Adding a version.{h,cpp}

- Simple compile time version to headers.
- Generated by cmake - so one less place to update.
- Also embedded version in the compiled library in case one needs sanity check.

Co-authored-by: Enrico Steffinlongo <enrylongo@gmail.com>

Author: hamishun

OLD_INSTALL.txt

@@ -2,6 +2,15 @@
 ===>          Refer to INSTALL.md for newer cmake-based installation.   <===
 ===>          We no longer recommend this method to install HElib.      <=== 
 
+Additional Notes, September 2020
+--------------------------------
+version.in.h header and some source code (version.in.cpp and
+TestVersion.in.cpp) has been added so that HElib can introspect on its version.
+These are template files that cmake fills in the version numbers for us during
+a build. The old Makefile does not compile these. So, if you wish to use them
+we recommend moving to the cmake build.
+
+
 HElib Installation Notes, August 2020
 ---------------------------------------
 Much has changed since the note in 2015 and there are many updates. So this 

include/helib/version.in.h

@@ -0,0 +1,78 @@
+/* Copyright (C) 2020 IBM Corp.
+ * This program is Licensed under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License. See accompanying LICENSE file.
+ */
+
+#ifndef HELIB_VERSION_H
+#define HELIB_VERSION_H
+
+namespace helib {
+
+/**
+ * @class version
+ * @brief The class acts as a namespace with all members static.
+ * Holds the version number for this code of HElib.
+ **/
+struct version
+{
+
+  // clang-format off
+  /**
+   * @brief The major number of this version of HElib.
+   **/
+  static constexpr long major = @PROJECT_VERSION_MAJOR@;
+  /**
+   * @brief The minor number of this version of HElib.
+   **/
+  static constexpr long minor = @PROJECT_VERSION_MINOR@;
+  /**
+   * @brief The patch number of this version of HElib.
+   **/
+  static constexpr long patch = @PROJECT_VERSION_PATCH@;
+  // clang-format on
+
+  /**
+   * @brief The string representation of this version of HElib.
+   **/
+  static constexpr auto asString = "v@PROJECT_VERSION@";
+
+  /**
+   * @brief Function that returns whether this version of HElib is equal to or
+   * higher than a specified version.
+   * @param major The major version number.
+   * @param minor The minor version number.
+   * @param patch The patch version number.
+   * @return `true` if current HElib version is greater than or equal to the
+   * specified version version.
+   **/
+  static inline constexpr bool greaterEquals(long major_,
+                                             long minor_ = 0,
+                                             long patch_ = 0)
+  {
+    if (major_ < 0 || minor_ < 0 || patch_ < 0)
+      return false;
+    long min_version = (((major_ << 8) ^ minor_) << 8) ^ patch_;
+    long our_version = (((major << 8) ^ minor) << 8) ^ patch;
+    return our_version >= min_version;
+  }
+
+  /**
+   * @brief Get the string version from the HElib compiled library instead of
+   * the one defined in the header.
+   * @return A string representing the version of HElib stored in the compiled
+   * library instead of from the one defined in the header.
+   **/
+  static const char* libString();
+
+}; // struct version
+
+} // namespace helib
+
+#endif // HELIB_VERSION_H

src/CMakeLists.txt

@@ -20,6 +20,8 @@ project(helib
 set(PROJECT_INCLUDE_DIR "${PROJECT_SOURCE_DIR}/../include")
 # Location of the google tests
 set(PROJECT_TESTS_DIR "${PROJECT_SOURCE_DIR}/../tests")
+# Location of helib headers
+set(HELIB_HEADER_DIR "${PROJECT_INCLUDE_DIR}/helib")
 
 # We assume enable threads is passed correctly (already checked)
 if (HELIB_REQUIRES_PTHREADS)
@@ -36,6 +38,14 @@ else ()
       "${CMAKE_INSTALL_DATAROOTDIR}/cmake/${PROJECT_NAME}")
 endif ()
 
+# Generate version.{h,cpp}
+configure_file(${HELIB_HEADER_DIR}/version.in.h
+               ${CMAKE_CURRENT_BINARY_DIR}/helib/version.h
+               @ONLY)
+configure_file(version.in.cpp
+               ${CMAKE_CURRENT_BINARY_DIR}/version.cpp
+               @ONLY)
+
 if (ENABLE_TEST)
   # Download and unpack googletest at configure time
   message(STATUS "Setting up googletest framework")
@@ -113,9 +123,10 @@ set(HELIB_SRCS
     "sample.cpp"
     "tableLookup.cpp"
     "timing.cpp"
-    "zzX.cpp")
+    "zzX.cpp"
+    "${CMAKE_CURRENT_BINARY_DIR}/version.cpp" # version.cpp is auto-generated in CMAKE_CURRENT_BINARY_DIR
+    )
 
-set(HELIB_HEADER_DIR "${PROJECT_INCLUDE_DIR}/helib")
 set(HELIB_HEADERS
     "${HELIB_HEADER_DIR}/helib.h"
     "${HELIB_HEADER_DIR}/apiAttributes.h"
@@ -171,7 +182,9 @@ set(HELIB_HEADERS
     "${HELIB_HEADER_DIR}/exceptions.h"
     "${HELIB_HEADER_DIR}/PGFFT.h"
     "${HELIB_HEADER_DIR}/fhe_stats.h"
-    "${HELIB_HEADER_DIR}/zeroValue.h")
+    "${HELIB_HEADER_DIR}/zeroValue.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/helib/version.h" # version.h is auto-generated in CMAKE_CURRENT_BINARY_DIR
+    )
 
 set(LEGACY_TEST_SRCS
     "Test_approxNums.cpp"
@@ -262,6 +275,9 @@ target_include_directories(
            # looking for HElib in /usr/local/include
            # Headers used from source/build location:
            "$<BUILD_INTERFACE:${PROJECT_INCLUDE_DIR}>"
+           # Adding CMAKE_CURRENT_BINARY_DIR to include files to access the
+           # auto-generated version.h file.
+           "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>"
            # Headers used from the installed location:
            "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
 

src/version.in.cpp

@@ -0,0 +1,10 @@
+#include <helib/version.h>
+
+namespace helib {
+
+// This is stored in the compiled library.
+static constexpr char versionInLib[] = "v@PROJECT_VERSION@";
+
+const char* version::libString() { return versionInLib; }
+
+} // namespace helib

tests/CMakeLists.txt

@@ -12,6 +12,11 @@
 
 # Gtests configuration file
 
+# TestVersion will be generated in CMAKE_CURRENT_BINARY_DIR.
+configure_file(TestVersion.in.cpp
+               ${CMAKE_CURRENT_BINARY_DIR}/TestVersion.cpp
+               @ONLY)
+
 set(GTEST_SRC
     "test_common.cpp"
     "TestArgMap.cpp"
@@ -27,6 +32,7 @@ set(GTEST_SRC
     "TestPolyModRing.cpp"
     "TestPtxt.cpp"
     "TestSet.cpp"
+    "${CMAKE_CURRENT_BINARY_DIR}/TestVersion.cpp" # TestVersion.cpp is auto-generated in CMAKE_CURRENT_BINARY_DIR
     )
 
 set(PORTED_LEGACY_TEST_SRC
@@ -100,13 +106,17 @@ set(TEST_NAMES
     "TestPtxt"
     "TestSet"
     "TestThinBootstrappingWithMultiplications"
+    "TestVersion"
     )
 
 # NOTE: Adding all PRIVATE_HELIB_CXX_FLAGS to the tests will add -fPIC too.
 # At the moment this does not affect compilation of the tests and does not
 # change their running time.
 target_compile_options(runTests PRIVATE ${PRIVATE_HELIB_CXX_FLAGS})
 
+# Adding CMAKE_CURRENT_SOURCE_DIR to include files to access test_common.h.
+target_include_directories(runTests PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+
 foreach (TEST_NAME ${TEST_NAMES})
   add_test(NAME "${TEST_NAME}" COMMAND runTests --gtest_filter=*${TEST_NAME}*)
 endforeach (TEST_NAME)

tests/TestVersion.in.cpp

@@ -0,0 +1,107 @@
+/* Copyright (C) 2020 IBM Corp.
+ * This program is Licensed under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License. See accompanying LICENSE file.
+ */
+
+#include <helib/version.h>
+#include <tuple>
+#include <string>
+#include <regex>
+#include <sstream>
+#include <fstream>
+#include "test_common.h"
+#include "gtest/gtest.h"
+
+namespace {
+
+// Util function to grab version from cmake file.
+std::tuple<int, int, int, std::string> readVersionFromCmakeFile()
+{
+  // File will be in src/, we are in tests/
+  const std::string cmakeFilePath = "@CMAKE_SOURCE_DIR@/src/CMakeLists.txt";
+
+  // Slurp the file. It isn't a large file.
+  std::string fileStr;
+
+  {
+    std::ifstream cmakeFile(cmakeFilePath);
+    if (!cmakeFile.is_open())
+      throw std::runtime_error("Could not find '" + cmakeFilePath + "'.");
+
+    std::ostringstream oss;
+    oss << cmakeFile.rdbuf();
+    fileStr = oss.str();
+  }
+
+  // Find the version.
+  // e.g.
+  // project(helib
+  //         VERSION x.y.z
+  //         LANGUAGES CXX)
+
+  std::regex re_version(
+      R"(project[\s\S]*?helib[\s\S]*?VERSION[\s\S]*?((\d+)\.(\d+)\.(\d)))");
+  std::smatch match;
+  std::regex_search(fileStr, match, re_version);
+  if (match.size() < 5) {
+    std::ostringstream oss;
+    oss << "Expected 5 matches, got " << match.size() << ".";
+    throw std::runtime_error(oss.str());
+  }
+
+  return std::tuple<int, int, int, std::string>(std::stoi(match[2]),
+                                                std::stoi(match[3]),
+                                                std::stoi(match[4]),
+                                                "v" + match[1].str());
+}
+
+TEST(TestVersion, versionMatchesThatFoundInCMakelists)
+{
+  int major;
+  int minor;
+  int patch;
+  std::string verStr;
+
+  std::tie(major, minor, patch, verStr) = readVersionFromCmakeFile();
+
+  // EXPECT_EQ does not like these class static members.
+  int cur_maj = helib::version::major;
+  int cur_min = helib::version::minor;
+  int cur_pat = helib::version::patch;
+
+  EXPECT_EQ(cur_maj, major);
+  EXPECT_EQ(cur_min, minor);
+  EXPECT_EQ(cur_pat, patch);
+  EXPECT_STREQ(helib::version::asString, verStr.c_str());
+}
+
+TEST(TestVersion, versionGreaterThanOrEqualTo)
+{
+  EXPECT_FALSE(helib::version::greaterEquals(3));
+  EXPECT_FALSE(helib::version::greaterEquals(3, 1));
+  EXPECT_FALSE(helib::version::greaterEquals(3, 1, 4));
+  // Shouldn't work for negative numbers
+  EXPECT_FALSE(helib::version::greaterEquals(1, -1, 0));
+  EXPECT_FALSE(helib::version::greaterEquals(0, -1, 0));
+  // Older version
+  EXPECT_TRUE(helib::version::greaterEquals(1, 0, 0));
+  // Current version
+  // clang-format off
+  EXPECT_TRUE(helib::version::greaterEquals(@PROJECT_VERSION_MAJOR@, @PROJECT_VERSION_MINOR@, @PROJECT_VERSION_PATCH@));
+  // clang-format on
+}
+
+TEST(TestVersion, versionLibString)
+{
+  const char* libString = helib::version::libString();
+  EXPECT_STREQ(libString, "v@PROJECT_VERSION@");
+}
+
+} // namespace