On Thu, 24 Oct 2024 14:57:19 GMT, Jonathan Lampérth <d...@openjdk.org> wrote:
> This PR includes changes to ensure `Code:` block indentation in `javap`for
> the `-verbose` case and non `-verbose` case is the same, which currently does
> not hold.
>
> Current behaviour of `javap` differs with and without `-verbose` in the
> following way:
> **Command**: `javap -c -XDdetails:stackMaps A.class`
>
> Without `-verbose`
>
>
> ...
> public void a();
> Code:
> 0: iconst_0
> 1: istore_1
> StackMap locals: this int
> StackMap stack:
> ...
>
>
> With `-verbose`
>
>
> ...
> public void a();
> descriptor: ()V
> flags: (0x0001) ACC_PUBLIC
> Code:
> stack=2, locals=2, args_size=1
> 0: iconst_0
> 1: istore_1
> StackMap locals: this int
> StackMap stack:
> ...
>
>
> With `-verbose` all contents of the `Code:` section include an extra (2
> space) indent, which is missing in the non `-verbose` case. This is because
> the `CodeWriter` is called via `CoderWriter.write(...)` in the `-verbose`
> case, which wraps the `Code:` block in `indent(+1);...indent(-1)`.
>
> In the non-verbose case this call is circumvented and a simplified version of
> `CoderWriter.write(...)` is included directly in `ClassWriter.writeMethod`.
>
> ---
>
> Alternatively to keep the logic within `CodeWriter` with the goal of keeping
> the logic for `-verbose` and non `-verbose` in the same place one could add
> `CodeWriter.writeSimple(...)`.
>
>
> void writeSimple(CodeAttribute attr) {
> println("Code:");
> indent(+1);
> writeInstrs(attr);
> writeExceptionTable(attr);
> indent(-1);
> }
>
>
> ---
>
> Note: Test setup is inspired by existing tests:
> [T6622232.java](https://github.com/openjdk/jdk/blob/master/test/langtools/tools/javap/T6622232.java)
> and
> [8244573](https://github.com/openjdk/jdk/blob/master/test/langtools/tools/javap/8244573)
test/langtools/tools/javap/8034066/EmptyLoop.jcod line 26:
> 24: /*
> 25: * Original source:
> 26: * public class EmptyLoop {
To reduce test file noise, I recommend adding this as a package-private class
to the end of your test file (so not a nested class) after it is renamed, like:
class EmptyLoop {
public void emptyLoop() {
for (int i = 0; i < 10; i++) {
}
}
}
After that, once your test class is compiled, the `EmptyLoop.class` is
available in `test.classes` property directory, so you can remove this jcod and
all code that converts the jcod to class.
You can see UndefinedAccessFlagTest for how we use such tricks.
Note: since you will only have one test class, you no longer need a dedicated
directory; you can just place our `CodeIndentTest.java` in the root javap
directory.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/21685#discussion_r1815931722
