Add JVM version of HLL::Backend.

src/vm/jvm/HLL/Backend.nqp

@@ -0,0 +1,91 @@
+# Backend class for the JVM.
+class HLL::Backend::JVM {
+    method apply_transcodings($s, $transcode) {
+        $s
+    }
+
+    method config() {
+        nqp::hash()
+    }
+
+    method force_gc() {
+        nqp::die("Cannot force GC on JVM backend yet");
+    }
+
+    method name() {
+        'jvm'
+    }
+
+    method nqpevent($spec?) {
+        # Doesn't do anything just yet
+    }
+
+    method run_profiled($what) {
+        nqp::printfh(nqp::getstderr(),
+            "Attach a profiler (e.g. JVisualVM) and press enter");
+        nqp::readlinefh(nqp::getstdin());
+        $what();
+    }
+
+    method run_traced($level, $what) {
+        nqp::die("No tracing support");
+    }
+
+    method version_string() {
+        "JVM"
+    }
+
+    method stages() {
+        'jast classfile jvm'
+    }
+
+    method is_precomp_stage($stage) {
+        $stage eq 'classfile'
+    }
+
+    method is_textual_stage($stage) {
+        0
+    }
+
+    method classname($source, *%adverbs) {
+        unless %*COMPILING<%?OPTIONS><javaclass> {
+            %*COMPILING<%?OPTIONS><javaclass> := nqp::sha1(nqp::sha1($source) ~ nqp::time_n());
+        }
+        $source
+    }
+
+    method jast($qast, *%adverbs) {
+        nqp::getcomp('qast').jast($qast, :classname(nqp::sha1('eval-at-' ~ nqp::time_n())));
+    }
+
+    method classfile($jast, *%adverbs) {
+        if %adverbs<target> eq 'classfile' && %adverbs<output> {
+            nqp::compilejasttofile($jast.dump(), %adverbs<output>);
+            nqp::null()
+        }
+        else {
+            nqp::compilejast($jast.dump());
+        }
+    }
+
+    method jvm($cu, *%adverbs) {
+        nqp::loadcompunit($cu)
+    }
+
+    method is_compunit($cuish) {
+        nqp::iscompunit($cuish)
+    }
+
+    method compunit_mainline($cu) {
+        nqp::compunitmainline($cu)
+    }
+
+    method compunit_coderefs($cu) {
+        nqp::compunitcodes($cu)
+    }
+}
+
+# Role specifying the default backend for this build.
+role HLL::Backend::Default {
+    method default_backend() { HLL::Backend::JVM }
+}