RFR: 8308655: Narrow types of ConstantPool and ConstMethod returns [v2]

[Matias Saavedra Silva]

On Wed, 24 May 2023 18:19:33 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> This change uses a number of ways to eliminate -Wconversion warnings in the metadata files in the oops directory. 
>> 
>> 1. narrow return types to u2 if the accessor is for a field or value that's u2 (u2 is most common for constMethod fields and constant pool indices)
>> 2. Use checked_cast<type> for places where we know the int value is u2 or s2 but propagating these types is too much fan out.
>> 3. Use plain casts where it's obvious that the int value fits in the casted-to type.
>> 4. Moved KlassKind to be contained in Klass to add the Unknown enum value to use instead of -1.
>> 5. Moved the compute_from_signature function into ConstMethod as it sets values in ConstMethod and the parameters are changed in the set functions.  Removed some pass through functions in Method.
>> 
>> Tested with tier1-4.
>
> Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fred's comments.

Looks good, I just had a few minor comments that might be unimportant. Otherwise, approved!

src/hotspot/share/classfile/classLoaderExt.cpp line 70:

> 68:   Arguments::assert_is_dumping_archive();
> 69:   int start_index = ClassLoader::num_boot_classpath_entries();
> 70:   _app_class_paths_start_index = checked_cast<jshort>(start_index);

This might be a misunderstanding but are these meant to be s2 instead of jshort?

src/hotspot/share/classfile/classLoaderExt.cpp line 122:

> 120:   int start_index = ClassLoader::num_boot_classpath_entries() +
> 121:                     ClassLoader::num_app_classpath_entries();
> 122:   _app_module_paths_start_index = checked_cast<jshort>(start_index);

Same question as above

src/hotspot/share/oops/klass.hpp line 79:

> 77:     TypeArrayKlassKind,
> 78:     ObjArrayKlassKind,
> 79:     Unknown

Maybe this should be `UnknownKind` to be consistent with the other options.

-------------

Marked as reviewed by matsaave (Committer).

PR Review: https://git.openjdk.org/jdk/pull/14092#pullrequestreview-1442597537
PR Review Comment: https://git.openjdk.org/jdk/pull/14092#discussion_r1204662039
PR Review Comment: https://git.openjdk.org/jdk/pull/14092#discussion_r1204662242
PR Review Comment: https://git.openjdk.org/jdk/pull/14092#discussion_r1204658756