I happened to notice while stepping through the StackUnwindingWin64 test
that it never actually encounters a runtime-compiled function despite
using %OptimizeFunctionOnNextCall. V8 compiles the function on the
subsequent call as requested, but the compiled function isn't very good
because there was no feedback data, and it immediately deopts. To fix,
we can call the function once between %PrepareFunctionForOptimization
and %OptimizeFunctionOnNextCall.
Change-Id: Icb25f16d43a60c36a1f85d15e2ce4535e08d1076
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2472780
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#70633}
On Windows ARM64, OS stack walking does not work because the V8 ARM64 backend
doesn't emit unwinding info and also because it doesn't emit ABI compliant
stack frames. This was fixed for Windows X64 (https://crrev.com/c/1469329) and
documented below:
https://docs.google.com/document/d/1-wf50jFlii0c_Pr52lm2ZU-49m220nhYMrHDi3vXnh0
This problem can be fixed similarly for Windows ARM64 by observing that V8
frames usually all have the same prolog which maintains a chain via frame
pointer (fp or x29 register).
stp fp, lr, [sp, ...]
One exception is JSEntry which stops fp pointer chain and needs to be handled
specially.
So it is possible to define XDATA with UNWIND_CODE which specify how Windows
should walk through V8 dynamic frames. The same as X64, since V8 Code objects
are all allocated in the same code-range for an Isolate, it is possible to
register at most 2 XDATA and a group of PDATA entries to cover stack walking
for all the code generated inside that code-range. This is more than 1
PDATA/XDATA because according to the Windows ARM64 exeption handling document,
1 PDATA can cover less than 1MB code range (see below doc).
https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling
This PR implements stackwalk for Windows ARM64 to be on par with X64, including
embedded builtins, jitted code and wasm jitted code, but not including register
handler for handling exception only, because there is no backward compatibility
to maintain for Windows ARM64 which was released since 1709 windows build.
Bug: chromium:893460
Change-Id: Ic74cbdad8af5cf342185030a4c53796f12ea5429
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1701133
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63002}
