jdk8-mips64-public/nashorn: src/jdk/nashorn/internal/codegen/types/Type.java@e1e27c4262be (annotated)

src/jdk/nashorn/internal/codegen/types/Type.java@e1e27c4262be (annotated)

src/jdk/nashorn/internal/codegen/types/Type.java

Mon, 03 Nov 2014 11:47:41 +0100

author: lagergren
date: Mon, 03 Nov 2014 11:47:41 +0100
changeset 1082: e1e27c4262be
parent 1071: 78eb2b415108
child 1086: d0b26e6f602c
permissions: -rw-r--r--

8060204: Fix warnings in Joni and tests
Reviewed-by: hannesw, sundar, attila

 /*
  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package jdk.nashorn.internal.codegen.types;
 import static jdk.internal.org.objectweb.asm.Opcodes.DALOAD;
 import static jdk.internal.org.objectweb.asm.Opcodes.DASTORE;
 import static jdk.internal.org.objectweb.asm.Opcodes.DUP;
 import static jdk.internal.org.objectweb.asm.Opcodes.DUP2;
 import static jdk.internal.org.objectweb.asm.Opcodes.DUP2_X1;
 import static jdk.internal.org.objectweb.asm.Opcodes.DUP2_X2;
 import static jdk.internal.org.objectweb.asm.Opcodes.DUP_X1;
 import static jdk.internal.org.objectweb.asm.Opcodes.DUP_X2;
 import static jdk.internal.org.objectweb.asm.Opcodes.H_INVOKESTATIC;
 import static jdk.internal.org.objectweb.asm.Opcodes.IALOAD;
 import static jdk.internal.org.objectweb.asm.Opcodes.IASTORE;
 import static jdk.internal.org.objectweb.asm.Opcodes.INVOKESTATIC;
 import static jdk.internal.org.objectweb.asm.Opcodes.LALOAD;
 import static jdk.internal.org.objectweb.asm.Opcodes.LASTORE;
 import static jdk.internal.org.objectweb.asm.Opcodes.NEWARRAY;
 import static jdk.internal.org.objectweb.asm.Opcodes.POP;
 import static jdk.internal.org.objectweb.asm.Opcodes.POP2;
 import static jdk.internal.org.objectweb.asm.Opcodes.SWAP;
 import static jdk.internal.org.objectweb.asm.Opcodes.T_DOUBLE;
 import static jdk.internal.org.objectweb.asm.Opcodes.T_INT;
 import static jdk.internal.org.objectweb.asm.Opcodes.T_LONG;
 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup;
 import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;
 import java.io.Serializable;
 import java.lang.invoke.CallSite;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
 import java.util.Collections;
 import java.util.Map;
 import java.util.TreeMap;
 import java.util.WeakHashMap;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import jdk.internal.org.objectweb.asm.Handle;
 import jdk.internal.org.objectweb.asm.MethodVisitor;
 import jdk.nashorn.internal.codegen.CompilerConstants.Call;
 import jdk.nashorn.internal.runtime.ScriptObject;
 import jdk.nashorn.internal.runtime.Undefined;
 import jdk.nashorn.internal.runtime.linker.Bootstrap;
 /**
  * This is the representation of a JavaScript type, disassociated from java
  * Classes, with the basis for conversion weight, mapping to ASM types
  * and implementing the ByteCodeOps interface which tells this type
  * how to generate code for various operations.
  *
  * Except for ClassEmitter, this is the only class that has to know
  * about the underlying byte code generation system.
  *
  * The different types know how to generate bytecode for the different
  * operations, inherited from BytecodeOps, that they support. This avoids
  * if/else chains depending on type in several cases and allows for
  * more readable and shorter code
  *
  * The Type class also contains logic used by the type inference and
  * for comparing types against each other, as well as the concepts
  * of narrower to wider types. The widest type is an object. Ideally we
  * would like as narrow types as possible for code to be efficient, e.g
  * INTs rather than OBJECTs
  */
 public abstract class Type implements Comparable<Type>, BytecodeOps, Serializable {
     private static final long serialVersionUID = 1L;
     /** Human readable name for type */
     private transient final String name;
     /** Descriptor for type */
     private transient final String descriptor;
     /** The "weight" of the type. Used for picking widest/least specific common type */
     private transient final int weight;
     /** How many bytecode slots does this type occupy */
     private transient final int slots;
     /** The class for this type */
     private final Class<?> clazz;
     /**
      * Cache for internal types - this is a query that requires complex stringbuilding inside
      * ASM and it saves startup time to cache the type mappings
      */
     private static final Map<Class<?>, jdk.internal.org.objectweb.asm.Type> INTERNAL_TYPE_CACHE =
             Collections.synchronizedMap(new WeakHashMap<Class<?>, jdk.internal.org.objectweb.asm.Type>());
     /** Internal ASM type for this Type - computed once at construction */
     private transient final jdk.internal.org.objectweb.asm.Type internalType;
     /** Weights are used to decide which types are "wider" than other types */
     protected static final int MIN_WEIGHT = -1;
     /** Set way below Integer.MAX_VALUE to prevent overflow when adding weights. Objects are still heaviest. */
     protected static final int MAX_WEIGHT = 20;
     static final Call BOOTSTRAP = staticCallNoLookup(Bootstrap.class, "mathBootstrap", CallSite.class, MethodHandles.Lookup.class, String.class, MethodType.class, int.class);
     static final Handle MATHBOOTSTRAP = new Handle(H_INVOKESTATIC, BOOTSTRAP.className(), "mathBootstrap", BOOTSTRAP.descriptor());
     /**
      * Constructor
      *
      * @param clazz       class for type
      * @param weight      weight - higher is more generic
      * @param slots       how many bytecode slots the type takes up
      */
     Type(final String name, final Class<?> clazz, final int weight, final int slots) {
         this.name         = name;
         this.clazz        = clazz;
         this.descriptor   = jdk.internal.org.objectweb.asm.Type.getDescriptor(clazz);
         this.weight       = weight;
         assert weight >= MIN_WEIGHT && weight <= MAX_WEIGHT : "illegal type weight: " + weight;
         this.slots        = slots;
         this.internalType = getInternalType(clazz);
     }
     /**
      * Get the weight of this type - use this e.g. for sorting method descriptors
      * @return the weight
      */
     public int getWeight() {
         return weight;
     }
     /**
      * Get the Class representing this type
      * @return the class for this type
      */
     public Class<?> getTypeClass() {
         return clazz;
     }
     /**
      * For specialization, return the next, slightly more difficulty, type
      * to test.
      *
      * @return the next Type
      */
     public Type nextWider() {
         return null;
     }
     /**
      * Get the boxed type for this class
      * @return the boxed version of this type or null if N/A
      */
     public Class<?> getBoxedType() {
         assert !getTypeClass().isPrimitive();
         return null;
     }
     /**
      * Returns the character describing the bytecode type for this value on the stack or local variable, identical to
      * what would be used as the prefix for a bytecode {@code LOAD} or {@code STORE} instruction, therefore it must be
      * one of {@code A, F, D, I, L}. Also, the special value {@code U} is used for local variable slots that haven't
      * been initialized yet (it can't appear for a value pushed to the operand stack, those always have known values).
      * Note that while we allow all JVM internal types, Nashorn doesn't necessarily use them all - currently we don't
      * have floats, only doubles, but that might change in the future.
      * @return the character describing the bytecode type for this value on the stack.
      */
     public abstract char getBytecodeStackType();
     /**
      * Generate a method descriptor given a return type and a param array
      *
      * @param returnType return type
      * @param types      parameters
      *
      * @return a descriptor string
      */
     public static String getMethodDescriptor(final Type returnType, final Type... types) {
         final jdk.internal.org.objectweb.asm.Type[] itypes = new jdk.internal.org.objectweb.asm.Type[types.length];
         for (int i = 0; i < types.length; i++) {
             itypes[i] = types[i].getInternalType();
         }
         return jdk.internal.org.objectweb.asm.Type.getMethodDescriptor(returnType.getInternalType(), itypes);
     }
     /**
      * Generate a method descriptor given a return type and a param array
      *
      * @param returnType return type
      * @param types      parameters
      *
      * @return a descriptor string
      */
     public static String getMethodDescriptor(final Class<?> returnType, final Class<?>... types) {
         final jdk.internal.org.objectweb.asm.Type[] itypes = new jdk.internal.org.objectweb.asm.Type[types.length];
         for (int i = 0; i < types.length; i++) {
             itypes[i] = getInternalType(types[i]);
         }
         return jdk.internal.org.objectweb.asm.Type.getMethodDescriptor(getInternalType(returnType), itypes);
     }
     /**
      * Return a character representing {@code type} in a method signature.
      *
      * @param type parameter type
      * @return descriptor character
      */
     public static char getShortSignatureDescriptor(final Type type) {
         // Use 'Z' for boolean parameters as we need to distinguish from int
         if (type instanceof BooleanType) {
             return 'Z';
         }
         return type.getBytecodeStackType();
     }
     /**
      * Return the type for an internal type, package private - do not use
      * outside code gen
      *
      * @param itype internal type
      * @return Nashorn type
      */
     @SuppressWarnings("fallthrough")
     static Type typeFor(final jdk.internal.org.objectweb.asm.Type itype) {
         switch (itype.getSort()) {
         case jdk.internal.org.objectweb.asm.Type.BOOLEAN:
             return BOOLEAN;
         case jdk.internal.org.objectweb.asm.Type.INT:
             return INT;
         case jdk.internal.org.objectweb.asm.Type.LONG:
             return LONG;
         case jdk.internal.org.objectweb.asm.Type.DOUBLE:
             return NUMBER;
         case jdk.internal.org.objectweb.asm.Type.OBJECT:
             try {
                 return Type.typeFor(Class.forName(itype.getClassName()));
             } catch(final ClassNotFoundException e) {
                 throw new AssertionError(e);
             }
         case jdk.internal.org.objectweb.asm.Type.VOID:
             return null;
         case jdk.internal.org.objectweb.asm.Type.ARRAY:
             switch (itype.getElementType().getSort()) {
             case jdk.internal.org.objectweb.asm.Type.DOUBLE:
                 return NUMBER_ARRAY;
             case jdk.internal.org.objectweb.asm.Type.INT:
                 return INT_ARRAY;
             case jdk.internal.org.objectweb.asm.Type.LONG:
                 return LONG_ARRAY;
             default:
                 assert false;
             case jdk.internal.org.objectweb.asm.Type.OBJECT:
                 return OBJECT_ARRAY;
             }
         default:
             assert false : "Unknown itype : " + itype + " sort " + itype.getSort();
             break;
         }
         return null;
     }
     /**
      * Get the return type for a method
      *
      * @param methodDescriptor method descriptor
      * @return return type
      */
     public static Type getMethodReturnType(final String methodDescriptor) {
         return Type.typeFor(jdk.internal.org.objectweb.asm.Type.getReturnType(methodDescriptor));
     }
     /**
      * Get type array representing arguments of a method in order
      *
      * @param methodDescriptor method descriptor
      * @return parameter type array
      */
     public static Type[] getMethodArguments(final String methodDescriptor) {
         final jdk.internal.org.objectweb.asm.Type itypes[] = jdk.internal.org.objectweb.asm.Type.getArgumentTypes(methodDescriptor);
         final Type types[] = new Type[itypes.length];
         for (int i = 0; i < itypes.length; i++) {
             types[i] = Type.typeFor(itypes[i]);
         }
         return types;
     }
     /**
      * Write a map of {@code int} to {@code Type} to an output stream. This is used to store deoptimization state.
      *
      * @param typeMap the type map
      * @param output data output
      * @throws IOException if write cannot be completed
      */
     public static void writeTypeMap(final Map<Integer, Type> typeMap, final DataOutput output) throws IOException {
         if (typeMap == null) {
             output.writeInt(0);
         } else {
             output.writeInt(typeMap.size());
             for(final Map.Entry<Integer, Type> e: typeMap.entrySet()) {
                 output.writeInt(e.getKey());
                 final byte typeChar;
                 final Type type = e.getValue();
                 if(type == Type.OBJECT) {
                     typeChar = 'L';
                 } else if (type == Type.NUMBER) {
                     typeChar = 'D';
                 } else if (type == Type.LONG) {
                     typeChar = 'J';
                 } else {
                     throw new AssertionError();
                 }
                 output.writeByte(typeChar);
             }
         }
     }
     /**
      * Read a map of {@code int} to {@code Type} from an input stream. This is used to store deoptimization state.
      *
      * @param input data input
      * @return type map
      * @throws IOException if read cannot be completed
      */
     public static Map<Integer, Type> readTypeMap(final DataInput input) throws IOException {
         final int size = input.readInt();
         if (size <= 0) {
             return null;
         }
         final Map<Integer, Type> map = new TreeMap<>();
         for(int i = 0; i < size; ++i) {
             final int pp = input.readInt();
             final int typeChar = input.readByte();
             final Type type;
             switch (typeChar) {
                 case 'L': type = Type.OBJECT; break;
                 case 'D': type = Type.NUMBER; break;
                 case 'J': type = Type.LONG; break;
                 default: continue;
             }
             map.put(pp, type);
         }
         return map;
     }
     static jdk.internal.org.objectweb.asm.Type getInternalType(final String className) {
         return jdk.internal.org.objectweb.asm.Type.getType(className);
     }
     private jdk.internal.org.objectweb.asm.Type getInternalType() {
         return internalType;
     }
     private static jdk.internal.org.objectweb.asm.Type lookupInternalType(final Class<?> type) {
         final Map<Class<?>, jdk.internal.org.objectweb.asm.Type> c = INTERNAL_TYPE_CACHE;
         jdk.internal.org.objectweb.asm.Type itype = c.get(type);
         if (itype != null) {
             return itype;
         }
         itype = jdk.internal.org.objectweb.asm.Type.getType(type);
         c.put(type, itype);
         return itype;
     }
     private static jdk.internal.org.objectweb.asm.Type getInternalType(final Class<?> type) {
         return lookupInternalType(type);
     }
     static void invokestatic(final MethodVisitor method, final Call call) {
         method.visitMethodInsn(INVOKESTATIC, call.className(), call.name(), call.descriptor(), false);
     }
     /**
      * Get the internal JVM name of a type
      * @return the internal name
      */
     public String getInternalName() {
         return jdk.internal.org.objectweb.asm.Type.getInternalName(getTypeClass());
     }
     /**
      * Get the internal JVM name of type type represented by a given Java class
      * @param clazz the class
      * @return the internal name
      */
     public static String getInternalName(final Class<?> clazz) {
         return jdk.internal.org.objectweb.asm.Type.getInternalName(clazz);
     }
     /**
      * Determines whether a type is the UNKNOWN type, i.e. not set yet
      * Used for type inference.
      *
      * @return true if UNKNOWN, false otherwise
      */
     public boolean isUnknown() {
         return this.equals(Type.UNKNOWN);
     }
     /**
      * Determines whether this type represents an primitive type according to the ECMAScript specification,
      * which includes Boolean, Number, and String.
      *
      * @return true if a JavaScript primitive type, false otherwise.
      */
     public boolean isJSPrimitive() {
         return !isObject() || isString();
     }
     /**
      * Determines whether a type is the BOOLEAN type
      * @return true if BOOLEAN, false otherwise
      */
     public boolean isBoolean() {
         return this.equals(Type.BOOLEAN);
     }
     /**
      * Determines whether a type is the INT type
      * @return true if INTEGER, false otherwise
      */
     public boolean isInteger() {
         return this.equals(Type.INT);
     }
     /**
      * Determines whether a type is the LONG type
      * @return true if LONG, false otherwise
      */
     public boolean isLong() {
         return this.equals(Type.LONG);
     }
     /**
      * Determines whether a type is the NUMBER type
      * @return true if NUMBER, false otherwise
      */
     public boolean isNumber() {
         return this.equals(Type.NUMBER);
     }
     /**
      * Determines whether a type is numeric, i.e. NUMBER,
      * INT, LONG.
      *
      * @return true if numeric, false otherwise
      */
     public boolean isNumeric() {
         return this instanceof NumericType;
     }
     /**
      * Determines whether a type is an array type, i.e.
      * OBJECT_ARRAY or NUMBER_ARRAY (for now)
      *
      * @return true if an array type, false otherwise
      */
     public boolean isArray() {
         return this instanceof ArrayType;
     }
     /**
      * Determines if a type takes up two bytecode slots or not
      *
      * @return true if type takes up two bytecode slots rather than one
      */
     public boolean isCategory2() {
         return getSlots() == 2;
     }
     /**
      * Determines whether a type is an OBJECT type, e.g. OBJECT, STRING,
      * NUMBER_ARRAY etc.
      *
      * @return true if object type, false otherwise
      */
     public boolean isObject() {
         return this instanceof ObjectType;
     }
     /**
      * Is this a primitive type (e.g int, long, double, boolean)
      * @return true if primitive
      */
     public boolean isPrimitive() {
         return !isObject();
     }
     /**
      * Determines whether a type is a STRING type
      *
      * @return true if object type, false otherwise
      */
     public boolean isString() {
         return this.equals(Type.STRING);
     }
     /**
      * Determines whether a type is a CHARSEQUENCE type used internally strings
      *
      * @return true if CharSequence (internal string) type, false otherwise
      */
     public boolean isCharSequence() {
         return this.equals(Type.CHARSEQUENCE);
     }
     /**
      * Determine if two types are equivalent, i.e. need no conversion
      *
      * @param type the second type to check
      *
      * @return true if types are equivalent, false otherwise
      */
     public boolean isEquivalentTo(final Type type) {
         return this.weight() == type.weight() || isObject() && type.isObject();
     }
     /**
      * Determine if a type can be assigned to from another
      *
      * @param type0 the first type to check
      * @param type1 the second type to check
      *
      * @return true if type1 can be written to type2, false otherwise
      */
     public static boolean isAssignableFrom(final Type type0, final Type type1) {
         if (type0.isObject() && type1.isObject()) {
             return type0.weight() >= type1.weight();
         }
         return type0.weight() == type1.weight();
     }
     /**
      * Determine if this type is assignable from another type
      * @param type the type to check against
      *
      * @return true if "type" can be written to this type, false otherwise
      */
     public boolean isAssignableFrom(final Type type) {
         return Type.isAssignableFrom(this, type);
     }
     /**
      * Determines is this type is equivalent to another, i.e. needs no conversion
      * to be assigned to it.
      *
      * @param type0 the first type to check
      * @param type1 the second type to check
      *
      * @return true if this type is equivalent to type, false otherwise
      */
     public static boolean areEquivalent(final Type type0, final Type type1) {
         return type0.isEquivalentTo(type1);
     }
     /**
      * Determine the number of bytecode slots a type takes up
      *
      * @return the number of slots for this type, 1 or 2.
      */
     public int getSlots() {
         return slots;
     }
     /**
      * Returns the widest or most common of two types
      *
      * @param type0 type one
      * @param type1 type two
      *
      * @return the widest type
      */
     public static Type widest(final Type type0, final Type type1) {
         if (type0.isArray() && type1.isArray()) {
             return ((ArrayType)type0).getElementType() == ((ArrayType)type1).getElementType() ? type0 : Type.OBJECT;
         } else if (type0.isArray() != type1.isArray()) {
             //array and non array is always object, widest(Object[], int) NEVER returns Object[], which has most weight. that does not make sense
             return Type.OBJECT;
         } else if (type0.isObject() && type1.isObject() && type0.getTypeClass() != type1.getTypeClass()) {
             // Object<type=String> and Object<type=ScriptFunction> will produce Object
             // TODO: maybe find most specific common superclass?
             return Type.OBJECT;
         }
         return type0.weight() > type1.weight() ? type0 : type1;
     }
     /**
      * Returns the widest or most common of two types, given as classes
      *
      * @param type0 type one
      * @param type1 type two
      *
      * @return the widest type
      */
     public static Class<?> widest(final Class<?> type0, final Class<?> type1) {
         return widest(Type.typeFor(type0), Type.typeFor(type1)).getTypeClass();
     }
     /**
      * When doing widening for return types of a function or a ternary operator, it is not valid to widen a boolean to
      * anything other than object. Note that this wouldn't be necessary if {@code Type.widest} did not allow
      * boolean-to-number widening. Eventually, we should address it there, but it affects too many other parts of the
      * system and is sometimes legitimate (e.g. whenever a boolean value would undergo ToNumber conversion anyway).
      * @param t1 type 1
      * @param t2 type 2
      * @return wider of t1 and t2, except if one is boolean and the other is neither boolean nor unknown, in which case
      * {@code Type.OBJECT} is returned.
      */
     public static Type widestReturnType(final Type t1, final Type t2) {
         if (t1.isUnknown()) {
             return t2;
         } else if (t2.isUnknown()) {
             return t1;
         } else if(t1.isBoolean() != t2.isBoolean() || t1.isNumeric() != t2.isNumeric()) {
             return Type.OBJECT;
         }
         return Type.widest(t1, t2);
     }
     /**
      * Returns a generic version of the type. Basically, if the type {@link #isObject()}, returns {@link #OBJECT},
      * otherwise returns the type unchanged.
      * @param type the type to generify
      * @return the generified type
      */
     public static Type generic(final Type type) {
         return type.isObject() ? Type.OBJECT : type;
     }
     /**
      * Returns the narrowest or least common of two types
      *
      * @param type0 type one
      * @param type1 type two
      *
      * @return the widest type
      */
     public static Type narrowest(final Type type0, final Type type1) {
         return type0.narrowerThan(type1) ? type0 : type1;
     }
     /**
      * Check whether this type is strictly narrower than another one
      * @param type type to check against
      * @return true if this type is strictly narrower
      */
     public boolean narrowerThan(final Type type) {
         return weight() < type.weight();
     }
     /**
      * Check whether this type is strictly wider than another one
      * @param type type to check against
      * @return true if this type is strictly wider
      */
     public boolean widerThan(final Type type) {
         return weight() > type.weight();
     }
     /**
      * Returns the widest or most common of two types, but no wider than "limit"
      *
      * @param type0 type one
      * @param type1 type two
      * @param limit limiting type
      *
      * @return the widest type, but no wider than limit
      */
     public static Type widest(final Type type0, final Type type1, final Type limit) {
         final Type type = Type.widest(type0,  type1);
         if (type.weight() > limit.weight()) {
             return limit;
         }
         return type;
     }
     /**
      * Returns the widest or most common of two types, but no narrower than "limit"
      *
      * @param type0 type one
      * @param type1 type two
      * @param limit limiting type
      *
      * @return the widest type, but no wider than limit
      */
     public static Type narrowest(final Type type0, final Type type1, final Type limit) {
         final Type type = type0.weight() < type1.weight() ? type0 : type1;
         if (type.weight() < limit.weight()) {
             return limit;
         }
         return type;
     }
     /**
      * Returns the narrowest of this type and another
      *
      * @param  other type to compare against
      *
      * @return the widest type
      */
     public Type narrowest(final Type other) {
         return Type.narrowest(this, other);
     }
     /**
      * Returns the widest of this type and another
      *
      * @param  other type to compare against
      *
      * @return the widest type
      */
     public Type widest(final Type other) {
         return Type.widest(this, other);
     }
     /**
      * Returns the weight of a type, used for type comparison
      * between wider and narrower types
      *
      * @return the weight
      */
     int weight() {
         return weight;
     }
     /**
      * Return the descriptor of a type, used for e.g. signature
      * generation
      *
      * @return the descriptor
      */
     public String getDescriptor() {
         return descriptor;
     }
     /**
      * Return the descriptor of a type, short version
      * Used mainly for debugging purposes
      *
      * @return the short descriptor
      */
     public String getShortDescriptor() {
         return descriptor;
     }
     @Override
     public String toString() {
         return name;
     }
     /**
      * Return the (possibly cached) Type object for this class
      *
      * @param clazz the class to check
      *
      * @return the Type representing this class
      */
     public static Type typeFor(final Class<?> clazz) {
         final Type type = cache.get(clazz);
         if(type != null) {
             return type;
         }
         assert !clazz.isPrimitive() || clazz == void.class;
         final Type newType;
         if (clazz.isArray()) {
             newType = new ArrayType(clazz);
         } else {
             newType = new ObjectType(clazz);
         }
         final Type existingType = cache.putIfAbsent(clazz, newType);
         return existingType == null ? newType : existingType;
     }
     @Override
     public int compareTo(final Type o) {
         return o.weight() - weight();
     }
     /**
      * Common logic for implementing dup for all types
      *
      * @param method method visitor
      * @param depth dup depth
      *
      * @return the type at the top of the stack afterwards
      */
     @Override
     public Type dup(final MethodVisitor method, final int depth) {
         return Type.dup(method, this, depth);
     }
     /**
      * Common logic for implementing swap for all types
      *
      * @param method method visitor
      * @param other  the type to swap with
      *
      * @return the type at the top of the stack afterwards, i.e. other
      */
     @Override
     public Type swap(final MethodVisitor method, final Type other) {
         Type.swap(method, this, other);
         return other;
     }
     /**
      * Common logic for implementing pop for all types
      *
      * @param method method visitor
      *
      * @return the type that was popped
      */
     @Override
     public Type pop(final MethodVisitor method) {
         Type.pop(method, this);
         return this;
     }
     @Override
     public Type loadEmpty(final MethodVisitor method) {
         assert false : "unsupported operation";
         return null;
     }
     /**
      * Superclass logic for pop for all types
      *
      * @param method method emitter
      * @param type   type to pop
      */
     protected static void pop(final MethodVisitor method, final Type type) {
         method.visitInsn(type.isCategory2() ? POP2 : POP);
     }
     private static Type dup(final MethodVisitor method, final Type type, final int depth) {
         final boolean       cat2 = type.isCategory2();
         switch (depth) {
         case 0:
             method.visitInsn(cat2 ? DUP2 : DUP);
             break;
         case 1:
             method.visitInsn(cat2 ? DUP2_X1 : DUP_X1);
             break;
         case 2:
             method.visitInsn(cat2 ? DUP2_X2 : DUP_X2);
             break;
         default:
             return null; //invalid depth
         }
         return type;
     }
     private static void swap(final MethodVisitor method, final Type above, final Type below) {
         if (below.isCategory2()) {
             if (above.isCategory2()) {
                 method.visitInsn(DUP2_X2);
                 method.visitInsn(POP2);
             } else {
                 method.visitInsn(DUP_X2);
                 method.visitInsn(POP);
             }
         } else {
             if (above.isCategory2()) {
                 method.visitInsn(DUP2_X1);
                 method.visitInsn(POP2);
             } else {
                 method.visitInsn(SWAP);
             }
         }
     }
     /** Mappings between java classes and their Type singletons */
     private static final ConcurrentMap<Class<?>, Type> cache = new ConcurrentHashMap<>();
     /**
      * This is the boolean singleton, used for all boolean types
      */
     public static final Type BOOLEAN = putInCache(new BooleanType());
     /**
      * This is an integer type, i.e INT, INT32.
      */
     public static final BitwiseType INT = putInCache(new IntType());
     /**
      * This is the number singleton, used for all number types
      */
     public static final NumericType NUMBER = putInCache(new NumberType());
     /**
      * This is the long singleton, used for all long types
      */
     public static final BitwiseType LONG = putInCache(new LongType());
     /**
      * A string singleton
      */
     public static final Type STRING = putInCache(new ObjectType(String.class));
     /**
      * This is the CharSequence singleton used to represent JS strings internally
      * (either a {@code java.lang.String} or {@code jdk.nashorn.internal.runtime.ConsString}.
      */
     public static final Type CHARSEQUENCE = putInCache(new ObjectType(CharSequence.class));
     /**
      * This is the object singleton, used for all object types
      */
     public static final Type OBJECT = putInCache(new ObjectType());
     /**
      * A undefined singleton
      */
     public static final Type UNDEFINED = putInCache(new ObjectType(Undefined.class));
     /**
      * This is the singleton for ScriptObjects
      */
     public static final Type SCRIPT_OBJECT = putInCache(new ObjectType(ScriptObject.class));
     /**
      * This is the singleton for integer arrays
      */
     public static final ArrayType INT_ARRAY = new ArrayType(int[].class) {
         private static final long serialVersionUID = 1L;
         @Override
         public void astore(final MethodVisitor method) {
             method.visitInsn(IASTORE);
         }
         @Override
         public Type aload(final MethodVisitor method) {
             method.visitInsn(IALOAD);
             return INT;
         }
         @Override
         public Type newarray(final MethodVisitor method) {
             method.visitIntInsn(NEWARRAY, T_INT);
             return this;
         }
         @Override
         public Type getElementType() {
             return INT;
         }
     };
     /**
      * This is the singleton for long arrays
      */
     public static final ArrayType LONG_ARRAY = new ArrayType(long[].class) {
         private static final long serialVersionUID = 1L;
         @Override
         public void astore(final MethodVisitor method) {
             method.visitInsn(LASTORE);
         }
         @Override
         public Type aload(final MethodVisitor method) {
             method.visitInsn(LALOAD);
             return LONG;
         }
         @Override
         public Type newarray(final MethodVisitor method) {
             method.visitIntInsn(NEWARRAY, T_LONG);
             return this;
         }
         @Override
         public Type getElementType() {
             return LONG;
         }
     };
     /**
      * This is the singleton for numeric arrays
      */
     public static final ArrayType NUMBER_ARRAY = new ArrayType(double[].class) {
         private static final long serialVersionUID = 1L;
         @Override
         public void astore(final MethodVisitor method) {
             method.visitInsn(DASTORE);
         }
         @Override
         public Type aload(final MethodVisitor method) {
             method.visitInsn(DALOAD);
             return NUMBER;
         }
         @Override
         public Type newarray(final MethodVisitor method) {
             method.visitIntInsn(NEWARRAY, T_DOUBLE);
             return this;
         }
         @Override
         public Type getElementType() {
             return NUMBER;
         }
     };
     /** Singleton for method handle arrays used for properties etc. */
     public static final ArrayType METHODHANDLE_ARRAY = putInCache(new ArrayType(MethodHandle[].class));
     /** This is the singleton for string arrays */
     public static final ArrayType STRING_ARRAY = putInCache(new ArrayType(String[].class));
     /** This is the singleton for object arrays */
     public static final ArrayType OBJECT_ARRAY = putInCache(new ArrayType(Object[].class));
     /** This type, always an object type, just a toString override */
     public static final Type THIS = new ObjectType() {
         private static final long serialVersionUID = 1L;
         @Override
         public String toString() {
             return "this";
         }
     };
     /** Scope type, always an object type, just a toString override */
     public static final Type SCOPE = new ObjectType() {
         private static final long serialVersionUID = 1L;
         @Override
         public String toString() {
             return "scope";
         }
     };
     private static interface Unknown {
         // EMPTY - used as a class that is absolutely not compatible with a type to represent "unknown"
     }
     private abstract static class ValueLessType extends Type {
         private static final long serialVersionUID = 1L;
         ValueLessType(final String name) {
             super(name, Unknown.class, MIN_WEIGHT, 1);
         }
         @Override
         public Type load(final MethodVisitor method, final int slot) {
             throw new UnsupportedOperationException("load " + slot);
         }
         @Override
         public void store(final MethodVisitor method, final int slot) {
             throw new UnsupportedOperationException("store " + slot);
         }
         @Override
         public Type ldc(final MethodVisitor method, final Object c) {
             throw new UnsupportedOperationException("ldc " + c);
         }
         @Override
         public Type loadUndefined(final MethodVisitor method) {
             throw new UnsupportedOperationException("load undefined");
         }
         @Override
         public Type loadForcedInitializer(final MethodVisitor method) {
             throw new UnsupportedOperationException("load forced initializer");
         }
         @Override
         public Type convert(final MethodVisitor method, final Type to) {
             throw new UnsupportedOperationException("convert => " + to);
         }
         @Override
         public void _return(final MethodVisitor method) {
             throw new UnsupportedOperationException("return");
        }
         @Override
         public Type add(final MethodVisitor method, final int programPoint) {
             throw new UnsupportedOperationException("add");
         }
     }
     /**
      * This is the unknown type which is used as initial type for type
      * inference. It has the minimum type width
      */
     public static final Type UNKNOWN = new ValueLessType("<unknown>") {
         private static final long serialVersionUID = 1L;
         @Override
         public String getDescriptor() {
             return "<unknown>";
         }
         @Override
         public char getBytecodeStackType() {
             return 'U';
         }
     };
     /**
      * This is the unknown type which is used as initial type for type
      * inference. It has the minimum type width
      */
     public static final Type SLOT_2 = new ValueLessType("<slot_2>") {
         private static final long serialVersionUID = 1L;
         @Override
         public String getDescriptor() {
             return "<slot_2>";
         }
         @Override
         public char getBytecodeStackType() {
             throw new UnsupportedOperationException("getBytecodeStackType");
         }
     };
     private static <T extends Type> T putInCache(final T type) {
         cache.put(type.getTypeClass(), type);
         return type;
     }
     protected final Object readResolve() {
         return Type.typeFor(clazz);
     }
 }

Mercurial > jdk8-mips64-public > nashorn / annotate

src/jdk/nashorn/internal/codegen/types/Type.java@e1e27c4262be (annotated)

src/jdk/nashorn/internal/codegen/types/Type.java