MethodVisitor


1   /***
2    * ASM: a very small and fast Java bytecode manipulation framework
3    * Copyright (c) 2000-2005 INRIA, France Telecom
4    * All rights reserved.
5    *
6    * Redistribution and use in source and binary forms, with or without
7    * modification, are permitted provided that the following conditions
8    * are met:
9    * 1. Redistributions of source code must retain the above copyright
10   *    notice, this list of conditions and the following disclaimer.
11   * 2. Redistributions in binary form must reproduce the above copyright
12   *    notice, this list of conditions and the following disclaimer in the
13   *    documentation and/or other materials provided with the distribution.
14   * 3. Neither the name of the copyright holders nor the names of its
15   *    contributors may be used to endorse or promote products derived from
16   *    this software without specific prior written permission.
17   *
18   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28   * THE POSSIBILITY OF SUCH DAMAGE.
29   */
30  package org.objectweb.asm;
31  
32  /**
33   * A visitor to visit a Java method. The methods of this interface must be
34   * called in the following order: [ <tt>visitAnnotationDefault</tt> ] (
35   * <tt>visitAnnotation</tt> | <tt>visitParameterAnnotation</tt> |
36   * <tt>visitAttribute</tt> )* [ <tt>visitCode</tt> ( <tt>visit</tt><i>X</i>Insn</tt> |
37   * <tt>visitLabel</tt> | <tt>visitTryCatchBlock</tt> | <tt>visitLocalVariable</tt> |
38   * <tt>visitLineNumber</tt>)* <tt>visitMaxs</tt> ] <tt>visitEnd</tt>. In
39   * addition, the <tt>visit</tt><i>X</i>Insn</tt> and <tt>visitLabel</tt>
40   * methods must be called in the sequential order of the bytecode instructions
41   * of the visited code, and the <tt>visitTryCatchBlock</tt>, <tt>visitLocalVariable</tt>
42   * and <tt>visitLineNumber</tt> methods must be called after the labels passed
43   * as arguments have been visited.
44   * 
45   * @author Eric Bruneton
46   */
47  public interface MethodVisitor {
48  
49      // -------------------------------------------------------------------------
50      // Annotations and non standard attributes
51      // -------------------------------------------------------------------------
52  
53      /**
54       * Visits the default value of this annotation interface method.
55       * 
56       * @return a non null visitor to the visit the actual default value of this
57       *         annotation interface method. The 'name' parameters passed to the
58       *         methods of this annotation visitor are ignored. Moreover, exacly
59       *         one visit method must be called on this annotation visitor,
60       *         followed by visitEnd.
61       */
62      AnnotationVisitor visitAnnotationDefault();
63  
64      /**
65       * Visits an annotation of this method.
66       * 
67       * @param desc the class descriptor of the annotation class.
68       * @param visible <tt>true</tt> if the annotation is visible at runtime.
69       * @return a non null visitor to visit the annotation values.
70       */
71      AnnotationVisitor visitAnnotation(String   desc, boolean visible);
72  
73      /**
74       * Visits an annotation of a parameter this method.
75       * 
76       * @param parameter the parameter index.
77       * @param desc the class descriptor of the annotation class.
78       * @param visible <tt>true</tt> if the annotation is visible at runtime.
79       * @return a non null visitor to visit the annotation values.
80       */
81      AnnotationVisitor visitParameterAnnotation(
82          int parameter,
83          String   desc,
84          boolean visible);
85  
86      /**
87       * Visits a non standard attribute of this method.
88       * 
89       * @param attr an attribute.
90       */
91      void visitAttribute(Attribute attr);
92  
93      /**
94       * Starts the visit of the method's code, if any (i.e. non abstract method).
95       */
96      void visitCode();
97  
98      // -------------------------------------------------------------------------
99      // Normal instructions
100     // -------------------------------------------------------------------------
101 
102     /**
103      * Visits a zero operand instruction.
104      * 
105      * @param opcode the opcode of the instruction to be visited. This opcode is
106      *        either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2,
107      *        ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0,
108      *        FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD, LALOAD, FALOAD,
109      *        DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IASTORE, LASTORE, FASTORE,
110      *        DASTORE, AASTORE, BASTORE, CASTORE, SASTORE, POP, POP2, DUP,
111      *        DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP, IADD, LADD, FADD,
112      *        DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV,
113      *        FDIV, DDIV, IREM, LREM, FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL,
114      *        LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR,
115      *        I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B,
116      *        I2C, I2S, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN,
117      *        FRETURN, DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW,
118      *        MONITORENTER, or MONITOREXIT.
119      */
120     void visitInsn(int opcode);
121 
122     /**
123      * Visits an instruction with a single int operand.
124      * 
125      * @param opcode the opcode of the instruction to be visited. This opcode is
126      *        either BIPUSH, SIPUSH or NEWARRAY.
127      * @param operand the operand of the instruction to be visited.
128      */
129     void visitIntInsn(int opcode, int operand);
130 
131     /**
132      * Visits a local variable instruction. A local variable instruction is an
133      * instruction that loads or stores the value of a local variable.
134      * 
135      * @param opcode the opcode of the local variable instruction to be visited.
136      *        This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE,
137      *        LSTORE, FSTORE, DSTORE, ASTORE or RET.
138      * @param var the operand of the instruction to be visited. This operand is
139      *        the index of a local variable.
140      */
141     void visitVarInsn(int opcode, int var);
142 
143     /**
144      * Visits a type instruction. A type instruction is an instruction that
145      * takes a type descriptor as parameter.
146      * 
147      * @param opcode the opcode of the type instruction to be visited. This
148      *        opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.
149      * @param desc the operand of the instruction to be visited. This operand is
150      *        must be a fully qualified class name in internal form, or the type
151      *        descriptor of an array type (see {@link Type Type}).
152      */
153     void visitTypeInsn(int opcode, String   desc);
154 
155     /**
156      * Visits a field instruction. A field instruction is an instruction that
157      * loads or stores the value of a field of an object.
158      * 
159      * @param opcode the opcode of the type instruction to be visited. This
160      *        opcode is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.
161      * @param owner the internal name of the field's owner class (see {@link
162      *        Type#getInternalName() getInternalName}).
163      * @param name the field's name.
164      * @param desc the field's descriptor (see {@link Type Type}).
165      */
166     void visitFieldInsn(int opcode, String   owner, String   name, String   desc);
167 
168     /**
169      * Visits a method instruction. A method instruction is an instruction that
170      * invokes a method.
171      * 
172      * @param opcode the opcode of the type instruction to be visited. This
173      *        opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or
174      *        INVOKEINTERFACE.
175      * @param owner the internal name of the method's owner class (see {@link
176      *        Type#getInternalName() getInternalName}).
177      * @param name the method's name.
178      * @param desc the method's descriptor (see {@link Type Type}).
179      */
180     void visitMethodInsn(int opcode, String   owner, String   name, String   desc);
181 
182     /**
183      * Visits a jump instruction. A jump instruction is an instruction that may
184      * jump to another instruction.
185      * 
186      * @param opcode the opcode of the type instruction to be visited. This
187      *        opcode is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ,
188      *        IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ,
189      *        IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.
190      * @param label the operand of the instruction to be visited. This operand
191      *        is a label that designates the instruction to which the jump
192      *        instruction may jump.
193      */
194     void visitJumpInsn(int opcode, Label label);
195 
196     /**
197      * Visits a label. A label designates the instruction that will be visited
198      * just after it.
199      * 
200      * @param label a {@link Label Label} object.
201      */
202     void visitLabel(Label label);
203 
204     // -------------------------------------------------------------------------
205     // Special instructions
206     // -------------------------------------------------------------------------
207 
208     /**
209      * Visits a LDC instruction.
210      * 
211      * @param cst the constant to be loaded on the stack. This parameter must be
212      *        a non null {@link Integer}, a {@link Float}, a {@link Long}, a
213      *        {@link Double} a {@link String} (or a {@link Type} for
214      *        <tt>.class</tt> constants, for classes whose version is 49.0 or
215      *        more).
216      */
217     void visitLdcInsn(Object   cst);
218 
219     /**
220      * Visits an IINC instruction.
221      * 
222      * @param var index of the local variable to be incremented.
223      * @param increment amount to increment the local variable by.
224      */
225     void visitIincInsn(int var, int increment);
226 
227     /**
228      * Visits a TABLESWITCH instruction.
229      * 
230      * @param min the minimum key value.
231      * @param max the maximum key value.
232      * @param dflt beginning of the default handler block.
233      * @param labels beginnings of the handler blocks. <tt>labels[i]</tt> is
234      *        the beginning of the handler block for the <tt>min + i</tt> key.
235      */
236     void visitTableSwitchInsn(int min, int max, Label dflt, Label labels[]);
237 
238     /**
239      * Visits a LOOKUPSWITCH instruction.
240      * 
241      * @param dflt beginning of the default handler block.
242      * @param keys the values of the keys.
243      * @param labels beginnings of the handler blocks. <tt>labels[i]</tt> is
244      *        the beginning of the handler block for the <tt>keys[i]</tt> key.
245      */
246     void visitLookupSwitchInsn(Label dflt, int keys[], Label labels[]);
247 
248     /**
249      * Visits a MULTIANEWARRAY instruction.
250      * 
251      * @param desc an array type descriptor (see {@link Type Type}).
252      * @param dims number of dimensions of the array to allocate.
253      */
254     void visitMultiANewArrayInsn(String   desc, int dims);
255 
256     // -------------------------------------------------------------------------
257     // Exceptions table entries, debug information, max stack size and max
258     // locals
259     // -------------------------------------------------------------------------
260 
261     /**
262      * Visits a try catch block.
263      * 
264      * @param start beginning of the exception handler's scope (inclusive).
265      * @param end end of the exception handler's scope (exclusive).
266      * @param handler beginning of the exception handler's code.
267      * @param type internal name of the type of exceptions handled by the
268      *        handler, or <tt>null</tt> to catch any exceptions (for "finally"
269      *        blocks).
270      * @throws IllegalArgumentException if one of the labels has not already
271      *         been visited by this visitor (by the
272      *         {@link #visitLabel visitLabel} method).
273      */
274     void visitTryCatchBlock(Label start, Label end, Label handler, String   type);
275 
276     /**
277      * Visits a local variable declaration.
278      * 
279      * @param name the name of a local variable.
280      * @param desc the type descriptor of this local variable.
281      * @param signature the type signature of this local variable. May be
282      *        <tt>null</tt> if the local variable type does not use generic
283      *        types.
284      * @param start the first instruction corresponding to the scope of this
285      *        local variable (inclusive).
286      * @param end the last instruction corresponding to the scope of this local
287      *        variable (exclusive).
288      * @param index the local variable's index.
289      * @throws IllegalArgumentException if one of the labels has not already
290      *         been visited by this visitor (by the
291      *         {@link #visitLabel visitLabel} method).
292      */
293     void visitLocalVariable(
294         String   name,
295         String   desc,
296         String   signature,
297         Label start,
298         Label end,
299         int index);
300 
301     /**
302      * Visits a line number declaration.
303      * 
304      * @param line a line number. This number refers to the source file from
305      *        which the class was compiled.
306      * @param start the first instruction corresponding to this line number.
307      * @throws IllegalArgumentException if <tt>start</tt> has not already been
308      *         visited by this visitor (by the {@link #visitLabel visitLabel}
309      *         method).
310      */
311     void visitLineNumber(int line, Label start);
312 
313     /**
314      * Visits the maximum stack size and the maximum number of local variables
315      * of the method.
316      * 
317      * @param maxStack maximum stack size of the method.
318      * @param maxLocals maximum number of local variables for the method.
319      */
320     void visitMaxs(int maxStack, int maxLocals);
321 
322     /**
323      * Visits the end of the method. This method, which is the last one to be
324      * called, is used to inform the visitor that all the annotations and
325      * attributes of the method have been visited.
326      */
327     void visitEnd();
328 }
329
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