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.

Source
InlineExceptionHandlers.scala
Linear Supertypes
SubComponent, AnyRef, Any
Known Subclasses
inlineExceptionHandlers
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Inherited
  1. InlineExceptionHandlers
  2. SubComponent
  3. AnyRef
  4. Any
Implicitly
  1. by any2stringadd
  2. by any2stringfmt
  3. by any2ArrowAssoc
  4. by any2Ensuring
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Visibility
  1. Public
  2. All

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]

    List of phase names, this phase should run after

    List of phase names, this phase should run after

    Definition Classes
    SubComponent

  3. abstract val runsRightAfter: Option[String]

    Phase name this phase will attach itself to, not allowing any phase to come between it and the phase name declared

    Phase name this phase will attach itself to, not allowing any phase to come between it and the phase name declared

    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 performed by method any2stringadd 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 any2ArrowAssoc 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 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 any2Ensuring in scala.Predef.
    Definition Classes
    Ensuring

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

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to Ensuring[InlineExceptionHandlers] performed by method any2Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  14. 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 any2Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  15. def ensuring(cond: Boolean): InlineExceptionHandlers

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to Ensuring[InlineExceptionHandlers] performed by method any2Ensuring in scala.Predef.
    Definition Classes
    Ensuring

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

    Definition Classes
    AnyRef

  17. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any

  18. def finalize(): Unit

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

  19. def formatted(fmtstr: String): String

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to StringFormat performed by method any2stringfmt in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()

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

    Definition Classes
    AnyRef → Any

  21. 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

  22. val internal: Boolean

    Internal flag to tell external from internal phases

    Internal flag to tell external from internal phases

    Definition Classes
    SubComponent

  23. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any

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

    Definition Classes
    AnyRef

  25. def newPhase(p: Phase): InlineExceptionHandlersPhase

    Create a new phase

    Create a new phase

    Definition Classes
    InlineExceptionHandlers → SubComponent

  26. final def notify(): Unit

    Definition Classes
    AnyRef

  27. final def notifyAll(): Unit

    Definition Classes
    AnyRef

  28. 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

  29. val phaseName: String

    The name of the phase

    The name of the phase

    Definition Classes
    InlineExceptionHandlers → SubComponent

  30. 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

  31. 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

  32. val runsBefore: List[String]

    List of phase names, this phase should run before

    List of phase names, this phase should run before

    Definition Classes
    SubComponent

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

    Definition Classes
    AnyRef

  34. def toString(): String

    Definition Classes
    AnyRef → Any

  35. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws()

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

    Definition Classes
    AnyRef
    Annotations
    @throws()

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

    Definition Classes
    AnyRef
    Annotations
    @throws()

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

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to ArrowAssoc[InlineExceptionHandlers] performed by method any2ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Shadowed Implict Value Members

  1. val self: Any

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to StringAdd performed by method any2stringadd in scala.Predef.
    Shadowing
    This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
    To access this member you can use a type ascription:
    (inlineExceptionHandlers: StringAdd).self
    Definition Classes
    StringAdd

  2. val self: Any

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to StringFormat performed by method any2stringfmt in scala.Predef.
    Shadowing
    This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
    To access this member you can use a type ascription:
    (inlineExceptionHandlers: StringFormat).self
    Definition Classes
    StringFormat

Deprecated Value Members

  1. def x: InlineExceptionHandlers

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to ArrowAssoc[InlineExceptionHandlers] performed by method any2ArrowAssoc in scala.Predef.
    Shadowing
    This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
    To access this member you can use a type ascription:
    (inlineExceptionHandlers: ArrowAssoc[InlineExceptionHandlers]).x
    Definition Classes
    ArrowAssoc
    Annotations
    @deprecated
    Deprecated

    (Since version 2.10.0) Use leftOfArrow instead

  2. def x: InlineExceptionHandlers

    Implicit information
    This member is added by an implicit conversion from InlineExceptionHandlers to Ensuring[InlineExceptionHandlers] performed by method any2Ensuring in scala.Predef.
    Shadowing
    This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
    To access this member you can use a type ascription:
    (inlineExceptionHandlers: Ensuring[InlineExceptionHandlers]).x
    Definition Classes
    Ensuring
    Annotations
    @deprecated
    Deprecated

    (Since version 2.10.0) Use resultOfEnsuring instead

Inherited from SubComponent

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from InlineExceptionHandlers to StringAdd

Inherited by implicit conversion any2stringfmt from InlineExceptionHandlers to StringFormat

Inherited by implicit conversion any2ArrowAssoc from InlineExceptionHandlers to ArrowAssoc[InlineExceptionHandlers]

Inherited by implicit conversion any2Ensuring from InlineExceptionHandlers to Ensuring[InlineExceptionHandlers]

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