1 //===- DriverUtils.cpp ----------------------------------------------------===//
2 //
3 //                             The LLVM Linker
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains utility functions for the driver. Because there
11 // are so many small functions, we created this separate file to make
12 // Driver.cpp less cluttered.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "Driver.h"
17 #include "Error.h"
18 #include "lld/Config/Version.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/Support/CommandLine.h"
21 #include "llvm/Support/FileSystem.h"
22 #include "llvm/Support/Path.h"
23 #include "llvm/Support/StringSaver.h"
24 
25 using namespace llvm;
26 
27 using namespace lld;
28 using namespace lld::elf;
29 
30 // Create OptTable
31 
32 // Create prefix string literals used in Options.td
33 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
34 #include "Options.inc"
35 #undef PREFIX
36 
37 // Create table mapping all options defined in Options.td
38 static const opt::OptTable::Info infoTable[] = {
39 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X6, X7, X8, X9, X10)            \
40   {                                                                            \
41     X1, X2, X9, X10, OPT_##ID, opt::Option::KIND##Class, X8, X7, OPT_##GROUP,  \
42         OPT_##ALIAS, X6                                                        \
43   }                                                                            \
44   ,
45 #include "Options.inc"
46 #undef OPTION
47 };
48 
49 ELFOptTable::ELFOptTable() : OptTable(infoTable) {}
50 
51 // Parses a given list of options.
52 opt::InputArgList ELFOptTable::parse(ArrayRef<const char *> Argv) {
53   // Make InputArgList from string vectors.
54   unsigned MissingIndex;
55   unsigned MissingCount;
56 
57   // Expand response files. '@<filename>' is replaced by the file's contents.
58   SmallVector<const char *, 256> Vec(Argv.data(), Argv.data() + Argv.size());
59   StringSaver Saver(Alloc);
60   llvm::cl::ExpandResponseFiles(Saver, llvm::cl::TokenizeGNUCommandLine, Vec);
61 
62   // Parse options and then do error checking.
63   opt::InputArgList Args = this->ParseArgs(Vec, MissingIndex, MissingCount);
64   if (MissingCount)
65     error(Twine("missing arg value for \"") + Args.getArgString(MissingIndex) +
66           "\", expected " + Twine(MissingCount) +
67           (MissingCount == 1 ? " argument.\n" : " arguments"));
68 
69   iterator_range<opt::arg_iterator> Unknowns = Args.filtered(OPT_UNKNOWN);
70   for (auto *Arg : Unknowns)
71     warning("warning: unknown argument: " + Arg->getSpelling());
72   if (Unknowns.begin() != Unknowns.end())
73     error("unknown argument(s) found");
74   return Args;
75 }
76 
77 void elf::printHelp(const char *Argv0) {
78   ELFOptTable Table;
79   Table.PrintHelp(outs(), Argv0, "lld", false);
80 }
81 
82 void elf::printVersion() {
83   outs() << "LLD " << getLLDVersion();
84   std::string S = getLLDRepositoryVersion();
85   if (!S.empty())
86     outs() << " " << S;
87   outs() << "\n";
88 }
89 
90 std::string elf::findFromSearchPaths(StringRef Path) {
91   for (StringRef Dir : Config->SearchPaths) {
92     std::string FullPath = buildSysrootedPath(Dir, Path);
93     if (sys::fs::exists(FullPath))
94       return FullPath;
95   }
96   return "";
97 }
98 
99 // Searches a given library from input search paths, which are filled
100 // from -L command line switches. Returns a path to an existent library file.
101 std::string elf::searchLibrary(StringRef Path) {
102   std::vector<std::string> Names;
103   if (Path[0] == ':') {
104     Names.push_back(Path.drop_front());
105   } else {
106     if (!Config->Static)
107       Names.push_back(("lib" + Path + ".so").str());
108     Names.push_back(("lib" + Path + ".a").str());
109   }
110   for (const std::string &Name : Names) {
111     std::string S = findFromSearchPaths(Name);
112     if (!S.empty())
113       return S;
114   }
115   return "";
116 }
117 
118 // Makes a path by concatenating Dir and File.
119 // If Dir starts with '=' the result will be preceded by Sysroot,
120 // which can be set with --sysroot command line switch.
121 std::string elf::buildSysrootedPath(StringRef Dir, StringRef File) {
122   SmallString<128> Path;
123   if (Dir.startswith("="))
124     sys::path::append(Path, Config->Sysroot, Dir.substr(1), File);
125   else
126     sys::path::append(Path, Dir, File);
127   return Path.str();
128 }
129