From 56aad5aafb84b87c9cdf8a237a3d7fdf632b2021 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Wed, 20 May 2009 00:04:08 +0200
Subject: [PATCH] * add a FindEigen2.cmake file for reference * parse the
 version number from the Macro.h header file

---
 CMakeLists.txt         | 32 +++++++++++-------
 cmake/FindEigen2.cmake | 73 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+), 11 deletions(-)
 create mode 100644 cmake/FindEigen2.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ffbf23d85..1d84e9107 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,19 +1,29 @@
 project(Eigen)
-set(EIGEN_VERSION_NUMBER "2.0.52-unstable")
 
-#if the svnversion program is absent, this will leave the SVN_REVISION string empty,
-#but won't stop CMake.
-execute_process(COMMAND svnversion -n ${CMAKE_SOURCE_DIR}
-                OUTPUT_VARIABLE EIGEN_SVNVERSION_OUTPUT)
+# automatically parse the version number
+file(READ "${CMAKE_SOURCE_DIR}/Eigen/src/Core/util/Macros.h" _eigen2_version_header LIMIT 5000 OFFSET 1000)
+string(REGEX MATCH "define *EIGEN_WORLD_VERSION ([0-9]*)" _eigen2_world_version_match "${_eigen2_version_header}")
+set(EIGEN2_WORLD_VERSION "${CMAKE_MATCH_1}")
+string(REGEX MATCH "define *EIGEN_MAJOR_VERSION ([0-9]*)" _eigen2_major_version_match "${_eigen2_version_header}")
+set(EIGEN2_MAJOR_VERSION "${CMAKE_MATCH_1}")
+string(REGEX MATCH "define *EIGEN_MINOR_VERSION ([0-9]*)" _eigen2_minor_version_match "${_eigen2_version_header}")
+set(EIGEN2_MINOR_VERSION "${CMAKE_MATCH_1}")
+# TODO find a way to automatically remove the unstable suffix
+set(EIGEN_VERSION_NUMBER ${EIGEN2_WORLD_VERSION}.${EIGEN2_MAJOR_VERSION}.${EIGEN2_MINOR_VERSION}-unstable)
 
-#we only want EIGEN_SVN_REVISION if it is an actual revision number, not a string like "exported"
-string(REGEX MATCH "^[0-9]+.*" EIGEN_SVN_REVISION "${EIGEN_SVNVERSION_OUTPUT}")
+# if the mercurial program is absent, this will leave the EIGEN_HG_REVISION string empty,
+# but won't stop CMake.
+execute_process(COMMAND hg tip -R ${CMAKE_SOURCE_DIR} OUTPUT_VARIABLE EIGEN_HGTIP_OUTPUT)
 
-if(EIGEN_SVN_REVISION)
-  set(EIGEN_VERSION "${EIGEN_VERSION_NUMBER} (SVN revision ${EIGEN_SVN_REVISION})")
-else(EIGEN_SVN_REVISION)
+# extract the mercurial revision number from the hg tip output
+string(REGEX MATCH "^changeset: *[0-9]*:([0-9;a-f]+).*" EIGEN_HG_REVISION_MATCH "${EIGEN_HGTIP_OUTPUT}")
+set(EIGEN_HG_REVISION "${CMAKE_MATCH_1}")
+
+if(EIGEN_HG_REVISION)
+  set(EIGEN_VERSION "${EIGEN_VERSION_NUMBER} (mercurial revision ${EIGEN_HG_REVISION})")
+else(EIGEN_HG_REVISION)
   set(EIGEN_VERSION "${EIGEN_VERSION_NUMBER}")
-endif(EIGEN_SVN_REVISION)
+endif(EIGEN_HG_REVISION)
 
 cmake_minimum_required(VERSION 2.6.2)
 
diff --git a/cmake/FindEigen2.cmake b/cmake/FindEigen2.cmake
new file mode 100644
index 000000000..f2f7f6eda
--- /dev/null
+++ b/cmake/FindEigen2.cmake
@@ -0,0 +1,73 @@
+# - Try to find Eigen2 lib
+# Once done this will define
+#
+#  EIGEN2_FOUND - system has eigen lib with correct version
+#  EIGEN2_INCLUDE_DIR - the eigen include directory
+#  EIGEN2_VERSION - eigen version
+
+# Copyright (c) 2006, 2007 Montel Laurent, <montel@kde.org>
+# Copyright (c) 2008, 2009 Gael Guennebaud, <g.gael@free.fr>
+# Redistribution and use is allowed according to the terms of the BSD license.
+
+include(MacroEnsureVersion)
+
+if(NOT EIGEN2_MIN_VERSION)
+  if(NOT Eigen2_FIND_VERSION_MAJOR)
+    set(Eigen2_FIND_VERSION_MAJOR 2)
+  endif(NOT Eigen2_FIND_VERSION_MAJOR)
+  if(NOT Eigen2_FIND_VERSION_MINOR)
+    set(Eigen2_FIND_VERSION_MINOR 0)
+  endif(NOT Eigen2_FIND_VERSION_MINOR)
+  if(NOT Eigen2_FIND_VERSION_PATCH)
+    set(Eigen2_FIND_VERSION_PATCH 0)
+  endif(NOT Eigen2_FIND_VERSION_PATCH)
+
+  set(EIGEN2_MIN_VERSION "${Eigen2_FIND_VERSION_MAJOR}.${Eigen2_FIND_VERSION_MINOR}.${Eigen2_FIND_VERSION_PATCH}")
+endif(NOT EIGEN2_MIN_VERSION)
+
+macro(_eigen2_check_version)
+  file(READ "${EIGEN2_INCLUDE_DIR}/Eigen/src/Core/util/Macros.h" _eigen2_version_header LIMIT 5000 OFFSET 1000)
+
+  string(REGEX MATCH "define *EIGEN_WORLD_VERSION ([0-9]*)" _eigen2_world_version_match "${_eigen2_version_header}")
+  set(EIGEN2_WORLD_VERSION "${CMAKE_MATCH_1}")
+  string(REGEX MATCH "define *EIGEN_MAJOR_VERSION ([0-9]*)" _eigen2_major_version_match "${_eigen2_version_header}")
+  set(EIGEN2_MAJOR_VERSION "${CMAKE_MATCH_1}")
+  string(REGEX MATCH "define *EIGEN_MINOR_VERSION ([0-9]*)" _eigen2_minor_version_match "${_eigen2_version_header}")
+  set(EIGEN2_MINOR_VERSION "${CMAKE_MATCH_1}")
+
+  set(EIGEN2_VERSION ${EIGEN2_WORLD_VERSION}.${EIGEN2_MAJOR_VERSION}.${EIGEN2_MINOR_VERSION})
+  MACRO_ENSURE_VERSION( ${EIGEN2_MIN_VERSION} ${EIGEN2_VERSION} EIGEN2_VERSION_OK)
+
+  if(NOT EIGEN2_VERSION_OK)
+  
+    message(STATUS "Eigen2 version ${EIGEN2_VERSION} found in ${EIGEN2_INCLUDE_DIR}, "
+                   "but at least version ${EIGEN2_MIN_VERSION} is required")
+  endif(NOT EIGEN2_VERSION_OK)
+endmacro(_eigen2_check_version)
+
+if (EIGEN2_INCLUDE_DIR)
+
+  # in cache already
+  _eigen2_check_version()
+  set(EIGEN2_FOUND ${EIGEN2_VERSION_OK})
+
+else (EIGEN2_INCLUDE_DIR)
+
+find_path(EIGEN2_INCLUDE_DIR NAMES Eigen/Core
+     PATHS
+     ${INCLUDE_INSTALL_DIR}
+     ${KDE4_INCLUDE_DIR}
+     PATH_SUFFIXES eigen2
+   )
+
+if(EIGEN2_INCLUDE_DIR)
+  _eigen2_check_version()
+endif(EIGEN2_INCLUDE_DIR)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Eigen2 DEFAULT_MSG EIGEN2_INCLUDE_DIR EIGEN2_VERSION_OK)
+
+mark_as_advanced(EIGEN2_INCLUDE_DIR)
+
+endif(EIGEN2_INCLUDE_DIR)
+