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Remove usages of old safe math #4153
Description
There are approximately 79 uses of old safe math. (a.k.a. the LongAdd, ShortAdd, and friends from intsafe.h).
This task represents removing them and transitioning them to an appropriate safe/saturating math function from the chromium safe math library introduced in #4144.
After removing usages of the old safe math functions, also remove the intsafe.h header.
Files with old safe math as of this writing:
- TerminalControl: TSFInputControl.cpp
- TerminalCore: TerminalDispatch.cpp
- TerminalCore: TerminalSelection.cpp
- Host: directio.cpp
- RendererGdi: invalidate.cpp
- RendererGdi: math.cpp
- RendererGdi: paint.cpp
- RendererVt: paint.cpp
- TerminalAdapter: adaptDispatch.cpp
- Types: viewport.cpp
- Types: WindowUiaProviderBase.cpp
Activity
miniksa commentedon Jan 8, 2020
If James Holderness (@j4james) doesn't take this, whomever takes this should consult with James Holderness (@j4james) on the ones in
adaptDispatch.cppbecause they should likely be saturating math instead of failing when exceeding bounds as they are today.j4james commentedon Jan 8, 2020
I don't mind doing this eventually, but I have bunch of stuff in progress that I would like to try and get finished first. If anyone else wants to take it on, though, I would recommend waiting at least until #3628 is merged, because there is a fair amount of safe math code in
AdaptDispatchthat will be nuked by that PR, so you'll be wasting your time if you're trying to refactor that.On a similar note, I expect issue #3849 will end up replacing most, if not all, of the
TerminalDispatchcode. That said, it may be a long time before that happens, so it's possibly still worth cleaning up the existing code in the mean time.j4james commentedon Jan 9, 2020
One other thing I wanted to add: there is another category of intsafe routines which I think isn't covered by the 79 uses mentioned above, and that is the type conversion functions, e.g.
SizeTToShort. In the VT code, I think many of those would probably need to be converted to something like asaturated_castwhen using the new chromium lib.Introduce chromium safe math (#4144)