1. 01 May, 2020 1 commit
    • Seth Brenith's avatar
      [debug] Don't crash when breaking on entry to functions with heap vars · 3c20dfed
      Seth Brenith authored
      Any function with heap-allocated variables starts by creating and
      pushing a new context for its execution. When entering the debugger due
      to the stack check in the beginning of InterpreterEntryTrampoline, the
      function has not yet had a chance to push that new context. The code in
      ScopeIterator currently assumes that any function which needs a context
      already has one by the time the debugger attempts to iterate scopes, but
      in this case that assumption is invalid, which can cause a null deref.
      
      This change introduces a new function ScopeIterator::NeedsAndHasContext
      to replace previous calls to current_scope_->NeedsContext(). This new
      function checks for the case where the current scope matches the closure
      scope but the context matches the containing context for the function,
      which implies that the function has not yet pushed its own context.
      
      Bug: v8:10319, chromium:1038747
      Change-Id: I29636f269c44d35b68d8446769d17170eed50e89
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2168021
      Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
      Reviewed-by: 's avatarSimon Zünd <szuend@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#67519}
      3c20dfed