[VERSION 1.4.2] Deleting debug-information - Bugreports and known bugs - Jabaco

Intermediate

Sunday, July 19th 2009, 6:37pm

Deleting debug-information

With Javac it is possible with the options "-g" and "-g:none" to either creating .class files with a lot of debug-code or small files without debug-code.
If you compile without any -g option, it compiles withsome debug-code.

Jabaco on the other side, creates only code with the same amount of debug code (for example the LineNumberTable and so).
If you want to remove it, have a look at
http://blogs.sun.com/ahe/entry/how_to_st…bug_information

There stand, that a

	Source code
1	pack200 -r -G debug.jar

will remove all debug-code.

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OlimilO

Intermediate

Posts: 277

Location: Germany

Occupation: software engineer

Sunday, July 19th 2009, 10:01pm

Hi theuserbl,

thanks for the idea.
There is a similar option in Jabaco:
In the project-explorer select your projectname (the very above item), then look into the properties editor.
Right next to the "Compile"-item you can select "Bytecode" or "Debug".

regards

OlimilO

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theuserbl

Intermediate

Posts: 233

Sunday, July 19th 2009, 10:37pm

Quoted from "OlimilO"

thanks for the idea.

Thanks for your response.

Quoted

There is a similar option in Jabaco:
In the project-explorer select your projectname (the very above item), then look into the properties editor.
Right next to the "Compile"-item you can select "Bytecode" or "Debug".

I have tried it now out, but it seems, that it don't work.

I have changed "Debug" to "Bytecode".
Then I have created a Button on the Form.
After it I have compiled it to jar. The jar I have then extracted.

With

	Source code
1	javap -c -s -l Module1

I have looked at the Module1.class

The output is

Source code

javap -s -l -c Modul
e1
Compiled from "Module1.jsrc"
public class Module1 extends java.lang.Object{
public static Form1 Form1;
  Signature: LForm1;

public static void main(java.lang.String[]);
  Signature: ([Ljava/lang/String;)V
  Code:
   0:   aconst_null
   1:   astore_1
   2:   aconst_null
   3:   astore_2
   4:   new     #22; //class VBA/VBArray
   7:   dup
   8:   invokespecial   #23; //Method VBA/VBArray."<init>":()V
   11:  astore_3
   12:  aload_0
   13:  invokestatic    #27; //Method VBA/VBArray.createVBArray:([Ljava/lang/Str
ing;)LVBA/VBArrayString;
   16:  astore_3
   17:  getstatic       #20; //Field Form1:LForm1;
   20:  invokevirtual   #32; //Method VB/AbstractForm.SetDefaultClose:()V
   23:  getstatic       #20; //Field Form1:LForm1;
   26:  invokevirtual   #35; //Method VB/AbstractForm.Show:()V
   29:  nop
   30:  return
   31:  nop
   32:  aload_1
   33:  checkcast       #37; //class java/lang/Exception
   36:  invokestatic    #43; //Method VBA/Interaction.MsgBoxError:(Ljava/lang/Ex
ception;)V
   39:  goto    29
   42:  astore_2
   43:  astore_1
   44:  ret     2
   46:  jsr     42
   49:  goto    31
  Exception table:
   from   to  target type
    12    29    46   any

  LineNumberTable:
   line 4: 0
   line 5: 4
   line 6: 12
   line 7: 17
   line 8: 23
   line 9: 29

  LocalVariableTable:
   Start  Length  Slot  Name   Signature
   0      52      0    args       [Ljava/lang/String;
   0      52      1    Err       Ljava/lang/Exception;
   0      52      2    h3       Ljava/lang/Exception;
   0      52      3    myArgs       LVBA/VBArrayString;


public Module1();
  Signature: ()V
  Code:
   0:   aload_0
   1:   invokespecial   #13; //Method java/lang/Object."<init>":()V
   4:   nop
   5:   return


  LocalVariableTable:
   Start  Length  Slot  Name   Signature
   0      6      0    me       LModule1;


public static {};
  Signature: ()V
  Code:
   0:   new     #16; //class Form1
   3:   dup
   4:   invokespecial   #17; //Method Form1."<init>":()V
   7:   putstatic       #20; //Field Form1:LForm1;
   10:  nop
   11:  return




}

For information:
The parts with "LocalVariableTable" and "LineNumberTable" are Debug-code.
For example the LineNumberTable says, which Line number of the Sourcecode, you can find as representation on the Asseblercode.
Only needed for debugging.

Greatings
theuserbl

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theuserbl

Intermediate

Posts: 233

Sunday, July 19th 2009, 10:42pm

And here the code of Form1.class in the same way deassembalted:

Source code

javap -s -l -c Form1

Compiled from "Form1.jsrc"
public class Form1 extends VB.Form{
public Form1();
  Signature: ()V
  Code:
   0:   aload_0
   1:   invokespecial   #9; //Method VB/Form."<init>":()V
   4:   aload_0
   5:   invokevirtual   #12; //Method initVars:()V
   8:   nop
   9:   return


  LocalVariableTable:
   Start  Length  Slot  Name   Signature
   0      10      0    me       LForm1;


}

It is shorter then Module1. But as you can see, there existing still "LocalVariableTable".
But Pack200 can remove it. :-)