On Thu, 16 Nov 2023 10:00:44 GMT, Adam Sotona <asot...@openjdk.org> wrote:
> Stack map generator in ClassFile API performs only minimal checks in favour
> of performance.
> However it led to situations where it generates invalid stack maps for
> corrupted code.
> This patch adds basic checks of stack when two frames are merged and throws
> an exception in case of stack size or content mismatch. Generated or
> transformed code with inconsistent stack will fail on stack maps generation.
> Relevant tests are added.
>
> Please review.
>
> Thanks,
> Adam
src/java.base/share/classes/jdk/internal/classfile/impl/StackMapGenerator.java
line 1138:
> 1136: }
> 1137: if (stackSize != target.stackSize) {
> 1138: generatorError("Stack size mismatch");
Just a side comment, `generatorError` should return a Throwable than throw
directly, so when used as `throw generatorError()`, it is more clear that the
code branch will terminate to javac.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/16685#discussion_r1395551761
