bytecode

What is the return type of a constructor in java?

巧了我就是萌 提交于 2019-11-28 23:20:43
As we know that we do not have to add any return type to a Java constructor. class Sample{ ..... Sample(){ ........ } } In Objective C, if we create a constructor, it returns a pointer to its class. But it is not compulsory, I think. AClass *anObject = [[AClass alloc] init];//init is the constructor with return type a pointer to AClass Similarly, Is the constructor converted to a method which return a reference to its own class?? Like this: class Sample{ ..... Sample Sample(){ ........ return this; } } Does the compiler add a return type a reference to same class to constructor? What is

Which library/program can be used to generate Java-bytecode? [closed]

╄→гoц情女王★ 提交于 2019-11-28 22:15:58
问题 I know about BCEL, but this project seems to be dead, as it had no releases for two years. And the Java-world moves on. For example JDK 1.6 has a new class-file-format. So what library can be used to create bytecode for the JVM. If no library, a program is ok too, if I can manipulate the generated code in detail, for example a bytecode-assembler. Which software can you recommend? Is it easy too use? has good examples/tutorials? EDIT: For all asking: Yes, the javac is fine. But for generating

Java Byte Code Visualizer

风流意气都作罢 提交于 2019-11-28 22:02:43
What could help me in helping writing highly compact(least byte code count) programs in Java. Possibly I'm looking at: A tool that tells me how many byte codes a Class or a method generates. To visualize byte codes. The tool could tell me which areas need optimization in terms of byte code count or cpu cycles. A byte code chart would also help indicating what byte codes exist in Java and its various properties. Any existing tools that would help me to realize this? Eclipse has a Byte Code Outline plug-in that shows you what Java byte code will be produced from your source code. The javap

does Java type erasure erase my generic type?

你说的曾经没有我的故事 提交于 2019-11-28 21:34:22
问题 I've thought java erasure wipes generic types out in compile time however when i test it by myself i realized there are some information about generic types in Bytecode. here is my test : i wrote 2 classes: import java.util.*; public class Test { List integerList; } and import java.util.*; public class Test { List<Integer> integerList; } i compiled both classes and somewhere in generic class i saw this line integerList{blah blah}Ljava/util/List;{blah blah} Signature{blah blah}%Ljava/util/List

Is it possible to implement an interface at runtime in Java?

拜拜、爱过 提交于 2019-11-28 21:23:18
I am working on a project where there are a lot of objects that are created by a library, and I have no access to the creation process of these objects. The following snippets serve as a good example to illustrate my problem. Code: public class Clazz { //The contents of Clazz are irrelevant //Clazz is NOT my class. I have no access to its internal structure. //However, I do have access to Clazz objects that were created elsewhere. } ExampleInterface is an interface that Clazz may or may not implement at compile time. Code: public interface ExampleInterface { public void run(); } The following

How can you extend Java to introduce passing by reference?

Deadly 提交于 2019-11-28 21:03:14
问题 Java is pass-by-value. How could you modify the language to introduce passing by reference (or some equivalent behavior)? Take for example something like public static void main(String[] args) { String variable = "'previous String reference'"; passByReference(ref variable); System.out.println(variable); // I want this to print 'new String reference' } public static void passByReference(ref String someString) { someString = "'new String reference'"; } which (without the ref ) compiles to the

From C Source to Java Bytecode? [closed]

陌路散爱 提交于 2019-11-28 19:44:30
I'm looking for a way to compile C source code into high-performance Java bytecode. I've successfully used NestedVM , but the performance hit is not acceptable for a project I'm working on. I've also seen various open source projects aimed at this problem and a couple of commercial products. This SO question deals with general problem of converting non-Java into Java source, but I only want to go from C to Java bytecode. What's the best way to compile C source code into high-performance, pure Java bytecode? Charlie Martin Um, that's called "a compiler". You're asking for a C compiler that

What is a bytecode cache and how can I use one in PHP?

為{幸葍}努か 提交于 2019-11-28 18:45:56
I searched on the Web and came to know that PHP code can be compiled to have performance boost. But how to do it? Can I compile both procedural and object oriented PHP code? Pascal MARTIN The basic idea, when executing a PHP script is in two steps : First: the PHP code, written in plain-text, is compiled to opcodes Then: those opcodes are executed . When you have one PHP script, as long as it is not modified, the opcodes will always be the same ; so, doing the compilation phase each time that script is to be executed is kind of a waste of CPU-time. To prevent that redundant-compilation, there

Is there a llvm java front end that converts java source to llvm's intermediate form?

淺唱寂寞╮ 提交于 2019-11-28 18:07:33
From what I've read, there is a llvm program that converts java bytecode to llvm's intermediate form called class2llvm. My question is, how do I access this. What front end do I have to install in order to access this. VMkit is their implementation of a JVM, but I am looking for how to compile the java source code with llvm, not how to run it. The Java frontend translates Java bytecode (.class files) into LLVM bytecode. Take a look at this link: https://llvm.org/svn/llvm-project/java/trunk/docs/java-frontend.txt lei_z You may take a look at dragonegg , which enables llvm to use gcc's frontends

`goto` in Python

元气小坏坏 提交于 2019-11-28 17:09:11
问题 I must use goto in Python. I found entrians goto but my Python implementation (CPython 2.7.1 on Mac) does not have this module, so it doesn't seem to be portable. It should at least work in all Python implementations which support CPython bytecode (esp. I care about CPython and PyPy). Then there is this related question, and cdjc's goto. And the ones given by answers below. I could go and build up the bytecode manually (i.e. write my own Python compiler) because there is such an instruction (