Commit Graph

1 Commits

Author SHA1 Message Date
Simon Zünd
2e11dff7f2 Change debug-evaluate from a whitelist to a blacklist approach
This CL changes how variables are resolved during debug evaluate.
We now re-parse the whole script when creating a ScopeIterator.
This gives us accurate scope information for all parent scopes of the
closure in which we stopped. Using this information, we build
blacklists of stack-allocated variables. Each context on the chain
in between the closure context up to the original native context is
wrapped in a debug-evaluate context with such a blacklist attached.
Variable lookup for debug-evalute contexts then works as follows:

  1) Look up in the materialized stack variables (stayed the same).
  2) Check the blacklist to find out whether to abort further lookup.
  3) Look up in the original context.

Steps 1-3 is repeated for each debug-evaluate context, since they
mirror the original context chain.

R=ulan@chromium.org, yangguo@chromium.org

Change-Id: Ied8e5786772c70566da9627ee3b7eff066fba2b4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1795354
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63666}
2019-09-11 07:52:45 +00:00