Merge pull request #42 from mattyclarkson/versioning

.gitignore

@@ -3,6 +3,7 @@
 *.so.?*
 *.dylib
 *.cmake
+!/cmake/*.cmake
 *~
 /test/benchmark_test
 /test/re_test

CMakeLists.txt

 cmake_minimum_required (VERSION 2.8)
 project (benchmark)
 
+# Make sure we can import out CMake functions
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+
+# We need threads in this project
 find_package(Threads REQUIRED)
 
 # Import and build Google Test
@@ -38,9 +42,17 @@ if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "x86")
 	add_definitions(-DARCH_X86)
 endif()
 
+# Read the git tags to determine the project version
+include(GetGitVersion)
+get_git_version(GIT_VERSION)
+
+# Tell the user what versions we are using
+string(REGEX MATCH "[0-9]+\\.[0-9]+\\.[0-9]+" VERSION ${GIT_VERSION})
+message("-- Version: ${VERSION}")
+
 # The version of the libraries
-set(GENERIC_LIB_VERSION "0.0.0")
-set(GENERIC_LIB_SOVERSION "0")
+set(GENERIC_LIB_VERSION ${VERSION})
+string(SUBSTRING ${VERSION} 0 1 GENERIC_LIB_SOVERSION)
 
 # Set up directories
 include_directories(${PROJECT_SOURCE_DIR}/include)

cmake/GetGitVersion.cmake

+# - Returns a version string from Git tags
+#
+# This function inspects the annotated git tags for the project and returns a string
+# into a CMake variable
+#
+#  get_git_version(<var>)
+#
+# - Example
+#
+# include(GetGitVersion)
+# get_git_version(GIT_VERSION)
+#
+# Requires CMake 2.6+
+
+if(__get_git_version)
+  return()
+endif()
+set(__get_git_version INCLUDED)
+
+function(get_git_version var)
+  execute_process(COMMAND git describe --match "v[0-9]*.[0-9]*.[0-9]*" --abbrev=8
+      RESULT_VARIABLE status
+      OUTPUT_VARIABLE GIT_VERSION
+      ERROR_QUIET)
+  if(${status})
+      set(GIT_VERSION "v0.0.0")
+  else()
+      string(STRIP ${GIT_VERSION} GIT_VERSION)
+      string(REGEX REPLACE "-[0-9]+-g" "-" GIT_VERSION ${GIT_VERSION})
+  endif()
+
+  # Work out if the repository is dirty
+  execute_process(COMMAND git update-index -q --refresh
+      OUTPUT_QUIET
+      ERROR_QUIET)
+  execute_process(COMMAND git diff-index --name-only HEAD --
+      OUTPUT_VARIABLE GIT_DIFF_INDEX
+      ERROR_QUIET)
+  string(COMPARE NOTEQUAL "${GIT_DIFF_INDEX}" "" GIT_DIRTY)
+  if (${GIT_DIRTY})
+      string(CONCAT GIT_VERSION ${GIT_VERSION} "-dirty")
+  endif()
+  message("-- git Version: ${GIT_VERSION}")
+  set(${var} ${GIT_VERSION} PARENT_SCOPE)
+endfunction()