Class

scala.tools.nsc.backend.opt

InlineExceptionHandlers

Related Doc: package opt

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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
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Inherited
  1. InlineExceptionHandlers
  2. SubComponent
  3. AnyRef
  4. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. All

Instance Constructors

  1. new InlineExceptionHandlers()

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Type Members

  1. class InlineExceptionHandlersPhase extends Global.icodes.ICodePhase

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    Inlining Exception Handlers

  2. abstract class StdPhase extends GlobalPhase

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    A standard phase template

    A standard phase template

    Definition Classes
    SubComponent

Abstract Value Members

  1. abstract val global: Global

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    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]

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    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]

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    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

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    Test two objects for inequality.

    Test two objects for inequality.

    returns

    true if !(this == that), false otherwise.

    Definition Classes
    AnyRef → Any
  2. final def ##(): Int

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    Equivalent to x.hashCode except for boxed numeric types and null.

    Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.

    returns

    a hash value consistent with ==

    Definition Classes
    AnyRef → Any
  3. def +(other: String): String

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    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)

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    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

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    The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

    The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    Definition Classes
    AnyRef → Any
  6. final def afterOwnPhase[T](op: ⇒ T): T

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    Definition Classes
    SubComponent
    Annotations
    @inline()
  7. final def asInstanceOf[T0]: T0

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    Cast the receiver object to be of type T0.

    Cast the receiver object to be of type T0.

    Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

    returns

    the receiver object.

    Definition Classes
    Any
    Exceptions thrown

    ClassCastException if the receiver object is not an instance of the erasure of type T0.

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

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    Definition Classes
    SubComponent
    Annotations
    @inline()
  9. def clone(): AnyRef

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    Create a copy of the receiver object.

    Create a copy of the receiver object.

    The default implementation of the clone method is platform dependent.

    returns

    a copy of the receiver object.

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

    not specified by SLS as a member of AnyRef

  10. def enabled: Boolean

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    Is this component enabled? Default is true.

    Is this component enabled? Default is true.

    Definition Classes
    InlineExceptionHandlersSubComponent
  11. def ensuring(cond: (InlineExceptionHandlers) ⇒ Boolean, msg: ⇒ Any): InlineExceptionHandlers

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    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

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    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

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    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

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    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

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    Tests whether the argument (that) is a reference to the receiver object (this).

    Tests whether the argument (that) is a reference to the receiver object (this).

    The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

    • It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.
    • For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
    • null.eq(null) returns true.

    When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

    returns

    true if the argument is a reference to the receiver object; false otherwise.

    Definition Classes
    AnyRef
  16. def equals(arg0: Any): Boolean

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    The equality method for reference types.

    The equality method for reference types. Default implementation delegates to eq.

    See also equals in scala.Any.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    Definition Classes
    AnyRef → Any
  17. def finalize(): Unit

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    Called by the garbage collector on the receiver object when there are no more references to the object.

    Called by the garbage collector on the receiver object when there are no more references to the object.

    The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

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

    not specified by SLS as a member of AnyRef

  18. def formatted(fmtstr: String): String

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    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[_]

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    A representation that corresponds to the dynamic class of the receiver object.

    A representation that corresponds to the dynamic class of the receiver object.

    The nature of the representation is platform dependent.

    returns

    a representation that corresponds to the dynamic class of the receiver object.

    Definition Classes
    AnyRef → Any
    Note

    not specified by SLS as a member of AnyRef

  20. def hashCode(): Int

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    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

    returns

    the hash code value for this object.

    Definition Classes
    SubComponent → AnyRef → Any
  21. val initial: Boolean

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    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

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    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

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    Test whether the dynamic type of the receiver object is T0.

    Test whether the dynamic type of the receiver object is T0.

    Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

    returns

    true if the receiver object is an instance of erasure of type T0; false otherwise.

    Definition Classes
    Any
  24. final def ne(arg0: AnyRef): Boolean

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    Equivalent to !(this eq that).

    Equivalent to !(this eq that).

    returns

    true if the argument is not a reference to the receiver object; false otherwise.

    Definition Classes
    AnyRef
  25. def newPhase(p: Phase): InlineExceptionHandlersPhase

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    Create a new phase

    Create a new phase

    Definition Classes
    InlineExceptionHandlersSubComponent
  26. final def notify(): Unit

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    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  27. final def notifyAll(): Unit

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    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  28. def ownPhase: Phase

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    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

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    The name of the phase

    The name of the phase

    Definition Classes
    InlineExceptionHandlersSubComponent
  30. def phaseNewFlags: Long

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    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

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    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]

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    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]

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    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

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    Definition Classes
    AnyRef
  35. val terminal: Boolean

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    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

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    Creates a String representation of this object.

    Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

    returns

    a String representation of the object.

    Definition Classes
    AnyRef → Any
  37. final def wait(): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  38. final def wait(arg0: Long, arg1: Int): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  39. final def wait(arg0: Long): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  40. def [B](y: B): (InlineExceptionHandlers, B)

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    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