clang/lib/Driver/Distro.cpp

   1 //===--- Distro.cpp - Linux distribution detection support ------*- 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 "clang/Driver/Distro.h"
  10 #include "clang/Basic/LLVM.h"
  11 #include "llvm/ADT/SmallVector.h"
  12 #include "llvm/ADT/StringRef.h"
  13 #include "llvm/ADT/StringSwitch.h"
  14 #include "llvm/ADT/Triple.h"
  15 #include "llvm/Support/ErrorOr.h"
  16 #include "llvm/Support/Host.h"
  17 #include "llvm/Support/MemoryBuffer.h"
  18 #include "llvm/Support/Threading.h"
  19
  20 using namespace clang::driver;
  21 using namespace clang;
  22
  23 static Distro::DistroType DetectOsRelease(llvm::vfs::FileSystem &VFS) {
  24   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
  25       VFS.getBufferForFile("/etc/os-release");
  26   if (!File)
  27     File = VFS.getBufferForFile("/usr/lib/os-release");
  28   if (!File)
  29     return Distro::UnknownDistro;
  30
  31   SmallVector<StringRef, 16> Lines;
  32   File.get()->getBuffer().split(Lines, "\n");
  33   Distro::DistroType Version = Distro::UnknownDistro;
  34
  35   // Obviously this can be improved a lot.
  36   for (StringRef Line : Lines)
  37     if (Version == Distro::UnknownDistro && Line.startswith("ID="))
  38       Version = llvm::StringSwitch<Distro::DistroType>(Line.substr(3))
  39                     .Case("alpine", Distro::AlpineLinux)
  40                     .Case("fedora", Distro::Fedora)
  41                     .Case("gentoo", Distro::Gentoo)
  42                     .Case("arch", Distro::ArchLinux)
  43                     // On SLES, /etc/os-release was introduced in SLES 11.
  44                     .Case("sles", Distro::OpenSUSE)
  45                     .Case("opensuse", Distro::OpenSUSE)
  46                     .Case("exherbo", Distro::Exherbo)
  47                     .Default(Distro::UnknownDistro);
  48   return Version;
  49 }
  50
  51 static Distro::DistroType DetectLsbRelease(llvm::vfs::FileSystem &VFS) {
  52   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
  53       VFS.getBufferForFile("/etc/lsb-release");
  54   if (!File)
  55     return Distro::UnknownDistro;
  56
  57   SmallVector<StringRef, 16> Lines;
  58   File.get()->getBuffer().split(Lines, "\n");
  59   Distro::DistroType Version = Distro::UnknownDistro;
  60
  61   for (StringRef Line : Lines)
  62     if (Version == Distro::UnknownDistro &&
  63         Line.startswith("DISTRIB_CODENAME="))
  64       Version = llvm::StringSwitch<Distro::DistroType>(Line.substr(17))
  65                     .Case("hardy", Distro::UbuntuHardy)
  66                     .Case("intrepid", Distro::UbuntuIntrepid)
  67                     .Case("jaunty", Distro::UbuntuJaunty)
  68                     .Case("karmic", Distro::UbuntuKarmic)
  69                     .Case("lucid", Distro::UbuntuLucid)
  70                     .Case("maverick", Distro::UbuntuMaverick)
  71                     .Case("natty", Distro::UbuntuNatty)
  72                     .Case("oneiric", Distro::UbuntuOneiric)
  73                     .Case("precise", Distro::UbuntuPrecise)
  74                     .Case("quantal", Distro::UbuntuQuantal)
  75                     .Case("raring", Distro::UbuntuRaring)
  76                     .Case("saucy", Distro::UbuntuSaucy)
  77                     .Case("trusty", Distro::UbuntuTrusty)
  78                     .Case("utopic", Distro::UbuntuUtopic)
  79                     .Case("vivid", Distro::UbuntuVivid)
  80                     .Case("wily", Distro::UbuntuWily)
  81                     .Case("xenial", Distro::UbuntuXenial)
  82                     .Case("yakkety", Distro::UbuntuYakkety)
  83                     .Case("zesty", Distro::UbuntuZesty)
  84                     .Case("artful", Distro::UbuntuArtful)
  85                     .Case("bionic", Distro::UbuntuBionic)
  86                     .Case("cosmic", Distro::UbuntuCosmic)
  87                     .Case("disco", Distro::UbuntuDisco)
  88                     .Case("eoan", Distro::UbuntuEoan)
  89                     .Case("focal", Distro::UbuntuFocal)
  90                     .Case("groovy", Distro::UbuntuGroovy)
  91                     .Case("hirsute", Distro::UbuntuHirsute)
  92                     .Case("impish", Distro::UbuntuImpish)
  93                     .Case("jammy", Distro::UbuntuJammy)
  94                     .Case("kinetic", Distro::UbuntuKinetic)
  95                     .Default(Distro::UnknownDistro);
  96   return Version;
  97 }
  98
  99 static Distro::DistroType DetectDistro(llvm::vfs::FileSystem &VFS) {
 100   Distro::DistroType Version = Distro::UnknownDistro;
 101
 102   // Newer freedesktop.org's compilant systemd-based systems
 103   // should provide /etc/os-release or /usr/lib/os-release.
 104   Version = DetectOsRelease(VFS);
 105   if (Version != Distro::UnknownDistro)
 106     return Version;
 107
 108   // Older systems might provide /etc/lsb-release.
 109   Version = DetectLsbRelease(VFS);
 110   if (Version != Distro::UnknownDistro)
 111     return Version;
 112
 113   // Otherwise try some distro-specific quirks for RedHat...
 114   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
 115       VFS.getBufferForFile("/etc/redhat-release");
 116
 117   if (File) {
 118     StringRef Data = File.get()->getBuffer();
 119     if (Data.startswith("Fedora release"))
 120       return Distro::Fedora;
 121     if (Data.startswith("Red Hat Enterprise Linux") ||
 122         Data.startswith("CentOS") || Data.startswith("Scientific Linux")) {
 123       if (Data.contains("release 7"))
 124         return Distro::RHEL7;
 125       else if (Data.contains("release 6"))
 126         return Distro::RHEL6;
 127       else if (Data.contains("release 5"))
 128         return Distro::RHEL5;
 129     }
 130     return Distro::UnknownDistro;
 131   }
 132
 133   // ...for Debian
 134   File = VFS.getBufferForFile("/etc/debian_version");
 135   if (File) {
 136     StringRef Data = File.get()->getBuffer();
 137     // Contents: < major.minor > or < codename/sid >
 138     int MajorVersion;
 139     if (!Data.split('.').first.getAsInteger(10, MajorVersion)) {
 140       switch (MajorVersion) {
 141       case 5:
 142         return Distro::DebianLenny;
 143       case 6:
 144         return Distro::DebianSqueeze;
 145       case 7:
 146         return Distro::DebianWheezy;
 147       case 8:
 148         return Distro::DebianJessie;
 149       case 9:
 150         return Distro::DebianStretch;
 151       case 10:
 152         return Distro::DebianBuster;
 153       case 11:
 154         return Distro::DebianBullseye;
 155       case 12:
 156         return Distro::DebianBookworm;
 157       case 13:
 158         return Distro::DebianTrixie;
 159       default:
 160         return Distro::UnknownDistro;
 161       }
 162     }
 163     return llvm::StringSwitch<Distro::DistroType>(Data.split("\n").first)
 164         .Case("squeeze/sid", Distro::DebianSqueeze)
 165         .Case("wheezy/sid", Distro::DebianWheezy)
 166         .Case("jessie/sid", Distro::DebianJessie)
 167         .Case("stretch/sid", Distro::DebianStretch)
 168         .Case("buster/sid", Distro::DebianBuster)
 169         .Case("bullseye/sid", Distro::DebianBullseye)
 170         .Case("bookworm/sid", Distro::DebianBookworm)
 171         .Default(Distro::UnknownDistro);
 172   }
 173
 174   // ...for SUSE
 175   File = VFS.getBufferForFile("/etc/SuSE-release");
 176   if (File) {
 177     StringRef Data = File.get()->getBuffer();
 178     SmallVector<StringRef, 8> Lines;
 179     Data.split(Lines, "\n");
 180     for (const StringRef &Line : Lines) {
 181       if (!Line.trim().startswith("VERSION"))
 182         continue;
 183       std::pair<StringRef, StringRef> SplitLine = Line.split('=');
 184       // Old versions have split VERSION and PATCHLEVEL
 185       // Newer versions use VERSION = x.y
 186       std::pair<StringRef, StringRef> SplitVer =
 187           SplitLine.second.trim().split('.');
 188       int Version;
 189
 190       // OpenSUSE/SLES 10 and older are not supported and not compatible
 191       // with our rules, so just treat them as Distro::UnknownDistro.
 192       if (!SplitVer.first.getAsInteger(10, Version) && Version > 10)
 193         return Distro::OpenSUSE;
 194       return Distro::UnknownDistro;
 195     }
 196     return Distro::UnknownDistro;
 197   }
 198
 199   // ...and others.
 200   if (VFS.exists("/etc/gentoo-release"))
 201     return Distro::Gentoo;
 202
 203   return Distro::UnknownDistro;
 204 }
 205
 206 static Distro::DistroType GetDistro(llvm::vfs::FileSystem &VFS,
 207                                     const llvm::Triple &TargetOrHost) {
 208   // If we don't target Linux, no need to check the distro. This saves a few
 209   // OS calls.
 210   if (!TargetOrHost.isOSLinux())
 211     return Distro::UnknownDistro;
 212
 213   // True if we're backed by a real file system.
 214   const bool onRealFS = (llvm::vfs::getRealFileSystem() == &VFS);
 215
 216   // If the host is not running Linux, and we're backed by a real file
 217   // system, no need to check the distro. This is the case where someone
 218   // is cross-compiling from BSD or Windows to Linux, and it would be
 219   // meaningless to try to figure out the "distro" of the non-Linux host.
 220   llvm::Triple HostTriple(llvm::sys::getProcessTriple());
 221   if (!HostTriple.isOSLinux() && onRealFS)
 222     return Distro::UnknownDistro;
 223
 224   if (onRealFS) {
 225     // If we're backed by a real file system, perform
 226     // the detection only once and save the result.
 227     static Distro::DistroType LinuxDistro = DetectDistro(VFS);
 228     return LinuxDistro;
 229   }
 230   // This is mostly for passing tests which uses llvm::vfs::InMemoryFileSystem,
 231   // which is not "real".
 232   return DetectDistro(VFS);
 233 }
 234
 235 Distro::Distro(llvm::vfs::FileSystem &VFS, const llvm::Triple &TargetOrHost)
 236     : DistroVal(GetDistro(VFS, TargetOrHost)) {}