1 files changed, 117 insertions, 0 deletions
diff --git a/src/proguard/shrink/SignatureUsageMarker.java b/src/proguard/shrink/SignatureUsageMarker.java
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+++ b/src/proguard/shrink/SignatureUsageMarker.java
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+/*
+ * ProGuard -- shrinking, optimization, obfuscation, and preverification
+ *             of Java bytecode.
+ *
+ * Copyright (c) 2002-2013 Eric Lafortune (eric@graphics.cornell.edu)
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+package proguard.shrink;
+
+import proguard.classfile.*;
+import proguard.classfile.attribute.*;
+import proguard.classfile.attribute.visitor.*;
+import proguard.classfile.constant.*;
+import proguard.classfile.constant.visitor.ConstantVisitor;
+import proguard.classfile.util.SimplifiedVisitor;
+import proguard.classfile.visitor.ClassVisitor;
+
+/**
+ * This AttributeVisitor recursively marks all Signature attributes that it
+ * visits and that point to used classes.
+ *
+ * @see UsageMarker
+ *
+ * @author Eric Lafortune
+ */
+public class SignatureUsageMarker
+extends      SimplifiedVisitor
+implements   AttributeVisitor,
+             ClassVisitor,
+             ConstantVisitor
+{
+    private final UsageMarker usageMarker;
+
+    // Fields acting as a return parameters for several methods.
+    private boolean attributeUsed;
+
+
+    /**
+     * Creates a new SignatureUsageMarker.
+     * @param usageMarker the usage marker that is used to mark the classes
+     *                    and class members.
+     */
+    public SignatureUsageMarker(UsageMarker usageMarker)
+    {
+        this.usageMarker = usageMarker;
+    }
+
+
+    // Implementations for AttributeVisitor.
+
+    public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}
+
+
+    public void visitSignatureAttribute(Clazz clazz, SignatureAttribute signatureAttribute)
+    {
+        // Only keep the signature if all of its classes are used.
+        attributeUsed = true;
+        signatureAttribute.referencedClassesAccept(this);
+
+        if (attributeUsed)
+        {
+            // We got a positive used flag, so the signature is useful.
+            usageMarker.markAsUsed(signatureAttribute);
+
+            markConstant(clazz, signatureAttribute.u2attributeNameIndex);
+            markConstant(clazz, signatureAttribute.u2signatureIndex);
+        }
+    }
+
+
+    // Implementations for ClassVisitor.
+
+    public void visitLibraryClass(LibraryClass libraryClass) {}
+
+
+    public void visitProgramClass(ProgramClass programClass)
+    {
+        // Don't keep the signature if one of its classes is not used.
+        if (!usageMarker.isUsed(programClass))
+        {
+            attributeUsed = false;
+        }
+    }
+
+
+    // Implementations for ConstantVisitor.
+
+    public void visitAnyConstant(Clazz clazz, Constant constant)
+    {
+        usageMarker.markAsUsed(constant);
+    }
+
+
+    // Small utility methods.
+
+    /**
+     * Marks the given constant pool entry of the given class.
+     */
+    private void markConstant(Clazz clazz, int index)
+    {
+         clazz.constantPoolEntryAccept(index, this);
+    }
+}