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|
/* NSC -- new Scala compiler
* Copyright 2005-2010 LAMP/EPFL
* @author Martin Odersky
*/
// $Id$
package scala.tools.nsc
package backend
package icode
import scala.tools.nsc.ast._
import scala.tools.nsc.util.{Position,NoPosition}
/*
A pattern match
case THIS(clasz) =>
case CONSTANT(const) =>
case LOAD_ARRAY_ITEM(kind) =>
case LOAD_LOCAL(local) =>
case LOAD_FIELD(field, isStatic) =>
case LOAD_MODULE(module) =>
case STORE_ARRAY_ITEM(kind) =>
case STORE_LOCAL(local) =>
case STORE_FIELD(field, isStatic) =>
case CALL_PRIMITIVE(primitive) =>
case CALL_METHOD(method, style) =>
case NEW(kind) =>
case CREATE_ARRAY(elem, dims) =>
case IS_INSTANCE(tpe) =>
case CHECK_CAST(tpe) =>
case SWITCH(tags, labels) =>
case JUMP(whereto) =>
case CJUMP(success, failure, cond, kind) =>
case CZJUMP(success, failure, cond, kind) =>
case RETURN(kind) =>
case THROW() =>
case DROP(kind) =>
case DUP(kind) =>
case MONITOR_ENTER() =>
case MONITOR_EXIT() =>
case SCOPE_ENTER(lv) =>
case SCOPE_EXIT(lv) =>
case LOAD_EXCEPTION() =>
*/
/**
* The ICode intermediate representation. It is a stack-based
* representation, very close to the JVM and .NET. It uses the
* erased types of Scala and references Symbols to refer named entities
* in the source files.
*/
trait Opcodes { self: ICodes =>
import global.{Symbol, NoSymbol, Type, Name, Constant};
/** This class represents an instruction of the intermediate code.
* Each case subclass will represent a specific operation.
*/
abstract class Instruction extends Cloneable {
/** This abstract method returns the number of used elements on the stack */
def consumed : Int = 0
/** This abstract method returns the number of produced elements on the stack */
def produced : Int = 0
/** This instruction consumes these types from the top of the stack, the first
* element in the list is the deepest element on the stack.
*/
def consumedTypes: List[TypeKind] = Nil
/** This instruction produces these types on top of the stack. */
def producedTypes: List[TypeKind] = Nil
/** This method returns the difference of size of the stack when the instruction is used */
def difference = produced-consumed
/** The corresponding position in the source file */
private var _pos: Position = NoPosition
def pos: Position = _pos
/** Used by dead code elimination. */
var useful: Boolean = false
def setPos(p: Position): this.type = {
_pos = p
this
}
/** Clone this instruction. */
override def clone: Instruction =
super.clone.asInstanceOf[Instruction]
}
object opcodes {
def mayThrow(i: Instruction): Boolean = i match {
case LOAD_LOCAL(_) | STORE_LOCAL(_) | CONSTANT(_) | THIS(_) | CZJUMP(_, _, _, _)
| DROP(_) | DUP(_) | RETURN(_) | LOAD_EXCEPTION() | JUMP(_) | CJUMP(_, _, _, _) => false
case _ => true
}
/** Loads "this" on top of the stack.
* Stack: ...
* ->: ...:ref
*/
case class THIS(clasz: Symbol) extends Instruction {
/** Returns a string representation of this constant */
override def toString(): String = "THIS"
override def consumed = 0
override def produced = 1
override def producedTypes = List(REFERENCE(clasz))
}
/** Loads a constant on the stack.
* Stack: ...
* ->: ...:constant
*/
case class CONSTANT(constant: Constant) extends Instruction {
/** Returns a string representation of this constant */
override def toString(): String = "CONSTANT ("+constant.toString()+")"
override def consumed = 0
override def produced = 1
override def producedTypes = List(toTypeKind(constant.tpe))
}
/** Loads an element of an array. The array and the index should
* be on top of the stack.
* Stack: ...:array[a](Ref):index(Int)
* ->: ...:element(a)
*/
case class LOAD_ARRAY_ITEM(kind: TypeKind) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String = "LOAD_ARRAY_ITEM (" + kind + ")"
override def consumed = 2
override def produced = 1
override def consumedTypes = List(ARRAY(kind), INT)
override def producedTypes = List(kind)
}
/** Load a local variable on the stack. It can be a method argument.
* Stack: ...
* ->: ...:value
*/
case class LOAD_LOCAL(local: Local) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String = "LOAD_LOCAL "+local.toString() //+isArgument?" (argument)":"";
override def consumed = 0
override def produced = 1
override def producedTypes = List(local.kind)
}
/** Load a field on the stack. The object to which it refers should be
* on the stack.
* Stack: ...:ref (assuming isStatic = false)
* ->: ...:value
*/
case class LOAD_FIELD(field: Symbol, isStatic: Boolean) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String =
"LOAD_FIELD " + (if (isStatic) field.fullName else field.toString());
override def consumed = if (isStatic) 0 else 1
override def produced = 1
override def consumedTypes = if (isStatic) Nil else List(REFERENCE(field.owner));
override def producedTypes = List(toTypeKind(field.tpe));
}
case class LOAD_MODULE(module: Symbol) extends Instruction {
assert(module != NoSymbol,
"Invalid module symbol");
/** Returns a string representation of this instruction */
override def toString(): String =
"LOAD_MODULE " + module.toString()
override def consumed = 0
override def produced = 1
override def producedTypes = List(REFERENCE(module))
}
/** Store a value into an array at a specified index.
* Stack: ...:array[a](Ref):index(Int):value(a)
* ->: ...
*/
case class STORE_ARRAY_ITEM(kind: TypeKind) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String = "STORE_ARRAY_ITEM (" + kind + ")"
override def consumed = 3
override def produced = 0
override def consumedTypes = List(ARRAY(kind), INT, kind)
}
/** Store a value into a local variable. It can be an argument.
* Stack: ...:value
* ->: ...
*/
case class STORE_LOCAL(local: Local) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String = "STORE_LOCAL "+local.toString(); //+isArgument?" (argument)":"";
override def consumed = 1
override def produced = 0
override def consumedTypes = List(local.kind)
}
/** Store a value into a field.
* Stack: ...:ref:value (assuming isStatic=false)
* ->: ...
*/
case class STORE_FIELD(field: Symbol, isStatic: Boolean) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String =
"STORE_FIELD "+field.toString() + (if (isStatic) " (static)" else " (dynamic)");
override def consumed = if(isStatic) 1 else 2;
override def produced = 0;
override def consumedTypes =
if (isStatic)
List(toTypeKind(field.tpe))
else
List(REFERENCE(field.owner), toTypeKind(field.tpe));
}
/** Store a value into the 'this' pointer.
* Stack: ...:ref
* ->: ...
*/
case class STORE_THIS(kind: TypeKind) extends Instruction {
override def toString() = "STORE_THIS(" + kind + ")"
override def consumed = 1
override def produced = 0
override def consumedTypes = List(kind)
}
/** Call a primitive function.
* Stack: ...:arg1:arg2:...:argn
* ->: ...:result
*/
case class CALL_PRIMITIVE(primitive: Primitive) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="CALL_PRIMITIVE "+primitive.toString()
override def consumed = primitive match {
case Negation(_) => 1
case Test(_,_, true) => 1
case Test(_,_, false) => 2
case Comparison(_,_) => 2
case Arithmetic(NOT,_) => 1
case Arithmetic(_,_) => 2
case Logical(_,_) => 2
case Shift(_,_) => 2
case Conversion(_,_) => 1
case ArrayLength(_) => 1
case StringConcat(_) => 2
case StartConcat => 0
case EndConcat => 1
}
override def produced = 1
override def consumedTypes = primitive match {
case Negation(kind) => List(kind)
case Test(_, kind, true) => List(kind)
case Test(_, kind, false) => List(kind, kind)
case Comparison(_, kind) => List(kind, kind)
case Arithmetic(NOT, kind) => List(kind)
case Arithmetic(_, kind) => List(kind, kind)
case Logical(_, kind) => List(kind, kind)
case Shift(_, kind) => List(kind, INT)
case Conversion(from, _) => List(from)
case ArrayLength(kind) => List(ARRAY(kind))
case StringConcat(kind) => List(ConcatClass, kind)
case StartConcat => Nil
case EndConcat => List(ConcatClass)
}
override def producedTypes = primitive match {
case Negation(kind) => List(kind)
case Test(_, _, true) => List(BOOL)
case Test(_, _, false) => List(BOOL)
case Comparison(_, _) => List(INT)
case Arithmetic(_, kind) => List(kind)
case Logical(_, kind) => List(kind)
case Shift(_, kind) => List(kind)
case Conversion(_, to) => List(to)
case ArrayLength(_) => List(INT)
case StringConcat(_) => List(ConcatClass)
case StartConcat => List(ConcatClass)
case EndConcat => List(REFERENCE(global.definitions.StringClass))
}
}
/** This class represents a CALL_METHOD instruction
* STYLE: dynamic / static(StaticInstance)
* Stack: ...:ref:arg1:arg2:...:argn
* ->: ...:result
*
* STYLE: static(StaticClass)
* Stack: ...:arg1:arg2:...:argn
* ->: ...:result
*
*/
case class CALL_METHOD(method: Symbol, style: InvokeStyle) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String =
"CALL_METHOD " + hostClass.fullName + method.fullName +" ("+style.toString()+")";
var hostClass: Symbol = method.owner;
def setHostClass(cls: Symbol): this.type = { hostClass = cls; this }
/** This is specifically for preserving the target native Array type long
* enough that clone() can generate the right call.
*/
var targetTypeKind: TypeKind = UNIT // the default should never be used, so UNIT should fail fast.
def setTargetTypeKind(tk: TypeKind) = targetTypeKind = tk
override def consumed = method.tpe.paramTypes.length + (
style match {
case Dynamic | InvokeDynamic => 1
case Static(true) => 1
case Static(false) => 0
case SuperCall(_) => 1
}
)
override def consumedTypes = {
val args = method.tpe.paramTypes map toTypeKind
style match {
case Dynamic | Static(true) => AnyRefReference :: args
case _ => args
}
}
override def produced =
if(toTypeKind(method.tpe.resultType) == UNIT)
0
else if(method.isConstructor)
0
else 1
/** object identity is equality for CALL_METHODs. Needed for
* being able to store such instructions into maps, when more
* than one CALL_METHOD to the same method might exist.
*/
override def equals(other: Any) = other match {
case o: AnyRef => this eq o
case _ => false
}
}
case class BOX(boxType: TypeKind) extends Instruction {
override def toString(): String = "BOX " + boxType
override def consumed = 1
override def consumedTypes = boxType :: Nil
override def produced = 1
}
case class UNBOX(boxType: TypeKind) extends Instruction {
override def toString(): String = "UNBOX " + boxType
override def consumed = 1
override def consumedTypes = AnyRefReference :: Nil
override def produced = 1
}
/** Create a new instance of a class through the specified constructor
* Stack: ...:arg1:arg2:...:argn
* ->: ...:ref
*/
case class NEW(kind: REFERENCE) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String = "NEW "+ kind;
override def consumed = 0;
override def produced = 1;
/** The corresponding constructor call. */
var init: CALL_METHOD = _
}
/** This class represents a CREATE_ARRAY instruction
* Stack: ...:size_1:size_2:..:size_n
* ->: ...:arrayref
*/
case class CREATE_ARRAY(elem: TypeKind, dims: Int) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="CREATE_ARRAY "+elem.toString() + " x " + dims;
override def consumed = dims;
override def consumedTypes = List.fill(dims)(INT)
override def produced = 1;
}
/** This class represents a IS_INSTANCE instruction
* Stack: ...:ref
* ->: ...:result(boolean)
*/
case class IS_INSTANCE(typ: TypeKind) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="IS_INSTANCE "+typ.toString()
override def consumed = 1
override def consumedTypes = AnyRefReference :: Nil
override def produced = 1
}
/** This class represents a CHECK_CAST instruction
* Stack: ...:ref(oldtype)
* ->: ...:ref(typ <=: oldtype)
*/
case class CHECK_CAST(typ: TypeKind) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="CHECK_CAST "+typ.toString()
override def consumed = 1
override def produced = 1
override val consumedTypes = List(AnyRefReference)
override def producedTypes = List(typ)
}
/** This class represents a SWITCH instruction
* Stack: ...:index(int)
* ->: ...:
*
* The tags array contains one entry per label, each entry consisting of
* an array of ints, any of which will trigger the jump to the corresponding label.
* labels should contain an extra label, which is the 'default' jump.
*/
case class SWITCH(tags: List[List[Int]], labels: List[BasicBlock]) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="SWITCH ..."
override def consumed = 1
override def produced = 0
}
/** This class represents a JUMP instruction
* Stack: ...
* ->: ...
*/
case class JUMP(whereto: BasicBlock) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="JUMP "+whereto.label
override def consumed = 0
override def produced = 0
}
/** This class represents a CJUMP instruction
* It compares the two values on the stack with the 'cond' test operator
* Stack: ...:value1:value2
* ->: ...
*/
case class CJUMP(successBlock: BasicBlock,
failureBlock: BasicBlock,
cond: TestOp,
kind: TypeKind) extends Instruction
{
/** Returns a string representation of this instruction */
override def toString(): String = (
"CJUMP (" + kind + ")" +
cond.toString()+" ? "+successBlock.label+" : "+failureBlock.label
);
override def consumed = 2
override def produced = 0
}
/** This class represents a CZJUMP instruction
* It compares the one value on the stack and zero with the 'cond' test operator
* Stack: ...:value:
* ->: ...
*/
case class CZJUMP(successBlock: BasicBlock,
failureBlock: BasicBlock,
cond: TestOp,
kind: TypeKind) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String = (
"CZJUMP (" + kind + ")" +
cond.toString()+" ? "+successBlock.label+" : "+failureBlock.label
);
override def consumed = 1
override def produced = 0
}
/** This class represents a RETURN instruction
* Stack: ...
* ->: ...
*/
case class RETURN(kind: TypeKind) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="RETURN (" + kind + ")"
override def consumed = if (kind == UNIT) 0 else 1
override def produced = 0
}
/** This class represents a THROW instruction
* Stack: ...:Throwable(Ref)
* ->: ...:
*/
case class THROW() extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="THROW"
override def consumed = 1
override def produced = 0
}
/** This class represents a DROP instruction
* Stack: ...:something
* ->: ...
*/
case class DROP (typ: TypeKind) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="DROP "+typ.toString()
override def consumed = 1
override def produced = 0
}
/** This class represents a DUP instruction
* Stack: ...:something
* ->: ...:something:something
*/
case class DUP (typ: TypeKind) extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="DUP"
override def consumed = 1
override def produced = 2
}
/** This class represents a MONITOR_ENTER instruction
* Stack: ...:object(ref)
* ->: ...:
*/
case class MONITOR_ENTER() extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="MONITOR_ENTER"
override def consumed = 1
override def produced = 0
}
/** This class represents a MONITOR_EXIT instruction
* Stack: ...:object(ref)
* ->: ...:
*/
case class MONITOR_EXIT() extends Instruction {
/** Returns a string representation of this instruction */
override def toString(): String ="MONITOR_EXIT";
override def consumed = 1;
override def produced = 0;
}
/** A local variable becomes visible at this point in code.
* Used only for generating precise local variable tables as
* debugging information.
*/
case class SCOPE_ENTER(lv: Local) extends Instruction {
override def toString(): String = "SCOPE_ENTER " + lv
override def consumed = 0
override def produced = 0
}
/** A local variable leaves its scope at this point in code.
* Used only for generating precise local variable tables as
* debugging information.
*/
case class SCOPE_EXIT(lv: Local) extends Instruction {
override def toString(): String = "SCOPE_EXIT " + lv
override def consumed = 0
override def produced = 0
}
/** Fake instruction. It designates the VM who pushes an exception
* on top of the /empty/ stack at the beginning of each exception handler.
* Note: Unlike other instructions, it consumes all elements on the stack!
* then pushes one exception instance.
*/
case class LOAD_EXCEPTION() extends Instruction {
override def toString(): String = "LOAD_EXCEPTION"
override def consumed = error("LOAD_EXCEPTION does clean the whole stack, no idea how many things it consumes!")
override def produced = 1
override def producedTypes = AnyRefReference :: Nil
}
/** This class represents a method invocation style. */
sealed abstract class InvokeStyle {
/** Is this a dynamic method call? */
def isDynamic: Boolean = this match {
case Dynamic => true
case _ => false
}
/** Is this a static method call? */
def isStatic: Boolean = this match {
case Static(_) => true
case _ => false
}
def isSuper: Boolean = this match {
case SuperCall(_) => true
case _ => false
}
/** Is this an instance method call? */
def hasInstance: Boolean = this match {
case Dynamic => true
case Static(onInstance) => onInstance
case SuperCall(_) => true
case _ => false
}
/** Returns a string representation of this style. */
override def toString(): String = this match {
case Dynamic => "dynamic"
case InvokeDynamic => "invoke-dynamic"
case Static(false) => "static-class"
case Static(true) => "static-instance"
case SuperCall(mix) => "super(" + mix + ")"
}
}
/** Virtual calls */
case object Dynamic extends InvokeStyle
/** InvokeDynamic a la JSR 292 (experimental). */
case object InvokeDynamic extends InvokeStyle
/**
* Special invoke. Static(true) is used for calls to private
* members.
*/
case class Static(onInstance: Boolean) extends InvokeStyle
/** Call through super[mix]. */
case class SuperCall(mix: Name) extends InvokeStyle
}
}
|