In the CR there is a simple jdb test case that shows if you try a "next" command (single step OVER) after getting a MethodExit event (enabled with the jdb "trace" command), the "next" does not stop after the method returns like it should. Instead it just effectively resumes the debuggee until it hits some other event (Breakpoint or MethodExit).
The problem is that if NotifyFramePop is called while handling a MethodExit event, OPAQUE_FRAME is returned. The debug agent mistakenly assumes this means the method was native, so step->fromNative is set true. This messed up initEvents() for the JDWP_STEP_DEPTH(OVER) case, which only enables events if step->fromNative is false. Initially I fixed this by doing a check to see if the method really is native so step->fromNative isn't incorrectly set true when the frame is not native. However, I eventually concluded that JDWP_STEP_DEPTH(OVER) should enable stepping even if the method is native. In fact it has to or else there will be no single step event when returning from the native method. I then noticed the comments in initEvents() seemed to be very bit rotten and did not describe what was actually going on in the code. In the end the concern isn't with whether or not the method is native, but whether or not NotifyFramePop failed, so I renamed fromNative to notifyFramePopFailed and c leaned up the comments. In JdbMethodExitTest, I made a very slight modification that caused the the failure reported in the CR. I replaced a "step up" call with "next". The causes the JDWP_STEP_DEPTH(OUT) case to be triggered instead of JDWP_STEP_DEPTH(OVER). Tested by running all tier1, tier2, tier3, and tier5 svc CI test tasks. ------------- Commit messages: - fix jcheck error - add bug reproducer - fix issues with single stepping during method exit event Changes: https://git.openjdk.org/jdk/pull/29849/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29849&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8377671 Stats: 38 lines in 3 files changed: 12 ins; 10 del; 16 mod Patch: https://git.openjdk.org/jdk/pull/29849.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/29849/head:pull/29849 PR: https://git.openjdk.org/jdk/pull/29849
