def transform_assignment_stmt(builder: IRBuilder, stmt: AssignmentStmt) -> None:
assert len(stmt.lvalues) >= 1
builder.disallow_class_assignments(stmt.lvalues, stmt.line)
lvalue = stmt.lvalues[0]
if stmt.type and isinstance(stmt.rvalue, TempNode):
# This is actually a variable annotation without initializer. Don't generate
# an assignment but we need to call get_assignment_target since it adds a
# name binding as a side effect.
builder.get_assignment_target(lvalue, stmt.line)
return
line = stmt.rvalue.line
rvalue_reg = builder.accept(stmt.rvalue)
if builder.non_function_scope() and stmt.is_final_def:
builder.init_final_static(lvalue, rvalue_reg)
for lvalue in stmt.lvalues:
target = builder.get_assignment_target(lvalue)
builder.assign(target, rvalue_reg, line)
def transform_operator_assignment_stmt(builder: IRBuilder, stmt: OperatorAssignmentStmt) -> None:
"""Operator assignment statement such as x += 1"""
builder.disallow_class_assignments([stmt.lvalue], stmt.line)
target = builder.get_assignment_target(stmt.lvalue)
target_value = builder.read(target, stmt.line)
rreg = builder.accept(stmt.rvalue)
# the Python parser strips the '=' from operator assignment statements, so re-add it
op = stmt.op + '='
res = builder.binary_op(target_value, rreg, op, stmt.line)
# usually operator assignments are done in-place
# but when target doesn't support that we need to manually assign
builder.assign(target, res, res.line)
def transform_name_expr(builder: IRBuilder, expr: NameExpr) -> Value:
assert expr.node, "RefExpr not resolved"
fullname = expr.node.fullname
if fullname in name_ref_ops:
# Use special access op for this particular name.
desc = name_ref_ops[fullname]
assert desc.result_type is not None
return builder.add(PrimitiveOp([], desc, expr.line))
if isinstance(expr.node, Var) and expr.node.is_final:
value = builder.emit_load_final(
expr.node,
fullname,
expr.name,
builder.is_native_ref_expr(expr),
builder.types[expr],
expr.line,
)
if value is not None:
return value
if isinstance(expr.node,
MypyFile) and expr.node.fullname in builder.imports:
return builder.load_module(expr.node.fullname)
# If the expression is locally defined, then read the result from the corresponding
# assignment target and return it. Otherwise if the expression is a global, load it from
# the globals dictionary.
# Except for imports, that currently always happens in the global namespace.
if expr.kind == LDEF and not (isinstance(expr.node, Var)
and expr.node.is_suppressed_import):
# Try to detect and error when we hit the irritating mypy bug
# where a local variable is cast to None. (#5423)
if (isinstance(expr.node, Var)
and is_none_rprimitive(builder.node_type(expr))
and expr.node.is_inferred):
builder.error(
"Local variable '{}' has inferred type None; add an annotation"
.format(expr.node.name), expr.node.line)
# TODO: Behavior currently only defined for Var and FuncDef node types.
return builder.read(builder.get_assignment_target(expr), expr.line)
return builder.load_global(expr)
def transform_del_stmt(builder: IRBuilder, o: DelStmt) -> None:
transform_del_item(builder, builder.get_assignment_target(o.expr), o.line)
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)