On 7/5/2019 10:39 AM, Gijs Kruitbosch wrote:
FWIW once in a while I have come across bugs caused by truncation of
integers where someone picked a specific size that was too small also,
e.g.
storing an offset into a text node in a 16-bit integer. I think that's
maybe something that's hiding between the lines there, being careful with
that direction also if you pick a type with a specific size to make sure
your type is large enough.
Yep. Recent example: https://bugzilla.mozilla.org/show_bug.cgi?id=1556019 .
If integer truncation bugs are something we're really concerned about,
clang 8 added a new -Wimplicit-int-conversion (and
-Wimplicit-float-conversion) warning. Unfortunately, there are a couple
thousand instances of these warnings in mozilla-central. I don't know if
fixing them is practical, but they could be selectively enabled (or
disabled) for individual directories.
https://clang.llvm.org/docs/DiagnosticsReference.html#wimplicit-int-conversion
warning: higher order bits are zeroes after implicit conversion
warning: implicit conversion loses integer precision: A to B
warning: implicit conversion loses floating-point precision: A to B
warning: implicit conversion when assigning computation result loses
floating-point precision: A to B
_______________________________________________
dev-platform mailing list
dev-platform@lists.mozilla.org
https://lists.mozilla.org/listinfo/dev-platform
