RFR: 8294982: Implementation of Classfile API [v36]

[Adam Sotona]

On Thu, 2 Mar 2023 20:54:39 GMT, Paul Sandoz <psandoz at openjdk.org> wrote:

>> Adam Sotona has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   StackMapFrameInfo extracted to top level from StackMapTableAttribute
>
> src/java.base/share/classes/jdk/internal/classfile/instruction/LoadInstruction.java line 66:
> 
>> 64:      * @param slot the local varaible slot to load from
>> 65:      */
>> 66:     static LoadInstruction of(Opcode op, int slot) {
> 
> Should you validate that `slot` is compatible with `op`? (same for the StoreInstruction?)

There are three aspects of this kind of validation:
1. similar to `arrayType` there was an architectural decision to less validate so to perform faster
2. static instruction factory does not have the information necessary to validate local variable slot, it could theoretically be validated in the `CodeBuilder`
3. incompatible slot would most probably prevent stack map generation and such code will fail in the later phase, or at least when verification is explicitly called on the generated code

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

PR: https://git.openjdk.org/jdk/pull/10982