[Soot-list] Question about inner class and failure to verify using ASM3.3.1

Henddher Pedroza hpedro2 at uic.edu
Fri Oct 26 12:20:05 EDT 2012


What about this 'default' initialization as empty string ?
(if 'info' is null, EnclosingMethodTag(class_name, "", "") will be 
created and added ... is that correct?)

Please help!

// soot.coffi.Util @398

         else if (coffiClass.attributes[i] instanceof 
EnclosingMethod_attribute){
             EnclosingMethod_attribute attr = 
(EnclosingMethod_attribute)coffiClass.attributes[i];
             String class_name = 
((CONSTANT_Utf8_info)coffiClass.constant_pool[((CONSTANT_Class_info)coffiClass.constant_pool[ 
attr.class_index  ]).name_index]).convert();
             CONSTANT_NameAndType_info info = 
(CONSTANT_NameAndType_info)coffiClass.constant_pool[attr.method_index];

*           String method_name = "";**
**            String method_sig = "";**
***
             if (info != null){
                 method_name = 
((CONSTANT_Utf8_info)coffiClass.constant_pool[info.name_index]).convert();
                 method_sig = 
((CONSTANT_Utf8_info)coffiClass.constant_pool[info.descriptor_index]).convert();
             }
*            bclass.addTag(new EnclosingMethodTag(class_name, 
method_name, method_sig));**
*        }


On 10/26/2012 11:05 AM, Henddher Pedroza wrote:
> More info:
>
> Issue$1 generated by soot:
>
> $ javap -c -v -s -sysinfo -constants Issue\$1.class
> Classfile ./innerclass_issue/output/Issue$1.class
>   Last modified Oct 25, 2012; size 352 bytes
>   MD5 checksum bdbeedc92127b3b4da92668ad64991e4
>   Compiled from "Issue.java"
> class Issue$1 implements java.io.Serializable
>   SourceFile: "Issue.java"
> *  EnclosingMethod: #22.#3                 // Issue.**
> *  InnerClasses:
>        #20; //class Issue$1
>   minor version: 0
>   major version: 46
>   flags: ACC_SUPER
> Constant pool:
>    #1 = Utf8               java/lang/Object
>    #2 = Utf8               EnclosingMethod
>    #3 = NameAndType        #25:#25        //  "":
>    #4 = Utf8               <init>
>    #5 = Utf8               (LIssue;)V
>    #6 = NameAndType        #4:#8          //  "<init>":()V
>    #7 = Class              #1             //  java/lang/Object
>    #8 = Utf8               ()V
>    #9 = Utf8               Code
>   #10 = Utf8               InnerClasses
>   #11 = Utf8               LIssue;
>   #12 = Utf8               Issue.java
>   #13 = NameAndType        #23:#11        //  this$0:LIssue;
>   #14 = Utf8               SourceFile
>   #15 = Utf8               Issue
>   #16 = Methodref          #7.#6          // java/lang/Object."<init>":()V
>   #17 = Utf8               java/io/Serializable
>   #18 = Fieldref           #20.#13        // Issue$1.this$0:LIssue;
>   #19 = Class              #17            // java/io/Serializable
>   #20 = Class              #21            //  Issue$1
>   #21 = Utf8               Issue$1
>   #22 = Class              #15            //  Issue
>   #23 = Utf8               this$0
>   #24 = Utf8               dummy
>   #25 = Utf8
> {
>   final Issue this$0;
>     Signature: LIssue;
>     flags: ACC_FINAL
>
>
>   Issue$1(Issue);
>     Signature: (LIssue;)V
>     flags:
>     Code:
>       stack=2, locals=2, args_size=2
>          0: aload_0
>          1: aload_1
>          2: putfield      #18                 // Field this$0:LIssue;
>          5: aload_0
>          6: invokespecial #16                 // Method 
> java/lang/Object."<init>":()V
>          9: return
>
>   public void dummy();
>     Signature: ()V
>     flags: ACC_PUBLIC
>     Code:
>       stack=0, locals=1, args_size=1
>          0: return
> }
>
> Issue$1 generated by compiler:
>
> Classfile ./innerclass_issue/Issue$1.class
>   Last modified Oct 25, 2012; size 389 bytes
>   MD5 checksum 2f3a83859d87f9451fc95cbd6a8744c8
>   Compiled from "Issue.java"
> class Issue$1 implements java.io.Serializable
>   SourceFile: "Issue.java"
> *EnclosingMethod: #17.#0                 // Issue**
> *** InnerClasses:
>        #3; //class Issue$1
>   minor version: 0
>   major version: 51
>   flags: ACC_SUPER
> Constant pool:
>    #1 = Fieldref           #3.#18         // Issue$1.this$0:LIssue;
>    #2 = Methodref          #4.#19         // java/lang/Object."<init>":()V
>    #3 = Class              #20            //  Issue$1
>    #4 = Class              #23            //  java/lang/Object
>    #5 = Class              #24            // java/io/Serializable
>    #6 = Utf8               this$0
>    #7 = Utf8               LIssue;
>    #8 = Utf8               <init>
>    #9 = Utf8               (LIssue;)V
>   #10 = Utf8               Code
>   #11 = Utf8               LineNumberTable
>   #12 = Utf8               dummy
>   #13 = Utf8               ()V
>   #14 = Utf8               SourceFile
>   #15 = Utf8               Issue.java
>   #16 = Utf8               EnclosingMethod
>   #17 = Class              #25            //  Issue
>   #18 = NameAndType        #6:#7          //  this$0:LIssue;
>   #19 = NameAndType        #8:#13         //  "<init>":()V
>   #20 = Utf8               Issue$1
>   #21 = Utf8
>   #22 = Utf8               InnerClasses
>   #23 = Utf8               java/lang/Object
>   #24 = Utf8               java/io/Serializable
>   #25 = Utf8               Issue
> {
>   final Issue this$0;
>     Signature: LIssue;
>     flags: ACC_FINAL, ACC_SYNTHETIC
>
>
>   Issue$1(Issue);
>     Signature: (LIssue;)V
>     flags:
>     Code:
>       stack=2, locals=2, args_size=2
>          0: aload_0
>          1: aload_1
>          2: putfield      #1                  // Field this$0:LIssue;
>          5: aload_0
>          6: invokespecial #2                  // Method 
> java/lang/Object."<init>":()V
>          9: return
>       LineNumberTable:
>         line 3: 0
>
>   public void dummy();
>     Signature: ()V
>     flags: ACC_PUBLIC
>     Code:
>       stack=0, locals=1, args_size=1
>          0: return
>       LineNumberTable:
>         line 5: 0
> }
>
> So in Issue$1 from compiler, EnclosingMethod refers to entry #0 but in 
> the one from Soot, it refers to #3 (NameAndType).
> Isn't this the issue?
> would this be something different between class version 46 and 51?
>
> - Henddher
>
> On 10/26/2012 09:38 AM, Henddher Pedroza wrote:
>> Hello all again,
>>
>> Posting again with original attachment replaced.
>>
>> Here is more info about the issue:
>>
>> Stepping through the verifier code in ASM 3.3.1 makes me believe that 
>> the issue is in the .class file generated by Soot 2.5.0. Soot 
>> generates 46 and compiler 1.7 generates 51.
>>
>> When Issue$1 is being verified by ASM, the enclosing name and 
>> enclosing desc of the inner class is read in preparation for visiting 
>> the outer class. However, ASM 3.3.1 expects enclosing desc to be null 
>> because the inner class is not defined within a method. When ASM 
>> checks if enclosing desc is null, it finds that it is empty-string 
>> instead which is unexpected.
>>
>> The fundamental question is this:
>>
>> When an inner class is defined within the body of another class, the 
>> field is tagged as synthetic and the class attribute of the inner 
>> class is tagged as "EnclosingMethod" but also the enclosing name and 
>> enclosing desc are empty strings both. Is this correct?
>> Where in the specification are these points explained?
>>
>> (the 4 classes are attached: both pairs, Issue.class and 
>> Issue$1.class pair, from compiler and from Soot 2.5.0. The source 
>> code Issue.java and a README)
>>
>> Thanks in advance. Any help is very appreciated.
>>
>> -Henddher
>>
>> On 10/25/2012 06:21 PM, Henddher Pedroza wrote:
>>>
>>> Hello,
>>>
>>> I am using Soot 2.5.0 and ASM3.3.1 BasicVerifier and Analyzer and came
>>> across an issue:
>>>
>>> BasicVerifier+Analyzer throws IAE "invalid method descr(null or empty)"
>>> when I try to verify a .jar file.
>>>
>>> The source .java is as follows:
>>>
>>> //Issue.java:
>>> import java.io.Serializable;
>>> public class Issue {
>>>      Serializable serializable = new Serializable() {
>>>          public void dummy() {
>>>          }
>>>      };
>>> }
>>>
>>> I compile the class with javac 1.7.0_05.
>>> $ javac -d . Issue.java
>>>
>>> Then, I ran the classes through Soot 2.5.0:
>>> $ java soot.Main -app -d output.jar -outjar Issue
>>>
>>> Soot started on Thu Oct 25 17:05:28 CDT 2012
>>> Transforming Issue...
>>> Transforming Issue$1...
>>> Writing to Issue.class
>>> Writing to Issue$1.class
>>> Soot finished on Thu Oct 25 17:05:29 CDT 2012
>>> Soot has run for 0 min. 1 sec.
>>>
>>> Finally, I run the .jar through ASM 3.3.1 Analyzer+BasicVerifier, the
>>> exception happens when checking Issue$1.class, after checking 
>>> Issue.class:
>>> $ java -jar asm311verifier.jar output.jar -pd
>>>
>>> java.lang.IllegalArgumentException: Invalid method descriptor (must not
>>> be null or empty)
>>>      at
>>> org.objectweb.asm.util.CheckMethodAdapter.checkMethodDesc(CheckMethodAdapter.java:1104) 
>>>
>>>      at
>>> org.objectweb.asm.util.CheckClassAdapter.visitOuterClass(CheckClassAdapter.java:405) 
>>>
>>>      at org.objectweb.asm.ClassReader.accept(ClassReader.java:572)
>>>      at org.objectweb.asm.ClassReader.accept(ClassReader.java:425)
>>>
>>> I have attached the source, original .class and transformed classes
>>> should anyone wanted to experiment.
>>>
>>> Any advice?
>>>
>>> Thanks in advance.
>>>
>>> - Henddher
>>>
>>>
>>>
>>>
>>>
>>
>

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