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
Type Hierarchy Learn more about scaladoc diagrams
Ordering

1. Alphabetic
2. By inheritance

Inherited

1. InlineExceptionHandlers
2. SubComponent
3. AnyRef
4. Any

Implicitly

1. by any2stringadd
2. by StringFormat
3. by Ensuring
4. by ArrowAssoc

1. Hide All
2. Show all

Learn more about member selection
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

   A standard phase template

   Definition Classes
     SubComponent

### 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: Any): Boolean

   Definition Classes
     AnyRef → Any

2. #### final def ##(): Int

   Definition Classes
     AnyRef → Any

3. #### def +(other: String): String

   Implicit information
     This member is added by an implicit conversion from InlineExceptionHandlers to any2stringadd[InlineExceptionHandlers] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd

4. #### 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()

5. #### final def ==(arg0: Any): Boolean

   Definition Classes
     AnyRef → Any

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

   Definition Classes
     SubComponent
   Annotations
     @inline()

7. #### final def asInstanceOf[T0]: T0

   Definition Classes
     Any

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

   Definition Classes
     SubComponent
   Annotations
     @inline()

9. #### def clone(): AnyRef

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

10. #### def enabled: Boolean

    Is this component enabled? Default is true.

    Is this component enabled? Default is true.

    Definition Classes
      InlineExceptionHandlers → SubComponent

11. #### 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

12. #### 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

13. #### 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

14. #### 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

15. #### final def eq(arg0: AnyRef): Boolean

    Definition Classes
      AnyRef

16. #### def equals(arg0: Any): Boolean

    Definition Classes
      AnyRef → Any

17. #### def finalize(): Unit

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

18. #### 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()

19. #### final def getClass(): Class[_]

    Definition Classes
      AnyRef → Any

20. #### 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

21. #### 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

22. #### 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

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 requires: List[String]

    Names of phases required by this component.

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

    Definition Classes
      SubComponent

33. #### 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

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

    Definition Classes
      AnyRef

35. #### 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

36. #### def toString(): String

    Definition Classes
      AnyRef → Any

37. #### final def wait(): Unit

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

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

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

39. #### final def wait(arg0: Long): Unit

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

40. #### 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 any2stringadd from InlineExceptionHandlers to any2stringadd[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