1 files changed, 75 insertions, 0 deletions
diff --git a/dexgen/src/com/android/dexgen/dex/code/OddSpacer.java b/dexgen/src/com/android/dexgen/dex/code/OddSpacer.java
new file mode 100644
index 0000000..8e2bab8
--- /dev/null
+++ b/dexgen/src/com/android/dexgen/dex/code/OddSpacer.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.dexgen.dex.code;
+
+import com.android.dexgen.rop.code.RegisterSpecList;
+import com.android.dexgen.rop.code.SourcePosition;
+import com.android.dexgen.util.AnnotatedOutput;
+
+/**
+ * Pseudo-instruction which either turns into a {@code nop} or
+ * nothingness, in order to make the subsequent instruction have an
+ * even address. This is used to align (subsequent) instructions that
+ * require it.
+ */
+public final class OddSpacer extends VariableSizeInsn {
+    /**
+     * Constructs an instance. The output address of this instance is initially
+     * unknown ({@code -1}).
+     *
+     * @param position {@code non-null;} source position
+     */
+    public OddSpacer(SourcePosition position) {
+        super(position, RegisterSpecList.EMPTY);
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public int codeSize() {
+        return (getAddress() & 1);
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public void writeTo(AnnotatedOutput out) {
+        if (codeSize() != 0) {
+            out.writeShort(InsnFormat.codeUnit(DalvOps.NOP, 0));
+        }
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public DalvInsn withRegisters(RegisterSpecList registers) {
+        return new OddSpacer(getPosition());
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    protected String argString() {
+        return null;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    protected String listingString0(boolean noteIndices) {
+        if (codeSize() == 0) {
+            return null;
+        }
+
+        return "nop // spacer";
+    }
+}