CODEWITHSUNDEEP
javacode-coveragebytecodeinstrumentationjava-bytecode-asm
bytaj
bytaj

Reputation: 23

Coverture of a method ASM Java

Hello and thank you in advance for your answers. I would like to know if there is any way to know (using ASM) which lines I've gone through and which ones I haven't on real time. In other words, a way in which, as soon as any method has finished executing, for each execution, I can inject an instrumentation instruction for it to print which lines it has or hasn't gone through

Upvotes: 1

Views: 400

Answers (1)

Charles Forsythe
Charles Forsythe

Reputation: 1861

First you should create a class with a static method that logs the line number execution events. It would have a method like this:

public static void lineExecution(String filename, int lineNumber)

Put whatever logic you need. Capture the event in-memory and report at the end, or just write it to stdout.

When you are modifying the target classes with ASM, you need to decorate the visitSource method in ClassVisitor.

This method should capture the "source" parameter (the source file) for use later. Then, you need to return a custom MethodVisitor from visitMethod with a decorated visitLineNumber method. This method should insert a call to your static method:

ldc (whatever the value of "source" is)
ldc (whatever line number was passed in)
invokestatic LineExecutionMonitor.lineExecution

Thus, whenever a new line number is executed, the first thing that happens it that a call is made to your static method. There you can trace execution within the instrumented class.

Hope this helps.

Upvotes: 1

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