Bug 1417 - Android: Support building using current SDK and NDK v20 as of 2019-12-10 (GlueGen w/ android-aarch64 patched)

Default Platform: Android 7.0 Nougat, API level 24 supports Java 1.8

Reworked gluegen/make/scripts/setenv-android-tools.sh,
following canonical environment variables and sets all
required variables for cross-compilation.
See file's comments!

ant files:
  - android.version -> android.api.level (default 24)
  - android.jar defaults to ${gluegen.root}/make/lib/android-sdk/24/android.jar (provided)

6 files changed, 375 insertions, 145 deletions

diff --git a/make/gluegen-properties.xml b/make/gluegen-properties.xml
index 54fbc8c..2f061fc 100755
--- a/make/gluegen-properties.xml
+++ b/make/gluegen-properties.xml
@@ -57,10 +57,9 @@
     <property name="ant-junit4.jar" value="${ant.home}/lib/ant-junit4.jar" />
     <property name="semver.jar" value="${gluegen.root}/make/lib/semantic-versioning/semver.jar" />
 
-    <property name="android.version" value="9" /> <!-- default - if not set by jogamp-env.xml:jogamp.env.init -->
-    <property name="android-min.jar" value="${gluegen.root}/make/lib/android-sdk/${android.version}/android.jar" />
-    <property name="android-015.jar" value="${gluegen.root}/make/lib/android-sdk/15/android.jar" />
-    <property name="android.jar"     value="${android-015.jar}" />
+    <property name="android.api.level" value="24" /> <!-- default - if not set by jogamp-env.xml:jogamp.env.init -->
+    <property name="android-min.jar"   value="${gluegen.root}/make/lib/android-sdk/${android.api.level}/android.jar" />
+    <property name="android.jar"       value="${android-min.jar}" />
     <condition property="android-jars.available">
         <and>
             <available file="${android-min.jar}"/>
diff --git a/make/jogamp-androidtasks.xml b/make/jogamp-androidtasks.xml
index 82679c4..172da7b 100644
--- a/make/jogamp-androidtasks.xml
+++ b/make/jogamp-androidtasks.xml
@@ -180,14 +180,6 @@
             <arg line="${m.aapt.build.apk}/temp/classes"/>
         </exec>
         
-        <path id="android.antlibs">
-            <pathelement path="${env.ANDROID_HOME}/tools/lib/anttasks.jar" />
-            <pathelement path="${env.ANDROID_HOME}/tools/lib/sdklib.jar" />
-            <pathelement path="${env.ANDROID_HOME}/tools/lib/androidprefs.jar" />
-            <pathelement path="${env.ANDROID_HOME}/tools/lib/apkbuilder.jar" />
-            <pathelement path="${env.ANDROID_HOME}/tools/lib/jarutils.jar" />
-        </path>
-
         <echo>aapt.signed ${m.aapt.apkbasename}: packaging</echo>
         <exec dir="." executable="aapt" logError="true" failonerror="true" failifexecutionfails="true">
             <arg line="package"/>
@@ -282,7 +274,7 @@
         </exec>
 
         <echo>aapt.signed ${m.aapt.apkbasename}: zip aligning</echo>
-        <exec dir="." executable="${env.ANDROID_HOME}/build-tools/${env.ANDROID_BUILD_TOOLS_VERSION}/zipalign" failonerror="true">
+        <exec dir="." executable="zipalign" failonerror="true">
             <arg line="-v" />
             <arg value="-f" />
             <arg value="4" />
diff --git a/make/jogamp-env.xml b/make/jogamp-env.xml
index 070c702..332554e 100755
--- a/make/jogamp-env.xml
+++ b/make/jogamp-env.xml
@@ -11,7 +11,7 @@
      Official production builds are performed _on_ OpenJDK 11
      and a Java JDK 11 or greater is required!
 
-     Android 7 API level 24 supports Java 1.8, 
+     Android 7.0 Nougat, API level 24 supports Java 1.8, 
      see https://developer.android.com/studio/write/java8-support
 
      Target Java 8 baseline is chosen today, June 2019, 
@@ -142,9 +142,9 @@
         </not>
     </condition>
 
-    <condition property="android.version" value="${env.ANDROID_VERSION}" else="24">
+    <condition property="android.api.level" value="${env.ANDROID_API_LEVEL}" else="24">
         <not>
-         <equals arg1="${env.ANDROID_VERSION}" arg2="$${env.ANDROID_VERSION}" casesensitive="true" />
+         <equals arg1="${env.ANDROID_API_LEVEL}" arg2="$${env.ANDROID_API_LEVEL}" casesensitive="true" />
         </not>
     </condition>
 
@@ -237,7 +237,7 @@
     <echo message="build.archiveon            ${build.archiveon}"/>
     <echo message="build.node.name            ${build.node.name}"/>
 
-    <echo message="android.version            ${android.version}"/>
+    <echo message="android.api.level          ${android.api.level}"/>
 
     <echo message="junit.run.arg0             ${junit.run.arg0}"/>
     <echo message="junit.run.arg1             ${junit.run.arg1}"/>
diff --git a/make/lib/gluegen-cpptasks-android-aarch64.xml b/make/lib/gluegen-cpptasks-android-aarch64.xml
index 1daa201..4b6401b 100644
--- a/make/lib/gluegen-cpptasks-android-aarch64.xml
+++ b/make/lib/gluegen-cpptasks-android-aarch64.xml
@@ -23,7 +23,7 @@
     <property name="isAndroidARM64"                   value="true" /> 
     <property name="jvmDataModel.arg"                 value="-Djnlp.no.jvm.data.model.set=true" /> 
     <property name="isCrosscompilation"               value="true" />
-    <property name="android.abi"                      value="arm64-v8a" />
+    <property name="android.abi"                      value="${env.ANDROID_ABI}" /> <!-- arm64-v8a -->
     <property name="isAbiEabiGnuArmel"                value="true" />
     <echo message="gluegen.cpptasks.detect.os.custom: GLUEGEN_CPPTASKS_FILE 'gluegen-cpptasks-android-aarch64' done"/>
 </target>
@@ -32,24 +32,27 @@
 
 <target name="gluegen.cpptasks.configure.compiler" depends="setup.java.home.dir,declare.linux.android">
     <echo message="Custom forced compiler Android NDK, linker.cfg.android" />
-    <compiler id="compiler.cfg.android" name="gcc">
-      <compilerarg value="--sysroot=${TARGET_PLATFORM_SYSROOT}" />
-      <!-- The default search dirs for 'gcc from $NDK_TOOLCHAIN_ROOT/$TARGET_TRIPLE/bin will not find
-        subprograms properly (see gcc -print-search-dirs). Not sure if this is a bug in the NDK
-        or not. Need to explicitly indicate where subprograms are with -B.
-        NOTE: This is not necessary if using '$TARGET_TRIPLE-gcc' from $NDK_TOOLCHAIN_ROOT/bin. -->
-      <compilerarg value="-B${env.NDK_TOOLCHAIN_ROOT}/libexec/gcc/${env.TARGET_TRIPLE}/${env.GCC_VERSION}" />
+    <compiler id="compiler.cfg.android" name="clang">
+      <compilerarg value="--sysroot=${env.ANDROID_TOOLCHAIN_SYSROOT}" />
+
+      <!-- compilerarg value="-v" / --> 
 
       <compilerarg value="-fpic" /> 
       <!-- compilerarg value="-fPIE" / -->  <!-- not for shared libs, won't produce symbols -->
       <!-- compilerarg value="-pie" / -->   <!-- not for shared libs, won't produce symbols -->
+
+      <!-- from sdk cmake start -->
+      <compilerarg value="-fdata-sections" />
       <compilerarg value="-ffunction-sections" />
       <compilerarg value="-funwind-tables" />
-      <compilerarg value="-fstack-protector" />
+      <compilerarg value="-fstack-protector-strong" />
       <!-- compilerarg value="-no-canonical-prefixes" / --> <!-- will disallow creating shared library -->
-      <compilerarg value="-Wa,--noexecstack" /> 
+      <!-- from sdk cmake end -->
 
+      <compilerarg value="-Wa,--noexecstack" /> 
 
+      <compilerarg value="-target" />
+      <compilerarg value="${env.ANDROID_LLVM_TRIPLE}" /> <!-- aarch64-none-linux-android -->
       <!-- compilerarg value="-mabi=lp64" />
       <compilerarg value="-mlittle-endian" />
       <compilerarg value="-march=armv8-a" / -->
@@ -60,15 +63,15 @@
       <!-- compilerarg value="-g"                   unless="c.compiler.use-debug" / -->
       <compilerarg value="-fomit-frame-pointer" unless="c.compiler.use-debug"/> 
       <compilerarg value="-fstrict-aliasing"    unless="c.compiler.use-debug"/> 
-      <compilerarg value="-funswitch-loops"     unless="c.compiler.use-debug"/> 
-      <compilerarg value="-finline-limit=300"   unless="c.compiler.use-debug"/> 
+      <!-- compilerarg value="-funswitch-loops"     unless="c.compiler.use-debug"/ not supported --> 
+      <!-- compilerarg value="-finline-limit=300"   unless="c.compiler.use-debug"/ not supported --> 
 
       <compilerarg value="-O0"                     if="c.compiler.use-debug" />
       <compilerarg value="-g"                      if="c.compiler.use-debug" />
       <compilerarg value="-fno-omit-frame-pointer" if="c.compiler.use-debug" /> 
       <compilerarg value="-fno-strict-aliasing"    if="c.compiler.use-debug" /> 
 
-      <includepath path="${env.NDK_TOOLCHAIN_ROOT}/lib/gcc/${env.TARGET_TRIPLE}/${env.GCC_VERSION}/include" /> <!-- for stdarg.h -->
+      <!-- includepath path="${env.ANDROID_TOOLCHAIN_SYSROOT_INC}" / -->
       <defineset>
         <define name="__unix__" />
         <!-- define name="__ARM_ARCH_5__" />
@@ -85,39 +88,44 @@
       </defineset>
     </compiler>
 
-    <linker id="linker.cfg.android" name="gcc">
-         <linkerarg value="--sysroot=${TARGET_PLATFORM_SYSROOT}" />
-
-         <linkerarg value="-fpic" /> 
-         <!-- linkerarg value="-fPIE" / --> <!-- not for shared libs, won't produce symbols -->
-         <!-- linkerarg value="-pie" / -->  <!-- not for shared libs, won't produce symbols -->
-         <!-- linkerarg value="-no-canonical-prefixes" / --> <!-- will disallow creating shared library -->
-
-         <linkerarg value="-fno-use-linker-plugin" /> 
-
-         <!-- linkerarg value="-mabi=lp64" />
-         <linkerarg value="-mlittle-endian" />
-         <linkerarg value="-march=armv8-a" / -->
-         <!-- linkerarg value="-mfloat-abi=softfp" / -->
-
-         <linkerarg value="-nostdlib" />
-         <linkerarg value="-Bdynamic" />
-         <linkerarg value="-Wl,-dynamic-linker,/system/bin/linker" />
-         <linkerarg value="-Wl,-z,nocopyreloc" />
-
-         <linkerarg value="--demangle" /> 
-         <linkerarg value="--gc-sections" /> 
-         <linkerarg value="--no-undefined" /> 
-         <linkerarg value="-static-libgcc" if="isGCC"/>
-         <linkerarg value="-static-libstdc++" if="isGCC"/>
-         <!-- The gcc from $NDK_TOOLCHAIN_ROOT/$TARGET_TRIPLE/bin needs to be told
-           where to find libgcc as the default location (gcc -print-search-dirs)
-           is not correct. Not sure if this is a bug in the NDK or not. We also
-           enforce that libgcc is linked after source files but before other shared
-           libraries. -->
-         <libset dir="${env.NDK_TOOLCHAIN_ROOT}/lib/gcc/${env.TARGET_TRIPLE}/${env.GCC_VERSION}" libs="gcc" />
-         <!-- libset libs="c,m,dl,log" / -->
-         <libset libs="c,m,dl" />
+    <linker id="linker.cfg.android" name="clang">
+      <linkerarg value="--sysroot=${env.ANDROID_TOOLCHAIN_SYSROOT}" />
+      <!-- linkerarg value="-Wl,-L,${env.ANDROID_TOOLCHAIN_SYSROOT_LIB_0}" / -->
+      <linkerarg value="-Wl,-L,${env.ANDROID_TOOLCHAIN_SYSROOT_LIB_1}" />
+      
+      <!-- linkerarg value="-v" / --> 
+
+      <linkerarg value="-fpic" /> 
+      <!-- linkerarg value="-fPIE" / --> <!-- not for shared libs, won't produce symbols -->
+      <!-- linkerarg value="-pie" / -->  <!-- not for shared libs, won't produce symbols -->
+      <!-- linkerarg value="-no-canonical-prefixes" / --> <!-- will disallow creating shared library -->
+
+      <!-- from sdk cmake start -->
+      <linkerarg value="-Wl,--build-id" /> 
+      <linkerarg value="-Wl,--warn-shared-textrel" /> 
+      <!-- linkerarg value="-Wl,- -fatal-warnings" / --> 
+      <!-- from sdk cmake end -->
+
+      <linkerarg value="-fno-use-linker-plugin" /> 
+
+      <!-- linkerarg value="-mabi=lp64" />
+      <linkerarg value="-mlittle-endian" />
+      <linkerarg value="-march=armv8-a" / -->
+      <!-- linkerarg value="-mfloat-abi=softfp" / -->
+
+      <linkerarg value="-nostdlib" />
+      <linkerarg value="-Bdynamic" />
+      <linkerarg value="-Wl,-dynamic-linker,/system/bin/linker" />
+      <linkerarg value="-Wl,-z,nocopyreloc" />
+
+      <linkerarg value="--demangle" /> 
+      <linkerarg value="--gc-sections" /> 
+      <linkerarg value="--no-undefined" /> 
+      <linkerarg value="-static-libgcc" if="isGCC"/>
+      <linkerarg value="-static-libstdc++" if="isGCC"/>
+
+      <!-- libset libs="c,m,dl,log" / -->
+      <libset libs="c,m,dl" />
     </linker>
 
 </target>
diff --git a/make/scripts/make.gluegen.all.android-aarch64-cross.sh b/make/scripts/make.gluegen.all.android-aarch64-cross.sh
index 32fea6d..78ccb08 100755
--- a/make/scripts/make.gluegen.all.android-aarch64-cross.sh
+++ b/make/scripts/make.gluegen.all.android-aarch64-cross.sh
@@ -2,14 +2,30 @@
 
 SDIR=`dirname $0` 
 
-if [ -e $SDIR/setenv-build-jogamp-x86_64.sh ] ; then
-    . $SDIR/setenv-build-jogamp-x86_64.sh
+if [ -e ${SDIR}/setenv-build-jogamp-x86_64.sh ] ; then
+    . ${SDIR}/setenv-build-jogamp-x86_64.sh
 fi
 
-if [ -e $SDIR/setenv-android-tools.sh ] ; then
-    . $SDIR/setenv-android-tools.sh
+LOGF=make.gluegen.all.android-aarch64-cross.log
+rm -f ${LOGF}
+
+export ANDROID_HOME=/opt-linux-x86_64/android-sdk-linux_x86_64
+export ANDROID_API_LEVEL=24
+export ANDROID_HOST_TAG=linux-x86_64
+export ANDROID_ABI=arm64-v8a
+
+if [ -e ${SDIR}/setenv-android-tools.sh ] ; then
+    . ${SDIR}/setenv-android-tools.sh >> $LOGF 2>&1
+else
+    echo "${SDIR}/setenv-android-tools.sh doesn't exist!" 2>&1 | tee -a ${LOGF}
+    exit 1
 fi
 
+export GLUEGEN_CPPTASKS_FILE="lib/gluegen-cpptasks-android-aarch64.xml"
+export PATH=${ANDROID_TOOLCHAIN_ROOT}/${ANDROID_TOOLCHAIN_NAME}/bin:${ANDROID_TOOLCHAIN_ROOT}/bin:${ANDROID_HOME}/platform-tools:${ANDROID_BUILDTOOLS_ROOT}:${PATH}
+echo PATH ${PATH} 2>&1 | tee -a ${LOGF}
+echo clang `which clang` 2>&1 | tee -a ${LOGF}
+
 export NODE_LABEL=.
 
 export HOST_UID=jogamp
@@ -26,36 +42,18 @@ export TARGET_ADB_PORT=5555
 export TARGET_ROOT=/data/projects
 export TARGET_ANT_HOME=/usr/share/ant
 
-export ANDROID_VERSION=24
 export SOURCE_LEVEL=1.8
 export TARGET_LEVEL=1.8
 export TARGET_RT_JAR=/opt-share/jre1.8.0_212/lib/rt.jar
 
-export GCC_VERSION=4.9
-HOST_ARCH=linux-x86_64
-export TARGET_TRIPLE=aarch64-linux-android
-
-export NDK_TOOLCHAIN_ROOT=$NDK_ROOT/toolchains/${TARGET_TRIPLE}-${GCC_VERSION}/prebuilt/${HOST_ARCH}
-export TARGET_PLATFORM_SYSROOT=${NDK_ROOT}/platforms/android-${ANDROID_VERSION}/arch-arm64
-
-# Need to add toolchain bins to the PATH. 
-# May need to create symbolic links within $NDK_TOOLCHAIN_ROOT/$TARGET_TRIPLE/bin
-#   cd $NDK_TOOLCHAIN_ROOT/$TARGET_TRIPLE/bin
-#   ln -s ../../bin/aarch64-linux-android-gcc gcc
-export PATH="$NDK_TOOLCHAIN_ROOT/$TARGET_TRIPLE/bin:$ANDROID_HOME/platform-tools:$ANDROID_HOME/build-tools/$ANDROID_BUILD_TOOLS_VERSION:$PATH"
-
-export GLUEGEN_CPPTASKS_FILE="lib/gluegen-cpptasks-android-aarch64.xml"
-
 #export JUNIT_DISABLED="true"
 #export JUNIT_RUN_ARG0="-Dnewt.test.Screen.disableScreenMode"
 
-echo PATH $PATH 2>&1 | tee make.gluegen.all.android-aarch64-cross.log
-echo gcc `which gcc` 2>&1 | tee -a make.gluegen.all.android-aarch64-cross.log
-
 #export JOGAMP_JAR_CODEBASE="Codebase: *.jogamp.org"
 export JOGAMP_JAR_CODEBASE="Codebase: *.goethel.localnet"
 
 #BUILD_ARCHIVE=true \
 ant \
     -Drootrel.build=build-android-aarch64 \
-    $* 2>&1 | tee -a make.gluegen.all.android-aarch64-cross.log
+    -Dgcc.compat.compiler=clang \
+    $* 2>&1 | tee -a ${LOGF}
diff --git a/make/scripts/setenv-android-tools.sh b/make/scripts/setenv-android-tools.sh
index a6384fa..b0e6144 100644
--- a/make/scripts/setenv-android-tools.sh
+++ b/make/scripts/setenv-android-tools.sh
@@ -1,83 +1,316 @@
 #! /bin/sh
 
+# Aligned with Android SDK build-tools 29 and NDK 20 as of 2019-12-10
+#
+# As it is no more easily achievable to download the complete SDK 
+# separately, I used Android-Studio to fetch all parts incl. the NDK.
+# Thereafter I copied ~/Android/Sdk -> /opt-linux-x86_64/android-sdk-linux_x86_64
+# which I also use for the official crosscompilation.
+#
+# Variable names borrowed from ~/Android/Sdk/ndk/20.1.5948944/build/cmake/android.toolchain.cmake
+# We only use ANDROID_API_LEVEL instead of ANDROID_PLATFORM_LEVEL, as it describes the API level.
+#
+#
+# User should set environment variables:
+# ==========================================
+#
+# - ANDROID_HOME - defaults to one of
+#        ~/Android/Sdk
+#        /opt-linux-x86_64/android-sdk-linux_x86_64
+#        /opt/android-sdk-linux_x86_64
+#        /usr/local/android-sdk-linux_x86_64
+#
+# - ANDROID_API_LEVEL - defaults to 24
+#
+# - ANDROID_HOST_TAG - defaults to linux-x86_64
+#
+# - ANDROID_ABI - defaults to x86_64, one of
+#        armeabi-v7a 
+#        arm64-v8a 
+#        x86_64
+#        x86
+#
+# Following environment variables will be set
+# ============================================
+#
+# - ANDROID_SYSROOT_ABI
+# - ANDROID_TOOLCHAIN_NAME
+# - ANDROID_LLVM_TRIPLE
+# - ANDROID_BUILD_TOOLS_VERSION
+# - ANDROID_NDK
+# - ANDROID_BUILDTOOLS_ROOT
+# - ANDROID_TOOLCHAIN_ROOT
+# - ANDROID_TOOLCHAIN_SYSROOT
+# - ANDROID_TOOLCHAIN_SYSROOT_INC
+# - ANDROID_TOOLCHAIN_SYSROOT_LIB_0
+# - ANDROID_TOOLCHAIN_SYSROOT_LIB_1
+#
+# Android Studio SDK + NDK Filesystem Layout (official)
+#
+# ~/Android/Sdk/
+# ~/Android/Sdk/build-tools/29.0.2/
+# ~/Android/Sdk/build-tools/29.0.2/zipalign (*)
+# ~/Android/Sdk/ndk/
+# ~/Android/Sdk/ndk/20.1.5948944/sysroot/ (gcc)
+# ~/Android/Sdk/ndk/20.1.5948944/sysroot/usr/include/ (gcc)
+# ~/Android/Sdk/ndk/20.1.5948944/sysroot/usr/lib/aarch64-linux-android/libc.a (gcc)
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/aarch64-linux-android/bin/ld (gcc)
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/bin/aarch64-linux-android-ld (gcc)
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android-ld (*)
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/aarch64-linux-android/bin/ld
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/bin/clang (*)
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/sysroot
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/aarch64-linux-android/libc.a (*)
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/aarch64-linux-android/24/libc.a (*)
+#
+# (*) tested by this script
+#
+# Having
+#   ANDROID_HOME=~/Android/Sdk
+#   ANDROID_API_LEVEL 24
+#   ANDROID_HOST_TAG linux-x86_64
+#   ANDROID_ABI arm64-v8a
+# Using derived values of
+#   ANDROID_BUILD_TOOLS_VERSION=29.0.2
+#   ANDROID_NDK_VERSION=20.1.5948944
+#   ANDROID_TOOLCHAIN_NAME aarch64-linux-android
+
 echo $0
 
-echo Presets
-echo   NDK_ROOT $NDK_ROOT
-echo   ANDROID_HOME $ANDROID_HOME
-echo   ANDROID_BUILD_TOOLS_VERSION $ANDROID_BUILD_TOOLS_VERSION
+NDK_TOOLCHAIN_VERSION=clang
+echo "Setting NDK_TOOLCHAIN_VERSION to ${NDK_TOOLCHAIN_VERSION} default!"
 
-if [ -z "$NDK_ROOT" ] ; then
-    #
-    # Generic android-ndk
-    #
-    if [ -e /usr/local/android-ndk ] ; then
-        NDK_ROOT=/usr/local/android-ndk
-    elif [ -e /opt-linux-x86_64/android-ndk ] ; then
-        NDK_ROOT=/opt-linux-x86_64/android-ndk
-    elif [ -e /opt-linux-x86/android-ndk ] ; then
-        NDK_ROOT=/opt-linux-x86/android-ndk
-    elif [ -e /opt/android-ndk ] ; then
-        NDK_ROOT=/opt/android-ndk
-    #
-    # Specific android-ndk-r10d
-    #
-    elif [ -e /usr/local/android-ndk-r10d ] ; then
-        NDK_ROOT=/usr/local/android-ndk-r10d
-    elif [ -e /opt-linux-x86_64/android-ndk-r10d ] ; then
-        NDK_ROOT=/opt-linux-x86_64/android-ndk-r10d
-    elif [ -e /opt-linux-x86/android-ndk-r10d ] ; then
-        NDK_ROOT=/opt-linux-x86/android-ndk-r10d
-    elif [ -e /opt/android-ndk-r10d ] ; then
-        NDK_ROOT=/opt/android-ndk-r10d
-    else 
-        echo NDK_ROOT is not specified and does not exist in default locations
-        exit 1
-    fi
-elif [ ! -e $NDK_ROOT ] ; then
-    echo NDK_ROOT $NDK_ROOT does not exist
+if [ -z "${ANDROID_API_LEVEL}" ] ; then
+    ANDROID_API_LEVEL=24
+    echo "Setting undefined ANDROID_API_LEVEL to ${ANDROID_API_LEVEL} default!"
+fi
+if [ -z "${ANDROID_HOST_TAG}" ] ; then
+    ANDROID_HOST_TAG=linux-x86_64
+    echo "Setting undefined ANDROID_HOST_TAG to ${ANDROID_HOST_TAG} default!"
+fi
+
+if [ -z "${ANDROID_ABI}" ] ; then
+    ANDROID_ABI=x86_64
+    echo "Setting undefined ANDROID_ABI to ${ANDROID_ABI} default!"
+fi
+if [ "${ANDROID_ABI}" = "armeabi-v7a" ] ; then
+    ANDROID_SYSROOT_ABI=arm
+    #CMAKE_SYSTEM_PROCESSOR=armv7-a
+    ANDROID_TOOLCHAIN_NAME=arm-linux-androideabi
+    ANDROID_LLVM_TRIPLE=armv7-none-linux-androideabi
+elif [ "${ANDROID_ABI}" = "arm64-v8a" ] ; then
+    ANDROID_SYSROOT_ABI=arm64
+    #CMAKE_SYSTEM_PROCESSOR=aarch64
+    ANDROID_TOOLCHAIN_NAME=aarch64-linux-android
+    ANDROID_LLVM_TRIPLE=aarch64-none-linux-android
+elif [ "${ANDROID_ABI}" = "x86_64" ] ; then
+    ANDROID_SYSROOT_ABI=x86_64
+    #CMAKE_SYSTEM_PROCESSOR=x86_64
+    ANDROID_TOOLCHAIN_NAME=x86_64-linux-android
+    ANDROID_LLVM_TRIPLE=x86_64-none-linux-android
+elif [ "${ANDROID_ABI}" = "x86" ] ; then
+    ANDROID_SYSROOT_ABI=x86
+    #CMAKE_SYSTEM_PROCESSOR=i686
+    ANDROID_TOOLCHAIN_NAME=i686-linux-android
+    ANDROID_LLVM_TRIPLE=i686-none-linux-android
+else
+    echo "ANDROID_ABI is ${ANDROID_ABI} and not supported!"
     exit 1
 fi
-export NDK_ROOT
 
-if [ -z "$ANDROID_HOME" ] ; then
-    if [ -e /usr/local/android-sdk-linux_x86 ] ; then
-        ANDROID_HOME=/usr/local/android-sdk-linux_x86
+echo "Preset-0 (user)"
+echo   ANDROID_HOME ${ANDROID_HOME}
+echo   ANDROID_API_LEVEL ${ANDROID_API_LEVEL}
+echo   ANDROID_HOST_TAG ${ANDROID_HOST_TAG}
+echo   ANDROID_ABI ${ANDROID_ABI}
+echo
+echo Preset-1
+echo   NDK_TOOLCHAIN_VERSION ${NDK_TOOLCHAIN_VERSION}
+echo   ANDROID_SYSROOT_ABI ${ANDROID_SYSROOT_ABI}
+echo   ANDROID_TOOLCHAIN_NAME ${ANDROID_TOOLCHAIN_NAME}
+echo   "ANDROID_LLVM_TRIPLE ${ANDROID_LLVM_TRIPLE} (compiler target)"
+echo   ANDROID_BUILD_TOOLS_VERSION ${ANDROID_BUILD_TOOLS_VERSION}
+echo   ANDROID_NDK ${ANDROID_NDK}
+echo
+echo Preset-2
+echo   ANDROID_BUILDTOOLS_ROOT ${ANDROID_BUILDTOOLS_ROOT}
+echo   ANDROID_TOOLCHAIN_ROOT ${ANDROID_TOOLCHAIN_ROOT}
+echo   ANDROID_TOOLCHAIN_SYSROOT ${ANDROID_TOOLCHAIN_SYSROOT}
+echo   ANDROID_TOOLCHAIN_SYSROOT_INC ${ANDROID_TOOLCHAIN_SYSROOT_INC}
+echo   ANDROID_TOOLCHAIN_SYSROOT_LIB_0 ${ANDROID_TOOLCHAIN_SYSROOT_LIB_0}
+echo   ANDROID_TOOLCHAIN_SYSROOT_LIB_1 ${ANDROID_TOOLCHAIN_SYSROOT_LIB_1}
+echo
+
+check_exists() {
+    if [ ! -e "$1" ] ; then
+        echo "$1" does not exist
+        exit 1
+    fi
+    return 0
+}
+
+if [ -z "${ANDROID_HOME}" ] ; then
+    if [ -e ${HOME}/Android/Sdk ] ; then
+        ANDROID_HOME=${HOME}/Android/Sdk
     elif [ -e /opt-linux-x86_64/android-sdk-linux_x86_64 ] ; then
-        ANDROID_HOME=/opt-linux-x86/android-sdk-linux_x86
-    elif [ -e /opt-linux-x86/android-sdk-linux_x86 ] ; then
-        ANDROID_HOME=/opt-linux-x86/android-sdk-linux_x86
+        ANDROID_HOME=/opt-linux-x86_64/android-sdk-linux_x86_64
     elif [ -e /opt/android-sdk-linux_x86_64 ] ; then
         ANDROID_HOME=/opt/android-sdk-linux_x86_64
-    elif [ -e /opt/android-sdk-linux_x86 ] ; then
-        ANDROID_HOME=/opt/android-sdk-linux_x86
+    elif [ -e /usr/local/android-sdk-linux_x86_64 ] ; then
+        ANDROID_HOME=/usr/local/android-sdk-linux_x86_64
     else 
         echo ANDROID_HOME is not specified and does not exist in default locations
         exit 1
     fi
-elif [ ! -e $ANDROID_HOME ] ; then
-    echo ANDROID_HOME $ANDROID_HOME does not exist
+elif [ ! -e ${ANDROID_HOME} ] ; then
+    echo ANDROID_HOME ${ANDROID_HOME} does not exist
     exit 1
 fi
-export ANDROID_HOME
 
-if [ -z "$ANDROID_BUILD_TOOLS_VERSION" ] ; then
-    if [ -e $ANDROID_HOME/build-tools/21.1.2/zipalign ] ; then
-        ANDROID_BUILD_TOOLS_VERSION=21.1.2
-    elif [ -e $ANDROID_HOME/build-tools/20.0.0/zipalign ] ; then
-        ANDROID_BUILD_TOOLS_VERSION=20.0.0
-    else 
-        echo ANDROID_BUILD_TOOLS_VERSION $ANDROID_HOME/build-tools/ANDROID_BUILD_TOOLS_VERSION/zipalign does not exist in default locations
+unset ANDROID_BUILD_TOOLS_VERSION
+if [ -z "${ANDROID_BUILD_TOOLS_VERSION}" ] ; then
+    # basename $(dirname `find /home/sven/Android/Sdk/build-tools -name zipalign | sort -u | tail -n1`)
+    fzipalign=`find ${ANDROID_HOME}/build-tools -name zipalign | sort -u | tail -n1`
+    if [ ! -z "${fzipalign}" ] ; then
+        dzipalign=`dirname ${fzipalign}`
+        vzipalign=`basename ${dzipalign}`
+        if [ -e ${ANDROID_HOME}/build-tools/${vzipalign}/zipalign ] ; then
+            ANDROID_BUILD_TOOLS_VERSION=${vzipalign}
+        fi
+    fi
+    if [ -z "${ANDROID_BUILD_TOOLS_VERSION}" ] ; then
+        echo ANDROID_BUILD_TOOLS_VERSION ${ANDROID_HOME}/build-tools/ANDROID_BUILD_TOOLS_VERSION/zipalign does not exist
+        exit 1
+    fi
+fi
+
+if [ -z "${ANDROID_NDK}" ] ; then
+    #
+    # Generic android-ndk
+    #
+    if [ -e ${ANDROID_HOME}/ndk ] ; then
+        # basename $(dirname `find ndk -name toolchains -a -type d | sort -u | tail -n1`)
+        d2toolchains=`find ${ANDROID_HOME}/ndk -name toolchains -a -type d | sort -u | tail -n1`
+        if [ ! -z "${d2toolchains}" ] ; then
+            dtoolchains=`dirname ${d2toolchains}`
+            vtoolchains=`basename ${dtoolchains}`
+            # ~/Android/Sdk/ndk/20.1.5948944/sysroot/usr/lib/aarch64-linux-android/libc.a (*)
+            if [ -e ${ANDROID_HOME}/ndk/${vtoolchains}/sysroot/usr/lib/aarch64-linux-android/libc.a ] ; then
+                ANDROID_NDK_VERSION=${vtoolchains}
+            fi
+        fi
+        if [ -z "${ANDROID_NDK_VERSION}" ] ; then
+            echo ANDROID_NDK_VERSION ${ANDROID_HOME}/ndk/ANDROID_NDK_VERSION/sysroot/usr/lib/aarch64-linux-android/libc.a does not exist
+        else
+            ANDROID_NDK=${ANDROID_HOME}/ndk/${vtoolchains}
+        fi
+    fi
+    if [ -z "${ANDROID_NDK}" ] ; then
+        if [ -e /usr/local/android-ndk ] ; then
+            ANDROID_NDK=/usr/local/android-ndk
+        elif [ -e /opt-linux-x86_64/android-ndk ] ; then
+            ANDROID_NDK=/opt-linux-x86_64/android-ndk
+        elif [ -e /opt/android-ndk ] ; then
+            ANDROID_NDK=/opt/android-ndk
+        fi
+    fi
+    if [ -z "${ANDROID_NDK}" ] ; then
+        echo ANDROID_NDK is not specified and does not exist in default locations
         exit 1
     fi
-elif [ ! -e $ANDROID_HOME/build-tools/$ANDROID_BUILD_TOOLS_VERSION/zipalign ] ; then
-    echo ANDROID_BUILD_TOOLS_VERSION $ANDROID_HOME/build-tools/$ANDROID_BUILD_TOOLS_VERSION/zipalign does not exist
+fi
+if [ ! -e "${ANDROID_NDK}" ] ; then
+    echo ANDROID_NDK ${ANDROID_NDK} does not exist
     exit 1
 fi
+
+ANDROID_BUILDTOOLS_ROOT=${ANDROID_HOME}/build-tools/${ANDROID_BUILD_TOOLS_VERSION}
+ANDROID_TOOLCHAIN_ROOT=${ANDROID_NDK}/toolchains/llvm/prebuilt/${ANDROID_HOST_TAG}
+ANDROID_TOOLCHAIN_SYSROOT=${ANDROID_TOOLCHAIN_ROOT}/sysroot
+ANDROID_TOOLCHAIN_SYSROOT_INC=${ANDROID_TOOLCHAIN_ROOT}/sysroot/usr/include
+ANDROID_TOOLCHAIN_SYSROOT_LIB_0=${ANDROID_TOOLCHAIN_ROOT}/sysroot/usr/lib/${ANDROID_TOOLCHAIN_NAME}
+ANDROID_TOOLCHAIN_SYSROOT_LIB_1=${ANDROID_TOOLCHAIN_ROOT}/sysroot/usr/lib/${ANDROID_TOOLCHAIN_NAME}/${ANDROID_API_LEVEL}
+
+# ~/Android/Sdk/build-tools/29.0.2/zipalign (*)
+check_exists ${ANDROID_BUILDTOOLS_ROOT}/zipalign
+
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android-ld (*)
+check_exists ${ANDROID_TOOLCHAIN_ROOT}/bin/${ANDROID_TOOLCHAIN_NAME}-ld
+
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/bin/clang (*)
+check_exists ${ANDROID_TOOLCHAIN_ROOT}/bin/clang
+
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/aarch64-linux-android/libc.a (*)
+check_exists ${ANDROID_TOOLCHAIN_SYSROOT_LIB_0}/libc.a
+
+# ~/Android/Sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/aarch64-linux-android/24/libc.a (*)
+check_exists ${ANDROID_TOOLCHAIN_SYSROOT_LIB_1}/libc.a
+
+export ANDROID_HOME
+export ANDROID_API_LEVEL
+export ANDROID_HOST_TAG
+export ANDROID_ABI
+
+export NDK_TOOLCHAIN_VERSION
+export ANDROID_SYSROOT_ABI
+export ANDROID_TOOLCHAIN_NAME
+export ANDROID_LLVM_TRIPLE
 export ANDROID_BUILD_TOOLS_VERSION
+export ANDROID_NDK
+
+export ANDROID_BUILDTOOLS_ROOT
+export ANDROID_TOOLCHAIN_ROOT
+export ANDROID_TOOLCHAIN_SYSROOT
+export ANDROID_TOOLCHAIN_SYSROOT_INC
+export ANDROID_TOOLCHAIN_SYSROOT_LIB_0
+export ANDROID_TOOLCHAIN_SYSROOT_LIB_1
+
+echo "Postset-0 (user)"
+echo   ANDROID_HOME ${ANDROID_HOME}
+echo   ANDROID_API_LEVEL ${ANDROID_API_LEVEL}
+echo   ANDROID_HOST_TAG ${ANDROID_HOST_TAG}
+echo   ANDROID_ABI ${ANDROID_ABI}
+echo
+echo Postset-1
+echo   NDK_TOOLCHAIN_VERSION ${NDK_TOOLCHAIN_VERSION}
+echo   ANDROID_SYSROOT_ABI ${ANDROID_SYSROOT_ABI}
+echo   ANDROID_TOOLCHAIN_NAME ${ANDROID_TOOLCHAIN_NAME}
+echo   "ANDROID_LLVM_TRIPLE ${ANDROID_LLVM_TRIPLE} (compiler target)"
+echo   ANDROID_BUILD_TOOLS_VERSION ${ANDROID_BUILD_TOOLS_VERSION}
+echo   ANDROID_NDK ${ANDROID_NDK}
+echo
+echo Postset-2
+echo   ANDROID_BUILDTOOLS_ROOT ${ANDROID_BUILDTOOLS_ROOT}
+echo   ANDROID_TOOLCHAIN_ROOT ${ANDROID_TOOLCHAIN_ROOT}
+echo   ANDROID_TOOLCHAIN_SYSROOT ${ANDROID_TOOLCHAIN_SYSROOT}
+echo   ANDROID_TOOLCHAIN_SYSROOT_INC ${ANDROID_TOOLCHAIN_SYSROOT_INC}
+echo   ANDROID_TOOLCHAIN_SYSROOT_LIB_0 ${ANDROID_TOOLCHAIN_SYSROOT_LIB_0}
+echo   ANDROID_TOOLCHAIN_SYSROOT_LIB_1 ${ANDROID_TOOLCHAIN_SYSROOT_LIB_1}
+echo
+
+export -p | grep ANDROID
 
-echo Set
-echo   NDK_ROOT $NDK_ROOT
-echo   ANDROID_HOME $ANDROID_HOME
-echo   ANDROID_BUILD_TOOLS_VERSION $ANDROID_BUILD_TOOLS_VERSION
+#
+# CC="$ANDROID_NDK/toolchains/llvm/prebuilt/$ANDROID_HOST_TAG/bin/clang -target $ANDROID_LLVM_TRIPLE"
+#
+## Generic flags.
+##list(APPEND ANDROID_COMPILER_FLAGS
+#  -g
+#  -DANDROID
+#  -fdata-sections
+#  -ffunction-sections
+#  -funwind-tables
+#  -fstack-protector-strong
+#  -no-canonical-prefixes)
+#list(APPEND ANDROID_LINKER_FLAGS
+#  -Wl,--build-id
+#  -Wl,--warn-shared-textrel
+#  -Wl,--fatal-warnings)
+#list(APPEND ANDROID_LINKER_FLAGS_EXE -Wl,--gc-sections)
+#
+#list(APPEND ANDROID_COMPILER_FLAGS_RELEASE -O2)
+#