https://gcc.gnu.org/bugzilla/show_bug.cgi?id=41227
--- Comment #13 from rguenther at suse dot de <rguenther at suse dot de> --- On Mon, 14 Jul 2014, fxcoudert at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=41227 > > --- Comment #12 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> > --- > I disagree with Tobias' reading: it seems to me that the single-variable > common > block should be interoperable with both the single-common C struct and C > variable. > > The Intel compiler makes both cases work: > > [fx@kelvin tmp]$ cat a.f90 > program test > use iso_c_binding > integer(c_int) :: i > common /a/ i > bind(c) :: /a/ > > interface > subroutine foo() bind(c) > end subroutine > end interface > > i = 42 > print *, i > call foo() > print *, i > end program test > [fx@kelvin tmp]$ cat a1.c > extern int a; > void foo (void) { a = -1; } > [fx@kelvin tmp]$ cat a2.c > extern struct { int i; } a; > void foo (void) { a.i = -1; } > [fx@kelvin tmp]$ icc -c a1.c && ifort a.f90 a1.o && ./a.out > 42 > -1 > [fx@kelvin tmp]$ icc -c a2.c && ifort a.f90 a2.o && ./a.out > 42 > -1 > > > I believe we should do so too. And if I understand correctly what Richard > said, > this means relaxing the LTO type rules, is that right? Yes (to get rid of the warning and to avoid eventual wrong-code bugs). Does it need to inter-operate with extern struct { struct { int i; } a; } a; ? Or extern union { int i; } a; ?
