| /* |
| * Copyright (c) 1994, 2003, 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 sun.tools.tree; |
| |
| import sun.tools.java.*; |
| import sun.tools.asm.Assembler; |
| import java.io.PrintStream; |
| import java.util.Hashtable; |
| |
| /** |
| * WARNING: The contents of this source file are not part of any |
| * supported API. Code that depends on them does so at its own risk: |
| * they are subject to change or removal without notice. |
| */ |
| public |
| class ArrayAccessExpression extends UnaryExpression { |
| |
| /** |
| * The index expression for the array access. Note that |
| * ArrayAccessExpression also `moonlights' as a structure for |
| * storing array types (like Object[]) which are used as part |
| * of cast expressions. For properly formed array types, the |
| * value of index is null. We need to be on the lookout for |
| * null indices in true array accesses, and non-null indices |
| * in array types. We also need to make sure general purpose |
| * methods (like copyInline(), which is called for both) are |
| * prepared to handle either null or non-null indices. |
| */ |
| Expression index; |
| |
| /** |
| * constructor |
| */ |
| public ArrayAccessExpression(long where, Expression right, Expression index) { |
| super(ARRAYACCESS, where, Type.tError, right); |
| this.index = index; |
| } |
| |
| /** |
| * Check expression type |
| */ |
| public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable exp) { |
| vset = right.checkValue(env, ctx, vset, exp); |
| if (index == null) { |
| env.error(where, "array.index.required"); |
| return vset; |
| } |
| vset = index.checkValue(env, ctx, vset, exp); |
| index = convert(env, ctx, Type.tInt, index); |
| |
| if (!right.type.isType(TC_ARRAY)) { |
| if (!right.type.isType(TC_ERROR)) { |
| env.error(where, "not.array", right.type); |
| } |
| return vset; |
| } |
| |
| type = right.type.getElementType(); |
| return vset; |
| } |
| |
| public Vset checkAmbigName(Environment env, Context ctx, |
| Vset vset, Hashtable exp, |
| UnaryExpression loc) { |
| if (index == null) { |
| vset = right.checkAmbigName(env, ctx, vset, exp, this); |
| if (right.type == Type.tPackage) { |
| FieldExpression.reportFailedPackagePrefix(env, right); |
| return vset; |
| } |
| |
| // Nope. Is this field expression a type? |
| if (right instanceof TypeExpression) { |
| Type atype = Type.tArray(right.type); |
| loc.right = new TypeExpression(where, atype); |
| return vset; |
| } |
| |
| env.error(where, "array.index.required"); |
| return vset; |
| } |
| return super.checkAmbigName(env, ctx, vset, exp, loc); |
| } |
| |
| /* |
| * Check the array if it appears on the LHS of an assignment |
| */ |
| public Vset checkLHS(Environment env, Context ctx, |
| Vset vset, Hashtable exp) { |
| return checkValue(env, ctx, vset, exp); |
| } |
| |
| /* |
| * Check the array if it appears on the LHS of an op= expression |
| */ |
| public Vset checkAssignOp(Environment env, Context ctx, |
| Vset vset, Hashtable exp, Expression outside) { |
| return checkValue(env, ctx, vset, exp); |
| } |
| |
| /** |
| * An array access expression never requires the use of an access method to perform |
| * an assignment to an array element, though an access method may be required to |
| * fetch the array object itself. |
| */ |
| public FieldUpdater getAssigner(Environment env, Context ctx) { |
| return null; |
| } |
| |
| /** |
| * An array access expression never requires a field updater. |
| */ |
| public FieldUpdater getUpdater(Environment env, Context ctx) { |
| return null; |
| } |
| |
| /** |
| * Convert to a type |
| */ |
| Type toType(Environment env, Context ctx) { |
| return toType(env, right.toType(env, ctx)); |
| } |
| Type toType(Environment env, Type t) { |
| if (index != null) { |
| env.error(index.where, "array.dim.in.type"); |
| } |
| return Type.tArray(t); |
| } |
| |
| /** |
| * Inline |
| */ |
| public Expression inline(Environment env, Context ctx) { |
| // It isn't possible to simply replace an array access |
| // with a CommaExpression as happens with many binary |
| // operators, because array accesses may have side effects |
| // such as NullPointerException or IndexOutOfBoundsException. |
| right = right.inlineValue(env, ctx); |
| index = index.inlineValue(env, ctx); |
| return this; |
| } |
| public Expression inlineValue(Environment env, Context ctx) { |
| // inlineValue() should not end up being called when the index is |
| // null. If it is null, we let this method fail with a |
| // NullPointerException. |
| |
| right = right.inlineValue(env, ctx); |
| index = index.inlineValue(env, ctx); |
| return this; |
| } |
| public Expression inlineLHS(Environment env, Context ctx) { |
| return inlineValue(env, ctx); |
| } |
| |
| /** |
| * Create a copy of the expression for method inlining |
| */ |
| public Expression copyInline(Context ctx) { |
| ArrayAccessExpression e = (ArrayAccessExpression)clone(); |
| e.right = right.copyInline(ctx); |
| if (index == null) { |
| // The index can be null when this node is being used to |
| // represent a type (e.g. Object[]) used in a cast expression. |
| // We need to copy such structures without complaint. |
| e.index = null; |
| } else { |
| e.index = index.copyInline(ctx); |
| } |
| return e; |
| } |
| |
| /** |
| * The cost of inlining this expression |
| */ |
| public int costInline(int thresh, Environment env, Context ctx) { |
| // costInline() should not end up being called when the index is |
| // null. If it is null, we let this method fail with a |
| // NullPointerException. |
| |
| return 1 + right.costInline(thresh, env, ctx) |
| + index.costInline(thresh, env, ctx); |
| } |
| |
| /** |
| * Code |
| */ |
| int codeLValue(Environment env, Context ctx, Assembler asm) { |
| // codeLValue() should not end up being called when the index is |
| // null. If it is null, we let this method fail with a |
| // NullPointerException. |
| |
| right.codeValue(env, ctx, asm); |
| index.codeValue(env, ctx, asm); |
| return 2; |
| } |
| void codeLoad(Environment env, Context ctx, Assembler asm) { |
| switch (type.getTypeCode()) { |
| case TC_BOOLEAN: |
| case TC_BYTE: |
| asm.add(where, opc_baload); |
| break; |
| case TC_CHAR: |
| asm.add(where, opc_caload); |
| break; |
| case TC_SHORT: |
| asm.add(where, opc_saload); |
| break; |
| default: |
| asm.add(where, opc_iaload + type.getTypeCodeOffset()); |
| } |
| } |
| void codeStore(Environment env, Context ctx, Assembler asm) { |
| switch (type.getTypeCode()) { |
| case TC_BOOLEAN: |
| case TC_BYTE: |
| asm.add(where, opc_bastore); |
| break; |
| case TC_CHAR: |
| asm.add(where, opc_castore); |
| break; |
| case TC_SHORT: |
| asm.add(where, opc_sastore); |
| break; |
| default: |
| asm.add(where, opc_iastore + type.getTypeCodeOffset()); |
| } |
| } |
| public void codeValue(Environment env, Context ctx, Assembler asm) { |
| codeLValue(env, ctx, asm); |
| codeLoad(env, ctx, asm); |
| } |
| |
| |
| /** |
| * Print |
| */ |
| public void print(PrintStream out) { |
| out.print("(" + opNames[op] + " "); |
| right.print(out); |
| out.print(" "); |
| if (index != null) { |
| index.print(out); |
| } else { |
| out.print("<empty>"); |
| } |
| out.print(")"); |
| } |
| } |