Add BUILD_LIBPYTHON_SHARED option, deprecate BUILD_SHARED and BUILD_STATIC

jcfr · adrianbroher · jcfr · commit 522feb13468c · 2016-04-19T03:53:54.000-04:00
Fixes python-cmake-buildsystem#121 Co-authored-by: Marcel Metz <mmetz@adrian-broher.net> Suggested-by: Marcel Metz <mmetz@adrian-broher.net>
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -39,8 +39,28 @@ include(CTest)
 
 # Options
 option(DOWNLOAD_SOURCES "Automatically download the Python sources" ON)
-option(BUILD_SHARED "Build a shared libpython library" OFF)
-option(BUILD_STATIC "Build a static libpython library" ON)
+set(_build_libpython_shared_default  0)
+set(_build_libpython_shared_desc "Build libpython as a shared library")
+
+if(DEFINED BUILD_SHARED OR DEFINED BUILD_STATIC)
+  message(AUTHOR_WARNING "Deprecated options `BUILD_SHARED` or `BUILD_STATIC` are set, "
+                         "please change configure options to use `BUILD_LIBPYTHON_SHARED` instead.")
+  if(BUILD_SHARED AND BUILD_STATIC)
+    message(AUTHOR_WARNING "Both BUILD_SHARED and BUILD_STATIC options are set to ON. Forcing BUILD_SHARED to OFF")
+  endif()
+  if(BUILD_STATIC)
+    set(_build_libpython_shared_default  0)
+    set(_build_libpython_shared_desc "Intialized from `BUILD_STATIC` (deprecated)")
+  elseif(BUILD_SHARED)
+    set(_build_libpython_shared_default  1)
+    set(_build_libpython_shared_desc "Intialized from `BUILD_SHARED` (deprecated)")
+  endif()
+  message(AUTHOR_WARNING "Unsetting cache variables BUILD_SHARED and BUILD_STATIC")
+  unset(BUILD_SHARED CACHE)
+  unset(BUILD_STATIC CACHE)
+endif()
+
+option(BUILD_LIBPYTHON_SHARED ${_build_libpython_shared_desc} ${_build_libpython_shared_default})
 option(BUILD_EXTENSIONS_AS_BUILTIN "Default all modules as builtin to libpython" OFF)
 option(USE_LIB64 "Search for dependencies and install to prefix/lib64 instead of prefix/lib" OFF)
 if(WIN32)
@@ -121,11 +141,8 @@ if(UNIX)
             set(BUILD_EXTENSIONS_AS_BUILTIN ON CACHE BOOL "Forced to ON${_reason}" FORCE)
             message(STATUS "Setting BUILD_EXTENSIONS_AS_BUILTIN to ON${_reason}")
 
-            set(BUILD_SHARED OFF CACHE BOOL "Forced to OFF${_reason}" FORCE)
-            message(STATUS "Setting BUILD_SHARED to OFF${_reason}")
-
-            set(BUILD_STATIC ON CACHE BOOL "Forced to ON${_reason}" FORCE)
-            message(STATUS "Setting BUILD_STATIC to ON${_reason}")
+            set(BUILD_LIBPYTHON_SHARED OFF CACHE BOOL "Forced to OFF${_reason}" FORCE)
+            message(STATUS "Setting BUILD_LIBPYTHON_SHARED to OFF${_reason}")
         endif()
     endif()
 else()
@@ -234,6 +251,14 @@ if(PY_VERSION_MAJOR VERSION_GREATER 2)
     set(IS_PY2 0)
 endif()
 
+# Convenience boolean variables to easily test the type of python library being build
+set(BUILD_STATIC 1)
+set(BUILD_SHARED 0)
+if(BUILD_LIBPYTHON_SHARED)
+  set(BUILD_STATIC 0)
+  set(BUILD_SHARED 1)
+endif()
+
 # Options depending of the python version
 if(IS_PY2)
   option(Py_USING_UNICODE "Enable unicode support" ON)
diff --git a/README.rst b/README.rst
@@ -68,12 +68,9 @@ options on the commandline with `-DOPTION=VALUE`, or use the "ccmake" gui.
     Download, check MD5 sum and extract python sources in the parent directory.
     Source archive is downloaded from http://www.python.org/ftp/python/2.7.8/Python-2.7.8.tgz
 
-  BUILD_SHARED=ON|OFF          (defaults to OFF)
-  BUILD_STATIC=ON|OFF          (defaults to ON)
+  BUILD_LIBPYTHON_SHARED=ON|OFF (defaults to OFF)
     Build libpython as a shared library (.so or .dll) or a static library
-    (.a).  At least one of these options must be set to ON - if they are both
-    set to ON then the Python executable will be linked against the shared
-    version of libpython.
+    (.a).
 
     Note that Python extensions are always built as shared libraries.  On
     Windows it is not possible to build shared .dll extensions against a
