Improve Java 8 detection m4 script to deal with pre-set JAVA_HOME

Change-Id: I38685530634fd43d0a46ff43e5ef7d62b9ee4d9b
Signed-off-by: Damjan Marion <damarion@cisco.com>

diff --git a/src/m4/ax_vpp_find_jdk8.m4 b/src/m4/ax_vpp_find_jdk8.m4
index 2945982..382a6c8 100644 (file)
--- a/src/m4/ax_vpp_find_jdk8.m4
+++ b/src/m4/ax_vpp_find_jdk8.m4
@@ -4,7 +4,21 @@ AC_DEFUN([AX_VPP_FIND_JDK8],
 [
 while true
 do
 [
 while true
 do

-  test "${JAVA_HOME+set}" = set && break
+  if test "${JAVA_HOME+set}" = set ; then
+    AC_MSG_CHECKING([${JAVA_HOME} for Java 8 compiler])
+    JAVAC=${JAVA_HOME}/bin/javac
+    JAVAH=${JAVA_HOME}/bin/javah
+    JAR=${JAVA_HOME}/bin/jar
+    JAVA_VERSION=$(${JAVA_HOME}/bin/javac -source 8 -version 2>&1)
+    if test 0 -eq "$?"; then
+      JAVA_VERSION=$(echo "${JAVA_VERSION}" | cut -d\  -f2)
+      AC_MSG_RESULT([ok])
+    else
+      AC_MSG_RESULT([no])
+      AC_MSG_ERROR([Java in ${JAVA_HOME} (path specified in JAVA_HOME) cannot compile Java 8 code])
+    fi
+    break
+  fi

 
   for dir in $(find /usr/lib/jvm/* -maxdepth 0 -type d); do
     AC_MSG_CHECKING([${dir} for Java 8 compiler])
 
   for dir in $(find /usr/lib/jvm/* -maxdepth 0 -type d); do
     AC_MSG_CHECKING([${dir} for Java 8 compiler])