+package org.simantics.scl.compiler.constants.singletons;\r
+\r
+import org.objectweb.asm.Label;\r
+import org.simantics.scl.compiler.constants.ComparisonFunction;\r
+import org.simantics.scl.compiler.constants.FunctionValue;\r
+import org.simantics.scl.compiler.internal.codegen.continuations.Cont;\r
+import org.simantics.scl.compiler.internal.codegen.references.Val;\r
+import org.simantics.scl.compiler.internal.codegen.utils.MethodBuilder;\r
+import org.simantics.scl.compiler.types.TVar;\r
+import org.simantics.scl.compiler.types.Type;\r
+import org.simantics.scl.compiler.types.Types;\r
+import org.simantics.scl.compiler.types.kinds.Kinds;\r
+\r
+public class NullCheck extends FunctionValue implements ComparisonFunction {\r
+ private static final TVar A = Types.var(Kinds.STAR);\r
+ public static final NullCheck INSTANCE = \r
+ new NullCheck();\r
+ \r
+ private NullCheck() {\r
+ super(new TVar[] {A}, Types.NO_EFFECTS, Types.BOOLEAN, A);\r
+ }\r
+ \r
+ @Override\r
+ public Type applyExact(MethodBuilder mb, Val[] parameters) {\r
+ parameters[0].push(mb);\r
+ Label join = mb.createLabel();\r
+ Label isNull = mb.createLabel();\r
+ mb.ifNullBranch(isNull, true);\r
+ mb.loadConstant(false);\r
+ mb.branch(join);\r
+ mb.setLocation(isNull);\r
+ mb.loadConstant(true);\r
+ mb.setLocation(join);\r
+ return getReturnType();\r
+ }\r
+ \r
+ @Override\r
+ public void generateCondition(MethodBuilder mb, Val[] parameters, Cont then_, Cont else_) {\r
+ parameters[0].push(mb);\r
+ mb.ifNullBranch(mb.getLabel(then_), true);\r
+ mb.jump(else_);\r
+ mb.ensureExists(then_);\r
+ }\r
+\r
+ @Override\r
+ public String toString() {\r
+ return "nullCheck";\r
+ }\r
+}\r