026a0c214a
During conflict lookup (for lexical variables and sloppy block function hoisting), we cache the looked-up variable on the current scope if the lookup goes through a ScopeInfo. However, for variable lookup during scope analysis, we use the "entry point" as the cache. Since both lookups can create Variables, this can cause us to create duplicate variables, e.g. a duplicate function name variable in the attached test. Instead, for ScopeInfo conflict lookups we can cache the result on the function's outer scope, which shoud be equivalent to the entry point. As a (necessary) drive-by, we can terminate the lookup early if we find a VAR with the same name, as we can safely assume that its existence means that it doesn't conflict, which means that our variable can't conflict either. Bug: chromium:1026603 Change-Id: I19f80f65597ba6573ebe0b48aa5698f55e5c3ea1 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1928861 Commit-Queue: Leszek Swirski <leszeks@chromium.org> Reviewed-by: Toon Verwaest <verwaest@chromium.org> Cr-Commit-Position: refs/heads/master@{#65138}
14 lines
521 B
JavaScript
14 lines
521 B
JavaScript
// Copyright 2019 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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(function f() {
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with ({}) {
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// Make sure that variable conflict resulution and variable lookup through
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// deserialized scopes use the same cache scope. Declare a variable which
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// checks for (and fails to find) a conflict, allocating the f variable as
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// it goes, then access f, which also looks up f.
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eval("var f; f;");
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}
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})();
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