Hemacandra, respectfully called kalikālasarvajña (the omniscient one of the Kali era), was not the first Jain author to write about the Cārvāka/Lokāyata. Long before him Haribhadra had dealt with this system of philosophy in his ṢDSam, SVS and LTN. So had Siddharṣi in his UBhPK. However, some passages in Hemacandra's works contain something of special interest in connection with the Cārvāka.
A passage in the AC runs as follows:
syādvādavādyā″rhataḥ syāt śūnyavādī tu saugataḥ|
naiyāyikastvākṣapādo yaugaḥ sāṃkhyastu kāpilaḥ|
vaiśeṣikaḥ syādaulūkyo bārhaspatyastu nāstikaḥ∥
cārvāko laukāyatikaścaite ṣaḍapi tārkikāḥ|
Hemacandra mentions six systems of philosophy:
1. Syādvādavādin or Ārhata (i.e. the Jain), 2. Śūnyavādin or Saugata (i.e. the Buddhist), 3. Naiyāyika or Ākṣapāda or Yauga, 4. Sāṃkhya or Kāpila, 5. Vaiśeṣika or Aulūkya, and 6. Bārhaspatya or Nāstika or Cārvāka or Laukāyatika.
Why Hemacandra excludes Mīmāṃsā, Vedānta and Yoga is rather puzzling. Haribhadra in his ṢDSam begins with a short exposition of the Buddhist system and proceeds to deal with Nyāya, Sāṃkhya, Jain, Vaiśeṣika, Mīmāṃsā, and Cārvāka. He too excludes Vedānta. But his inclusion of the Cārvāka seems to have been an afterthought. Having concluded the section on the doctrine of Jaimini (i.e. Mīmāṃsā), Haribhadra suddenly remembers that some scholars preferred to treat Nyāya and Vaiśeṣika as a single system and, according to them, the number of the āstikavādin-s is five, not six (v. 78).