[PATCH] D13446: [PATCH] Add checker discouraging definition of variadic function definitions in C++

[Aaron Ballman via cfe-commits]

On Tue, Oct 6, 2015 at 4:12 PM, Joerg Sonnenberger via cfe-commits
<cfe-commits at lists.llvm.org> wrote:
> On Mon, Oct 05, 2015 at 07:36:08PM +0000, Aaron Ballman via cfe-commits wrote:
>> C-style variadic functions (using an ellipsis) can be dangerous in C++
>> due to the inherit lack of type safety with argument passing. Better
>> alternatives exist, such as function currying (like STL stream objects
>> use), or function parameter packs. This patch adds a checker to
>> diagnose definitions of variadic functions in C++ code, but still
>> allows variadic function declarations, as those can be safely used to
>> good effect for SFINAE patterns.
>
> I would restrict this a bit to exclude function definitions with C
> linkage. If you have such a ABI requirement, you normally can't replace
> it with any of the alternatives.

Under what circumstances would you run into this issue with C++ code?
The only circumstance I can think of is if you have a C API that takes
a function pointer to a varargs function as an argument. Is that the
situation you are thinking of, or are there others?

Thank you for the feedback!

~Aaron