On Thu, 14 Jun 2018, Martin Sebor wrote: > There's a comment in the code about the weak checking being > deliberate (the word harmless here suggests the author may > not have fully appreciated all the conversions it allows): > > /* Accept harmless mismatch in function types. > This is for the ffs and fprintf builtins. */ > > If you concerned about the change causing trouble in this > context, then if there are legacy systems that GCC still > supports that declare standard functions with non-standard > signatures they should be taken into consideration somehow.
For fprintf and various related functions, you need to allow for the built-in function being declared without the compiler knowing what the FILE type will end up being a typedef for - i.e., you can't avoid having some special case somewhere for built-in functions using fileptr_type_node, if nothing else. For other functions, the issue as per <https://gcc.gnu.org/ml/gcc-patches/2001-04/msg00435.html> may well have been bad types in some system headers such as "char *sprintf();". To the extent that any such systems with bad (but ABI-compatible) types for some functions in system headers are still supported as GCC targets, I think it would be reasonable to say that fixincludes, not extra laxity in built-in function types, is the way to deal with the bad types in headers. -- Joseph S. Myers jos...@codesourcery.com
