From b96d0bd240c0b81947244e47a6568680d41ae348 Mon Sep 17 00:00:00 2001
From: Hauke Heibel <hauke.heibel@gmail.com>
Date: Tue, 4 Oct 2011 11:23:55 +0200
Subject: [PATCH] Added a flag to build blas/lapack.

---
 CMakeLists.txt | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ab44f22c1..44ff6d188 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -343,12 +343,24 @@ else()
   add_subdirectory(test EXCLUDE_FROM_ALL)
 endif()
 
-if(EIGEN_LEAVE_TEST_IN_ALL_TARGET)
-  add_subdirectory(blas)
-  add_subdirectory(lapack)
+ # The flag below can be removed when the CMake issue
+ #   http://public.kitware.com/Bug/view.php?id=9220
+ # is fixed and when the cmake_minimum_required(VERSION ...)
+ # is accordingly adapted.
+if(MSVC)
+  set(EIGEN_BUILD_BLAS_LAPACK FALSE CACHE BOOL "Activates blas and lapack subfolders inclusion.")
 else()
-  add_subdirectory(blas EXCLUDE_FROM_ALL)
-  add_subdirectory(lapack EXCLUDE_FROM_ALL)
+  set(EIGEN_BUILD_BLAS_LAPACK TRUE CACHE BOOL "Activates blas and lapack subfolders inclusion.")
+endif()
+
+if(EIGEN_BUILD_BLAS_LAPACK)
+  if(EIGEN_LEAVE_TEST_IN_ALL_TARGET)
+    add_subdirectory(blas)
+    add_subdirectory(lapack)
+  else()
+    add_subdirectory(blas EXCLUDE_FROM_ALL)
+    add_subdirectory(lapack EXCLUDE_FROM_ALL)
+  endif()
 endif()
 
 add_subdirectory(unsupported)