Add slf4j support

pom.xml

@@ -83,6 +83,7 @@
     <module>teavm-cli</module>
     <module>teavm-chrome-rdp</module>
     <module>teavm-tests</module>
+    <module>teavm-extras-slf4j</module>
   </modules>
 
   <dependencyManagement>

teavm-extras-slf4j/.gitignore

@@ -0,0 +1,4 @@
+/target/
+/.settings/
+/.classpath
+/.project

teavm-extras-slf4j/pom.xml

@@ -0,0 +1,68 @@
+<!--
+    Copyright 2015 Alexey Andreev.
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.teavm</groupId>
+    <artifactId>teavm</artifactId>
+    <version>0.3.0-SNAPSHOT</version>
+  </parent>
+  <artifactId>teavm-extras-slf4j</artifactId>
+
+  <name>TeaVM slf4j</name>
+  <description>TeaVM backend for slf4j</description>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.teavm</groupId>
+      <artifactId>teavm-core</artifactId>
+      <version>${project.version}</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.teavm</groupId>
+      <artifactId>teavm-jso</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+      <scope>provided</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-checkstyle-plugin</artifactId>
+        <configuration>
+          <configLocation>../checkstyle.xml</configLocation>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-source-plugin</artifactId>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+</project>

teavm-extras-slf4j/src/main/java/org/teavm/extras/slf4j/LoggerFactoryTransformer.java

@@ -0,0 +1,81 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.extras.slf4j;
+
+import org.slf4j.ILoggerFactory;
+import org.slf4j.LoggerFactory;
+import org.teavm.diagnostics.Diagnostics;
+import org.teavm.model.*;
+import org.teavm.model.instructions.*;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class LoggerFactoryTransformer implements ClassHolderTransformer {
+    @Override
+    public void transformClass(ClassHolder cls, ClassReaderSource innerSource, Diagnostics diagnostics) {
+        if (!cls.getName().equals(LoggerFactory.class.getName())) {
+            return;
+        }
+        addCacheField(cls);
+        modifyClinit(cls);
+        replaceGetFactory(cls);
+    }
+
+    private void addCacheField(ClassHolder cls) {
+        FieldHolder cacheField = new FieldHolder("loggerFactoryCache");
+        cacheField.setLevel(AccessLevel.PRIVATE);
+        cacheField.getModifiers().add(ElementModifier.STATIC);
+        cacheField.setType(ValueType.object(TeaVMLoggerFactory.class.getName()));
+        cls.addField(cacheField);
+    }
+
+    private void modifyClinit(ClassHolder cls) {
+        MethodHolder clinit = cls.getMethod(new MethodDescriptor("<clinit>", void.class));
+        BasicBlock clinitBlock = clinit.getProgram().basicBlockAt(0);
+        Variable factoryVar = clinit.getProgram().createVariable();
+        ConstructInstruction construct = new ConstructInstruction();
+        construct.setType(TeaVMLoggerFactory.class.getName());
+        construct.setReceiver(factoryVar);
+        clinitBlock.getInstructions().add(0, construct);
+        InvokeInstruction init = new InvokeInstruction();
+        init.setInstance(factoryVar);
+        init.setMethod(new MethodReference(TeaVMLoggerFactory.class, "<init>", void.class));
+        init.setType(InvocationType.SPECIAL);
+        clinitBlock.getInstructions().add(1, init);
+        PutFieldInstruction put = new PutFieldInstruction();
+        put.setValue(factoryVar);
+        put.setField(new FieldReference(LoggerFactory.class.getName(), "loggerFactoryCache"));
+        clinitBlock.getInstructions().add(2, put);
+    }
+
+    private void replaceGetFactory(ClassHolder cls) {
+        MethodHolder method = cls.getMethod(new MethodDescriptor("getILoggerFactory", ILoggerFactory.class));
+        Program program = new Program();
+        BasicBlock block = program.createBasicBlock();
+        Variable cacheVar = program.createVariable();
+        GetFieldInstruction get = new GetFieldInstruction();
+        get.setField(new FieldReference(LoggerFactory.class.getName(), "loggerFactoryCache"));
+        get.setFieldType(ValueType.object(ILoggerFactory.class.getName()));
+        get.setReceiver(cacheVar);
+        block.getInstructions().add(get);
+        ExitInstruction exit = new ExitInstruction();
+        exit.setValueToReturn(cacheVar);
+        block.getInstructions().add(exit);
+        method.setProgram(program);
+    }
+}

teavm-extras-slf4j/src/main/java/org/teavm/extras/slf4j/Slf4jPlugin.java

@@ -0,0 +1,30 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.extras.slf4j;
+
+import org.teavm.vm.spi.TeaVMHost;
+import org.teavm.vm.spi.TeaVMPlugin;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class Slf4jPlugin implements TeaVMPlugin {
+    @Override
+    public void install(TeaVMHost host) {
+        host.add(new LoggerFactoryTransformer());
+    }
+}