jdk8-mips64-public/langtools: src/share/classes/com/sun/tools/javac/jvm/Items.java@89f67512b635 (annotated)

src/share/classes/com/sun/tools/javac/jvm/Items.java@89f67512b635 (annotated)

src/share/classes/com/sun/tools/javac/jvm/Items.java

Tue, 31 Mar 2009 11:07:55 -0700

author: jjg
date: Tue, 31 Mar 2009 11:07:55 -0700
changeset 256: 89f67512b635
parent 117: 24a47c3062fe
child 267: e2722bd43f3a
permissions: -rw-r--r--

6817950: refactor ClassReader to improve attribute handling
Reviewed-by: mcimadamore

 /*
  * Copyright 1999-2008 Sun Microsystems, Inc.  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.  Sun designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  */
 package com.sun.tools.javac.jvm;
 import com.sun.tools.javac.code.*;
 import com.sun.tools.javac.code.Symbol.*;
 import com.sun.tools.javac.code.Type.*;
 import com.sun.tools.javac.jvm.Code.*;
 import com.sun.tools.javac.tree.JCTree;
 import static com.sun.tools.javac.jvm.ByteCodes.*;
 /** A helper class for code generation. Items are objects
  *  that stand for addressable entities in the bytecode. Each item
  *  supports a fixed protocol for loading the item on the stack, storing
  *  into it, converting it into a jump condition, and several others.
  *  There are many individual forms of items, such as local, static,
  *  indexed, or instance variables, values on the top of stack, the
  *  special values this or super, etc. Individual items are represented as
  *  inner classes in class Items.
  *
  *  <p><b>This is NOT part of any API supported by Sun Microsystems.  If
  *  you write code that depends on this, you do so at your own risk.
  *  This code and its internal interfaces are subject to change or
  *  deletion without notice.</b>
  */
 public class Items {
     /** The current constant pool.
      */
     Pool pool;
     /** The current code buffer.
      */
     Code code;
     /** The current symbol table.
      */
     Symtab syms;
     /** Type utilities. */
     Types types;
     /** Items that exist only once (flyweight pattern).
      */
     private final Item voidItem;
     private final Item thisItem;
     private final Item superItem;
     private final Item[] stackItem = new Item[TypeCodeCount];
     public Items(Pool pool, Code code, Symtab syms, Types types) {
         this.code = code;
         this.pool = pool;
         this.types = types;
         voidItem = new Item(VOIDcode) {
                 public String toString() { return "void"; }
             };
         thisItem = new SelfItem(false);
         superItem = new SelfItem(true);
         for (int i = 0; i < VOIDcode; i++) stackItem[i] = new StackItem(i);
         stackItem[VOIDcode] = voidItem;
         this.syms = syms;
     }
     /** Make a void item
      */
     Item makeVoidItem() {
         return voidItem;
     }
     /** Make an item representing `this'.
      */
     Item makeThisItem() {
         return thisItem;
     }
     /** Make an item representing `super'.
      */
     Item makeSuperItem() {
         return superItem;
     }
     /** Make an item representing a value on stack.
      *  @param type    The value's type.
      */
     Item makeStackItem(Type type) {
         return stackItem[Code.typecode(type)];
     }
     /** Make an item representing an indexed expression.
      *  @param type    The expression's type.
      */
     Item makeIndexedItem(Type type) {
         return new IndexedItem(type);
     }
     /** Make an item representing a local variable.
      *  @param v    The represented variable.
      */
     LocalItem makeLocalItem(VarSymbol v) {
         return new LocalItem(v.erasure(types), v.adr);
     }
     /** Make an item representing a local anonymous variable.
      *  @param type  The represented variable's type.
      *  @param reg   The represented variable's register.
      */
     private LocalItem makeLocalItem(Type type, int reg) {
         return new LocalItem(type, reg);
     }
     /** Make an item representing a static variable or method.
      *  @param member   The represented symbol.
      */
     Item makeStaticItem(Symbol member) {
         return new StaticItem(member);
     }
     /** Make an item representing an instance variable or method.
      *  @param member       The represented symbol.
      *  @param nonvirtual   Is the reference not virtual? (true for constructors
      *                      and private members).
      */
     Item makeMemberItem(Symbol member, boolean nonvirtual) {
         return new MemberItem(member, nonvirtual);
     }
     /** Make an item representing a literal.
      *  @param type     The literal's type.
      *  @param value    The literal's value.
      */
     Item makeImmediateItem(Type type, Object value) {
         return new ImmediateItem(type, value);
     }
     /** Make an item representing an assignment expression.
      *  @param lhs      The item representing the assignment's left hand side.
      */
     Item makeAssignItem(Item lhs) {
         return new AssignItem(lhs);
     }
     /** Make an item representing a conditional or unconditional jump.
      *  @param opcode      The jump's opcode.
      *  @param trueJumps   A chain encomassing all jumps that can be taken
      *                     if the condition evaluates to true.
      *  @param falseJumps  A chain encomassing all jumps that can be taken
      *                     if the condition evaluates to false.
      */
     CondItem makeCondItem(int opcode, Chain trueJumps, Chain falseJumps) {
         return new CondItem(opcode, trueJumps, falseJumps);
     }
     /** Make an item representing a conditional or unconditional jump.
      *  @param opcode      The jump's opcode.
      */
     CondItem makeCondItem(int opcode) {
         return makeCondItem(opcode, null, null);
     }
     /** The base class of all items, which implements default behavior.
      */
     abstract class Item {
         /** The type code of values represented by this item.
          */
         int typecode;
         Item(int typecode) {
             this.typecode = typecode;
         }
         /** Generate code to load this item onto stack.
          */
         Item load() {
             throw new AssertionError();
         }
         /** Generate code to store top of stack into this item.
          */
         void store() {
             throw new AssertionError("store unsupported: " + this);
         }
         /** Generate code to invoke method represented by this item.
          */
         Item invoke() {
             throw new AssertionError(this);
         }
         /** Generate code to use this item twice.
          */
         void duplicate() {}
         /** Generate code to avoid having to use this item.
          */
         void drop() {}
         /** Generate code to stash a copy of top of stack - of typecode toscode -
          *  under this item.
          */
         void stash(int toscode) {
             stackItem[toscode].duplicate();
         }
         /** Generate code to turn item into a testable condition.
          */
         CondItem mkCond() {
             load();
             return makeCondItem(ifne);
         }
         /** Generate code to coerce item to given type code.
          *  @param targetcode    The type code to coerce to.
          */
         Item coerce(int targetcode) {
             if (typecode == targetcode)
                 return this;
             else {
                 load();
                 int typecode1 = Code.truncate(typecode);
                 int targetcode1 = Code.truncate(targetcode);
                 if (typecode1 != targetcode1) {
                     int offset = targetcode1 > typecode1 ? targetcode1 - 1
                         : targetcode1;
                     code.emitop0(i2l + typecode1 * 3 + offset);
                 }
                 if (targetcode != targetcode1) {
                     code.emitop0(int2byte + targetcode - BYTEcode);
                 }
                 return stackItem[targetcode];
             }
         }
         /** Generate code to coerce item to given type.
          *  @param targettype    The type to coerce to.
          */
         Item coerce(Type targettype) {
             return coerce(Code.typecode(targettype));
         }
         /** Return the width of this item on stack as a number of words.
          */
         int width() {
             return 0;
         }
         public abstract String toString();
     }
     /** An item representing a value on stack.
      */
     class StackItem extends Item {
         StackItem(int typecode) {
             super(typecode);
         }
         Item load() {
             return this;
         }
         void duplicate() {
             code.emitop0(width() == 2 ? dup2 : dup);
         }
         void drop() {
             code.emitop0(width() == 2 ? pop2 : pop);
         }
         void stash(int toscode) {
             code.emitop0(
                 (width() == 2 ? dup_x2 : dup_x1) + 3 * (Code.width(toscode) - 1));
         }
         int width() {
             return Code.width(typecode);
         }
         public String toString() {
             return "stack(" + typecodeNames[typecode] + ")";
         }
     }
     /** An item representing an indexed expression.
      */
     class IndexedItem extends Item {
         IndexedItem(Type type) {
             super(Code.typecode(type));
         }
         Item load() {
             code.emitop0(iaload + typecode);
             return stackItem[typecode];
         }
         void store() {
             code.emitop0(iastore + typecode);
         }
         void duplicate() {
             code.emitop0(dup2);
         }
         void drop() {
             code.emitop0(pop2);
         }
         void stash(int toscode) {
             code.emitop0(dup_x2 + 3 * (Code.width(toscode) - 1));
         }
         int width() {
             return 2;
         }
         public String toString() {
             return "indexed(" + ByteCodes.typecodeNames[typecode] + ")";
         }
     }
     /** An item representing `this' or `super'.
      */
     class SelfItem extends Item {
         /** Flag which determines whether this item represents `this' or `super'.
          */
         boolean isSuper;
         SelfItem(boolean isSuper) {
             super(OBJECTcode);
             this.isSuper = isSuper;
         }
         Item load() {
             code.emitop0(aload_0);
             return stackItem[typecode];
         }
         public String toString() {
             return isSuper ? "super" : "this";
         }
     }
     /** An item representing a local variable.
      */
     class LocalItem extends Item {
         /** The variable's register.
          */
         int reg;
         /** The variable's type.
          */
         Type type;
         LocalItem(Type type, int reg) {
             super(Code.typecode(type));
             assert reg >= 0;
             this.type = type;
             this.reg = reg;
         }
         Item load() {
             if (reg <= 3)
                 code.emitop0(iload_0 + Code.truncate(typecode) * 4 + reg);
             else
                 code.emitop1w(iload + Code.truncate(typecode), reg);
             return stackItem[typecode];
         }
         void store() {
             if (reg <= 3)
                 code.emitop0(istore_0 + Code.truncate(typecode) * 4 + reg);
             else
                 code.emitop1w(istore + Code.truncate(typecode), reg);
             code.setDefined(reg);
         }
         void incr(int x) {
             if (typecode == INTcode && x >= -32768 && x <= 32767) {
                 code.emitop1w(iinc, reg, x);
             } else {
                 load();
                 if (x >= 0) {
                     makeImmediateItem(syms.intType, x).load();
                     code.emitop0(iadd);
                 } else {
                     makeImmediateItem(syms.intType, -x).load();
                     code.emitop0(isub);
                 }
                 makeStackItem(syms.intType).coerce(typecode);
                 store();
             }
         }
         public String toString() {
             return "localItem(type=" + type + "; reg=" + reg + ")";
         }
     }
     /** An item representing a static variable or method.
      */
     class StaticItem extends Item {
         /** The represented symbol.
          */
         Symbol member;
         StaticItem(Symbol member) {
             super(Code.typecode(member.erasure(types)));
             this.member = member;
         }
         Item load() {
             code.emitop2(getstatic, pool.put(member));
             return stackItem[typecode];
         }
         void store() {
             code.emitop2(putstatic, pool.put(member));
         }
         Item invoke() {
             MethodType mtype = (MethodType)member.erasure(types);
             int rescode = Code.typecode(mtype.restype);
             code.emitInvokestatic(pool.put(member), mtype);
             return stackItem[rescode];
         }
         public String toString() {
             return "static(" + member + ")";
         }
     }
     /** An item representing an instance variable or method.
      */
     class MemberItem extends Item {
         /** The represented symbol.
          */
         Symbol member;
         /** Flag that determines whether or not access is virtual.
          */
         boolean nonvirtual;
         MemberItem(Symbol member, boolean nonvirtual) {
             super(Code.typecode(member.erasure(types)));
             this.member = member;
             this.nonvirtual = nonvirtual;
         }
         Item load() {
             code.emitop2(getfield, pool.put(member));
             return stackItem[typecode];
         }
         void store() {
             code.emitop2(putfield, pool.put(member));
         }
         Item invoke() {
             MethodType mtype = (MethodType)member.externalType(types);
             int rescode = Code.typecode(mtype.restype);
             if ((member.owner.flags() & Flags.INTERFACE) != 0) {
                 code.emitInvokeinterface(pool.put(member), mtype);
             } else if (nonvirtual) {
                 code.emitInvokespecial(pool.put(member), mtype);
             } else {
                 code.emitInvokevirtual(pool.put(member), mtype);
             }
             return stackItem[rescode];
         }
         void duplicate() {
             stackItem[OBJECTcode].duplicate();
         }
         void drop() {
             stackItem[OBJECTcode].drop();
         }
         void stash(int toscode) {
             stackItem[OBJECTcode].stash(toscode);
         }
         int width() {
             return 1;
         }
         public String toString() {
             return "member(" + member + (nonvirtual ? " nonvirtual)" : ")");
         }
     }
     /** An item representing a literal.
      */
     class ImmediateItem extends Item {
         /** The literal's value.
          */
         Object value;
         ImmediateItem(Type type, Object value) {
             super(Code.typecode(type));
             this.value = value;
         }
         private void ldc() {
             int idx = pool.put(value);
             if (typecode == LONGcode || typecode == DOUBLEcode) {
                 code.emitop2(ldc2w, idx);
             } else if (idx <= 255) {
                 code.emitop1(ldc1, idx);
             } else {
                 code.emitop2(ldc2, idx);
             }
         }
         Item load() {
             switch (typecode) {
             case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
                 int ival = ((Number)value).intValue();
                 if (-1 <= ival && ival <= 5)
                     code.emitop0(iconst_0 + ival);
                 else if (Byte.MIN_VALUE <= ival && ival <= Byte.MAX_VALUE)
                     code.emitop1(bipush, ival);
                 else if (Short.MIN_VALUE <= ival && ival <= Short.MAX_VALUE)
                     code.emitop2(sipush, ival);
                 else
                     ldc();
                 break;
             case LONGcode:
                 long lval = ((Number)value).longValue();
                 if (lval == 0 || lval == 1)
                     code.emitop0(lconst_0 + (int)lval);
                 else
                     ldc();
                 break;
             case FLOATcode:
                 float fval = ((Number)value).floatValue();
                 if (isPosZero(fval) || fval == 1.0 || fval == 2.0)
                     code.emitop0(fconst_0 + (int)fval);
                 else {
                     ldc();
                 }
                 break;
             case DOUBLEcode:
                 double dval = ((Number)value).doubleValue();
                 if (isPosZero(dval) || dval == 1.0)
                     code.emitop0(dconst_0 + (int)dval);
                 else
                     ldc();
                 break;
             case OBJECTcode:
                 ldc();
                 break;
             default:
                 assert false;
             }
             return stackItem[typecode];
         }
         //where
             /** Return true iff float number is positive 0.
              */
             private boolean isPosZero(float x) {
                 return x == 0.0f && 1.0f / x > 0.0f;
             }
             /** Return true iff double number is positive 0.
              */
             private boolean isPosZero(double x) {
                 return x == 0.0d && 1.0d / x > 0.0d;
             }
         CondItem mkCond() {
             int ival = ((Number)value).intValue();
             return makeCondItem(ival != 0 ? goto_ : dontgoto);
         }
         Item coerce(int targetcode) {
             if (typecode == targetcode) {
                 return this;
             } else {
                 switch (targetcode) {
                 case INTcode:
                     if (Code.truncate(typecode) == INTcode)
                         return this;
                     else
                         return new ImmediateItem(
                             syms.intType,
                             ((Number)value).intValue());
                 case LONGcode:
                     return new ImmediateItem(
                         syms.longType,
                         ((Number)value).longValue());
                 case FLOATcode:
                     return new ImmediateItem(
                         syms.floatType,
                         ((Number)value).floatValue());
                 case DOUBLEcode:
                     return new ImmediateItem(
                         syms.doubleType,
                         ((Number)value).doubleValue());
                 case BYTEcode:
                     return new ImmediateItem(
                         syms.byteType,
                         (int)(byte)((Number)value).intValue());
                 case CHARcode:
                     return new ImmediateItem(
                         syms.charType,
                         (int)(char)((Number)value).intValue());
                 case SHORTcode:
                     return new ImmediateItem(
                         syms.shortType,
                         (int)(short)((Number)value).intValue());
                 default:
                     return super.coerce(targetcode);
                 }
             }
         }
         public String toString() {
             return "immediate(" + value + ")";
         }
     }
     /** An item representing an assignment expressions.
      */
     class AssignItem extends Item {
         /** The item representing the assignment's left hand side.
          */
         Item lhs;
         AssignItem(Item lhs) {
             super(lhs.typecode);
             this.lhs = lhs;
         }
         Item load() {
             lhs.stash(typecode);
             lhs.store();
             return stackItem[typecode];
         }
         void duplicate() {
             load().duplicate();
         }
         void drop() {
             lhs.store();
         }
         void stash(int toscode) {
             assert false;
         }
         int width() {
             return lhs.width() + Code.width(typecode);
         }
         public String toString() {
             return "assign(lhs = " + lhs + ")";
         }
     }
     /** An item representing a conditional or unconditional jump.
      */
     class CondItem extends Item {
         /** A chain encomassing all jumps that can be taken
          *  if the condition evaluates to true.
          */
         Chain trueJumps;
         /** A chain encomassing all jumps that can be taken
          *  if the condition evaluates to false.
          */
         Chain falseJumps;
         /** The jump's opcode.
          */
         int opcode;
         /*
          *  An abstract syntax tree of this item. It is needed
          *  for branch entries in 'CharacterRangeTable' attribute.
          */
         JCTree tree;
         CondItem(int opcode, Chain truejumps, Chain falsejumps) {
             super(BYTEcode);
             this.opcode = opcode;
             this.trueJumps = truejumps;
             this.falseJumps = falsejumps;
         }
         Item load() {
             Chain trueChain = null;
             Chain falseChain = jumpFalse();
             if (!isFalse()) {
                 code.resolve(trueJumps);
                 code.emitop0(iconst_1);
                 trueChain = code.branch(goto_);
             }
             if (falseChain != null) {
                 code.resolve(falseChain);
                 code.emitop0(iconst_0);
             }
             code.resolve(trueChain);
             return stackItem[typecode];
         }
         void duplicate() {
             load().duplicate();
         }
         void drop() {
             load().drop();
         }
         void stash(int toscode) {
             assert false;
         }
         CondItem mkCond() {
             return this;
         }
         Chain jumpTrue() {
             if (tree == null) return code.mergeChains(trueJumps, code.branch(opcode));
             // we should proceed further in -Xjcov mode only
             int startpc = code.curPc();
             Chain c = code.mergeChains(trueJumps, code.branch(opcode));
             code.crt.put(tree, CRTable.CRT_BRANCH_TRUE, startpc, code.curPc());
             return c;
         }
         Chain jumpFalse() {
             if (tree == null) return code.mergeChains(falseJumps, code.branch(code.negate(opcode)));
             // we should proceed further in -Xjcov mode only
             int startpc = code.curPc();
             Chain c = code.mergeChains(falseJumps, code.branch(code.negate(opcode)));
             code.crt.put(tree, CRTable.CRT_BRANCH_FALSE, startpc, code.curPc());
             return c;
         }
         CondItem negate() {
             CondItem c = new CondItem(code.negate(opcode), falseJumps, trueJumps);
             c.tree = tree;
             return c;
         }
         int width() {
             // a CondItem doesn't have a size on the stack per se.
             throw new AssertionError();
         }
         boolean isTrue() {
             return falseJumps == null && opcode == goto_;
         }
         boolean isFalse() {
             return trueJumps == null && opcode == dontgoto;
         }
         public String toString() {
             return "cond(" + Code.mnem(opcode) + ")";
         }
     }
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/com/sun/tools/javac/jvm/Items.java@89f67512b635 (annotated)

src/share/classes/com/sun/tools/javac/jvm/Items.java