def split_blocks_at_errors(blocks: List[BasicBlock],
default_error_handler: BasicBlock,
func: str) -> List[BasicBlock]:
new_blocks = [] # type: List[BasicBlock]
# First split blocks on ops that may raise.
for block in blocks:
ops = block.ops
block.ops = []
cur_block = block
new_blocks.append(cur_block)
# If the block has an error handler specified, use it. Otherwise
# fall back to the default.
error_label = block.error_handler or default_error_handler
block.error_handler = None
for op in ops:
cur_block.ops.append(op)
if isinstance(op, RegisterOp) and op.error_kind != ERR_NEVER:
# Split
new_block = BasicBlock()
new_blocks.append(new_block)
if op.error_kind == ERR_MAGIC:
# Op returns an error value on error that depends on result RType.
variant = Branch.IS_ERROR
negated = False
elif op.error_kind == ERR_FALSE:
# Op returns a C false value on error.
variant = Branch.BOOL_EXPR
negated = True
else:
assert False, 'unknown error kind %d' % op.error_kind
# Void ops can't generate errors since error is always
# indicated by a special value stored in a register.
assert not op.is_void, "void op generating errors?"
branch = Branch(op,
true_label=error_label,
false_label=new_block,
op=variant,
line=op.line)
branch.negated = negated
if op.line != NO_TRACEBACK_LINE_NO:
branch.traceback_entry = (func, op.line)
cur_block.ops.append(branch)
cur_block = new_block
return new_blocks
def gen_cleanup(self, builder: 'IRBuilder', line: int) -> None:
# Do an error branch on the return value register, which
# may be undefined. This will allow it to be properly
# decrefed if it is not null. This is kind of a hack.
if self.ret_reg:
target = BasicBlock()
builder.add(Branch(self.ret_reg, target, target, Branch.IS_ERROR))
builder.activate_block(target)
# Restore the old exc_info
target, cleanup = BasicBlock(), BasicBlock()
builder.add(Branch(self.saved, target, cleanup, Branch.IS_ERROR))
builder.activate_block(cleanup)
builder.primitive_op(restore_exc_info_op, [self.saved], line)
builder.goto_and_activate(target)
def test_branch(self) -> None:
self.assert_emit(Branch(self.b, BasicBlock(8), BasicBlock(9), Branch.BOOL_EXPR),
"""if (cpy_r_b) {
goto CPyL8;
} else
goto CPyL9;
""")
b = Branch(self.b, BasicBlock(8), BasicBlock(9), Branch.BOOL_EXPR)
b.negated = True
self.assert_emit(b,
"""if (!cpy_r_b) {
goto CPyL8;
} else
goto CPyL9;
""")
def test_branch_eq(self) -> None:
self.assert_emit(
Branch(self.n, self.m, Label(8), Label(9), Branch.INT_EQ),
"""if (CPyTagged_IsEq(cpy_r_n, cpy_r_m))
goto CPyL8;
else
goto CPyL9;
""")
b = Branch(self.n, self.m, Label(8), Label(9), Branch.INT_LT)
b.negated = True
self.assert_emit(
b, """if (!CPyTagged_IsLt(cpy_r_n, cpy_r_m))
goto CPyL8;
else
goto CPyL9;
""")
def gen_condition(self) -> None:
# We call __next__ on the iterator and check to see if the return value
# is NULL, which signals either the end of the Iterable being traversed
# or an exception being raised. Note that Branch.IS_ERROR checks only
# for NULL (an exception does not necessarily have to be raised).
builder = self.builder
line = self.line
self.next_reg = builder.primitive_op(next_op, [builder.read(self.iter_target, line)], line)
builder.add(Branch(self.next_reg, self.loop_exit, self.body_block, Branch.IS_ERROR))
def add_bool_branch(self, value: Value, true: BasicBlock,
false: BasicBlock) -> None:
if is_runtime_subtype(value.type, int_rprimitive):
zero = self.add(LoadInt(0))
value = self.binary_op(value, zero, '!=', value.line)
elif is_same_type(value.type, list_rprimitive):
length = self.primitive_op(list_len_op, [value], value.line)
zero = self.add(LoadInt(0))
value = self.binary_op(length, zero, '!=', value.line)
elif (isinstance(value.type, RInstance)
and value.type.class_ir.is_ext_class
and value.type.class_ir.has_method('__bool__')):
# Directly call the __bool__ method on classes that have it.
value = self.gen_method_call(value, '__bool__', [],
bool_rprimitive, value.line)
else:
value_type = optional_value_type(value.type)
if value_type is not None:
is_none = self.binary_op(value, self.none_object(), 'is not',
value.line)
branch = Branch(is_none, true, false, Branch.BOOL_EXPR)
self.add(branch)
always_truthy = False
if isinstance(value_type, RInstance):
# check whether X.__bool__ is always just the default (object.__bool__)
if (not value_type.class_ir.has_method('__bool__') and
value_type.class_ir.is_method_final('__bool__')):
always_truthy = True
if not always_truthy:
# Optional[X] where X may be falsey and requires a check
branch.true = BasicBlock()
self.activate_block(branch.true)
# unbox_or_cast instead of coerce because we want the
# type to change even if it is a subtype.
remaining = self.unbox_or_cast(value, value_type,
value.line)
self.add_bool_branch(remaining, true, false)
return
elif not is_same_type(value.type, bool_rprimitive):
value = self.primitive_op(bool_op, [value], value.line)
self.add(Branch(value, true, false, Branch.BOOL_EXPR))
def finally_body() -> None:
out_block, exit_block = BasicBlock(), BasicBlock()
builder.add(
Branch(builder.read(exc), exit_block, out_block, Branch.BOOL_EXPR)
)
builder.activate_block(exit_block)
none = builder.none_object()
builder.py_call(
builder.read(exit_), [builder.read(mgr), none, none, none], line
)
builder.goto_and_activate(out_block)
def try_finally_resolve_control(builder: IRBuilder,
cleanup_block: BasicBlock,
finally_control: FinallyNonlocalControl,
old_exc: Value,
ret_reg: Optional[Value]) -> BasicBlock:
"""Resolve the control flow out of a finally block.
This means returning if there was a return, propagating
exceptions, break/continue (soon), or just continuing on.
"""
reraise, rest = BasicBlock(), BasicBlock()
builder.add(Branch(old_exc, rest, reraise, Branch.IS_ERROR))
# Reraise the exception if there was one
builder.activate_block(reraise)
builder.primitive_op(reraise_exception_op, [], NO_TRACEBACK_LINE_NO)
builder.add(Unreachable())
builder.builder.pop_error_handler()
# If there was a return, keep returning
if ret_reg:
builder.activate_block(rest)
return_block, rest = BasicBlock(), BasicBlock()
builder.add(Branch(ret_reg, rest, return_block, Branch.IS_ERROR))
builder.activate_block(return_block)
builder.nonlocal_control[-1].gen_return(builder, ret_reg, -1)
# TODO: handle break/continue
builder.activate_block(rest)
out_block = BasicBlock()
builder.goto(out_block)
# If there was an exception, restore again
builder.activate_block(cleanup_block)
finally_control.gen_cleanup(builder, -1)
builder.primitive_op(keep_propagating_op, [], NO_TRACEBACK_LINE_NO)
builder.add(Unreachable())
return out_block
def split_blocks_at_uninits(
env: Environment, blocks: List[BasicBlock],
pre_must_defined: 'AnalysisDict[Value]') -> List[BasicBlock]:
new_blocks = [] # type: List[BasicBlock]
# First split blocks on ops that may raise.
for block in blocks:
ops = block.ops
block.ops = []
cur_block = block
new_blocks.append(cur_block)
for i, op in enumerate(ops):
defined = pre_must_defined[block, i]
for src in op.unique_sources():
# If a register operand is not guarenteed to be
# initialized is an operand to something other than a
# check that it is defined, insert a check.
if (isinstance(src, Register) and src not in defined
and not (isinstance(op, Branch)
and op.op == Branch.IS_ERROR)):
new_block, error_block = BasicBlock(), BasicBlock()
new_block.error_handler = error_block.error_handler = cur_block.error_handler
new_blocks += [error_block, new_block]
env.vars_needing_init.add(src)
cur_block.ops.append(
Branch(src,
true_label=error_block,
false_label=new_block,
op=Branch.IS_ERROR,
line=op.line))
raise_std = RaiseStandardError(
RaiseStandardError.UNBOUND_LOCAL_ERROR,
"local variable '{}' referenced before assignment".
format(src.name), op.line)
env.add_op(raise_std)
error_block.ops.append(raise_std)
error_block.ops.append(Unreachable())
cur_block = new_block
cur_block.ops.append(op)
return new_blocks
def gen_glue_ne_method(self, cls: ClassIR, line: int) -> FuncIR:
"""Generate a __ne__ method from a __eq__ method. """
self.builder.enter()
rt_args = (RuntimeArg("self", RInstance(cls)), RuntimeArg("rhs", object_rprimitive))
# The environment operates on Vars, so we make some up
fake_vars = [(Var(arg.name), arg.type) for arg in rt_args]
args = [
self.builder.read(
self.builder.environment.add_local_reg(
var, type, is_arg=True
),
line
)
for var, type in fake_vars
] # type: List[Value]
self.builder.ret_types[-1] = object_rprimitive
# If __eq__ returns NotImplemented, then __ne__ should also
not_implemented_block, regular_block = BasicBlock(), BasicBlock()
eqval = self.add(MethodCall(args[0], '__eq__', [args[1]], line))
not_implemented = self.primitive_op(not_implemented_op, [], line)
self.add(Branch(
self.builder.binary_op(eqval, not_implemented, 'is', line),
not_implemented_block,
regular_block,
Branch.BOOL_EXPR))
self.builder.activate_block(regular_block)
retval = self.builder.coerce(
self.builder.unary_op(eqval, 'not', line), object_rprimitive, line
)
self.add(Return(retval))
self.builder.activate_block(not_implemented_block)
self.add(Return(not_implemented))
blocks, env, ret_type, _ = self.builder.leave()
return FuncIR(
FuncDecl('__ne__', cls.name, self.module_name,
FuncSignature(rt_args, ret_type)),
blocks, env)
def visit_branch(self, op: Branch) -> GenAndKill:
return set(op.sources()), set()
def split_blocks_at_errors(blocks: List[BasicBlock],
default_error_handler: BasicBlock,
func: str) -> List[BasicBlock]:
new_blocks = [] # type: List[BasicBlock]
mapping = {}
partial_ops = set()
# First split blocks on ops that may raise.
for block in blocks:
ops = block.ops
i0 = 0
i = 0
next_block = BasicBlock()
while i < len(ops) - 1:
op = ops[i]
if isinstance(op, RegisterOp) and op.error_kind != ERR_NEVER:
# Split
new_blocks.append(next_block)
new_block = next_block
next_block = BasicBlock()
new_block.ops.extend(ops[i0:i + 1])
if op.error_kind == ERR_MAGIC:
# Op returns an error value on error that depends on result RType.
variant = Branch.IS_ERROR
negated = False
elif op.error_kind == ERR_FALSE:
# Op returns a C false value on error.
variant = Branch.BOOL_EXPR
negated = True
else:
assert False, 'unknown error kind %d' % op.error_kind
# Void ops can't generate errors since error is always
# indicated by a special value stored in a register.
assert not op.is_void, "void op generating errors?"
# If the block has an error handler specified, use it. Otherwise
# fall back to the default.
error_label = block.error_handler or default_error_handler
branch = Branch(op,
true_label=error_label,
false_label=next_block,
op=variant,
line=op.line)
branch.negated = negated
if op.line != NO_TRACEBACK_LINE_NO:
branch.traceback_entry = (func, op.line)
partial_ops.add(branch) # Only tweak true label of these
new_block.ops.append(branch)
if i0 == 0:
mapping[block] = new_block
i += 1
i0 = i
else:
i += 1
new_blocks.append(next_block)
next_block.ops.extend(ops[i0:i + 1])
if i0 == 0:
mapping[block] = next_block
# Adjust all labels to reflect the new blocks.
for block in new_blocks:
for op in block.ops:
if isinstance(op, Goto):
op.label = mapping[op.label]
elif isinstance(op, Branch):
if op not in partial_ops:
op.false = mapping[op.false]
op.true = mapping[op.true]
return new_blocks
def transform_try_except(builder: IRBuilder,
body: GenFunc,
handlers: Sequence[
Tuple[Optional[Expression], Optional[Expression], GenFunc]],
else_body: Optional[GenFunc],
line: int) -> None:
"""Generalized try/except/else handling that takes functions to gen the bodies.
The point of this is to also be able to support with."""
assert handlers, "try needs except"
except_entry, exit_block, cleanup_block = BasicBlock(), BasicBlock(), BasicBlock()
double_except_block = BasicBlock()
# If there is an else block, jump there after the try, otherwise just leave
else_block = BasicBlock() if else_body else exit_block
# Compile the try block with an error handler
builder.builder.push_error_handler(except_entry)
builder.goto_and_activate(BasicBlock())
body()
builder.goto(else_block)
builder.builder.pop_error_handler()
# The error handler catches the error and then checks it
# against the except clauses. We compile the error handler
# itself with an error handler so that it can properly restore
# the *old* exc_info if an exception occurs.
# The exception chaining will be done automatically when the
# exception is raised, based on the exception in exc_info.
builder.builder.push_error_handler(double_except_block)
builder.activate_block(except_entry)
old_exc = builder.maybe_spill(builder.primitive_op(error_catch_op, [], line))
# Compile the except blocks with the nonlocal control flow overridden to clear exc_info
builder.nonlocal_control.append(
ExceptNonlocalControl(builder.nonlocal_control[-1], old_exc))
# Process the bodies
for type, var, handler_body in handlers:
next_block = None
if type:
next_block, body_block = BasicBlock(), BasicBlock()
matches = builder.primitive_op(
exc_matches_op, [builder.accept(type)], type.line
)
builder.add(Branch(matches, body_block, next_block, Branch.BOOL_EXPR))
builder.activate_block(body_block)
if var:
target = builder.get_assignment_target(var)
builder.assign(
target,
builder.primitive_op(get_exc_value_op, [], var.line),
var.line
)
handler_body()
builder.goto(cleanup_block)
if next_block:
builder.activate_block(next_block)
# Reraise the exception if needed
if next_block:
builder.primitive_op(reraise_exception_op, [], NO_TRACEBACK_LINE_NO)
builder.add(Unreachable())
builder.nonlocal_control.pop()
builder.builder.pop_error_handler()
# Cleanup for if we leave except through normal control flow:
# restore the saved exc_info information and continue propagating
# the exception if it exists.
builder.activate_block(cleanup_block)
builder.primitive_op(restore_exc_info_op, [builder.read(old_exc)], line)
builder.goto(exit_block)
# Cleanup for if we leave except through a raised exception:
# restore the saved exc_info information and continue propagating
# the exception.
builder.activate_block(double_except_block)
builder.primitive_op(restore_exc_info_op, [builder.read(old_exc)], line)
builder.primitive_op(keep_propagating_op, [], NO_TRACEBACK_LINE_NO)
builder.add(Unreachable())
# If present, compile the else body in the obvious way
if else_body:
builder.activate_block(else_block)
else_body()
builder.goto(exit_block)
builder.activate_block(exit_block)
def process_conditional(self, e: Node) -> List[Branch]:
if isinstance(e, ComparisonExpr):
# TODO: Verify operand types.
assert len(e.operators) == 1, 'more than 1 operator not supported'
op = e.operators[0]
if op in ['==', '!=', '<', '<=', '>', '>=']:
# TODO: check operand types
left = self.accept(e.operands[0])
right = self.accept(e.operands[1])
opcode = self.int_relative_ops[op]
branch = Branch(left, right, INVALID_LABEL, INVALID_LABEL,
opcode)
elif op in ['is', 'is not']:
# TODO: check if right operand is None
left = self.accept(e.operands[0])
branch = Branch(left, INVALID_REGISTER, INVALID_LABEL,
INVALID_LABEL, Branch.IS_NONE)
if op == 'is not':
branch.negated = True
elif op in ['in', 'not in']:
left = self.accept(e.operands[0])
ltype = self.node_type(e.operands[0])
right = self.accept(e.operands[1])
rtype = self.node_type(e.operands[1])
target = self.alloc_temp(self.node_type(e))
self.binary_op(ltype, left, rtype, right, 'in', target=target)
branch = Branch(target, INVALID_REGISTER, INVALID_LABEL,
INVALID_LABEL, Branch.BOOL_EXPR)
if op == 'not in':
branch.negated = True
else:
assert False, "unsupported comparison epxression"
self.add(branch)
return [branch]
elif isinstance(e, OpExpr) and e.op in ['and', 'or']:
if e.op == 'and':
# Short circuit 'and' in a conditional context.
lbranches = self.process_conditional(e.left)
new = self.new_block()
self.set_branches(lbranches, True, new)
rbranches = self.process_conditional(e.right)
return lbranches + rbranches
else:
# Short circuit 'or' in a conditional context.
lbranches = self.process_conditional(e.left)
new = self.new_block()
self.set_branches(lbranches, False, new)
rbranches = self.process_conditional(e.right)
return lbranches + rbranches
elif isinstance(e, UnaryExpr) and e.op == 'not':
branches = self.process_conditional(e.expr)
for b in branches:
b.invert()
return branches
# Catch-all for arbitrary expressions.
else:
reg = self.accept(e)
branch = Branch(reg, INVALID_REGISTER, INVALID_LABEL,
INVALID_LABEL, Branch.BOOL_EXPR)
self.add(branch)
return [branch]
def visit_for_stmt(self, s: ForStmt) -> Register:
if (isinstance(s.expr, CallExpr)
and isinstance(s.expr.callee, RefExpr)
and s.expr.callee.fullname == 'builtins.range'):
self.push_loop_stack()
# Special case for x in range(...)
# TODO: Check argument counts and kinds; check the lvalue
end = s.expr.args[0]
end_reg = self.accept(end)
# Initialize loop index to 0.
index_reg = self.assign(s.index,
IntExpr(0),
IntRType(),
IntRType(),
declare_new=True)
goto = Goto(INVALID_LABEL)
self.add(goto)
# Add loop condition check.
top = self.new_block()
goto.label = top.label
branch = Branch(index_reg, end_reg, INVALID_LABEL, INVALID_LABEL,
Branch.INT_LT)
self.add(branch)
branches = [branch]
body = self.new_block()
self.set_branches(branches, True, body)
s.body.accept(self)
end_goto = Goto(INVALID_LABEL)
self.add(end_goto)
end_block = self.new_block()
end_goto.label = end_block.label
# Increment index register.
one_reg = self.alloc_temp(IntRType())
self.add(LoadInt(one_reg, 1))
self.add(
PrimitiveOp(index_reg, PrimitiveOp.INT_ADD, index_reg,
one_reg))
# Go back to loop condition check.
self.add(Goto(top.label))
next = self.new_block()
self.set_branches(branches, False, next)
self.pop_loop_stack(end_block, next)
return INVALID_REGISTER
if self.node_type(s.expr).name == 'list':
self.push_loop_stack()
expr_reg = self.accept(s.expr)
index_reg = self.alloc_temp(IntRType())
self.add(LoadInt(index_reg, 0))
one_reg = self.alloc_temp(IntRType())
self.add(LoadInt(one_reg, 1))
assert isinstance(s.index, NameExpr)
assert isinstance(s.index.node, Var)
lvalue_reg = self.environment.add_local(s.index.node,
self.node_type(s.index))
condition_block = self.goto_new_block()
# For compatibility with python semantics we recalculate the length
# at every iteration.
len_reg = self.alloc_temp(IntRType())
self.add(PrimitiveOp(len_reg, PrimitiveOp.LIST_LEN, expr_reg))
branch = Branch(index_reg, len_reg, INVALID_LABEL, INVALID_LABEL,
Branch.INT_LT)
self.add(branch)
branches = [branch]
body_block = self.new_block()
self.set_branches(branches, True, body_block)
target_list_type = self.types[s.expr]
assert isinstance(target_list_type, Instance)
target_type = self.type_to_rtype(target_list_type.args[0])
value_box = self.alloc_temp(ObjectRType())
self.add(
PrimitiveOp(value_box, PrimitiveOp.LIST_GET, expr_reg,
index_reg))
self.unbox_or_cast(value_box, target_type, target=lvalue_reg)
s.body.accept(self)
end_block = self.goto_new_block()
self.add(
PrimitiveOp(index_reg, PrimitiveOp.INT_ADD, index_reg,
one_reg))
self.add(Goto(condition_block.label))
next_block = self.new_block()
self.set_branches(branches, False, next_block)
self.pop_loop_stack(end_block, next_block)
return INVALID_REGISTER
assert False, 'for not supported'