gnu-classpath: fix configure failure with modern Java

Signed-off-by: Paul Guyot <pguyot@kallisys.net>

java/gnu-classpath/Portfile

@@ -1,13 +1,16 @@
+# -*- coding: utf-8; mode: tcl; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- vim:fenc=utf-8:ft=tcl:et:sw=4:ts=4:sts=4
+
 PortSystem      1.0
+PortGroup       java 1.0
 
 name            gnu-classpath
 set my_name     classpath
 version         0.99
+revision        0
 maintainers     nomaintainer
 categories      java
 # has a runtime exception similar to gcc's
 license         {GPL-2+ Permissive}
-platforms       darwin 
 description     Essential libraries for Java.
 
 long_description \
@@ -21,13 +24,28 @@ master_sites    gnu:${my_name}
 distname        ${my_name}-${version}
 
 checksums       rmd160  eb1d9c93b3c3acaaa3e0cba69a8935d44812e181 \
-                sha256  f929297f8ae9b613a1a167e231566861893260651d913ad9b6c11933895fecc8
+                sha256  f929297f8ae9b613a1a167e231566861893260651d913ad9b6c11933895fecc8 \
+                size    11078232
 
-patchfiles      patch-native-jni-java-nio-Makefile.in
-patchfiles-append patch-native-jni-java-io-java_io_VMConsole.c.diff
+# configure tests javac with -source 1.5, removed in JDK 11+
+java.version    1.8-10
+java.fallback   openjdk8
+java.deptypes   build
 
-depends_build   port:antlr
-depends_lib     port:libiconv
+patchfiles      patch-native-jni-java-nio-Makefile.in.diff
+patchfiles-append patch-native-jni-java-io-java_io_VMConsole.c.diff \
+                patch-native-fdlibm-ieeefp.h.diff
+
+depends_build-append \
+                port:antlr
+depends_lib-append \
+                port:libiconv
+
+pre-configure {
+    if {${java.home} ne {}} {
+        configure.env-append JAVAC=${java.home}/bin/javac
+    }
+}
 
 configure.args  --mandir=${prefix}/share/man \
                 --infodir=${prefix}/share/info \
@@ -36,7 +54,7 @@ configure.args  --mandir=${prefix}/share/man \
                 --disable-plugin \
                 --with-antlr-jar=${prefix}/lib/antlr.jar
 
-variant gtk {
+variant gtk description {Enable GTK peer support} {
     depends_lib-append      path:lib/pkgconfig/gtk+-2.0.pc:gtk2 \
                             port:gconf
 

java/gnu-classpath/files/patch-native-fdlibm-ieeefp.h.diff

@@ -0,0 +1,13 @@
+--- native/fdlibm/ieeefp.h.orig	2026-05-18 20:32:49
++++ native/fdlibm/ieeefp.h	2026-05-18 20:32:49
+@@ -158,6 +158,10 @@
+ #define __IEEE_BIG_ENDIAN
+ #endif
+ 
++#ifdef __aarch64__
++#define __IEEE_LITTLE_ENDIAN
++#endif
++
+ #ifndef __IEEE_BIG_ENDIAN
+ #ifndef __IEEE_LITTLE_ENDIAN
+ #error Endianess not declared!!