43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 * ====================================================================
54 *
55 * This software consists of voluntary contributions made by many
56 * individuals on behalf of the Apache Software Foundation. For more
57 * information on the Apache Software Foundation, please see
58 * <http://www.apache.org/>.
59 */
60
61 import com.sun.org.apache.bcel.internal.Constants;
62 import com.sun.org.apache.bcel.internal.classfile.*;
63
64 /**
65 * This class represents a local variable within a method. It contains its
66 * scope, name and type. The generated LocalVariable object can be obtained
67 * with getLocalVariable which needs the instruction list and the constant
68 * pool as parameters.
69 *
70 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
71 * @see LocalVariable
72 * @see MethodGen
73 */
74 public class LocalVariableGen
75 implements InstructionTargeter, NamedAndTyped, Cloneable,
76 java.io.Serializable
77 {
78 private int index;
79 private String name;
80 private Type type;
81 private InstructionHandle start, end;
82
83 /**
84 * Generate a local variable that with index `index'. Note that double and long
85 * variables need two indexs. Index indices have to be provided by the user.
86 *
87 * @param index index of local variable
88 * @param name its name
89 * @param type its type
90 * @param start from where the instruction is valid (null means from the start)
91 * @param end until where the instruction is valid (null means to the end)
92 */
93 public LocalVariableGen(int index, String name, Type type,
94 InstructionHandle start, InstructionHandle end) {
95 if((index < 0) || (index > Constants.MAX_SHORT))
96 throw new ClassGenException("Invalid index index: " + index);
97
98 this.name = name;
114 * start_pc+length ending at first index beyond the end of the code are
115 * valid.
116 *
117 * @param il instruction list (byte code) which this variable belongs to
118 * @param cp constant pool
119 */
120 public LocalVariable getLocalVariable(ConstantPoolGen cp) {
121 int start_pc = start.getPosition();
122 int length = end.getPosition() - start_pc;
123
124 if(length > 0)
125 length += end.getInstruction().getLength();
126
127 int name_index = cp.addUtf8(name);
128 int signature_index = cp.addUtf8(type.getSignature());
129
130 return new LocalVariable(start_pc, length, name_index,
131 signature_index, index, cp.getConstantPool());
132 }
133
134 public void setIndex(int index) { this.index = index; }
135 public int getIndex() { return index; }
136 public void setName(String name) { this.name = name; }
137 public String getName() { return name; }
138 public void setType(Type type) { this.type = type; }
139 public Type getType() { return type; }
140
141 public InstructionHandle getStart() { return start; }
142 public InstructionHandle getEnd() { return end; }
143
144 public void setStart(InstructionHandle start) {
145 BranchInstruction.notifyTarget(this.start, start, this);
146 this.start = start;
147 }
148
149 public void setEnd(InstructionHandle end) {
150 BranchInstruction.notifyTarget(this.end, end, this);
151 this.end = end;
152 }
153
154 /**
155 * @param old_ih old target, either start or end
156 * @param new_ih new target
157 */
158 public void updateTarget(InstructionHandle old_ih, InstructionHandle new_ih) {
159 boolean targeted = false;
160
161 if(start == old_ih) {
162 targeted = true;
163 setStart(new_ih);
164 }
165
166 if(end == old_ih) {
167 targeted = true;
168 setEnd(new_ih);
169 }
170
171 if(!targeted)
172 throw new ClassGenException("Not targeting " + old_ih + ", but {" + start + ", " +
173 end + "}");
174 }
175
176 /**
177 * @return true, if ih is target of this variable
178 */
179 public boolean containsTarget(InstructionHandle ih) {
180 return (start == ih) || (end == ih);
181 }
182
183 /**
184 * We consider to local variables to be equal, if the use the same index and
185 * are valid in the same range.
186 */
187 public boolean equals(Object o) {
188 if(!(o instanceof LocalVariableGen))
189 return false;
190
191 LocalVariableGen l = (LocalVariableGen)o;
192 return (l.index == index) && (l.start == start) && (l.end == end);
193 }
194
195 public String toString() {
196 return "LocalVariableGen(" + name + ", " + type + ", " + start + ", " + end + ")";
197 }
198
199 public Object clone() {
200 try {
201 return super.clone();
202 } catch(CloneNotSupportedException e) {
203 System.err.println(e);
204 return null;
205 }
206 }
207 }
|
43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 * ====================================================================
54 *
55 * This software consists of voluntary contributions made by many
56 * individuals on behalf of the Apache Software Foundation. For more
57 * information on the Apache Software Foundation, please see
58 * <http://www.apache.org/>.
59 */
60
61 import com.sun.org.apache.bcel.internal.Constants;
62 import com.sun.org.apache.bcel.internal.classfile.*;
63 import java.util.Objects;
64
65 /**
66 * This class represents a local variable within a method. It contains its
67 * scope, name and type. The generated LocalVariable object can be obtained
68 * with getLocalVariable which needs the instruction list and the constant
69 * pool as parameters.
70 *
71 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
72 * @see LocalVariable
73 * @see MethodGen
74 */
75 public class LocalVariableGen
76 implements InstructionTargeter, NamedAndTyped, Cloneable,
77 java.io.Serializable
78 {
79 private final int index;
80 private String name;
81 private Type type;
82 private InstructionHandle start, end;
83
84 /**
85 * Generate a local variable that with index `index'. Note that double and long
86 * variables need two indexs. Index indices have to be provided by the user.
87 *
88 * @param index index of local variable
89 * @param name its name
90 * @param type its type
91 * @param start from where the instruction is valid (null means from the start)
92 * @param end until where the instruction is valid (null means to the end)
93 */
94 public LocalVariableGen(int index, String name, Type type,
95 InstructionHandle start, InstructionHandle end) {
96 if((index < 0) || (index > Constants.MAX_SHORT))
97 throw new ClassGenException("Invalid index index: " + index);
98
99 this.name = name;
115 * start_pc+length ending at first index beyond the end of the code are
116 * valid.
117 *
118 * @param il instruction list (byte code) which this variable belongs to
119 * @param cp constant pool
120 */
121 public LocalVariable getLocalVariable(ConstantPoolGen cp) {
122 int start_pc = start.getPosition();
123 int length = end.getPosition() - start_pc;
124
125 if(length > 0)
126 length += end.getInstruction().getLength();
127
128 int name_index = cp.addUtf8(name);
129 int signature_index = cp.addUtf8(type.getSignature());
130
131 return new LocalVariable(start_pc, length, name_index,
132 signature_index, index, cp.getConstantPool());
133 }
134
135 public int getIndex() { return index; }
136 @Override
137 public void setName(String name) { this.name = name; }
138 @Override
139 public String getName() { return name; }
140 @Override
141 public void setType(Type type) { this.type = type; }
142 @Override
143 public Type getType() { return type; }
144
145 public InstructionHandle getStart() { return start; }
146 public InstructionHandle getEnd() { return end; }
147
148 /**
149 * Remove this from any known HashSet in which it might be registered.
150 */
151 void notifyTargetChanging() {
152 // hashCode depends on 'index', 'start', and 'end'.
153 // Therefore before changing any of these values we
154 // need to unregister 'this' from any HashSet where
155 // this is registered, and then we need to add it
156 // back...
157
158 // Unregister 'this' from the HashSet held by 'start'.
159 BranchInstruction.notifyTargetChanging(this.start, this);
160 if (this.end != this.start) {
161 // Since hashCode() is going to change we need to unregister
162 // 'this' both form 'start' and 'end'.
163 // Unregister 'this' from the HashSet held by 'end'.
164 BranchInstruction.notifyTargetChanging(this.end, this);
165 }
166 }
167
168 /**
169 * Add back 'this' in all HashSet in which it should be registered.
170 **/
171 void notifyTargetChanged() {
172 // hashCode depends on 'index', 'start', and 'end'.
173 // Therefore before changing any of these values we
174 // need to unregister 'this' from any HashSet where
175 // this is registered, and then we need to add it
176 // back...
177
178 // Register 'this' in the HashSet held by start.
179 BranchInstruction.notifyTargetChanged(this.start, this);
180 if (this.end != this.start) {
181 // Since hashCode() has changed we need to register
182 // 'this' again in 'end'.
183 // Add back 'this' in the HashSet held by 'end'.
184 BranchInstruction.notifyTargetChanged(this.end, this);
185 }
186 }
187
188 public final void setStart(InstructionHandle start) {
189
190 // Call notifyTargetChanging *before* modifying this,
191 // as the code triggered by notifyTargetChanging
192 // depends on this pointing to the 'old' start.
193 notifyTargetChanging();
194
195 this.start = start;
196
197 // call notifyTargetChanged *after* modifying this,
198 // as the code triggered by notifyTargetChanged
199 // depends on this pointing to the 'new' start.
200 notifyTargetChanged();
201 }
202
203 public final void setEnd(InstructionHandle end) {
204 // call notifyTargetChanging *before* modifying this,
205 // as the code triggered by notifyTargetChanging
206 // depends on this pointing to the 'old' end.
207 // Unregister 'this' from the HashSet held by the 'old' end.
208 notifyTargetChanging();
209
210 this.end = end;
211
212 // call notifyTargetChanged *after* modifying this,
213 // as the code triggered by notifyTargetChanged
214 // depends on this pointing to the 'new' end.
215 // Register 'this' in the HashSet held by the 'new' end.
216 notifyTargetChanged();
217
218 }
219
220 /**
221 * @param old_ih old target, either start or end
222 * @param new_ih new target
223 */
224 @Override
225 public void updateTarget(InstructionHandle old_ih, InstructionHandle new_ih) {
226 boolean targeted = false;
227
228 if(start == old_ih) {
229 targeted = true;
230 setStart(new_ih);
231 }
232
233 if(end == old_ih) {
234 targeted = true;
235 setEnd(new_ih);
236 }
237
238 if(!targeted)
239 throw new ClassGenException("Not targeting " + old_ih + ", but {" + start + ", " +
240 end + "}");
241 }
242
243 /**
244 * @return true, if ih is target of this variable
245 */
246 @Override
247 public boolean containsTarget(InstructionHandle ih) {
248 return (start == ih) || (end == ih);
249 }
250
251 /**
252 * We consider two local variables to be equal, if they use the same index and
253 * are valid in the same range.
254 */
255 @Override
256 public boolean equals(Object o) {
257 if (o==this)
258 return true;
259
260 if(!(o instanceof LocalVariableGen))
261 return false;
262
263 LocalVariableGen l = (LocalVariableGen)o;
264 return (l.index == index) && (l.start == start) && (l.end == end);
265 }
266
267 @Override
268 public int hashCode() {
269 int hash = 7;
270 hash = 59 * hash + this.index;
271 hash = 59 * hash + Objects.hashCode(this.start);
272 hash = 59 * hash + Objects.hashCode(this.end);
273 return hash;
274 }
275
276 @Override
277 public String toString() {
278 return "LocalVariableGen(" + name + ", " + type + ", " + start + ", " + end + ")";
279 }
280
281 @Override
282 public Object clone() {
283 try {
284 return super.clone();
285 } catch(CloneNotSupportedException e) {
286 System.err.println(e);
287 return null;
288 }
289 }
290 }
|