From d79d9ebbe9cdbec7f386d3db0cdb9e57893d28e6 Mon Sep 17 00:00:00 2001
From: "JesusFreke@JesusFreke.com"
 <JesusFreke@JesusFreke.com@55b6fa8a-2a1e-11de-a435-ffa8d773f76a>
Date: Mon, 22 Feb 2010 00:56:26 +0000
Subject: [PATCH] Tweak dexlib's "skip instructions" functionality so that it
 doesn't read in the CodeItems or DebugInfoItems at all

git-svn-id: https://smali.googlecode.com/svn/trunk@635 55b6fa8a-2a1e-11de-a435-ffa8d773f76a
---
 .../java/org/jf/dexlib/ClassDataItem.java     |   9 +-
 .../src/main/java/org/jf/dexlib/CodeItem.java | 106 +++++++-----------
 .../src/main/java/org/jf/dexlib/DexFile.java  |   4 +
 3 files changed, 53 insertions(+), 66 deletions(-)

diff --git a/dexlib/src/main/java/org/jf/dexlib/ClassDataItem.java b/dexlib/src/main/java/org/jf/dexlib/ClassDataItem.java
index 9a4dd32e..3f65ead4 100644
--- a/dexlib/src/main/java/org/jf/dexlib/ClassDataItem.java
+++ b/dexlib/src/main/java/org/jf/dexlib/ClassDataItem.java
@@ -478,8 +478,13 @@ public class ClassDataItem extends Item<ClassDataItem> {
             int previousIndex = previousEncodedMethod==null?0:previousEncodedMethod.method.getIndex();
             method = dexFile.MethodIdsSection.getItemByIndex(in.readUnsignedLeb128() + previousIndex);
             accessFlags = in.readUnsignedLeb128();
-            codeItem = (CodeItem)readContext.getOptionalOffsettedItemByOffset(ItemType.TYPE_CODE_ITEM,
-                    in.readUnsignedLeb128());
+            if (dexFile.skipInstructions()) {
+                in.readUnsignedLeb128();
+                codeItem = null;
+            } else {
+                codeItem = (CodeItem)readContext.getOptionalOffsettedItemByOffset(ItemType.TYPE_CODE_ITEM,
+                        in.readUnsignedLeb128());
+            }
             if (codeItem != null) {
                 codeItem.setParent(this);
             }
diff --git a/dexlib/src/main/java/org/jf/dexlib/CodeItem.java b/dexlib/src/main/java/org/jf/dexlib/CodeItem.java
index 4f27d959..c4f8eac7 100644
--- a/dexlib/src/main/java/org/jf/dexlib/CodeItem.java
+++ b/dexlib/src/main/java/org/jf/dexlib/CodeItem.java
@@ -151,77 +151,55 @@ public class CodeItem extends Item<CodeItem> {
 
         int instructionCount = in.readInt();
 
-        if (dexFile.skipInstructions()) {
-            in.skipBytes(instructionCount * 2);
+        final ArrayList<Instruction> instructionList = new ArrayList<Instruction>();
 
-            if (triesCount > 0) {
-                in.alignTo(4);
-                in.skipBytes(8 * triesCount);
+        byte[] encodedInstructions = in.readBytes(instructionCount * 2);
+        InstructionIterator.IterateInstructions(dexFile, encodedInstructions,
+                new InstructionIterator.ProcessInstructionDelegate() {
+                    public void ProcessInstruction(int codeAddress, Instruction instruction) {
+                        instructionList.add(instruction);
+                    }
+                });
 
-                int handlerCount = in.readUnsignedLeb128();
-                for (int i=0; i<handlerCount; i++) {
-                    int size = in.readSignedLeb128();
-                    int absSize = Math.abs(size);
-                    for (int j=0; j<absSize; j++) {
-                        in.readUnsignedLeb128();
-                        in.readUnsignedLeb128();
-                    }
-                    if (size <= 0) {
-                        in.readUnsignedLeb128();
-                    }
+        this.instructions = new Instruction[instructionList.size()];
+        instructionList.toArray(instructions);
+
+        if (triesCount > 0) {
+            in.alignTo(4);
+
+            //we need to read in the catch handlers first, so save the offset to the try items for future reference
+            int triesOffset = in.getCursor();
+            in.setCursor(triesOffset + 8 * triesCount);
+
+            //read in the encoded catch handlers
+            int encodedHandlerStart = in.getCursor();
+            int handlerCount = in.readUnsignedLeb128();
+            SparseArray<EncodedCatchHandler> handlerMap = new SparseArray<EncodedCatchHandler>(handlerCount);
+            encodedCatchHandlers = new EncodedCatchHandler[handlerCount];
+            for (int i=0; i<handlerCount; i++) {
+                try {
+                    int position = in.getCursor() - encodedHandlerStart;
+                    encodedCatchHandlers[i] = new EncodedCatchHandler(dexFile, in);
+                    handlerMap.append(position, encodedCatchHandlers[i]);
+                } catch (Exception ex) {
+                    throw ExceptionWithContext.withContext(ex, "Error while reading EncodedCatchHandler at index " + i);
                 }
             }
-        } else {
-            final ArrayList<Instruction> instructionList = new ArrayList<Instruction>();
+            int codeItemEnd = in.getCursor();
 
-            byte[] encodedInstructions = in.readBytes(instructionCount * 2);
-            InstructionIterator.IterateInstructions(dexFile, encodedInstructions,
-                    new InstructionIterator.ProcessInstructionDelegate() {
-                        public void ProcessInstruction(int codeAddress, Instruction instruction) {
-                            instructionList.add(instruction);
-                        }
-                    });
-
-            this.instructions = new Instruction[instructionList.size()];
-            instructionList.toArray(instructions);
-
-            if (triesCount > 0) {
-                in.alignTo(4);
-
-                //we need to read in the catch handlers first, so save the offset to the try items for future reference
-                int triesOffset = in.getCursor();
-                in.setCursor(triesOffset + 8 * triesCount);
-
-                //read in the encoded catch handlers
-                int encodedHandlerStart = in.getCursor();
-                int handlerCount = in.readUnsignedLeb128();
-                SparseArray<EncodedCatchHandler> handlerMap = new SparseArray<EncodedCatchHandler>(handlerCount);
-                encodedCatchHandlers = new EncodedCatchHandler[handlerCount];
-                for (int i=0; i<handlerCount; i++) {
-                    try {
-                        int position = in.getCursor() - encodedHandlerStart;
-                        encodedCatchHandlers[i] = new EncodedCatchHandler(dexFile, in);
-                        handlerMap.append(position, encodedCatchHandlers[i]);
-                    } catch (Exception ex) {
-                        throw ExceptionWithContext.withContext(ex, "Error while reading EncodedCatchHandler at index " + i);
-                    }
+            //now go back and read the tries
+            in.setCursor(triesOffset);
+            tries = new TryItem[triesCount];
+            for (int i=0; i<triesCount; i++) {
+                try {
+                    tries[i] = new TryItem(in, handlerMap);
+                } catch (Exception ex) {
+                    throw ExceptionWithContext.withContext(ex, "Error while reading TryItem at index " + i);
                 }
-                int codeItemEnd = in.getCursor();
-
-                //now go back and read the tries
-                in.setCursor(triesOffset);
-                tries = new TryItem[triesCount];
-                for (int i=0; i<triesCount; i++) {
-                    try {
-                        tries[i] = new TryItem(in, handlerMap);
-                    } catch (Exception ex) {
-                        throw ExceptionWithContext.withContext(ex, "Error while reading TryItem at index " + i);
-                    }
-                }
-
-                //and now back to the end of the code item
-                in.setCursor(codeItemEnd);
             }
+
+            //and now back to the end of the code item
+            in.setCursor(codeItemEnd);
         }
     }
 
diff --git a/dexlib/src/main/java/org/jf/dexlib/DexFile.java b/dexlib/src/main/java/org/jf/dexlib/DexFile.java
index db98eae0..9e11617a 100644
--- a/dexlib/src/main/java/org/jf/dexlib/DexFile.java
+++ b/dexlib/src/main/java/org/jf/dexlib/DexFile.java
@@ -409,6 +409,10 @@ public class DexFile
                 continue;
             }
 
+            if (skipInstructions && (section == CodeItemsSection || section == DebugInfoItemsSection)) {
+                continue;
+            }
+
             int sectionOffset = readContext.getSectionOffset(section.ItemType);
             if (sectionOffset > 0) {
                 int sectionSize = readContext.getSectionSize(section.ItemType);