add platform check for how to link to the standard math library.

This allows to support QNX.

1 files changed, 37 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f5f10ab81..5418a06ef 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,10 +2,17 @@ project(Eigen)
 
 cmake_minimum_required(VERSION 2.6.2)
 
+
+# guard against in-source builds
+
 if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_BINARY_DIR})
   message(FATAL_ERROR "In-source builds not allowed. Please make a new directory (called a build directory) and run CMake from there. (you may need to remove CMakeCache.txt ")
 endif()
 
+#############################################################################
+# retrieve version infomation                                               #
+#############################################################################
+
 # automatically parse the version number
 file(READ "${CMAKE_SOURCE_DIR}/Eigen/src/Core/util/Macros.h" _eigen_version_header)
 string(REGEX MATCH "define[ \t]+EIGEN_WORLD_VERSION[ \t]+([0-9]+)" _eigen_world_version_match "${_eigen_version_header}")
@@ -33,10 +40,40 @@ else(EIGEN_HG_CHANGESET)
   set(EIGEN_VERSION "${EIGEN_VERSION_NUMBER}")
 endif(EIGEN_HG_CHANGESET)
 
+
 include(CheckCXXCompilerFlag)
 
 set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
 
+#############################################################################
+# find how to link to the standard libraries                                #
+#############################################################################
+
+find_package(StandardMathLibrary)
+
+set(EIGEN_STANDARD_LIBRARIES_TO_LINK_TO "")
+
+if(NOT STANDARD_MATH_LIBRARY_FOUND)
+
+  message(FATAL_ERROR
+    "Can't link to the standard math library. Please report to the Eigen developers, telling them about your platform.")
+
+else()
+
+  if(EIGEN_STANDARD_LIBRARIES_TO_LINK_TO)
+    set(EIGEN_STANDARD_LIBRARIES_TO_LINK_TO "${EIGEN_STANDARD_LIBRARIES_TO_LINK_TO} ${STANDARD_MATH_LIBRARY}")
+  else()
+    set(EIGEN_STANDARD_LIBRARIES_TO_LINK_TO "${STANDARD_MATH_LIBRARY}")
+  endif()
+
+endif()
+
+if(EIGEN_STANDARD_LIBRARIES_TO_LINK_TO)
+  message(STATUS "Standard libraries to link to explicitly: ${EIGEN_STANDARD_LIBRARIES_TO_LINK_TO}")
+else()
+  message(STATUS "Standard libraries to link to explicitly: none")
+endif()
+
 option(EIGEN_BUILD_BTL "Build benchmark suite" OFF)
 if(NOT WIN32)
   option(EIGEN_BUILD_PKGCONFIG "Build pkg-config .pc file for Eigen" ON)