From 96b803c8821bac22418e48f976adf0132e3d9b24 Mon Sep 17 00:00:00 2001
From: Ben Gruver <bgruv@google.com>
Date: Wed, 11 Jan 2012 21:42:08 -0800
Subject: [PATCH] Add support for version 36 dex files

---
 .../src/main/java/org/jf/dexlib/DexFile.java  | 19 ++++---
 .../main/java/org/jf/dexlib/HeaderItem.java   | 52 ++++++++++++++++---
 smali/src/main/java/org/jf/smali/main.java    |  6 +++
 3 files changed, 65 insertions(+), 12 deletions(-)

diff --git a/dexlib/src/main/java/org/jf/dexlib/DexFile.java b/dexlib/src/main/java/org/jf/dexlib/DexFile.java
index df9fa1ae..24e92921 100644
--- a/dexlib/src/main/java/org/jf/dexlib/DexFile.java
+++ b/dexlib/src/main/java/org/jf/dexlib/DexFile.java
@@ -336,12 +336,19 @@ public class DexFile
             boolean isDex = false;
             this.isOdex = false;
 
-            if (Arrays.equals(magic, HeaderItem.MAGIC)) {
-                isDex = true;
-            } else if (Arrays.equals(magic, OdexHeader.MAGIC_35)) {
-                isOdex = true;
-            } else if (Arrays.equals(magic, OdexHeader.MAGIC_36)) {
-                isOdex = true;
+            for (int i=0; i<HeaderItem.MAGIC_VALUES.length; i++) {
+                byte[] magic_value = HeaderItem.MAGIC_VALUES[i];
+                if (Arrays.equals(magic, magic_value)) {
+                    isDex = true;
+                    break;
+                }
+            }
+            if (!isDex) {
+                if (Arrays.equals(magic, OdexHeader.MAGIC_35)) {
+                    isOdex = true;
+                } else if (Arrays.equals(magic, OdexHeader.MAGIC_36)) {
+                    isOdex = true;
+                }
             }
 
             if (isOdex) {
diff --git a/dexlib/src/main/java/org/jf/dexlib/HeaderItem.java b/dexlib/src/main/java/org/jf/dexlib/HeaderItem.java
index 5daf00c9..b395ef15 100644
--- a/dexlib/src/main/java/org/jf/dexlib/HeaderItem.java
+++ b/dexlib/src/main/java/org/jf/dexlib/HeaderItem.java
@@ -37,7 +37,9 @@ public class HeaderItem extends Item<HeaderItem> {
      * the file format magic number, represented as the
      * low-order bytes of a string
      */
-    public static final byte[] MAGIC = new byte[] {0x64, 0x65, 0x78, 0x0A, 0x30, 0x33, 0x35, 0x00};//"dex\n035" + '\0';
+    public static final byte[][] MAGIC_VALUES = new byte[][] {
+            new byte[] {0x64, 0x65, 0x78, 0x0A, 0x30, 0x33, 0x35, 0x00}, //"dex\n035" + '\0';
+            new byte[] {0x64, 0x65, 0x78, 0x0A, 0x30, 0x33, 0x36, 0x00}}; //"dex\n036" + '\0';
 
 
     /** size of this section, in bytes */
@@ -47,6 +49,9 @@ public class HeaderItem extends Item<HeaderItem> {
     private static final int LITTLE_ENDIAN = 0x12345678;
     private static final int BIG_ENDIAN = 0x78562312;
 
+    /* Which magic value to use when writing out the header item */
+    private int magic_index = 0;
+
     /**
      * Create a new uninitialized <code>HeaderItem</code>
      * @param dexFile The <code>DexFile</code> containing this <code>HeaderItem</code>
@@ -59,10 +64,25 @@ public class HeaderItem extends Item<HeaderItem> {
     protected void readItem(Input in, ReadContext readContext) {
         byte[] readMagic = in.readBytes(8);
 
-        for (int i=0; i<8; i++) {
-            if (MAGIC[i] != readMagic[i]) {
-                throw new RuntimeException("The magic value is not the expected value");
+        boolean success = false;
+        for (int i=0; i<MAGIC_VALUES.length; i++) {
+            byte[] magic_value = MAGIC_VALUES[i];
+            boolean matched = true;
+            for (int j=0; j<8; i++) {
+                if (magic_value[j] != readMagic[j]) {
+                    matched = false;
+                    break;
+                }
             }
+            if (matched) {
+                success = true;
+                magic_index = i;
+                break;
+            }
+        }
+
+        if (!success) {
+            throw new RuntimeException("Unrecognized dex magic value");
         }
 
         in.readBytes(20); //checksum
@@ -125,6 +145,26 @@ public class HeaderItem extends Item<HeaderItem> {
         in.readInt(); //data_off
     }
 
+    /**
+     * Sets the dex version number.
+     *
+     * 35 is the default.
+     * 36 is for dex files that use extended opcodes (only works with ICS+)
+     *
+     * @param version - must be either 35 or 36
+     */
+    public void setVersion(int version) {
+        if (version == 35) {
+            magic_index = 0;
+            return;
+        }
+        if (version == 36) {
+            magic_index = 1;
+            return;
+        }
+        throw new RuntimeException("Invalid dex version number passed to setVersion");
+    }
+
     /** {@inheritDoc} */
     protected int placeItem(int offset) {
         return HEADER_SIZE;
@@ -134,11 +174,11 @@ public class HeaderItem extends Item<HeaderItem> {
     protected void writeItem(AnnotatedOutput out) {
         StringBuilder magicBuilder = new StringBuilder();
         for (int i=0; i<8; i++) {
-            magicBuilder.append((char)MAGIC[i]);
+            magicBuilder.append((char)MAGIC_VALUES[magic_index][i]);
         }
 
         out.annotate("magic: " + Utf8Utils.escapeString(magicBuilder.toString()));
-        out.write(MAGIC);
+        out.write(MAGIC_VALUES[magic_index]);
 
         out.annotate("checksum");
         out.writeInt(0);
diff --git a/smali/src/main/java/org/jf/smali/main.java b/smali/src/main/java/org/jf/smali/main.java
index e65f4e65..39a48f35 100644
--- a/smali/src/main/java/org/jf/smali/main.java
+++ b/smali/src/main/java/org/jf/smali/main.java
@@ -107,6 +107,7 @@ public class main {
         boolean oldLexer = false;
         boolean printTokens = false;
 
+        boolean apiSet = false;
         int apiLevel = 14;
 
         String outputDexFile = "out.dex";
@@ -141,6 +142,7 @@ public class main {
                     break;
                 case 'a':
                     apiLevel = Integer.parseInt(commandLine.getOptionValue("a"));
+                    apiSet = true;
                     break;
                 case 'D':
                     dumpFileName = commandLine.getOptionValue("D", outputDexFile + ".dump");
@@ -194,6 +196,10 @@ public class main {
 
             DexFile dexFile = new DexFile();
 
+            if (apiSet && apiLevel >= 14) {
+                dexFile.HeaderItem.setVersion(36);
+            }
+
             boolean errors = false;
 
             for (File file: filesToProcess) {