Given a set of referenced types, works out which of them should be imported and what the resulting spelling of each one is.

This method operates on a Set<TypeMirror> rather than just a Set<String> because it is not strictly possible to determine what part of a fully-qualified type name is the package and what part is the top-level class. For example, java.util.Map.Entry is a class called Map.Entry in a package called java.util assuming Java conventions are being followed, but it could theoretically also be a class called Entry in a package called java.util.Map. Since we are operating as part of the compiler, our goal should be complete correctness, and the only way to achieve that is to operate on the real representations of types.

Parameters

codePackageName:String

The name of the package where the class containing these references is defined. Other classes within the same package do not need to be imported.

referenced:Set<javax.lang.model.type.TypeMirror>

The complete set of declared types (classes and interfaces) that will be referenced in the generated code.

defined:Set<javax.lang.model.type.TypeMirror>

The complete set of declared types (classes and interfaces) that are defined within the scope of the generated class (i.e. nested somewhere in its superclass chain, or in its interface set)

Returns:Map<String, TypeSimplifier.Spelling>

a map where the keys are fully-qualified types and the corresponding values indicate whether the type should be imported, and how the type should be spelled in the source code.

Handles the tricky case where the class being referred to is in java.lang, but the package of the referring code contains another class of the same name. For example, if the current package is foo.bar and there is a foo.bar.Compiler, then we will refer to java.lang.Compiler by its full name. The plain name Compiler would reference foo.bar.Compiler in this case. We need to write java.lang.Compiler even if the other Compiler class is not being considered here, so the ambiguousNames logic is not enough. We have to look to see if the class exists.

Finds all types that are declared with non private visibility by the given TypeMirror, any class in its superclass chain, or any interface it implements.

Finds the top-level types for all the declared types (classes and interfaces) in the given Set<TypeMirror>.

The returned set contains only top-level types. If we reference java.util.Map.Entry then the returned set will contain java.util.Map. This is because we want to write Map.Entry everywhere rather than Entry.