ReChecking

check that annotation annot is applicable to symbol sym

Check that catch can generate a good CanThrow exception

1. Check that all case classes that extend scala.reflect.Enum are enum cases
2. Check that parameterised enum cases do not extend java.lang.Enum.
3. Check that only a static enum base class can extend java.lang.Enum.
4. Check that user does not implement an ordinal method in the body of an enum class.

Check that all references coming from enum cases in an enum companion object are legal.

Check that the firstParent for an enum case derives from the declaring enum class, if not, adds it as a parent after emitting an error.

This check will have no effect on simple enum cases as their parents are inferred by the compiler.

Issue a feature warning if feature is not enabled

Check that user-defined (result) type is fully applied

Check that module sym does not clash with a class of the same name that is concurrently compiled in another source file.

Check that all non-synthetic references of the form <ident> or this.<ident> in tree that refer to a member of badOwner are allowed. Also check that there are no other explicit this references to badOwner.

Check arguments of compiler-defined annotations

Check that case classes are not inherited by case classes.

Check that tp is a class type. Also, if traitReq is true, check that tp is a trait. Also, if stablePrefixReq is true and phase is not after RefChecks, check that class prefix is stable.

Verify classes extending AnyVal meet the requirements

Check that tp is a class type and that any top-level type arguments in this type are feasible, i.e. that their lower bound conforms to their upper bound. If a type argument is infeasible, issue and error and continue with upper bound.

If sym is an old-style implicit conversion, check that implicit conversions are enabled.

If tree is an application of a new-style implicit conversion (using the apply method of a scala.Conversion instance), check that implicit conversions are enabled.

Check that we are in an inline context (inside an inline method or in inline code)

Check that pattern pat is irrefutable for scrutinee type sel.tpe. This means sel is either marked @unchecked or sel.tpe conforms to the pattern's type. If pattern is an UnApply, also check that the extractor is irrefutable, and do the check recursively.

Check that path is a legal prefix for an export clause

Check that path is a legal prefix for an import clause

Check that all named types that form part of this type have a denotation. Called on inferred (result) types of ValDefs and DefDefs. This could fail for types where the member was originally available as part of the self type, yet is no longer visible once the this has been replaced by some other prefix. See neg/i3083.scala

Check that class does not declare same symbol twice

Check that method parameter types do not reference their own parameter or later parameters in the same parameter section.

Check that symbol's external name does not clash with symbols defined in the same scope

Check that all type members of tp have realizable bounds

Check that tpt does not define a higher-kinded type

Check that type tp is stable.

Given a parent parent of a class cls, if parent is a trait check that the superclass of cls derived from the superclass of parent.

An exception is made if cls extends Any, and parent is java.io.Serializable or java.lang.Comparable. These two classes are treated by Scala as universal traits. E.g. the following is OK:

... extends Any with java.io.Serializable

The standard library relies on this idiom.

Check that tree is a valid infix operation. That is, if the operator is alphanumeric, it must be declared infix.

A hook to exclude selected symbols from double declaration check