| Message ID | 1757013.atdPhlSkOF@fomalhaut |
|---|---|
| State | New |
| Headers | show |
| Series | Do not apply scalar storage order to pointer fields | expand |
On Fri, May 7, 2021 at 12:42 PM Eric Botcazou <botcazou@adacore.com> wrote: > > Hi, > > I didn't really think of pointer fields (nor of vector fields originally) when > implementing the scalar_storage_order attribute, so they are swapped as well. > As Ulrich pointed out, this is problematic to describe in DWARF and probably > not very useful in any case, so the attached patch pulls them out. > > Tested on x86-64/Linux, OK for mainline? OK. Richard. > > 2021-05-07 Eric Botcazou <ebotcazou@adacore.com> > > * doc/extend.texi (scalar_storage_order): Mention effect on pointer > and vector fields. > * tree.h (reverse_storage_order_for_component_p): Return false if > the type is a pointer. > c/ > * c-typeck.c (build_unary_op) <ADDR_EXPR>: Do not issue an error > on the address of a pointer field in a record with reverse SSO. > > > 2021-05-07 Eric Botcazou <ebotcazou@adacore.com> > > * gcc.dg/sso-12.c: New test. > > -- > Eric Botcazou
diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c index fdc7bb6125c..5bdc673d03a 100644 --- a/gcc/c/c-typeck.c +++ b/gcc/c/c-typeck.c @@ -4866,6 +4866,7 @@ build_unary_op (location_t location, enum tree_code code, tree xarg, if (TYPE_REVERSE_STORAGE_ORDER (TREE_TYPE (TREE_OPERAND (arg, 0)))) { if (!AGGREGATE_TYPE_P (TREE_TYPE (arg)) + && !POINTER_TYPE_P (TREE_TYPE (arg)) && !VECTOR_TYPE_P (TREE_TYPE (arg))) { error_at (location, "cannot take address of scalar with " diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index c8caf36f293..fd9175d1b3b 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -8551,6 +8551,9 @@ or an array whose component is a @code{union} or a @code{struct}, and it is possible for these fields to have a different scalar storage order than the enclosing type. +Note that neither pointer nor vector fields are considered scalar fields in +this context, so the attribute has no effects on these fields. + This attribute is supported only for targets that use a uniform default scalar storage order (fortunately, most of them), i.e.@: targets that store the scalars either all in big-endian or all in little-endian. diff --git a/gcc/tree.h b/gcc/tree.h index 6d3cfc4c588..784452ca490 100644 --- a/gcc/tree.h +++ b/gcc/tree.h @@ -4989,7 +4989,9 @@ static inline bool reverse_storage_order_for_component_p (tree t) { /* The storage order only applies to scalar components. */ - if (AGGREGATE_TYPE_P (TREE_TYPE (t)) || VECTOR_TYPE_P (TREE_TYPE (t))) + if (AGGREGATE_TYPE_P (TREE_TYPE (t)) + || POINTER_TYPE_P (TREE_TYPE (t)) + || VECTOR_TYPE_P (TREE_TYPE (t))) return false; if (TREE_CODE (t) == REALPART_EXPR || TREE_CODE (t) == IMAGPART_EXPR)