, missingIndex, missingCount);
125
126 // Expand response files (arguments in the form of @<filename>)
127 // and then parse the argument again.
128 cl::ExpandResponseFiles(saver, getQuotingStyle(args), vec);
129 concatLTOPluginOptions(vec);
130 args = this->ParseArgs(vec, missingIndex, missingCount);
131
132 handleColorDiagnostics(args);
133 if (missingCount)
134 error(Twine(args.getArgString(missingIndex)) + ": missing argument");
135
136 for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
137 std::string nearest;
138 if (findNearest(arg->getAsString(args), nearest) > 1)
139 error("unknown argument '" + arg->getAsString(args) + "'");
140 else
141 error("unknown argument '" + arg->getAsString(args) +
142 "', did you mean '" + nearest + "'");
143 }
144 return args;
145 }
146
printHelp()147 void elf::printHelp() {
148 ELFOptTable().PrintHelp(
149 lld::outs(), (config->progName + " [options] file...").str().c_str(),
150 "lld", false /*ShowHidden*/, true /*ShowAllAliases*/);
151 lld::outs() << "\n";
152
153 // Scripts generated by Libtool versions up to at least 2.4.6 (the most
154 // recent version as of March 2017) expect /: supported targets:.* elf/
155 // in a message for the -help option. If it doesn't match, the scripts
156 // assume that the linker doesn't support very basic features such as
157 // shared libraries. Therefore, we need to print out at least "elf".
158 lld::outs() << config->progName << ": supported targets: elf\n";
159 }
160
rewritePath(StringRef s)161 static std::string rewritePath(StringRef s) {
162 if (fs::exists(s))
163 return relativeToRoot(s);
164 return std::string(s);
165 }
166
167 // Reconstructs command line arguments so that so that you can re-run
168 // the same command with the same inputs. This is for --reproduce.
createResponseFile(const opt::InputArgList & args)169 std::string elf::createResponseFile(const opt::InputArgList &args) {
170 SmallString<0> data;
171 raw_svector_ostream os(data);
172 os << "--chroot .\n";
173
174 // Copy the command line to the output while rewriting paths.
175 for (auto *arg : args) {
176 switch (arg->getOption().getID()) {
177 case OPT_reproduce:
178 break;
179 case OPT_INPUT:
180 os << quote(rewritePath(arg->getValue())) << "\n";
181 break;
182 case OPT_o:
183 // If -o path contains directories, "lld @response.txt" will likely
184 // fail because the archive we are creating doesn't contain empty
185 // directories for the output path (-o doesn't create directories).
186 // Strip directories to prevent the issue.
187 os << "-o " << quote(path::filename(arg->getValue())) << "\n";
188 break;
189 case OPT_call_graph_ordering_file:
190 case OPT_dynamic_list:
191 case OPT_just_symbols:
192 case OPT_library_path:
193 case OPT_retain_symbols_file:
194 case OPT_rpath:
195 case OPT_script:
196 case OPT_symbol_ordering_file:
197 case OPT_sysroot:
198 case OPT_version_script:
199 os << arg->getSpelling() << " " << quote(rewritePath(arg->getValue()))
200 << "\n";
201 break;
202 default:
203 os << toString(*arg) << "\n";
204 }
205 }
206 return std::string(data.str());
207 }
208
209 // Find a file by concatenating given paths. If a resulting path
210 // starts with "=", the character is replaced with a --sysroot value.
findFile(StringRef path1,const Twine & path2)211 static Optional<std::string> findFile(StringRef path1, const Twine &path2) {
212 SmallString<128> s;
213 if (path1.startswith("="))
214 path::append(s, config->sysroot, path1.substr(1), path2);
215 else
216 path::append(s, path1, path2);
217
218 if (fs::exists(s))
219 return std::string(s);
220 return None;
221 }
222
findFromSearchPaths(StringRef path)223 Optional<std::string> elf::findFromSearchPaths(StringRef path) {
224 for (StringRef dir : config->searchPaths)
225 if (Optional<std::string> s = findFile(dir, path))
226 return s;
227 return None;
228 }
229
230 // This is for -l<basename>. We'll look for lib<basename>.so or lib<basename>.a from
231 // search paths.
searchLibraryBaseName(StringRef name)232 Optional<std::string> elf::searchLibraryBaseName(StringRef name) {
233 for (StringRef dir : config->searchPaths) {
234 if (!config->isStatic)
235 if (Optional<std::string> s = findFile(dir, "lib" + name + ".so"))
236 return s;
237 if (Optional<std::string> s = findFile(dir, "lib" + name + ".a"))
238 return s;
239 }
240 return None;
241 }
242
243 // This is for -l<namespec>.
searchLibrary(StringRef name)244 Optional<std::string> elf::searchLibrary(StringRef name) {
245 llvm::TimeTraceScope timeScope("Locate library", name);
246 if (name.startswith(":"))
247 return findFromSearchPaths(name.substr(1));
248 return searchLibraryBaseName(name);
249 }
250
251 // If a linker/version script doesn't exist in the current directory, we also
252 // look for the script in the '-L' search paths. This matches the behaviour of
253 // '-T', --version-script=, and linker script INPUT() command in ld.bfd.
searchScript(StringRef name)254 Optional<std::string> elf::searchScript(StringRef name) {
255 if (fs::exists(name))
256 return name.str();
257 return findFromSearchPaths(name);
258 }
259