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Re:Bytecode features not available in the Java language by malft on Friday April 17, 2015 @10:02AM (#9394329)
Didn't see my favorite on the list: creating the bool 2. I believe there are a couple of methods in the JDK that do

    if (dangerousFlag == true) doCheck();
    ...
    foo(dangerousFlag ? bar : baz);
Re:Bytecode features not available in the Java language by TheLoneWolfling on Friday April 17, 2015 @02:36PM (#9396270)
That's in the list:

> Overflow and implicitly assign byte, short, char and boolean values

Re:Bytecode features not available in the Java language by peeters on Friday April 17, 2015 @04:38PM (#9397072)
Wait, I love learning new things about Java, but I feel in the dark here. What is your example demonstrating?
Re:Bytecode features not available in the Java language by TheLoneWolfling on Saturday April 18, 2015 @08:44AM (#9399246)
The valid values of booleans / bytes / shorts / chars are only enforced in the Java compiler, not actually in bytecode.

But the Java compiler assumes values will be in range - i.e. that a boolean will be zero or one, that sort of thing.

And as such it makes some optimizations that are... questionable, if you're interfacing with bytecode that wasn't produced by the Java compiler.

For example, if `flag` is supposedly a boolean, but you gave it the value `2` directly via bytecode, flag==true is false, as it gets compiled down to flag == 1, which is false, but flag?bar:baz will return bar.

This can seriously break static analysis, among other things.

Re:Bytecode features not available in the Java language by onedognight on Friday April 17, 2015 @11:02PM (#9398176)
If true is book(1) then the check

    bool(2) == true
will fail but

    bool(2) ? a : b
will act as if bool(2) were true and this inconsistency could lead to unintended execution paths.
Re:Bytecode features not available in the Java language by peeters on Saturday April 18, 2015 @06:05PM (#9401256)
Ah, I'm with you. Thanks.