On Tue, 20 Sep 2016, Jakub Jelinek wrote: > Hi! > > fold_builtin_atomic_always_lock_free has an assertion that if the 2nd > argument isn't INTEGER_CST, it has POINTER_TYPE_P, but additionally for > casts to void * it looks through the cast. That means though for invalid > code if an integral expression etc. is converted to pointer, we violate the > assertion. This patch instead doesn't look through such casts, so > type_align is effectively alignment of void and thus it considers objects > insufficiently aligned, but doesn't ICE. > > Another approach (incomplete) is what I've attached to the PR - instead of > prototyping __atomic_{always,is}_lock_free it uses ... and only checks that > it has 2 arguments and that the last one is a pointer - that way we don't > have to try to undo implicit cast to void * and know the conversion in there > is the user conversion. Unfortunately the C++ FE isn't prepared for the > check_builtin_function_arguments to change the arguments (unlike C). > > I've bootstrapped/regtested on x86_64-linux and i686-linux the following > fix, ok for trunk, or should I invest more time into the other approach?
Ok for trunk. I think the other solution would be to somehow mark the builtin to not get the (void *) cast applied in the first place ... (make it varargs?) Thanks, Richard. > 2016-09-19 Jakub Jelinek <ja...@redhat.com> > > PR middle-end/77624 > * builtins.c (fold_builtin_atomic_always_lock_free): Only look through > cast to void * if the cast is from some other pointer type. > > * c-c++-common/pr77624-1.c: New test. > * c-c++-common/pr77624-2.c: New test. > > --- gcc/builtins.c.jj 2016-09-16 22:19:38.000000000 +0200 > +++ gcc/builtins.c 2016-09-19 15:28:41.100412521 +0200 > @@ -5575,8 +5575,10 @@ fold_builtin_atomic_always_lock_free (tr > end before anything else has a chance to look at it. The pointer > parameter at this point is usually cast to a void *, so check for that > and look past the cast. */ > - if (CONVERT_EXPR_P (arg1) && POINTER_TYPE_P (ttype) > - && VOID_TYPE_P (TREE_TYPE (ttype))) > + if (CONVERT_EXPR_P (arg1) > + && POINTER_TYPE_P (ttype) > + && VOID_TYPE_P (TREE_TYPE (ttype)) > + && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg1, 0)))) > arg1 = TREE_OPERAND (arg1, 0); > > ttype = TREE_TYPE (arg1); > --- gcc/testsuite/c-c++-common/pr77624-1.c.jj 2016-09-19 15:18:09.049394093 > +0200 > +++ gcc/testsuite/c-c++-common/pr77624-1.c 2016-09-19 15:41:09.972949880 > +0200 > @@ -0,0 +1,14 @@ > +/* PR middle-end/77624 */ > +/* { dg-do compile } */ > + > +int > +foo (int a) > +{ > + return __atomic_is_lock_free (2, a); /* { dg-warning > "pointer from integer" "" { target c } } */ > +} /* { dg-error "invalid > conversion" "" { target c++ } 7 } */ > + > +int > +bar (int a) > +{ > + return __atomic_always_lock_free (2, a); /* { dg-warning "pointer from > integer" "" { target c } } */ > +} /* { dg-error "invalid > conversion" "" { target c++ } 13 } */ > --- gcc/testsuite/c-c++-common/pr77624-2.c.jj 2016-09-19 15:18:12.280353292 > +0200 > +++ gcc/testsuite/c-c++-common/pr77624-2.c 2016-09-19 15:42:37.441844581 > +0200 > @@ -0,0 +1,26 @@ > +/* PR middle-end/77624 */ > +/* { dg-do compile } */ > + > +void > +foo (int *a) > +{ > + double b = 0; > + __atomic_is_lock_free (2, a, 2); /* { dg-error "too many arguments" } */ > + __atomic_is_lock_free (2); /* { dg-error "too few arguments" } */ > + __atomic_is_lock_free (2, b); /* { dg-error "incompatible > type" "" { target c } } */ > + /* { dg-message "expected" "" { target > c } 10 } */ > + /* { dg-error "convert" "" { target c++ > } 10 } */ > + __atomic_is_lock_free (2, 0); > +} > + > +void > +bar (int *a) > +{ > + double b = 0; > + __atomic_always_lock_free (2, a, 2); /* { dg-error "too many > arguments" } */ > + __atomic_always_lock_free (2); /* { dg-error "too few arguments" } */ > + __atomic_always_lock_free (2, b); /* { dg-error "incompatible type" "" { > target c } } */ > + /* { dg-message "expected" "" { target > c } 22 } */ > + /* { dg-error "convert" "" { target c++ > } 22 } */ > + __atomic_always_lock_free (2, 0); > +} > > Jakub > > -- Richard Biener <rguent...@suse.de> SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)