RFR: 8034066: Incorrect alignment in the "Code" section for "-c -XDdetails" options [v2]

[Chen Liang]

On Fri, 25 Oct 2024 09:28:53 GMT, Jonathan Lampérth <duke at 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)
>
> Jonathan Lampérth has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - adress feedback in implementation
>  - address feedback in tests

Looks good.

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Marked as reviewed by liach (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/21685#pullrequestreview-2395574746