java-bytecode-asm

问题 I'm trying to verify "on the fly" generated bytecode! I already had several attempts, one attempt was to compile my classes in runtime with the eclipse compiler another was to compile from memory as mentioned here: Compile From Memory First results looked okay but I'm still not a 100% sure if the verification process is truly valid according to the JAVA 6 guidelines and security measurements as well to normal OOP Models. Any better way on how to verify bytecode? 回答1: If you load the generated

问题 I am using ASM (for the first time) in an application to create Java class files. This is for the backend of a compiler I am writing. I read the relevant parts of the ASM documentation and have a question about stack map frames. ASM says it can automatically compute those frames if the class writer is initialized with the appropriate flags. My question is, does that mean I will not ever have to call the visitLocalVariable() method on the method visitors myself? I am not sure what that method

问题 I need to transform Java bytecode with ASM to initialize public static final fields inside a static {...} block in the class. For example: Input: public static final int CONSTANT = 10; Output: public static final int CONSTANT; static { CONSTANT = 10; } I need this transformation because the compiler replaces primitive constants by their actual value in the bytecode, so their usage becomes untraceable. This transformation allows tracing the usage of constants. 回答1: For such a transformation,

问题 I need to transform Java bytecode with ASM to initialize public static final fields inside a static {...} block in the class. For example: Input: public static final int CONSTANT = 10; Output: public static final int CONSTANT; static { CONSTANT = 10; } I need this transformation because the compiler replaces primitive constants by their actual value in the bytecode, so their usage becomes untraceable. This transformation allows tracing the usage of constants. 回答1: For such a transformation,

问题 I need to transform Java bytecode with ASM to initialize public static final fields inside a static {...} block in the class. For example: Input: public static final int CONSTANT = 10; Output: public static final int CONSTANT; static { CONSTANT = 10; } I need this transformation because the compiler replaces primitive constants by their actual value in the bytecode, so their usage becomes untraceable. This transformation allows tracing the usage of constants. 回答1: For such a transformation,

问题 I'm trying to use the ASM library to translate byte code into a different format, which can be done with a MethodVisitor, as with this simple test code: return new MethodVisitor(ASM7) { @Override public void visitInsn(int opcode) { System.out.println(String.format("%02x", opcode)); } @Override public void visitMaxs(int maxStack, int maxLocals) { System.out.println(maxStack); } }; One issue is that I only get to see maxStack after the actual instructions – I've tested it, and that is the order

问题 I'm trying to use the ASM library to translate byte code into a different format, which can be done with a MethodVisitor, as with this simple test code: return new MethodVisitor(ASM7) { @Override public void visitInsn(int opcode) { System.out.println(String.format("%02x", opcode)); } @Override public void visitMaxs(int maxStack, int maxLocals) { System.out.println(maxStack); } }; One issue is that I only get to see maxStack after the actual instructions – I've tested it, and that is the order

问题 I am using ASM 7.0 in a short Java 11 project, which convert a class file to a text using the following code: final var charset = StandardCharsets.UTF_8; final ByteArrayOutputStream bos = new ByteArrayOutputStream(); try (var pw = new PrintWriter(bos, false, charset)) { final org.objectweb.asm.ClassVisitor traceClassVisitor = new TraceClassVisitor(null, new org.objectweb.asm.util.Textifier(), new PrintWriter(bos)); new ClassReader(stream.getStream()).accept(traceClassVisitor, ClassReader.SKIP

问题 I have a Java project and internally it is dependent on asm jar . Strangely, I don't even know why my project somehow is dependent on this library ( might be brought in by maven as a transitive dependency )? Can anyone help me know why some one needs asm jar ? Thanks in advance ! EDIT: Can you also mention for what purposes/use-cases one might need asm jar? 回答1: ASM is a bytecode manipulation framework (see this page for a nice introduction) and is used by many things performing... bytecode

问题 I have a Java project and internally it is dependent on asm jar . Strangely, I don't even know why my project somehow is dependent on this library ( might be brought in by maven as a transitive dependency )? Can anyone help me know why some one needs asm jar ? Thanks in advance ! EDIT: Can you also mention for what purposes/use-cases one might need asm jar? 回答1: ASM is a bytecode manipulation framework (see this page for a nice introduction) and is used by many things performing... bytecode