# Basic SSA tests for the new-CFG SSA adapter.
#
# The shared SSA implementation prunes its construction by liveness:
# definitions of variables that are not read are never materialised.
# This is by design — write-only variables would only bloat the SSA
# graph. Tests therefore must always include a read of each variable
# being verified.
#
# Annotations:
#   def=<var>: there is an SSA write definition of <var> at this line
#   use=<var>: <var> is used here and the read resolves to some def


def basic_param(x):  # $ def=x
    return x  # $ use=x


def basic_assign():
    y = 1  # $ def=y
    return y  # $ use=y


def reassignment():
    x = 1
    x = 2  # $ def=x
    return x  # $ use=x


def if_else_phi(cond):  # $ def=cond
    if cond:  # $ use=cond phi=x
        x = 1  # $ def=x
    else:
        x = 2  # $ def=x
    return x  # $ use=x


def use_global():
    return some_undefined  # $ use=some_undefined