redirect.md

@Redirect

<- Return

Redirects a method call, field access, or object construction. To access the target method's parameters, simply append them to the redirector's parameters.

Return type: same as the redirected method call/field access/object construction's return type

Parameters, in order:

• Instance accesses: Target instance type
• Parameters of method call or constructor (none in case of field accesses)

This conflicts with any other mixin targetting the same method call, field access, or object construction. Handle with care.

Example mixin:

@Redirect(method = "target(I)V", at = @At(value = "INVOKE", target = "Lnet/example/Dummy;dummy(I)D"))
private double mixin(Dummy self, int i) {
    return i * 7.5;
}

Method modification:

  public void target(int a) {
+     double result;
+     {
+         Dummy self = Dummy.getInstance();
+         int i = 5;
+
+         result = i * 7.5;
+     }
-     double result = Dummy.getInstance().dummy(5);
  }

@Redirect Instanceof Mode

Parameters, in order:

• Object that will be the tested object
• The original Class being tested against
• Returns either a boolean or Class<?> your choice.

This conflicts with any other mixin targetting the same method call, field access, or object construction. Handle with care.

Example mixin:

@Redirect(method = "target()Z", at = @At(value = "CONSTANT", args = "classValue=net/example/Dummy", shift = Shift.AFTER, ordinal = 0))
public boolean mixin(Object targetObj, Class<?> classValue) {
    return false;
}

//or

@Redirect(method = "target()Z", at = @At(value = "CONSTANT", args = "classValue=net/example/Dummy", shift = Shift.AFTER, ordinal = 0))
public Class<?> mixin(Object targetObj, Class<?> classValue) {
  return Smartie.class;
}

Method modification:

  public boolean target(IDummy obj) {
+   return this.mixin(obj,Dummy.class);
-   return obj instanceof Dummy;
  }
  
  // or
  
  public boolean target(IDummy obj) {
+   return obj != null && obj.getClass().isAssignableFrom(this.mixin(obj,Dummy.class));
-   return obj instanceof Dummy;
  }