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);
}
}
static void
create_common (gfc_common_head *com)
{
segment_info *s, *next_s;
tree union_type;
tree *field_link;
record_layout_info rli;
tree decl;
bool is_init = false;
/* Declare the variables inside the common block. */
union_type = make_node (UNION_TYPE);
rli = start_record_layout (union_type);
field_link = &TYPE_FIELDS (union_type);
for (s = current_common; s; s = s->next)
{
build_field (s, union_type, rli);
/* Link the field into the type. */
*field_link = s->field;
field_link = &TREE_CHAIN (s->field);
/* Has initial value. */
if (s->sym->value)
is_init = 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);
if (is_init)
{
tree list, ctor, tmp;
HOST_WIDE_INT offset = 0;
list = NULL_TREE;
for (s = current_common; s; s = s->next)
{
if (s->sym->value)
{
if (s->offset < offset)
{
/* We have overlapping initializers. It could either be
partially initialized arrays (legal), or the user
specified multiple initial values (illegal).
We don't implement this yet, so bail out. */
gfc_todo_error ("Initialization of overlapping variables");
}
/* 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);
list = tree_cons (s->field, tmp, list);
offset = s->offset + s->length;
}
}
gcc_assert (list);
ctor = build1 (CONSTRUCTOR, union_type, nreverse(list));
TREE_CONSTANT (ctor) = 1;
TREE_INVARIANT (ctor) = 1;
TREE_STATIC (ctor) = 1;
DECL_INITIAL (decl) = ctor;
#ifdef ENABLE_CHECKING
for (tmp = CONSTRUCTOR_ELTS (ctor); tmp; tmp = TREE_CHAIN (tmp))
gcc_assert (TREE_CODE (TREE_PURPOSE (tmp)) == FIELD_DECL);
#endif
}
/* Build component reference for each variable. */
for (s = current_common; s; s = next_s)
{
s->sym->backend_decl = build3 (COMPONENT_REF, TREE_TYPE (s->field),
decl, s->field, NULL_TREE);
next_s = s->next;
gfc_free (s);
}
}