Add support of clinit

core/src/main/java/org/teavm/wasm/Example.java

@@ -56,6 +56,10 @@ public final class Example {
         for (int i = 0; i < str.length(); ++i) {
             WasmRuntime.print(str.charAt(i));
         }
+
+        Initialized.foo();
+        Initialized.foo();
+        Initialized.foo();
     }
 
     private static Base instance(int index) {
@@ -110,4 +114,14 @@ public final class Example {
             return 123;
         }
     }
+
+    static class Initialized {
+        static {
+            WasmRuntime.print(9999);
+        }
+
+        public static void foo() {
+            WasmRuntime.print(8888);
+        }
+    }
 }

core/src/main/java/org/teavm/wasm/WasmTarget.java

@@ -264,7 +264,8 @@ public class WasmTarget implements TeaVMTarget {
 
             WasmBlock block = new WasmBlock(false);
 
-            int index = classGenerator.getClassPointer(ValueType.object(className));
+            int index = classGenerator.getClassPointer(ValueType.object(className))
+                    + classGenerator.getFieldOffset(new FieldReference(RuntimeClass.class.getName(), "flags"));
             WasmExpression initFlag = new WasmLoadInt32(4, new WasmInt32Constant(index), WasmInt32Subtype.INT32);
             initFlag = new WasmIntBinary(WasmIntType.INT32, WasmIntBinaryOperation.AND, initFlag,
                     new WasmInt32Constant(RuntimeClass.INITIALIZED));

core/src/main/java/org/teavm/wasm/generate/WasmClassGenerator.java

@@ -29,6 +29,7 @@ import org.teavm.model.ClassReaderSource;
 import org.teavm.model.ElementModifier;
 import org.teavm.model.FieldReader;
 import org.teavm.model.FieldReference;
+import org.teavm.model.MethodDescriptor;
 import org.teavm.model.MethodReference;
 import org.teavm.model.ValueType;
 import org.teavm.model.classes.TagRegistry;
@@ -281,6 +282,17 @@ public class WasmClassGenerator {
         return 4;
     }
 
+    public boolean hasClinit(String className) {
+        if (isStructure(className)) {
+            return false;
+        }
+        ClassReader cls = classSource.get(className);
+        if (cls == null) {
+            return false;
+        }
+        return cls.getMethod(new MethodDescriptor("<clinit>", ValueType.VOID)) != null;
+    }
+
     private class ClassBinaryData {
         ValueType type;
         int size;

core/src/main/java/org/teavm/wasm/generate/WasmGenerationContext.java

@@ -33,6 +33,7 @@ import org.teavm.model.classes.TagRegistry;
 import org.teavm.model.classes.VirtualTableProvider;
 import org.teavm.wasm.binary.BinaryWriter;
 import org.teavm.wasm.intrinsics.WasmIntrinsic;
+import org.teavm.wasm.model.expression.WasmExpression;
 
 public class WasmGenerationContext {
     private ClassReaderSource classSource;

core/src/main/java/org/teavm/wasm/generate/WasmGenerationVisitor.java

@@ -962,24 +962,13 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
 
     @Override
     public void visit(InitClassStatement statement) {
-        if (hasClinit(statement.getClassName())) {
+        if (classGenerator.hasClinit(statement.getClassName())) {
             result = new WasmCall(WasmMangling.mangleInitializer(statement.getClassName()));
         } else {
             result = null;
         }
     }
 
-    private boolean hasClinit(String className) {
-        if (classGenerator.isStructure(className)) {
-            return false;
-        }
-        ClassReader cls = context.getClassSource().get(className);
-        if (cls == null) {
-            return false;
-        }
-        return cls.getMethod(new MethodDescriptor("<clinit>", ValueType.VOID)) != null;
-    }
-
     @Override
     public void visit(PrimitiveCastExpr expr) {
         expr.getValue().acceptVisitor(this);

core/src/main/java/org/teavm/wasm/generate/WasmGenerator.java

@@ -21,11 +21,22 @@ import org.teavm.ast.decompilation.Decompiler;
 import org.teavm.model.ClassHolder;
 import org.teavm.model.ClassHolderSource;
 import org.teavm.model.ElementModifier;
+import org.teavm.model.FieldReference;
 import org.teavm.model.MethodHolder;
 import org.teavm.model.MethodReference;
 import org.teavm.model.ValueType;
+import org.teavm.runtime.RuntimeClass;
 import org.teavm.wasm.model.WasmFunction;
 import org.teavm.wasm.model.WasmLocal;
+import org.teavm.wasm.model.expression.WasmCall;
+import org.teavm.wasm.model.expression.WasmConditional;
+import org.teavm.wasm.model.expression.WasmExpression;
+import org.teavm.wasm.model.expression.WasmInt32Constant;
+import org.teavm.wasm.model.expression.WasmInt32Subtype;
+import org.teavm.wasm.model.expression.WasmIntBinary;
+import org.teavm.wasm.model.expression.WasmIntBinaryOperation;
+import org.teavm.wasm.model.expression.WasmIntType;
+import org.teavm.wasm.model.expression.WasmLoadInt32;
 
 public class WasmGenerator {
     private Decompiler decompiler;
@@ -60,6 +71,20 @@ public class WasmGenerator {
             function.setResult(WasmGeneratorUtil.mapType(methodReference.getReturnType()));
         }
 
+        if (needsClinitCall(method) && classGenerator.hasClinit(method.getOwnerName())) {
+            int index = classGenerator.getClassPointer(ValueType.object(method.getOwnerName()))
+                    + classGenerator.getFieldOffset(new FieldReference(RuntimeClass.class.getName(), "flags"));
+            WasmExpression initFlag = new WasmLoadInt32(4, new WasmInt32Constant(index), WasmInt32Subtype.INT32);
+            initFlag = new WasmIntBinary(WasmIntType.INT32, WasmIntBinaryOperation.AND, initFlag,
+                    new WasmInt32Constant(RuntimeClass.INITIALIZED));
+
+            WasmConditional conditional = new WasmConditional(initFlag);
+            MethodReference clinit = new MethodReference(method.getOwnerName(),
+                    "<clinit>", ValueType.VOID);
+            conditional.getThenBlock().getBody().add(new WasmCall(WasmMangling.mangleMethod(clinit)));
+            function.getBody().add(conditional);
+        }
+
         WasmGenerationVisitor visitor = new WasmGenerationVisitor(context, classGenerator, function, firstVariable);
         methodAst.getBody().acceptVisitor(visitor);
         function.getBody().add(visitor.result);
@@ -67,6 +92,16 @@ public class WasmGenerator {
         return function;
     }
 
+    private static boolean needsClinitCall(MethodHolder method) {
+        if (method.getName().equals("<clinit>")) {
+            return false;
+        }
+        if (method.getName().equals("<init>")) {
+            return true;
+        }
+        return method.hasModifier(ElementModifier.STATIC);
+    }
+
     public WasmFunction generateNative(MethodReference methodReference) {
         WasmFunction function = new WasmFunction(WasmMangling.mangleMethod(methodReference));
         for (int i = 0; i < methodReference.parameterCount(); ++i) {

core/src/main/java/org/teavm/wasm/render/WasmRenderingVisitor.java

@@ -183,8 +183,10 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
         lf();
         renderBlock(expression.getThenBlock(), "then");
 
+        if (!expression.getElseBlock().getBody().isEmpty()) {
             lf();
             renderBlock(expression.getElseBlock(), "else");
+        }
 
         close();
     }