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 OptInfo[] = {
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 #include "Options.inc"
45 #undef OPTION
46 };
47 
48 ELFOptTable::ELFOptTable() : OptTable(OptInfo) {}
49 
50 // Parses a given list of options.
51 opt::InputArgList ELFOptTable::parse(ArrayRef<const char *> Argv) {
52   // Make InputArgList from string vectors.
53   unsigned MissingIndex;
54   unsigned MissingCount;
55 
56   // Expand response files. '@<filename>' is replaced by the file's contents.
57   SmallVector<const char *, 256> Vec(Argv.data(), Argv.data() + Argv.size());
58   StringSaver Saver(Alloc);
59   llvm::cl::ExpandResponseFiles(Saver, llvm::cl::TokenizeGNUCommandLine, Vec);
60 
61   // Parse options and then do error checking.
62   opt::InputArgList Args = this->ParseArgs(Vec, MissingIndex, MissingCount);
63   if (MissingCount)
64     error(Twine("missing arg value for \"") + Args.getArgString(MissingIndex) +
65           "\", expected " + Twine(MissingCount) +
66           (MissingCount == 1 ? " argument.\n" : " arguments"));
67 
68   iterator_range<opt::arg_iterator> Unknowns = Args.filtered(OPT_UNKNOWN);
69   for (auto *Arg : Unknowns)
70     warning("warning: unknown argument: " + Arg->getSpelling());
71   if (Unknowns.begin() != Unknowns.end())
72     error("unknown argument(s) found");
73   return Args;
74 }
75 
76 void elf::printHelp(const char *Argv0) {
77   ELFOptTable Table;
78   Table.PrintHelp(outs(), Argv0, "lld", false);
79 }
80 
81 void elf::printVersion() {
82   outs() << "LLD " << getLLDVersion();
83   std::string S = getLLDRepositoryVersion();
84   if (!S.empty())
85     outs() << " " << S;
86   outs() << "\n";
87 }
88 
89 std::string elf::findFromSearchPaths(StringRef Path) {
90   for (StringRef Dir : Config->SearchPaths) {
91     std::string FullPath = buildSysrootedPath(Dir, Path);
92     if (sys::fs::exists(FullPath))
93       return FullPath;
94   }
95   return "";
96 }
97 
98 // Searches a given library from input search paths, which are filled
99 // from -L command line switches. Returns a path to an existent library file.
100 std::string elf::searchLibrary(StringRef Path) {
101   if (Path.startswith(":"))
102     return findFromSearchPaths(Path.substr(1));
103   if (!Config->Static) {
104     std::string S = findFromSearchPaths(("lib" + Path + ".so").str());
105     if (!S.empty())
106       return S;
107   }
108   return findFromSearchPaths(("lib" + Path + ".a").str());
109 }
110 
111 // Makes a path by concatenating Dir and File.
112 // If Dir starts with '=' the result will be preceded by Sysroot,
113 // which can be set with --sysroot command line switch.
114 std::string elf::buildSysrootedPath(StringRef Dir, StringRef File) {
115   SmallString<128> Path;
116   if (Dir.startswith("="))
117     sys::path::append(Path, Config->Sysroot, Dir.substr(1), File);
118   else
119     sys::path::append(Path, Dir, File);
120   return Path.str();
121 }
122