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/StringRef.h"
12#include "llvm/ADT/StringSwitch.h"
13#include "llvm/Support/ErrorOr.h"
14#include "llvm/Support/MemoryBuffer.h"
15#include "llvm/Support/Threading.h"
16#include "llvm/TargetParser/Host.h"
17#include "llvm/TargetParser/Triple.h"
18
19using namespace clang::driver;
20using namespace clang;
21
22static Distro::DistroType DetectOsRelease(llvm::vfs::FileSystem &VFS) {
23 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
24 VFS.getBufferForFile(Name: "/etc/os-release");
25 if (!File)
26 File = VFS.getBufferForFile(Name: "/usr/lib/os-release");
27 if (!File)
28 return Distro::UnknownDistro;
29
30 SmallVector<StringRef, 16> Lines;
31 File.get()->getBuffer().split(A&: Lines, Separator: "\n");
32 Distro::DistroType Version = Distro::UnknownDistro;
33
34 // Obviously this can be improved a lot.
35 for (StringRef Line : Lines)
36 if (Version == Distro::UnknownDistro && Line.starts_with(Prefix: "ID="))
37 Version = llvm::StringSwitch<Distro::DistroType>(Line.substr(Start: 3))
38 .Case(S: "alpine", Value: Distro::AlpineLinux)
39 .Case(S: "fedora", Value: Distro::Fedora)
40 .Case(S: "gentoo", Value: Distro::Gentoo)
41 .Case(S: "arch", Value: Distro::ArchLinux)
42 // On SLES, /etc/os-release was introduced in SLES 11.
43 .Case(S: "sles", Value: Distro::OpenSUSE)
44 .Case(S: "opensuse", Value: Distro::OpenSUSE)
45 .Case(S: "exherbo", Value: Distro::Exherbo)
46 .Default(Value: Distro::UnknownDistro);
47 return Version;
48}
49
50static Distro::DistroType DetectLsbRelease(llvm::vfs::FileSystem &VFS) {
51 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
52 VFS.getBufferForFile(Name: "/etc/lsb-release");
53 if (!File)
54 return Distro::UnknownDistro;
55
56 SmallVector<StringRef, 16> Lines;
57 File.get()->getBuffer().split(A&: Lines, Separator: "\n");
58 Distro::DistroType Version = Distro::UnknownDistro;
59
60 for (StringRef Line : Lines)
61 if (Version == Distro::UnknownDistro &&
62 Line.starts_with(Prefix: "DISTRIB_CODENAME="))
63 Version = llvm::StringSwitch<Distro::DistroType>(Line.substr(Start: 17))
64 .Case(S: "hardy", Value: Distro::UbuntuHardy)
65 .Case(S: "intrepid", Value: Distro::UbuntuIntrepid)
66 .Case(S: "jaunty", Value: Distro::UbuntuJaunty)
67 .Case(S: "karmic", Value: Distro::UbuntuKarmic)
68 .Case(S: "lucid", Value: Distro::UbuntuLucid)
69 .Case(S: "maverick", Value: Distro::UbuntuMaverick)
70 .Case(S: "natty", Value: Distro::UbuntuNatty)
71 .Case(S: "oneiric", Value: Distro::UbuntuOneiric)
72 .Case(S: "precise", Value: Distro::UbuntuPrecise)
73 .Case(S: "quantal", Value: Distro::UbuntuQuantal)
74 .Case(S: "raring", Value: Distro::UbuntuRaring)
75 .Case(S: "saucy", Value: Distro::UbuntuSaucy)
76 .Case(S: "trusty", Value: Distro::UbuntuTrusty)
77 .Case(S: "utopic", Value: Distro::UbuntuUtopic)
78 .Case(S: "vivid", Value: Distro::UbuntuVivid)
79 .Case(S: "wily", Value: Distro::UbuntuWily)
80 .Case(S: "xenial", Value: Distro::UbuntuXenial)
81 .Case(S: "yakkety", Value: Distro::UbuntuYakkety)
82 .Case(S: "zesty", Value: Distro::UbuntuZesty)
83 .Case(S: "artful", Value: Distro::UbuntuArtful)
84 .Case(S: "bionic", Value: Distro::UbuntuBionic)
85 .Case(S: "cosmic", Value: Distro::UbuntuCosmic)
86 .Case(S: "disco", Value: Distro::UbuntuDisco)
87 .Case(S: "eoan", Value: Distro::UbuntuEoan)
88 .Case(S: "focal", Value: Distro::UbuntuFocal)
89 .Case(S: "groovy", Value: Distro::UbuntuGroovy)
90 .Case(S: "hirsute", Value: Distro::UbuntuHirsute)
91 .Case(S: "impish", Value: Distro::UbuntuImpish)
92 .Case(S: "jammy", Value: Distro::UbuntuJammy)
93 .Case(S: "kinetic", Value: Distro::UbuntuKinetic)
94 .Case(S: "lunar", Value: Distro::UbuntuLunar)
95 .Case(S: "mantic", Value: Distro::UbuntuMantic)
96 .Case(S: "noble", Value: Distro::UbuntuNoble)
97 .Case(S: "oracular", Value: Distro::UbuntuOracular)
98 .Case(S: "plucky", Value: Distro::UbuntuPlucky)
99 .Case(S: "questing", Value: Distro::UbuntuQuesting)
100 .Default(Value: Distro::UnknownDistro);
101 return Version;
102}
103
104static Distro::DistroType DetectDistro(llvm::vfs::FileSystem &VFS) {
105 Distro::DistroType Version = Distro::UnknownDistro;
106
107 // Newer freedesktop.org's compilant systemd-based systems
108 // should provide /etc/os-release or /usr/lib/os-release.
109 Version = DetectOsRelease(VFS);
110 if (Version != Distro::UnknownDistro)
111 return Version;
112
113 // Older systems might provide /etc/lsb-release.
114 Version = DetectLsbRelease(VFS);
115 if (Version != Distro::UnknownDistro)
116 return Version;
117
118 // Otherwise try some distro-specific quirks for Red Hat...
119 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
120 VFS.getBufferForFile(Name: "/etc/redhat-release");
121
122 if (File) {
123 StringRef Data = File.get()->getBuffer();
124 if (Data.starts_with(Prefix: "Fedora release"))
125 return Distro::Fedora;
126 if (Data.starts_with(Prefix: "Red Hat Enterprise Linux") ||
127 Data.starts_with(Prefix: "CentOS") || Data.starts_with(Prefix: "Scientific Linux")) {
128 if (Data.contains(Other: "release 7"))
129 return Distro::RHEL7;
130 else if (Data.contains(Other: "release 6"))
131 return Distro::RHEL6;
132 else if (Data.contains(Other: "release 5"))
133 return Distro::RHEL5;
134 }
135 return Distro::UnknownDistro;
136 }
137
138 // ...for Debian
139 File = VFS.getBufferForFile(Name: "/etc/debian_version");
140 if (File) {
141 StringRef Data = File.get()->getBuffer();
142 // Contents: < major.minor > or < codename/sid >
143 int MajorVersion;
144 if (!Data.split(Separator: '.').first.getAsInteger(Radix: 10, Result&: MajorVersion)) {
145 switch (MajorVersion) {
146 case 5:
147 return Distro::DebianLenny;
148 case 6:
149 return Distro::DebianSqueeze;
150 case 7:
151 return Distro::DebianWheezy;
152 case 8:
153 return Distro::DebianJessie;
154 case 9:
155 return Distro::DebianStretch;
156 case 10:
157 return Distro::DebianBuster;
158 case 11:
159 return Distro::DebianBullseye;
160 case 12:
161 return Distro::DebianBookworm;
162 case 13:
163 return Distro::DebianTrixie;
164 case 14:
165 return Distro::DebianForky;
166 case 15:
167 return Distro::DebianDuke;
168 default:
169 return Distro::UnknownDistro;
170 }
171 }
172 return llvm::StringSwitch<Distro::DistroType>(Data.split(Separator: "\n").first)
173 .Case(S: "squeeze/sid", Value: Distro::DebianSqueeze)
174 .Case(S: "wheezy/sid", Value: Distro::DebianWheezy)
175 .Case(S: "jessie/sid", Value: Distro::DebianJessie)
176 .Case(S: "stretch/sid", Value: Distro::DebianStretch)
177 .Case(S: "buster/sid", Value: Distro::DebianBuster)
178 .Case(S: "bullseye/sid", Value: Distro::DebianBullseye)
179 .Case(S: "bookworm/sid", Value: Distro::DebianBookworm)
180 .Case(S: "trixie/sid", Value: Distro::DebianTrixie)
181 .Case(S: "forky/sid", Value: Distro::DebianForky)
182 .Case(S: "duke/sid", Value: Distro::DebianDuke)
183 .Default(Value: Distro::UnknownDistro);
184 }
185
186 // ...for SUSE
187 File = VFS.getBufferForFile(Name: "/etc/SuSE-release");
188 if (File) {
189 StringRef Data = File.get()->getBuffer();
190 SmallVector<StringRef, 8> Lines;
191 Data.split(A&: Lines, Separator: "\n");
192 for (const StringRef &Line : Lines) {
193 if (!Line.trim().starts_with(Prefix: "VERSION"))
194 continue;
195 std::pair<StringRef, StringRef> SplitLine = Line.split(Separator: '=');
196 // Old versions have split VERSION and PATCHLEVEL
197 // Newer versions use VERSION = x.y
198 std::pair<StringRef, StringRef> SplitVer =
199 SplitLine.second.trim().split(Separator: '.');
200 int Version;
201
202 // OpenSUSE/SLES 10 and older are not supported and not compatible
203 // with our rules, so just treat them as Distro::UnknownDistro.
204 if (!SplitVer.first.getAsInteger(Radix: 10, Result&: Version) && Version > 10)
205 return Distro::OpenSUSE;
206 return Distro::UnknownDistro;
207 }
208 return Distro::UnknownDistro;
209 }
210
211 // ...and others.
212 if (VFS.exists(Path: "/etc/gentoo-release"))
213 return Distro::Gentoo;
214
215 return Distro::UnknownDistro;
216}
217
218static Distro::DistroType GetDistro(llvm::vfs::FileSystem &VFS,
219 const llvm::Triple &TargetOrHost) {
220 // If we don't target Linux, no need to check the distro. This saves a few
221 // OS calls.
222 if (!TargetOrHost.isOSLinux())
223 return Distro::UnknownDistro;
224
225 // True if we're backed by a real file system.
226 const bool onRealFS = (llvm::vfs::getRealFileSystem() == &VFS);
227
228 // If the host is not running Linux, and we're backed by a real file
229 // system, no need to check the distro. This is the case where someone
230 // is cross-compiling from BSD or Windows to Linux, and it would be
231 // meaningless to try to figure out the "distro" of the non-Linux host.
232 llvm::Triple HostTriple(llvm::sys::getProcessTriple());
233 if (!HostTriple.isOSLinux() && onRealFS)
234 return Distro::UnknownDistro;
235
236 if (onRealFS) {
237 // If we're backed by a real file system, perform
238 // the detection only once and save the result.
239 static Distro::DistroType LinuxDistro = DetectDistro(VFS);
240 return LinuxDistro;
241 }
242 // This is mostly for passing tests which uses llvm::vfs::InMemoryFileSystem,
243 // which is not "real".
244 return DetectDistro(VFS);
245}
246
247Distro::Distro(llvm::vfs::FileSystem &VFS, const llvm::Triple &TargetOrHost)
248 : DistroVal(GetDistro(VFS, TargetOrHost)) {}
249