J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1994-2003 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.tools.tree; |
| 27 | |
| 28 | import sun.tools.java.*; |
| 29 | import sun.tools.asm.Assembler; |
| 30 | import java.io.PrintStream; |
| 31 | import java.util.Hashtable; |
| 32 | |
| 33 | /** |
| 34 | * WARNING: The contents of this source file are not part of any |
| 35 | * supported API. Code that depends on them does so at its own risk: |
| 36 | * they are subject to change or removal without notice. |
| 37 | */ |
| 38 | public |
| 39 | class AssignExpression extends BinaryAssignExpression { |
| 40 | |
| 41 | private FieldUpdater updater = null; |
| 42 | |
| 43 | /** |
| 44 | * Constructor |
| 45 | */ |
| 46 | public AssignExpression(long where, Expression left, Expression right) { |
| 47 | super(ASSIGN, where, left, right); |
| 48 | } |
| 49 | |
| 50 | /** |
| 51 | * Check an assignment expression |
| 52 | */ |
| 53 | public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable exp) { |
| 54 | if (left instanceof IdentifierExpression) { |
| 55 | // we don't want to mark an identifier as having a value |
| 56 | // until having evaluated the right-hand side |
| 57 | vset = right.checkValue(env, ctx, vset, exp); |
| 58 | vset = left.checkLHS(env, ctx, vset, exp); |
| 59 | } else { |
| 60 | // normally left to right evaluation. |
| 61 | vset = left.checkLHS(env, ctx, vset, exp); |
| 62 | vset = right.checkValue(env, ctx, vset, exp); |
| 63 | } |
| 64 | type = left.type; |
| 65 | right = convert(env, ctx, type, right); |
| 66 | |
| 67 | // Get field updater (access method) if needed, else null. |
| 68 | updater = left.getAssigner(env, ctx); |
| 69 | |
| 70 | return vset; |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * Inline |
| 75 | */ |
| 76 | public Expression inlineValue(Environment env, Context ctx) { |
| 77 | if (implementation != null) |
| 78 | return implementation.inlineValue(env, ctx); |
| 79 | // Must be 'inlineLHS' here. But compare with similar case in |
| 80 | // 'AssignOpExpression' and 'IncDecExpression', which needs 'inlineValue'. |
| 81 | left = left.inlineLHS(env, ctx); |
| 82 | right = right.inlineValue(env, ctx); |
| 83 | if (updater != null) { |
| 84 | updater = updater.inline(env, ctx); |
| 85 | } |
| 86 | return this; |
| 87 | } |
| 88 | |
| 89 | /** |
| 90 | * Create a copy of the expression for method inlining |
| 91 | */ |
| 92 | public Expression copyInline(Context ctx) { |
| 93 | if (implementation != null) |
| 94 | return implementation.copyInline(ctx); |
| 95 | AssignExpression e = (AssignExpression)clone(); |
| 96 | e.left = left.copyInline(ctx); |
| 97 | e.right = right.copyInline(ctx); |
| 98 | if (updater != null) { |
| 99 | e.updater = updater.copyInline(ctx); |
| 100 | } |
| 101 | return e; |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * The cost of inlining this expression |
| 106 | */ |
| 107 | public int costInline(int thresh, Environment env, Context ctx) { |
| 108 | /*----------* |
| 109 | return 2 + super.costInline(thresh, env, ctx); |
| 110 | *----------*/ |
| 111 | return (updater != null) |
| 112 | // Cost of rhs expression + cost of access method call. |
| 113 | // Access method call cost includes lhs cost. |
| 114 | ? right.costInline(thresh, env, ctx) + |
| 115 | updater.costInline(thresh, env, ctx, false) |
| 116 | // Cost of rhs expression + cost of lhs expression + |
| 117 | // cost of store instruction. |
| 118 | : right.costInline(thresh, env, ctx) + |
| 119 | left.costInline(thresh, env, ctx) + 2; |
| 120 | } |
| 121 | |
| 122 | /** |
| 123 | * Code |
| 124 | */ |
| 125 | public void codeValue(Environment env, Context ctx, Assembler asm) { |
| 126 | if (updater == null) { |
| 127 | // Field is directly accessible. |
| 128 | int depth = left.codeLValue(env, ctx, asm); |
| 129 | right.codeValue(env, ctx, asm); |
| 130 | codeDup(env, ctx, asm, right.type.stackSize(), depth); |
| 131 | left.codeStore(env, ctx, asm); |
| 132 | } else { |
| 133 | // Must use access method. |
| 134 | // Left operand is always a 'FieldExpression', or |
| 135 | // is rewritten as one via 'implementation'. |
| 136 | updater.startAssign(env, ctx, asm); |
| 137 | right.codeValue(env, ctx, asm); |
| 138 | updater.finishAssign(env, ctx, asm, true); |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | public void code(Environment env, Context ctx, Assembler asm) { |
| 143 | if (updater == null) { |
| 144 | // Field is directly accessible. |
| 145 | left.codeLValue(env, ctx, asm); |
| 146 | right.codeValue(env, ctx, asm); |
| 147 | left.codeStore(env, ctx, asm); |
| 148 | } else { |
| 149 | // Must use access method. |
| 150 | // Left operand is always a 'FieldExpression', or |
| 151 | // is rewritten as one via 'implementation'. |
| 152 | updater.startAssign(env, ctx, asm); |
| 153 | right.codeValue(env, ctx, asm); |
| 154 | updater.finishAssign(env, ctx, asm, false); |
| 155 | } |
| 156 | } |
| 157 | } |