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/* NEST (New Scala Test)
* Copyright 2007-2013 LAMP/EPFL
* @author Grzegorz Kossakowski
*/
package scala.tools.partest.javaagent;
import scala.tools.asm.ClassVisitor;
import scala.tools.asm.MethodVisitor;
import scala.tools.asm.Opcodes;
public class ProfilerVisitor extends ClassVisitor implements Opcodes {
private static String profilerClass = "scala/tools/partest/instrumented/Profiler";
public ProfilerVisitor(final ClassVisitor cv) {
super(ASM4, cv);
}
private String className = null;
@Override
public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
className = name;
super.visit(version, access, name, signature, superName, interfaces);
}
public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
// delegate the method call to the next
// chained visitor
MethodVisitor mv = cv.visitMethod(access, name, desc, signature, exceptions);
if (!profilerClass.equals(className)) {
// only instrument non-abstract methods
if((access & ACC_ABSTRACT) == 0) {
assert(className != null);
/* The following instructions do not modify compressed stack frame map so
* we don't need to worry about recalculating stack frame map. Specifically,
* let's quote "ASM 4.0, A Java bytecode engineering library" guide (p. 40):
*
* In order to save space, a compiled method does not contain one frame per
* instruction: in fact it contains only the frames for the instructions
* that correspond to jump targets or exception handlers, or that follow
* unconditional jump instructions. Indeed the other frames can be easily
* and quickly inferred from these ones.
*
* Instructions below are just loading constants and calling a method so according
* to definition above they do not contribute to compressed stack frame map.
*/
mv.visitLdcInsn(className);
mv.visitLdcInsn(name);
mv.visitLdcInsn(desc);
mv.visitMethodInsn(INVOKESTATIC, profilerClass, "methodCalled",
"(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V", false);
}
}
return mv;
}
}
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