scala.tools.nsc.backend.icode.ICodeCheckers

# ICodeChecker

#### class ICodeChecker extends AnyRef

This class performs a set of checks similar to what the bytecode verifier does. For each basic block, it checks that:

- for primitive operations: the type and numer of operands match the type of the operation

- for method calls: the method exists in the type of the receiver and the number and type of arguments match the declared type of the method.

- for object creation: the constructor can be called.

- for load/stores: the field/local/param exists and the type of the value matches that of the target.

For a control flow graph it checks that type stacks at entry to each basic block 'agree':

- they have the same length
- there exists a lub for all types at the same position in stacks.

Version

  1.0, 06/09/2005

To do

  Iulian says: I think there's some outdated logic in the checker. The issue with exception handlers being special for least upper bounds pointed out some refactoring in the lattice class. Maybe a worthwhile refactoring would be to make the checker use the DataFlowAnalysis class, and use the lattice trait. In the implementation of LUB, there's a flag telling if one of the successors is 'exceptional'. The inliner is using this mechanism.

  ,

  Better checks for `MONITOR_ENTER/EXIT` Better checks for local var initializations

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Known Subclasses
icodeChecker
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Inherited

1. ICodeChecker
2. AnyRef
3. Any

Implicitly

1. by any2stringadd
2. by any2stringfmt
3. by any2ArrowAssoc
4. by any2Ensuring

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### Instance Constructors

1. #### new ICodeChecker()

### 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 ICodeChecker to StringAdd performed by method any2stringadd in scala.Predef.
   Definition Classes
     StringAdd

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

   Implicit information
     This member is added by an implicit conversion from ICodeChecker to ArrowAssoc[ICodeChecker] 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 asInstanceOf[T0]: T0

   Definition Classes
     Any

9. #### def check(b: Global.icodes.BasicBlock, initial: Global.icodes.TypeStack): Global.icodes.TypeStack

   Check the basic block to be type correct and return the produced type stack.

10. #### def check(c: Global.icodes.Code): Unit

11. #### def check(m: Global.icodes.IMethod): Unit

12. #### def check(cls: Global.icodes.IClass): Unit

13. #### def checkICodes(): Unit

14. #### var clasz: Global.icodes.IClass

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

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

16. #### var code: Global.icodes.Code

17. #### def defaultInstrPrinter: () ⇒ String

18. #### val emptyStack: Global.icodes.TypeStack

19. #### def ensuring(cond: (ICodeChecker) ⇒ Boolean, msg: ⇒ Any): ICodeChecker

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

20. #### def ensuring(cond: (ICodeChecker) ⇒ Boolean): ICodeChecker

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

21. #### def ensuring(cond: Boolean, msg: ⇒ Any): ICodeChecker

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

22. #### def ensuring(cond: Boolean): ICodeChecker

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

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

    Definition Classes
      AnyRef

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

    Definition Classes
      AnyRef → Any

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

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

26. #### def formatted(fmtstr: String): String

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

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

    Definition Classes
      AnyRef → Any

28. #### def hashCode(): Int

    Definition Classes
      AnyRef → Any

29. #### def icodeError(msg: String, stack: Global.icodes.TypeStack): Unit

30. #### def icodeError(msg: String): Unit

31. #### val in: Map[Global.icodes.BasicBlock, Global.icodes.TypeStack]

32. #### def initMaps(bs: Seq[Global.icodes.BasicBlock]): Unit

33. #### final def isInstanceOf[T0]: Boolean

    Definition Classes
      Any

34. #### def logChecker(msg: String): Unit

    A wrapper to route log messages to debug output also.

35. #### def meet(bl: Global.icodes.BasicBlock): Unit

    Apply the meet operator of the stack lattice on bl's predecessors.

    Apply the meet operator of the stack lattice on bl's predecessors. :-). Compute the input to bl by checking that all stacks have the same length, and taking the lub of types at the same positions.

36. #### var method: Global.icodes.IMethod

37. #### def mkInstrPrinter(f: (Int) ⇒ String): () ⇒ String

    A couple closure creators to reduce noise in the output: when multiple items are pushed or popped, this lets us print something short and sensible for those beyond the first.

38. #### final def ne(arg0: AnyRef): Boolean

    Definition Classes
      AnyRef

39. #### def notChecked(ts: Global.icodes.TypeStack): Boolean

    The presence of emptyStack means that path has not yet been checked (and may not be empty).

40. #### final def notify(): Unit

    Definition Classes
      AnyRef

41. #### final def notifyAll(): Unit

    Definition Classes
      AnyRef

42. #### val out: Map[Global.icodes.BasicBlock, Global.icodes.TypeStack]

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

    Definition Classes
      AnyRef

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

    Definition Classes
      AnyRef → Any

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

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

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

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

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

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

48. #### def →[B](y: B): (ICodeChecker, B)

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

### Shadowed Implicit Value Members

1. #### val self: Any

   Implicit information
     This member is added by an implicit conversion from ICodeChecker 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:

         (iCodeChecker: StringAdd).self

   Definition Classes
     StringAdd

2. #### val self: Any

   Implicit information
     This member is added by an implicit conversion from ICodeChecker 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:

         (iCodeChecker: StringFormat).self

   Definition Classes
     StringFormat

### Deprecated Value Members

1. #### def x: ICodeChecker

   Implicit information
     This member is added by an implicit conversion from ICodeChecker to ArrowAssoc[ICodeChecker] 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:

         (iCodeChecker: ArrowAssoc[ICodeChecker]).x

   Definition Classes
     ArrowAssoc
   Annotations
     @deprecated
   Deprecated

     (Since version 2.10.0) Use `leftOfArrow`instead``

2. #### def x: ICodeChecker

   Implicit information
     This member is added by an implicit conversion from ICodeChecker to Ensuring[ICodeChecker] 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:

         (iCodeChecker: Ensuring[ICodeChecker]).x

   Definition Classes
     Ensuring
   Annotations
     @deprecated
   Deprecated

     (Since version 2.10.0) Use `resultOfEnsuring`instead``

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion any2stringadd from ICodeChecker to StringAdd

### Inherited by implicit conversion any2stringfmt from ICodeChecker to StringFormat

### Inherited by implicit conversion any2ArrowAssoc from ICodeChecker to ArrowAssoc[ICodeChecker]

### Inherited by implicit conversion any2Ensuring from ICodeChecker to Ensuring[ICodeChecker]

### Ungrouped