Packages

  • package root

    The Scala compiler API.

    The Scala compiler API.

    The following resources are useful for Scala plugin/compiler development:

    Definition Classes
    root
  • package scala
    Definition Classes
    root
  • package tools
    Definition Classes
    scala
  • package nsc
    Definition Classes
    tools
  • package backend
    Definition Classes
    nsc
  • package jvm
    Definition Classes
    backend
  • package analysis

    Summary on the ASM analyzer framework --------------------------------------

    Summary on the ASM analyzer framework --------------------------------------

    Value

    • Abstract, needs to be implemented for each analysis.
    • Represents the desired information about local variables and stack values, for example:
      • Is this value known to be null / not null?
      • What are the instructions that could potentially have produced this value?

    Interpreter

    • Abstract, needs to be implemented for each analysis. Sometimes one can subclass an existing interpreter, e.g., SourceInterpreter or BasicInterpreter.
    • Multiple abstract methods that receive an instruction and the instruction's input values, and return a value representing the result of that instruction.
      • Note: due to control flow, the interpreter can be invoked multiple times for the same instruction, until reaching a fixed point.
    • Abstract merge function that computes the least upper bound of two values. Used by Frame.merge (see below).

    Frame

    • Can be used directly for many analyses, no subclass required.
    • Every frame has an array of values: one for each local variable and for each stack slot.
      • A top index stores the index of the current stack top
      • NOTE: for a size-2 local variable at index i, the local variable at i+1 is set to an empty value. However, for a size-2 value at index i on the stack, the value at i+1 holds the next stack value. IMPORTANT: this is only the case in ASM's analysis framework, not in bytecode. See comment below.
    • Defines the execute(instruction) method.
      • executing mutates the state of the frame according to the effect of the instruction
        • pop consumed values from the stack
        • pass them to the interpreter together with the instruction
        • if applicable, push the resulting value on the stack
    • Defines the merge(otherFrame) method
      • called by the analyzer when multiple control flow paths lead to an instruction
        • the frame at the branching instruction is merged into the current frame of the instruction (held by the analyzer)
        • mutates the values of the current frame, merges all values using interpreter.merge.

    Analyzer

    • Stores a frame for each instruction
    • merge function takes an instruction and a frame, merges the existing frame for that instr (from the frames array) with the new frame passed as argument. if the frame changed, puts the instruction on the work queue (fixpiont).
    • initial frame: initialized for first instr by calling interpreter.new[...]Value for each slot (locals and params), stored in frames[firstInstr] by calling merge
    • work queue of instructions (queue array, top index for next instruction to analyze)
    • analyze(method): simulate control flow. while work queue non-empty:
      • copy the state of frames[instr] into a local frame current
      • call current.execute(instr, interpreter), mutating the current frame
      • if it's a branching instruction
        • for all potential destination instructions
          • merge the destination instruction frame with the current frame (this enqueues the destination instr if its frame changed)
        • invoke newControlFlowEdge (see below)
    • the analyzer also tracks active exception handlers at each instruction
    • the empty method newControlFlowEdge can be overridden to track control flow if required

    MaxLocals and MaxStack ----------------------

    At the JVM level, long and double values occupy two slots, both as local variables and on the stack, as specified in the JVM spec 2.6.2: "At any point in time, an operand stack has an associated depth, where a value of type long or double contributes two units to the depth and a value of any other type contributes one unit."

    For example, a method class A { def f(a: Long, b: Long) = a + b } has MAXSTACK=4 in the classfile. This value is computed by the ClassWriter / MethodWriter when generating the classfile (we always pass COMPUTE_MAXS to the ClassWriter).

    For running an ASM Analyzer, long and double values occupy two local variable slots, but only a single slot on the call stack, as shown by the following snippet:

    import scala.tools.nsc.backend.jvm._ import scala.tools.nsc.backend.jvm.opt.BytecodeUtils._ import scala.collection.convert.decorateAsScala._ import scala.tools.asm.tree.analysis._

    val cn = AsmUtils.readClass("/Users/luc/scala/scala/sandbox/A.class") val m = cn.methods.iterator.asScala.find(_.name == "f").head

    // the value is read from the classfile, so it's 4 println(s"maxLocals: ${m.maxLocals}, maxStack: ${m.maxStack}") // maxLocals: 5, maxStack: 4

    // we can safely set it to 2 for running the analyzer. m.maxStack = 2

    val a = new Analyzer(new BasicInterpreter) a.analyze(cn.name, m) val addInsn = m.instructions.iterator.asScala.find(_.getOpcode == 97).get // LADD Opcode val addFrame = a.frameAt(addInsn, m)

    addFrame.getStackSize // 2: the two long values only take one slot each addFrame.getLocals // 5: this takes one slot, the two long parameters take 2 slots each

    While running the optimizer, we need to make sure that the maxStack value of a method is large enough for running an ASM analyzer. We don't need to worry if the value is incorrect in the JVM perspective: the value will be re-computed and overwritten in the ClassWriter.

    Lessons learnt while benchmarking the alias tracking analysis -------------------------------------------------------------

    Profiling

    • Use YourKit for finding hotspots (cpu profiling). when it comes to drilling down into the details of a hotspot, don't pay too much attention to the percentages / time counts.
    • Should also try other profilers.
    • Use timers. When a method showed up as a hotspot, i added a timer around that method, and a second one within the method to measure specific parts. The timers slow things down, but the relative numbers show what parts of a method are slow.

    ASM analyzer insights

    • The time for running an analysis depends on the number of locals and the number of instructions. Reducing the number of locals helps speeding up the analysis: there are less values to merge when merging to frames. See also https://github.com/scala/scala-dev/issues/47
    • The common hot spot of an ASM analysis is Frame.merge, for example in producers / consumers.
    • For nullness analysis the time is spent as follows
      • 20% merging nullness values. this is as expected: for example, the same absolute amount of time is spent in merging BasicValues when running a BasicInterpreter.
      • 50% merging alias sets. i tried to optimize what i could out of this.
      • 20% is spent creating new frames from existing ones, see comment on AliasingFrame.init.
    • The implementation of Frame.merge (the main hot spot) contains a megamorphic callsite to interpreter.merge. This can be observed easily by running a test program that either runs a BasicValue analysis only, versus a program that first runs a nullness analysis and then a BasicValue. In an example, the time for the BasicValue analysis goes from 519ms to 1963ms, a 3.8x slowdown.
    • I added counters to the Frame.merge methods for nullness and BasicValue analysis. In the examples I benchmarked, the number of merge invocations was always exactly the same. It would probably be possible to come up with an example where alias set merging forces additional analysis rounds until reaching the fixpoint, but I did not observe such cases.

    To benchmark an analysis, instead of benchmarking analysis while it runs in the compiler backend, one can easily run it from a separate program (or the repl). The bytecode to analyze can simply be parsed from a classfile. See example at the end of this comment.

    Nullness Analysis in Miguel's Optimizer ---------------------------------------

    Miguel implemented alias tracking for nullness analysis differently [1]. Remember that every frame has an array of values. Miguel's idea was to represent aliasing using reference equality in the values array: if two entries in the array point to the same value object, the two entries are aliases in the frame of the given instruction.

    While this idea seems elegant at first sight, Miguel's implementation does not merge frames correctly when it comes to aliasing. Assume in frame 1, values (a, b, c) are aliases, while in frame 2 (a, b) are aliases. When merging the second into the first, we have to make sure that c is removed as an alias of (a, b).

    It would be possible to implement correct alias set merging in Miguel's approach. However, frame merging is the main hot spot of analysis. The computational complexity of implementing alias set merging by traversing the values array and comparing references is too high. The concrete alias set representation that is used in the current implementation (see class AliasingFrame) makes alias set merging more efficient.

    [1] https://github.com/scala-opt/scala/blob/opt/rebase/src/compiler/scala/tools/nsc/backend/bcode/NullnessPropagator.java

    Complexity and scaling of analysis ----------------------------------

    The time complexity of a data flow analysis depends on:

    • The size of the method. The complexity factor is linear (assuming the number of locals and branching instructions remains constant). The main analysis loop runs through all instructions of a method once. Instructions are only re-enqueued if a control flow merge changes the frame at some instruction.
    • The branching instructions. When a second (third, ..) control flow edge arrives at an instruction, the existing frame at the instruction is merged with the one computed on the new branch. If the merge function changes the existing frame, the instruction is enqueued for another analysis. This results in a merge operation for the successors of the instruction.
    • The number of local variables. The hot spot of analysis is frame merging. The merge function iterates through the values in the frame (locals and stack values) and merges them.

    I measured the running time of an analysis for two examples:

    • Keep the number of locals and branching instructions constant, increase the number of instructions. The running time grows linearly with the method size.
    • Increase the size and number of locals in a method. The method size and number of locals grow in the same pace. Here, the running time increase is polynomial. It looks like the complexity is be #instructions * #locals^2 (see below).

    I measured nullness analysis (which tracks aliases) and a SimpleValue analysis. Nullness runs roughly 5x slower (because of alias tracking) at every problem size - this factor doesn't change.

    The numbers below are for nullness. Note that the the last column is constant, i.e., the running time is proportional to #ins * #loc^2. Therefore we use this factor when limiting the maximal method size for running an analysis.

    #insns #locals time (ms) time / #ins * #loc2 * 106 1305 156 34 1.07 2610 311 165 0.65 3915 466 490 0.57 5220 621 1200 0.59 6525 776 2220 0.56 7830 931 3830 0.56 9135 1086 6570 0.60 10440 1241 9700 0.60 11745 1396 13800 0.60

    As a second experiment, nullness analysis was run with varying #insns but constant #locals. The last column shows linear complexity with respect to the method size (linearOffset = 2279):

    #insns #locals time (ms) (time + linearOffset) / #insns 5220 621 1090 0.645 6224 621 1690 0.637 7226 621 2280 0.630 8228 621 2870 0.625 9230 621 3530 0.629 10232 621 4130 0.626 11234 621 4770 0.627 12236 621 5520 0.637 13238 621 6170 0.638

    When running a BasicValue analysis, the complexity observation is the same (time is proportional to #ins * #loc^2).

    Measuring analysis execution time ---------------------------------

    See code below.

    Definition Classes
    jvm
  • package opt
    Definition Classes
    jvm
  • BCodeBodyBuilder
  • BCodeHelpers
  • BCodeIdiomatic
  • BCodeSkelBuilder
  • BCodeSyncAndTry
  • BTypes
  • BTypesFromSymbols
  • BackendReporting
  • BackendReportingImpl
  • BytecodeWriters
  • CoreBTypes
  • CoreBTypesProxy
  • CoreBTypesProxyGlobalIndependent
  • FileConflictException
  • GenBCode
c

scala.tools.nsc.backend.jvm

BTypesFromSymbols

class BTypesFromSymbols[G <: Global] extends BTypes

This class mainly contains the method classBTypeFromSymbol, which extracts the necessary information from a symbol and its type to create the corresponding ClassBType. It requires access to the compiler (global parameter).

The mixin CoreBTypes defines core BTypes that are used in the backend. Building these BTypes uses classBTypeFromSymbol, hence requires access to the compiler (global).

BTypesFromSymbols extends BTypes because the implementation of BTypes requires access to some of the core btypes. They are declared in BTypes as abstract members. Note that BTypes does not have access to the compiler instance.

Source
BTypesFromSymbols.scala
Linear Supertypes
BTypes, AnyRef, Any
Type Hierarchy
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. BTypesFromSymbols
  2. BTypes
  3. AnyRef
  4. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. All

Instance Constructors

  1. new BTypesFromSymbols(global: G)

Type Members

  1. final case class ArrayBType (componentType: BType) extends RefBType with Product with Serializable
    Definition Classes
    BTypes
  2. sealed trait BType extends AnyRef

    A BType is either a primitive type, a ClassBType, an ArrayBType of one of these, or a MethodType referring to BTypes.

    A BType is either a primitive type, a ClassBType, an ArrayBType of one of these, or a MethodType referring to BTypes.

    Definition Classes
    BTypes
  3. final case class ClassBType (internalName: InternalName) extends RefBType with Product with Serializable

    A ClassBType represents a class or interface type.

    A ClassBType represents a class or interface type. The necessary information to build a ClassBType is extracted from compiler symbols and types, see BTypesFromSymbols.

    The info field contains either the class information on an error message why the info could not be computed. There are two reasons for an erroneous info:

    1. The ClassBType was built from a class symbol that stems from a java source file, and the symbol's type could not be completed successfully (SI-9111) 2. The ClassBType should be built from a classfile, but the class could not be found on the compilation classpath.

    Note that all ClassBTypes required in a non-optimized run are built during code generation from the class symbols referenced by the ASTs, so they have a valid info. Therefore the backend often invokes info.get (which asserts the info to exist) when reading data from the ClassBType.

    The inliner on the other hand uses ClassBTypes that are built from classfiles, which may have a missing info. In order not to crash the compiler unnecessarily, the inliner does not force infos using get, but it reports inliner warnings for missing infos that prevent inlining.

    Definition Classes
    BTypes
  4. final case class ClassInfo (superClass: Option[ClassBType], interfaces: List[ClassBType], flags: Int, nestedClasses: List[ClassBType], nestedInfo: Option[NestedInfo], inlineInfo: InlineInfo) extends Product with Serializable

    The type info for a class.

    The type info for a class. Used for symboltable-independent subtype checks in the backend.

    superClass

    The super class, not defined for class java/lang/Object.

    interfaces

    All transitively implemented interfaces, except for those inherited through the superclass.

    flags

    The java flags, obtained through javaFlags. Used also to derive the flags for InnerClass entries.

    nestedClasses

    Classes nested in this class. Those need to be added to the InnerClass table, see the InnerClass spec summary above.

    nestedInfo

    If this describes a nested class, information for the InnerClass table.

    inlineInfo

    Information about this class for the inliner.

    Definition Classes
    BTypes
  5. final case class InnerClassEntry (name: String, outerName: String, innerName: String, flags: Int) extends Product with Serializable

    This class holds the data for an entry in the InnerClass table.

    This class holds the data for an entry in the InnerClass table. See the InnerClass summary above in this file.

    There's some overlap with the class NestedInfo, but it's not exactly the same and cleaner to keep separate.

    name

    The internal name of the class.

    outerName

    The internal name of the outer class, may be null.

    innerName

    The simple name of the inner class, may be null.

    flags

    The flags for this class in the InnerClass entry.

    Definition Classes
    BTypes
  6. final case class MethodBType (argumentTypes: List[BType], returnType: BType) extends BType with Product with Serializable
    Definition Classes
    BTypes
  7. final case class MethodNameAndType (name: String, methodType: MethodBType) extends Product with Serializable

    Just a named pair, used in CoreBTypes.srBoxesRuntimeBoxToMethods/srBoxesRuntimeUnboxToMethods.

    Just a named pair, used in CoreBTypes.srBoxesRuntimeBoxToMethods/srBoxesRuntimeUnboxToMethods.

    Definition Classes
    BTypes
  8. final case class NestedInfo (enclosingClass: ClassBType, outerName: Option[String], innerName: Option[String], isStaticNestedClass: Boolean) extends Product with Serializable

    Information required to add a class to an InnerClass table.

    Information required to add a class to an InnerClass table. The spec summary above explains what information is required for the InnerClass entry.

    enclosingClass

    The enclosing class, if it is also nested. When adding a class to the InnerClass table, enclosing nested classes are also added.

    outerName

    The outerName field in the InnerClass entry, may be None.

    innerName

    The innerName field, may be None.

    isStaticNestedClass

    True if this is a static nested class (not inner class) (*) (*) Note that the STATIC flag in ClassInfo.flags, obtained through javaFlags(classSym), is not correct for the InnerClass entry, see javaFlags. The static flag in the InnerClass describes a source-level property: if the class is in a static context (does not have an outer pointer). This is checked when building the NestedInfo.

    Definition Classes
    BTypes
  9. sealed trait PrimitiveBType extends BType
    Definition Classes
    BTypes
  10. sealed trait RefBType extends BType
    Definition Classes
    BTypes

Value Members

  1. object BOOL extends PrimitiveBType with Product with Serializable
    Definition Classes
    BTypes
  2. object BYTE extends PrimitiveBType with Product with Serializable
    Definition Classes
    BTypes
  3. object CHAR extends PrimitiveBType with Product with Serializable
    Definition Classes
    BTypes
  4. object ClassBType extends Serializable
    Definition Classes
    BTypes
  5. object DOUBLE extends PrimitiveBType with Product with Serializable
    Definition Classes
    BTypes
  6. object FLOAT extends PrimitiveBType with Product with Serializable
    Definition Classes
    BTypes
  7. object INT extends PrimitiveBType with Product with Serializable
    Definition Classes
    BTypes
  8. object LONG extends PrimitiveBType with Product with Serializable
    Definition Classes
    BTypes
  9. object SHORT extends PrimitiveBType with Product with Serializable
    Definition Classes
    BTypes
  10. object UNIT extends PrimitiveBType with Product with Serializable
    Definition Classes
    BTypes
  11. final def !=(arg0: Any): Boolean

    Test two objects for inequality.

    Test two objects for inequality.

    returns

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

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

    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
  13. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from BTypesFromSymbols[G] to any2stringadd[BTypesFromSymbols[G]] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  14. def ->[B](y: B): (BTypesFromSymbols[G], B)
    Implicit
    This member is added by an implicit conversion from BTypesFromSymbols[G] to ArrowAssoc[BTypesFromSymbols[G]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  15. final def ==(arg0: Any): Boolean

    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
  16. final def asInstanceOf[T0]: T0

    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.

  17. def assertClassNotArray(sym: G.Symbol): Unit
  18. def assertClassNotArrayNotPrimitive(sym: G.Symbol): Unit
  19. def bTypeForDescriptorOrInternalNameFromClassfile(desc: String): BType

    Obtain the BType for a type descriptor or internal name.

    Obtain the BType for a type descriptor or internal name. For class descriptors, the ClassBType is constructed by parsing the corresponding classfile.

    Some JVM operations use either a full descriptor or only an internal name. Example: ANEWARRAY java/lang/String // a new array of strings (internal name for the String class) ANEWARRAY [Ljava/lang/String; // a new array of array of string (full descriptor for the String class)

    This method supports both descriptors and internal names.

    Definition Classes
    BTypes
  20. val backendReporting: BackendReporting
    Definition Classes
    BTypesFromSymbols → BTypes
  21. val backendUtils: BackendUtils[BTypesFromSymbols.this.type]
    Definition Classes
    BTypesFromSymbols → BTypes
  22. def beanInfoClassClassBType(mainClass: G.Symbol): ClassBType
  23. def bootstrapMethodArg(t: G.Constant, pos: G.Position): AnyRef
  24. val byteCodeRepository: ByteCodeRepository[BTypesFromSymbols.this.type]

    Tools for parsing classfiles, used by the inliner.

    Tools for parsing classfiles, used by the inliner.

    Definition Classes
    BTypesFromSymbols → BTypes
  25. val callGraph: CallGraph[BTypesFromSymbols.this.type]
    Definition Classes
    BTypesFromSymbols → BTypes
  26. val callsitePositions: Map[MethodInsnNode, Position]

    Store the position of every MethodInsnNode during code generation.

    Store the position of every MethodInsnNode during code generation. This allows each callsite in the call graph to remember its source position, which is required for inliner warnings.

    Definition Classes
    BTypes
  27. def classBTypeFromClassNode(classNode: ClassNode): ClassBType

    Construct the ClassBType for a parsed classfile.

    Construct the ClassBType for a parsed classfile.

    Definition Classes
    BTypes
  28. val classBTypeFromInternalName: Map[InternalName, ClassBType]

    A map from internal names to ClassBTypes.

    A map from internal names to ClassBTypes. Every ClassBType is added to this map on its construction.

    This map is used when computing stack map frames. The asm.ClassWriter invokes the method getCommonSuperClass. In this method we need to obtain the ClassBType for a given internal name. The method assumes that every class type that appears in the bytecode exists in the map.

    Concurrent because stack map frames are computed when in the class writer, which might run on multiple classes concurrently.

    Definition Classes
    BTypes
  29. def classBTypeFromParsedClassfile(internalName: InternalName): ClassBType

    Parse the classfile for internalName and construct the ClassBType.

    Parse the classfile for internalName and construct the ClassBType. If the classfile cannot be found in the byteCodeRepository, the info of the resulting ClassBType is undefined.

    Definition Classes
    BTypes
  30. final def classBTypeFromSymbol(classSym: G.Symbol): ClassBType

    The ClassBType for a class symbol classSym.

    The ClassBType for a class symbol classSym.

    The class symbol scala.Nothing is mapped to the class scala.runtime.Nothing$. Similarly, scala.Null is mapped to scala.runtime.Null$. This is because there exist no class files for the Nothing / Null. If used for example as a parameter type, we use the runtime classes in the classfile method signature.

    Note that the referenced class symbol may be an implementation class. For example when compiling a mixed-in method that forwards to the static method in the implementation class, the class descriptor of the receiver (the implementation class) is obtained by creating the ClassBType.

  31. def clone(): AnyRef

    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

  32. val closureOptimizer: ClosureOptimizer[BTypesFromSymbols.this.type]
    Definition Classes
    BTypesFromSymbols → BTypes
  33. def compilerSettings: ScalaSettings
    Definition Classes
    BTypesFromSymbols → BTypes
  34. val coreBTypes: CoreBTypesProxy[BTypesFromSymbols.this.type]
    Definition Classes
    BTypesFromSymbols → BTypes
  35. def ensuring(cond: (BTypesFromSymbols[G]) ⇒ Boolean, msg: ⇒ Any): BTypesFromSymbols[G]
    Implicit
    This member is added by an implicit conversion from BTypesFromSymbols[G] to Ensuring[BTypesFromSymbols[G]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  36. def ensuring(cond: (BTypesFromSymbols[G]) ⇒ Boolean): BTypesFromSymbols[G]
    Implicit
    This member is added by an implicit conversion from BTypesFromSymbols[G] to Ensuring[BTypesFromSymbols[G]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  37. def ensuring(cond: Boolean, msg: ⇒ Any): BTypesFromSymbols[G]
    Implicit
    This member is added by an implicit conversion from BTypesFromSymbols[G] to Ensuring[BTypesFromSymbols[G]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  38. def ensuring(cond: Boolean): BTypesFromSymbols[G]
    Implicit
    This member is added by an implicit conversion from BTypesFromSymbols[G] to Ensuring[BTypesFromSymbols[G]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  39. final def eq(arg0: AnyRef): Boolean

    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
  40. def equals(arg0: Any): Boolean

    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
  41. def finalize(): Unit

    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

  42. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from BTypesFromSymbols[G] to StringFormat[BTypesFromSymbols[G]] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  43. final def getClass(): Class[_]

    Returns the runtime class representation of the object.

    Returns the runtime class representation of the object.

    returns

    a class object corresponding to the runtime type of the receiver.

    Definition Classes
    AnyRef → Any
  44. val global: G
  45. final def hasPublicBitSet(flags: Int): Boolean
  46. def hashCode(): Int

    The hashCode method for reference types.

    The hashCode method for reference types. See hashCode in scala.Any.

    returns

    the hash code value for this object.

    Definition Classes
    AnyRef → Any
  47. def implementedInterfaces(classSym: G.Symbol): List[G.Symbol]
  48. val indyLambdaHosts: Set[InternalName]

    Classes with indyLambda closure instantiations where the SAM type is serializable (e.g.

    Classes with indyLambda closure instantiations where the SAM type is serializable (e.g. Scala's FunctionN) need a $deserializeLambda$ method. This map contains classes for which such a method has been generated. It is used during ordinary code generation, as well as during inlining: when inlining an indyLambda instruction into a class, we need to make sure the class has the method.

    Definition Classes
    BTypes
  49. final def initializeCoreBTypes(): Unit
  50. val inlineAnnotatedCallsites: Set[MethodInsnNode]

    Stores callsite instructions of invocatinos annotated f(): @inline/noinline.

    Stores callsite instructions of invocatinos annotated f(): @inline/noinline. Instructions are added during code generation (BCodeBodyBuilder). The maps are then queried when building the CallGraph, every Callsite object has an annotated(No)Inline field.

    Definition Classes
    BTypes
  51. def inlineInfoFromClassfile(classNode: ClassNode): InlineInfo

    Build the InlineInfo for a class.

    Build the InlineInfo for a class. For Scala classes, the information is stored in the ScalaInlineInfo attribute. If the attribute is missing, the InlineInfo is built using the metadata available in the classfile (ACC_FINAL flags, etc).

    Definition Classes
    BTypes
  52. val inliner: Inliner[BTypesFromSymbols.this.type]
    Definition Classes
    BTypesFromSymbols → BTypes
  53. val inlinerHeuristics: InlinerHeuristics[BTypesFromSymbols.this.type]
    Definition Classes
    BTypesFromSymbols → BTypes
  54. def isCompilingArray: Boolean
  55. def isCompilingPrimitive: Boolean

    True if the current compilation unit is of a primitive class (scala.Boolean et al).

    True if the current compilation unit is of a primitive class (scala.Boolean et al). Used only in assertions.

    Definition Classes
    BTypesFromSymbols → BTypes
  56. final def isInstanceOf[T0]: Boolean

    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
  57. final def isRemote(s: G.Symbol): Boolean
  58. final def isStaticModuleClass(sym: G.Symbol): Boolean

    True for module classes of modules that are top-level or owned only by objects.

    True for module classes of modules that are top-level or owned only by objects. Module classes for such objects will get a MODULE$ flag and a corresponding static initializer.

  59. final def isTopLevelModuleClass(sym: G.Symbol): Boolean

    True for module classes of package level objects.

    True for module classes of package level objects. The backend will generate a mirror class for such objects.

  60. val javaDefinedClasses: Set[InternalName]

    Contains the internal names of all classes that are defined in Java source files of the current compilation run (mixed compilation).

    Contains the internal names of all classes that are defined in Java source files of the current compilation run (mixed compilation). Used for more detailed error reporting.

    Definition Classes
    BTypes
  61. def javaFieldFlags(sym: G.Symbol): Int
  62. final def javaFlags(sym: G.Symbol): Int

    Return the Java modifiers for the given symbol.

    Return the Java modifiers for the given symbol. Java modifiers for classes:

    • public, abstract, final, strictfp (not used) for interfaces:
    • the same as for classes, without 'final' for fields:
    • public, private (*)
    • static, final for methods:
    • the same as for fields, plus:
    • abstract, synchronized (not used), strictfp (not used), native (not used) for all:
    • deprecated

    (*) protected cannot be used, since inner classes 'see' protected members, and they would fail verification after lifted.

  63. val localOpt: LocalOpt[BTypesFromSymbols.this.type]
    Definition Classes
    BTypesFromSymbols → BTypes
  64. val maxLocalsMaxStackComputed: Set[MethodNode]

    Cache of methods which have correct maxLocals / maxStack values assigned.

    Cache of methods which have correct maxLocals / maxStack values assigned. This allows invoking computeMaxLocalsMaxStack whenever running an analyzer but performing the actual computation only when necessary.

    Definition Classes
    BTypes
  65. final def methodBTypeFromMethodType(tpe: G.Type, isConstructor: Boolean): MethodBType

    Builds a MethodBType for a method type.

  66. final def methodBTypeFromSymbol(methodSymbol: G.Symbol): MethodBType

    Builds a MethodBType for a method symbol.

  67. def mirrorClassClassBType(moduleClassSym: G.Symbol): ClassBType

    For top-level objects without a companion class, the compiler generates a mirror class with static forwarders (Java compat).

    For top-level objects without a companion class, the compiler generates a mirror class with static forwarders (Java compat). There's no symbol for the mirror class, but we still need a ClassBType (its info.nestedClasses will hold the InnerClass entries, see comment in BTypes).

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

    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
  69. val noInlineAnnotatedCallsites: Set[MethodInsnNode]
    Definition Classes
    BTypes
  70. final def notify(): Unit

    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

  71. final def notifyAll(): Unit

    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

  72. def recordPerRunCache[T <: Clearable](cache: T): T
    Definition Classes
    BTypesFromSymbols → BTypes
  73. def staticHandleFromSymbol(sym: G.Symbol): Handle
  74. final val strMODULE_INSTANCE_FIELD: String
  75. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  76. def toString(): String

    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
  77. final def typeToBType(t: G.Type): BType

    This method returns the BType for a type reference, for example a parameter type.

    This method returns the BType for a type reference, for example a parameter type.

    If t references a class, typeToBType ensures that the class is not an implementation class. See also comment on classBTypeFromSymbol, which is invoked for implementation classes.

  78. val unreachableCodeEliminated: Set[MethodNode]

    Cache, contains methods whose unreachable instructions are eliminated.

    Cache, contains methods whose unreachable instructions are eliminated.

    The ASM Analyzer class does not compute any frame information for unreachable instructions. Transformations that use an analyzer (including inlining) therefore require unreachable code to be eliminated.

    This cache allows running dead code elimination whenever an analyzer is used. If the method is already optimized, DCE can return early.

    Definition Classes
    BTypes
  79. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  80. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  81. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  82. def →[B](y: B): (BTypesFromSymbols[G], B)
    Implicit
    This member is added by an implicit conversion from BTypesFromSymbols[G] to ArrowAssoc[BTypesFromSymbols[G]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Inherited from BTypes

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from BTypesFromSymbols[G] to any2stringadd[BTypesFromSymbols[G]]

Inherited by implicit conversion StringFormat from BTypesFromSymbols[G] to StringFormat[BTypesFromSymbols[G]]

Inherited by implicit conversion Ensuring from BTypesFromSymbols[G] to Ensuring[BTypesFromSymbols[G]]

Inherited by implicit conversion ArrowAssoc from BTypesFromSymbols[G] to ArrowAssoc[BTypesFromSymbols[G]]

Ungrouped