InitialProducer

A class for pseudo-instructions representing the initial producers of local values that have no producer instruction in the method:

• parameters, including this
• uninitialized local variables
• exception values in handlers

The ASM built-in SourceValue analysis yields an empty producers set for such values. This leads to ambiguities. Example (in Java one can re-assign parameter):

int foo(int a) { if (a == 0) a = 1; return a; }

In the first frame of the method, the SourceValue for parameter a gives an empty set of producer instructions.

In the frame of the IRETURN instruction, the SourceValue for parameter a lists a single producer instruction: the ISTORE 1. This makes it look as if there was a single producer for a, where in fact it might still hold the parameter's initial value.