I'm not so sure this offense is a misdemeanor.
§ 38.05. HINDERING APPREHENSION OR PROSECUTION. (a) A
person commits an offense if, with intent to hinder the arrest,
prosecution, conviction, or punishment of another for an offense
or, with intent to hinder the arrest, detention, adjudication, or
disposition of a child for engaging in delinquent conduct that
violates a penal law of the state, or with intent to hinder the
arrest of another under the authority of a warrant or capias, he:
(1) harbors or conceals the other;
(2) provides or aids in providing the other with any
means of avoiding arrest or effecting escape; or
(3) warns the other of impending discovery or
apprehension.
(b) It is a defense to prosecution under Subsection (a)(3)
that the warning was given in connection with an effort to bring
another into compliance with the law.
(c) An offense under this section is a Class A misdemeanor,
except that the offense is a felony of the third degree if the
person who is harbored, concealed, provided with a means of
avoiding arrest or effecting escape, or warned of discovery or
apprehension is under arrest for, charged with, or convicted of a
felony, or is in custody or detention for, is alleged in a petition
to have engaged in, or has been adjudicated as having engaged in
delinquent conduct that violates a penal law of the grade of felony,
and the person charged under this section knew that the person they
harbored, concealed, provided with a means of avoiding arrest or
effecting escape, or warned of discovery or apprehension is under
arrest for, charged with, or convicted of a felony, or is in custody
or detention for, is alleged in a petition to have engaged in, or
has been adjudicated as having engaged in delinquent conduct that
violates a penal law of the grade of felony.
http://law.onecle.com/texas/penal/38.05.00.html