scala.tools.nsc.backend.opt

InlineExceptionHandlers

abstract class InlineExceptionHandlers extends SubComponent

This optimization phase inlines the exception handlers so that further phases can optimize the code better

try {
  ...
  if (condition)
    throw IllegalArgumentException("sth")
} catch {
  case e: IllegalArgumentException => <handler code>
  case e: ... => ...
}

will inline the exception handler code to:

try {
  ...
  if (condition)
    <handler code> // + jump to the end of the catch statement
} catch {
  case e: IllegalArgumentException => <handler code>
  case e: ... => ...
}

Q: How does the inlining work, ICode level? A: if a block contains a THROW(A) instruction AND there is a handler that takes A or a superclass of A we do:

  1. We duplicate the handler code such that we can transform THROW into a JUMP 2. We analyze the handler to see what local it expects the exception to be placed in 3. We place the exception that is thrown in the correct "local variable" slot and clean up the stack 4. We finally JUMP to the duplicate handler All the above logic is implemented in InlineExceptionHandlersPhase.apply(bblock: BasicBlock)

Q: Why do we need to duplicate the handler? A: An exception might be thrown in a method that we invoke in the function and we cannot see that THROW command directly. In order to catch such exceptions, we keep the exception handler in place and duplicate it in order to inline its code.

Linear Supertypes
SubComponent, AnyRef, Any
Known Subclasses
inlineExceptionHandlers
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Inherited
  1. InlineExceptionHandlers
  2. SubComponent
  3. AnyRef
  4. Any
Implicitly
  1. by StringAdd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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  1. Public
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Instance Constructors

  1. new InlineExceptionHandlers()

Type Members

  1. class InlineExceptionHandlersPhase extends Global.icodes.ICodePhase

    Inlining Exception Handlers

  2. abstract class StdPhase extends GlobalPhase

    A standard phase template

Abstract Value Members

  1. abstract val global: Global

    The global environment; overridden by instantiation in Global.

    The global environment; overridden by instantiation in Global.

    Definition Classes
    SubComponent

  2. abstract val runsAfter: List[String]

    Names of phases that must run before this phase.

    Names of phases that must run before this phase.

    Definition Classes
    SubComponent

  3. abstract val runsRightAfter: Option[String]

    Name of the phase that this phase must follow immediately.

    Name of the phase that this phase must follow immediately.

    Definition Classes
    SubComponent

Concrete Value Members

  1. final def !=(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  2. final def !=(arg0: Any): Boolean

    Definition Classes
    Any

  3. final def ##(): Int

    Definition Classes
    AnyRef → Any

  4. def +(other: String): String

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to StringAdd[InlineExceptionHandlers] performed by method StringAdd in scala.Predef.
    Definition Classes
    StringAdd

  5. def ->[B](y: B): (InlineExceptionHandlers, B)

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to ArrowAssoc[InlineExceptionHandlers] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()

  6. final def ==(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  7. final def ==(arg0: Any): Boolean

    Definition Classes
    Any

  8. final def afterOwnPhase[T](op: ⇒ T): T

    Definition Classes
    SubComponent
    Annotations
    @inline()

  9. final def asInstanceOf[T0]: T0

    Definition Classes
    Any

  10. final def beforeOwnPhase[T](op: ⇒ T): T

    Definition Classes
    SubComponent
    Annotations
    @inline()

  11. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  12. def enabled: Boolean

    Is this component enabled? Default is true.

    Is this component enabled? Default is true.

    Definition Classes
    InlineExceptionHandlers → SubComponent

  13. def ensuring(cond: (InlineExceptionHandlers) ⇒ Boolean, msg: ⇒ Any): InlineExceptionHandlers

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to Ensuring[InlineExceptionHandlers] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  14. def ensuring(cond: (InlineExceptionHandlers) ⇒ Boolean): InlineExceptionHandlers

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to Ensuring[InlineExceptionHandlers] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  15. def ensuring(cond: Boolean, msg: ⇒ Any): InlineExceptionHandlers

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to Ensuring[InlineExceptionHandlers] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  16. def ensuring(cond: Boolean): InlineExceptionHandlers

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to Ensuring[InlineExceptionHandlers] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  17. final def eq(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  18. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any

  19. def finalize(): Unit

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )

  20. def formatted(fmtstr: String): String

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to StringFormat[InlineExceptionHandlers] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()

  21. final def getClass(): Class[_]

    Definition Classes
    AnyRef → Any

  22. def hashCode(): Int

    SubComponent are added to a HashSet and two phases are the same if they have the same name

    SubComponent are added to a HashSet and two phases are the same if they have the same name

    Definition Classes
    SubComponent → AnyRef → Any

  23. val initial: Boolean

    True if this phase runs before all other phases.

    True if this phase runs before all other phases. Usually, parser.

    Definition Classes
    SubComponent

  24. val internal: Boolean

    True if this phase is not provided by a plug-in.

    True if this phase is not provided by a plug-in.

    Definition Classes
    SubComponent

  25. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any

  26. final def ne(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  27. def newPhase(p: Phase): InlineExceptionHandlersPhase

    Create a new phase

    Create a new phase

    Definition Classes
    InlineExceptionHandlers → SubComponent

  28. final def notify(): Unit

    Definition Classes
    AnyRef

  29. final def notifyAll(): Unit

    Definition Classes
    AnyRef

  30. def ownPhase: Phase

    The phase corresponding to this subcomponent in the current compiler run

    The phase corresponding to this subcomponent in the current compiler run

    Definition Classes
    SubComponent

  31. val phaseName: String

    The name of the phase

    The name of the phase

    Definition Classes
    InlineExceptionHandlers → SubComponent

  32. def phaseNewFlags: Long

    New flags defined by the phase which are not valid before

    New flags defined by the phase which are not valid before

    Definition Classes
    SubComponent

  33. def phaseNextFlags: Long

    New flags defined by the phase which are not valid until immediately after it

    New flags defined by the phase which are not valid until immediately after it

    Definition Classes
    SubComponent

  34. val requires: List[String]

    Names of phases required by this component.

    Names of phases required by this component. Default is Nil.

    Definition Classes
    SubComponent

  35. val runsBefore: List[String]

    Names of phases that must run after this phase.

    Names of phases that must run after this phase. Default is Nil.

    Definition Classes
    SubComponent

  36. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef

  37. val terminal: Boolean

    True if this phase runs after all other phases.

    True if this phase runs after all other phases. Usually, terminal.

    Definition Classes
    SubComponent

  38. def toString(): String

    Definition Classes
    AnyRef → Any

  39. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  40. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  41. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  42. def →[B](y: B): (InlineExceptionHandlers, B)

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to ArrowAssoc[InlineExceptionHandlers] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Inherited from SubComponent

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion StringAdd from InlineExceptionHandlers to StringAdd[InlineExceptionHandlers]

Inherited by implicit conversion StringFormat from InlineExceptionHandlers to StringFormat[InlineExceptionHandlers]

Inherited by implicit conversion Ensuring from InlineExceptionHandlers to Ensuring[InlineExceptionHandlers]

Inherited by implicit conversion ArrowAssoc from InlineExceptionHandlers to ArrowAssoc[InlineExceptionHandlers]

Ungrouped