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Benedikt Meurer authored
When creating a new JSError object (or using the non-standard API `Error.captureStackTrace`) V8 would previously capture the "simple stack trace" (as FixedArray of CallSiteInfo instances) to be used for the non- standard `error.stack` property, and if the inspector was active also capture the "detailed stack trace" (as FixedArray of StackFrameInfo instances). This turns out to be quite a lot of overhead, both in terms of execution time as well as memory pressure, especially since the information needed for the inspector is a proper subset of the information needed by `error.stack`. So this CL addresses the above issue by capturing only the "simple stack trace" (in the common case) and computing the "detailed stack trace" from the "simple stack trace" when on demand. This is accomplished by introducing a new ErrorStackData container that is used to store the stack trace information on JSErrors when the inspector is active. When capturing stack trace for a JSError object while the inspector is active, we take the maximum of the program controlled stack trace limit and the inspector requested stack trace limit, and memorize the program controlled stack trace limit for later formatting (to ensure that the presence of the inspector is not observable by the program). On the `standalone.js` benchmark from crbug.com/1283162 (with the default max call stack size of 200) we reduce execution time by around 16% compared to ToT. And compared to V8 9.9.4 (the version prior to the regression in crbug.com/1280831), we are 6% faster now. Doc: https://bit.ly/v8-cheaper-inspector-stack-traces Bug: chromium:1280831, chromium:1278650, chromium:1258599 Bug: chromium:1280803, chromium:1280832, chromium:1280818 Fixed: chromium:1283162 Change-Id: I57dac73e0ecf7d50ea57c3eb4981067deb28133e Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3366660Reviewed-by: Leszek Swirski <leszeks@chromium.org> Reviewed-by: Yang Guo <yangguo@chromium.org> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org> Cr-Commit-Position: refs/heads/main@{#78542}
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