From 09d7122468fb9b9adf813cf32167ab212511c4d8 Mon Sep 17 00:00:00 2001
From: "Daniel N. Miller (APD)" <Daniel.Miller@intusurg.com>
Date: Wed, 23 Jun 2021 21:09:53 -0700
Subject: [PATCH] Do not build shared libs if not supported

---
 CMakeLists.txt        |  3 +++
 blas/CMakeLists.txt   | 27 +++++++++++++++++----------
 lapack/CMakeLists.txt | 30 +++++++++++++++++-------------
 3 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bd1af32b2..f3e69b845 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -88,6 +88,9 @@ else()
   ei_add_cxx_compiler_flag("-std=c++03")
 endif()
 
+# Determine if we should build shared libraries on this platform.
+get_cmake_property(EIGEN_BUILD_SHARED_LIBS TARGET_SUPPORTS_SHARED_LIBS)
+
 #############################################################################
 # find how to link to the standard libraries                                #
 #############################################################################
diff --git a/blas/CMakeLists.txt b/blas/CMakeLists.txt
index 545bc989c..f3a94ec4a 100644
--- a/blas/CMakeLists.txt
+++ b/blas/CMakeLists.txt
@@ -26,20 +26,27 @@ else()
   set(EigenBlas_SRCS ${EigenBlas_SRCS} f2c/complexdots.c)
 endif()
 
-add_library(eigen_blas_static ${EigenBlas_SRCS})
-add_library(eigen_blas SHARED ${EigenBlas_SRCS})
+set(EIGEN_BLAS_TARGETS "")
 
-if(EIGEN_STANDARD_LIBRARIES_TO_LINK_TO)
-  target_link_libraries(eigen_blas_static ${EIGEN_STANDARD_LIBRARIES_TO_LINK_TO})
-  target_link_libraries(eigen_blas        ${EIGEN_STANDARD_LIBRARIES_TO_LINK_TO})
+add_library(eigen_blas_static ${EigenBlas_SRCS})
+list(APPEND EIGEN_BLAS_TARGETS eigen_blas_static)
+
+if (EIGEN_BUILD_SHARED_LIBS)
+  add_library(eigen_blas SHARED ${EigenBlas_SRCS})
+  list(APPEND EIGEN_BLAS_TARGETS eigen_blas)
 endif()
 
-add_dependencies(blas eigen_blas eigen_blas_static)
+foreach(target IN LISTS EIGEN_BLAS_TARGETS)
+  if(EIGEN_STANDARD_LIBRARIES_TO_LINK_TO)
+      target_link_libraries(${target} ${EIGEN_STANDARD_LIBRARIES_TO_LINK_TO})
+  endif()
 
-install(TARGETS eigen_blas eigen_blas_static
-        RUNTIME DESTINATION bin
-        LIBRARY DESTINATION lib
-        ARCHIVE DESTINATION lib)
+  add_dependencies(blas ${target})
+  install(TARGETS ${target}
+          RUNTIME DESTINATION bin
+          LIBRARY DESTINATION lib
+          ARCHIVE DESTINATION lib)
+endforeach()
 
 if(EIGEN_Fortran_COMPILER_WORKS)
 
diff --git a/lapack/CMakeLists.txt b/lapack/CMakeLists.txt
index 9eec81076..e48497fda 100644
--- a/lapack/CMakeLists.txt
+++ b/lapack/CMakeLists.txt
@@ -88,25 +88,29 @@ endif()
 
 endif()
 
+set(EIGEN_LAPACK_TARGETS "")
+
 add_library(eigen_lapack_static ${EigenLapack_SRCS} ${ReferenceLapack_SRCS})
-add_library(eigen_lapack SHARED ${EigenLapack_SRCS})
+list(APPEND EIGEN_LAPACK_TARGETS eigen_lapack_static)
 
-target_link_libraries(eigen_lapack  eigen_blas)
-
-if(EIGEN_STANDARD_LIBRARIES_TO_LINK_TO)
-  target_link_libraries(eigen_lapack_static ${EIGEN_STANDARD_LIBRARIES_TO_LINK_TO})
-  target_link_libraries(eigen_lapack        ${EIGEN_STANDARD_LIBRARIES_TO_LINK_TO})
+if (EIGEN_BUILD_SHARED_LIBS)
+  add_library(eigen_lapack SHARED ${EigenLapack_SRCS})
+  list(APPEND EIGEN_LAPACK_TARGETS eigen_lapack)
+  target_link_libraries(eigen_lapack  eigen_blas)
 endif()
 
-add_dependencies(lapack eigen_lapack eigen_lapack_static)
+foreach(target IN LISTS EIGEN_LAPACK_TARGETS)
+  if(EIGEN_STANDARD_LIBRARIES_TO_LINK_TO)
+    target_link_libraries(${target} ${EIGEN_STANDARD_LIBRARIES_TO_LINK_TO})
+  endif()
+  add_dependencies(lapack ${target})
+  install(TARGETS ${target}
+          RUNTIME DESTINATION bin
+          LIBRARY DESTINATION lib
+          ARCHIVE DESTINATION lib)
+endforeach()
 
-install(TARGETS eigen_lapack eigen_lapack_static
-        RUNTIME DESTINATION bin
-        LIBRARY DESTINATION lib
-        ARCHIVE DESTINATION lib)
 
-        
-        
 get_filename_component(eigen_full_path_to_testing_lapack "./testing/" ABSOLUTE)
 if(EXISTS ${eigen_full_path_to_testing_lapack})