Add tests and related fixes for DexFileBuffer

dexlib2/build.gradle

@@ -33,4 +33,6 @@ dependencies {
     compile project(':util')
     compile 'com.google.code.findbugs:jsr305:1.3.9'
     compile 'com.google.guava:guava:13.0.1'
+
+    testCompile 'junit:junit:4.6'
 }

dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexFileBuffer.java

@@ -93,7 +93,7 @@ public class DexFileBuffer {
         int result = (buf[offset] & 0xff) |
                      ((buf[offset+1] & 0xff) << 8) |
                      ((buf[offset+2] & 0xff) << 16) |
-                     ((buf[offset+3] & 0xff) << 24);  // TODO: can get rid of last & 0xff?
+                     ((buf[offset+3]) << 24);
         if (result < 0) {
             throw new ExceptionWithContext("Encountered uint that is out of range at offset 0x%x", offset);
         }
@@ -113,10 +113,10 @@ public class DexFileBuffer {
     public long readLong(int offset) {
         // TODO: use | or +?
         byte[] buf = this.buf;
-        return (buf[offset] & 0xffL) |
+        return (buf[offset] & 0xff) |
                ((buf[offset+1] & 0xff) << 8) |
                ((buf[offset+2] & 0xff) << 16) |
-               ((buf[offset+3] & 0xff) << 24) |
+               ((buf[offset+3] & 0xffL) << 24) |
                ((buf[offset+4] & 0xffL) << 32) |
                ((buf[offset+5] & 0xffL) << 40) |
                ((buf[offset+6] & 0xffL) << 48) |

dexlib2/src/test/java/org/jf/dexlib2/dexbacked/DexFileBufferTest.java

@@ -0,0 +1,230 @@
+/*
+ * Copyright 2012, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.jf.dexlib2.dexbacked;
+
+import junit.framework.Assert;
+import org.jf.util.ExceptionWithContext;
+import org.junit.Test;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.Random;
+
+public class DexFileBufferTest {
+    @Test
+    public void testReadSmallUintSuccess() {
+        DexFileBuffer dexFile = new DexFileBuffer(new byte[] {0x11, 0x22, 0x33, 0x44});
+        Assert.assertEquals(0x44332211, dexFile.readSmallUint(0));
+
+        dexFile = new DexFileBuffer(new byte[] {0x00, 0x00, 0x00, 0x00});
+        Assert.assertEquals(0, dexFile.readSmallUint(0));
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff, (byte)0xff, 0x7f});
+        Assert.assertEquals(0x7fffffff, dexFile.readSmallUint(0));
+    }
+
+    @Test(expected=ExceptionWithContext.class)
+    public void testReadSmallUintTooLarge1() {
+        DexFileBuffer dexFile = new DexFileBuffer(new byte[] {0x00, 0x00, 0x00, (byte)0x80});
+        dexFile.readSmallUint(0);
+    }
+
+    @Test(expected=ExceptionWithContext.class)
+    public void testReadSmallUintTooLarge2() {
+        DexFileBuffer dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff, (byte)0xff, (byte)0x80});
+        dexFile.readSmallUint(0);
+    }
+
+    @Test(expected=ExceptionWithContext.class)
+    public void testReadSmallUintTooLarge3() {
+        DexFileBuffer dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff, (byte)0xff, (byte)0xff});
+        dexFile.readSmallUint(0);
+    }
+
+    @Test
+    public void testReadUshort() {
+        DexFileBuffer dexFile = new DexFileBuffer(new byte[] {0x11, 0x22});
+        Assert.assertEquals(dexFile.readUshort(0), 0x2211);
+
+        dexFile = new DexFileBuffer(new byte[] {0x00, 0x00});
+        Assert.assertEquals(dexFile.readUshort(0), 0);
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff});
+        Assert.assertEquals(dexFile.readUshort(0), 0xffff);
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0x00, (byte)0x80});
+        Assert.assertEquals(dexFile.readUshort(0), 0x8000);
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0x7f});
+        Assert.assertEquals(dexFile.readUshort(0), 0x7fff);
+    }
+
+    @Test
+    public void testReadUbyte() {
+        byte[] buf = new byte[1];
+        DexFileBuffer dexFile = new DexFileBuffer(buf);
+
+        for (int i=0; i<=0xff; i++) {
+            buf[0] = (byte)i;
+            Assert.assertEquals(i, dexFile.readUbyte(0));
+        }
+    }
+
+    @Test
+    public void testReadLong() {
+        DexFileBuffer dexFile = new DexFileBuffer(new byte[] {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77});
+        Assert.assertEquals(0x7766554433221100L, dexFile.readLong(0));
+
+        dexFile = new DexFileBuffer(new byte[] {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+        Assert.assertEquals(0, dexFile.readLong(0));
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff, (byte)0xff, (byte)0xff,
+                (byte)0xff, (byte)0xff, (byte)0xff, 0x7f});
+        Assert.assertEquals(Long.MAX_VALUE, dexFile.readLong(0));
+
+        dexFile = new DexFileBuffer(new byte[] {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, (byte)0x80});
+        Assert.assertEquals(Long.MIN_VALUE, dexFile.readLong(0));
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff, (byte)0xff, (byte)0xff,
+                (byte)0xff, (byte)0xff, (byte)0xff, (byte)0x80});
+        Assert.assertEquals(0x80ffffffffffffffL, dexFile.readLong(0));
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff, (byte)0xff, (byte)0xff,
+                (byte)0xff, (byte)0xff, (byte)0xff, (byte)0xff});
+        Assert.assertEquals(-1, dexFile.readLong(0));
+
+    }
+
+    @Test
+    public void testReadInt() {
+        DexFileBuffer dexFile = new DexFileBuffer(new byte[] {0x11, 0x22, 0x33, 0x44});
+        Assert.assertEquals(0x44332211, dexFile.readInt(0));
+
+        dexFile = new DexFileBuffer(new byte[] {0x00, 0x00, 0x00, 0x00});
+        Assert.assertEquals(0, dexFile.readInt(0));
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff, (byte)0xff, 0x7f});
+        Assert.assertEquals(Integer.MAX_VALUE, dexFile.readInt(0));
+
+        dexFile = new DexFileBuffer(new byte[] {0x00, 0x00, 0x00, (byte)0x80});
+        Assert.assertEquals(Integer.MIN_VALUE, dexFile.readInt(0));
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff, (byte)0xff, (byte)0x80});
+        Assert.assertEquals(0x80ffffff, dexFile.readInt(0));
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff, (byte)0xff, (byte)0xff});
+        Assert.assertEquals(-1, dexFile.readInt(0));
+    }
+
+    @Test
+    public void testReadShort() {
+        DexFileBuffer dexFile = new DexFileBuffer(new byte[] {0x11, 0x22});
+        Assert.assertEquals(dexFile.readShort(0), 0x2211);
+
+        dexFile = new DexFileBuffer(new byte[] {0x00, 0x00});
+        Assert.assertEquals(dexFile.readShort(0), 0);
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0xff});
+        Assert.assertEquals(dexFile.readShort(0), -1);
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0x00, (byte)0x80});
+        Assert.assertEquals(dexFile.readShort(0), Short.MIN_VALUE);
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0x7f});
+        Assert.assertEquals(dexFile.readShort(0), 0x7fff);
+
+        dexFile = new DexFileBuffer(new byte[] {(byte)0xff, (byte)0x80});
+        Assert.assertEquals(dexFile.readShort(0), 0xffff80ff);
+    }
+
+    @Test
+    public void testReadByte() {
+        byte[] buf = new byte[1];
+        DexFileBuffer dexFile = new DexFileBuffer(buf);
+
+        for (int i=0; i<=0xff; i++) {
+            buf[0] = (byte)i;
+            Assert.assertEquals((byte)i, dexFile.readByte(0));
+        }
+    }
+
+    @Test
+    public void testReadRandom() {
+        Random r = new Random(1234567890);
+        ByteBuffer byteBuf = ByteBuffer.allocateDirect(4).order(ByteOrder.LITTLE_ENDIAN);
+        byte[] buf = new byte[4];
+        DexFileBuffer dexFile = new DexFileBuffer(buf);
+
+        for (int i=0; i<10000; i++) {
+            int val = r.nextInt();
+            byteBuf.putInt(0, val);
+            byteBuf.position(0);
+            byteBuf.get(buf);
+
+            boolean expectException = val < 0;
+            try {
+                int returnedVal = dexFile.readSmallUint(0);
+                Assert.assertFalse(String.format("Didn't throw an exception for value: %x", val), expectException);
+                Assert.assertEquals(val, returnedVal);
+            } catch (Exception ex) {
+                Assert.assertTrue(String.format("Threw an exception for value: %x", val), expectException);
+            }
+
+            Assert.assertEquals(val, dexFile.readInt(0));
+
+            Assert.assertEquals(val & 0xFFFF, dexFile.readUshort(0));
+            Assert.assertEquals((val >> 8) & 0xFFFF, dexFile.readUshort(1));
+            Assert.assertEquals((val >> 16) & 0xFFFF, dexFile.readUshort(2));
+
+            Assert.assertEquals((short)val, dexFile.readShort(0));
+            Assert.assertEquals((short)(val >> 8), dexFile.readShort(1));
+            Assert.assertEquals((short)(val >> 16), dexFile.readShort(2));
+        }
+    }
+
+    @Test
+    public void testReadLongRandom() {
+        Random r = new Random(1234567890);
+        ByteBuffer byteBuf = ByteBuffer.allocateDirect(8).order(ByteOrder.LITTLE_ENDIAN);
+        byte[] buf = new byte[8];
+        DexFileBuffer dexFile = new DexFileBuffer(buf);
+
+        for (int i=0; i<10000; i++) {
+            int val = r.nextInt();
+            byteBuf.putLong(0, val);
+            byteBuf.position(0);
+            byteBuf.get(buf);
+
+            Assert.assertEquals(val, dexFile.readLong(0));
+        }
+    }
+}