Find{Java,JNI}: Consider JAVA_HOME before ENV{JAVA_HOME}

Add a helper module CMakeFindJavaCommon shared between FindJava
and FindJNI to select a JAVA_HOME value.  Prefer a CMake variable
or cache entry first, then an environment variable.

1 files changed, 30 insertions, 0 deletions

diff --git a/Modules/CMakeFindJavaCommon.cmake b/Modules/CMakeFindJavaCommon.cmake
new file mode 100644
index 0000000000..fd5268905a
--- /dev/null
+++ b/Modules/CMakeFindJavaCommon.cmake
@@ -0,0 +1,30 @@
+
+#=============================================================================
+# Copyright 2013-2014 Kitware, Inc.
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+# Do not include this module directly from code outside CMake!
+set(_JAVA_HOME "")
+if(JAVA_HOME AND IS_DIRECTORY "${JAVA_HOME}")
+  set(_JAVA_HOME "${JAVA_HOME}")
+  set(_JAVA_HOME_EXPLICIT 1)
+else()
+  set(_ENV_JAVA_HOME "")
+  if(DEFINED ENV{JAVA_HOME})
+    file(TO_CMAKE_PATH "$ENV{JAVA_HOME}" _ENV_JAVA_HOME)
+  endif()
+  if(_ENV_JAVA_HOME AND IS_DIRECTORY "${_ENV_JAVA_HOME}")
+    set(_JAVA_HOME "${_ENV_JAVA_HOME}")
+    set(_JAVA_HOME_EXPLICIT 1)
+  endif()
+  unset(_ENV_JAVA_HOME)
+endif()