JIRA JASSIST-224

1 files changed, 87 insertions, 0 deletions

diff --git a/src/main/javassist/bytecode/MethodParametersAttribute.java b/src/main/javassist/bytecode/MethodParametersAttribute.java
new file mode 100644
index 00000000..b67a0f54
--- /dev/null
+++ b/src/main/javassist/bytecode/MethodParametersAttribute.java
@@ -0,0 +1,87 @@
+package javassist.bytecode;
+
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ * <code>MethodParameters_attribute</code>.
+ */
+public class MethodParametersAttribute extends AttributeInfo {
+    /**
+     * The name of this attribute <code>"MethodParameters"</code>.
+     */
+    public static final String tag = "MethodParameters";
+
+    MethodParametersAttribute(ConstPool cp, int n, DataInputStream in)
+        throws IOException
+    {
+        super(cp, n, in);
+    }
+
+    /**
+     * Constructs an attribute.
+     *
+     * @param cp            a constant pool table.
+     * @param names         an array of parameter names.
+     *                      The i-th element is the name of the i-th parameter.
+     * @param flags         an array of parameter access flags.
+     */
+    public MethodParametersAttribute(ConstPool cp, String[] names, int[] flags) {
+        super(cp, tag);
+        byte[] data = new byte[names.length * 4 + 1];
+        data[0] = (byte)names.length;
+        for (int i = 0; i < names.length; i++) {
+            ByteArray.write16bit(cp.addUtf8Info(names[i]), data, i * 4 + 1);
+            ByteArray.write16bit(flags[i], data, i * 4 + 3);
+        }
+
+        set(data);
+    }
+
+    /**
+     * Returns <code>parameters_count</code>, which is the number of
+     * parameters.
+     */
+    public int size() {
+        return info[0] & 0xff;
+    }
+
+    /**
+     * Returns the value of <code>name_index</code> of the i-th element of <code>parameters</code>.
+     *
+     * @param i         the position of the parameter.
+     */
+    public int name(int i) {
+        return ByteArray.readU16bit(info, i * 4 + 1);
+    }
+
+    /**
+     * Returns the value of <code>access_flags</code> of the i-th element of <code>parameters</code>.
+     *
+     * @param i         the position of the parameter.
+     * @see AccessFlag
+     */
+    public int accessFlags(int i) {
+        return ByteArray.readU16bit(info, i * 4 + 3);
+    }
+
+    /**
+     * Makes a copy.
+     *
+     * @param newCp     the constant pool table used by the new copy.
+     * @param classnames        ignored.
+     */
+    public AttributeInfo copy(ConstPool newCp, Map classnames) {
+        int s = size();
+        ConstPool cp = getConstPool();
+        String[] names = new String[s];
+        int[] flags = new int[s];
+        for (int i = 0; i < s; i++) {
+            names[i] = cp.getUtf8Info(name(i));
+            flags[i] = accessFlags(i);
+        }
+
+        return new MethodParametersAttribute(newCp, names, flags);
+    }
+}