Author: ebourg
Date: Thu Feb 19 22:49:34 2015
New Revision: 1661026
URL: http://svn.apache.org/r1661026
Log:
Reformatted the code samples in the manual
Modified:
commons/proper/bcel/trunk/src/site/xdoc/manual.xml
Modified: commons/proper/bcel/trunk/src/site/xdoc/manual.xml
URL:
http://svn.apache.org/viewvc/commons/proper/bcel/trunk/src/site/xdoc/manual.xml?rev=1661026&r1=1661025&r2=1661026&view=diff
==============================================================================
--- commons/proper/bcel/trunk/src/site/xdoc/manual.xml (original)
+++ commons/proper/bcel/trunk/src/site/xdoc/manual.xml Thu Feb 19 22:49:34 2015
@@ -458,27 +458,29 @@
import java.io.*;
public class Factorial {
- private static BufferedReader in = new BufferedReader(new
- InputStreamReader(System.in));
+ private static BufferedReader in = new BufferedReader(new
InputStreamReader(System.in));
- public static int fac(int n) {
- return (n == 0)? 1 : n * fac(n - 1);
- }
+ public static int fac(int n) {
+ return (n == 0) ? 1 : n * fac(n - 1);
+ }
- public static int readInt() {
- int n = 4711;
- try {
- System.out.print("Please enter a number> ");
- n = Integer.parseInt(in.readLine());
- } catch(IOException e1) { System.err.println(e1); }
- catch(NumberFormatException e2) { System.err.println(e2); }
- return n;
- }
+ public static int readInt() {
+ int n = 4711;
+ try {
+ System.out.print("Please enter a number> ");
+ n = Integer.parseInt(in.readLine());
+ } catch (IOException e1) {
+ System.err.println(e1);
+ } catch (NumberFormatException e2) {
+ System.err.println(e2);
+ }
+ return n;
+ }
- public static void main(String[] argv) {
- int n = readInt();
- System.out.println("Factorial of " + n + " is " + fac(n));
- }
+ public static void main(String[] argv) {
+ int n = readInt();
+ System.out.println("Factorial of " + n + " is " + fac(n));
+ }
}
</source>
@@ -701,8 +703,8 @@
</p>
<source>
- if(Repository.instanceOf(clazz, super_class) {
- ...
+ if (Repository.instanceOf(clazz, super_class)) {
+ ...
}</source>
</section>
@@ -722,13 +724,13 @@
printCode(clazz.getMethods());
...
public static void printCode(Method[] methods) {
- for(int i=0; i < methods.length; i++) {
- System.out.println(methods[i]);
+ for (int i = 0; i < methods.length; i++) {
+ System.out.println(methods[i]);
- Code code = methods[i].getCode();
- if(code != null) // Non-abstract method
- System.out.println(code);
- }
+ Code code = methods[i].getCode();
+ if (code != null) // Non-abstract method
+ System.out.println(code);
+ }
}
</source>
@@ -784,8 +786,8 @@
</p>
<source>
- Type return_type = Type.VOID;
- Type[] arg_types = new Type[] { new ArrayType(Type.STRING, 1) };
+ Type return_type = Type.VOID;
+ Type[] arg_types = new Type[] { new ArrayType(Type.STRING, 1) };
</source>
<p>
@@ -934,8 +936,7 @@
</p>
<source>
- InstructionHandle start = il.insert(insertion_point,
- InstructionConstants.NOP);
+ InstructionHandle start = il.insert(insertion_point,
InstructionConstants.NOP);
...
mg.addExceptionHandler(start, end, handler, "java.io.IOException");
</source>
@@ -955,14 +956,15 @@
<source>
try {
- il.delete(first, last);
- } catch(TargetLostException e) {
- InstructionHandle[] targets = e.getTargets();
- for(int i=0; i < targets.length; i++) {
- InstructionTargeter[] targeters = targets[i].getTargeters();
- for(int j=0; j < targeters.length; j++)
- targeters[j].updateTarget(targets[i], new_target);
- }
+ il.delete(first, last);
+ } catch (TargetLostException e) {
+ InstructionHandle[] targets = e.getTargets();
+ for (int i = 0; i < targets.length; i++) {
+ InstructionTargeter[] targeters = targets[i].getTargeters();
+ for (int j = 0; j < targeters.length; j++) {
+ targeters[j].updateTarget(targets[i], new_target);
+ }
+ }
}
</source>
@@ -1128,25 +1130,27 @@
<source>
CodeConstraint constraint = new CodeConstraint() {
- public boolean checkCode(InstructionHandle[] match) {
- IfInstruction if1 = (IfInstruction)match[0].getInstruction();
- GOTO g = (GOTO)match[2].getInstruction();
- return (if1.getTarget() == match[3]) &&
- (g.getTarget() == match[4]);
- }
+ public boolean checkCode(InstructionHandle[] match) {
+ IfInstruction if1 = (IfInstruction) match[0].getInstruction();
+ GOTO g = (GOTO) match[2].getInstruction();
+ return (if1.getTarget() == match[3]) &&
+ (g.getTarget() == match[4]);
+ }
};
- InstructionFinder f = new InstructionFinder(il);
- String pat = "IfInstruction ICONST_0 GOTO ICONST_1
NOP(IFEQ|IFNE)";
+ InstructionFinder f = new InstructionFinder(il);
+ String pat = "IfInstruction ICONST_0 GOTO ICONST_1 NOP(IFEQ|IFNE)";
- for(Iterator e = f.search(pat, constraint); e.hasNext(); ) {
- InstructionHandle[] match = (InstructionHandle[])e.next();;
- ...
- match[0].setTarget(match[5].getTarget()); // Update target
- ...
- try {
- il.delete(match[1], match[5]);
- } catch(TargetLostException ex) { ... }
+ for (Iterator e = f.search(pat, constraint); e.hasNext(); ) {
+ InstructionHandle[] match = (InstructionHandle[]) e.next();;
+ ...
+ match[0].setTarget(match[5].getTarget()); // Update target
+ ...
+ try {
+ il.delete(match[1], match[5]);
+ } catch (TargetLostException ex) {
+ ...
+ }
}
</source>
@@ -1166,8 +1170,8 @@
</p>
<source>
- if((a == null) || (i < 2))
- System.out.println("Ooops");
+ if ((a == null) || (i < 2))
+ System.out.println("Ooops");
</source>
<p>
@@ -1359,17 +1363,19 @@
import java.io.*;
public class HelloWorld {
- public static void main(String[] argv) {
- BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
- String name = null;
-
- try {
- System.out.print("Please enter your name> ");
- name = in.readLine();
- } catch(IOException e) { return; }
-
- System.out.println("Hello, " + name);
- }
+ public static void main(String[] argv) {
+ BufferedReader in = new BufferedReader(new
InputStreamReader(System.in));
+ String name = null;
+
+ try {
+ System.out.print("Please enter your name> ");
+ name = in.readLine();
+ } catch (IOException e) {
+ return;
+ }
+
+ System.out.println("Hello, " + name);
+ }
}
</source>
@@ -1394,8 +1400,7 @@
<source>
ClassGen cg = new ClassGen("HelloWorld", "java.lang.Object",
- "<generated>", ACC_PUBLIC | ACC_SUPER,
- null);
+ "<generated>", ACC_PUBLIC | ACC_SUPER,
null);
ConstantPoolGen cp = cg.getConstantPool(); // cg creates constant pool
InstructionList il = new InstructionList();
</source>
@@ -1437,8 +1442,7 @@ symbolic type signature encoded with <tt
il.append(InstructionConstants.DUP); // Use predefined constant
il.append(factory.createNew("java.io.InputStreamReader"));
il.append(InstructionConstants.DUP);
- il.append(factory.createFieldAccess("java.lang.System", "in", i_stream,
- Constants.GETSTATIC));
+ il.append(factory.createFieldAccess("java.lang.System", "in", i_stream,
Constants.GETSTATIC));
il.append(factory.createInvoke("java.io.InputStreamReader", "<init>",
Type.VOID, new Type[] { i_stream },
Constants.INVOKESPECIAL));
@@ -1470,8 +1474,7 @@ symbolic type signature encoded with <tt
<source>
InstructionHandle try_start =
- il.append(factory.createFieldAccess("java.lang.System", "out", p_stream,
- Constants.GETSTATIC));
+ il.append(factory.createFieldAccess("java.lang.System", "out", p_stream,
Constants.GETSTATIC));
il.append(new PUSH(cp, "Please enter your name> "));
il.append(factory.createInvoke("java.io.PrintStream", "print", Type.VOID,
@@ -1509,8 +1512,7 @@ symbolic type signature encoded with <tt
<source>
InstructionHandle ih =
- il.append(factory.createFieldAccess("java.lang.System", "out", p_stream,
- Constants.GETSTATIC));
+ il.append(factory.createFieldAccess("java.lang.System", "out", p_stream,
Constants.GETSTATIC));
g.setTarget(ih);
</source>
@@ -1559,8 +1561,10 @@ symbolic type signature encoded with <tt
<source>
try {
- cg.getJavaClass().dump("HelloWorld.class");
- } catch(java.io.IOException e) { System.err.println(e); }
+ cg.getJavaClass().dump("HelloWorld.class");
+ } catch (IOException e) {
+ System.err.println(e);
+ }
</source>
</section>
@@ -1581,78 +1585,78 @@ import org.apache.bcel.Repository;
import org.apache.bcel.util.InstructionFinder;
public class Peephole {
- public static void main(String[] argv) {
- try {
- /* Load the class from CLASSPATH.
- */
- JavaClass clazz = Repository.lookupClass(argv[0]);
- Method[] methods = clazz.getMethods();
- ConstantPoolGen cp = new ConstantPoolGen(clazz.getConstantPool());
-
- for(int i=0; i < methods.length; i++) {
- if(!(methods[i].isAbstract() || methods[i].isNative())) {
- MethodGen mg = new MethodGen(methods[i],
- clazz.getClassName(), cp);
- Method stripped = removeNOPs(mg);
-
- if(stripped != null) // Any NOPs stripped?
- methods[i] = stripped; // Overwrite with stripped method
+
+ public static void main(String[] argv) {
+ try {
+ // Load the class from CLASSPATH.
+ JavaClass clazz = Repository.lookupClass(argv[0]);
+ Method[] methods = clazz.getMethods();
+ ConstantPoolGen cp = new ConstantPoolGen(clazz.getConstantPool());
+
+ for (int i = 0; i < methods.length; i++) {
+ if (!(methods[i].isAbstract() || methods[i].isNative())) {
+ MethodGen mg = new MethodGen(methods[i],
clazz.getClassName(), cp);
+ Method stripped = removeNOPs(mg);
+
+ if (stripped != null) // Any NOPs stripped?
+ methods[i] = stripped; // Overwrite with stripped
method
+ }
+ }
+
+ // Dump the class to "class name"_.class
+ clazz.setConstantPool(cp.getFinalConstantPool());
+ clazz.dump(clazz.getClassName() + "_.class");
+ } catch (Exception e) {
+ e.printStackTrace();
}
- }
+ }
- /* Dump the class to "class name"_.class
- */
- clazz.setConstantPool(cp.getFinalConstantPool());
- clazz.dump(clazz.getClassName() + "_.class");
- } catch(Exception e) { e.printStackTrace(); }
- }
+ private static Method removeNOPs(MethodGen mg) {
+ InstructionList il = mg.getInstructionList();
+ InstructionFinder f = new InstructionFinder(il);
+ String pat = "NOP+"; // Find at least one NOP
+ InstructionHandle next = null;
+ int count = 0;
+
+ for (Iterator iter = f.search(pat); iter.hasNext();) {
+ InstructionHandle[] match = (InstructionHandle[]) iter.next();
+ InstructionHandle first = match[0];
+ InstructionHandle last = match[match.length - 1];
+
+ // Some nasty Java compilers may add NOP at end of method.
+ if ((next = last.getNext()) == null) {
+ break;
+ }
+
+ count += match.length;
+
+ /**
+ * Delete NOPs and redirect any references to them to the
following (non-nop) instruction.
+ */
+ try {
+ il.delete(first, last);
+ } catch (TargetLostException e) {
+ InstructionHandle[] targets = e.getTargets();
+ for (int i = 0; i < targets.length; i++) {
+ InstructionTargeter[] targeters =
targets[i].getTargeters();
+
+ for (int j = 0; j < targeters.length; j++) {
+ targeters[j].updateTarget(targets[i], next);
+ }
+ }
+ }
+ }
- private static Method removeNOPs(MethodGen mg) {
- InstructionList il = mg.getInstructionList();
- InstructionFinder f = new InstructionFinder(il);
- String pat = "NOP+"; // Find at least one NOP
- InstructionHandle next = null;
- int count = 0;
-
- for(Iterator iter = f.search(pat); iter.hasNext(); ) {
- InstructionHandle[] match = (InstructionHandle[])iter.next();
- InstructionHandle first = match[0];
- InstructionHandle last = match[match.length - 1];
-
- /* Some nasty Java compilers may add NOP at end of method.
- */
- if((next = last.getNext()) == null)
- break;
-
- count += match.length;
-
- /* Delete NOPs and redirect any references to them to the following
- * (non-nop) instruction.
- */
- try {
- il.delete(first, last);
- } catch(TargetLostException e) {
- InstructionHandle[] targets = e.getTargets();
- for(int i=0; i < targets.length; i++) {
- InstructionTargeter[] targeters = targets[i].getTargeters();
-
- for(int j=0; j < targeters.length; j++)
- targeters[j].updateTarget(targets[i], next);
- }
- }
- }
+ Method m = null;
+
+ if (count > 0) {
+ System.out.println("Removed " + count + " NOP instructions from
method " + mg.getName());
+ m = mg.getMethod();
+ }
- Method m = null;
-
- if(count > 0) {
- System.out.println("Removed " + count + " NOP instructions from method "
+
- mg.getName());
- m = mg.getMethod();
+ il.dispose(); // Reuse instruction handles
+ return m;
}
-
- il.dispose(); // Reuse instruction handles
- return m;
- }
}
</source>
</section>
