[Driver] Refactor distro detection & classification as a separate API

Refactor the Distro enum along with helper functions into a full-fledged
Distro class, inspired by llvm::Triple, and make it a public API.
The new class wraps the enum with necessary comparison operators, adding
the convenience Is*() methods and a constructor performing
the detection. The public API is needed to run the unit tests (D25869).

Differential Revision: https://reviews.llvm.org/D25949

llvm-svn: 288060

1 files changed, 131 insertions, 0 deletions

diff --git a/clang/lib/Driver/Distro.cpp b/clang/lib/Driver/Distro.cpp
new file mode 100644
index 00000000000..7a12643405d
--- /dev/null
+++ b/clang/lib/Driver/Distro.cpp
@@ -0,0 +1,131 @@
+//===--- Distro.cpp - Linux distribution detection support ------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Driver/Distro.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/ErrorOr.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+using namespace clang::driver;
+using namespace clang;
+
+static Distro::DistroType DetectDistro(vfs::FileSystem &VFS) {
+  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
+      VFS.getBufferForFile("/etc/lsb-release");
+  if (File) {
+    StringRef Data = File.get()->getBuffer();
+    SmallVector<StringRef, 16> Lines;
+    Data.split(Lines, "\n");
+	Distro::DistroType Version = Distro::UnknownDistro;
+    for (StringRef Line : Lines)
+      if (Version == Distro::UnknownDistro && Line.startswith("DISTRIB_CODENAME="))
+        Version = llvm::StringSwitch<Distro::DistroType>(Line.substr(17))
+                      .Case("hardy", Distro::UbuntuHardy)
+                      .Case("intrepid", Distro::UbuntuIntrepid)
+                      .Case("jaunty", Distro::UbuntuJaunty)
+                      .Case("karmic", Distro::UbuntuKarmic)
+                      .Case("lucid", Distro::UbuntuLucid)
+                      .Case("maverick", Distro::UbuntuMaverick)
+                      .Case("natty", Distro::UbuntuNatty)
+                      .Case("oneiric", Distro::UbuntuOneiric)
+                      .Case("precise", Distro::UbuntuPrecise)
+                      .Case("quantal", Distro::UbuntuQuantal)
+                      .Case("raring", Distro::UbuntuRaring)
+                      .Case("saucy", Distro::UbuntuSaucy)
+                      .Case("trusty", Distro::UbuntuTrusty)
+                      .Case("utopic", Distro::UbuntuUtopic)
+                      .Case("vivid", Distro::UbuntuVivid)
+                      .Case("wily", Distro::UbuntuWily)
+                      .Case("xenial", Distro::UbuntuXenial)
+                      .Case("yakkety", Distro::UbuntuYakkety)
+                      .Case("zesty", Distro::UbuntuZesty)
+                      .Default(Distro::UnknownDistro);
+    if (Version != Distro::UnknownDistro)
+      return Version;
+  }
+
+  File = VFS.getBufferForFile("/etc/redhat-release");
+  if (File) {
+    StringRef Data = File.get()->getBuffer();
+    if (Data.startswith("Fedora release"))
+      return Distro::Fedora;
+    if (Data.startswith("Red Hat Enterprise Linux") ||
+        Data.startswith("CentOS") ||
+        Data.startswith("Scientific Linux")) {
+      if (Data.find("release 7") != StringRef::npos)
+        return Distro::RHEL7;
+      else if (Data.find("release 6") != StringRef::npos)
+        return Distro::RHEL6;
+      else if (Data.find("release 5") != StringRef::npos)
+        return Distro::RHEL5;
+    }
+    return Distro::UnknownDistro;
+  }
+
+  File = VFS.getBufferForFile("/etc/debian_version");
+  if (File) {
+    StringRef Data = File.get()->getBuffer();
+    // Contents: < major.minor > or < codename/sid >
+    int MajorVersion;
+    if (!Data.split('.').first.getAsInteger(10, MajorVersion)) {
+      switch (MajorVersion) {
+      case 5:
+        return Distro::DebianLenny;
+      case 6:
+        return Distro::DebianSqueeze;
+      case 7:
+        return Distro::DebianWheezy;
+      case 8:
+        return Distro::DebianJessie;
+      case 9:
+        return Distro::DebianStretch;
+      default:
+        return Distro::UnknownDistro;
+      }
+    }
+    return llvm::StringSwitch<Distro::DistroType>(Data.split("\n").first)
+        .Case("squeeze/sid", Distro::DebianSqueeze)
+        .Case("wheezy/sid", Distro::DebianWheezy)
+        .Case("jessie/sid", Distro::DebianJessie)
+        .Case("stretch/sid", Distro::DebianStretch)
+        .Default(Distro::UnknownDistro);
+  }
+
+  File = VFS.getBufferForFile("/etc/SuSE-release");
+  if (File) {
+    StringRef Data = File.get()->getBuffer();
+    SmallVector<StringRef, 8> Lines;
+    Data.split(Lines, "\n");
+    for (const StringRef& Line : Lines) {
+      if (!Line.trim().startswith("VERSION"))
+        continue;
+      std::pair<StringRef, StringRef> SplitLine = Line.split('=');
+      int Version;
+      // OpenSUSE/SLES 10 and older are not supported and not compatible
+      // with our rules, so just treat them as Distro::UnknownDistro.
+      if (!SplitLine.second.trim().getAsInteger(10, Version) &&
+          Version > 10)
+        return Distro::OpenSUSE;
+      return Distro::UnknownDistro;
+    }
+    return Distro::UnknownDistro;
+  }
+
+  if (VFS.exists("/etc/exherbo-release"))
+    return Distro::Exherbo;
+
+  if (VFS.exists("/etc/arch-release"))
+    return Distro::ArchLinux;
+
+  return Distro::UnknownDistro;
+}
+
+Distro::Distro(vfs::FileSystem &VFS) : DistroVal(DetectDistro(VFS)) {}