• Jakob Gruber's avatar
    [regexp] Don't update last match info in @@split special case · 51fcfd58
    Jakob Gruber authored
    V8 implements a fast-path for RegExp.prototype.split which diverges
    from the spec: instead of creating a new sticky regexp instance
    `splitter` and running it in a loop, we reuse the existing non-sticky
    regexp without looping through each character.
    
    This works fine in most cases, but we run into issues when matching at
    the very end of the string. According to the spec, matches at the end
    of the string are impossible in @@split, but in our fast-path
    implementation they can happen.
    
    The obvious fix would be to remove our fast-path but this comes with
    high performance costs. The fix implemented in this CL adds a special
    flag to `exec` s.t. matches at the end of the string can be treated as
    failures. This is only relevant for @@split.
    
    Bug: chromium:1075514
    Change-Id: Ifb790ed116793998d7aeb37e307f3f3f764023d3
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2681950
    Commit-Queue: Jakob Gruber <jgruber@chromium.org>
    Auto-Submit: Jakob Gruber <jgruber@chromium.org>
    Reviewed-by: 's avatarShu-yu Guo <syg@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#72644}
    51fcfd58
builtins-regexp-gen.h 8.41 KB