Fix up line number handling to be unsigned int safe

baksmali/src/main/java/org/jf/baksmali/Adaptors/Debug/LineNumberMethodItem.java

@@ -48,7 +48,7 @@ public class LineNumberMethodItem extends DebugMethodItem {
     @Override
     public boolean writeTo(IndentingWriter writer) throws IOException {
         writer.write(".line ");
-        writer.printSignedIntAsDec(lineNumber);
+        writer.printUnsignedIntAsDec(lineNumber);
         return true;
     }
 }

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

@@ -128,6 +128,46 @@ public class BaseDexReader<T extends BaseDexBuffer> {
         return result;
     }
 
+    /**
+     * Reads a "big" uleb128 that can legitimately be > 2^31. The value is returned as a signed integer, with the
+     * expected semantics of re-interpreting an unsigned value as a signed value.
+     *
+     * @return The unsigned value, reinterpreted as a signed int
+     */
+    public int readBigUleb128() {
+        int end = offset;
+        int currentByteValue;
+        int result;
+        byte[] buf = dexBuf.buf;
+
+        result = buf[end++] & 0xff;
+        if (result > 0x7f) {
+            currentByteValue = buf[end++] & 0xff;
+            result = (result & 0x7f) | ((currentByteValue & 0x7f) << 7);
+            if (currentByteValue > 0x7f) {
+                currentByteValue = buf[end++] & 0xff;
+                result |= (currentByteValue & 0x7f) << 14;
+                if (currentByteValue > 0x7f) {
+                    currentByteValue = buf[end++] & 0xff;
+                    result |= (currentByteValue & 0x7f) << 21;
+                    if (currentByteValue > 0x7f) {
+                        currentByteValue = buf[end++];
+
+                        // MSB shouldn't be set on last byte
+                        if (currentByteValue < 0) {
+                            throw new ExceptionWithContext(
+                                    "Invalid uleb128 integer encountered at offset 0x%x", offset);
+                        }
+                        result |= currentByteValue << 28;
+                    }
+                }
+            }
+        }
+
+        offset = end;
+        return result;
+    }
+
     public void skipUleb128() {
         int end = offset;
         byte currentByteValue;

dexlib2/src/main/java/org/jf/dexlib2/dexbacked/util/DebugInfo.java

@@ -99,8 +99,7 @@ public abstract class DebugInfo implements Iterable<DebugItem> {
         @Override
         public Iterator<DebugItem> iterator() {
             DexReader reader = dexFile.readerAt(debugInfoOffset);
-            // TODO: this unsigned value could legitimally be > MAX_INT
+            final int lineNumberStart = reader.readBigUleb128();
-            final int lineNumberStart = reader.readSmallUleb128();
             int registerCount = methodImpl.getRegisterCount();
 
             //TODO: does dalvik allow references to invalid registers?

dexlib2/src/main/java/org/jf/dexlib2/iface/debug/LineNumber.java

@@ -32,5 +32,11 @@
 package org.jf.dexlib2.iface.debug;
 
 public interface LineNumber extends DebugItem {
+    /**
+     * The line number associated with this code address. This value should be treated as an unsigned integer, with
+     * negative values indicating a value > 2^31, using the usual two's complement semantics.
+     *
+     * @return The line number associated with this code address.
+     */
     int getLineNumber();
 }

util/src/main/java/org/jf/util/IndentingWriter.java

@@ -192,6 +192,26 @@ public class IndentingWriter extends Writer {
         writeLine(buffer, bufferIndex, 24-bufferIndex);
     }
 
+    public void printSignedLongAsDec(long value) throws IOException {
+        int bufferIndex = 23;
+
+        if (value < 0) {
+            value *= -1;
+            write('-');
+        }
+
+        do {
+            long digit = value % 10;
+            buffer[bufferIndex--] = (char)(digit + '0');
+
+            value = value / 10;
+        } while (value != 0);
+
+        bufferIndex++;
+
+        writeLine(buffer, bufferIndex, 24-bufferIndex);
+    }
+
     public void printSignedIntAsDec(int value) throws IOException {
         int bufferIndex = 15;
 
@@ -211,4 +231,14 @@ public class IndentingWriter extends Writer {
 
         writeLine(buffer, bufferIndex, 16-bufferIndex);
     }
+
+    public void printUnsignedIntAsDec(int value) throws IOException {
+        int bufferIndex = 15;
+
+        if (value < 0) {
+            printSignedLongAsDec(value & 0xFFFFFFFFL);
+        } else {
+            printSignedIntAsDec(value);
+        }
+    }
 }

util/src/test/java/org/jf/util/IndentingWriterTest.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2013, 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.util;
+
+import junit.framework.Assert;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.io.StringWriter;
+
+public class IndentingWriterTest {
+    @Test
+    public void testPrintSignedLongAsDec() throws IOException {
+        StringWriter stringWriter = new StringWriter();
+        IndentingWriter writer = new IndentingWriter(stringWriter);
+
+        writer.printUnsignedIntAsDec(-1);
+        writer.close();
+
+        Assert.assertEquals("4294967295", stringWriter.toString());
+    }
+}