On Mon, 17 Jun 2024 13:55:41 GMT, Chen Liang <[email protected]> wrote:
>> Currently, javap crashes for class files that have set non-zero values for
>> undefined access flag bits, as
>> `java.lang.reflect.AccessFlag.maskToAccessFlag` and
>> `java.lang.classfile.AccessFlags.flags` fail. In contrast, the JVMS, though
>> asking for these bits to be set to 0, requires VM to proceed and ignore
>> these bits. javap should emulate the VM behavior and proceed rendering,
>> ignoring these undefined bits.
>>
>> In addition, a few bytecode generation utilities in the JDK set unused bits,
>> such as in
>> `java.lang.invoke.MethodHandleImpl.BindCaller#generateInvokerTemplate` and
>> `java.lang.invoke.GenerateJLIClassesHelper#generateCodeBytesForLFs`. Those
>> can be updated in a later cleanup.
>
> Chen Liang has updated the pull request incrementally with two additional
> commits since the last revision:
>
> - Improve tests to check unmatched bit position and failure for
> non-inner-classes
> - Report error for flag problems
src/jdk.jdeps/share/classes/com/sun/tools/javap/BasicWriter.java line 84:
> 82: } catch (IllegalArgumentException ex) {
> 83: mask &= LOCATION_MASKS.get(location);
> 84: report(ex);
Unfortunately the original exception message is missing any info that it is
related to access flags and it is not very clear what "Error: Unmatched bit
position 0x2 for location CLASS" means.
I would add at least a message prefix, for example "Error: Access Flags:
Unmatched bit position 0x2 for location CLASS".
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/19708#discussion_r1643041633
