dev-java/lz4-java: switch to newer mvel:2.5 - W I P

- uses java-pkg-simple.eclass instead of java-ant-2.eclass
- Java code generation with mvel translated to ebuild
- compiled java classes are complete, no differences

- headers created using ejavac -h, should be checked
- shared object file created with gcc. should also be checked
  https://github.com/lz4/lz4-java/blob/1.8.0/build.xml#L206-L227

- Tests to be completed
- Shared object file to be compared with upstream.

Bug: https://bugs.gentoo.org/916973
Signed-off-by: Volkmar W. Pogatzki <gentoo@pogatzki.net>

dev-java/lz4-java/lz4-java-1.8.0-r2.ebuild

@@ -0,0 +1,75 @@
+# Copyright 2023 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+JAVA_PKG_IUSE="doc source test"
+MAVEN_ID="org.lz4:lz4-java:1.8.0"
+JAVA_TESTING_FRAMEWORKS="junit-4"
+
+inherit java-pkg-2 java-pkg-simple toolchain-funcs
+
+DESCRIPTION="LZ4 compression for Java"
+HOMEPAGE="https://github.com/lz4/lz4-java"
+SRC_URI="https://github.com/lz4/lz4-java/archive/${PV}.tar.gz -> ${P}.tar.gz"
+S="${WORKDIR}/${P}"
+
+LICENSE="Apache-2.0"
+SLOT="0"
+KEYWORDS="~amd64"
+
+DEPEND="
+	dev-java/mvel:2.5
+	>=virtual/jdk-1.8:*
+	test? ( dev-java/randomized-runner:0 )"
+RDEPEND=">=virtual/jre-1.8:*"
+
+JAVA_AUTOMATIC_MODULE_NAME="org.lz4.java"
+JAVA_SRC_DIR=( src/java{,-unsafe} )
+JAVA_TEST_GENTOO_CLASSPATH="junit-4 randomized-runner"
+JAVA_TEST_RESOURCE_DIRS="src/test-resources"
+JAVA_TEST_SRC_DIR="src/test"
+
+src_compile() {
+	# remove precompiled native libraries
+	rm -r src/resources || die
+
+	# cannot include template 'decompressor.template': file not found.]
+	cp src/build/source_templates/* . || die
+
+	"$(java-config -J)" \
+		-Dout.dir="src/java" \
+		-cp "$(java-pkg_getjars --build-only mvel-2.5)" \
+		org.mvel2.sh.Main \
+		src/build/gen_sources.mvel \
+		|| die
+
+	java-pkg-simple_src_compile
+
+	einfo "Generate headers" # build.xml lines 194-204
+	ejavac -h build/jni-headers -classpath "target/classes" \
+		src/java/net/jpountz/xxhash/XXHashJNI.java \
+		src/java/net/jpountz/lz4/LZ4JNI.java || die
+
+	einfo "Generate native library"
+	mkdir -p build/objects/src/jni
+	mkdir -p build/jni/net/jpountz/util/linux/amd64
+	"$(tc-getCC)" -fPIC -march=native -O2 -pipe -frecord-gcc-switches \
+		-I$(java-config -O)/../include -I$(java-config -O)/../include/linux \
+		-I$(java-config -O)/include -I$(java-config -O)/include/linux \
+		-Ibuild/jni-headers \
+		-o build/objects/src/jni/net_jpountz_lz4_LZ4JNI.o \
+		src/jni/net_jpountz_lz4_LZ4JNI.c
+	"$(tc-getCC)" -fPIC -march=native -O2 -pipe -frecord-gcc-switches \
+		-I$(java-config -O)/../include -I$(java-config -O)/../include/linux \
+		-I$(java-config -O)/include -I$(java-config -O)/include/linux \
+		-Ibuild/jni-headers \
+		-o build/objects/src/jni/net_jpountz_xxhash_XXHashJNI.o \
+		src/jni/net_jpountz_xxhash_XXHashJNI.c
+
+	"$(tc-getCC)" -shared -o liblz4-java.so \
+		build/objects/src/jni/net_jpountz_lz4_LZ4JNI.o \
+		build/objects/src/jni/net_jpountz_xxhash_XXHashJNI.o
+
+	# Still need to check the resulting "liblz4-java.so"
+}