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 class ELFOptTable : public opt::OptTable {
50 public:
51   ELFOptTable() : OptTable(infoTable) {}
52 };
53 
54 // Parses a given list of options.
55 opt::InputArgList elf::parseArgs(llvm::BumpPtrAllocator *A,
56                                  ArrayRef<const char *> Argv) {
57   // Make InputArgList from string vectors.
58   ELFOptTable Table;
59   unsigned MissingIndex;
60   unsigned MissingCount;
61 
62   // Expand response files. '@<filename>' is replaced by the file's contents.
63   SmallVector<const char *, 256> Vec(Argv.data(), Argv.data() + Argv.size());
64   StringSaver Saver(*A);
65   llvm::cl::ExpandResponseFiles(Saver, llvm::cl::TokenizeGNUCommandLine, Vec);
66 
67   // Parse options and then do error checking.
68   opt::InputArgList Args = Table.ParseArgs(Vec, MissingIndex, MissingCount);
69   if (MissingCount)
70     error(Twine("missing arg value for \"") + Args.getArgString(MissingIndex) +
71           "\", expected " + Twine(MissingCount) +
72           (MissingCount == 1 ? " argument.\n" : " arguments"));
73 
74   iterator_range<opt::arg_iterator> Unknowns = Args.filtered(OPT_UNKNOWN);
75   for (auto *Arg : Unknowns)
76     warning("warning: unknown argument: " + Arg->getSpelling());
77   if (Unknowns.begin() != Unknowns.end())
78     error("unknown argument(s) found");
79   return Args;
80 }
81 
82 void elf::printHelp(const char *Argv0) {
83   ELFOptTable Table;
84   Table.PrintHelp(outs(), Argv0, "lld", false);
85 }
86 
87 void elf::printVersion() {
88   outs() << "LLD " << getLLDVersion();
89   std::string S = getLLDRepositoryVersion();
90   if (!S.empty())
91     outs() << " " << S;
92   outs() << "\n";
93 }
94 
95 std::string elf::findFromSearchPaths(StringRef Path) {
96   for (StringRef Dir : Config->SearchPaths) {
97     std::string FullPath = buildSysrootedPath(Dir, Path);
98     if (sys::fs::exists(FullPath))
99       return FullPath;
100   }
101   return "";
102 }
103 
104 // Searches a given library from input search paths, which are filled
105 // from -L command line switches. Returns a path to an existent library file.
106 std::string elf::searchLibrary(StringRef Path) {
107   std::vector<std::string> Names;
108   if (Path[0] == ':') {
109     Names.push_back(Path.drop_front());
110   } else {
111     if (!Config->Static)
112       Names.push_back(("lib" + Path + ".so").str());
113     Names.push_back(("lib" + Path + ".a").str());
114   }
115   for (const std::string &Name : Names) {
116     std::string S = findFromSearchPaths(Name);
117     if (!S.empty())
118       return S;
119   }
120   return "";
121 }
122 
123 // Makes a path by concatenating Dir and File.
124 // If Dir starts with '=' the result will be preceded by Sysroot,
125 // which can be set with --sysroot command line switch.
126 std::string elf::buildSysrootedPath(StringRef Dir, StringRef File) {
127   SmallString<128> Path;
128   if (Dir.startswith("="))
129     sys::path::append(Path, Config->Sysroot, Dir.substr(1), File);
130   else
131     sys::path::append(Path, Dir, File);
132   return Path.str();
133 }
134