  We study the intrinsic fully-gapped odd-parity superconducting order in doped
nodal-loop materials with a torus-shaped Fermi surface. We show that the mirror
symmetry, which protects the nodal loop in the normal state, also protects the
superconducting state as a topological crystalline superconductor. As a result,
the surfaces preserving the mirror symmetry host gapless Majorana cones.
Moreover, for a Weyl loop system (two-fold degenerate at the nodal loop), the
surfaces that break the mirror symmetry (those parallel to the bulk nodal loop)
contribute a Chern (winding) number to the quasi-two-dimensional system in a
slab geometry, which leads to a quantized thermal Hall effect and a single
Majorana zero mode bound at a vortex line penetrating the system. This Chern
number can be viewed as a higher-order topological invariant, which supports
hinge modes in a cubic sample when mirror symmetry is broken. For a Dirac loop
system (four-fold degenerate at the nodal loop), the fully gapped odd-parity
state can be either time-reversal symmetry-breaking or symmetric, similar to
the $A$- and $B$- phases of $^3$He. In a slab geometry, the $A$-phase has a
Chern number two, while the $B$-phase carries a nontrivial $\mathbb{Z}_2$
invariant. We discuss the experimental relevance of our results to nodal-loop
materials such as CaAgAs.

Strongly Correlated Electrons;Materials Science;Superconductivity