abstract class SpecializeTypes extends SubComponent with InfoTransform with TypingTransformers
Specialize code on types.
Make sure you've read the thesis:
Iulian Dragos: Compiling Scala for Performance (chapter 4)
There are some things worth noting, (possibly) not mentioned there:
0) Make sure you understand the meaning of various SpecializedInfo
descriptors
defined below.
1) Specializing traits by introducing bridges in specialized methods
of the specialized trait may introduce problems during mixin composition.
Concretely, it may cause cyclic calls and result in a stack overflow.
See ticket #4351.
This was solved by introducing an Abstract
specialized info descriptor.
Instead of generating a bridge in the trait, an abstract method is generated.
2) Specialized private members sometimes have to be switched to protected. In some cases, even this is not enough. Example:
class A[@specialized T](protected val d: T) { def foo(that: A[T]) = that.d }
Specialization will generate a specialized class and a specialized method:
class A$mcI$sp(protected val d: Int) extends A[Int] { def foo(that: A[Int]) = foo$mcI$sp(that) def foo(that: A[Int]) = that.d }
Above, A$mcI$sp
cannot access d
, so the method cannot be typechecked.
- Source
- SpecializeTypes.scala
- Alphabetic
- By Inheritance
- SpecializeTypes
- TypingTransformers
- InfoTransform
- Transform
- SubComponent
- AnyRef
- Any
- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
- Hide All
- Show All
- Public
- Protected
Instance Constructors
- new SpecializeTypes()
Type Members
- abstract class StdPhase extends GlobalPhase
A standard phase template
A standard phase template
- Definition Classes
- SubComponent
- class Phase extends InfoTransform.Phase
- Definition Classes
- InfoTransform
- case class Abstract(t: Global.Symbol) extends SpecializedInfo with Product with Serializable
Symbol is a specialized abstract method, either specialized or original.
Symbol is a specialized abstract method, either specialized or original. The original
t
is abstract. - class Duplicator extends Duplicators
This duplicator additionally performs casts of expressions if that is allowed by the
casts
map. - case class Forward(t: Global.Symbol) extends SpecializedInfo with Product with Serializable
Symbol is a method that should be forwarded to 't'
- case class Implementation(target: Global.Symbol) extends SpecializedInfo with Product with Serializable
Symbol is a specialized method whose body should be the target's method body.
- class ImplementationAdapter extends Global.TreeSymSubstituter
A tree symbol substituter that substitutes on type skolems.
A tree symbol substituter that substitutes on type skolems. If a type parameter is a skolem, it looks for the original symbol in the 'from' and maps it to the corresponding new symbol. The new symbol should probably be a type skolem as well (not enforced).
All private members are made protected in order to be accessible from specialized classes.
- case class NormalizedMember(target: Global.Symbol) extends SpecializedInfo with Product with Serializable
Symbol is a normalized member obtained by specializing 'target'.
- case class Overload(sym: Global.Symbol, env: TypeEnv) extends Product with Serializable
- case class SpecialOverload(original: Global.Symbol, env: TypeEnv) extends SpecializedInfo with Product with Serializable
Symbol is a special overloaded method of 'original', in the environment env.
- case class SpecialOverride(target: Global.Symbol) extends SpecializedInfo with Product with Serializable
Symbol is a specialized override paired with
target
. - case class SpecialSuperAccessor(t: Global.Symbol) extends SpecializedInfo with Product with Serializable
Symbol is a special overload of the super accessor.
Symbol is a special overload of the super accessor. Treated like an abstract method with no specialized overload.
- class SpecializationDuplicator extends Duplicator
Introduced to fix scala/bug#7343: Phase ordering problem between Duplicators and Specialization.
Introduced to fix scala/bug#7343: Phase ordering problem between Duplicators and Specialization. brief explanation: specialization rewires class parents during info transformation, and the new info then guides the tree changes. But if a symbol is created during duplication, which runs after specialization, its info is not visited and thus the corresponding tree is not specialized. One manifestation is the following:
object Test { class Parent[@specialized(Int) T] def spec_method[@specialized(Int) T](t: T, expectedXSuper: String) = { class X extends Parent[T]() // even in the specialized variant, the local X class // doesn't extend Parent$mcI$sp, since its symbol has // been created after specialization and was not seen // by specialization's info transformer. ... } }
We fix this by forcing duplication to take place before specialization.
Note: The constructors phase (which also uses duplication) comes after erasure and uses the post-erasure typer => we must protect it from the beforeSpecialization phase shifting.
- class SpecializationPhase extends Phase
- class SpecializationTransformer extends TypingTransformer
- case class SpecializedAccessor(target: Global.Symbol) extends SpecializedInfo with Product with Serializable
Symbol is a specialized accessor for the
target
field. - abstract class SpecializedInfo extends AnyRef
- case class SpecializedInnerClass(target: Global.Symbol, env: TypeEnv) extends SpecializedInfo with Product with Serializable
A specialized inner class that specializes original inner class
target
on a type parameter of the enclosing class, in the typeenvenv
. - type TypeEnv = Map[Global.Symbol, Global.Type]
- abstract class TypingTransformer extends Global.Transformer
- Definition Classes
- TypingTransformers
Abstract Value Members
- abstract val global: Global
- Definition Classes
- TypingTransformers
- 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
- 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
- final def !=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- final def ##: Int
- Definition Classes
- AnyRef → Any
- def +(other: String): String
- Implicit
- This member is added by an implicit conversion from SpecializeTypes toany2stringadd[SpecializeTypes] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
- def ->[B](y: B): (SpecializeTypes, B)
- Implicit
- This member is added by an implicit conversion from SpecializeTypes toArrowAssoc[SpecializeTypes] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
- final def ==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- def addConcreteSpecMethod(m: Global.Symbol): Unit
Add method m to the set of symbols for which we need an implementation tree in the tree transformer.
Add method m to the set of symbols for which we need an implementation tree in the tree transformer.
- Note
This field is part of the specializeTypes subcomponent, so any symbols that here are not garbage collected at the end of a compiler run!
- final def afterOwnPhase[T](op: => T): T
- Definition Classes
- SubComponent
- Annotations
- @inline()
- final def asInstanceOf[T0]: T0
- Definition Classes
- Any
- final def beforeOwnPhase[T](op: => T): T
- Definition Classes
- SubComponent
- Annotations
- @inline()
- def changesBaseClasses: Boolean
This phase changes base classes.
This phase changes base classes.
- Definition Classes
- SpecializeTypes → InfoTransform
- def clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.CloneNotSupportedException]) @native()
- def concreteTypes(sym: Global.Symbol): List[Global.Type]
Return the types
sym
should be specialized at.Return the types
sym
should be specialized at. This may be some of the primitive types or AnyRef. AnyRef means that a new type parameter T will be generated later, known to be a subtype of AnyRef (T <: AnyRef). These are in a meaningful order for stability purposes. - def emptyEnv: TypeEnv
- def enabled: Boolean
Is this component enabled? Default is true.
Is this component enabled? Default is true.
- Definition Classes
- SubComponent
- def ensuring(cond: (SpecializeTypes) => Boolean, msg: => Any): SpecializeTypes
- Implicit
- This member is added by an implicit conversion from SpecializeTypes toEnsuring[SpecializeTypes] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: (SpecializeTypes) => Boolean): SpecializeTypes
- Implicit
- This member is added by an implicit conversion from SpecializeTypes toEnsuring[SpecializeTypes] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: Boolean, msg: => Any): SpecializeTypes
- Implicit
- This member is added by an implicit conversion from SpecializeTypes toEnsuring[SpecializeTypes] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: Boolean): SpecializeTypes
- Implicit
- This member is added by an implicit conversion from SpecializeTypes toEnsuring[SpecializeTypes] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- final def eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- def equals(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef → Any
- def finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.Throwable])
- def formatted(fmtstr: String): String
- Implicit
- This member is added by an implicit conversion from SpecializeTypes toStringFormat[SpecializeTypes] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
- final def getClass(): Class[_ <: AnyRef]
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
- def hasSpecializedParams(clazz: Global.Symbol): Boolean
Has
clazz
any type parameters that need be specialized? - 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
- def illegalSpecializedInheritance(clazz: Global.Symbol): Boolean
- 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
- 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
- final def isInstanceOf[T0]: Boolean
- Definition Classes
- Any
- def isNormalizedMember(m: Global.Symbol): Boolean
- def isSpecializedIn(sym: Global.Symbol, site: Global.Type): Boolean
Refines possiblySpecialized taking into account the instantiation of the specialized type variables at
site
- def keepsTypeParams: Boolean
- Definition Classes
- SpecializeTypes → InfoTransform
- final def ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- def newPhase(prev: nsc.Phase): StdPhase
Just to mark uncheckable
Just to mark uncheckable
- Definition Classes
- SpecializeTypes → InfoTransform → Transform → SubComponent
- def newTransformer(unit: Global.CompilationUnit): Global.Transformer
The transformer factory
The transformer factory
- Attributes
- protected
- Definition Classes
- SpecializeTypes → Transform
- def nonConflicting(env: TypeEnv): Boolean
Is any type variable in
env
conflicting with any if its type bounds, when type bindings inenv
are taken into account?Is any type variable in
env
conflicting with any if its type bounds, when type bindings inenv
are taken into account?A conflicting type environment could still be satisfiable.
- final def notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
- final def notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
- def originalClass(clazz: Global.Symbol): Global.Symbol
Return the generic class corresponding to this specialized class.
- def ownPhase: nsc.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
- val phaseName: String
the name of the phase:
the name of the phase:
- Definition Classes
- SpecializeTypes → SubComponent
- def phaseNewFlags: Long
The following flags may be set by this phase:
The following flags may be set by this phase:
- Definition Classes
- SpecializeTypes → SubComponent
- 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
- def possiblySpecialized(sym: Global.Symbol): Boolean
Is
member
potentially affected by specialization? This is a gross overapproximation, but it should be okay for use outside of specialization. - def produceTypeParameters(syms: List[Global.Symbol], nowner: Global.Symbol, env: TypeEnv): collection.immutable.List[Global.Symbol]
Produces the symbols from type parameters
syms
of the original owner, in the given type environmentenv
.Produces the symbols from type parameters
syms
of the original owner, in the given type environmentenv
. The new owner isnowner
.Non-specialized type parameters are cloned into new ones. Type parameters specialized on AnyRef have preexisting symbols.
For instance, a @specialized(AnyRef) T, will become T$sp <: AnyRef.
- val requires: List[String]
Names of phases required by this component.
Names of phases required by this component. Default is
Nil
.- Definition Classes
- SubComponent
- 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
- def satisfiabilityConstraints(env: TypeEnv): Option[TypeEnv]
- def satisfiable(env: TypeEnv, warnings: Boolean): Boolean
- def satisfiable(env: TypeEnv): Boolean
The type environment is sound w.r.t.
The type environment is sound w.r.t. to all type bounds or only soft conflicts appear. An environment is sound if all bindings are within the bounds of the given type variable. A soft conflict is a binding that does not fall within the bounds, but whose bounds contain type variables that are @specialized, (that could become satisfiable).
- def specializeClass(clazz: Global.Symbol, outerEnv: TypeEnv): List[Global.Symbol]
Specialize 'clazz', in the environment
outerEnv
.Specialize 'clazz', in the environment
outerEnv
. The outer environment contains bindings for specialized types of enclosing classes.A class C is specialized w.r.t to its own specialized type params
stps
, by specializing its members, and creating a new class for each combination ofstps
. - val specializedClass: AnyRefMap[Global.Symbol, AnyRefMap[TypeEnv, Global.Symbol]]
For a given class and concrete type arguments, give its specialized class
- def specializedFunctionName(sym: Global.Symbol, args: List[Global.Type]): reflect.internal.Symbols.Symbol.NameType
- def specializedParams(sym: Global.Symbol): List[Global.Symbol]
Return specialized type parameters.
- val specializedType: Global.TypeMap
- def specializedTypeVars(tpe: Global.Type): Set[Global.Symbol]
Return the set of @specialized type variables mentioned by the given type.
Return the set of @specialized type variables mentioned by the given type. It only counts type variables that appear:
- naked
- as arguments to type constructors in @specialized positions (arrays are considered as Array[@specialized T])
- def specializedTypeVars(sym: Global.Symbol): Set[Global.Symbol]
- def specializedTypeVars(tpes: List[Global.Type]): Set[Global.Symbol]
- def specializedTypeVarsBuffer(tpe: Global.Type, result: Buffer[Global.Symbol]): Unit
Return the set of @specialized type variables mentioned by the given type.
Return the set of @specialized type variables mentioned by the given type. It only counts type variables that appear:
- naked
- as arguments to type constructors in @specialized positions (arrays are considered as Array[@specialized T])
- def specializedTypeVarsBuffer(sym: Global.Symbol, result: Buffer[Global.Symbol]): Unit
- def specializesClass(sym: Global.Symbol): Global.Symbol
If the symbol is the companion of a value class, the value class.
If the symbol is the companion of a value class, the value class. Otherwise, AnyRef.
- def survivingArgs(sym: Global.Symbol, args: List[Global.Type]): List[Global.Type]
Given an original class symbol and a list of types its type parameters are instantiated at returns a list of type parameters that should remain in the TypeRef when instantiating a specialized type.
- def survivingParams(params: List[Global.Symbol], env: TypeEnv): collection.immutable.List[Global.Symbol]
Type parameters that survive when specializing in the specified environment.
- final def synchronized[T0](arg0: => T0): T0
- Definition Classes
- AnyRef
- 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
- def toString(): String
- Definition Classes
- AnyRef → Any
- def transformInfo(sym: Global.Symbol, tpe: Global.Type): Global.Type
Type transformation.
Type transformation. It is applied to all symbols, compiled or loaded. If it is a 'no-specialization' run, it is applied only to loaded symbols.
- Definition Classes
- SpecializeTypes → InfoTransform
- final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException]) @native()
- object SpecializedSuperConstructorCallArgument
- object TypeEnv
- case object UnifyError extends ControlThrowable with Product with Serializable
Deprecated Value Members
- def →[B](y: B): (SpecializeTypes, B)
- Implicit
- This member is added by an implicit conversion from SpecializeTypes toArrowAssoc[SpecializeTypes] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use
->
instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.
The Scala compiler and reflection APIs.