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 ctx.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 "Config.h"
16#include "Driver.h"
17#include "lld/Common/CommonLinkerContext.h"
18#include "lld/Common/Reproduce.h"
19#include "llvm/Option/Option.h"
20#include "llvm/Support/CommandLine.h"
21#include "llvm/Support/FileSystem.h"
22#include "llvm/Support/Path.h"
23#include "llvm/Support/TimeProfiler.h"
24#include "llvm/TargetParser/Host.h"
25#include "llvm/TargetParser/Triple.h"
26#include <optional>
27
28using namespace llvm;
29using namespace llvm::sys;
30using namespace llvm::opt;
31using namespace lld;
32using namespace lld::elf;
33
34// Create OptTable
35
36// Create prefix string literals used in Options.td
37#define PREFIX(NAME, VALUE) \
38 static constexpr StringLiteral NAME##_init[] = VALUE; \
39 static constexpr ArrayRef<StringLiteral> NAME(NAME##_init, \
40 std::size(NAME##_init) - 1);
41#include "Options.inc"
42#undef PREFIX
43
44// Create table mapping all options defined in Options.td
45static constexpr opt::OptTable::Info optInfo[] = {
46#define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
47#include "Options.inc"
48#undef OPTION
49};
50
51ELFOptTable::ELFOptTable() : GenericOptTable(optInfo) {}
52
53// Set color diagnostics according to --color-diagnostics={auto,always,never}
54// or --no-color-diagnostics flags.
55static void handleColorDiagnostics(opt::InputArgList &args) {
56 auto *arg = args.getLastArg(OPT_color_diagnostics);
57 if (!arg)
58 return;
59 StringRef s = arg->getValue();
60 if (s == "always")
61 lld::errs().enable_colors(enable: true);
62 else if (s == "never")
63 lld::errs().enable_colors(enable: false);
64 else if (s != "auto")
65 error(msg: "unknown option: --color-diagnostics=" + s);
66}
67
68static cl::TokenizerCallback getQuotingStyle(opt::InputArgList &args) {
69 if (auto *arg = args.getLastArg(OPT_rsp_quoting)) {
70 StringRef s = arg->getValue();
71 if (s != "windows" && s != "posix")
72 error(msg: "invalid response file quoting: " + s);
73 if (s == "windows")
74 return cl::TokenizeWindowsCommandLine;
75 return cl::TokenizeGNUCommandLine;
76 }
77 if (Triple(sys::getProcessTriple()).isOSWindows())
78 return cl::TokenizeWindowsCommandLine;
79 return cl::TokenizeGNUCommandLine;
80}
81
82// Gold LTO plugin takes a `--plugin-opt foo=bar` option as an alias for
83// `--plugin-opt=foo=bar`. We want to handle `--plugin-opt=foo=` as an
84// option name and `bar` as a value. Unfortunately, OptParser cannot
85// handle an option with a space in it.
86//
87// In this function, we concatenate command line arguments so that
88// `--plugin-opt <foo>` is converted to `--plugin-opt=<foo>`. This is a
89// bit hacky, but looks like it is still better than handling --plugin-opt
90// options by hand.
91static void concatLTOPluginOptions(SmallVectorImpl<const char *> &args) {
92 SmallVector<const char *, 256> v;
93 for (size_t i = 0, e = args.size(); i != e; ++i) {
94 StringRef s = args[i];
95 if ((s == "-plugin-opt" || s == "--plugin-opt") && i + 1 != e) {
96 v.push_back(Elt: saver().save(S: s + "=" + args[i + 1]).data());
97 ++i;
98 } else {
99 v.push_back(Elt: args[i]);
100 }
101 }
102 args = std::move(v);
103}
104
105// Parses a given list of options.
106opt::InputArgList ELFOptTable::parse(ArrayRef<const char *> argv) {
107 // Make InputArgList from string vectors.
108 unsigned missingIndex;
109 unsigned missingCount;
110 SmallVector<const char *, 256> vec(argv.data(), argv.data() + argv.size());
111
112 // We need to get the quoting style for response files before parsing all
113 // options so we parse here before and ignore all the options but
114 // --rsp-quoting.
115 opt::InputArgList args = this->ParseArgs(Args: vec, MissingArgIndex&: missingIndex, MissingArgCount&: missingCount);
116
117 // Expand response files (arguments in the form of @<filename>)
118 // and then parse the argument again.
119 cl::ExpandResponseFiles(Saver&: saver(), Tokenizer: getQuotingStyle(args), Argv&: vec);
120 concatLTOPluginOptions(args&: vec);
121 args = this->ParseArgs(Args: vec, MissingArgIndex&: missingIndex, MissingArgCount&: missingCount);
122
123 handleColorDiagnostics(args);
124 if (missingCount)
125 error(msg: Twine(args.getArgString(Index: missingIndex)) + ": missing argument");
126
127 for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
128 std::string nearest;
129 if (findNearest(arg->getAsString(args), nearest) > 1)
130 error("unknown argument '" + arg->getAsString(args) + "'");
131 else
132 error("unknown argument '" + arg->getAsString(args) +
133 "', did you mean '" + nearest + "'");
134 }
135 return args;
136}
137
138void elf::printHelp() {
139 ELFOptTable().printHelp(
140 OS&: lld::outs(), Usage: (config->progName + " [options] file...").str().c_str(),
141 Title: "lld", ShowHidden: false /*ShowHidden*/, ShowAllAliases: true /*ShowAllAliases*/);
142 lld::outs() << "\n";
143
144 // Scripts generated by Libtool versions up to 2021-10 expect /: supported
145 // targets:.* elf/ in a message for the --help option. If it doesn't match,
146 // the scripts assume that the linker doesn't support very basic features
147 // such as shared libraries. Therefore, we need to print out at least "elf".
148 lld::outs() << config->progName << ": supported targets: elf\n";
149}
150
151static std::string rewritePath(StringRef s) {
152 if (fs::exists(Path: s))
153 return relativeToRoot(path: s);
154 return std::string(s);
155}
156
157// Reconstructs command line arguments so that so that you can re-run
158// the same command with the same inputs. This is for --reproduce.
159std::string elf::createResponseFile(const opt::InputArgList &args) {
160 SmallString<0> data;
161 raw_svector_ostream os(data);
162 os << "--chroot .\n";
163
164 // Copy the command line to the output while rewriting paths.
165 for (auto *arg : args) {
166 switch (arg->getOption().getID()) {
167 case OPT_reproduce:
168 break;
169 case OPT_INPUT:
170 os << quote(s: rewritePath(s: arg->getValue())) << "\n";
171 break;
172 case OPT_o:
173 case OPT_Map:
174 case OPT_print_archive_stats:
175 case OPT_why_extract:
176 // If an output path contains directories, "lld @response.txt" will
177 // likely fail because the archive we are creating doesn't contain empty
178 // directories for the output path (-o doesn't create directories).
179 // Strip directories to prevent the issue.
180 os << arg->getSpelling();
181 if (arg->getOption().getRenderStyle() == opt::Option::RenderSeparateStyle)
182 os << ' ';
183 os << quote(s: path::filename(path: arg->getValue())) << '\n';
184 break;
185 case OPT_lto_sample_profile:
186 os << arg->getSpelling() << quote(s: rewritePath(s: arg->getValue())) << "\n";
187 break;
188 case OPT_call_graph_ordering_file:
189 case OPT_default_script:
190 case OPT_dynamic_list:
191 case OPT_export_dynamic_symbol_list:
192 case OPT_just_symbols:
193 case OPT_library_path:
194 case OPT_remap_inputs_file:
195 case OPT_retain_symbols_file:
196 case OPT_rpath:
197 case OPT_script:
198 case OPT_symbol_ordering_file:
199 case OPT_sysroot:
200 case OPT_version_script:
201 os << arg->getSpelling() << " " << quote(s: rewritePath(s: arg->getValue()))
202 << "\n";
203 break;
204 default:
205 os << toString(arg: *arg) << "\n";
206 }
207 }
208 return std::string(data);
209}
210
211// Find a file by concatenating given paths. If a resulting path
212// starts with "=", the character is replaced with a --sysroot value.
213static std::optional<std::string> findFile(StringRef path1,
214 const Twine &path2) {
215 SmallString<128> s;
216 if (path1.starts_with(Prefix: "="))
217 path::append(path&: s, a: config->sysroot, b: path1.substr(Start: 1), c: path2);
218 else
219 path::append(path&: s, a: path1, b: path2);
220
221 if (fs::exists(Path: s))
222 return std::string(s);
223 return std::nullopt;
224}
225
226std::optional<std::string> elf::findFromSearchPaths(StringRef path) {
227 for (StringRef dir : config->searchPaths)
228 if (std::optional<std::string> s = findFile(path1: dir, path2: path))
229 return s;
230 return std::nullopt;
231}
232
233// This is for -l<basename>. We'll look for lib<basename>.so or lib<basename>.a from
234// search paths.
235std::optional<std::string> elf::searchLibraryBaseName(StringRef name) {
236 for (StringRef dir : config->searchPaths) {
237 if (!config->isStatic)
238 if (std::optional<std::string> s = findFile(path1: dir, path2: "lib" + name + ".so"))
239 return s;
240 if (std::optional<std::string> s = findFile(path1: dir, path2: "lib" + name + ".a"))
241 return s;
242 }
243 return std::nullopt;
244}
245
246// This is for -l<namespec>.
247std::optional<std::string> elf::searchLibrary(StringRef name) {
248 llvm::TimeTraceScope timeScope("Locate library", name);
249 if (name.starts_with(Prefix: ":"))
250 return findFromSearchPaths(path: name.substr(Start: 1));
251 return searchLibraryBaseName(name);
252}
253
254// If a linker/version script doesn't exist in the current directory, we also
255// look for the script in the '-L' search paths. This matches the behaviour of
256// '-T', --version-script=, and linker script INPUT() command in ld.bfd.
257std::optional<std::string> elf::searchScript(StringRef name) {
258 if (fs::exists(Path: name))
259 return name.str();
260 return findFromSearchPaths(path: name);
261}
262

source code of lld/ELF/DriverUtils.cpp