def allocate_ex(cls, context, builder, list_type, nitems):
"""
Allocate a ListInstance with its storage.
Return a (ok, instance) tuple where *ok* is a LLVM boolean and
*instance* is a ListInstance object (the object's contents are
only valid when *ok* is true).
"""
intp_t = context.get_value_type(types.intp)
if isinstance(nitems, int):
nitems = ir.Constant(intp_t, nitems)
payload_type = context.get_data_type(types.ListPayload(list_type))
payload_size = context.get_abi_sizeof(payload_type)
itemsize = get_itemsize(context, list_type)
# Account for the fact that the payload struct contains one entry
payload_size -= itemsize
ok = cgutils.alloca_once_value(builder, cgutils.true_bit)
self = cls(context, builder, list_type, None)
# Total allocation size = <payload header size> + nitems * itemsize
allocsize, ovf = cgutils.muladd_with_overflow(
builder,
nitems,
ir.Constant(intp_t, itemsize),
ir.Constant(intp_t, payload_size),
)
with builder.if_then(ovf, likely=False):
builder.store(cgutils.false_bit, ok)
with builder.if_then(builder.load(ok), likely=True):
meminfo = context.nrt.meminfo_new_varsize_dtor(
builder, size=allocsize, dtor=self.get_dtor()
)
with builder.if_else(cgutils.is_null(builder, meminfo), likely=False) as (
if_error,
if_ok,
):
with if_error:
builder.store(cgutils.false_bit, ok)
with if_ok:
self._list.meminfo = meminfo
self._list.parent = context.get_constant_null(types.pyobject)
self._payload.allocated = nitems
self._payload.size = ir.Constant(intp_t, 0) # for safety
self._payload.dirty = cgutils.false_bit
# Zero the allocated region
self.zfill(self.size.type(0), nitems)
return builder.load(ok), self
def _payload_realloc(new_allocated):
payload_type = context.get_data_type(types.ListPayload(self._ty))
payload_size = context.get_abi_sizeof(payload_type)
# Account for the fact that the payload struct contains one entry
payload_size -= itemsize
allocsize, ovf = cgutils.muladd_with_overflow(
builder, new_allocated, ir.Constant(intp_t, itemsize),
ir.Constant(intp_t, payload_size))
with builder.if_then(ovf, likely=False):
context.call_conv.return_user_exc(builder, MemoryError,
("cannot resize list", ))
ptr = context.nrt.meminfo_varsize_realloc_unchecked(
builder, self._list.meminfo, size=allocsize)
cgutils.guard_memory_error(context, builder, ptr,
"cannot resize list")
self._payload.allocated = new_allocated