arichardson marked 5 inline comments as done. arichardson added inline comments.
================ Comment at: include/clang/Basic/Attr.td:1072 def AllocSize : InheritableAttr { let Spellings = [GCC<"alloc_size">]; + let Subjects = SubjectList<[HasFunctionProto]>; ---------------- aaron.ballman wrote: > Does GCC support writing `alloc_size` on function pointers? Yes it does and it seems to be used by some projects. I first discovered this while compiling libxml2: https://github.com/GNOME/libxml2/blob/35e83488505d501864826125cfe6a7950d6cba78/include/libxml/xmlmemory.h#L66 ================ Comment at: test/Sema/alloc-size.c:46 +// This typedef applies the alloc_size to the pointer to the function pointer and should not be allowed +void *(**__attribute__((alloc_size(1, 2))) * allocator_function_typdef4)(int, int); // expected-warning{{'alloc_size' attribute only applies to non-K&R-style functions}} ---------------- aaron.ballman wrote: > What should happen in these situations? > ``` > typedef void * (__attribute__((alloc_size(1))) * > my_malloc_fn_pointer_type)(int); > typedef void * (* my_other_malloc_fn_pointer_type)(int); > > void *fn(int i); > __attribute__((alloc_size(1))) void *fn2(int i); > > int main() { > my_malloc_fn_pointer_type f = fn; // ??? > my_other_malloc_fn_pointer_type f2 = fn2; // ??? > } > ``` > Should this code do something special? > ``` > typedef void * (__attribute__((alloc_size(1))) * > my_malloc_fn_pointer_type)(int); > typedef void * (* my_other_malloc_fn_pointer_type)(int); > > void overloaded(my_malloc_fn_pointer_type fn); > void overloaded(my_other_malloc_fn_pointer_type fn); > > void *fn(int i); > __attribute__((alloc_size(1))) void *fn2(int i); > > int main() { > overloaded(fn); > overloaded(fn2); > } > > ``` If I define two overloaded functions that only differ on the attribute GCC gives me the following error: ``` <source>:14:6: error: redefinition of 'overloaded' 14 | void overloaded(my_other_malloc_fn_pointer_type fn) { | ^~~~~~~~~~ <source>:11:6: note: previous definition of 'overloaded' was here 11 | void overloaded(my_malloc_fn_pointer_type fn) { | ^~~~~~~~~~ ``` Assigning function pointers with and without the attribute seems to work just fine: https://godbolt.org/z/-i5zUK Repository: rC Clang CHANGES SINCE LAST ACTION https://reviews.llvm.org/D55212/new/ https://reviews.llvm.org/D55212 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits