final object Contexts

Constructors

Members

[+] abstract class Context

A context is passed basically everywhere in dotc. This is convenient but carries the risk of captured contexts in objects that turn into space leaks. To...

    A context is passed basically everywhere in dotc. This is convenient but carries the risk of captured contexts in objects that turn into space leaks. To combat this risk, here are some conventions to follow:

    • Never let an implicit context be an argument of a class whose instances live longer than the context.
    • Classes that need contexts for their initialization take an explicit parameter named initctx. They pass initctx to all positions where it is needed (and these positions should all be part of the intialization sequence of the class).
    • Classes that need contexts that survive initialization are instead passed a "condensed context", typically named cctx (or they create one). Condensed contexts just add some basic information to the context base without the risk of capturing complete trees.
    • To make sure these rules are kept, it would be good to do a sanity check using bytecode inspection with javap or scalap: Keep track of all class fields of type context; allow them only in whitelisted classes (which should be short-lived).
    final object Context
    class ContextBase

    A context base defines state and associated methods that exist once per compiler run.

    A context base defines state and associated methods that exist once per compiler run.

    class ContextState

    The essential mutable state of a context base, collected into a common class

    The essential mutable state of a context base, collected into a common class

    abstract class FreshContext

    A fresh context allows selective modification of its attributes using the with... methods.

    A fresh context allows selective modification of its attributes using the with... methods.

    final class FreshModeChanges
    final object FreshModeChanges
    class GADTMap
    private class InitialContext

    A class defining the initial context with given context base and set of possible settings.

    A class defining the initial context with given context base and set of possible settings.

    final class ModeChanges
    final object ModeChanges
    @sharable final object NoContext
    class RunInfo

    Info that changes on each compiler run

    Info that changes on each compiler run

    implicit def FreshModeChanges ( c: FreshContext ) : FreshModeChanges
    implicit def ModeChanges ( c: Context ) : ModeChanges