Move VersionTuple from clang/Basic to llvm/Support

Summary:
This kind of functionality is useful to other project apart from clang.
LLDB works with version numbers a lot, but it does not have a convenient
abstraction for this. Moving this class to a lower level library allows
it to be freely used within LLDB.

Since this class is used in a lot of places in clang, and it used to be
in the clang namespace, it seemed appropriate to add it to the list of
adopted classes in LLVM.h to avoid prefixing all uses with "llvm::".

Also, I didn't find any tests specific for this class, so I wrote a
couple of quick ones for the more interesting bits of functionality.

Reviewers: zturner, erik.pilkington

Subscribers: mgorny, cfe-commits, llvm-commits

Differential Revision: https://reviews.llvm.org/D47887

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334399 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 316 insertions, 0 deletions

diff --git a/include/llvm/Support/VersionTuple.h b/include/llvm/Support/VersionTuple.h
new file mode 100644
index 00000000000..e85a188e54b
--- /dev/null
+++ b/include/llvm/Support/VersionTuple.h
@@ -0,0 +1,154 @@
+//===- VersionTuple.h - Version Number Handling -----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Defines the llvm::VersionTuple class, which represents a version in
+/// the form major[.minor[.subminor]].
+///
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_SUPPORT_VERSIONTUPLE_H
+#define LLVM_SUPPORT_VERSIONTUPLE_H
+
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+#include <tuple>
+
+namespace llvm {
+
+/// Represents a version number in the form major[.minor[.subminor[.build]]].
+class VersionTuple {
+  unsigned Major : 32;
+
+  unsigned Minor : 31;
+  unsigned HasMinor : 1;
+
+  unsigned Subminor : 31;
+  unsigned HasSubminor : 1;
+
+  unsigned Build : 31;
+  unsigned HasBuild : 1;
+
+public:
+  VersionTuple()
+      : Major(0), Minor(0), HasMinor(false), Subminor(0), HasSubminor(false),
+        Build(0), HasBuild(false) {}
+
+  explicit VersionTuple(unsigned Major)
+      : Major(Major), Minor(0), HasMinor(false), Subminor(0),
+        HasSubminor(false), Build(0), HasBuild(false) {}
+
+  explicit VersionTuple(unsigned Major, unsigned Minor)
+      : Major(Major), Minor(Minor), HasMinor(true), Subminor(0),
+        HasSubminor(false), Build(0), HasBuild(false) {}
+
+  explicit VersionTuple(unsigned Major, unsigned Minor, unsigned Subminor)
+      : Major(Major), Minor(Minor), HasMinor(true), Subminor(Subminor),
+        HasSubminor(true), Build(0), HasBuild(false) {}
+
+  explicit VersionTuple(unsigned Major, unsigned Minor, unsigned Subminor,
+                        unsigned Build)
+      : Major(Major), Minor(Minor), HasMinor(true), Subminor(Subminor),
+        HasSubminor(true), Build(Build), HasBuild(true) {}
+
+  /// Determine whether this version information is empty
+  /// (e.g., all version components are zero).
+  bool empty() const {
+    return Major == 0 && Minor == 0 && Subminor == 0 && Build == 0;
+  }
+
+  /// Retrieve the major version number.
+  unsigned getMajor() const { return Major; }
+
+  /// Retrieve the minor version number, if provided.
+  Optional<unsigned> getMinor() const {
+    if (!HasMinor)
+      return None;
+    return Minor;
+  }
+
+  /// Retrieve the subminor version number, if provided.
+  Optional<unsigned> getSubminor() const {
+    if (!HasSubminor)
+      return None;
+    return Subminor;
+  }
+
+  /// Retrieve the build version number, if provided.
+  Optional<unsigned> getBuild() const {
+    if (!HasBuild)
+      return None;
+    return Build;
+  }
+
+  /// Determine if two version numbers are equivalent. If not
+  /// provided, minor and subminor version numbers are considered to be zero.
+  friend bool operator==(const VersionTuple &X, const VersionTuple &Y) {
+    return X.Major == Y.Major && X.Minor == Y.Minor &&
+           X.Subminor == Y.Subminor && X.Build == Y.Build;
+  }
+
+  /// Determine if two version numbers are not equivalent.
+  ///
+  /// If not provided, minor and subminor version numbers are considered to be
+  /// zero.
+  friend bool operator!=(const VersionTuple &X, const VersionTuple &Y) {
+    return !(X == Y);
+  }
+
+  /// Determine whether one version number precedes another.
+  ///
+  /// If not provided, minor and subminor version numbers are considered to be
+  /// zero.
+  friend bool operator<(const VersionTuple &X, const VersionTuple &Y) {
+    return std::tie(X.Major, X.Minor, X.Subminor, X.Build) <
+           std::tie(Y.Major, Y.Minor, Y.Subminor, Y.Build);
+  }
+
+  /// Determine whether one version number follows another.
+  ///
+  /// If not provided, minor and subminor version numbers are considered to be
+  /// zero.
+  friend bool operator>(const VersionTuple &X, const VersionTuple &Y) {
+    return Y < X;
+  }
+
+  /// Determine whether one version number precedes or is
+  /// equivalent to another.
+  ///
+  /// If not provided, minor and subminor version numbers are considered to be
+  /// zero.
+  friend bool operator<=(const VersionTuple &X, const VersionTuple &Y) {
+    return !(Y < X);
+  }
+
+  /// Determine whether one version number follows or is
+  /// equivalent to another.
+  ///
+  /// If not provided, minor and subminor version numbers are considered to be
+  /// zero.
+  friend bool operator>=(const VersionTuple &X, const VersionTuple &Y) {
+    return !(X < Y);
+  }
+
+  /// Retrieve a string representation of the version number.
+  std::string getAsString() const;
+
+  /// Try to parse the given string as a version number.
+  /// \returns \c true if the string does not match the regular expression
+  ///   [0-9]+(\.[0-9]+){0,3}
+  bool tryParse(StringRef string);
+};
+
+/// Print a version number.
+raw_ostream &operator<<(raw_ostream &Out, const VersionTuple &V);
+
+} // end namespace llvm
+#endif // LLVM_SUPPORT_VERSIONTUPLE_H
diff --git a/lib/Support/CMakeLists.txt b/lib/Support/CMakeLists.txt
index 3548a99934c..e1a48ac97fb 100644
--- a/lib/Support/CMakeLists.txt
+++ b/lib/Support/CMakeLists.txt
@@ -124,6 +124,7 @@ add_llvm_library(LLVMSupport
   Twine.cpp
   Unicode.cpp
   UnicodeCaseFold.cpp
+  VersionTuple.cpp
   WithColor.cpp
   YAMLParser.cpp
   YAMLTraits.cpp
diff --git a/lib/Support/VersionTuple.cpp b/lib/Support/VersionTuple.cpp
new file mode 100644
index 00000000000..3f219bfbedf
--- /dev/null
+++ b/lib/Support/VersionTuple.cpp
@@ -0,0 +1,110 @@
+//===- VersionTuple.cpp - Version Number Handling ---------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the VersionTuple class, which represents a version in
+// the form major[.minor[.subminor]].
+//
+//===----------------------------------------------------------------------===//
+#include "llvm/Support/VersionTuple.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+std::string VersionTuple::getAsString() const {
+  std::string Result;
+  {
+    llvm::raw_string_ostream Out(Result);
+    Out << *this;
+  }
+  return Result;
+}
+
+raw_ostream &llvm::operator<<(raw_ostream &Out, const VersionTuple &V) {
+  Out << V.getMajor();
+  if (Optional<unsigned> Minor = V.getMinor())
+    Out << '.' << *Minor;
+  if (Optional<unsigned> Subminor = V.getSubminor())
+    Out << '.' << *Subminor;
+  if (Optional<unsigned> Build = V.getBuild())
+    Out << '.' << *Build;
+  return Out;
+}
+
+static bool parseInt(StringRef &input, unsigned &value) {
+  assert(value == 0);
+  if (input.empty())
+    return true;
+
+  char next = input[0];
+  input = input.substr(1);
+  if (next < '0' || next > '9')
+    return true;
+  value = (unsigned)(next - '0');
+
+  while (!input.empty()) {
+    next = input[0];
+    if (next < '0' || next > '9')
+      return false;
+    input = input.substr(1);
+    value = value * 10 + (unsigned)(next - '0');
+  }
+
+  return false;
+}
+
+bool VersionTuple::tryParse(StringRef input) {
+  unsigned major = 0, minor = 0, micro = 0, build = 0;
+
+  // Parse the major version, [0-9]+
+  if (parseInt(input, major))
+    return true;
+
+  if (input.empty()) {
+    *this = VersionTuple(major);
+    return false;
+  }
+
+  // If we're not done, parse the minor version, \.[0-9]+
+  if (input[0] != '.')
+    return true;
+  input = input.substr(1);
+  if (parseInt(input, minor))
+    return true;
+
+  if (input.empty()) {
+    *this = VersionTuple(major, minor);
+    return false;
+  }
+
+  // If we're not done, parse the micro version, \.[0-9]+
+  if (input[0] != '.')
+    return true;
+  input = input.substr(1);
+  if (parseInt(input, micro))
+    return true;
+
+  if (input.empty()) {
+    *this = VersionTuple(major, minor, micro);
+    return false;
+  }
+
+  // If we're not done, parse the micro version, \.[0-9]+
+  if (input[0] != '.')
+    return true;
+  input = input.substr(1);
+  if (parseInt(input, build))
+    return true;
+
+  // If we have characters left over, it's an error.
+  if (!input.empty())
+    return true;
+
+  *this = VersionTuple(major, minor, micro, build);
+  return false;
+}
diff --git a/unittests/Support/CMakeLists.txt b/unittests/Support/CMakeLists.txt
index 89e16ef4b3f..4b46387a471 100644
--- a/unittests/Support/CMakeLists.txt
+++ b/unittests/Support/CMakeLists.txt
@@ -61,6 +61,7 @@ add_llvm_unittest(SupportTests
   TrailingObjectsTest.cpp
   TrigramIndexTest.cpp
   UnicodeTest.cpp
+  VersionTupleTest.cpp
   YAMLIOTest.cpp
   YAMLParserTest.cpp
   formatted_raw_ostream_test.cpp
diff --git a/unittests/Support/VersionTupleTest.cpp b/unittests/Support/VersionTupleTest.cpp
new file mode 100644
index 00000000000..cd7ecda5fef
--- /dev/null
+++ b/unittests/Support/VersionTupleTest.cpp
@@ -0,0 +1,50 @@
+//===- VersionTupleTests.cpp - Version Number Handling Tests --------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/VersionTuple.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+TEST(VersionTuple, getAsString) {
+  EXPECT_EQ("0", VersionTuple().getAsString());
+  EXPECT_EQ("1", VersionTuple(1).getAsString());
+  EXPECT_EQ("1.2", VersionTuple(1, 2).getAsString());
+  EXPECT_EQ("1.2.3", VersionTuple(1, 2, 3).getAsString());
+  EXPECT_EQ("1.2.3.4", VersionTuple(1, 2, 3, 4).getAsString());
+}
+
+TEST(VersionTuple, tryParse) {
+  VersionTuple VT;
+
+  EXPECT_FALSE(VT.tryParse("1"));
+  EXPECT_EQ("1", VT.getAsString());
+
+  EXPECT_FALSE(VT.tryParse("1.2"));
+  EXPECT_EQ("1.2", VT.getAsString());
+
+  EXPECT_FALSE(VT.tryParse("1.2.3"));
+  EXPECT_EQ("1.2.3", VT.getAsString());
+
+  EXPECT_FALSE(VT.tryParse("1.2.3.4"));
+  EXPECT_EQ("1.2.3.4", VT.getAsString());
+
+  EXPECT_TRUE(VT.tryParse(""));
+  EXPECT_TRUE(VT.tryParse("1."));
+  EXPECT_TRUE(VT.tryParse("1.2."));
+  EXPECT_TRUE(VT.tryParse("1.2.3."));
+  EXPECT_TRUE(VT.tryParse("1.2.3.4."));
+  EXPECT_TRUE(VT.tryParse("1.2.3.4.5"));
+  EXPECT_TRUE(VT.tryParse("1-2"));
+  EXPECT_TRUE(VT.tryParse("1+2"));
+  EXPECT_TRUE(VT.tryParse(".1"));
+  EXPECT_TRUE(VT.tryParse(" 1"));
+  EXPECT_TRUE(VT.tryParse("1 "));
+  EXPECT_TRUE(VT.tryParse("."));
+}