On Wed, 8 May 2024 19:06:35 GMT, ExE Boss <d...@openjdk.org> wrote:
>> Claes Redestad has updated the pull request incrementally with one
>> additional commit since the last revision:
>>
>> Refactor to further avoid re-validating arguments
>
> src/java.base/share/classes/jdk/internal/constant/MethodTypeDescImpl.java
> line 179:
>
>> 177:
>> 178: for (ClassDesc param : paramTypes)
>> 179: validateArgument(param);
>
> This check should be performed as part of copying `paramTypes` to `newArgs`
> to avoid TOC/TOU issues, e.g.:
>
> @Override
> public MethodTypeDesc insertParameterTypes(int pos, ClassDesc... paramTypes) {
> if (pos < 0 || pos > argTypes.length)
> throw new IndexOutOfBoundsException(pos);
>
> ClassDesc[] newArgs = new ClassDesc[argTypes.length +
> paramTypes.length];
> if (pos > 0) {
> System.arraycopy(argTypes, 0, newArgs, 0, pos);
> }
> for (int i = 0; i < paramTypes.length; i++) {
> newArgs[pos + i] = validateArgument(paramTypes[i]);
> }
> if (pos < argTypes.length) {
> System.arraycopy(argTypes, pos, newArgs, pos +
> paramTypes.length, argTypes.length - pos);
> }
> return ofValidated(returnType, newArgs);
> }
>
>
> See also:
> https://github.com/openjdk/jdk/blob/230fac80f25e9608006c8928a8a7708bf13a818c/src/java.base/share/classes/java/util/ImmutableCollections.java#L186-L195
Nice catch! I conservatively just move the validation loop after to keep the
arraycopying.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/19105#discussion_r1594579344
