In JSStackFrame::GetMethodName() we try to infer a useful method name to
show for the closure to which the stack frame belongs. This is done by
first considering the functions name, and checking if the receiver has a
property with that name and if that property's value is the closure. In
case the function doesn't have a name or the property's value is not the
closure itself, we fall back to a reverse lookup of the closure within
the object (and its prototypes).
This CL speeds up this logic by attacking two problems:
1. The reverse lookup was performed by first using the KeyAccumulator to
extract the names of all enumerable properties, and afterwards using
the LookupIterator on each name, and testing the resulting property
value against the closure. This is fairly slow and creates a lot of
temporary objects and handles. We now look into the descriptor arrays
or dictionary backing stores of the objects directly instead, which
is easily 2-10x faster.
2. For the common case of `o.foo = function() { ... }` the parser already
places an "inferred name" of `o.foo` onto the SharedFunctionInfo,
which we can use as a hint to infer the name of the function instead
of immediately falling back to the expensive reverse lookup.
This repairs the regression reported in http://crbug.com/1069425 and
recovers most of the slowdown reported in http://crbug.com/1077657
(there's still some overhead left from the async stack trace tracking).
Fixed: chromium:1069425
Bug: chromium:1077657
Change-Id: I88d23ccad123906df70c5217e815493106e03ccf
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2676635
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72545}
We cannot assume that the receiver is a JSObject, nor can we assume
ToObject() completes successfully.
TBR=yangguo@chromium.org
Bug: chromium:739954
Change-Id: Id55571131ef8755e86f15cd2acb918ff0f1b7788
Reviewed-on: https://chromium-review.googlesource.com/632376
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47611}
CallSite depends on using the function name to get ahold of the property
name from which an exception was thrown. This fix properly handles the
ES2015 names for getters and setters. The new tests pass both with
--harmony-function-name off and on.
BUG=v8:3699
LOG=n
Review URL: https://codereview.chromium.org/1751403004
Cr-Commit-Position: refs/heads/master@{#34469}
