/*******************************************************************************
* Copyright 2011 See AUTHORS file.
*
* 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 com.badlogic.gdx.jnigen;
import java.io.InputStream;
import java.nio.Buffer;
import java.util.ArrayList;
import com.badlogic.gdx.jnigen.parsing.CMethodParser;
import com.badlogic.gdx.jnigen.parsing.CMethodParser.CMethod;
import com.badlogic.gdx.jnigen.parsing.CMethodParser.CMethodParserResult;
import com.badlogic.gdx.jnigen.parsing.JavaMethodParser;
import com.badlogic.gdx.jnigen.parsing.JavaMethodParser.Argument;
import com.badlogic.gdx.jnigen.parsing.JavaMethodParser.JavaMethod;
import com.badlogic.gdx.jnigen.parsing.JavaMethodParser.JavaSegment;
import com.badlogic.gdx.jnigen.parsing.JavaMethodParser.JniSection;
import com.badlogic.gdx.jnigen.parsing.JniHeaderCMethodParser;
import com.badlogic.gdx.jnigen.parsing.RobustJavaMethodParser;
/** Goes through a Java source directory, checks each .java file for native methods and emits C/C++ code accordingly, both .h and
* .cpp files.
*
* <h2>Augmenting Java Files with C/C++</h2> C/C++ code can be directly added to native methods in the Java file as block comments
* starting at the same line as the method signature. Custom JNI code that is not associated with a native method can be added via
* a special block comment as shown below.</p>
*
* All arguments can be accessed by the name specified in the Java native method signature (unless you use $ in your identifier
* which is allowed in Java).
*
* <pre>
* package com.badlogic.jnigen;
*
* public class MyJniClass {
* /*JNI
* #include <math.h>
* *<i>/</i>
*
* public native void addToArray(float[] array, int len, float value); /*
* for(int i = 0; i < len; i++) {
* array[i] = value;
* }
* *<i>/</i>
* }
* </pre>
*
* The generated header file is automatically included in the .cpp file. Methods and custom JNI code can be mixed throughout the
* Java file, their order is preserved in the generated .cpp file. Method overloading is supported but not recommended as the
* overloading detection is very basic.</p>
*
* If a native method has strings, one dimensional primitive arrays or direct {@link Buffer} instances as arguments, JNI setup and
* cleanup code is automatically generated.</p>
*
* The following list gives the mapping from Java to C/C++ types for arguments:
*
* <table border="1">
* <tr>
* <td>Java</td>
* <td>C/C++</td>
* </tr>
* <tr>
* <td>String</td>
* <td>char* (UTF-8)</td>
* </tr>
* <tr>
* <td>boolean[]</td>
* <td>bool*</td>
* </tr>
* <tr>
* <td>byte[]</td>
* <td>char*</td>
* </tr>
* <tr>
* <td>char[]</td>
* <td>unsigned short*</td>
* </tr>
* <tr>
* <td>short[]</td>
* <td>short*</td>
* </tr>
* <tr>
* <td>int[]</td>
* <td>int*</td>
* </tr>
* <tr>
* <td>long[]</td>
* <td>long long*</td>
* </tr>
* <tr>
* <td>float[]</td>
* <td>float*</td>
* </tr>
* <tr>
* <td>double[]</td>
* <td>double*</td>
* </tr>
* <tr>
* <td>Buffer</td>
* <td>unsigned char*</td>
* </tr>
* <tr>
* <td>ByteBuffer</td>
* <td>char*</td>
* </tr>
* <tr>
* <td>CharBuffer</td>
* <td>unsigned short*</td>
* </tr>
* <tr>
* <td>ShortBuffer</td>
* <td>short*</td>
* </tr>
* <tr>
* <td>IntBuffer</td>
* <td>int*</td>
* </tr>
* <tr>
* <td>LongBuffer</td>
* <td>long long*</td>
* </tr>
* <tr>
* <td>FloatBuffer</td>
* <td>float*</td>
* </tr>
* <tr>
* <td>DoubleBuffer</td>
* <td>double*</td>
* </tr>
* <tr>
* <td>Anything else</td>
* <td>jobject/jobjectArray</td>
* </tr>
* </table>
*
* If you need control over setting up and cleaning up arrays/strings and direct buffers you can tell the NativeCodeGenerator to
* omit setup and cleanup code by starting the native code block comment with "/*MANUAL" instead of just "/*" to the method name.
* See libgdx's Gdx2DPixmap load() method for an example.
*
* <h2>.h/.cpp File Generation</h2> The .h files are created via javah, which has to be on your path. The Java classes have to be
* compiled and accessible to the javah tool. The name of the generated .h/.cpp files is the fully qualified name of the class,
* e.g. com.badlogic.jnigen.MyJniClass.h/.cpp. The generator takes the following parameters as input:
*
* <ul>
* <li>Java source directory, containing the .java files, e.g. src/ in an Eclipse project</li>
* <li>Java class directory, containing the compiled .class files, e.g. bin/ in an Eclipse project</li>
* <li>JNI output directory, where the resulting .h and .cpp files will be stored, e.g. jni/</li>
* </ul>
*
* A default invocation of the generator looks like this:
*
* <pre>
* new NativeCodeGenerator().generate("src", "bin", "jni");
* </pre>
*
* To automatically compile and load the native code, see the classes {@link AntScriptGenerator}, {@link BuildExecutor} and
* {@link JniGenSharedLibraryLoader} classes. </p>
*
* @author mzechner */
public class NativeCodeGenerator {
private static final String JNI_METHOD_MARKER = "native";
private static final String JNI_ARG_PREFIX = "obj_";
private static final String JNI_RETURN_VALUE = "JNI_returnValue";
private static final String JNI_WRAPPER_PREFIX = "wrapped_";
FileDescriptor sourceDir;
String classpath;
FileDescriptor jniDir;
String[] includes;
String[] excludes;
AntPathMatcher matcher = new AntPathMatcher();
JavaMethodParser javaMethodParser = new RobustJavaMethodParser();
CMethodParser cMethodParser = new JniHeaderCMethodParser();
CMethodParserResult cResult;
/** Generates .h/.cpp files from the Java files found in "src/", with their .class files being in "bin/". The generated files
* will be stored in "jni/". All paths are relative to the applications working directory.
* @throws Exception */
public void generate () throws Exception {
generate("src", "bin", "jni", null, null);
}
/** Generates .h/.cpp fiels from the Java files found in <code>sourceDir</code>, with their .class files being in
* <code>classpath</code>. The generated files will be stored in <code>jniDir</code>. All paths are relative to the
* applications working directory.
* @param sourceDir the directory containing the Java files
* @param classpath the directory containing the .class files
* @param jniDir the output directory
* @throws Exception */
public void generate (String sourceDir, String classpath, String jniDir) throws Exception {
generate(sourceDir, classpath, jniDir, null, null);
}
/** Generates .h/.cpp fiels from the Java files found in <code>sourceDir</code>, with their .class files being in
* <code>classpath</code>. The generated files will be stored in <code>jniDir</code>. The <code>includes</code> and
* <code>excludes</code> parameters allow to specify directories and files that should be included/excluded from the
* generation. These can be given in the Ant path format. All paths are relative to the applications working directory.
* @param sourceDir the directory containing the Java files
* @param classpath the directory containing the .class files
* @param jniDir the output directory
* @param includes files/directories to include, can be null (all files are used)
* @param excludes files/directories to exclude, can be null (no files are excluded)
* @throws Exception */
public void generate (String sourceDir, String classpath, String jniDir, String[] includes, String[] excludes)
throws Exception {
this.sourceDir = new FileDescriptor(sourceDir);
this.jniDir = new FileDescriptor(jniDir);
this.classpath = classpath;
this.includes = includes;
this.excludes = excludes;
// check if source directory exists
if (!this.sourceDir.exists()) {
throw new Exception("Java source directory '" + sourceDir + "' does not exist");
}
// generate jni directory if necessary
if (!this.jniDir.exists()) {
if (!this.jniDir.mkdirs()) {
throw new Exception("Couldn't create JNI directory '" + jniDir + "'");
}
}
// process the source directory, emitting c/c++ files to jniDir
processDirectory(this.sourceDir);
}
private void processDirectory (FileDescriptor dir) throws Exception {
FileDescriptor[] files = dir.list();
for (FileDescriptor file : files) {
if (file.isDirectory()) {
if (file.path().contains(".svn")) continue;
if (excludes != null && matcher.match(file.path(), excludes)) continue;
processDirectory(file);
} else {
if (file.extension().equals("java")) {
if (file.name().contains("NativeCodeGenerator")) continue;
if (includes != null && !matcher.match(file.path(), includes)) continue;
if (excludes != null && matcher.match(file.path(), excludes)) continue;
String className = getFullyQualifiedClassName(file);
FileDescriptor hFile = new FileDescriptor(jniDir.path() + "/" + className + ".h");
FileDescriptor cppFile = new FileDescriptor(jniDir + "/" + className + ".cpp");
if (file.lastModified() < cppFile.lastModified()) {
System.out.println("C/C++ for '" + file.path() + "' up to date");
continue;
}
String javaContent = file.readString();
if (javaContent.contains(JNI_METHOD_MARKER)) {
ArrayList<JavaSegment> javaSegments = javaMethodParser.parse(javaContent);
if (javaSegments.size() == 0) {
System.out.println("Skipping '" + file + "', no JNI code found.");
continue;
}
System.out.print("Generating C/C++ for '" + file + "'...");
generateHFile(file);
generateCppFile(javaSegments, hFile, cppFile);
System.out.println("done");
}
}
}
}
}
private String getFullyQualifiedClassName (FileDescriptor file) {
String className = file.path().replace(sourceDir.path(), "").replace('\\', '.').replace('/', '.').replace(".java", "");
if (className.startsWith(".")) className = className.substring(1);
return className;
}
private void generateHFile (FileDescriptor file) throws Exception {
String className = getFullyQualifiedClassName(file);
String command = "javah -classpath " + classpath + " -o " + jniDir.path() + "/" + className + ".h " + className;
Process process = Runtime.getRuntime().exec(command);
process.waitFor();
if (process.exitValue() != 0) {
InputStream errorStream = process.getErrorStream();
int c = 0;
while ((c = errorStream.read()) != -1) {
System.out.print((char)c);
}
}
}
private void generateCppFile (ArrayList<JavaSegment> javaSegments, FileDescriptor hFile, FileDescriptor cppFile)
throws Exception {
String headerFileContent = hFile.readString();
ArrayList<CMethod> cMethods = cMethodParser.parse(headerFileContent).getMethods();
StringBuffer buffer = new StringBuffer();
buffer.append("#include <" + hFile.name() + ">\n");
for (JavaSegment segment : javaSegments) {
if (segment instanceof JniSection) {
emitJniSection(buffer, (JniSection)segment);
}
if (segment instanceof JavaMethod) {
JavaMethod javaMethod = (JavaMethod)segment;
if (javaMethod.getNativeCode() == null) {
throw new RuntimeException("Method '" + javaMethod.getName() + "' has no body");
}
CMethod cMethod = findCMethod(javaMethod, cMethods);
if (cMethod == null)
throw new RuntimeException("Couldn't find C method for Java method '" + javaMethod.getClassName() + "#"
+ javaMethod.getName() + "'");
emitJavaMethod(buffer, javaMethod, cMethod);
}
}
cppFile.writeString(buffer.toString(), false, "UTF-8");
}
private CMethod findCMethod (JavaMethod javaMethod, ArrayList<CMethod> cMethods) {
for (CMethod cMethod : cMethods) {
if (cMethod.getHead().endsWith(javaMethod.getClassName() + "_" + javaMethod.getName()) ||
cMethod.getHead().contains(javaMethod.getClassName() + "_" + javaMethod.getName() + "__")) {
// FIXME poor man's overloaded method check...
// FIXME float test[] won't work, needs to be float[] test.
if (cMethod.getArgumentTypes().length - 2 == javaMethod.getArguments().size()) {
boolean match = true;
for (int i = 2; i < cMethod.getArgumentTypes().length; i++) {
String cType = cMethod.getArgumentTypes()[i];
String javaType = javaMethod.getArguments().get(i - 2).getType().getJniType();
if (!cType.equals(javaType)) {
match = false;
break;
}
}
if (match) {
return cMethod;
}
}
}
}
return null;
}
private void emitLineMarker (StringBuffer buffer, int line) {
buffer.append("\n//@line:");
buffer.append(line);
buffer.append("\n");
}
private void emitJniSection (StringBuffer buffer, JniSection section) {
emitLineMarker(buffer, section.getStartIndex());
buffer.append(section.getNativeCode().replace("\r", ""));
}
private void emitJavaMethod (StringBuffer buffer, JavaMethod javaMethod, CMethod cMethod) {
// get the setup and cleanup code for arrays, buffers and strings
StringBuffer jniSetupCode = new StringBuffer();
StringBuffer jniCleanupCode = new StringBuffer();
StringBuffer additionalArgs = new StringBuffer();
StringBuffer wrapperArgs = new StringBuffer();
emitJniSetupCode(jniSetupCode, javaMethod, additionalArgs, wrapperArgs);
emitJniCleanupCode(jniCleanupCode, javaMethod, cMethod);
// check if the user wants to do manual setup of JNI args
boolean isManual = javaMethod.isManual();
// if we have disposable arguments (string, buffer, array) and if there is a return
// in the native code (conservative, not syntactically checked), emit a wrapper method.
if (javaMethod.hasDisposableArgument() && javaMethod.getNativeCode().contains("return")) {
// if the method is marked as manual, we just emit the signature and let the
// user do whatever she wants.
if (isManual) {
emitMethodSignature(buffer, javaMethod, cMethod, null, false);
emitMethodBody(buffer, javaMethod);
buffer.append("}\n\n");
} else {
// emit the method containing the actual code, called by the wrapper
// method with setup pointers to arrays, buffers and strings
String wrappedMethodName = emitMethodSignature(buffer, javaMethod, cMethod, additionalArgs.toString());
emitMethodBody(buffer, javaMethod);
buffer.append("}\n\n");
// emit the wrapper method, the one with the declaration in the header file
emitMethodSignature(buffer, javaMethod, cMethod, null);
if (!isManual) {
buffer.append(jniSetupCode);
}
if (cMethod.getReturnType().equals("void")) {
buffer.append("\t" + wrappedMethodName + "(" + wrapperArgs.toString() + ");\n\n");
if (!isManual) {
buffer.append(jniCleanupCode);
}
buffer.append("\treturn;\n");
} else {
buffer.append("\t" + cMethod.getReturnType() + " " + JNI_RETURN_VALUE + " = " + wrappedMethodName + "("
+ wrapperArgs.toString() + ");\n\n");
if (!isManual) {
buffer.append(jniCleanupCode);
}
buffer.append("\treturn " + JNI_RETURN_VALUE + ";\n");
}
buffer.append("}\n\n");
}
} else {
emitMethodSignature(buffer, javaMethod, cMethod, null);
if (!isManual) {
buffer.append(jniSetupCode);
}
emitMethodBody(buffer, javaMethod);
if (!isManual) {
buffer.append(jniCleanupCode);
}
buffer.append("}\n\n");
}
}
private void emitMethodBody (StringBuffer buffer, JavaMethod javaMethod) {
// emit a line marker
emitLineMarker(buffer, javaMethod.getEndIndex());
// FIXME add tabs cleanup
buffer.append(javaMethod.getNativeCode());
buffer.append("\n");
}
private String emitMethodSignature (StringBuffer buffer, JavaMethod javaMethod, CMethod cMethod, String additionalArguments) {
return emitMethodSignature(buffer, javaMethod, cMethod, additionalArguments, true);
}
private String emitMethodSignature (StringBuffer buffer, JavaMethod javaMethod, CMethod cMethod, String additionalArguments,
boolean appendPrefix) {
// emit head, consisting of JNIEXPORT,return type and method name
// if this is a wrapped method, prefix the method name
String wrappedMethodName = null;
if (additionalArguments != null) {
String[] tokens = cMethod.getHead().replace("\r\n", "").replace("\n", "").split(" ");
wrappedMethodName = JNI_WRAPPER_PREFIX + tokens[3];
buffer.append("static inline ");
buffer.append(tokens[1]);
buffer.append(" ");
buffer.append(wrappedMethodName);
buffer.append("\n");
} else {
buffer.append(cMethod.getHead());
}
// construct argument list
// Differentiate between static and instance method, then output each argument
if (javaMethod.isStatic()) {
buffer.append("(JNIEnv* env, jclass clazz");
} else {
buffer.append("(JNIEnv* env, jobject object");
}
if (javaMethod.getArguments().size() > 0) buffer.append(", ");
for (int i = 0; i < javaMethod.getArguments().size(); i++) {
// output the argument type as defined in the header
buffer.append(cMethod.getArgumentTypes()[i + 2]);
buffer.append(" ");
// if this is not a POD or an object, we need to add a prefix
// as we will output JNI code to get pointers to strings, arrays
// and direct buffers.
Argument javaArg = javaMethod.getArguments().get(i);
if (!javaArg.getType().isPlainOldDataType() && !javaArg.getType().isObject() && appendPrefix) {
buffer.append(JNI_ARG_PREFIX);
}
// output the name of the argument
buffer.append(javaArg.getName());
// comma, if this is not the last argument
if (i < javaMethod.getArguments().size() - 1) buffer.append(", ");
}
// if this is a wrapper method signature, add the additional arguments
if (additionalArguments != null) {
buffer.append(additionalArguments);
}
// close signature, open method body
buffer.append(") {\n");
// return the wrapped method name if any
return wrappedMethodName;
}
private void emitJniSetupCode (StringBuffer buffer, JavaMethod javaMethod, StringBuffer additionalArgs,
StringBuffer wrapperArgs) {
// add environment and class/object as the two first arguments for
// wrapped method.
if (javaMethod.isStatic()) {
wrapperArgs.append("env, clazz, ");
} else {
wrapperArgs.append("env, object, ");
}
// arguments for wrapper method
for (int i = 0; i < javaMethod.getArguments().size(); i++) {
Argument arg = javaMethod.getArguments().get(i);
if (!arg.getType().isPlainOldDataType() && !arg.getType().isObject()) {
wrapperArgs.append(JNI_ARG_PREFIX);
}
// output the name of the argument
wrapperArgs.append(arg.getName());
if (i < javaMethod.getArguments().size() - 1) wrapperArgs.append(", ");
}
// direct buffer pointers
for (Argument arg : javaMethod.getArguments()) {
if (arg.getType().isBuffer()) {
String type = arg.getType().getBufferCType();
buffer.append("\t" + type + " " + arg.getName() + " = (" + type + ")(" + JNI_ARG_PREFIX
+ arg.getName() + "?env->GetDirectBufferAddress(" + JNI_ARG_PREFIX + arg.getName() + "):0);\n");
additionalArgs.append(", ");
additionalArgs.append(type);
additionalArgs.append(" ");
additionalArgs.append(arg.getName());
wrapperArgs.append(", ");
wrapperArgs.append(arg.getName());
}
}
// string pointers
for (Argument arg : javaMethod.getArguments()) {
if (arg.getType().isString()) {
String type = "char*";
buffer.append("\t" + type + " " + arg.getName() + " = (" + type + ")env->GetStringUTFChars(" + JNI_ARG_PREFIX
+ arg.getName() + ", 0);\n");
additionalArgs.append(", ");
additionalArgs.append(type);
additionalArgs.append(" ");
additionalArgs.append(arg.getName());
wrapperArgs.append(", ");
wrapperArgs.append(arg.getName());
}
}
// Array pointers, we have to collect those last as GetPrimitiveArrayCritical
// will explode into our face if we call another JNI method after that.
for (Argument arg : javaMethod.getArguments()) {
if (arg.getType().isPrimitiveArray()) {
String type = arg.getType().getArrayCType();
buffer.append("\t" + type + " " + arg.getName() + " = (" + type + ")env->GetPrimitiveArrayCritical(" + JNI_ARG_PREFIX
+ arg.getName() + ", 0);\n");
additionalArgs.append(", ");
additionalArgs.append(type);
additionalArgs.append(" ");
additionalArgs.append(arg.getName());
wrapperArgs.append(", ");
wrapperArgs.append(arg.getName());
}
}
// new line for separation
buffer.append("\n");
}
private void emitJniCleanupCode (StringBuffer buffer, JavaMethod javaMethod, CMethod cMethod) {
// emit cleanup code for arrays, must come first
for (Argument arg : javaMethod.getArguments()) {
if (arg.getType().isPrimitiveArray()) {
buffer.append("\tenv->ReleasePrimitiveArrayCritical(" + JNI_ARG_PREFIX + arg.getName() + ", " + arg.getName()
+ ", 0);\n");
}
}
// emit cleanup code for strings
for (Argument arg : javaMethod.getArguments()) {
if (arg.getType().isString()) {
buffer.append("\tenv->ReleaseStringUTFChars(" + JNI_ARG_PREFIX + arg.getName() + ", " + arg.getName() + ");\n");
}
}
// new line for separation
buffer.append("\n");
}
}