[driver] Use if/else instead of ternary, to please VS2017. #35073
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VS2017 seems to have problems with ternaries where the two branches are given as std::move() (see https://stackoverflow.com/questions/53374182) and the compiler was given a warning C4172 "returning address of local or temporary". Switching the ternary operator into a `if/else` works correctly for VS2017 and should work for other compilers too, without changing the meaning (as far as I see). This was causing the Windows VS2017 CI to fail compiling the stdlib. When bisecting, the problem was reduced to the changes in swiftlang#35034. In a debugger I managed to see the problem being a heap corruption. With all the moves I was suspicious that something was being used while destroyed, but the code was correct. While recompiling the compiler warning gave me the clue.
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@swift-ci please smoke test |
compnerd
approved these changes
Dec 12, 2020
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VS2017 seems to have problems with ternaries where the two branches are
given as std::move() (see https://stackoverflow.com/questions/53374182)
and the compiler was given a warning C4172 "returning address of local
or temporary".
Switching the ternary operator into a
if/elseworks correctly forVS2017 and should work for other compilers too, without changing the
meaning (as far as I see).
This was causing the Windows VS2017 CI to fail compiling the stdlib.
When bisecting, the problem was reduced to the changes in #35034. In a
debugger I managed to see the problem being a heap corruption. With all
the moves I was suspicious that something was being used while
destroyed, but the code was correct. While recompiling, the compiler
warning gave me the clue.