[Soot-list] Spark Error with Flowdroid

[Quentin Sabah]

So I managed to get the .class

I think what we have here is the perfect example of the limits of use-original-names in the current implementation. 

The local "l8" indicates that we are tracking the local slot #8. However, the local variable name table isn't complete, the name "part" is only flagged for 3 bytecodes [463:463+3]. There are many other use of slot 8 that should be associated with "part", but they aren't.

    LocalVariableTable:
      Start  Length  Slot  Name   Signature
             0     467     0  this   Lcom/oreilly/servlet/MultipartRequest;
             0     467     1 request   Ljavax/servlet/http/HttpServletRequest;
             0     467     2 saveDirectory   Ljava/lang/String;
             0     467     3 maxPostSize   I
             0     467     4 encoding   Ljava/lang/String;
             0     467     5 policy   Lcom/oreilly/servlet/multipart/FileRenamePolicy;
            78     388     6   dir   Ljava/io/File;
           163     303     7 parser   Lcom/oreilly/servlet/multipart/MultipartParser;
           183      90     8 queryParameters   Ljava/util/Hashtable;
           190      83     9 queryParameterNames   Ljava/util/Enumeration;
           202      61    10 paramName   Ljava/lang/Object;
           214      49    11 values   [Ljava/lang/String;
           223      40    12 newValues   Ljava/util/Vector;
           226      37    13     i   I
           463       3     8  part   Lcom/oreilly/servlet/multipart/Part;
           283     172     9  name   Ljava/lang/String;
           298      54    10 paramPart   Lcom/oreilly/servlet/multipart/ParamPart;
           305      47    11 value   Ljava/lang/String;
           319      33    12 existingValues   Ljava/util/Vector;
           370      85    10 filePart   Lcom/oreilly/servlet/multipart/FilePart;
           377      78    11 fileName   Ljava/lang/String;

Because in Soot we rely too much on this table when use-original-names is enabled, we generate two Local for the same local variable in this case. It can be corrected, the original name should be some kind of Tag associated with each Unit, telling what probable original name should be associated with each Local.

-- 
Quentin Sabah, CIFRE Ph.D. student
Grenoble University
INRIA-SARDES                   | STMicroelectronics/AST
Montbonnot, France             | Grenoble, France
mailto:quentin.sabah at inria.fr  | mailto:quentin.sabah at st.com
phone: +33 476 61 52 42        | phone: +33 476 58 44 14