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 using namespace llvm::sys;
27 
28 using namespace lld;
29 using namespace lld::elf;
30 
31 // Create OptTable
32 
33 // Create prefix string literals used in Options.td
34 #define PREFIX(NAME, VALUE) const char *const 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, X6, X7, X8, X9, X10)            \
41   {                                                                            \
42     X1, X2, X9, X10, OPT_##ID, opt::Option::KIND##Class, X8, X7, OPT_##GROUP,  \
43         OPT_##ALIAS, X6                                                        \
44   },
45 #include "Options.inc"
46 #undef OPTION
47 };
48 
49 ELFOptTable::ELFOptTable() : OptTable(OptInfo) {}
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 // Concatenates S and T so that the resulting path becomes S/T.
91 // There are a few exceptions:
92 //
93 //  1. The result will never escape from S. Therefore, all ".."
94 //     are removed from T before concatenatig them.
95 //  2. Windows drive letters are removed from T before concatenation.
96 std::string elf::concat_paths(StringRef S, StringRef T) {
97   // Remove leading '/' or a drive letter, and then remove "..".
98   SmallString<128> T2(path::relative_path(T));
99   path::remove_dots(T2, /*remove_dot_dot=*/true);
100 
101   SmallString<128> Res;
102   path::append(Res, S, T2);
103   return Res.str();
104 }
105 
106 void elf::copyFile(StringRef Src, StringRef Dest) {
107   SmallString<128> Dir(Dest);
108   path::remove_filename(Dir);
109   if (std::error_code EC = sys::fs::create_directories(Dir)) {
110     error(EC, Dir + ": can't create directory");
111     return;
112   }
113   if (std::error_code EC = sys::fs::copy_file(Src, Dest))
114     error(EC, "failed to copy file: " + Dest);
115 }
116 
117 std::string elf::findFromSearchPaths(StringRef Path) {
118   for (StringRef Dir : Config->SearchPaths) {
119     std::string FullPath = buildSysrootedPath(Dir, Path);
120     if (sys::fs::exists(FullPath))
121       return FullPath;
122   }
123   return "";
124 }
125 
126 // Searches a given library from input search paths, which are filled
127 // from -L command line switches. Returns a path to an existent library file.
128 std::string elf::searchLibrary(StringRef Path) {
129   if (Path.startswith(":"))
130     return findFromSearchPaths(Path.substr(1));
131   if (!Config->Static) {
132     std::string S = findFromSearchPaths(("lib" + Path + ".so").str());
133     if (!S.empty())
134       return S;
135   }
136   return findFromSearchPaths(("lib" + Path + ".a").str());
137 }
138 
139 // Makes a path by concatenating Dir and File.
140 // If Dir starts with '=' the result will be preceded by Sysroot,
141 // which can be set with --sysroot command line switch.
142 std::string elf::buildSysrootedPath(StringRef Dir, StringRef File) {
143   SmallString<128> Path;
144   if (Dir.startswith("="))
145     sys::path::append(Path, Config->Sysroot, Dir.substr(1), File);
146   else
147     sys::path::append(Path, Dir, File);
148   return Path.str();
149 }
150