static void
build_field (segment_info *h, tree union_type, record_layout_info rli)
{
tree field;
tree name;
HOST_WIDE_INT offset = h->offset;
unsigned HOST_WIDE_INT desired_align, known_align;
name = get_identifier (h->sym->name);
field = build_decl (h->sym->declared_at.lb->location,
FIELD_DECL, name, h->field);
known_align = (offset & -offset) * BITS_PER_UNIT;
if (known_align == 0 || known_align > BIGGEST_ALIGNMENT)
known_align = BIGGEST_ALIGNMENT;
desired_align = update_alignment_for_field (rli, field, known_align);
if (desired_align > known_align)
DECL_PACKED (field) = 1;
DECL_FIELD_CONTEXT (field) = union_type;
DECL_FIELD_OFFSET (field) = size_int (offset);
DECL_FIELD_BIT_OFFSET (field) = bitsize_zero_node;
SET_DECL_OFFSET_ALIGN (field, known_align);
rli->offset = size_binop (MAX_EXPR, rli->offset,
size_binop (PLUS_EXPR,
DECL_FIELD_OFFSET (field),
DECL_SIZE_UNIT (field)));
/* If this field is assigned to a label, we create another two variables.
One will hold the address of target label or format label. The other will
hold the length of format label string. */
if (h->sym->attr.assign)
{
tree len;
tree addr;
gfc_allocate_lang_decl (field);
GFC_DECL_ASSIGN (field) = 1;
len = gfc_create_var_np (gfc_charlen_type_node,h->sym->name);
addr = gfc_create_var_np (pvoid_type_node, h->sym->name);
TREE_STATIC (len) = 1;
TREE_STATIC (addr) = 1;
DECL_INITIAL (len) = build_int_cst (NULL_TREE, -2);
gfc_set_decl_location (len, &h->sym->declared_at);
gfc_set_decl_location (addr, &h->sym->declared_at);
GFC_DECL_STRING_LEN (field) = pushdecl_top_level (len);
GFC_DECL_ASSIGN_ADDR (field) = pushdecl_top_level (addr);
}
/* If this field is volatile, mark it. */
if (h->sym->attr.volatile_)
{
tree new_type;
TREE_THIS_VOLATILE (field) = 1;
new_type = build_qualified_type (TREE_TYPE (field), TYPE_QUAL_VOLATILE);
TREE_TYPE (field) = new_type;
}
h->field = field;
}
static void
create_common (gfc_common_head *com, segment_info *head, bool saw_equiv)
{
segment_info *s, *next_s;
tree union_type;
tree *field_link;
tree field;
tree field_init = NULL_TREE;
record_layout_info rli;
tree decl;
bool is_init = false;
bool is_saved = false;
/* Declare the variables inside the common block.
If the current common block contains any equivalence object, then
make a UNION_TYPE node, otherwise RECORD_TYPE. This will let the
alias analyzer work well when there is no address overlapping for
common variables in the current common block. */
if (saw_equiv)
union_type = make_node (UNION_TYPE);
else
union_type = make_node (RECORD_TYPE);
rli = start_record_layout (union_type);
field_link = &TYPE_FIELDS (union_type);
/* Check for overlapping initializers and replace them with a single,
artificial field that contains all the data. */
if (saw_equiv)
field = get_init_field (head, union_type, &field_init, rli);
else
field = NULL_TREE;
if (field != NULL_TREE)
{
is_init = true;
*field_link = field;
field_link = &DECL_CHAIN (field);
}
for (s = head; s; s = s->next)
{
build_field (s, union_type, rli);
/* Link the field into the type. */
*field_link = s->field;
field_link = &DECL_CHAIN (s->field);
/* Has initial value. */
if (s->sym->value)
is_init = true;
/* Has SAVE attribute. */
if (s->sym->attr.save)
is_saved = true;
}
finish_record_layout (rli, true);
if (com)
decl = build_common_decl (com, union_type, is_init);
else
decl = build_equiv_decl (union_type, is_init, is_saved);
if (is_init)
{
tree ctor, tmp;
VEC(constructor_elt,gc) *v = NULL;
if (field != NULL_TREE && field_init != NULL_TREE)
CONSTRUCTOR_APPEND_ELT (v, field, field_init);
else
for (s = head; s; s = s->next)
{
if (s->sym->value)
{
/* Add the initializer for this field. */
tmp = gfc_conv_initializer (s->sym->value, &s->sym->ts,
TREE_TYPE (s->field),
s->sym->attr.dimension,
s->sym->attr.pointer
|| s->sym->attr.allocatable, false);
CONSTRUCTOR_APPEND_ELT (v, s->field, tmp);
}
}
gcc_assert (!VEC_empty (constructor_elt, v));
ctor = build_constructor (union_type, v);
TREE_CONSTANT (ctor) = 1;
TREE_STATIC (ctor) = 1;
DECL_INITIAL (decl) = ctor;
#ifdef ENABLE_CHECKING
{
tree field, value;
unsigned HOST_WIDE_INT idx;
FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), idx, field, value)
gcc_assert (TREE_CODE (field) == FIELD_DECL);
}
#endif
}
/* Build component reference for each variable. */
for (s = head; s; s = next_s)
{
tree var_decl;
var_decl = build_decl (s->sym->declared_at.lb->location,
VAR_DECL, DECL_NAME (s->field),
TREE_TYPE (s->field));
TREE_STATIC (var_decl) = TREE_STATIC (decl);
/* Mark the variable as used in order to avoid warnings about
unused variables. */
TREE_USED (var_decl) = 1;
if (s->sym->attr.use_assoc)
DECL_IGNORED_P (var_decl) = 1;
if (s->sym->attr.target)
TREE_ADDRESSABLE (var_decl) = 1;
/* Fake variables are not visible from other translation units. */
TREE_PUBLIC (var_decl) = 0;
/* To preserve identifier names in COMMON, chain to procedure
scope unless at top level in a module definition. */
if (com
&& s->sym->ns->proc_name
&& s->sym->ns->proc_name->attr.flavor == FL_MODULE)
var_decl = pushdecl_top_level (var_decl);
else
gfc_add_decl_to_function (var_decl);
SET_DECL_VALUE_EXPR (var_decl,
fold_build3_loc (input_location, COMPONENT_REF,
TREE_TYPE (s->field),
decl, s->field, NULL_TREE));
DECL_HAS_VALUE_EXPR_P (var_decl) = 1;
GFC_DECL_COMMON_OR_EQUIV (var_decl) = 1;
if (s->sym->attr.assign)
{
gfc_allocate_lang_decl (var_decl);
GFC_DECL_ASSIGN (var_decl) = 1;
GFC_DECL_STRING_LEN (var_decl) = GFC_DECL_STRING_LEN (s->field);
GFC_DECL_ASSIGN_ADDR (var_decl) = GFC_DECL_ASSIGN_ADDR (s->field);
}
s->sym->backend_decl = var_decl;
next_s = s->next;
free (s);
}
}