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 "Memory.h"
19 #include "lld/Config/Version.h"
20 #include "lld/Core/Reproduce.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/Option/Option.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/Path.h"
27 
28 using namespace llvm;
29 using namespace llvm::sys;
30 
31 using namespace lld;
32 using namespace lld::elf;
33 
34 // Create OptTable
35 
36 // Create prefix string literals used in Options.td
37 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
38 #include "Options.inc"
39 #undef PREFIX
40 
41 // Create table mapping all options defined in Options.td
42 static const opt::OptTable::Info OptInfo[] = {
43 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X6, X7, X8, X9, X10)            \
44   {X1, X2, X9,          X10,         OPT_##ID, opt::Option::KIND##Class,       \
45    X8, X7, OPT_##GROUP, OPT_##ALIAS, X6},
46 #include "Options.inc"
47 #undef OPTION
48 };
49 
50 ELFOptTable::ELFOptTable() : OptTable(OptInfo) {}
51 
52 static cl::TokenizerCallback getQuotingStyle(opt::InputArgList &Args) {
53   if (auto *Arg = Args.getLastArg(OPT_rsp_quoting)) {
54     StringRef S = Arg->getValue();
55     if (S != "windows" && S != "posix")
56       error("invalid response file quoting: " + S);
57     if (S == "windows")
58       return cl::TokenizeWindowsCommandLine;
59     return cl::TokenizeGNUCommandLine;
60   }
61   if (Triple(sys::getProcessTriple()).getOS() == Triple::Win32)
62     return cl::TokenizeWindowsCommandLine;
63   return cl::TokenizeGNUCommandLine;
64 }
65 
66 // Parses a given list of options.
67 opt::InputArgList ELFOptTable::parse(ArrayRef<const char *> Argv) {
68   // Make InputArgList from string vectors.
69   unsigned MissingIndex;
70   unsigned MissingCount;
71   SmallVector<const char *, 256> Vec(Argv.data(), Argv.data() + Argv.size());
72 
73   // We need to get the quoting style for response files before parsing all
74   // options so we parse here before and ignore all the options but
75   // --rsp-quoting.
76   opt::InputArgList Args = this->ParseArgs(Vec, MissingIndex, MissingCount);
77 
78   // Expand response files. '@<filename>' is replaced by the file's contents.
79   cl::ExpandResponseFiles(Saver, getQuotingStyle(Args), Vec);
80 
81   // Parse options and then do error checking.
82   Args = this->ParseArgs(Vec, MissingIndex, MissingCount);
83   if (MissingCount)
84     error(Twine("missing arg value for \"") + Args.getArgString(MissingIndex) +
85           "\", expected " + Twine(MissingCount) +
86           (MissingCount == 1 ? " argument.\n" : " arguments"));
87 
88   for (auto *Arg : Args.filtered(OPT_UNKNOWN))
89     error("unknown argument: " + Arg->getSpelling());
90   return Args;
91 }
92 
93 void elf::printHelp(const char *Argv0) {
94   ELFOptTable Table;
95   Table.PrintHelp(outs(), Argv0, "lld", false);
96 }
97 
98 // Reconstructs command line arguments so that so that you can re-run
99 // the same command with the same inputs. This is for --reproduce.
100 std::string elf::createResponseFile(const opt::InputArgList &Args) {
101   SmallString<0> Data;
102   raw_svector_ostream OS(Data);
103 
104   // Copy the command line to the output while rewriting paths.
105   for (auto *Arg : Args) {
106     switch (Arg->getOption().getID()) {
107     case OPT_reproduce:
108       break;
109     case OPT_INPUT:
110       OS << quote(rewritePath(Arg->getValue())) << "\n";
111       break;
112     case OPT_L:
113     case OPT_dynamic_list:
114     case OPT_rpath:
115     case OPT_alias_script_T:
116     case OPT_script:
117     case OPT_version_script:
118       OS << Arg->getSpelling() << " " << quote(rewritePath(Arg->getValue()))
119          << "\n";
120       break;
121     default:
122       OS << stringize(Arg) << "\n";
123     }
124   }
125   return Data.str();
126 }
127 
128 std::string elf::findFromSearchPaths(StringRef Path) {
129   for (StringRef Dir : Config->SearchPaths) {
130     std::string FullPath = buildSysrootedPath(Dir, Path);
131     if (fs::exists(FullPath))
132       return FullPath;
133   }
134   return "";
135 }
136 
137 // Searches a given library from input search paths, which are filled
138 // from -L command line switches. Returns a path to an existent library file.
139 std::string elf::searchLibrary(StringRef Path) {
140   if (Path.startswith(":"))
141     return findFromSearchPaths(Path.substr(1));
142   for (StringRef Dir : Config->SearchPaths) {
143     if (!Config->Static) {
144       std::string S = buildSysrootedPath(Dir, ("lib" + Path + ".so").str());
145       if (fs::exists(S))
146         return S;
147     }
148     std::string S = buildSysrootedPath(Dir, ("lib" + Path + ".a").str());
149     if (fs::exists(S))
150       return S;
151   }
152   return "";
153 }
154 
155 // Makes a path by concatenating Dir and File.
156 // If Dir starts with '=' the result will be preceded by Sysroot,
157 // which can be set with --sysroot command line switch.
158 std::string elf::buildSysrootedPath(StringRef Dir, StringRef File) {
159   SmallString<128> Path;
160   if (Dir.startswith("="))
161     path::append(Path, Config->Sysroot, Dir.substr(1), File);
162   else
163     path::append(Path, Dir, File);
164   return Path.str();
165 }
166