clang/lib/Driver/ToolChains/Hurd.cpp

   1 //===--- Hurd.cpp - Hurd ToolChain Implementations --------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "Hurd.h"
  10 #include "CommonArgs.h"
  11 #include "clang/Config/config.h"
  12 #include "clang/Driver/Driver.h"
  13 #include "clang/Driver/Options.h"
  14 #include "llvm/Support/Path.h"
  15 #include "llvm/Support/VirtualFileSystem.h"
  16
  17 using namespace clang::driver;
  18 using namespace clang::driver::toolchains;
  19 using namespace clang;
  20 using namespace llvm::opt;
  21
  22 using tools::addPathIfExists;
  23
  24 /// Get our best guess at the multiarch triple for a target.
  25 ///
  26 /// Debian-based systems are starting to use a multiarch setup where they use
  27 /// a target-triple directory in the library and header search paths.
  28 /// Unfortunately, this triple does not align with the vanilla target triple,
  29 /// so we provide a rough mapping here.
  30 std::string Hurd::getMultiarchTriple(const Driver &D,
  31                                      const llvm::Triple &TargetTriple,
  32                                      StringRef SysRoot) const {
  33   if (TargetTriple.getArch() == llvm::Triple::x86) {
  34     // We use the existence of '/lib/<triple>' as a directory to detect some
  35     // common hurd triples that don't quite match the Clang triple for both
  36     // 32-bit and 64-bit targets. Multiarch fixes its install triples to these
  37     // regardless of what the actual target triple is.
  38     if (D.getVFS().exists(SysRoot + "/lib/i386-gnu"))
  39       return "i386-gnu";
  40   }
  41
  42   // For most architectures, just use whatever we have rather than trying to be
  43   // clever.
  44   return TargetTriple.str();
  45 }
  46
  47 static StringRef getOSLibDir(const llvm::Triple &Triple, const ArgList &Args) {
  48   // It happens that only x86 and PPC use the 'lib32' variant of oslibdir, and
  49   // using that variant while targeting other architectures causes problems
  50   // because the libraries are laid out in shared system roots that can't cope
  51   // with a 'lib32' library search path being considered. So we only enable
  52   // them when we know we may need it.
  53   //
  54   // FIXME: This is a bit of a hack. We should really unify this code for
  55   // reasoning about oslibdir spellings with the lib dir spellings in the
  56   // GCCInstallationDetector, but that is a more significant refactoring.
  57
  58   if (Triple.getArch() == llvm::Triple::x86)
  59     return "lib32";
  60
  61   return Triple.isArch32Bit() ? "lib" : "lib64";
  62 }
  63
  64 Hurd::Hurd(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  65     : Generic_ELF(D, Triple, Args) {
  66   GCCInstallation.init(Triple, Args);
  67   Multilibs = GCCInstallation.getMultilibs();
  68   SelectedMultilibs.assign({GCCInstallation.getMultilib()});
  69   std::string SysRoot = computeSysRoot();
  70   ToolChain::path_list &PPaths = getProgramPaths();
  71
  72   Generic_GCC::PushPPaths(PPaths);
  73
  74   // The selection of paths to try here is designed to match the patterns which
  75   // the GCC driver itself uses, as this is part of the GCC-compatible driver.
  76   // This was determined by running GCC in a fake filesystem, creating all
  77   // possible permutations of these directories, and seeing which ones it added
  78   // to the link paths.
  79   path_list &Paths = getFilePaths();
  80
  81   const std::string OSLibDir = std::string(getOSLibDir(Triple, Args));
  82   const std::string MultiarchTriple = getMultiarchTriple(D, Triple, SysRoot);
  83
  84 #ifdef ENABLE_LINKER_BUILD_ID
  85   ExtraOpts.push_back("--build-id");
  86 #endif
  87
  88   Generic_GCC::AddMultilibPaths(D, SysRoot, OSLibDir, MultiarchTriple, Paths);
  89
  90   // Similar to the logic for GCC above, if we currently running Clang inside
  91   // of the requested system root, add its parent library paths to
  92   // those searched.
  93   // FIXME: It's not clear whether we should use the driver's installed
  94   // directory ('Dir' below) or the ResourceDir.
  95   if (StringRef(D.Dir).startswith(SysRoot)) {
  96     addPathIfExists(D, D.Dir + "/../lib/" + MultiarchTriple, Paths);
  97     addPathIfExists(D, D.Dir + "/../" + OSLibDir, Paths);
  98   }
  99
 100   addPathIfExists(D, SysRoot + "/lib/" + MultiarchTriple, Paths);
 101   addPathIfExists(D, SysRoot + "/lib/../" + OSLibDir, Paths);
 102
 103   addPathIfExists(D, SysRoot + "/usr/lib/" + MultiarchTriple, Paths);
 104   addPathIfExists(D, SysRoot + "/usr/lib/../" + OSLibDir, Paths);
 105
 106   Generic_GCC::AddMultiarchPaths(D, SysRoot, OSLibDir, Paths);
 107
 108   // Similar to the logic for GCC above, if we are currently running Clang
 109   // inside of the requested system root, add its parent library path to those
 110   // searched.
 111   // FIXME: It's not clear whether we should use the driver's installed
 112   // directory ('Dir' below) or the ResourceDir.
 113   if (StringRef(D.Dir).startswith(SysRoot))
 114     addPathIfExists(D, D.Dir + "/../lib", Paths);
 115
 116   addPathIfExists(D, SysRoot + "/lib", Paths);
 117   addPathIfExists(D, SysRoot + "/usr/lib", Paths);
 118 }
 119
 120 bool Hurd::HasNativeLLVMSupport() const { return true; }
 121
 122 Tool *Hurd::buildLinker() const { return new tools::gnutools::Linker(*this); }
 123
 124 Tool *Hurd::buildAssembler() const {
 125   return new tools::gnutools::Assembler(*this);
 126 }
 127
 128 std::string Hurd::getDynamicLinker(const ArgList &Args) const {
 129   if (getArch() == llvm::Triple::x86)
 130     return "/lib/ld.so";
 131
 132   llvm_unreachable("unsupported architecture");
 133 }
 134
 135 void Hurd::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
 136                                      ArgStringList &CC1Args) const {
 137   const Driver &D = getDriver();
 138   std::string SysRoot = computeSysRoot();
 139
 140   if (DriverArgs.hasArg(clang::driver::options::OPT_nostdinc))
 141     return;
 142
 143   if (!DriverArgs.hasArg(options::OPT_nostdlibinc))
 144     addSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/local/include");
 145
 146   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
 147     SmallString<128> P(D.ResourceDir);
 148     llvm::sys::path::append(P, "include");
 149     addSystemInclude(DriverArgs, CC1Args, P);
 150   }
 151
 152   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
 153     return;
 154
 155   // Check for configure-time C include directories.
 156   StringRef CIncludeDirs(C_INCLUDE_DIRS);
 157   if (CIncludeDirs != "") {
 158     SmallVector<StringRef, 5> Dirs;
 159     CIncludeDirs.split(Dirs, ":");
 160     for (StringRef Dir : Dirs) {
 161       StringRef Prefix =
 162           llvm::sys::path::is_absolute(Dir) ? "" : StringRef(SysRoot);
 163       addExternCSystemInclude(DriverArgs, CC1Args, Prefix + Dir);
 164     }
 165     return;
 166   }
 167
 168   // Lacking those, try to detect the correct set of system includes for the
 169   // target triple.
 170
 171   AddMultilibIncludeArgs(DriverArgs, CC1Args);
 172
 173   // On systems using multiarch, add /usr/include/$triple before
 174   // /usr/include.
 175   std::string MultiarchIncludeDir = getMultiarchTriple(D, getTriple(), SysRoot);
 176   if (!MultiarchIncludeDir.empty() &&
 177       D.getVFS().exists(SysRoot + "/usr/include/" + MultiarchIncludeDir))
 178     addExternCSystemInclude(DriverArgs, CC1Args,
 179                             SysRoot + "/usr/include/" + MultiarchIncludeDir);
 180
 181   // Add an include of '/include' directly. This isn't provided by default by
 182   // system GCCs, but is often used with cross-compiling GCCs, and harmless to
 183   // add even when Clang is acting as-if it were a system compiler.
 184   addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/include");
 185
 186   addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/include");
 187 }
 188
 189 void Hurd::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
 190                                     llvm::opt::ArgStringList &CC1Args) const {
 191   // We need a detected GCC installation on Linux to provide libstdc++'s
 192   // headers in odd Linuxish places.
 193   if (!GCCInstallation.isValid())
 194     return;
 195
 196   StringRef TripleStr = GCCInstallation.getTriple().str();
 197   StringRef DebianMultiarch =
 198       GCCInstallation.getTriple().getArch() == llvm::Triple::x86 ? "i386-gnu"
 199                                                                  : TripleStr;
 200
 201   addGCCLibStdCxxIncludePaths(DriverArgs, CC1Args, DebianMultiarch);
 202 }
 203
 204 void Hurd::addExtraOpts(llvm::opt::ArgStringList &CmdArgs) const {
 205   for (const auto &Opt : ExtraOpts)
 206     CmdArgs.push_back(Opt.c_str());
 207 }