Packing Observation

[DavidRM 47]

Not really a *bug*...but it looks like case statements get compiled to if-then-else statements that aren't "packed". That is, each case statement condition is kept on a single line, not combined with the line ahead of it.

Is that by design?

-David

[jarto 428]

Weird. When I test this, the statements are on one line.

[DavidRM 47]

I'll poke at it some more. I just noticed because I was packing and obfuscating for deployment.

[jarto 428]

For deployment, you can also add extra complexity against preying eyes by using Google's closure-compiler.

1. Download the latest binary from: https://github.com/google/closure-compiler/wiki/Binary-Downloads
2. Uncheck "Embed Javascripg into HTML file" in Project options
3. Select both Code packing and Code obfuscation
4. Build
5. Run closure-compiler on the generated main.js:

java -jar closure-compiler.jar --js main.js --js_output_file mainp.js

And then replace main.js with mainp.js. The compiler will give some warnings about unreachable code but they are safe to ignore.

[DavidRM 47]

I wonder if the not-packing is related to ASM blocks? I have no idea.

I can scroll through my packed-and-obfuscated JS file and see blocks like this:

I think that's from RTL code, not mine. This is from mine:

I don't know that it makes a lot of difference, but there it is.

-David

[jarto 428]

Now I can reproduce the problem. If you compare against string values, they are split on separate lines:

  case Trunc(Now) of
    1: WriteLn('One');
    2: WriteLn('Two');
    3: WriteLn('One');
    else WriteLn('Something else');
  end;

  case IntToStr(Trunc(Now)) of
    '1': WriteLn('One');
    '2': WriteLn('Two');
    '3': WriteLn('One');
    else WriteLn('Something else');
  end;

  case IntToStr(Trunc(Now)) of
    "1": WriteLn('One');
    "2": WriteLn('Two');
    "3": WriteLn('One');
    else WriteLn('Something else');
  end;

That first one is compressed on one line. Other ones are split on multiple lines.

[DavidRM 47]

On 1/5/2019 at 3:59 AM, jarto said:

For deployment, you can also add extra complexity against preying eyes by using Google's closure-compiler.

1. Download the latest binary from: https://github.com/google/closure-compiler/wiki/Binary-Downloads
2. Uncheck "Embed Javascripg into HTML file" in Project options
3. Select both Code packing and Code obfuscation
4. Build
5. Run closure-compiler on the generated main.js:

java -jar closure-compiler.jar --js main.js --js_output_file mainp.js

And then replace main.js with mainp.js. The compiler will give some warnings about unreachable code but they are safe to ignore.

@jarto That does add a bit more obfuscation, yup yup. Thanks! 😃 -David